Search

O 6 -methylguanine methyltransferase (MGMT) is responsible for dealkylation of naturally occurring O 6 -methylguanines, and it is closely related with DNA replication, transcription, and cancers. Herein, we develop a chemiluminescent biosensor based on enzymatic extension and click chemistry for sensitive measurement of MGMT activity. When MGMT is present, the MGMT-catalyzed demethylation reaction initiates the cleavage of biotinylated dumbbell probes by PvuII restrictive enzyme, releasing two DNA fragments with 3'-OH end. The resultant DNA fragments can trigger terminal transferase (TdT)- and click chemistry-assisted isothermal amplification to obtain abundant G-rich sequences. The G-rich sequences can be captured by magnetic beads to produce a high chemiluminescence signal. This biosensor can greatly amplify the chemiluminescence signal, facilitating label-free and template-free measurement of MGMT. Especially, the introduction of dumbbell probe and PvuII enzyme can efficiently eliminate the false positive and improve the assay specificity. This biosensor possesses high sensitivity with a detection limit of 1.4 × 10 -9  ng/μL, and it may accurately quantify the intracellular MGMT. Importantly, this biosensor can be used to screen the MGMT inhibitors and distinguish the MGMT level in breast tumor tissues and normal tissues, with great potential in drug discovery and cancer diagnosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objectives: High-grade gliomas (HGGs) are highly malignant, aggressive, and have a high incidence and mortality rate. The aim of this study was to investigate survival outcomes and prognostic factors in patients with HGGs., Methods: In this retrospective study, a total of 159 patients with histologically confirmed HGGs were included. The recruitment period was from January 2011 to December 2019. We evaluated patient demographic data, tumor characteristics, treatment methods, immunocytochemistry results, overall survival (OS) time, and progression-free survival (PFS) time using Kaplan-<>Meier survival analysis with log-rank testing. Additionally, we employed Cox regression analysis to identify independent factors associated with survival outcomes., Results: Kaplan-Meier survival analysis revealed that the 1-, 2-, and 5-years OS rates were 81.8%, 50.3%, and 12.6%, respectively. Similarly, the 1-, 2-, and 5-years PFS rates were 50.9%, 22.4%, and 3.1%, respectively. The median OS duration was 35.0 months. The univariate analysis indicated that postoperative pathological classification, grade, and age were significantly associated with patient outcomes (p < 0.01). Among the patients, 147 received concurrent chemoradiotherapy, while 12 did not. The immunohistochemical markers of ki-67, MGMT, IDH1R132H, and p53 demonstrated statistically significant differences in their prognostic impact (p = 0.001, p = 0.020, p = 0.003, and p = 0.021, respectively). In conclusion, we found that grades, age, pathological classification, ki-67, MGMT, and IDH1R132H expression were statistically significantly associated with PFS (p < 0.01, p = 0.004, p = 0.003, p = 0.001, p = 0.036, and p = 0.028). Additionally, immunohistochemical expressions of TRIB3 and AURKA were significantly higher in patients with shorter survival (p = 0.015 and p = 0.023)., Conclusions: Tumor grade and the use of concurrent chemoradiotherapy after surgery were independent prognostic factors that significantly influenced patient survival. Additionally, tumor grade and MGMT expression were found to be independent factors affecting progression-free survival (PFS). Notably, the expression of TRIB3 and AURKA was higher in patients with poor survival outcomes., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Background: The O6-methylguanine-DNA methyltransferase (MGMT) gene prevents mismatch in DNA replication and transcription by repairing mutagenic DNA lesions. MGMT is a predictor biomarker of chemotherapy in high-grade and low-grade gliomas based on high-risk clinical conditions. It also can be used for therapeutic decisions to predict hypermutation in recurrence in newly diagnosed low-grade gliomas. The gold standard  examination for the methylation is Polymerase Chain Reaction (PCR). However, this technique is not widely available in Indonesia for daily practice. Thus, an uncomplicated and simpler method such as immunohistochemistry (IHC) is needed as an alternative examination. This study aimed to predict the diagnostic accuracy of immunohistochemistry (IHC) in detecting the methylation status of O6-methylguanine-DNA methyltransferase (MGMT) in glioma., Methods: This research was a cross-sectional study using formalin-fixed paraffin embedded (FFPE) tissue samples of glioma patients, dating between October 2017 until March 2021. Diagnosis of glioma was established based on clinical, radiological, and histopathological findings. MGMT methylation status was investigated using the IHC and PCR techniques. Diagnostic value of IHC was analyzed, with PCR as a gold standard method. Optimum threshold to determine positivity of IHC was determined by the Area Under the Curve (AUC) on Receiver Operating Characteristics (ROC) curve and Youden index., Results: Among 75 samples examined, 29 (38.7%) patients were methylated. IHC detected MGMT methylation with sensitivity of 86.2%, specificity of 63.0%, positive predictive value of 59.5%, negative predictive value of 87.9% and accuracy of 72.0%. The AUC was 0.746, indicating moderate diagnostic value. Optimum positivity threshold of the IHC examination based on Youden Index was 10%., Conclusion: IHC examination can be used to detect MGMT methylation status of glioma patients in limited resources setting, where PCR technique is not available.

Introduction: Microsatellite instability occurs due to a series of mutations in the DNA pairing error repair (Mismatch repair; MMR) genes, which can affect germ cells as occurs in Lynch syndrome, whose patients are at high risk of developing multiple cancers. The loss of MMR protein is commonly determined by immunohistochemical studies. Although the relation between microsatellite instability and urothelial carcinomas has been widely studied, its evaluation is not currently performed in the analysis of urothelial carcinomas., Methods: In this study, the microsatellite status of 139 urothelial carcinomas was analyzed and their clinicopathological characteristics were evaluated. We identified that 10.3% (13 patients) of urothelial carcinomas had loss of MMR protein expression (9 MLH1; 5 MSH2; 2 PMS2; 2 PSH6; n = 139)., Results: Results suggest that these tumors occur more frequently in males, are more frequently located in the bladder or ureters, and present a high tumor grade with a papillary histological pattern that does not infiltrate the lamina propria or, in the case of infiltrating tumors, that grows into perivesical tissues., Conclusions: We identified patients with the aforementioned tumor characteristics as patients with a high probability of presenting loss of MMR protein expression, and consider that only these patients should undergo further immunohistochemical and molecular techniques for proper diagnosis. Therefore, we propose that the clinicopathological characteristics found in the present study could become possible markers to determine which cases should undergo additional tests., (© 2021. The Author(s).)

Background: Programmed-cell-death-ligand 1 (PD-L1) inhibitor treatment is approved for metastatic/recurrent, PD-L1 positive, triple-negative breast cancer (TNBC) and solid tumors with mismatch repair (MMR) defect regardless of PD-L1 status. The analytical validity of PD-L1 has been questioned and adding evaluation of tumor-infiltrating lymphocytes (TILs) may identify patients likely to respond to immunotherapy. We investigated the association between MMR-deficiency and PD-L1 in TNBC; aiming to identify PD-L1 negative, TNBC patients that may be candidates for anti-PD-L1 immunotherapy., Methodology: Paraffin-embedded tumor material from 44 TNBC patients was included. In 38 cases, immunohistochemical-staining´s on whole-slide sections were successful for all four MMR proteins (MSH2, MSH6, MLH1 and PMS2) and PD-L1 in 36 cases. MMR-status was categorized as positive (pMMR), heterogeneous (hMMR) or deficient (dMMR). Tumor-infiltrating lymphocytes (TILs) were evaluated on H&E sections., Results: MMR stainings showed substantial intratumor heterogeneity. Four of 38 cases (11%) were recorded as dMMR with loss of ≥ 1 MMR-protein and 19 cases (50%) showed heterogeneous expression or partial loss (hMMR) of ≥ 1 MMR-protein. Three of 22 PD-L1 negative cases were dMMR (14%) and ten cases hMMR (45%). 16 of 22 PD-L1 negative cases (73%) showed high TILs., Conclusions: A substantial proportion of PD-L1 negative, TNBC patients showed complete/partial loss of MMR and/or high TILs indicating that supplementing PD-L1 examination with these biomarkers may identify TNBC-patients that may be selected for immunotherapy., (Copyright © 2021 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Aims: The hallmark of Lynch syndrome (LS) is DNA mismatch repair protein (MMR) deficiency. Recently, MMR deficiency in non-neoplastic colonic crypts has been identified as a novel indicator of LS. We aimed to determine whether MMR-deficient non-neoplastic endometrial glands can distinguish patients with and without LS, and to compare the level of MMR deficiency in the normal endometrium and colon in LS patients., Methods and Results: We evaluated the immunohistochemical expression of MMR proteins in the normal endometrial mucosa from 64 patients, including 34 patients with confirmed LS (17 with endometrial cancer and 17 without cancer), 30 patients with endometrial cancer without LS (10 with tumours with MLH1 promoter hypermethylation and 20 with MMR-proficient tumours), and in the normal colonic mucosa from 30 LS patients. MMR-deficient non-neoplastic endometrial glands were identified in 47% of LS patients and in no patients without LS (P < 0.001). MMR-deficient non-neoplastic glands were more often identified in LS patients with endometrial cancer (65%) than in those without endometrial cancer (29%) (P = 0.04). In contrast to what was seen in the normal colon, MMR-deficient glands in the normal endometrium were seen as large, contiguous groups, ranging in number from two to 101 (87% versus 45%, P = 0.02). MMR-deficient glands were identified at a higher density in the endometrium than in the colon in LS patients (median number of MMR-deficient glands, 22 versus two, P = 0.02)., Conclusions: Our findings indicate that MMR-deficient non-neoplastic endometrial glands constitute an indicator of LS, and that MMR-deficient glands in the endometrium are present in a pattern of contiguous large groups., (© 2021 John Wiley & Sons Ltd.)

Universal testing of microsatellite instability (MSI) is recommended for colorectal cancer (CRC) and endometrial cancer (EC) to screen for Lynch syndrome and to aid in assessing prognosis and optimal treatment. We compared the performance of Idylla MSI test to immunohistochemistry (IHC) of mismatch repair (MMR) proteins in consecutive series of 100 CRC and 108 EC samples, as well as in retrospective series of 28 CRC and 33 EC specimens with known deficient MMR protein expression. The concordance between the Idylla test and IHC was 100% in all CRC samples (n=128) but lower in EC samples (87.2%; n=141). In the EC samples, sensitivity of Idylla test was 72.7% and specificity 100%. EC MSI/dMMR agreement was 85.4% for MLH1, 87.5% for MSH2, and only 35.3% for MSH6. When we analyzed 14 EC samples that were discrepant, i.e., dMMR using IHC and microsatellite stable using Idylla, with microsatellite markers BAT25 and BAT26, we found four cases to be replication error (RER) positive. All RER positive cases were deficient for MSH6 protein expression. We also re-analyzed EC samples with variable tumor cellularity to determine the limit of detection of the Idylla test and found that a 30% or higher tumor cellularity is required. We conclude that Idylla MSI test offers a sensitive and specific method for CRC diagnostics but is less sensitive in EC samples especially in the case of MSH6 deficiency., (© 2021. The Author(s).)

Mismatch repair (MMR) testing is recommended in the Netherlands for all patients under 70 years of age with newly diagnosed colorectal cancer (CRC) in order to identify Lynch syndrome. T1 CRC can be removed by local excision or oncological surgical resection. We evaluated the frequency of MMR testing in pT1 lesions within the Dutch CRC screening cohort. pT1 CRC diagnosed within the Dutch population-based screening program from 2016-2018 were identified by the Dutch pathology registry (PALGA). Pathology reports were evaluated, including registration of MMR testing (by immunohistochemistry and/or microsatellite instability PCR). Frequency of MMR testing was compared between pT1 tumors that were treated by local (endoscopic or transanal) excision and oncological surgical resections. A total of 3.692 pT1 CRCs were diagnosed (median age 63 years, 61.4% males). MMR testing was performed in 83% and uptake increased over time (71% in 2016 to 92% in 2018, p<0.01). MMR testing was significantly more often performed in younger patients and in academic hospitals. When pT1 CRC was treated by oncological surgical resection (n=1.132), MMR testing was performed in 89% of cases and was known prior to oncological resection in 51% of cases. MMR testing occurred significantly less often in case of local excision (80% of n=2.560) compared to oncological surgical resection (p<0.01). MMR testing was performed in 83% of T1 CRCs and uptake increased over time. MMR testing was more frequently performed in pT1 CRC resected by oncological surgical resection compared with local excision., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Immune-checkpoint inhibitors (ICIs) play a key role in the treatment of advanced stage colorectal cancer (CRC) patients featuring a deficient DNA mismatch repair (dMMR) system or a high microsatellite instability (MSI-H) profile. However, beyond the established role in CRC patients, ICIs have highly proven efficacy in other solid tumors featuring MSI-H/dMMR status represented by endometrial, gastric, ovarian, prostatic, and pancreatic carcinomas (EC, GC, OC, PrC, and PaC). Our aim was to compare the concordance rates among the Idylla™ MSI test, TapeStation 4200, and immunohistochemical (IHC) analysis in assessing MSI-H/dMMR status in EC, GC, OC, PrC, and PaC patients. The Sanger sequencing-based Titano MSI test was used in discordant cases. One hundred and eighty-five cases ( n = 40 PrC, n = 39 GC, n = 38 OC, n = 35 PaC, and n = 33 EC) were retrospectively selected. MMR protein expression was evaluated by IHC. After DNA quality and quantity evaluations, the Idylla TM and TapeStation 4200 platforms were adopted for the evaluation of MSI status. Remarkably, compared to IHC, the Idylla™ platform achieved a global concordance rate of 94.5% (154/163) for the microsatellite stable (MSS)/proficient MMR (pMMR) cases and 77.3% (17/22) for the MSI-H/dMMR cases. Similarly, a global concordance rate of 91.4% (149/163) and 68.2% (15/22) for MSS/pMMR and MSI-H/dMMR cases was also identified between IHC and the TapeStation 4200 microfluidic system. In addition, a global concordance of 93.1% (148/159) and 69.2% (18/26) for MSS/pMMR and MSI-H/dMMR cases was observed between the Idylla™ and TapeStation 4200 platforms. Discordant cases were analyzed using the Titano MSI kit. Overall, our data pinpointed a central role for molecular techniques in the diagnostic evaluation of dMMR/MSI-H status not only in CRC patients but also in other types of solid tumors.

In the modern era of precision medicine, a number of class II immunohistochemistry (IHC) biomarkers are routinely tested in pathologic laboratories to select cancer patients who may be candidates for hormonal, targeted, and immune therapies. Pre-analytical factors, including tissue processing, are critical components of biomarker testing and require validation to ensure reliable results. In this study, we aimed to study the impact of tissue processing on biomarkers (including ER, PR, HER2, mismatch repair (MMR) proteins, BRAF V600E, and PD-L1) in a large prospective cohort of 109 tumors. We found that ER and MMR were not impacted; PR, HER2, and BRAF V600E were minimally affected; and PD-L1 regardless of the antibody clone was strongly influenced by a combination of tissue processing procedures and intratumoral heterogeneity. Our findings suggest that validation of pre-analytical parameters, such as tissue processing, is important for certain class II biomarkers, in particular PD-L1 IHC.

Mixed endometrial carcinoma (MEC) is defined as a tumor composed of two or more spatially distinct subtypes, at least one of which is serous or clear cell carcinoma. In this study, the clinicopathological features of 15 MEC cases containing a clear cell component (MEC-C) were investigated. The ages of patients ranged from 32 to 83 years (median, 61 years). The combinations of carcinoma components observed were endometrioid and clear cell in ten patients; endometrioid, clear cell and serous in three; and clear cell and serous in two. Immunohistochemically, nine had DNA mismatch repair (MMR) protein deficiency (MMR-d), nine had loss of ARID1A and three cases had aberrant p53 expression. MMR-d and loss of ARID1A showed a strong correlation. Only one case showed both MMR-d and aberrant p53 expression. The patients with MMR-d were younger than those without MMR-d (median; 58 years vs. 71 years). Loss of ARID1A also showed significant predilection for younger women than ARID1A intact cases. In conclusion, MMR-d was observed in 60 % of MEC-C, showed predilection for young women, and was associated with ARID1A loss. In contrast, non- MMR-d MEC-C occurred in elder women and some tumors may associate with TP53 mutation. These findings suggest that MEC-C develop via two different molecular mechanisms and they are age-related events., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Mismatch repair (MMR) deficiency is an indicator of good prognosis in localized colon cancer but also associated with lack of expression of caudal-type homeobox transcription factor 2 (CDX2) and high tumor grade; markers that in isolation indicate a poor prognosis. Our study aims to identify clinically relevant prognostic subgroups by combining information about tumor grade, MMR phenotype, and CDX2 expression. Immunohistochemistry for MMR proteins and CDX2 was performed in 544 patients with colon cancer stage II-III, including a cohort from a randomized trial. In patients with proficient MMR (pMMR) and CDX2 negativity, hazard ratio (HR) for cancer death was 2.93 (95% CI 1.23-6.99, p = 0.015). Cancer-specific survival for pMMR/CDX2-negative cases was 35.8 months (95% CI 23.4-48.3) versus 52.1-53.5 months (95% CI 45.6-58.6, p = 0.001) for the remaining cases (CDX2-positive tumors or deficient MMR (dMMR)/CDX2-negative tumors). In our randomized cohort, high tumor grade was predictive of response to adjuvant fluorouracil-levamisole in pMMR patients, with a significant interaction between tumor grade and treatment (p = 0.036). For pMMR patients, high tumor grade was a significant marker of poor prognosis in the surgery-only group (HR 4.60 (95% CI 1.68-12.61), p = 0.003) but not in the group receiving chemotherapy (HR 0.66 (95% CI 0.15-3.00), p = 0.587). To conclude, patients with pMMR and CDX2 negativity have a very poor prognosis. Patients with pMMR and high-graded tumors have a poor prognosis but respond well to adjuvant chemotherapy. CDX2 expression and tumor grade did not impact prognosis in patients with dMMR.

Background: Pancreatic neuroendocrine tumors are rare neoplasms for which few predictive and/or prognostic biomarkers have been validated. Our previous work suggested the potential of the combined expression of N-myc downstream-regulated gen-1 (NDRG-1), O6-methylguanine DNA methyltransferase (MGMT) and Pleckstrin homology-like domain family A member 3 (PHLDA-3) as prognostic factors for relapse and survival., Methods: In this new multicenter study we evaluated immunohistochemistry expression in 76 patients with advanced PanNET who were treated with capecitabine-temozolomide or everolimus. Based on the immunohistochemistry panel, an immunohistochemistry prognostic score (IPS) was developed., Results: In patients treated with capecitabine and temozolomide, low IPS was an independent prognostic factor for progression-free-survival and overall-survival. Similar findings were observed with highest IPS for overall-survival in patients treated with everolimus., Conclusion: From our knowledge, it is the first time that a simple IPS could be useful to predict outcome for patients with metastatic pancreatic neuroendocrine tumors treated with everolimus or capecitabine and temozolomide., (Copyright © 2020 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Microsatellite instability (MSI) is reflective of a deficient mismatch repair (dMMR) system, which is mostly associated with the methylation of mismatch repair (MMR) genes and BRAF mutations in sporadic colorectal cancers (CRCs). We performed a retrospective study to analyze the clinicopathological features of dMMR CRCs and their association with the BRAF V600E mutation. The incidence of dMMR CRCs in our cohort was 7.4 % (118/1603). Immunohistochemistry (IHC) revealed four common dMMR IHC patterns in 116 dMMR CRCs from 110 patients. dMMR type 1 (MLH1-/PMS2-) CRCs were the most frequent pattern, usually showing typical proximal location and MSI histology. The BRAF V600E mutation was almost exclusively observed in dMMR type 1 (32 of 72) and dMMR type 2 (PMS- only, 7 of 18) CRCs (p = 0.001). Patients with dMMR type 3 (MSH2-/MSH6-) CRCs were usually diagnosed at younger ages (p < 0.001) and had the strongest family history of Lynch syndrome-associated tumors (p = 0.002). dMMR type 3 CRCs frequently presented at advanced stages (p = 0.005) with perineural invasion (p = 0.021). We also found a significant positive association of dMMR type 1 and type 3 with advanced stages of CRC, whereas dMMR types 2 and 4 (MSH6- only) were usually diagnosed at early stages of CRC (p < 0.001). In conclusion, BRAF V600E mutations almost exclusively occurred in dMMR type 1 and 2 CRCs. Patterns of MMR protein expression display distinct associations with tumor staging and age at diagnosis., (Copyright © 2020 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Purpose: Glioma, especially glioblastoma (GBM), is the most aggressive malignant brain tumor and its standard therapy is often ineffective because of temozolomide (TMZ) resistance. Reversal of the TMZ resistance might improve the prognosis of glioma patients. We previously found that interferon-α (IFN-α) and anti-epileptic drug levetiracetam (LEV) could sensitize glioma to TMZ, respectively. In this study, we further investigated the efficiency of combining of LEV and IFN-α for improving the efficacy of TMZ., Methods: We evaluated whether LEV and IFN-α could increase TMZ efficacy using colony formation assay and cell viability assay with MGMT-positive and MGMT-negative glioma cell lines in vitro. Subcutaneous xenografts and orthotopic xenografts mice models were used in vivo to observe the tumor growth and mice survival upon treatments with TMZ, TMZ + IFN-α, TMZ + LEV, or TMZ + LEV + IFN-α. The expression levels of MGMT, markers of pro-apoptotic and anti-apoptotic in tumor samples were analyzed by Western blotting., Results: The combinational use of IFN-α, LEV, and TMZ showed the best anti-tumor activity in MGMT-positive cell lines (U138, GSC-1, U118, and T98 G). TMZ + LEV + IFN-α further obviously increased TMZ + LEV or TMZ + IFN-α efficiency in MGMT-positive cell lines, while not in negative cell lines (SKMG-4, U87, U373, and U251) in vitro, which were also observed in subcutaneous mice models (U138, GSC-1 compared to SKMG-4, U87) and orthotopic models (GSC-1) in vivo. Strikingly, the combination of LEV and IFN-α together with TMZ significantly prolonged the survival of mice with orthotopic GSC-1 glioma. Furthermore, we confirmed that the combination of LEV and IFN-α enhanced the inhibition of MGMT and the activation of apoptosis in U138 tumor on the basis of TMZ treatment., Conclusions: The combination use of LEV and IFN-α could be an optimal method to overcome TMZ resistance through obvious MGMT inhibition in MGMT-positive glioma.

Advanced colorectal cancer (CRC) consensus molecular subtype 4 (CMS4) or CRC with a low immunoscore is associated with shorter survival times. Non-metastatic CRC with microsatellite instability (MSI) is associated with a lower risk of recurrence. We evaluated outcome (lymph node metastases [LNM] or cancer recurrence) in these tumor subtypes in patients with surgically-removed non-pedunculated T1 CRC by performing a multicenter case-cohort study. We included all patients in 13 hospitals in the Netherlands from 2000-2014 (n = 651). We randomly selected a subgroup of patients (n = 223) and all patients with LNM or recurrence (n = 63), and median follow-up of 44 months. We centrally reviewed tumor-slides, and constructed and immunostained tissue microarrays determining MSI, CMS (MSI/CMS1, CMS2/3, or CMS4), and immunoscore (I-low/I-high). We used weighted Cox proportional hazard models to evaluate the association of MSI, CMS, and immunoscore with LNM or recurrence, adjusting for conventional histologic risk factors. In the randomly selected subgroup of patients, 7.1% of tumors were MSI/CMS1, 91.0% CMS2/3, 1.8% CMS4, and 25% I-low. In the case-cohort, patients with CMS4 tumors had an increased risk for LNM or recurrence compared with patients with tumors of other CMSs (adjusted hazard ratio [HR], 3.97; 95% CI, 1.12-14.06; P = 0.03). Albeit not significant, tumors with MSI had a lower risk for LNM or recurrence than other tumor subtypes (adjusted HR, 0.52; 95% CI, 0.12-2.30; P = 0.39), whereas tumors with a low immunoscore had an increased risk for LNM or recurrence (adjusted HR, 1.30; 95% CI, 0.68-2.48; P = 0.43). In conclusion, in a case-cohort study of patients with non-pedunculated T1 CRC, MSI, and immunoscore were not significantly associated with adverse outcome after surgery. CMS4 substantially increased the risk of adverse outcome. However, CMS4 is rare in T1 CRCs, limiting its value for determining the risk in patients.

Colorectal carcinoma (CRC) is the third most common cancer type in the United States. While the incidence of CRC is decreasing among an older population undergoing screening, the incidence of early-onset CRC is rising. There is a growing understanding that the molecular underpinnings of colorectal carcinoma vary by age. In this study, we report the genetic alterations and clinicopathologic features of a single-institution colorectal carcinoma cohort over a 2-year period using a next-generation sequencing (NGS) approach and microsatellite stability (MS) status determined by immunohistochemical staining. Forty cases were identified in an early-onset colorectal carcinoma cohort (eCRC) defined by age <40 years, and 164 cases were identified in an age-related colorectal carcinoma cohort (arCRC) defined by age >70 years. eCRC was more often-left-sided/rectal and more likely to present high rates of lymph node positivity with metastatic disease. NGS mutational analysis revealed distinct differences between eCRC and arCRC, with eCRC being characterized by low frequency of PIK3CA mutations, elevated frequency of KRAS and CTNNB1 mutations in microsatellite instability high tumors, and very low frequency of BRAF mutations., (Copyright © 2020 Elsevier Inc. All rights reserved.)

This study aims to evaluated the prognostic and predictive roles of DNA mismatch repair status in colon cancer patients treated with oxaliplatin-based chemotherapy. From 2005 to 2008, patients who underwent curative surgical resection for high-risk stage II or stage III colon cancer were recruited in this study. These patients had been received oxaliplatin-based chemotherapy. A total 324 patients were included (41.7% at stage II and 58.3% at stage III), and 59 patients (18.2%) exhibited mismatch repair-deficient (dMMR). The prognostic analysis revealed an increase in disease-free survival (DFS) for dMMR patients versus proficient MMR (pMMR) patients (81.4% versus 64.2%, P = 0.009), and overall survival (OS) (86.4% versus 69.1%, P = 0.004). Among the 82 patients who did not receive adjuvant therapy, the 5-year DFS was significantly higher in patients with dMMR (81.3%) than in patients with pMMR (49.7%, P = 0.040). In the multivariate models, dMMR was independently associated with improved DFS (HR = 2.171, 95% CI: 1.108 - 4.253, P = 0.024) and OS (HR = 2.521, 95% CI: 1.190 - 5.339, P = 0.016). In the predictive analysis, it was observed that the benefit of treatment significantly differed according to the DNA MMR status (P = 0.020). Compared with surgery alone, oxaliplatin-based adjuvant chemotherapy improved the 5-year DFS (69.9% versus 56.2%, P = 0.024) among patients with pMMR in the multivariable analysis (HR = 0.794, 95% CI = 0.646 - 0.976, P = 0.029). In contrast, the oxaliplatin-based chemotherapy in the group with dMMR had no benefit in DFS (83.1% versus 81.8%, HR 1.040, 95% CI: 0.276 - 3.922, P = 0.954). Patients with dMMR colon cancer are associated with improved survival rates, compared with pMMR colon cancer. MMR status is an independent prognostic biomarker for DFS in patients with high-risk stage II and stage III colon cancer. Oxaliplatin-based adjuvant chemotherapy mainly benefits patients with pMMR, but may not benefit patients with tumors exhibiting dMMR.

Microsatellite instability (MSI) defines one of the four molecular groups of endometrial carcinoma identified by The Cancer Genome Atlas (TCGA). Immunohistochemistry for mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, PMS2) has been proposed as a widely applicable technique to identify this group in the common practice. However, the diagnostic accuracy of such approach has never been calculated. We aimed to assess: 1) the diagnostic accuracy of MMR proteins immunohistochemistry as surrogate of MSI molecular testing in endometrial carcinoma; 2) whether a combination of only two MMR proteins may be used as a still cheaper test. A systematic review and meta-analysis of was performed by searching electronic databases from their inception to September 2019. All studies assessing endometrial carcinoma with both MMR proteins immunohistochemistry and MSI molecular testing were included. Diagnostic accuracy was assessed as sensitivity, specificity, positive and negative likelihood ratios (LR+, LR-), diagnostic odds ratio (DOR) and area under the curve (AUC) on SROC curves. A subgroup analysis was performed for a combination of only two MMR proteins (MLH1-MSH2 vs MSH6-PMS2). Ten studies with 3097 patients were included. Out of these, 1110 were suitable for the meta-analysis. Immunohistochemistry for all the four MMR proteins showed sensitivity = 0.96, specificity = 0.95, LR + =17.7, LR- = 0.05, DOR = 429.77, and high diagnostic accuracy (AUC = 0.988). The combination of MLH1 and MSH2 showed sensitivity = 0.88, specificity = 0.96, LR + =22.36, LR- = 0.15, DOR = 200.69, and high diagnostic accuracy (AUC = 0.9838). The combination of MSH6 and PMS2 showed the same results as the complete panel of four MMR proteins. In conclusion, MMR proteins immunohistochemistry is a highly accurate surrogate of MSI molecular testing in endometrial carcinoma. A combination of MSH6 and PMS2 may allow reducing the cost without decrease in the diagnostic accuracy.

Immunohistochemistry for mismatch repair protein expression is widely used as a surrogate for microsatellite instability status-an important signature for immunotherapy and germline testing. There are no systematic analyses examining the sensitivity of immunohistochemistry for microsatellite instability-high status. Mismatch repair immunohistochemistry and microsatellite instability testing were performed routinely as clinically validated assays. We classified germline/somatic mutation types as truncating (nonsense, frameshift, and in/del) versus missense and predicted pathogenicity of the latter. Discordant cases were compared with concordant groups: microsatellite instability-high/mismatch repair-deficient for mutation comparison and microsatellite stable/mismatch repair-proficient for immunohistochemical comparison. 32 of 443 (7%) microsatellite instability-high cases had immunohistochemistry. Four additional microsatellite instability-high research cases had discordant immunohistochemistry. Of 36 microsatellite instability-high cases with discordant immunohistochemistry, 30 were mismatch repair-proficient, while six (five MLH1 and one MSH2) retained expression of the defective mismatch repair protein and lost its partner. In microsatellite instability-high tumors with discordant immunohistochemistry, we observed an enrichment in deleterious missense mutations over truncating mutations, with 69% (25/36) of cases having pathogenic germline or somatic missense mutations, as opposed to only 19% (7/36) in a matched microsatellite instability-high group with concordant immunohistochemistry (p = 0.0007).  In microsatellite instability-high cases with discordant immunohistochemistry and MLH1 or PMS2 abnormalities, less cells showed expression (p = 0.015 and p = 0.00095, respectively) compared with microsatellite stable/mismatch repair-proficient cases. Tumor mutation burden, MSIsensor score, and truncating mismatch repair gene mutations were similar between microsatellite instability-high cases with concordant versus discordant immunohistochemical expression. Approximately 6% of microsatellite instability-high cases have retained mismatch repair protein expression and would be missed by immunohistochemistry-based testing, hindering patient access to immunotherapy. Another 1% of microsatellite instability-high cases show isolated loss of the defective gene's dimerization partner, which may lead to germline testing of the wrong gene. These cases are enriched for pathogenic mismatch repair missense mutations.

Nudix proteins are members of a large family of homologous enzymes that hydrolyze nucleoside diphosphates linked to other compounds. The substrates for a subset of Nudix enzymes are all nucleotides linked to RNA, like the m 7 G mRNA caps and the more recently discovered NAD(H) RNA caps. However, the RNA affinity and nucleic acid specificity of Nudix proteins has not yet been explored in depth. In this study we designed new fluorescence-based assays to examine the interaction of purified recombinant E. coli NudC and human Nudt1 (aka MTH1) Nudt3, Nudt12, Nudt16, and Nudt20 (aka Dcp2). All Nudix proteins except Nudt1 and Nudt12 bound both RNA and DNA stoichiometrically with high affinity (dissociation constants in the nanomolar range) and no clear sequence specificity. In stark contrast, Nudt12 binds RNA but not similar DNA oligonucleotides. Nudt12 also bound RNAs with 5' NAD + caps more tightly than those with NADH or m 7 G cap. NudC was similarly selective against m 7 G caps but did not differentiate between NAD + and NADH capped RNA. Nudt3, Nudt16, and Nudt20 bound m 7 G capped RNA more tightly than RNA with NADH caps., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Currently, no single diagnostic modality allows the distinction between early progression (EP) and pseudo-progression (Psp) in glioblastoma patients. Herein we aimed to identify the characteristics associated with EP and Psp, and to analyze their diagnostic value alone and in combination., Material and Methods: We reviewed the clinical, conventional magnetic resonance imaging (MRI), and molecular characteristics (MGMT promoter methylation, IDH mutation, and EGFR amplification) of glioblastoma patients who presented an EP (n=59) or a Psp (n=24) within six months after temozolomide radiochemotherapy. We analyzed relative cerebral blood volume (rCBV) and relative vessel permeability on K2 maps (rK2) in a subset of 33 patients using dynamic-susceptibility-contrast MRI., Results: In univariate analysis, EP was associated with neurological deterioration, higher doses of dexamethasone, appearance of a new enhanced lesion, subependymal enhancement, higher rCBV and rK2 values. Psp occurred earlier after radiotherapy completion and was associated with IDH1 R132H mutation, and MGMT methylation. In multivariate analysis, rCBV, rK2, and MGMT methylation status were independently associated with EP and Psp. All patients with a methylated MGMT promoter and a low rCBV (<1.75) were classified as Psp while all patients with an unmethylated MGMT promoter and a high rCBV (≥1.75) were classified as EP. Among patients with discordant MGMT methylation and rCBV characteristics, higher rK2 values tended to be associated with EP., Conclusion: Combined analysis of MGMT methylation, rCBV and vessel permeability on K2 maps seems helpful to distinguish EP from Psp. A prospective study is warranted to confirm these results., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

All organisms must protect their genome from constantly occurring DNA damage. To this end, cells have evolved complex pathways for repairing sites of DNA lesions, and multiple in vitro and in vivo techniques have been developed to study these processes. In this review, we discuss the commonly used laser microirradiation method for monitoring the accumulation of repair proteins at DNA damage sites in cells, and we outline several strategies for deriving kinetic models from such experimental data. We discuss an example of how in vitro measurements and in vivo microirradation experiments complement each other to provide insight into the mechanism of PARP1 recruitment to DNA lesions. We also discuss a strategy to combine data obtained for the recruitment of many different proteins in a move toward fully quantitating the spatiotemporal relationships between various damage responses, and we outline potential venues for future development in the field., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: The aim of this study was to examine DNA ligase activity and expression of DNA damage response pathway (DDR) genes in patients with stable angina (SA) and non-ST elevation myocardial infarction (NSTEMI) and determine whether they correlate with plaque morphology., Background: Patients with coronary artery disease (CAD) have evidence of deoxyribonucleic acid (DNA) damage in peripheral blood mononuclear cells (PBMCs). It is unclear whether this represents excess damage or defective DNA repair activity., Methods: DNA ligase activity and the expression of 22 DDR genes were measured in PBMCs of patients (both SA (n = 47) and NSTEMI (n = 42)) and in age and gender-matched controls (n = 35). Target lesion anatomical assessment was undertaken with frequency domain optical coherent tomography., Results: DNA ligase activity was different across the three groups of patients (control = 119 ± 53, NSTEMI = 115.6 ± 85.1, SA = 81 ± 55.7 units/g of nuclear protein; ANOVA p = 0.023). Pair wise comparison demonstrated that this significance is due to differences between the control and SA patients (p = 0.046). Genes involved in double strand break repair and nucleotide excision repair pathways were differentially expressed in patients with SA and NSTEMI. In SA patients, fibrocalcific plaques were strongly associated with GTSE1, DDB1, MLH3 and ERCC1 expression. By contrast, in NSTEMI patients the strongest association was observed between fibrous plaques and ATM and XPA expression., Conclusion: PBMCs from patients with CAD exhibit differences in DNA ligase activity and expression of DDR genes. Expression levels of certain DDR genes are strongly associated with plaque morphology and may play a role in plaque development and progression. Trial Registration Number URL: www.Clinicaltrials.gov; NCT02335086., (Copyright © 2019 Elsevier Inc. All rights reserved.)

DNA repair pathways are closely associated with the maintenance of genomic integrity, disease outbreak, and the development of therapeutics. Owing to these significances, novel analytical methods for enzymes that are involved in the DNA repair pathways have been actively investigated. This review focuses on discussions on nucleic acid-based methods, especially those based on the fluorescence, for the determination of DNA repair enzymes. Furthermore, this review not only provides meaningful insights in creating ingenious fluorescent detection methods but it also suggests future directions that will be followed in developing new analytical technologies for the DNA repair enzymes., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The study investigated the pattern of MGMT promoter methylation and the expression of MGMT, P53, EGFR, MDM2 and PTEN proteins in glioblastomas multiforme (GBM) and evaluated their prognostic significance. We carried out a retrospective study of 80 GBM. Expression of MGMT as well as of P53, EGFR, MDM2 and PTEN was investigated by immunohistochemistry. MGMT promoter methylation was investigated by methylation specific-PCR of bisulfite-treated DNA. Twenty-five GBM exhibited MGMT expression. Methylation of MGMT promoter was detected in 35.1% of cases. No significant concordance was reported between MGMT promoter methylation and protein expression (κ=-0.047, p=0.11). MGMT promoter methylation was significantly associated only with PTEN expression (p=0.001): no other significant association was identified with clinical parameters as well as with expression of P53, EGFR and MDM2 (p >0.05). Tumor recurrence was significantly associated with unmethylated MGMT promoter (p=0.01) but not with MGMT expression (p=0.51). Recurrence-free survival (RFS) was significantly better among patients with methylated MGMT promoter (log rank, p <0.0001) and PTEN expression (log rank, p=0.025) but not with MGMT expression (log rank, p=0.308). As well, using univariate analysis, MGMT promoter methylation (p=0.001) and PTEN expression (p=0.044) were significantly associated with RFS. In multivariate analysis, only MGMT promoter methylation was significantly associated with RFS (p=0.003). Together, our findings support that MGMT protein expression doesn't reflect the MGMT promoter methylation status. Furthermore, MGMT promoter methylation remains a useful prognostic marker in Tunisian patients with GBM. PTEN expression could be a potential prognostic marker of this tumor.

Immunohistochemistry (IHC) for mismatch repair (MMR) proteins is an established test to identify Lynch syndrome (LS) in patients with colorectal cancer and is being increasingly used to identify LS in women with endometrial and/or nonserous ovarian cancer (OC). We assessed interobserver agreement in the interpretation of MMR-IHC on endometrial and ovarian carcinomas. The study consisted of 73 consecutive endometrial cancers (n=48) and nonserous, nonmucinous epithelial OCs (n=25). Six pathologists from 2 cancer centers, one with and the other without, previous experience in interpreting MMR-IHC, evaluated MLH1, MSH2, MSH6, and PMS2 stains. Before the study, an experienced pathologist led a review of 9 teaching cases. A decision tool was developed as a guide in MMR-IHC interpretation. Staining was interpreted as intact, deficient, or equivocal for each protein. Interobserver agreement for the patient MMR status was categorized as "almost perfect" with κ=0.919 (95% CI, 0.863-0.976). All observers were in agreement in 66 (92%) tumors. Four of the less experienced pathologists had at least 1 discrepant interpretation. There were 6 discordant cases: 3 MMR-deficient cases and 2 MMR-intact cases by majority opinion were called equivocal by at least 1 observer, and 1 MMR-deficient case by majority opinion was interpreted as MMR intact by 1 pathologist. Only the latter case (1/73 patients, 1.4%) had an unequivocal disagreement that could affect patient management. Issues associated with discordant interpretation included heterogeneous staining, intratumoral lymphocytes, regional reduced internal control tissue staining, and scattered absent/weak staining adjacent to tumor cells with strong nuclear staining.

Human homologue of yeast UV excision repair protein Rad23b (HR23B) inclusions are found in a number of neurodegenerative diseases, including frontotemporal dementia (FTD), Huntington's disease (HD), spinocerebellar ataxia type 3 and 7 (SCA3/7), fragile X associated tremor/ataxia syndrome (FXTAS) and Parkinson's disease (PD). Here, we describe HR23B pathology in C9ORF72 linked FTD and amyotrophic lateral sclerosis (ALS) cases. HR23B presented in neuropils, intranuclear inclusions and cytoplasmic and perinuclear inclusions and was predominantly found in cortices (frontal, temporal and motor), spinal cord and hippocampal dentate gyrus. HR23B co-localized with poly-GA-, pTDP-43- and p62-positive inclusions in frontal cortex and in hippocampal dentate gyrus, the latter showing higher co-localization percentages. HR23B binding partners XPC, 20S and ataxin-3, which are involved in nucleotide excision repair (NER) and the ubiquitin-proteasome system (UPS), did not show an aberrant distribution. However, C9ORF72 fibroblasts were more sensitive for UV-C damage than healthy control fibroblasts, even though all factors involved in NER localized normally to DNA damage and the efficiency of DNA repair was not reduced. HR23Bs other binding partner NGly1/PNGase, involved in ER-associated degradation (ERAD) of misfolded proteins, was not expressed in the majority of neurons in C9FTD/ALS brain sections compared to non-demented controls. Our results suggest a difference in HR23B aggregation and co-localization pattern with DPRs, pTDP-43 and p62 between different brain areas from C9FTD/ALS cases. We hypothesize that HR23B may play a role in C9ORF72 pathogenesis, possibly by aberrant ERAD functioning.

Background: The objective of this study was to assess the correlation between mismatch repair (MMR) status, disease recurrence patterns, and recurrence-free survival (RFS) in patients with high-intermediate-risk (HIR) endometrioid endometrial cancer (EEC)., Methods: A single-institution chart review for consecutive patients who were diagnosed with ECC between 2007 and 2016 was undertaken. Tumor MMR status was determined for all patients based on reported findings for mutL homolog 1 (MLH1), postmeiotic segregation (PMS2), mutS homolog 2 (MSH2), and MSH6 immunohistochemistry; and defective MMR (dMMR) status was defined as the lack of expression of at least 1 of these proteins. Patients were classified with HIR EEC according to criteria used for Gynecologic Oncology Group study 249. The factors associated with recurrence were assessed by logistic regression. RFS and associated factors were assessed by Kaplan-Meier survival analysis and Cox proportional-hazards models., Results: In total, 197 patients who had HIR EEC (64 with dMMR and 133 with intact MMR [iMMR]) were identified, of whom 32 (16.2%) developed recurrent disease. The median follow-up was 54 months. The recurrence rate for women who had dMMR was 28% compared with 10.5% for those who had iMMR (P = .002), independent of the type of adjuvant therapy they received. The increase in distant recurrences among patients who had dMMR was even more pronounced (14.1% vs 3%; P = .003). The estimated 5-year RFS was 66% for women who had dMMR compared with 89% for those who had iMMR (P = .001). Excluding isolated vaginal recurrences, the difference in 5-year RFS was 73.5% versus 95%, respectively (P = .0004)., Conclusions: Patients who had HIR EEC with dMMR had increased rates of recurrence and decreased RFS compared with those who had HIR EEC with iMMR, despite the receipt of similar adjuvant treatment. The current findings highlight the need for alternative treatment options and the importance of MMR status as a biomarker for patients with HIR EEC., (© 2018 American Cancer Society.)

DNA double-strand breaks (DSBs) are a potentially lethal DNA lesions that disrupt both the physical and genetic continuity of the DNA duplex. Homologous recombination (HR) is a universally conserved genome maintenance pathway that initiates via nucleolytic processing of the broken DNA ends (resection). Eukaryotic DNA resection is catalyzed by the resectosome-a multicomponent molecular machine consisting of the nucleases DNA2 or Exonuclease 1 (EXO1), Bloom's helicase (BLM), the MRE11-RAD50-NBS1 (MRN) complex, and additional regulatory factors. Here, we describe methods for purification and single-molecule imaging and analysis of EXO1, DNA2, and BLM. We also describe how to adapt resection assays to the high-throughput single-molecule DNA curtain assay. By organizing hundreds of individual molecules on the surface of a microfluidic flowcell, DNA curtains visualize protein complexes with the required spatial and temporal resolution to resolve the molecular choreography during critical DNA-processing reactions.

Glioma therapeutic resistance to alkylating chemotherapy is mediated via O6-methylguanine-DNA methyltransferase (MGMT). We hypothesized that a CD45/HAM56/MGMT double-stained cocktail would improve MGMT discrimination in tumor cells versus inflammatory and endothelial cells (IEC). Total MGMT protein was quantified by IHC on 982 glioblastomas (GBM) and 199 anaplastic astrocytomas. Correcting for IEC was done by a CD45/HAM56/MGMT 2-color cocktail. Lowest IEC infiltrates (IEC "cold spots") were identified to quantitate MGMT as well as the percentage of IEC% in the IEC cold spots. MGMT promoter methylation (PM) was also determined. Among the GBM biopsies, mean uncorrected and corrected MGMT% were 19.87 (range 0-90) and 16.67; mean IEC% was 18.65 (range 1-80). Four hundred and fifty one (45.9%) GBM biopsies were positive MGMT PM. Both uncorrected and corrected MGMT% positivity correlated with PM. All 3 MGMT scores correlated with overall survival (OS) in GBM's. Cold spot IEC% was also positively associated with OS. These effects remained in a multivariate model after adjusting for age and disease status. Prognosis determined by correcting MGMT% score for IEC% is not improved in this analysis. However, IEC COLD SPOT score does provide additional prognostic information that can be gained from this correction method.

Background and Purpose: Our objectives were: (1) compare dynamic susceptibility-weighted (DSC) and dynamic contrast-enhanced (DCE) permeability parameters, (2) evaluate diagnostic accuracy of DSC and DCE discriminating high- and low-grade tumors, (3) analyze relationship of permeability parameters with overall (OS) and progression-free survival (PFS) and (4) assess differences in high-grade tumors classified according to molecular biomarkers., Materials and Methods: 49 patients with histologically proved diffuse gliomas underwent DSC and DCE imaging. Parametric maps of cerebral blood volume (CBV), CBV-leakage corrected, volume transfer coefficient (Ktrans), fractional volume of the extravascular extracellular space (EES) (Ve), fractional blood plasma volume (Vp) and rate constant between EES and blood plasma (Kep) were calculated. High-grade gliomas were also classified according to isocitrate dehydrogenase (IDH), alpha-thalassemia/mental retardation syndrome X-linked (ATRX) and O6-methylguanine-dna-methyltransferase promoter methylation (MGMT) status., Results: There is correlation between parameters leakage, Ktrans and Vp. ROC curve analysis showed significance in both Ktrans and Ve for glioma grading. Threshold value of 0.075 for Ve generated the best combination of sensitivity (80%) and specificity (75%) in tumor gradation. Leakage was the only permeability parameter related to OS (P=0.006) and PFS (0.012); with prolonged survival for leakage values lower than 1.2. IDH-mutated high-grade tumors showed lower leakage and Ktrans values. High-grade tumors with loss of ATRX presented lower leakage and Vp values., Conclusions: Both DSC and DCE permeability parameters serve as non-invasive method for glioma grading. Leakage was the unique permeability parameter related to survival and the best discriminating high-grade gliomas classified according to IDH and ATRX status., (Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.)

The special AT-rich sequence binding protein (SATB2) has been reported to be a specific immunohistochemical marker for colorectal carcinoma; however, correlation of SATB2 expression with molecular alterations commonly assessed in colorectal carcinoma has not been performed. We examined the immunohistochemical expression of SATB2 in 586 adenocarcinomas of the gastrointestinal (GI) tract and pancreas to assess its utility in diagnosis and analyze the clinicopathologic and molecular characteristics of colorectal carcinoma stratified by SATB2 expression. SATB2 and CDX2 expression were evaluated in 266 adenocarcinomas of lower GI tract origin (246 colorectal and 20 appendiceal mucinous), 208 adenocarcinomas of upper GI tract and small intestinal origin (74 esophagus/esophagogastric junction, 103 stomach, 20 duodenal, and 11 jejunoileal), and 112 pancreatic ductal adenocarcinomas. SATB2 expression was more frequently identified in adenocarcinomas of lower GI tract origin (222/266, 83%) compared with upper GI tract, small intestinal, or pancreatic origin (26/320, 8%) (P<0.001). Compared with CDX2 alone, dual positive expression for SATB2 and CDX2 (SATB2/CDX2) has a significantly higher specificity for adenocarcinoma of lower GI tract origin (94% vs. 57%, P<0.001). In colorectal carcinoma, loss of SATB2 expression was more frequently observed in DNA mismatch repair (MMR) protein deficient tumors (31%) compared with MMR protein proficient tumors (13%) (P<0.01). A BRAF V600E mutation was more frequently identified in colorectal carcinomas with loss of SATB2 expression compared with those with positive SATB2 expression (29% vs. 3%) (P<0.001). In summary, SATB2 expression is a relatively specific marker of lower GI tract origin; however, loss of SATB2 expression is more commonly seen in colorectal carcinoma with MMR protein deficiency and BRAF mutation.

Background: Microsatellite instability is reflective of a deficient mismatch repair system (dMMR), which may be due to either sporadic or germline mutations in the relevant mismatch repair (MMR) gene. MMR status is frequently determined by immunohistochemistry (IHC) for mismatch repair proteins (MMRPs) on colorectal cancer (CRC) resection specimens. However, IHC testing performed on endoscopic biopsy may be as reliable as that performed on surgical resections., Aim: We aimed to evaluate the reliability of MMR IHC staining on preoperative CRC endoscopic biopsies compared with matched-surgical resection specimens., Methods: A retrospective search of our institution's histopathology electronic database was performed. Patients with CRC who had MMR IHC performed on both their preoperative endoscopic biopsy and subsequent resection from January 2010 to January 2016 were included. Concordance of MMR staining between biopsy and resection specimens was assessed., Results: From 2000 to 2016, 53 patients had MMR IHC performed on both their preoperative colorectal endoscopic biopsy and resection specimens; 10 patients (18.87%) demonstrated loss of ≥1 MMRP on their initial endoscopic tumour biopsy. The remainder (81.13%) showed preservation of staining for all MMRPs. There was complete agreement in MMR IHC status between the preoperative endoscopic biopsies and corresponding resection specimens in all cases (κ=1.000, P<0.000) with a sensitivity of 100% (95% CI 69.15 to 100) and specificity of 100% (95% CI 91.78 to 100) for detection of dMMR., Conclusion: Endoscopic biopsies are a suitable source of tissue for MMR IHC analysis. This may provide a number of advantages to both patients and clinicians in the management of CRC., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: We studied the expression of some major proteins involved in cell-cycle regulation and DNA repair, the roles of which are not well known in pancreatic ductal adenocarcinoma (PDAC), but which have a significant impact on carcinogenesis of many other cancers., Methods: We immunohistochemically assessed expression levels of the cell-cycle regulators Rb1, p16 and cyclin-dependent kinase 4 (CDK4), and the DNA repair enzymes O6-methylguanine-DNA-alkyltransferase (MGMT) and flap endonuclease-1 (FEN1) separately in malignant tissue and benign tissue from resection margins in 102 cases of PDAC. Nearly all (95.1%) patients had undergone pancreaticoduodenectomy., Results: The studied proteins showed wide but somewhat variable expression in both benign and malignant pancreatic tissues. Strong CDK4 expression in islets of Langerhans predicted poor relapse-free survival (RFS) (HR 2.874; 95% CI 1.261-6.550; p = .012) and within T3-4 tumors CDK4 expression in adenocarcinoma cells also predicted poor disease-free survival (DFS) (RR 2.148; 95% CI 1.081-4.272; p = .029). Strong MGMT expression was associated in N1 patients with weak local relapse-free survival (RFS), DFS and overall survival; all significantly in Cox regression analysis. FEN1 was also an independent predictor of decreased DFS (in the whole study population) and worse RFS (in the patients with T3-4 tumors)., Conclusions: Major cell-cycle regulator also have predictive significance, but further studies are required to evaluate this., (Copyright © 2018. Published by Elsevier GmbH.)

Background: Gliomas are the most common intrinsic tumors of the brain, with an incidence of 6 per 100 000 persons per year. Recent years have seen marked changes in the diagnosis and treatment of gliomas, with molecular parameters now being an integral part of the diagnostic evaluation., Methods: This review is based on pertinent articles retrieved by a selective search in PubMed, with special attention to the new WHO glioma classification., Results: The classification of gliomas on the basis of additional molecular parameters enables more accurate prognostication and serves as a basis for therapeutic decision-making and treatment according to precisely specified algorithms. PET scanning with 18F-fluoroethyl tyrosine and 11C-methionine for the measurement of metabolic activity in gliomas has further refined the diagnostic evaluation. The median overall survival of patients with glioblastoma who have undergone resection of all tumor tissue with a disrupted blood-brain barrier (i.e., all contrast-enhancing tumor tissue) has been prolonged to up to 20 months. The 5-year survival of patients with WHO grade II gliomas is now as high as 97% after near-total resection. The surgical resection of all contrast-enhancing tumor tissue and subsequent radiotherapy and chemotherapy remain the key elements of treatment. New surgical strategies and new methods of planning radiotherapy have made these techniques safer and more effective. The percutaneous application of tumor-treating fields is a new therapeutic option that has gained a degree of acceptance. Accompanying measures such as psycho-oncology and palliative care are very important for patients and should be considered mandatory., Conclusion: The consistent application of the existing multimodal treatment options for glioma has led in recent years to improved survival. Areas of important current and future scientific activity include immunotherapy and targeted and combined chemotherapy, as well as altered neurocognition, modern approaches to palliative care, and complementary therapies.

Objective: To analyze the prognostic factors for survival in elderly patients with glioma.
 Methods: We performed a retrospective analysis of prognostic factors for elderly patients with glioma, who were treated by the same attending doctor during June 2014 and June 2016, to investigate the correlations of the age, dimension of pathology, histological grade, extent of resection, adjuvant therapy, preoperative Karnofsky Performance Scale (KPS) score, postoperative KPS score, molecular markers [isocitrate dehydrogenase-1 (IDH-1), O6-methylguanine DNA-transferase (MGMT), epidermal growth factor receptor (EGFR), Ki-67] with the prognosis.
 Results: A total of 45 patients were included in the study. The median overall survival (OS) was 11 months. The median progression-free survival (PFS) was 6 months. Univariate analysis revealed that the age, gender, dimension of pathology, histological grade and preoperative KPS score had no significant correlation with survival (P>0.05). The gross total resection, higher postoperative KPS score, adjuvant therapy, lower Ki-67 index were significantly correlated with survival. The expressions of MGMT and EGFR were significant factors for survival. High postoperative KPS score (P=0.019), adjuvant therapy (P=0.024), and the expression of MGMT (P=0.026) were independent predictors for increased median OS in a multivariate regression model.
 Conclusion: The extent of resection, adjuvant therapy, postoperative KPS score and molecular markers are the influential factors for survival. Larger prospective studies are needed to confirm these findings.

Two types of molecular tests have been established to assess the deficiency of the DNA mismatch repair (MMR) system: microsatellite instability (MSI) and immunohistochemical (IHC) analysis. We have developed a reliable method to analyze the MSI status by next-generation sequencing (NGS) based on read-count distribution. A total of 91 patients with primary colorectal cancer were recruited. These patients included 54 cases with loss of expression of any MMR protein in IHC, suggesting deficient MMR (dMMR), and 37 cases of colorectal cancer with staining of all four MMR proteins in IHC, suggesting proficient MMR in the sample after surgery. DNA was extracted from paired tumor-normal tissue for MSI detection by both the ColonCore NGS panel and PCR. The sequencing data from the NGS panel was processed using various MSI detection pipelines for a comparison with the ColonCore panel. Using the MSI-PCR test as the gold standard, MSI-ColonCore achieved 97.9% sensitivity (47 of 48) and 100% specificity (37 of 37) for the detection of MSI status. MSI-ColonCore also showed more efficient and robust performance compared with other NGS-based MSI detection algorithms. The concordance rate was 92.3% between MSI-ColonCore and IHC testing, and 93.4% between MSI-PCR and IHC testing. These results suggest that MSI-ColonCore is a reliable and robust method for MSI status detection by NGS based on read-count distribution., (Copyright © 2018 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.)

Mismatch repair (MMR) deficiency in solid tumors has recently been linked to susceptibility to immunotherapies targeting the programmed cell death-1 (PD-1)/programmed cell death-1 ligand (PD-L1) axis. Loss of MMR proteins has been shown to correlate with tumoral PD-L1 expression in colorectal and endometrial carcinomas, but the association between expression of MMR proteins and PD-L1 has not previously been studied in breast carcinoma, where MMR deficiency is less common. We assessed the relationship between PD-L1 and MMR protein expression by immunohistochemistry in 245 primary and 40 metastatic breast carcinomas. Tumoral staining for PD-L1 was positive in 12% of all cases, including 32% of triple-negative cancers. MMR deficiency was observed in 0.04% of breast cancers; the single MMR-deficient case was a high-grade, triple-negative ductal carcinoma which showed dual loss of MLH1 and PMS2 proteins and expressed PD-L1. Two ER carcinomas initially were scored with MMR protein loss in tissue microarray format but were subsequently shown to be MMR-intact on whole sections. Analysis of MMR gene mutation in The Cancer Genome Atlas corroborates low frequency of MMR deficiency for invasive breast cancer. MMR protein expression is therefore unlikely to show utility as a screen for immunotherapeutic vulnerability in this tumor type, and may provoke unwarranted genetic testing in patients unlikely to have a heritable cancer syndrome. PD-L1 may be a more clinically relevant biomarker for anti-PD-1/PD-L1 therapies in this setting.

Synchronous colorectal carcinoma (CRC) is a unique disease associated with a high prevalence (∼35%) of microsatellite instability and occasionally with Lynch syndrome. The clinicopathologic and molecular features of synchronous CRC are poorly understood, particularly in Japanese patients. We examined 118 Japanese patients (236 tumors) with synchronous CRC and 117 Japanese patients (117 tumors) with solitary CRC with immunohistochemical staining for TP53 and mismatch repair (MMR) protein (MLH1, MSH2, PMS2, and MSH6) and mutation analyses of KRAS and BRAF genes. The results revealed no significant differences in clinicopathologic, histologic, and molecular findings between the synchronous and solitary CRC groups. Among the 118 synchronous CRC patients, 15 (12.7%) showed loss of MMR protein(s) expression in at least 1 tumor, whereas 103 (87.3%) showed intact expression of all 4 MMR proteins in both tumors. Of note, all patients with MMR deficiency had excellent prognoses. The 15 patients were further subdivided into 2 groups: the Concordant group, with concordant MMR loss (n=9, 7.6%) and the Discordant group, with discordant MMR loss (n=6, 5.1%). The Concordant patients showed concurrent MLH1/PMS2 loss (n=3), concurrent MSH2/MSH6 loss (n=4) and isolated MSH6 loss (n=2) in both tumors, whereas the Discordant patients showed concurrent MLH1/PMS2 loss (n=2), isolated PMS2 loss (n=2) and isolated MSH6 loss (n=2) in a single tumor. On the basis of the MMR expression pattern and BRAF mutation, the Concordant and Discordant groups were suspected to include Lynch syndrome, Lynch-like syndrome and sporadic MLH1 promoter hypermethylated CRC. In addition, KRAS mutation was present in only 1 tumor in a single patient in each group. In conclusion, the frequency of MMR protein deficiency in synchronous CRC in the Japanese population may be lower compared with the reported data from Western populations. MMR protein loss and KRAS and BRAF mutations in synchronous CRCs were heterogenous even in an individual patient.

By catalyzing highly specific and tightly controlled chemical reactions, enzymes are essential to maintaining normal cellular physiology. However, aberrant enzymatic activity can be linked to the pathogenesis of various diseases. Therefore, the unusual activity of particular enzymes can represent testable biomarkers for the diagnosis or screening of certain diseases. In recent years, G-quadruplex-based platforms have attracted wide attention for the monitoring of enzymatic activities. In this Personal Account, we discuss our group's works on the development of G-quadruplex-based sensing system for enzyme activities by using mainly iridium(III) complexes as luminescent label-free probes. These studies showcase the versatility of the G-quadruplex for developing assays for a variety of different enzymes., (© 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Context: Clinical study of breast cancer patients in Chicago, IL, USA., Objective: Ascertain the utility of measurements of single-strand breaks (SSB) in DNA for assessment of breast cancer risk., Methods: Fine-needle aspirates of the breast, SSB by nick translation, percent breast density (PBD), Gail model risk, cumulative methylation index (CMI), enzymes of DNA repair and tissue antioxidants., Results: DNA repair enzymes and 4-hydroxyestradiol were negatively associated with SSB; CMI and PBD were positively associated., Conclusions: Quantitative measurement of SSBs by this procedure indicates the relative number of SSBs and is related to promoter methylation, antioxidant availability and percent breast density.

Endometrial intraepithelial neoplasia (EIN) and atypical endometrial hyperplasia (AH) are histomorphologically defined precursors to endometrioid adenocarcinoma, which are unified as EIN/AH by the World Health Organization. EIN/AH harbors a constellation of molecular alterations similar to those found in endometrioid adenocarcinoma. However, the process of clonal evolution from EIN/AH to carcinoma is poorly characterized. To investigate, we performed next-generation sequencing, copy number alteration (CNA) analysis, and immunohistochemistry for mismatch repair protein expression on EIN/AH and endometrioid adenocarcinoma samples from 6 hysterectomy cases with spatially distinct EIN/AH and carcinoma. In evaluating all samples, EIN/AH and carcinoma did not differ in mutational burden, CNA burden, or specific genes mutated (all P>.1). All paired EIN/AH and carcinoma samples shared at least one identical somatic mutation, frequently in PI(3)K pathway members. Large CNAs (>10 genes in length) were identified in 83% of cases; paired EIN/AH and carcinoma samples shared at least one identical CNA in these cases. Mismatch repair protein expression matched in all paired EIN/AH and carcinoma samples. All paired EIN/AH and carcinoma samples had identical The Cancer Genome Atlas subtype, with 3 classified as "copy number low endometrioid" and 3 classified as "microsatellite instability hypermutated." Although paired EIN/AH and carcinoma samples were clonal, private mutations (ie, present in only one sample) were identified in EIN/AH and carcinoma in all cases, frequently in established cancer-driving genes. These findings indicate that EIN/AH gives rise to endometrioid adenocarcinoma by a complex process of subclone evolution, not a linear accumulation of molecular events., (Copyright © 2017 Elsevier Inc. All rights reserved.)

MGMT promoter methylation and IDH1 mutation in high-grade gliomas (HGG) have proven to be the two important molecular indicators associated with better prognosis. Traditionally, the statuses of MGMT and IDH1 are obtained via surgical biopsy, which is laborious, invasive and time-consuming. Accurate presurgical prediction of their statuses based on preoperative imaging data is of great clinical value towards better treatment plan. In this paper, we propose a novel Multi-label Inductive Matrix Completion (MIMC) model, highlighted by the online inductive learning strategy, to jointly predict both MGMT and IDH1 statuses. Our MIMC model not only uses the training subjects with possibly missing MGMT/IDH1 labels, but also leverages the unlabeled testing subjects as a supplement to the limited training dataset. More importantly, we learn inductive labels, instead of directly using transductive labels, as the prediction results for the testing subjects, to alleviate the overfitting issue in small-sample-size studies. Furthermore, we design an optimization algorithm with guaranteed convergence based on the block coordinate descent method to solve the multivariate non-smooth MIMC model. Finally, by using a precious single-center multi-modality presurgical brain imaging and genetic dataset of primary HGG, we demonstrate that our method can produce accurate prediction results, outperforming the previous widely-used single- or multi-task machine learning methods. This study shows the promise of utilizing imaging-derived brain connectome phenotypes for prognosis of HGG in a non-invasive manner.

Objectives: Alkylating agents have activity in well-differentiated pancreatic neuroendocrine tumors (WD panNETs). In glioblastoma multiforme, decreased activity of O-methylguanine DNA methyltransferase (MGMT) predicts response; in panNETs, MGMT relevance is unknown., Methods: We identified patients with WD panNETs treated with alkylating agents, determined best overall response by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, and performed MGMT activity testing., Results: Fifty-six patients were identified; 26 (46%) of the 56 patients experienced partial response, 24 (43%) of 56 experienced stable disease, and 6 (11%) of 56 experienced progression of disease. O-methylguanine DNA methyltransferase status was available for 36 tumors. For tumors with partial response, 10 (67%) of 15 were MGMT deficient, and 5 (33%) of 15 were MGMT intact. For tumors with stable disease, 7 (47%) of 15 were MGMT deficient, and 8 (53%) of 15 were MGMT intact. For tumors with progression of disease, 3 (50%) of 6 were MGMT deficient, and 3 (50%) of 6 were MGMT intact., Conclusions: We observed response and resistance to alkylating agents in MGMT-deficient and MGMT-intact tumors. O-methylguanine DNA methyltransferase status should not guide alkylating agent therapy in WD panNETs.

Objective: Temozolomide (TMZ) is an alkylating agent frequently used in well-differentiated metastatic pancreatic neuroendocrine tumors (PNETs) with very variable responses. O-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme whose loss of expression has been suggested to be predictive of response to TMZ in various human tumors. We evaluated the predictive value of MGMT status, assessed by immunohistochemistry (IHC) and methylation-specific PCR (MS-PCR), in well-differentiated metastatic PNETs treated by a TMZ-based chemotherapy., Patients and Methods: All patients with metastatic PNETs treated with TMZ-based chemotherapy between 2010 and 2016 in two academic centers, for whom the tumor samples were available, were included. Clinical data were collected and the MGMT status of the tumors was analyzed using MS-PCR and IHC., Results: Twenty-two patients (nine men, median age 61 years) were included. The loss of MGMT protein expression detected by IHC was observed in 13 (59%) patients and MGMT promoter hypermethylation was detected by MS-PCR in three (15%) out of 20 interpretable cases. MGMT status did not correlate significantly with the best radiological response according to the Response Evaluation Criteria In Solid Tumors criteria or with progression-free survival. There was no correlation between MGMT protein expression and MGMT gene promoter methylation., Conclusion: These results indicate that a deficient MGMT status in PNETs, determined by loss of protein expression in IHC or by the presence of MGMT gene promoter methylation measured by MS-PCR, is not associated with a better response to TMZ-based chemotherapy and cannot be used as a predictive marker to lead treatment decisions.

Colorectal medullary carcinoma, recognized by the World Health Organization as a distinct histologic subtype, is commonly regarded as a specific entity with an improved prognosis and unique molecular pathogenesis. A fundamental but as yet unaddressed question, however, is whether it can be diagnosed reproducibly. In this study, by analyzing 80 colorectal adenocarcinomas whose dominant growth pattern was solid (thus encompassing medullary carcinoma and its mimics), we provided a detailed description of the morphological spectrum from "classic medullary histology" to nonmedullary poorly differentiated histologies and demonstrated significant overlapping between categories. By assessing a selected subset (n=30) that represented the spectrum of histologies, we showed that the interobserver agreement for diagnosing medullary carcinoma by using 2010 World Health Organization criteria was poor; the κ value among 5 gastrointestinal pathologists was only 0.157 (95% confidence interval, 0.127-0.263; P=.001). When we arbitrarily classified the entire cohort into "classic" and "indeterminate" medullary tumors (group 1, n=19; group 2, n=26, respectively) and nonmedullary poorly differentiated tumors (group 3, n=35), groups 1 and 2 were more likely to exhibit mismatch repair protein deficiency than group 3 (P<.001); however, improved survival could not be detected in either group compared with group 3. Our findings suggest that the diagnosis of medullary carcinoma, as currently applied, may only serve as a morphological descriptor indicating an increased likelihood of mismatch-repair deficiency. Additional evidence including a more objective classification system is needed before medullary carcinoma can be regarded as a distinct entity with prognostic relevance. Until such evidence becomes available, caution should be exercised when making this diagnosis, as well as when comparing results across different studies., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Although many studies have evaluated the impact of mismatch repair protein loss of expression (MMR LOE) or microcystic, elongated, and fragmented (MELF) pattern of myometrial invasion as individual factors in endometrial cancer, we analyzed the combined impact of both. We reviewed every case of International Federation of Gynecology and Obstetrics (FIGO) grade 1 endometrioid endometrial cancers (EECs) from our institution, between 2011 and 2015, that had a sentinel lymph node biopsy and/or a lymphadenectomy, and examined the following data: age, myometrial infiltration, MELF infiltration, lymphovascular space invasion, and lymph node status. These cases were then grouped according to the absence of lymph node metastases, the presence of isolated tumor cell (ITC) lymph node metastases, or the presence of non-ITC metastases. Among the 127 cases that were in our study, 105 patients did not have nodal metastases, whereas 22 patients showed metastases, of which 11 were ITC. MMR LOE was only significantly associated with a higher odds ratio (OR) of metastases (OR, 7.44; P < .001). MELF was only associated with a higher OR of ITC-pattern metastases (OR, 32.3; P < .001). This study distinguished the effects of MELF and MMR LOE on the risk of metastases in FIGO grade 1 EEC. Further research on the clinical impact of MELF and ITC-pattern metastases is warranted to better guide clinicians on the management of patients with FIGO grade 1 EEC harboring such characteristics, which are still considered low-risk cancer., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Among different DNA repair processes that cells use to face with DNA damage, nucleotide excision repair (NER) is particularly important for the removal of a high variety of lesions, including those generated by some antitumor drugs. A number of factors participating in NER, such as the TFIIH complex and the endonuclease XPG are also involved in basal processes, e.g. transcription. For this reason, localization of these factors at DNA damage sites may be difficult. Here we have applied a mild digestion of chromatin with DNase I to improve the in situ extraction necessary to detect chromatin-bound proteins by immunofluorescence. We have compared this method with different extraction protocols and investigated its application on different cell types, and with different antibodies. Our results show that a short DNase I treatment before the immunoreaction, enhances the fluorescence signal of NER proteins, such as XPG, DDB2 and XPC. In addition, our findings indicate that the antibody choice is a critical factor for accurate localization of DNA repair proteins at DNA damage sites. In conclusion, a mild DNA digestion with DNase I improves the immunofluorescence detection of the recruitment of NER factors at local DNA damage sites by enhancing accessibility to the antibodies, independently of the cell type., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Human MutT homologue 1 (MTH1) is a human 8-oxo-dGTPase that eradicates oxidized bases in the nucleotide pool and DNA. MTH1 is critical for RAS-transformed cancer cell survival, whereas it is dispensable in normal cells and tissues. Here, we determined the expression of MTH1 in multiple myeloma (MM) cell lines and MM patients' CD138 (+) cells and analyzed its potential clinical significance. We detected overexpression of MTH1 mRNA in three cell lines (RPMI 8226, U266, and H929). MTH1 mRNA expression of RPMI8226 was higher than that of U266 and H929. In 59 MM patients, overexpression of MTH1 mRNA was detected in 27 cases (45.7%). MTH1 mRNA expression was significantly higher in ISS III stage (P < 0.001) and refractory relapse patients (P < 0.05). MTH1 mRNA expression in patients achieving less than partial response (PR) was significantly higher than in those achieving PR and better in newly diagnosed MM (P = 0.04). In conclusion, higher MTH1 may be associated with later disease stage and advanced disease progression. MTH1 mRNA overexpression is also correlated poor efficacy of bortezomib in newly diagnosed MM patients.