Search

Tissue inhibitor of metalloproteinases‐1 (TIMP‐1) regulates the proteolytic activity of matrix metalloproteinases (MMPs), playing an important role in the homeostasis of the extracellular matrix. Beyond its well‐known role in tissue maintenance, TIMP‐1 has been associated with multiple MMP‐independent cytokine‐like functions. The protein structure of TIMP‐1, with two distinct domains, one interacting with MMPs and another able to bind multiple partners, provides a rationale for this multifunctionality. The identification of CD63 as a cell surface receptor for TIMP‐1, able to mediate intracellular signaling through the Erk/MAPK axis, provided a molecular basis for the role of TIMP‐1 in cellular signaling. However, several lines of evidence suggest that TIMP‐1 may be able to associate with many interaction partners, thus attaining multiple functions. To enable the identification of previously unknown interaction partners that may underpin the core cellular functions of TIMP‐1, known as well as unknown, we performed a yeast two‐hybrid screening using a mammary gland complementary DNA (cDNA) library. We report here the identification of multiple interactors, including MHC class II‐associated invariant chain γ (CD74). We verified that CD74 interacts with TIMP‐1 in breast cancer cells and that this interaction contributes to cellular internalization of TIMP‐1 and mediates intracellular signaling through the Akt signaling axis in breast cancer cells. These data provide new insights into the complex nature of the functions of TIMP‐1 and their potential mechanistic basis. [ABSTRACT FROM AUTHOR]

To investigate the relationship between non-coding RNAs [especially circular RNAs (circRNAs)] and docetaxel resistance in breast cancer, and to find potential predictive biomarkers for taxane-containing therapies, we have performed transcriptome and microRNA (miRNA) sequencing for two established docetaxel-resistant breast cancer (DRBC) cell lines and their docetaxel-sensitive parental cell lines. Our analyses revealed differences between circRNA signatures in the docetaxel-resistant and -sensitive breast cancer cells, and discovered circRNAs generated by multidrug-resistance genes in taxane-resistant cancer cells. In DRBC cells, circABCB1 was identified and validated as a circRNA that is strongly up-regulated, whereas circEPHA3.1 and circEPHA3.2 are strongly down-regulated. Furthermore, we investigated the potential functions of these circRNAs by bioinformatics analysis, and miRNA analysis was performed to uncover potential interactions between circRNAs and miRNAs. Our data showed that circABCB1, circEPHA3.1 and circEPHA3.2 may sponge up eight significantly differentially expressed miRNAs that are associated with chemotherapy and contribute to docetaxel resistance via the PI3K-Akt and AGE-RAGE signaling pathways. We also integrated differential expression data of mRNA, long non-coding RNA, circRNA, and miRNA to gain a global profile of multi-level RNA changes in DRBC cells, and compared them with changes in DNA copy numbers in the same cell lines. We found that Chromosome 7 q21.12-q21.2 was a common region dominated by multi-level RNA overexpression and DNA amplification, indicating that overexpression of the RNA molecules transcribed from this region may result from DNA amplification during stepwise exposure to docetaxel. These findings may help to further our understanding of the mechanisms underlying docetaxel resistance in breast cancer. [ABSTRACT FROM AUTHOR]

A series of nine novel thiazole linked chalcones, (E)-3-(4-methyl-2-(4(trifluoromethyl)phenyl)thiazol-5-yl)-1-phenylprop-2-en-1-one derivatives 7–15 were synthesized. To establish the structure–activity relationship (SAR), furthermore, the corresponding, ring-closed pyrimidine analogs 17–23 were synthesized. The derivatives thus obtained were evaluated for their anti-cancer activity against three genetically different colorectal cancer (CRC) cell lines. Thiazole derivatives 7, 9, and10 showed anti-cancer activity with GI50 values ranging from 0.19 to 100 µM. Importantly, compounds 7 and 10 outperformed the standard drug cisplatin in the tested cell lines and thus show promise for further optimization. Some of pyrimidine derivatives retain activity comparable to cisplatin in the HT-29 cell line, e.g. compounds 17 and 18 with IC50 of 25 µM, however, none of these compounds demonstrated improved antiproliferative activity as compared with the starting thiazole, thus the enone linker was critical for obtaining more active compounds in this series. [ABSTRACT FROM AUTHOR]

SCO‐101 (Endovion) was discontinued 20 years ago as a new drug under development against sickle cell anaemia. Data from the phase 1 studies remained unpublished. New data indicate that SCO‐101 might be efficacious as add‐on therapy in cancer. Thus, we report the results from the four phase 1 trials performed between 2001 and 2002. Adult volunteers received SCO‐101 or placebo in four independent trials. Adverse events were recorded, and SCO‐101 was determined for pharmacokinetic analysis. Ninety‐two volunteers completed the trials. The most remarkable adverse effect was a transient and dose‐dependent increase in unconjugated bilirubin. Plasma SCO‐101 elimination was approximately log linear, with apparent oral clearances of between 315 and 2103 mL/h for single doses, and between 121 and 2433 mL/h at steady state following oral administration. There was a marked decrease in clearance with increasing dose, and for repeated dose versus single dose. Tmax was greater, and Cmax and AUC∞ were lower in the fed state compared to the fasted state. Exposure was equivalent in males and females and for African Americans and Caucasians. In conclusion, SCO‐101 appears to be a safe drug with a predictable PK profile. Its efficacy as add‐on to standard anticancer drugs has yet to be defined. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is the third most prevalent cancer worldwide causing an estimated 700 000 deaths annually. Different types of treatment are available for patients with advanced metastatic colorectal cancer, including targeted biological agents, such as cetuximab, a monoclonal antibody that targets EGFR. We have previously reported a study indicating multiple levels of interaction between metallopeptidase inhibitor 1 (TIMP‐1) and the epidermal growth factor (EGF) signaling axis, which could explain how TIMP‐1 levels can affect the antitumor effects of EGFR inhibitors. We also reported an association between TIMP‐1‐mediated cell invasive behavior and KRAS status. To gain insight into the molecular mechanisms underlying the effects of TIMP‐1 in CRC, we examined by transcriptomics, proteomics, and kinase activity profiling a matched pair of isogenic human CRC isogenic DLD‐1 CRC cell clones, bearing either an hemizygous KRAS wild‐type allele or KRAS G13D mutant allele, exposed, or not, to TIMP‐1. Omics analysis of the two cell lines identified the receptor tyrosine kinase c‐Kit, a proto‐oncogene that can modulate cell proliferation and invasion in CRC, as a target for TIMP‐1. We found that exposure of DLD‐1 CRC cells to exogenously added TIMP‐1 promoted phosphorylation of c‐Kit, indicative of a stimulatory effect of TIMP‐1 on the c‐Kit signaling axis. In addition, TIMP‐1 inhibited c‐Kit shedding in CRC cells grown in the presence of exogenous TIMP‐1. Given the regulatory roles that c‐Kit plays in cell proliferation and migration, and the realization that c‐Kit is an important oncogene in CRC, it is likely that some of the biological effects of TIMP‐1 overexpression in CRC may be exerted through its effect on c‐Kit signaling. [ABSTRACT FROM AUTHOR]

In the article, the authors present their phase II study on the effectiveness of epirubicin in patients with oxaliplatin refractory metastatic colorectal cancer (mCRC). Topics include the routine clinical management of mCRC patients like oxaliplatin-containing therapy and irinotecan-containing therapy at progression and the proof of effective therapy like overall survival (OS) and progression-free survival (PFS).

Cell therapy is an emerging fields in the treatment of various diseases such as cardiovascular, pulmonary, hepatic, and neoplastic diseases. Stem cells are an integral tool for cell therapy. Multipotent stem cells are an important class of stem cells which have the ability to self-renew through dividing and developing into multiple specific cell types in a specific tissue or organ. These cells are capable to activate or inhibit a sequence of cellular and molecular pathways leading to anti-inflammatory and antiapoptotic effects which might contribute to the treatment of various diseases. It has been showed that multipotent stem cells exert their therapeutic effects via inhibition/activation of a sequence of cellular and molecular pathways. Although the advantages of multipotent stem cells are numerous, further investigation is still necessary to clarify the biology and safety of these cells before they could be considered as a potential treatment for different types of diseases. This review summarizes different features of multipotent stem cells including isolation, differentiation, and therapeutic applications. [ABSTRACT FROM AUTHOR]

Early diagnostic is one of the most important steps in cancer therapy which helps to design and choose a better therapeutic approach. The finding of biomarkers in various levels including genomics, transcriptomics, and proteomics levels could provide better treatment for various cancers such as chronic lymphocytic leukemia (CLL). The CLL is the one of main lymphoid malignancies which is specified by aggregation of mature B lymphocytes. Among different biomarkers (e.g., CD38, chromosomes abnormalities, ZAP-70, TP53, and microRNA [miRNA]), miRNAs have appeared as new diagnostic and therapeutic biomarkers in patients with the CLL disease. Multiple lines of evidence indicated that deregulation of miRNAs could be associated with pathological events which are present in the CLL. These molecules have an effect on a variety of targets such as Bcl2, c-fos, c-Myc, TP53, TCL1, and STAT3 which play critical roles in the CLL pathogenesis. It has been shown that expression of miRNAs could lead to the activation of B cells and B cell antigen receptor (BCR). Moreover, exosomes containing miRNAs are one of the other molecules which could contribute to BCR stimulation and progression of CLL cells. Hence, miRNAs and exosomes released from CLL cells could be used as potential diagnostic and therapeutic biomarkers for CLL. This critical review focuses on a very important aspect of CLL based on biomarker discovery covers the pros and cons of using miRNAs as important diagnostics and therapeutics biomarkers for this deadly disease. [ABSTRACT FROM AUTHOR]

Background: One of the main chemotherapeutic drugs used on a routine basis in patients with metastatic colorectal cancer ((m)CRC) is the topoisomerase-1 inhibitor, irinotecan. However, its usefulness is limited by the pre-existing or inevitable development of resistance. The ATP-binding cassette (ABC) transporter ABCG2/breast cancer resistance protein (BRCP) through its function in xenobiotic clearance might play an important role in irinotecan resistance. With a goal to evaluate the clinical significance of ABCG2 measurements, we here review the current literature on ABCG2 in relation to irinotecan treatment in CRC patients. Results: Few studies have evaluated the association between ABCG2 gene or protein expression and prognosis in CRC patients. Discordant results were reported. The discrepancies might be explained by the use of different criteria for interpretation of results in the immunohistochemistry studies. Only one large study evaluated the ABCG2 protein expression and efficacy of irinotecan in mCRC (CAIRO study, n = 566). This study failed to demonstrate any correlation between ABCG2 protein expression in the primary tumor and response to irinotecan-based treatment. We recently raised questions on how to evaluate ABCG2 immunoreactivity patterns, and the results in the CAIRO study might be influenced by using a different scoring protocol than the one proposed by us. In contrast, our recent exploratory study of ABCG2 mRNA expression in 580 patients with stage III primary CRC (subgroup from the randomized PETACC-3 study) indicated that high ABCG2 tumor tissue mRNA expression might be predictive for lack of efficacy of irinotecan. Conclusion: The biological role of ABCG2 in predicting clinical irinotecan sensitivity/resistance in CRC is uncertain. In particular, the significance of ABCG2 cellular localization needs to be established. Data concerning ABCG2 mRNA expression and prediction of adjuvant irinotecan efficacy are still sparse and need to be confirmed. [ABSTRACT FROM AUTHOR]

Background: No biomarker exists to guide the optimal choice of chemotherapy for patients with metastatic colorectal cancer. We examined the copy numbers (CN) of topoisomerase I (TOP1) as well as the ratios of TOP1/CEN-20 and TOP1/CEN-2 as biomarkers for irinotecan efficacy in patients with metastatic colorectal cancer.Methods: From a national cohort, we identified 163 patients treated every third week with irinotecan 350 mg/m2 as second-line therapy. Among these 108 were eligible for analyses and thus entered the study. Primary tumors samples were collected and tissue microarray (TMA) blocks were produced. FISH analysis was performed using two probe-mixes: TOP1/CEN-20 and TOP1/CEN-2. Only samples harboring all three signals (TOP1, CEN-20 and CEN-2) using FISH were included in the analyses.Results: In the TOP1/CEN-20 probe-mix the median TOP1- and CEN-20 CN were 4.46 (range: 1.5-9.5) and 2.00 (range: 0.55-4.55), respectively. The median TOP1- and CEN-2 CN in the TOP1/CEN-2 probe-mix, were 4.57 (range: 1.82-10.43) and 1.98 (range: 1.22-6.14), respectively. The median TOP1/CEN-20 ratio and TOP1/CEN-2 ratio were 1.25 (range: 0.92-2.90) and 2.05 (range: 1.00-6.00), respectively. None of the markers TOP1 CN, TOP1/CEN-20-ratio or TOP1/CEN-2-ratio were associated with progression free survival, overall survival or baseline characteristics. Yet, we observed a borderline association for a stepwise increase of the TOP1 CN in relation to objective response as hazard ratio were 1.35 (95% CI 0.96-1.90; p = 0.081).Conclusions: We verified a borderline significant association between increasing TOP1 CN and objective response as previously reported. Applying the probes representing CEN-20 and CEN-2, in order to investigate the ratios of TOP1/CEN-20 and TOP1/CEN-2 provided no further information in search of a biomarker driven patient stratification. Other biomarkers to be paired with TOP1 CN are therefore highly warranted. [ABSTRACT FROM AUTHOR]

Background: Resistance to taxane-based therapy in breast cancer patients is a major clinical problem that may be addressed through insight of the genomic alterations leading to taxane resistance in breast cancer cells. In the current study we used whole exome sequencing to discover somatic genomic alterations, evolving across evolutionary stages during the acquisition of docetaxel resistance in breast cancer cell lines. Results: Two human breast cancer in vitro models (MCF-7 and MDA-MB-231) of the step-wise acquisition of docetaxel resistance were developed by exposing cells to 18 gradually increasing concentrations of docetaxel. Whole exome sequencing performed at five successive stages during this process was used to identify single point mutational events, insertions/deletions and copy number alterations associated with the acquisition of docetaxel resistance. Acquired coding variation undergoing positive selection and harboring characteristics likely to be functional were further prioritized using network-based approaches. A number of genomic changes were found to be undergoing evolutionary selection, some of which were likely to be functional. Of the five stages of progression toward resistance, most resistance relevant genomic variation appeared to arise midway towards fully resistant cells corresponding to passage 31 (5 nM docetaxel) for MDA-MB-231 and passage 16 (1.2 nM docetaxel) for MCF-7, and where the cells also exhibited a period of reduced growth rate or arrest, respectively. MCF-7 cell acquired several copy number gains on chromosome 7, including ABC transporter genes, including ABCB1 and ABCB4, as well as DMTF1, CLDN12, CROT, and SRI. For MDA-MB-231 numerous copy number losses on chromosome X involving more than 30 genes was observed. Of these genes, CASK, POLA1, PRDX4, MED14 and PIGA were highly prioritized by the applied network-based gene ranking approach. At higher docetaxel concentration MCF-7 sub clones exhibited a copy number loss in E2F4, and the gene encoding this important transcription factor was down-regulated in MCF-7 resistant cells. Conclusions: Our study of the evolution of acquired docetaxel resistance identified several genomic changes that might explain development of docetaxel resistance. Interestingly, the most relevant resistance-associated changes appeared to originate midway through the evolution towards fully resistant cell lines. Our data suggest that no single genomic event sufficiently predicts resistance to docetaxel, but require genomic alterations affecting multiple pathways that in concert establish the final resistance stage. [ABSTRACT FROM AUTHOR]

Background: DNA topoisomerase I (Top1) is a DNA unwinding protein and the specific target of the camptothecin class of chemotherapeutic drugs. One of these, irinotecan, acting through its active metabolite SN-38, is used in the treatment of metastatic colorectal cancer. However, resistance to irinotecan represents a major clinical problem. Since molecular alterations in Top1 may result in resistance to irinotecan, we characterized Top1 in three human colon cancer cell lines with acquired resistance to SN-38. Methods: Three SN-38 resistant (20-67 fold increased resistance) cell lines were generated and compared to wildtype parental cells with regards to: TOP1 gene copy number and gene sequence, Top1 expression (mRNA and protein), Top1 enzymatic activity in the absence and presence of drug, and Top1-DNA cleavage complexes in drug treated cells. TOP1 mutations were validated by PCR using mutant specific primers. Furthermore, cross-resistance to two indenoisoquinoline Top1-targeting drugs (NSC 725776 and NSC 743400) and two Top2-targeting drugs (epirubicin and etoposide) was investigated. Results: Two of three SN-38 resistant cell lines carried TOP1 gene copy number aberrations: A TOP1 gene copy gain and a loss of chromosome 20, respectively. One resistant cell line harbored a pair of yet unreported TOP1 mutations (R364K and G717R) in close proximity to the drug binding site. Mutant TOP1 was expressed at a markedly higher level than wild-type TOP1. None or very small reductions were observed in Top1 expression or Top1 activity in the absence of drug. In all three SN-38 resistant cell lines Top1 activity was maintained in the presence of high concentrations of SN-38. None or only partial cross-resistance were observed for etoposide and epirubicin, respectively. SN-38 resistant cells with wild-type TOP1 remained sensitive to NSC 743400, while cells with mutant TOP1 was fully cross-resistant to both indenoisoquinolines. Top1-DNA cleavage complex formation following drug treatment supported the other findings. Conclusions: This study adds to the growing knowledge about resistance mechanisms for Top1-targeting chemotherapeutic drugs. Importantly, two yet unreported TOP1 mutations were identified, and it was underlined that cross-resistance to the new indenoisoquinoline drugs depends on the specific underlying molecular mechanism of resistance to SN-38. [ABSTRACT FROM AUTHOR]

The overall purpose of this study is to provide proof of concept for introducing the anthracycline epirubicin as an effective, biomarker-guided treatment for metastatic colorectal cancer (mCRC) patients who are refractory to treatment with oxaliplatin-based chemotherapy and have TOP2A gene amplification in their tumor cells. Background: Epirubicin is an anthracycline that targets DNA topoisomerase 2-α enzyme encoded by the TOP2A gene. It is used for treatment of several malignancies, but currently not in CRC. TOP2A gene amplifications predict improved efficacy of epirubicin in patients with breast cancer and thus could be an alternative option for patients with CRC and amplified TOP2A gene. We have previously analysed the frequency of TOP2A gene aberrations in CRC and found that 46.6 % of these tumors had TOP2A copy gain and 2.0 % had loss of TOP2A when compared to adjacent normal tissue. The TOP2A gene is located on chromosome 17 and when the TOP2A/CEN-17 ratio was applied to identify tumors with gene loss or amplifications, 10.5 % had a ratio ≥ 1.5 consistent with gene amplification and 2.6 % had a ratio ≤ 0.8 suggesting gene deletions. Based on these observations and the knowledge gained from treatment of breast cancer patients, we have initiated a prospective clinical, phase II protocol using epirubicin (90 mg/m² iv q 3 weeks) in mCRC patients, who are refractory to treatment with oxaliplatin. Methods/Design: The study is an open label, single arm, phase II study, investigating the efficacy of epirubicin in patients with oxaliplatin refractory mCRC and with a cancer cell TOP2A/CEN-17 ratio ≥ 1.5. TOP2A gene amplification measured by fluorescence in situ hybridization. A total of 25 evaluable patients (15 + 10 in two steps) will be included (Simon's two-stage minimax design). Every nine weeks, response is measured by computed tomography imaging and evaluated according to RECIST 1.1. The primary end-point of the study is progression-free survival. [ABSTRACT FROM AUTHOR]

Cancer cells secrete small membranous extracellular vesicles (EVs) into their microenvironment and circulation. These contain biomolecules, including proteins and microRNAs (miRNAs). Both circulating EVs and miRNAs have received much attention as biomarker candidates for non-invasive diagnostics. Here we describe a sensitive analytical method for isolation and subsequent miRNA profiling of epithelial-derived EVs from blood samples of patients with colorectal cancer (CRC). The epithelial-derived EVs were isolated by immunoaffinity-capture using the epithelial cell adhesion molecule (EpCAM) as marker. This approach mitigates some of the specificity issues observed in earlier studies of circulating miRNAs, in particular the negative influence of miRNAs released by erythrocytes, platelets and non-epithelial cells. By applying this method to 2 small-scale patient cohorts, we showed that blood plasma isolated from CRC patients prior to surgery contained elevated levels of 13 EpCAM+-EV miRNAs compared with healthy individuals. Upon surgical tumour removal, the plasma levels of 8 of these were reduced (miR-16-5p, miR-23a-3p, miR-23b-3p, miR-27a-3p, miR-27b-3p, miR-30b-5p, miR-30c-5p and miR-222-3p). These findings indicate that the miRNAs are of tumour origin and may have potential as non-invasive biomarkers for detection of CRC. This work describes a non-invasive blood-based method for sensitive detection of cancer with potential for clinical use in relation to diagnosis and screening. We used the method to study CRC; however, it is not restricted to this disease. It may in principle be used to study any cancer that release epithelial-derived EVs into circulation. [ABSTRACT FROM AUTHOR]

Despite the advances that have taken place in the past decade, including the development of novel molecular targeted agents, cytotoxic chemotherapy remains the mainstay of cancer treatment. In breast cancer, anthracyclines and taxanes are the two main chemotherapeutic options used on a routine basis. Although effective, their usefulness is limited by the inevitable development of resistance, a lack of response to drug-induced cancer cell death. A large body of research has resulted in the characterization of a plethora of mechanisms involved in resistance; ATP-binding cassette transporter proteins, through their function in xenobiotic clearance, play an important role in resistance. We review here the current evidence for drug transporters as biomarkers and the benefit of adding drug transporter modulators to conventional chemotherapy. [ABSTRACT FROM PUBLISHER]

Background: Irinotecan (SN38) and oxaliplatin are chemotherapeutic agents used in the treatment of colorectal cancer. However, the frequent development of resistance to these drugs represents a considerable challenge in the clinic. Alus as retrotransposons comprise 11% of the human genome. Genomic toxicity induced by carcinogens or drugs can reactivate Alus by altering DNA methylation. Whether or not reactivation of Alus occurs in SN38 and oxaliplatin resistance remains unknown. Results: We applied reduced representation bisulfite sequencing (RRBS) to investigate the DNA methylome in SN38 or oxaliplatin resistant colorectal cancer cell line models. Moreover, we extended the RRBS analysis to tumor tissue from 14 patients with colorectal cancer who either did or did not benefit from capecitabine + oxaliplatin treatment. For the clinical samples, we applied a concept of 'DNA methylation entropy' to estimate the diversity of DNA methylation states of the identified resistance phenotype-associated methylation loci observed in the cell line models. We identified different loci being characteristic for the different resistant cell lines. Interestingly, 53% of the identified loci were Alu sequences- especially the Alu Y subfamily. Furthermore, we identified an enrichment of Alu Y sequences that likely results from increased integration of new copies of Alu Y sequence in the drug-resistant cell lines. In the clinical samples, SOX1 and other SOX gene family members were shown to display variable DNA methylation states in their gene regions. The Alu Y sequences showed remarkable variation in DNA methylation states across the clinical samples. Conclusion: Our findings imply a crucial role of Alu Y in colorectal cancer drug resistance. Our study underscores the complexity of colorectal cancer aggravated by mobility of Alu elements and stresses the importance of personalized strategies, using a systematic and dynamic view, for effective cancer therapy. [ABSTRACT FROM AUTHOR]

Background: Colorectal cancer (CRC) is a leading cause of cancer death globally and new biomarkers and treatments are severely needed. Methods: Here, we employed HCT116 and LoVo human CRC cells made resistant to either SN38 or oxaliplatin, to investigate whether altered expression of the high affinity glutamate transporters Solute Carrier (SLC)-1A1 and -1A3 (EAAT3, EAAT1) is associated with the resistant phenotypes. Analyses included real-time quantitative PCR, immunoblotting and immunofluorescence analyses, radioactive tracer flux measurements, and biochemical analyses of cell viability and glutathione content. Results were evaluated using one- and two-way ANOVA and Students two-tailed t-test, as relevant. Results: In SN38-resistant HCT116 and LoVo cells, SLC1A1 expression was down-regulated ~60 % and up-regulated ~4-fold, respectively, at both mRNA and protein level, whereas SLC1A3 protein was undetectable. The changes in SLC1A1 expression were accompanied by parallel changes in DL-Threo-β-Benzyloxyaspartic acid (TBOA)-sensitive, UCPH101-insensitive [³H]-D-Aspartate uptake, consistent with increased activity of SLC1A1 (or other family members), yet not of SLC1A3. DL-TBOA co-treatment concentration-dependently augmented loss of cell viability induced by SN38, while strongly counteracting that induced by oxaliplatin, in both HCT116 and LoVo cells. This reflected neither altered expression of the oxaliplatin transporter Cu2+-transporter-1 (CTR1), nor changes in cellular reduced glutathione (GSH), although HCT116 cell resistance per se correlated with increased cellular GSH. DL-TBOA did not significantly alter cellular levels of p21, cleaved PARP-1, or phospho-Retinoblastoma protein, yet altered SLC1A1 subcellular localization, and reduced chemotherapy-induced p53 induction. Conclusions: SLC1A1 expression and glutamate transporter activity are altered in SN38-resistant CRC cells. Importantly, the non-selective glutamate transporter inhibitor DL-TBOA reduces chemotherapy-induced p53 induction and augments CRC cell death induced by SN38, while attenuating that induced by oxaliplatin. These findings may point to novel treatment options in treatment-resistant CRC. [ABSTRACT FROM AUTHOR]

Background. Bile duct and pancreatic cancer (PC) have poor prognoses and treatment options for inoperable patients are scarce. In order to improve outcome for these patients, there is an urgent need for biomarkers predictive of treatment effect. Irinotecan is a topoisomerase 1 (Top1) poison. Top1 protein, TOP1 gene copy number and mRNA expression, respectively, have been proposed as predictive biomarkers of response to irinotecan in other cancers. Here we investigate the occurrence of TOP1 gene aberrations in cancers of the bile ducts and pancreas. Material and methods. TOP1 and centromere 20 (CEN-20) numbers were investigated by fluorescence in situ hybridization analyses in tumor tissue from 226 patients. The frequencies of aberration in the TOP1 gene copy number, the CEN-20 copy number and the TOP1/CEN-20 ratio were analyzed. As TOP1 is located on chromosome 20, the CEN-20 probe was included to distinguish between chromosomal and gene amplifications. Results. In PC, 29.8% had an increased TOP1 copy number (≥3.5n gene copies per cell) and 10.8% had a TOP1/CEN-20 ratio >1.5. In bile duct cancer, 12.8 % had an increased TOP1 copy number and 6.4% had a TOP1/CEN-20 ratio >1.5. Neither the TOP1 copy number nor the TOP1/CEN-20 ratios could predict overall survival. Conclusion. We here report that a substantial number of patients with bile duct or PC have increased TOP1 copy number and increased TOP1/CEN-20 ratio making further analyses on the association between TOP1 gene copy number and irinotecan efficacy clinically relevant. [ABSTRACT FROM AUTHOR]

Background: About 20% of patients with primary breast cancer develop metastatic disease during the course of the disease. At this point the disease is considered incurable and thus treatment is aimed at palliation and life prolongation. As many patients will have received both an anthracycline and a taxane in the adjuvant setting, treatment options for metastatic breast cancer are limited. Furthermore response rates for the most commonly used drugs range from around 30% to 12% . Thus new treatment options are needed and preferably coupled to biomarkers predictive of response. Irinotecan is a topoisomerase 1 inhibitor used for decades for the treatment of colorectal cancer. Four studies have investigated the efficacy of irinotecan monotherapy in breast cancer and all have included non-biomarker selected patients. In these studies response rates for irinotecan ranged from 5%-23% and are thus comparable to response rates obtained with drugs commonly used in the metastatic setting. If a predictive biomarker could be identified for irinotecan, response rates might be even higher. Methods/Design: This multi-centre phase II single arm trial was designed to investigate if patients with metastatic breast cancer and increased expression of the topoisomerase 1 gene have a high likelihood of obtaining a clinical benefit from treatment with irinotecan. Trial recruitment is two-staged as 19 patients are planned to participate in the first part. If less than 7 patients have clinical benefit the trial stops, if more than 7 patients have clinical benefit a total of 40 patients will be included. Discussion: This ongoing trial is the first to prospectively test copy number of the topoisomerase I gene as a predictive biomarker of response to irinotecan. Trial registration: EudraCT number 2012-002348-26. [ABSTRACT FROM AUTHOR]

Background Progesterone receptors play a key role in the development of canine mammary tumours, and recent research has focussed on their possible value as therapeutic targets using antiprogestins. Cloning and sequencing of the progesterone receptor gene has shown that the receptor has two isoforms, A and B, transcribed from a single gene. Experimental studies in human breast cancer suggest that the differential expression of progesterone receptor isoforms has implications for hormone therapy responsiveness. This study examined the effects of the antiprogestin aglepristone on cell proliferation and mRNA expression of progesterone receptor isoforms A and B in mammary carcinomas in dogs treated with 20 mg/Kg of aglepristone (n = 22) or vehicle (n = 5) twice before surgery. Results Formalin-fixed, paraffin-embedded tissue samples taken before and after treatment were used to analyse total progesterone receptor and both isoforms by RT-qPCR and Ki67 antigen labelling. Both total progesterone receptor and isoform A mRNA expression levels decreased after treatment with aglepristone. Furthermore, a significant decrease in the proliferation index (percentage of Ki67-labelled cells) was observed in progesterone-receptor positive and isoform-A positive tumours in aglepristone-treated dogs. Conclusions These findings suggest that the antiproliferative effects of aglepristone in canine mammary carcinomas are mediated by progesterone receptor isoform A. [ABSTRACT FROM AUTHOR]

Medical research is developing an ever greater need for comprehensive high-quality data generation to realize the promises of personalized health care based on molecular biomarkers. The nucleic acid proximity-based methods proximity ligation and proximity extension assays have, with their dual reporters, shown potential to relieve the shortcomings of antibodies and their inherent cross-reactivity in multiplex protein quantification applications. The aim of the present study was to develop a robust 96-plex immunoassay based on the proximity extension assay (PEA) for improved high throughput detection of protein biomarkers. This was enabled by: (1) a modified design leading to a reduced number of pipetting steps compared to the existing PEA protocol, as well as improved intra-assay precision; (2) a new enzymatic system that uses a hyper-thermostabile enzyme, Pwo, for uniting the two probes allowing for room temperature addition of all reagents and improved the sensitivity; (3) introduction of an inter-plate control and a new normalization procedure leading to improved inter-assay precision (reproducibility). The multiplex proximity extension assay was found to perform well in complex samples, such as serum and plasma, and also in xenografted mice and resuspended dried blood spots, consuming only 1 µL sample per test. All-in-all, the development of the current multiplex technique is a step toward robust high throughput protein marker discovery and research. [ABSTRACT FROM AUTHOR]