Search

Abstract Background Gastric cancer (GC) is known for its high heterogeneity, presenting challenges in current clinical treatment strategies. Accurate subtyping and in-depth analysis of the molecular heterogeneity of GC at the molecular level are still not fully understood. Methods This study categorized GC into two subtypes based on apoptosis-related genes (ARGs) and investigated differences in tumor immune microenvironment, intratumoral microorganisms distribution, gene expression, and signaling pathways. Key prognostic genes related to apoptosis in GC were identified through random survival forest analysis, and their specific signaling mechanisms were explored. Expression levels of key genes were validated through PCR in paired GC tissues and cancer cell lines. Moreover, biological functions of these key genes were verified in vitro experiments. Results A consistent clustering of GC was conducted using 161 apoptosis-related genes (ARGs), resulting in the identification of two subtypes, C1 and C2. Subsequently, significant differences were found in the tumor immune microenvironment, intratumoral microorganisms, gene expression, signaling pathways, and protein interaction networks between the two subtypes. GPX3, PLAT, and CAV1 were identified as key prognostic genes related to apoptosis in GC, with a focus on their impact on disease progression-related pathways. Furthermore, PCR assays validated that these three key genes exhibited significantly low expression levels in both GC cell lines and tissues. Finally, knocking down key genes expression significantly promoted cell proliferation, colony formation and invasion of GC. Conclusions Our study conducted a comprehensive analysis of the molecular characteristics of ARGs in GC, revealed their association with the tumor immune microenvironment and intratumoral microorganisms. These findings provide new ideas for the molecular classification of GC.

Abstract Background Intrahepatic cholangiocarcinoma (iCCA) is one of the most lethal malignancies and highly heterogeneous. We thus aimed to identify and characterize iCCA cell subpopulations with severe malignant features. Methods Transcriptomic datasets from three independent iCCA cohorts (iCCA cohorts 1–3, n = 382) and formalin-fixed and paraffin-embedded tissues from iCCA cohort 4 (n = 31) were used. An unbiased global screening strategy was established, including the transcriptome analysis with the activated malignancy/stemness (MS) signature in iCCA cohorts 1–3 and the mass spectrometry analysis of the sorted stemness reporter-positive iCCA cells. A group of cellular assays and subcutaneous tumor xenograft assay were performed to investigate functional roles of the candidate. Immunohistochemistry was performed in iCCA cohort 4 to examine the expression and localization of the candidate. Molecular and biochemical assays were used to evaluate the membrane localization and functional protein domains of the candidate. Cell sorting was performed and the corresponding cellular molecular assays were utilized to examine cancer stem cell features of the sorted cells. Results The unbiased global screening identified RRM2 as the top candidate, with a significantly higher level in iCCA patients with the MS signature activation and in iCCA cells positive for the stemness reporter. Consistently, silencing RRM2 significantly suppressed iCCA malignancy phenotypes both in vitro and in vivo. Moreover, immunohistochemistry in tumor tissues of iCCA patients revealed an unreported cell membrane localization of RRM2, in contrast to its usual cytoplasmic localization. RRM2 cell membrane localization was then confirmed in iCCA cells via immunofluorescence with or without cell membrane permeabilization, cell fractionation assay and cell surface biotinylation assay. Meanwhile, an unclassical signal peptide and a transmembrane domain of RRM2 were revealed experimentally. They were essential for RRM2 trafficking to cell membrane via the conventional endoplasmic reticulum (ER)–Golgi secretory pathway. Furthermore, the membrane RRM2-positive iCCA cells were successfully sorted. These cells possessed significant cancer stem cell malignant features including cell differentiation ability, self-renewal ability, tumor initiation ability, and stemness/malignancy gene signatures. Patients with membrane RRM2-positive iCCA cells had poor prognosis. Conclusions RRM2 had an alternative cell membrane localization. The membrane RRM2-positive iCCA cells represented a malignant subpopulation with cancer stem cell features.

Circular RNAs (circRNAs), a class of endogenous RNA molecules, are produced by alternative splicing of precursor RNA and are covalently linked at the 5′ and 3′ ends. Recent studies have revealed that dysregulated circRNAs are closely related to the occurrence and progression of gastrointestinal malignancies. Accumulating evidence indicates that circRNAs, including circPVT1, circLARP4, circ-SFMBT2, cir-ITCH, circRNA_100782, circ_100395, circ-DONSON, hsa_circ_0001368, circNRIP1, circFAT1(e2), circCCDC66, circSMARCA5, circ-ZNF652, and circ_0030235 play important roles in the proliferation, differentiation, invasion, and metastasis of cancer cells through a variety of mechanisms, such as acting as microRNA sponges, interacting with RNA-binding proteins, regulating gene transcription and alternative splicing, and being translated into proteins. With the characteristics of high abundance, high stability, extensive functions, and certain tissue-, time- and disease-specific expressions, circRNAs are expected to provide novel perspectives for the diagnoses and treatments of gastrointestinal malignancies.

Abstract Background Tumor deposits (TDs) have been identified as an independent prognostic factor in gastric cancer (GC). However, the associated clinicopathological factors and how to simply and reasonably incorporate TD into the TNM staging system remain undetermined. The aim of the current study was therefore to assess the significance of TD among radically resected GC patients. Methods We retrospectively reviewed 1915 patients undergoing radical resection between 2007 and 2012. The patients were classified into two groups according to TD status (absent vs. present), and the clinicopathologic characteristics, DFS, and OS were compared. Associations of TD presence with other clinicopathologic factors were evaluated by logistic regression analysis. Univariate and multivariate Cox regression analyses were performed to determine the prognostic factors for DFS and OS in the primary cohort. Propensity score matching (PSM) was performed to reduce the possibility of selection bias according to the presence of TD. External validation of previously proposed modified staging systems incorporating TD was conducted. Results The detection rate of TD was 10.5% (201/1915). The presence of TD was significantly related to unfavorable clinicopathologic variables, including advanced T and N categories. According to the multivariate Cox regression analysis, the presence of TD was identified as an independent prognostic factor for DFS and OS in the primary cohort (both P < 0.001). In the after-PSM cohort, TD presence also significantly shortened DFS and OS. In the external validation, one system that incorporated TD into the pTNM stage had the best performance. Conclusions The presence of TD was significantly associated with poor survival in radically resected GC patients. The incorporation of TD into the TNM staging system can further improve the predictive capability. A multicenter cohort with a large sample size is needed to determine the appropriate method of incorporation.

BackgroundFibrosarcoma is a rare sarcoma of the soft tissue in adults, occurring most commonly in the extremities. This study aimed to construct two web-based nomograms to predict overall survival (OS) and cancer-specific survival (CSS) in patients with extremity fibrosarcoma (EF) and validate it with multicenter data from the Asian/Chinese population.MethodPatients with EF in the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015 were included in this study and were randomly divided into a training cohort and a verification cohort. The nomogram was developed based on the independent prognostic factors determined by univariate and multivariate Cox proportional hazard regression analyses. The predictive accuracy of the nomogram was validated with the Harrell’s concordance index (C-index), receiver operating curve, and calibration curve. Decision curve analysis (DCA) was utilized to compare the clinical usefulness between the novel model and the existing staging system.ResultA total of 931 patients finally were obtained in our study. Multivariate Cox analysis determined five independent prognostic factors for OS and CSS, namely, age, M stage, tumor size, grade, and surgery. The nomogram and the corresponding web-based calculator were developed to predict OS (https://orthosurgery.shinyapps.io/osnomogram/) and CSS (https://orthosurgery.shinyapps.io/cssnomogram/) probability at 24, 36, and 48 months. The C-index of the nomogram was 0.784 in the training cohort and 0.825 in the verification cohort for OS and 0.798 in the training cohort and 0.813 in the verification cohort for CSS, respectively, indicating excellent predictive performance. The calibration curves showed excellent agreement between the prediction by the nomogram and actual outcomes. Additionally, the results of DCA showed that the newly proposed nomogram was significantly better than the conventional staging system with more clinical net benefits. The Kaplan–Meier survival curves showed that patients assigned into the low-risk group had a more satisfactory survival outcome than the high-risk group.ConclusionIn this study, we constructed two nomograms and web-based survival calculators including five independent prognostic factors for the survival prediction of patients with EF, which could help clinicians make personalized clinical decisions.

Abstract Purpose It is recommended for colorectal cancer to harvest at least 12 lymph nodes (LNs) during surgery to avoid understaging of the disease. However, it is still controversial whether it is necessary to harvest from locally advanced rectal cancer (LARC) patients who underwent neoadjuvant chemoradiotherapy (neo‐CRT). The impact of lymph node yield (LNY) on prognosis in LARC patients was analyzed. Materials/Methods In total, 495 LARC patients who underwent neo‐CRT in 2006‐2015 were analyzed. After examining clinicopathological distribution differences between the LNY subgroups (with the threshold of 12), univariate and multivariate Cox survival analyses were performed. Survival plots were obtained from Kaplan‐Meier analyses. Similar subgroup analyses were performed according to the tumor regression grade (TRG) and metastatic status of post‐operational LNs. Results Of the 495 patients, 287 (57.98%) had an LNY of less than 12. Nearly no significant clinicopathological difference was found between the LNY subgroups, including the TRG scores. Multivariate survival analysis demonstrated that at least 12 LNs examined was an independent prognostic feature of good overall survival (OS), disease‐free survival (DFS), and distant metastasis free survival (DMFS), but not local recurrence free survival (LRFS). However, in the subgroup analyses, no association was found between LNY and prognosis in patients with good TRG scores (0‐1) or negative LNs. Conclusions For LARC patients treated with neo‐CRT, an LNY of at least 12 indicated an improved survival. Decreased LNY was not related to better tumor regression. It suggests that a sufficiently high LNY is still required, especially in those with a potentially poor tumor response.