PROX1-mediated epigenetic silencing of SIRT3 contributes to proliferation and glucose metabolism in colorectal cancer

Prospero-related homeobox 1 (PROX1) is a homeobox transcription factor known to promote malignant transformation and stemness in human colorectal cancer (CRC). However, the biological function of PROX1 in metabolic rearrangement in CRC remains unclear. Here, we aimed to uncover the relationship between the expression profile and role of PROX1 and CRC cell glucose metabolism and to elucidate the underlying molecular mechanism. PROX1 expression was significantly upregulated in human CRC tissues and positively associated with the maximum standardized uptake value (SUVmax), a measure of tissue 18-fluoro-2-deoxy-D-glucose uptake and an indicator of glycolysis and tumor cell activity, in patients with CRC. Knockdown of PROX1 suppressed CRC cell proliferation and glucose metabolism in vitro and in vivo. Mechanistically, through a physical interaction, PROX1 recruited EZH2 to the SIRT3 promoter and inhibited SIRT3 promoter activity. Moreover, PROX1 or EZH2 knockdown decreased cell glycolysis by targeting SIRT3. Clinically, high PROX1 expression combined with low SIRT3 expression predicted poor prognosis in patients with CRC. Thus, our study suggests that the PROX1-EZH2 complex positively regulates cell proliferation and glucose metabolism by engaging SIRT3 in CRC, which may serve as a promising therapeutic strategy for CRC.

Multiplexed immunofluorescence analysis of CAF-markers, EZH2 and FOXM1 in gastric tissue: associations with clinicopathological parameters and clinical outcomes

Background

The aim of this study is to explore the expression and clinical relevance of CAF-associated markers, EZH2 and FOXM1 in gastric samples.

Methods

Protein expression were detected and evaluated by multi-plex immunofluorescence (mIF) in 93 cases of gastric cancer (GC) and 31 cases of gastric intraepithelial neoplasia (GIN). The correlation among their expression, and the relationship of them with clinicopathological parameters and prognosis in GC were then analyzed.

Results

FAP was specific expressed in the CAFs of GC samples, and thus be utilized as a CAF-associated marker in our subsequently analysis. The immunostaining of EZH2, FOXM1 and FAP were significantly upregulated in patients with GC tissues than in those normal gastric mucosa or GIN tissues. The average fluorescence intensity of FAP was slightly positively correlated with EZH2 in GC, GIN and normal samples, whereas the percentage of FAP positive cells has no correlation with that of EZH2. Both the percentage of positive cells and the average fluorescence intensity of FOXM1 were positively correlated with that of FAP and EZH2 in GC, GIN and normal samples, except for FOXM1 and EZH2 expression in normal tissue samples. No significant association was observed between FAP expression and any clinicopathological parameters, whereas the positive frequency of EZH2 and FOXM1 were correlated with tumor location significantly and tumor invasion depth, respectively. In addition, there was strong positive correlations between FAP protein expression and overall survival (OS) and disease-free survival (DFS), and EZH2 expression was positively associated with OS in patients with GC. Furthermore, EZH2 and FAP protein expression was an independent prognostic factor for OS and DFS, respectively.

Conclusions

These results suggest that both EZH2 and FOXM1 expression was positively associated with CAFs abundance in GC. They may be potential cellular target for therapeutic intervention, especially in patients with a large number of CAFs.

Transcriptomic characterization and construction of M2 macrophage-related prognostic and immunotherapeutic signature in ovarian metastasis of gastric cancer

BACKGROUND

Ovarian metastasis (OM) poses a major threat to the outcome of gastric cancer (GC) patients. Recently, immunotherapy emerged as a novel promising therapeutic strategy to treat late-stage GC, whereas its efficacy is influenced by tumor immune microenvironment (TIME). M2 macrophage, a key subset within TIME, plays dual immunosuppressive and pro-tumorigenic roles in cancer progression and is recognized as a potential therapeutic target. However, molecular mechanisms underlying OM remain elusive and the TIME-related prognostic and immunotherapeutic index for these patients is yet to establish.

METHODS

Differential expressed genes (DEGs) between paired normal mucosa, primary GC and OM of patients from Fudan University Shanghai Cancer Center (FUSCC) cohort (n = 6) were identified by transcriptome sequencing, followed by the functional annotation of enriched hallmark pathways of DEGs between them. CIBERSORT was used to profile the relative expression level of 22 immune cell subsets in normal tissues, primary and metastatic tumors, followed by weighted gene coexpression network analysis (WGCNA) uncovering immune cell-correlated gene sets. The intersected genes between DEGs and M2 macrophage-related genes were processed by least absolute shrinkage and selection operator (LASSO) regression analysis to construct a predictive signature, M2GO, which was further validated by training set and test set of The Cancer Genome Atlas-Stomach Adenocarcinoma (TCGA-STAD), GSE62254 and GSE84437 cohorts. GC patients were divided into M2GO-high and -low subgroup according to the optimal cutoff value of the M2GO score. Furthermore, the clinical, molecular and immune features between M2GO-high and -low subgroups were analyzed. Clinical cohorts of immunotherapy were used to validate the predictive value of M2GO in regard to immunotherapy effectiveness.

RESULTS

Transcriptomic sequencing and follow-up analyses of triple-matched normal tissues, primary and ovarian metastatic tumors identified distinctive sets of DEGs and enriched immune-, cancer- and metastasis-related pathways between them. Of note, M2 macrophage, a major immunosuppressive and pro-tumorigenic component within TIME, was significantly up-regulated in OMs. WGCNA and LASSO regression were applied to establish a novel OM- and M2 macrophage-related predictive signature, M2GO, based on M2 macrophage-related prognostic genes including GJA1, MAGED1 and SERPINE1. M2GO served as an independent prognostic factor of GC patients. Comprehensive molecular and immune characterization of M2GO-based subgroups uncovered their distinctive features in terms of enriched functional pathways, tumor mutation burden, key immune checkpoints, major regulators of natural immune cGAS-STING pathway, infiltrated subsets of immune cells and tumor immune exclusion/dysfunction (TIDE) score. Notably, the M2GO score was significantly lower in responsive group than non-responsive group (P < 0.05) in clinical cohort of metastatic GC patients undergoing immunotherapy.

CONCLUSION

Transcriptomic characterization of paired normal mucosae, primary and ovarian metastatic tumors revealed their unique molecular and immune features. Follow-up analyses established a novel OM- and M2 macrophage-related signature, M2GO, which served as a promising prognostic and immunotherapeutic biomarker to distinguish the clinical outcome, molecular and immune features of GC patients and predict their differential responses to immunotherapy.

The role of cancer-associated fibroblasts in tumorigenesis of gastric cancer

Despite advances in anticancer therapy, the prognosis of gastric cancer (GC) remains unsatisfactory. Research in recent years has shown that the malignant behavior of cancer is not only attributable to tumor cells but is partly mediated by the activity of the cancer stroma and controlled by various molecular networks in the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) are one of the most abundant mesenchymal cell components of the stroma and extensively participate in the malignant development of GC malignancy. CAFs modulate the biological properties of tumor cells in multiple ways, including the secretion of various bioactive molecules that have effects through paracrine and autocrine signaling, the release of exosomes, and direct interactions, thereby affecting GC initiation and development. However, there is marked heterogeneity in the cellular origins, phenotypes, and functions of CAFs in the TME of GC. Furthermore, variations in factors, such as proteins, microRNAs, and lncRNAs, affect interactions between CAFs and GC cells, although, the potential molecular mechanisms are still poorly understood. In this review, we aim to describe the current knowledge of the cellular features and heterogeneity of CAFs and discuss how these factors are regulated in CAFs, with a focus on how they affect GC biology. This review provides mechanistic insight that could inform therapeutic strategies and improve the prognosis of GC patients.

Molecular signatures of tumor progression in pancreatic adenocarcinoma identified by energy metabolism characteristics

BACKGROUND

In this study, we performed a molecular evaluation of primary pancreatic adenocarcinoma (PAAD) based on the comprehensive analysis of energy metabolism-related gene (EMRG) expression profiles.

METHODS

Molecular subtypes were identified by nonnegative matrix clustering of 565 EMRGs. An overall survival (OS) predictive gene signature was developed and internally and externally validated based on three online PAAD datasets. Hub genes were identified in molecular subtypes by weighted gene correlation network analysis (WGCNA) coexpression algorithm analysis and considered as prognostic genes. LASSO cox regression was conducted to establish a robust prognostic gene model, a four-gene signature, which performed better in survival prediction than four previously reported models. In addition, a novel nomogram constructed by combining clinical features and the 4-gene signature showed high-confidence clinical utility. According to gene set enrichment analysis (GSEA), gene sets related to the high-risk group participate in the neuroactive ligand receptor interaction pathway.

CONCLUSIONS

In summary, EMRG-based molecular subtypes and prognostic gene models may provide a novel research direction for patient stratification and trials of targeted therapies.

Comprehensive molecular characterization and identification of prognostic signature in stomach adenocarcinoma on the basis of energy-metabolism-related genes

BACKGROUND

Stomach adenocarcinoma (STAD) is a leading cause of cancer deaths, but its molecular and prognostic characteristics has never been fully illustrated.

AIM

To describe a molecular evaluation of primary STAD and develop new therapies and identify promising prognostic signatures.

METHODS

We describe a comprehensive molecular evaluation of primary STAD based on comprehensive analysis of energy-metabolism-related gene (EMRG) expression profiles.

RESULTS

On the basis of 86 EMRGs that were significantly associated to patients’ progression-free survival (PFS), we propose a molecular classification dividing gastric cancer into two subtypes: Cluster 1, most of which are young patients and display more immune and stromal cell components in tumor microenvironment and lower tumor priority; and Cluster 2, which show early stages and better PFS. Moreover, we construct a 6-gene signature that can classify the prognostic risk of patients after a three-phase training test and validation process. Compared with patients with low-risk score, patients with high-risk score had shorter overall survival. Furthermore, calibration and DCA analysis plots indicate the excellent predictive performance of the 6-gene signature, and which present higher robustness and clinical usability compared with three previous reported prognostic gene signatures. According to gene set enrichment analysis, gene sets related to the high-risk group were participated in the ECM receptor interaction and hedgehog signaling pathway.

CONCLUSION

Identification of the EMRG-based molecular subtypes and prognostic gene model provides a roadmap for patient stratification and trials of targeted therapies.

FBP1 regulates proliferation, metastasis, and chemoresistance by participating in C-MYC/STAT3 signaling axis in ovarian cancer

Fructose-1,6-bisphosphatase (FBP1) is a rate-limiting enzyme in gluconeogenesis and an important tumor suppressor in human malignancies. Here, we aimed to investigate the expression profile of FBP1 in ovarian cancer, the molecular mechanisms that regulate FBP1 expression and to examine how the FBP1 regulatory axis contributes to tumorigenesis and progression in ovarian cancer. We showed that FBP1 expression was significantly decreased in ovarian cancer tissues compared with normal ovarian tissues, and low-FBP1 expression predicted poor prognosis in patients with ovarian cancer. The enhanced expression of FBP1 in ovarian cancer cell lines suppressed proliferation and 2-D/3-D invasion, reduced aerobic glycolysis, and sensitized cancer cells to cisplatin-induced apoptosis. Moreover, DNA methylation and C-MYC binding at the promoter inhibited FBP1 expression. Furthermore, through physical interactions with signal transducer and activator of transcription 3 (STAT3), FBP1 suppressed nuclear translocation of STAT3 and exerted its non-metabolic enzymatic activity to induce the dysfunction of STAT3. Thus, our study suggests that FBP1 may be a valuable prognostic predictor for ovarian cancer. C-MYC-dependent downregulation of FBP1 acted as a tumor suppressor via modulating STAT3, and the C-MYC/FBP1/STAT3 axis could be a therapeutic target.

Stanniocalcin-2 promotes cell EMT and glycolysis via activating ITGB2/FAK/SOX6 signaling pathway in nasopharyngeal carcinoma

Stanniocalcin-2 (STC2) has been proved to regulate a variety of signaling pathways including cell growth, metastasis, and therapeutic resistance. However, the role of STC2 in the regulation of nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, we investigated the regulatory function of STC2 on epithelial-mesenchymal transition (EMT) and glycolysis traits in NPC and revealed the underlying molecular mechanisms. We found that STC2 was highly expressed in primary nasopharyngeal carcinoma tissues and lymph node metastatic tissues. Silencing of STC2 inhibited cell proliferation, invasion, and glycolysis. Further analyses for the clinical samples demonstrated that STC2 expression was associated with the poor clinical progression. Moreover, we demonstrated the interaction of ITGB2 with STC2 and its involvement in STC2-mediated ITGB2/FAK/SOX6 axis. Collectively, our results provide new insights into understanding the regulatory mechanism of STC2 and suggest that the STC2/ITGB2/FAK/SOX6 signaling axis may be a potential therapeutic target for NPC.

Atezolizumab prolongs overall survival over docetaxel in advanced non-small-cell lung cancer patients harboring STK11 or KEAP1 mutation

Somatic mutations of STK11 or KEAP1 are associated with poor clinical outcomes for advanced non-small-cell lung cancer (aNSCLC) patients receiving immune checkpoint inhibitors (ICIs), chemotherapy, or targeted therapy. Which treatment regimens work better for STK11 or KEAP1 mutated (SKmut) aNSCLC patients is unknown. In this study, the efficacy of atezolizumab versus docetaxel in SKmut aNSCLC was compared. A total of 157 SKmut aNSCLC patients were identified from POPLAR and OAK trials, who were tested by blood-based FoundationOne next-generation sequencing assay. Detailed clinical data and genetic alterations were collected. Two independent cohorts were used for biomarker validation (n = 30 and 20, respectively). Median overall survival was 7.3 months (95% confidence interval [CI], 4.8 to 9.9) in the atezolizumab group versus 5.8 months (95% CI, 4.4 to 7.2) in the docetaxel group (adjusted hazard ratio [HR] for death, 0.70; 95% CI, 0.49 to 0.99; P = .042). Among atezolizumab-treated patients, objective response rate, disease control rate, and durable clinical benefit were higher when blood tumor mutation burden (bTMB) and PD-L1 being higher (biomarker 1, n = 61) or with FAT3 mutation-positive tumors (biomarker 2, n = 83) than otherwise. The interactions for survival between these two biomarkers and treatments were significant, which were further validated in two independent cohorts. In SKmut patients with aNSCLC, atezolizumab was associated with significantly longer overall survival in comparison to docetaxel. Having FAT3 mutation or high TMB and PD-L1 expression potentially predict favorable response in SKmut patients receiving atezolizumab.

GCNT4 is Associated with Prognosis and Suppress Cell Proliferation in Gastric Cancer

Background

GCNT4 is a member of the glucosaminyl (N-acetyl) transferases family that has been implicated in multiple human malignancies. However, the role of GCNT4 in gastric cancer (GC) is unknown. In this present study, we aimed to explore the role and clinicopathological correlation of GCNT4 in GC.

Materials and Methods

We first evaluated the dysregulation of GCNT4 in The Cancer Genome Atlas (TCGA) and then we performed RT-qPCR and immunohistochemistry to validate the results in a cohort of in-house patients. The clinicopathological correlation and function of GCNT4 in GC were also analysed.

Results

GCNT4 was found to be significantly downregulated in GC. In addition, GCNT4 expression correlated with tumour depth, nervous invasion and pathological tumor-node-metastasis (pTNM) stage. Moreover, lower GCNT4 levels conferred poor overall survival (OS) and disease-free survival (DFS) to GC patients. Multivariate Cox regression analysis revealed that GCNT4 protein expression is an independent prognostic factor for OS in patients with GC. Further functional experimental results revealed that overexpression of GCNT4 appears to halt GC cell proliferation and the cell cycle.

Conclusion

Altogether, these findings indicated that GCNT4 regulates the GC cell cycle and have important implications for the selection of therapeutic targets to prevent tumour proliferation.

Appendiceal mucinous neoplasm mimics ovarian tumors: Challenges for preoperative and intraoperative diagnosis and clinical implication

OBJECTIVE

The aim of this study was to investigate the clinicopathological characteristics of appendiceal mucinous neoplasm that had been preoperatively misdiagnosed as a mucinous ovarian tumor and to discuss the clinical impacts of misdiagnosis.

METHODS

Seventy-eight patients with a final pathologic diagnosis of appendiceal mucinous neoplasm during a 10-year period were retrospectively reviewed. All patients were diagnosed with ovarian tumor before treatment. A univariate analysis was performed to evaluate predictors of the diagnostic accuracy of a frozen section.

RESULTS

The patients' median age was 61 years (range, 21-82 years), and most were diagnosed as low-grade appendiceal mucinous neoplasm (LAMN) (84.62%). The diagnostic concordance between the frozen section and the final pathology was 56.92%. The most consistent diagnosis was LAMN (64.14%). Univariate analysis indicated that maximal diameter of the ovarian tumor (unilateral), laterality of the ovarian tumors (unilateral or bilateral), and frozen section site (appendix or extra-appendix) significantly correlated with the accuracy of frozen section diagnosis (all p < 0.05). Although the diagnostic discordance between the frozen section and the final pathology was 43.08%, only one patient was clinically impacted because of suboptimal surgery.

CONCLUSION

Appendiceal mucinous neoplasm should be considered as a differential diagnosis of pelvic mass in women. For patients who do not require fertility-sparing surgery, excision and frozen section of the bilateral ovaries and appendix regardless of the appearance of the appendix might improve the diagnosis. For older patients with peritoneal dissemination, appropriate cytoreductive surgery is recommended to reduce the clinical impact of misdiagnosis.

MET amplification, expression, and exon 14 mutations in colorectal adenocarcinoma

MET amplification, expression, and splice mutations at exon 14 result in dysregulation of the MET signaling pathway. The aim of this study was to identify the relationship between MET amplification, protein or mRNA expression, and mutations in colorectal cancer (CRC). MET immunohistochemistry was used for MET protein expression analysis, and fluorescence in situ hybridization was used for MET amplification detection. Both analyses were performed in tissue microarrays containing 294 colorectal adenocarcinoma tissue samples and 131 samples of adjacent normal epithelial tissue. MET mRNA expression was examined by real-time quantitative polymerase chain reaction in 72 fresh colorectal adenocarcinoma tissue samples and adjacent normal colon tissue. Polymerase chain reaction sequencing was performed to screen for MET exon 14 splice mutations in 59 fresh CRC tissue samples. Our results showed that MET protein expression was higher in colorectal tumor tissue than in adjacent normal intestinal epithelium. Positive MET protein expression was associated with significantly poorer overall survival and disease-free survival. Multivariate analysis revealed that positive MET protein expression was an independent risk factor for disease-free survival but not for overall survival. MET mRNA expression was upregulated in tumor tissues compared with the adjacent normal tissues. The incidence of MET amplification was 4.4%. None of the patients was positive for MET mutation. Collectively, MET was overexpressed in colorectal adenocarcinoma, and its positive protein expression predicted a poorer outcome in CRC patients. Furthermore, according to our results, MET amplification and exon 14 mutation are extremely rare events in colorectal adenocarcinoma.

Pituitary tumor-transforming gene-1 serves as an independent prognostic biomarker for gastric cancer

BACKGROUND

Pituitary tumor-transforming gene-1 (PTTG1) is a transcription factor that can affect transcriptional activity, angiogenesis, and cell senescence. We examined PTTG1 mRNA and protein expression in gastric cancer (GC) cell lines and tissues to determine its value as a biomarker for GC diagnosis and therapy.

METHODS

PTTG1 mRNA expression from 78 GC cases and paired adjacent normal mucosa (PCR cohort) as well as from five gastric cell lines was assessed using qRT-PCR. Nuclear and cytoplasmic RNA were extracted from two gastric cell lines to determine PTTG1 mRNA localization. PTTG1 protein expression from 98 GC cases, their paired adjacent normal mucosa, and 23 gastric intraepithelial neoplasia (GIN) cases was examined using immunohistochemistry (IHC cohort). The correlation between PTTG1 mRNA and protein expression and GC clinicopathological parameters was analyzed.

RESULTS

PTTG1 mRNA expression in GC tissues and cell lines was significantly increased compared with adjacent normal gastric mucosa and normal gastric mucous cell lines (p < 0.05). PTTG1 expression was nuclear and cytoplasmic, with higher cytoplasmic expression. PTTG1 immunostaining significantly differed in GC (95.66 ± 20.65), GIN (84.00 ± 34.16), and normal adjacent mucosa (28 ± 22.25) (p < 0.001). Multivariate Cox regression analysis revealed that PTTG1 mRNA and protein expression are independent prognostic factors for GC patient survival.

CONCLUSION

Our results suggest that PTTG1 is a promising target for GC diagnosis and therapy.