Project description:Tumors of advanced gastric cancer patients were biopsied and subjected to gene expression profiling using the Affymetrix Human Genome U133 Plus 2.0 Arrays. Patients were then segregated into G1, G2 or G3 groups based on their tumor genomic profiles. Patients in the G1 and G3 cohorts were assigned SOX (oxaliplatin plus S-1) chemotherapy whereas those in the G2 cohort were given SP (cisplatin plus S-1) regimen. This bench-to-bedside effort indicated the feasibility of using molecular profiling to tailor treatment for advanced gastric cancer.
Project description:Introduction Chemotherapy, particularly with oxaliplatin, is a key treatment for advanced gastric cancer (GC), and exosomes derived from human bone marrow mesenchymal stem cells (hBM-MSCs) play a vital role in the tumor microenvironment. Objectives The study aims to elucidate the previously unexplored role of exosomes derived from hBM-MSCs in GC tumorigenesis, especially under the influence of chemotherapy. Methods We conducted an integrated study, utilizing miRNA sequencing and biological experiments, to analyze the tumorigenicity of exosomal miR-424-3p secreted by hBM-MSCs and its target gene RHOXF2 in GC cell lines. The results were confirmed through experimentation using a xenograft mouse model. Results This study demonstrated the role of hBM-MSCs in the GC microenvironment, focusing on their Epithelial-Mesenchymal Transition (EMT) facilitation through exosomes, which led to enhanced tumorigenicity of in GC cells. Intriguingly, this pro-tumor effect was abrogated when hBM-MSCs were treated with oxaliplatin. Exosomal miRNA sequencing revealed that oxaliplatin can upregulate the levels of miR-424-3p in exosomes secreted by hBM-MSCs, thereby inhibiting the EMT process in GC cells. Furthermore, miR-424-3p was identified to target and downregulate RHOXF2 expression, impeding the malignant behavior of GC cells both in vitro and in the mouse model. Conclusions These findings uncover a potential hidden mechanism of oxaliplatin's anti-tumor action and propose the delivery of miR-424-3p via exosomes as a promising avenue for anti-tumor therapy.
Project description:We elucidated the functional significance and molecular mechanisms of DUSP5P1 lncRNA (dual specificity phosphatase 5 pseudogene 1) in gastric carcinogenesis. We demonstrated that gastric cancer (GC) patients with high DUSP5P1 expression had shortened survival in two independent cohorts. DUSP5P1 promoted GC cell migration and invasion in vitro and metastasis in vivo. Mechanistically, DUSP5P1 activated ARHGAP5 transcription by directly binding to the promoter of ARHGAP5 with a binding motif of TATGTG. RNA-seq revealed that ARHGAP5 activated focal adhesion and MAPK signalling pathways to promote GC metastasis. DUSP5P1 also dysregulated platinum drug resistance pathway. Consistently, DUSP5P1 overexpression in GC cells antagonized cytotoxic effect of Oxaliplatin, and shDUSP5P1 plus Oxaliplatin exerted synergistic effect on inhibiting GC metastasis in vitro and in vivo. DUSP5P1 depletion also suppressed the growth of platinum drug-resistant PDO models. In conclusion, DUSP5P1 promoted GC metastasis by directly modulating ARHGAP5 expression to activate focal adhesion and MAPK pathways, serves as therapeutic target for platinum drug resistant GC, and is an independent prognostic factor in GC.
Project description:The gut microbiota influences both local and systemic inflammation. Inflammation contributes to development, progression and treatment of cancer, but it remains unclear whether commensal bacteria affect inflammation in the sterile tumor microenvironment. Here we show that disruption of the microbiota impairs the response of subcutaneous tumors to CpG-oligonucleotide immunotherapy and platinum chemotherapy. In antibiotic-treated or germ-free mice, tumor-infiltrating myeloid-derived cells responded poorly to therapy, resulting in lower cytokine production and tumor necrosis after CpG-oligonucleotide treatment, and deficient production of reactive oxygen species and cytotoxicity following chemotherapy. Thus, optimal responses to cancer therapy require an intact commensal microbiota that mediates its effects by modulating myeloid-derived cell functions in the tumor microenvironment. These findings underscore the importance of the microbiota in the outcome of disease treatment. Oxaliplatin treatment induces expression of pro-inflammatory genes, which are inhibited by antibiotic pretreatment. Our goal was to ascertain the effect of antibiotic on the tumor gene expression profile prior to treatment and early on after the treatment with chemotherapy (oxaliplatin). The time points were selected t
Project description:Although there are plenty of researches about nucleic acid in small extracellular vesicles (sEVs), properties of proteins identified as sEVs’ cargos and the mechanism of their action in recipient cell are poorly understood. Here, we show that lysine specific demethylase 1 (LSD1), the first identified histone demethylase in 2004, existed in the cell cultured medium of gastric cancer cells. Further investigation confirmed the presence of LSD1 in sEVs from gastric cancer cells and gastric cancer patient plasma, which is the first identified histone demethylase in sEVs. By shuttling from donor cells to recipient gastric cancer cells, sEVs-delivered LSD1 promoted the cancer cell stemness by positively regulating the expression of Nanog, OCT4, SOX2 and CD44, and suppressed the oxaliplatin response of the recipient cells in vitro and in vivo, while LSD1 depleted sEVs failed to suppress the oxaliplatin response. Collectively, our findings give an evidence for LSD1 as a sEVs protein to promote stemness and suppress oxaliplatin response for the first time and constitute a future avenue to predict oxaliplatin response in gastric cancer clinically.
Project description:Although there are plenty of researches about nucleic acid in small extracellular vesicles (sEVs), properties of proteins identified as sEVs’ cargos and the mechanism of their action in recipient cell are poorly understood. Here, we show that lysine specific demethylase 1 (LSD1), the first identified histone demethylase in 2004, existed in the cell cultured medium of gastric cancer cells. Further investigation confirmed the presence of LSD1 in sEVs from gastric cancer cells and gastric cancer patient plasma, which is the first identified histone demethylase in sEVs. By shuttling from donor cells to recipient gastric cancer cells, sEVs-delivered LSD1 promoted the cancer cell stemness by positively regulating the expression of Nanog, OCT4, SOX2 and CD44, and suppressed the oxaliplatin response of the recipient cells in vitro and in vivo, while LSD1 depleted sEVs failed to suppress the oxaliplatin response. Collectively, our findings give an evidence for LSD1 as a sEVs protein to promote stemness and suppress oxaliplatin response for the first time and constitute a future avenue to predict oxaliplatin response in gastric cancer clinically.
Project description:We elucidated the functional significance and molecular mechanisms of DUSP5P1 lncRNA (dual specificity phosphatase 5 pseudogene 1) in gastric carcinogenesis. We demonstrated that gastric cancer (GC) patients with high DUSP5P1 expression had shortened survival in two independent cohorts. DUSP5P1 promoted GC cell migration and invasion in vitro and metastasis in vivo. Mechanistically, DUSP5P1 activated ARHGAP5 transcription by directly binding to the promoter of ARHGAP5 with a binding motif of TATGTG. RNA-seq revealed that ARHGAP5 activated focal adhesion and MAPK signalling pathways to promote GC metastasis. DUSP5P1 also dysregulated platinum drug resistance pathway. Consistently, DUSP5P1 overexpression in GC cells antagonized cytotoxic effect of Oxaliplatin, and shDUSP5P1 plus Oxaliplatin exerted synergistic effect on inhibiting GC metastasis in vitro and in vivo. DUSP5P1 depletion also suppressed the growth of platinum drug-resistant PDO models. In conclusion, DUSP5P1 promoted GC metastasis by directly modulating ARHGAP5 expression to activate focal adhesion and MAPK pathways, serves as therapeutic target for platinum drug resistant GC, and is an independent prognostic factor in GC.
Project description:Tumor chemoresistance is often associated to high aerobic glycolysis rates and reduced oxidative phosphorylation by cancer cells, a phenomenon called the “Warburg effect”. Thus, a treatment reversing the Warburg effect could decrease tumor cell survival both in the presence or absence of chemotherapy. Short-term starvation (STS) could accomplish this task since it is accompanied by a glucose and amino acid decrease and fatty acid increase, which require respiration for energy production. We tested the cytotoxicity of STS+Oxaliplatin on colon cancer cells by Trypan Blue, Carboxyfluorescein Succinimidyl ester and Annexin V staining. Reactive oxygen species production was measured by 2',7'-dichlorodihydrofluorescein diacetate staining. In vitro glucose consumption was evaluated by 18F-Fluoro-deoxyglucose uptake. Gene expression was tested by microarray analysis. Protein expression and activity were studied by western blot, proteomic analyses and spectrophotometric assays. CT26 bearing mice consumed only water for 48 hours (STS) before oxaliplatin treatment. Dynamic micro-Positron Emission Tomography and tumor growth measurements were performed. STS+Oxaliplatin cause a potent suppression of colon carcinoma growth and glucose consumption in in vitro and in vivo models. In CT26 cells, STS down-regulates aerobic glycolysis, and glutaminolysis, while increasing oxidative phosphorylation. STS-dependent increase in O2 consumption is associated with reduced ATP synthesis and increased oxidation. In combination with chemotherapy, these effects of STS cause additive toxicity to cancer cells. Our findings indicate that during and following STS the decreased glucose levels promote an anti-Warburg effect characterized by increased oxygen consumption but failure to generate ATP, resulting in oxidative damage and apoptosis. The experiment comprised for conditions: Control, Starvation, Oxaliplatin, and Starvation plus Oxaliplatin
Project description:The comprehensive DNA methylation status of gastric cancer cells obtained from an advanced Epstein-Barr virus-associated gastric cancer case, in which complete response to S-1 plus cisplatin chemotherapy was achieved, was analyzed with DNA methylation microarray (Illumina Infinium MethylationEPIC BeadChip). DNA was extracted from metastatic lesion (lymph node).
Project description:The primary objective of this study was to determine the effectiveness of bortezomib alone or in combination with irinotecan in patients with advanced gastric and gastroesphageal cancer. A secondary objecitve was to determine whether treatment was associated with changes in gene expression in the tumor and normal adjascent tissue. Tumor biopsies and biopsies of normal adjascent tissue were obtained before therapy and 24 hours after therapy. Differences in gene expression were evaluated between tumor and normal tissue (N=8 patients), and between post-treatment and pretreatment specimens for bortezomib alone (N=2 patients) and bortezomib plus irinotecan (N=10 patients).