Project description:To investigate the specific roles of HDAC2 in the development of gastric cancer, we employed large-scale gene expression analysis to identify the molecular signature that may affect enabling characteristics of cancer cells. Differentially expressed genes were analyzed on the MKN-1 cells transfected with HDAC2 shRNAs, and recapitulated molecular signatures that related to hallmarks of cancer. DNA methylation of p16INK4a promoter region was assessed by methylation specific polymerase chain reaction. Recruiting the HDAC2 at the p16INK4a promoter was identified using chromatin immunoprecipitation assay. RNA interference-mediated protein knockdown method was used to investigate oncogenic potential of HDAC2 in in vitro and in vivo gastrocarcinogenesis of MKN-1 cells. RNA interference-mediated protein knockdown versus mock treatment
Project description:To investigate the specific roles of HDAC2 in the development of gastric cancer, we employed large-scale gene expression analysis to identify the molecular signature that may affect enabling characteristics of cancer cells. Differentially expressed genes were analyzed on the MKN-1 cells transfected with HDAC2 shRNAs, and recapitulated molecular signatures that related to hallmarks of cancer. DNA methylation of p16INK4a promoter region was assessed by methylation specific polymerase chain reaction. Recruiting the HDAC2 at the p16INK4a promoter was identified using chromatin immunoprecipitation assay. RNA interference-mediated protein knockdown method was used to investigate oncogenic potential of HDAC2 in in vitro and in vivo gastrocarcinogenesis of MKN-1 cells.
Project description:Knockdown of BHLHE40 expression significantly reduced primary tumor growth and spontaneous lung metastasis in an orthotopic xenograft model of human breast cancer. Gene expression analysis implicated a role of BHLHE40 in hypoxia-induced exosomic secretion of Heparin Binding Epidermal Growth Factor HBEGF, which promotes cell survival and invasion. BHLHE40 induces HBEGF transcription by blocking DNA binding of HDAC1 and HDAC2.
Project description:Cellular senescence plays a causal role in ageing and, in mouse, depletion of p16INK4a-expressing senescent cells delays ageing-associated disorders. Adenosine deaminases acting on RNA (ADARs) RNA editing enzymes are also implicated as important regulators of human ageing and ADAR inactivation causes age-associated pathologies such as neurodegeneration in model organisms. However, the role, if any, of ADARs in cellular senescence is unknown. Here we show that ADAR1 is post-transcriptionally downregulated by autophagic degradation to promote senescence through upregulating p16INK4a. ADAR1 is downregulated during senescence post-transcriptionally by autophagy-lysosomal pathway and the downregulation is sufficient to drive senescence in both in vitro and in vivo models. Senescence induced by ADAR1 downregulation is p16INK4a dependent and independent of its RNA editing function. Mechanistically, ADAR1 promotes SIRT1 expression by affecting its RNA stability through HuR, an RNA binding protein that increases the half-life and steady state levels of its target mRNAs. And SIRT1, in turn, antagonizes translation of mRNA encoding p16INK4a. Hence, downregulation of ADAR1 and SIRT1 mediates p16INK4aupregulation by enhancing its mRNA translation. Finally, Adar1 is downregulated during ageing of mouse tissues such as brain, ovary, and intestine, and Adar1 expression correlates with Sirt1 expression in these tissues in mice. Together, our study reveals an RNA-editing independent role of ADAR1 in regulating senescence by post-transcriptionally controlling p16INK4a expression.
Project description:Gastric cancer is one of the most common causes of cancer-related death worldwide. The N6-methyladenosine (m6A) reader IGF2BP1 (insulin-like growth factor-2 mRNA binding protein 1) has been reported to promote cancer progression by stabilizing oncogenic mRNAs through its m6A-binding activity in some tumors. However, the role of IGF2BP1 in gastric carcinogenesis remains unclear. In this study, we find that IGF2BP1 is significantly downregulated in tumor tissues from patients with gastric cancer. Lower expression of IGF2BP1 is associated with poor prognosis. IGF2BP1 suppresses gastric cancer cell proliferation in an m6A-dependent manner. Additionally, IGF2BP1 is able to significantly attenuate tumor growth of gastric cancer cells. Further m6A sequencing and m6A-RIP (RNA immunoprecipitation) assays show that MYC (c-myc proto-oncogene) mRNA is a target transcript of IGF2BP1 in gastric cancer cells. IGF2BP1 inhibits gastric cancer cell proliferation by reducing the mRNA and protein expression of MYC. Mechanistically, IGF2BP1 promotes the degradation of MYC mRNA and inhibits its translation efficiency. Taken together, these data suggest that IGF2BP1 plays a tumor-suppressive role in gastric carcinogenesis by downregulating MYC in an m6A-dependent manner, thereby making the IGF2BP1-MYC axis a potential target for gastric cancer treatment.
Project description:Non-small cell lung cancer (NSCLC) has a poor prognosis and effective therapeutic strategies are lacking. The diabetes drug canagliflozin inhibits NSCLC cell proliferation and the mammalian target of rapamycin (mTOR) pathway, which mediates cell growth and survival, but it is unclear whether this drug can enhance response rates when combined with cytotoxic therapy. Here, we evaluated the effects of canagliflozin on human NSCLC response to cytotoxic therapy in tissue cultures and xenografts. Ribonucleic acid sequencing (RNA-seq), real-time quantitative PCR (RT-qPCR), metabolic function, small interfering ribonucleic acid (siRNA) knockdown and protein expression assays were used in mechanistic analyses. We found that canagliflozin inhibited proliferation and clonogenic survival of NSCLC cells, and augmented the efficacy of radiotherapy to mediate these effects and inhibit NSCLC xenograft growth. Canagliflozin treatment alone moderately inhibited mitochondrial oxidative phosphorylation and exhibited greater anti-proliferative capacity than specific mitochondrial complex-I inhibitors. The treament downregulated genes mediating hypoxia-inducible factor (HIF)-1a stability, metabolism and survival, activated adenosine monophosphate-activated protein kinase (AMPK) and inhibited mTOR, a critical activator of HIF-1a signaling. HIF-1a knockdown and stabilization experiments suggested that canagliflozin mediates anti-proliferative effects, in part, through suppression of HIF-1a. Transcriptional regulatory network analysis pinpointed histone deacetylase 2 (HDAC2), a gene suppressed by canagliflozin, as a key mediator of canagliflozin’s transcriptional reprogramming. HDAC2 knockdown eliminated HIF-1a levels and enhanced the anti-proliferative effects of canagliflozin. HDAC2-regulated genes suppressed by canagliflozin are associated with poor prognosis in several clinical NSCLC datasets. In addition, we include evidence that canagliflozin also improves NSCLC response to chemotherapy. In summary, canagliflozin may be a promising therapy to develop in combination with cytotoxic therapy in NSCLC.
Project description:Although gastric cancer is a leading cause of cancer-related deaths, systemic treatment strategies remain scarce. Here, we report the pro-tumorigenic properties of the crosstalk between intestinal tuft cells and type 2 innate lymphoid cells (ILC2) that is evolutionarily optimized for epithelial remodeling in response to helminth infection. We demonstrate that tuft cell-derived interleukin 25 (IL25) drives ILC2 activation, inducing the release of IL13 and promoting tuft cell hyperplasia. This reciprocal tuft cell - ILC2 circuit promotes early gastric metaplasia and tumor formation while genetic ablation of tuft cells, ILC2s or therapeutic targeting of IL13 or IL25 alleviates these phenotypes. Importantly, tuft cell and ILC2 gene signatures predict worsening survival in intestinal-type gastric cancer patients, with ~50% of these tumors showing enrichment for tuft cells and ILC2s. Thus, we reveal an unanticipated function of the tuft cell - ILC2 circuit in promoting multiple steps towards gastric carcinogenesis. Together, this may provide an opportunity to therapeutically inhibit early-stage gastric cancer through repurposing antibody-mediated therapies.
Project description:Gastric cancer is characterized by prolonged, well-defined precancerous stages. In our study, we performed the whole genome gene expression mircroarray of 22 gastric tissues at different pathological stages. We aim to find genes that closely related to the changes of TCR repertoire during gastric carcinogenesis. By integrative analysis of the microarray data and TCR variation degrees, we identified a 11-gene module that can predict the overall survival of gastric cancer patients.
Project description:WNT signaling promotes pancreatic ductal adenocarcinoma (PDAC) through diverse effects on proliferation, differentiation, survival, and stemness. A subset of PDAC with inactivating mutations in ring finger protein 43 (RNF43) have growth dependency on autocrine WNT ligand signaling, which renders them susceptible to porcupine inhibitors (PORCNi) that block WNT ligand acylation and secretion. For this study, non-targeted metabolomic analyses were performed to explore the therapeutic response of RNF43-mutant PDAC to the PORCNi LGK974. AsPC-1 (RNF43-mutant) PDAC cells were treated with 25 nM LGK974 to explore stable isotope-resolved metabolomics with uniform 1, D-glucose [U13-C6] labeling.