SRSF3-mediated regulation of N6-methyladenosine modification-related lncRNA ANRIL splicing in promotion of pancreatic cancer resistance to gemcitabine I
Ontology highlight
ABSTRACT: Serine/arginine-rich splicing factor 3 (SRSF3) functions to regulate mRNA alternative splicing, a molecular mechanism to process more than 90% of the protein-coding genes and provides an essential source for the biological versatility and targeting of SRSF3 could be a novel approach for cancer therapy. This study identify that SRSF3 expression was upregulated in pancreatic cancer tissues and associated with drug resistance and poor prognosis. Thus, we found that SRSF3 regulated ANRIL splicing and modified m6A modification of ANRIL in pancreatic cancer cells. More importantly, we demonstrated that the m6A methylation on lncRNA-ANRIL was essential for splicing process. Meanwhile, we also found that the different isoforms of ANRIL were differentially expressed in drug-resistant pancreatic cancer cell lines, and SRSF3 promotes gemcitabine resistance by regulating the expression of ANRIL-208. In addition, ANRIL-208 regulated pancreatic cancer cell chemoresistance by forming a complex with Ring1b and EZH2 and enhanced DNA homologous recombination repair (HR) capacity. In conclusion, the current study first established the link among SRSF3, m6A modification, lncRNA splicing, and DNA HR repair in pancreatic cancer, and first demonstrated that abnormal alternative splicing and m6A modification are closely related to chemotherapy resistance in pancreatic cancer.
Project description:Serine/arginine-rich splicing factor 3 (SRSF3) functions to regulate mRNA alternative splicing, a molecular mechanism to process more than 90% of the protein-coding genes and provides an essential source for the biological versatility and targeting of SRSF3 could be a novel approach for cancer therapy. This study identify that SRSF3 expression was upregulated in pancreatic cancer tissues and associated with drug resistance and poor prognosis. Thus, we found that SRSF3 regulated ANRIL splicing and modified m6A modification of ANRIL in pancreatic cancer cells. More importantly, we demonstrated that the m6A methylation on lncRNA-ANRIL was essential for splicing process. Meanwhile, we also found that the different isoforms of ANRIL were differentially expressed in drug-resistant pancreatic cancer cell lines, and SRSF3 promotes gemcitabine resistance by regulating the expression of ANRIL-208. In addition, ANRIL-208 regulated pancreatic cancer cell chemoresistance by forming a complex with Ring1b and EZH2 and enhanced DNA homologous recombination repair (HR) capacity. In conclusion, the current study first established the link among SRSF3, m6A modification, lncRNA splicing, and DNA HR repair in pancreatic cancer, and first demonstrated that abnormal alternative splicing and m6A modification are closely related to chemotherapy resistance in pancreatic cancer.
Project description:SRSF3-mediated regulation of N6-methyladenosine modification-related lncRNA ANRIL splicing in promotion of pancreatic cancer resistance to gemcitabine
Project description:SRSF3-mediated regulation of N6-methyladenosine modification-related lncRNA ANRIL splicing in promotion of pancreatic cancer resistance to gemcitabine II
Project description:SRSF3-mediated regulation of N6-methyladenosine modification-related lncRNA ANRIL splicing in promotion of pancreatic cancer resistance to gemcitabine I
Project description:The antisense non-coding RNA in the INK locus (ANRIL), which originates from the CDKN2A/B (INK4-ARF) locus, has been identified as a hotspot for genetic variants associated with cardiometabolic disease including coronary artery disease (CAD) and Type 2 diabetes (T2D). We recently found that ANRIL abundance in human pancreatic islets was increased in donors carrying certain T2D risk-SNPs, and that a T2D risk-SNP located within exon2 of ANRIL conferred reduced beta cell proliferation index, pointing to a role for ANRIL in the regulation of T2D pathogenicity via an impact on insulin secretory capacity. Recent studies in other cell types have found that the balance between linear and circular species of ANRIL is linked to the regulation of cardiovascular disease phenotypes. Less is known about circular ANRIL expression in diabetes-relevant cell types and how their abundance might influence the risk of T2D. Herein, we use high-throughput and divergent primer sequencing of circular RNA in human pancreatic islet cells to quantify and characterize circular isoforms of ANRIL. We identified several circular ANRIL isoforms that are more abundant than linear ANRIL and whose expression was correlated across dozens of individuals. Back-splicing did not occur with equal probability at all ANRIL splice sites. Rather, some specific splice sites were found to have a higher propensity to be involved in back-splicing and are weakly enriched for sequence features known to promote back-splicing. Finally, we found that islets from carriers of the T2D risk allele at rs564398 in exon 2 of ANRIL had a higher ratio of circular ANRIL relative to linear ANRIL compared to protective-allele carriers, and that higher circular:linear ANRIL ratio was associated with a decreased beta cell proliferation index. Together, our study points to the combined involvement of both linear and circular ANRIL species in T2D phenotypes and opens the door for future studies to understand the molecular mechanisms by which ANRIL impacts cellular function in human pancreatic islets.
Project description:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RIP-seq was conducted to investigate the occupancy of N6-methyladenosine RNA binding protein 3 (YTHDF3) served as “readers” that can recognize m6A modification site in HCT116 cells with oxaliplatin resistance (HCT116R). Then, YTHDF3 was knockdown by siRNA in HCT116 cells with oxaliplatin resistance, and RIP-seq was further conducted to investigate m6A methylation of HCT116, HCT116R and HCT116R cells with YTHDF3 knockdown.
Project description:SRSF3 is overexpressed in human invasive ovarian cancer and its overexpression is required for cancer cell growth and survival. To decipher the mechnisms behind the role of SRSF3 in ovarian cancer, we examined the gene expression and splicing in the ovarian cancer cell line that was engineered to express a doxycycline-induced SRSF3 siRNA, which was able to knockdown SRSF3 expression by 90% and induce apoptosis. Total RNAs extracted from A2780/SRSF3si2, a subline of ovarian cancer cell line A2780, treated with or without doxycycline at 0.1ug/ml for three days were analyzed using Affymetrix GeneChip® Human Exon 1.0 ST Array
Project description:SRSF3 is overexpressed in human invasive ovarian cancer and its overexpression is required for cancer cell growth and survival. To decipher the mechnisms behind the role of SRSF3 in ovarian cancer, we examined the gene expression and splicing in the ovarian cancer cell line that was engineered to express a doxycycline-induced SRSF3 siRNA, which was able to knockdown SRSF3 expression by 90% and induce apoptosis.
Project description:Long non-coding RNAs(LncRNAs)have important cellular functions and some have roles in different mechanisms of gene regulation. LncRNA-antisense noncoding RNA in the INK4 locus (ANRIL) were found to affect cell inflammation,Nevertheless, the potential genes related to the inflammatory response regulated by ANRIL remain unclear. In this study, we investigated the potential function of ANRIL in regulating expression and alternative splicing. ANRIL-regulated human umbilical vein endothelial (HUVEC) cell transcriptome achieved by high-throughput RNA sequencing(RNA-seq) was obtained to investigate the potential role of ANRIL. Lipofectamine 2000 was used for plasmid transfection. The gene expression profile and alternative splicing pattern of HUVEC overexpressed by ANRIL were analyzed by RNA-seq and compared with the control group. ANRIL overexpression (ANRIL-OE) widely affects the transcription levels of genes related to inflammatory response, NF-κB pathway, type I interferon-mediated signal transduction pathway, and innate immune response. ANRIL extensively regulates the alternative splicing of hundreds of genes through functions such as gene expression, translation, DNA repair, RNA processing, and NF-κB pathway. Many of these genes have an indispensable role in the inflammatory response. ANRIL regulated inflammatory response may be achieved by regulating alternating splicing and potential transcription, which broadens the understanding of ANRIL-mediated gene regulation mechanisms and clarifies the role of ANRIL in mediating inflammatory response mechanisms.
Project description:N6-methyladenosine (m6A) is a type of nucleotide modification abundant in mRNA, which regulates mRNA stability, splicing and translation. However, its physiological role in intratumoral microenvironment and drug resistancehave not been fully understood. We demonstrated that METTL3,a primary m6A methyltransferase, was significantly down-regulated in human sorafenib-resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promoted sorafenib-resistance and angiogenesis and exacerbated progression by activating autophagy-associated pathway. Mechanistically, we identified FOXO3 as a key downstream target of the METTL3-mediated m6A modification. The m6A modification of FOXO3 at the 3'-untranslated region increased FOXO3 mRNA stability. Analysis of clinical samples showed that METTL3levels aretightly correlated with FOXO3levels in patients with HCC, and suppression of FOXO3 predicted poor clinical outcomes. Importantly, METTL3-depletion significantly enhanced sorafenib-resistance of HCC via a METTL3-FOXO3 axis, whereasoverexpression of FOXO3 restored the m6A-dependent sorafenib-sensitivity. Collectively, our work revealedthe critical function of the METTL3-mediated m6A modification in HCC in hypoxic tumor microenvironment, and provided insights into the molecular mechanism of the m6A modification in the resistance of HCC to sorafenib therapy.