DHX38 restricts chemoresistance by regulating the alternative pre-mRNA splicing of RELL2 in pancreatic ductal adenocarcinoma

PLoS Genet. 2023 Jul 28;19(7):e1010847. doi: 10.1371/journal.pgen.1010847. eCollection 2023 Jul.

Abstract

Intron retention plays an important role in cancer progression and chemotherapy resistance and seems to be essential for the maintenance of genome stability in cancer. Here, our goal was to analyze the role of receptor expressed in lymphoid tissue (Relt)-like 2 (RELL2) intron 4 retention in promoting pancreatic ductal adenocarcinoma (PDAC) progression. Our results showed that intron retention (IR) occurs at the fourth intron of RELL2 transcript in gemcitabine resistant PDAC cells, however, the regulatory mechanism and the clinical implications of IR of RELL2 are unclear. Firstly, we found that RELL2 plays an anti-oncogenic role in PDAC by performing in vitro functional assays including cell proliferation, GEM cytotoxicity assay and apoptosis. Subsequently, we identified the upstream gene of RELL2, DEAH-Box Helicase 38 (DHX38), and demonstrated the direct interaction between DHX38 and RELL2 by RIP-qPCR. We also found that altered expression of DHX38 resulted in corresponding changes in intron 4 retention of RELL2. Importantly, we unveiled that overexpression of DHX38 on the basis of knocking down of the fourth intron of RELL2 resulted in an impaired intron 4 intention. Overall, our study identified a new IR site in PDAC, which could be a possible target for PDAC therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Pancreatic Ductal* / drug therapy
  • Carcinoma, Pancreatic Ductal* / genetics
  • Carcinoma, Pancreatic Ductal* / metabolism
  • Carrier Proteins
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • DEAD-box RNA Helicases / genetics
  • DEAD-box RNA Helicases / metabolism
  • Deoxycytidine / pharmacology
  • Deoxycytidine / therapeutic use
  • Drug Resistance, Neoplasm / genetics
  • Humans
  • Membrane Proteins / metabolism
  • Pancreatic Neoplasms* / drug therapy
  • Pancreatic Neoplasms* / genetics
  • Pancreatic Neoplasms* / metabolism
  • RNA Precursors / genetics
  • RNA Precursors / metabolism
  • RNA Splicing Factors

Substances

  • RNA Precursors
  • Deoxycytidine
  • DHX38 protein, human
  • RNA Splicing Factors
  • DEAD-box RNA Helicases
  • RELL2 protein, human
  • Carrier Proteins
  • Membrane Proteins

Grants and funding

This work was supported by the National Natural Science Foundation of China (No.82173074 to WWB), and the Beijing Natural Science Foundation (No.7232127 to WWB), and the National High Level Hospital Clinical Research Funding (No.2022-PUMCH-D-001 to WWB, No. 2022-PUMCH-B-004 to WWB), and the CAMS Innovation Fund for Medical Sciences (No. 2021-I2M-1-002 to WWB), and the Non-profit Central Research Institute Fund of Chinese Academy of Medical Science (2018PT32014 to WWB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.