Abstract
ObjectivePancreatic cancer is one of the most lethal human malignancies. Gemcitabine is widely used to treat pancreatic cancer, and the resistance to chemotherapy is the major difficulty in treating the disease. N 6-methyladenosine (m6A) modification, which regulates RNA splicing, stability, translocation, and translation, plays critical roles in cancer physiological and pathological processes. METTL14, an m6A Lmethyltransferase, was found deregulated in multiple cancer types. However, its role in gemcitabine resistance in pancreatic cancer remains elusive.MethodsThe mRNA and protein level of m6A modification associated genes were assessed by QRT-PCR and western blotting. Then, gemcitabine‐resistant pancreatic cancer cells were established. The growth of pancreatic cancer cells were analyzed using CCK8 assay and colony formation assay. METTL14 was depleted by using shRNA. The binding of p65 on METTL14 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Protein level of deoxycytidine kinase (DCK) and cytidine deaminase (CDA) was evaluated by western blotting. In vivo experiments were conducted to further confirm the critical role of METTL14 in gemcitabine resistance.ResultsWe found that gemcitabine treatment significantly increased the expression of m6A methyltransferase METTL14, and METTL14 was up-regulated in gemcitabine-resistance human pancreatic cancer cells. Suppression of METTL14 obviously increased the sensitivity of gemcitabine in resistant cells. Moreover, we identified that transcriptional factor p65 targeted the promoter region of METTL14 and up-regulated its expression, which then increased the expression of cytidine deaminase (CDA), an enzyme inactivates gemcitabine. Furthermore, in vivo experiment showed that depletion of METTL14 rescue the response of resistance cell to gemcitabine in a xenograft model.ConclusionOur study suggested that METTL14 is a potential target for chemotherapy resistance in pancreatic cancer.
Highlights
Pancreatic cancer (PC) is one of the most aggressive and lethal cancer diseases worldwide, with only about 5% of patients survived 5 years after diagnosis [1, 2]
We identified that transcriptional factor p65 targeted the promoter region of METTL14 and up-regulated its expression, which increased the expression of cytidine deaminase (CDA), an enzyme inactivates gemcitabine
Antibodies against methyltransferaselike enzyme 3 (METTL3), METTL14, Wilms tumor 1-associated protein (WTAP), fat and obesityrelated protein (FTO), alkB homolog 5 (ALKBH5), p65, p-p65, and GAPDH were obtained from Cell Signaling; antibodies against vir-like m6A methyltransferase-associated (VIRMA), deoxycytidine kinase (DCK) and CDA were purchased from Proteintech
Summary
Pancreatic cancer (PC) is one of the most aggressive and lethal cancer diseases worldwide, with only about 5% of patients survived 5 years after diagnosis [1, 2]. The treatments of PC include surgery, chemotherapy, and radiation therapy. Since surgery alone is insufficient to achieve long-term survival, adjuvant chemotherapy is always involved in the treatment regimen of PC patients [4, 5]. The current standard chemotherapy treatment regimen includes gemcitabine monotherapy and its combinations with other drugs, such as 5-fluorouracil, capecitabine, and carboplatin et al [6, 7]. Most patients acquired resistance to gemcitabine, and the mechanism remains largely unknown [8]. Investigating the underlying mechanism of gemcitabine resistance in pancreatic cancer is urgently required
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
