title: miR-20a induces cisplatin resistance of a human gastric cancer cell line via targeting CYLD.
abstract: The dysregulation of microRNAs (miRNAs) has been demonstrated to contribute to drug resistance of cancer cells, and sustained nuclear factor (NF)κB activation is also pivotal in tumor resistance to chemotherapy. In the present study, an essential role for miRNA (miR)-20a was identified in the regulation of gastric cancer (GC) chemoresistance. The expression level of miR‑20a was assayed by reverse transcription‑quantitative polymerase chain reaction. Additionally, 3-(4,5-dimethylthiazol-2‑yl)-2,5-diphenyltetrazolium bromide was used to detect the drug‑resistance phenotype changes of cancer cells associated with upregulation or downregulation of miR‑20a. Protein expression levelss were measured by western blotting and immunohistochemistry. Flow cytometry was used to detect cisplatin‑induced apoptosis. It was found that miR‑20a was markedly upregulated in GC plasma and tissue samples. Additionally, miR‑20a was upregulated in GC plasma and tissues from patients with cisplatin (DDP) resistance, and in the DPP‑resistant gastric cancer cell line (SGC7901/DDP). The expression of miR‑20a was inversely correlated with the expression of cylindromatosis (CYLD). Subsequently, the assessment of luciferase activity verified that CYLD was a direct target gene of miR‑20a. Treatment with miR‑20a inhibitor increased the protein expression of CYLD, downregulated the expression levels of p65, livin and survivin, and led to a higher proportion of apoptotic cells in the SGC7901/DDP cells. By contrast, ectopic expression of miR‑20a significantly repressed the expression of CYLD, upregulated the expression levels of p65, livin and survivin, and resulted in a decrease in the apoptosis induced by DDP in the SGC7901 cells. Taken together, the results of the present study suggested that miR‑20a directly repressed the expression of CYLD, leading to activation of the NFκB pathway and the downstream targets, livin and survivin, which potentially induced GC chemoresistance. Altering miR‑20a expression may be a potential therapeutic strategy for the treatment of chemoresistance in GC in the future.
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Mingxia
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Oncology, The First People's Hospital of Kunshan Affiliated With Jiangsu University, Suzhou, Jiangsu 215300, P.R. China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Du
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Zebo
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Radiation Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, P.R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of General Surgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Gongming
authors.initials: G
authors.lastname: Cheng
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Shu
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Tongshan
authors.initials: T
authors.lastname: Wang
mesh_terms: D020413:3' Untranslated Regions; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001665:Binding Sites; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002945:Cisplatin / Q000494:pharmacology*; D000074749:Deubiquitinating Enzyme CYLD; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics; D034622:RNA Interference; D013274:Stomach Neoplasms / Q000235:genetics*; D000077022:Survivin; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; C107489:BIRC5 protein, human; C419866:BIRC7 protein, human; D051034:Inhibitor of Apoptosis Proteins; C534451:MIRN20a microRNA, human; D035683:MicroRNAs; D016328:NF-kappa B; D009363:Neoplasm Proteins; D000077022:Survivin; D025521:Tumor Suppressor Proteins; C409984:CYLD protein, human; D000074749:Deubiquitinating Enzyme CYLD; D002945:Cisplatin