title: Involvement of microRNA-141-3p in 5-fluorouracil and oxaliplatin chemo-resistance in esophageal cancer cells via regulation of PTEN.
abstract: microRNAs (miRNAs) act as a major regulator of acquired chemo-resistance in various types of cancer therapeutics. This study investigated the contribution of miRNAs in influencing multiple drug resistance in esophageal squamous cell carcinoma (ESCC). The sensitivity of four ESCC cell lines (EC109, EC9706, TE-1 and KYSE-150) to 5-fluorouracil (5-FU) and oxaliplatin (OX) was determined by MTT assay. A 5-FU and OX-resistant subline, EC9706R, was established by continuous exposure to stepwise increasing concentration of 5-FU and OX. Microarray technology was used to compare the differential expression of miRNAs between resistant cells and parental cells. Chemo-sensitivity assay was performed to evaluate drug response in EC9706R cells transfected with miRNA mimic or inhibitor. The direct targets of miRNA were identified by employing pathway analysis and then confirmed with luciferase assay. Sixty ESCC tissue samples and their paired adjacent normal tissues were collected to validate the expression of identified miRNA. Mouse models were further utilized to investigate the function of miRNA on acquired chemo-resistance. MicroRNA panel results indicated that a total of 12 miRNAs were differentially expressed and miR-141-3p was highly over expressed in resistant cells. Inhibition of miR-141-3p reversed acquired chemo-resistance in EC9706R cells by stimulating apoptosis. The expression of miR-141-3p was significantly increased in ESCC tissue samples compared to their matched distant normal tissues. In addition, the elevated miR-141-3p expression was found to be associated with ESCC differentiation status and TNM stage. Moreover, Phosphatase and tensin homolog (PTEN) was identified as direct target of miR-141-3p. Western blot exhibited altered protein levels of PTEN, Akt, and PI3k with miR-141-3p inhibitor. An inverse correlation between PTEN expression and miR-141-3p expression was also observed in tissue samples. EC9706R xenograft mouse model became sensitized to 5-FU and OX treatment following miR-141-3p inhibitor transfection in vivo. Our study demonstrated that miR-141-3p contributed to an acquired chemo-resistance through PTEN modulation both in vitro and in vivo.
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157, Xiwulu, Xi'an, 710004, Shaanxi, China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Jin
authors.affiliation: Department of Oncology, Xian Yang Center Hospital, Xian Yang, 610041, Shaanxi, China.
authors.forename: Qing-Juan
authors.initials: QJ
authors.lastname: Chen
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157, Xiwulu, Xi'an, 710004, Shaanxi, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xu
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157, Xiwulu, Xi'an, 710004, Shaanxi, China.
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Ren
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157, Xiwulu, Xi'an, 710004, Shaanxi, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Bao
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157, Xiwulu, Xi'an, 710004, Shaanxi, China.
authors.forename: Yi-Nan
authors.initials: YN
authors.lastname: Ma
authors.affiliation: Scientific Research Center, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157, Xiwulu, Xi'an, 710004, Shaanxi, China. mhbxian@sina.com.
authors.forename: Hong Bing
authors.initials: HB
authors.lastname: Ma
mesh_terms: D000818:Animals; D019008:Drug Resistance, Neoplasm; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009944:Organoplatinum Compounds / Q000494:pharmacology*; D000077150:Oxaliplatin; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis* / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis* / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: C533895:MIRN141 microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; D009944:Organoplatinum Compounds; D012334:RNA, Neoplasm; D000077150:Oxaliplatin; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D005472:Fluorouracil
keywords: Cell line; Chemotherapy; Esophageal squamous cell carcinoma; Resistance; Xenograft; microRNA