Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jun 7, 2012; 18(21): 2630-2639
Published online Jun 7, 2012. doi: 10.3748/wjg.v18.i21.2630
High dose glargine alters the expression profiles of microRNAs in pancreatic cancer cells
Wei-Guang Li, Yao-Zong Yuan, Min-Min Qiao, Yong-Ping Zhang
Wei-Guang Li, Yao-Zong Yuan, Min-Min Qiao, Yong-Ping Zhang, Department of Gastroenterology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025, China
Author contributions: Li WG and Yuan YZ designed the research; Li WG performed the majority of experiments; Qiao MM and Zhang YP were involved in editing the manuscript; Yuan YZ and Li WG analyzed the data; Li WG and Yuan YZ wrote the paper.
Correspondence to: Dr. Yao-Zong Yuan, Professor, Department of Gastroenterology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, 197 Ruijin Second Road, Shanghai 200025, China. yaozongyuan@yahoo.com.cn
Telephone: +86-21-64370045 Fax: +86-21-64150773
Received: December 19, 2011
Revised: February 29, 2012
Accepted: March 20, 2012
Published online: June 7, 2012
Abstract

AIM: To investigate the effect of high dose glargine on the expression profiles of microRNAs in human pancreatic cancer cells.

METHODS: Real-time polymerase chain reaction array (RT-PCR) was applied to investigate miRNAs differentially expressed in Sw1990 cells treated with or without 100 IU/L glargine. Stem-loop RT-PCR was used to confirm the results of the array assay in Sw1990 and Panc-1 cells. The effects of miR-95 on cell growth, apoptosis, invasion and migration abilities were respectively examined by CCK8 assay, apoptosis assay, Matrigel invasion and migration assay in Sw1990 and Panc-1 cells. Nude mice xenograft models with Sw1990 cells were built to investigate pancreatic cancer growth in vivo after transfection by the lentivirus pGLV3-GFP- miR-95.

RESULTS: Ten miRNAs were significantly up-regulated and 2 miRNAs down-regulated in glargine treated Sw1990 cells when compared with non-treated cells (2.48-fold changes on average, P < 0.01). miR-95, miR-134 and miR-34c-3p are the top three miRNAs regulated by glargine (3.65-fold, 2.67-fold and 2.60-fold changes respectively, P < 0.01) in Sw1990 cells. Stem-loop RT-PCR confirmed that high dose glargine up-regulated the expression of miR-95 and miR-134 in both Sw1990 and Panc-1 cells. The most obvious change is the apparent increase of miR-95. Forced expression of miR-95 significantly increased cell proliferation (Sw1990: 2.510 ± 0.129 vs 2.305 ± 0.187, P < 0.05; Panc-1: 2.439 ± 0.211 vs 2.264 ± 0.117, P < 0.05), invasion (Sw1990: 67.90 ± 12.33 vs 47.30 ± 5.89, P < 0.01; Panc-1: 37.80 ± 8.93 vs 30.20 ± 5.14, P < 0.01), migration (Sw1990: 101 ± 6.00 vs 51.20 ± 8.34, P < 0.01; Panc-1: 91.80 ± 9.22 vs 81.50 ± 7.47, P < 0.01) and inhibited cell apoptosis (Sw1990: 22.05% ± 1.92% vs 40.32% ± 1.93%, P < 0.05; Panc-1: 20.17% ± 0.85% vs 45.60% ± 1.43%, P < 0.05) when compared with paired negative controls, whereas knockdown of miR-95 obtained the opposite effect. Nude mice xenograft models confirmed that miR-95 promoted the growth of pancreatic cancer in vivo when compared with negative control (tumor volume: 373.82 ± 23.67 mL vs 219.69 ± 17.82 mL, P < 0.05).

CONCLUSION: These observations suggested that modulation of miRNA expression may be an important mechanism underlying the biological effects of glargine.

Keywords: Glargine, MicroRNAs, Pancreatic cancer, Lentivirus, Cancer growth