Visit our Expo - Redox and Inflammation signaling 2012

Session X : Cell death in cancer Poster X, 80
Over-expression of microRNA-21 modulates phosphoinositide-3 kinase and PTEN
signaling and promotes tumor cell survival.
Tushar Patel, Fanyin Meng, Roger Henson, Hania Wehbe, Molly Lang
Scott and White Clinic, Texas A&M University System Health Science Center College of
Medicine, 2401 South 31st Street, Temple, TX 76508, U.S.A. E-mail:
tpatel@swmail.sw.org
MicroRNAs (miRNAs) are endogenous RNA molecules that can regulate gene expression.
Altered expression of miRNA such as miR-21 has been reported for several different cancers.
However the role of miR-21 in tumor progression and the mechanisms involved remain
unknown. Our aims were to assess the effect of miR-21 on critical survival signaling
pathways. Methods: A miRNA microarray was used to profile the miRNA expression in
malignant (KMCH, Mz-ChA-1 and TFK) and non-malignant (H69) cholangiocyte cell lines.
Expression of miR-21 was confirmed by Northern blot and real-time PCR. miR-21
expression was altered using mir-21 specific antisense oligonulceotides or mir-21 precursor
miRNAs. Expression of PTEN and p85 was assessed by Western blots. For in vivo studies,
homogenates were obtained from xenografts of Mz-ChA-1 cells in nude mice under basal
conditions or following treatment with gemcitabine. Results: miR-21 expression was
increased in all malignant cell lines compared to non-malignant H69 cholangiocytes (2.74 ±
0.11 fold in Mz-ChA-1 cells, 4.35 ± 0.14 fold in TFK cells, and 1.84 ± 0.03 fold in KMCH-1
cells; all p