Adenovirus expressing dual c-Met-specific shRNA exhibits potent antitumor effect through autophagic cell death accompanied by senescence-like phenotypes in glioblastoma cells.
c-Met, a cognate receptor tyrosine kinase of hepatocyte growth factor, is overexpressed and/or mutated in number of tumors. Therefore, abrogation of c-Met signaling may serve as potential therapeutic targets. In this study, we generated Ads expressing single shRNA specific to c-Met (shMet) (dl/shMet4 and dl/shMet5) or dual shRNAs specific to c-Met (dl/shMet4+5); and examined the therapeutic potential of these newly engineered Ads in targeting c-Met, and delineated their mechanism of action in vitro and in vivo. Ads expressing shMet induced knock-down in c-Met, and phenotypically resulted in autophagy-like features including appearance of membranousvacuoles, formation of acidic vesicular organelles, and cleavage and recruitment of microtubule-associated protein1 light chain 3 to autophagosomes. Ads expressing shMet also suppressed Akt phosphorylation and increased number of senescence-related gene products including SM22, TGase II, and PAI-1. These changes resulted in inhibition of cell proliferation and G2/M arrest of U343 cells. In vivo, intratumoral injection with dl/shMet4+5 resulted in a significant reduction of tumor growth with corresponding increasing overall survival. Histopathological analysis of these treated tumors revealed that Atg5 was highly up-regulated, indicating the therapeutic induction of autophagy. In sum, these results reveal that autophagic cell death induced by shMet-expressing Ads provide a novel strategy for targeting c-Met-expressing tumors through non-apoptotic mechanism of cell death.
Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Korea.
Jung-Sun
JS
Lee
Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea.
Eonju
E
Oh
Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Korea.
Ji Young
JY
Yoo
Department of Molecular Science & Technology, Institute for Medical Sciences, Ajou University School of Medicine, Suwon, Korea.
Kyeong Sook
KS
Choi
Department of Molecular Science & Technology, Institute for Medical Sciences, Ajou University School of Medicine, Suwon, Korea.
Mi Jin
MJ
Yoon
Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea.
Chae-Ok
CO
Yun
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001343:Autophagy / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D055785:Gene Knockdown Techniques / Q000379:methods; D015316:Genetic Therapy / Q000379:methods*; D005909:Glioblastoma / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010641:Phenotype; D019859:Proto-Oncogene Proteins c-met / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction; D023041:Xenograft Model Antitumor Assays
D034741:RNA, Small Interfering; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met