Long Noncoding RNA IGF2AS is Acting as an Epigenetic Tumor Suppressor in Human Prostate Cancer

OBJECTIVE To assess the expression profile and functional mechanism of long noncoding RNA (lncRNA) insulin growth factor 2 antisense (IGF2AS) in human prostate cancer (PCa). METHODS Quantitative reverse transcriptase-polymerase chain reaction was applied to assess IGF2AS expression in immortal PCa cell lines and in situ human PCa tumors. IGF2AS was overexpressed in VCaP and PC3 cells to assess its effect on PCa cell proliferation and invasion in vitro, and xenograft in vivo. The effect of IGF2AS overexpression on IGF2 was also assessed in PCa cells. Then, IGF2 was upregulated in IGF2AS-overexpressed PCa cells to assess the functional involvement of IGF2 in IGF2AS-mediated PCa cell development. RESULTS IGF2AS was downregulated in both PCa cell lines and human PCa tumors. In VCaP and PC3 cells, lentivirus-induced IGF2AS overexpression suppressed cancer cell proliferation and invasion in vitro, and xenograft development in vivo. IGF2 was downregulated by IGF2AS overexpression. Conversely, IGF2 upregulation revered the suppressing function of IGF2AS on PCa proliferation and invasion. CONCLUSION LncRNA IGF2AS is acting as an epigenetic tumor suppressor in human PCa, likely through inverse regulation on IGF2. IGF2AS/IGF2 axis may be a future therapeutic target for PCa treatment.(C) 2018 Elsevier Inc.