9.B.134 The Lysosomal autophagy and apoptosis-related protein, TMEM192 (TMEM192) Family
Lysosomal membrane proteins play roles in lysosome-related autophagy and apoptosis. Transmembrane protein 192 (TMEM192) shows a wide expression pattern in mouse tissues and is highly expressed in tumor cell lines, but at low levels in normal cell lines. By knockdown of TMEM192 expression using specific siRNAs, TMEM192-deficient HepG2 hepatoma cells showed growth inhibition and increased apoptosis, and autophagy was activated through LC3II expression. Increased apoptosis was inhibited by blocking the expression of the key autophagy gene Atg7 in TMEM192-deficient HepG2 cells. Thus, TMEM192 may be important for tumor cell growth and proliferation, and its deficiency can induce autophagy in tumor cells while activating apoptosis via the mitochondrial pathway through autophagy (Liu et al., 2012).