Ribonuclease inhibitor up-regulation inhibits the growth and induces apoptosis in murine melanoma cells through repression of angiogenin and ILK/PI3K/AKT signaling pathway.
Human ribonuclease inhibitor (RI), a cytoplasmic protein, is constructed almost entirely of leucine rich repeats. RI could suppress activities of ribonuclease and angiogenin (ANG) through closely combining with them. ANG is a potent inducer of blood vessel growth and has been implicated in the establishment, growth, and metastasis of tumors. ILK/PI3K/AKT signaling pathway also plays important roles in cell growth, cell-cycle progression, tumor angiogenesis, and cell apoptosis. Our previous experiments demonstrated that RI might effectively inhibit some tumor growth and metastasis. Our recent study showed that ILK siRNA inhibited the growth and induced apoptosis in bladder cancer cells as well as increased RI expression, which suggest a correlation between RI and ILK. However, the exact molecular mechanism of RI in anti-tumor and in the cross-talk of ANG and ILK signaling pathway remains largely unknown. Here we investigated the effects of up-regulating RI on the growth and apoptosis in murine melanoma cells through angiogenin and ILK/PI3K/AKT signaling pathway. We demonstrated that up-regulating RI obviously decreased ANG expression and activity. We also discovered that RI overexpression could remarkably inhibit cell proliferation, regulate cell cycle and induce apoptosis. Furthermore, up-regulation of RI inhibited phosphorylation of ILK downstream signaling targets protein kinase B/Akt, glycogen synthase kinase 3-beta (GSK-3β), and reduced β-catenin expression in vivo and vitro. More importantly, RI significant inhibited the tumor growth and angiogenesis of tumor bearing C57BL/6 mice. In conclusion, our findings, for the first time, suggest that angiogenin and ILK signaling pathway plays a pivotal role in mediating the inhibitory effects of RI on melanoma cells growth. This study identifies that RI may be a useful molecular target for melanoma therapy.
Department of Cell Biology and Genetics, Chongqing Medical University, Chongqing 400016, PR China.
Lin
L
Li
Department of Cell Biology and Genetics, Chongqing Medical University, Chongqing 400016, PR China.
Xiang-Yang
XY
Pan
Department of Cell Biology and Genetics, Chongqing Medical University, Chongqing 400016, PR China.
Jing
J
Shu
Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China.
Rong
R
Jiang
The Experimental Teaching Center, Chongqing Medical University, Chongqing 400016, PR China.
Yu-Jian
YJ
Zhou
Department of Cell Biology and Genetics, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: chjunxia@126.com.
Jun-Xia
JX
Chen
D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015870:Gene Expression; D006801:Humans; D008545:Melanoma / Q000473:pathology*; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010926:Placental Hormones / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021381:Protein Transport; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012259:Ribonuclease, Pancreatic / Q000378:metabolism*; D015398:Signal Transduction; D015854:Up-Regulation; D000099200:Scaffold Protein ILK
D019869:Phosphatidylinositol 3-Kinases; D010926:Placental Hormones; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D012259:Ribonuclease, Pancreatic; D000099200:Scaffold Protein ILK; C022052:placental ribonuclease inhibitor; C046366:angiogenin
Angiogenin; Apoptosis; ILK/PI3K/AKT; Melanoma cells; Ribonuclease inhibitor