Overexpression of BLCAP induces S phase arrest and apoptosis independent of p53 and NF-kappaB in human tongue carcinoma : BLCAP overexpression induces S phase arrest and apoptosis.
Bladder cancer-associated protein gene (BLCAP) is a novel candidate tumor suppressor gene identified from the human bladder carcinoma. Our previous studies have shown that BLCAP overexpression could inhibit cell growth by inducing apoptosis in HeLa cells [Zuo Z, Zhao M, Liu J, Gao G, Wu X: Tumor Biol 27: 221-226, 2006]. Such evidence suggests the alterations in BLCAP may play an important role in tumorigenesis. To further study the biological function of the BLCAP gene, we constructed a recombinant retroviral vector encoding BLCAP cDNA. Overexpressed BLCAP, via stable infection of exogenous BLCAP, resulted in growth inhibition of the human tongue cancer cell line Tca8113 in vitro, accompanied by S phase cell cycle arrest and apoptosis. The growth inhibition was correlated with up-regulation of p21(WAF1/CIP1 )expression and down-regulation of Bcl-XL and Bcl-2 expressions. However, p53 expression and NF-kappaB activity remained unchanged post infection. Furthermore, no changes in p53 phosphorylation at Ser46 and nuclear localization, which are critical to p53 function, were observed in BLCAP-overexpressed cells. Taken together, BLCAP may play a role not only in regulating cell proliferation but also in coordinating apoptosis and cell cycle via a novel way independent of p53 and NF-kappaB.
Yao
Jun
J
School of Medicine, Wuhan University, Wuhan, Hubei 430071, PR China.
Duan
Li
L
Fan
Mingwen
M
Yuan
Jianhuan
J
Wu
Xinxing
X
D000818:Animals; D017209:Apoptosis; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004273:DNA, Neoplasm / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D041681:NIH 3T3 Cells; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D012190:Retroviridae; D016196:S Phase; D014062:Tongue Neoplasms / Q000235:genetics / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics; D051020:bcl-X Protein / Q000235:genetics / Q000378:metabolism
C453739:BLCAP protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004273:DNA, Neoplasm; D016328:NF-kappa B; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53; D051020:bcl-X Protein