[Effects of two variants of ING1 expression on tumor cell growth regulation].
OBJECTIVE
To study effects of alternative transcripts of ING1 transfection on human cancer cell lines.


METHODS
p47/ING1A and p33/ING1B expression vehicles were constructed and introduced into a human breast cancer cell line MCF-7 and a human lung cancer cell line PAa, both expressing wild-type p53 protein. Growth characteristics of the transfectants and potentially related genes were analyzed.


RESULTS
The levels of p47/ING1A and p33/ING1B protein elevated respectively in tumor cells of MCF-7 and PAa after transfected with p47/ING1A and p33/ING1B, and the latter was much higher than that of the former. Ectopic overexpression of p33/ING1B effectively blocked tumor cell growth and arrested cells in the G(0) approximately G(1) phase of the cell cycle (P < 0.01), while p47/ING1A gave no effect on cell growth or cell cycle. Tumor cells overexpressing p33/ING1B contained more p21(WAF1) protein than that of the control cells, with undisturbed p53 protein level.


CONCLUSIONS
Expression of two different transcripts of ING1 may have different effects on tumor cell growth. p33/ING1B may cooperate with p53 in stimulating expression of p21(WAF1) gene, thus to arrest cell cycle and to inhibit tumor cell growth. p33/ING1B may be considered to be a candidate as a partner of p53 in gene therapy.
Liu
Jian-ying
JY
Department of Pathology, Health Science Center, Peking University, Beijing 100083, China. liujianying139@yahoo.com
Wu
Bing-quan
BQ
Zheng
Jie
J
You
Jiang-feng
JF
Zhong
Hao-hao
HH
Wang
Jie-liang
JL
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D017398:Alternative Splicing; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002455:Cell Division; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis; D004268:DNA-Binding Proteins; D016147:Genes, Tumor Suppressor; D006801:Humans; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis; D025521:Tumor Suppressor Proteins
C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004268:DNA-Binding Proteins; C501503:ING1 protein, human; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D011506:Proteins; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins