[The effects of CT120B over-expression on growth suppression and changes of gene expression profiles in lung adenocarcinoma cells].
OBJECTIVE
CT120B gene is a splicing variant of CT120A, which deletes 96 nucleotides and leads to an in-frame loss of 32 amino acids between the codon 136 and 167 as compared with CT120A. This study was undertaken to assess the effects of CT120B expression on lung cancer cell growth and to explore the gene expression profiles.


METHODS
CT120B cDNA was transfected into the human lung adenocarcinoma SPC-A-1 cells, and stable cell lines overexpressing CT120B were established. CCK-8 assay and tumorigenecity in a xenograft model were performed to analyze cell proliferation in vitro and in vivo. The differential gene expression induced by overexpressed CT120B was investigated using Atlas cDNA expression array. Flow cytometry was performed to analyze cell cycle and cell apoptosis.


RESULTS
Overexpression of CT120B in SPC-A-1 cells resulted in a reduced cell growth rate in vitro, and decrease of the tumorigenicity in nude mice. A total of 38 genes were identified as differential expressions with more than a 2.0-fold change by Atlas cDNA expression array analysis, including downregulated cyclin E1, cdk 2, c-kit, CXCR4 and upregulated caspase 8 gene. Overexpression of CT120B also induced G1 phase arrest, but had no effect on cell apoptosis.


CONCLUSIONS
The G1 cell cycle arrest, but not apoptosis, underlay the growth inhibitory activities of CT120B. The down-regulation of c-kit and CXCR4 expression might also contribute to the suppressive effects on cell growth of CT120B.
Pan
Dong-ning
DN
National Laboratory for Oncogenes and Related Genes, Shanghai Cancer Institute, Shanghai 200032, China.
Wei
Lin
L
Yao
Ming
M
Wan
Da-fang
DF
Gu
Jian-ren
JR
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018076:DNA, Complementary / Q000235:genetics; D016193:G1 Phase; D020869:Gene Expression Profiling; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009368:Neoplasm Transplantation; D020411:Oligonucleotide Array Sequence Analysis; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000378:metabolism; D014162:Transfection
D018076:DNA, Complementary; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019718:Receptors, CXCR4; C467481:TLCD3A protein, human; D019009:Proto-Oncogene Proteins c-kit