Cell cycle activation by c-myc in a burkitt lymphoma model cell line

Effects of E2F-1 gene overexpression on gastric cancer cell dynamics

AIM: To understand the effect of E2F-1's over-expression on gastric cancer cell proliferation, growth and cell cycle and to investigate the molecular mechanism of E2F-1's influence on gastric cancer cell dynamics.

METHODS: The MGC-803/ E2F-1 (experimental group) gastric cancer cells which were stably transfected with E2F-1, and containing unpossessed carriers (negative control group), and the cells without transfection were performed MTT test to draw growing curve, and to compute cell proliferation rate. Cell cycles were examined by flow cytometry. The total RNA was extracted, and the cDNA was obtained using reverse transcription polymerase chain reaction (RT-PCR), and then the fluorescent probes were hybridized with gene chip containing 21 522 human 22K gene expression profiles. Subsequently, the two signal images were scanned by Lux Scan 10K/A dual pathways laser scanner and analyzed by LuxScan 3.0 image analysis software.

RESULTS: Compared with two control groups, the growth of the MGC-803 gastric cancer cells stably transfected with E2F-1 was obviously inhibited, and proliferation rate was decreased (26.61% ± 5.19% vs 93.4% ± 10.29%, 100% ± 0.00%, both P < 0.05), cell cycle staged in periods of G₀/G₁. Of the 21 522 target genes, there were 20 cell proliferation, growth and cell cycle-related differential expression ones. Of the 20 genes, 9 were up-regulated and 11 were down-regulated.

CONCLUSION: E2F-1 overexpression inhibits gastric cancer cell proliferation, growth and cell cycle, then cell cycle remains in periods of G₀/G₁, and perhaps the molecular mechanism has direct relationship with the 20 selected differential expression genes.