[Analysis of gene expression profiles in gastric cancer cell cycle].
OBJECTIVE
To detect the gene expression profile in gastric cancer cell cycle and explain the mechanism of gastric cancer cell proliferation by a genomic study.


METHODS
Gastric cancer cells MKN45 were synchronized at G2/M and G1/S point by nocodazole-thymidine and double thymidine methods. The synchronizing degree of cells was monitored by flow cytometry. The gene expression profiles at G2/M point, M/G1 transition, G1 early phase, G1 late phase, G1/S point, S early phase, S late phase, G2 early phase and G2 late phase in MKN45 cell cycling were examined using cDNA microarray chips. Hierarchy analysis was conducted with a professional software package and the up-regulated genes at G1 late and G2 phase were analyzed according to gene database. Furthermore, the mRNA level of cyclin E, cyclin B, plk1 and STK15 in above mentioned nine points were measured by quatitative PCR.


RESULTS
2001 genes were detected to be available at all 9 points via software processing, out of which 959 appeared up-regulated or down-regulated. 379 genes showed to be up-regulated at late G1 (147) or G2 phases (232), 40 at S and M phases (also up-regulated at G1 late and G2 phases). The 147 up-regulated genes at G1 late phase are involved in DNA metabolism, transcription and translation, protein transportation, ubiquitination and signal transduction, etc. The 232 up-regulated genes in G2 phase are involved in RNA synthesis and processing, intracellular protein transportation, cytoskeleton synthesis, signal transduction, apoptosis and anti-apoptosis, transcription regulation, ubiquitination, mitosis regulation and oncogene expression, etc. The mRNA level of 4 genes detected by quantitative PCR during cell cycle was in agreement with that detected by microarray.


CONCLUSIONS
During MKN45 cell cycling, the preparation for DNA synthesis and chromosome separation are conducted in G1 and G2, which are implicated in multiple genes, may be the main impetus of driving MKN45 cell cycle. Some of these genes may be related to tumor over-proliferation. The cDNA microarray technique has characteristic features such as reliability and can provide a great deal for future research on cell cycle related genes in gastric cancer.
Lan
Bin
B
Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Affiliated Hospital of Shanghai Second Medical University, Shanghai 200025, China.
Liu
Bin-ya
BY
Cheng
Xue-hua
XH
Zhang
Ji
J
Wang
Kan-kan
KK
Zhu
Zheng-gang
ZG
D064096:Aurora Kinase A; D064127:Aurora Kinases; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics; D045744:Cell Line, Tumor; D019926:Cyclin B / Q000235:genetics; D019927:Cyclin E / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics / Q000473:pathology; D000097869:Polo-Like Kinase 1
D064096:Aurora Kinase A; D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D019926:Cyclin B; D019927:Cyclin E; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D000097869:Polo-Like Kinase 1; C576917:AURKA protein, human