Elevated level of spindle checkprotein MAD2 correlates with cellular mitotic arrest, but not with aneuploidy and clinicopathological characteristics in gastric cancer.
OBJECTIVE
To study the relevance of spindle assembly checkprotein MAD2 to cellular mitotic status, aneuploidy and other clinicopathological characteristics in gastric cancer.


METHODS
Western blot analyses were performed to analyze the protein levels of MAD2 and cyclin B1 in the tumorous and adjacent nontumorous tissues of 34 gastric cancer patients. Cell cycle distribution and DNA ploidy of cancer tissues were also determined by flow cytometry. Conventional statistical methods were adopted to determine the relevance of abnormal MAD2 level to mitotic status, aneuploidy and clinicopathological parameters.


RESULTS
Out of 34 gastric cancer patients 25 (74%) exhibited elevated MAD2 levels in their tumorous tissues compared with the corresponding nontumorous tissues. Elevation of MAD2 levels significantly correlated with the increased levels of cyclin B1 expression and G(2)/M-phase distribution (P = 0.038 and P = 0.033, respectively), but was not relevant to aneuploidy. The gastric cancer patients with elevated MAD2 levels showed a tendency toward better disease-free and overall survival (P>0.05). However, no association was found between elevated MAD2 levels and patients' clinicopathological characteristics.


CONCLUSIONS
Elevation of MAD2 level is present in 74% of gastric cancer patients, and correlates with increased mitotic checkpoint activity. However, elevation of MAD2 level is not associated with patients' aneuploidy and any of the clinicopathological characteristics.
Wu
Chew-Wun
CW
Department of Surgery, Taipei-Veterans General Hospital, Taiwan, China.
Chi
Chin-Wen
CW
Huang
Tze-Sing
TS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000782:Aneuploidy; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002455:Cell Division; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D018572:Disease-Free Survival; D005260:Female; D016195:G2 Phase; D006801:Humans; D064246:Mad2 Proteins; D008297:Male; D008875:Middle Aged; D008938:Mitosis; D012097:Repressor Proteins; D008941:Spindle Apparatus / Q000378:metabolism; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*
C534699:CCNB1 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D019926:Cyclin B; D056744:Cyclin B1; C577697:MAD2L1 protein, human; D064246:Mad2 Proteins; D012097:Repressor Proteins