Expression of Chk2 and P53 in Sporadic Breast Cancer

mutations in 7 cases by DNA sequence analysis of the entire coding region. Results: Seven of 30 (23.3%) breast cancers had reduced immuno-expression of Chk2, one of them (1/7, 14.3%) showed a p53 immuno-expression and all of them revealed no Chk2 mutation. Conclusion: Expression of Chk2 protein more reduced in breast cancer with no abnormal p53 immuno-expression. No Chk2 mutation was found in all of Chk2 reduced expression, we hypothesize that there may be a posttranscriptional/ posttranslational mechanism (s) in breast caner to downregulate Chk2 protein expression. (Journal of Korean Breast Cancer Society 2003;6:141-147)