DNA mismatch binding in human lung tumor cell lines

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• 作者：Zienolddiny ; Shanbeh ; Ryberg ; David ; Gazdar ; Adi F. ; Haugen ; Aage
• 关键词：Lung cancer ; Mismatch repair ; Alkylation resistance ; Microsatellite instability ; Bandshift ; Immunoblotting ; AGT ; O⁶-alkylguanine-DNA alkyltransferase ; BG ; O⁶-benzylguanine ; HNPCC ; hereditary non-polyposis colon cancer ; MMR ; mismatch
• 刊名：Lung Cancer
• 出版年：1999
• 出版时间：October, 1999
• 年：1999
• 卷：26
• 期：1
• 页码：15-25
• 全文大小：330 K

文摘

Defects in mismatch repair (MMR) genes have been involved in several types of sporadic and hereditary cancers. In order to elucidate the role of MMR in human lung carcinogenesis we examined DNA mismatch binding in cell-free extracts of seven lung tumor cell lines and five corresponding lymphoblastoid cell lines from lung cancer patients. Using the technique of bandshift assay we have demonstrated that 2/7 of the tumor cell lines are aberrant in binding to specific DNA mismatches while all lymphoblastoid cell lines were proficient in binding to all tested mismatches. Both extracts were aberrant in binding to G/T mismatch whereas one of the cell lines showed deficiency in binding to the C:A mismatches as well. Immunoblotting analysis showed that all known DNA mismatch repair (MMR) proteins were present in these extracts. The cell line deficient in binding to both G:T and C:A mismatches showed microsatellite instability (MSI) in tumor DNA and higher resistance to the alkylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). This report indicates that DNA mismatch binding deficiencies may be implicated in at least a subgroup of human lung cancer.