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Expression of MDR1 and glutatione S transferase‐π genes and chemosensitivities in human gastrointestinal cancer
Author(s) -
Satta Tetsuya,
Isobe KenIchi,
Yamauchi Masaji,
Nakashima Izumi,
Takagi Hiroshi
Publication year - 1992
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/1097-0142(19920215)69:4<941::aid-cncr2820690418>3.0.co;2-h
Subject(s) - northern blot , cell culture , microbiology and biotechnology , gene expression , biology , in situ hybridization , cisplatin , cell , messenger rna , cancer , stomach , cancer research , gene , genetics , biochemistry , chemotherapy
The relationship was analyzed between drug resistance and MDR1 (with MDR signifying multiple drug resistance) and glutatione S transferase‐π (GST‐π) gene expression in four stomach and four colon cancer cell lines. Northern blot analysis by pmdr1 probe showed that stomach cancer cell lines had no detectable level of MDR1 mRNA expression. By contrast, some levels of MDR1 mRNA expression were found in two colon cancer cell lines, indicating doxorubicin resistance. To examine the MDR1 mRNA in each cell level, in situ hybridization was used. It was found that all colon cell lines and two stomach cell lines had more silver grains per cell than KB cells (a human KB kidney epidermoid carcinoma cell line). However, the number of silver grains in each cell was heterogeneous in the colon and stomach cell lines. Low‐level MDR1 mRNA expression could be detected even in cell lines without MDR1 mRNA expression by northern blot hybridization. These results suggest the possibility that all gastrointestinal cell lines can acquire multiple drug resistance. In addition, all examined gastrointestinal cell lines had high GST‐π mRNA expression. This GST‐π gene expression shows cisplatin resistance in the examined cell lines. Heterogeneity of GST‐π mRNA expression also was shown at the cellular level. Cancer 1992; 69:941–946.