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The expression of multidrug resistance protein in human gastrointestinal tract carcinomas
Author(s) -
Takebayashi Yuji,
Akiyama Shinichi,
Natsugoe Shoji,
Hokita Shuichi,
Niwa Kiyoshi,
Kitazono Masaki,
Sumizawa Tomoyuki,
Tani Ayako,
Furukawa Tatsuhiko,
Aikou Takashi
Publication year - 1998
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/(sici)1097-0142(19980215)82:4<661::aid-cncr7>3.0.co;2-o
Subject(s) - medicine , multiple drug resistance , gastrointestinal tract , protein expression , microbiology and biotechnology , cancer research , drug resistance , gene , biology , genetics
BACKGROUND Multidrug resistance protein (MRP) is a membrane phosphoglycoprotein with an Mr of 190,000 that is involved in the non‐P‐glycoprotein mediated multidrug resistance of human tumor cells. The aim of this study was to determine the clinicopathologic relevance of MRP expression in human gastrointestinal tract carcinomas. METHODS The authors prepared a rabbit antiserum against MRP that does not cross‐react with P‐glycoprotein and retrospectively examined the expression of MRP in 86 squamous cell carcinomas of the esophagus, 103 adenocarcinomas of the stomach, and 139 colorectal adenocarcinomas by immunohistochemistry. None of the patients in this study had received prior chemotherapy. RESULTS The proportion of MRP positive samples in the squamous cell carcinomas of the esophagus (62.8%, 54 of 86) was significantly higher than that in the adenocarcinomas of the stomach (34.1%, 35 of 103) and the colorectal adenocarcinomas (40.3%, 56 of 139) ( P <0.01). The proportion of MRP positivity in the well‐differentiated carcinomas was significantly higher than that in moderately or poorly differentiated carcinomas. MRP expression was independent of gender, lymph node metastasis, and tumor progression. CONCLUSIONS These data indicate that the expression of MRP is correlated with the differentiation of carcinoma cells in the gastrointestinal tract and may be involved in the intrinsic drug resistance of well‐differentiated squamous cell carcinoma of the esophagus. Cancer 1998;82:661‐6. © 1998 American Cancer Society.