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Differential expression of multidrug resistance gene product, P‐glycoprotein, in normal, dysplastic and malignant oral mucosa in India
Author(s) -
Jain Vibhor,
Das Satya N.,
Luthra Kalpana,
Shukla Nootan K.,
Ralhan Ranju
Publication year - 1997
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19970220)74:1<128::aid-ijc21>3.0.co;2-a
Subject(s) - p glycoprotein , carcinogenesis , pathology , cancer , multiple drug resistance , oral mucosa , biology , flow cytometry , monoclonal antibody , population , medicine , antibody , cancer research , microbiology and biotechnology , immunology , drug resistance , genetics , environmental health
Multidrug resistance (MDR) in human cancer is often associated with over‐expression of the mdr‐1 gene, which encodes a 170‐kDa transmembrane protein, termed P‐glycoprotein (P‐gp). We evaluated the immunoreactivity of P‐gp in oral tissues at different stages of tumorigenesis in the Indian population by flow cytometry, using the MRK‐16 monoclonal antibody, which recognizes an external epitope of P‐gp. The expression of P‐gp was studied in human oral normal tissues (12 cases), dysplastic lesions (13 cases), primary untreated squamous‐cell carcinomas (12 cases) and recurrent tumors (18 cases). Quantitative flow‐cytometric analysis of P‐gp expression showed a significant increase in P‐gp levels in untreated primary oral tumors ( p < 0.01) and in dysplastic lesions ( p < 0.05) as compared with normal oral tissues. A marked significant increase in P‐gp expression was observed in recurrent oral carcinomas as compared with normal oral tissues ( p < 0.001) and dysplastic lesions ( p < 0.01). Among recurrent tumors, a significant increase in the level of P‐gp was observed in T4‐stage tumors as compared with T3‐stage tumors ( p < 0.01). We conclude that P‐gp is differentially expressed during oral tumorigenesis, and may be an indicator of the biological behavior of oral malignancies. Int. J. Cancer 74:128–133. © 1997 Wiley‐Liss, Inc.