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Detection of P‐glycoprotein in frozen and paraffin‐embedded gastric adenocarcinoma tissues using a panel of monoclonal antibodies
Author(s) -
Lacueva Fj,
Ana Teruel,
Rafael Calpena,
J Medrano,
Mayol Mj,
Pérez-Vázquez Mt,
C Rufete,
Camarasa Mv,
Ferragut Ja
Publication year - 1998
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1046/j.1365-2559.1998.00381.x
Subject(s) - monoclonal antibody , immunohistochemistry , p glycoprotein , antibody , glycoprotein , frozen section procedure , pathology , staining , carcinoma , membrane glycoproteins , microbiology and biotechnology , biology , monoclonal , medicine , immunology , multiple drug resistance , biochemistry , antibiotics
Aims: Most chemotherapeutic regimens used against gastric carcinoma include anthracyclines whose effectiveness can be impaired by the presence of P‐glycoprotein. In order to obtain a reliable pattern of P‐glycoprotein expression in these tumours an immunohistochemical study using a panel of anti‐P‐glycoprotein antibodies was performed in frozen and paraffinized tissues. Methods and results: Frozen and paraffinized samples from 25 gastric carcinomas were immunohistochemically analysed using a panel of four anti‐P‐glycoprotein monoclonal antibodies including C219, MRK16, JSB‐1 and C494. Semiquantitative analysis indicated that moderate or high P‐glycoprotein levels were detected in 40% to 76% of gastric adenocarcinomas, depending on the anti‐P‐glycoprotein antibody used. The antibody C494 was the most sensitive in detecting P‐glycoprotein in both frozen and paraffinized gastric carcinoma samples. Moreover, C494 showed a pattern of staining exclusively associated with the plasma membrane, in contrast to the cytoplasmic with reinforcement of plasma membrane pattern displayed by the other three antibodies. Significant differences in P‐glycoprotein levels were obtained when C494 and MRK16 were used in frozen tissues. Finally, detection of P‐glycoprotein in frozen samples did not improve when compared to paraffinized ones. Conclusions: It appears that P‐glycoprotein is frequently expressed in gastric adenocarcinomas, and the use of C494 complemented by JSB‐1 is recommended for reliable detection of P‐glycoprotein in this neoplasm.