Immunohistochemical identification of P-glycoprotein in previously untreated, diffuse large cell and immunoblastic lymphomas

• Published in: Cancer research (Chicago, Ill.) Ill.), 1992-07, Vol.52 (13), p.3768-3775
• Main Authors: NIEHANS, G. A, JASZCZ, W, BRUNETTO, V, PERRI, R. T, GAJL-PECZALSKA, K, WICK, M. R, TSURUO, T, BLOOMFIELD, C. D
• Format: Article
• Language: English
• Subjects: ABO Blood-Group System; ATP-Binding Cassette, Sub-Family B, Member 1; Biological and medical sciences; Drug Resistance - genetics; Humans; Immunohistochemistry; Lymphoma, Large B-Cell, Diffuse - drug therapy; Lymphoma, Large B-Cell, Diffuse - metabolism; Lymphoma, Large-Cell, Immunoblastic - drug therapy; Lymphoma, Large-Cell, Immunoblastic - metabolism; Medical sciences; Membrane Glycoproteins - analysis; Membrane Glycoproteins - immunology; Ophthalmology; RNA, Messenger - analysis; Tumors and pseudotumors of the eye, orbit, eyelid, lacrimal apparatus
• ISSN: 0008-5472; 1538-7445

Expression of P-glycoprotein has been linked to multidrug resistance in cancer cell lines and human tumors. We investigated the frequency and clinical significance of P-glycoprotein immunoreactivity in 57 previously untreated diffuse large cell and immunoblastic lymphomas. Banked frozen tissue, which had been obtained prior to chemotherapy, was tested for reactivity with 2 monoclonal antibodies (MRK16 and C219) that recognize different domains of P-glycoprotein, using an immunoperoxidase technique. Thirteen of 57 lymphomas (23%) showed strong staining of greater than 50% of neoplastic cells; 15 of 57 (26%) showed labeling of a minority (11-50%) of neoplastic lymphocytes; 14 of 57 (25%) yielded equivocal results (reactivity in less than 10% of cells); and 15 of 57 (26%) were negative for P-glycoprotein. The 2 monoclonal antibodies were comparable in reactivity. Expression of MDR-1 mRNA was determined in 6 cases with sufficient available tissue, and did not correlate well with the percentages of cells reactive for P-glycoprotein by immunohistochemistry. Thirty-nine of our 57 patients completed multiagent chemotherapy. Contrary to our expectations, we found that P-glycoprotein immunoreactivity did not decrease the likelihood of response to induction chemotherapy. Median survival also was not adversely affected.