p-glycoprotein expression in malignant melanoma

• Published in: Journal of cancer research and clinical oncology Vol. 117; no. 2; p. 168
• Main Authors: Fuchs, B, Ostmeier, H, Suter, L
• Format: Journal Article
• Language: English
• Published: Germany 01.01.1991
• Subjects: ATP Binding Cassette Transporter, Subfamily B, Member 1; Drug Resistance - physiology; Humans; Lymphatic Metastasis - genetics; Melanoma - genetics; Melanoma - metabolism; Membrane Glycoproteins - biosynthesis; Neoplasm Proteins - biosynthesis; Skin Neoplasms - genetics; Skin Neoplasms - metabolism; Skin Neoplasms - secondary
• ISSN: 0171-5216
• DOI: 10.1007/BF01613142

In some human malignancies resistance to chemotherapy is caused by an energy-dependent efflux system, responsible for the removal of chemotherapeutics out of the resistant tumor cells. A major component of this efflux system is the permeability glycoprotein (p-glycoprotein), which depends on the multidrug-resistance gene MDR1. We have tested p-glycoprotein in primary and metastatic human melanoma by use of the monoclonal antibody C219; a substantial expression was only observed in 1/37 primary melanomas and in 1/27 melanoma metastases. None of the patients with negative metastases responded to chemotherapy. Moreover a complete remission of metastatic growth was observed in the patient with the metastasis significantly expressing the p-glycoprotein. Sequential studies revealed no significant increase of p-glycoprotein-positive cells during and after chemotherapy. We conclude that drug resistance in human melanoma does not usually depend on the p-glycoprotein-related efflux system. Other mechanisms are obviously responsible for drug resistance in this human malignancy.