A multidrug-resistant ovarian carcinoma cell line with a malignant suppressed phenotype is a CD44 gene expression defective mutant.

A multidrug-resistant cell subline (OV1/VCR) derived from an ovarian adenocarcinoma cell line (OV1/P) was characterized by a typical suppressed malignant phenotype and by a unique karyotypic change: del(11)(p13). In an attempt to discern some genetic alteration of 11p genes that may be relevant to the phenotypic shift, cells were analyzed with DNA probes mapped in the deleted region and with monoclonal antibodies (MoAbs) against 11p-encoded membrane molecules. Southern blot did not detect abnormal restriction patterns of the probed sequences.