Expression of the novel mitoxantrone resistance associated gene MXR7 in colorectal malignancies.

It was shown previously that a glypican encoding gene (MXR7/GPC3/OCI-5) was associated with mitoxantrone resistance in vitro. This study describes and investigation of an association between multidrug resistance and MXR7 in surgical cryo-specimens of 51 gastrointestinal tumors. The mRNA expression levels differ widely according to tumor species. In primary colorectal cancers, the level of MXR7 mRNA expression correlated loosely with the mRNA expression level of the multidrug-resistance-associated protein (MRP). In colorectal metastases an elevated MXR7 mRNkA expression level was observed when compared to primary colorectal carcinomas.