Expression of MDR1, HIF-1α and MRP1 in sacral chordoma and chordoma cell line CM-319

Using immunohistochemical techniques, the expression of MDR1, HIF-1α and MRP1 was investigated in 50 chordoma specimen. Using RT-PCR and Western blot, the expression of MDR1, HIF-1α and MRP1 was investigated in chordoma and chordoma cell line CM-319.Expression of MDR1, HIF-1α and MRP1 was observed in 10%, 80% and 74% of all cases, respectively. Expression of MRP1 was correlated with HIF-1α. On the other hand, expression of MDR1 was not correlated with the expression of HIF-1α or MRP1. The expression of HIF-1α and MRP1 was observed, but MDR1 was not observed in chordoma and CM-319.Expression of HIF-1α and MRP1 was observed in most chordoma specimen and CM-319 cell line; expression of HIF-1α correlated with MRP1. HIF-1α and MRP1 may play a role in the multidrug resistance of chordoma to chemotherapy.Chordoma, a primary malignant tumor of the skeleton, was considered to develop from a remnant of notochordal cells in the midline skeletal axis [1]. The most common sites are the skull base and the sacrococcygeal region. It is typically slow-growing tumor, and initial symptoms are usually related to local progression of the disease with subsequent compression of adjacent structures. The natural course of chordoma is quite grim; most patients do not survive 10 years because of high local recurrence rates [2,3]. The therapeutic approach to chordoma has traditionally relied heavily on surgical control. More recently, radiation therapy has been demonstrated to be a valuable modality for local control, particularly with the advent of charged particle radiotherapy. Medical therapy continues to be suboptimal in chordoma which is relatively refractory to cytotoxic chemotherapy. The main reason for therapeutic failure in cases of chordoma involves resistance to chemotherapy and radiotherapy. The refractory reason to chemotherapy and radiotherapy may be associated to the over-expression of some multidrug resistance related genes and hypoxia inducible factor-1α. These factors could a