Multidrug resistance related molecules in human and murine lung.

Aims: Transporter proteins known to mediate multidrug resistance (MDR) in tumour cells--MDR1 P-glycoprotein (P-gp) and multidrug resistance related protein 1 (MRP1)--are thought to be involved in protecting the lungs against inhaled toxic pollutants. Recently, several new transporter family members have been identified--for example, MRP2, MRP3, and breast cancer resistance protein (BCRP). To study the possible contribution of these proteins and the earlier defined MDR1 and MDR3 P-gp molecules, MRP1, and the major vault protein (MVP) to lung functioning, their expression was analysed in normal lung tissue of humans and several animal species.

Tissue distribution and induction of human multidrug resistant protein 3.

The multidrug resistance protein (MRP) family consists of several members and, for some of these transporter proteins, distinct roles in multidrug resistance and normal tissue functions have been well established (MRP1 and MRP2) or are still under investigation (MRP3). MRP3 expression studies in human tissues have been largely restricted to the mRNA level. In this report we extended these studies and further explored MRP3 expression at the protein level.

Aberrant expression of complement regulatory proteins, membrane cofactor protein and decay accelerating factor, in the involved epidermis of patients with vitiligo.

Background: Vitiligo is a pigmentary disorder of the skin characterized by the complete absence of melanocytes from the lesion. Complement-activating antimelanocyte antibodies have been implicated in vitiligo pathogenesis. As membrane regulators of complement activation, membrane cofactor protein, decay accelerating factor and CD59 protect cells from elimination by autologous complement, their absence or downregulation on melanocytes may be associated with autoantibody and complement-mediated melanocyte destruction in vitiligo.

Detection of the Mr 110,000 lung resistance-related protein LRP/MVP with monoclonal antibodies.

The Mr 110,000 lung resistance-related protein (LRP), also termed the major vault protein (MVP), constitutes >70% of subcellular ribonucleoprotein particles called vaults. Overexpression of LRP/MVP and vaults has been linked directly to MDR in cancer cells. Clinically, LRP/MVP expression can be of value to predict response to chemotherapy and prognosis.

Subcellular localization and distribution of the breast cancer resistance protein transporter in normal human tissues.

High expression of the Breast Cancer Resistance Protein (BCRP) gene has been shown to be involved in resistance to chemotherapeutic drugs. Knowledge of the localization of BCRP protein in normal tissues may help unravel the normal function of this protein. Therefore, we characterized the tissue distribution and cellular localization of BCRP in frozen sections of normal human tissues.

Specific detection of multidrug resistance proteins MRP1, MRP2, MRP3, MRP5, and MDR3 P-glycoprotein with a panel of monoclonal antibodies.

Tumor cells may display a multidrug resistance phenotype by overexpression of ATP binding cassette transporter genes such as multidrug resistance (MDR) 1 P-glycoprotein (P-gp) or the multidrug resistance protein 1 (MRP1). MDR3 P-gp is a close homologue of MDR1 P-gp, but its role in MDR is probably minor and remains to be established. The MRP1 protein belongs to a family of at least six members.

Breast cancer resistance protein is localized at the plasma membrane in mitoxantrone- and topotecan-resistant cell lines.

Tumor cells may display a multidrug resistant phenotype by overexpression of ATP-binding cassette transporters such as multidrug resistance (MDRI) P-glycoprotein, multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP). The presence of BCRP has thus far been reported solely using mRNA data. In this study, we describe a BCRP-specific monoclonal antibody, BXP-34, obtained from mice, immunized with mitoxantrone-resistant, BCRP mRNA-positive MCF-7 MR human breast cancer cells.