RESUMO
IgG4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition of autoimmune etiology in recent twenty years, mainly manifesting as mass-forming lesions in single or multiple organs. In the past, it was often missed or misdiagnosed as inflammation or tumor. Patients may die from multiple organ failure due to end-stage fibrosis if they are not treated promptly. However, the number of clinically confirmed cases has gradually increased with the improvement of diagnostic level in recent years, and these patients have benefited greatly after receiving early treatment. Although patients generally respond well to traditional immunosuppressors including glucocorticoids and disease-modifying anti-rheumatic drugs, refractory and recurrent cases, even patients with glucocorticoid contraindication are common. Important mechanistic insights have been derived from studies of B-cell depletion therapy, but greater awareness of the pathophysiology of IgG4-RD is still badly needed to identify novel therapeutic targets. In this article, we reviewed the pathogenesis progress and promising therapy of IgG4-RD to seek better clinical management of IgG4-RD.
RESUMO
Multidrug resistance protein 7 (MRP7, ABCC10) is a recently discovered member of the ATP-binding cassette (ABC) family which are capable of conferring resistance to a variety of anticancer drugs, including taxanes and nucleoside analogs, in vivo. MRP7 is highly expressed in non-small cell lung cancer cells, and Mrp7-KO mice are highly sensitive to paclitaxel, making MRP7 an attractive chemotherapeutic target of non-small cell lung cancer. However, only a few inhibitors of MRP7 are currently identified, with none of them having progressed to clinical trials. We used MRP7-expressing cells to investigate whether tariquidar, a third generation inhibitor of P-glycoprotein, could inhibit MRP7-mediated multidrug resistance (MDR). We found that tariquidar, at 0.1 and 0.3 µM, significantly potentiated the sensitivity of MRP7-transfected HEK293 cells to MRP7 substrates and increased the intracellular accumulation of paclitaxel. We further demonstrated that tariquidar directly impaired paclitaxel efflux and could downregulate MRP7 protein expression in a concentration- and time-dependent manner after prolonged treatment. Our findings suggest that tariquidar, at pharmacologically achievable concentrations, reverses MRP7-mediated MDR through inhibition of MRP7 protein expression and function, and thus represents a promising therapeutic agent in the clinical treatment of chemoresistant cancer patients.
