MRP1 is known for its ability to actively decrease intracellular drug concentration, limiting the efficacy of cancer chemotherapy; however, data on the clinical relevance of MRP1 is inconclusive.
MRP mRNA expression was detected in 70% of the breast cancer tissues and its expression levels were significantly increased in the cancer group compared with the noncancerous breast tissues.
Also evident was the association between cancer susceptibility and the variant rs212090 genotype (adenosine/thymidine [A/T] + T/T) of ABCC1 (OR, 1.37; 95% CI, 1.03-1.83).
Although the processes involved in metastasis have not yet been clearly elucidated, our previous studies have shown that higher expression levels of MRP-1/CD9 and KAI1/CD82 in cancer cells are significantly correlated with less metastatic potency.
Among the ABC proteins, some members including ABCB1, ABCC1, ABCC2 and ABCG2 are believed to contribute to multidrug resistance of cancer chemotherapy.
Among these exporters, P-glycoprotein and MRP1 are involved in cancer multidrug resistance, protection from endo and xenobiotics, determination of drug pharmacokinetics, and the pathophysiology of a variety of disorders.
Based on the findings, a set of proteins, including ATP binding cassette subfamily C member 1 (ABCC1), neurogenic locus notch homologue protein 1 (NOTCH1), hepatocyte growth factor receptor (MET), RAF proto-oncogene serine/threonine-protein kinase (RAF1) and proto-oncogene vav (VAV1) was found in NDP and was involved in over-represented terms correlated with cell-mediated immunity and cancer.
Collectively, our data revealed that targeted HDAC2 can suppress the malignancy of GBM cells and increase their sensitivity of TMZ via down-regulation of MRP1.
Generally, the expression level of P-glycoprotein in urothelial cancer is low, so we accordingly investigated the expression of multidrug resistance-associated protein (MRP).
Genes encoding both MRP1 and the catalytic subunit of gamma-glutamylcysteine synthetase (gamma-GCS) are coordinately regulated in cultured cancer cell lines as well as colorectal cancer tissues from colon cancer patients.
Glutathione-S-transferase Pi1 (GSTP1) and multidrug resistance protein 1 (MRP1) are overexpressed in melanoma, a skin cancer notoriously resistant to all current modalities of cancer therapy.
However, it was observed that generating rate of the cancer stem-like cells was lower than that of TJ905 cells, that expression of the anti-apoptotic and multidrug resistance-associated protein (MRP) genes were paradoxical to the literatures, which showed the uncertainty of cancer stem cells, and that some stem cell was not the solo factor to maintain tumor growth and resist apoptosis and anti-tumor drugs.
However, of the various mechanisms that are involved in conferring resistance, upregulation of drug efflux ATP-binding cassette (ABC) transporters, such as P-glycoprotein (ABCB1), multidrug resistance protein 1 (ABCC1) and ABCG2, has become a major obstacle to cancer chemotherapy and seriously affects the clinical outcome.
In addition, Twist-overexpressing cells exhibit high efflux of Hoechst 33342 and Rhodamine 123 as a result of increased expression of ABCC1 (MRP1) transporters, a property of cancer stem cells.
In addition, we investigated if aberrant promoter methylation levels of ABCB1, ABCC1 and ABCG2 occur in tumor and tumor-surrounding tissues from breast cancer patients.Our data indicates that hypomethylation of the ABCC1 promoter is not cancer type-specific but occurs in cancer cell lines of different origins.
In contrast, it had no effect on P-glycoprotein-mediated paclitaxel resistance in MDR1-transduced human leukemia K562 cells and multidrug resistance-related protein 1-mediated doxorubicin resistance in MRP1-transfected human epidermoid cancer KB-3-1 cells.
In the recent past it has been identified that various N(10)-substituted acridones can reverse the multidrug resistance (MDR) in cancer by selectively inhibiting the multidrug resistance associated protein (MRP) and calmodulin dependent cyclic AMP phosphodiesterase.