Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melanoma cells often display a multidrug-resistant phenotype, but the mechanisms involved are largely unknown. We have studied here the recently identified transport-associated proteins, MRP and LRP, and the well-known drug resistance marker P-glycoprotein using a panel of 16 human melanoma cell lines and 71 benign and malignant melanocytic tissue samples. By flow cytometry and immunohistochemistry, expression of P-glycoprotein was not detectable on the protein level in the 10 cell lines analyzed, although by reverse transcriptase polymerase chain reaction, MDR-1 gene expression was demonstrated in 2 of 10 cell lines. In addition, immunohistology revealed P-glycoprotein expression in only 1 of 71 melanocytic lesions. In contrast, MRP was detected in a subset of melanoma cell lines by reverse transcriptase polymerase chain reaction and immunohistology (4 of 10). LRP expression was observed in 8 of 10 melanoma cell lines by immunochemistry and in 10 of 10 by reverse transcriptase polymerase chain reaction. Furthermore, MRP was detected immunohistologically in almost 50% of primary and metastatic melanoma specimens, although no significant differences were found between metastases taken before or after chemotherapy. Expression of LRP was detected in a subset of nevi with nevus cells exhibiting up to 25% positive LRP reactivity. In 13 of 21 primary melanomas and 23 of 37 metastases, more than 25% of tumor cells were stained by the LRP-56 monoclonal antibody. Particularly in the group of metastases with more than 50% of LRP-positive cells, 7 of 11 of the metastases had been previously exposed to chemotherapeutic drugs. Although the expression of membrane transport proteins may explain only the chemoresistance toward lipophilic, natural compounds and not resistance against alkylating agents, the lack of P-glycoprotein expression after chemotherapeutic treatment and the significant expression of MRP and LRP in melanoma cells provide first insights into the drug-resistant phenotype in melanoma. Additional studies analyzing the role of MRP and LRP in chemoresistance of melanoma are warranted.
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PMID:Membrane transport proteins associated with drug resistance expressed in human melanoma. 749 78

Pluronic modified polyamidoamine (PAMAM) conjugate (PF127-PAMAM) was prepared and the inhibiting effect of MDR against MCF-7/ADR was investigated with doxorubicin (DOX) as model drug. 1H NMR and FTIR spectra showed that the conjugate was synthesized successfully. Element analysis accurately measured that 27.63% amino of per PAMAM was modified by pluronic (PAMAM : PF127, 1 : 35.37 mole ratio). PF127-PAMAM showed an increased size and a reduced zeta potential compared to PAMAM. PF127-PAMAM had lower hemolytic toxicity and cytotoxicity due to the reduced zeta potential and the protection of PF127. Each PF127-PAMAM molecular could load 19.58 DOX molecules, and the complex exhibited sustained and pH-sensitive release behavior. PF127-PAMAM/DOX exhibited weaker cytotoxicity than free DOX in MCF-7 cells; while the complex showed much stronger reverse effect of drug resistance in MCF-7/ADR cells, and resistance reversion index (RRI) was as high as 33.15.
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PMID:[Inhibition of MCF-7/ADR cells by DOX-loaded pluronic-attached PAMAM dendrimer conjugate]. 2532 63