Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3098
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Attempt to read property "Count" on bool
Filename: helpers/my_audit_helper.php
Line Number: 3100
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3100
Function: _error_handler
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Vemurafenib [N-(3-{[5-(4-chlorophenyl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl}-2,4-difluorophenyl)propane-1-sulfonamide(PLX4032)] is a novel small-molecule BRAF inhibitor, recently approved by the Food and Drug Administration for the treatment of patients with metastatic melanoma with a BRAF(V600E) mutation. The objective of this study was to investigate the role of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) in the distribution of vemurafenib to the central nervous system. In vitro studies conducted in transfected Madin-Darby canine kidney II cells show that the intracellular accumulation of vemurafenib is significantly restricted because of active efflux by P-gp and BCRP. Bidirectional flux studies indicated greater transport in the basolateral-to-apical direction than the apical-to-basolateral direction because of active efflux by P-gp and BCRP. The selective P-gp and BCRP inhibitors zosuquidar and (3S,6S,12aS)-1,2,3,4,6,7,12,12a-octahydro-9-methoxy-6-(2-methylpropyl)-1,4-dioxopyrazino(1',2':1,6)pyrido(3,4-b)indole-3-propanoic acid-1,1-dimethylethyl ester (Ko143) were able to restore the intracellular accumulation and bidirectional net flux of vemurafenib. The in vivo studies revealed that the brain distribution coefficient (area under the concentration time profile of brain/area under the concentration time profile of plasma) of vemurafenib was 0.004 in wild-type mice. The steady-state brain-to-plasma ratio of vemurafenib was 0.035 ± 0.009 in Mdr1a/b(-/-) mice, 0.009 ± 0.006 in Bcrp1(-/-) mice, and 1.00 ± 0.19 in Mdr1a/b(-/-)Bcrp1(-/-) mice compared with 0.012 ± 0.004 in wild-type mice. These data indicate that the brain distribution of vemurafenib is severely restricted at the blood-brain barrier because of active efflux by both P-gp and BCRP. This finding has important clinical significance given the ongoing trials examining the efficacy of vemurafenib in brain metastases of melanoma.
Download full-text PDF |
Source |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3383040 | PMC |
http://dx.doi.org/10.1124/jpet.112.192195 | DOI Listing |
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