I did have one reported BRAF mutation, but it's G466E (not V600E). According to UCSF, Roche apparently is finding that a few mutations close to V600E would also indicate use of their BRAF inhibitor (PLX4032) but G466E (which may show up in older literature as G465) is pretty far away. UCSF thinks that a MEK inhibitor may be a reasonable match for the G466E mutation, they'll be thinking about that as a post-IL2 treatment option.
Based on the full results of the BRAF test, UCSF fully supports a course of IL-2 to see if I'm a responder.
From http://www.biomedcentral.com/1472-6807/9/47: Recently, large-scale genomic screens have detected mutations in B-RAF in about 70% of malignant melanomas and at a lower frequency in colorectal and ovarian cancers [2]. Other cancer types have been found to harbour B-RAF mutations. Over 40 mutations have already been identified [3,4]. Some of these mutants, B-RAFE586K, B-RAFV600E, B-RAFV600D, B-RAFV600K, B-RAFV600R and B-RAFK601E, have a much higher kinase activity in vitro than the basal wild type B-RAF (B-RAFWT) activity and were classified as strongly activating [4]. Mutations at nine amino acid positions that are less activating, but exhibit activity above the basal, belong to an intermediate activity group [4]. Although most B-RAF mutants display elevated kinase activity compared to the B-RAFWT, four cancer-derived mutants have reduced kinase activity: B-RAFG466E, B-RAFG466V, B-RAFG596R and B-RAFD594V [3,4].
From http://jcem.endojournals.org/cgi/content/full/93/11/4398: Functionally, cancer-associated BRAF mutants can be divided into three categories: high activity (exemplified by V600E in the A-loop), low activity (exemplified by G466E/V in the P-loop and G596R in the A-loop), and rare impaired activity (exemplified by D594V in the A-loop) (14, 15). These mutants differ in the extent and mechanism of MAPK kinase (MEK), the BRAF downstream kinase, activation. Low-activity mutants, which have impaired MEK kinase activity, can activate MEK indirectly by binding and allosterically activating CRAF. High-activity BRAF mutants signal directly to MEK (although they can also activate MEK through CRAF). No effect has yet been ascribed to impaired-activity BRAF mutants.
Based on the full results of the BRAF test, UCSF fully supports a course of IL-2 to see if I'm a responder.
From http://www.biomedcentral.com/1472-6807/9/47: Recently, large-scale genomic screens have detected mutations in B-RAF in about 70% of malignant melanomas and at a lower frequency in colorectal and ovarian cancers [2]. Other cancer types have been found to harbour B-RAF mutations. Over 40 mutations have already been identified [3,4]. Some of these mutants, B-RAFE586K, B-RAFV600E, B-RAFV600D, B-RAFV600K, B-RAFV600R and B-RAFK601E, have a much higher kinase activity in vitro than the basal wild type B-RAF (B-RAFWT) activity and were classified as strongly activating [4]. Mutations at nine amino acid positions that are less activating, but exhibit activity above the basal, belong to an intermediate activity group [4]. Although most B-RAF mutants display elevated kinase activity compared to the B-RAFWT, four cancer-derived mutants have reduced kinase activity: B-RAFG466E, B-RAFG466V, B-RAFG596R and B-RAFD594V [3,4].
From http://jcem.endojournals.org/cgi/content/full/93/11/4398: Functionally, cancer-associated BRAF mutants can be divided into three categories: high activity (exemplified by V600E in the A-loop), low activity (exemplified by G466E/V in the P-loop and G596R in the A-loop), and rare impaired activity (exemplified by D594V in the A-loop) (14, 15). These mutants differ in the extent and mechanism of MAPK kinase (MEK), the BRAF downstream kinase, activation. Low-activity mutants, which have impaired MEK kinase activity, can activate MEK indirectly by binding and allosterically activating CRAF. High-activity BRAF mutants signal directly to MEK (although they can also activate MEK through CRAF). No effect has yet been ascribed to impaired-activity BRAF mutants.
Comments
Post a Comment