title: PLX4032 Mediated Melanoma Associated Antigen Potentiation in Patient Derived Primary Melanoma Cells.
abstract: Over expression of various immunogenic melanoma associated antigens (MAAs) has been exploited in the development of immunotherapeutic melanoma vaccines. Expression of MAAs such as MART-1 and gp100 is modulated by the MAPK signaling pathway, which is often deregulated in melanoma. The protein BRAF, a member of the MAPK pathway, is mutated in over 60% of melanomas providing an opportunity for the identification and approval by the FDA of a small molecule MAPK signaling inhibitor PLX4032 that functions to inactivate mutant BRAF(V600E). To this end, we characterized five patient derived primary melanoma cell lines with respect to treatment with PLX4032. Cells were treated with 5μM PLX4032 and harvested. Western blotting analysis, RT-PCR and in vitro transwell migration and invasion assays were utilized to determine treatment effects. PLX4032 treatment modulated phosphorylation of signaling proteins belonging to the MAPK pathway including BRAF, MEK, and ERK and abrogated cell phenotypic characteristics such as migration and invasion. Most significantly, PLX4032 led to an up regulation of many MAA proteins in three of the four BRAF mutated cell lines, as determined at the protein and RNA level. Interestingly, MAGE-A1 protein and mRNA levels were reduced upon PLX4032 treatment in two of the primary lines. Taken together, our findings suggest that the BRAF(V600E) inhibitor PLX4032 has therapeutic potential over and above its known target and in combination with specific melanoma targeting vaccine strategies may have further clinical utility.
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595;
authors.forename: Andrea L
authors.initials: AL
authors.lastname: George
authors.affiliation: 2. College of Mount Saint Vincent, Division of Natural Sciences, Bronx, New York, 10471;
authors.forename: Robert
authors.initials: R
authors.lastname: Suriano
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595;
authors.forename: Shilpi
authors.initials: S
authors.lastname: Rajoria
authors.affiliation: 4. McDaniel College, Westminster, Maryland 21157;
authors.forename: Maria C
authors.initials: MC
authors.lastname: Osso
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595;
authors.forename: Neha
authors.initials: N
authors.lastname: Tuli
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595;
authors.forename: Elyse
authors.initials: E
authors.lastname: Hanly
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595;
authors.forename: Jan
authors.initials: J
authors.lastname: Geliebter
authors.affiliation: 5. Westchester Medical Center, Transplant Immunogenetics Laboratory, Valhalla, New York, 10595.
authors.forename: Angelo N
authors.initials: AN
authors.lastname: Arnold
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595; ; 3. Metropolitan Hospital Center GNS, Department of Surgery, New York, New York, 10029;
authors.forename: Marc
authors.initials: M
authors.lastname: Wallack
authors.affiliation: 1. New York Medical College, Department of Microbiology and Immunology, Valhalla, New York, 10595;
authors.forename: Raj K
authors.initials: RK
authors.lastname: Tiwari
keywords: BRAF Kinases; MAPK; Melanoma; Melanoma Associated Antigens; PLX4032; Vaccine.