Cancer Therapy : Preclinical Vemurafenib SynergizeswithNutlin-3 toDeplete Survivin and Suppresses Melanoma Viability and Tumor Growth

Purpose: For patients with advanced melanoma, primary and secondary resistance to selective BRAF inhibition remains one of the most critically compelling challenges. One rationale argues that novel biologically informed strategies are needed to maximally cripple melanoma cells up front before compensatory mechanisms emerge. As p53 is uncommonly mutated in melanoma, restoration of its function represents an attractive adjunct to selective BRAF inhibition. Experimental Design: Thirty-seven BRAF(V600E)-mutated melanoma lines were subjected to synergy studies in vitro using a combination of vemurafenib and nutlin-3 (Nt-3). In addition, cellular responses and in vivo efficacy were also determined. We also analyzed changes in the levels of canonical apoptotic/survival factors in response to vemurafenib. Results: Dual targeting of BRAF(V600E) and Hdm2 with vemurafenib and Nt-3, respectively, synergistically induced apoptosis and suppressedmelanoma viability in vitro and tumor growth in vivo. Suppression of p53 in melanoma cells abrogated Nt-30s effects fully and vemurafenib’s effects partially. A survey of canonical survival factors revealed that both vemurafenib and Nt-3 independently attenuated levels of the antiapoptotic protein, survivin. Genetic depletion of survivin reproduces the cytotoxic effects of the combination strategy. Conclusion: These results show preclinical feasibility for overcoming primary vemurafenib resistance by restoring p53 function. Moreover, it identifies survivin as one downstream mediator of the observed synergism and a potential secondary target. Clin Cancer Res; 19(16); 4383–91. 2013 AACR.

[1]  K. Flaherty,et al.  Phase I study of PLX4032: Proof of concept for V600E BRAF mutation as a therapeutic target in human cancer. , 2016, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[2]  K. Flaherty,et al.  Combined BRAF and MEK inhibition in melanoma with BRAF V600 mutations. , 2012, The New England journal of medicine.

[3]  Hubing Shi,et al.  MDM4 is a key therapeutic target in cutaneous melanoma , 2012, Nature Medicine.

[4]  J. Becker,et al.  Survivin-specific T-cell reactivity correlates with tumor response and patient survival: a phase-II peptide vaccination trial in metastatic melanoma , 2012, Cancer Immunology, Immunotherapy.

[5]  K. Flaherty,et al.  p53 rescue through HDM2 antagonism suppresses melanoma growth and potentiates MEK inhibition. , 2012, The Journal of investigative dermatology.

[6]  D. Grossman,et al.  Role of the apoptotic and mitotic regulator survivin in melanoma. , 2012, Anticancer research.

[7]  S. Nelson,et al.  Melanoma whole exome sequencing identifies V600EB-RAF amplification-mediated acquired B-RAF inhibitor resistance , 2012, Nature Communications.

[8]  Tom Misteli,et al.  RAF inhibitor resistance is mediated by dimerization of aberrantly spliced BRAF(V600E) , 2011, Nature.

[9]  Nikhil Wagle,et al.  Dissecting therapeutic resistance to RAF inhibition in melanoma by tumor genomic profiling. , 2011, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[10]  V. Sondak,et al.  PTEN loss confers BRAF inhibitor resistance to melanoma cells through the suppression of BIM expression. , 2011, Cancer research.

[11]  John Kirkwood,et al.  A multi-center phase II evaluation of the small molecule survivin suppressor YM155 in patients with unresectable stage III or IV melanoma , 2011, Investigational New Drugs.

[12]  S. Nelson,et al.  Melanomas acquire resistance to B-RAF(V600E) inhibition by RTK or N-RAS upregulation , 2010, Nature.

[13]  Damien Kee,et al.  Acquired resistance to BRAF inhibitors mediated by a RAF kinase switch in melanoma can be overcome by cotargeting MEK and IGF-1R/PI3K. , 2010, Cancer cell.

[14]  Marc Vidal,et al.  COT/MAP3K8 drives resistance to RAF inhibition through MAP kinase pathway reactivation , 2010, Nature.

[15]  T. Chou.  Drug combination studies and their synergy quantification using the Chou-Talalay method. , 2010, Cancer research.

[16]  Kam Y. J. Zhang,et al.  Discovery of a selective inhibitor of oncogenic B-Raf kinase with potent antimelanoma activity , 2008, Proceedings of the National Academy of Sciences.

[17]  A. Iafrate,et al.  Identification of genotype-correlated sensitivity to selective kinase inhibitors by using high-throughput tumor cell line profiling , 2007, Proceedings of the National Academy of Sciences.

[18]  M. Andreeff,et al.  Regulation of survivin expression through Bcr-Abl/MAPK cascade: targeting survivin overcomes imatinib resistance and increases imatinib sensitivity in imatinib-responsive CML cells. , 2006, Blood.

[19]  Guang Yang,et al.  Recurrent patterns of dual RB and p53 pathway inactivation in melanoma. , 2005, The Journal of investigative dermatology.

[20]  F. Haluska,et al.  Genetic interaction between NRAS and BRAF mutations and PTEN/MMAC1 inactivation in melanoma. , 2004, The Journal of investigative dermatology.

[21]  Jiandong Chen,et al.  Transcriptional Repression of the Anti-apoptoticsurvivin Gene by Wild Type p53* , 2002, The Journal of Biological Chemistry.

[22]  J. Wisell,et al.  Improved Survival with MEK Inhibition in BRAF-Mutated Melanoma , 2013 .

[23]  T. Eberlein,et al.  Improved Survival with Vemurafenib in Melanoma with BRAF V600E Mutation , 2012 .

[24]  A. Almasan,et al.  Apoptosis assays. , 2006, Methods in molecular medicine.