Lesions with driver mutations, including atypical nevi and seborrheic keratoses, are very common in dermatology, and are prone to senescence. The molecular events that prevent senescent lesions from becoming malignant are not well understood. We have developed a model of vascular proliferation using a temperature-sensitive, large T antigen and oncogenic HRas. By elevating the temperature to 39 °C, we can turn off large T antigen and study the molecular events in cells with the Ras driver mutation. To assess the signaling events associated with the switch from a proliferative to a nonproliferative state in the constant presence of a driver oncogene, SVR cells were cultivated for 24 and 48 h and compared with SVR cells at 37 °C. Cells were evaluated by Western Blot (WB) gene chip microarray (GC) and quantitative reverse transcription polymerase chain reaction (RT-qPCR). Upon evaluation, a novel phenotype was observed in endothelial cells after switching off the large T antigen. This phenotype was characterized by Notch activation, downregulation of p38 phosphorylation, downregulation of the master immune switch IRF7, and downregulation of hnRNP A0. Switching off proliferative signaling may result in immune privilege and Notch activation, which may account, in part, for the survival of common skin lesions.
// Elgilda Musi 1 , Gary K. Schwartz 1 , 2 , Jae Hyuk Yoo 3 , Shannon J. Odelberg 3 , 4 , 6 , Dean Y. Li 3 , 5 , 6 , 7 , Michael Y. Bonner 8 , Ponniah Selvakumar 9 , Shikha Rao 8 , Linda C. Gilbert 8 , 10 , Justin Elsey 8 and Jack L. Arbiser 8 , 10 1 Department of Medicine, Columbia University Medical Center, New York, New York, USA 2 Herbert Irving Comprehensive Cancer Center, Columbia University College of Medicine, New York, New York, USA 3 Department of Medicine, Program in Molecular Medicine, University of Utah, Salt Lake City, Utah, USA 4 Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, USA 5 Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA 6 Department of Internal Medicine, Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah, USA 7 Department of Oncological Sciences, University of Utah, Salt Lake City, Utah, USA 8 Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia, USA 9 Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada 10 Veterans Affairs Medical Center, Decatur, Georgia, USA Correspondence to: Jack L. Arbiser, email: jarbise@emory.edu Keywords: melanoma; chemotherapy Received: April 09, 2019 Accepted: June 05, 2019 Published: July 09, 2019 ABSTRACT Uveal melanoma is a rare but often lethal malignancy and is the leading cause of death due to an ophthalmic condition. Uveal melanoma is often diagnosed at a late stage and has a strong propensity to hepatic metastasis. Recently, the most common driver mutations in uveal melanoma have been identified, predominantly in the G-proteins GNAQ. This pattern differs from that of cutaneous melanoma in which Braf and Nras predominate. There are no current clinically used agents that target GNAQ mutations, unlike the use of Braf inhibitors in cutaneous melanoma. We tested the novel agent Tris DBA palladium and found that it was markedly more effective against GNAQ mutant melanomas than wild type uveal melanomas. Given that ARF6 has recently been discovered as a node in GNAQ mutations, we evaluated the efficacy of Tris DBA palladium on ARF6 signaling and found that it was effective in inhibiting ARF6 activation. Finally, Tris DBA palladium was orally effective against GNAQ mutant melanoma in vivo . Tris DBA Palladium deserves further evaluation as a systemic agent for uveal melanoma.
Abstract Cancer is the second leading cause of death in the United States, and is an increasing cause of death in the developing world. While there is great heterogeneity in the anatomic site and mutations involved in human cancer, there are common features, including immortal growth, angiogenesis, apoptosis evasion, and other features, that are common to most if not all cancers. However, new features of human cancers have been found as a result of clinical use of novel “targeted therapies,” angiogenesis inhibitors, and immunotherapies, including checkpoint inhibitors. These findings indicate that cancer is a moving target, which can change signaling and metabolic features based upon the therapies offered. It is well-known that there is significant heterogeneity within a tumor and it is possible that treatment might reduce the heterogeneity as a tumor adapts to therapy and, thus, a tumor might be synchronized, even if there is no major clinical response. Understanding this concept is important, as concurrent and sequential therapies might lead to improved tumor responses and cures. We posit that the repertoire of tumor responses is both predictable and limited, thus giving hope that eventually we can be more effective against solid tumors. Currently, among solid tumors, we observe a response of 1/3 of tumors to immunotherapy, perhaps less to angiogenesis inhibition, a varied response to targeted therapies, with relapse and resistance being the rule, and a large fraction being insensitive to all of these therapies, thus requiring the older therapies of chemotherapy, surgery, and radiation. Tumor phenotypes can be seen as a continuum between binary extremes, which will be discussed further. The biology of cancer is undoubtedly more complex than duality, but thinking of cancer as a duality may help scientists and oncologists discover optimal treatments that can be given either simultaneously or sequentially.
