A Platform of Synthetic Lethal Gene Interaction Networks Reveals that the GNAQ Uveal Melanoma Oncogene Controls the Hippo Pathway through FAK

Illuminating the Onco-GPCRome: Novel G protein-coupled receptor-driven oncocrine networks and targets for cancer immunotherapy

G protein-coupled receptors (GPCRs) are the largest gene family of cell membrane-associated molecules mediating signal transmission, and their involvement in key physiological functions is well-established. The ability of GPCRs to regulate a vast array of fundamental biological processes, such as cardiovascular functions, immune responses, hormone and enzyme release from endocrine and exocrine glands, neurotransmission, and sensory perception (e.g. vision, odor, and taste), is largely due to the diversity of these receptors and the layers of their downstream signaling circuits. Dysregulated expression and aberrant functions of GPCRs have been linked to some of the most prevalent human diseases, which renders GPCRs one of the top targets for pharmaceutical drug development. However, the study of the role of GPCRs in tumor biology has only just begun to make headway. Recent studies have shown that GPCRs can contribute to the many facets of tumorigenesis, including proliferation, survival, angiogenesis, invasion, metastasis, therapy resistance, and immune evasion. Indeed, GPCRs are widely dysregulated in cancer and yet are underexploited in oncology. We present here a comprehensive analysis of GPCR gene expression, copy number variation, and mutational signatures in 33 cancer types. We also highlight the emerging role of GPCRs as part of oncocrine networks promoting tumor growth, dissemination, and immune evasion, and we stress the potential benefits of targeting GPCRs and their signaling circuits in the new era of precision medicine and cancer immunotherapies.

PARP Inhibition Increases the Response to Chemotherapy in Uveal Melanoma

Uveal melanoma (UM) remains without effective therapy at the metastatic stage, which is associated with BAP-1 (BRCA1 associated protein) mutations. However, no data on DNA repair capacities in UM are available. Here, we use UM patient-derived xenografts (PDXs) to study the therapeutic activity of the PARP inhibitor olaparib, alone or in combination. First, we show that the expression and the activity of PARP proteins is similar between the PDXs and the corresponding patient’s tumors. In vivo experiments in the PDX models showed that olaparib was not efficient alone, but significantly increased the efficacy of dacarbazine. Finally, using reverse phase protein arrays and immunohistochemistry, we identified proteins involved in DNA repair and apoptosis as potential biomarkers predicting response to the combination of olaparib and dacarbazine. We also observed a high increase of phosphorylated YAP and TAZ proteins after dacarbazine + olaparib treatment. Our results suggest that PARP inhibition in combination with the alkylating agent dacarbazine could be of clinical interest for UM treatment. We also observe an interesting effect of dacarbazine on the Hippo pathway, confirming the importance of this pathway in UM.

AACR 2019 — Congrès de l’association américaine de recherche contre le cancer

Dans ce numéro spécial de la revueOncologie, les principaux points discutés au congrès de l’Association américaine pour la recherche sur le cancer (AACR) sont rapportés. L’objectif ici est de présenter de manière concise des exposés qui méritent une attention toute particulière. Le programme de la réunion de l’AACR de cette année, qui a eu lieu à Atlanta, a couvert les dernières découvertes de tout le spectre de la recherche sur le cancer — des sciences de la population à la prévention ; biologie du cancer, études translationnelles et cliniques ; à la survie et à la défense des droits — et souligne le travail des meilleurs esprits en matière de recherche et de médecine d’institutions du monde entier. Le congrès qui a duré cinq jours a proposé un programme multidisciplinaire couvrant tous les aspects de la recherche sur le cancer depuis ses bases fondamentales jusqu’à ses applications translationnelles et cliniques. Grâce à notre compréhension accrue des bases moléculaires du cancer, de nombreuses thérapies ciblées nouvelles ont émergé. Ainsi, notre compréhension sur la façon dont les tumeurs échappent aux attaques du système immunitaire a conduit au développement de nouvelles thérapies. Compte tenu de l’importance accrue de l’immunothérapie dans le traitement du cancer, nous présentons ici les dernières avancées dans ce domaine. Enfin, d’autres approches telles que l’étude du microbiome, l’épigénétique et l’intelligence artificielle comme un outil dans la recherche sur le cancer ont aussi été discutées au congrès de l’AACR 2019.