Papers by Justine Paradis

Experimental and Molecular Therapeutics, Aug 13, 2020
Uveal melanoma (UM) is characterized by gain-of-function mutations in GNAQ or GNA11, encoding Gα ... more Uveal melanoma (UM) is characterized by gain-of-function mutations in GNAQ or GNA11, encoding Gα proteins from the Gq/11 family. UM is the most common eye malignancy in adults. Approximately 50% of UM patients develop liver metastasis (mUM) within 5-10 years after diagnosis, independently of the successful treatment of the primary lesions. mUM is refractory to cytotoxic, targeted, and immunotherapies, with most mUM patients dying within a year. Recent information suggests that GNAQ-oncogenic signaling involves a non-canonical pathway distinct from the activation of PLCβ and PKC-MEK-ERK, which may explain the failure of MEK inhibitors (MEKi) in increasing mUM patient survival. Instead, we found that GNAQ promotes the activation of YAP1, a key oncogenic driver, by a mechanism involving the activation of RhoA by the direct association of Gαq to TRIO, a Rho-GEF (Cancer Cell, 2014). In turn, YAP1 is essential for uveal melanoma cell growth, however no effective and safe YAP1 inhibitors are currently available. Using a novel bioinformatics pipeline, we recently found that PTK2, encoding Focal Adhesion Kinase (FAK), is a synthetic lethal gene with GNAQ activation, and uncovered that GNAQ controls YAP1 through FAK (Cancer Cell, 2019). This study identified FAK as a druggable signaling hub downstream from GNAQ in UM. However, activation of compensatory pathways often results in resistance to targeted agents. Here, we combined the use of CRISPR-Cas9 sgRNA screens with a recently described Cancer Signaling Toolkit approach to identify synthetic lethal interactions enhancing the response to FAKi and signaling networks mediating drug resistance, respectively. Remarkably, both approaches converged to reveal that co-targeting FAK and the MEK-ERK pathway would be a promising combination for treatment of UM. Indeed, MEK-ERK pathway inhibition by multiple approved MEKis (e.g., trametinib), combined with FAK inhibition (VS-4718 or defactinib), showed remarkable synergistic growth inhibitory effects in UM cells. Additionally, the novel RAF/MEK inhibitor RO5126766 also showed synergistic anti-proliferative effects with defactinib. Accordingly, FAKi combination with MEKi exerted cytotoxic effects (apoptotic death) leading to rapid tumor shrinkage in UM xenografts, whereas single drugs were primarily cytostatic. Furthermore, the FAKi/MEKi combination was successful at reducing tumor burden in recently developed liver metastasis UM models. By coupling the unique genetic landscape of UM with the power of unbiased computational pipelines and systems biology genetic screens, our studies revealed that FAK and MEK-ERK co-targeting may provide a new network-based precision therapeutic strategy for mUM treatment. Indeed, the combination of defactinib and RO5126766 is currently being evaluated in patients with various solid tumors (NCT03875820), and could be explored in mUM based on these preclinical findings. Citation Format: Justine S. Paradis, Monica Acosta, Nadia Arang, Robert Saddawi-Konefka, Ayush Kishore, Takahito Sugase, Xiaodong Feng, Kris C. Wood, Silvia Coma, Mizue Terai, Takami Sato, Jonathan A. Pachter, J. Silvio Gutkind. FAK and MEK co-targeting: A new multimodal precision therapy for GNAQ-driven uveal melanoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6406.
Supplementary figure S1. Synthetic lethality of FAK and ERK/MAPK pathway inhibition.
Supplementary Figure S4. MEKi/FAKi combination reduces B2905 syngeneic cells growth in allograft ... more Supplementary Figure S4. MEKi/FAKi combination reduces B2905 syngeneic cells growth in allograft tumor models.
Supplementary figure 3. MEKi/FAKi combination reduces UM cells growth in xenograft tumor models w... more Supplementary figure 3. MEKi/FAKi combination reduces UM cells growth in xenograft tumor models with limited toxicity.
Thèse présentée en vue de l'obtention du grade de Philosophiae Doctor (Ph.D) en Biologie Molécula... more Thèse présentée en vue de l'obtention du grade de Philosophiae Doctor (Ph.D) en Biologie Moléculaire option Biologie des Systèmes Avril 2017

Cancer Research, Jul 1, 2021
The RAS/RAF/MEK/ERK pathway is the most mutated oncogenic pathway in cancer, and RAS pathway muta... more The RAS/RAF/MEK/ERK pathway is the most mutated oncogenic pathway in cancer, and RAS pathway mutations often present with an overall worse prognosis. Although RAF and MEK have been validated as anticancer targets and several BRAF and MEK inhibitors (MEKi) are FDA approved, acquired resistance develops in most patients. Preclinically, inhibition of RAF or MEK has been found to activate focal adhesion kinase (FAK) signaling which may bypass RAS pathway blockade by driving tumor growth through activation of downstream pathways such as RhoA and YAP. VS-6766 is a unique dual RAF/MEK inhibitor which allows VS-6766 to block MEK signaling without the compensatory MEK activation that limits the efficacy of other MEK inhibitors. Defactinib is a selective FAK inhibitor (FAKi). Clinical studies are ongoing evaluating VS-6766 and defactinib for the treatment of various solid tumors. In 3D proliferation assays in vitro, defactinib was synergistic with VS-6766 or trametinib (MEKi) in reducing viability of several human tumor cell lines, including KRAS mutant (mt) ovarian cancer (TOV-21G) and KRAS-G12V mt non-small cell lung cancer (NSCLC; H441). We next investigated whether FAKi augments the efficacy of VS-6766 in solid tumor models. Combination of a FAKi with VS-6766 in a KRAS mt ovarian xenograft model (TOV21G) induced >30% tumor regression in 9/10 mice, whereas each agent alone induced mainly tumor stasis (>30% tumor regression with FAKi monotherapy or VS-6766 monotherapy in 1/10 and 3/10 mice, respectively) following 11 days of treatment. Similar results were observed in KRAS mt NSCLC (H2122) and GNAQ mt uveal melanoma (92.1) models in which the combination of FAKi with VS-6766 or trametinib induced tumor regression. In several patients with KRAS mt tumors, sequential biopsies showed that treatment with VS-6766 induced FAK activation (pY397) as a potential resistance mechanism, and this increased FAK activation was reversed in the presence of the defactinib/VS-6766 combination. Accordingly, the combination of VS-6766 with defactinib showed clinical activity in low grade serous ovarian cancer (LGSOC; ORR = 56% in KRAS-G12 mt and ORR = 41% in all 17 LGSOC patients; 8/17/20 data cut off). Importantly, the combination of defactinib with VS-6766 also induced responses in patients who had progressed on previous MEK inhibitor regimens. VS-6766 with defactinib also showed clinical activity in KRAS-G12V mt NSCLC. Furthermore, this combination regimen of VS-6766 with defactinib exhibited a manageable safety profile with no patients discontinuing for adverse events (NCT03875820). These preclinical and clinical data support the recent initiation of two registration-directed studies evaluating VS-6766 ± defactinib for the treatment of recurrent LGSOC with or without a KRAS mutation (NCT04625270) and recurrent NSCLC with KRAS-G12V or other KRAS mutation (NCT04620330). Citation Format: Silvia Coma, Justine S. Paradis, J Silvio Gutkind, Jonathan A. Pachter. Synergistic antitumor efficacy of the dual RAF/MEK inhibitor VS-6766 with FAK inhibition for treatment of RAS-dependent solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1425.
Journal of Biological Chemistry

Purpose: Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients wi... more Purpose: Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients with uveal melanoma develop metastatic uveal melanoma (mUM) in the liver, even after successful treatment of the primary lesions. mUM is refractory to current chemo-and immune-therapies, and most mUM patients die within a year. Uveal melanoma is characterized by gain-of-function mutations in GNAQ/GNA11, encoding Gaq proteins. We have recently shown that the Gaq-oncogenic signaling circuitry involves a noncanonical pathway distinct from the classical activation of PLCb and MEK-ERK. GNAQ promotes the activation of YAP1, a key oncogenic driver, through focal adhesion kinase (FAK), thereby identifying FAK as a druggable signaling hub downstream from GNAQ. However, targeted therapies often activate compensatory resistance mechanisms leading to cancer relapse and treatment failure. Experimental Design: We performed a kinome-wide CRISPR-Cas9 sgRNA screen to identify synthetic lethal gene interactions that can be exploited therapeutically. Candidate adaptive resistance mechanisms were investigated by cotargeting strategies in uveal melanoma and mUM in vitro and in vivo experimental systems. Results: sgRNAs targeting the PKC and MEK-ERK signaling pathways were significantly depleted after FAK inhibition, with ERK activation representing a predominant resistance mechanism. Pharmacologic inhibition of MEK and FAK showed remarkable synergistic growth-inhibitory effects in uveal melanoma cells and exerted cytotoxic effects, leading to tumor collapse in uveal melanoma xenograft and liver mUM models in vivo. Conclusions: Coupling the unique genetic landscape of uveal melanoma with the power of unbiased genetic screens, our studies reveal that FAK and MEK-ERK cotargeting may provide a new network-based precision therapeutic strategy for mUM treatment.
Supplementary figure S2. Isobologram analysis.
Supplementary figure S1. Synthetic lethality of FAK and ERK/MAPK pathway inhibition.
Supplementary figure 3. MEKi/FAKi combination reduces UM cells growth in xenograft tumor models w... more Supplementary figure 3. MEKi/FAKi combination reduces UM cells growth in xenograft tumor models with limited toxicity.

Purpose:Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients wit... more Purpose:Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients with uveal melanoma develop metastatic uveal melanoma (mUM) in the liver, even after successful treatment of the primary lesions. mUM is refractory to current chemo- and immune-therapies, and most mUM patients die within a year. Uveal melanoma is characterized by gain-of-function mutations in GNAQ/GNA11, encoding Gαq proteins. We have recently shown that the Gαq–oncogenic signaling circuitry involves a noncanonical pathway distinct from the classical activation of PLCβ and MEK–ERK. GNAQ promotes the activation of YAP1, a key oncogenic driver, through focal adhesion kinase (FAK), thereby identifying FAK as a druggable signaling hub downstream from GNAQ. However, targeted therapies often activate compensatory resistance mechanisms leading to cancer relapse and treatment failure.Experimental Design:We performed a kinome-wide CRISPR-Cas9 sgRNA screen to identify synthetic lethal gene interactio...
Supplementary Figure S4. MEKi/FAKi combination reduces B2905 syngeneic cells growth in allograft ... more Supplementary Figure S4. MEKi/FAKi combination reduces B2905 syngeneic cells growth in allograft tumor models.

Cells
Parkinson’s disease (PD) patients suffer not only from the primary motor symptoms of the disease ... more Parkinson’s disease (PD) patients suffer not only from the primary motor symptoms of the disease but also from a range of non-motor symptoms (NMS) that cause disability and low quality of life. Excessive glutamate activity in the basal ganglia resulting from degeneration of the nigrostriatal dopamine pathway has been implicated in the motor symptoms, NMS and dyskinesias in PD patients. In this study, we investigated the effects of a selective mGlu5 negative allosteric modulator (NAM), dipraglurant, in a rodent motor symptoms model of PD, but also in models of anxiety, depression and obsessive-compulsive disorder, all of which are among the most prevalent NMS symptoms. Dipraglurant is rapidly absorbed after oral administration, readily crosses the blood-brain barrier, and exhibits a high correlation between plasma concentration and efficacy in behavioral models. In vivo, dipraglurant dose-dependently reduced haloperidol-induced catalepsy, increased punished licks in the Vogel conflic...

Cancer Research, 2021
The RAS/RAF/MEK/ERK pathway is the most mutated oncogenic pathway in cancer, and RAS pathway muta... more The RAS/RAF/MEK/ERK pathway is the most mutated oncogenic pathway in cancer, and RAS pathway mutations often present with an overall worse prognosis. Although RAF and MEK have been validated as anticancer targets and several BRAF and MEK inhibitors (MEKi) are FDA approved, acquired resistance develops in most patients. Preclinically, inhibition of RAF or MEK has been found to activate focal adhesion kinase (FAK) signaling which may bypass RAS pathway blockade by driving tumor growth through activation of downstream pathways such as RhoA and YAP. VS-6766 is a unique dual RAF/MEK inhibitor which allows VS-6766 to block MEK signaling without the compensatory MEK activation that limits the efficacy of other MEK inhibitors. Defactinib is a selective FAK inhibitor (FAKi). Clinical studies are ongoing evaluating VS-6766 and defactinib for the treatment of various solid tumors. In 3D proliferation assays in vitro, defactinib was synergistic with VS-6766 or trametinib (MEKi) in reducing viab...
Thèse présentée en vue de l'obtention du grade de Philosophiae Doctor (Ph.D) en Biologie Molécula... more Thèse présentée en vue de l'obtention du grade de Philosophiae Doctor (Ph.D) en Biologie Moléculaire option Biologie des Systèmes Avril 2017

Clinical Cancer Research, 2021
Purpose:Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients wit... more Purpose:Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients with uveal melanoma develop metastatic uveal melanoma (mUM) in the liver, even after successful treatment of the primary lesions. mUM is refractory to current chemo- and immune-therapies, and most mUM patients die within a year. Uveal melanoma is characterized by gain-of-function mutations in GNAQ/GNA11, encoding Gαq proteins. We have recently shown that the Gαq–oncogenic signaling circuitry involves a noncanonical pathway distinct from the classical activation of PLCβ and MEK–ERK. GNAQ promotes the activation of YAP1, a key oncogenic driver, through focal adhesion kinase (FAK), thereby identifying FAK as a druggable signaling hub downstream from GNAQ. However, targeted therapies often activate compensatory resistance mechanisms leading to cancer relapse and treatment failure.Experimental Design:We performed a kinome-wide CRISPR-Cas9 sgRNA screen to identify synthetic lethal gene interactio...

Communication across membranes controls critical cellular processes and is achieved by receptors ... more Communication across membranes controls critical cellular processes and is achieved by receptors translating extracellular signals into selective cytoplasmic responses. While receptor tertiary structures can now be readily characterized, receptor associations into quaternary structures are very challenging to study and their implications in signal transduction remain poorly understood. Here, we report a computational approach for predicting membrane receptor self-associations, and designing receptor oligomers with various quaternary structures and signaling properties. Using this approach, we designed chemokine receptor CXCR4 dimers with reprogrammed stabilities, conformations, and abilities to activate distinct intracellular signaling proteins. In agreement with our predictions, the designed CXCR4s dimerized through distinct conformations and displayed different quaternary structural changes upon activation. Consistent with the active state models, all engineered CXCR4 oligomers ac...
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Papers by Justine Paradis