Cerezo-Wallis, D. | bioRxiv Science

bioRxiv2022

Systemic effects of melanoma-secreted MIDKINE in the inhibition of dendritic cell differentiation and function

Cutaneous melanomas are a prime example of potentially immunogenic tumors, and as such, ideal targets for immune therapy. These lesions have the largest mutational burden described to date, and accumulate a broad spectrum of post-transcriptional and translational alterations that could conceptually result in a plethora of neoantigens for immune recognition. However, a significant fraction of metastatic melanoma patients is or becomes resistant to current immunotherapeutic agents. How lesions that should represent an inherently hot milieu for immune attack shift into immunologically cold or irresponsive neoplasms is not well understood. Combining cellular systems, mouse models and clinical datasets, here we identify the growth factor Midkine (MDK) as a multipronged blocker of antigen presentation. Mechanistically, we found MDK to repress all main aspects of the maturation, activation and function of dendritic cells, particularly of conventional type 1 (cDC1). These roles of MDK were found to involve primary tumors and lymph nodes, and were traced back to suppressive effects on myeloid precursor cells in the bone marrow. Moreover, MDK shifted the transcriptional profile of DCs towards a tolerogenic state that prevented and bypassed CD8+ T cell activation. Blocking MDK enhanced the response to DC-based vaccination and improved the response to immune checkpoint blockade.Together, these data provide insight into how melanomas overcome immune surveillance and support MDK as a target for therapeutic intervention.

cancer biology↗

bioRxiv2019

Antimetastatic dsRNA mimics identified by live imaging of pathogenic neolymphangiogenesis

The crosstalk between cancer cells and the lymphatic vasculature has long been proposed to define competency for metastasis. Nevertheless, the discovery of selective blockers of lymphovascular niches has been compromised by the paucity of experimental systems for whole-body analyses of tumor progression. Here we present immunocompetent and immunodeficient mouse models for live imaging of melanoma-induced neolymphangiogenesis (driven by Vegfr3) as a cost-effective platform for drug screening in vivo. Spatio-temporal analyses in autochthonous melanomas and patient-derived xenografts identified double stranded RNA mimics (dsRNA nanoplexes) as potent repressors of lymphangiogenesis and metastasis. Mechanistically, dsRNA nanoplexes were found to suppress lymphangiogenic drivers in both tumor cells and their associated lymphatic vasculature (via MIDKINE and Vegfr3, respectively). This dual inhibitory action, driven by type I interferon, was not shared by FDA-approved antimelanoma treatments or by lymphangiogenic blockers in clinical testing. These results underscore the power of Vegfr3-lymphoreporters for pharmacological testing in otherwise aggressive cancers. RELEVANCEAlthough tumor-induced lymphangiogenesis has long been associated with metastasis, selective targeting of this process has been compromised by the paucity of experimental platforms for whole-body imaging of tumor progression and drug response. Here we present animal models engineered for spatio-temporal analyses of neolymphangiogenesis in clinically relevant autochthonous melanomas and patient-derived xenografts, and identify a unique action of double stranded-RNA nanoplexes as potent repressors of lymphatic dissemination and metastatic relapse.

cancer biology↗