miR-214 and miR-148-driven metabolic alterations in tumor progression and chimeric aptamer-based targeted therapy

Background Cancer usually leads to patient death because cells can detach from primary tumors and form metastases in distant organs. Malignant Melanoma (MM) and malignant Breast Cancer (BC), in particular Triple Negative (TN) BC, are highly aggressive neoplasia and often fatal because of frequent dissemination in distant organs since specific therapies are still missing. Tumor invasiveness depends on the capability of cancer cells to detach from the primary mass however it is not cell autonomous since the microenvironment plays a major role here. In fact, the acquisition of malignancy is based on the alteration of metabolic and migration/invasion features linked to the cross-talk between tumor and stroma cells. Deregulation of microRNAs (miRs) is strongly impacting the control of metastatic traits. Hypothesis We identified miR-214 and miR-148b as, respectively, upregulated and downregulated in MM and malignant BC and unravelled the pro-metastatic role of miR-214 and the protective anti-metastatic function of miR-148b. We observed that miR-214 acts via a complex molecular network of direct and indirect targets, including transcription factors, adhesion molecules as well as miR-148b, which is negatively regulated by miR-214. We evidenced that miR-214 is upregulated not only in tumor cells but also in the stroma counterparts and that the stromal miR-214 controls metastasis formation. We learned that tumor cells can stimulate miR-214 expression in stroma cells via the IL-6/STAT-3 signalling. miRs have been found involved in cancer metabolism. We made the hypothesis that miR-214 and miR-148b could coordinate tumor metabolic features and that stromal miR- 214 could affect tumor cell metabolism thus leading to malignancy and dissemination. We hypothesized that miR-214 and miR-148b as well as specific metabolic players could act as therapeutic targets. Aims We aim at: (1) investigating how miR-214 and miR-148b act on tumor metabolic features and how metabolic changes can coordinate tumor progression; (2) understanding the role of stroma miR-214 in the control of metabolism and metastasis formation; (3) generating stable aptamer-based conjugates to target miR-214, miR- 148b and metabolic players specifically in tumor or stroma cells to transfer to the clinics. Experimental Design We will: (1) perform metabolic and molecular analyses of tumor cells alone or in co-culture with stroma cells or treated with Conditioned Medium (CM) or Extracellular Vesicles (EVs) derived from stroma components, following miR-214/miR-148b modulations; (2) conduct metabolic and molecular investigations (including single-cell and spatial transcriptomic analyses) of xenotransplants/metastases generated by control or miR- 214/miR-148b-modulated cells in wild type or miR-214OVER/miR-214KO mice; (3) generate and apply stable tumor/stroma cell specific aptamer-based conjugates to target miR-214, miR-148b and metabolic players. Expected Results We expect to: (1) understand the link between miR-214/miR-148b (tumor/stroma cells), metabolism modulations and metastasis formation; (2) unravel the molecular mechanism behind these regulations; (3) develop stable chimeric aptamers to specifically hit tumor/stroma cells to target miR-214, miR-148b and metabolic players for a transfer to the clinics. Impact On Cancer This research will reveal new mechanisms of cancer progression linked to metabolic alterations driven by miR- 214/miR-148b in tumor or stoma cells and will generate cell-specific therapeutic tools with good potential for clinical trials.