TY - JOUR AU - Cheli, Yann AU - Tulic, Meri K. AU - El Hachem, Najla AU - Nottet, Nicolas AU - Jacquel, Arnaud AU - Gesson, Maeva AU - Strub, Thomas AU - Bille, Karine AU - Picard-Gauci, Alexandra AU - Montaudié, Henri AU - Beranger, Guillaume E. AU - Passeron, Thierry AU - Close, Pierre AU - Bertolotto, Corine AU - Ballotti, Robert PY - 2021 DA - 2021/01/07 TI - ITGBL1 is a new immunomodulator that favors development of melanoma tumors by inhibiting natural killer cells cytotoxicity JO - Molecular Cancer SP - 12 VL - 20 IS - 1 AB - Resistances to immunotherapies remains a major hurdle towards a cure for melanoma in numerous patients. An increase in the mesenchymal phenotype and a loss of differentiation have been clearly associated with resistance to targeted therapies. Similar phenotypes have been more recently also linked to resistance to immune checkpoint therapies. We demonstrated here that the loss of MIcrophthalmia associated Transcription Factor (MITF), a pivotal player in melanocyte differentiation, favors the escape of melanoma cells from the immune system. We identified Integrin beta-like protein 1 (ITGBL1), a secreted protein, upregulated in anti-PD1 resistant patients and in MITFlow melanoma cells, as the key immunomodulator. ITGBL1 inhibited immune cell cytotoxicity against melanoma cells by inhibiting NK cells cytotoxicity and counteracting beneficial effects of anti-PD1 treatment, both in vitro and in vivo. Mechanistically, MITF inhibited RUNX2, an activator of ITGBL1 transcription. Interestingly, VitaminD3, an inhibitor of RUNX2, improved melanoma cells to death by immune cells. In conclusion, our data suggest that inhibition of ITGBL1 might improve melanoma response to immunotherapies. SN - 1476-4598 UR - https://doi.org/10.1186/s12943-020-01306-2 DO - 10.1186/s12943-020-01306-2 ID - Cheli2021 ER -