PKA drives paracrine crisis and WNT4-dependent testis tumor in Carney complex

Large Cell Calcifying Sertoli Cell Tumors (LCCSCTs) are among the most frequent lesions occurring in Carney complex (CNC) male patients. Although they constitute a key diagnostic criterion for this rare multiple neoplasia syndrome resulting from inactivating mutations of the tumor suppressor PRKAR1A leading to unrepressed PKA activity, the LCCSCT pathogenesis and origin remain elusive. Mouse models targeting Prkar1a inactivation in all somatic populations or separately in each cell type were generated to decipher the molecular and paracrine networks involved in the CNC testis lesion induction. We demonstrate that Prkar1a mutation is required in both stromal and Sertoli cells for the occurrence of LCCSCT. Integrative analyses comparing transcriptomic, immunohistological data and phenotype of mutant mouse combinations led to understand the human LCCSCT pathogenesis and demonstrated unprecedented PKA-induced paracrine molecular circuits in which the aberrant WNT4 signal production is a limiting step in shaping intratubular lesions and tumor expansion both in mouse model and human CNC testes.