Development of New Therapeutic Combinations for Ovarian Cancer Using Genetically Defined, Syngeneic Organoid Platform. Development of New Therapeutic Combinations for Ovarian Cancer Using Genetically Defined, Syngeneic Organoid Platform

The paucity of genetically informed, immune-competent tumor models impedes evaluation of conventional, targeted, and immune therapies. By engineering mouse fallopian tube (FT) organoids using lentiviral gene transduction and/or CRISPR/Cas9 mutagenesis, we generated multiple high grade serous ovarian carcinoma (HGSOC) models exhibiting combinations of mutations seen in patients. Detailed analysis of homologous recombination (HR)-proficient (Tp53-/-;Ccne1OE;Akt2OE ;KrasOE), HR-deficient (Tp53-/-;Brca1-/-;MycOE ) and unclassified (Tp53-/-;Pten-/-;Nf1-/-) examples revealed differences in in vitro properties and tumorigenicity/metastasis. Tumorigenic organoids had differential sensitivity to HGSOC chemotherapeutics and evoked distinct immune microenvironments. These findings enabled development of a chemotherapy/immunotherapy regimen that yielded durable, T-cell dependent responses in Tp53-/-;Ccne1OE;Akt2OE;Kras HGSOC; by contrast, Tp53-/-;Pten-/-;Nf1-/- tumors failed to respond. Genotype-informed, syngeneic organoid models could provide an improved platform for rapid evaluation of tumor biology and therapeutics. Overall design: mRNA profiles of 4 independent tumors derived from organoid injection of Tp53-/-;Ccne1OE;Akt2OE;KrasOE, Tp53-/-;Pten-/-;Nf1-/- and Tp53-/-;Brca1-/-;MycOE, respectively.