Fig. 5: Cdk6-deficiency inhibits tumor growth in vivo and vitro and activates type I interferon pathway.

a Vector and Cdk6^−/− MCA205 tumor growth curve in C57BL/6 N mice. Vector or two clones of Cdk6^−/− (A43 and A57) MCA205 tumor cells were transplanted subcutaneously on the right flank of C57BL/6 N mice (n = 5). b Vector and Cdk6^−/− MCA205 tumor growth curve in Nu/Nu mice. c Tumor growth curve of vector and Cdk6^−/− MCA205 in NSG mice. d Vector and Cdk6^−/− TC1 tumor growth curve in C57BL/6 N mice. Vector or two clones of Cdk6^−/− (7# and 19#) TC1 tumor cells were transplanted subcutaneously on the right flank of C57BL/6 N mice (n = 5). e Vector and Cdk6^−/− TC1 (7# and 19#) tumor growth curve in Nu/Nu mice (n = 5). f Cell proliferation of vector, Cdk4^−/− and Cdk6^−/− MCA205 cells detected by CCK8 assay. g Colony formation assay conducted with vector, Cdk4^−/− and Cdk6^−/− MCA205 cells. h Cell proliferation of vector, Cdk4^−/− and Cdk6^−/− TC1 cells detected by CCK8 assay. i Heat map of mRNA expression involved in “cellular response to interferon-β” in vector and Cdk6^−/− MCA205 cells. j mRNA expression of Stat1, Stat2, Isg15, Ifi204, Ifit1 by RT-PCR in vector and two clones of Cdk6^−/− (A43 and A57) MCA205 cells. k IFN-β expression in vector, Cdk4^−/− and Cdk6^−/− MCA205 cells supernatant detected by ELISA assay. l Protein expression of total and phosphorylated STAT1 in vector, Cdk6^−/− (A43 and A57) MCA205 cells determined by Western Blot assay. m Vector and Cdk6^−/− MCA205 tumor growth in Ifnar1^−/− mice. Data are representative of three independent experiments and presented as and mean ± SD. Statistical significance was analyzed by the Mann–Whitney U test and unpaired Student’s t-test. ns, no significant,*p < 0.05, **p < 0.01.