Fig. 3: APOE decreases TMZ sensitivity by Homologous recombination pathway.

A GO functional enrichment analysis in TMZ-treated cells reveals the activation of various DNA damage pathways. B ssGSEA analysis indicates the score of DNA damage pathways in APOE (10 ng/ml)-treated cells based on transcriptomic data at different time points. C The expression of different genes related to the Homologous recombination (HR) pathway in APOE (10 ng/ml)-treated cells. D Based on GEPIA and TCGA data, the correlation between APOE expression and the HR genes BRCA1 and BRCA2 in pancreatic tissues. E Western blotting and RT-PCR experiments revealed that APOE enhances the expression of the HR genes BRCA1/2. F Knocking down APOE decreased expression of the HR genes BRCA1/2 induced by TMZ. G Comparison of various DNA damage repair pathway scores among the 10%FBS culture medium, 10% DLPS culture medium, and APOE (10 ng/ml)+10% DLPS culture medium, based on the transcriptomic data (48 h). H Comparison of functional enrichment analysis between the APOE(10 ng/ml)+10% DLPS culture medium and 10% DLPS culture medium group. I Comparison of various DNA damage repair pathway genes among the 10% FBS culture medium, 10% DLPS culture medium, and APOE(10 ng/ml)+10% DLPS culture medium cell. J Comparison of various DNA damage repair pathway genes among the 10% FBS culture medium, 10% DLPS culture medium, 10% FBS culture medium + TMZ, and 10% DLPS culture medium + TMZ cell. K Cell fluorescence response of APOE reduced the proportion of TMZ-induced DNA damage cells. Data in the graph are shown as the means ± SD from three independent experiment. *P < 0.05, **P < 0.01, ***P < 0.001, ns: no significance.