Figure 8. Atrx deletion increases sarcoma sensitivity to oncolytic herpesvirus therapy.

(A) Diagram showing the interaction between oncolytic herpesvirus and CGAS/STING pathway in Atrx WT sarcoma cells. Oncolytic herpes virus dsDNA is detected and CGAS/STING signaling activates the innate immune response, which inhibits viral spread and oncolytic herpesvirus efficacy. (B) RT-PCR of Ifnb1 for Atrx WT and Atrx KO isogenic sarcoma cell lines (n = 3) assayed 24 hours after treatment with HSV-60, a 60-bp dsDNA oligonucleotide derived from HSV-1 that is a known inducer of CGAS/STING signaling. For statistical analysis, a ratio paired t test was performed, pairing each Atrx KO cell line to its Atrx WT isogenic cell line counterpart. (C) IC₅₀ assays for isogenic mouse sarcoma cell lines (n = 3) treated with oncolytic herpesvirus (oHSV) ordered from Imanis Life Sciences. Differences between all paired cell lines are statistically significant (P <.05) as analyzed by a ratio paired t test. Each data point represents a biological replicate. (D) IC₅₀ assays for the 143B human Sarcoma cell line with or without ATRX deletion, as well as the U2OS human sarcoma cell line, which is lacks protein expression of both ATRX and STING. Each dot represents a separate experimental replicate of the IC₅₀ assay (n = 3 per cell line). Statistical analysis was performed using multiple Welch’s t tests corrected for multiple comparisons using the Holm-Šídák method. (E) Measurement of P7 KP (n = 21) and P7KPA (n = 12) tumor growth after treatment with a mouse optimized version of TVEC oncolytic herpesvirus, as measured by time for tumor to quintuple in size relative to size at treatment. Comparison of survival curves was performed using log-rank (Mantel Cox) test. (F) Measurement of P7 KP (n = 31) and P7 KPA (n = 23) tumor growth rates after 20 Gy hindlimb irradiation followed by treatment with a mouse optimized TVEC oncolytic herpesvirus, as measured by time for tumor to quintuple in size relative to size at treatment. Comparison of survival curves was performed using log-rank (Mantel Cox) test.