Figure 3.

TOP1 inhibitor irinotecan boosts SASP through TOP1cc-regulated cGAS pathway

(A) Expression of TOP1 and a loading control β-actin in UPK10 cells expressing the indicated shTOP1s or a shControl was determined by immunoblot.

(B) Expression of cGAS and a loading control β-actin in UPK10 cells expressing the indicated shcGASs or a shControl was determined by immunoblot.

(C) Expression of TOP1cc in UPK10 cells expressing the indicated shTOP1s or a shControl was determined by slot blot. Expression of histone H3 was used as a control.

(D) UPK10 cells were treated with 10μM cisplatin, 10μM irinotecan, or a combination for three days and released for three days. Expression of the indicated SASP factors in the sorted non-senescent and senescent cells was determined by qRT-PCR (n = 3 biologically independent experiments).

(E and F) Secretion of SASP factors under the indicated conditions was determined by an antibody array (E). Examples of changes in the secreted SASP factors were highlighted. The heatmap indicates the fold change (FC) in comparison with the control (Ctrl) or senescent UPK10 cells sorted from cisplatin and irinotecan combination treatment (Cisp + IRT). Relative expression levels per replicate and average fold change differences are shown (F).

Data represent mean ± SEM of. p values were calculated using a two-tailed t test. See also Figure S3.