Mild Photothermal Therapy Combined With SR4835 And SB431542 Induces Immunogenic Cell Death In Triple Negative Breast Cancer

Objective:Abstract:Gold nanorods(AuNR,As a photothermal agent),CDK12/13 inhibitor SR4835 and TGF-β inhibitor SB431542 injectable hydrogel platform(AuNR/SR/SB@Gel)to develop a targeted,non-invasive,low-toxicity combined immunotherapy for triple negative breast cancer(TNBC),and explore its specific molecular mechanism.Methods:(1)AuNR(CTAB-AuNR)was synthesized by gold seed method.The AuNR(mPEG-SH)was modified to produce AuNR(mPEG-AuNR)with low toxicity.(2)Zeta potential analyzer,scanning electron microscope,infrared imager,detection of AuNR characterization and the effect of modification on breast cancer cytotoxicity;(3)An injectable hydrogel platform loaded with AuNR,SR4835 and SB431542(AuNR/SR/SB@Gel)was constructed;(4)CCK-8,plate clone formation,Caspase3 activity assay and Hoechst staining were used to determine AuNR/SR/SB@Gel-MPTT activity,survival and apoptosis of breast cancer cells.(5)The effects of AuNR/SR/SB@Gel-MPTT on the expression and release of DAMPs(including CRT,HSP70 and HSP90),markers of immunogenic cell death(ICD),were detected by western blots,immunofluorescence and flow cytometry.(6)Flow cytometry was used to detect the activation of AuNR/SR/SB@Gel-MPTT-treated cells after coculture with bone-marrow derived dendritic cells(BMDCs)or immortal cell lines(DC2.4).(7)The bilateral tumor model was established in mice,and the volume and weight of bilateral tumors were analyzed by treating one tumor.(8)The number and activity of T cells and DC cells in spleen,blood and tumor of AuNR/SR/SB@Gel-MPTT treated mice were determined by flow cytometry.Results:(1)AuNR was synthesized successfully.(2)AuNR with photothermal effect and low dark toxicity was successfully modified.(3)The injectable hydrogel platform loaded with AuNR,SR4835 and SB431542 was successfully constructed.(4)AuNR/SR/SB@Gel-MPTT combined therapy reduced the viability and survival rate of breast cancer cells and activated caspase-3.(5)AuNR/SR/SB@Gel-MPTT promoted the expression and release of DAMPs(CRT,HSP70,HSP90)in breast cancer cells;(6)AuNR/SR/SB@Gel-MPTT treated breast cancer cells can effectively activate BMDCs and DC2.4 cells.(7)In the bilateral mouse tumor model,AuNR/SR/SB@Gel-MPTT could inhibit both the primary tumor and the distant tumor.(8)The number of T cells and activated DC cells in spleen,blood and tumor tissues of AuNR/SR/SB@Gel-MPTT group increased.Conclusion:The injectable hydrogel platform(AuNR/SR/SB@Gel)loaded with AuNR,SR4835 and SB431542 was successfully constructed,and the immunotherapy of MPTT combined with chemotherapy hydrogel loaded with drugs was realized.AuNR/SR/SB@gel-MPTT induces immunogenic cell death in breast cancer cells,activates DC cells in vitro,inhibits primary and distal tumor growth,and induces antitumor immune effects.AuNR/SR/SB@Gel-MPTT offers TNBC patients a novel targeted,low-invasive treatment strategy and a potential tumor vaccine based on cellular immunogenic death.Figures 9,Table 4,References 84...