Immunotherapy of triple-negative breast cancer(TNBC)is significantly hindered by the immunosuppressive tumor microenvironment(TME).Notably,tumor-associated macrophages(TAMs),which constitute the predominant infiltrati...Immunotherapy of triple-negative breast cancer(TNBC)is significantly hindered by the immunosuppressive tumor microenvironment(TME).Notably,tumor-associated macrophages(TAMs),which constitute the predominant infiltrating immune cell type in TNBC,represent a critical target for“turning off”immunosuppressive TME.Despite numerous ongoing clinical trials,current strategies exhibit limited efficacy in overcoming immunosuppressive TME.Interestingly,regulation of son of sevenless 1(SOS1),which is overexpressed in TNBC patients,shows promising potential for TAM repolarization.Herein,we developed a biomimetic liposomal platform(CCM/Cil-lipo@TD),which integrates cilengitide(Cil)-functionalized breast cancer cell membranes(CCM)to co-deliver tetrandrine(TET)and low-dose docetaxel(DTX)for TNBC therapy.This system synergistically enhanced immunotherapy by coupling SOS1 blockade-driven TAM repolarization with immune cell death(ICD)-mediated dendritic cell(DC)maturation,thereby reshaping the highly immunosuppressive TME in TNBC.Critically,the low-density Cil-anchored,CCM-fused liposomes overcome the penetration limitations inherent to conventional CCM-based delivery systems,achieving deep intratumoral accumulation of therapeutic payloads.Mechanistically,the CCM/Cil-lipo@TD ensured that TET-mediated SOS1 inhibition in tumor cells efficiently polarized TAM2(protumor)toward TAM1(antitumor).Furthermore,SOS1 blockade synergized with low-dose DTX-induced ICD to remodel TME,as evidenced by sustained cytotoxic T-cell infiltration and suppression of regulatory T cells.The CCM/Cil-lipo@TD exerted superior tumor inhibition(82.9%)in 4T1 orthotopic models and effectively inhibited postoperative local recurrence and distant metastasis.Taken together,the Cil-engineered,cellmembrane-anchoring CCM/Cil-lipo@TD provides a promising approach for TNBC immunotherapy.展开更多
The Kirsten rat sarcoma virus—son of sevenless 1(KRAS-SOS1)axis drives tumor growth preferentially in pancreatic,colon,and lung cancer.Now,KRAS G12C mutated tumors can be successfully treated with inhibitors that cov...The Kirsten rat sarcoma virus—son of sevenless 1(KRAS-SOS1)axis drives tumor growth preferentially in pancreatic,colon,and lung cancer.Now,KRAS G12C mutated tumors can be successfully treated with inhibitors that covalently block the cysteine of the switch II binding pocket of KRAS.However,the range of other KRAS mutations is not amenable to treatment and the G12C-directed agents Sotorasib and Adragrasib show a response rate of only approximately 40%,lasting for a mean period of 8 months.One approach to increase the efficacy of inhibitors is their inclusion into proteolysis-targeting chimeras(PROTACs),which degrade the proteins of interest and exhibit much higher antitumor activity through multiple cycles of activity.Accordingly,PROTACs have been developed based on KRAS-or SOS1-directed inhibitors coupled to either von Hippel-Lindau(VHL)or Cereblon(CRBN)ligands that invoke the proteasomal degradation.Several of these PROTACs show increased activity in vitro and in vivo compared to their cognate inhibitors but their toxicity in normal tissues is not clear.The CRBN PROTACs containing thalidomide derivatives cannot be tested in experimental animals.Resistance to such PROTACS arises through downregulation or inactivation of CRBN or factors of the functional VHL E3 ubiquitin ligase.Although highly active KRAS and SOS1 PROTACs have been formulated their clinical application remains difficult.展开更多
基金the National Facility for Protein Science in Shanghai(NFPS),Shanghai Advanced Research Institute,Chinese Academy of Science,China for providing the Electron Microscopy System technical support and assistance in data collection and analysisfunded by“Shuguang Program”supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(22SG41)the combination of the medical care and health project of the Shanghai University of Traditional Chinese Medicine(YYKC-2021-01-008).
文摘Immunotherapy of triple-negative breast cancer(TNBC)is significantly hindered by the immunosuppressive tumor microenvironment(TME).Notably,tumor-associated macrophages(TAMs),which constitute the predominant infiltrating immune cell type in TNBC,represent a critical target for“turning off”immunosuppressive TME.Despite numerous ongoing clinical trials,current strategies exhibit limited efficacy in overcoming immunosuppressive TME.Interestingly,regulation of son of sevenless 1(SOS1),which is overexpressed in TNBC patients,shows promising potential for TAM repolarization.Herein,we developed a biomimetic liposomal platform(CCM/Cil-lipo@TD),which integrates cilengitide(Cil)-functionalized breast cancer cell membranes(CCM)to co-deliver tetrandrine(TET)and low-dose docetaxel(DTX)for TNBC therapy.This system synergistically enhanced immunotherapy by coupling SOS1 blockade-driven TAM repolarization with immune cell death(ICD)-mediated dendritic cell(DC)maturation,thereby reshaping the highly immunosuppressive TME in TNBC.Critically,the low-density Cil-anchored,CCM-fused liposomes overcome the penetration limitations inherent to conventional CCM-based delivery systems,achieving deep intratumoral accumulation of therapeutic payloads.Mechanistically,the CCM/Cil-lipo@TD ensured that TET-mediated SOS1 inhibition in tumor cells efficiently polarized TAM2(protumor)toward TAM1(antitumor).Furthermore,SOS1 blockade synergized with low-dose DTX-induced ICD to remodel TME,as evidenced by sustained cytotoxic T-cell infiltration and suppression of regulatory T cells.The CCM/Cil-lipo@TD exerted superior tumor inhibition(82.9%)in 4T1 orthotopic models and effectively inhibited postoperative local recurrence and distant metastasis.Taken together,the Cil-engineered,cellmembrane-anchoring CCM/Cil-lipo@TD provides a promising approach for TNBC immunotherapy.
文摘The Kirsten rat sarcoma virus—son of sevenless 1(KRAS-SOS1)axis drives tumor growth preferentially in pancreatic,colon,and lung cancer.Now,KRAS G12C mutated tumors can be successfully treated with inhibitors that covalently block the cysteine of the switch II binding pocket of KRAS.However,the range of other KRAS mutations is not amenable to treatment and the G12C-directed agents Sotorasib and Adragrasib show a response rate of only approximately 40%,lasting for a mean period of 8 months.One approach to increase the efficacy of inhibitors is their inclusion into proteolysis-targeting chimeras(PROTACs),which degrade the proteins of interest and exhibit much higher antitumor activity through multiple cycles of activity.Accordingly,PROTACs have been developed based on KRAS-or SOS1-directed inhibitors coupled to either von Hippel-Lindau(VHL)or Cereblon(CRBN)ligands that invoke the proteasomal degradation.Several of these PROTACs show increased activity in vitro and in vivo compared to their cognate inhibitors but their toxicity in normal tissues is not clear.The CRBN PROTACs containing thalidomide derivatives cannot be tested in experimental animals.Resistance to such PROTACS arises through downregulation or inactivation of CRBN or factors of the functional VHL E3 ubiquitin ligase.Although highly active KRAS and SOS1 PROTACs have been formulated their clinical application remains difficult.
