R1-ICR-5 is a highly selective RIPK1 PROTAC degrader. Mediated by VHL, R1-ICR-5 induces the degradation of RIPK1, which in turn dysregulates the TNFR1 and TLR3/4 signaling hubs, enhances the signaling outputs of NF-κB, MAPK and IFN, and simultaneously promotes RIPK3 activation and necroptosis ( necroptosis ). R1-ICR-5 can be used in the research of triple-negative breast cancer and skin inflammation [1]. (Pink: RIPK1 ligand; Blue: VHL ligand; Black: linker ).
In Vivo, Combination of R1-ICR-5 (40 µg per dose; intratumoral injection; 3 doses total) with 8 Gy radiotherapy enhances anti-tumor immunity, prolongs median survival to 35 days, induces durable tumor regression, and generates protective anti-tumor immune memory in a mouse orthotopic triple-negative breast cancer model[1]. Combination treatment with R1-ICR-5 (40 µg per dose; intratumoral injection; 3 doses total), 4 Gy radiotherapy, and anti-CTLA-4 immune checkpoint blockade induces near-complete tumor regression and significantly prolongs survival in a mouse orthotopic triple-negative breast cancer model[1]. When used in combination with anti-PD-1 immune checkpoint blockade therapy, R1-ICR-5 (40 µg per dose; intratumoral injection; 4 doses total) slows tumor growth, increases the response rate to 60%, and extends the median survival time to 36.5 days in a mouse orthotopic triple-negative breast cancer model[1]. R1-ICR-5 (10 mM; subcutaneous injection; single administration) blocks RIPK1-dependent skin inflammation and tissue damage induced by combined treatment with SMAC mimetic and pan-caspase inhibitor in mice[1]. R1-ICR-5 (10 mM; subcutaneous injection; single administration) completely inhibits TBK1 inhibition- and TNF-mediated skin inflammation and tissue damage in mice[1].
In Vitro, R1-ICR-5 (1 μM; 2-24 h) induces time-dependent, VHL- and proteasome-dependent degradation of RIPK1 in mouse bone marrow-derived macrophages (BMDMs) without off-target effects on related kinases[1]. R1-ICR-5 (20 h) potently degrades endogenous RIPK1 protein in human HT1080 and HT29 cells, as well as mouse EMT6 and L929 cells[1]. R1-ICR-5 (1 μM; 24 h) reduces the resynthesis rate of RIPK1 in mouse Mlkl-/- BMDMs, and after washout following initial treatment with 1 μM R1-ICR-5, its protein level requires more than 72 h to recover to the pre-treatment level[1]. R1-ICR-5 (1 μM; 4 h) enhances the expression of TNF-induced NF-κB target genes Tnf, A20 and Sod2 in mouse BMDMs[1]. R1-ICR-5 (1 μM; 4 h) enhances the expression of TLR3-mediated NF-κB and IFN target genes in mouse BMDMs[1]. R1-ICR-5 (1 μM; 18 h) sensitizes human HT1080 cells to TNF-induced necroptosis[1]. R1-ICR-5 (1 μM; 5 h) sensitizes mouse BMDMs to TNF-induced necroptosis[1]. R1-ICR-5 (1 μM; 24 h) induces autocrine TNF-mediated necroptosis in mouse BMDMs, a process dependent on the TNFR1 signaling pathway and MK2-mediated TNF biosynthesis[1]. R1-ICR-5 (1 μM; 24 h) enhances the sensitivity of murine EO771 triple-negative breast cancer (TNBC) cells to radiation-induced necroptosis[1].
References:
[1]. Mannion J, et al. A RIPK1-specific PROTAC degrader achieves potent antitumor activity by enhancing immunogenic cell death. Immunity. 2024 Jul 9;57(7):1514-1532.e15.
In Vivo, Combination of R1-ICR-5 (40 µg per dose; intratumoral injection; 3 doses total) with 8 Gy radiotherapy enhances anti-tumor immunity, prolongs median survival to 35 days, induces durable tumor regression, and generates protective anti-tumor immune memory in a mouse orthotopic triple-negative breast cancer model[1]. Combination treatment with R1-ICR-5 (40 µg per dose; intratumoral injection; 3 doses total), 4 Gy radiotherapy, and anti-CTLA-4 immune checkpoint blockade induces near-complete tumor regression and significantly prolongs survival in a mouse orthotopic triple-negative breast cancer model[1]. When used in combination with anti-PD-1 immune checkpoint blockade therapy, R1-ICR-5 (40 µg per dose; intratumoral injection; 4 doses total) slows tumor growth, increases the response rate to 60%, and extends the median survival time to 36.5 days in a mouse orthotopic triple-negative breast cancer model[1]. R1-ICR-5 (10 mM; subcutaneous injection; single administration) blocks RIPK1-dependent skin inflammation and tissue damage induced by combined treatment with SMAC mimetic and pan-caspase inhibitor in mice[1]. R1-ICR-5 (10 mM; subcutaneous injection; single administration) completely inhibits TBK1 inhibition- and TNF-mediated skin inflammation and tissue damage in mice[1].
In Vitro, R1-ICR-5 (1 μM; 2-24 h) induces time-dependent, VHL- and proteasome-dependent degradation of RIPK1 in mouse bone marrow-derived macrophages (BMDMs) without off-target effects on related kinases[1]. R1-ICR-5 (20 h) potently degrades endogenous RIPK1 protein in human HT1080 and HT29 cells, as well as mouse EMT6 and L929 cells[1]. R1-ICR-5 (1 μM; 24 h) reduces the resynthesis rate of RIPK1 in mouse Mlkl-/- BMDMs, and after washout following initial treatment with 1 μM R1-ICR-5, its protein level requires more than 72 h to recover to the pre-treatment level[1]. R1-ICR-5 (1 μM; 4 h) enhances the expression of TNF-induced NF-κB target genes Tnf, A20 and Sod2 in mouse BMDMs[1]. R1-ICR-5 (1 μM; 4 h) enhances the expression of TLR3-mediated NF-κB and IFN target genes in mouse BMDMs[1]. R1-ICR-5 (1 μM; 18 h) sensitizes human HT1080 cells to TNF-induced necroptosis[1]. R1-ICR-5 (1 μM; 5 h) sensitizes mouse BMDMs to TNF-induced necroptosis[1]. R1-ICR-5 (1 μM; 24 h) induces autocrine TNF-mediated necroptosis in mouse BMDMs, a process dependent on the TNFR1 signaling pathway and MK2-mediated TNF biosynthesis[1]. R1-ICR-5 (1 μM; 24 h) enhances the sensitivity of murine EO771 triple-negative breast cancer (TNBC) cells to radiation-induced necroptosis[1].
References:
[1]. Mannion J, et al. A RIPK1-specific PROTAC degrader achieves potent antitumor activity by enhancing immunogenic cell death. Immunity. 2024 Jul 9;57(7):1514-1532.e15.