ICD inducer-2

ICD inducer-2 is an inducer of immunogenic cell death that binds to the colchicine binding site on tubulin, thereby inhibiting tubulin polymerization. It demonstrates broad-spectrum antiproliferative activity across various cancer cell lines and inhibits cell migration while causing G2/M phase arrest and inducing apoptosis. Additionally, it promotes CD4+ and CD8+ T cell infiltration into the tumor microenvironment. ICD inducer-2 decreases Bcl-2, an anti-apoptotic protein, and increases pro-apoptotic proteins Bax and Bim-1, as well as cleaved forms of caspase 3, caspase 9, and PARP. It also overcomes paclitaxel resistance in xenograft models, leading to tumor growth inhibition, and is applicable in cancer-related research, such as lung cancer studies.

ICD inducer-2 (Compound 17) demonstrates several biological activities. It inhibits the polymerization of purified tubulin in a dose-dependent manner at concentrations between 1.25-5 μM over 60 minutes. At 0.2-25 μM for 2 hours, it binds to the colchicine-binding site on tubulin in A549 cells. Concentrations of 10-20 nM over 48 hours disrupt the microtubule network in A549 cells. Moreover, at 20-80 nM for 12 hours, it potently induces immunogenic cell death (ICD) in A549 cells. It shows in vitro immune-stimulating potential at 8-64 nM across 12-24 hours by reducing A549 cell viability when co-cultured with Jurkat cells. ICD inducer-2 exhibits broad-spectrum antiproliferative activity across various cancer cell lines with IC50 values ranging from 8 ± 3 nM (MCF-7) to 47 ± 12 nM (A549/TxR), and reverses paclitaxel resistance in A549/TxR cells, with an RI of 4.7. At 5-20 nM for 48 hours, it induces dose-dependent G2/M phase arrest in A549 cells, with arrest rates of 20.16%, 32.83%, and 40.30%, while modulating cell cycle regulatory proteins. Additionally, it prompts mitochondrial-mediated apoptosis in A549 cells, increasing late apoptosis levels and regulating the expression of apoptosis-related proteins. It also inhibits A549 cell migration and HUVEC tube formation in a dose-dependent manner at 5-20 nM for 24 hours and 8 hours, respectively.

ICD inducer-2 (Compound 17) administered intravenously at doses of 5-15 mg/kg every other day for 28 days demonstrated dose-dependent tumor growth inhibition in a paclitaxel-resistant A549/TxR xenograft mouse model, achieving up to an 82.0% inhibition rate without significant toxicity to major organs at the highest tested dose. Additionally, ICD inducer-2 at doses of 10-15 mg/kg, provided intravenously every other day for 14 days, achieved up to 81.6% dose-dependent tumor growth inhibition in the Lewis lung carcinoma xenograft mouse model. It effectively activated the antitumor immune response by enhancing T cell infiltration and pro-inflammatory cytokine production, while exhibiting a favorable safety profile at tested doses.