Trilaciclib hydrochloride

Trilaciclib hydrochloride is an inhibitor of CDK4/6 (IC50s: 1 nM and 4 nM for CDK4 and CDK6) .Incubation with Trilaciclib hydrochloride (G1T28) for 24 hours can induce a strong G1 cell cycle arrest (time=0) . Cells have re-entered the cell cycle and demonstrate cell-cycle kinetics similar to untreated control cells By 16 hours after Trilaciclib hydrochloride washout. These results demonstrate that Trilaciclib hydrochloride causes a transient, and reversible G1 arrest. A transient Trilaciclib hydrochloride-mediated G1 cell-cycle arrest in CDK4/6-sensitive cells decreases the in vitro toxicity of a variety of commonly used cytotoxic chemotherapy agents associated with myelosuppression.G1T28 inhibits the phosphorylation of RB and induces an exclusive, reversible G1 arrest.n vivo, G1T28 reversibly and in a dose-dependent manner, regulates the proliferation of HSPCs. Pretreatment of mice with oral G1T28 allows for the faster recovery of CBCs following chemotherapy treatment. Likewise, oral G1T28 does not protect RB-deficient tumors from chemotherapy but adds to the antitumor effect. Although this effect was found in athymic mice that lack T lymphocytes, it is still possible that the enhanced efficacy is due to preservation of other immune cell types such as natural killer cells. (In Vitro) :Incubation with Trilaciclib hydrochloride (G1T28) for 24 hours induces a robust G1 cell-cycle arrest (time=0) . By 16 hours after Trilaciclib hydrochloride washout, cells have reentered the cell cycle and demonstrate cell-cycle kinetics similar to untreated control cells. These results demonstrate that Trilaciclib hydrochloride causes a transient, and reversible G1 arrest. A transient Trilaciclib hydrochloride-mediated G1 cell-cycle arrest in CDK4/6-sensitive cells decreases the in vitro toxicity of a variety of commonly used cytotoxic chemotherapy agents associated with myelosuppression. (In Vivo) :Trilaciclib hydrochloride (G1T28) treatment results in a robust and dose-dependent suppression of proliferation in HSPCs at 12 hours, with 5-ethynyl-2′-deoxyuridine (EdU) incorporation returning near baseline levels in a dose-dependent manner by 24 hours after administration. These data demonstrate that a single oral dose of Trilaciclib hydrochloride can produce reversible cell-cycle arrest in HSPCs in a dose-dependent manner in vivo. Mice given 100 mg/kg Trilaciclib hydrochloride 30 minutes prior to etoposide treatment, exhibits only background levels of caspase-3/7 activity. These data demonstrate that Trilaciclib hydrochloride can protect the bone marrow from chemotherapy-induced apoptosis in vivo. The data demonstrate that treatment with Trilaciclib hydrochloride prior to 5-fluorouracil (5-FU) likely decreases 5-FU-induced damage by chemotherapy in HSPCs, thus accelerating blood count recovery after chemotherapy.