THP-001

Atorvastatin (ATOR) acts on certain antitumor pathways; the consequences of chemotherapies continue to be a major concern, notwithstanding the increased efficacy provided by contemporary therapies. This study investigated the synergistic effects and underlying mechanisms of different treatment protocols using ATOR on the THP-1 cell line and on lung cancer in mice. For the in vitro study, an MTT assay was performed, and then different combinations against the THP-1 cell line were used as follows: non-treated cells, THP-1/ATOR IC₅₀, THP-1/cytarabine (CYT) IC₅₀, THP-1/doxorubicin (DOX) IC₅₀, THP-1/DOX/CYT, THP-1/ATOR/CYT, THP-1/ATOR/DOX, and THP-1/ATOR/CYT/DOX. For the in vivo study, CD-1 male mice were used; G1 was the normal control. Gs2-5 were administered with urethane (Ure) and butylated hydroxytoluene (BHT). G2 was the positive control. G3 was treated with ATOR (20 mg/kg). G4 was treated with Bevacizumab (Bev) (5 mg/kg). G5 was co-treated with ATOR/Bev. Histopathological and immunohistochemical investigations, flow cytometry and molecular analysis of PI3K, Akt, and mTOR genes were performed after different treatment protocols. The results showed that different combinatorial treatment settings of ATOR in vitro increase the apoptotic-inducing capacity and cell cycle arrest. Co-treatment with ATOR and Bev led to a significant decrease in S-phase and G2/M percentages. Furthermore, in vivo co-treatment with ATOR/Bev decreased tumor incidence and size with a significant reduction of the immunohistochemical PCNA (LI%) in lung parenchyma, targeting PI3K/Akt/mTOR, and VEGF-A signaling pathways. Co-treatment with ATOR and chemotherapies led to cell cycle arrest, modulation of the PI3K/Akt/mTOR, and VEGF-A signaling pathways in tumor cells.

Dihydroorotate dehydrogenase (DHODH) remains as an active target at the preclinical level against acute myeloid leukemia (AML). Herein we report potent second generation benzylidene chromanone (SBL-105) analogues to inhibit DHODH in AML cells. Virtual docking and molecular dynamic simulations were performed. Human-recombinant (rh)DHODH, THP-1, TF-1 and HL-60 cell lines were used. MTT assay was used for cell viability. Flow cytometry was used for differentiation analysis. Computational modeling and simulations predict, SBL-105 analogs bind efficiently to DHODH with improved binding energies. While all tested analogues of SBL-105 inhibited rh DHODH enzyme, SBL-105-4 and SBL-105-6 more effectively inhibited rh DHODH with an IC₅₀ value of 3.62 and 13.61 nM respectively. SBL-105-4 exhibited excellent anti proliferative effects against THP-1, TF-1 and HL-60 cells with GI₅₀ values of 18.78, 38.11 and 63.83 nM respectively. A similar effect was also observed in SBL-105-6 treated AML cells with respective GI₅₀ values of 34.56, 44.40 and 38.65 nM in THP-1, TF-1 and HL-60 cells. An increase in apoptotic populations were enumerated in all three AML cells. Both these compounds also increased the differentiation marker CD11b positive populations in all the three AML cells tested. In conclusion, SBL-105-4 and SBL-105-6 were identified as potent second generation DHODH inhibitors, which drives attention for further preclinical developments.Communicated by Ramaswamy H. Sarma.