In vitro and in silico evaluation of new thieno[2,3-d]pyrimidines as anti-cancer agents and apoptosis inducers targeting VEGFR-2

In this study, new thieno[2,3-d]pyrimidine derivatives that could have potential anticancer activity by inhibiting the VEGFR-2 receptor have been designed, synthesized, and investigated. The thieno[2,3-d]pyrimidine derivatives showed strong in vitro abilities to inhibit VEGFR-2 and to prevent cancer cell growth in two different types of cancer cells, MCF-7 and HepG2. Particularly, compound 22 showed the most potent anti-VEGFR-2 activity with an IC₅₀ value of 0.58 µM. Additionally, compound 22 exhibited good anti-proliferative activity against both MCF-7 and HepG2 cancer cell lines, with IC₅₀ values of 11.32 ± 0.32 and 16.66 ± 1.22 µM, respectively. Further investigations revealed that compound 22 induced cell cycle arrest at the G2/M phase and promoted both early and late apoptosis in the MCF-7 cancer cells. Compound 22 also increased the level of BAX (2.8-fold), and reduced the level of Bcl-2 (2.2-fold), hence increasing the rate of apoptosis. Compound 22 also revealed 2.9-fold and 2.8-fold higher levels of caspase-8 and caspase-9, respectively, in the treated MCF-7 cancer cells compared to the control cell lines. The MD simulations showed that the VEGFR-2-22 complex was structurally and energytically stable over 100 ns, while the MM-GBSA study indicated its stable thermodynamic behavior. The bi-dimensional projection analysis confirmed the proper binding of the VEGFR-2-22 complex, while the DFT studies provided optimized geometry, charge distribution, FMO, ESP, the total density of state, and QTAIM maps of compound 22. Finally, computational ADMET studies were performed to assess the drug development potential of the thieno[2,3-d]pyrimidine derivatives. Overall, this study suggests that compound 22 has the potential as an anticancer lead compound by inhibiting VEGFR-2, which may be a guide for future drug design and development.