Design and Synthesis of Novel 2-Trifuoromethyl-Quinazolin-4-Amine Derivatives as Potential WRN-Dependent Anti-Prostate Cancer Agents

Werner helicase (WRN) with multiple activities plays an essential role in treating microsatellite instability cancers as a synthetic lethal target. With our ongoing research on anticancer drugs targeting WRN, a class of 2-trifluoromethyl-quinazolin-4-amine derivatives was synthesized by optimizing the structure of 2-substituted-quinazolin-4-amine nuclear parent at the 6-position and 7-position. The anti-proliferative activity in vitro against LNCaP cells was evaluated, and the preliminary structure–activity relationship was summarized. Among these compounds, the inhibition rates of 5b, 5d, 7, 9a, 11a, and 17a against the LNCaP cell line were more than 50% at a 5 μM test concentration. The sensitivities of the active compounds to WRN were assessed by establishing WRN overexpression in LNCaP cells (LNCaP-WRN). The results indicated that compounds 5b, 15, 17a, and 7 were more sensitive to LNCaP-WRN than LNCaP-NC by the MTT assay. Notably, the selectivity ratios (LNCaP-NC IC₂₀/LNCaP-WRN IC₂₀) for 5b and 15 were 587 and 1766, respectively. Furthermore, these compounds showed lower cytotoxicity in normal LX-2 and HK-2 cell lines when compared with the positive control doxorubicin. Moreover, further research showed that 5b and 15 significantly repressed the cell survival of LNCaP-WRN by the colony formation assay. In addition, the results of molecular docking suggested that compounds 5b and 15 can directly bind to WRN, and the docking scores toward the receptor are −9.34 and −8.87 kcal/mol, respectively. Collectively, compounds 5b and 15 are identified as potential anti-prostate cancer agents targeting WRN.