Modulation of several targets in cancer cells enhances the effect of anti-cancer drugs. This can be achieved by using combinations of anti-cancer drugs or by designing new drugs with novel pharmacophore structures that target different molecules within cancer cells. We developed a panel of such compounds by accommodating two chemical entities (5-Aminoslicylic acid and thiazolin-4-one) known to have anti-cancer activities into a single framework structure. Using a panel of 7 cancer cell lines, two compounds (HH3 and HH13) showed efficient cytotoxic effects on some types of cancer comparable to the standard anti-cancer drug doxorubicin with tumor specificity and minimal effects on normal fibroblasts. Investigating the molecular mechanisms of the two compounds revealed (i) induction of DNA damage, (ii) cell cycle arrest in G2/M phase and (iii) induction of apoptosis as indicated by annexin-V staining and activation of caspases. These effects were more prominent in HH compounds-sensitive cells (with IC₅₀ < 0.5μM) than -resistant or normal cells (with IC₅₀ > 1μM). Moreover, both compounds modulate the expression and activity of several factors in the DNA damage response pathway (γ–H2AX, ATM, ATR, CHK1, CHK2), cyclins/cyclin dependent kinases and CDC25 phosphatase. Altogether, our results show that both HH3 and HH13 compounds are good candidates as anti-cancer drug leads for certain types of cancer and worth further detailed investigations of their safety and effectiveness on animal/xenograft models.

癌细胞中几种靶的调节增强了抗癌药的作用。这可以通过使用抗癌药的组合或设计具有靶向癌细胞内不同分子的新颖药效团结构的新药来实现。我们通过将已知具有抗癌活性的两个化学实体（5-氨基水杨酸和噻唑啉-4-酮）容纳到一个单一的骨架结构中，从而开发出这类化合物。使用一组7种癌细胞系，两种化合物（HH3和HH13）对某些类型的癌症表现出有效的细胞毒性作用，可与标准抗癌药阿霉素相比，具有肿瘤特异性且对正常成纤维细胞的作用极小。研究这两种化合物的分子机理揭示了（i）诱导DNA损伤，（ii）细胞周期停滞在G2 / M期，以及（iii）膜联蛋白-V染色和胱天蛋白酶激活表明细胞凋亡。这些效应在对HH化合物敏感的细胞（带有IC比抗性或正常细胞（IC ₅₀ >1μM）低₅₀ <0.5μM ）。此外，这两种化合物均可调节DNA损伤反应途径中几种因子（γ- H2AX，ATM，ATR，CHK1，CHK2），细胞周期蛋白/细胞周期蛋白依赖性激酶和CDC25磷酸酶的表达和活性。总而言之，我们的结果表明，HH3和HH13化合物都是某些类型癌症的抗癌药物，是很好的候选药物，值得进一步研究其在动物/异种移植模型中的安全性和有效性。