A new series of imidazo[2,1-b]pyridine/pyrimidine chalcone derivatives were synthesized and evaluated for their anticancer activity. These chalcone derivatives showed promising activity with GI₅₀ values ranging from 0.28 to 30.0 μM. The detailed biological aspects of one of the promising compound 3f on the MCF-7 cell line were studied. Interestingly, compound 3f induced G1 cell cycle arrest, down regulation of G1 phase cell cycle regulatory proteins such as cyclin D1, E1, and CDK2. Moreover, compound 3f showed the characteristic features of apoptosis such as enhancement in the levels of p27 and TNFR1 proteins with concomitant down regulation of procaspase-9. One of the representative compound of this series 3f could be considered as the potential lead for its development as a new anticancer agent.

Topoisomerases are very important enzymes that regulate DNA topology and are vital for biological actions like DNA replication, transcription, and repair. The emergence and spread of cancer has been intimately associated with topoisomerase dysregulation. Topoisomerase inhibitors have consequently become potential anti-cancer medications because of their ability to obstruct the normal function of these enzymes, which leads to DNA damage and subsequently causes cell death. This review emphasizes the importance of topoisomerase inhibitors as marketed, clinical and preclinical anti-cancer medications. In the present review, various types of topoisomerase inhibitors and their mechanisms of action have been discussed. Topoisomerase I inhibitors, which include irinotecan and topotecan, are agents that interact with the DNA-topoisomerase I complex and avert resealing of the DNA. The accretion of DNA breaks leads to the inhibition of DNA replication and cell death. On the other hand, topoisomerase II inhibitors like etoposide and teniposide, function by cleaving the DNA-topoisomerase II complex thereby effectively impeding the release of double-strand DNA breaks. Moreover, the recent advances in exploring the therapeutic efficacy, toxicity, and MDR (multidrug resistance) issues of new topoisomerase inhibitors have been reviewed in the present review.

(2013). Naphthalimide derivatives with therapeutic characteristics: a patent review. Expert Opinion on Therapeutic Patents: Vol. 23, No. 3, pp. 299-317.