Drug repositioning for cancer therapy: Overview of my current research

Chemotherapy is widely used for the treatment of various cancers. DNA-damaging and anti-mitotic drugs are the two types of chemotherapeutic drugs. DNAdamaging drugs such as doxorubicin, etoposide, and cisplatin, are involved directly in DNA double strand breaks. Anti-mitotic drugs inhibit mitosis by targeting microtubules and preventing their polymerization or depolymerization. Paclitaxel, docetaxel, vincristine, vinorelbine, vinblastine, and halaven are some examples of anti-mitotic drugs. While chemotherapeutic drugs are widely used to treat cancer, patients develop resistance to these drugs, specifically after prior exposure to chemotherapy. One of the important resistance mechanisms involves increased expression of P-glycoprotein (P-gp) on the cancer cell membranes to pump-out the chemotherapeutic drugs, in an attempt to avoid drug-induced toxicity. Identifying sensitizing mechanisms or sensitizing drugs for these resistant cancer cells would contribute to a better understanding of the mechanism of drug-induced resistance treatments. For example, it would be beneficial if a drug could inhibit P-gp expression as well induce cellular apoptosis. Such drugs can be effective not only for single treatment and but also show increased efficacy in combination with other chemotherapeutic drugs. In addition, identification of both non-P-gp substrates and toxic drugs would be a prominent contribution for treating resistant cancer. Drug repositioning or drug repurposing is the application of known drugs to new indications. It has been