AI Based Discovery of a New AKR1C3 Inhibitor for Anticancer Applications.

AKR1C3 is an upregulated enzyme in prostate and other cancers; in addition to regulating hormone synthesis, this enzyme is thought to play a role in the aggressiveness of tumors and in the defense against drugs. We here used an unbiased method to discover new potent AKR1C3 inhibitors: through an AI-based virtual drug screen, compound 4 was identified as a potent and selective enzymatic inhibitor able to translate this activity into a pronounced antiproliferative effect in the 22RV1 prostate cancer cell model. As other known AKR1C3 inhibitors, compound 4 determined a significantly increased activity of abiraterone, a drug approved for advanced prostate cancer. Compound 4 also showed a synergic effect with doxorubicin in osteosarcoma cell lines; specifically, the effect is correlated with AKR1C3 expression. In this research work, therefore, the use of AI allowed the identification of a new structure as an AKR1C3 inhibitor and its potential to enhance the effect of chemotherapeutics.

Structure-guided optimization of 3-hydroxybenzoisoxazole derivatives as inhibitors of Aldo-keto reductase 1C3 (AKR1C3) to target prostate cancer.

AKR1C3 is an enzyme that is overexpressed in several types of radiotherapy- and chemotherapy-resistant cancers. Despite AKR1C3 is a validated target for drug development, no inhibitor has been approved for clinical use. In this manuscript, we describe our study of a new series of potent AKR1C3-targeting 3-hydroxybenzoisoxazole based inhibitors that display high selectivity over the AKR1C2 isoform and low micromolar activity in inhibiting 22Rv1 prostate cancer cell proliferation. In silico studies suggested proper substituents to increase compound potency and provided with a mechanistic explanation that could clarify their different activity, later confirmed by X-ray crystallography. Both the in-silico studies and the crystallographic data highlight the importance of 90° rotation around the single bond of the biphenyl group, in ensuring that the inhibitor can adopt the optimal binding mode within the active pocket. The p-biphenyls that bear the meta-methoxy, and the ortho- and meta-trifluoromethyl substituents (in compounds 6a, 6e and 6f respectively) proved to be the best contributors to cellular potency as they provided the best IC50 values in series (2.3, 2.0 and 2.4 µM respectively) and showed no toxicity towards human MRC-5 cells. Co-treatment with scalar dilutions of either compound 6 or 6e and the clinically used drug abiraterone led to a significant reduction in cell proliferation, and thus confirmed that treatment with both CYP171A1-and AKR1C3-targeting compounds possess the potential to intervene in key steps in the steroidogenic pathway. Taken together, the novel compounds display desirable biochemical potency and cellular target inhibition as well as good in-vitro ADME properties, which highlight their potential for further preclinical studies.

Phenothiazines as anti-cancer agents: SAR overview and synthetic strategies.

Cancer is a leading cause of death worldwide and there are still limited options for cure. Chemotherapy is the most significant treatment for cancer which increased survival rates, despite this, it is associated with numerous side effects, as well as cancer relapsing due to drug resistance insurgence; consequently, it is still a challenging task to develop new potent and less toxic anti-cancer agents for patients' care. Phenothiazine moiety, which leads a class of well-known antipsychotic drugs, possesses a wide range of biological activities and has been also introduced in cancer chemotherapy. This review aims in disclosing the use of phenothiazines during the last five years for the development of different anti-cancer drug candidates. The design and the synthetic strategies adopted, the SAR investigations and the role of reviewed phenothiazine derivatives as anti-cancer agents and multi-drug resistance (MDR) reversals are here fully described and discussed.