Synthesis and biological evaluation of histone deacetylase and DNA topoisomerase II-Targeted inhibitors

Understanding Cancer's Defense against Topoisomerase-Active Drugs: A Comprehensive Review

In recent years, the emergence of cancer drug resistance has been one of the crucial tumor hallmarks that are supported by the level of genetic heterogeneity and complexities at cellular levels. Oxidative stress, immune evasion, metabolic reprogramming, overexpression of ABC transporters, and stemness are among the several key contributing molecular and cellular response mechanisms. Topo-active drugs, e.g., doxorubicin and topotecan, are clinically active and are utilized extensively against a wide variety of human tumors and often result in the development of resistance and failure to therapy. Thus, there is an urgent need for an incremental and comprehensive understanding of mechanisms of cancer drug resistance specifically in the context of topo-active drugs. This review delves into the intricate mechanistic aspects of these intracellular and extracellular topo-active drug resistance mechanisms and explores the use of potential combinatorial approaches by utilizing various topo-active drugs and inhibitors of pathways involved in drug resistance. We believe that this review will help guide basic scientists, pre-clinicians, clinicians, and policymakers toward holistic and interdisciplinary strategies that transcend resistance, renewing optimism in the ongoing battle against cancer.

Potential of histone deacetylase inhibitors in the control and regulation of prostate, breast and ovarian cancer

Histone deacetylases (HDACs) are enzymes that play a role in chromatin remodeling and epigenetics. They belong to a specific category of enzymes that eliminate the acetyl part of the histones' -N-acetyl lysine, causing the histones to be wrapped compactly around DNA. Numerous biological processes rely on HDACs, including cell proliferation and differentiation, angiogenesis, metastasis, gene regulation, and transcription. Epigenetic changes, specifically increased expression and activity of HDACs, are commonly detected in cancer. As a result, HDACi could be used to develop anticancer drugs. Although preclinical outcomes with HDACs as monotherapy have been promising clinical trials have had mixed results and limited success. In both preclinical and clinical trials, however, combination therapy with different anticancer medicines has proved to have synergistic effects. Furthermore, these combinations improved efficacy, decreased tumor resistance to therapy, and decreased toxicity. In the present review, the detailed modes of action, classification of HDACs, and their correlation with different cancers like prostate, breast, and ovarian cancer were discussed. Further, the different cell signaling pathways and the structure-activity relationship and pharmaco-toxicological properties of the HDACi, and their synergistic effects with other anticancer drugs observed in recent preclinical and clinical studies used in combination therapy were discussed for prostate, breast, and ovarian cancer treatment.

Potential therapeutic targets shared between leishmaniasis and cancer

The association of leishmaniasis and malignancies in human and animal models has been highlighted in recent years. The misdiagnosis of coexistence of leishmaniasis and cancer and the use of common drugs in the treatment of such diseases prompt us to further survey the molecular biology of Leishmania parasites and cancer cells. The information regarding common expressed proteins, as possible therapeutic targets, in Leishmania parasites and cancer cells is scarce. Therefore, the current study reviews proteins, and investigates the regulation and functions of several key proteins in Leishmania parasites and cancer cells. The up- and down-regulations of such proteins were mostly related to survival, development, pathogenicity, metabolic pathways and vital signalling in Leishmania parasites and cancer cells. The presence of common expressed proteins in Leishmania parasites and cancer cells reveals valuable information regarding the possible shared mechanisms of pathogenicity and opportunities for therapeutic targeting in leishmaniasis and cancers in the future.

A Review of Progress in Histone Deacetylase 6 Inhibitors Research: Structural Specificity and Functional Diversity

Histone deacetylases (HDACs) are essential for maintaining homeostasis by catalyzing histone deacetylation. Aberrant expression of HDACs is associated with various human diseases. Although HDAC inhibitors are used as effective chemotherapeutic agents in clinical practice, their applications remain limited due to associated side effects induced by weak isoform selectivity. HDAC6 displays unique structure and cellular localization as well as diverse substrates and exhibits a wider range of biological functions than other isoforms. HDAC6 inhibitors have been effectively used to treat cancers, neurodegenerative diseases, and autoimmune disorders without exerting significant toxic effects. Progress has been made in defining the crystal structures of HDAC6 catalytic domains which has influenced the structure-based drug design of HDAC6 inhibitors. This review summarizes recent literature on HDAC6 inhibitors with particular reference to structural specificity and functional diversity. It may provide up-to-date guidance for the development of HDAC6 inhibitors and perspectives for optimization of therapeutic applications.

Dual inhibitors of histone deacetylases and other cancer-related targets: A pharmacological perspective

Epigenetic enzymes histone deacetylases (HDACs) are clinically validated anticancer drug targets which have been studied intensively in the past few decades. Although several drugs have been approved in this field, they are still limited to a subset of hematological malignancies (in particular T-cell lymphomas), with therapeutic potential not fully realized and the drug-resistance occurred after a certain period of use. To maximize the therapeutic potential of these classes of anticancer drugs, and to extend their application to solid tumors, numerous combination therapies containing an HDACi and an anticancer agent from other mechanisms are currently ongoing in clinical trials. Recently, dual targeting strategy comprising the HDACs component has emerged as an alternative approach for combination therapies. In this perspective, we intend to gather all HDACs-containing dual inhibitors related to cancer therapy published in literature since 2015, classify them into five categories based on targets' biological functions, and discuss the rationale why dual acting agents should work better than combinatorial therapies using two separate drugs. The article discusses the pharmacological aspects of these dual inhibitors, including in vitro biological activities, pharmacokinetic studies, in vivo efficacy studies, as well as available clinical trials. The review of the current status and advances should provide better analysis for future opportunities and challenges of this field.

Paradigm shift of "classical" HDAC inhibitors to "hybrid" HDAC inhibitors in therapeutic interventions

'Epigenetic' regulation of genes via post-translational modulation of proteins is the current mainstay approach for the disease therapies, particularly explored in the Histone Deacetylase (HDAC) class of enzymes. Mainly sight saw in cancer chemotherapeutics, HDAC inhibitors have also found a promising role in other diseases (neurodegenerative disorders, cardiovascular diseases, and viral infections) and successfully entered in various combination therapies (pre-clinical/clinical stages). The prevalent flexibility in the structural design of HDAC inhibitors makes them easily tuneable to merge with other pharmacophore modules for generating multi-targeted single hybrids as a novel tactic to overcome drawbacks of polypharmacy. Herein, we reviewed the putative role of prevalent HDAC hybrids inhibitors in the current and prospective stage as a translational approach to overcome the limitations of the existing conventional drug candidates (parent molecule) when used either alone (drug resistance, solubility issues, adverse side effects, selectivity profile) or in combination (pharmacokinetic interactions, patient compliance) for treating various diseases.

Synthesis of novel 2-oxospiro[indoline-3,4'-[1,3]dithiine]-5'-carbonitrile derivatives by new spiro[indoline-3,4'-[1,3]dithiine]@Cu(NO3)2 supported on Fe3O4@gly@CE MNPs as efficient catalyst and evaluation of biological activity

New spiro[indoline-3,4'-[1,3]dithiine]@Cu(NO₃)₂ supported on Fe₃O₄@gly@CE magnetic nanoparticle were synthesized and used as efficient and recyclable catalyst in the synthesis of 2-oxospiro[indoline-3,4'-[1,3]dithiine]-5'-carbonitrile derivatives. The structure of magnetic nanoparticles were confirmed using energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), infrared spectroscopy (FT-IR) and inductively coupled plasma optical emission spectroscopy (ICP-OES). Subsequently, antibacterial and antifungal activities in terms of inhibition zone diameter, minimum inhibitory concentration, minimum bactericidal concentration and antioxidant activity against the DPPH free radical of the derivatives were investigated. The results revealed acceptable biological effects of the synthetic derivatives and a significant relationship between their structure and biological activity were observed.

Novel Curcumin Inspired Antineoplastic 1-Sulfonyl-4-Piperidones: Design, Synthesis and Molecular Modeling Studies

Background:

Curcumin is a well-known example of plant origin exhibiting promising diverse biological properties such as, anti-inflammatory and antitumor as well as poor pharmacokinetic/pharmacodynamic properties. This is why effective agents based on its chemical scaffold were explored.

Methods:

A set of 3,5-bis(ylidene)-1-(alkylsulfonyl)piperidin-4-ones were synthesized in excellent yield (80- 96%) through dehydrohalogenation reaction of 3,5-bis(ylidene)-4-piperidinones with the corresponding alkane sulfonyl chloride in the presence of triethylamine. Antiproliferative properties of the synthesized compounds (dienone/curcumin inspired analogues) were studied by the standard MTT technique.

Results:

Most of the synthesized compounds revealed antiproliferative properties against HCT116 (colon) and A431 (skin/squamous) cancer cell lines with IC50 values at sub-micromolar level. Compound 36 also exhibited potency against MCF7 (breast) and A549 (lung) cancer cell lines (IC50 = 2.23, 4.27µM, respectively) higher than that of the reference standards (IC50 = 3.15, 5.93µM for 5-fluorouracil and doxorubicin against MCF7 and A549 cell lines, respectively). Cytotoxic properties of the synthesized compounds against non-cancer RPE1 cell line supported the safety profile of the effective agents against normal cells. Molecular modeling (3Dpharmacophore and 2D-QSAR) studies validated the observed bio-properties and explained the parameters governing activity. Inhibitory properties of compounds 27 and 29 (representative examples of the promising antiproliferative agents synthesized) supported their mode of action against topoisomerase IIα

Conclusion:

The synthesized scaffold is a promising antitumor agent (with special selectivity against colon and skin/squamous cancer cell lines) so, it can be considered for further investigation and development of highly effective hits/leads based on the computational models obtained.