Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 22, Issue 14, 2022

Background: The discovery of trastuzumab as anti-HER2 therapy has markedly improved disease control and the survival rates of patients with HER2+ breast cancer. However, as trastuzumab is considered a complex molecule, the cost of production is usually elevated, which significantly affects health budgets and limits the treatment access for patients who live in underdeveloped countries. Recently, trastuzumab production has become more accessible and sustainable due to the patents’ expiration, allowing biosimilar versions of trastuzumab to be developed. Objective: Our main goal was to shed more light on the uses of biosimilars in breast cancer treatment, emphasizing trastuzumab. Method: An integrative search was carried out on the PubMed, Scielo, Web of Science, and SCOPUS databases using the terms “biosimilar,” “breast cancer,” “monoclonal antibody,” and “trastuzumab.” The time range included scientific articles published from 2015 to 2021. Results and Discussion: The bibliographic survey showed the complexities in biological medicine manufacturing and how the monoclonal antibody’s therapy with trastuzumab improved the patients’ life expectancy, revolutionizing HER2+ breast cancer treatment. Nonetheless, despite its benefits, trastuzumab generates certain restrictions, especially from the economic perspective. Trastuzumab biosimilars have high selectivity and rarely cause adverse effects compared to conventional chemotherapy. Conclusion: This study shows that trastuzumab biosimilars improve patients’ accessibility to breast cancer treatment through a safe and effective therapy compared to the drug reference.

Regardless of the growing discovery of anticancer treatments targeting cancer-specific pathways, cytotoxic therapy still maintained its abundant clinical significance because tumours harbor a greater population of actively dividing cells than normal tissues. Conventional anti-mitotic agents or microtubule poisons acting on the major mitotic spindle protein tubulin have been effectively used in clinical settings for cancer chemotherapy over the last three decades. However, the use of these drugs is associated with limited clinical utility due to serious side effects such as debilitating and dose-limiting peripheral neuropathy, myelosuppression, drug resistance, and allergic reactions. Therefore, research initiatives have been undertaken to develop novel microtubule motor proteins inhibitors that can potentially circumvent the limitations associated with conventional microtubule poisons. Kinesin spindle proteins (KSP) belonging to the kinesin-5 family play a crucial role during mitosis and unregulated cell proliferation. Evidence from preclinical studies and different phases of clinical trials have presented kinesin spindle protein as a promising target for cancer therapeutics. Kinesin spindle protein inhibitors causing mitosis disruption without interfering with microtubule dynamics in non-dividing cells offer a potential therapeutic alternative for the management of several major cancer types and are devoid of side effects associated with classical anti-mitotic drugs. This review summarizes recent data highlighting progress in the discovery of targeted KSP inhibitors and presents the development of scaffolds, structure-activity relationships, and outcomes of biological and enzyme inhibition studies. We reviewed the recent literature reports published over the last decade, using various electronic database searches such as PubMed, Embase, Medline, Web of Science, and Google Scholar. Clinical trial data till 2021 was retrieved from ClinicalTrial.gov. Major chemical classes developed as selective KSP inhibitors include dihydropyrimidines, β-carbolines, carbazoles, benzimidazoles, fused aryl derivatives, pyrimidines, fused pyrimidines, quinazolines, quinolones, thiadiazolines, spiropyran, and azobenzenes. Drugs such as filanesib, litronesib, ispinesib have entered clinical trials; the most advanced phase explored is Phase II. KSP inhibitors have exhibited promising results; however, continued exploration is greatly required to establish the clinical potential of KSP inhibitors.

Objective: The clinical management of anaplastic thyroid cancer (ATC) remains challenging, and novel treatment methods are needed. Monensin is a carboxyl polyether ionophore that potently inhibits the growth of various cancer types. Our current work investigates whether monensin has selective anti-ATC activity and systematically explores its underlying mechanisms. Methods: Proliferation and apoptosis assays were performed using a panel of thyroid cancer cell lines. Mitochondrial biogenesis profiles, ATP levels, oxidative stress, AMPK, and mTOR were examined in these cells after monensin treatment. Results: Monensin is effective in inhibiting proliferation and inducing apoptosis in a number of thyroid cancer cell lines. The results are consistent across cell lines of varying cellular origins and genetic mutations. Compared to other thyroid cancer cell types, ATC cell lines are the most sensitive to monensin. Of note, monensin used at our experimental concentration affects less of normal cells. Mechanistic studies reveal that monensin acts on ATC cells by disrupting mitochondrial function, inducing oxidative stress and damage, and AMPK activation-induced mTOR inhibition. We further show that mitochondrial respiration is a critical target for monensin in ATC cells. Conclusions: Our pre-clinical findings demonstrate the selective anti-ATC activities of monensin. This is supported by increasing evidence that monensin can be repurposed as a potential anti-cancer drug.

Aim: The objective of this study was to analyze the antitumor effect of BisBAL NP in a mouse melanoma model. Materials and Methods: The antitumor activity of BisBAL NP on murine B16-F10 melanoma cells was determined both in vitro (PrestoBlue cell viability assay and Live/Dead fluorescence) and in vivo, in a mouse model, with the following 15-day treatments: BisBAL NP, negative control (PBS), and cell-death control (docetaxel; DTX). Mouse survival and weight, as well as the tumor volume, were recorded daily during the in vivo study. Results: BisBAL NP were homogeneous in size (mean diameter, 14.7 nm) and bismuth content. In vitro, 0.1 mg/mL BisBAL NP inhibited B16-F10 cell growth stronger (88%) than 0.1 mg/mL DTX (82%) (*p<0.0001). In vivo, tumors in mice treated with BisBAL NP (50 mg/kg/day) or DTX (10 mg/kg/day) were 76% and 85% smaller than the tumors of negative control mice (*p<0.0001). The average weight of mice was 18.1 g and no statistically significant difference was detected among groups during the study. Alopecia was only observed in all DTX-treated mice. The survival rate was 100% for the control and BisBAL NP groups, but one DTX- treated mouse died at the end of the treatment period. The histopathological analysis revealed that exposure to BisBAL NP was cytotoxic for tumor tissue only, without affecting the liver or kidney. Conclusion: BisBAL NP decreased the tumor growing in a mouse melanoma model without secondary effects, constituting an innovative low-cost alternative to treat melanoma.

Background: Cancer is a disease illustrated by a shift in the controlled mechanisms that control both cell proliferation and differentiation. It is regarded as a prime health problem worldwide and a leading cause of human death rate exceeded only by cardiovascular diseases. Many reported works are concerned with discovering new antitumor compounds, encouraging us to synthesize new anticancer agents. Objective: In this work, we aimed to synthesize target molecules from 1,3-dicarbonyl compounds through heterocyclization reactions. Methods: The reaction of either 4-methylaniline (1a) or 1-naphthylamine (1b) with diethyl malonate (2) gave the anilide derivatives 3a and 3b, respectively. The latter underwent a series of heterocyclization reactions to give the pyridine, pyran, and thiazole derivatives confirmed by the required spectral data. Results: The in-vitro antitumor evaluation of the newly synthesized products against three cancer cell lines, MCF-7, NCI-H460, SF-268, and WI 38, which were used as the normal cell lines, was conducted, and the data revealed that compounds 11a, 18b, 18c, and 20d showed high antitumor activity and 20d individualized with potential antitumor activity towards cell lines with lowest cytotoxicity effect. Both EGFR and PIM-1 enzymes inhibition were investigated for the compound 20d, and it was found that the inhibition effect of compound 20d was promising for each enzyme, showing IC50 = 45.67 ng and 553.3 ng for EGFR and PIM-1, respectively. Conclusion: Molecular docking results of compound 20d showed strong binding interactions with both the enzymes, where good binding modes were obtained in the case of EGFR, which was closely similar to the binding mode of standard Erlotinib.While 20d showed complete superimposition binding interactions with VRV-cocrystallized ligand of PIM-1 that may expound the in-vitro antitumor activity.

Background: Laccifer lacca (Kerr) produces a mixture of polyhydroxy anthraquinones (laccaic acid) known as lac dye. Literature suggests that these laccaic acids have a structural resemblance with the anticancer drug Adriamycin (ADR). Hence, they may possess potential anticancer activity. Methods: This study was designed to explore the in vitro anticancer activity of the three fractions of lac dye, i.e., chloroform (C), methanol (M), and water (W) fractions, and isolation of constituents from bioactive fraction. Results: SRB (Sulforhodamine B) assay method was employed to evaluate the inhibitory action of all three fractions. However, only methanolic showed promising inhibitory action with GI50 <10; this runs in parallel with Adriamycin inhibition (GI50 <10). Two active constituents of the methanolic extract were isolated using column chromatography and were characterized using UV (UV visible spectrophotometer), IR (Infrared spectroscopy), NMR (nuclear magnetic resonance), and mass spectrometry methods. The final structure of the isolated constituents (laccaic acid D and laccaic acid B) was confirmed by ¹³C and 2D NMR data. Conclusion: Conclusively, only the methanol fraction (M) showed promising anticancer activity against in vitro MDAMB- 231 and SiHa cell lines compared to the standard adriamycin.

Background: Herein, we have designed and synthesized a series of the novel (E)-N'-((1-(4-chlorobenzyl)- 1H-indol-3-yl)methylene)-2-(4-oxoquinazolin-3(4H)-yl)acetohydrazides (5) as potent small molecules activating procaspase- 3. The compounds were designed by the amalgamation of structural features of PAC-1 (the first procaspase-3 activator) and oncrasin-1, one potential anticancer agent. Methods: The target acetohydrazides (5a-m) were prepared via the Niementowski condensation of anthranilic acid (1a) or 5-substituted-2-aminobenzoic acid (1b-m) and formamide. The compound libraries were evaluated for their cytotoxicity, caspase-3 activation, cell cycle analysis, and apoptosis. In addition, computational chemistry is also performed. Results: A biological evaluation revealed that all thirteen compounds designed and synthesized showed strong cytotoxicity against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer) with eight compounds (5a, 5c-i, 5k), which were clearly more potent than both PAC-1 and oncrasin-1. In this series, four compounds, including 5c, 5e, 5f, and 5h, were the most potent members with approximately 4- to 5-fold stronger than the reference compounds PAC-1 and oncrasin-1 in terms of IC50. In comparison to 5-FU, these compounds were even 18- to 29-fold more potent in terms of cytotoxicity in three human cell lines tested. In the caspase activation assay, the caspase activity was activated to 285% by compound 5e compared to PAC-1, the first procaspase activating compound, which was used as a control. Our docking simulation revealed that compound 5e was a potent allosteric inhibitor of procaspase-3 through chelation of inhibitory zinc ion. Physicochemical and ADMET calculations for 5e provided useful information of its suitable absorption profile and some toxicological effects that need further optimization to be developed as a promising anticancer agent. Conclusion: Compound 5e has emerged as a potential hit for further design and development of caspases activators and anticancer agents.

Background: The development of resistance to available anticancer drugs is increasingly becoming a major challenge and new chemical entities could be unveiled to compensate for this therapeutic failure. Objectives: The current study demonstrated whether N-protected and deprotected amino acid derivatives of 2- aminopyridine could attenuate tumor development using colorectal cancer cell lines. Methods: Biological assays were performed to investigate the anticancer potential of synthesized compounds. The in silico ADME profiling and docking studies were also performed by docking the designed compounds against the active binding site of beta-catenin (CTNNB1) to analyze the binding mode of these compounds. Four derivatives 4a, 4b, 4c, and 4d were selected for investigation of in vitro anticancer potential using colorectal cancer cell line HCT 116. The anti-tumor activities of synthesized compounds were further validated by evaluating the inhibitory effects of these compounds on the target protein beta-catenin through in vitro enzyme inhibitory assay. Results: The docking analysis revealed favorable binding energies and interactions with the target proteins. The in vitro MTT assay on colorectal cancer cell line HCT 116 and HT29 revealed potential anti-tumor activities with an IC50 range of 3.7-8.1μM and 3.27-7.7 μM, respectively. The inhibitory properties of these compounds on the concentration of beta-catenin by ELISA revealed significant percent inhibition of target protein at 100 μg/ml. Conclusion: In conclusion, the synthesized compounds showed significant anti-tumor activities both in silico and in vitro, having potential for further investigating its role in colorectal cancer.

Background: Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer deaths in the US due to the lack of effective targeted therapeutics and extremely poor prognosis. Objective: The study aims to investigate the role of miR-193b and related signaling mechanisms in PDAC cell proliferation, invasion, and tumor growth. Methods: Using PDAC cell lines, we performed cell viability, colony formation, in vitro wound healing, and matrigel invasion assays following transfection with miR-193b mimic or control-miR. To identify potential downstream targets of miR-193b, we utilized miRNA-target prediction algorithms and investigated the regulation of eukaryotic elongation factor-2 kinase (eEF2K) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathways and mediators of epithelial mesenchymal transition (EMT). The role of miR-193b in PDAC tumorigenesis was evaluated in in vivo tumor growth of Panc-1 xenograft model in nude mice. Results: We found that miR-193b is under expressed in PDAC cells compared to corresponding normal pancreatic epithelial cells and demonstrated that ectopic expression of miR-193b reduced cell proliferation, migration, invasion, and EMT through downregulation of eEF2K signaling in PDAC cells. miR-193b expression led to increased expression of E-Cadherin and Claudin-1 while decreasing Snail and TCF8/ZEB1 expressions via eEF2K and MAPK/ERK axis. In vivo systemic injection of miR-193b using lipid-nanoparticles twice a week reduced tumor growth of Panc-1 xenografts and eEF2K expression in nude mice. Conclusions: Our findings suggest that miR-193b expression suppresses PDAC cell proliferation, migration, invasion, and EMT through inhibition of eEF2K/MAPK-ERK oncogenic axis and that miR-193b-based RNA therapy might be an effective therapeutic strategy to control the growth of PDAC.

Background & Objective: The insulin/IGF-1R/PI3K/Akt signalling cascade is increasingly being linked to breast cancer development, with aldose reductase (AR) playing a key role in mediating the crosstalk between this pathway and angiogenesis. The current study was designed to investigate whether nimbolide, a neem limonoid, targets the oncogenic signaling network to prevent angiogenesis in breast cancer. Methods: Breast cancer cells (MCF-7, MDA-MB-231), EAhy926 endothelial cells, MDA-MB-231 xenografted nude mice, and tumour tissues from breast cancer patients were used for the study. The expression of AR and key players in IGF-1/PI3K/Akt signaling and angiogenesis was evaluated by qRT-PCR, immunoblotting, and immunohistochemistry. Molecular docking and simulation, overexpression, and knockdown experiments were performed to determine whether nimbolide targets AR and IGF-1R. Results: Nimbolide inhibited AR with consequent blockade of the IGF-1/PI3K/Akt and /HIF-1alpha/VEGF signalling circuit by influencing the phosphorylation and intracellular localisation of key signaling molecules. The downregulation of DNMT-1, HDAC-6, miR-21, HOTAIR, and H19 with the upregulation of miR-148a/miR-152 indicated that nimbolide regulates AR and IGF-1/PI3K/Akt signaling via epigenetic modifications. Coadministration of nimbolide with metformin and the chemotherapeutic drugs tamoxifen/cisplatin displayed higher efficacy than single agents in inhibiting IGF-1/PI3K/Akt/AR signaling. Grade-wise increases in IGF-1R and AR expression in breast cancer tissues underscore their value as biomarkers of progression. Conclusion: This study provides evidence for the anticancer effects of nimbolide in cellular and mouse models of breast cancer besides providing leads for new drug combinations. It has also opened up avenues for investigating potential molecules such as AR for therapeutic targeting of cancer.

Background: The positively charged membrane impermeant sulfonamides were evaluated as a remarkable class of carbonic anhydrase inhibitors (CAIs) previously. Without affecting the human carbonic anhydrase (hCA), cytosolic isoforms hCA I and II, inhibition of two membrane-associated isoforms hCA IX and XII especially overexpressed in hypoxic tumour cells, makes the pyridinium salt derivatives potent promising therapeutic agents. Objective: A novel series of tri, tetra, and cyclo-substituted pyridinium salt derivatives of the lead compound 2- (hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide has been prepared by using sixteen different pyrylium salts, for the search of selective inhibitors of transmembrane tumour-associated human carbonic anhydrase hCA IX and XII. Methods: Molecular modeling studies were carried out to understand and rationalize the in vitro enzyme inhibition data. Results: Six of the new compounds showed good inhibitory profiles with low nanomolar range (< 100 nM) against hCA IX/XII, and compound 5 showed excellent potency with Ki values lower than 10 nM. In addition, molecular modelling studies have presented the possible binding modes of the ligands. Conclusion: Most of the compounds displayed potent inhibitory activity against the tumor-associated hCA IX and XII in the low nanomolar range and selectivity over the off-targeted isoforms hCA I and II. Due to their cationic structure and membrane-impermeant behavior, it is also expected to maximize the selectivity over cytosolic isoforms hCA I/II while inhibiting tumor overexpressed isoforms hCA XI/XII of new compounds in in vivo conditions.

Background: Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the reversible hydration of carbon dioxide to bicarbonate and proton. Inhibition of isoforms IX and XII could aid in the amelioration of cancer. Objective: A series of coumarin carboxamides (6a-j) were synthesized and were assayed against hCA isoforms I, II, IX, and XII. Methods: Thin Layer Chromatography (TLC) analysis was done by utilizing Merck silica gel 60 F254 aluminum plates. Stuart Digital Melting Point Apparatus (SMP 30) was used in determining the melting points of the compounds, which are uncorrected. High Resolution Mass Spectra (HRMS) were determined by Agilent QTOF mass spectrometer 6540 series instrument and were performed using ESI techniques at 70eV. Results: All the compounds selectively inhibited isoforms IX and XII as against hCAs I and II. Compounds 6a-e exhibited the best inhibitory profiles against hCA IX (Ki < 25 nM). The isoform hCA XII was effectively inhibited by all compounds showing the Ki values less than 65 nM. The Compounds 6a, 6b, 6g, 6h, and 6j exhibited Ki values less than 10 nM. The binding interactions of the most potent compounds, 6a and 6b, were investigated through docking studies with hCAs IX and XII. Conclusion: These compounds may be utilized as useful starting points for the design and development of selective and potent hCA IX and XII inhibitors.