Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 23, Issue 8, 2023

After cardiovascular disease, cancer is the most common cause of death worldwide. Due to their versatility, heterocyclic compounds play an important role in drug discovery. Medical remedies are constantly being discovered, especially for catastrophic disorders such as cancer. Here, this review is focused on sulphur containing heterocyclic compounds as anticancer agents. Sulphur is found in a variety of vitamin cofactors, sugars, and nucleic acids, and it also plays a function in controlling translation by sulphurating transfer RNA. Sulphur has obtained a lot of interest in the anticancer research medicinal fields. Thiophene derivatives were tested for anti-proliferative activity against breast cancer cells in a recent screening study, and the bulk of chemicals exhibited potent inhibitory effects. In recent years, azoles such as thiazole and thiadiazole structures have gained prominence in cancer research.

Objectives: Hepatocellular carcinoma (HCC) is the sixth most common type of cancer and accounts for ~90% of cases, with an approximated incidence of >1 million cases by 2025. Currently, the backbone of HCC therapy is the oral multi-kinase inhibitor, Sorafenib, which consists of a Pyridine heterocycle ring system. This review highlights the introspective characteristics of seven anticancer drugs of heterocyclic nature against HCC along with their structural activity relationships and molecular targets. Methods: Literature collection was performed using PubMed, Google Scholar, SCOPUS, and Cross ref. Additional information was taken from the official website of the FDA and GLOBOCAN. Key findings/ Results: Based on the available literature, approved heterocyclic compounds show promising results against HCC, including Sorafenib (Pyridine), Regorafenib (Pyridine), Lenvatinib (Quinoline), Cabozantinib (Quinoline), Gemcitabine (Pyrimidine), 5-Fluorouracil (Pyrimidine)and Capecitabine (Pyrimidine), their mechanism of action and key aspects regarding its structural activity were included in the review. Conclusion: Heterocyclic compounds represent almost two-thirds of the novel drugs approved by FDA between 2010 and 2020 against Cancer. This review summarizes the clinical relevance, mechanism of action, structural activity relationship, and challenges of the seven available anticancer drugs with heterocyclic ring systems against HCC.

The current study demonstrates amygdalin’s (vitamin B17) postulated mechanism of action on cancer cells where it kills cells by selective toxicity, promotes apoptosis via cell cycle arrest, induces apoptosis via intrinsic cell death pathway (the mitochondria-initiated pathway), and enhances immunity. Thus, amygdalin can be considered a valuable natural cancer therapeutic agent. The toxicity of Amygdalin was reviewed. Moreover, solutions to avoid the cyanide poisoning have been proposed.

Presently, several protein kinases have been discovered with the aim to treat various cancers. Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor that plays a role in the pathogenesis of a wide variety of human cancers known as ALCLs, NSCLC, ovarian cancer, breast cancer, colorectal cancer, neuroblastoma, etc. The fulllength ALK receptor is a classical receptor tyrosine kinase composed of an amino-terminal extracellular domain and an intracellular tyrosine kinase domain. Crizotinib is a strong oral small-molecule first tyrosine kinase inhibitor of ALK to be used in the treatment of ALK-dependent NSCLC. Due to the drug resistance of first generation ALK inhibitors, researchers are trying to design and synthesize novel ALK inhibitors with various heterocyclic rings in which 2,4- diarylaminopyrimidine derivatives with a specific N-(3-pyridinylmethyl)urea moiety, 2-amino-4-(1-piperidine) pyridine derivatives, 7-azaindole and carboxamide derivatives and some others produced potential compounds. To overcome drug resistance, to get better affinity and to reduce drug toxicity, there is an urgent need for novel ALK inhibitors. The present review describes the ALK signaling, their inhibitors and related structure activity relationships for the development of potential ALK inhibitors.

Aims: Retrospective clinical studies have shown that opioids could potentially affect the risk of cancer recurrence and metastasis. Better understanding of the effects of opioids on cancer will help to select the optimal anesthetic regimens to achieve better outcomes in cancer patients. Background: Increasing evidence has shown the direct effects of opioids on bulk cancer cells and cancer stem cells. Opioid such as nalbuphine is approved to control cancer-associated pain but little is known on their possible cancer effects. Objective: To assess the biological effects of nalbuphine on acute myeloid leukemia (AML) differentiated and stem/progenitor CD34⁺ cells. Methods: AML CD34⁺ cells were isolated with colony formation, growth and apoptosis assays performed. Biochemical and immunoblotting analyses were conducted in AML cells exposed to nalbuphine. Results: Nalbuphine at clinically relevant concentrations was active against a panel of AML cell lines with varying IC50. Importantly, nalbuphine augmented the efficacy of cytarabine and daunorubicin in decreasing AML cell viability/ growth. Besides bulk AML cells, we noted that nalbuphine was effective and selective in decreasing viability and colony formation of AML CD34⁺ cells while sparing normal hematopoietic CD34⁺ cells. The action of nalbuphine on AML cells is not associated with opioid receptors but via inhibiting Ras/Raf/MEK/ERK signaling pathway. Overexpression of constitutively active Ras partially but significantly reversed the inhibitory effects of nalbuphine on AML cells. Conclusion: Our findings reveal the selective anti-AML activity of nalbuphine and its ability in inhibiting Ras signaling. Our work suggests that nalbuphine may be beneficial for leukemia patients.

Background: Tamoxifen is the most commonly used hormonal treatment for ERα-positive breast cancer. Tamoxifen resistance is still a big problem for ERα target therapy. RBP7 is a member of the cellular retinol-binding protein family. Objective: This study aims to investigate the prognostic role of RBP7 and the relationship between RBP7 expression and sensitivity or resistance to tamoxifen in ERα-positive breast cancer. Methods: A bioinformatics method was used to investigate RBP7 expression and the prognostic value of RBP7 in different subtypes of breast cancer. The relationship between RBP7 expression and sensitivity or resistance to tamoxifen was studied using clinical data (GSE1379) and cell line data (GSE27473, GSE2645923, GSM3715281, and GSM3715282). Transfection of RBP7 experiments was used to testify to the function of RBP7 in MCF7 cell. Results: RBP7 is a member of the family of cellular retinol-binding proteins. RBP7 expression was down-regulated at both mRNA and protein levels in breast cancer and was not associated with different TNM (Tumor, Node, Metastasis) stages. High expression of RBP7 was significantly related to good relative percent survival in the luminal A subtype, but in negative breast cancer, the result was opposite. The ROC plot showed that RBP7 had a significant predictive value for the tamoxifen response in the luminal A subtype. The expression of RBP7 from patients with recurrence treated with tamoxifen was significantly reduced. Gene Expression Omnibus showed that RBP7 expression was reduced considerably in tamoxifen-resistant MCF7 cells and T47D cells. The expression of RBP7 was positively correlated with some microRNAs involved in negatively regulating tamoxifen-resistant breast cancer. We also found that the expression of RBP7 decreased significantly in tamoxifen-resistant MCF7 cells, and transfection of RBP7 increased the sensitivity of resistant cells to tamoxifen. Conclusion: Reduced expression of RBP7 is associated with resistance to tamoxifen in luminal A breast cancer. Our research may help to explore the mechanisms of resistance of breast cancer to tamoxifen.

Background: Glioblastoma multiforme (GBM) is a lethal form of central nervous system cancer with a lack of efficient therapy options. Aggressiveness and invasiveness of the GBM result in poor prognosis and low overall survival. Therefore, the necessity to develop new anti-carcinogenic agents in GBM treatment is still a priority for researchers. Ion channels are one of the primary regulators of physiological homeostasis with additional critical roles in many essential biological processes related to cancer, such as invasion and metastasis. A multi-channel blocker, hydroquinidine (HQ), is currently in use to treat short-QT and Brugada arrhythmia syndromes. Objective: The objective of the study was to examine the alterations in survival, clonogenicity, migration, tumorigenicity, proliferation, apoptosis, and gene expression profile of temozolomide (TMZ)-sensitive and TMZ-resistant GBM cells upon HQ treatment. Methods: The possible anti-neoplastic activity of HQ on GBM cells was investigated by several widely applied cell culture methods. The IC50 values were determined using the MTT assay. Upon HQ treatment, the clonogenicity and migration capacity of cells were evaluated via colony-formation and wound healing assay, respectively. For antiproliferative and apoptotic effects, EdU and CFSE, and Annexin-V labeling were applied. Tumorigenicity level was depicted by employing soft agar assay. The expression level of multiple genes functioning in the cell cycle and apoptosis- related processes was checked utilizing qPCR. Results: A significant anti-carcinogenic effect of HQ on TMZ-sensitive and -resistant GBM cells characterized by the increased apoptosis and decreased proliferation rate was revealed due to the altered gene expression profile related to cell cycle and cell death. Conclusion: In this study, the anti-carcinogenic effect of HQ has been demonstrated for the first time. Our data suggest the possible utilization of HQ to suppress the growth of GBM cells. Further studies on GBM-bearing animal models are required to assess its therapeutic potential in GBM treatment.

Background: Heterozygous mutations in the cytoplasmic and mitochondrial isoforms of isocitrate dehydrogenase enzymes 1 and 2 subtypes have been extensively exploited as viable druggable targets, as they decrease the affinity of isocitrate and higher affinity of D-2-hydroxyglutarate, an oncometabolite. Objective: Vorasidenib (AG-881) has recently been reported as a promising dual inhibitor of mutant isocitrate dehydrogenase 1 and 2 with the ability to penetrate the blood-brain barrier towards the treatment of low-grade glioma. In order to combat drug resistance and toxicity levels, this compelled us to further investigate this substance as a basis for the creation of potential selective inhibitors of mutant isocitrate dehydrogenases 1 and 2. Methods: By employing a wide range of computational techniques, binding moieties of AG-881 that contributed towards its selective binding to isocitrate dehydrogenase enzymes 1 and 2 were identified and subsequently used to generate pharmacophore models for the screening of potential inhibitor drugs that were further assessed by their pharmacokinetics and physicochemical properties. Results: AG-881 was identified as the most favorable candidate for isocitrate dehydrogenase enzyme 1, exhibiting a binding free energy of -28.69 kcal/mol. ZINC93978407 was the most favorable candidatefor isocitrate dehydrogenase enzyme 2, displaying a strong binding free energy of -27.10 kcal/mol. ZINC9449923 and ZINC93978407 towards isocitrate dehydrogenase enzyme 1 and 2 showed good protein structural stability with a low radius of gyration values relative to AG-881. Conclusion: We investigated that ZINC9449923 of isocitrate dehydrogenase enzyme 1 and ZINC 93978407 of isocitrate dehydrogenase enzyme 2 could serve as promising candidates for the treatment of lower-grade glioma as they cross the blood-brain barrier, and present with lower toxicity levels relative to AG-881.

Background: The success of drug treatment of colon cancer (CC), which is in the top three in terms of incidence and mortality among all cancers, is adversely affected by reasons, such as severe side effects and chemoresistance. Clinical, epidemiological and experimental studies have indicated the need for developing new alternative drugs for the treatment of CC. Plants are an important source of traditional medicines that have proven to be highly beneficial for the treatment of CC. Aim: In this study, we aimed to reveal the antioxidant properties and anti-carcinogenic activity of Salsola grandis methanol extract (SGME) on HT-29. Methods: For this purpose, we used spectrophotometric methods to determine the antioxidant properties of SGME and LC-MS/MS analysis to measure the phenolic acid composition. We applied 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide, the thiazolyl blue (MTT) method, to evaluate its effects on cell viability and ELISA assay, realtime PCR, and western blot method to reveal its effects on apoptosis. Results: Spectrophotometric analyzes showed that SGME has the highest phenolic acid content, inhibits plasma lipid peroxidation and shows chelating activity and radical scavenging activity. Gene and protein expression analysis revealed the effects of SGME treatment on apoptosis genes/proteins. Conclusion: These findings showed that SGME has anticarcinogenic activity on CC due to its antioxidant, cell viability- suppressing and apoptosis-inducing properties.

This application describes the synthesis of new 1,4-dihydropyrido[2,3-b]pyrazine-2,3-dione derivatives and methods of using these compounds as KRAS covalent inhibitors. This class of compounds is useful for treating cancer and other diseases associated with KRAS activity.