Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 22, Issue 11, 2022

Apoptosis is a programmed cell death that occurs due to the production of several catabolic enzymes. During this process, several morphological and biochemical changes occur in mitochondria, the main organelle in the cell that participates in apoptosis and controls apoptotic pathways. During apoptosis, cytochrome c is released from mitochondria, and different proteins activate caspase cascades that carry out the cell towards the death process. Apoptosis mainly occurs due to p53 protein that allows the abnormal cells to proliferate. Bcl-2 and Bcl-xl are two anti-apoptotic members of the protein family that prevents apoptosis. The membrane potential of mitochondria decreases by the opening of the permeability transition pore (PTP). These PTP are formed by the binding of Bax with adenine nucleotide translocator (ANT) and cause depolarization in the membrane. The depolarization releases apoptogenic factors (cytochrome c) that result in the loss of oxidative phosphorylation. Knockdown in lactate dehydrogenase (LDH) is the cause of the decrease in mitochondrial membrane potential elevating the levels of reactive oxygen species (ROS) and Bax. Consequently, causing an increase in the release of cytochrome c that ultimately leads to apoptosis. In this review, we have summarized the combined effect of mitochondrial membrane potential and LDH enzyme that triggers apoptosis in cells and their role in the mechanism of apoptosis.

World Health Organization categorized breast cancer as one of the leading cancer types in females worldwide, and its treatment remains challenging. Accumulated evidence suggested the role of estrogen and its metabolites in pre- and post-menopausal women. Upregulation of estrogen-dependent aromatase is significantly involved in the pathogenesis of breast cancer. Several aromatase inhibitors, such as exemestane, formestane, and letrozole, are being used clinically, owing to their estrogen suppression role. Apart from these drugs, several other molecules, such as natural and synthetic flavonoids, have been reported widely for a similar biological activity. However, some reasonable modifications are required for these structures to achieve desired efficacy and to alleviate toxicity. Designing a novel aromatase inhibitor will be possible if we can establish a rational correlation between the chemistry and biological features of the existing molecules. The benzopyranone- ring system, present in the flavonoid molecules, has been reported as a pharmacophore due to its inhibitory activity on aromatase, which helps repress breast cancer progression. This essential feature has been utilized to modify several natural flavonoids into 5 and 7 hydroxy/methoxy flavone, 4-imidazolyl/triazolyl flavone, 5,4’- diamino flavone, 7,8- benzo-4-imidazolyl flavone, α-naphthoflavone, and 2-azole/thiazolyl isoflavone derivatives. These scaffolds have been considered in this review for meticulous study in aspects of the structure-activity relationship for aromatase inhibitory activity, and it would likely pave the way for designing a potential lead candidate in the future.

Cancer therapy is based on the killing of cancer cells using various therapeutic agents, such as radiation, chemotherapy or targeted therapy drugs, and immunotherapy. Cancer cells may undergo apoptosis, mitotic catastrophe, necrosis, autophagy, mitophagy, senescence, etc., depending on the therapeutic modality and nature of cancer cells. Mutations in some critical genes, such as p53 and Phosphatase and Tensin Homolog (PTEN) tumor suppressor genes, are associated with immune escape of cancer cells and tumor progression. Furthermore, the overexpression of some genes. such as phosphatidylinositol-3-kinase (PI3K), Nuclear Factor of Kappa B (NF-ΚB), cyclooxygenase-2 (COX-2) and mammalian Target of Rapamycin (mTOR), is associated with the resistance of cancer cells to various types of cell death. Melatonin is known as a circadian regulator hormone that has several anti-cancer properties. It has the ability to activate tumor suppressor genes and attenuate the expression of survival genes in cancer cells. Modulation of cell death or survival genes that have been disrupted or overexpressed in cancer cells can improve cancer therapy. In this review, we explain the potential of melatonin in regulating various mechanisms of cancer cell death.

Background: Increasing evidence shows that GSDME is involved in tumor chemotherapy. Lobaplatin is an important chemotherapy drug for the treatment of cervical cancer. However, the exact mechanism of lobaplatin in the treatment of cervical cancer remains unclear. Objective: In this study, whether GSDME is a new mechanism of lobaplatin in the treatment of cervical cancer has been explored. Methods: Cell pyroptosis was measured by Cell Counting Kit-8 and flow cytometry analyses. Western blot analysis was used to check proteins expression. Results: The cell viability was significantly decreased by lobaplatin treatment. Compared with the control group, the percentage of pyroptosis (PI and Annexin-V double-positive cells) increased after lobaplatin treatment. In addition, lobaplatin induced caspase-3 activation and GSDME cleavage. z-DEVD, a specific inhibitor of caspase-3, reduced lobaplatin-mediated GSDME cleavage and concurrently inhibited pyroptosis. More importantly, GSDME deficiency obviously reduced lobaplatin-induced pyroptosis. Conclusion: These data demonstrate that caspase-3/GSDME axis contributed to the lobaplatin-mediated pyroptosis in cervical cancer cells. This finding indicates that GSDME-mediated pyroptosis is a new mechanism for lobaplatin to kill tumor cells and suggests that the caspase-3/GSDME pathway offers new insights into cancer chemotherapy.

Background: Recent studies have shown that propofol and sevoflurane, two common anesthetics, can prevent tumor development. The prevalence of lung adenocarcinoma in China is highest in Yunnan Xuanwei, and many patients with lung cancer in this area are often resistant to platinum-based treatments. Objective: The objective of the study was to investigate the effects of propofol and sevoflurane on malignant biological behavior and cisplatin resistance of Xuanwei lung adenocarcinoma. Methods: Herein, XWLC-05/R, a cisplatin-resistant cell line of XWLC-05 cells from Xuanwei lung adenocarcinoma, was constructed. The XWLC-05 cells and XWLC-05/R cells were treated with propofol and sevoflurane singly or as a combination and subjected to CCK-8 assay, clone formation tests, and flow cytometry analysis to assess the proliferation level of cells. The morphology and number of apoptotic bodies in XWLC-05 cells and XWLC-05/R were examined with a transmission electron microscope. The ANNEXIN V-FITC/PI and transwell assays were performed to evaluate apoptosis, invasion, and migration of the cells. Subsequently, we constructed a Xuanwei lung adenocarcinoma xenograft model to investigate the effects of propofol and sevoflurane on the tumorigenicity of XWLC-05 cells in vivo. Results: Treatment with propofol and sevoflurane significantly inhibited proliferation, invasion, migration, and induced apoptosis of XWLC-05 and XWLC-05/R cells. These effects were more pronounced when propofol and sevoflurane were co-incubated with the cells. Moreover, both propofol and sevoflurane significantly inhibited Wnt/β- catenin and PI3K/AKT pathways. Moreover, the two drugs effects suppressed the malignant biological behavior of XWLC-05 cells and XWLC-05/R cells, and this effect was counteracted by 740Y-P (PI3K/AKT pathway activator) and Wnt pathway activator 1 (Wnt/β-catenin pathway activator). In vivo experiments confirmed that propofol and sevoflurane alleviated the tumorigenicity of XWLC-05 cells. Conclusions: In summary, this study shows, for the first time, that propofol and sevoflurane decrease the proliferation, invasion, migration and induce apoptosis of XWLC-05 cells and XWLC-05/R cells by impeding the Wnt/β-catenin and PI3K/AKT signaling pathways, thereby alleviating the development of Xuanwei lung adenocarcinoma in vivo. Moreover, these effects are more pronounced when the two drugs are combined.

Background: Investigating the effects of newly synthesized agents on various molecular mechanisms to understand their mechanism of action is an important step of pre-clinical screening. Benzimidazoles are composed of a unique fused benzene and imidazole ring and have attracted great attention due to their broad bioactivities, including antitumor. Objective: In the current study, we reported the synthesis of novel benzimidazole derivatives and investigated the possible cytotoxic and anti-angiogenic effects on human prostate cancer and umbilical vein endothelial cells (HUVECs). Methods: MTT assay was used to assess cell viability. A scratch assay was conducted to monitor the migration of cells. mRNA expression levels of VEGF, MMP-2, and MMP-9 were evaluated using qPCR. Changes in protein levels were evaluated by western blotting. Results: Compound G1, having a chlorine moiety, showed a potent cytotoxic activity on both prostate cancer cells and HUVECs, and inhibited cell migration via decreasing the mRNA and protein levels of key angiogenesis-related molecules such as VEGF, MMP-2, and MMP-9. Conclusion: These results suggest that newly synthesized G1 may be a novel anti-angiogenic agent for prostate cancer treatment.

Background: Chalcones are precursors of flavonoids or isoflavonoids, and they are abundant in edible plants. Chalcones constitute an important group of natural and synthetic products with a wide range of pharmacological activities. Objective: To determine the seeds of the anti-tumor agents, we focused on the potential bioactive materials obtained from chalcone derivatives. Methods: Two series of chalcone derivatives containing aminoguanidine or bis-chalone were designed, synthesized, and screened for their cytotoxicity, proliferation inhibition, and apoptosis-promoting activity in vitro against a panel of human tumor cell lines. Results: Among the various compounds studied in this work, 2-((E)-4-((E)-3-oxo-3-(p-tolyl)prop-1-en-1- yl)benzylidene)hydrazine-1-carboximidamide (5f) was the most potent, with IC50 values of 7.17 μM and 3.05 μM antiproliferative activity in vitro against human hepatocarcinoma HepG2 cells and SMMC-7721 cells, respectively. This result showed that the compound possessed a certain degree of selectivity for human hepatocarcinoma cells, especially for SMMC-7721. Then, Annexin V/PI flow cytometry assay was used to investigate different concentrations of compound 5f to demonstrate the ability of compound 5f in inducing apoptosis of SMMC-7721 cells in a concentrationdependent manner. Finally, these results were further verified by Western blot analysis. Conclusion: Based on the collective results, compound 5f may be a promising anti-cancer compound, and may play a significant role in subsequent research.

Background: 1,3-Diones are versatile reagents used for many heterocyclic transformations. Among such groups of compounds, cyclohexane-1,3-dione is widely used in organic synthesis to produce biologically active compounds. Objective: In this work, target molecules were synthesized from tetrahydrobenzo[b]thiophen-3- carboxamide derivative with different substituents, and their structure-activity relationships were discussed in detail. Methods: Cyclohexane-1,3-dione underwent different multi-component reactions to produce fused thiophene, thiazole, coumarin, pyran, and pyridine derivatives. The anti-proliferative activity of the newly synthesized compounds toward the six cancer cell lines, namely A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721 was studied. In addition, inhibitions of the most active compounds toward cancer cell lines classified according to the disease were also studied. Furthermore, Pan Assay Interference compounds (PAINS) of the selected compounds were analyzed, along with the c- Met inhibitions. Results: Anti-proliferative evaluations were performed for all of the synthesized compounds, in which the varieties of substituents through the aryl ring and the heterocyclic ring afforded compounds with high activities. Inhibition activity against the cancer cell lines classified according to the disease, c-Met, and PAINS of the synthesized compounds were measured. Conclusion: Compounds 3, 13a, 13b, 14a, 16f, 17a, 28, 30a, and 31were the most cytotoxic compounds toward the six cancer cell lines. Inhibition toward cancer cell lines classified according to the disease showed that, in most cases, the presence of the electronegative CN and or Cl groups within the molecule was responsible for its high activity.

Background: Hexahydroquinoline as a small molecule was reported for good cytotoxicity and affinity towards Mcl-1. Hence, new compounds were explored as Mcl-1 inhibitors to be potent anticancer agents. Objective: Compounds were synthesized and screened for cytotoxicity. The active compound was evaluated for cell cycle analysis, Mcl-1 inhibition, caspase-3, and caspase-9 activation. Further compounds were docked with Mcl-1 to confirm the mechanism of cytotoxicity. Methods: Compounds were confirmed by spectral techniques and screened for cytotoxicity at National Cancer Institute (USA). The active derivatives were screened by SRB and MTT. In addition, the potent compound was studied for apoptosis and cell cycle analysis by PI staining, Mcl-1 inhibition by TR-FRET assay, and activation assay of caspase-3 and caspase-9 with the Elisa technique. Results: Compounds 6a and 6b exhibited the highest growth inhibition of 86.28% and 93.20% against SR and HOP- 62, respectively. Compound 6a showed higher cytotoxicity (IC50 = 0.4 μM) against THP-1 and HL-60. It showed 15- fold higher apoptosis compared to control by arresting cells at the Sub-G1 in the cell cycle. It also showed a potent inhibition with IC50 of 1.5 μM against the anti-apoptotic protein Mcl-1, which may induce apoptosis. Furthermore, apoptosis was evidenced by an increase in cleaved caspase-3 and caspase-9 to 4.20 and 3 folds, respectively higher than control. The docking score of compound 6a was in good agreement with the Mcl-1 inhibition assay. Conclusion: Compound 6a inhibited anti-apoptotic protein Mcl-1 and induced activation of pro-apoptotic proteins caspase-3 and caspase-9. These dual results suggested the mechanism of apoptosis and cytotoxicity.

Background: The World Health Organization (WHO) estimated that the number of cancer-related deaths was 9.6 million in 2018 and 2.09 million deaths occurred by lung cancer. The American Institute for Cancer Research (AICR) also observed gender preferences in lung cancer, common in men than women. Since the past decade, nanoparticles have now been widely documented for their anti-cancer properties, which signifies that the development of nanotechnology would be a future diagnosis and treatment strategy for lung cancer. Objective: The current study aimed to investigate the role of biosynthesized CdS nanoparticles (CdS NPs) in lung cancer cells (A549). Therefore, whether the CdS NP induces lung cancer cell death and the underlying mechanism is yet to be elucidated. Methods: Literature was searched from various archives of biomedical and life science journals. Then, CdS NPs were biosynthesized and characterized by traditional and cutting-edge protocols. The CdS NP-mediated cell death was elucidated following standard protocols. Results: CdS NPs induced cytotoxicity towards A549 cells in a dose-dependent manner. However, such a death mechanism does not go through necrosis. Intracellular reactive oxygen species (ROS) accumulation and mitochondrial membrane depolarization demonstrated that cell death is associated with intracellular ROS production. Furthermore, increased sub-G1 population, Bax expression, and decreased Bcl-2 expression revealed that the death was caused by apoptosis. Conclusion: CdS NPs promote apoptosis-mediated lung cancer cell death through ROS production.

Background: Indoline-2,3-dione comprises a leading course group of heterocycles endowed with appealing biological actions, including anticancer activity. There are significant justifications for exploring the anticancer activity of Schiff base derivatives of isatin as a vast number of reports have documented remarkable antiproliferative action of isatin nucleus against various cancer cell lines. Aims and Objectives: A series of arylthiazole linked 2H-indol-2-one derivatives (5a-t) was designed and synthesized as potential VEGFR-2 kinase inhibitors keeping the essential pharmacophoric features of standard drugs, like sunitinib, sorafenib, nintedanib, etc. They were evaluated for their in vitro anticancer activity. The aim of this study was to investigate and assess the anticancer potential of isatin-containing compounds along with their kinase inhibition activity. Methods: The title compounds were synthesized by reacting substituted isatins with para-substituted arylthiazoles using appropriate reaction conditions. Selected synthesized derivatives went under preliminary screening against a panel of 60 cancer cell lines at NCI, the USA, for single-dose and five dose assays. Molecular docking was performed to explore the binding and interactions with the active sites of the VEGFR-2 receptor (PDB Id: 3VHE). Derivatives 5a, 5b, 5c, 5d, 5g, 5h, and 5m were assessed for in vitro inhibition potency against Human VEGFR-2 using ELISA (Enzyme- Linked Immunosorbent Assay) kit. All the target compounds were determined against human colon cancer cell line SW480 (colorectal adenocarcinoma cells). Cellular apoptosis/necrosis was determined by flow cytometry using annexin V-FITC. DNA content of the cells was analyzed by flow cytometry and the cycle distribution was quantified. Results: Compounds 5a and 5g exhibited noteworthy inhibition during a five-dose assay against a panel of 60 cell lines with MID GI50 values of 1.69 and 1.54 μM, respectively. Also, both the lead compounds 5a and 5g demonstrated promising VEGFR-2 inhibitory activity with IC50 values of 5.43±0.95 and 9.63±1.32 μM, respectively. The aforesaid potent compounds were found effective against SW480 (colorectal adenocarcinoma cells) with IC50 values of 31.44 μM and 106.91 μM, respectively. Compound 5a was found to arrest the cell cycle at the G2/M phase, increasing apoptotic cell death. The docking study also supported VEGFR-2 inhibitory activity as both compounds 5a and 5g displayed promising binding and interactions with the active sites of VEGFR-2 receptor (PDB: 3VHE) with docking scores - 9.355 and -7.758, respectively. All the compounds obeyed Lipinski’s rule of five. Conclusion: Indoline-2,3-dione and thiazole have huge potential to be considered a steer combination approach for developing promising kinase inhibitors as cancer therapeutics.

Background: Gemini Curcumin (Gemini-Cur) is the latest nanoformulation of curcumin with a significant apoptotic effect on cancer cell lines. Objective: This in vitro study aims to evaluate the apoptotic effects of Gemini-Cur toward MDA-MB-468 breast cancer cell lines and further the related mechanism of apoptosis. Methods: The cytotoxicity of Gemini-Cur toward MDA-MB-468 cell lines was tested using MTT assay. Furthermore, the expression ratio of Bax/Bcl-2 was evaluated by qRT-PCR. Consequently, the protein expression of Bax/Bcl-2, survivin, and caspase-3 was measured using western blotting. Results: Having treated MDA-MB-468 cell lines with Gemini-Cur, the IC50 values were found to be 44.44 and 31.63 μM at 24 and 48 h, respectively. Our findings showed that Gemini-Cur significantly suppresses cancer cell proliferation in a time- and dose-dependent manner. Furthermore, the data revealed that curcumin nanoformulation induces apoptosis in MDA-MB-468 cells through modulation of the expression of Bax, Bcl-2, Survivin, and Caspase-3. Conclusion: The data of the current study propose that Gemini-Cur can be considered a promising candidate against triple-negative breast cancer.

Background: Eryngium is a genus flowering plant in the Umbelliferae family, having pharmacological properties, such as anti-inflammatory and anti-diabetic. Given the nature of melanoma and breast cancers in recent years and the fact that the anti-cancer properties of Eryngium billardieri on mentioned cell lines have not been studied, the present study was conducted to explore these properties. Objective: The mechanisms of cytotoxicity and apoptosis of aerial parts of various extracts and fractions of E. billardieri on cancerous cells and normal cells were investigated. Methods: Samples were collected from natural habitats, dried and then extracted by Soxhlet apparatus with solvents of n-Hex, DCM and methanol, respectively. The cytotoxic effects of the extracts were investigated by the MTT method on MCF7, B16 and HFF-2 classes for 24 and 48 hours. Flow cytometry was also used to investigate the mechanism of cytotoxicity, and it has been confirmed by Real-time PCR of p53 and Bax genes as to which comprise the apoptosis regulatory proteins. Meanwhile, volatile compounds of extracts were identified by the GC-MS method. Results: The obtained data showed that the n-Hex extract of E. billardieri on B-16 and MCF7 cell lines and dichromethane extract on MCF7 cell line had the most significant cytotoxic effect compared to DMSO control (p-value <0.001). Our finding showed that the mechanism of n-Hex extract with 80% and 100% vlc fractions on B16 induced apoptotis compared to HFF-2 control cells; moreover, n-Hex extract and 80% vlc fraction on MCF7 were apoptotic. The major compounds of n-Hex, DCM, and 80% and 100% fractions of n-Hex extract obtained from GC-MS were non-terpenoid. Conclusion: Non-terpenoid compounds of E. billardieri can be responsible for exhibiting the most cytotoxic effects on MCF7 and B16 cell lines with apoptotic mechanism, and n-Hex extract was found to have the most significant inhibitory effect on cancerous cells compared to the HFF-2 control cells by employing the mechanism of apoptosis.