Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 23, Issue 4, 2023

Glioblastoma is an aggressive and recurrent tumour that affects our brain and spinal cord with an extensively poor prognosis and death of the patient within 14-15 months of diagnosis. The tumour originates from astrocytes and therefore comes under the glioma known as astrocytoma. These tumours exhibit miscellaneous properties and contain cancer stem cells (CSCs). The stem cells exhibit diverse mechanisms through which these cells indulge in the proliferation and renewal of their systems. CSCs pose a significant obstacle as far as a cancer therapy is concerned, which incorporates blocking important signalling pathways involved in CSCs’ self-renewal and survival which may also include inhibition of the ATP-binding cassette transporters. Nanomedicine, biomarkers and drug delivery technologybased approaches using nanoparticles have tremendous ability to tackle the restrictions impending clinical applications, such as diagnosis and targeting of CSC-specific agents. Nanocarrier-based therapeutic agents have shown the potential of penetrating CSCs and increasing drug accumulation in CSCs. Nanomedicine can overcome ATP-driven pumpmediated multidrug resistance while also reducing the harmful effects on non-cancerous cells. The objective of this review is to examine the advantages of nanomedicine and the innovative approaches that have been explored to address the challenges presented by CSCs in order to control the progression of glioblastomas by developing novel nanotherapeutic interventions which target CSCs.

Cyclin Dependent Kinase 9 (CDK9), which controls transcriptional elongation, is a promising pharmacological target for a variety of cancerous cells, specifically those characterized by transcriptional dysregulation. CDK9 promotes the pause or release of RNA polymerase II, a rate-limiting stage in normal transcriptional regulation that is often disturbed in cancers. New indications suggest that selective CDK9 antagonism may be beneficial in the treatment of some cancers. CDK9 modulators (inhibitors and degraders) have gained a lot of attention recently, and many molecules are currently in clinical trials. In this review, the CDK9 antagonists under clinical and preclinical trials have been discussed, as well as the structure-activity relationship has been studied, which will help scientists generate more target- specific drug molecules in the future with less toxicity.

Cancer is becoming a global threat as its treatment accounts for many challenges. Hence, newer inventions prioritize the requirement of developing novel anticancer agents. In this context, kinases have been exclusively investigated and developed as a promising and novel class of drug targets for anticancer regimen. Indole derivatives have been found to be most effective for targeting multiple kinases, such as PIM, CDK, TK, AKT, SRC, PI3K, PKD, GSK, etc., to inhibit cell proliferation for cancer. Recently, a group of researchers have proposed their research outcomes related to this moiety, such as Zhang et al. described some potent PI3K inhibitors by substitution at the 4th position of the indole ring. Kassis et al. enumerated several potent CDK5 inhibitors by substituting the 2nd and 6th positions of the indole ring. In the present review, we have taken the initiative to summarize structure-activity relationship (SAR) studies of indole derivatives as kinase inhibitors for the development of potential inhibitors.

Flavonoid metal ion complexes are one of the classes of biologically active molecules with immense pharmacological potential, including antioxidant, antidiabetic, antimicrobial, and anticancer activity, to name a few. The effectiveness of this complexion depends on the state and nature of the transition metal ions and on the position to which the metal ion coordinates with their corresponding parent flavonoid. The metal coordination of flavonoids also improves the biological activities to a maximum extent compared to the parent compound. This may be attributed to many factors such as metal ions, coordination sites, structural configuration, and stability of the complexes. On the other hand, some of the metal ion complexes reduce the biological efficiency of the corresponding parent flavonoids, which can be due to the shift from antioxidant to pro-oxidant nature as well as the stability of the complexes both in in vitro and in vivo conditions. However, the literature on the stability of flavonoid metal ion complexes in in vivo conditions is very scanty. Therefore, this review summarizes and critically addresses all these parameters a favor together in a single slot that favours for the researchers to put forward to understand the mode and detailed molecular mechanism of flavonoid metals complexes compared with their corresponding parent flavonoids.

Abstract: Aim: The study aims to investigate the combined effects of chrysin and cisplatin on hepatoma(HepG2) cell lines in vivo and in vitro. Objective: Studies have suggested that chrysin can enhance the sensitivity of tumor cells to apoptosis. Drug resistance in tumor cells reduced the effectiveness of chemotherapy drugs such as cisplatin. We investigated whether the combination of chrysin and cisplatin can induce more apoptosis than chrysin alone and cisplatin alone. Methods: HepG2 cells were pretreated with chrysin for 2 h, followed by the addition of cisplatin for another 24 h. The morphologic changes were observed under inverted microscope and the cell viability was measured using the MTT test. The protein and cleavage of caspase-3,8,9, PARP, and cFLIP were determined by Western blotting. Results: The cell viability of the HepG2 cell can be reduced by the combination of chrysin pretreatment for 2 h and cisplatin addition for 24 h; Caspase-3,8,9 and PARP were cleaved after 12 h treatment with chrysin and cisplatin; Pancaspase inhibitor, Z-VAD-fmk, could reverse the apoptosis induced by chrysin and cisplatin in HepG2 cells; cFLIP was down-regulated by the combination of chrysin and cisplatin, and could be reversed by Z-VAD-fmk; the xenografted HepG2 cells formed a tumor in one week; At the end of the experiment, there were significant differences in relative tumor volume (RTV) and relative tumor proliferation rate between the combined group and the control group, the chrysin group and the cisplatin group; Western blotting showed that the levels of PARP, cFLIP, and caspase-3 proteins in isolated tumor tissues also decreased under the combined action of chrysin and cisplatin. Conclusion: The combination of chrysin and cisplatin induces apoptosis of hepatic tumor in vivo and in vitro. It downregulates cFLIP and then activates caspase-8, which triggers caspase-mediated apoptosis of HepG2 cell.

Background: In-depth and clear mechanistic study is a prerequisite for new drugs to enter clinical research. Methods: New chemical entity BY4008 was identified by our lab as a novel and highly potent EGFR and JAK3 dualtarget inhibitor. A cell-based test exhibited strong antiproliferative activities against SW620 and HCT116 colon cancer cells harboring KRAS mutation with IC50 of nanomolar potency. Furthermore, acridine orange/ethidium bromide (AO/EB), Hematoxylin-Eosin (H) and DAPI staining assays and flow cytometry analyses indicated that BY4008 has the function of pro-apoptosis and arresting the cell cycle. In addition, BY4008 inhibited the autophosphorylation of EGFR and blocked the activation of downstream signaling and the JAK-STAT3 pathway. Results: Meanwhile, a decreased level of reactive oxygen species (ROS) and an increased level of malondialdehyde (MDA) in SW620 and HCT116 cells were observed after exposure to BY4008. Conclusion: In summary, this study provides an important structural basis and mechanistic study for future effective treatment of colorectal cancer.

Aims: To find out the role of secretory phospholipase A2 (sPLA2) isozymes as potential targets in tobacco condensate-induced colon damage. Background: The effects of cigarette smoke condensate (CSC) and the molecular mechanisms involved in the regulation of phospholipase A2 (PLA2) and its isozymes in colon cells, which are still unclear and emerging, are studied. Objectives: The study aimed to check the effect of CSC on cell viability and reactive oxygen species (ROS) and superoxide. Also, the effect of CSC on gene expression of different secretory phospholipase A2 (sPLA2) was evaluated. Moreover, the impact of inhibition of sPLA2 on various cell properties i.e. cell viability, cell proliferation, membrane damage and free radicals’ generation is also studied. Methods: CSC-induced changes were evaluated in cell viability by MTT assay, followed by the evaluation of membrane modulation by flow cytometry, free radical generation by fluorescent dyes, PLA2 isoforms gene expression patterns and their suppression by small interfering RNA (siRNA) studied in HCT-15 male and HT-29 female colon cells. Results: Our results demonstrate that HCT-15 and HT-29 cells treated with CSC significantly reduced the cell viability by 50% within 48 h and significantly enhanced the total reactive oxygen species (ROS) by 2 to 10-fold, and mitochondrial ROS (mtROS) and superoxide radicals (SOR) by 2-fold each. Treatment with CSC significantly unregulated secretory phospholipase A2 (sPLA2) IID group and down-regulated IB and cytosolic phospholipase (cPLA2) IVA groups in HCT-15 cells without affecting them in HT-29 cells. Silencing the sPLA2 IID group results in an increase in cell viability and a decrease in ROS. Silencing the PLA2 IVA gene in the HCT-15 cells showed a reduced expression which had no impact on the CSC-induced cell proliferation, membrane damage and free radicals (ROS, mtROS, and SOR) generation. Conclusion: Therefore, identifying cell-specific sPLA2 isozymes seems to play a key role in controlling the ROSinduced damage by CSC and helps develop specific therapeutic strategies.

Purpose: To investigate the safety and efficacy of lobaplatin-TACE in treating primary hepatocellular carcinoma. Methods: The data of 536 patients who underwent TACE in the interventional department from January 2016 to January 2020 were collected. Patients were divided into two groups according to the chemotherapeutic drugs used in TACE.: the epirubicin-TACE group (N = 260) and the lobaplatin-TACE group (N = 276). Primary study endpoint: (1) The tumor response after TACE; (2) The survival rates; Secondary study endpoints:(1) Changes in liver function and blood routine before and after TACE; (2) Occurrence of the post-embolization syndrome and infection after TACE. Results: The ORR was 35.0% in the epirubicin-TACE group and 51.1% in the lobaplatin-TACE group (p=0.001). The DCR was 73.1% in the epirubicin-TACE group and 82.2% in the lobaplatin-TACE group (p=0.011). The 6-month, 9- month, 12-month, and 15-month survival rates were higher in the lobaplatin-TACE group than in the epirubicin-TACE group (p=0.029, p=0.001, p=0.005, p=0.002). mOS: Epirubicin-TACE group,14.8 months; Lobaplatin-TACE group,18.6 months (p=0.007). mPFS: Epirubicin-TACE group,9.5 months; Lobaplatin-TACE group,12.8 months (P =0.000). There was no statistical difference in ALT, AST, total bilirubin and Leucocyte after TACE between the two groups (p=0.343, p=0.368, p=0.288, p=0.359). The platelet decrease after TACE was more significant in the lobaplatin- TACE group than in the epirubicin-TACE group (p=0.046). There was no statistical difference in the incidence rate of abdominal pain, fever and infection after TACE between the two groups (p=0.502, p=0.602, p=0.726). The incidence of vomiting after TACE in the lobaplatin-TACE group was higher than that in the epirubicin-TACE group (p=0.003). Conclusion: Lobaplatin-TACE has a higher tumor response rate and survival rate. Lobaplatin-TACE is a safe and effective treatment strategy; it is worthy of clinical application.

Background: Triple-negative breast cancer (TNBC) is considered to be the most malignant subtype of breast cancer (BC). Heparanase (HPSE) has been reported to contribute to tumor development, but its potential function in TNBC is not clear. The intention of this study was to investigate whether HPSE affects TNBC progression and to explore the possible mechanisms. Methods: Bioinformatics analyses were applied to analyze the expression of HPSE in TNBC samples and normal breast samples. The mRNA and protein levels of HPSE in TNBC cells were detected by RT-qPCR and western blot. Function assays, including CCK-8 assay, colony formation assay, transwell assay and wound healing assay, were conducted to validate the effects of HPSE silencing on TNBC cell proliferation and migration. Mechanism experiments were performed to explore the upstream molecular mechanism of HPSE in TNBC cells. Results: Silencing of HPSE suppressed the proliferation and migration of TNBC cells. Moreover, hypoxia-inducible factor-1 alpha (HIF-1α) interacted with the HPSE promoter and promoted the transcription of HPSE. Isoproterenol (ISO), a pharmacological substitute for chronic stress-induced sympathetic activation, was proven to induce HIF-1α upregulation, so as to transcriptionally activate HPSE in TNBC cells. Furthermore, it manifested that ISO facilitated TNBC cell proliferation and migration in an HPSE-dependent way. Conclusion: HPSE activated by ISO-induced HIF-1α promoted TNBC cell proliferation and migration, which might offer a novel insight for TNBC treatment.

Background: Aesculetin (AE), a natural coumarin derivative found in traditional medicinal herbs, has a variety of pharmacological effects. However, the role of AE and its molecular mechanisms of action on bladder cancer remains undefined. Objective: The study aims to explore the anti-tumor effects of AE on bladder cancer cells and the associated molecular mechanisms. Methods: We performed a Cell Counting Kit-8 assay to examine the inhibitory effects of AE on 5637 and T24 cells. The anti-tumor effects of AE on 5637 cells were evaluated by performing colony formation, living/dead cell staining, apoptosis, cell cycle, migration and invasion assays. The expression levels of related proteins were determined using western blotting. Results: The viability of 5637 and T24 cells was decreased by AE. AE significantly inhibited colony formation, arrested the cell cycle at the G0/G1 phase, decreased migration and invasion, decreased the mitochondrial membrane potential and increased apoptosis in 5637 cells. Western blotting results showed the release of cytochrome C from mitochondria; the activation of caspase-9 and caspase-3; decrease in CDK4, CCND1, MMP2 and MMP9 levels and an increase in the BAX/BCL-2 protein ratio after treatment with AE. AE also downregulated the levels of p-ERK and p- MEK proteins. Pre-treatment with U0126 significantly enhanced the anti-tumor effects of AE. Conclusions: AE inhibited the proliferation and induced the apoptosis of bladder cancer cells through the MEK/ERK pathway. These findings provide possible therapeutic strategies for bladder cancer.