Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 22, Issue 18, 2022

Acute lymphoblastic leukemia (ALL) is a common form of pediatric cancer affecting the lymphoblast, a type of white blood cell found in the bone marrow. In this disease, the normal lymphoblast cells transform into leukemic cells and subsequently enter the bloodstream. Leukemic cells found in patients with ALL have shown differences in cholesterol uptake and utilization. Current treatment consists of chemotherapy, chimeric antigen receptor (CAR) therapy, and hematopoietic stem cell transplantation (HSCT). In addition, minimal residual disease (MRD) has become an effective tool for measuring treatment efficacy and the potential for relapse. Chemotherapy resistance remains a significant barrier in the treatment of ALL. Biomarkers such as an upregulated Akt signaling pathway and an overexpressed VLA-4 integrin-protein have been associated with drug resistance. Nanoparticles have been used to favorably alter the pharmacokinetic profile of conventional drug agents. These drug-delivery systems are designed to selectively deliver their drug payloads to desired targets. Therefore, nanoparticles offer advantages such as improved efficacy and reduced toxicity. This review highlights conventional treatment options, distinctive characteristics of pediatric ALL, therapeutic challenges encountered during therapy, and the key role that nanotherapeutics play in the treatment of ALL.

Glioblastoma multiforme (GBM) is among the most critical and aggressive carcinomas of CNS, characterised by poor prognosis, low survival rate and difficult clinical correlations. Current treatment opportunities have proved to be insufficient due to high chemoresistance and relapse of the disease with enhanced malignancy. Molecular diagnostics and epigenetic profiling of GBM have discovered several signaling pathways and cellular mediators, which play key roles in triggering GBM phenotypic manifestations via somatic and genetic aberrations and recruitment of GBM stem-like cells (GSCs). Lysine specific demethylase 1 (LSD1), a flavin-containing oxidoreductase encoded by the KDM1A gene and containing the unique CoREST component, is an important histone-modifying enzyme belonging to the histone demethylase (KDM) subfamily and is responsible for master regulation of several signaling pathways in glioma cells. Pharmacological inhibition of LSD1, either individually or in a dual-targeted approach, is a logical strategy for the management of GBM. The current review discusses the role of LSD1 in various epigenetic modulations in differentiated glioma cells and GSCs. The 2D and 3D structural similarities/dissimilarities between LSD1 and MAOs have been analysed and presented along with a detailed discussion on different chemical classes of small molecule LSD1 inhibitors (both standalone and hybrid pharmacophores) that have shown promise in GBM chemotherapy.

Schiff bases and their transition metal complexes play an important role in the field of medicine, in particular in the treatment of cancer. Since the discovery of the cisplatin anticancer activity, great efforts have focused on the rational design of metal-based anticancer drugs that can be potentially used for the treatment of cancer. However, drug resistance and significant side effects greatly limit its clinical application. This has inspired medicinal chemists to employ various strategies in the development of novel and effective anticancer drugs. Recently, a greater number of transition metal complexes have been designed and evaluated for their anticancer activities, and some of them were at different stages of clinical studies. Amongst these, platinum, palladium, gold and silver complexes have an important place within medicinal and inorganic chemistry. This review article discusses Schiff bases and their complexes with selected transition metals (Pd, Pt, Ag, Au) for anticancer activity against different cancer cell lines.

Objective: The aim of the study was to investigate the therapeutic potential of Berbamine-loaded lipid nanoparticles (BBM-NPs) in pancreatic cancer. Methods: Dopamine polymerization-polylactide-TPGS nanoparticles were synthesized to prepare BBM-NPs, and the change in particle size of BBM-NPs was measured. Cell Counting Kit-8 (CCK8) assay, plate cloning experiment, and apoptosis analysis were performed to evaluate the cytotoxicity of BBM-NPs against the pancreatic cancer cells (PANC-1 and AsPC-1). Migration and invasion abilities of the tumor cells were determined by Transwell and wound healing assays. The intracellular level of ROS and expression of tumor progression-related proteins were measured using ROS-kit and western blot assay. Besides, an in vivo study was performed in the Balb/c nude mice to analyze the function of BBM-NPs in tumor growth. Results: The in vitro studies showed that BBM-NPs with stable particle size and sustained drug release effectively inhibited the viability, proliferation, migration, and invasion of pancreatic cancer cells, while promoting cell apoptosis. Moreover, the in vivo experiments revealed that compared to Free BBM, BBM-NPs exhibited a stronger inhibitory effect on the growth of xenograft tumors derived from PANC-1 cells in mice. In addition, increased expressions of ROS, Bax, Cleaved Caspase-3, and γ-H2AX, as well as decreased expressions of MMP2, MMP9 and Bcl-2 were identified in both Free BBM and BBM-NPs groups, while BBM-NPs exhibited a stronger effect on protein expression than Free BBM. Conclusion: In summary, BBM-loaded lipid nanoparticles enhanced the therapeutic effects of BBM on pancreatic cancer, providing a promising strategy for targeted cancer therapy.

Background: This study is part of a larger research effort to explore the molecular mechanism of hepatocellular carcinoma, reduce drug resistance and seek new targets. Objective: The objective of this study is to investigate the effect and mechanism of fibroblast growth factor receptor inhibitor AZD4547 on Sorafenib-resistant hepatoma cells. Methods: First, we constructed a Sorafenib-resistant hepatoma cell line Huh7R. Different groups of Huh7R cells were treated with Sorafenib, AZD4547, Sorafenib combined with AZD4547, and normal saline. The cell viability was detected by Cell Counting Kit-8. Then Fibroblast growth factor receptor and Toll-like receptor 4 were detected by Western blot, as well as the LC3 II/I, Beclin1, and P62. In addition, we used the autophagy inhibitor 3-methyladenine to identify the mechanism of AZD4547 combined with Sorafenib for inducing Sorafenib-resistant hepatoma cell death. Results: We find that AZD4547 combined with Sorafenib significantly inhibited the viability of Sorafenib-resistant hepatoma cell Huh7R. As for its mechanism, AZD4547 was able to inhibit fibroblast growth factor receptor activity, promote autophagy and regulate immunity. AZD4547 increased LC3 II/I, Beclin1, and Toll-like receptor 4 proteins, and decreased P62 protein level in Huh7R cells significantly when given in combination with sorafenib. Furthermore, 3-methyladenine inhibited autophagy and reversed the killing effect of the combination of AZD4547 and Sorafenib on Huh7R cells. Conclusion: The inhibition of fibroblast growth factor receptor activity by AZD4547 can significantly enhance autophagy and immune response, as well as promote the death of Sorafenib-resistant hepatoma cells.

Background: Lung tumors express high levels of aromatase enzyme compared to surrounding normal tissue. Inhibition of aromatase has emerged as a recent therapeutic approach for the treatment of breast cancer. However, the role of aromatase inhibition in lung cancer treatment requires further investigation. Methods: The anti-proliferative effects of aromatase inhibitors were evaluated by MTT assay. Cell migration was assessed using a wound healing assay. The mechanism of cell death was determined using the annexin VFITC/ propidium iodide staining flow cytometry method. The soft agar colony formation assay evaluated cells’ capability to form colonies. Result: Exemestane and curcumin significantly inhibited the growth of lung cancer cell lines in a dose- and timedependent manner. The IC50 values after 48 hours of treatment with exemestane were 176, 180, and 120 μM in A549, H661, and H1299, respectively. Curcumin IC50 values after 48 hours were 80, 43, and 68 μM in A549, H661, and H1299, respectively. The combined treatment of exemestane or curcumin with cisplatin, raloxifene, and celecoxib resulted in a synergistic effect in the A549 lung cell line with a combination index of less than 1, suggesting synergism. Exemestane resulted in approximately 96% inhibition of wound closure at 100 μM, while curcumin resulted in approximately 63% inhibition of wound closure at 50 μM. Exemestane and curcumin inhibited the formation of cell colonies by reducing the number and size of formed colonies of A549, H661, and H1299 cell lines in a concentration dependent manner. Exemestane and curcumin had significantly induced apoptosis in A549 cells compared to control of untreated cells. Conclusion: Aromatase inhibition by exemestane or curcumin had significantly inhibited the growth of lung cancer cell lines, synergized with cisplatin, raloxifene, and celecoxib, suppressed lung cancer cell migratory potential, induced apoptosis, and reduced colony formation of lung cancer cells.

Background: Gastric cancer is a common global disease. So far, the best choice for diagnosis and treatment of gastric cancer includes surgical resection, chemotherapy, and other targeted drug therapies; however, the overall survival rate of patients with gastric cancer is still very low. The hypoxic microenvironment facilitates tumor cells to develop tolerance to chemotherapy and radiotherapy and promotes the early invasion and metastasis of various tumors. Celastrus Orbiculatus extract (COE) has shown inhibitory activities against a variety of tumor cells. In this study, we found that COE could inhibit the invasion and migration of gastric cancer cells by inhibiting epithelial-mesenchymal transformation (EMT) in the hypoxia microenvironment. Methods: CoCl2 was first diluted to various concentrations and then used to treat MKN28 and AGS cells. The MTT (thiazolyl blue) assay was used to evaluate cell proliferation. The transwell assay was used to measure the invasion and migration abilities of the cells. Wound healing assays were used to detect the healing ability of the cells. Western blotting was used to assess the effects of COE on the expression of EMT and matrix metalloproteinase (MMP) signaling pathway-related proteins. Results: We found that gastric cancer cells showed stronger proliferation, invasion, and metastasis in the hypoxia microenvironment. COE inhibited the migration and invasion of AGS and MKN28 cells in both hypoxic and normoxic environments. Additionally, COE decreased the expression of EMT and MMP signaling pathway-related proteins in gastric cancer cells. Conclusion: Therefore, it can be concluded that COE suppresses the migration and invasion of gastric cancer cells by inhibiting EMT and MMP in the hypoxia microenvironment.

Introduction: Calotropis procera (Aiton) Dryand (Apocynaceae) is an herb that has been commonly used in folk medicine to treat various diseases for more than 1500 years. Aims: Our goal was to investigate the anti-metastatic effects of phenolics extracted from C. procera (CphE) against 4T1 breast cancer cells and in BALB/c mice. Methods: 4T1 cells were treated with CphE and quercetin (positive control) at concentrations that inhibited cell viability by 50% (IC50). Levels of reactive oxygen species (ROS), wound healing, and protein expressions were determined following standard protocols. For the in vivo pilot study, the syngeneic BALB/c mouse model was used. 4T1 cells were injected into mammary fat pads. Tumors were allowed to grow for 9 days before gavage treatment with CphE (150 mg GAE/kg/day) or PBS (controls) for one week. Excised tumors, liver, and lungs were analyzed for gene and protein expression and histology. Results: In vitro results showed that CphE suppressed cell viability through apoptosis induction, via caspase-3 cleavage and total PARP reduction. CphE also scavenged ROS and suppressed Akt, mTOR, ERK1/2, CREB, and Src activation contributing to cell motility inhibition. CphE reduced IR, PTEN, TSC2, p70S6, and RPS6, protein levels, which are proteins involved in the PI3K/Akt/mTOR pathway, suggesting this pathway as CphE primary target. In vivo results showed downregulation of ERK1/2 activation by phosphorylation in tumor tissues, accompanied by angiogenesis reduction in tumor and lung tissues. A reduction of Cenpf mRNA levels in liver and lung tissues strongly suggested anti-invasive cancer activity of CphE. Conclusion: CphE inhibited 4T1 cell signal pathways that play a key role in cell growth and invasion. The potential for in vitro results to be translated in vivo was confirmed. A complete animal study is a guarantee to confirm the CphE anticancer and antimetastatic activity in vivo.

Background: Abiraterone acetate (AA) is a selective inhibitor of CYP17 α-hydroxylase, which is crucial for androgen biosynthesis. Apigenin (Api) is a natural plant-derived flavonoid with potent antiproliferative and antimigration effects. Objectives: We aimed to investigate the possible role of Api in combination with the androgen receptor inhibitor AA in the treatment of androgen-sensitive human prostate cancer LNCaP cells. Methods: The cells were either exposed to 10 μM AA, 25 μM Api, or in combination for 48 hours, then the viability rate was determined by the MTT test, whilst apoptosis and cell cycle phases were assessed by image-based cytometry. The expression of selected mRNA and proteins were evaluated by RT-qPCR and Western blot, respectively. Results: The combination of AA and Api significantly inhibited LNCaP as well as androgen-insensitive PC3 cell survival in a manner more marked than observed with either single treatment. Co-administration of Api with AA triggered apoptosis. This effect was demonstrated by Hoechst staining, and up-regulation of Bax, cytochrome c, caspase -3, and - 8 and down-regulation of Bcl-2 expression confirmed the effect. AA and Api each individually arrested the cell cycle in the G1 phase, with dual applications, leading to no further increase in the effect produced. The expression of NF-ΚB p105/p50 and the phosphorylation of AKT markedly decreased after apigenin treatment, with combination treatment leading to a favourable effect in terms of further augmenting the reduction. Conclusion: The co-administration of Api with AA strongly enhanced the efficacy of AA therapy in the treatment of prostate cancer cells. These data suggested that the combination of AA and Api would be a potential chemotherapeutic strategy against prostate cancer.

Aim: Cervical cancer is the deadliest gynecological malignancy. This study aims to examine the anticancer effects of L-citrulline on HeLa cell culture. Materials and Methods: HeLa cells were cultured in complete Eagle's minimum essential medium. HeLa cells were seeded in 96-well plates and incubated with L-citrulline. After incubation, MTT dye was added and incubated. Annexin- V technique was used to test the apoptosis. The activated caspases of HeLa cells by L-citrulline exposure were measured with the Caspase 3/7 technique. One-way variance analysis was conducted for statistical analysis by using GraphPad Prism 6.0 for Windows. Results: L-citrulline showed its toxicity on HeLa cells in a dose-dependent manner in application times of 24 and 48 hours. The IC50 dose of L-citrulline was 0.19 and 0.16 mg/mL at 24 and 48 hours, respectively. When HeLa cells were exposed to an IC50 dose of L-citrulline for 24 hours, the percentages of the dead, early apoptotic, and late apoptotic cells were detected to be 0.75%, 23.05%, and 12.75%, respectively. The differences in the wideness of the scratch area were observed at the initial stage and after 24 hours of applying L-citrulline. Conclusion: L-citrulline showed its toxicity on HeLa cells in a dose-dependent manner. Based on Annexin and Caspase findings, it can be concluded that L-citrulline exerted a pro-apoptotic effect on HeLa cells in only a short exposure time. L-citrulline also showed a migration inhibitory effect. The findings of this study indicate L-citrulline to be worthy of investigation for its anticancer activities in vitro and in vivo, and as a candidate for cancer therapy.

Background: Calotropis procera is a laticiferous plant (Apocynaceae) found in tropical regions all over the world. The ultrastructural characteristics of laticifers, their restricted distribution among different taxonomic groups, and in some species in each clade, as peptidases from latex, make them very attractive for biological analysis. Objective: The study aims to investigate the effects of LP-PII-IAA (laticifer protein (LP) sub-fraction II (PII) of C. procera presenting an iodoacetamide-inhibited cysteine proteinase activity) on irinotecan-induced intestinal mucositis, a serious adverse effect of this medicine for the treatment of cancer. Methods: LP-PII-IAA is composed of closely related isoforms (90%) of peptidases derived from catalysis and an osmotin protein (5%). Animals receiving co-administration of LP-PII-IAA presented a significant decrease in mortality, absence of diarrhea, histological preservation, and normalization of intestinal functions. Results: Clinical homeostasis was accompanied by a reduction in MPO activity and declined levels of IL-1β, IL-6 and KC, while the IL-10 level increased in LP-PII-IAA-treated animals. COX-2 and NF-kB immunostaining was reduced and the levels of oxidative markers (GSH, MDA) were normalized in animals that received LP-PII-IAA. Conclusion: We suggest that peptidases from the latex of Calotropis procera were instrumental in the suppression of the adverse clinical and physiological effects of irinotecan.

Background and Purpose: Osteosarcoma is the most commonly seen type of primary malignant bone tumors in children and adolescents. Partial patients with osteosarcoma cannot tolerate the side effects of chemotherapy drugs. Hence, it is urgent to find anti-osteosarcoma drugs with low side effects. Melittin is an anti-tumor Traditional Chinese Medicine with low side effects. The purpose of this study was to explore the anti-osteosarcoma effect of melittin and its possible molecular mechanisms. Methods: The effects of melittin on cell growth were detected by CCK-8, clonal formation, and flow cytometry. The related molecules were also investigated by Real-time PCR and Western blot. A xenograft model in nude mice was established to observe the effects of melittin on tumor growth and the related molecular expression was detected by immunohistochemistry. Results: Melittin can inhibit the proliferation of osteosarcoma 143B cells, reduce colony formation, and induce apoptosis while significantly up-regulating the expression of Bax and Caspase-3 and down-regulating the expression of Bcl-2 proteins. Moreover, treatment with melittin significantly reduced the mRNA and protein levels of β-catenin and Wnt/β- catenin related genes (LRP5, c-Myc, and Survivin) in osteosarcoma 143B cells in vitro. The xenograft model found that melittin significantly inhibited tumor growth and decreased the protein expression levels of β-catenin and Wnt/β- catenin related genes in vivo. Conclusion: These findings show that melittin could inhibit the growth of osteosarcoma 143B cells, which may be related to the inhibition of Wnt/β-catenin signaling pathway activity and induce apoptosis by up-regulating the ratio of Bax/Bcl-2 in osteosarcoma 143B cells. Therefore, melittin is a promising anti-tumor drug for the treatment of osteosarcoma.

Background: Camptothecin is a naturally occurring alkaloid obtained from the stem wood of the Chinese tree, Camptotheca acuminata. It exerts pharmacological effects due to its ability to selectively inhibit the type-I topoisomerase DNA nuclear enzyme. Several semisynthetic analogs of camptothecin have been synthesized to date possessing antitumor activity. Objective: Camptothecin (CPT) is one of the most promising anticancer drugs but it produces various side effects because of its non-selectivity towards cancer cells. To overcome these adverse effects, we synthesized biotin conjugate of camptothecin, which was linked via a self-immolative disulfide linker (CPT-SS-Biotin). Methods: Biotin conjugated camptothecin linked through a disulfide bond was synthesized following schemes, and the structural characterization was carried out. The stability and drug release studies were performed in the presence of glutathione (GSH) while in vitro studies were performed on 4T1 tumor cell lines. In vivo pharmacological investigation was done using an antitumor Wistar rat model. Results: The stability and drug release studies were performed in the presence of glutathione (GSH), and CPT-SSBiotin was found to be physiologically stable moiety and can only be cleaved in the presence of GSH to release free CPT. The CPT-SS-Biotin showed higher toxicity in the biotin-overexpressing 4T1 tumor cell line with a lower IC50 value (8.44 μM) compared to camptothecin alone (IC50 > 30 μM). CPT-SS-Biotin also showed 10.6% higher cellular uptake by cells in comparison to free camptothecin. The CPT-SS-Biotin was delivered to cells by binding to the biotin receptors on the cell surface, followed by energy-dependent endocytosis and internalization to cause cellular toxicity. Conclusion: In-vivo tumor suppression studies and in vitro cell line studies along with serological parameters and histopathological studies showed that conjugate produced a high therapeutic effect and remarkably reduced toxic effects in comparison to free CPT. The results suggested that biotinylation of camptothecin via disulfide linker can be a safe and efficacious method in cancer therapeutics.