Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 21, Issue 15, 2021

Background: Vitamin D has a widely acknowledged role in regulating the metabolism of calcium and phosphate, both essential to bone remodeling. However, numerous studies in recent decades have emphasized the association between low sun exposure and vitamin D deficiency, and an increased risk of extra-skeletal disorders such as cancer. Objective: This mini-review of literature aims to present an objective overview of several recent studies and meta- analyses evaluating the role of vitamin D in cancer prevention, its potential to improve cancer treatment outcomes, as well as the negative effects of vitamin D deficiencies. Methods: The antitumor effects of calcitriol and analogs in the treatment of cancer, either as single agent or in combination with other anticancer agents, are based on several mechanisms: inhibition of cancer cell proliferation and invasiveness, induction of differentiation and apoptosis, and promotion of angiogenesis, all recorded in numerous preclinical studies of various cancer types. Results: The importance of VDR polymorphisms for individual malignancies remains a topic of debate. Contradictory effects have been recorded in recent studies, the results of which include positive associations of VDR when cumulated with other risk factors, both an increase and a decrease in cancer risks, as well as no correlation between VDR polymorphisms and individual malignancies. Conclusion: The scientific evidence reviewed in this paper suggests that health care providers and individuals should consider increasing concentrations of 25 (OH) D through sensitive sun exposure and / or by supplementing with vitamin D to reduce cancer risk and, in combination with standard care, to treat cancer.

Background: Bone metastasis is one of the most common complications of Prostate Cancer (PCa). The detection of distal bone metastasis at the time of initial PCa diagnosis is valuable for the determination of therapeutic methods and for the prognosis of PCa. Many current therapeutic methods target PCa bone metastasis, but no uniform evaluation standard for therapeutic efficacy has been established; in addition, traditional therapeutic evaluation standards that rely on changes in the measured tumor volume are quite controversial. In clinical practice, the volumes of some tumors often change nonsignificantly at the early stage of therapy (especially targeted therapy), while the volumes of other tumors, such as metastatic bone lesions, are difficult to measure. Diffusion-Weighted Imaging (DWI) not only reflects the diffusion characteristics of tissues but can also allow the analysis of microstructural and functional changes in tissues. Therefore, DWI is suitable for evaluations of early responses to tumor therapy. Objective: This study mainly reviews the principle of DWI and its progress in the detection and therapy evaluation of PCa bone metastasis. Methods: PubMed was searched to identify eligible articles up to December 26, 2020. The keywords of the analysis included DWI, PCa, bone metastasis, therapeutic response, targeted therapy, Bone Scintigraphy (BS), Positron Emission Tomography/Computed Tomography (PET/CT) and metastatic Castration-Resistant Prostate Cancer (mCRPC). Results: This review based on collected articles achieved an imaging biomarker for detection and therapy evaluation of PCa bone metastasis. Conclusion: DWI is a promising imaging method for the detection and therapeutic evaluation of PCa bone metastases.

Background: Despite significant advancement in oncology research, cancer still poses one of the leading causes of mortality worldwide. The increased incidences of cancer may be attributed to the limited efficacy and disastrous side effects of conventional therapies like chemotherapy, radiotherapy and surgery. Azole containing medicinal agents are known for plethora of medicinal properties, including anticancer potential. Objective: In this review, we highlighted azole containing natural products with anticancer potential from marine sources. Methods: A comprehensive literature search was performed for writing the review. Updated views about various marine sponges, cyanobacteria, tunicates and microalgae producing azole nucleus containing secondary metabolites with anticancer potential have been discussed. Results: The present article describes the structural, chemical, and biological features of azoles containing natural agents from marine sources with promising anti-cancer potential. Additionally, current challenges and future perspectives of azoles in cancer prevention and treatment are also discussed. Conclusion: This review might encourage scientific community to explore marine sources for developing novel and potent azole containing anti-cancer agents with better safety profile.

Nanotechnology and material science developments emerge in the manufacturing of various novel modes of drug delivery, which have proven scientifically promising. Polymer nanoparticles have high stability, high specificity, high drug-carrying power, control release, and potential to be used in various pathways. They usually supply hydrophilic and hydrophobic molecules with medicines. In this review, we have discussed the different types of brain tumour, different PLGA (Poly Lactic-co-Glycolic Acid) nanostructures, PLGA in brain tumour targeting, and the recent advancement of PLGA based nanoparticles. This review focused on the method of preparation of polymeric nanoparticles, the significance of EPR (Enhanced Permeability and Retention) effect with PLGA, the significance of TPGS in cancer, and discussed the pharmaceutical application of PLGA nanoparticles. We expect these polymeric nanoparticles will be very successful and efficient for disease targeting in the future and new techniques will emerge.

Background: Anlotinib is a multi-target tyrosine kinase inhibitor that has been reported to have activity against colorectal cancer. However, the mechanisms of how anlotinib mediates drug-resistance of colorectal cancer have not been fully described. Particularly the potential mechanisms regarding the inhibition of proliferation and induction of apoptosis remain unknown. Objective: In this study, we intended to study the effect and related-mechanism of the proliferation, migration, invasion and induced apoptosis of anlotinib overcoming multidrug resistant colorectal cancer cells through in vitro experiments. Methods: Cell viability was determined by MTT assays and the resistant index was calculated. Colony formation and PI/RNase Staining were used for testing the proliferation of resistant cells. DAPI staining and Annexin V-FITC/PI staining were used to detect cell apoptosis. Migration and invasion were examined by transwell. Protein expression and activation of PI3K/AKT pathway were detected by western blot. LY294002 was used to verify whether anlotinib overcomes the drug-resistance of CRC cells by inactivating the PI3K/AKT pathway. Results: The results showed that the HCT-8/5-FU cells were resistant to multiple chemotherapy drugs (5-FU, ADM and DDP). Anlotinib significantly inhibited cell viability, proliferation, migration, invasion and induced cell apoptosis. Moreover, anlotinib down-regulated the expression of survivin, cyclin D1, CDK4, caspase-3, Bcl-2, MMP-2, MMP-9, vimentin and N-cadherin, but up-regulated cleaved-caspase-3, Bax and E-cadherin and blocked the activity of the PI3K/AKT in HCT-8/5-FU cells. We found anlotinib and LY294002 overcame the drug resistance of HCT-8/5-FU cells by reducing the expression of PI3K/p-AKT. Conclusion: Anlotinib inhibited the proliferation, migration, invasion and induced apoptosis of HCT-8/5-FU cells, and the mechanisms may be that anlotinib conquered multidrug resistance of colorectal cancer cells via inactivating of PI3K/AKT pathway.

Background: Interleukin-11 (IL-11) could promote invasion and metastasis of cancer cells, however, its mechanism is unclear. Objective: This study aimed to investigate the effects of recombinant human IL-11 (rhIL-11) on lung cancer cell metastasis and growth. Methods: Human lung cancer cell, A549, was cultured and subcutaneously injected into mice to establish Xenograft tumor models. Tumor models were divided into control, rhIL-11 transplantation (250 μg/kg/day), and rhIL-11 transplantation (500 μg/kg/day) group. Tumor volumes were recorded and measured 6 times. Hypoxia- Inducible Factor 1α (HIF1α), snail, slug, Signal Transducers/Activators of Transcription-3 (STAT3), E-cadherin, twist, and vimentin levels were evaluated using western blot and Real-Time PCR (RT-PCR). Results: Sizes of subcutaneous tumors increased following measurement time. rhIL-11 treatment significantly enhanced HIF1α and STAT3 expression in rhIL-11 treatment groups compared to the control group (p<0.05). However, no remarkable differences were discovered between rhIL-11 (250 μg/kg/day) and rhIL-11 (500 μg/kg/day) group (p>0.05). rhIL-11 treatments significantly increased twist, and slug expressions compared to control group (p<0.05), especially for rhIL-11 (500 μg/kg/day) treatment, which triggered significantly higher effects on twist and slug expressions compared to those in the control group (p<0.05). Vimentin and snail mRNA levels were significantly up-regulated and E-cadherin level was significantly down-regulated in rhIL-11 treatment groups compared to the control group (p<0.05). Meanwhile, rhIL-11 at a dosage of 500 μg/kg/day triggered remarkably higher effects on vimentin, snail, and E-cadherin expressions compared to those in rhIL-11 (250 μg/kg/day) group (p<0.05). Conclusion: rhIL-11 transplantation promoted growth and Epithelial-Mesenchymal Transition (EMT) of A549 cells, which might be associated with STAT3/HIF-1α/EMT signaling pathway activation.

Background: The development of Cancer Stem-like Cells (CSCs) is one of the main causes of ovarian cancer tolerance to radiotherapy. Autophagy is an adaptive process by which cells damage due to radiation. As a metabolite of riboflavin, lumiflavin can enhance the chemotherapeutic effects of cisplatin on ovarian cancer CSCs. Objective: This study aimed to investigate the synergistic effects of lumiflavin and ionising radiation on ovarian cancer CSCs and explore the association of this metabolite with autophagy. Methods: CSCs of human ovarian cancer cell lines HO8910 were treated with lumiflavin and rapamycin and then subjected to irradiation at a cumulative dose of 8 Gy. Cell proliferation ability, clonal formation ability, apoptosis rate, autophagy changes and autophagy-related protein changes were detected. Results: Lumiflavin and ionising radiation synergistically reduced cell vitality and clone formation and increased the apoptosis of CSCs compared with irradiation alone. In addition, ionising radiation increased autophagy and the expression of associated proteins, whereas lumiflavin reduced those changes in autophagy progression. Moreover, rapamycin, an autophagy inhibitor, was observed to block the synergistic effects of lumiflavin and ionising radiation on CSC apoptosis. Conclusion: Lumiflavin can enhance the effects of ionising radiation on ovarian cancer CSCs. The mechanism by which these effects are exerted is related to blocking the autophagy pathway.

Background: Compound Kushen Injection (CKI) is used clinically for relieving cancer pain and treating various solid tumors, particularly lung cancer. However, the underlying mechanisms of CKI in lung cancer remain to be further elucidated. Objective: This study aimed to obtain evidence regarding the potential efficacy of the active compounds and therapeutic targets of CKI at a molecular level by using Network Pharmacology (NP), which is an emerging technique for dealing with complex systems, such as those of herbal medicine. Methods: The chemical and predicted target information of CKI was obtained from databases and computational prediction, respectively; lung-cancer drugs and their corresponding targets were retrieved from Drugbank and Drugcentral. The online tool, STRING, was used to gather target–pathway interactions for establishing a target–(pathway)–target network to identify the target group that was most relevant to cancer. Based on this module, a protein-protein interaction network was established for identifying the potential therapeutic targets and the potential active ingredients. Results: CKI might affect lung cancer drug targets or their neighbor nodes to trigger anti-cancer effects. The compounds that were predicted to bind to the potential therapeutic targets were recommended as potential active ingredients of CKI, which included naringenin from Baituling, and kurarinone and isoxanthohumol from Kushen. Conclusion: This NP-based study might provide insights into understanding CKI from the perspective of modern science with reference to approved Western medicine for lung cancer. Moreover, network-based methods could also be further used with distinct advantages in dealing with complex information and systems of medicine.

Background: Alpha-terpineol is monoterpene alcohol with anti-tumor activity against different tumor cell lines (lung, breast, leukemias and colorectal) through blockage of NF-kB expression, which play an important role in tumor cells growth. Objective: Evaluate the antitumor activity of alpha-terpineol in murine Sarcoma 180 cell line. Methods: For the tests, different cytotoxic and genotoxic assays were used, including Trypan blue, cytokinesis- blocked micronucleus assay, comet assay, agarose gel DNA fragmentation, flow cytometry and cell viability using fluorescence. Ascitic fluid cells from sarcoma 180 were obtained from Mus musculus peritoneal cavity and Alpha-terpineol was tested at 100, 250 and 500 μg/mL. Doxorubicin and Cisplatin were used as positive controls. Results: Cytotoxic effects of alpha-terpineol were found in all concentrations tested, reducing cell viability in 50.9; 38.53; 30.82% at 100, 250 and 500 μg/mL, respectively. Alpha-terpineol induced genotoxic effects due to DNA fragmentation (increased frequency and index of damage), and was clastogenic by increased micronuclei formation, nucleoplasmic bridges and nuclear buds. DNA fragmentation and increased cell death indicated that alpha-terpineol can cause early, late, and necrotic apoptosis. Conclusion: Our data indicate that alpha-terpineol has antitumor activity revealed by cytogenetic mechanisms and / or loss of cell membrane integrity.

Background: Oxidative stress that leads to an imbalanced prooxidant/antioxidant status can be a critical factor affecting lung cancer etiopathology. The antioxidant system provides primary protection under oxidative stress. Objective: The purpose of the study was to investigate the serum antioxidant system status in brain metastatic and non-metastatic lung cancer patients with different cell types. Methods: In this prospective study, 33 patients with lung cancer metastasis (metastatic patient group), 36 lung cancer patients (non-metastatic patient group), and 25 healthy control groups were included. Enzymatic (Superoxide Dismutase, SOD; Glutathione Peroxidase, GPX; and Glutathione Reductase, GR) and non-enzymatic (Glutathione, GSH) antioxidant system biomarkers with Thiobarbituric Acid Reactive Substances (TBARS) levels were studied in the serum samples of the control and patient groups. The oxidative stress biomarkers were measured spectrophotometrically. Results: SOD activity increased though TBARS levels and GR activity decreased in both patient groups compared to the control. GPX activity increased only in the non-metastatic group. Antioxidant biomarkers varied between small cell and non-small cell group patients. GR activity and GSH levels were significantly higher in the non-metastatic group compared to the metastatic group. Correlations were also found between antioxidant parameters in the non-metastatic group. Conclusion: It was emphasized the imbalanced antioxidant system in the duration of the disease is related to not only cell type but also the metastatic structure. This is the preliminary study exhibiting the contribution of antioxidant imbalance in different subtypes with varied prognosis and behavior of lung cancer in the presence of brain metastasis. Therefore, oxidative stress biomarkers can serve as a useful tool to get information about the progression of lung cancer. Thus, it may provide fundamental data for further cancer research when considering the diagnosis of the disease.

Background: Thiadiazole has attracted a great deal of interest as a versatile heterocycle for the discovery and development of potent anticancer agents. Thiadiazole derivatives exert potent antitumor activity against a variety of human cancer cell lines through various mechanisms. Objective: The goal of this work was to design and synthesize thiadiazole-based anticancer agents with anti-angiogenic activity. Methods: N-aryl-2-[(5-(aryl)amino-1,3,4-thiadiazol-2-yl)thio]acetamides (4a-r) were synthesized via the reaction of 5-(aryl)amino-1,3,4-thiadiazole-2(3H)-thiones with N-(aryl)-2-chloroacetamides in the presence of potassium carbonate. The compounds were investigated for their cytotoxic effects on three cancer (A549, HepG2, SH-SY5Y), two normal (HUVEC and 3T3-L1) cell lines using MTT and WST-1 assays. In order to examine whether the compounds have anti-angiogenic effects or not, HUVECs were cultured on matrigel matrix to create a vascular-like tube formation. Results: Compounds 4d, 4m and 4n were more effective on A549 human lung adenocarcinoma cells than cisplatin. The IC50 values of compounds 4d, 4m and 4n for A549 cell line were found to be 7.82 ± 0.4, 12.5 ± 0.22, 10.1 ± 0.52 μM, respectively when compared with cisplatin (IC50= 20 ± 0.51 μM), whilst their IC50 values for HUVEC cell line were determined as 138.7 ± 0.84, 78 ± 0.44, 177.6 ± 0.2 μM, respectively after 48 h of the treatment. The concentrations (10-20-50 μM) of compounds 4d, 4e, 4l, 4m, 4n, 4q and 4r were found to inhibit vascular like tube formation. Conclusion: According to their anticancer and anti-angiogenic effects, compounds 4d, 4m and 4n may be potential anticancer agents for further in vivo studies.

Background: 1,3,4-thiadiazolo pyrimidine is a lead molecule that is versatile for a wide variety of biological activities and in continuation of our interest in establishing some novel heterocyclic compounds for antitumor activity. Objective: The objective of the study was to synthesize a series of 5-amino-7-(substituted aldehyde)-2[(naphthalene- 2-yloxy)methyl] -[1,3,4]thiadiazolo-[3,2-α]-pyrimidine-6- carbonitrile derivatives and evaluate their possible in vitro and in vivo anticancer activity. Methods: Herein, we report the synthetic scheme, which was followed for the preparation of a series of title compounds B1- B9 outlined in scheme 1. The intermediate 5-[(naphthalen-2- yloxy)methyl]-1,3,4-thiadiazolo- 2-amine was prepared by heating 2-naphthoxyacetic acid and thiosemicarbazide in the presence of phosphoryl chloride at a temperature of 65-75°C. The obtained compound reacted with malononitrile and an appropriate amount of aromatic and heteroaromatic aldehydes in refluxing ethanol yielded 5-amino-7-(substituted aldehyde)-2[(naphthalene-2-yloxy)methyl] -[1,3,4]thiadiazolo-[3,2-α]-pyrimidine-6- carbonitrile derivatives (B1 – B9). The purity of the synthesized compounds was ensured by various spectral analyses. Results: In in silico molecular docking studies, compounds B3 and B9 show binding affinity like known PARP1 inhibitor olaparib. The cellular evaluation indicates that the anticancer profile of compounds B1, B3, and B9 is significant when compared to the standard drug (olaparib) against MDA-MB-232 cell line and compounds B3, B6, and B7 are the most active against MCF-7 cell lines. The most active compound B3 was subjected to acute oral toxicity studies by OECD 423 guidelines and in vivo anti-cancer studies were carried out using DMBA induced model. Conclusion: The in silico docking study of the newly synthesized compounds was performed; the results showed good binding mode in the active site of PARP1 enzyme. In silico ADME properties of synthesized compounds were also studied and showed good drug-like properties.

Background: Melanoma is one of the most common forms of skin cancer, and B-RAF is a mutated protein found in most melanomas. The important function of B-RAF is normal cell growth and survival. Most of the known B-RAF mutations are V600E mutations. Vemurafenib is the fluorine-based drug currently used for V600E mutations. However, this drug has side effects, therefore, more potent drugs with fewer side effects are required. Objective: This study aims to develop a more effective lead compound as a B-RAF inhibitor from hydroxyquinone by structural modification of embelin, a naturally occurring hydroxybenzoquinone. It has the potency of detoxifying blood and is hence useful in a wide range of skin diseases. Thus, a fluorine substituted semisynthetic derivative of embelin, 5-(3-chloro-4-trifluoromethoxy phenyl amino)-2-hydroxy-3-undecyl- [1, 4] benzoquinone to fight against skin cancer was prepared. Methods: Fluoro derivative of embelin was synthesized by the direct condensation of embelin with 3-chloro-4- trifluoromethoxy aniline. The structure of the product was characterized using various spectral data obtained from IR, ¹H NMR, ¹⁹F NMR, ¹³C NMR, and mass spectrum. Various in vitro studies like antiproliferative study in A375 Cell Lines (B-RAF Elisa), western blotting analysis, gene expression study by reverse transcriptase PCR, caspase assay, flow cytometry analysis, clonogenic assay, and transwell migration assay were carried out to find its biological activity. Results: A semisynthetic derivative of Embelin 5-(3-Chloro-4-trifluoromethoxy phenyl amino)-2-hydroxy-3- undecyl- [1, 4] benzoquinone (EOCF) was prepared, and the structure of the derivative was confirmed by spectral analysis. The MTT assay proves that the fluoro derivative of embelin exhibited better anti-cancer activity in melanoma cell lines than the parent compound, embelin. Western blot analysis showed that B-RAF expression level was reduced by the addition of derivative than the parent compound embelin. The Caspase ELISA analysis indicated that the derivative was found to be a good apoptotic marker. From the flow cytometry analysis, it was observed that cell arrest occurs at the G0/G1 phase. Its antimetastatic activity was determined using clonogenic assay. It indicated that the derivative EOCF inhibits the metastatic effects in melanoma cell lines. The migratory potential of melanoma cells was significantly reduced in the presence of EOCF when the transwell migration assay was conducted. Conclusion: This work established that the potency of the synthesized compound was more than the parent compound, embelin, when it was structurally modified with 3-chloro-4-trifluoromethoxy aniline. The derivative can be used as a lead molecule for further drug discovery.

Background: Cancer is a very dangerous disease whose treatment can be improved by removing the factors that cause side effects if the drugs prescribed for cancer are chiral in nature. Objectives: A computational evaluation for the most biologically active enantiomeric form of chiral drugs attacking the DNA of the cell, was made for the first time, and compared with the experimental work done by others previously. Methods: All the enantiomeric structures of the drugs taken in the present study were obtained using Marvin sketch, and the structure of DNA to be docked with enantiomers, was obtained from the protein data bank. After that, all the enantiomers of the chiral drugs were docked with DNA one by one for the evaluation of the most biologically active enantiomeric form. Results: The docking study showed that the different enantiomers interacted with DNA differently because of having different arrangements of atoms/groups. The binding affinity of one of the two enantiomeric forms was higher than that of another. Conclusion: R-methotrexate for breast cancer; R-mitotane for adrenocortical cancer; R-duvelisib for blood cancer, and S-irinotecan for colon cancer would be a suitable drug with less toxicity as well as other side effects.

Background: This study aimed to evaluate the effects of hydrophobic and hydrophilic Film-Forming Gels (FFGs) on the controlled delivery of drugs with different levels of hydrophobicity. Methods: This evaluation was carried out by employing zein and polyvinylpyrrolidone as hydrophobic and hydrophilic film-forming agents, respectively, in combination with hydroxypropyl methylcellulose functionalized as a hydrogel basement at a ratio that had been optimized to achieve the fastest drying time. Free curcumin or terbinafine hydrochloride was subsequently dispersed into blank FFGs to produce the final FFG formulations. Results: Although the extreme hydrophobicity of curcumin strongly limited its topical permeability compared to that of terbinafine hydrochloride, zein FFGs clearly resulted in a favourable sustained release system for highly hydrophobic drugs, such as curcumin. Moreover, polyvinylpyrrolidone would be highly effective for the sustained release of a less hydrophobic drug, such as terbinafine hydrochloride. Analyses of the wettability, surface morphology, chemical interactions and crystallinity of FFGs also helped to elucidate the mechanisms of their drug release profiles. Conclusion: This fundamental finding is beneficial for further design studies on FFGs as sustained drug delivery systems for topical drugs with a wide range of hydrophobicities.

Background: Cancer being a genetically heterogeneous and complex disease and the available therapies are not very effective, rendering them the predominant cause of mortality across the world. The discovery of new anticancer drugs with higher efficacy and milder side effects is a great challenge for health professionals. Objective: The current study focused on the anticancer potential of two known dimeric napthoquiones, diospyrin (1) and 8-hydroxydiospyrin (2) isolated from the roots of Diospyros lotus. Methods: In vitro Epstein-Barr-Virus (EVA) an early antigen activation assay was used to evaluate the antitumor potential of tested compounds followed by a two-stage carcinogenesis assay on mouse skin for anti-carcinogenic effect. Compounds were also assessed for their multidrug resistance reversal potential. The in vitro heatinduced protein denaturation assay was used for the anti-inflammatory effect of the tested compounds. Results: Both compounds evoked marked cytotoxic activity with IC50 of 47.40 and 36.91 ppm, respectively. In Epstein-Barr-Virus (EVA) early antigen activation assay compounds 1 and 2 showed IC50 values of 426 ppm and 412 ppm, respectively. The tested compounds showed 60% survival rate of the lymphoblastoid Raji cells at a concentration of 1000 (mol / ratio 32 pmol TPA). In a two-stage carcinogenesis assay on mouse skin, both compounds significantly delayed the formation of papillomas on mouse skin. Compound 1 showed 50% effect at 14^th week, whereas compound 2 exerted the same effect at 13^th week, while both provoked 100% effect at 20^th week. Both compounds significantly attenuated thermal-induced protein denaturation with EC50 values of 298 and 264 μg/mL, respectively. The dimeric napthoquiones were evaluated for their effects on the reversion of Multidrug-Resistant (MDR) cell lines mediated by P-glycoprotein using rhodamine 123 dye-based exclusion screening test on human mdr1 gene transfected thymic lymphoma L5178 cell line. The compounds 1 and 2 exhibited promising MDR reversal effect in a dose-dependent manner against mouse T-lymphoma cell line. Docking results also showed that both compounds have good docking statistics as compared with standard. Conclusion: Both the compounds demonstrated marked anti-tumor, anti-carcinogenic, and MDR reversal effects with significant attenuation of thermal-induced denaturation of the protein. These compounds may explain the traditional uses of D. lotus which might be effective anticancer agents.