Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 18, Issue 2, 2018

Background: Propofol, a widely used intravenous anesthetic agent, is traditionally applied for sedation and general anesthesia. Explanation: Recent attention has been drawn to explore the effect and mechanisms of propofol against cancer progression in vitro and in vivo. Specifically, the proliferation-inhibiting and apoptosis-inducing properties of propofol in cancer have been studied. However, the underlying mechanisms remain unclear. Conclusion: This review focused on the findings within the past ten years and aimed to provide a general overview of propofol's malignance-modulating properties and the potential molecular mechanisms.

Melanoma is an aggressive form of skin cancer characterized by poor prognosis and high mortality. The development of targeted agents based on the discovery of driver mutations as well as the implementation of checkpoint inhibitor-based immunotherapy represents a major breakthrough in the treatment of metastatic melanoma. However, in both cases the development of drug resistance and immune escape mechanisms as well as the lack of predictive biomarkers limits their extraordinary clinical efficacy. In this article, we summarize the available therapeutic options for patients with metastatic melanoma, outline the mechanisms implicated in the resistance to both targeted agents and immunotherapy, discuss potential predictive biomarkers and outline future therapeutic approaches under investigation.

Background: Cancer is a multifaceted metabolic disease that affects sizeable dwellers of rural and urban areas. Among the various types of cancer, mammary cancer is one of the most frequently diagnosed cancers in women. Its menace can be curbed with locally consumed spices due to their multiple bioactive phytochemicals. Aims: This review focuses on the breast cancer chemopreventive and therapeutic potentials of locally consumed spices. Methods/Results: The most commonly consumed spices with breast cancer chemopreventive and chemotherapeutic phytochemical include pepper, onions, ginger, garlic, curry and thyme containing many biologically active metabolites ranging from vitamins, fatty acids esters, polyphenols/phenolics, sulfurcontaining compounds and anthraquinones with proven antioxidant, anti-inflammatory, immuno-modulatory, antitumor and anticancer properties against breast cancer/carcinogenesis. Therefore, extracts and active principles of these spices could be explored in breast cancer chemoprevention and possibly therapeutically which may provide an avenue for reducing the risk and prevalence of breast cancer.

Backgroun/Methods: In attempt to develop new potent anti-tumor agents, a series of quinoxaline derivatives was designed and synthesized. The novel compounds were tested in vitro for their anti-proliferative activities against HePG-2, MCF-7 and HCT-116 cell lines. Additionally, DNA binding affinities as well as DNA-top II inhibitory activities of the synthesized compounds were investigated as potential mechanism for anticancer activity. Compounds 13, 15, 16 and 19 exhibited good cytotoxicity activities against the three cell lines (IC50 ranging from 7.6 to 32.4 μM) comparable to that of doxorubicin (IC50 = 9.8 μM). Results: Interestingly, the results of DNA binding and DNA-top II inhibition assays were in agreement with those of the cytotoxicity tests, where the most potent anticancer compounds showed good DNA binding affinities (IC50 ranging from 25.1 to 32.4 μM) and DNA-top II inhibitory activities (IC50 ranging from 6.4 to 15.3 μM) comparable to those of doxorubicin (IC50 = 28.1 and 3.8 μM, respectively). Furthermore, molecular docking studies were carried out for the new compounds in order to investigate their binding pattern with the prospective target, DNA-top II complex (PDB-code: 3qx3).

Introduction: Adult T-cell leukemia (ATL) is an aggressive form of malignancy caused by human T- cell lymphotropic virus 1 (HTLV-1). Currently, there is no effective treatment for ATL. Thymoquinone has been reported to have anti-cancer properties. Objective: The aim of this study is to investigatthe effects of TQ on proliferation, apoptosis induction and the underlying mechanism of action in both HTLV-1 positive (C91-PL and HuT-102) and HTLV-1 negative (CEM and Jurkat) malignant T-lymphocytes. Materials and methods: Cells were incubated with different thymoquinone concentrations for 24h. Cell cytotoxicity was assayed using the CytoTox 96® Non-Radioactive Cytotoxicity Assay Kit. Cell proliferation was determined using CellTiter 96® Non-Radioactive Cell Proliferation. Cell cycle analysis was performed by staining with propidium iodide. Apoptosis was assessed using cell death ELISA kit. The effect of TQ on p53, p21, Bcl-2 protein expression was determined using Western blot analysis while TGF mRNA expression was determined by RT-PCR. Results: At non-cytotoxic concentrations of TQ, it resulted in the inhibition of proliferation in a dose dependent manner. Flow cytometric analysis revealed a shift in the cell cycle distribution to the PreG1 phase which is a marker of apoptosis. Also TQ increase DNA fragmentation. TQ mediated its anti-proliferative effect and apoptosis induction by an up-regulation of TGFβ1, p53 and p21 and a down-regulation of TGF-α and Bcl-2α. Conclusion: Thymoquinone presents antiproliferative and proapoptotic effects in ATL cells. For this reason, further research is required to investigate its possible application in the treatment of ATL.

Background: Prostate cancer-associated mortality is increasing at an alarming rate, which highlights the inevitability for unearthing novel agent for the management of this disease. Anethole, a major constituent of Foeniculum vulgare (fennel) essential oil, is widely used in folk medicine; it possesses anti-oxidant, antiinflammatory, anti-proliferative and tumoricidal potentialities. Objective: The current research was conducted to assess the impact of anethole on prostate cancer cell line, PC- 3, and to delineate the molecular mechanism of action. Methods: To achieve this aim, the growth-inhibitory effect of anethole was evaluated by MTT assay. Apoptotic death and cell cycle analyses were assessed by flow cytometry and alterations in gene expression were investigated by qPCR and Western blot analyses. Results: The observations indicated that anethole inhibited proliferation, clonal growth and migration of PC-3 cells. It also suppressed growth of PC-3 derived cancer stem cells (tumorspheres). Pro-apoptotic potential of anethole was accompanied by generation of ROS, permeabilization of the mitochondrial and lysosomal membranes, activation of caspase-3 and -9, DNA damage, PARP cleavage and induction of Bax/Bcl-2 protein ratio. Further, anethole induced G2/M phase arrest, downregulation of cyclins D1, CDK-4 and c-Myc proteins and upregulation of p21 and p27. Anethole suppressed nuclear localization of NF-ΚB protein and downregulated transcription of NF-ΚB-dependent genes. Conclusion: Overall, the above findings highlight the effectiveness of anethole as a potential candidate for prostate cancer therapy.

Background: HTLV1 is a retrovirus that infects CD4-positive cells and leads to Adult T-cell leukemia by constitutive activation of nuclear factor kappa B. Ascorbic acid (AA) is an essential nutrient that possess anti-proliferative and pro-apoptotic activity against a number of malignant cell lines. This study delineates the effect of AA on Tax protein expression as well as NF-ΚB and MMP9 activity in two HTLV1-positive leukemia cells (HuT-102 and C91-PL). Methods: The cytotoxic and antiproliferative effect of AA were studied by LDH release and MTT tests, respectively. The proteins expression level was assessed by western blotting. RT-PCR was used to study mRNAs level. Finally, ELISA/EMSA and Zymography were used to evaluate NF-ΚB and MMP-9 activities, respectively. Results: Cell lines were treated with non-cytotoxic concentrations of AA for 48h and 96h, which resulted in a significant inhibition of proliferation at a concentration of 50μg/ml at 96h in both cell lines. The same concentration inhibited Tax protein expression as well as the NF-ΚB nuclearization and DNA binding activity. The inhibitory effect of AA on MMP9 protein expression and activity started at 100μg/ml and 50μg/ml in HuT-102 and C91-PL cells respectively, with no effect at the transcriptional levels of MMP-9 in either one of the two cell lines. Conclusion: These results indicated that while AA exerted its anti-proliferative effect on the NF- ΚB activation pathway by suppressing Tax expression, its effects on MMP9 seemed to be independent of this mechanism and follow a different approach.

Background: Recognition of a new therapeutic agent may activate an alternative programmed cell death for the treatment of breast cancer. Objective: Here, it has been tried to evaluate the effects of Shikonin, a naphthoquinone derivative of Lithospermum erythrorhizon, on the induction of necroptosis and apoptosis mediated by RIPK1-RIPK3 in the ER+ breast cancer cell line, MCF-7. Methods: In the current study, cell death modalities, cell cycle patterns, RIPK1 and RIPK3 expressions, caspase-3 and caspase-8 activities, reactive oxygen species and mitochondrial membrane potential have been evaluated in the Shikonin-treated MCF-7 cells. Results: Necroptosis and apoptosis have been occurred by Shikonin, with a significant increase in RIPK1 and RIPK3 expressions, although necroptosis was the major rout in MCF-7 cells. Shikonin significantly increased the percentage of the cells in sub-G1 and also those in the later stages of cell cycle, which represents an increase in necroptosis and apoptosis. Under caspase inhibition by Z-VAD-FMK, Shikonin has stimulated necroptosis, which could be arrested by Nec-1. An increase in ROS levels and a decrease in the mitochondrial membrane potential have also been observed. Conclusion: On the basis of present findings, Shikonin has been suggested as a good candidate for the induction of cell death in ER+ breast cancer, although further investigations, experimental and clinical, are required.

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.

Background: Oncogenic potential of phosphatidylinositol 3-kinase (PI3Kα) has been highlighted as a therapeutic target for anticancer drug design. Objective: Target compounds were designed to address the effect of different substitution patterns at the N atom of the carboxamide moiety on the bioactivity of this series. Methods: Synthesis of the targeted compounds, crystallography, biological evaluation tests against human colon carcinoma (HCT-116), and Glide docking studies. Results: A new series of N-substituted- 4-hydroxy-2-quinolone-3-carboxamides was prepared and characterized by means of FT-IR, 1H and 13C NMR, and elemental analysis. In addition, the identity of the core nucleus 5 was successfully characterized with the aid of X-ray crystallography. Biological activity of prepared compounds was investigated in vitro against human colon carcinoma (HCT-116) cell line. Results revealed that these compounds inhibit cell proliferation and induce apoptosis through an increase in caspase-3 activity and a decrease in DNA cellular content. Compounds 7, 14, and 17 which have H-bond acceptor moiety on p-position displayed promising PI3Kα inhibitory activity. On the other hand, derivatives tailored with bulky and hydrophobic motifs (16 and 18) on o- and m-positions exhibited moderate activity. Molecular docking studies against PI3Kα and caspase-3 showed an agreement between the predicted binding affinity (ΔGobsd) and IC50 values of the derivatives for the caspase-3 model. Furthermore, Glide docking studies against PI3Kα demonstrated that the newly synthesized compounds accommodate PI3Kα kinase catalytic domain and form H-bonding with key binding residues. Conclusion: The series exhibited a potential PI3Kα inhibitory activity in HCT-116 cell line.

Background: Human fibronectin extra-domain B (EDB) is particularly expressed during angiogenesis progression. It is, thus, a promising marker of tumour growth. Aptides are a novel class of peptides with high-affinity binding to specific protein targets. APTEDB is an antagonist-like ligand that especially interacts with human fibronectin EDB. Objective: This study was the first attempt in which the hydrazinonicotinamide (HYNIC)-conjugated APTEDB was labelled with technetium-99m (99mTc) as an appropriate radiotracer and tricine/EDDA exchange labeling. Methods: Radiochemical purity, normal saline, and serum stability were evaluated by HPLC and radio-isotope TLC scanner. Other examinations, such as protein-binding calculation, dissociation radioligand binding assay, and partition coefficient constant determination, were also carried out. The cellular-specific binding of 99mTc- HYNIC-conjugated APTEDB was assessed in two EDB-positive (U87MG) and EDB-negative (U373MG) cell lines. Bio-distribution was investigated in normal mice as well as in U87MG and U373MG tumour-bearing mice. Eventually, the radiolabelled APTEDB was used for tumour imaging using planar SPECT. Results: Radiolabelling was achieved with high purity (up to 97%) and accompanied by high solution (over 90% after overnight) and serum (80% after 2 hours) stability. The obtained cellular-specific binding ratio was greater than nine-fold. In-vivo experiments showed rapid blood clearance with mainly renal excretion and tumour uptake specificity (0.48±0.03% ID/g after 1h). The results of the imaging also confirmed considerable tumour uptake for EDB-positive cell line compared with the EDB-negative one. Conclusion: Aptides are considered to be a potent candidate for biopharmaceutical applications. They can be modified with imaging or therapeutic agents. This report shows the capability of 99mTc-HYNIC-APTEDB for human EDB-expressing tumours detection.

Background: Multi-drug resistance (MDR) remains a major impediment in cancer therapy. A major goal for scientists is to discover more effective compounds that are able to circumvent MDR and simultaneously have minimal adverse side effects. Objective: In the present study, we aim to determine the anti-MDR effects of pyramidatine (Z88), a cinnamic acid-derived bisamide compound isolated from the leaves of Aglaia perviridis, on KB/VCR (vincristineresistant human oral cancer cells) and MCF-7/ADR (adriamycin-resistant human breast adenocarcinoma) cells. Methods: Cell viability and average resistant fold (RF) of Z88 were examined by Cell Counting Kit-8 (CCK-8) assay. Flow cytometry, western blot, RT-PCR, Rhodamine 123 accumulation assay and P-glycoprotein (P-gp) ATPase assay were used to demonstrate the anti-MDR activity and mechanism of Z88. Results: The average RF of Z88 is 0.09 and 0.51 in KB/VCR and MCF-7/ADR cells. A CCK-8 assay showed that Z88 could enhance the cytotoxicity of VCR toward KB/VCR cells. A FACS analysis revealed that Z88 could enhance the VCR-induced apoptosis as well as G2/M arrest in a dose-dependent manner in KB/VCR cells. Western blot results showed that the expression levels of PARP, Bax, and cyclin B1 all increased after treatment with 0.2 μmol/L (μM) of VCR combined with 10 μM of Z88 for 24 h in KB/VCR cells. Z88 also could enhance the accumulation of rhodamine 123. Further studies showed that Z88 could inhibit the verapamil stimulated Pgp ATPase activity. Additionally, qPCR detection and western blot assays revealed that Z88 could decrease the expression of P-gp at both RNA and protein level. Conclusion: Z88 exerted potent anti-MDR activity in vitro and its mechanisms are associated with dualinhibition of the function and expression of P-gp. These findings encourage efforts to develop more effective reversal agents to circumvent MDR based on Z88.

Background: Due to the astonishing properties of ferrocene and its derivatives, it has a broad application in diverse areas. Numerous ferrocene derivatives demonstrated anti-proliferative activity. Also COX-2, as a key isoenzyme for production of prostaglandins, is frequently overexpressed in various cancers. It is now recognized that COX-2 over expression promotes tumorigenic functions which can be suppressed by COX-2 inhibitors, a phenomenon useful for the preventing of tumor progression. The combination of COX-2 inhibitors with other anti-cancer or cancer prevention drugs may reduce their side effects in future cancer prevention and treatment. Objective: Owing to high anticancer potential of ferrocene derivatives and considerable COX-2 inhibitory and cytotoxicity effects of our previously synthesized chalcones, we decided to incorporate the ferrocenyl moiety into appropriate COX-2 inhibitor chalcone based scaffold, to evaluate COX-2 inhibitory activity as well as anticancer activities. Methods: Chalcones were synthesized via clasien-schmidt condensation of methylsulfonyl aldehyde and acetyl ferrocene. Further different amines with solvent free and ultra sound condition were reacted with chalcones to have different 1-ferrocenyl-3-amino carbonyl compounds. Docking study was carried out with Auto Dock vina software. All the newly-synthesized compounds were evaluated for their cyclooxygenase-2 (COX-2) inhibitory activity using chemiluminescent enzyme assays as well as cytotoxicity activity against MCF-7 and T47D and fibroblast cell lines by MTT assay. Results: In vitro COX-1/COX-2 inhibition studies demonstrated that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the highly potent 0.05-0.12 μM range, and COX-2 selectivity indexes (SI) in the 148.3-313.7 range. These results indicated that either potency or selectivity of COX-2 inhibitory activity was affected by the nature and size of the substituents on C-3 of propane-1-one. Also anti-proliferative and toxicity activities of synthesized compounds against breast cancer cell lines MCF-7 and T47D and fibroblast cell lines showed that the synthesized compounds had mild to moderate cytotoxicity against MCT7 and T47D breast cancer cell lines at 10 μM concentration. In vitro COX-1/COX-2 inhibition studies and anticancer activity against MCF-7, identified 1-ferrocenyl-3-(4-methylsulfonylphenyl) propen-1-one as a potent compound (IC50 COX-2 = 0.05 μM, MCF-7: % inhibition (at concentration of 10 μM) = 32.7%), and also 1-ferrocenyl-3- (propan-1-amine)-3-(4-methylsulfonylphenyl) propan-1-one showed the most selectivity on COX-2 inhibition (selectivity index= 313.7). Conclusion: A novel group of ferrocene compounds, possessing a methyl sulfonyl COX-2 pharmacophore were synthesized to investigate the effect of different substituents on selectivity and potency of COX-2 inhibitory activity and their cytotoxicity effects. This study indicates that 1-ferrocenyl-3-amino carbonyl compounds having ferrocene motif and methyl sulfonyl COX-2 pharmacophore is a suitable scaffold to design COX-2 inhibitors and anti-cancer agents.

Background: Micelles as drug carriers are characterized by their inherent instability due to the weak physical interactions that facilitate the self-assembly of amphiphilic block copolymers. As one of the strong physical interactions, the stereocomplexation between the equal molar of enantiomeric polylactides, i.e., the poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), may be harnessed to obtain micelles with enhanced stability and drug loading capacity and consequent sustained release. Aims/Methods: In this paper, stereocomplexed micelles gama-PGA-g-PLA micelles) were fabricated from the stereocomplexation between poly(gama-glutamic acid)-graft-PLLA gama-PGA-g-PLA) and poly(gamaglutamic acid)-graft-PDLA gama-PGA-g-PLA). These stereocomplexed micelles exhibited a lower CMC than the corresponding enantiomeric micelles. Result: Furthermore, they showed higher drug loading content and drug loading efficiency in addition to more sustained drug release profile in vitro. In vivo imaging confirmed that the DiR-encapsulated stereocomplexed gama-PGA-g-PLA micelles can deliver anti-cancer drug to tumors with enhanced tissue penetration. Overall, gama-PGA-g-PLA micelles exhibited greater anti-cancer effects as compared with the free drug and the stereocomplexation may be a promising strategy for fabrication of anti-cancer drug carriers with significantly enhanced efficacy.