Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 19, Issue 17, 2019

The JAK-STAT pathway is an important physiologic regulator of different cellular functions including proliferation, apoptosis, differentiation, and immunological responses. Out of six different STAT proteins, STAT5 plays its main role in hematopoiesis and constitutive STAT5 activation seems to be a key event in the pathogenesis of several hematological malignancies. This has led many researchers to develop compounds capable of inhibiting STAT5 activation or interfering with its functions. Several anti-STAT5 molecules have shown potent STAT5 inhibitory activity in vitro. However, compared to the large amount of clinical studies with JAK inhibitors that are currently widely used in the clinics to treat myeloproliferative disorders, the clinical trials with STAT5 inhibitors are very limited. At present, a few STAT5 inhibitors are in phase I or II clinical trials for the treatment of leukemias and graft vs host disease. These studies seem to indicate that such compounds could be well tolerated and useful in reducing the occurrence of resistance to tyrosine kinase inhibitors in chronic myeloid leukemia. Of interest, STAT5 seems to play an important role in the regulation of hematopoietic stem cell self-renewal suggesting that combination therapies including STAT5 inhibitors can erode the cancer stem cell pool and possibly open the way for the complete cancer eradication. In this review, we discuss the implication of STAT5 in hematological malignancies and the results obtained with the novel STAT5 inhibitors.

Background: Diffuse Large B Cell Lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma which is heterogeneous both clinically and morphologically. Over the past decades, significant advances have been made in the understanding of the molecular genesis, leading to the identification of multiple pathways and molecules that can be targeted for clinical benefit. Objective: The current review aims to present a brief overview of signal pathways of DLBCL, which mainly focus on B-cell antigen Receptor (BCR), Nuclear Factor-ΚB (NF-ΚB), Phosphatidylinositol-3-Kinase (PI3K) – protein kinase B (Akt) – mammalian Target of Rapamycin (mTOR), Janus Kinase (JAK) – Signal Transducer and Activator (STAT), Wnt/β-catenin, and P53 pathways. Methods: Activation of signal pathways may contribute to the generation, development, chemotherapy sensitivity of DLBCL, and expression of pathway molecules is associated with the prognosis of DLBCL. Some agents targeting these pathways have been proved effective and relevant clinical trials are in progress. These agents used single or combined with chemotherapy/each other might raise the possibility of improving clinical outcomes in DLBCL. Conclusion: This review presents several signal pathways of DLBCL and targeted agents had a tendency to improve the curative effect, especially in high-risk or relapsed/refractory DLBCL.

Background: Atorvastatin belongs to the group of statins and is the leading drug for hypercholesterolemia treatment. Although, its anticancer effects are highly appreciated, its properties are still unclear. The aim of this study was to explore the underlying anticancer mechanisms induced by atorvastatin and enlarge the potential target in non-small cell lung cancer. Methods: Target genes of atorvastatin were collected by the DrugBank database. Prediction of interaction between primary targets and secondary targets was performed, and protein-protein interaction network was constructed though the STRING. Then, KEGG pathway enrichment analysis was performed with WebGestalt and ClueGO, including the pathways in non-small cell lung cancer. Furthermore, a genomic alteration analysis of the selected seed genes of atorvastatin benefit and non-small cell lung cancer pathway was conducted by cBioPortal. Finally, a survival analysis with the selected seed genes in lung cancer (lung adenocarcinoma, lung squamous cell carcinoma) was conducted using Kaplan-Meier (KM) plotter. Results: To identify seed genes, 65 potential candidate genes were screened as targets for atorvastatin using STRING with DrugBank database, while the KEGG pathway was enriched to get the overlap match of pathways in non-small cell lung cancer. Then 4 seed genes, Epidermal Growth Factor Receptor (EGFR), erb-b2 receptor tyrosine kinase 2 (ERBB2), AKT serine/threonine kinase 1 (AKT1) and tumor protein p53 (TP53), were selected and their genomic alternation were evaluated by cBioPortal. Survival analysis found that TP53 and EGFR showed a significant correlation (log rank P = 3e-07 and 0.023) with lung adenocarcinoma and lung squamous cell carcinoma, according to the KM analysis. Conclusion: Gene-phenotype connectivity for atorvastatin in non-small cell lung cancer was identified using functional/activity network analysis method, and our findings demonstrated that TP53 and EGFR could be the potential targets in cancer patients with atorvastatin therapy.

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) is a common malignancy that is associated with high morbidity and mortality all over the world. We explored the role of mRNA expression of both subunits of LDH in the early diagnosis of HNSCC. Materials and Methods: This was a case-control study on 62 healthy individuals and 62 patients with HNSCC. The expression of LDH in tumors and healthy tissue margins, and in the serum of both HNSCC patients and healthy individuals was evaluated using a quantitative real-time PCR method. Analysis of LDH-A and LDH-B expression and sensitivity-specificity analysis were carried out using SPSS software. Results: mRNA expression levels of LDH-A (4.18±1.29) and LDH-B (2.85±1.07) isoenzymes in tumor tissues were significantly higher than the expressions in the corresponding healthy tissue margins (1.85±0.56 and 1.61±0.56 for LDH-A and LDH-B, respectively). A comparison of LDH-B expression between histological grade I tumor tissue (2.74±0.19) and marginal tissue (1.62±0.90) showed a significant difference (P=0.016). Patients with a positive history of alcohol consumption and cigarette smoking had significantly higher mRNA expression of LDH-A (P=0.024) and LDH-B (P=0.03) in the marginal tissue and blood, respectively. The highest sensitivity and specificity values pertained to the mRNA expression of LDH-A (90.9%) and LDH-B (85.5%) in the blood. Conclusion: This is the first study reporting LDH gene expression as a biomarker in blood and tumoral tissue of HNSCC patients. Given the highest sensitivity and specificity values for LDH-A and LDH-B in blood, we recommend the simultaneous evaluation of both LDH isoenzymes in blood samples as a potential diagnostic method.

Background: L-kynurenine, derivate of L-tryptophan, is synthetized by indoleamine 2,3-dioxygenase (IDO). The effects of L-kynurenine depend on its binding to an aryl hydrocarbon receptor (AhR). Objective: The aim of this study was to investigate the changes within the apoptotic pathway in PANC-1 cells subjected to L-kynurenine or L-tryptophan considering the production of anti-apoptotic proteins from the IAPs and Bcl-2 family, as well as the regulation of NF-ΚB signaling. Methods: The investigated substances were added alone or in combination with the AhR inhibitor (CH223191) to cultures of PANC-1 cells. Cytoplasmic and nuclear proteins were analyzed by immunoblotting and cells were incubated with the investigated substances to determine cytotoxicity and proliferative effects. Results: Incubation of PANC-1 cells with L-kynurenine or L-tryptophan resulted in the increase in antiapoptotic cIAP-1, cIAP-2, XIAP and Bcl-2 expression and a decrease in pro-apoptotic Bax. These changes were accompanied by the reduction of active caspases -9, -3 and PARP-1. The treatment leads to translocation and enhanced production of nuclear NF-ΚB p50 and Bcl-3. Incubation of the cells with AhR blocker either alone or together with L-kynurenine or L-tryptophan resulted in the opposite effect, leading to the downregulation of IAPs and Bcl-2, upregulation of Bax and caspases expression. Conclusion: 1) L-kynurenine and its precursor promote anti-apoptotic effects through the modulation of IDOdependent pathway and regulation of IAPs, Bcl-2 and NF-ΚB family members in pancreatic carcinoma cells 2) inhibition of AhR by CH223191 exerts an apoptosis-promoting effect, and this observation might suggest the potential use of this compound in pancreatic cancer therapy.

Background and Objective: The fruit of Fructus liquidambaris, which is recently being used for cancer treatment, has a history to be used as a traditional medicine in China for thousands of years. Materials and Methods: Ten kg of dried F. liquidambaris was obtained with 70% alcohol-water solution under reflux for three times. The condensed extract was obtained from petroleum ether, ethyl acetate and N-butyl alcohol, respectively. Ethyl acetate extract was subjected to silica gel column, Sephadex LH-20, ODS column chromatography and RP-HPLC column chromatography to yield a new compound (1). The structure was identified through intensive analysis of NMR and MS spectra. The antitumor mechanism of the furanocoumarin A on human lung cancer A549 cells was confirmed by detecting the apoptosis-related proteins. Results: Furanocoumarin A (1), a novel furanocoumarin constituent was isolated and identified from F. Liquidambaris. The IC50 value of furanocoumarin A on A549 cell lines was 65.28±5.36μM obtained by the method of MTT. The compound could induce the apoptosis of A549 cells by inducing 21.5% early apoptosis and 32.4% late apoptosis at the concentration of 60μmol/L. Western blot analysis indicated that protein expressions of p53, caspase 3 and Bax increased in a dose-dependent manner between the concentrations from 40 to 80μM. The protein expression of Bcl-2 decreased the concentration of 60 and 80μM. The ratio of Bcl-2 to Bax was inversely proportional to the dose concentration. Conclusion: Furanocoumarin A could be a novel anticancer agent from herbal medicine.

Background: Despite worthy biologic rationale and numerous studies introducing therapeutic strategies targeting Epidermal Growth Factor Receptor (EGFR), phase III clinical trials have claimed that these current anti-EGFR agents did not significantly improve overall survival of Gastric Cancer (GC) patients. Therefore, to discover flawless candidates of anti-EGFR therapy and ideal prognostic markers, innovative studies are warranted. Methods: The aim of this study was to assess the expression profile of EGFR in GC, adjacent non-tumor and normal gastric tissues by qRT-PCR, investigating the association of EGFR expression with clinicopathological features, evaluating possible molecular interaction between EGFR and Androgen Receptor (AR), and elucidating novel prognostic marker using Cox regression model. Results: Among 60 GC patients, 70% (42/60) overexpressed EGFR relative to normal gastric tissues. EGFR overexpression was significantly correlated with the AR overexpression in GC patients. Although EGFR overexpression was remarkably associated with unfavorable outcomes (HR= 4.067, 95% CI= 1.228-13.467, p= 0.022), it was not an independent prognostic factor adjusted for other variables. However, we provided evidences that simultaneous evaluation of EGFR and AR expression, could independently predict the outcome of GC patients and could use as a precise prognostic marker. Moreover, it was revealed that induction or inhibition of AR signaling could alter the mRNA expression of EGFR in GC cell lines. Conclusion: By targeting AR and EGFR using a potent AR inhibitor such as Enzalutamide, we postulate the possible crosstalk between EGFR and AR pathways in GC. Moreover, our study provided evidences elucidating a novel promising marker, simultaneous evaluation of EGFR and AR expression, which could properly predict prognosis of gastric cancer patients.

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23μM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: These results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.

Background: Receptor Tyrosine Kinases (RTK) are the main family of cell surface receptors for growth factors, hormones and cytokines which are responsible for cell growth and differentiation and are considered as an important therapeutic target in cancer. Objective: The aim of this study was to design, synthesise and conduct the biological evaluation of benzimidazole/ benzoxazole substituted triazolotriazines as new anticancer agents. Methods: A series of benzimidazolyl and benzoxazolyl-linked triazolotriazines 8a-e and 9a-e were synthesized as receptor tyrosine kinase inhibitors. Target compounds were evaluated in HGF-induced cell proliferation assay in A549, MCF-7, HepG2 and MDA-MB-231 cancer cells. Results: Hepatocellular carcinoma was the most sensitive cell line towards the tested compounds and 8e was the most potent one on HepG2 cells with an IC50 value of 5.13μM which was close to crizotinib (HepG2 IC50 = 4.35μM) as a standard c-Met kinase inhibitor. c-Met kinase assay of 8e showed that this compound is not capable of inhibiting this enzyme and subsequently molecular docking confirmed the low affinity of 8e towards c- Met active site and its possible anticancer mechanism through VEGFR-2 inhibition. Conclusion: Further in silico predictions revealed that 8e can be a drug candidate with favorable pharmacokinetic properties.

Background: Triple-Negative Breast Cancers (TNBC) are among the most aggressive and therapyresistant breast tumors. Development of new treatment strategies that target pathways involved in cancer cells resistance is an attractive candidate to overcome therapeutic resistance. Objective: To clarify the antitumor activity of [VO (bpy)2 Cl] Cl complex as a new therapeutic agent through studying the interplay between apoptosis, autophagy and notch signaling pathways. Methods: Proliferation of MDA-MB-231 cells and IC50 value of the vanadium complex were assessed by MTT assay. Flow cytometry was utilized to detect cell cycle distribution, apoptosis assay, LC3 levels and Acid Vascular Organelles (AVOs). Caspase 3 levels were detected by ELISA. Changes in Notch1 gene expression were assessed by real-time PCR. AVOs qualitative detection was assessed by a fluorescence microscope. Results: The growth of MDA-MB-231 cells was suppressed after treatment with [VO (bpy)2 Cl] Cl complex, in a dose-dependent manner. The affinity for apoptotic cell death induction was shown through the increase in the sub G0 peak, the percentage of early and late apoptotic phases, and the elevation in caspase 3 levels. The affinity for autophagic cell death induction was observed through the increase in the G0/G1 phase, G2/M arrest, the increase of AVOs red fluorescence and elevated LC3 levels. The affinity for notch pathway inhibition was shown through the suppression of Notch 1 gene expression. Conclusion: [VO (bpy)2 Cl] Cl complex could be a promising candidate as therapeutic agent targeting different therapeutic targets including apoptosis, autophagy and notch signaling pathways.

Background: Green synthesis of silver nanoparticles (AgNPs) is limited to produce AgNPs with only relatively low concentrations, and is unsuitable for large-scale productions. The use of Myrtus communis (MC) leaf methanolic extract (rich in hydrolyzable tannins) has been recommended to resolve the issues related to the aggregation of nanoparticles at high concentrations of silver ions with added facet of antioxidant properties. Methods: The produced highly concentrated MC-AgNPs were characterized by using imaging and spectroscopic methods. Subsequently, antioxidant, anticancer and antifungal activities of the nanoparticles were evaluated. Results: The thermogravimetric analysis and energy dispersive spectroscopy quantitative results suggested that the nanoparticles are biphasic in nature (bio-molecule + Ag0) and layered in structure, suggesting the formation of nanoparticles through a different mechanism than those described in the literature. MC-AgNPs showed greater scavenging activity of nitric oxide and iron (II) chelating ability than the extract. It also showed good reducing power compared to the standard antioxidant. Remarkable anticancer activity of MC-AgNPs (IC50 = 5.99μg/mL) was found against HCT-116 (human colon carcinoma) cell lines after 24h exposure with a therapeutic index value 2-fold higher than the therapeutic index of standard doxorubicin. Furthermore, distinct antifungal activity (MIC = 4μg/mL) was found against Candida krusei. Conclusion: The current method outperforms the existing methods because it produces a large amount of multifunctional nanoscale hybrid materials more efficiently using natural sources; thus, it may be used for diverse biomedical applications.