A498 Renal Cancer Research Articles

A new herbal extract carbon nanodot nanomedicine for anti-renal cell carcinoma through the PI3K/AKT signaling pathway.

New Re carbon nanodots with narrow size distribution, good water solubility and high cell membrane permeability were prepared from a herbal extract. They exhibited high inhibitory effects on renal cancer A498 cells and renal cell carcinoma. They could stimulate the production of ROS, induce mitochondrial dysfunction, and accelerate the release of intracellular calcium ions in the A498 cells. Transcriptomic tests were performed on A498 cells after administration, and the results were analyzed by qPCR and immunofluorescence. The results suggested that the Re carbon nanodots could downregulate the abnormally activated PI3K/AKT signaling pathway and perform cell cycle arrest in the S phase along with the inhibition of cell proliferation. Finally, in conjunction with the abnormal mitochondrial function, the Re carbon nanodots could ultimately promote the apoptosis of the A498 cells. In vivo tumor-bearing mouse experiments further showed that the Re carbon nanodots had a strong inhibitory effect on xenograft kidney cancer tumors. The prepared Re carbon nanodots have good anti-renal cancer A498 cell and renal cell carcinoma bioactivity and are expected to be a potential drug for the treatment of kidney cancer with low toxicity and high safety.

Design, synthesis and mechanistic study of N-4-Piperazinyl Butyryl Thiazolidinedione derivatives of ciprofloxacin with Anticancer Activity via Topoisomerase I/II inhibition

A new group of thiazolidine-2,4-dione derivatives of ciprofloxacin having butyryl linker 3a-l was synthesized via an alkylation of thiazolidine-2,4-diones with butyryl ciprofloxacin with yield range 48–77% andfully characterized by various spectroscopic and analytical tools. Anti-cancer screening outcomes indicated that 3a and 3i possess antiproliferative activities against human melanoma LOX IMVI cancer cell line with IC50 values of 26.7 ± 1.50 and 25.4 ± 1.43 µM, respectively, using doxorubicin and cisplatin as positive controls with an IC50 of 7.03 ± 0.40 and 5.07 ± 0.29 µM, respectively. Additionally, compound 3j showed promising anticancer activity against human renal cancer A498 cell line with IC50 value of 33.9 ± 1.91 µM while doxorubicin and cisplatin showed IC50 values of 3.59 ± 0.20 and 7.92 ± 0.45, respectively. On the other hand, compound 3i did not show considerable anti-bacterial activity against S. aureus, E. coli and P. aeruginosa, and only moderate activity against K. pneumoniae with only a tenth of the activity of ciprofloxacin, confirming the cytotoxicity observed. Mechanistically, compound 3i inhibited both topoisomerase I and II with IC50 of 4.77 ± 0.26 and 15 ± 0.81 µM. Furthermore, it induced cell cycle arrest at S phase in melanoma LOX IMVI cells. Moreover, 3i provoked substantial levels of early, late apoptosis and necrosis in melanoma LOX IMVI cell line comparable to that induced by doxorubicin. Furthermore, compound 3i increased the expression level of active caspase-3 by 49 folds higher in LOX IMVI cell, increased protein expression level of Bax more than the control by 3 folds and inhibited PARP-1by 33% in LOX IMVI. All results were supported by theoretical docking studies on both tested enzymes confirming potential cytotoxicity for the synthesized hybrids.

Cs2CO3-Promoted Alkylation of 3-Cyano-2(1H)-Pyridones: Anticancer Evaluation and Molecular Docking.

Herein, a Cs2CO3-promoted N-alkylation of 3-cyano-2(1H)-pyridones containing alkyl groups with diverse alkyl halides to synthesize N-alkyl-2-pyridones over O-alkylpyridines is reported. The use of alkyl dihalides resulted in complex mixtures of N- and O-alkylated products. The primary factor influencing regioselectivity in these reactions is the electronic effects of substituents on the 2(1H)-pyridone ring, as evidenced by the preferential formation of O-alkylpyridines upon the introduction of aryl groups. Remarkably, we efficiently employed CuAAC and Ti(Oi-Pr)4-catalyzed amidation reactions to functionalize N-alkyl-2-pyridones containing propargyl and ester groups, leading to the synthesis of 1,2,3-triazoles and amides, respectively. Moreover, O-alkylpyridines 10 b and 10 d displayed remarkable selectivity toward the A-498 renal cancer cell line with growth inhibition percentages (%GI) of 54.75 and 67.64, respectively. The binding modes of compounds 10 b and 10 d to the PIM-1 kinase enzyme were determined through molecular docking studies.

Pachymic acid activates TP53INP2/TRAF6/caspase-8 pathway to promote apoptosis in renal cell carcinoma cells.

While pachymic acid (PA), a key component of Poria cocos (Schw.), has demonstrated anti-tumor effects in lung, breast, and pancreatic cancers, its impact on renal cell carcinoma (RCC) is unclear. This study evaluated the effect of PA on proliferation, migration, and apoptosis in human renal cancer A498 and ACHN cells as well as in cancer xenograft mice using wound scratch test, Western blotting, and co-immunoprecipitation assays. In a dose- and time-dependent manner, PA exhibited significant inhibition of RCC cell proliferation, migration, and invasion, accompanied by the induction of apoptosis. Additionally, PA upregulated the expression of tumor protein p53-inducible nuclear protein 2 (TP53INP2) and tumor necrosis factor receptor-associated factor 6 (TRAF6), which were downregulated in renal papillary and chromophobe carcinoma, resulting in inhibited tumor growth in mice. PA treatment elevated cleaved-caspase 3 and 8, and PARP levels, and facilitated TP53INP2 and TRAF6 binding to caspase 8, promoting its ubiquitination. Molecular docking revealed interactions between PA and TP53INP2, TRAF6. In summary, PA inhibits RCC development by upregulating TP53INP2 and promoting TRAF6-induced caspase 8 ubiquitination, activating apoptotic pathways.

Synthesis and antitumor activity of 1,3,4-oxadiazole substituted 2-(5-ylidene-2,4-dioxothiazolidin-3-yl)-acetamides

A series of novel 1,3,4-oxadiazole substituted 2-(5-aryl/heterylidene-2,4-dioxothiazolidine-3-ylidene)-acetamides and their 5-unsubstituted analogues have been synthesized following N-alkylation reaction of 2-chloro-N-(5-aryl-[1,3,4]oxadiazol-2-yl)-acetamides with thiazolidinedione and potassium salts of its arylidene derivatives. The structures of target compounds were confirmed by using 1H NMR spectroscopy and elemental analysis. Evaluation of anticancer activity in vitro for the synthesized compounds was performed in accordance with the National Cancer Institute protocol. A selective influence of some tested compounds against leukaemia MOLT-4 (3e, GP = 76.85%) and K-562 (3e, GP = 79.84%), colon cancer HCT-15 (3d, GP = 76.86%), renal cancer A498 (4a, GP = 74.37%), CAKI-1 (3d, GP = 68.49%) and UO-31 (3b-e, 4a-b, GP = 66.67 ÷ 86.30%) cell lines was established. Grafical abstract:

Design, synthesis and mechanistic studies of benzophenones hydrazone derivatives as cathepsin inhibitors

A novel series of benzophenone hydrazone derivatives were synthesized and evaluated for their antiproliferative activity. The thiosemicarbazone derivative 5c and guanylhydrazone derivatives 6d-f showed potent antiproliferative activities against A498 renal cancer cells with IC50= 14.5, 0.28, 0.30 and 0.3 µM, respectively. Compounds 5c, 6d, 6e and 6f showed inhibitory activities against cathepsin L and cathepsin B (IC50 ranged from 0.071 to 0.303 µM. A mechanistic study revealed that compound 6e induced apoptosis on A498 cell line by 38.02% compared to 1.64% in control. This apoptotic effect was supported by an 8.58-fold increase in the level of caspase-3 compared to the control cells. Additionally, compound 6e inhibited A498 cell growth mostly at the S phase. Furthermore, molecular modeling studies showed that compound 6e possessed good fitting with cathepsin L and cathepsin B binding sites through their interaction with essential amino acids through hydrophobic H-bonding interactions. Therefore, compound 6e could be considered as a prospective anticancer lead compound and it worth further exploration/optimization as an antiproliferative agent via cathepsins inhibition.

Nonselective TRPC channel inhibition and suppression of aminoglycoside-induced premature termination codon readthrough by the small molecule AC1903

Nonsense mutations, which occur in ∼11% of patients with genetic disorders, introduce premature termination codons (PTCs) that lead to truncated proteins and promote nonsense-mediated mRNA decay. Aminoglycosides such as G418 permit PTC readthrough and so may be used to address this problem. However, their effects are variable between patients, making clinical use of aminoglycosides challenging. In this study, we tested whether TRPC nonselective cation channels contribute to the variable PTC readthrough effect of aminoglycosides by controlling their cellular uptake. Indeed, a recently reported selective TRPC5 inhibitor, AC1903, consistently suppressed G418 uptake and G418-induced PTC readthrough in the DMS-114 cancer cell line and junctional epidermolysis bullosa (JEB) patient-derived keratinocytes. Interestingly, the effect of AC1903 in DMS-114 cells was mimicked by nonselective TRPC inhibitors, but not by well-characterized inhibitors of TRPC1/4/5 (Pico145, GFB-8438) or TRPC3/6/7 (SAR7334), suggesting that AC1903 may work through additional or undefined targets. Indeed, in our experiments, AC1903 inhibited multiple TRPC channels including TRPC3, TRPC4, TRPC5, TRPC6, TRPC4–C1, and TRPC5–C1, as well as endogenous TRPC1:C4 channels in A498 renal cancer cells, all with low micromolar IC50 values (1.8–18 μM). We also show that AC1903 inhibited TRPV4 channels, but had weak or no effects on TRPV1 and no effect on the nonselective cation channel PIEZO1. Our study reveals that AC1903 has previously unrecognized targets, which need to be considered when interpreting results from experiments with this compound. In addition, our data strengthen the hypothesis that nonselective calcium channels are involved in aminoglycoside uptake.

Broussochalcone A Induces Apoptosis in Human Renal Cancer Cells via ROS Level Elevation and Activation of FOXO3 Signaling Pathway.

Broussochalcone A (BCA) is a chalcone compound extracted from the cortex of Broussonetiapapyrifera (L.) Ventenat that exerts various effects, such as potent antioxidant, antiplatelet, and anticancer effects. However, the effects of BCA against cancers have been seldom studied. This study is aimed at demonstrating the apoptotic mechanisms of BCA in A498 and ACHN cells, which are two types of human renal cancer cell lines. MTT, cell counting, and colony formation assays indicated that BCA treatment inhibited cell viability and cell growth. Further, cell cycle analysis revealed that BCA induced cell cycle arrest at the G2/M phase. Annexin V/PI staining and TUNEL assays were performed to determine the apoptotic effects and DNA fragmentation after treatment with BCA. Based on western blot analysis, BCA induced the upregulation of cleaved PARP, FOXO3, Bax, p21, p27, p53, phosphorylated p53 (ser15, ser20, and ser46), and active forms of caspase-3, caspase-7, and caspase-9 proteins, but downregulated the proforms of the proteins. The expression levels of pAkt, Bcl-2, and Bcl-xL were also found to be downregulated. Western blot analysis of nuclear fractionation results revealed that BCA induced the nuclear translocation of FOXO3, which might be induced by DNA damage owing to the accumulation of reactive oxygen species (ROS). Elevated intracellular ROS levels were also found following BCA treatment. Furthermore, DNA damage was detected after BCA treatment using a comet assay. The purpose of this study was to elucidate the apoptotic effects of BCA against renal cancer A498 and ACHN cells. Collectively, our study findings revealed that the apoptotic effects of BCA against human renal cancer cells occur via the elevation of ROS level and activation of the FOXO3 signaling pathway.

Design, synthesis, in vitro anticancer evaluation, kinase inhibitory effects, and pharmacokinetic profile of new 1,3,4-triarylpyrazole derivatives possessing terminal sulfonamide moiety

The present work describes the design and synthesis of a novel series of 1,3-diaryl-4-sulfonamidoarylpyrazole derivatives 1a–q and 2a–q and their in vitro biological activities. The target compounds were evaluated for antiproliferative activity against NCI-60 cell line panel. Compounds 1c, 1g, 1k–m, 1o, 2g, 2h, 2k–m, 2o, and 2q showed the highest mean inhibition percentages at 10 µM single-dose testing and were selected to be tested at 5-dose mode. The ICs50 of the most potent compounds were determined over the 60 cell lines. Compound 2l exhibited the strongest activity against different cell lines with IC50 0.33 µM against A498 renal cancer cell line. Compound 2l was tested over a panel of 20 kinases to determine its molecular target(s), and its IC50 values over the most sensitive kinases were defined. In vitro stability and in vivo pharmacokinetic profile of compound 2l was also investigated.

Abstract 2908: Characteristics of triple negative breast cancer that result in sensitivity to englerin A

Abstract New approaches are needed to improve long term survival for patients with metastatic triple negative breast cancers (TNBCs). Patients with metastatic TNBC have a poorer 3-year survival compared to patients with metastatic HER2+ or ER/PR+ disease. Identifying new therapeutic targets of TNBC subgroups could provide opportunities for more effective treatments. We conduct a screening program to identify compounds with selective activity against a panel of TNBC cell lines, reasoning that mechanism of action studies of selective cytotoxins could identify new therapeutic targets. Englerin A was identified as a compound with highly selective actions against two TNBC cell lines: BT-549 (>1800-fold selectively) and Hs578T (>600-fold selectivity) as compared to other TNBC cell lines. Previous studies showed that englerin A is an agonist of TRPC1/4/5 non-specific cation channels and PKCθ in renal cancer cells.1–4 RT-PCR analyses showed that BT-549 and Hs578T cells express more TRPC4 than either the insensitive MDA-MB-231 TNBC cells or the A498 renal cancer cells. If BT-549 and Hs578T cells are sensitive to englerin A due to high expression of TRPC4 channels, then treatment with TRPC4 channel inhibitors should decrease sensitivity to englerin A. These studies show that the TRPC1/4/5 channel inhibitor Pico1455 caused a rightward shift in the concentration response curve of englerin A in both BT-549 and Hs578T cells. These data are consistent with TRPC1/4/5 channel activation contributing to englerin A-induced cell death of BT-549 and Hs578T cells. TRPC channels are non-specific cation channels, therefore their activation is expected to cause an influx of cations including calcium and sodium. Live cell calcium imaging showed the influx of calcium into BT-549 cells following englerin A treatment, further supporting the hypothesis that englerin A-induced cell death in these cell lines is the result of TRPC channel activation. TRPC channel activation initiates disruption of intracellular cation homeostasis, therefore we tested ouabain, a Na+/K+ATPase inhibitor, to determine if BT-549 and Hs578T cells were also sensitive to TRPC-independent methods of intracellular cation homeostasis disruption. BT-549 and Hs578T cells were 12- and 2-fold more sensitive to ouabain as compared to other TNBC cell lines, suggesting that some TNBC cells lines are particularly sensitive to disruption of intracellular cation homeostasis. Ongoing work is aimed at identifying additional factors in englerin A's mechanism of action in BT-549 and Hs578T cells. Our studies suggest that effective treatments for this subgroup of TNBC may include agents which disrupt cation homeostasis. 1.Ludlow, M. J. et al. (2016). 2.Akbulut, Y. et al. (2015). 3.Carson, C. et al. (2015). 4.Sourbier, C. et al. (2013). 5.Rubaiy, H. N. et al. (2017). Citation Format: Corena V. Shaffer, April L. Risinger, John A. Beutler, Susan L. Mooberry. Characteristics of triple negative breast cancer that result in sensitivity to englerin A [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2908.

Bioassay-guided isolation of triterpene from brown alga Padina boergesenii possess anti-inflammatory and anti-angiogenic potential with kinetic inhibition of β-carotene linoleate system

We aimed to investigate the bioassay-guided extraction and characterization of triterpene isolated from brown alga Padina boergesenii in establishing antioxidant, anti-angiogenic and anti-inflammatory activities. The n-hexane defatted methanol crude extract (HDME) was subjected to column chromatography through combination of n-butanol:ethylacetate (BE); chloroform:ethylacetae (CE) and methanol:ethylacetate (ME) solvent system at 1:3 ratio. Five fractions (F1-F5) from each solvent system (BE, CE and ME) was collected and analyzed. Among all, the third fraction from ME (ME-F3) had potential DPPH, deoxyribose and total antioxidant activities (TAA) than CE and BE. Reducing power (RP) of ME-F3 increased with increasing concentrations of triterpene. Saturation curve of triterpene in reduction of β-carotene bleaching at different time-points and at various concentrations have identified kinetic inhibition of free radicals. Antiangiogenic (VEGF) and anti-inflammatory (IL-1β) activities in A498 renal cancer cells have established the potential role of squalene. Molecular characterization by gas chromatography and mass spectrometry has identified the triterpene from ME-F3 fraction.

Hybrid imidazole (benzimidazole)/pyridine (quinoline) derivatives and evaluation of their anticancer and antimycobacterial activity

The design, synthesis, structure, and in vitro anticancer and antimycobacterial activity of new hybrid imidazole (benzimidazole)/pyridine (quinoline) derivatives are described. The strategy adopted for synthesis is straight and efficient, involving a three-step setup procedure: N-acylation, N-alkylation, and quaternization of nitrogen heterocycle. The solubility in microbiological medium and anticancer and antimycobacterial activity of a selection of new synthesized compounds were evaluated. The hybrid derivatives have an excellent solubility in microbiological medium, which make them promising from the pharmacological properties point of view. One of the hybrid compounds, 9 (with a benzimidazole and 8-aminoquinoline skeleton), exhibits a very good and selective antitumor activity against Renal Cancer A498 and Breast Cancer MDA-MB-468. Moreover, the anticancer assay suggests that the hybrid Imz (Bimz)/2-AP (8-AQ) compounds present a specific affinity to Renal Cancer A498. Concerning the antimycobacterial activity, only the hybrid compound, 9, has a significant activity. SAR correlations have been performed.

Synthesis, structure elucidation, DNA-PK and PI3K and anti-cancer activity of 8- and 6-aryl-substituted-1-3-benzoxazines

The synthesis of 6-aryl, 8- aryl, and 8-aryl-6-chloro-2-morpholino-1,3-benzoxazines with potent activity against PI3K and DNA-PK is described. Synthesis of thirty one analogues was facilitated by an improved synthesis of 3-bromo-2-hydroxybenzoic acid 13 by de-sulphonation of 3-bromo-2-hydroxy-5-sulfobenzoic acid 12 en route to 2-methylthio-substituted-benzoxazine intermediates 17–19.From this series, compound 20k (LTURM34) (dibenzo[b,d]thiophen-4-yl) (IC50 = 0.034 μM) was identified as a specific DNA-PK inhibitor, 170 fold more selective for DNA-PK activity compared to PI3K activity.Other compounds of the series show markedly altered selectivity for various PI3K isoforms including compound 20i (8-(naphthalen-1-yl) a potent and quite selective PI3Kδ inhibitor (IC50 = 0.64 μM).Finally, nine compounds were evaluated and showed antiproliferative activity against an NCI panel of cancer cell lines. Compound 20i (8-(naphthalen-1-yl) showed strong anti-proliferative activity against A498 renal cancer cells that warrants further investigation.

1-Benzyl-2-methyl-3-indolylmethylene barbituric acid derivatives: Anti-cancer agents that target nucleophosmin 1 (NPM1)

In the present study, we have designed and synthesized a series of 1-benzyl-2-methyl-3-indolylmethylene barbituric acid analogs (7a–7h) and 1-benzyl-2-methyl-3-indolylmethylene thiobarbituric acid analogs (7i–7l) as nucleophosmin 1 (NPM1) inhibitors and have evaluated them for their anti-cancer activity against a panel of 60 different human cancer cell lines. Among these analogs 7i, 7j, and 7k demonstrated potent growth inhibitory effects in various cancer cell types with GI50 values <2μM. Compound 7k exhibited growth inhibitory effects on a sub-panel of six leukemia cell lines with GI50 values in the range 0.22–0.35μM. Analog 7i also exhibited GI50 values <0.35μM against three of the leukemia cell lines in the sub-panel. Analogs 7i, 7j, 7k and 7l were also evaluated against the mutant NPM1 expressing OCI-AML3 cell line and compounds 7k and 7l were found to cause dose-dependent apoptosis (AP50=1.75μM and 3.3μM, respectively). Compound 7k also exhibited potent growth inhibition against a wide variety of solid tumor cell lines: that is, A498 renal cancer (GI50=0.19μM), HOP-92 and NCI-H522 lung cancer (GI50=0.25μM), COLO 205 and HCT-116 colon cancer (GI50=0.20 and 0.26μM, respectively), CNS cancer SF-539 (GI50=0.22μM), melanoma MDA-MB-435 (GI50=0.22μM), and breast cancer HS 578T (GI50=0.22μM) cell lines. Molecular docking studies suggest that compounds 7k and 7l exert their anti-leukemic activity by binding to a pocket in the central channel of the NPM1 pentameric structure. These results indicate that the small molecule inhibitors 7i, 7j, 7k, and 7l could be potentially developed into anti-NPM1 drugs for the treatment of a variety of hematologic malignancies and solid tumors.

Cu (I) catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC): Synthesis of 17α-[1-(substituted phenyl)-1,2,3-triazol-4-yl]-19-nor-testosterone-17β-yl acetates targeting progestational and antipro-liferative activities

The progestational potency and selectivity of synthetic steroidal agonists can be enhanced by even larger chemical moieties at 17α-position of the steroid backbones. Hereby a series 5a-c and 6a-c of novel 17α-[1-(substituted phenyl)-1,2,3-triazol-4-yl]-19-nortestosterone-17β-yl acetates were designed and synthesized using click chemistry approach searching progestogenic derivatives with potential anticancer activity. Compounds 5a,b and 6a,c have affected to different extents the three histopatho-logical parameters considered for evaluation of their progestational activity. The compounds 5a,b and 6a,c showed modifications in rat uterus at 35.7–34.8 nM levels with privileged endometrial thickening effect and least change of uterine weight relative to NEA at 52.9 nM level. Up to 40 mg/kg dose compounds 5b and 6c were non-toxic. Molecular docking of the ligands in PR showed in the majority of cases a conformational fitting into the active site different from that of the reference steroid NEA. Compound 6b revealed about 46.4% growth inhibition of CNS cancer SNB-75 cell line, 56% growth inhibition of renal cancer A498 cell line and 56.7% growth inhibition of prostate cancer PC-3 cell line which was mediated by cell cycle arrest. Drugability of the screened compounds showed tolerated results after being challenged to diverse physicochemical parameters.

Synthesis, in vitro antiproliferative activity, and in silico studies of fused tricyclic coumarin sulfonate derivatives

A series of fused tricyclic coumarin sulfonate derivatives was synthesized. Their in vitro antiproliferative activities against a panel of 57 human cancer cell lines of nine different cancer types were tested at the NCI. Compounds 1e, 1f, 1h, 1i, and 1o showed the highest mean percentage of inhibition values over the 57 cell line panel at 10 μM, and they were further tested in 5-dose testing mode to determine their IC50 values. Compounds 1e, 1f, and 1o were more selective against leukemia and colon cancer subpanels, while compounds 1h and 1i showed broad-spectrum anticancer activities. Compounds 1e, 1f, 1h, 1i, and 1o demonstrated high selectivity towards cancer cell lines than RAW 264.7 macrophages. Compound 1h exerted lethal effect over NCI-H522 NSCLC, SK-MEL-5 melanoma, and A498 renal cancer cell lines with percentage of inhibition values of 114.10%, 103.23%, and 100.52% at 10 μM concentration, respectively. Moreover, the IC50 value of compound 1o against HT29 colon cancer cell line was 532 nM. Compounds 1e, 1f, 1h, 1i, and 1o were tested for inhibitory effect over cyclooxygenase-2 (COX-2) enzyme as a possible mechanism of action. Furthermore, in silico studies were conducted to check the compliance of those five compounds with Lipinski's rule of five, and hence estimate their oral bioavailability.

Renal cancer-selective Englerin A induces multiple mechanisms of cell death and autophagy

Renal cell carcinoma (RCC), the most common malignancy of the kidney, is refractory to standard therapy and has an incidence that continues to rise. Screening of plant extracts in search of new agents to treat RCC resulted in the discovery of englerin A (EA), a natural product exhibiting potent selective cytotoxicity against renal cancer cells. Despite the establishment of synthetic routes to the synthesis of EA, very little is known about its mechanism of action. The results of the current study demonstrate for the first time that EA induces apoptosis in A498 renal cancer cells in addition to necrosis. The induction of apoptosis by EA required at least 24 h and was caspase independent. In addition, EA induced increased levels of autophagic vesicles in A498 cells which could be inhibited by nonessential amino acids (NEAA), known inhibitors of autophagy. Interestingly, inhibition of autophagy by NEAA did not diminish cell death suggesting that autophagy is not a cell death mechanism and likely represents a cell survival mechanism which ultimately fails. Apart from cell death, our results demonstrated that cells treated with EA accumulated in the G2 phase of the cell cycle indicating a block in G2/M transition. Moreover, our results determined that EA inhibited the activation of both AKT and ERK, kinases which are activated in cancer and implicated in unrestricted cell proliferation and induction of autophagy. The phosphorylation status of the cellular energy sensor, AMPK, appeared unaffected by EA. The high renal cancer selectivity of EA combined with its ability to induce multiple mechanisms of cell death while inhibiting pathways driving cell proliferation, suggest that EA is a highly unique agent with great potential as a therapeutic lead for the treatment of RCC.

Synthesis and anticancer activity of 2,4-disubstituted furo[3,2-b]indole derivatives

We synthesized and evaluated a series of 2,4-disubstituted furo[3,2-b]indole derivatives for anticancer activity and established the structure–activity relationships (SARs) of these compounds. Among all tested compounds, we found (5-((2-(hydroxymethyl)-4H-furo[3,2-b]indol-4-yl)methyl)furan-2-yl)methanol (10a) to be the most promising agent. In screening against NCI-60 human tumor cell lines, 10a exhibited highly selective anticancer activity and significant inhibitory activity against A498 renal cancer cells. Our COMPARE analysis results suggest that the 10a fingerprint is similar to that of NSC-754549, which is an isostere of YC-1. We further confirmed the significant antitumor activity of compound 10a with tests in the A498 xenograft nude mice model. Therefore, compound 10a should be further developed as a new drug candidate for treating renal cancer.

New nitric oxide donating 1,2,4-triazole/oxime hybrids: Synthesis, investigation of anti-inflammatory, ulceroginic liability and antiproliferative activities

A series of novel nitric oxide (NO) donating triazole/oxime hybrids was prepared and evaluated for their anti-inflammatory activity. Most of the tested compounds showed significant anti-inflammatory activity using carrageenan-induced rat paw edema method compared to indomethacin. Calculation of the ulcer indices and histopathological investigation indicated that the prepared NO-donating oximes exhibited less ulcerogenicity compared to their intermediate ketones and indomethacin. The NO-donating oxime 6i revealed significant activity against renal cancer A498 cell lines with 50.52 cell growth inhibition.

Design, synthesis and in vitro anti-proliferative activity of 4,6-quinazolinediamines as potent EGFR-TK inhibitors

4-Anilino-6-substituted-quinazolines were designed, synthesized and evaluated for EGFR-TK and tumor growth inhibitory activities. The target compounds were designed with enamine ester or urea moieties appended at the C-6 of quinazoline as additional hydrogen bond acceptor functions. Most of the synthesized compounds displayed potent EGFR-TK inhibitory activity at 10 μM and the 6-ureido-anilinoquinazoline derivative 7a showed IC50 value of 0.061 μM. Moreover, six compounds were tested by National Cancer Institute (NCI), USA for their anti-proliferative activity at 10 μM in full NCI 60 cell panel. Compound 7a was further assayed for five dose molar ranges in full NCI 60 cell panel and exhibited remarkable growth inhibitory activity pattern against Non-Small Cell Lung Cancer EKVX (GI50 = 0.37 μM), NCI-H322M (GI50 = 0.36 μM), Renal Cancer A498 (GI50 = 0.46 μM), TK-10 (GI50 = 0.99 μM) and Breast Cancer MDA-MB-468 (GI50 = 1.096 μM) which are of high EGFR expression. Docking study was performed for the active compounds into ATP binding site of EGFR-TK which showed similar binding mode to gefitinib and additional binding with Cys-773 at the gatekeeper of EGFR-TK enzyme.