Invitro Antitumor Activity Research Articles

Synthesis and invitro antitumor activity of galactosamine-docetaxel conjugates.

Docetaxel (DTX) is a semi-synthetic analogue of paclitaxel which has attracted extensive attention in the treatment of cancer. However, the current clinically used DTX formulations display low tumor targeting ability, leading to unsatisfactory therapeutic outcomes with adverse effects, which poses significant challenges to the clinical application. In this study, three galactosamine (Gal) and docetaxel conjugates with different linkers were synthesized, namely DTX-(suc-Gal)2, DTX-(DTDPA-Gal)2, and DTX-(DSeDPA-Gal)2. These three conjugates were characterized by 1H NMR, FT-IR and HRMS. The invitro drug release study shows that DTX-(DTDPA-Gal)2 and DTX-(DSeDPA-Gal)2 exhibit glutathione (GSH)-responsive drug release and DTX-(DSeDPA-Gal)2 displays higher GSH-responsiveness. The invitro antitumor activity study shows that DTX-(DTDPA-Gal)2 and DTX-(DSeDPA-Gal)2 exhibit enhanced cytotoxicity, cell apoptosis rate and G2/M phase arrest against HepG2 cells as compared to DTX-(suc-Gal)2, DTX-(DSeDPA-Gal)2 displays the highest cytotoxicity, cell apoptosis rate and G2/M phase arrest among these three conjugates. In addition, DTX-(DSeDPA-Gal)2 exhibits higher selectivity to HepG2 cells as compared to free DTX. The DTX-(DSeDPA-Gal)2 developed in this study has been proven to be an effective DTX conjugate for selective killing hepatoma cells.

A versatile CRISPR-Cas13d platform for multiplexed transcriptomic regulation and metabolic engineering in primary human T cells

CRISPR technologies have begun to revolutionize Tcell therapies; however, conventional CRISPR-Cas9 genome-editing tools are limited in their safety, efficacy, and scope. To address these challenges, we developed multiplexed effector guide arrays (MEGA), a platform for programmable and scalable regulation of the Tcell transcriptome using the RNA-guided, RNA-targeting activity of CRISPR-Cas13d. MEGA enables quantitative, reversible, and massively multiplexed gene knockdown in primary human Tcells without targeting or cutting genomic DNA. Applying MEGA to a model of CAR Tcell exhaustion, we robustly suppressed inhibitory receptor upregulation and uncovered paired regulators of Tcell function through combinatorial CRISPR screening. We additionally implemented druggable regulation of MEGA to control CAR activation in a receptor-independent manner. Lastly, MEGA enabled multiplexed disruption of immunoregulatory metabolic pathwaysto enhance CAR Tcell fitness and anti-tumor activity invitro and invivo. MEGA offers a versatile synthetic toolkit for applications in cancer immunotherapy and beyond.

Superantigen-fused T cell engagers for tumor antigen-mediated robust T cell activation and tumor cell killing

Inadequate Tcell activation has severely limited the success of Tcell engager (TCE) therapy, especially in solid tumors. Enhancing Tcell activity while maintaining the tumor specificity of TCEs is the key to improving their clinical efficacy. However, currently, there needs to be more effective strategies in clinical practice. Here, we design novel superantigen-fused TCEs that display robust tumor antigen-mediated Tcell activation effects. These innovative drugs are not only armed with the powerful Tcell activation ability of superantigens but also retain the dependence of TCEs on tumor antigens, realizing the ingenious combination of the advantages of two existing drugs. Superantigen-fused TCEs have been preliminarily proven to have good (>30-fold more potent) and specific (>25-fold more potent) antitumor activity invitro and invivo. Surprisingly, they can also induce the activation of Tcell chemotaxis signals, which may promote Tcell infiltration and further provide an additional guarantee for improving TCE efficacy in solid tumors. Overall, this proof-of-concept provides a potential strategy for improving the clinical efficacy of TCEs.

Identification of a 2-phenylthiazole derivative acetylcholinesterase modulator with invitro antitumor activity in breast cancer cells.

Acetylcholinesterase (AchE) is a serine hydrolase with classical function to degrade acetylcholine and terminate neurotransmission. While "nonclassical" functions of AchE were involved in cell growth, death, invasion, etc. The expression and activity of AchE is changed in tumors, suggesting AChE inhibitors (AchEIs) may serve as potential antitumor drugs. In this study, the antitumor activity of a series of 2-phenylthiazole derivatives originally designed and synthesized as AchEIs were investigated. One compound named A6, was screened out with superior antitumor efficacy, especially against breast cancer MCF-7 cells. A6 significantly disrupted the amino acid metabolism and inhibited migration of MCF-7. In addition, A6 induced apoptosis of MCF-7 cells. To clarify how A6 affected on MCF-7 cells, RNA-seq analysis was conducted to evaluate the whole genome effect of A6 on gene expression. A total of 153 genes were increased, and the expression of 81 genes was decreased. GO and KEGG enrichment analysis showed A6 treatment mainly disrupted sterol/cholesterol pathway, Ras signaling pathway, VEGF signaling pathway, etc. Moreover, bioinformatic analysis and cell viability test showed A6 plays anticancer role by regulating Best1 and HIST1H2BJ. These results indicate that AchEI A6 could be a potential antitumor agent for breast cancer patients and could help the development of novel therapies.

Locally secreted BiTEs complement CAR T cells by enhancing killing of antigen heterogeneous solid tumors

Bispecific Tcell engagers (BiTEs) are bispecific antibodies that redirect Tcells to target antigen-expressing tumors. We hypothesized that BiTE-secreting Tcells could be a valuable therapy in solid tumors, with distinct properties in mono- or multi-valent strategies incorporating chimeric antigen receptor (CAR) Tcells. Glioblastomas represent a good model for solidtumor heterogeneity, representing a significant therapeutic challenge. We detected expression of tumor-associated epidermal growth factor receptor (EGFR), EGFR variant III, and interleukin-13 receptor alpha 2 (IL13Rα2) on glioma tissues and cancer stem cells. These antigens formed the basis of a multivalent approach, using a conformation-specific tumor-related EGFR targeting antibody (806) and Hu08, an IL13Rα2-targeting antibody, as the single chain variable fragments to generate new BiTE molecules. Compared with CAR Tcells, BiTE Tcells demonstrated prominent activation, cytokine production, and cytotoxicity in response to target-positive gliomas. Superior response activity was also demonstrated in BiTE-secreting bivalent Tcells compared with bivalent CAR Tcells in a glioma mouse model at early phase, but not in the long term. In summary, BiTEs secreted by mono- or multi-valent Tcells have potent anti-tumor activity invitro and invivo with significant sensitivity and specificity, demonstrating a promising strategy in solid tumor therapy.

Retracted] Invitro antitumor activity of the ethyl acetate extract Potentillachinensis in osteosarcoma cancer cells.

Following the publication of the above paper, a concerned reader drew to the Editor's attention that several figures bore striking similarities to other papers that were published at around the same time written by different authors based in different research institutions. Fig.3 (in colour) was essentially the same as a greyscale figure (Fig.4) in a paper published in Oncology Reports, which has now been retracted [WanG, TaoJ‑G, Wang G‑D, Liu S‑P, Zhao H‑X and LiangQ‑D: 3‑β‑Εrythrodiol isolated from Conyza canadensis inhibits MKN‑45 human gastric cancer cell proliferation by inducing apoptosis, cell cycle arrest, DNA fragmentation, ROS generation and reduces tumor weight and volume in mouse xenograft mode. Oncol Rep35: 2328‑2338, 2016]. Furthermore, Figs.5 and6 in the above paper appeared to share data with Figs.7 and11, respectively, in a paper published in Phytomedicine [Sui C‑G, Meng F‑D and JiangY‑h: Antiproliferative activity of rosamultic acid is associated with induction of apoptosis, cell cycle arrest, inhibition of cell migration and caspase activation in human gastric cancer (SGC‑7901)cells. Phyomedicine22: 796‑806, 2015]. After having conducted an independent investigation in the Editorial Office, the Editor of Molecular Medicine Reports has determined that the above paper should be retracted from the Journal on account of a lack of confidence concerning the originality and the authenticity of the data. The authors were asked for an explanation to account for these concerns, but the Editorial Office never received any reply. The Editor regrets any inconvenience that has been caused to the readership of the Journal. [the original article was published in Molecular Medicine Reports14: 3634‑3640, 2016; DOI: 10.3892/mmr.2016.5679].

Retracted] 3‑β‑Εrythrodiol isolated from Conyzacanadensis inhibits MKN‑45 human gastric cancer cell proliferation by inducing apoptosis, cell cycle arrest, DNA fragmentation, ROS generation and reduces tumor weight and volume in mouse xenograft model.

Following the publication of the above paper, an interested reader drew to our attention that a number of apparent anomalies existed with the data presented in the above paper; specifically, there appeared to be strikingly similar and replicated patternings of the cells within the cellular images featured in Figs.4A‑D and 5A‑D (affecting all the figure parts). Secondly, Fig.4 in the above study appeared to have been a reproduction of Fig.3 from following paper featuring different authors, albeit Fig.4 appeared in greyscale, and not in colour, in the above paper [Wan G, Tao J‑G, Wang G‑D, Liu.S‑P, ZhaoH‑X and Liang Q‑D: Invitro antitumor activity of the ethyl acetate extract of Potentillachinensis in osteosarcoma cancer cells. Mol Med Rep14: 3634‑3640, 2016]. Following an internal enquiry, the Editor of Oncology Reports was able to verify the claims made by the interested reader; therefore, in view of the number of potential anomalies that have been identified and owing to a lack of overall confidence in the presented data, the Editorial Board have decided to retract the above paper from the publication. The Journal were also contacted independently by the authors, who wished to retract the paper on account of not being able to reproduce the results shown in Fig..2. The Editor apologizes to the readership of the Journal for any inconvenience caused. [the original article was published in Oncology Reports 35: 2328‑2338, 2016; DOI: 10.3892/or.2016.4610].

Conjugating a groove binder analogue to a styryl-quinolinium scaffold for the light-up detection of duplex and G-Quadruplex DNA with different binding modes.

The rational design of novel small molecules, which can target specific DNA sequences or secondary structural DNAs, is one of the most important goals in medicinal chemistry. Also the studies of DNA binding potency which can give fundamental insight into binding mechanisms and specificity are essential. In this paper, a N-methylated quinolinium probe NSQ functionalized with a G-Quadruplex DNA groove binder analogue was designed and synthesized. NSQ was found to express selective and sensitive for "light-up" detection of both G-Quadruplex and duplex DNAs over RNA and other biomolecules. The characteristics of NSQ and its interactions with DNAs were comprehensively evaluated by means of fluorescence, UV-Vis, circular dichroism, FID assay, DFT calculation and molecular docking. NSQ exhibited higher binding affinity to G-Quadruplex than to duplex DNA. Binding mechanism analysis indicated NSQ interacted with G-Quadruplex DNA mainly through end-stacking mode, while bound with duplex DNA into the minor groove of AT-rich regions. Further, NSQ exhibited potent invitro anti-tumor activity, and to elucidate the cellular applications, confocal cell imaging was carried out and validated its mainly nuclear localization.

Design and Synthesis of 1,3,4-Thiadiazole Derivatives as Novel Anticancer and Antitubercular Agents

A series of novel 5-phenyl-substituted 1,3,4-thiadiazole-2-amines were designed, synthesized, and screened for their antitumor and antitubercular activities. The target compounds were synthesized starting from isocyanates and acid hydrazides by conventional and microwave-assisted protocols. The structures of the products were confirmed by 1H NMR, 13C NMR, high-resolution mass spectrometry, and IR spectroscopy and elemental analysis. Some of the synthesized compounds showed significant invitro antitumor activities against breast cancer and normal human cell lines. Among them, N-benzyl-5-(4-fluorophenyl)-, N-benzyl-5-(4-nitrophenyl)-, and 5-phenyl-N-(p-tolyl)-1,3,4-thiadiazole-2-amines demonstrated higher inhibitory activities against the MDA-MB-231 cell line than the cisplatin control (IC50 3.3 ώM). N-Benzyl-5-(4-methoxyphenyl)-, 5-phenyl-N-[4-(trifluoromethyl)phenyl]methyl-, N-benzyl-5-(4-fluorophenyl)-, and N-benzyl-5-(4-nitrophenyl)-1,3,4-thiadiazole-2-amines exhibited high inhibitory activities against the HEK293T cell line (IC50 52.63, 42.67, 34.71, and 33.74 ώM, respectively), which were higher compared to the cisplatin control. In antitubercular activity testing against mycobacterium smegmatis MC155, 5-phenyl-N-[4-(trifluoromethyl)-phenyl]methyl-1,3,4-thiadiazole-2-amine proved to be a more potent agent (MIC 26.46 ώg/mL) compared to the Isoniazid control (12 ώg/mL). Potential bioactivities of the synthesized compounds were computed using Molinspiration and Molsoft software tools.

Dihydrocelastrol exerts potent antitumor activity in mantle cell lymphoma cells via dual inhibition of mTORC1 and mTORC2.

Mantle cell lymphoma (MCL) is a distinct and highly aggressive subtype of B-cell non-Hodgkin lymphoma. Dihydrocelastrol (DHCE) is a dihydro-analog of celastrol, which is isolated from the traditional Chinese medicinal plant Tripterygium wilfordii. The present study aimed to investigate the effects of DHCE treatment on MCL cells, and to determine the mechanism underlying its potent antitumor activity invitro and invivo using the Cell Counting kit-8 assay, clonogenic assay, apoptosis assay, cell cycle analysis, immunofluorescence staining, western blotting and tumor xenograft models. The results demonstrated that DHCE treatment exerted minimal cytotoxic effects on normal cells, but markedly suppressed MCL cell proliferation by inducing G0/G1 phase cell cycle arrest, and inhibited MCL cell viability by stimulating apoptosis via extrinsic and intrinsic pathways. In addition, the results revealed that DHCE suppressed cell growth and proliferation by inhibiting mammalian target of rapamycin complex (mTORC)1-mediated phosphorylation of ribosomal proteinS6 kinase and eukaryotic initiation factor4E binding protein. Simultaneously, DHCE induced apoptosis and inhibited cell survival by suppressing mTORC2-mediated phosphorylation of protein kinaseB and nuclear factor-κB activity. In addition to invitro findings, DHCE treatment reduced the MCL tumor burden in a xenograft mouse model, without indications of toxicity. Furthermore, combined treatment with DHCE and bortezomib, a proteasome inhibitor, induced a synergistic cytotoxic effect on MCL cells. These findings indicated that DHCE may have the potential to serve as a novel therapeutic agent for the treatment of MCL through dually inhibiting mTORC1 and mTORC2.

Synthesis, Biological Evaluation and Molecular Docking Studies of 4Hbenzo[ h]chromenes, 7H-benzo[h]chromeno[2,3-d]pyrimidines as Antitumor Agents

In the present study, novel derivatives of 7H-benzo[h]chromeno[2,3-d]pyrimidine were prepared from 4H-benzo[h]chromene-3-carbonitrile and ethyl 4H-benzo[h]chromene-3-carboxylate derivatives and were evaluated as potential cytotoxic agents. The structures of the synthesized compounds were established on the basis of spectral data, IR, 1H NMR, 13C NMR and MS data. The invitro antitumor activity of the synthesized compounds was investigated in comparison with the standard drug Colchicine using MTT colorimetric assay. We explored the Structure-Activity Relationship (SAR) of 4Hbenzo[ h]chromenes with modification at the 2- or 3-positions and 2,3-positions. It was found that some compounds showed good antitumor activity against the cell lines MCF-7, HCT-116 and HepG-2 as compared with Colchicine. The SAR study revealed that the antitumor activity of the synthesized compounds were significantly affected by the lipophilicity (hydrophobic or hydrophilic) of the substituent at 2- or 3-positions and 2,3-positions. Keywords: 4H-Benzo[h]chromenes, 7H-Benzo[h]chromeno[2, 3-d]pyrimidines, antitumor, SAR, molecular docking.

Biological and Histological Studies of Purified Product from Streptomyces janthinus M7 Metabolites

Fifteen clinical samples were taken out from patients suffering cancer, these patients being under the treatment with radio- and/or chemotherapy. The samples were used for the isolation of bacterial cells surrounding tumor; the samples were collected from Center of Cancer Therapy, Ain Shams University, Cairo, Egypt. The clinical bacterial isolates were purified and identified according to Bergey's manual of determinative bacteriology ninth edition (1994). The bacterial isolates were found to be Klebsiella oxytoca m1; Enterobacter cancerogenus m2; P. aeruginosa m3; Citrobacter diversus m4; Enterobacter agglomerans m5; Klebsiella oxytoca m6; Enterobacter dissolvens m7; Serratia fonticola m8; Escherichia coli m9; Citrobacter freundii m10; Staphylococcus aureus m11; Escherichia coli m12; P. aeruginosa m13; Staphylococcus aureus m14; and Bacillus cereus m15. In the present study both primary and secondary screening methods were used to screen the antibacterial activity of St. janthinus M7 against fifteen clinical bacterial isolates. The St. janthinus M7 showed an increase in antibacterial activity against all the tested human bacterial pathogens. In this study Gamma irradiation at dose levels (0.5 and 1.5 kGy) was used for the enhancement of the antibacterial activity of Streptomyces strain against the clinical isolates. Several commercial antibiotic discs (Doxorubicin, Augmentin, Norfloxacin, Ofloxacin, Oxacillin, and Cefazolin) were used for comparing their antimicrobial activity with purified product. The results declared a significant increase in the antibacterial activity in most cases. The physiochemical properties of the purified product were carried out for determination of Rf, empirical formula, M.W, and chemical structure of product and then analyzed by thin layer chromatography, elemental analysis, UV, Mass, and NMR. The result exhibited brown color, one spot, Rf (0.76), M.W (473), while it recorded 270 nm in UV region and the calculated empirical formula was (C22H19NS2O7). In in vitro antitumor activity of the purified product against human tumor cell lines (Hepg2) the IC50 was measured to be 3.0 μg/ml and in in vitro antitumor activity of purified product measured against Ehrlich ascites carcinoma (EAC) the IC50 was measured to be 33.0 μg/ml. In in vivo study of the cytotoxic effect of St. janthinus M7 purified product MYN7 was investigated. The result of histopathological alteration in female mice infected with Ehrlich tumor showed a significant effect on abnormal cells.

Apo2L/TRAIL and the Death Receptor 5 Agonist Antibody AMG 655 Cooperate to Promote Receptor Clustering and Antitumor Activity

Death receptor agonist therapies have exhibited limited clinical benefit to date. Investigations into why Apo2L/TRAIL and AMG 655 preclinical data were not predictive of clinical response revealed that coadministration of Apo2L/TRAIL with AMG 655 leads to increased antitumor activity invitro and invivo. The combination of Apo2L/TRAIL and AMG 655 results in enhanced signaling and can sensitize Apo2L/TRAIL-resistant cells. Structure determination of the Apo2L/TRAIL-DR5-AMG 655 ternary complex illustrates how higher order clustering of DR5 is achieved when both agents are combined. Enhanced agonism generated by combining Apo2L/TRAIL and AMG 655 provides insight into the limited efficacy observed in previous clinical trials and suggests testable hypotheses to reconsider death receptor agonism as a therapeutic strategy.