TCH-1030 targeting on topoisomerase I induces S-phase arrest, DNA fragmentation, and cell death of breast cancer cells

Antitumor Effects of Tryptanthrin on Colorectal Cancer by Regulating the Mitogen-Activated Protein Kinase Signaling Pathway and Targeting Topo I and IDO1

Tryptanthrin (TRYP) is an indole quinazoline alkaloid with a range of pharmaceutical activities, but the specific mechanism of TRYP against colorectal cancer (CRC) remains obscure. The purpose of this study was to evaluate the antitumor effects of TRYP on CRC models both in vitro and in vivo and further analyze its concrete mechanisms. The results of the in vitro experiment show that TRYP effectively inhibited the proliferation and migration of SW620 cells, arrested the cell cycle at the S phase, and induced cell apoptosis. Deeply, TRYP dramatically increased the expression of Bax and cleaved caspase 3 while decreasing the expression of Bcl-2. The results of transcriptome sequencing implied that the inhibitory effects of TRYP were closely related to the mitogen-activated protein kinase (MAPK) signaling pathway, and the results of western blotting verified that TRYP could decrease the expression of p-Erk and increase the expression of p-p38 and p-Jnk. Besides, our results identified that topoisomerase I (Topo I) and indole amine 2,3-dioxygenase 1 (IDO1) were the targets of TRYP. In vivo, the results showed that different TRYP doses significantly inhibited tumor growth in mice, induced different degrees of necrosis in tumor tissues, decreased the expression level of Ki67 protein, and increased the apoptotic signal in tumor tissues. The findings demonstrated the inhibitory effects of TRYP on CRC, and the mechanisms were tightly connected to inhibiting the activity of Topo I and IDO1 and regulating the expression of the MAPK signaling pathway. Especially, it was first identified that TRYP could directly inhibit Topo I to arrest SW620 at the S phase. Therefore, this work established a scientific basis for the development of TRYP.

Quinoline anticancer agents active on DNA and DNA-interacting proteins: From classical to emerging therapeutic targets

Quinoline is one of the most important and versatile nitrogen heterocycles embodied in several biologically active molecules. Within the numerous quinolines developed as antiproliferative agents, this review is focused on compounds interfering with DNA structure or with proteins/enzymes involved in the regulation of double helix functional processes. In this light, a special focus is given to the quinoline compounds, acting with classical/well-known mechanisms of action (DNA intercalators or Topoisomerase inhibitors). In particular, the quinoline drugs amsacrine and camptothecin (CPT) have been studied as key lead compounds for the development of new agents with improved PK and tolerability properties. Moreover, notable attention has been paid to the quinoline molecules, which are able to interfere with emerging targets involved in cancer progression, as G-quadruplexes or the epigenetic ones (e.g.: histone deacetylase, DNA and histones methyltransferase). The antiproliferative and the enzymatic inhibition data of the reviewed compounds have been analyzed. Furthermore, concerning the SAR (structure-activity relationship) aspects, the most recurrent ligand-protein interactions are summarized, underling the structural requirements for each kind of mechanism of action.

The Phenoxyphenol Compound 4-HPPP Selectively Induces Antiproliferation Effects and Apoptosis in Human Lung Cancer Cells through Aneupolyploidization and ATR DNA Repair Signaling

Lung cancer is a leading cause of cancer death worldwide, and non-small-cell lung cancer (NSCLC) accounts for 85% of lung cancer, which is highly metastatic, leading to the poor survival rate of patients. We recently reported that 4-[4-(4-hydroxyphenoxy)phenoxy]phenol (4-HPPP), a phenoxyphenol, exerts antihepatoma effects by inducing apoptosis and autophagy. In this study, we further examined the effect of 4-HPPP and its analogs on NSCLC cells. Colony formation assays showed that 4-HPPP exerts selective cytotoxicity against NSCLC H1299 cells; furthermore, the inhibitory effect of 4-HPPP on the proliferation and migration of NSCLC cells was validated using an in vivo zebrafish-based tumor xenograft assay. The flow cytometry-based dichlorofluorescein diacetate (DCF-DA) assays indicated that 4-HPPP caused an increase in reactive oxygen species (ROS) in NSCLC cells, and Western blot assays showed that the major ROS scavenging enzymes superoxide dismutases- (SODs-) 1/2 were upregulated, whereas peroxidase (PRX) was downregulated. Furthermore, 4-HPPP caused both aneuploidization and the accumulation of γH2AX, a sensor of DNA damage, as well as the activation of double-strand break (DSB) markers, especially Ataxia-telangiectasia-mutated and Rad3-related (ATR) in NSCLC cells. Our present work suggests that the antiproliferative effects of 4-HPPP on lung cancer cells could be due to its phenoxyphenol structure, and 4-HPPP could be a candidate molecule for treating NSCLC by modulating ROS levels and lowering the threshold of polyploidy-specific cell death in the future.

Synthesis and evaluation of new amidrazone-derived hydrazides as a potential anti-inflammatory agents

ABSTRACT

The series of new hydrazide derivatives were synthesized in reactions of N3-substituted amidrazones with cyclic anhydrides as potential anti-inflammatory and antibacterial agents. The compounds were characterized by 1H-13C two-dimensional NMR techniques, which revealed the presence of two tautomeric forms in DMSO-d6 solutions, while the molecular structure of one species was confirmed by single-crystal X-ray diffraction. The anti-inflammatory effects of hydrazides on peripheral blood mononuclear cells were experimentally evaluated. Three compounds showed antiproliferative activity comparable to ibuprofen. One derivative demonstrated strong reduction of lymphocyte proliferation stimulated by anti-CD3 antibody (by 90%) and PHA, as well as low cell toxicity. The obtained compounds exhibited relatively weak antibacterial activity; they were more effective against Gram-positive bacterial strains.

GRAPHICAL ABSTRACT

Expression of Topoisomerase 1 and carboxylesterase 2 correlates with irinotecan treatment response in metastatic colorectal cancer

Topoisomerase 1 (TOPO-1) and carboxylesterase 2 (CES-2) are found to play crucial roles in the pathogenesis of various cancers. The prognostic role of TOPO-1 and CES-2 in patients with metastatic colorectal cancer (mCRC) who underwent irinotecan chemotherapy was largely unknown. In the current study, we assessed the expression of TOPO-1 and CES-2 in mCRC and analyzed its potential relevance to irinotecan based therapy. A total of 98 patients with mCRC were included in this study. The expression of TOPO-1 and CES-2 in mCRC tissues was evaluated by immunohistochemistry. For TOPO-1, 46 patients showed high expression and 52 patients showed low expression. For CES-2, 53 patients showed high expression and 45 patients showed low expression. The correlation between TOPO-1 or CES-2 expression and clinicopathological characteristics of mCRC patients was analyzed. Neither TOPO-1 nor CES-2 had significant correlation with age, gender, tumor site, tumor grade and metastatic sites in mCRC patients. However, high expression of CES-2 but not TOP-1 was positively correlated with better curative effect. Kaplan-Meier and log-rank test were applied to assess the correlation between progression-free survival (PFS)/overall survival (OS) and TOPO-1 or CES-2 expression in mCRC patients. High expression of TOPO-1 and CES-2 are correlated with longer PFS and OS. In summary, our findings suggest that TOPO-1 and CES-2 may play important roles irinotecan sensitivity in mCRC patients. Evaluation of expression of TOPO-1 and CES-2 may provide preliminary clinical evidence for the management of irinotecan-based therapy in mCRC patients.

Effects of cinobufacini injection on cell proliferation and the expression of topoisomerases in human HepG-2 hepatocellular carcinoma cells

The present study aimed to investigate the effects of cinobufacini injection on the proliferation and expression of topoisomerases in human HepG-2 hepatocarcinoma cells. The cells were divided into a control group and an experimental group, in which 0.105, 0.21, 0.42 mg/l cinobufacini was injected. Cell proliferation was assessed using a 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay, levels of apoptosis were detected using annexin V/propidium iodide staining and cell cycles were analyzed using flow cytometric analysis. The mRNA and protein expression levels of topoisomerase (TOPO) I and TOPO II were determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. Cinobufacini injection significantly inhibited the proliferation of the HepG-2 cells (P<0.05), induced apoptosis (P<0.05) in a dose- and time-dependent manner, induced tumor cell arrest at the S phase in a dose-dependent manner, and downregulated the mRNA and protein expression levels of TOPO I and TOPO II (P<0.05) in a dose-dependent manner. Therefore, cinobufacini was found to inhibit human HepG-2 hepatocellular carcinoma cell proliferation, and downregulation of the expression levels of TOPO I and TOPO II may contribute to the effect on proliferation observed in the Hep‑G2 cells following cinobbufacini injection.

Biological Activity of N-Hydroxyethyl-4-aza-2,3-didehydropodophyllotoxin Derivatives upon Colorectal Adenocarcinoma Cells

Etoposide is a chemotherapy drug derived from the natural lignin podophyllotoxin. Our novel generated Aza-podophyllotoxin compounds (AZP 8a & AZP 9a) are analogues of podophyllotoxin and were previously screened for anti-cancer activity through the NCI 60 cell line screening panel showing activity on various cell types including colon cancer. This study expands the toxicological screening by studying apoptosis and various hallmark events as part of the mechanism of action of these compounds on colon cancer cells. The COLO 205 cell line was selected and exposed to AZP to determine the IC50 doses at 24 hours treatment. Apoptosis hallmark events such as migration of phosphatidylserine (PS) to the cell membrane, DNA fragmentation, cell cycle effects, mitochondrial membrane permeabilization and caspase activation were included. Experiments were performed in triplicates for all tested compounds including AZP 8a, AZP 9a, camptothecin as positive control and vehicle as negative control. Our results present contrasting apoptotic activity between the experimental compounds. Compound 8a presented migration of PS (annexin V assay), DNA fragmentation and cell cycle arrest at S phase. Compound 9a presented PS migration with fragmented DNA, cell cycle arrest at S phase, mitochondrial membrane permeabilization and activation of caspase 3, 8 and 9. Compound 8a without the oxygen atoms in ring A appears to cause effects similarly to autophagy as induced by etoposide, a cancer drug analogue of our heterocyclic compounds. Compound 9a with the oxygen atoms in expanded ring A presented induction of cell death following activation of a classical apoptosis pathway. Our results suggest that minor structural differences among these AZP can account for the difference in biological response and cancer cell toxicity.

Structure-based hybridization, synthesis and biological evaluation of novel tetracyclic heterocyclic azathioxanthone analogues as potential antitumor agents

A series of tetracyclic heterocyclic azathioxanthones were synthesized and evaluated for cell proliferations, topoisomerase inhibitions, and NCI-60 cell panel assay, respectively. Compounds 5, 7, 8, 16, and 19 were selected for topoisomerase assay after MTT assay. 7 not only showed cytotoxic effect (IC50 = 2.84 ± 0.64 μM) in PC-3 cells but also revealed topoisomerases inhibition with IC50 (10-25 μM) and increased apoptotic cleavage of PARP and caspase 3 activity. The overall of novel azathioxanthones with different cytostatic and cytotoxic activities should be further developed as new potential candidates for anticancer drugs.