A network pharmacology approach to investigate the anticancer mechanism of cinobufagin against hepatocellular carcinoma via downregulation of EGFR-CDK2 signaling.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers with high mortality and poor prognosis, and the investigation on new approaches and effective drugs for HCC therapy is of great significance. In our study, we demonstrate that treatment with cinobufagin, a natural compound isolated from traditional chinese medicine Chansu, reduces proliferation and the colony formation capacity of the human hepatoma cells in vitro, in addition, cinobufagin induces mitotic arrest in human hepatoma cells. The results of a network pharmacology-based analysis show that EGFR, MAPK1, PTK2, CDK2, MAPK3, ESR1, CDK1, PRKCA, AR, and CSNK2A1 are the key targets involved in the anti-tumor activities of cinobufagin, additionally, several signaling pathways such as proteoglycans in cancer, pathways in cancer, HIF-1 signaling pathway, VEGF signaling pathway, ErbB signaling pathway, and PI3K-AKT signaling pathway are identified as the potential pathways involved in the inhibitory effects of cinobufagin against HCC. Furthermore, at the molecular level, we find that cinobufagin decreases EGFR expression and CDK2 activity in human hepatoma cells. Inhibition of EGFR or CDK2 expression could not only suppress the growth of tumor cells but also enhance the inhibitory effects of cinobufagin on the proliferative potential of human hepatoma cells. We also demonstrate that EGFR positively regulates CDK2 expression. Furthermore, EGFR inhibitor gefitinib or CDK2 inhibitor CVT-313 synergistically enhances anticancer effects of cinobufagin in human hepatoma cells. Taken together, these findings indicate that cinobufagin may exert antitumor effects by suppressing EGFR-CDK2 signaling, and our study suggests that cinobufagin may be a novel, promising anticancer agent for the treatment of HCC.

Hyperthermia Enhances Doxorubicin Therapeutic Efficacy against A375 and MNT-1 Melanoma Cells.

Melanoma is the deadliest form of skin cancer, and its incidence has alarmingly increased in the last few decades, creating a need for novel treatment approaches. Thus, we evaluated the combinatorial effect of doxorubicin (DOX) and hyperthermia on A375 and MNT-1 human melanoma cell lines. Cells were treated with DOX for 24, 48, and 72 h and their viabilities were assessed. The effect of DOX IC10 and IC20 (combined at 43 °C for 30, 60, and 120 min) on cell viability was further analyzed. Interference on cell cycle dynamics, reactive oxygen species (ROS) production, and apoptosis upon treatment (with 30 min at 43 °C and DOX at the IC20 for 48 h) were analyzed by flow cytometry. Combined treatment significantly decreased cell viability, but not in all tested conditions, suggesting that the effect depends on the drug concentration and heat treatment duration. Combined treatment also mediated a G2/M phase arrest in both cell lines, as well as increasing ROS levels. Additionally, it induced early apoptosis in MNT-1 cells, while in A375 cells this effect was similar to the one caused by hyperthermia alone. These findings demonstrate that hyperthermia enhances DOX effect through cell cycle arrest, oxidative stress, and apoptotic cell death.

Norcantharidin induces G2/M arrest and apoptosis via activation of ERK and JNK, but not p38 signaling in human renal cell carcinoma ACHN cells.

Renal cell carcinoma (RCC) is generally acknowledged as the most resistant primary malignancy unresponsive to conventional radiotherapy and chemotherapy treatments. Norcantharidin (NCTD), a therapeutic compound derived from medicinal plants, has been shown to trigger apoptosis, as well as antimetastatic and antioxidant activities in several tumor cells. However, NCTD's mechanism of antitumor activity in the RCC cell line remains unclear. In this study, we report that NCTD led to a time- and dose-dependent inhibition of cell proliferation. It had also markedly induced apoptosis and G2/M phase cell cycle arrest in a dose-dependent manner by decreasing the expressions of pro-caspase-3, pro-caspase-9, cyclin B1, and pCDC25C while increasing active caspase-3, cleaved-PARP, P21, and pCDC2 levels. Interestingly, NCTD treatment provoked the phosphorylation of extracellular-regulated protein kinase (ERK) and c-Jun-N-terminal kinase (JNK), but not of p38 MAPK. Moreover, SCH772984 and SP600125, ERK and JNK inhibitors, respectively, could partially abolish NCTD-induced apoptosis and G2/M phase cell cycle arrest. Collectively, these findings suggest that NCTD might activate JNK and ERK signaling pathways, consequently inducing apoptosis and G2/M arrest through the modulation of related proteins. This study provided evidence that NCTD is a promising therapeutic drug for the treatment of RCC.

Chloroform extract of Citrus unshiu Markovich peel induces apoptosis and inhibits stemness in HeLa human cervical cancer cells.

Cervical cancer is the second most common cancer among women worldwide. However, chemotherapies for this cancer often cause many side effects and chemoresistance. Citrus unshiu Markovich peel (CECU) has been used as a traditional medicine for the treatment of various diseases in East Asia. Recently, the anticancer activities and mechanisms of action of CECU extract have been reported in a number of different cancer cell types, but no study has evaluated the therapeutic effect of this natural product on cervical cancer cells. In the current study, the anticancer activity and the underlying molecular mechanism of the chloroform extract of CECU was investigated on HeLa human cervical cancer cells. The results showed that CECU effectively inhibited the proliferation and migration of HeLa cells. Treatment of cells with CECU led to cell cycle arrest at the G2/M phase and activation of extrinsic and intrinsic apoptotic pathways. Furthermore, the proliferation inhibitory effect of CECU was due to the inactivation of AKT and ERK signaling, upregulation of p53 and p21, and downregulation of cyclin B1 and cyclin D1, but not reactive oxygen species (ROS) generation. Furthermore, CECU inhibited the stem­like features of HeLa cells by downregulating key cancer stemness biomarkers. Therefore, CECU may be an effective complementary and alternative medicine for the prevention and treatment of cervical cancer.

Glucose-coated Berberine Nanodrug for Glioma Therapy through Mitochondrial Pathway.

INTRODUCTION: Glioma is the primary malignant brain tumor with poor prognosis. Berberine (BBR) was the potential drug for anti-tumor in glioma cells. Based on its limitation of poor aqueous solubility and instability, little information of BBR nanoparticles is reported in glioma. METHODS: Different solutions including 5% glucose, 1*PBS, ddH2O, 0.9% NaCl, cell culture medium were selected, and only 5% glucose and ddH2O exhibited BBR-related nanoparticles. After heating for a longer time or adding a higher concentration of glucose solution, BBR nanoparticles were detected by TEM analysis. The uptake of BBR-Glu or BBR-Water nanoparticles were detected by immunofluorescence analysis for BBR autofluorescence. Cell viability was measured by MTT assay and Western blotting analysis. Apoptosis was performed with flow cytometric analysis and was detected by cleaved caspase-3 immuno-fluorescent staining. Cell cycle was used by flow cytometric analysis. Cytoskeleton was observed by confocal analysis using the neuron specific Class III ß-tubulin and ß-tubulin antibodies. Mitochondrial-related proteins were detected by Western blotting analyses and mito-tracker staining in live cells. Mitochondrion structures were observed by TEM analysis. ROS generation and ATP production were detected by related commercial kits. The tracking of BBR-Glu or BBR-Water nanoparticles into blood-brain barrier was observed in primary tumor-bearing models. The fluorescence of BBR was detected by confocal analyses in brains and gliomas. RESULTS: BBR-Glu nanoparticles became more homogenized and smaller with dose- and time-dependent manners. BBR-Glu nanoparticles were easily absorbed in glioma cells. The IC50 of BBR-Glu in U87 and U251 was far lower than that of BBR-Water. BBR-Glu performed better cytotoxicity, with higher G2/M phase arrest, decreased cell viability by targeting mitochondrion. In primary U87 glioma-bearing mice, BBR-Glu exhibited better imaging in brains and gliomas, indicating that more BBR moved across the blood-brain tumor barrier. DISCUSSION: BBR-Glu nanoparticles have better solubility and stability, providing a promising strategy in glioma precision treatment.

A steroidal saponin isolated from Allium chinense simultaneously induces apoptosis and autophagy by modulating the PI3K/Akt/mTOR signaling pathway in human gastric adenocarcinoma.

Allium chinense, as a side dish on Asian table, is often used in folk medicine for its health benefits. (25R)-5α-spirostan-3ß-yl-3-O-acetyl-O-ß-d-glucopyranosyl-(1 â†’ 2)-O-[ß-d-glucopyranosyl-(1 â†’ 3)]-O-ß-d-glucopyranosyl-(1 â†’ 4)-ß-d-galactopyranoside (A-24) is a bioactive steroidal saponin isolated from Allium chinense. Previously, we have shown that A-24 has cytotoxic effects on cancer cells, but not on normal cells. To further explore the underlying mechanisms, in this study, we investigated the anticancer activity of A-24 in human gastric cancer cell lines in terms of cell proliferation, colony formation, cell cycle, induction of apoptosis/autophagy, and PI3K/Akt/mTOR pathway. A-24 showed dose-dependent cytotoxicity in SGC-7901 and AGS cell lines, it induced intrinsic mitochondrial pathway of apoptosis as well as autophagy, G2/M phase arrest and modulation of cyclinB1, p-cdc2, p-wee1 and p-Histone H3 expression. Furthermore, A-24 downregulated the phosphorylation of Akt at Ser473 and mTOR at Ser2448 in PI3K/Akt/mTOR pathway, and its downstream substrates p-p70S6K and p-4EBP1 in a dose-dependent manner. In addition, the pre-treatment of tumor cells with 3-methyladenine (3-MA) and LY294002 increased A-24-induced apoptosis. Collectively, these findings highlight the significance of downregulation of PI3K/Akt/mTOR pathway in A-24-induced apoptosis and autophagy, and the potential application of A-24 as a novel candidate in the treatment of human gastric adenocarcinoma.

Treating Cancer by Spindle Assembly Checkpoint Abrogation: Discovery of Two Clinical Candidates, BAY 1161909 and BAY 1217389, Targeting MPS1 Kinase.

Inhibition of monopolar spindle 1 (MPS1) kinase represents a novel approach to cancer treatment: instead of arresting the cell cycle in tumor cells, cells are driven into mitosis irrespective of DNA damage and unattached/misattached chromosomes, resulting in aneuploidy and cell death. Starting points for our optimization efforts with the goal to identify MPS1 inhibitors were two HTS hits from the distinct chemical series "triazolopyridines" and "imidazopyrazines". The major initial issue of the triazolopyridine series was the moderate potency of the HTS hits. The imidazopyrazine series displayed more than 10-fold higher potencies; however, in the early project phase, this series suffered from poor metabolic stability. Here, we outline the evolution of the two hit series to clinical candidates BAY 1161909 and BAY 1217389 and reveal how both clinical candidates bind to the ATP site of MPS1 kinase, while addressing different pockets utilizing different binding interactions, along with their synthesis and preclinical characterization in selected in vivo efficacy models.

Pectolinarigenin flavonoid exhibits selective anti-proliferative activity in cisplatin-resistant hepatocellular carcinoma, autophagy activation, inhibiting cell migration and invasion, G2/M phase cell cycle arrest and targeting ERK1/2 MAP kinases.

PURPOSE: The main purpose of the present research article was to investigate the anticancer properties of pectolinarigenin flavonoid in cisplatin-resistant hepatocellular carcinoma cells (SK-HEP-1) and normal liver cells (AML-12), along with examining its effects on autophagy, cell migration and invasion, cell cycle arrest and ERK1/2 MAP signalling pathways. METHODS: Antiproliferative effects in cancer and normal cells were assessed by MTT cell viability assay. Cell autophagy effects were studied by electron microscopy as well as western blot. Effects on cell cycle were evaluated by flow cytometry using Annexin V/propidium iodide (PI) staining. Transwell migration assay and in vitro wound healing assay were performed to study the effects on cell migration and invasion, respectively. RESULTS: The results indicated that pectolinarigenin inhibited significantly the growth of the SK-HEP-1 liver cancer cells and exhibited an IC50 of 10 µM, while against normal cells the cytotoxic effects were much less pronounced. Further, it was observed that the anticancer effects of pectolinarigenin were due to induction of autophagy which was also associated with upregulation of the expression of Beclin-1, LC3-I and LC3-II. Transmission electron microscopy showed the formation of autophagosomes and vesicles. Pectolinarigenin also caused arrest of the SK-HEP-1 cells at the G2/M-phase of the cell cycle. Wound healing and transwell assays showed pectolinarigenin suppressed the migration and invasive potential of the SK-HEP-1 cells. CONCLUSIONS: The present study revealed that pectolinarigenin exhibits antitumor activity in SK-HEP-1 liver cancer cells via multiple mechanisms and may prove promising in the development of systemic therapy for liver cancer.

Modification of radiosensitivity by Curcumin in human pancreatic cancer cell lines.

Pancreatic cancer is one of the most aggressive malignancies and is characterized by a low 5-year survival rate, a broad genetic diversity and a high resistance to conventional therapies. As a result, novel therapeutic agents to improve the current situation are needed urgently. Curcumin, a polyphenolic colorant derived from Curcuma longa root, showed pleiotropic influences on cellular pathways in vitro and amongst others anti-cancer properties including sensitization of tumor cells to chemo- and radiation-therapy. In this study, we evaluated the impact of Curcumin on the radiosensitivity of the established human pancreatic cancer cell lines Panc-1 and MiaPaCa-2 in vitro. In contrast to MiaPaCa-2 cells, we found a significant radiosensitization by Curcumin in the more radioresistant Panc-1 cells, possibly caused by cell cycle arrest in the most radiation-sensitive G2/M-phase at the time of irradiation. Furthermore, a significant enhancement of radiation-induced apoptosis, DNA-double-strand breaks and G2/M-arrest after curcumin treatment was observed in both cell lines. These in vitro findings suggest that especially patients with more radioresistant tumors could benefit from a radiation-concomitant, phytotherapeutic therapy with Curcumin.

Anticancer Action of Psilostachyin-A in 5-Fluorouracil-Resistant Human Liver Carcinoma are Mediated Through Autophagy Induction, G2/M Phase Cell Cycle Arrest and Inhibiting Extracellular-Signal-Regulated Kinase/Mitogen Activated Protein Kinase (ERK/MAPK) Signaling Pathway.

BACKGROUND Liver cancer is one of the most common malignancies around the world and one of the major causes of cancer related mortality. The objective of this study was to evaluate the anticancer effect of the natural compound psilostachyin-A on 5-fluorouracil-resistant human liver carcinoma cells and its effects on autophagy, cell cycle, caspase activation, and the ERK/MAPK signaling pathway. MATERIAL AND METHODS Cell Counting Kit 8 (CCK-8) assay was used to evaluate the effects on HepG2 cell viability at different doses of psilostachyin-A. Cell cycle analysis was performed using flow cytometry, and Transwell assay was used to check effects on cell invasion. Transmission electron microscopic studies were done to evaluate autophagy induced by psilostachyin-A, and the western blot method was carried out to evaluate the effects on autophagy and the ERK/MAPK signaling pathway. RESULTS CCK-8 assay revealed that the psilostachyin-A reduced the cell viability of HepG2 cancer cells in a dose dependent manner. Psilostachyin-A also reduced the colony forming potential of HepG2 cells, concentration dependently. The IC50 of psilostachyin was found to be 25 µM. The anticancer effects of psilostachyin-A were due to the induction of autophagy which was accompanied by enhancement of LC3B II expression. Psilostachyin also caused cell cycle arrest by enhancing the accumulation of HepG2 cells in the G2/M phase. Transwell assay showed that psilostachyin-A suppressed the invasion of HepG2 cells. The results also showed that psilostachyin-A could block the ERK/MAPK pathway, indicative of the cytotoxic effects of psilostachyin-A on liver cancer. CONCLUSIONS These preliminary observations suggested that psilostachyin-A might prove beneficial in the treatment of liver cancer.

Melatonin Improves In Vitro Development of Vitrified-Warmed Mouse Germinal Vesicle Oocytes Potentially via Modulation of Spindle Assembly Checkpoint-Related Genes.

The present study aimed to investigate the effect of melatonin (MT) supplementation on in vitro maturation of vitrified mouse germinal vesicle (GV) oocytes. The fresh oocytes were randomly divided into three groups: untreated (control), or vitrified by open-pulled straw method without (vitrification group) or with MT supplementation (vitrification + MT group). After warming, oocytes were cultured in vitro, then the reactive oxygen species (ROS) and glutathione (GSH) levels, mitochondrial membrane potential, ATP levels, spindle morphology, mRNA expression of spindle assembly checkpoint (SAC)-related genes (Mps1, BubR1, Mad1, Mad2), and their subsequent developmental potential in vitro were evaluated. The results showed that vitrification/warming procedures significantly decreased the percentage of GV oocytes developed to metaphase II (MII) stage, the mitochondrial membrane potential, ATP content, and GSH levels, remarkably increased the ROS levels, and significantly impaired the spindle morphology. The expressions of SAC-related genes were also altered in vitrified oocytes. However, when 10-7 mol/L MT was administered during the whole length of the experiment, the percentage of GV oocytes matured to MII stage was significantly increased, and the other indicators were also significantly improved and almost recovered to the normal levels relative to the control. Thus, we speculate that MT might regulate the mitochondrial membrane potential, ATP content, ROS, GSH, and expression of SAC-related genes, potentially increasing the in vitro maturation of vitrified-warmed mouse GV oocytes.

Plumbagin inhibits the proliferation of nasopharyngeal carcinoma 6-10B cells by upregulation of reactive oxygen species.

Plumbagin (PLB) is the primary component of the traditional Chinese medicine Baihua Dan, and possesses anti-infection and anticancer effects, with the ability to enhance the sensitivity of tumor cells to radiation therapy. However, the anticancer effect of PLB on nasopharyngeal carcinoma and the underlying mechanisms remain unclear. In this study, we investigated the anticancer effects of PLB on nasopharyngeal carcinoma 6-10B cells and clarified its molecular mechanisms in vitro. The results showed that PLB was effective against 6-10B cells proliferation in a dose-dependent manner by inducing G2/M phase cell cycle arrest. Furthermore, our data showed that PLB induced reactive oxygen species accumulation, which inhibited the GSK3ß/STAT3 pathway and arrested the G2/M phase. Therefore, our results provided new insight into the mechanism of the antitumor effects of PLB, supporting PLB as a prospective therapeutic drug in nasopharyngeal carcinoma by modulating intracellular redox balance.

Calotroposid A: a Glycosides Terpenoids from Calotropis gigantea Induces Apoptosis of Colon Cancer WiDr Cells through Cell Cycle Arrest G2/M and Caspase 8 Expression

Objective: This study aims to isolate the active anticancer compound from ethyl acetate fraction extracted from the roots of Calotropis gigantea and to determine the operating mechanism of the isolates towards WiDr colon cancer cells. Methods: the isolation was conducted by using bioassay guided isolation approach method. The cytotoxic potential was determined by using MTT method. The chemical structure was identified by using UPLCMS/MS and NMR-1H spectroscopy. The cell cycle arrest and apoptosis induction were determined by flow cytometry method. The expression of caspase-8 was determined by immunocytochemistry method. Results: The results showed that the active compounds are obtained calotroposid A compound which is glycosides terpenoids. Calotroposide A is capable of inhibiting the growth of WiDr colon cancer cells at IC50 17.23µg/ml. Cell apoptosis induction took place and was indicated by cell apoptosis increase, S and G2/M accumulation and by caspase-8 expression. Conclusion: Calotroposide A induces anticancer activity against WiDr colon cancer cells by means of apoptosis induction mechanism through extrinsic pathway with increased expression of caspase-8.

Curcumin inhibits autocrine growth hormone-mediated invasion and metastasis by targeting NF-κB signaling and polyamine metabolism in breast cancer cells.

Curcumin is assumed to be a plant-derived therapeutic drug that triggers apoptotic cell death in vitro and in vivo by affecting different molecular targets such as NF-κB. Phase I/II trial of curcumin alone or with chemotherapeutic drugs has been accomplished in pancreatic, colon, prostate and breast cancer cases. Recently, autocrine growth hormone (GH) signaling-induced cell growth, metastasis and drug resistance have been demonstrated in breast cancer. In this study, our aim was to investigate the potential therapeutic effect of curcumin by evaluating the molecular machinery of curcumin-triggered apoptotic cell death via focusing on NF-κB signaling and polyamine (PA) metabolism in autocrine GH-expressing MCF-7, MDA-MB-453 and MDA-MB-231 breast cancer cells. For this purpose, a pcDNA3.1 (+) vector with a GH gene insert was transfected by a liposomal agent in all breast cancer cells and then selection was conducted in neomycin (G418) included media. Autocrine GH-induced curcumin resistance was overcome in a dose-dependent manner and curcumin inhibited cell proliferation, invasion-metastasis and phosphorylation of p65 (Ser536), and thereby partly prevented its DNA binding activity in breast cancer cells. Moreover, curcumin induced caspase-mediated apoptotic cell death by activating the PA catabolic enzyme expressions, which led to generation of toxic by-products such as H2O2 in MCF-7, MDA-MB-453 and MDA-MB-231 GH+ breast cancer cells. In addition, transient silencing of SSAT prevented curcumin-induced cell viability loss and apoptotic cell death in each breast cancer cells. In conclusion, curcumin could overcome the GH-mediated resistant phenotype via modulating cell survival, death-related signaling routes and activating PA catabolic pathway.

ITRAQ-Based Proteomics Analysis of Triptolide On Human A549 Lung Adenocarcinoma Cells.

BACKGROUND/AIMS: Triptolide (TP) is a diterpenoid triepoxide extracted from the traditional Chinese medical herb Tripterygium wilfordii that exerts prominent broad-spectrum anticancer activity to repress proliferation and induce cancer cell apoptosis through various molecular pathways. We previously observed that TP inhibits the progression of A549 cells and pancreatic cancer cells (PNCA-1) in vitro. However, the complex molecular mechanism underlying the anticancer activity of TP is not well understood. METHODS: To explore the molecular mechanisms by which TP induces lung cancer cell apoptosis, we investigated changes in the protein profile of A549 cells treated with TP using a proteomics approach (iTRAQ [isobaric tags for relative and absolute quantitation] combined with NanoLC-MS/MS [nano liquid chromatography-mass spectrometry]). Changes in the profiles of the expressed proteins were analyzed using the bioinformatics tools OmicsBean and the Kyoto Encyclopedia of Genes and Genomes (KEGG) and were verified using western blotting. Apoptosis and cell cycle effects were analyzed using flow cytometry. RESULTS: TP induced apoptosis in A549 cells and blocked A549 cells at the G2/M phase. Using iTRAQ technology, we observed 312 differentially expressed proteins associated in networks and implicated in different KEGG pathways. Gene Ontology (GO) analysis showed the overviews of dysregulated proteins in the biological process (BP), cell component (CC), and molecular function (MF) categories. Moreover, some candidate proteins involved in PARP1/AIF and nuclear Akt signaling pathways or metastasis processes were validated by western blotting. CONCLUSION: TP exerted anti-tumor activity on non-small cell lung cancer (NSCLC) A549 lung adenocarcinoma cells by dysregulating tumor-related protein expression. Herein, we provide a preliminary study of TP-related cytotoxicity on A549 cells using proteomics tools. These findings may improve the current understanding of the anti-tumor effects of TP on lung cancer cells and may reveal candidate proteins as potential targets for the treatment of lung cancer.

Ovatodiolide isolated from Anisomeles indica induces cell cycle G2/M arrest and apoptosis via a ROS-dependent ATM/ATR signaling pathways.

Ovatodiolide was isolated from the traditional Chinese medicinal herb Anisomeles indica, possesses anti-bacterial and anti-inflammatory properties; however, the anti-cancer activity and its mechanisms have been limitedly reported. This study aimed to examine the effect and molecular action of ovatodiolide in lung cancer cells. Cell cycle distribution and reactive oxygen species (ROS) generation were measured by flow cytometry. Apoptosis was detected by propidium iodide/annexin V staining and TUNEL assay. DNA damage was investigated by comet assay and γ-H2AX staining. Caspase activity was determined using caspase fluorometric kits. Moreover, protein levels were examined by western blot. Ovatodiolide provoked reactive oxygen species generation and DNA damage, as well as inhibited cell growth and induced apoptosis in human lung cancer A549 and H1299 cell lines. DNA damage-related molecules, ATM/ATR and CHK1/CHK2 were activated by ovatodiolide. Moreover, ovatodiolide-mediated G2/M arrest was associated with the decrease of Cyclin B1 and CDC25C levels, and increase of p21WAF1/CIP1 expression. Additionally, ovatodiolide-triggered apoptosis was through both intrinsic and extrinsic pathways characterized by the elevating PUMA, Bax, and DR5 proteins, decreasing Bcl-2 and Mcl-1, and activating caspase-8, caspase-9 and caspase-3. Caffeine, an ATM/ATR inhibitor, rescued ovatodiolide-mediated cell cycle arrest and apoptosis, but not reactive oxygen species generation. Nevertheless, antioxidant N-acetyl-cysteine completely blocked ovatodiolide-mediated molecular events, G2/M arrest, and apoptosis. These observations suggest that ovatodiolide stimulates reactive oxygen species generation, causes oxidative stress and DNA damage; subsequently, provokes DNA damage signaling pathways, eventually leads to block cell cycle at G2/M phase and trigger apoptosis in lung cancer A549 and H1299 cells.

The effects of combined selenium nanoparticles and radiation therapy on breast cancer cells in vitro.

Radiosensitizers that increase cancer cell radio-sensitivity can enhance the effectiveness of irradiation and minimize collateral damage. Nanomaterial has been employed in conjunction with radiotherapy as radiosensitizers, due to its unique physicochemical properties. In this article, we evaluated selenium nanoparticles (Nano-Se) as a new radiosensitizer. Nano-Se was used in conjunction with irradiation on MCF-7 breast cancer cells, and efficacy and mechanisms of this combined treatment approach were evaluated. Nano-Se reinforced the toxic effects of irradiation, leading to a higher mortality rate than either treatment used alone, inducing cell cycle arrest at the G2/M phase and the activation of autophagy, and increasing both endogenous and irradiation-induced reactive oxygen species formation. These results suggest that Nano-Se can be used as an adjuvant drug to improve cancer cell sensitivity to the toxic effects of irradiation and thereby reduce damage to normal tissue nearby.

Synthesis and in vitro biological evaluation of thiosulfinate derivatives for the treatment of human multidrug-resistant breast cancer.

Organosulfur compounds derived from Allium vegetables have long been recognized for various therapeutic effects, including anticancer activity. Allicin, one of the main biologically active components of garlic, shows promise as an anticancer agent; however, instability makes it unsuitable for clinical application. The aim of this study was to investigate the effect of stabilized allicin derivatives on human breast cancer cells in vitro. In this study, a total of 22 stabilized thiosulfinate derivatives were synthesized and screened for their in vitro antiproliferative activities against drug-sensitive (MCF-7) and multidrug-resistant (MCF-7/Dx) human adenocarcinoma breast cancer cells. Assays for cell death, apoptosis, cell cycle progression and mitochondrial bioenergetic function were performed. Seven compounds (4b, 7b, 8b, 13b, 14b, 15b and 18b) showed greater antiproliferative activity against MCF-7/Dx cells than allicin. These compounds were also selective towards multidrug-resistant (MDR) cells, a consequence attributed to collateral sensitivity. Among them, 13b exhibited the greatest anticancer activity in both MCF-7/Dx and MCF-7 cells, with IC50 values of 18.54±0.24 and 46.50±1.98 µmol/L, respectively. 13b altered cellular morphology and arrested the cell cycle at the G2/M phase. Additionally, 13b dose-dependently induced apoptosis, and inhibited cellular mitochondrial respiration in cells at rest and under stress. MDR presents a significant obstacle to the successful treatment of cancer clinically. These results demonstrate that thiosulfinate derivatives have potential as novel anticancer agents and may offer new therapeutic strategies for the treatment of chemoresistant cancers.

Ailanthone induces G2/M cell cycle arrest and apoptosis of SGC­7901 human gastric cancer cells.

Ailanthone is a major quassinoid extracted from the Chinese medicinal herb Ailanthus altissima, which has been reported to exert antiproliferative effects on various cancer cells. The present study aimed to investigate the antitumor effects of ailanthone on SGC­7901 cells, and to analyze its underlying molecular mechanisms. Following treatment with ailanthone, Cell Counting kit­8 was used to detect the cytotoxic effects of ailanthone on SGC­7901 cells in vitro. The typical apoptotic morphology of SGC­7901 cells was observed by Hoechst 33258 staining. Cell cycle progression and apoptosis were measured by flow cytometry, and the protein and mRNA expression levels of Bcl­2 and Bax were analyzed by western blot analysis and reverse transcription­quantitative polymerase chain reaction (RT­qPCR) respectively, in SGC­7901 cells. The results of the present study indicated that ailanthone inhibited the proliferation of SGC­7901 cells in a dose­ and time­dependent manner in vitro, and also demonstrated that ailanthone induced G2/M phase cell cycle arrest and apoptosis of SGC­7901 cells. Furthermore, analysis of the underlying molecular mechanisms revealed that ailanthone downregulated the expression levels of Bcl­2, whereas the expression levels of Bax were upregulated at the protein and mRNA levels. In conclusion, ailanthone may inhibit the proliferation of SGC­7901 cells by inducing G2/M phase cell cycle arrest and apoptosis via altering the protein and mRNA expression levels of Bcl­2 and Bax in SGC­7901 cells.

Licochalcone A Inhibits the Proliferation of Human Lung Cancer Cell Lines A549 and H460 by Inducing G2/M Cell Cycle Arrest and ER Stress.

Licochalcone A (LicA), a flavonoid isolated from the famous Chinese medicinal herb Glycyrrhiza uralensis Fisch, has wide spectrum of pharmacological activities. In this study, the anti-cancer effects and potential mechanisms of LicA in non-small cell lung cancer (NSCLC) cells were studied. LicA decreased cell viability and induced apoptosis in a dose-dependent manner in NSCLC cells. LicA inhibited lung cancer cells growth by blocking cell cycle progression at the G2/M transition and inducing apoptosis. LicA treatment decreased the expression of MDM2, Cyclin B1, Cdc2 and Cdc25C in H460 and A549 cancer cell lines. In addition, LicA induced caspase-3 activation and poly-ADP-ribose polymerase (PARP) cleavage, which displayed features of apoptotic signals. Furthermore, LicA increased the expression of endoplasmic reticulum (ER) stress related proteins, such as p-EIF2α and ATF4. These data provide evidence that LicA has the potential to be used in the treatment of lung cancer.