Coleusin factor exerts cytotoxic activity by inducing G0/G1 cell cycle arrest and apoptosis in human gastric cancer BGC-823 cells

Isoforms of the p53 Family and Gastric Cancer: A Ménage à Trois for an Unfinished Affair

Simple Summary

The p53 family is a complex family of transcription factors with different cellular functions that are involved in several physiological processes. A massive amount of data has been accumulated on their critical role in the tumorigenesis and the aggressiveness of cancers of different origins. If common features are observed, there are numerous specificities that may reflect particularities of the tissues from which the cancers originated. In this regard, gastric cancer tumorigenesis is rather remarkable, as it is induced by bacterial and viral infections, various chemical carcinogens, and familial genetic alterations, which provide an example of the variety of molecular mechanisms responsible for cell transformation and how they impact the p53 family. This review summarizes the knowledge gathered from over 40 years of research on the role of the p53 family in gastric cancer, which still displays one of the most elevated mortality rates amongst all types of cancers.

Abstract

Gastric cancer is one of the most aggressive cancers, with a median survival of 12 months. This illustrates its complexity and the lack of therapeutic options, such as personalized therapy, because predictive markers do not exist. Thus, gastric cancer remains mostly treated with cytotoxic chemotherapies. In addition, less than 20% of patients respond to immunotherapy. TP53 mutations are particularly frequent in gastric cancer (±50% and up to 70% in metastatic) and are considered an early event in the tumorigenic process. Alterations in the expression of other members of the p53 family, i.e., p63 and p73, have also been described. In this context, the role of the members of the p53 family and their isoforms have been investigated over the years, resulting in conflicting data. For instance, whether mutations of TP53 or the dysregulation of its homologs may represent biomarkers for aggressivity or response to therapy still remains a matter of debate. This uncertainty illustrates the lack of information on the molecular pathways involving the p53 family in gastric cancer. In this review, we summarize and discuss the most relevant molecular and clinical data on the role of the p53 family in gastric cancer and enumerate potential therapeutic innovative strategies.

Research on anti-hepatocellular carcinoma activity and mechanism of Polygala fallax Hemsl

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala fallax Hemsl. is a kind of traditional medicine of Yao Minority in China. In Chinese medicine practice, Polygala fallax Hemsl. is commonly prescribed to treat all kinds of acute and chronic hepatitis.

AIM OF THE STUDY

The present study aimed at investigating the effects and its possible mechanism of Polygala fallax Hemsl. on the proliferation and apoptosis of HepG2 cells (a kind of human hepatoma cell).

MATERIALS AND METHODS

Through a variety of experimental methods, including MTT technique and Hoechst staining to detect apoptosis in Hepatocyte HepG2 cells, flow cytometry to observe the pro-apoptotic and circulatory arrest effects as well as real-time fluorescence quantitative polymerase chain reaction (q-PCR) technique to examine the expression levels of Bcl-2/Bax gene and prote Western blot to examine the expression levels of bcl-2/bax,caspase3,8,9,CyclinA,p21,p27,ERK.Phospho-ERK and AKT, Phospho-AKT in HepG2 cells.

RESULTS

The results showed that compared with the control group, all polarity fractions of P. fallax had inhibitory effects on HepG2 cells, among which the inhibition effect of ethyl acetate fraction in 0.036 ± 0.001 mg/mL of IC₅₀ for 24 h was the most obvious (P < 0.01). And the HepG2 cells induced at the ethyl acetate fraction could up-regulate Bax gene and protein, while down-regulating Bcl-2 gene and protein (P < 0.05) during S phase in a dose-dependent manner. In addition, the ethyl acetate site of Larch can also down regulate the expression of ERK, AKT and activate caspase 3, 8 and 9.

CONCLUSION

It could be concluded that the ethyl acetate fraction of Polygala fallax Hemsl. can significantly prohibit the proliferation of HepG2 cells. The possible mechanism is to promote the expression of Bax, inhibit the expression of Bcl-2, and down regulate the expression of AKT and ERK.

Coleus forskohlii: advancements and prospects of in vitro biotechnology

Coleus forskohlii syn. Plectranthus barbatus is a popular medicinal plant belonging to the family Lamiaceae and order Lamiales. The leaf and root extracts can be utilized for the treatment of various ailments like bronchitis, asthma, hay fever, angina and abdominal disorders. The major metabolite that is found exclusively in the cork cells of the root in C. forskohlii is forskolin, which is used commercially for the treatment of glaucoma, asthma and several heart ailments. The essential oil extracted from the tubers of the plant also exhibits anti-microbial properties. The present review recounts the existing reports on biotechnological approaches like direct, indirect organogenesis and somatic embryogenesis for mass propagation of plantlets; the amelioration of forskolin production through cell suspension and genetic transformation as well as slow growth storage for germplasm conservation. Additionally, the unexplored arenas and the prospective novel approaches are also addressed in this review that can be utilized in designing new experiments in near future on this plant.

Mechanisms Underlying Therapeutic Effects Of Traditional Chinese Medicine On Gastric Cancer

Gastric cancer (GC) is one of the most common malignant tumors in the world. It is the fourth most common cancer and has the second highest mortality rate globally. Metastasis is an important feature of gastric cancer and is the most common cause of death. Exploring the mechanism underlying the metastasis of gastric cancer and searching for new drug targets has become the focus of several studies. Traditional Chinese medicine may show promise for treatment of gastric cancer. In this review, we report the recent progress in research on the anti-metastasis activity of Chinese medicine, to facilitate clinical development of treatments for gastric cancer.

Procyanidin from peanut skin induces antiproliferative effect in human prostate carcinoma cells DU145

In this study, the antiproliferative activity of peanut skin procyanidins (PSP) and six fractions (PSP-1∼6) isolated from PSP by several chromatographic steps on the human prostate cancer DU145 cells were evaluated. The results showed that PSP and PSP-1∼6 significantly inhibited the proliferation of DU145 cells. PSP-2 was the most effective fraction, which was identified as procyanidin B₃ mainly and procyanidin dimer [(E)C-luteolin or keampferol] secondarily. Moreover, the mechanism of antiproliferative activity of PSP-2 was investigated. It was observed that PSP-2 induced apoptotic cell death and cell cycle arrest at S phase in DU145 cells. PSP-2 caused the increase of intracellular ROS level and the decrease of Bcl-2/Bax ratio, and triggered the activation of p53 and caspases-3 in DU145 cells. Our findings demonstrated that procyanidins from peanut skin have the potential to be developed as an anti-prostate cancer agent.

Graphene oxide and reduced graphene oxide induced neural pheochromocytoma-derived PC12 cell lines apoptosis and cell cycle alterations via the ERK signaling pathways

Given the novel applications of graphene materials in biomedical and electronics industry, the health hazards of these particles have attracted extensive worldwide attention. Although many studies have been performed on graphene material-induced toxic effects, toxicological data for the effect of graphene materials on the nervous system are lacking. In this study, we focused on the biological effects of graphene oxide (GO) and reduced graphene oxide (rGO) materials on PC12 cells, a type of traditional neural cell line. We found that GO and rGO exerted significant toxic effects on PC12 cells in a dose- and time-dependent manner. Moreover, apoptosis appeared to be a response to toxicity. A potent increase in the number of PC12 cells at G0/G1 phase after GO and rGO exposure was detected by cell cycle analysis. We found that phosphorylation levels of ERK signaling molecules, which are related to cell cycle regulation and apoptosis, were significantly altered after GO and rGO exposure. In conclusion, our results show that GO has more potent toxic effects than rGO and that apoptosis and cell cycle arrest are the main toxicity responses to GO and rGO treatments, which are likely due to ERK pathway regulation.

Characterization and immunostimulating effects on murine peritoneal macrophages of a novel protein isolated from Panax quinquefolius L

ETHNOPHARMACOLOGICAL RELEVANCE

Panax quinquefolius L. has been used as a proverbial tonic in oriental countries for hundreds of years. It is used as a traditional medicinal herb to nourish vitality.

AIM OF THE STUDY

The purpose of our study was to inquiry the activation effects on murine peritoneal macrophages of a novel protein separated from the roots of Panax quinquefolius L.

MATERIALS AND METHODS

In our work, a novel protein of the roots of American ginseng (AGNP) was separated and purified from the roots of Panax quinquefolius L. The characteristic was investigated with SDS-PAGE, high pressure gel filtration chromatography (HPGFC) and matrix-assisted laser desorption ionization/time-of-flight mass (MALDI-TOF-MS) spectrometry method. The method of neutral red was carried out to investigate the phagocytosis of peritoneal macrophages. And Griess method and colorimetry were executed to detect the level of nitric oxide and iNOS activity respectively. Tumor necrosis factor-α and interleukin-6 were analyzed by enzyme linked immunosorbent assay (ELISA).

RESULTS

Our results demonstrated that the subunit molecular weight of AGNP determined by SDS-PAGE was 15kD and the content of proteins determined by Bradford assay was 2.31mg/mL. The molecular weight of the AGNP was15, 114Da both of electrophoresis and MS purity. And the result of HPGFC showed that the molecular weight of AGNP was 31,086Da, Immunological studied indicated that AGNP could conspicuously increase phagocytosis of macrophages, facilitate the nitric oxide production, Tumor necrosis factor-α and interleukin-6 production. What is more, AGNP dose-dependently stimulated NO formation through the up-regulation of iNOS activity.

CONCLUSIONS

In conclusion, AGNP had good immunoregulatory effects supporting the traditional claims and may provide a valuable therapeutic strategy to promoting immune function and metabolism.

Graphene Enhances Cellular Proliferation through Activating the Epidermal Growth Factor Receptor

Graphene has promising applications in food packaging, water purification, and detective sensors for contamination monitoring. However, the biological effects of graphene are not fully understood. It is necessary to clarify the potential risks of graphene exposure to humans through diverse routes, such as foods. In the present study, graphene, as the model nanomaterial, was used to test its potential effects on the cell proliferation based on multiple representative cell lines, including HepG2, A549, MCF-7, and HeLa cells. Graphene was characterized by Raman spectroscopy, particle size analysis, atomic force microscopy, and transmission electron microscopy. The cellular responses to graphene exposure were evaluated using flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and alamarBlue assays. Rat cerebral astrocyte cultures, as the non-cancer cells, were used to assess the potential cytotoxicity of graphene as well. The results showed that graphene stimulation enhanced cell proliferation in all tested cell cultures and the highest elevation in cell growth was up to 60%. A western blot assay showed that the expression of epidermal growth factor (EGF) was upregulated upon graphene treatment. The phosphorylation of EGF receptor (EGFR) and the downstream proteins, ShC and extracellular regulating kinase (ERK), were remarkably induced, indicating that the activation of the mitogen-activated protein kinase (MAPK)/ERK signaling pathway was triggered. The activation of PI3 kinase p85 and AKT showed that the PI3K/AKT signaling pathway was also involved in graphene-induced cell proliferation, causing the increase of cell ratios in the G2/M phase. No influences on cell apoptosis were observed in graphene-treated cells when compared to the negative controls, proving the low cytotoxicity of this emerging nanomaterial. The findings in this study revealed the potential cellular biological effect of graphene, which may give useful hints on its biosafety evaluation and the further exploration of the bioapplication.

Morusin suppresses breast cancer cell growth in vitro and in vivo through C/EBPβ and PPARγ mediated lipoapoptosis

Background

Breast cancer is the most fatal malignant cancer among women, the conventional therapeutic modalities of it are limited. Morusin possesses cytotoxicity against some cancer cells in vitro. The purpose of this study is to test the growth inhibition effect of morusin on human breast cancer growth in vitro and in vivo and to explore the potential mechanism of its action.

Methods

The growth inhibition effect of morusin on human breast cancer cells in vitro and in vivo were tested by cell cytotoxicity, colony formation inhibition, adipogenic differentiation, apoptosis induction, and tumor growth inhibition in vivo assays. The potential molecular mechanisms underlying the growth inhibition effect of morusin on human breast cancer cells in vitro and in vivo were investigated with Western blotting evaluation of expression levels of transcription factors, C/EBPβ and PPARγ, adipogenic and apoptotic proteins in morusin treated breast cancer cells and tumor tissues.

Results

Morusin inhibited breast cancer cells growth in vitro and in vivo; it induced adipogenic differentiation, apoptosis and lipoapoptosis of cancer cells.

Conclusions

Morusin has the potential to inhibit human breast cancer cell growth in vitro and in vivo through C/EBPβ and PPARγ mediated lipoapoptosis.

Compositions and anti-tumor activity of Pyropolyporus fomentarius petroleum ether fraction in vitro and in vivo

The chemical compositions and anti-tumor activities of the petroleum ether fraction (PE), from mushroom Pyropolyporus fomentarius, were studied. Upon gas chromatography-mass spectrometry (GC-MS) analysis, nine major constituents were identified in the fraction. In vitro, the PE showed cytotoxic activity against murine sarcoma S180 (S180) cells in a dose- and time-dependent manner, and the cytotoxic effects were associated with apoptosis. The mitochondrial membrane potential loss and the intracellular ROS generation were greatly increased in the Pyropolyporus fomentarius PE treated group, suggesting cell apoptosis, induced by the PE in S180 cells, might be mitochondria dependent and ROS mediated. Consistent with in vitro findings, the in vivo study showed that the Pyropolyporus fomentarius PE was also effective in inhibiting the tumor growth induced by S180 cells and had lower immune organ toxicity. We found that the Pyropolyporus fomentarius PE has significant anti-tumor activity and great potential in screening anti-tumor drugs.

In vitro evaluation of graphene oxide nanosheets on immune function

HYPOTHESIS

Graphene oxide (GO) has attracted the scientific community attention due to its novel properties and wide range of potential applications including hyperthermia cancer therapy. However, little is known about the GO effects on the immune function which involves both innate and adaptive defence mechanisms through the activation of different cell populations and secretion of several cytokines. The effect of different GO nanosheets designed for hyperthermia cancer therapy on macrophage and lymphocyte function should be determined before using GO for this application.

EXPERIMENTS

The effects of GO nanosheets with 1 (1-GOs) and 6 arms (6-GOs) of polyethylene glycol on RAW-264.7 macrophages and primary splenocytes (as approximation to the in vivo situation) were evaluated through the proinflammatory cytokine secretion and the modulation of cell proliferation in the presence of specific stimuli for either T-lymphocytes (concanavalin A, anti-CD3 antibody) or B-lymphocytes/macrophages (lipopolysaccharide).

FINDINGS

6-GOs significantly increased the secretion of TNF-α by RAW-264.7 macrophages without alteration of IL-6 and IL-1β levels. The treatment of primary splenocytes with 1-GOs and 6-GOs in the presence of concanavalin A, anti-CD3 antibody and lipopolysaccharide, produced significant dose-dependent decreases of cell proliferation and IL-6 levels, revealing weak inflammatory properties of GOs which are favourable for hyperthermia cancer therapy.

Antitumor activity of ethanolic extract of Dendrobium formosum in T-cell lymphoma: an in vitro and in vivo study

Dendrobium, a genus of orchid, was found to possess useful therapeutic activities like anticancer, hypoglycaemic, antimicrobial, immunomodulatory, hepatoprotective, antioxidant, and neuroprotective activities. The study was aimed to evaluate the anticancer property of the ethanolic extract of Dendrobium formosum on Dalton's lymphoma. In vitro cytotoxicity was determined by MTT assay, apoptosis was determined by fluorescence microscopy, and cell cycle progression was analysed using flow cytometry; in vivo antitumor activity was performed in Dalton's lymphoma bearing mice. The IC₅₀ value of ethanolic extract was obtained at 350 μg/mL in Dalton's lymphoma cells. Fluorescence microscopy analysis showed significant increase in apoptotic cell death in dose- and time-dependent manner which was further confirmed through the resulting DNA fragmentation. Further, flow cytometry analysis showed that the ethanolic extract arrests the cells in G₂/M phase of the cell cycle. The in vivo anticancer activity study illustrates significant increase in the survival time of Dalton's lymphoma bearing mice on treatment with ethanolic extract when compared to control. These results substantiate the antitumor properties of ethanolic extract of Dendrobium formosum and suggest an alternative in treatment of cancer. Further studies are required regarding the isolation and characterization of bioactive components along with the analysis of molecular mechanism involved.

Coleusin factor, a novel anticancer diterpenoid, inhibits osteosarcoma growth by inducing bone morphogenetic protein-2-dependent differentiation

Coleusin factor is a diterpenoid compound isolated from the root of a tropical plant, Coleus forskohlii. Although Coleusin factor has been reported to suppress proliferation of and induce apoptosis in several types of cancer cells, the effects of Coleusin factor on osteosarcoma and the underlying mechanism are still not fully understood. In this study, we show that Coleusin factor treatment potently inhibits the growth of osteosarcoma cells associated with G(1) cell-cycle arrest. Interestingly, apoptosis and cell death are not induced. Instead, Coleusin factor causes osteosarcoma cells to exhibit typical properties of differentiated osteoblasts, including a morphologic alteration resembling osteoblasts, the expression of osteoblast differentiation markers, elevated alkaline phosphatase activity, and increased cellular mineralization. Coleusin factor treatment significantly increases the expression of bone morphogenetic protein-2 (BMP-2), a crucial osteogenic regulator, and runt-related transcription factor 2 (RUNX2), one of the key transcription factors of the BMP pathway. When BMP-2 signaling is blocked, Coleusin factor fails to inhibit cell proliferation and to induce osteoblast differentiation. Thus, upregulation of BMP-2 autocrine is critical for Coleusin factor to induce osteoblast differentiation and exert its anticancer effects on osteosarcoma. Importantly, administration of Coleusin factor inhibits the growth of osteosarcoma xenografted in nude mice without systemic or immunologic toxicity. Osteosarcoma is a highly aggressive cancer marked by the loss of normal differentiation. Coleusin factor represents a new type of BMP-2 inducer that restores differentiation in osteosarcoma cells. It may provide a promising therapeutic strategy against osteosarcoma with minimal side effects.

The effect of Lfcin-B on non-small cell lung cancer H460 cells is mediated by inhibiting VEGF expression and inducing apoptosis

Lfcin-B, an antimicrobial peptide found in various exocrine secretions of mammals, showed antitumor effects. However, the effect and relative mechanism of Lfcin-B on non-small cell lung cancer is unclear. In this study, assay of cell viability, quantitative real-time PCR, Western blot, annexin V/propidium iodide assay, flow cytometry and tumor-xenograft model were applied to elucidate the mechanism of Lfcin-B on non-small cell lung cancer NCI-H460 (H460) cells. Lfcin-B significantly suppressed the proliferation of H460 cells in vitro. Additionally, the transcription and translation of the VEGF gene in H460 cells were restrained after exposure to Lfcin-B. Moreover, the apoptosis of H460 cells was induced by Lfcin-B through stimulating caspase-3, caspase-9 and preventing survivin expression on both the transcription and translation level. Meanwhile, Lfcin-B increased the production of reactive oxygen species and suppressed the RNA of antioxidant enzymes (GPX1, GPX2, SOD3 and catalase) in H460 cells. Finally, Lfcin-B significantly prevented the tumor growth in the H460-bearing mice model. These results indicated that Lfcin-B could be a potential candidate for the treatment of lung cancer.

Induction of apoptosis and G2 /M cell cycle arrest by Scrophularia striata in a human leukaemia cell line

OBJECTIVES

Scrophularia striata Boiss (Scrophulariaceae) is a plant that grows in northeastern Iran; it has been used traditionally to treat various inflammatory disorders. This study was designed to investigate cytotoxic effects of S. striata extract, on the Jurkat human leukaemia cell line (T-cell leukaemia).

MATERIALS AND METHODS

Phytochemical assay by thin layer chromatography and 2, 2 diphenyl-1-picryl-hydrazyl were used to evaluate main compounds and antioxidant capacity of the plant extract, respectively. Its inhibitory effect on Jurkat cells was evaluated by MTT assay. In addition, cell cycle distribution and apoptotic cell death were evaluated by propidium iodide and annexin V-FITC/ propidium iodide staining.

RESULTS

These showed that the main components present in S. striata extract included flavonoids, phenolic compounds and phenyl propanoids. Treatment with extract was significantly cytotoxic to the tumour cell line. In addition, flow cytometry analysis indicated that S. striata extract induced cell cycle arrest in G2 /M phase and apoptosis of tumour cells.

CONCLUSIONS

Results of the study indicated that S. striata extract could inhibit leukaemia cell proliferation by inducing G2 /M phase arrest and apoptosis.

Anti-tumor activity and relative mechanism of ethanolic extract of Marsdenia tenacissima (Asclepiadaceae) against human hematologic neoplasm in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Marsdenia tenacissima, a traditional Chinese medicinal herb, endemic to Yunnan Province is widely used to treat cough, asthma, expectorant, esophageal cancer, gastric cancer, lung cancer, and hepatocellular carcinoma. The aim of this study was to evaluate in vitro and in vivo anti-hematologic neoplasm potential of the ethanolic extract of this herb (crude ethanolic extract of Marsdenia tenacissima, CME) and by using different assays to elucidate its possible mechanism of action.

MATERIALS AND METHODS

The cytotoxicity of CME on tumor cells and peripheral blood mononuclear cells (PBMCs) was evaluated using MTT and apoptosis assays. We also tested the effect of CME on colony formation inhibition and cell cycle distribution of tumor cells. The protein expressions of Cyclin D1, Bax, Bcl-2, caspase-3 and caspase-9 were detected through Western blotting. In vivo anti-tumor effect was evaluated by measuring tumor volume changes, measuring tumor weight, evaluation of tumor microvessel density (MVD) and TUNEL staining by using immunohistochemistry staining in tumor models of nude mice.

RESULTS

Marsdenia tenacissima ethanolic extract exhibited effects of proliferation inhibition and induction of apoptosis on human hematologic neoplasm tumor cells in vitro, as well as hematologic neoplasm growth in vivo.

CONCLUSION

This study clearly indicated that the ethanolic extract of Marsdenia tenacissima displayed strong anti-tumor effects against hematologic neoplasm cells and could induce tumor cells apoptosis in vitro and in vivo, and also had a significant anti-angiogenic effect in vivo against tumor cell apoptosis. Its multi-mechanism of action might be associated with the cell cycle (G0/G1) arrest, induction of apoptosis through up-regulation protein expressions of Bax, caspase-9 and caspase-3 genes and down-regulation of the expressions of Cyclin D1 and Bcl-2 genes, a decrease in tumor microvessel density and an increase of TUNEL-positive cells in vivo. These findings provided the molecular theoretical basis of clinical application.

Panax ginseng polysaccharide induces apoptosis by targeting Twist/AKR1C2/NF-1 pathway in human gastric cancer

In the present study, we isolated and screened an antitumor polysaccharide (PGP2a) from the roots of Panax ginseng. Chemical composition analysis indicated PGP2a was an acidic protein-polysaccharide. The average molecular weight was estimated to be 3.2 × 10(4)Da. According to gas chromatography (GC) result, PGP2a consisted of galactose, arabinose, glucose and galacturonic acid in the molar ratio of 3.7:1.6:0.5:5.4, respectively. MTT assay showed that PGP2a had a potent inhibitory effect on the growth of HGC-27 cells in a dose-dependent fashion. Furthermore, the number of HGC-27 cells arrested in G2/M phase, and the percentage of apoptotic cells were increased in response to PGP2a treatment along with concentration increasing. Moreover, western blotting analysis showed that protein expressions of Twist and AKR1C2 were suppressed by PGP2a, whereas an increase of NF1 was observed at protein level. Taken together, these findings suggested that PGP2a could be developed as a novel antitumor agent acting on Twist related gene for human gastric cancer therapy.

A combination of alkaloids and triterpenes of Alstonia scholaris (Linn.) R. Br. leaves enhances immunomodulatory activity in C57BL/6 mice and induces apoptosis in the A549 cell line

Experiments were conducted to evaluate the induction of apoptosis and the immunomodulatory activities of alkaloids and triterpenes of Alstonia scholaris (Linn.) R. Br. leaves (ASL). Importantly, their possible synergistic properties were also explored in this study. Human lung adenocarcinoma cell line A549 and Lewis tumor-bearing C57BL/6 mice were used for the evaluation of their activities. A MTT assay was used to determine the proliferation inhibition in A549 cells. Annexin-V/PI double staining as well as flow cytometry was performed to detect apoptosis and cell cycle status. Enzyme-linked immunosorbent assay (ELISA) was conducted to determine the levels of inflammatory mediators interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in serum. Furthermore, western blot analysis was applied to evaluate the expressions of proteins associated with cell death. Alkaloids or triterpenes showed a high anti-proliferative activity in A549 cells, with IC₅₀ values of 14.4 µg/mL and 9.3 µg/mL, respectively. The alkaloids and triterpenes combination could significantly inhibit tumor growth in tumor-bearing C57BL/6 mice, compared with alkaloids or triterpenes alone (7.5, 15, 30 g raw material/kg). The immune organs indexes including spleen index and thymus index were increased remarkably by the combination of alkaloids and triterpenes, whereas the levels of IL-6 and TNF-α were up-regulated significantly. Moreover, Annexin-V/PI double staining and flow cytometry showed that the combination of alkaloids and triterpenes (1, 2 and 3 mg raw material/kg) could induce apoptosis and cause S cell cycle arrest in A549 cells. Western blot analysis also showed that their combination (2 mg raw material/kg) significantly down-regulated Bcl-2 expression and pro-casp8 level, whereas it remarkably increased the level of cleaved caspase-8 leading to apoptosis in A549 cells. These observations provide preliminary evidence that both alkaloids and triterpenes possess immune regulation and induction apoptosis activities. Their combination has a stronger activity than that of either class alone. Our findings suggested that these components might be beneficial for the prevention and treatment of NSCLC through a significant synergy effect.

Regulation of the Hippo pathway and implications for anticancer drug development

Research in the past decade has revealed key components of the Hippo tumor suppressor pathway and its critical role in organ size regulation and tumorigenesis. Recent progress has identified a wide range of upstream factors that control the Hippo pathway, which include cell-cell contact, various diffusible signals, and cognate receptors. Dysregulation of the Hippo pathway, caused by gene mutation or aberrant expression, promotes cell proliferation and tumorigenesis. Here, we discuss the current state of Hippo pathway research, primarily focusing on upstream regulators and protein-protein interactions as potential therapeutic targets. Consideration of pharmacological intervention of the Hippo pathway may provide novel avenues for future therapeutic treatment of human diseases, particularly in cancer.

Antiproliferation and anti-migration induced by gypenosides in human colon cancer SW620 and esophageal cancer Eca-109 cells

Gypenosides (Gyp), found in Gynostemma pentaphyllum Makino, has attracted more attention owing to its wide bioactivities. However, the effects of Gyp on esophageal cancer cells and colon cancer cells are still unknown. The present study was to investigate the possible anti-proliferative and anti-migration activity of Gyp on human colon cancer cells SW620 and esophageal cancer cells Eca-109. Cell viability was evaluated using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell membrane integrity was evaluated using flow cytometry following propidium iodide staining. Apoptotic cell death was determined by nuclear 4′-6-diamidino-2-phenylindole staining. Generation of intracellular reactive oxygen species (ROS) and changes in mitochondrial membrane potential (Δ ψm) was analyzed by flow cytometry using 2′,7′-dichlorofluorescein–diacetate and rhodamine 123 staining, respectively. Wound healing assay was carried out to investigate Gyp-inhibited migration of SW620 and Eca-109 cells. The results indicated that Gyp inhibited cell proliferation and migration in SW620 and Eca-109 cells in dose- and time-dependent manner. Gyp elevated intracellular ROS level, decreased the Δ ψm, and induced apoptotic morphology such as cell shrinkage and chromatin condensation, suggesting oxidative stress and mitochondria-dependent cell apoptosis that might be involved in Gyp-induced cell viability loss in SW620 and Eca-109 cells. The findings indicate Gyp may have valuable application in clinical colon cancer and esophageal cancer treatments.

Panax ginseng polysaccharide suppresses metastasis via modulating Twist expression in gastric cancer

It was previously reported that an antitumor polysaccharide (PGPW1) was isolated from the root of Panax ginseng. To extend our study, we investigated here the anti-invasive and metastatic effects of PGPW1 on human gastric cancer cell line HGC-27 and tried to determine its possible mechanism of action. Both scratch wound-healing and Transwell assay identified that PGPW1 dose-dependently inhibited migration and invasiveness of HGC-27 cells. Furthermore, results of western blot showed that protein levels of Twist and AKR1C2 were inhibited by PGPW1, whereas an increase of NF1 was observed. Moreover, down-regulation of Twist expression by PGPW1 blocked epithelial-mesenchymal transition (EMT), characterized by a gain of epithelial cell markers, E-cadherin, and loss of the mesenchymal markers, vimentin and N-cadherin, at protein levels. Collectively, we confirmed that PGPW1 decreased migration and invasion of HGC-27 cells by regulation of Twist, AKR1C2, NF1, E-cadherin, vimentin and N-cadherin expression. In conclusion, PGPW1 may serve as a powerful chemopreventive agent against gastric cancer metastasis.

MGC29506 induces cell cycle arrest and is downregulated in gastric cancer

The proapoptotic caspase adaptor protein (PACAP) is involved in cell-cycle regulation and promotes apoptosis. Both MGC29506 and PACAP are isoforms of the MGC29506 gene and are generated by differential splicing of the alternative splice-acceptor. In studying PACAP, we inadvertently constructed the eukaryotic expression vector MGC29506. At present, the function of the MGC29506 gene is largely unknown with the key exception of information obtained by bioinformatics. We studied the role of MGC29506 in gastric cancer cell proliferation, the cell cycle and apoptosis. In addition, we studied MGC29506 expression in gastric cancer patients and explored its significance. We found that the expression of MGC29506 in gastric cancer samples was lower than in samples from adjacent non-tumor tissues. We found that the MGC29506 protein was localized in the cell nucleus of AGS cells and inhibited their proliferation. Higher percentages of G0/G1 and S phase cells were induced by transfection with the MGC29506 gene than were induced by transfection with the negative control. We showed that cells transfected with MGC29506 were arrested at the G0/G1 and S phases of the cell cycle. However, we found no significant increases in apoptosis of cells transfected with MGC29506 compared with cells transfected with the negative control. Our results suggested that MGC29506 has the potential of functioning as a novel suppressor gene in gastric cancer. Downregulation of MGC29506 may also promote the progression of gastric cancer.

Cell cycle arrest and cell apoptosis induced by Equisetum hyemale extract in murine leukemia L1210 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Equisetum hyemale has been used as a traditional herbal medicine to treat various diseases such as hypertension, inflammatory diseases, acute stroke, bleeding and cancer. The present study aimed to investigate the anti-proliferative effect and the underlying mechanisms of E.hyemale extract on murine leukemia L1210 cells.

MATERIALS AND METHODS

The inhibitory effect of Ehyemale extract on L1210cells was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cell cycle distribution was evaluated with flow cytometry following PI (propidium iodide) staining. Apoptotic cell death was determined by Annexin V-FITC/PI and nuclear DAPI (4'-6-diamidino-2-phenylindole) staining. DNA damage and changes of mitochondrial membrane potential were also detected with flow cytometry analysis.

RESULTS

E.hyemale extract exerted significant antiproliferative effects on L1210 cells in a dose- and time-dependent manner. Flow cytometry analysis showed that E.hyemale extract induced cell cycle arrest at G2/M phase in L1210 cells. Phosphatidylserine exposure, chromatin condensation, DNA damage and loss of mitochondrial membrane potential were observed clearly after treatment with Ehyemale extract.

CONCLUSION

The results in this study indicate that E.hyemale extract could inhibit L1210 cell proliferation through inducing G2/M arrest and cell apoptosis.

A novel chenodeoxycholic acid-verticinone ester induces apoptosis and cell cycle arrest in HepG2 cells

In this study, the in vitro antitumor activity of chenodeoxycholic acid-verticinone ester (CDCA-Ver), a novel compound and its underlying mechanisms were evaluated. Results showed that CDCA-Ver significantly inhibited HepG2 cell viability in a both dose- and time-dependent manner, moreover CDCA-Ver induced apoptotic cell death and G(0)/G(1) cell cycle arrest in HepG2 cells. ROS generation, loss of balance of Bax/Bcl-2 ratio, loss of mitochondrial transmembrane potential, activation of caspases and elevation of intracellular free Ca(2+) concentration were involved in the CDCA-Ver induced apoptosis pathway in HepG2 cells. We concluded that CDCA-Ver may be a potential candidate for the therapy of cancer.

Anticancer potential of aqueous extract of alocasia macrorrhiza against hepatic cancer in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Alocasia macrorrhiza has been used as a folk medicine for cancer treatment in the Southwest of China.

AIM OF THE STUDY

The purpose of this study is to confirm the anticancer activity of aqueous extract of alocasia macrorrhiza against hepatic cancer and to elucidate its mechanism of action.

MATERIALS AND METHODS

Human normal liver cells and hepatocellular carcinoma cells were tested in vitro for cytotoxicity, colony formation inhibition, EdU incorporation, AO/EB staining apoptotic cells, apoptotic DNA fragmentation, and cell cycle distribution in response to alocasia macrorrhiza extract. The mRNA and protein expressions of PPARγ, Cyclin D1, Rb, P21, Bax, Bcl-2 and caspase-3 were detected through RT-PCR and Western blotting; the tumor growth inhibition in vivo was tested by oral administration of the extract.

RESULTS

Alocasia macrorrhiza aqueous extract exhibited proliferation inhibition and apoptosis effects on human hepatocellular carcinoma cells in vitro, inhibited hepatoma growth in vivo.

CONCLUSION

Alocasia macrorrhiza extract has potential cytotoxic and apoptotic effect on human hepatocellular carcinoma cells and inhibits hepatoma growth in vivo, its mechanism of action might be associated with the inhibition of DNA synthesis, cell cycle (G(0)/G(1)) arrest, apoptosis induction through up-regulation the mRNA and protein expressions of PPARγ, Rb, Bax and capase-3genes and down-regulation of the expressions of Cyclin D1 and Bcl-2 genes.