Matrine inhibits proliferation and induces apoptosis via BID-mediated mitochondrial pathway in esophageal cancer cells

Matrine, as a member of Sophora family, is an alkaloid found in plants, and produces plethora pharmacological effects, including anti-cancer effects. However, the mechanism involved remains largely unknown. This study is conducted to investigate the anti-cancer mechanisms of matrine in human esophageal cancer in vitro and in vivo. In human esophageal cancer cell Eca-109, matrine significantly decreased the cell viability in a dose-dependent manner, and induced apoptosis as well as cell cycle arrest in G0/G1 phase by up-regulation of P53 and P21. The expression of several apoptosis-related proteins in cells and tumor tissues were evaluated by Western blot analysis. We found that matrine induced cell apoptosis by down-regulation of the ratio of BCL-2/BID and increasing activation of caspase-9. Further studies indicated that matrine induced apoptosis of Eca-109 was through the mitochondria-mediated internal pathway, but not by death receptor-mediated extrinsic apoptotic pathway, which was confirmed by the fact that Bid translocated from the nucleus to mitochondria during the process of the apoptosis induced by matrine. In vivo study found that matrine effectively inhibited the tumor formation of Eca-109 cells in nude mice. Our study suggests that matrine could serve as a potential novel agent from natural products to treat esophageal cancer.     

PI3K/Akt pathway involving into apoptosis and invasion in human colon cancer cells LoVo

In this study we determined the effects of Curcumin on human colon cancer cells line LoVo. We found that Curcumin significantly inhibited the proliferation, migration and invasion, and clone formation of LoVo cells in a dose-dependent manner. Curcumin also dose-dependently reduced the phosphorylation of proteins Akt and increased expression levels of the genes caspase-3, cytochrome-c, Bax mRNA in LoVo cells. In addition, Curcumin dose-dependently decreased gene Bcl-2 mRNA expression. Similar results were observed in LoVo cells treated with LY294002. These in vitro studies suggest that Curcumin may play its anti-cancer actions partly via suppressing PI3K/Akt signal pathway in LoVo cells.     

Leflunomide inhibits PDK1/Akt pathway and induces apoptosis of human mast cells

Mast cells release many inflammatory mediators that play an important role not only in allergic diseases but also in chronic inflammatory diseases, autoimmune diseases, and others. A lot of mast cells exist in synovium of rheumatoid arthritis, and it is known that synovitis does not occur in mast cell-deficient mice. Thus, it is thought that mast cells play a very important role in rheumatoid arthritis pathogenesis. Leflunomide is a drug used clinically in the treatment of rheumatoid arthritis. We used clinical doses of 2-cyano-3-hydroxy-N-(4-trifluoromethylphenyl)-butenamide (A77 1726), which is an active metabolite of leflunomide, and decreased the number of viable human primary mast cells in a concentration-dependent manner. This decrease was not reversed by uridine. Inhibition of pyrimidine synthesis by dihydro-orotic acid dehydrogenase inhibition, which is the primary mechanism of action of A77 1726, was not involved. A77 1726 dramatically induced apoptosis of human mast cells and inhibited the phosphorylation of Akt, an important survival signal of mast cells, in a concentration-dependent manner. Caspases 3 and 9, downstream molecules of Akt survival pathway, were also fragmented by A77 1726. In addition, it became evident for the first time that the mechanism involved in this result was the concentration-dependent inhibition of PDK1 phosphorylation, which controls the activation of Akt. These results indicate a new way of controlling mast cells and may therefore be the basis for innovative approaches to the treatment of various diseases related to mast cells.     

Plumbagin inhibits proliferation and promotes apoptosis of ovarian granulosa cells in polycystic ovary syndrome by inactivating PI3K/Akt/mTOR pathway

ABSTRACT

Polycystic ovary syndrome (PCOS) is recognized as a general endocrine disease and reproductive disorder. Although evidence indicates that PCOS has a complex etiology and genetic basis, the pathogenic mechanisms and signal pathway in PCOS remain unclear. In this study, the normal structure of follicle and corpus luteum were observed, and no cyst nor hyperemia was observed under the light microscopic study with hematoxylin and eosin (H&E) staining. Eestosterone and progesterone were evaluated by radioimmunoassay in rat serum. The alterations of proliferative ability and cell cycle distribution of each group were assessed by Cell Counting Kit-8 (CCK8) assay and flow cytometry. The protein expression of p-mTOR/mTOR, p-PI3K/PI3K, p-AKT/AKT, and GAPDH were analyzed by western blotting. Both doses of PLB could benefit the ovarian morphology and polycystic property. PLBinduced a suppress effect on the proliferation of rat ovarian granulosa cells. In addition, PLB also induced concentration-dependent apoptosis in rat ovarian granulosa cells. The rat ovarian granulosa cells treated with PLB that the expression levels of p-AKT, p-mTOR, and p-PI3K were significantly decreased in a concentration-dependent manner. PLB not only plays a critical role in attenuating the pathology and polycystic property changes in the ovary but can also induce rat ovarian granulosa cell apoptosis through the PI3K/Akt/mTOR signal pathway. This study showed the innovative role of PLB in the pathogenesis of PCOS and provides a new therapeutic modality for the treatment of PCOS.     

MicroRNA-1284 inhibits proliferation and induces apoptosis in SGC-7901 human gastric cancer cells

Objectives

To explore the functional effects of miR-1284 on gastric cancer cells.

Results

Overexpression of miR-1284 significantly reduced SGC-7901 cell proliferation, but improved apoptosis. However, miR-1284 suppression displayed the inversed impacts. Furthermore, the protein levels of p27, Bax, procaspase-3 and active caspase-3 were up-regulated by miR-1284 overexpression, but were down-regulated by miR-1284 suppression. The level of Bcl-2 was down-regulated by miR-1284 overexpression, while it was up-regulated by miR-1284 suppression. The level of p21 was unaffected.

Conclusion

These results suggest that miR-1284 overexpression might be a suppressor for gastric cancer via controlling of cell proliferation and apoptosis.

     

Melissa officinalis extract induces apoptosis and inhibits proliferation in colon cancer cells through formation of reactive oxygen species

PurposeEfficient strategies for the prevention of colon cancer are extensively being explored, including dietary intervention and the development of novel phytopharmaceuticals. Safe extracts of edible plants contain structurally diverse molecules that can effectively interfere with multi-factorial diseases such as colon cancer. In this study, we describe the antiproliferative and proapoptotic effects of ethanolic lemon balm (Melissa officinalis) leaves extract in human colon carcinoma cells. We further investigated the role of extra- and intracellular reactive oxygen species (ROS).MethodsAntitumor effects of lemon balm extract (LBE) were investigated in HT-29 and T84 human colon carcinoma cells. Inhibition of proliferation was analyzed by DNA quantification. The causal cell cycle arrest was determined by flow cytometry of propidium iodide-stained cells and by immunoblotting of cell cycle regulator proteins. To investigate apoptosis, cleavage of caspases 3 and 7 was detected by immunoblotting and fluorescence microscopy. Phosphatidylserine externalization was measured by Annexin V assays. Mechanistic insights were gained by measurement of ROS using the indicator dyes CM-H₂DCFDA and Cell ROX Green.ResultsAfter 3 and 4 days of treatment, LBE inhibited the proliferation of HT-29 and T84 colon carcinoma cells with an inhibitory concentration (IC₅₀) of 346 and 120 µg/ml, respectively. Antiproliferative effects were associated with a G2/M cell cycle arrest and reduced protein expression of cyclin dependent kinases (CDK) 2, 4, 6, cyclin D3, and induced expression of cyclin-dependent kinase inhibitor 2C (p18) and 1A (p21). LBE (600 µg/ml) induced cleavage of caspases 3 and 7 and phosphatidylserine externalization. LBE-induced apoptosis was further associated with formation of ROS, whereas quenching of ROS by antioxidants completely rescued the colon carcinoma cells from LBE-induced apoptosis.ConclusionsLemon balm (Melissa officinalis) extract inhibits the proliferation of colon carcinoma cells and induces apoptosis through formation of ROS. Taken together, LBE or subfractions thereof could be used for the prevention of colon cancer.     

Erianin induces triple-negative breast cancer cells apoptosis by activating PI3K/Akt pathway

Background: Triple-negative breast cancer (TNBC) is a refractory subtype of breast cancer, 25–30% of which have dysregulation in the PI3K/AKT pathway. The present study investigated the anticancer effect of erianin on TNBC cell line and its underlying mechanism.Methods: After treatment with erianin, MTT assay was employed to determine the MDA-MB-231 and EFM-192A cell proliferation, the nucleus morphological changes were observed by DAPI staining. The cell cycle and apoptotic proportion were detected by flow cytometry. Western blot was performed to determine the cell cycle and apoptosis-related protein expression and PI3K pathways. Finally, the antiproliferative activity of erianin was further confirmed by adding or not adding PI3K agonists SC79.Results: Erianin inhibited the proliferation of MDA-MB-231 and EFM-192A cells in a dose-dependent manner, the IC₅₀ were 70.96 and 78.58 nM, respectively. Erianin could cause cell cycle arrest at the G₂/M phase, and the expressions of p21 and p27 were up-regulated, while the expressions of CDK1 and Cyclin B1 were down-regulated. Erianin also induced apoptosis via the mitochondrial pathway, with the up-regulation of the expression of Cyto C, PARP, Bax, active form of Caspase-3, and Caspase-9. Furthermore, p-PI3K and p-Akt expression were down-regulated by erianin. After co-incubation with SC79, the cell inhibition rate of erianin was decreased, which further confirmed that the attenuated PI3K/Akt pathway was relevant to the pro-apoptotic effect of erianin.Conclusions: Erianin can inhibit the proliferation of TNBC cells and induce cell cycle arrest and apoptosis, which may ascribe to the abolish the activation of the PI3K/Akt pathway.     

Dehydrocostus lactone inhibits cell proliferation and induces apoptosis by PI3K/Akt/Bad and ERS signalling pathway in human laryngeal carcinoma

The anti-cancer effect of dehydrocostus lactone (DHL) derived from Saussurea costus (Falc.) Lipech against laryngeal carcinoma was assessed. The cytotoxic activity of DHL against laryngeal carcinoma is still obscure. Therefore, our study investigated the role of DHL in the growth inhibition of laryngeal carcinoma in vitro and in vivo, and the molecular mechanism of DHL-induced apoptosis in cancer cells of the larynx. The results showed that DHL inhibits the viability, migration and proliferation of Hep-2 and TU212 cells with little toxic effects on human normal larynx epithelial HBE cell line. Flow cytometry analysis (FAC) analysis and staining assay (Hoechst 33258) indicated that DHL stimulated Hep-2 and TU212 cell apoptosis in a dose-dependent manner. Mechanistically, DHL is capable of inhibiting Hep-2 and TU212 cell viability via promoting p53 and P21 function, meanwhile DHL dose-dependently induces Hep-2 and TU212 cells apoptosis via activating mitochondrial apoptosis by inhibiting PI3K/Akt/Bad pathway and stimulating endoplasmic reticulum stress-mediated apoptosis pathway. In vivo, DHL inhibited the growth of the Hep-2 nude mouse xenograft model and observed no significant signs of toxicity in the organs of nude mice. In vivo experiments further confirmed the anti-cancer effect of DHL on laryngeal carcinoma cells in vitro, and DHL-treated nude mice can reduce the volume of tumours. Together, our study indicated that DHL has the potential to inhibit human laryngeal carcinoma via activating mitochondrial apoptosis pathway by inhibiting PI3K/Akt/Bad signalling pathway and stimulating endoplasmic reticulum stress-mediated apoptosis pathway, providing a strategy for the treatment of human laryngeal carcinoma.     

Dictyopteris undulata extract induces apoptosis in human colon cancer cells

The present study investigated the cytotoxic and apoptotic effects of an ethanol extract derived from the marine brown alga Dictyopteris undulata against human colon adenocarcinoma cells. The Dictyopteris undulata extract (DUE) showed cytotoxic activity against SW480 cells in a dose-dependent manner, with 50% inhibition of cell viability at a concentration of 40 μg/mL. DUE also induced programmed cell death in SW480 cells, as evidenced by apoptotic body formation, DNA fragmentation, an increase in the population of apoptotic sub-G1 phase cells, and mitochondrial membrane depolarization. Moreover, DUE significantly modulated the expression of apoptosisassociated proteins, resulting in a decrease in B cell lymphoma-2 expression and an increase in Bcl-2-associated X protein expression, as well as the activation of caspase-9 and caspase-3. Furthermore, DUE showed apoptotic cell death in two other colon cancer cell lines, SNU407 and HT29. These observations suggest that DUE may prove useful as a therapeutic agent for the attenuation of colon cancer.     

Dauricine induces apoptosis,inhibits proliferation and invasion through inhibiting NF‐κB signaling pathway in colon cancer cells

Dauricine, a bioactive component of Asiatic Moonseed Rhizome, has been widely used to treat a large number of inflammatory diseases in traditional Chinese medicine. In our study, we demonstrated that dauricine inhibited colon cancer cell proliferation and invasion, and induced apoptosis by suppressing nuclear factor‐kappaB (NF‐κB) activation in a dose‐ and time‐dependent manner. Addition of dauricine inhibited the phosphorylation and degradation of IκBα, and the phosphorylation and translocation of p65. Moreover, dauricine down‐regulated the expression of various NF‐κB‐regulated genes, including genes involved cell proliferation (cyclinD1, COX2, and c‐Myc), anti‐apoptosis (survivin, Bcl‐2, XIAP, and IAP1), invasion (MMP‐9 and ICAM‐1), and angiogenesis (VEGF). In athymic nu/nu mouse model, we further demonstrated that dauricine significantly suppressed colonic tumor growth. Taken together, our results demonstrated that dauricine inhibited colon cancer cell proliferation, invasion, and induced cell apoptosis by suppressing NF‐κB activity and the expression profile of its downstream genes. These findings provide evidence for a novel role of dauricine in preventing or treating colon cancer through modulation of NF‐κB singling pathway. J. Cell. Physiol. 225: 266–275, 2010. © 2010 Wiley‐Liss, Inc.     

Shikonin inhibits the proliferation and induces the apoptosis of human HepG2 cells

This study investigated the potential of shikonin as an anticancer agent against liver cancer and an in vitro human hepatoma cancer model system. The HepG2 cell line was the hepatoma cancer model in the present study. The inhibitory effect of shikonin on the growth of HepG2 cells was measured by MTT assay. To explore the underlying mechanism of cell growth inhibition of shikonin, the cell cycle distribution, DNA fragmentation, mitochondrial membrane potential (ΔΨm) disruption, and expression of Bax and Bcl-2 were measured in HepG2 cells. The activity of shikonin in inducing apoptosis was investigated through the detection of Annexin V signal and CD95 expression by flow cytometry and electron microscopy, respectively. Shikonin inhibited the growth of HepG2 cells in a dose-dependent manner. The IC50 value (inhibiting cell growth by 50%) was 4.30 mg/mL. Shikonin inhibited cell growth in a dose-dependent manner and blocked HepG2 cell cycle progression at the S phase. The changes in mitochondrial morphology, dose-dependently decreased in ΔΨm, were observed in different concentrations of the drug treatment group. Western blot analysis showed that cajanol inhibited Bcl-2 expression and induced Bax expression. Furthermore, we show that shikonin increases Annexin V signal and CD95 (Fas/APO) expression, resulting in apoptotic cell death of HepG2 cells. In addition, lump formation of intranuclear chromatin, pyknosis of cell nucleus, deletion of microvillus, vacuolar degeneration of mitochondria, reduction of rough endoplasmic reticulum, and resolution of free ribosome, etc., associated with apoptosis were discovered by electron microscopy in HepG2 cells after 48 h treatment. Shikonin inhibited HepG2 cells, possibly through the pathway of inducing early apoptosis, and was beneficial for restoring the apoptotic sensitivity of HepG2 cells by CD95, and should therefore be considered as a candidate agent for the prevention or treatment of human hepatoma.     

Knockdown of Rab21 inhibits proliferation and induces apoptosis in human glioma cells

Background

Gliomas are commonly malignant tumors that arise in the human central nervous system and have a low overall five-year survival rate. Previous studies reported that several members of Rab GTPase family are involved in the development of glioma, and abnormal expression of Rab small GTPases is known to cause aberrant tumor cell behavior. In this study, we characterized the roles of Rab21 (Rab GTPase 21), a member of Rab GTPase family, in glioma cells.

Methods

The study involved downregulation of Rab21 in two glioma cell lines (T98G and U87) through transfection with specific-siRNA. Experiments using the MTT assay, cell cycle analysis, apoptosis assay, real-time PCR and western blot were performed to establish the expression levels of related genes.

Results

The results show that downregulation of Rab21 can significantly inhibit cell growth and remarkably induce cell apoptosis in T98G and U87 cell lines. Silencing Rab21 resulted in significantly increased expression of apoptosis-related proteins (caspase7, Bim and Bax) in glioma cells.

Conclusions

We inferred that Rab21 silencing can induce apoptosis and inhibit proliferation in human glioma cells, indicating that Rab21 might act as an oncogene and serve as a novel target for glioma therapy.

     

Canstatin inhibits Akt activation and induces Fas-dependent apoptosis in endothelial cells

Canstatin, a 24-kDa peptide derived from the C-terminal globular non-collagenous (NC1) domain of the alpha2 chain of type IV collagen, was previously shown to induce apoptosis in cultured endothelial cells and to inhibit angiogenesis in vitro and in vivo. In this report, we demonstrate that canstatin inhibits the phosphorylation of Akt, focal adhesion kinase, mammalian target of rapamycin, eukaryotic initiation factor-4E-binding protein-1, and ribosomal S6 kinase in cultured human umbilical vein endothelial cells. It also induces Fas ligand expression, activates procaspases 8 and 9 cleavage, reduces mitochondrial membrane potential, and increases cell death (as determined by propidium iodide staining). Canstatin-induced activation of procaspases 8 and 9 as well as the induced reduction in mitochondrial membrane potential and cell viability were attenuated by the forced expression of FLICE-inhibitory protein. Canstatin-induced procaspase 8 activation and cell death were also inhibited by a neutralizing anti-Fas antibody. Collectively, these data indicate that canstatin-induced apoptosis is associated with phosphatidylinositol 3-kinase/Akt inhibition and is dependent upon signaling events transduced through membrane death receptors.     

LncRNA POU3F3 promotes proliferation and inhibits apoptosis of cancer cells in triple-negative breast cancer by inactivating caspase 9

It has been reported that lncRNA POU3F3 was upregulated in esophageal squamous-cell carcinomas, indicating its role as an oncogene in this disease. However, the mechanism of its function and its involvement in other malignancies is unknown. In the present study we found that expression levels of lncRNA POU3F3 were higher in tumor tissues than in adjacent healthy tissues of triple negative breast cancer (TNBC) patients and were significantly and inversely correlated with levels of cleaved caspase 9 only in tumor tissues. In addition, plasma levels of lncRNA POU3F3 were higher in TNBC patients than in healthy controls and were significantly and inversely correlated with levels of cleaved caspase 9 only in TNBC patients. In addition, treatment of exogenous Cleaved Caspase-9 significantly attenuated the effects of lncRNA POU3F3 overexpression on cancer cell proliferation and apoptosis. lncRNA POU3F3 may promote proliferation and inhibit apoptosis of cancer cells in triple-negative breast cancer.     

Matrine inhibits the growth of retinoblastoma cells (SO-Rb50) by decreasing proliferation and inducing apoptosis in a mitochondrial pathway

Matrine, one of the main active components of extracts from the dry roots of Sophora flavescens, has potent anti-tumor activity in vitro and in vivo. Here, we investigated the apoptosis in matrine-treated retinoblastoma cells. The results showed that matrine could inhibit cell proliferation and induce apoptosis in a dose- and time-dependent manner. Further investigation revealed that a disruption of mitochondrial transmembrane potential and an up-regulation of reactive oxygen species in matrine-treated cells. By western blot analysis, we found that the up-regulation of cleaved Apaf-1, cleaved caspase-3, cleaved caspase-9, cleaved caspase-7, Bax/Bcl-2, varying with different concentration of matrine. These protein interactions may play a pivotal role in the regulation of apoptosis. Taken together, these results overall indicate that matrine could be used as an effective anti-tumor agent in therapy of retinoblastoma targets the caspase-dependent signaling pathway.