ABSTRACT
Oridonin (ORI) has been reported as an antiproliferation and apoptosis-inducing natural product in various cancer cells. However, the exact molecular mechanism underlying these effects remains unclear. In the present study, we demonstrated the antiproliferation effect of ORI in HCT116 cells, and analyzed the possible molecular mechanism which mediates this effect. We found that ORI inhibits proliferation, induces cell cycle arrest and apoptosis in HCT116 cells, thus also tumor growth. Mechanically, we found that ORI has no substantial effect on mRNA expression of phosphatase and tensin homologue (PTEN), but increases the total protein level of PTEN and markedly reduces the phosphorylation of PTEN; Exogenous expression of PTEN potentiates the anticancer effect of ORI, while knockdown of PTEN attenuates it. ORI also increases the phosphorylation of p38 MAPK, and p38 MAPK-specific inhibitor reduces the antiproliferation effect ORI in HCT116 cells. Moreover, inhibition of p38 MAPK increases the phosphorylation of PTEN, and reverses ORI-induced decrease of PTEN phosphorylation. Our findings suggested that ORI may be a potential anticancer drug for colon cancer, this effect may be mediated by enhancing the function of PTEN through reducing its phosphorylation, which may be resulted from the ORI-induced activation of p38 MAPK.
Subject(s)
Colonic Neoplasms/drug therapy , Diterpenes, Kaurane/pharmacology , PTEN Phosphohydrolase/physiology , p38 Mitogen-Activated Protein Kinases/physiology , Animals , Apoptosis/drug effects , Cell Proliferation/drug effects , Colonic Neoplasms/pathology , Female , HCT116 Cells , Humans , MiceABSTRACT
Oridonin (ORI), a diterpenoid purified from Rabdosia rubescens, has been reported as a promising chemotherapy drug for colon cancer treatment; yet, the precise mechanisms underlying this anticancer activity remain unclear. In the present study, we investigated the anticancer effect of ORI in HCT116 cells, and dissected the possible molecular mechanisms underlying this activity. With crystal violet staining, flow cytometry and western blot assay, we found that ORI effectively inhibited the proliferation and induced the apoptosis of HCT116 cells. Further analysis of the results indicated that BMP7 was greatly upregulated by ORI in the HCT116 cells, but its endogenous expression in FHC cells was apparently lower than that in the colon cancer cell lines. Exogenous expression of BMP7 inhibited the proliferation of the HCT116 cells, and substantially potentiated the anticancer effect of ORI. However, the specific antibody of BMP7 nearly abolished this anticancer activity of ORI in the HCT116 cells. Meanwhile, ORI exerted no significant effect on the level of phosphorylated Smad1/5/8 or total p38 MAPK, but greatly increased the level of phosphorylated p38 MAPK in the HCT116 cells. A p38 MAPK-specific inhibitor partly reversed the antiproliferative effect of BMP7 in the HCT116 cells, but prominently promoted the effect of the BMP7 antibody on proliferation. Exogenous expression of BMP7 increased the ORI-induced phosphorylation of p38 MAPK, while the BMP7 antibody almost abolished the ORI-elevated p38 MAPK phosphorylation. Our findings suggest that ORI may be an efficacious drug for colon cancer treatment. This anticancer activity of ORI may be mediated by upregulating BMP7 at least to increase the activation of p38 MAPK.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Bone Morphogenetic Protein 7/metabolism , Cell Proliferation/drug effects , Diterpenes, Kaurane/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism , Apoptosis/drug effects , Bone Morphogenetic Protein 7/genetics , Colonic Neoplasms/drug therapy , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Drug Screening Assays, Antitumor , Gene Expression , HCT116 Cells , Humans , MAP Kinase Signaling System , Up-RegulationABSTRACT
Colon cancer is one of the most common malignancies of the digestive system. Although more effective therapeutic strategies have been developed in the last decades, there is still a great clinical need to explore new treatment regimens for colon cancer due to the undesirable prognosis. In the present study, we investigated the anticancer activity of resveratrol (Res) in human colon cancer cells, and the possible mechanism underlying this effect. We employed crystal violet staining, flow cytometry and western blotting to test the antiproliferation- and apoptosis-inducing effects of Res in LoVo cells. A xenograft tumor model was also introduced to confirm the in vivo anticancer effect of Res. Using PCR, western blotting, a recombinant adenovirus and a specific inhibitor of p38 MAPK or bone morphogenetic protein receptor (BMPR) to explore the possible molecular mechanisms. We found that Res markedly inhibited the proliferation and promoted the apoptosis of LoVo cells, and suppressed the in vivo tumor growth of colon cancer. Res substantially upregulated the expression of bone morphogenetic protein 9 (BMP9). Exogenous expression of BMP9 enhanced the anticancer effect of Res in LoVo cells, while BMP9 knockdown partly reduced this activity. Res increased the activation of p38 MAPK, which was enhanced by the exogenous expression of BMP9. The anticancer activity of Res, or Res combined with BMP9, was reduced partly by the p38 MAPK inhibitor. The BMPR inhibitor almost abolished the Res-induced activation of p38 MAPK, and attenuated the antiproliferative effect of Res in the LoVo cells. Our findings strongly suggest that the anticancer effect of Res in human colon cancer cells may be partly mediated by upregulation of BMP9 to activate p38 MAPK in a BMPR-dependent manner.
Subject(s)
Antineoplastic Agents/pharmacology , Colonic Neoplasms/pathology , Growth Differentiation Factors/metabolism , Stilbenes/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , Apoptosis/drug effects , Blotting, Western , Cell Line, Tumor , Cell Proliferation/drug effects , Flow Cytometry , Growth Differentiation Factor 2 , Humans , Immunohistochemistry , Mice , Mice, Nude , Resveratrol , Reverse Transcriptase Polymerase Chain Reaction , Xenograft Model Antitumor AssaysABSTRACT
Colon cancer is one of the most common malignancies. Although the current treatment regimes for colon cancer have been well-developed in the past decades, the prognosis remains still undesirable. It is still urgent to explore new treatment strategies for colon cancer. Natural products is one of the most useful sources for anticancer agents, although some of them have serious side-effects. Evodiamine (Evo) is an quinolone alkaloid from the traditional herb medicine Evodia rutaecarpa. In the present study, we investigated the anticancer effect of Evo in human colon cancer cells. We found that Evo exhibits prominent antiproliferation and apoptosis inducing effects in LoVo cells. Evo leads to apparent downregulation of HIF-1α either in vitro or in vivo; exogenous expression of HIF-1α can attenuate the antiproliferation effect of Evo in LoVo cells, while HIF-1α knockdown potentiates this effect greatly. Further analysis indicated that Evo can also inhibit the phosphorylation of Akt1/2/3 and decrease greatly the expression of IGF-1. Thus, our findings strongly suggested that the anticancer effect of Evo in human colon cancer may be partly mediated by downregulating HIF-1α expression, which is initiated by inactivating PI3K/Akt signaling transduction though decreasing the expression of IGF-1 in colon cancer cells. Therefore, Evo may be used alone or in combination as a potential anticancer agent for colon cancer treatment.
Subject(s)
Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/biosynthesis , Insulin-Like Growth Factor I/biosynthesis , Quinazolines/administration & dosage , Antineoplastic Agents, Phytogenic/administration & dosage , Cell Line, Tumor , Cell Proliferation/drug effects , Colonic Neoplasms/pathology , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Insulin-Like Growth Factor I/genetics , Phosphatidylinositol 3-Kinases/genetics , Proto-Oncogene Proteins c-akt/genetics , Signal Transduction/drug effectsABSTRACT
Colon cancer is one of the most common malignancies, causes considerable morbidity and mortality. The current treatment for colon cancer is more modest than had been hoped. There is an urgent clinical need to explore new agents or adjuvants for colon cancer treatment. Natural products and their derivates act as one of the major source for anticancer agent. In the present study, we investigated the anti-proliferation and chemoprevention effects of tetrandrine (Tet) on colon cancer cells to uncover the possible molecular basis of this effect. We found that Tet can inhibit proliferation and induce apoptosis in LoVo cells. With dimethylhydrazine (DMH) and dextran sodium sulfate (DSS) induced colon cancer model, we found that Tet can prevent or inhibit DMH plus DSS induced aberrant crypt foci (ACF) and colon cancer formation, as well as suppress tumor growth in the xenograft colon cancer model. Tet can downregulate the expression of IGFBP-5 in LoVo cells. Exogenous expression of IGFBP-5 can attenuate the anti-cancer activity of Tet, while IGFBP-5 knockdown potentiates this effect of Tet on LoVo cells. Tet can inhibit Wnt/ß-catenin signaling transduction, which can be partly reversed by exogenous expression of IGFBP-5, but is enhanced by IGFBP-5 knockdown. Our results demonstrated that the anticancer activity of Tet in colon cancer cells may be mediated partly by downregulating the expression of IGFBP-5, thus inactivating Wnt/ß-catenin signaling transduction.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Benzylisoquinolines/pharmacology , Cell Proliferation/drug effects , Colonic Neoplasms/pathology , Insulin-Like Growth Factor Binding Protein 5/physiology , Animals , Cell Proliferation/genetics , Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , Female , Humans , Insulin-Like Growth Factor Binding Protein 5/antagonists & inhibitors , Male , Mice , Mice, Nude , RNA, Small Interfering/pharmacology , Rats , Rats, Sprague-Dawley , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Mouse embryonic fibroblasts (MEFs) are multi-potent progenitor cells (MPCs), can differentiate into different lineages, such as osteogenic, and adipogenic. PTEN, a tumor suppressor, may be involved in regulating bone development through interacting with COX-2. BMP9, the most potent osteogenic BMPs, can up-regulate COX-2 in MPCs. Whether PTEN is involved in BMP9 induced osteogenic differentiation in MPCs remains unknown. The goal of this investigation is to identify the effect of PTEN on BMP9-induced osteogenic differentiation in MPCs and dissect the possible mechanism underlay this. We found that BMP9 down-regulates PTEN, and PTEN inhibitor (VO) effectively increases different osteogenic markers induced by BMP9 in MEFs. Exogenous expression of PTEN inhibits BMP9 induced ectopic bone formation apparently. Mechanistically, we found that VO can enhance BMP9 induced BMPs/Smads signaling prominently without no substantial effects on cell cycle. Further analysis indicates that VO can promote BMP9-induced expression of COX-2 in MEFs, which can be eliminated by PI3K inhibitor. Additionally, COX-2 knockdown abolishes the effect of VO on BMP9-induced ALP activities in MEFs. Our findings suggest that PTEN plays an important role in regulating BMP9 induced osteogenic differentiation in MPCs, which may be mediated by PTEN/PI3K/Akt signaling to modulate the expression of COX-2.
