[Corrigendum] All-trans retinoic acid restored the osteogenic ability of BMP9 in osteosarcoma through the p38 MAPK pathway.

Subsequently to the publication of the above paper, the authors have realized that the images presented in Fig. 1A were selected erroneously (essentially, the images for group 'AdBMP9 +++' were chosen to represent the group 'AdGFP'). A corrected version of Fig. 1, including the correct data for the experiments depicted in Fig. 1A, is shown opposite. Note that this change does not affect the results or the conclusions reported in this paper, and all the authors agree to this correction. The authors apologize to the Editor and to the readership of the Journal for any inconvenience caused. [the original article was published in International Journal of Oncology 50: 1363­1371, 2017; DOI: 10.3892/ijo.2017.3910].

Resveratrol inactivates PI3K/Akt signaling through upregulating BMP7 in human colon cancer cells.

Colon cancer is common worldwide and accounts for the significant cancer related morbidity and mortality in patients. Although extensive advancement has been made in colon cancer treatment and diagnosis in the last decades, there is still a giant gap between the clinical expectation. It has been reported that resveratrol (Res) may be a potential candidate for cancer treatment. However, the specific mechanism underlying this activity remains unclear. In this study, we investigated the anticancer activity of Res in human colon cancer cells, and unveiled the possible mechanism for this effect. With cell viability, flow cytometry, PCR and western blot analysis, we demonstrated the efficacious anticancer activity of Res in HCT116 cells. Mechanically, we found that Res greatly upregulates BMP7 in HCT116 cells. Exogenous BMP7 enhances the anticancer effect of Res in HCT116 cells, which was almost reversed by the BMP7 specific antibody. Res does not activate the BMPs/Smads signaling, but decreases the phosphorylation of Akt1/2/3 substantially in HCT116 cells. Exogenous BMP7 enhances the inhibitory effect of Res on the phosphorylation of Akt1/2/3, while BMP7 immunodepletion reverses this effect notably. Res markedly decreases the phosphorylation of PTEN, which can be enhanced by exogenous BMP7 but partly reversed by the BMP7 antibody. Our findings suggested that Res may be a promising candidate for colon cancer treatment, and the anticancer activity may be mediated by inactivating PI3K/Akt signaling through upregulating BMP7 to decrease, at least, the phosphorylation of PTEN.

All-trans retinoic acid restored the osteogenic ability of BMP9 in osteosarcoma through the p38 MAPK pathway Corrigendum in /10.3892/ijo.2019.4817.

Osteosarcoma (OS) is the most common malignant bone tumour and is considered to be a disease caused by a dysfunction in differentiation. Bone morphogenetic protein 9 (BMP9) is the most potent osteogenic factor in mesenchymal stem cells, but it cannot induce osteogenic differentiation in OS cells; this might be one of the determinants in the pathogenesis of OS. All-trans retinoic acid (ATRA) can induce osteogenic differentiation of OS cells and potentiate BMP9-induced osteogenesis in preadipocytes. However, the concomitant effect of ATRA and BMP9 in OS cells is unclear; therefore, in the present study, we focused on this topic. The results showed that BMP9 significantly promoted the proliferation of human OS 143B cells and did not induce osteogenic differentiation of cells in vitro (p<0.01). ATRA inhibited proliferation and induced osteogenesis in 143B cells; these effects could be enhanced by BMP9 overexpression (p<0.05). ATRA could significantly increase the level of phosphorylated p38 MAPK (p-p38) in 143B cells, while BMP9 did not have any significant effect. Notably, BMP9 overexpression enhanced the ability of ATRA to increase the levels of p-p38. Both the osteogenic differentiation and the anti-proliferative activity of BMP9 in the presence of ATRA decreased upon treatment with a specific inhibitor of p38 MAPK (SB203580) (p<0.01). This study indicates that the osteogenic differentiation ability of BMP9 in 143B cells can be restored by ATRA, and the combination of BMP9 and ATRA generated a stronger anti-proliferative effect on 143B cells than ATRA alone. This result may be due to the activation of the p38 MAPK pathway.

TGF-ß1/PTEN/PI3K signaling plays a critical role in the anti-proliferation effect of tetrandrine in human colon cancer cells.

The diagnosis and treatment for colon cancer have been greatly developed, but the prognosis remains unsatisfactory. There is still a great clinical need to explore new efficacious drugs for colon cancer treatment. Tetrandrine (Tet) is a bis-benzylisoquinoline alkaloid. It has been shown that Tet may be a potential candidate for cancer treatment, but the explicit mechanism underlying this activity remains unclear. In this study, we investigated the anticancer activity of Tet in human colon cancer cells and dissected the possible mechanism. With cell viability assay and flow cytometry analysis, we confirmed that Tet can effectively inhibit the proliferation and induce apoptosis in HCT116 cells. Mechanically, we found that Tet greatly increases the mRNA and protein level of TGF-ß1 in HCT116 cells. Exogenous TGF-ß1 enhances the anti-proliferation and apoptosis inducing effect of Tet in HCT116 cells, which has been partly reversed by TGF-ß1 inhibitor. Tet decreases the phosphorylation of Akt1/2/3 in HCT116 cells. This effect can be enhanced by exogenous TGF-ß1, but partly reversed by TGF-ß1 inhibitor. Tet exhibits no effect on total level of PTEN, but decreases the phosphorylation of PTEN; exogenous TGF-ß1 enhances the effect of Tet on decreasing the phosphorylation of PTEN, which was partly reversed by TGF-ß1 inhibitor. Our findings suggested that Tet may be a promising candidate for colon cancer treatment, and the anticancer activity may be mediated by inactivating PI3K/Akt signaling through upregulating TGF-ß1 to decrease the phosphorylation of PTEN.

Follicle-Stimulating Hormone ß-Subunit Potentiates Bone Morphogenetic Protein 9-Induced Osteogenic Differentiation in Mouse Embryonic Fibroblasts.

Postmenopausal osteoporosis (PMOP)-related fractures usually result in morbidity and mortality in aging women, so it remains a global public health concern, and new effective safe treatments are urgently needed recently. Efficient osteogenesis from mesenchymal stem cells (MSCs) would have the clinical application potential in treating multiple osteal disorders. Follicle-stimulating hormone (FSH), a pituitary glycoprotein hormone highly associated with menopausal bone turnover, whose peculiar part of receptor binding is follicle-stimulating hormone ß-subunit (FSHß). Bone morphogenetic protein 9 (BMP9), a potent osteogenic factor, can up-regulate FSHß in mouse embryonic fibroblasts (MEFs). However, it is unclear, whether extrapituitary FSHß affects BMP9-induced osteogenesis in MEFs. In this study, we investigated the role of FSHß in BMP9-induced osteogenesis in MEFs. We found that exogenous expression of FSHß significantly increased BMP9-induced alkaline phosphatase activity (ALP), the expression of osteogenic transcriptional factors, Runx2 and Osx, and the established late osteogenic markers, osteopontin (OPN) and osteocalcin (OCN), so does the ectopic bone formation. Mechanistically, FSHß dramatically enhanced BMP9-induced BMP/Smad signal transduction, presenting the augment phosphorylation of Smad1/5/8, whereas treatment with anti-FSHß antibodies suppressed these effects. An adenylate cyclase inhibitor obviously suppressed ALP and BMP/Smad signal transduction induced by BMP9 or the combination of BMP9 and FSHß in MEFs. Collectively, our findings suggested that FSHß may promote BMP9-induced activation of BMP/Smad signaling through a FSH/FSH receptor (FSHR)/cAMP dependent pathway in MEFs partly. J. Cell. Biochem. 118: 1792-1802, 2017. © 2016 Wiley Periodicals, Inc.

All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts.

Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis.

Ursolic acid inhibits proliferation and induces apoptosis by inactivating Wnt/ß-catenin signaling in human osteosarcoma cells.

Although multiple chemotherapeutic agents have been used for osteosarcoma (OS) treatment, their mechanisms need further study. Ursolic acid (UA), a pentacyclic triterpenoid, can reduce cell proliferation and induce apoptosis in various cancer cells, such as OS. However, the exact mechanism underlying this function remains unclear. In this study, we investigated the anti­proliferative effect of UA in human OS 143B cells and dissected the possible molecular mechanism underlying this effect. We demonstrated that UA can reduce cell proliferation, induce apoptosis and arrest cell cycle in 143B cells, as well as inhibit OS tumor growth in a mouse xenograft model. Using a luciferase reporter assay, we found that the Wnt/ß­catenin signaling is inhibited by UA in 143B cells. Correspondingly, the expression level and nuclear translocation of ß­catenin are both decreased by UA. Exogenous expression of ß­catenin attenuates the anticancer effect of UA in 143B cells, while knockdown of ß­catenin enhances this effect. UA increases the expression level of p53 in a concentration­dependent manner, and inhibition of p53 reduces the anticancer effect of UA in 143B cells. Moreover, inhibition of p53 partly reverses the UA­induced downregulation of ß­catenin, as do the targets of Wnt/ß­catenin signaling, such as c­Myc and cyclin D1. Our findings indicated that UA can inhibit the proliferation of 143B OS cells through inactivation of Wnt/ß-catenin signaling, which may be mediated partly by upregulating the expression of p53.

Oridonin inhibits the proliferation of human colon cancer cells by upregulating BMP7 to activate p38 MAPK.

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.

BMP9/p38 MAPK is essential for the antiproliferative effect of resveratrol on human colon cancer.

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.

Antiproliferation effect of evodiamine in human colon cancer cells is associated with IGF-1/HIF-1α downregulation.

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.