Retinoic Acid Receptor α Knockdown Suppresses the Tumorigenicity of Esophageal Carcinoma via Wnt/ß-catenin Pathway.

BACKGROUND: Aberrant expression of retinoic acid receptor α (RARα) was correlated with diverse carcinomas such as acute promyelocytic leukemia and colorectal carcinoma. Nevertheless, the function and mechanism of RARα in esophageal carcinoma (EC) remain unclear. AIM: To investigate the expression of RARα in EC and its effect in the tumorigenesis of EC. METHODS AND RESULTS: In immunohistochemistry study, RARα was overexpressed in human EC tissues, and its overexpression was closely related to the pathological differentiation, lymph node metastasis, and clinical stages in EC patients. Functionally, RARα knockdown suppressed the proliferation and metastasis of EC cells through downregulating the expression of PCNA, Ki67, MMP7, and MMP9, as well as enhanced drug susceptibility of EC cells to 5-fluorouracil and cisplatin. Mechanistically, RARα knockdown inhibited the activity of Wnt/ß-catenin pathway through reducing the phosphorylation level of GSK3ß at Ser-9 and inducing phosphorylation level at Tyr-216, which resulted in downregulation of its downstream targets such as MMP7, MMP9, and P-gP. CONCLUSIONS: Our results demonstrated that RARα knockdown suppressed the tumorigenicity of EC via Wnt/ß-catenin pathway. RARα might be a potential molecular target for EC clinical therapy.

Tankyrase Promotes Aerobic Glycolysis and Proliferation of Ovarian Cancer through Activation of Wnt/ß-Catenin Signaling.

Tankyrase (TNKS) plays important roles in the malignancy of several cancers such as human lung tumor, breast cancer, and hepatocellular cancer. However, its exact functions and molecular mechanisms in ovarian cancer remain unclear. In this study, we found that TNKS was aberrantly overexpressed in human ovarian cancer tissues and associated with poor patient prognosis. TNKS inhibition or knockdown not only reduced ovarian cancer cell proliferation, colony formation, migration, invasion, and tumorigenic potential in nude mice but also enhanced the drug susceptibility of ovarian cancer cells through arresting cell cycle and inducing apoptosis. These phenotypic changes correlated with downregulation of targets (Cyclin D1, MDR, and MMP-9) of Wnt/ß-catenin signaling. Furthermore, downregulation of TNKS suppressed the glucose uptake, lactate excretion, and cellular ATP levels and increased cellular O2 consumption rates. Molecular mechanism studies revealed that TNKS promoted aerobic glycolysis at least in part due to upregulation of pyruvate carboxylase (PC) via activation of Wnt/ß-catenin/snail signaling. In agreement with these findings, expression of TNKS is positively associated with snail and PC in clinical ovarian cancer samples. Our findings identified TNKS as an oncogenic regulator of ovarian cancer cells proliferation that promotes aerobic glycolysis via activation of Wnt/ß-catenin signaling, indicating that the TNKS might serve as a potential molecular target for clinical therapy of Wnt/ß-catenin dependent ovarian cancer.

Correlation Between Tumor Vasculogenic Mimicry and Poor Prognosis of Human Digestive Cancer Patients: A Systematic Review and Meta-Analysis.

Vasculogenic mimicry (VM) is a new pattern of blood supplement independent of endothelial vessels, which is related with tumor invasion, metastasis and prognosis. However, the role of VM in the prognosis of cancer patients is controversial. This study aimed to perform a meta-analysis of the published data to attempt to clarify the prognostic value of VM in the digestive cancer. Relevant studies were retrieved from the PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure and VIP databases published before March 29, 2018. Studies were included if they detected VM in the digestive cancer and analyzed the overall survival (OS) or disease-free survival (DFS) according to VM status. Two independent reviewers screened the studies, extracted data, and evaluated the quality of included studies with the Newcastle-Ottawa scale. Meta-analysis was performed using STATA 12.0 software. A total of 22 studies with 2411 patients were included in this meta-analysis. Meta-analysis showed that VM was related with the poor OS (HR = 2.30, 95% CI: 2.06-2.56, P < 0.001) and DFS (HR = 2.60, 95% CI: 2.07-3.27, P < 0.001) of patients with digestive cancer. Subgroup analysis showed VM was related with tumor differentiation, lymph node metastasis and TNM stage. Moreover, the present meta-analysis was reliable, and there was no obvious publication bias. This meta-analysis suggested that VM was a poor prognosis of digestive cancer patients. Further large and well-designed studies are required.

Diosgenin Suppresses Cholangiocarcinoma Cells Via Inducing Cell Cycle Arrest And Mitochondria-Mediated Apoptosis.

PURPOSE: Diosgenin (DSG) is the precursor of steroid hormones and plays a crucial part in the proliferation of various carcinomas including human colorectal cancer and gastric carcinoma. Nevertheless, its specific features and mechanisms in human cholangiocarcinoma (CCA) remain unknown. METHODS: MTS assay, colony-forming assay, and EdU assay were performed to determine the role of DSG on the progression of human CCA cells. The distributions of cell cycle, the ratio of apoptosis, and the mitochondrial membrane potential (ΔΨm) were studied by flow cytometry (FCM). AO/EB and Hoechst 33258 staining were performed to observe the morphological features of cell apoptosis. TEM was performed to observe the ultrastructures of QBC939 and HuCCT1 cells. The mRNA and protein expression of mitochondrial apoptotic pathway and GSK3ß/ß-catenin pathway were further confirmed by qPCR and Western blotting. The xenograft tumor model of HuCCT1 cells was built. Immunohistochemistry of tumor tissues was performed. RESULTS: Our results indicated that DSG inhibited the progression of six CCA cell lines. In vivo tumor studies also indicated that DSG significantly inhibited tumor growth in xenografts in nude mice. The expression of mitosis-promoting factor cyclinB1 was decreased along with the elevating level of cell cycle inhibitor p21, resulting in arresting CCA cell cycles at G2/M phase. Furthermore, DSG induced apoptosis with the increased expressions of cytosol cytochrome C, cleaved-caspase-3, cleaved-PARP1 and the Bax/Bcl-2 ratio. Mechanistically, our study showed that GSK3ß/ß-catenin pathway was involved in the apoptosis of CCA cells. Thus, DSG might provide a new clue for the drug therapy of CCA. CONCLUSION: In our data, DSG was found to have efficient antitumor potential of human CCA cells in vitro and in vivo.

Magnolol suppresses the proliferation and invasion of cholangiocarcinoma cells via inhibiting the NF-κB signaling pathway.

BACKGROUND: Magnolol has shown the potential anticancer properties against a variety of cancers. However, the role of magnolol in cholangiocarcinoma (CCA) cells is unknown. In this study, we assessed the effect of magnolol on the CCA cells. METHODS: CCA cells were treated with magnolol in the absence or presence of TNFα, the activator for NF-κB. After co-incubation with magnolol, cell proliferation and growth were examined by MTT, colony formation and xenograft tumors; cell cycle was analyzed by flow cytometry; cell migration and invasion were detected by wound healing and transwell assays; the expression of PCNA, Ki67, CyclinD1, MMP-2, MMP-7 and MMP-9 and NF-κB pathway were evaluated by using Western blot. RESULTS: Magnolol inhibited the abilities of CCA cell growth, migration and invasion accompanying with a decreased expression of PCNA, Ki67, MMP-2, MMP-7 and MMP-9 (all P<0.05). TREATMENT: with magnolol induced cell cycle arrest in G1 phase with a downregulation of cell cycle protein CyclinD1 (all P<0.05). In addition, magnolol suppressed the expression of p-IκBα and p-P65 and the effect of magnolol on CCA cells could be inhibited by TNFα. CONCLUSIONS: Magnolol could inhibit the growth, migration and invasion of CCA cells through regulation of NF-κB pathway, and these data indicate that magnolol is a potential candidate for treating of CCA.

Positive feedback loop of IL-1ß/Akt/RARα/Akt signaling mediates oncogenic property of RARα in gastric carcinoma.

Abnormal expression and function of retinoic acid receptor α (RARα) have been reported to be associated with various cancers including acute promyelocytic leukemia and hepatocellular carcinoma. However, the role and the mechanism of RARα in gastric carcinoma (GC) were unknown. Here, the expression of RARα was frequently elevated in human GC tissues and cell lines, and its overexpression was closely correlated with tumor size, lymph node metastasis and clinical stages in GC patients. Moreover, RARα overexpression was related with pathological differentiation. Functionally, RARα knockdown inhibited the proliferation and metastasis of GC cells, as well as enhanced drug susceptibility both in vitro and in vivo. Additionally, RARα knockdown suppressed GC progression through regulating the expression of cell proliferation, cell cycle, invasion and drug resistance associated proteins, such as PCNA, CyclinB1, CyclinD2, CyclinE, p21, MMP9 and MDR1. Mechanistically, the above oncogenic properties of RARα in GC were closely associated with Akt signaling activation. Moreover, overexpression of RARα was induced by IL-1ß/Akt signaling activation, which suggested a positive feedback loop of IL-1ß/Akt/RARα/Akt signaling in GC. Taken together, we demonstrated that RARα was frequently elevated in GC and exerted oncogenic properties. It might be a potential molecular target for GC treatment.