Zhenran Wang

Embelin-induced MCF-7 breast cancer cell apoptosis and blockade of MCF-7 cells in the G2/M phase via the mitochondrial pathway

Embelin is a small molecular inhibitor extracted from Myrsinaceae plants that specifically inhibits XIAP, affecting the proliferation and apoptosis of various types of tumor cells. In our previous studies, we have demonstrated that embelin is able to induce the apoptosis of MCF-7 breast cancer cells in a dose-dependent manner. However, its mechanism of action is not yet clear. The purpose of this study was to investigate the involvement of the mitochondrial pathway in embelin-induced apoptosis and the effect of embelin on the cell cycle. Different doses of embelin were added to MCF-7 breast cancer cells and it was found that embelin was able to induce apoptosis of MCF-7 breast cancer cells in a dose- and time-dependent manner. Flow cytometry analysis revealed that embelin caused changes in the MCF-7 cell mitochondrial membrane potential and blocked the cell cycle of MCF-7 cells in the G2/M phase. Moreover, embelin was demonstrated to promote mitochondrial release of cytochrome C via regulation of Bax and Bcl-2, resulting in the activation of caspase-3 and -9, while no significant changes in the level of caspase-8 were observed. The results have demonstrated that embelin-induced apoptosis of MCF-7 breast cancer cells involves the mitochondrial pathway.

MicroRNA-506 suppresses tumor proliferation and metastasis in colon cancer by directly targeting the oncogene EZH2

Increasing evidence reveals that aberrant expression of microRNA contributes to the development and progression of colon cancer, but the roles of microRNA-506 (miR-506) in colon cancer remain elusive. Here, we demonstrated that miR-506 was down-regulated in colon cancer tissue and cells and that miR-506 expression was inversely correlated with EZH2 expression, tumor size, lymph node invasion, TNM stage and metastasis. A high level of miR-506 identified patients with a favorable prognosis. In vitro and in vivo experiments confirmed that miR-506 inhibits the proliferation and metastasis of colon cancer, and a luciferase reporter assay confirmed that EZH2 is a direct and functional target of miR-506 via the 3′UTR of EZH2. The restoration of EZH2 expression partially reversed the proliferation and invasion of miR-506-overexpressing colon cancer cells. Moreover, we confirmed that the miR-506-EZH2 axis inhibits proliferation and metastasis by activating/suppressing specific downstream tumor-associated genes and the Wnt/β-catenin signaling pathway. Taking together, our study sheds light on the role of miR-506 as a suppressor for tumor growth and metastasis and raises the intriguing possibility that miR-506 may serve as a new potential marker for monitoring and treating colon cancer.

MicroRNA-155-3p promotes hepatocellular carcinoma formation by suppressing FBXW7 expression.

BackgroundMicroRNAs (miRNAs) are small non-coding RNAs frequently dysregulated in human malignant tumors. In the present study, we analyzed the role miR-155-3p plays in Hepatocellular carcinoma (HCC), which has been reported participation in some other types of cancer.MethodsqRT-PCR was used to measure the levels of miR-155-3p in HCC specimens and HCC cell lines. Overexpression of miR-155-3p and miR-155-3p inhibitor were transfected into HCC cell lines to investigate its role in HCC. Colony formation assay and 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assays were used to analyses cell proliferation in vitro. In vivo tumor formation assays were performed in BALB/c nude mice. Luciferase reporter assay was carried out to measure the translation of F-Box and WD repeat romain containing 7 (FBXW7).ResultsWe found that miR-155-3p was remarkably upregulated both in HCC tissue and cell lines. Overexpression of miR-155-3p enhanced HCC cell proliferation in vitro and tumorigenesis in vivo. In addition, overexpression of miR-155-3p is correlated with decreased levels FBXW7 mainly through inhibiting the expression of FBXW7.ConclusionsOur studies suggest that miR-155-3p plays an important role in the pathogenesis of HCC and implicates its potential applications in the treatment of HCC cancer.

Overexpression of CTNND1 in hepatocellular carcinoma promotes carcinous characters through activation of Wnt/β-catenin signaling

BackgroundIncreasing evidence supports the association of CTNND1 with tumor development and progression. However, the mechanism and clinical significance of CTNND1 deregulation in hepatocellular carcinoma (HCC) remains unknown. In this study, we aim to investigate the role of CTNND1 in HCC.MethodsqRT-PCR and immunohistochemical analyses were used to measure the levels of CTNND1 in HCC specimens and HCC cell lines. CTNND1 and shCTNND1 were transfected into HCC cell lines to investigate its role in HCC. Cell migration and invasion were measured by Transwell and Matrigel analyses in vitro. In vivo metastasis assays were performed in SCID mice.ResultsIn clinical HCC samples, we found that CTNND1 expression was significantly up-regulated in cancer lesions compared with paired normal liver tissues. By silencing or overexpressing CTNND1 in HCC cells, we found that CTNND1 could promote cell proliferation, migration, and invasion in vitro. An in-vivo assay showed that CTNND1 dramatically promoted HCC cell tumor formation and metastasis. Moreover, CTNND1 promoted HCC metastasis, at least in part, by indirectly enhancing Wnt/β-catenin signaling. Consistent with these results, the expression of CTNND1 was positively correlated with β-catenin, WNT11, Cyclin D1, and BMP7 expression in human HCC specimens.ConclusionsOur study provides evidence that CTNND1 functions as a novel tumor oncogene in HCC, and may be a potential therapeutic target for HCC management.

Upregulation of Akt/NF-κB-regulated inflammation and Akt/Bad-related apoptosis signaling pathway involved in hepatic carcinoma process: suppression by carnosic acid nanoparticle.

Primary liver cancer is globally the sixth most frequent cancer, and the second leading cause of cancer death and its incidence is increasing in many countries, becoming a serious threat to human health. Many researches focused on the treatment and prevention of liver cancer. However, due to the underlying molecular mechanism of liver cancer still not fully understood, the studies and development of treatments were forced to be delayed. Akt has been suggested to play an essential role in the progression of inflammation response and apoptosis. Hence, in this study, Akt-knockout mice and cells of liver cancer were used as a model to investigate the molecular mechanism of Akt-associated inflammatory and apoptotic signaling pathway linked with NF-κB and Bcl-2-associated death promoter (Bad) for the progression of liver cancer. Carnosic acid (CA), as a phenolic diterpene with anticancer, antibacterial, antidiabetic, as well as neuroprotective properties, is produced by many species from Lamiaceae family. Administration of CA nanoparticles was sufficient to lead to considerable inhibition of liver cancer progression. The results indicated that, compared to the normal liver cells, the expression of Akt was significantly higher in liver cancer cell lines. Also, we found that Akt-knockout cancer cell lines modulated inflammation response and apoptosis via inhibiting NF-κB activation and inducing apoptotic reaction. Our results indicated that the downstream signals, including cytokines regulated by NF-κB and caspase-3-activated apoptosis affected by Bad, were re-modulated for knockout of Akt. And CA nanoparticles, acting as Akt-knockout, could inhibit inflammation and accelerate apoptosis in liver cancer by altering NF-κB activation and activating caspase-3 through Bad pathway. These findings demonstrated that the nanoparticulate drug CA performed its effective role owing to its ability to reduce inflammatory action and enhance apoptosis for the overexpression of NF-κB and Bad via Akt signaling pathway, playing a direct role in liver cancer progression. Thus, nanoparticle CA might be an important and potential choice for the clinical treatment in the future.

MicroRNA-155 deficiency attenuates ischemia-reperfusion injury after liver transplantation in mice.

Liver ischemia–reperfusion injury (IRI) is a major cause of morbidity and mortality after resection surgery, liver transplantation, and hemorrhagic and septic shock. Mir‐155 is upregulated by a broad range of inflammatory mediators, and it has been demonstrated to be involved in both innate and adaptive immune responses. However, the role of mir‐155 in liver IRI has never been investigated. In this study, mir‐155 deficiency protected mice from liver IRI, as shown by lower serum alanine aminotransferase (ALT) levels and Suzuki scores. Mir‐155 deficiency results in the development of M2 macrophages, which respond to IR‐induced innate immune stimulation by producing a regulatory inflammatory response with higher level of IL‐10, but lower levels of TNF‐α, IL‐6, and IL‐12p40. Mir‐155 deficiency suppresses IL‐17 expression, which contributes to the liver IRI development. In our further in vitro study, the results show that the Th17 differentiation is inhibited by SOCS1 overexpression and the promoted M2 macrophage development induced by mir‐155 deficiency is abolished by SOCS1 knockdown. In conclusion, mir‐155 deficiency attenuates liver IRI through upregulation of SOCS1, and this was associated with promoted M2 macrophage and inhibited Th17 differentiation.

Aberrant JMJD3 expression upregulates Slug to promote migration, invasion and stem cell-like behaviors in hepatocellular carcinoma.

The Jumonji domain-containing chromatin remodeling factor JMJD3 has important roles in development and cancer. Here, we report a pivotal role for JMJD3 in sustaining the phenotype of aggressive hepatocellular carcinomas. Expression levels of JMJD3 in clinical specimens of hepatocellular carcinoma correlated inversely with patient survival. In hepatocellular carcinoma cells, we found that enforcing its overexpression induced epithelial-mesenchymal transition (EMT), invasive migration, stem cell-like traits, and metastatic properties. Conversely, silencing JMJD3 in hepatocellular carcinoma cells overexpressing it inhibited these aggressive phenotypes. Mechanistically, JMJD3 modulated H3K27me3 in the SLUG gene promoter, a histone mark associated with active SLUG transcription. SLUG silencing blocked JMJD3-induced EMT, stemness, and metastasis. Furthermore, SLUG expression in hepatocellular carcinoma clinical specimens correlated positively with JMJD3 expression. Our results establish JMJD3 as a critical driver of hepatocellular carcinoma stem cell-like and metastatic behaviors, with implications for prognosis and treatment. Cancer Res; 76(22); 6520-32. ©2016 AACR.

Protection of rat intestinal epithelial cells from ischemia/reperfusion injury by (D‑Ala2, D‑Leu5)‑enkephalin through inhibition of the MKK7‑JNK signaling pathway

Previous studies have demonstrated that (D-Ala2, D-Leu5)-enkephalin (DADLE) protects rats from hepatic ischemia/reperfusion (I/R) injury. In the present study, DADLE was also observed to alleviate IR-induced intestinal epithelial cell injury in rats by inhibiting mitogen-activated protein kinase kinase 7 (MKK7)-c-Jun N-terminal kinase (JNK) pathway signaling. To investigate the protective effect of DADLE on hypoxia/reoxygenation injury in rat intestinal epithelial cells, rat intestinal epithelial cells were treated with different concentrations of DADLE, following which the cell survival rate was determined using a tetrazolium (MTT) colorimetric assay, and apoptosis was determined using flow cytometry. To confirm whether the protective effect of DADLE was due to its effect on MKK7-JNK signaling, the phosphorylation levels of MKK7 and JNK were analyzed using western blot analysis following treatment with different concentrations of DADLE. The results demonstrated that, following treatment with DADLE, the survival rate of the rat intestinal cells subjected to I/R-induced injury increased significantly and the apoptotic rate decreased in a concentration-dependent manner. In addition, the levels of phosphorylated MKK7 and JNK decreased in a concentration-dependent manner following treatment with DADLE. Silencing the gene expression of MKK7 using small interfering RNA prior to DADLE treatment resulted in a reduction in the protective effects of DADLE on the rat intestinal epithelial cells subjected to I/R injury. Collectively, the results of the present study demonstrated that the protective effects of DADLE in I/R injury in rat intestinal cells occurred through inhibition of the MKK7-JNK pathway.

EZH2 elevates the proliferation of human cholangiocarcinoma cells through the downregulation of RUNX3.

To investigate the impact of histone methyltransferase enhancer of zeste homolog 2 (EZH2) on the proliferation and apoptosis of human cholangiocarcinoma cells as well as its related mechanisms. Immunohistochemistry and Western blot analyses were used to examine the expression of EZH2 in 40 cases of human cholangiocarcinoma tissues and four strains of human cholangiocarcinoma cells. The influence of EZH2 on cell growth and apoptosis were assessed by knockdown experiments, and a xenograft experiment in nude mice was performed to evaluate the impact of siEZH2 on the tumorigenicity of tumor cells. The correlation of EZH2, clinic pathological features and overall survival rates was also analyzed. EZH2 was highly expressed in human cholangiocarcinoma tissues and cells. Silencing of EZH2 could significantly reduce the methylation level of RUNX3 DNA in human cholangiocarcinoma cells and improve its protein expression as well as inhibit cell proliferation, induce apoptosis and slow down the growth of tumor in nude mice. In addition, the expression of EZH2 was associated with the tumor stage, lymph node positivity and poor prognoses. Overexpression of EZH2 can promote the proliferation of cholangiocarcinoma cells and inhibit their apoptosis. It is associated with poor prognoses in patients with cholangiocarcinoma. Therefore, EZH2 could be a potential clinical therapeutic target for the treatment of cholangiocarcinoma.

Relationship between female hormonal and menstrual factors and pancreatic cancer: a meta-analysis of observational studies.

AbstractThe objective of this study was to assess the relationship between female hormone and menstrual factors and pancreatic cancer (PC) through a meta-analysis of observational studies.We undertook a systematic literature search up to July 10, 2014 in PubMed and EMBASE databases. Combined relative risks (RRs) were estimated by random-effects models. Subgroup analysis was performed by study design, source of control, and geographic regions. Sensitivity analyses and publication bias were utilized to evaluate the robustness of our results.A total of 27 case–control and cohort studies were retrieved for this meta-analysis. No significant associations were observed between the risk of PC and age at menarche (RR = 0.94, 95% confidence interval [CI] 0.83–1.07), age at menopause (RR = 0.98, 95% CI 0.85–1.13), hysterectomy (RR = 0.97, 95% CI 0.84–1.11), oophorectomy (RR = 1.02, 95% CI 0.82–1.26), hormone replacement therapy (RR = 0.97, 95% CI 0.87–1.08), and oral contraceptives (RR = 1.09, 95% CI 0.96–1.23).This meta-analysis of observational studies does not support the hypothesis that exogenous hormone use and menstrual factors are associated with PC.