Chaoqin Yu

Tumor-specific Expression of MicroRNA-26a Suppresses Human Hepatocellular Carcinoma Growth via Cyclin-dependent and -independent Pathways

MicroRNA-26a (miR-26a) is a tumor suppressor that is reduced in hepatocellular carcinoma (HCC). Increasing evidence indicates that the liver is a hormone-responsive organ like the breast. The purpose of this study was to investigate whether miR-26a, regulated by a human α-fetoprotein (hAFP) and human telomerase reverse transcriptase (hTERT) dual promoter, could be specifically expressed in liver tumor cells to suppress their growth and to clarify whether estrogen receptor-α (ERα) is regulated by miR-26a and involved in the HCC process. Our data show that miR-26a expression driven by a hAFP-TERT dual promoter was tumor-specific and decreased the viability of tumor cells by regulating ERα, progesterone receptor (PR) and P53 except for cyclin D2 or cyclin E2 in vitro and in vivo. Our data also show that estradiol (E2) promotes the growth of liver cancer cells similar to breast cancer cells partly via the E2-ERα pathway and that miR-26a significantly down regulates ERα and prevents the stimulation of hepatoma cell growth by E2. These data suggest that ERα, which is regulated by miR-26a, is important for liver tumor cell growth. Moreover, hAFP-TERT dual promoter-mediated miR-26a expression could specifically exert potential antitumor activity and provide a novel targeting approach for cancer therapy.

Puerarin Suppresses Invasion and Vascularization of Endometriosis Tissue Stimulated by 17β-Estradiol

Background Puerarin, a phytoestrogen with a weak estrogenic effect, binds to estrogen receptors, thereby competing with 17β-estradiol (E2) and producing an anti-estrogenic effect. This study was to investigate whether puerarin could suppress the invasion and vascularization of E2-stimulated endometriotic tissue. Methodology/Principal Findings The endometriotic stromal cells (ESCs) were successfully established and their invasive ability under different treatments was assessed through a Transwell Assay. Simultaneously, matrix metallopeptidase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) were detected by western blotting. Vascularization of endometriotic tissues was observed by chicken chorioallantoic membrane (CAM) assay. The staining of MMP-9, intercellular adhesion molecule 1 (ICAM-1), TIMP-1, and vascular endothelial growth factor (VEGF) in grafted endometriotic tissues was examined using immunohistochemistry analysis. The purity of ESCs in isolated cells was >95%, as determined by the fluoroimmunoassay of vimentin. E2 (10−8 mol/L) promoted the invasiveness of ESCs by increasing MMP-9 accumulation and decreasing TIMP-1 accumulation. Interestingly, puerarin (10−9 mol/L) significantly reversed these effects (P<0.01). The CAM assay indicated that puerarin (10−9 mol/L) also inhibited the angiopoiesis of endometriotic tissue stimulated by the E2 (10−8 mol/L) treatment (P<0.05). Accordingly, immunohistochemistry showed that the accumulation of MMP-9, ICAM-1, and VEGF was reduced whereas that of TIMP-1 increased in the combination treatment group compared with the E2 treatment group. Conclusions/Significance This study demonstrated that puerarin could suppress the tissue invasion by ESCs and the vascularization of ectopic endometrial tissues stimulated by E2, suggesting that puerarin may be a potential drug for the treatment of endometriosis.

Endometriotic Implants Regress in Rat Models Treated With Puerarin by Decreasing Estradiol Level

Phytoestrogens, which have a weak estrogenic effect, bind to estrogen receptors (ERs), thereby competing with estradiol, have an antiestrogenic effect on women of reproductive age with high estrogenic level. Herein, we examined the ability of the phytoestrogen Puerarin to treat endometriosis in rat models of endometriosis. In total, 75 adult, mature female Sprague-Dawley rats in which endometriotic implants were successfully induced by transplanting autologous endometrial tissue to ectopic sites were used in this study. Oral gavage of Puerarin (at doses of 600, 200, or 60 mg/kg per day) or Danazol (80 mg/kg per day) started 4 weeks after implantation. Control model rats received vehicle alone. After administration for 4 weeks, the weight of the ectopic implants, estradiol concentration, as well as ER-α and Aromatase P450 (P450arom) expression in different groups of rat tissues were evaluated after treatment. The endometriotic tissue weight and serum estrogen levels were significantly lower in high, medium, low dose of Puerarin and Danazol treatment groups than that in control group (P < .05 or P < .01). Low-dose Puerarin inhibited P450arom expression and significantly reduced estrogen levels in endometriotic tissue (P < .01). Three doses of Puerarin had no adverse effects on liver, kidney, and ovary, whereas high-dose Puerarin administration caused thinner bone trabecula with distortion and breakage and Danazol administration caused mild or moderate hepatic cell damage. These data demonstrate that Puerarin was able to effectively suppress the growth and development of ectopic endometrium in the rat endometriosis model, even at low doses, suggesting it may be an effective treatment for endometriosis.

Puerarin Suppresses Proliferation of Endometriotic Stromal Cells Partly via the MAPK Signaling Pathway Induced by 17ß-estradiol-BSA

Background Puerarin is a major isoflavonoid compound extracted from Radix puerariae. It has a weak estrogenic action by binding to estrogen receptors (ERs). In our early clinical practice to treat endometriosis, a better therapeutic effect was achieved if the formula of traditional Chinese medicine included Radix puerariae. The genomic and non-genomic effects of puerarin were studied in our Lab. This study aims to investigate the ability of puerarin to bind competitively to ERs in human endometriotic stromal cells (ESCs), determine whether and how puerarin may influence phosphorylation of the non-genomic signaling pathway induced by 17ß-estradiol conjugated to BSA (E2-BSA). Methodology ESCs were successfully established. Binding of puerarin to ERs was assessed by a radioactive competitive binding assay in ESCs. Activation of the signaling pathway was screened by human phospho-kinase array, and was further confirmed by western blot. Cell proliferation was analyzed according to the protocol of CCK-8. The mRNA and protein levels of cyclin D1, Cox-2 and Cyp19 were determined by real-time PCR and western blotting. Inhibitor of MEK1/2 or ER antagonist was used to confirm the involved signal pathway. Principal Findings Our data demonstrated that the total binding ability of puerarin to ERs on viable cells is around 1/3 that of 17ß-estradiol (E2). E2-BSA was able to trigger a rapid, non-genomic, membrane-mediated activation of ERK1/2 in ESCs and this phenomenon was associated with an increased proliferation of ESCs. Treating ESCs with puerarin abrogated the phosphorylation of ERK and significantly decreased cell proliferation, as well as related gene expression levels enhanced by E2-BSA. Conclusions/Significance Puerarin suppresses proliferation of ESCs induced by E2-BSA partly via impeding a rapid, non-genomic, membrane-initiated ERK pathway, and down-regulation of Cyclin D1, Cox-2 and Cyp19 are involved in the process. Our data further show that puerarin may be a new candidate to treat endometriosis.

Role of JNK Activation and Mitochondrial Bax Translocation in Allicin-Induced Apoptosis in Human Ovarian Cancer SKOV3 Cells

Background. Allicin, the major component of freshly crushed garlic, is one of the most biologically active compounds of garlic; it has been reported to induce apoptosis in cancer cells; however, the mechanism by which allicin exerts its apoptotic effects is not fully understood. The aim of the present study was to further elucidate the apoptotic pathways induced by allicin in the human ovarian cancer cell line SKOV3. Methods. Cell proliferation and apoptosis were measured by cell-counting assay and flow cytometry analysis. Activation of the signaling pathway was screened by human phospho-kinase array analysis, and the activated pathway and its related proteins were further confirmed by western blot analysis. Results. Allicin induced SKOV3 cell apoptosis and JNK phosphorylation in a time- and dose-dependent manner, but these were significantly blocked by SP600125 (an inhibitor of JNK). The findings suggest that JNK phosphorylation is related to the action of allicin on SKOV3 cells. Furthermore, JNK activation induced Bcl-2 family activation, triggered mitochondria-mediated signaling pathways, and led to the translocation of a considerable amount of Bax and cytochrome c release. Conclusions. JNK activation and mitochondrial Bax translocation are involved in allicin-induced apoptosis in SKOV3 cells. Our data input new insights to the literature of allicin-induced apoptosis.

p53-insensitive PUMA down-regulation is essential in the early phase of liver regeneration after partial hepatectomy in mice

BACKGROUND & AIMS Liver regeneration after partial hepatectomy involve proliferation and apoptosis of hepatocytes. PUMA, the well-known proapoptotic member of the Bcl-2 family, can respond to distinct stimuli. This study explores the role of PUMA and its relationship with other Bcl-2 family members in this process. METHODS The expression patterns of PUMA and its related proteins were investigated in livers after 70% hepatectomies. The contributions of PUMA to liver regeneration were assessed by manipulating its expression levels using adenovirus vectors. The differences in PUMA expression levels in human normal livers and hepatitis, as well as hepatoma tissues were characterised. RESULTS During the first 72h after hepatectomy, PUMA was highly down-regulated transcriptionally, while the levels of p53, Slug, Bax, and Bcl-X(L) proteins increased continuously. Highly induced expression of PUMA in the liver by Ad-PUMA caused lethal fulminant hepatitis 48h after treatment. Slightly induced expression was enough to impair liver regeneration, with an elevation of post-hepatectomy mortality, an increase of apoptosis, a decrease of proliferation, an up-regulation of Bax levels, an induction of inflammatory chemokines (KC and macrophage inflammatory protein-2), and an increase in the neutrophil infiltration relative to the control. In contrast to the results from the regenerating liver, PUMA expression showed an increased trend in human hepatitis and hepatoma tissues. CONCLUSIONS Sharply p53-insensitive down-regulation of PUMA, coupled with Bcl-X(L) up-regulation, may play a cytoprotective role in liver regeneration after hepatectomy. Furthermore, the increased expression of PUMA in hepatitis and hepatoma may indicate misregulation of the apoptotic network in these diseases.

Puerarin suppresses proliferation of endometriotic stromal cells in part via differential recruitment of nuclear receptor coregulators to estrogen receptor-α

BACKGROUND AND OBJECTIVES Puerarin, a phytoestrogen with a weak estrogenic effect, binds to estrogen receptors, thereby competing with 17β-estradiol and producing an anti-estrogenic effect. In our early clinical practice to treat endometriosis, a better therapeutic effect was achieved if the formula of traditional Chinese medicine included Radix puerariae. This study was to investigate whether puerarin could suppress the proliferation of endometriotic stromal cells (ESCs) and to further elucidate the potential mechanism. METHODS AND RESULTS The ESCs were successfully established. The effects of puerarin on the proliferation of ESCs, cell cycle and apoptosis were determined by Cell Counting Kit-8 assay and flow cytometry. The mRNA and protein levels of cyclin D1 and cdc25A were detected by real-time PCR and Western blot analysis. Coimmunoprecipitation was applied to examine the recruitment of nuclear receptor coregulators to the estrogen receptor-α. We found that puerarin can suppress estrogen-stimulated proliferation partly through down-regulating the transcription of cyclin D1 and cdc25A by promoting the recruitment of corepressors to estrogen receptor-α as well as limiting that of coactivators in ESCs. CONCLUSIONS Our data suggest that puerarin could suppress the proliferation of ESCs and could be a potential therapeutic agent for the treatment of endometriosis.

Increased Expression of SETD7 Promotes Cell Proliferation by Regulating Cell Cycle and Indicates Poor Prognosis in Hepatocellular Carcinoma

Purpose To investigate the role of SET domain containing 7 (SETD7) in hepatocellular carcinoma (HCC) and determine whether SETD7 can be used as a predictor of overall survival in HCC patients. Methods mRNAs and proteins of SETD7 and related genes in HCC tumor samples and paired adjacent non-tumorous liver tissues (ANLTs) (n = 20) or culture cells were determined by quantitative real-time PCR and Western blot. Cell proliferation and apoptosis with SETD7 knockdown SMMC-7721 cells or SETD7 overexpressed HepG2 cells were analyzed by CCK8 assay or flow cytometry. Gene expression alterations in SETD7 knockdown of SMMC-7721 cells were determined by digital gene expression (DGE) profiling. Defined data on patients (n = 225) with HCC were retrieved for the further study. Tissue microarrays (TMAs) were performed using paraffin tissues with tumor and ANLTs. SETD7 and related proteins were determined by TMAs immunohistochemistry. Statistical analyses were conducted to associate SETD7 expression with tumor features and patient outcomes, as well as related proteins expression. Results SETD7 expression was significantly higher in HCC tumor tissues than in ANLTs. SETD7 overexpression in vitro can promote HepG2 cell proliferation, whereas SETD7 knockdown can inhibit SMMC-7721 cell proliferation by regulating the cell cycle. SETD7 expression was significantly correlated with five genes expression. Increased SETD7 is associated with metastasis, recurrence, large tumor size, and poor tumor differentiation, and indicates poor prognosis in HCC patients. Conclusions SETD7 plays a critical role in HCC, and its immunohistochemistry signature provides potential clinical significance for personalized prediction of HCC prognosis.

Peritoneal fluid of patients with endometriosis promotes proliferation of endometrial stromal cells and induces COX-2 expression.

Cell proliferation of endometrial stromal cells treated with peritoneal fluid of women (aged 25 to 43 years) with endometriosis (n = 12) statistically significantly increased compared with the control treatment (peritoneal fluid of women without endometriosis, n = 8). Also, COX-2 gene expression and prostaglandin E(2) production were induced in those cells by increasing COX-2 promoter transcription activity, which could be attenuated by a specific p38MAPK inhibitor, suggesting a role for peritoneal fluid in the etiopathogenesis of endometriosis.

Quercetin Decreases Insulin Resistance in a Polycystic Ovary Syndrome Rat Model by Improving Inflammatory Microenvironment.

Insulin resistance (IR) is a clinical feature of polycystic ovary syndrome (PCOS). Quercetin, derived from Chinese medicinal herbs such as hawthorn, has been proven practical in the management of IR in diabetes. However, whether quercetin could decrease IR in PCOS is unknown. This study aims to observe the therapeutic effect of quercetin on IR in a PCOS rat model and explore the underlying mechanism. An IR PCOS rat model was established by subcutaneous injection with dehydroepiandrosterone. The body weight, estrous cycle, and ovary morphology of the quercetin-treated rats were observed. Serum inflammatory cytokines were analyzed using enzyme-linked immunosorbent assay. In ovarian tissues, the expression of key genes involved in the inflammatory signaling pathway was detected through Western blot, real-time polymerase chain reaction, or immunohistochemistry. The nuclear translocation of nuclear factor κB (NF-κB) was also observed by immunofluorescence. The estrous cycle recovery rate of the insulin-resistant PCOS model after quercetin treatment was 58.33%. Quercetin significantly reduced the levels of blood insulin, interleukin 1β, IL-6, and tumor necrosis factor α. Quercetin also significantly decreased the granulosa cell nuclear translocation of NF-κB in the insulin-resistant PCOS rat model. The treatment inhibited the expression of inflammation-related genes, including the nicotinamide adenine dinucleotide phosphate oxidase subunit p22phox, oxidized low-density lipoprotein, and Toll-like receptor 4, in ovarian tissue. Quercetin improved IR and demonstrated a favorable therapeutic effect on the PCOS rats. The underlying mechanism of quercetin potentially involves the inhibition of the Toll-like receptor/NF-κB signaling pathway and the improvement in the inflammatory microenvironment of the ovarian tissue of the PCOS rat model.Insulin resistance (IR) is a clinical feature of polycystic ovary syndrome (PCOS). Quercetin, derived from Chinese medicinal herbs such as hawthorn, has been proven practical in the management of IR in diabetes. However, whether quercetin could decrease IR in PCOS is unknown. This study aims to observe the therapeutic effect of quercetin on IR in a PCOS rat model and explore the underlying mechanism. An IR PCOS rat model was established by subcutaneous injection with dehydroepian-drosterone. The body weight, estrous cycle, and ovary morphology of the quercetin-treated rats were observed. Serum inflammatory cytokines were analyzed using enzyme-linked immunosorbent assay. In ovarian tissues, the expression of key genes involved in the inflammatory signaling pathway was detected through Western blot, real-time polymerase chain reaction, or immunohistochemistry. The nuclear translocation of nuclear factor κB (NF-κB) was also observed by immunofluorescence. The estrous cycle recovery rate of the insulin-resistant PCOS model after quercetin treatment was 58.33%. Quercetin significantly reduced the levels of blood insulin, interleukin 1β, IL-6, and tumor necrosis factor α. Quercetin also significantly decreased the granulosa cell nuclear translocation of NF-κB in the insulin-resistant PCOS rat model. The treatment inhibited the expression of inflammation-related genes, including the nicotinamide adenine dinucleotide phosphate oxidase subunit p22phox, oxidized low-density lipoprotein, and Toll-like receptor 4, in ovarian tissue. Quercetin improved IR and demonstrated a favorable therapeutic effect on the PCOS rats. The underlying mechanism of quercetin potentially involves the inhibition of the Toll-like receptor/NF-κB signaling pathway and the improvement in the inflammatory microenvironment of the ovarian tissue of the PCOS rat model.