Upregulation of miR-137 Expression Suppresses Tumor Growth and Progression via Interacting with DNMT3a Through Inhibiting the PTEN/Akt Signaling in HCC.

BACKGROUND: Downregulation of miR-137 regulates tumor growth in hepatocellular carcinoma (HCC). Yet, the underlying molecular mechanisms stay unclear. MATERIALS AND METHODS: miR-137 and DNA methyltransferase 3a (DNMT3a) expression levels were detected by Western blot, immunohistochemistry and qRT-PCR assays. Luciferase reporter and Western blot assays were also carried out to explore the correlation of miR-137 and DNMT3a. Flow cytometry assay, MTT analysis, transwell and wound healing assay were used to evaluate cell apoptosis, proliferation, as well as invasive and migratory abilities. Western blot was used to examine the caspase-3, cleaved caspase-3, PCNA, MMP-2, and MMP-7 protein levels, as well as PTEN/Akt signaling alternations. Methylation-specific PCR was applied to detect the PTEN promoter methylation status. Xenograft tumor assay, Western blot and immunohistochemistry analyses were taken to confirm the miR-137 regulation in vivo. RESULTS: Downregulation of miR-137, upregulation of DNMT3a, as well as an inverse correlation between them were observed in HCC clinical samples and cells. Moreover, miR-137 targeted directly and inhibited DNMT3a in HCC cells, which further retarded cell proliferative, migratory and invasive capabilities, while promoted apoptotic ones. Additionally, miR-137 overexpression inactivated the PTEN/Akt pathway in HCC cell by decreasing DNMT3a expression. Furthermore, miR-137 overexpression inhibited tumor growth in vivo in HCC via interacting with DNMT3a through inhibiting the PTEN/Akt cascades. CONCLUSION: Our findings suggested that miR-137 inhibited HCC tumor growth and progression via interacting with DNMT3a and suppressing the PTEN/Akt signaling in vitro and in vivo.

The positive feedback between ACSL4 expression and O-GlcNAcylation contributes to the growth and survival of hepatocellular carcinoma.

Acyl-CoA ligase 4 (ACSL4) has been reported to be overexpressed in hepatocellular carcinoma (HCC) and to enhance cell proliferation. However, the molecular mechanisms underlying the role of ACSL4 in HCC progression remain largely unclear. Here, we aimed to investigate whether and how O-GlcNAcylation and ACSL4 regulate each other and HCC progression. The clinical significance of ACSL4, O-GlcNAc and GLUT1 in HCC was determined by Pearson chi-squared test and Kaplan-Meier analysis. CCK-8, flow cytometry and in vivo tumour formation assays were performed to detect cell proliferation, apoptosis and tumorigenesis. IP technology was used to evaluate the relationship between ACSL4 and O-GlcNAc. ACSL4, GLUT1 and O-GlcNAc levels were elevated in HCC tissues and predicted poor prognosis in HCC patients. ACSL4 overexpression significantly promoted cell proliferation and tumorigenesis and inhibited cell apoptosis, whereas these effects were all obviously impaired when mTOR signalling was repressed or GLUT1 was downregulated. ACSL4 could be O-GlcNAcylated, and silencing of ACSL4 abolished the effects of O-GlcNAcylation on cell growth promotion and apoptosis inhibition. Collectively, this study demonstrates that ACSL4 contributes to the growth and survival of HCC by enhancing GLUT1-mediated O-GlcNAcylation. In turn, O-GlcNAcylation promotes HCC growth partially by increasing ACSL4 expression.

Quercetin inhibits the growth of human gastric cancer stem cells by inducing mitochondrial-dependent apoptosis through the inhibition of PI3K/Akt signaling.

Cancer stem cells (CSCs) have recently been linked to new treatment strategies for gastric cancer due to the critical role which they play as the 'heartbeat' of cancer. In the present study, we explored the effects of quercetin, an anti-inflammatory and antiviral compound, on gastric CSCs (GCSCs). We noted that quercetin exerted pronounced inhibitory effects on GCSC survival. Moreover, quercetin induced cell apoptosis in a mitochondrial-dependent manner, as shown by the reduction in mitochondrial membrane potential, the activation of caspase-3 and -9, and the downregulation of Bcl-2, as well as the upregulation of Bax and cytochrome c (Cyt-c). Additionally, a marked decrease in Akt phosphorylation levels was observed following treatment with quercetin, whereas pre-treatment with fumonisin B1 (FB1, Akt activator) significantly attenuated the inhibitory effects of quercetin on cell growth and its promoting effects on mitochondrial-dependent apoptosis. Notably, FB1 enhanced the expression of Bcl-2, which was inhibited by quercetin, and prevented the decrease in mitochondrial membrane potential induced by quercetin. However, the increase in the levels of caspases, Bax and Cyt-c induced by quercetin was also attenuated by the addition of FB1 to the GCSCs. Therefore, our results demonstrate that quercetin triggers mitochondrial apoptotic-dependent growth inhibition via the blockade of phosphoinositide 3-kinase (PI3K)-Akt signaling in GCSCs, indicating a potential target for the treatment of gastric cancer.

Intensive Versus Conventional Glycemic Control in Patients with Diabetes During Enteral Nutrition After Gastrectomy.

BACKGROUND: This study compared intensive and conventional glycemic management strategies in diabetic patients receiving enteral nutrition after gastrectomy. METHODS: Diabetic patients (n = 212) who underwent gastrectomy between September 2006 and March 2014 were randomized to intensive glycemic (IG) management with continuous insulin infusion (target glucose 4.4-6.1 mmol/l (80-110 mg/dl)) or conventional glycemic (CG) management with intermittent bolus insulin (target glucose <11.1 mmol/l (<200 mg/dl)). Outcomes included blood glucose concentrations, insulin administration, and postoperative morbidity and mortality. RESULTS: Blood glucose levels were lower (5.4 ± 1.2 vs. 9.5 ± 1.8 mmol/l, P < 0.001) and mean insulin dose was higher (55 ± 15 vs.32 ± 16 units/day, P < 0.001) in the IG than in the CG group. Rates of severe hypoglycemia (7.5 vs. 0.9%, P = 0.035) and achievement of target blood glucose (86.3 vs. 72.6%, P = 0.023) were higher, while severe hyperglycemia rate was lower (1.9 vs. 11.3%, P = 0.010), in the IG group. Surgical site infection rate was lower in the IG group (4.7 vs. 13.2%, P < 0.030). Rates of other infective complications, bleeding, delayed gastric emptying, obstruction, hepatic dysfunction, renal dysfunction, and circulatory insufficiency were similar in the two groups. CONCLUSIONS: Intensive glycemic control in diabetic patients receiving enteral nutrition after gastrectomy was associated with a lower surgical site infection rate but a higher hypoglycemia rate.

MicroRNA-542-3p suppresses cell growth of gastric cancer cells via targeting oncogene astrocyte-elevated gene-1.

MicroRNAs (miRNAs) have been suggested to play critical roles in tumorigenesis as well as in the development of therapies for the treatment of cancers. However, the tumor-associated miRNAs in gastric cancers remain poorly understood. Here, we report on miR-542-3p in gastric cancers, which has been widely studied in other cancers as a tumor suppressor. Real-time quantitative PCR analysis demonstrated that miR-542-3p was significantly down-regulated in gastric cancer tissues (p < 0.0001) and cell lines (p < 0.001). Overexpression of miR-542-3p significantly inhibited cell growth of gastric cancer cells both in vitro (p < 0.01) and in vivo (p < 0.01). Notably, overexpression of miR-542-3p apparently reduced the protein expression of astrocyte-elevated gene-1 (AEG-1) (p < 0.01). The dual-luciferase reporter assay validated that miR-542-3p directly bound the 3'-untranslated region (UTR) of AEG-1, which could be abolished by mutation of the predicted miR-542-3p binding site. Furthermore, overexpression of miR-542-3p markedly inhibited the activation of oncogenic signaling pathways including the Akt, ß-catenin and nuclear factor-κB pathways. Additionally, overexpression of AEG-1 without the 3'-UTR partially reversed the cell growth arrest induced by miR-542-3p overexpression in gastric cancer cells (p < 0.05). Taken together, these data suggest that miR-542-3p might function as a tumor suppressor in gastric cancer, potentially by targeting the oncogene AEG-1, implying a potential role for miR-542-3p in the development of therapeutic methods for gastric cancer.

The unfolded protein response potentiates epithelial-to-mesenchymal transition (EMT) of gastric cancer cells under severe hypoxic conditions.

The hypoxic condition occurs in most types of solid tumors and has been shown to be associated with the metastatic ability of gastric cancer. A previous study has demonstrated that hypoxia might stimulate epithelial-to-mesenchymal transition (EMT) of gastric cancer cells. Nevertheless, the mechanism has not yet been completely understood. In the current study, the human gastric cancer cell lines HGC27 and MGC803 were presented to normoxic (21 % O2), hypoxic (1 % O2) or severe hypoxic (0.1 % O2) conditions for 24 h. We found that hypoxia exposure induced EMT of gastric cancer cells, which was promoted by severe hypoxia condition. Meanwhile, expressions of PERK, ATF4 and ATF6 proteins were elevated in cells under conditions of severe hypoxia but not by normoxia or hypoxia. Knockdown of PERK, ATF4 or ATF6 impeded EMT of gastric cancer cells induced by severe hypoxia. Furthermore, severe hypoxia exposure extremely boosted the expression of TGF-ß, which was blocked by the knockdown of PERK, ATF4 or ATF6 expression. Additionally, we found that TGF-ß release caused by hypoxia is facilitated by elevated UPR proteins and led to the activation of Smad2/3 and PI3K/Akt signaling. Our data suggest that UPR potentiates the EMT of gastric cancer cells under conditions of severe hypoxia.

Effects of HMG on revascularization and follicular survival in heterotopic autotransplants of mouse ovarian tissue.

Ovarian tissue transplantation is now considered as a procedure to preserve the fertility of young women patients undergoing cancer therapy. The present study investigated the effects and mechanism of human menopausal gonadotrophin (HMG) intervention on vascular remoulding in ovarian heterotopic autotransplantation. Ovaries of 8-week-old mice were cultured in vitro with different concentrations of HMG for 3h for measuring the expression of vascular endothelial growth factor (VEGF). The cultured ovaries were implanted under the kidney capsule and removed 24, 36, 48 h or 1 month after transplantation. Revascularization, fluid exudation and the number of surviving ovarian follicles were observed. The results showed that VEGF was increased 1.6-6.5 times in the HMG intervention groups. Revascularization appeared 24-36 h after transplantation and was earlier than that of the control. Fluid exudation increased incrementally with increasing HMG concentrations. The total number of surviving ovarian follicles was increased by 1.2-1.5 times in the HMG 0.15 IU/ml group as compared with the other groups 1 month after transplantation. It is concluded that intervention with HMG in vitro before transplantation could improve the blood supply reconstruction and survival of the autotransplanted ovarian follicles, which might be associated with increased VEGF expression.

Drug synergistic antifertility effect of combined administration of low-dose gossypol with steroid hormones in rats.

BACKGROUND: Our previous studies suggested that low-dose gossypol combined with steroid hormones has a reversible antifertility role in adult male rats, and the course of treatment was shorter than that of either gossypol or steroid hormones alone. This result suggested that low-dose gossypol and steroid hormones have a drug synergistic effect on antifertility. The aim of the study was to find the target organs of the antifertility synergistic effect of the combined regimen. METHODS: Thirty-two adult male rats were divided into four groups randomly: group GH, rats were fed orally with gossypol acetic acid (GA, 12.5 mg×kg(-1)×d(-1)) and desogestrel (DSG, 0.125 mg×kg(-1)×d(-1))/ethinylestradiol (EE, 0.025 mg×kg(-1)×d(-1))/testosterone undecanoate (TU, 100 mg×kg(-1)×d(-1)); group G, a single dose of GA (12.5 mg×kg(-1)×d(-1)) was given; group H, the same dosage of DSG/EE/TU as in group GH were administered; group C, rats were treated with vehicle (1% methyl cellulose) as control. Testes and epididymis were removed at 8 weeks post-treatment for evaluating their weight, volumes, volume fraction, and total volume of testicular tissue structures and the seminiferous tubule diameter using stereological assay. Sperm cell numbers and the motility of epididymal sperm were quantitated by flow cytometry and morphological methods. RESULTS: Compared with group C, spermatogenesis was normal in group G and suppressed in groups H and GH. Similar changes of testicular tissue structures and sperm number were found in groups H and GH. The decreases of epididymal sperm number and motility in group GH were greater than that of the low-dose gossypol or steroid hormones alone group. CONCLUSIONS: The suppression of spermatogenesis was induced by steroid hormones in the combined regimen, and the epididymis was the target organ of low-dose gossypol. Combined use of low-dose gossypol and steroid hormones played a comprehensive antifertility role in their synergistic effect on reducing the number and motility of epididymal sperm.

Endocrine function and lymphocyte infiltration of newborn rat ovaries after ultrarapid freezing and allotransplantation.

OBJECTIVE: To evaluate the endocrine function and lymphocyte infiltration of ultrarapidly frozen newborn rat ovaries in adult recipients. DESIGN: Animal study. SETTING: Reproductive Medicine Laboratory of Ningxia Medical College. ANIMAL(S): Newborn rats within 24 hours after birth and Sprague-Dawley female adult rats. INTERVENTION(S): Newborn or adult rat ovary tissues were cryopreserved with ultrarapid freezing method, using 1.5 M propylene glycol and 0.1 M sucrose as a cryoprotectant agent. After thawing, they were allotransplanted under the kidney capsule of ovariectomized adult female rats to assess the function and the microstructure. MAIN OUTCOME MEASURE(S): Vaginal smear, serum E2 level in recipients, grafts histologic observation, 3beta-hydroxy steroid dehydrogenase histochemistry staining, and CD4(+)/CD8(+) T cell immunohistochemistry staining. RESULT(S): Frozen-thawed newborn rat ovaries survived and established a vascular network with the kidney of recipients. More growing follicles were found in these survival grafts. No significant differences were found in both resumption rates, the day of initiating estrous cycles, and E2 level between the frozen adult and frozen newborn rat ovaries transplant group. Among all the groups, the number of lymphocyte in the frozen newborn rat ovary transplant group is the lowest. CONCLUSION(S): This is the first report for ultrarapid cryopreservation that can preserve the development potential of immature ovaries in ovariectomized adult recipients and further reduce their immunogenicity successfully.