Qing Cong

Altered protein expression in serum from endometrial hyperplasia and carcinoma patients

BackgroundEndometrial carcinoma is one of the most common gynecological malignancies in women. The diagnosis of the disease at early or premalignant stages is crucial for the patients prognosis. To date, diagnosis and follow-up of endometrial carcinoma and hyperplasia require invasive procedures. Therefore, there is considerable demand for the identification of biomarkers to allow non-invasive detection of these conditions.MethodsIn this study, we performed a quantitative proteomics analysis on serum samples from simple endometrial hyperplasia, complex endometrial hyperplasia, atypical endometrial hyperplasia, and endometrial carcinoma patients, as well as healthy women. Serum samples were first depleted of high-abundance proteins, labeled with isobaric tags (iTRAQ™), and then analyzed via two-dimensional liquid chromatography and tandem mass spectrometry. Protein identification and quantitation information were acquired by comparing the mass spectrometry data against the International Protein Index Database using ProteinPilot software. Bioinformatics annotation of identified proteins was performed by searching against the PANTHER database.ResultsIn total, 74 proteins were identified and quantified in serum samples from endometrial lesion patients and healthy women. Using a 1.6-fold change as the benchmark, 12 proteins showed significantly altered expression levels in at least one disease group compared with healthy women. Among them, 7 proteins were found, for the first time, to be differentially expressed in atypical endometrial hyperplasia. These proteins are orosomucoid 1, haptoglobin, SERPINC 1, alpha-1-antichymotrypsin, apolipoprotein A-IV, inter-alpha-trypsin inhibitor heavy chain H4, and histidine-rich glycoprotein.ConclusionsThe differentially expressed proteins we discovered in this study may serve as biomarkers in the diagnosis and follow-up of endometrial hyperplasia and endometrial carcinoma.

Hexokinase 2 confers resistance to cisplatin in ovarian cancer cells by enhancing cisplatin-induced autophagy

The high mortality rate of ovarian cancer is connected with the development of acquired resistance to multiple cancer drugs, especially cisplatin. Activation of cytoprotective autophagy has been implicated as a contributing mechanism for acquired cisplatin resistance in ovarian cancer cells. Hexokinase 2 (HK2) phosphorylates glucose to generate glucose-6-phosphate, the rate-limiting step in glycolysis. Higher HK2 expression has been associated with chemoresistance in ovarian cancer. However, whether HK2 functionally contributes to cisplatin resistance in ovarian cancer is unclear. In this study, we investigated the role of HK2 in regulating ovarian cancer cisplatin resistance. Increased HK2 levels were detected in drug-resistant human ovarian cancer cells and tissues. Cisplatin downregulated HK2 in cisplatin-sensitive but not in resistant ovarian cancer cells. HK2 knockdown sensitized resistant ovarian cancer cells to cisplatin-induced cell death and apoptosis. Conversely, HK2 overexpression in cisplatin-sensitive cells induced cisplatin resistance. Mechanistically, cisplatin increased ERK1/2 phosphorylation as well as autophagic activity. Blocking autophagy with the autophagy inhibitor 3-MA sensitized resistant ovarian cancer cells to cisplatin. HK2 overexpression enhanced cisplatin-induced ERK1/2 phosphorylation and autophagy while HK2 knockdown showed the opposite effects. Blocking the MEK/ERK pathway using the MEK inhibitor U0126 prevented cisplatin-induced autophagy enhanced by HK2 overexpression. Furthermore, HK2 knockdown sensitized resistance ovarian tumor xenografts to cisplatin in vivo. In conclusion, our data supported that HK2 promotes cisplatin resistance in ovarian cancer by enhancing drug-induced, ERK-mediated autophagy. Therefore, targeting HK2 may be a new therapeutic strategy to combat chemoresistance in ovarian cancer.

Ginkgo may prevent genetic-associated ovarian cancer risk: multiple biomarkers and anticancer pathways induced by ginkgolide B in BRCA1-mutant ovarian epithelial cells.

Women carrying BRCA1 mutations have a higher risk of developing ovarian cancers. Options to reduce this risk are largely limited to prophylactic surgery, which leads to a decrease in the quality of life and permanently damages fertility. There is a obvious and an urgent need to identify a noninvasive approach to effectively prevent the ovarian cancer risk, specifically for those women of reproductive age. Our previous studies showed that the use of the herbal remedy Ginkgo biloba may reduce the risk for nonmucinous ovarian cancer. Here, we explored whether Ginkgo biloba might also be an effective agent to reduce BRCA1-associated ovarian cancer (always serous-type) risk. A human ovarian surface epithelial cell line-636 was developed from a BRCA1-mutant carrier. Cells were treated with ginkgolide B (GB) or dimethyl sulfoxide, and protein lysates from the cells were applied to antibody microarrays to determine upregulated or downregulated protein expression patterns. Anticancer activities and the associated networking pathways with the altered proteins were analyzed by using the Pathway Studio software. After GB treatment, 28 proteins were shown to be consistently upregulated (1.5–15.5-fold), and 22 proteins were downregulated (1.5–28.3-fold). Bioinformatics software analysis indicated that multiple mechanisms and signal pathways are involved in anticancer activities in BRCA1-mutant cells induced by GB treatment. These pathways include cell proliferation, tumor suppression, and DNA damage repair. Our study suggested that GB found in the herbal Ginkgo biloba may have cancer-preventive activities in BRCA1-mutant ovarian epithelial cells.

Enhanced efficacy and specificity of epithelial ovarian carcinogenesis by embedding a DMBA-coated cloth strip in the ovary of rat

BackgroundOvarian cancer is predominant of epithelial cell origin and often present at an advanced stage with poor prognosis. Most animal models of ovarian carcinoma yield thecal/granulose cell tumors, rather than adenocarcinomas. The best reported induction rate of adenocarcinoma in rats is 10-45% by an ovarian implantation of 7, 12-dimethylbenz[a]anthracene (DMBA) coated silk suture. We provided an improved procedure to construct the model by the ovarian implantation of DMBA-coated cloth strip.MethodsA sterile suture (as S group) or a piece of cloth strip (as CS group) was soaked in DMBA before ovarian implantation in Wistar rats. Tumor size, incidence rate and pathological type were analyzed.ResultsOvarian tumors in rats of CS group were first noted at 16 wk post implantation and reached a cumulative incidence of 75% (96/128) at 32 wk, while the tumor incidence rate in S group at 32 wk was only 46.25% (37/80). The tumor size in CS group (3.63 ± 0.89 cm) was larger than that of S group (2.44 ± 1.89 cm) (P < 0.05). In CS group, there were only two types of tumor formed: adenocarcinoma (90/96) and sarcoma (6/96). While in S group, there were different types, including adenocarcinoma (21/37), squamous carcinoma (3/37), granulosa cell tumor (3/37), sarcoma (4/37), undifferentiated carcinoma with no adeno character (2/37), benign ovarian tumor (2/37), and malignant teratoma (1/37).ConclusionThe model in our study yields much higher incidence and specificity of epithelial derived tumors and showed histological similarities to human ovarian cancers, which would be more suitable for therapeutic research.

Ginkgo May Sensitize Ovarian Cancer Cells to Cisplatin Antiproliferative and Apoptosis-Inducing Effects of Ginkgolide B on Ovarian Cancer Cells

Ginkgolide B (GB), the primary active component of Ginkgo biloba extracts, may have antitumor properties. The objective of this study was to determine the effects and possible mechanisms of GB in ovarian cancer cells. In this study, human ovarian cancer cell lines (SKOV3 and CAOV3) were treated with different concentrations of GB alone or in combination with Cis-diaminodichloroplatinum (CDDP). An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to determine cell viability. The apoptosis rates of cells were measured by flow cytometric analysis. The expression of apoptosis-associated and proliferation-associated proteins was detected by Western blot. The cytotoxicity of GB was analyzed using a lactate dehydrogenase assay. Treatment with 100 µM GB for 3 days significantly inhibited SKOV3 and CAOV3 cell proliferation by 57.3% and 63.1% compared with control cells, respectively, as determined by MTT assay. Similarly, the apoptotic cell population was increased when treated with GB in a dose-dependent manner both in SKOV3 and CAOV3 cells. These effects were characterized by the upregulation of p21, p27, cleaved capase-3, and cleaved caspase-8 and downregulation of cyclin D1. In addition, a combined treatment of low concentrations of GB and CDDP showed an additive effect on the inhibition of SKOV3 cell proliferation. Furthermore, GB had significantly less cytotoxicity than CDDP in normal human ovarian surface epithelial cells. This study suggests that GB can be proposed as an effective antiproliferative and apoptosis-inducing agent with interesting translational application in ovarian cancers, used in addition to conventional chemotherapy.

Postoperative ascites of unknown origin after laparoscopic gynecologic surgery: a 5-year experience of 8 cases and review of the literature.

Purpose: We performed an observational study over 5 years on patients with postoperative ascites who had undergone laparoscopic surgery in our hospital. Methods: Patients with postoperative ascites of unknown origin were monitored in the hospital from July 2006 to June 2010. Clinical manifestations, biochemical analysis, and treatment are discussed in the study. Results: Of 21,380 laparoscopic surgeries, 8 cases of postoperative ascites of unknown origin were identified in otherwise healthy women. None of the patients revealed any definitive causes even after an extensive diagnostic work-up and recovered uneventfully with general supportive treatments. Conclusions: Postoperative ascites of unknown origin are a rare complication of laparoscopic gynecologic surgery. We surmised that the most likely cause of the ascites is a diffuse peritoneal injury by some substances used during the operation, and supportive therapy is very important.

Pyruvate dehydrogenase kinase 1 contributes to cisplatin resistance of ovarian cancer through EGFR activation: ZHANG et al.

Patients with ovarian cancer frequently develop acquired drug resistance after the long‐term chemotherapy, leading to disease progression. Enhanced epithelial–mesenchymal transition (EMT) has been implicated in chemoresistance of ovarian cancer cells; however, the molecular mechanisms involved are largely undefined. Pyruvate dehydrogenase kinase 1 (PDK1), a key regulatory enzyme in glucose metabolism, has been recognized as a gatekeeper of the Warburg effect, a hallmark of cancer. In this study, the function of PDK1 in cisplatin resistance of ovarian cancer in terms of growth and EMT was investigated. PDK1 was upregulated in cisplatin‐resistant ovarian cancer cells. PDK1 knockdown in resistant cells led to increased sensitivity to cisplatin‐induced cell death and apoptosis. PDK1 downregulation also reversed the EMT and cell motility in cisplatin‐resistant cells. In a mouse xenograft model, tumors derived from PDK1‐silenced ovarian cancer cells exhibited decreased tumor growth and EMT compared with control after the cisplatin treatment. Mechanistically, PDK1 overexpression led to increased phosphorylation of EGFR, and blocking EGFR kinase activity by erlotinib reversed cisplatin resistance induced by PDK1 overexpression. Furthermore, in patients with ovarian cancer, higher PDK1 and p‐EGFR levels were associated with chemoresistance. These results supported that PDK1 contributes to chemoresistance of ovarian cancer by activating EGFR. Therefore, PDK1 may serve as a promising target to combat chemoresistance of ovarian cancer.