Shaohua Ge

The pretreatment platelet and plasma fibrinogen level correlate with tumor progression and metastasis in patients with pancreatic cancer

Abstract Cancer patients frequently present with activated coagulation pathways and thrombocytosis, which are potentially associated with tumor progression and prognosis. However, the prognostic value of abnormal plasma fibrinogen and platelet levels for the treatment of pancreatic cancer is unclear. The purpose of our study was to evaluate the prognostic value of plasma fibrinogen and platelet levels in pancreatic cancer, and to devise a prognostic model to identify the patients with greatest risk for a poor overall survival. One hundred and twenty-five patients diagnosed with pancreatic ductal adenocarcinoma in our hospital between May 2000 and June 2005 were included in this study. The plasma fibrinogen and platelet levels were examined before treatment and analyzed along with patient clinicopathological parameters and overall survival. The foundation of prognostic model was based on the risk factors according to the Cox proportional hazard model. The incidence of hyperfibrinogenemia and thrombocytosis was 24.8% (31/125) and 15.2% (19/125), respectively. The mean fibrinogen concentration differed significantly between the early (I/II) and late (III/IV) stage patients (3.19 ± 0.70 vs. 3.65 ± 0.90 g/l, p = 0.008). Patients with a higher concentration of plasma fibrinogen and platelets had a worse prognosis (p < 0.05). There also existed a significant correlation between higher fibrinogen/platelet levels and distant organ metastasis (p < 0.05, respectively). Bivariate correlation analysis showed that plasma fibrinogen levels correlated significantly with platelet levels (p = 0.000). Multivariate analysis revealed that pretreatment plasma fibrinogen levels (p = 0.027), tumor stage (p = 0.026) and distant metastasis (p = 0.027) were independent prognostic factors. The median survival time for the low-, intermediate-, and high-risk groups was 9.6 months (95% CI 6.2–13.0), 3.8 months (95% CI 2.3–5.3), and 2.3 months (95% CI 0.9–3.7), respectively (p = 0.000). Pretreatment plasma fibrinogen and platelet levels closely correlated with tumor progression, metastasis and overall survival in pancreatic cancer. The foundation of prognostic model may help us identify the greatest risk populations with pancreatic cancer.

MiRNA27a is a biomarker for predicting chemosensitivity and prognosis in metastatic or recurrent gastric cancer

We previously identified five miRNAs (miR‐1, miR‐20a, miR‐27a, miR‐34a, and miR‐423‐5p) that are up‐regulated in gastric cancer. The goal of this study was to investigate the value of these miRNAs as potential biomarkers for predicting chemosensitivity and prognosis in metastatic or recurrent gastric cancer patients who received first‐line chemotherapy. A total of 82 patients with metastatic or recurrent GC receiving first‐line chemotherapy were included in our study. The expression levels of the five miRNAs were evaluated using hydrolysis probe‐based stem‐loop quantitative reverse transcription polymerase chain reaction (qRT‐PCR) in individual samples before first‐line chemotherapy. Patients receiving first‐line chemotherapy with fluoropyrimidine combined with oxaliplatin or paclitaxel were chosen for the chemosensitivity analysis. The relationships between expression of the five‐miRNAs and clinicopathological parameters, response to chemotherapy and prognosis were analyzed statistically. Patients with higher miRNA1 expression levels tended to have a higher rate of liver metastasis, and higher miRNA34a expression levels occurred more frequently in males (P = 0.022). The expression of the remaining three miRNAs showed no obvious relationship to any of the clinicopathological features. The partial response rates of the patients with high miRNA1 expression and low miRNA1 expression were 11.1% and 23.1%, respectively (P = 0.048). Similar results were observed for miRNA27a (the partial response rate was 7.7% vs. 25.9%, P = 0.018). Patients with up‐regulated miRNA27a expression had a significantly worse overall survival (OS) than patients with lower miRNA27a expression (P = 0.024). In patients with MRGC, miRNA27a is a potential biomarker for predicting resistance to fluoropyrimidine‐based chemotherapy and a novel prognostic marker for gastric cancer. J. Cell. Biochem. 115: 549–556, 2014.

Cell-derived microvesicles mediate the delivery of miR-29a/c to suppress angiogenesis in gastric carcinoma

Microvesicles (MVs) secreted from cells have been found to mediate signal transduction between cells. In the tumor microenvironment, VEGF released from cancer cells plays a key role in promoting tumor angiogenesis. In this study, we characterized the inhibitory effect of MV-delivered miR-29a/c on angiogenesis and tumor growth in gastric cancer (GC). We found that the downregulation of miR-29a/c increases VEGF expression and release in GC cells, promoting the growth of vascular cells. By simulating the tumor microenvironment, the MV-delivered miR-29a/c significantly suppresses VEGF expression in GC cells, inhibiting vascular cell growth, metastasis, and tube formation. We also used a tumor implantation mouse model to show that secreted MVs containing overexpressed miR-29a/c significantly reduced the growth rate of the vasculature and tumors in vivo. To conclude, our results contribute to a novel anti-cancer strategy using miRNA-containing MVs to control tumor cell growth by blocking angiogenesis.

Onco-miR-24 regulates cell growth and apoptosis by targeting BCL2L11 in gastric cancer

ABSTRACTGastric cancer is one of the most common malignancies worldwide; however, the molecular mechanism in tumorigenesis still needs exploration. BCL2L11 belongs to the BCL-2 family, and acts as a central regulator of the intrinsic apoptotic cascade and mediates cell apoptosis. Although miRNAs have been reported to be involved in each stage of cancer development, the role of miR-24 in GC has not been reported yet. In the present study, miR-24 was found to be up-regulated while the expression of BCL2L11 was inhibited in tumor tissues of GC. Studies from both in vitro and in vivo shown that miR-24 regulates BCL2L11 expression by directly binding with 3′UTR of mRNA, thus promoting cell growth, migration while inhibiting cell apoptosis. Therefore, miR-24 is a novel onco-miRNA that can be potential drug targets for future clinical use.

Systemic therapies for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common cancer with high incidence and mortality worldwide. The main treatments for HCC include radical hepatectomy, liver transplant, locoregional therapies, and systemic therapies. Systemic treatments include targeted agent treatment, chemotherapies, antiviral therapies, and nutritional treatments. According to the results of SHARP and ORIENTAL study, sorafenib became the standard first-line therapy since 2008 because of nearly three months of survival improvement in patients with advanced HCC. Subsequent studies on targeted agents found that neither sunitinib nor brivanib were superior to sorafenib as first-line therapy. After progression or intolerance of sorafenib, brivanib did not improve the overall survival (OS) compared with placebo as second-line therapy. Randomized controlled EACH study and retrospective AGEO study for systemic chemotherapy showed that oxaliplatin-based or gemcitabine-based regimen was effective for advanced HCC patients. Randomized controlled trial for adjuvant chemotherapy in China showed that capecitabine could reduce the risk of recurrence and improve postoperative survival of HCC. Comparing sorafenib with other treatments, several retrospective studies found that other treatments were not inferior to sorafenib in terms of OS. In the systemic treatment of HCC, antiviral treatment can decrease the recurrence of HBV-related HCC postoperation and prolong the survival of patients. Based on the etiology, symptoms, complications, and treatment-related side effects, nutritional treatment is also very important for HCC patients. Systemic chemotherapy, newer targeted agents, and immune therapy are the new directions in future research.

The miR-24-Bim pathway promotes tumor growth and angiogenesis in pancreatic carcinoma

miRNAs are a group of small RNAs that have been reported to play a key role at each stage of tumorigenesis and are believed to have future practical value. We now demonstrate that Bim, which stimulates cell apoptosis, is obviously down-regulated in pancreatic cancer (PaC) tissues and cell lines. And Bim-related miR-24 is significantly up-regulated in PaC. The repressed expression of Bim is proved to be a result of miR-24, thus promoting cell growth of both cancer and vascular cells, and accelerating vascular ring formation. By using mouse tumor model, we clearly showed that miR-24 promotes tumor growth and angiogenesis by suppressing Bim expression in vivo. Therefore, a new pathway comprising miR-24 and Bim can be used in the exploration of drug-target therapy of PaC.

MiR-17-5p regulates cell proliferation and migration by targeting transforming growth factor-β receptor 2 in gastric cancer

TGFBR2 serves as an initial regulator of the TGF-β signaling pathway, and loss or reduction of its expression leads to uncontrolled cell growth and invasion. TGFBR2 plays a crucial role in the carcinogenesis and malignant process of gastric cancer, but the mechanism remains unclear. In this study, we found that TGFBR2 protein levels were consistently upregulated in gastric cancer tissues, whereas TGFBR2 mRNA levels varied among these tissues, indicating that a post-transcriptional mechanism is involved in the regulation of TGFBR2. MiRNAs are known to regulate gene expression at the post-transcriptional level. Therefore, we performed bioinformatics analyses to search for miRNAs potentially targeting TGFBR2. MiR-17-5p was found to bind to the 3′UTR of TGFBR2 mRNA, and further validation of this specific binding was performed through a reporter assay. An inverse correlation between miR-17-5p and TGFBR2 protein was observed in gastric cancer tissues. Cell studies revealed that miR-17-5p negatively regulated TGFBR2 expression by directly binding to the 3′UTR of TGFBR2 mRNA, thereby promoting cell growth and migration. We also validated the role of TGFBR2 using siRNA and an overexpression plasmid. The results of our study suggest a novel regulatory network in gastric cancer mediated by miR-17-5p and TGFBR2 and may indicate that TGFBR2 could serve as a new therapeutic target in gastric cancer.

Integrated analysis of the miRNA, gene and pathway regulatory network in gastric cancer

Gastric cancer is one of the most common malignant tumors worldwide; however, the efficacy of clinical treatment is limited. MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been reported to play a key role in the development of cancer. They also provide novel candidates for targeted therapy. To date, in-depth studies on the molecular mechanisms of gastric cancer involving miRNAs are still absent. We previously reported that 5 miRNAs were identified as being significantly increased in gastric cancer, and the role of these miRNAs was investigated in the present study. By using bioinformatics tools, we found that more than 4,000 unique genes are potential downstream targets of gastric cancer miRNAs, and these targets belong to the protein class of nucleic acid binding, transcription factor, enzyme modulator, transferase and receptor. Pathway mapping showed that the targets of gastric cancer miRNAs are involved in the MAPK signaling pathway, pathways in cancer, the PI3K-Akt signaling pathway, the HTLV-1 signaling pathway and Ras signaling pathway, thus regulating cell growth, differentiation, apoptosis and metastasis. Analysis of the pathways related to miRNAs may provides potential drug targets for future therapy of gastric cancer.

Exosomes serve as nanoparticles to suppress tumor growth and angiogenesis in gastric cancer by delivering hepatocyte growth factor siRNA

Exosomes derived from cells have been found to mediate signal transduction between cells and to act as efficient carriers to deliver drugs and small RNA. Hepatocyte growth factor (HGF) is known to promote the growth of both cancer cells and vascular cells, and the HGF‐cMET pathway is a potential clinical target. Here, we characterized the inhibitory effect of HGF siRNA on tumor growth and angiogenesis in gastric cancer. In addition, we showed that HGF siRNA packed in exosomes can be transported into cancer cells, where it dramatically downregulates HGF expression. A cell co‐culture model was used to show that exosomes loaded with HGF siRNA suppress proliferation and migration of both cancer cells and vascular cells. Moreover, exosomes were able to transfer HGF siRNA in vivo, decreasing the growth rates of tumors and blood vessels. The results of our study demonstrate that exosomes have potential for use in targeted cancer therapy by delivering siRNA.

MiR-221 and miR-222 synergistically regulate hepatocyte growth factor activator inhibitor type 1 to promote cell proliferation and migration in gastric cancer

Gastric cancer is a common malignancy with limited treatment options and poor prognosis. Introduction of novel pathways of gastric cancer will provide candidates for target therapy. Hepatocyte growth factor activator inhibitor type 1 is an integral-membrane proteinase inhibitor. Hepatocyte growth factor activator inhibitor type 1 abnormality is found in various cancers and correlates with tumor progression and metastasis. However, the mechanisms underlying the dysregulation of hepatocyte growth factor activator inhibitor type 1 expression in gastric cancer remain unclear. Although microRNAs have been reported to be involved in the development of cancer, the roles of miR-221 and miR-222 in gastric cancer have not been reported yet. In this study, we showed that hepatocyte growth factor activator inhibitor type 1 protein was downregulated, while miR-221 and miR-222 were significantly increased in gastric cancer tissues. Bioinformatic predictions and luciferase assay verified that the 3′-untranslated region of the HAI-1 gene is a direct target site for miR-221 and miR-222. Overexpression of miR-221 and miR-222 in MGC-803 cells leads to the inhibition of hepatocyte growth factor activator inhibitor type 1 protein expression, thus promoting cell proliferation and migration; whereas knockdown of miR-221 and miR-222 showed opposite effects. Moreover, we found that the expression level of hepatocyte growth factor activator protein was increased when hepatocyte growth factor activator inhibitor type 1 was knocked down in MGC-803 cells. Thus, gastric cancer is probably an autocrine tumor, and the antitumor mechanism of hepatocyte growth factor activator inhibitor type 1 in vitro might be mediated by regulating the expression of hepatocyte growth factor activator protein. Therefore, our data illustrated a novel pathway comprising miR-221and miR-222 and hepatocyte growth factor activator inhibitor type 1 in gastric cancer, which is a potential target for future clinical use.