Long Noncoding RNA CRNDE Promotes Proliferation of Gastric Cancer Cells by Targeting miR-145.

BACKGROUND/AIMS: The colorectal neoplasia differentially expressed (CRNDE) gene is a long noncoding RNA (lncRNAs) that is upregulated in colorectal cancer and glioma. Here, we investigated the regulatory function of CRNDE in gastric cancer (GC). METHODS: CRNDE and miR-145 expression were assayed by qRT-PCR, and E2F3 protein expression was measured by western blotting. A luciferase reporter assay was used to detect the direct regulation of miR-145 by CRNDE. Cell viability and colony formation of human GC cells were detected using MTT and colony formation assay, respectively. RESULTS: CRNDE was highly expressed in GC cell lines and tissues; overexpression of CRNDE increased GC cell viability and promoted colony formation. Knockdown of CRNDE did not result in loss of expression-related effects on cell proliferation and colony formation. Further investigation revealed that the miR-145 target gene E2F3 was strongly expressed following CRNDE competitive molecular sponging of miR-145. CONCLUSION: CRNDE acted as a growth-promoting lncRNA in GC and maybe a potential target of GC treatment.

JMJD2A predicts prognosis and regulates cell growth in human gastric cancer.

A number of JmjC domain-containing histone demethylases have been identified and biochemically characterized in mammalian. JMJD2A is a transcriptional cofactor and enzyme that catalyzes demethylation of histone H3 lysines 9 and 36. Here in this study, we aim to explore the role of JMJD2A in human gastric cancer. Quantitative real-time PCR, Western blot and immunohistochemistry analyses reveal higher expression of JMJD2A in clinical gastric cancer tissues than that in normal gastric mucosa. JMJD2A expression is associated with tumor stage and nodal status, and high level of JMJD2A predicts poor overall and disease-free survival. Univariate and multivariate survival analyses demonstrate that JMJD2A could serve as an independent prognostic factor. Furthermore, we show that inhibition the expression of JMJD2A attenuates the growth and transformation of three lines of gastric cancer cells. Mechanically, JMJD2A knockdown induces apoptosis of gastric cancer cells by up-regulating the expression of pro-apoptotic proteins and by down-regulating anti-apoptotic protein. Finally, we show that JMJD2A level is correlated with the level of the pro-apoptotic microRNA miR-34a in gastric cancer tissues and JMJD2A represses the expression of miR-34a by decreasing its promoter activity. Those findings demonstrate that JMJD2A regulates gastric cancer growth and serves as an independent prognostic factor, and implicate that JMJD2A may be a promising target for intervention.

The RNA-binding protein PCBP2 facilitates gastric carcinoma growth by targeting miR-34a.

Gastric carcinoma is the fourth most common cancer worldwide, with a high rate of death and low 5-year survival rate. However, the mechanism underling gastric cancer is still not fully understood. Here in the present study, we identify the RNA-binding protein PCBP2 as an oncogenic protein in human gastric carcinoma. Our results show that PCBP2 is up-regulated in human gastric cancer tissues compared to adjacent normal tissues, and that high level of PCBP2 predicts poor overall and disease-free survival. Knockdown of PCBP2 in gastric cancer cells inhibits cell proliferation and colony formation in vitro, whereas opposing results are obtained when PCBP2 is overexpressed. Our in vivo subcutaneous xenograft results also show that PCBP2 can critically regulate gastric cancer cell growth. In addition, we find that PCBP2-depletion induces apoptosis in gastric cancer cells via up-regulating expression of pro-apoptotic proteins and down-regulating anti-apoptotic proteins. Mechanically, we identify that miR-34a as a target of PCBP2, and that miR-34a is critically essential for the function of PCBP2. In summary, PCBP2 promotes gastric carcinoma development by regulating the level of miR-34a.

Up-regulated myeloid-derived suppressor cell contributes to hepatocellular carcinoma development by impairing dendritic cell function.

OBJECTIVE: Defective immune function is an important cause of tumor development. Accumulation of myeloid-derived suppressor cell (MDSC) associated with inhibition of dendritic cell (DC) function is one of the major immunological abnormalities in cancer. However, the molecular mechanism of the phenomenon remains unclear. MATERIAL AND METHODS: We evaluated T cell stimulatory activity and interleukin (IL)-12 production of DC in a mouse model of liver cancer (hepatocellular carcinoma [HCC] mice). Then we detected the frequency of MDSC in spleen, peripheral blood (PB), lymph node (LN) and tumor tissue of HCC mice and its potential mechanisms. We also evaluated IL-10 production of MDSC and mechanism by which MDSC inhibit DC function. RESULTS: Toll-like receptor (TLR)-ligand (LPS, CpG, poly(I:C))-induced IL-12 production of DC was decreased in HCC mice compared with control. The T cell stimulatory activity of DC was lower in HCC mice than in controls. Meanwhile, an increase in the frequency of MDSC in tumor development was detected in spleen, PB, LN and tumor, and the IL-10 levels were higher in HCC mice derived MDSC than in control. Furthermore, the MDSC inhibited TLR-ligand-induced IL-12 production of DC by IL-10 production and suppressed T cell stimulatory activity of DC. Finally, we demonstrated that the increase in the frequency of MDSC was mediated by MyD88-NF-kB pathway. CONCLUSIONS: Our study suggests a new role for MDSCs in HCC development by suppressing host immune responses, and these findings have important implications when designing immunotherapy protocols.

[Intralymphatic chemotherapy with adriamycin-adsorbing nanometric activated carbon:pharmacokinetic experiment with dogs].

OBJECTIVE: To observe the pharmacokinetics of adriamycin-adsorbing nanometric activated carbon in intralymphatic chemotherapy. METHODS: Two ml of suspension of activated carbon with the diameter of 21 nm was mixed with adriamycin 5 mg. Eighteen dogs were randomly divided into 6 equal groups. The above mentioned mixture was injected subserosally to the anterior wall of gastric antrum of the dogs. Thirty minutes, 1 h, 2 h, 1 day, and 3 days after the injection the gastroepiploic lymph nodes of the Groups 1 - 5 were obtained. And Group 6 underwent extraction of venous blood samples 5, 15, 30, 60, 120, and 240 minutes after the injection and extraction of thoracic duct fluid 5, 15, 30, 60, 120, 240, and 360 minutes after the injection. The adriamycin concentrations at different time points were determined by mass spectrometer. The lymphatic vessels and nodes at the gastric wall were observed by the naked eyes. RESULTS: Black tiny lymphatic vessels and lymph nodes were visualized around the injection areas immediately after the injection. Adriamycin content could be detected 30 min after the injection and lasted for 72 h at high levels with the peak content of (84.6 +/- 2.0) microg per gram tissue at 60 min in the perilymph node of gastroepiploic artery. The adriamycin concentration in the lymph fluid of thoracic duct reached the top level of 162.5 ng/ml 30 min after the injection, and then decreased slowly. Adriamycin could be still detected in lymph fluid 6 h after injection. No trace of adriamycin was found in the blood at any time points. CONCLUSION: The content of adriamycin can keep high and last long in the drainage of lymph node and lymph fluid in the treatment of intralymphatic chemotherapy using adriamycin-adsorbing nanometric activated carbon.

[Effect of injecting activated carbon ultramicroparticles around the gastric tumor on staining lymph node].

OBJECTIVE: To observe the effect of injecting activated carbon ultramicroparticles around the gastric tumor before or during operation on staining lymph nodes and guiding the lymphadenectomy of gastric cancer. METHODS: Forty-three cases of gastric cancer received activated carbon (AC) ultramicroparticles around the tumor by submucosal endoscopic injection 1 approximately 6 days before the operation and/or intraoperative subserosal injection (AC group), whereas 82 cases of gastric cancer without the injection were used as control group. The number of dissected lymph nodes, number of black-stained lymph nodes and its relation to the injection time, metastasis of lymph nodes, and the side effect of the procedure were analyzed. RESULTS: The average numbers of resected lymph nodes were 34 +/- 13 in the AC group, significantly higher than that in the control group (16 +/- 9, P < 0.05). The dissected N(2) lymph nodes in the AC group was 25 +/- 9, significantly higher than that in the control group (8 +/- 4, P < 0.05). The total ratio of black-stained lymph node was 60.3% in general, 71.3% for the N1 lymph nodes and 56.3% for the N(2) lymph nodes in the AC group. Satisfactory effect of black staining of lymph nodes could be seen 2 days after local gastric tissue injection of activated carbon ultramicroparticles. The metastasis rate was 67.4% in the AC group, not significantly different from that in the control group (63.4%, P > 0.05). In the patients of AC group the metastasis rate of black-stained lymph node was 26.8%, significantly higher than that of the unstained lymph nodes (3.3%) and higher than that of the control group (18.4%). No serious side effect happened after the activated carbon ultramicroparticles injection in local gastric tissue. CONCLUSION: Local injection of activated carbon ultramicroparticles around the tumor is an effective, easy and safe procedure to guide gastric cancer lymphadenectomy.

[The clinical study on application of using a novel blockade technique for gastric cancer to decrease blood-borne metastasis of cancer cells].

OBJECTIVE: To evaluate the effect of a novel blockade technique for gastric cancer on blood-borne metastasis of gastric cancer cells to portal vein. METHODS: Twenty-three cases of gastric cancer were divided into routine operation group (8 cases intraoperatively without blockade technique) and blockade group (15 cases with blockade technique). Blood samples from portal vein pre- and intraoperatively, as well as gastroepiploic vein limited within the blockade area were obtained to detect CK19 mRNA expression by using RT-PCR technique. RESULTS: Before the dissection of gastric lesion, the overall positive rate of CK19 mRNA expression in portal vein blood is 34.7% (9/23), including 37.5% (3/8) in routine operation group and 33.3% (5/15) in blockade group. While the course of tumor resection, those positive rates were 87.5% (7/8) in routine operation group and 6.7% (1/15) in blockade group respectively (P < 0.05). CK19 mRNA expression in the right gastroepiploic venous blood limited within the blocking area was all positive in 15 cases of blockade group. CONCLUSION: This blockade technique can be used effectively to block the intraoperative spread of gastric cancer cells, thus prevent blood-borne metastasis due to operative manipulation.

Comprehensive analysis of vascular endothelial growth factor-C related factors in stomach cancer.

BACKGROUND: Vascular endothelial growth factor-C (VEGF-C), which contributes to lymphatic metastasis (LM) in malignant disease, is one of the most important factors involved in physical and pathological lymphangiogenesis. Some VEGF-C related factors such as sine oculis homeobox homolog (SIX) 1, contactin (CNTN) 1 and dual specificity phosphatase (DUSP) 6 have been extensively studied in malignancies, but their expression levels and associations have still to be elucidated in stomach cancer. METHODS: We detected their expression levels in 30 paired stomach cancer tissues using quantitative real-time reverse transcription-PCR (qRT-PCR). The expression and clinical significance of each factor was analyzed using Wilcoxon signed rank sum test. The correlation among all the factors was performed by Spearman rank correlation analysis. RESULTS: The results suggest that VEGF-C and CNTN1 are significantly correlated with tumor size, SIX1 with the age and CNTN1 also with the cTNM stage. There are significant correlations of expression levels among VEGF-C, SIX1, CNTN1 and DUSP6. CONCLUSIONS: There exists an important regulatory crosstalk involving SIX1, VEGF-C, CNTN1 and DUSP6 in stomach cancer.