Prognostic significance of CUEDC2 expression in hepatocellular carcinoma

AIM: To investigate the expression of CUE domain-containing 2 (CUEDC2) in hepatocellular carcinoma (HCC) and to analyze its clinical prognostic significance. METHODS: Total 186 formalin-fixed paraffin-embedded tissues obtained from surgical HCC with detailed clinicopathological and follow-up data were used. The expression of CUEDC2 was detected by immunohistochemistry. The relationships between the expression of CUEDC2 and clinicopathological characteristics and prognosis were analyzed. RESULTS: The positive rate of CUEDC2 in HCC was 85.5% (159/186), among which, the low expression was 52.2% (97/186) and the high expression was 47.8% (89/186). CUEDC2 expression was correlated with serum alpha-fetal protein (AFP) level, tumor size, tumor number, tumor differentiation and TNM stage (P<0.05). Kaplan-Meier survival curves showed that the patients with high expression of CUEDC2 were associated with significantly shorter overall survival and recurrence-free survival than those with low CUEDC2 expression (P<0.05). Multivariate Cox regression analysis revealed 3 independent prognostic factors including CUEDC2 expression, serum AFP and tumor number. CONCLUSION: CUEDC2 was expressed in most HCC tissues, which was relevant to tumor growth, tumor differentiation and prognosis. CUEDC2 could be a novel valuable molecular marker to predict the HCC prognosis.     

Apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol

AIM: To investigate the molecular mechanism of the apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol. METHODS: Human primary gastric cancer cells were planted into nude mice to establish the cancer model. Resveratrol at different doses were injected near the carcinoma on the nude mice. After treatment, transmission electron microscope and TUNEL staining method were used to detect the apoptosis of implanted tumor cells. Immunohistochemical staining and RT-PCR were used to detect the expression of apoptosis-related genes bcl-2 and bax in implanted tumor. RESULTS: Resveratrol significantly inhibited carcinoma growth when it was injected near the carcinoma. The apoptotic cells in implanted tumor induced by resveratrol were detected by transmission electron microscope and TUNEL staining, immunohistochemical staining and RT-PCR showed resveratrol inhibited bcl-2 expression and increased bax expression in human primary gastric cancer cells. CONCLUSION: Resveratrol inhibits implanted tumor of human primary gastric cancer cells in nude mice through inducing apoptosis. This apoptosis may be mediated by down-regulation of bcl-2 expression and up-regulation of bax expression.     

Effects of lovastatin on differentially expressed genes in HepG2 cells

AIM: To analyze the lovastatin-induced differential gene expression in HepG2 cells using a cDNA microarray assay. METHODS: Total RNA was extracted from the lovastatin-treated HepG2 cells and control group. cDNA was synthesized from RNA with Cy3/Cy5-labelled dCTP. Then the hybridization was conducted. The result was analyzed using Imagene and Genespring software. RT-PCR was carried to confirm the hybridization results. RESULTS: 30 genes were up-regulated while 11 genes were down-regulated in lovastatin-treated HepG2 cells, involved in some major functional areas including signal transduction, cell cycle regulation, tumor immunity, and so on. CONCLUSION: The analysis of differentially expressed genes in lovastatin-treated HepG2 cells is helpful to explore the mechanism of the anti-tumor activity of statins.     

Effects of RNA interference of FABP5 on subcutaneous tumor of human hepatocellular carcinoma cell line HepG 2 transplanted in nude mice

AIM: To investigate the effect of recombinant lentiviral vector for RNA interference (RNAi) on the expression of fatty acid-binding protein 5 (FABP5) gene in hepatocellular carcinoma HepG2 cells and tumor formation in nude mice.METHODS: RNAi lentiviral vector was used in the experiment. Human hepatocellular carcinoma HepG2 cells were divided into 3 groups:the HepG2 cells in experimental group were transfected with the recombinant lentivirirus vector LV-shRNA-FABP5, the cells in negative control group were transfected with a control lentiviral vector LV-shRNA-NC, and the cells in normal control group were without any treatment. The nude mice were randomly divided into 3 groups. The growth of the transplanted tumor cells in the nude mice was observed. The tumor growth curve, volume and weight were determined 4 weeks after the cell inoculation. The expression of FABP5 was detected by real-time PCR, Western blot and immunohistochemical staining.RESULTS: Transfection of the lentiviral vector FABP5-shRNA obviously reduced FABP5 expression in the HepG2 cells. Tumor formation was all positive in the 3 groups of the nude mice inoculated with the tumor cells. Compared with normal control group and negative control group, the tumor growth slowed significantly in experimental group with smaller volume and weight. FABP5 expression in the transplanted tumor tissues was significantly down-regulated at mRNA and protein levels in experimental group as compared with normal control group and negative control group.CONCLUSION: RNAi-induced down-regulation of FABP5 effectively inhibits the growth of transplanted hepatocellular carcinoma, suggesting that FABP5 gene may be an effective target for gene therapy in treating liver cancer.     

Significance of expression of Flt-4 in different histopathological grades of astrocytoma

AIM: To study the significance of expression of fms-like tyrosine kinase 4 (Flt-4) in different histopathological grades of astrocytoma. METHODS: The surgical specimens from 50 brain astrocytoma patients were stained immunohistochemically for examining Flt-4 and vascular endothelial growth factor (VEGF) expression. Intratumoral microvessel density (IMVD) was calculated by labeling the endothelial cells of the blood vessels within the tumor. RESULTS: Flt-4, VEGF expression were closely correlated with histopathological grades of astrocytoma. Flt-4 and VEGF expression were found in 52% (26/50), 60% (30/50) of tumors. A significant correlation was found between Flt-4 and VEGF expression (P<0.01). CONCLUSIONS: Flt-4 is presented in human brain astrocytoma. Flt-4 expression is mainly expressed in vascular endothelial cells and some tumor cells. Flt-4 may not only come from autocrine secretion of vascular endothelial cells, but also from paracrine secretion of tumor cells. The expression of Flt-4 is significantly associated with histopathological grades of astrocytoma.     

Regulation of MMP-2 and TIMP-3 expression by uPA signal transduction system in human bone giant cell tumor

AIM: To study effects of urokinase-type plasminogen activator (uPA) signal transduction on expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) in giant cell tumor of bone (GCT). METHODS: Expression of uPAR, MMP-2 and TIMP-3 in GCT tissue was detected by immunohistochemistry. Phosphorylation level of mitogen-activated protein kinase (p44) in uPA/uPAR signal pathway in cultured GCT cells was detected by immunoprecipitation. The expression of MMP-2 and TIMP-3 in cultured cells after treatment with uPA-ATF or anti-uPAR antibody was also detected by Western blotting. RESULTS: 1) Urokinase-type plasminogen activator receptor (uPAR) was positive on the cell membrane and in cytoplasm of some mononuclear stromal cells (MSCs) and multinucleated giant cells (MGCs); 2) MMP-2 was positive in the cytoplasm and on the cell membrane of almost all of MSCs and some of MGCs. The polar distribution of MMP-2 in the cytoplasm of MGCs was especially obvious; 3) The expression of TIMP-3 of some MSCs and MGCs in GCT was much lower than MMP-2. The positive signal also showed a prominent polarity; 4) After treatment with uPA-ATF, the phosphorylation level of p44 in GCT cultured cells was much higher than the control. Addition of anti-uPAR antibody in the cells remarkably down-regulated the phosphorylation level of p44 as compared with the control group, suggesting that uPA-ATF participates cell signal transduction and this reaction can be inhibited by anti-uPAR antibody; 5) uPA-ATF cell signal pathway up-regulated expression of MMP-2 and TIMP-3, while anti-uPAR antibody down-regulated the expression of MMP-2 and TIMP-3. CONCLUSION: These results demonstrate for the first time that uPA-ATF directly regulates the expression of MMP-2 and TIMP-3 by signal transduction pathway, and the over-expression of MMP-2 and TIMP-3 may play an important role in local osteolysis of GCT.     

NFATc1 promotes vascular generation of epithelial ovarian cancer transplanted tumor by regulating CXCR2, FGF-2 and PDGF-BB

AIM: To investigate the role of NFATc1 in vascular generation in the nude mice transplanted with human ovarian cancer SKOV3 cells. METHODS: NFATc1 expression was silenced by siRNA in SKOV3 cells. Human ovarian cancer transplantation nude mouse model was established by transplanting with SKOV3 cells in which the NFATc1 gene was silenced by siRNA technique. The expression of NFATc1, CXCR2, FGF-2 and PDGF-BB at mRNA and protein levels was determined by RT-PCR, Western blotting and immunohistochemical staining. The tumor growth, angiogenesis and lymphangiogenesis were also observed. RESULTS: Over-expression of NFATc1 was observed in human ovarian cancer tissues. The silencing of NFATc1 expression by siRNA decreased tumorigenesis of transplanted ovarian cancer cells in the nude mice, reduced tumor vascular generation and inhibited the expression of CXCR2, FGF-2 and PDGF-BB at mRNA and protein levels. CONCLUSION: NFATc1 is overexpressed in ovarian cancer. NFATc1 silencing regulates the tumor vascular generation. NFATc1 thus has potential as a therapeutic target and for use in the diagnosis and evaluating prognosis of epithelial ovarian cancer.     

Significance of STC1 expression in peripheral blood and tissue of gastric carcinoma

AIM: To investigate stanniocalcin 1 (STC1) mRNA expression in the blood and tissue of gastric carcinoma. METHODS: The samples of peripheral blood and tumor tissues were collected from 74 patients with stage I-IV gastric carcinoma. STC1 mRNA was detected by RT-PCR, STC1 protein in tumor tissue was also detected by immunohistochemical method. RESULTS: The expression of STC1 mRNA in blood was significantly correlated with multiple histopathological prognostic factors, including primary tumor size, number of positive lymph nodes, and TNM stage. STC1 mRNA was not detected in the blood of volunteers without cancer, but detected in all gastric carcinoma tissue, and STC1 protein was expressed in all gastric carcinomas. CONCLUSION: STC1 is proposed as a novel, specific, and clinically useful molecular marker for detecting occult gastric carcinoma cells in blood. STC1 expression may play an important role in the progression of gastric carcinoma.     

Progress on regulation of PD-L1 expression by major inflammatory cytokines in tumor microenvironment

Programmed cell death protein 1 ligand 1 （PD-L1） is an important immune checkpoint protein, and its high expression in tumors often affects the effect of immunotherapy and promotes the malignant progression of tumors. Besides the own factors of the cells, the expression of PD-L1 is regulated by a variety of factors. In recent years, many studies have shown that some inflammatory cytokines in the tumor microenvironment, such as interferon-γ （IFN-γ）, transforming growth factor-β （TGF-β）, tumor necrosis factor-α （TNF-α）, interleukin-6 （IL-6） and so on, regulate PD-L1 expression through various mechanisms, thus promoting the immune escape of tumor cells and affecting the prognosis of patients. In this article, we briefly review the regulatory effects of major inflammatory cytokines on tumor cell PD-L1 expression and the mechanisms in order to provide a reference for improving the clinical efficacy of anti-PD-L1 treatment and studying new tumor immunotherapy pathways.     

Expression of Wnt/β-catenin signaling pathway-related proteins in breast cancer and its clinical significance

AIM: To evaluate the expression of Wnt/β-catenin signaling pathway-related proteins in breast cancer and the significance. METHODS: The patients with breast cancer (n=150) in our hospital from January 2015 to January 2017 were selected as study object. The tumor tissue samples of these patients were obtained from paraffin section of breast cancer by surgical resection with complete clinicopathological data. The corresponding paracancerous tissue sam-ples were taken from the non-tumor tissue samples from the above breast cancer patients, which were 0.5~1 cm away from the tumor tissue. The methods of real-time PCR and Western blot were performed to examine the expression of Wnt-1 and β-catenin at mRNA and protein levels. Human breat cancer MCF-7 cells were divided into 3 groups:control group (MCF-7 cells without treatment), agonist group[MCF-7 cells+Wnt3a (1 mg/L)] and antagonit group[MCF-7 cells+DKK1 (16 μmol/L)]. The expression of Wnt-1 and β-catenin at mRNA and protein levels was detected by real-time PCR and Western blot. RESULTS: Compared with the paracancerous tissues, the expression levels of Wnt-1 and β-catenin were higher in tumor tissues at mRNA and proteins levels (P<0.05). Notably, the positive expression rates of Wnt-1 and β-catenin were significantly higher in tumor tissues than that in the paracancerous tissues. Furthermore, Wnt-1 expression was associated with tumor metastasis (χ²=5.352, P=0.021), tumor stage (χ²=9.412, P=0.002) and tumor size (χ²=9.412, P=0.002). In addition, β-catenin expression was also associated with tumor metastasis (χ²=9.851, P=0.002) and tumor stage (χ²=5.661, P=0.017). Compared with control group, the expression of Wnt-1 and β-catenin at mRNA and protein levels in agonist group was increased (P<0.05),while that in antagonist group was decreased (P<0.05). CONCLUSION: The expression levels of Wnt-1 and β-catenin related with Wnt/β-catenin signaling pathway are increased in the breast cancer, which are closely related to the malignant state of the tumor.     

Antisense c-myc sensitizes osteosarcoma cells to cisplatin-induced apoptosis

AIM: To down-regulate expression of c-myc through antisense therapy and to investigate its effect on the sensitivity of osteosarcoma MG-63 cells to cisplatin-induced apoptosis. METHODS: The recombinant adenovirus (Ad-Asc-myc) encoding antisense c-myc fragment was constructed and transfected into osteosarcoma MG-63 cells in vitro in order to down-regulate the expression of c-myc, and the change in the sensitivity to cisplatin-induced apoptosis was observed. MTT, Western blot, RT-PCR, flow cytometry (FCM) and electron microscope were used to evaluate tumor cell proliferation in vitro, genes expression related to apoptosis regulation and effects on the sensitivity of osteosarcoma MG-63 cells to cisplatin-induced apoptosis. RESULTS: Ad-Asc-myc down-regulated the expression of c-myc protein after transfected MG-63 cells for 48 h, combined with the treatment of 2.0 mg/L cisplatin for 2 h inhibited tumor cell proliferation in vitro by 38.0%. RT-PCR revealed that Ad-Asc-myc down-regulated the expression of Bcl-2 and up-regulated the expression of Bax. No appreciable change was observed in the expression of E2F-1. FCM showed that Ad-Asc-myc induced apoptosis in intransfected cells, and rendered it more sensitive to cisplatin. CONCLUSION: Antisense c-myc is able per se to induce apoptosis and sensitize osteosarcoma cells to cisplatin-induced apoptosis.     

Regulation of octreotide on SSTR2 expression in hepatocellular carcinoma

AIM: To observe the regulation of octreotide (OCT) on the expression of somatostatin receptor 2 (SSTR2) in Bel7402 hepatocellular carcinoma (HCC) cells, and the inhibition effect of OCT on the growth of HCC. METHODS: The effect of OCT on proliferative ability of Bel7402 cells was observed by MTT assay. The cell form was observed by light invert microscope. The adhesive and invasive ability was detected by cell adhesion and migration experiments. The cell cycle, SSTR2 expression of 7402 cells were determined by immunofluorescence flow cytometry. Nude mice bearing xenografts in situ were treated with OCT or saline control for 7 weeks since tumor implantation. The immunohistochemistry for SSTR2 was performed. SSTR2 mRNA expression in cell line and xenografts was measured by semi-quantitative RT-PCR. RESULTS: After OCT treatment, the proliferative ability and cell form of 7402 cells didn't change significantly. The adhesive and invasive ability decreased significantly. The ratio of cells in resting state (G₀/G₁) increased, but no apoptosis peak was observed. The SSTR2 expression on 7402 cell membranes decreased significantly. SSTR2 expression in cell line of OCT group was higher than control group, but there was no significant difference between them. The mean tumor weight in mice given OCT was significantly lower than that in control group. SSTR2 immunostaining in tumor cells of treatment group showed stronger positivity, compared with control group. SSTR2 mRNA expression in xenografts after OCT treatment was significantly higher than that in control group. CONCLUSIONS: OCT inhibits the growth of HCC through SSTR2. SSTR2 is regulated by its ligand, the long-term OCT treatment increases the SSTR2 expression and enhances the effect of inhibiting HCC, however, short-term treatment may induces its desensitization and the decrease in anti-tumor effect.     

Gene silencing of indoleamine 2,3-dioxygenase 2 influences proliferation,migration and invasion of B16-BL6 melanoma cells

AIM: To investigate the effects of indoleamine 2, 3-dioxygenase 2 (IDO2) silencing on proliferation, migration and invasion of B16-BL6 melanoma cells.METHODS: IDO2-siRNA was transfected into the B16-BL6 melanoma cells in vitro. The expression of IDO2 or IDO1 at mRNA and protein levels was detected by real-time PCR and Western blot. Colony formation assay was performed to analyze the proliferation of IDO2-silencing tumor cells. The migration ability of B16-BL6 cells after silencing of IDO2 was measured by wound healing assay and Transwell cell migration assay. The invasion ability of the tumor cells was detected by Transwell cell invasion assay.RESULTS: IDO2-siRNA signi-ficantly down-regulated IDO2 expression in B16-BL6 melanoma cells, and did not affect IDO1 expression. Compared with control group, the colony formation ability, the migratory distance measured by wound healing assay, and the migration and the invasion cell numbers detected by Transwell assay all remarkably decreased in the IDO2-silencing cells.CONCLUSION: IDO2 silencing affects the proliferation, migration and invasion abilities of the B16-BL6 melanoma cells.     

Role of VEGF-C in lymphangiogenesis and lymphatic metastasis of breast cancer

AIM: To study the inhibitory effect of VEGF-C/Flt-4 system on lymphangiogenesis and lymphatic metastasis of breast cancer. METHODS: Lymphatic endothelial cells (LEC) were cultured in vitro, the effects of VEGF-C and anti-Flt-4 antibody on the proliferation of treated cells were observed. The antisense oligodeoxynucleotides (ASODN) targeting VEGF-C was designed and its effect on VEGF-C gene expression in vitro experiments was observed. The nude mice transplantation tumor model was made and the effects of VEGF-C ASODN on lymphangiogenesis and metastasis in the model were determined. RESULTS: The supernatant of cultured PC3 cells promoted LEC proliferation obviously while the cells treated with anti-Flt-4 antibody were obviously decreased whenever cell counting. The mRNA and protein expression of VEGF-C in MCF-7 cells treated with ASODN were significantly lower than that in control groups in vitro. In vivo ASODN also significantly reduced the VEGF-C mRNA expression detected by RT-PCR. The result of 5-Nase-ALPase enzyme -histochemistry showed that ASODN had obvious inhibitory effect on tumor lymphangiogenesis. Tumor growth velocity in ASODN group was much slower than that in control group. ASODN also inhibited tumor volume and lymphatic metastasis. CONCLUSION: The strong relationships between VEGF-C/Flt-4 system and lymphangiogenesis and lymphatic metastasis of breast cancer have been observed. If the expression of Flt-4 is blocked, the proliferation of LEC induced by tumor cells can be blocked in some degree. ASODN inhibits tumor lymphangiogenesis and lymphatic metastasis by down-regulating VEGF-C expressions.     

Cloning of p15INK4b related gene CCRG and expression analysis in the renal carcinoma

AIM and METHODS:To analysis the factor that involved in renal carcinogenesis, we used the bait gene AK001518 to screen GenBank. To understand the relationship between cell cycle related gene(CCRG) and p15, we did RT-PCR and Northern Blot experiments. Then we examined CCRG expression level in renal carcinogenesis. RESULTS:Gained a function unknown gene CCRG that was 67% a mino acid identical with the gene AK001518 that was regulated by p15. It was shown that the CCRG mRNA was dramatically decreased when p15 gene was over-expressed. CCRG expression level was much higher in tumor tissues and cells than normal tissues and cells. CONCLUSION:The novel gene CCRG expressed highly in the renal carcinoma, which might play a significant role in the renal carcinogenesis.     

Expression of STC1 in colorectal cancer and its significance in tumor microenvironment

AIM:To explore the expression of stanniocalcin 1 (STC1) in colorectal cancer tissues and to analyze its relationship with prognosis, further to investigate the correlation between STC1 and tumor microenvironment. METHODS:The data of the STC1 mRNA expression were accessed by the UALCAN database (http://ualcan.path.uab.edu/index.html) and Oncomine database (https://www.oncomine.org). RT-qPCR and Western blot were used to detect the expression of STC1 in the clinical samples. OncoLnc (http://www.oncolnc.org/) analytical tool was adopted to evaluate the correlation of STC1 level and the prognosis of colorectal cancer. CoCl₂ was used to establish the hypoxia status and lipopolysaccharide (LPS) was utilized to establish inflammatory condition in the colorectal cancer HT-29 cells, respectively, and then STC1 expression was examined by RT-qPCR and Western blot. RESULTS:STC1 was over-expressed in the colorectal cancer tissues, and its high expression was positively correlated with poor prognosis of the colorectal cancer patients (P<0.01). In colorectal cancer HT-29 cells, treatment of CoCl₂ up-regulated the expression of STC1. Under the condition of inflammation by stimulating with LPS, the expression of STC1 was significantly increased. In the colorectal cancer, STC1 level was positively correlated with hypoxia-inducible factor-1α or inflammatory molecules expression, and the levels of tumor-infiltrating immune cells in colorectal cancer tissue. CONCLUSION:STC1 is over-expressed in the colorectal tumor tissue, and the high level of STC1 is an important prognosis indicator for colorectal cancer. Furthermore, STC1 is closely correlated with tumor microenvironment, especially with the tumor hypoxia and tumor immune regulation of colorectal cancer.     

Activated NK cells against human hepatocellular carcinoma cell lines in vitro and in vivo

AIM: To evaluate the role of natural killer(NK) cells against a variety of human hepatocellular carcinoma (HCC) cell lines in vitro and in vivo, and to investigate the expression of MHC class I chain-related protein (MIC protein) in these HCC cell lines. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated from 50 mL peripheral blood donored by a healthy volunteer and cultured in the NK cell kit followed by amplification and cytokine activation. The release of lactate dehydrogenase (LDH) was detected by lysis experiment. Animal experiments were performed following vaccination with HCC cell lines (BEL7402, HepG2 and SMMC7721) in BALB/c-nu/nu mice. The diameters of the tumors were measured and the growth curves of difference cell lines were delineated. Three weeks later, these mice were sacrificed and the weight of the transplanted tumors was also detected. Furthermore, the expression of MIC protein was determined. RESULTS: The obvious differences of lysis effects of NK cells on different cell lines were observed, in which the lysis effect of NK cells on K562 cells was the strongest, the effect on BEL7402 cells was in the middle and the effect on SMMC7721 cells was the weakest. In animal experiments, NK cells also showed obvious and different restraining effects on a variety of HCC cell line-transplanted tumors in nude mice. The tumor inhibitory rates of NK cells were 43.5% in BEL-7402 cell-transplanted tumor, 40.7% in HepG2 cell-transplanted tumor and 36.0% in SMMC-7721 cell-transplanted tumor. The protein expression of MIC was 48.7%, 32.8% and 0.9% in the 3 cell lines,respectively. CONCLUSION: The lysis effects of NK cells on a variety of human HCC cell lines are different. The expression of MIC in the tumor cells may play distinct role in evaluating these differences.     

Effects of angiotensin-converting enzyme 2 gene transfection on the expression of macrophage migration inhibitory factor in human endothelial cells

AIM: To implore the effects of recombinant angiotensin- converting enzyme 2 (ACE2) gene transfection on the expression of macrophage migration inhibitory factor (MIF) induced by angiotensin (Ang) II in cultured human endothelial cells. METHODS: A recombinant plasmid encompassing human ACE2 gene (pACE2) was constructed and transfected into human endothelial cells. Endothelial cells were stimulated with Ang II or Ang IV in the presence and absence of pACE2 gene transfer. The mRNA and protein levels of MIF in endothelial cells were determined by real-time PCR and Western blotting, respectively. RESULTS: The mRNA and protein expressions of MIF were strikingly enhanced after exposures of endothelial cells to 100 nmol/L Ang Ⅱ and 100 nmol/L Ang Ⅳ (P<0.01, respectively). However, significant downregulations of MIF mRNA and protein expression were observed in endothelial cells pretreated with pACE2 gene transfer (P<0.05, respectively). CONCLUSION: ACE2 gene overexpression contributes to diminishments of inflammation mediator MIF expression in endothelial cells, suggesting that ACE2 gene has anti-inflammatory properties to some extent and may provide novel therapeutic strategies for the inflammation-related diseases such as atherosclerosis.