Expression of plasma vascular endothelial growth factor in patients with hepatocellular carcinoma and effect of transcatheter arterial chemoembolization therapy on plasma vascular endothelial growth factor level

AIM: To investigate the expression level of plasma vascularendothelial growth factor (P-VEGF) in patients withhepatocellular carcinoma (HCC) and its relationship withthe clinicopathologic characteristics, and to examine thechanges of P-VEGF in the course of transcatheter arterialchemoembolization (TACE).METHODS: Peripheral blood samples were taken from 45HCC patients before and 1, 3, 7 d, and 1 mo after TACE.Plasma VEGF level was measured with the quantitativesandwich enzyme-linked immunosorbent assay (ELISA).Twenty patients with benign liver lesions and 17 healthycontrol subjects were also included in this study.RESULTS: Plasma VEGF levels in HCC patients weresignificantly elevated as compared to those in patients withbenign liver lesions (P = 0.006) and in the normal controls(P = 0.003). Significant differences were observed whenP-VEGF was categorized by tumor size (P = 0.006), portalvein thrombosis (P= 0.011), distant metastasis (P= 0.017),arterial-portal vein shunting (P = 0.026), and InternationalUnion Against Cancer (UICC) TNM stage (P = 0.044). Therewas no correlation between plasma level of VEGF and thelevel of alpha fetoprotein (^-FP) (r = 0.068, P = 0.658) andweakly correlated with the number of platelets (r = 0.312,P = 0.038). P-VEGF levels increased significantly andreached the peak value on the first day after TACE, and thendecreased gradually. The change rate of P-VEGF concentration(one month post-TACE/pre-TACExl00%) was correlatedwith the retention rate of lipiodol oil (rs = 0.494, P= 0.001)and the tumor volume change (r s = 0.340, P = 0.034).The patients who achieved a partial or complete responseto TACE therapy showed significantly less pre-treatmentP-VEGF than those nonresponders (P = 0.025). A high pre-therapeutic P-VEGF level was associated with poor responseto treatment (P = 0.018).CONCLUSION: A high pre-treatment P-VEGF level is auseful marker for tumor nroeression, esBeciallv for vascularinvasion. TACE increases the level of P-VEGF onlytemporarily which may be associated with tumor ischemia.P-VEGF may be useful in predicting treatment response,monitoring disease course after TACE and judging the effectof different TACE regimens.

Combined interventional therapies of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most commonmalignancies in the world, responsible for an estimated one million deaths annually. It has a poor prognosis due to its rapid infiltrating growth and complicating liver cirrhosis.Surgical resection, liver transplantation and cryosurgery are considered the best curative options, achieving a high rate of complete response, especially in patients with small HCC and good residual liver function. In nonsurgery, regional interventional therapies have led to a major breakthrough in the management of unresectable HCC, which include transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), microwave coagulation therapy (MCT), laser-induced thermotherapy (LITT), etc. As a result of the technical development of locoregional approaches for HCC during the recent decades,the range of combined interventional therapies has been continuously extended. Most combined multimodal interventional therapies reveal their enormous advantages as compared with any single therapeutic regimen alone,and play more important roles in treating unresectable HCC.

Selection of optimal antisense accessible sites of survivin and its application in treatment of gastric cancer

AIM: To select the optimal antisense accessible sites of survivin, a highly expressed gene in tumor tissues, in order to explore a novel approach to improve biological therapy of gastric cancer.METHODS: The 20 mer random oligonucleotide library was synthesized, hybridized with in vitro transcribed total survivin cRNA, then digested by RNase H. After primer extension and autoradiography, the antisense accessible sites (AAS) of survivin were selected. Then RNADraw software was used to analyze and choose the AAS with obvious stem-loop structures, according to which the complementary antisense oligonucleotides (AS-ODNs) were synthesized and transferred into survivin highly- expressing gastric cancer cell line MKN-45. Survivin expression was detected by RT-PCR and Western Blotting. Cellular growth activities were assayed by tetrazolium bromide (MTT)colorimetry. Cellular ultrastructure was observed by electronic microscopy, while apoptosis was detected by annexin V-FITC and propidium iodide staining flow cytometry.RESULTS: Thirteen AAS of survivin were selected in vitro.Four AAS with stem-loop structures were chosen, locating at 207-226 bp, 187-206 bp, 126-145 bp and 44-63 bp of survivin cDNA respectively. When compared with nontranfection controls, their corresponding AS-ODNs (AS-ODN1,AS-ODN2, AS-ODN3 and AS-ODN4) could reduce Survivin mRNA levels in MKN-45 cells by 54.3±1.1% (t= 6.12, P＜0.01),86.1±1.0% (t= 5.27, P＜0.01), 32.2±1.3% (t= 7.34, P＜0.01)and 56.2±0.9% (t= 6.45, P＜0.01) respectively, while survivin protein levels were decreased by 42.2±2.5% (t = 6.26,P＜0.01), 75.4±3.1% (t= 7.11, P＜0.01), 28.3±2.0% (t= 6.04,P＜0.01) and 45.8±1.2% (t = 6.38, P＜0.01) respectively.After transfection with 600 nmol/L AS-ODN1～AS-ODN4 for24 h, cell growth was inhibited by 28.12±1.54% (t= 7.62,P＜0.01), 38.42±3.12% (t = 7.75, P＜0.01), 21.46±2.63%(t= 5.94, P＜0.01) and 32.12±1.77% (t= 6.17, P＜0.01)respectively. Partial cancer cells presented the characteristic morphological changes of apoptosis, with apoptotic rates being 19.31±1.16% (t=7.16, P＜0.01), 29.24±1.94%(t = 8.15, P＜0.01), 11.87±0.68% (t= 6.68, P＜0.01) and21.68±2.14% (t = 7.53, P＜0.01) respectively.CONCLUSION: The AAS of survivin could be effectively selected in vitro by random oligonucleotide library/RNase H cleavage method combined with computer software analysis, this has important reference values for further studying survivin-targeted therapy strategies for gastric cancer.

Antiangiogenic effect of somatostatin receptor subtype 2 on pancreatic cancer cell line:Inhibition of vascular endothelial growth factor and matrix metalloproteinase-2 expression in vitro

AIM:To investigate the anti-angiogenic effect of somatostatin receptor subtype 2 (SSTR2) gene transfer into pancreatic cancer cell line PC-3, and the mechanisms involved in this effect.METHODS: The full length human SSTR2 cDNA was introduced into pancreatic cancer cell line PC-3 by lipofectamine-mediated transfection. Positive clones were screened by G418 and stable expression of SSTR2 was detected by immunohistochemistry SABC methods and RT-PCR. Enzyme-linked immunosorbent assay (ELISA) was used to detect vascular endothelial growth factor (VEGF) levels in the cell culture supernatants of SSTR2-expressing cells, vector control and mock control cells. Furthermore, the expressions of VEGF and matrix metalloproteinase-2 (MMP-2) were detected by immunohistochemistry SABC methods and RT-PCR in these cells.RESULTS: VEGF levels in the cell culture supernatants were significantly reduced in the SSTR2-expressing cells (first week,172.63±21.2ng/L and after two months, 198.85±26.44ng/L)compared with the vector control (first week, 790.39±86.52ng/L and after two months, 795.69±72.35ng/L) and mock control (first week, 786.42±90.62ng/L and after two months,805.32±84.36ng/L) (P<0.05).The immunohistochemical assay showed a significant reduction of the integral optical density of VEGF and MMP-2 in the SSTR2-expressing cells (42.25±8.6 and 70.5±6.25, respectively) compared with the vector control (85.75±12.9 and 110.52±13.5, respectively) and mock control (82.6±9.28 and 113.56±9.62,respectively) (P<0.05).Conversely, the average gray value of VEGF and MMP-2 was significantly increased in the SSTR2-expressing cells (121.56±8.43 and 134.46±19.95, respectively) compared with the vector control (55.72±5.6 and 62.26±12.68,respectively) and mock control cells (58.48±6.2 and 65.49±9.16, respectively) (P<0.05). Moreover, the expressions of VEGF mRNA and MMP-2 mRNA were significantly reduced in the SSTR2-expressing cells (0.1384±0.017 and 0.2343±0.070, respectively) compared with the vector control (1.024±0.117 and 0.806±0.119,respectively) and mock control (1.085±0.105 and 0.714±0.079,respectively) (P<0.05).CONCLUSION: The expression of reintroduced human SSTR2 gene exerts its antiangiogenic effects by downregulating the expressions of the factors involved in tumor angiogenesis and metastasis, suggesting SSTR2 gene transfer as a new strategy of gene therapy for pancreatic cancer.

Expression of IGF-II in early experimental hepatocellular carcinomas and its significance in early diagnosis

AIM: To investigate the serum level and expression of insulin growth factor II (IGF-II) in liver tissues of rats with early experimental hepatocellular carcinomas (HCC) and its significance in early diagnosis.METHODS: Early experimental hepatocellular carcinomas were induced by diethylnitrosamine (DENA) in 180 male SD rats. Another 20 male SD rats served as control. The IGF-IIserum level was measured by ELISA. Immunohistochemistry and electron microscopic immunohistochemistry were usedto observe the expression of IGF-II in normal and tumor liver tissues and its ultrastructural location in malignant hepatocytes. The expressions of IGF-II in human hepatoma cell lines HepG2, SMMC7721 and human embryonic liver cell line L-02 were measured by immunocytochemistry. IGF-II mRNA level was studied by in situ hybridization.RESULTS: IGF-II was expressed in the cytoplasm of both sinusoidal cells in paracancerous cirrhotic liver tissue and malignant hepatocytes in early experimental HCC tissues.Gold particles were seen on the rough endoplasrnic reticulum and the mitochondrion in malignant hepatocytes. IGF-II was expressed in the human hepatoma cell lines. The mRNA level of IGF-II was higher in rat liver tumor tissue than in normal rat liver tissue. The serum IGF-II level of the early experimental HCC group was 34.67±10.53 ng.ml^-1 and that of the control group was 11.75±5.84 ng.ml^-1. The rank sum test was used for statistical analysis. There was a significant difference between the two groups (P<0.01).CONCLUSION: During the induction of early experimental HCC by DENA, IGF-II may promote hepatocytic proliferation via a paracrine mechanism in the pre-cancerous stage. When hepatocytes are transformed into malignant cells, they may secrete IGF-II and promote malignant cell proliferation by an autocrine mechanism. IGF-II may be a possible biological marker in the early diagnosis of HCC.

Identification of effective siRNA against K-ras in human pancreatic cancer cell line MiaPaCa-2 by siRNA expression cassette

AIM: We shall construct the small interfering RNA (siRNA)expression cassette (SEC) targeting activated K-ras gene sequence, identify more effective siRNA sequence against K-ras gene in human pancreatic cancer cell line MiaPaCa-2 by SEC and reveal the anti-cancer effects of RNA interference (RNAi) and its therapeutic possibilities.WETHODS: Three different sites of SECs were constructed by PCR. K1/siRNA, K2/siRNA and K3/siRNA are located at sites 194, 491 and 327, respectively. They were transfected into MiaPaCa-2 cells by liposome to inhibit the expression of activated K-ras. In the interfering groups of sites 194 and 491, we detected the apoptosis in cells by FACS after they were incubated for 48 h, then we tested the alternation of K-ras gene in MiaPaCa-2 cells by RT-PCR immunofluorescence, respectively.RESULTS: Introduction of the K1/siRNA and K2/siRNA against K-ras into MiaPaCa-2 cells leads to increased apoptosis, and the number of apoptotic cells is increased compared with control cells. The tests of RT-PCR immunofluorescence show the effects of inhibiting expression of activated K-ras gene by RNA interference in the K1/siRNA and K2/siRNA groups. We also find that the introduction of K3/siRNA has no effect on MiaPaCa-2 cells.CONCLUSION: K1/siRNA and K2/siRNA can inhibit the expression of activated K-fas but K3/siRNA has no effect,demonstrating that K1/siRNA and K2/siRNA are effective sequences against K-ras gene and K3/siRNA are not. We conclude that specific siRNA against K-ras expression may be a powerful tool to be used therapeutically against human pancreatic cancer.

Effects of emodin on treating murine nonalcoholic fatty liver induced by high caloric laboratory chaw

AIM: To investigate the effects of emodin on the treatment of non-alcoholic fatty liver in rats induced by high caloric laboratory chaw.METHODS: Non-alcoholic fatty liver model was successfully established by feeding with high caloric laboratory chaw for 12 wk. Then the model rats were randomly divided into 3 groups, namely model control group, emodin group and dietary treatment group. The rats in emodin group in othergroups were given distilled water of the same volume. The rats in model control group were fed with high caloric laboratory chaw while animals in other groups were fed with normal diet. Four weeks later, liver index (liver/body weight ratio), serum activities of liver-associated enzymes, blood lipid, fasting blood glucose, fasting plasma insulin, HOMA insulin resistance index (HOMA-IR), hepatic triglyceride content and histology features of all groups were assayed. The expression of hepatic peroxisomal proliferator activated receptor (PPAR) gamma was determined by RT-PCR.RESULTS: The body weight, liver index, serum activities of alanine aminotransferase (ALT), blood lipid, hepatic triglyceride content of model control group were significantly elevated, with moderate to severe hepatocyte steatosis.The expression of hepatic PPAR gamma mRNA was obviously reduced in model control group. Compared with model control group, the body weight, liver index, serum activities of ALT, blood lipids and hepatic triglyceride of emodin group significantly decreased and hepatic histology display was also greatly improved. Meanwhile, the expression of hepatic PPAR gamma mRNA was elevated.However, high serum activities of ALT and hyperlipidemia were persisted in dietary treatment group although liver index was decreased and liver histology was somewhat improved.CONCLUSION: It is suggested that emodin might be effective in the treatment of non-alcoholic fatty liver in rats. Its therapeutic mechanism could be associated with increasing the expression of hepatic PPAR gamma mRNA.

Involvement of extracellular signal-regulated kinase/mitogenactivated protein kinase pathway in multidrug resistance induced by HBx in hepatoma cell line

AIM: To investigate the molecular mechanism of the influence of HBx protein on multidrug resistance associated genes: multidrug resistance 1 (MDR-1), multidrug related protein (MRP-1), lung resistance related protein (LRP) in hepatoma cells and the potential role of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathway in this process.METHODS: A cell model stably expressing the HBx protein was established by liposome-mediated transfection of HBx gene into HepG2 cell line. The expression of multidrug resistance associated genes and proteins was detected by RT-PCR and Western blot. AnnexinV-FITC/PI assay was used to confirm the multidrug resistance (MDR) phenotype of transfected cells by fluorescence cytometry (FACS). The ERK/MAPK pathway activation was measured by Western blot through comparing the ratio of phosphorylation of ERK/MAPK to total ERK/MAPK protein. After treated with the ERK/MAPK pathway inhibitor U0126, the HBx-expressing cells were harvested. Then RT-PCR, Western blot and FACS were used to analyze the alterations in the expression of multidrug resistance associated genes and the MDR phenotype after exposure.RESULTS: Compared with the control group, the transfected cells showed a higher expression of MDR associated genes and proteins. Marked elevations in MDR-1 (64.3%), MRP-1 (87.5%) and LRP (90.8%) were observed in the transfected cells (P<0.05). RT-PCR revealed that the over-expression of MDR associated proteins was due to amplification of such genes (MDR1 2.9 fold, MRP1 1.67 fold, LRP1.95 fold).Furthermore, we found that the ERK/MAPK activity was remarkably high in the HBx-expressing cells. The activation of ERK/MAPK, as measured by the ratio of phosphorylated ERK bands normalized to the total ERK bands, was increased by 2.3-fold in HBx-transfected cells compared with cells transfected with the empty vector. After treated with the ERK/MAPK pathway inhibitor, the level of MDR associated genes and proteins in the transfected cells decreased to some extent. Compared with controls, a significant decrease in MDR-1 mRNA (53.3%), MRP-1 mRNA (59.7%) as well as LRP mRNA (56.4%) was observed in the UO126 treated transfected cells after 12 h. Western blot also demonstrated that the protein expression of these MDR associated genes slightly reduced after treated with U0126 for 12 h (MDR-1 40.1%, MRP-1 29.4%, LRP35.7%). This change was accompanied with the rise of cell apoptosis ratio confirmed by Annexin V-PI detection. The apoptosis index of UO126treated cells increased by 1.28 fold, compared with that of transfected cells. Obviously, the MDR phenotype of these cells was obviously related with increased activities of the ERK/MAPK pathway.CONCLUSION: HBx protein might be one of the causes for the occurrence of MDR in HCC, and ERK/MAPK pathway might be involved in this change.

Effects of pentoxifylline on the hepatic content of TGF-β1 and collagen in Schistosomiasis japonica mice with liver fibrosis

AIM: To study the effects of pentoxifylline (PTX) on thecontent of hepatic TGF-β1, type Ⅰ and type Ⅲ collagen inschistosomiasis japonica mice with liver fibrosis and itsmechanism of anti-fibrosis.METHODS: Forty mice with schistosomiasis were dividedinto four groups: one group as control without anytreatment, other three were treated with Praziquantel 500mg/(kg.d)for 2 d, high dose PTX 360 mg/(kg.d) for 8 wk,and low dose PTX 180 mg/(kg.d) for 8 wk respectively.Immunohistochemical technique and multimedia colorpathographic analysis system were applied to observe thecontent change of hepatic TGF-β1, type Ⅰ and type Ⅲcollagen in schistosomiasis japonica mice with liver fibrosisbefore and after PTX treatment.RESULTS: Effects of PTX on the content change of hepaticTGF-β1, type Ⅰ and type Ⅲ collagen in schistosomiasis japonicamice with liver fibrosis were related to the dosage of PTX,high dose PTX treated group could significantly reduce thecontent of TGF-β1 (0.709±0.111), type Ⅰ (0.644±0.108) andtype Ⅲ (0.654±0.152) collagen compared with those ofcontrol group (0.883±0.140, 0.771±0.156, 0.822±0.129)with statistical significance (P＜0.05). Low dose PTX couldalso reduce the hepatic content of TGF-β1 (0.752±0.152),type Ⅰ (0.733±0.117) and type Ⅲ (0.788±0.147) collagen,but without statistical significance (P＞0.05). Both high doseand low dose PTX groups have significant differences onthe content of TGF-β1, type Ⅰ and type Ⅲ collagen (P＜0.05,P＜0.05, P＜ 0.01,respectively).CONCLUSION: High dose of PTX treatment could reducethe content of hepatic TGF-β1, type Ⅰ and type Ⅲ collagensignificantly in schistosomiasis japonica mice with liverfibrosis, and thus plays its role of antifibrosis.

Inactivation of RASSF1A, the tumor suppressor gene at 3p21.3 in extrahepatic cholangiocarcinoma

AIM: To evaluate the genetic and epigenetic inactivation mechanism of the RASSF1A tumor suppressor gene at 3p21.3 in extrahepatic cholangiocarcinoma.METHODS: RT-PCR was used to investigate the transcriptional expressing and re-expression of RASSF1A.RASSF1A mutation was analyzed with SSCP and selective sequencing. PCR was performed to detect the loss of heterozygosity (LOH) at the region of chromosome 3p21.3.Genomic DNA were modificated bisulfite and the frequency of methylation of CpG islands in RASSF1A promoter were evaluated by methylation specific PCR (MS-PCR).RESULTS: In all 48 samples and one cell lines of extrahepatic cholangiocarcinoma, the RASSF1A mutation is rare (6.12%, 3/49), 33 samples (68.75%) and QBC-939cell lines (x2 = 14.270, P= 0.001＜0.01) showed RASSF1A express inactivation with LOH at microsatellite loci D3S4604. Among these 33 samples and QBC-939, 28 of 33 (84.85%) tumor samples and 1 cell lines were methylated for majority of 16 CpGs, the average frequency is 73.42%.CONCLUSION: The data we present suggest that RASSF1A which we have been searching for at 3p21.3may be one of the key tumor suppressor gene and play an important role in the pathogenesis of extrahepatic cholangiocarcinoma, and the promoter methylation and allelic loss are the major mechanism for inactivation of RASSF1A.

Effects of carbon dioxide and nitrogen on adhesive growth and expressions of E-cadherin and VEGF of human colon cancer cell CCL-228

AIM: To study the effects of carbon dioxide on the metastatic capability of cancer cells, and to compare them with that of nitrogen.METHODS: The colon cancer cell CCL-228 was treated with 100 % carbon dioxide or nitrogen at different time points and then cultured under normal condition. Twelve hours after the treatment, the survival rates of suspension cells and the expressions of e-cadherin and VEGF were examined.RESULTS: After 60 min of carbon dioxide and longer time of nitrogen treatment, the suspended cells increased and the expression of e-cadherin decreased while the expression of VEGF was enhanced significantly. And the effects of nitrogen were similar to, but weaker than, those of carbon dioxide.CONCLUSION: Carbon dioxide may improve the metastatic capability of cancer cells and its effects are significantly stronger than that of nitrogen. A sequential use of carbon dioxide and nitrogen in pneumoperitoneum may take the advantage of both gases.

Expression and significance of new inhibitor of apoptosis protein survivin in hepatocellular carcinoma

AIM: To investigate expression and significance of inhibitor of apoptosis protein survivin in hepatocellular carcinoma (HCC).METHODS: The expression of survivin and vascular endothelial growth factor (VEGF) was investigated in 38cases of HCC tissues and 38 liver cirrhosis tissues by immunohistochemistry and Western blot. The relationship between the expression of survivin and clinicopathological factors of HCC was analyzed.RESULTS: Survivin protein was detected in 23 (60.5%)of 38 HCCs and 3 (7.9%) of 38 liver cirrhosis tissues. In 23 cases of HCC which expressed survivin, the expression of VEGF was positive in 18 cases and slight positive or negative in 5 cases. While in 15 cases of HCC which did not express survivin, 12 cases did not express or slightly expressed, and 3 cases expressed VEGF. In liver cirrhosis tissues, the expression of VEGF was as follows: 24 cases were negative, 10 cases were weak positive and 4 cases were strong positive. The expression of survivin was coincident with the expression of VEGF in HCC (P＜0.01).The expression of survivin in HCC had no relationship with the patients' age, gender, tumor size and differentiation level of HCC, while it was related to the metastasis of HCC. The protein quantitative analysis by Western blot also showed that overexpression of survivin in HCC was closely correlated to the expression of VEGF (P＜0.01).Furthermore, stronger expression of survivin and VEGF was also found in patients with metastasis rather than in those with no metastasis (P＜0.01).CONCLUSION: Survivin plays a pivotal role in the metastasis of HCC, and it has some correlation with tumorigenesis. The expression of survivin in the primary lesion is very useful as an indicator for metastasis and prognosis of HCC. It could become a new target of gene therapy of HCC.

Association of polymorphisms of interleukin-18 gene promoter region with chronic hepatitis B in Chinese Han population

AIM: To investigate the polymorphisms of interleukin-18(IL-18) gene promoters, and to disclose whether such polymorphisms are associated with susceptibility to chronic hepatitis B in Chinese Han population.METHODS: Using polymerase chain reaction with sequence specific primers (PCR-SSP) method, the single nucleotide polymorphisms (SNPs) of the promoter region of IL-18 gene at position -607 and -137 were detected in 231 patients with chronic hepatitis B and 300 normal controls.RESULTS: Allele C at position -607 in the promoter of IL-18 gene was detected in 48.7% of normal controls and 51.9% of patients, while allele A at position -607 was detected in 51.3% of normal controls and 48.1% of patients. The frequencies of -607CC, -607 CA and -607AAgenotypes in normal controls were 22.0%, 53.3% and 24.7% respectively and in chronic hepatitis B patients were 26.8%, 50.2% and 23.0% respectively. Allele G at position -137 in the promoter of IL-18 gene was detected in 82.3% of normal controls and 88.5% of chronic hepatitis B patients, while allele C at position -137 was detected in 17.7% of normal controls and 11.5% of patients. The frequencies of -137GG, GC and CC genotype were 67.3%,30.0% and 2.7% in normal controls respectively, while in chronic hepatitis B patients were 78.8%, 19.5% and 1.7% respectively. The frequency of-137GG genotype in chronic hepatitis B groups was significantly higher than that in normal controls (χ2 = 8.55, P = 0.003 ＜0.05),whereas the frequencies of -607C/-137C and -607A/-137Chaplotypes in chronic hepatitis B groups were significantly lower than that in normal controls. The association between genotypes of IL-18 promoter region polymorphisms and HBV copies showed that the frequency of -607AAgenotype in high HBV-DNA copies groups was lower than that in low HBV-DNA copies groups (χ2 = 6.03, P = 0.014＜0.05).CONCLUSION: The polymorphisms of the promoter region of IL-18 gene at position -607 and -137 are closely associated with susceptibility to chronic hepatitis B. The people with allele C at position -137 in the promoter of IL-18 gene may be protected against HBV infection;moreover AA genotype at position -607 may be closely linked to inhibit HBV-DNA replication. These findings give some new clues to the study of pathogenesis of chronic hepatitis B.

Combined transarterial chemoembolization and arterial administration of Bletilla striata in treatment of liver tumor in rats

AIM: To evaluate and compare the effect of combined transarterial chemoembolization (TACE) and arterial administration of Bletilla striata (a Chinese traditionalmedicine against liver tumor) versusTACE alone for the treatment of hepatocellular carcinoma (HCC) in ACI rats.METHODS: Subcapsular implantation of a solid Morris hepatoma 3 924A (2 mm3) in the liver was carried out in 30 male ACI rats. Tumor volume (V1) was measured by magnetic resonance imaging (MRI) on day 13 after implantation. The following different agents of interventional treatment were injected after retrograde catheterization via gastroduodenal artery (on day 14), namely, (A) TACE (0.1 mg mitomycin +0.1 mi Lipiodol) + Bletilla striata (1.0 mg) (n= 10); (B) TACE + Blebilla stnata(1.0 mg) + ligation of hepatic artery (n=10),(C) TACE alone (control group, n=10). Tumor volume (V2)was assessed by MRI (on day 13 after treatment) and the tumor growth ratio (V2/V1) was calculated.RESULTS: The mean tumor volume before (V1) and after (V2) treatment was 0.0355 cm3 and 0.2248 cm3 in group A,0.0374 cm3 and 0.0573 cm3 in group B, 0.0380 cm3 and 0.3674 cm3 in group C, respectively. The mean ratio (V2/V1)was 6.2791 in group A, 1.5324 in group B and 9.1382 in group C. Compared with the control group (group C), group B showed significant inhibition of tumor growth (P＜0.01),while group A did not (P＞0.05). None of the animals died during implantation or in the postoperative period.CONCLUSION: Combination of TACE and arterial administration of Bletilla striata plus ligation of hepatic artery is more effective than TACE alone in the treatment of HCC in rats.

Stable Fault-tolerance Control for a Class of Networked Control Systems

In this paper, we use the matrix measure technique to study stable fault-tolerance control of networked control systems. State feedback networked control systems with the network-induced delay, parameter uncertainties, sensor failures and actuator failures are considered. State feedback gain K is designed for any invariant delay τ, and some theorems and sufficient conditions for stable fault-tolerance control are given. Example is presented to illustrate the effectiveness of these theorems.

Reversal of the phenotype by K-ras^(val12) silencing mediated by adenovirus-delivered siRNA in human pancreatic cancer cell line Panc-1

AIM: To investigate the in vitro antitumor effect of adenovirus-mediated small interfering RNAs (siRNAs) on pancreatic cancer and the associated mechanism.METHODS: A 63-nucleotide (nt) oligonucleotide encoding K-ras^val12 and specific siRNA were introduced into pSilencer 3.1-H1, then the H1-RNA promoter and siRNA coding insert were subcloned into pAdTrack to get plasmid pAdTrackH1-K-ras^val12. After homologous recombination in bacteria and transfections of such plasmids into a mammalian packaging cell line 293, siRNA expressing adenovirus AdH1-K-ras^val12 was obtained. Stable suppression of K-ras^val2 was detected by Northern blot and Western blot. Apoptosis in Panc-1 cells was detected by flow cytometry.RESULTS: We obtained adenovirus AdH1-K-ras^val12 carrying the pSilencer 3.1-H1 cassette, which could mediate gene silencing. Through siRNA targeted K-ras^val12, the oncogenic phenotype of cancer cells was reversed. Flow cytometry showed that apoptotic index of Panc-1 cells was significantly higher in the AdH1-K-ras^val12-treatment group (18.70% at 72 h post-infection, 49.55% at 96 h post-infection)compared to the control groups (3.47%, 3.98% at 72 and 96 h post-infection of AdHl-empty, respectively, 4.21%,3.78% at 72 and 96 h post-infection of AdH1-p53,respectively) (P<0.05).CONCLUSION: These results demonstrate that adenoviral vectors can be used to mediate RNA interference (RNAi)to induce persistent loss of functional phenotypes. In gene therapy, the selective down-regulation of only the mutant version of a gene allows for highly specific effects on tumor cells, while leaving the normal cells untouched. In addition, the apoptosis of pancreatic cancer cell line Panc-1 can be induced after AdH1-K-ras^val12 infection. This kind of adenovirus based on RNAi might be a promising vector for cancer therapy.

Hepatitis B virus X gene induces human telomerase reverse transcriptase mRNA expression in cultured normal human cholangiocytes

AIM: To study the transcriptional regulation of human telomerase reverse transcriptase (hTERT) mRNA in normal human cholangiocytes (HBECs) after hepatitis B virus X (HBx) gene transfection and to elucidate the possible mechanism of HBV infection underlying cholangiocarcinoma.METHODS: HBECs were cultured in vitroand co-transfected with a eukaryotic expression vector containing the HBx coding region and a doning vector containing coding sequences of enhanced green fluorescent protein (EGFP) using lipidmediated gene transfer. The transfection efficiency was determined by the expression of EGFP. The expressions of hTERT mRNA and HBx protein in HBECs were detected by RT-PCR and immunocytochemical stain, respectively.RESULTS: The transfection efficiencies were about 15% for both HBx gene expression plasmid and empty vector.No hTERT mRNA was expressed in HBECs when transfected with OPTI-NEN medium and empty vector, but a dramatic increase was observed for hTERT mRNA expression in HBECs when transfected with HBx expression vector. HBx proyein was only expressed in HBECs when transfected with HBx expression vector.CONCLUSION: HBx transfection can activate thet ranscriptional expression of hTERT mRNA. Cis-activation of hTERT mRNA by HBx gene is the primary mechanism underlying the proliferation, differentiation and tumorigenesis of biliary epithelia.

Assessment of hepatocellular carcinoma vascularity before and after transcatheter arterial chemoembolization by using first pass perfusion weighted MR imaging

To assess the vascularity of hepatocllular carcinoma (HCC)before and after transcatheter arterial chemoembolization(TACE) with the quantitative parameters obtained by firstpass perfusion weighted MR imaging (FP-MRI).

Construction of single chain Fv antibody against transferrin receptor and its protein fusion with alkaline phosphatase

AIM: To construct fusion protein of a single-chain antibody(scFv) against transferrin receptor (TfR) with alkalinephosphatase (AP).METHODS: The VH-linker-VL, namely scFv gene, wasprepared by amplifying the VH and VL genes from plasmid pGEM-T-VH and pGEM-T-VL with splicing overlap extension polymerase chain reaction (SOE PCR). After the ScFv gene was modified by SfiⅠ and NotⅠ, it was subcloned into the secretory expression vector pUC19/119, and then was transformed into E. coli TG1. The positive colonies were screened by colony PCR and their expressions were induced by IPTG. ScFv gene was gained by digesting ScFv expression vector pUC19/119 with Sfi I and NotⅠ restriction enzymes, then subcloned into expression vector pDAP2, followed by transformation in E. coli TG1. The positive colonies were selected by bacterial colony PCR. The expression of fusion protein (scFv-AP) was induced by IPTG. Its activity was detected by enzyme immunoassay. The molecular weights of scFv and scFv-AP were measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).RESULTS: The product of SOE PCR formed a band of 700 bp in agarose gel electrophoresis. SDS-PAGE demonstrated the molecular weight of scFv was 27 ku. Immunofluorescent assay (IFA) demonstrated its reactivity with TfR. The molecular weight of scFv-AP was 75 ku. Enzyme immunoassay showed that scFv-AP could specifically bind to human TfR and play AP activity.CONCLUSION: We have successfully prepared the antihuman TfR scFv and constructed the fusion protein of scFv and AP. It is promising for immunological experiments.

Changes of tumor microcirculation after transcatheter arterial chemoembolization:First pass perfusion MR imaging and Chinese ink casting in a rabbit model

AIM: To observe the change of tumor microcirculation after transcatheter arterial chemoembolization (TACE) with bletilla microspheres by using first pass perfusion MR imaging (FP) and Chinese ink casting.METHODS: VX2 carcinoma cells were surgically implanted into the left and right lobes of liver of 30 New Zealand white rabbits, which were divided into 3 groups at random. Emulsion of lipiodol mixed with mitomydn C, and 5-FU bletilla microspheres were injected into the hepatic artery respectively, and saline was used as control agent. MR imaging was performed with turbo-flash sequence 14 d after tumor implantation and 7 d after interventional therapy. The steepest slopes (SS) of the signal intensity versus time curves were created for quantitative analysis, 7.5% Chinese ink gelatin solution was injected through ascending artery (17 cases) or portal vein(2 cases) for lesion microvessel area (MVA) measurement after the last MRI examination.The correlation between perfusion imaging and MVA was studied blindly.RESULTS: The SS values at the rim of tumor in lipiodol group (mean, 49% per second) and bletilla group (mean,35% per second) were significantly decreased (P<0.05) as compared with control group (mean, 124% per second), no difference was found between lipiodol and bletilla groups(P>0.05). In lipiodol group, the MVAs (24 974±11 836μm^2) in the center of the tumor were significantly smaller than those of the control group (35 510±15 675 μm^2) (P<0.05),while the MVAs (80 031±22 745 μm^2) around the tumor were significantly increased because small and dense plexuses appeared around the tumor which correlated to intense reaction of granulation tissue. None of the vessels was seen in the tumor in bletilla group, the peripheral MVAs of the tumor were significantly smaller than those of the control group (P<0.05) and lipiodol group (P<0.05). There was a good correlation between SS and MVAs in control group (rsl, 0.985, P<0.0001) and bletilla group (rsl, 0.743,P<0.05), the correlation was not significant in lipiodol group(rsl, 0.527, P>0.05).CONCLUSION: TACE with bletilla microspheres may enhance its anti-tumor effect by inhibiting the angiogenesis,and FP-MRI provides useful information to assess the TACE effect by depicting tumor vascularization and perfusion,