[Expression of metastasis associated 1 family member 2 (MTA2) in gastric cancer and its relationship with transcription factor Sp1].

OBJECTIVE: To determine the expression patterns of metastasis associated 1 family member 2 (MTA2) in gastric cancer and non-cancerous gastric mucosa, and analyze its relationship with nuclear transcription factor Sp1 expression. METHODS: Tissue samples and clinicopathological information from 83 gastric cancer patients, who underwent surgery, were collected from Shanghai Rui Jin Hospital. All samples included cancer tissue and non-cancerous mucosa which was 5 cm away from the tumor lesion. The expression of MTA2 and Sp1 were detected by immunohistochemistry (IHC) staining. The mRNA of MTA2 was also detected by reverse transcription-polymerase chain reaction (RT-PCR). SPSS software was used for statistical analysis. RESULTS: The expression of MTA2 protein was significantly higher in primary lesions of the gastric cancer than that in non-cancerous mucosa by IHC (31.3% vs 12.0%, P < 0.01). MTA2 expression was closely related with tumor invasion or T staging (χ(2) = 5.677, P < 0.05). Yet, no significant relationship was observed between MTA2 expression and other clinicopathological parameters, including the age, sex, tumor differentiation, Lauren classification, lymph node metastasis, distant metastasis, as well as pathological staging. Furthermore, MTA2 expression was concomitant with Sp1 expression (r = 0.320, P < 0.05). Elevated MTA2 expression was observed in Sp1 positive cancer tissues (χ(2) = 9.565, P < 0.01). RT-PCR results also demonstrated that MTA2 mRNA was also highly expressed in the tissue samples with Sp1 expression. CONCLUSIONS: MTA2 is highly expressed in the primary lesions of gastric cancer than that in adjacent non-cancerous tissues, and is closely related with tumor invasion. MTA2 expression is elevated in Sp1 positive gastric cancer.

Helicobacter pylori induces promoter hypermethylation and downregulates gene expression of IRX1 transcription factor on human gastric mucosa.

BACKGROUND AND AIM: Gene silence of IRX1 tumor suppressor by promoter CpG methylation combined with loss of heterozygosity (LOH) has been identified in human gastric cancer. This study investigated the association between methylation of IRX1 and Helicobacter pylori infection in gastric mucosa tissues and cell line. METHODS: IRX1 methylation was studied by methylation specific polymerase chain reaction (MSP) and bisulfate sequencing polymerase chain reaction (BSP) methods in gastric mucosa tissues from H. pylori-positive chronic gastritis patients or H. pylori-negative chronic gastritis patients. Promoter activity, methylation status and gene expressing level of IRX1 were evaluated by persistent infecting H. pylori on human gastric cells GES-1 in vitro. Electron microscopy was used to observe the effect of H. pylori infection on GES-1 gastric mucosa cells. RESULTS: The methylation level of IRX1 promoter in H. pylori positive chronic gastritis and H. pylori negative chronic gastritis was 55.30%±13.17 versus 5.20%±6.31, respectively (P<0.01). H. pylori infection stimulated increased microvillus, and mucous secretion on GES-1 cells. Infection of H. pylori induced IRX1 promoter methylation and downregulation of the promoter activity as well as gene expression significantly. CONCLUSIONS: This study firstly demonstrated that H. pylori infection contributes to IRX1 promoter methylation on gastric mucosa.

Cell cycle dependent genes from the gastric cancer cell MKN45 can affect tumorigenesis.

BACKGROUND/AIMS: To investigate the cell cycle dependent genes involved in gastric tumorigenesis, possibly determining the relationship between the cell cycle and tumorigenesis. METHODOLOGY: MKN45 cells were collected every hour from Oh to 12h after release from G2/M and G1/S blocks. Nine samples (a-i), chosen at key times of the cell cycle, were prepared for RNA isolation and cDNA microarray analysis. RESULTS: In 2001 viable clones, 959 genes showed periodic variations during the cell cycle. Among 2001 genes that were clustered, a series of up-regulated genes were assigned to different cell cycle phases. Many periodically dependent genes in the cell cycle were ubiquitously expressed and participated in various cell physiological functions, such as transcription, translation, ubiquitination and signal transduction. These cell cycle dependent genes could affect cancer cell proliferation, apoptosis, activation of oncogenes and inactivation of tumor suppressor genes. CONCLUSIONS: We provided a comprehensive understanding of the gene expression profile involved in gastric cancer cell cycles and laid a foundation for further research on mechanisms of gastric tumorigenesis.

[Establishment of experimental angiogenic models with applications of quantitative digital image analysis].

OBJECTIVE: To establish experimental models for tumor neovascularization and to apply quantitative digital imaging analysis in the study. METHODS: An endothelial tube formation model was established by human umbilical vein endothelial cells (HUVECs). A vasculogenic mimicry model was established by SGC-7901 gastric cancer cell line. Fertilized eggs were used to establish a chorioallantoic membrane angiogenesis model. Using gene transfection experiment, IRX1 tumor suppressor gene was chosen as a therapeutic target. Image Pro Plus (IPP) analysis software was used for digital vascular images analysis with parameters including points, lines, angles and integral absorbance (IA) for the tubular formation or vasculogenic mimicry. RESULTS: Digital image analysis by IPP showed that HUVEC tubular formation was significantly inhibited in IRX1 transfectant, compared with controls. The tubular numbers in three groups were 12.80 +/- 3.83, 29.00 +/- 5.34 and 28.20 +/- 4.32 (P<0.01). The connection points of tubules in three groups were 13.20 +/- 2.59, 25.00 +/- 2.24 and 24.60 +/- 3.21 (P<0.01). The tubular lengths of three groups were (821.5 +/- 12.5), (930.9 +/- 13.5) and (948.4 +/- 18.1) microm (P=0.022). The IA values of PAS stain in three groups were 3606 +/- 363, 14 200 +/- 1251 and 15 043 +/- 1220 (P<0.01). In chick chorioallantoic membrane model, the angular numbers of tubules in three groups were 6.41 +/- 2.60, 10.27 +/- 2.65 and 9.18 +/- 1.99 (P<0.01). CONCLUSIONS: The endothelial tube formation model, vasculogenic mimicry model and chorioallantoic membrane angiogenesis model are useful for gene therapy and drug screening with targeting neoplastic vascularization. Professional image analysis software may greatly facilitate the quantitative analysis of tumor neovascularization.

[Discovery and verification of matrix gla protein, a TNM staging and prognosis-related biomarker for gastric cancer].

OBJECTIVE: To analyze microarray datasets deposited in the public database and to identify TNM associated genes in gastric cancers. METHODS: Microarray datasets of gastric cancer were selected from GEO database. Differentially expressed genes related to TNM staging were evaluated by significant analysis of the microarray using MultiExperiment Viewer (MEV) platform. Candidate gene expressions in gastric cancer tissues and cell lines were verified by reverse transcriptase polymerase chain reaction (RT-PCR), quantitative RT-PCR, Western blot and immunohistochemistry. RESULTS: GES4007 dataset was re-analyzed leading to the identification of 14 genes associated with TNM staging. Over-expression of matrix gla protein (MGP) was confirmed in gastric cancer cell lines and tumor tissues by quantitative RT-PCR, Western blot and immunohistochemistry. Increased MGP expression was found in 22 of 54 cases of (40.7%) gastric cancer specimens compared to the normal gastric tissues. The up-regulation of MGP mRNA expression closely correlated with TNM stage (P = 0.001) and prognosis (P = 0.006). CONCLUSIONS: Public databases of microarray studies are the valuable resources for data mining. MGP has been identified and confirmed as a novel biomarker for the TNM stage and prognosis of gastric cancer.

[EGFR-blockade by antibody Cetuximab inhibits the growth of human gastric cancer xenograft in nude mice and its possible mechanism].

OBJECTIVE: EGFR-mediated tumor proliferation plays an important role in the development of cancer, and is a key candidate for targeted therapy. The aim of this study is to evaluate the impact of EGFR monoclonal antibody Cetuximab (C225) on the growth, proliferation and apoptsis of gastric cancer xenograft in nude mice, and its possible mechanisms. METHODS: A gastric cancer cell line SGC-7901 with high EGFR expression level was screened from 7 gastric cancer cell lines. Gastric cancer xenografts in nude mice were established, and randomly divided into C225 treatment group and PBS control group. Tumor growth curves were calculated, the impact of C225 on the tumor growth, proliferation and angiogenesis was evaluated by immunohistochemical (IHC) staining Ki67 and CD34, respectively. The effect of C225 on apoptosis in the gastric cancer cells was evaluated by TUNEL assay. The expression levels of EGFR and its transcription factor Sp1 were detected by IHC staining and Western blot. RESULTS: After C225 treatment, the proliferation and growth of gastric cancer xenograft in nude mice were significantly decreased. In the contrast, the apopotic indexes in C225 treatment group and PBS control group were (16.4% +/- 0.3%) and (3.1% +/- 0.9%), respectively, with a significant difference (P < 0.001). There was no significant difference of the densities of CD34-positive microvessels between C225 treatment group and control group. Elevated expression of EGFR and Sp1 after C225 treatment was observed by IHC staining and Western blot assay. CONCLUSION: EGFR monoclonal antibody cetuximab (C225) can effectively inhibit the growth of gastric cancer xenografts in nude mice, and trigger its apoptosis. Yet, C225 treatment may upregulate the expression of EGFR and its transcription factor Sp1. A "block-transcription activation-compensation" mechanism may exist to explain the molecular mechanism of acquired resistance of a single target blockade treatment.

[Correlation between liver stem cell activation and histopathologic changes in liver with hepatic failure].

OBJECTIVE: To investigate the correlation between liver stem cell activation and histopathologic changes in liver transplant recipients with hepatic failure. METHODS: A total of 33 cases of hepatic failure were enrolled into the study. Donor liver tissues were used as normal controls. Histopathologic changes, presence of hepatotropic virus antigens, history of artificial liver therapy and number of c-kit positive cells were analyzed. RESULTS: There were a total of 25 males and 8 females. The age of patients ranged from 21 to 64 years. Among the 33 patients studied, 6 suffered from acute liver failure, 5 from subacute liver failure and the remaining from acute-on-chronic liver failure (associated with cirrhosis). Thirteen patients had a history of artificial liver therapy. Activated liver stem cells expressed c-kit monoclonal antibody but were negative for toluidine blue stain. The number of c-kit-positive cells in acute liver failure, subacute liver failure and acute-on-chronic liver failure were 3.50 +/- 2.66 (0 to 8) per mm(2), 11.47 +/- 8.85 (3 to 30) per mm(2) and 15.50 +/- 10.95 (5 to 45) per mm(2), respectively (P < 0.05). The number of c-kit-positive cells in cases with or without artificial liver therapy showed no statistically significant difference. CONCLUSIONS: The poor prognosis of acute liver failure is mainly due to massive liver necrosis and insufficient stem cell activation. Liver stem cell level is increased whenever there is progression into subacute liver failure and chronic liver failure. Actively treating acute liver failure with stimulation of the self-regeneration system in liver is thus useful.

Disordered beta-catenin expression and E-cadherin/CDH1 promoter methylation in gastric carcinoma.

AIM: To investigate the distribution of beta-catenin in nuclei or membrane/cytoplasm of gastric carcinoma cells, the relationship between E-cadherin gene methylation and its expression, and the role of beta-catenin and E-cadherin as potential molecular markers in predicting tumor infiltration. METHODS: Twenty-nine cases of gastric carcinoma, classified as diffuse and intestinal variants, were selected for study. Nuclear and cytoplasmic proteins were purified and beta-catenin content was detected by ELISA. DNA methylation of E-cadherin/CDH1 gene promoter was studied by methylation-specific PCR and compaired with E-cadherin expression detected by immunohistochemistry. RESULTS: In 27 cases of gastric carcinoma, the ratio of beta-catenin content between nuclei and membrane/cytoplasm was correlated with the T-classification (r = 0.392, P = 0.043). The significance was present between T2 and T3 groups. No correlation was detected between diffuse and intestinal variants in terms of their beta-catenin distribution. In 21 cases of diffuse variants of gastric carcinoma, there was a difference in E-cadherin expression between CDH1 gene-methylated group and non-methylated group (29 % vs 71 %, P = 0.027). No correlation between CDH1 gene methylation and T-classification was found, neither was the significance between E-cadherin expression and tumor infiltration grade. CONCLUSION: Comparative analysis of nuclear and membrane/cytoplasmic beta-catenin can predict local tumor infiltration. E-cadherin/CDH1 gene methylation is an important cause for its gene silence in diffuse variant gastric carcinoma. Methylation of CDH1 gene in the absence of E-cadherin is an early event in gastric carcinogenesis.

[High-resolution analysis of chromosome 5 and identification of candidate genes in gastric cancer].

OBJECTIVE: To explore the relationship between loss of heterozygosity (LOH) of 5p with the histological phenotype in gastric cancer. METHODS: Eighty pairs of tumor and adjacent normal mucosa samples were collected and genomic DNA was extracted. Total of 17 polymorphic microsatellite markers for 5p were used for LOH analysis. A part of samples were fixed in 10% buffered formalin and stained with H&E. Histological type of gastric cancer was defined according to Lauren's classification. RESULTS: The average informative rate of all seventeen markers was 60.0%. The LOH at least in one locus was detected in 28 of the 80 (35.0%) cases. The highest LOH frequency occurring at D5S2849 (7.77 cM), with LOH frequency of 35.2% (19/54). The minimal LOH region was spanned from 6.67 to 9.41 cM (1.18 Mb, covering 2.7 cM), including D5S417, D5S2849, D5S1492 and D5S2088. In 28 with LOH, 24 (85.7%) cases were of intestinal type, and only 4 cases (14.3%) were of diffuse type. There is significant difference between LOH frequency in intestinal-type and diffuse-type gastric cancers (P < 0.01). Searching the NCBI database disclosed that this minimal deletion region at 5p15.33 covered 3 candidate genes, IRX1, IRX2, and CEI. CONCLUSION: The molecular events in 5p 15.33 may be related with the morphological differentiation and development of gastric cancer. Gastric cancer with LOH of 5p15.33 locus tends to develop in to intestinal type. The cluster of candidate genes in 5p15.33 may be closely implicated in carcinogenesis of intestinal type gastric carcinoma.

Cognitive impairment in two subtypes of a single subcortical infarction / 中华医学杂志(英文版)

BACKGROUND@#Single subcortical infarction (SSI) is caused by two main etiological subtypes, which are branch atheromatous disease (BAD) and cerebral small vessel disease (CSVD)-related SSI. We applied the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ), the Shape Trail Test (STT), and the Stroop Color and Word Test (SCWT) to investigate the differences in cognitive performance between these two subtypes of SSI.@*METHODS@#Patients with acute SSIs were prospectively enrolled. The differences of MoCA-BJ, STT, and SCWT between the BAD group and CSVD-related SSI group were analyzed. A generalized linear model was used to analyze the associations between SSI patients with different etiological mechanisms and cognitive function. We investigated the correlations between MoCA-BJ, STT, and SCWT using Spearman's correlation analysis and established cut-off scores for Shape Trail Test A (STT-A) and STT-B to identify cognitive impairment in patients with SSI.@*RESULTS@#This study enrolled a total of 106 patients, including 49 and 57 patients with BAD and CSVD-related SSI, respectively. The BAD group performances were worse than those of the CSVD-related SSI group for STT-A (83 [60.5-120.0] vs. 68 [49.0-86.5], P = 0.01), STT-B (204 [151.5-294.5] vs. 153 [126.5-212.5], P = 0.015), and the number of correct answers on Stroop-C (46 [41-49] vs. 49 [45-50], P = 0.035). After adjusting for age, years of education, National Institutes of Health Stroke Scale and lesion location, the performance of SSI patients with different etiological mechanisms still differed significantly for STT-A and STT-B.@*CONCLUSIONS@#BAD patients were more likely to perform worse than CSVD-related SSI patients in the domains of language, attention, executive function, and memory. The mechanism of cognitive impairment after BAD remains unclear.

Transcription factor Sp1 expression in gastric cancer and its relationship to long-term prognosis.

AIM: To explore the expression of Sp1 in gastric carcinoma as well as its association with other clinicopathologic features, and to evaluate the role of Sp1 as a prognostic indicator of gastric carcinoma. METHODS: By using immunohistochemistry, we examined the Sp1 expression patterns in 65 cases of human gastric cancer, and 40 normal gastric mucosa specimens. Simultaneously, the correlation between Sp1 expression and clinical outcome or clinicopathologic features was investigated. RESULTS: The percentage of Sp1 expression was 12.5% (5/40) in normal gastric mucosa, and the Sp1 protein was mainly expressed in the nuclei of cells located in the mucous neck region. In sharp contrast, strong Sp1 expression was detected in tumor cells, whereas no or faint Sp1 staining was detected in stromal cells and normal glandular cells surrounding the tumors. The expression rate of Sp1 in gastric cancer lesions was 53.85% (35/65). The medium survival duration in patients who had a tumor with negative, weak and strong Sp1 expressions was 1 700, 1 560 and 1 026 d, respectively (P<0.05). Sp1 protein expression was closely related to the depth of tumor infiltration (chi(2) = 13.223, P<0.01) and TNM stage (chi(2) = 11.009, P<0.05), but had no relationship with the number of lymph nodes and Lauren's classification (P>0.05). Cox regression model for multivariate analysis revealed that high Sp1 expression (P<0.05) and advanced stage (P<0.01) were independent predictors of poor survival. CONCLUSION: Normal and malignant gastric tissues have unique Sp1 expression patterns. Sp1 might serve as an independent prognostic factor, by influencing the tumor infiltration and progression.

[Transcription factor Sp1 expression in gastric cancer and its prognostic value].

OBJECTIVE: To investigate the expression of transcription factor Sp1 in human gastric cancer tissues and normal gastric mucosa, and its prognostic significance. METHODS: By using immunohistochemistry, we studied the Sp1 expression patterns in 65 cases of gastric cancer with various clinico-pathologic characteristics, and 40 normal gastric mucosa specimens obtained from patients who underwent partial gastrectomy for benign gastric diseases. The significance of Sp1 expression on the survival of patients was evaluated. RESULTS: The expression rate of Sp1 in normal gastric mucosa was 12.5% (5/40). The positively stained glandular cells were mainly limited to those in the neck region. Cells at the basal portion of the gland were essentially negative. In sharp contrast, Sp1 expression rate in gastric cancer lesions was 53.8% (35/65). The medium survival time in patients who had a tumor with negative, weak and strong Sp1 expression was 1700, 1560 and 1026 days, respectively (P = 0.036). Sp1 protein expression was closely related to the depth of tumor invasion and TNM stage (P = 0.001, P = 0.026), but not related to the number of metastatic lymph nodes and Lauren's classification (P = 0.306, P = 0.667). CONCLUSION: Normal and malignant gastric tissues have unique Sp1 expression patterns. Sp1 might be served as an independent prognostic factor.

[uPA expression of gastric cancer cell lines and its correlation with peritoneal seeding].

OBJECTIVE: To study the correlation between expression of urokinase-type plasminogen activator (uPA) and capability of tumor cell seeding to the peritoneal membrane by different gastric cancer lines. METHODS: Expression of uPA in 4 human gastric cancer cell lines was examined by semi-quantitative RT-PCR, ELISA and Western blot. uPA activity was determined by an assay kit. After ip inoculation of cancer cells to nude mice, tumors on peritoneal membrane was grossly examined for tumor cell seedings. RESULTS: SGC7901 was the highest in uPA expression among human gastric cancer cell lines AGS, SGC7901, MKN45, and MKN28. MKN45 had the strongest uPA activity, while AGS was lowest in both uPA expression and activity. Peritoneal seeding tumors of various sizes were observed in mice inoculated with SGC7901 and MKN45 cells. In addition to peritoneal seedings, bloody ascites was present in mice inoculated with MKN28. The MKN45-inoculated mice took the least time to develop tumors and had the shortest surviving period. No peritoneal seeding was seen in mice inoculated with AGS cells. CONCLUSION: Three of 4 human gastric cancer cell lines studied express uPA mRNA and activity, which correlate with their peritoneal seeding potentials.

[Sensitivity and specificity of granzyme B and perforin in diagnosing acute rejection after liver transplantation].

OBJECTIVE: To study the roles of granzyme B and perforin in diagnosing acute rejection after liver transplantation, and the relationship between their activity index (AI) and Banff's histological grading criteria. METHODS: Liver biopsies were processed as for routine surgical specimens and labeled with granzyme B and perforin monoclonal antibodies. The number of positive cells/mm(2) was determined as activity index (AI) by IPP image analysis software. Histologic findings were used as the "gold standard" in diagnosing acute rejection. RESULTS: Of 41 liver biopsy samples studied, acute rejection was noted in 21 cases, the remaining 20 cases showed no evidence of rejection. The AI of granzyme B and perforin in the acute rejection group was significantly higher than that in the non-acute rejection group (< 0.001). In the acute rejection group, the AI in moderate to severe acute rejection was higher than that in mild to indeterminate acute rejection (< 0.001). Compared with the "golden" histologic criteria, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of granzyme B in diagnosing acute rejection were 90.0%, 95.2%, 94.7%, 90.9% and 92.7% respectively. The values of these parameters for perforin were also above 80%. CONCLUSIONS: Granzyme B and perforin are key markers of activated immune cells in acute rejection and highly expressed during acute liver rejection episodes. As ancillary investigations, these parameters demonstrated high sensitivity and specificity in diagnosing acute rejection in allograft post-transplant liver biopsies.

Epigenetic silencing of microRNA-149 in cancer-associated fibroblasts mediates prostaglandin E2/interleukin-6 signaling in the tumor microenvironment.

Tumor initiation and growth depend on its microenvironment in which cancer-associated fibroblasts (CAFs) in tumor stroma play an important role. Prostaglandin E2 (PGE2) and interleukin (IL)-6 signal pathways are involved in the crosstalk between tumor and stromal cells. However, how PGE2-mediated signaling modulates this crosstalk remains unclear. Here, we show that microRNA (miR)-149 links PGE2 and IL-6 signaling in mediating the crosstalk between tumor cells and CAFs in gastric cancer (GC). miR-149 inhibited fibroblast activation by targeting IL-6 and miR-149 expression was substantially suppressed in the CAFs of GC. miR-149 negatively regulated CAFs and their effect on GC development both in vitro and in vivo. CAFs enhanced epithelial-to-mesenchymal transition (EMT) and the stem-like properties of GC cells in a miR-149-IL-6-dependent manner. In addition to IL-6, PGE2 receptor 2 (PTGER2/EP2) was revealed as another potential target of miR-149 in fibroblasts. Furthermore, H. pylori infection, a leading cause of human GC, was able to induce cyclooxygenase-2 (COX-2)/PGE2 signaling and to enhance PGE2 production, resulting in the hypermethylation of miR-149 in CAFs and increased IL-6 secretion. Our findings indicate that miR-149 mediates the crosstalk between tumor cells and CAFs in GC and highlight the potential of interfering miRNAs in stromal cells to improve cancer therapy.

Liver biopsy in evaluation of complications following liver transplantation.

AIM: To analyze the role of liver biopsies in differential diagnosis after liver transplantation. METHODS: A total of 50 biopsies from 27 patients with liver dysfunction out of 52 liver transplantation cases were included. Biopsies were obtained 0-330 d after operation, in which, 44 were fine needle biopsies, another 6 were wedge biopsies during surgery. All tissues were stained with haemotoxylin-eosin. Histochemical or immunohistochemical stain was done. RESULTS: The rate of acute rejection in detected cases and total transplantation cases was 48.2% and 25.0%, chronic rejection rate in detected cases and total transplantation cases was 14.8% and 7.7%, preservation-reperfusion injury in detected cases and total transplantation cases was 25.9% and 13.5%, hepatic artery thrombosis rate in detected cases and total transplantation cases was 11.1% and 5.8%, intrahepatic biliary injury rate in detected cases and total transplantation cases was 7.4 % and 3.8%, CMV infection rate in detected cases and total transplantation cases was 3.7% and 1.9%, hepatitis B recurrence rate in detected cases and total transplantation cases was 3.7% and 1.9%, the ratio of suspicious drug-induced hepatic injury in detected cases and total transplantation cases was 11.1% and 5.8%. CONCLUSION: Acute rejection and preservation-reperfusion injury are the major factors in early liver dysfunction after liver transplantation. Hepatic artery thrombosis and prolonged cold preservation may result in intrahepatic biliary injury. Acute rejection and viral infection may involve in the pathogenesis of chronic rejection. Since there are no specific lesions in drug-induced hepatic injury, the diagnosis must closely combine clinical history and rule out other possible complications.

Correlation of thymidylate synthase, thymidine phosphorylase and dihydropyrimidine dehydrogenase with sensitivity of gastrointestinal cancer cells to 5-fluorouracil and 5-fluoro-2'-deoxyuridine.

AIM: To determine the expression levels of three metabolic enzymes of fluoropyrimidines: thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in seven human gastrointestinal cancer cell lines, and to compare the enzyme levels with the sensitivity to 5-fluorouracil (5-FU) and 5-fluoro-2'-deoxyuridine (FdUrd). METHODS: TS, TP and DPD mRNA levels were assessed by semi-quantitative RT-PCR, TP and DPD protein contents were measured by ELISA. Fifty percent inhibitory concentrations of growth (IC50), representing the sensitivity to drugs, were determined by MTT assay. RESULTS: IC50 values ranged from 1.28 to 12.26 microM for 5-FU, and from 5.02 to 24.21 microM for FdUrd, respectively. Cell lines with lower DPD mRNA and protein levels tended to be more sensitive to 5-FU (P<0.05), but neither TS nor TP correlated with 5-FU IC50 (P>0.05). Only TS mRNA level was sharply related with FdUrd sensitivity (P<0.05), but TP and DPD were not (P>0.05). A correlation was found between mRNA and protein levels of DPD (P<0.05), but not TP (P<0.05). CONCLUSION: DPD and TS enzyme levels may be useful indicators in predicting the antitumor activity of 5-FU or FdUrd, respectively.

Protective effect of doxorubicin induced heat shock protein 72 on cold preservation injury of rat livers.

AIM: To observe the protective effect of heat shock protein 72 (HSP 72) induced by pretreatment of doxorubicin (DXR) on long-term cold preservation injury of rat livers. METHODS: Sprague-Dawley rats were administered intravenously DXR at a dose of 1 mg/kg body mass in DXR group and saline in control group. After 48 h, the rat liver was perfused with cold Linger's and University of Wisconsin (UW) solutions and then was preserved in UW solution at 4 degrees for 24, 36 and 48 h. AST, ALT, LDH and hyaluronic acid in preservative solution were determined. Routine HE, immunohistochemical staining for HSP 72 and electron microscopic examination of hepatic tissues were performed. RESULTS: After 24, 36 and 48 h, the levels of AST, ALT and hyaluronic acid in preservative solution were significantly higher in control group than in DXR group (P<0.05), while LDH level was not significantly different between the 2 groups (P>0.05). Hepatic tissues in DXR group were morphologically normal and significantly injured in control group. HSP 72 was expressed in hepatocytes and sinusoidal endothelial cells in DXR group but not in control group. CONCLUSION: Pretreatment of DXR may extend the time of rat liver cold preservation and keep liver alive. The expression of HSP 72 in liver can prevent hepatocytes and sinusoidal endothelial cells from long-term cold preservation injury.

Expression of vascular endothelial growth factor C and chemokine receptor CCR7 in gastric carcinoma and their values in predicting lymph node metastasis.

AIM: To study the expression of vascular endothelial growth factor C (VEGF-C) and chemokine receptor CCR7 in gastric carcinoma and to investigate their associations with lymph node metastasis of gastric carcinoma and their values in predicting lymph node metastasis. METHODS: The expression of VEGF-C and CCR7 in gastric carcinoma tissues obtained from 118 patients who underwent curative gastrectomy was examined by immunohistochemistry. Among these patients, 39 patients underwent multi-slice spiral CT (MSCT) examination. RESULTS: VEGF-C and CCR7 were positively expressed in 52.5 and 53.4% of patients. VEGF-C expression was more frequently found in tumors with lymph node metastasis than those without it (P<0.001). VEGF-C expression was also closely related to lymphatic invasion (P<0.001), vascular invasion (P<0.01), and TNM stage (P<0.001). However, there was no significant correlation between VEGF-C expression and age at surgery, gender, tumor size, tumor location, Lauren classification, and depth of invasion. CCR7 expression was significantly higher in patients with lymph node metastasis compared with those without lymph node metastasis (P<0.001) and was also associated with tumor size (P<0.01), depth of invasion (P<0.001), lymphatic invasion (P<0.001), and TNM stage (P<0.001). However, the presence of CCR7 had no correlation to age at surgery, gender, tumor location, Lauren classification, and vascular invasion. Among the 39 patients who underwent MSCT examination, only CCR7 expression was related to lymph node metastasis determined by MSCT (P<0.05). In the current retrospective study, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of VEGF-C and CCR7 expression in the diagnosis of lymph node metastasis for patients with gastric carcinoma were 73.8%, 70.2%, 72.6%, 71.4% and 72.0%, and 82.0%, 77.2%, 79.4%, 80.0% and 79.7%, respectively. After subdivision according to the combination of VEGF-C and CCR7 expression, receiver operating characteristic (ROC) analysis showed that the accuracy of the combined examination of VEGF-C and CCR7 expression in predicting lymph node metastasis was relatively high (area under ROC curve [Az]=0.83). CONCLUSION: The expression of VEGF-C and CCR7 is related to lymph node metastasis of gastric carcinoma and both of them may become new targets for the treatment of gastric carcinoma. Furthermore, the combined examination of VEGF-C and CCR7 expression in endoscopic biopsy specimens may be useful in predicting lymph node metastasis of gastric carcinoma and deciding the extent of surgical lymph node resection.