Review of 336 patients with hepatocellular carcinoma at Songklanagarind Hospital

AIM: To determine the clinical presentations, survival and prognostic factors of hepatocellular carcinoma (HCC) in Southern Thailand.

METHODS: Retrospective analysis was performed on the 336 hepatocellular carcinoma patients treated at Songklanagarind hospital between 1 January 1991 and 31 January 1999.

RESULTS: Of these 336 patients, 276 were males and 60 were females. The mean age was 54.4 years. The common symptoms and signs were abdominal pain and hepatomegaly. The most common presentation of tumor was a dominant mass with daughter nodules. Portal vein involvement was found in 50% of total. Extra hepatic metastasis was found in 13%, and the lung was the most common site. There were 65.4% with evidence of cirrhosis and half of them were in Child's class B. HBsAg was positive in 72.6%. Regarding Okuda's tumor staging, 15%, 61% and 24% were stage I, II and III, respectively. Overall median survival was 2.1 months (11.5, 2.6 and 0.7 months for stage I, II and III respectively). Treatments of HCC improved patient survival (5.5 months vs 1.6 months for untreated patients). Most common causes of death were hepatic failure. Using multivariate analysis, the prognostic factors identified were tumor staging, alpha-fetoprotein level above 10000 μg·L^-1, extrahepatic metastasis, portal vein thrombosis and treatment.

CONCLUSION: HCC in Thailand is a fatal disease with poor outcome due to late presentation and high prevalence of liver cirrhosis. Early detection and proper management may improve outcome.

Relationship between insulin A chain regions and insulin biological activities

AIM: To study the relationship between insulin A chain regions and insulin biological activities, we designed a series of insulin analogues with changes at A21, A12-18 of C-terminal helical region and A8-10 located in the region of A6-A11 intra-chain disulphide bond.

METHODS: Insulin A-chain analogues were prepared by stepwise Fmoc solid-phase manual synthesis and then combined with natural B-chain of porcine insulin to yield corresponding insulin analogues. Their biological activities were tested by receptor binding, mouse convulsion and immunological assay.

RESULTS: [A21Ala]Ins retains 70.3% receptor binding capacity and 60% in vivo biological activity. [DesA13-14, A21Ala]Ins and [DesA12-13-14-15, A21Ala] Ins still have definite biological activity, 7.9% and 4.0% receptor binding, and 6.2% and 3.3% in vivo biological activity respectively. [A15Asn, A17Pro, A21Ala]Ins maintains 10.4% receptor binding and 10% in vivo biological activity. [A8His, A9Arg, A10Pro, A21Ala]Ins, [A8His, A9Lys, A10Pro, A21Ala]Ins and [A8His, A9Lys, A10Arg, A21Ala]Ins have 51.9%, 44.3% and 32.1% receptor binding respectively, 50%, 40% and 30% in vivo biological activity respectively, and 28.8%, 29.6% and 15.4% immunological activity respectively.

CONCLUSION: A21Asn can be replaced by simple amino acid residues. The A chains with gradually damaged structur al integrity in A12-18 helical region and the demolition of the A12-18 helical region by the substitution of Pro and Asn for A17Glu and A15Gln respectively ca n combine with the B chain and the combination products show definite biological activity, the helical structure of A12-18 is essential for biological activities of insulin. A8-10 is not much concerned with biological activities, but is much more important antigenically in binding to its antibodies, these results may help us design a new type of insulin analogue molecule.

Helicobacter pylori infection and risk of gastric cancer in Changle County, Fujian Province, China

AIM: To evaluate the effects of Helicobacter pylori infection and other environmental factors on the development of gastric cancer.

METHODS: A population-based case-control study was conducted in Changle County, Fujian Province. The primary gastric cancer cases were histologically confirmed or diagnosed by surgery between January 1996 and March 1998. Healthy controls were randomly selected and matched by age, sex, and neighborhood of residence. A total of 101 pairs were included in the study. Specially trained interviewers conducted face-to-face interviews with the subjects according to a standardized questionnaire. Helicobacter pylori infections w ere measured by serum IgG antibody to Helicobacter pylori. Conditional Logistic Regression analysis was used.

RESULTS: The presence of IgG antibody to Helicobacter pylori was 63.7% in study subjects, 56.0% in patients with cardiac cancer, and 60.5% in patients with non-cardiac gastric cancer. The risk factors of gastric cancer in Changle County were identified such as low educational level [OR = 3.864; 95% confidence interval (95%CI) 1.604-9.311], low consumption of fresh vegetables (OR = 4.925; 95%CI: 1.356-17.885), high intake of fish sauce (OR = 10.587; 95%CI: 2.821-39.738), unscheduled meals (OR = 4.254; 95%CI: 1.445-12.552), and Helicobacter pylori infection (OR = 3.453; 95%CI: 0.901-13.224).

CONCLUSION: Helicobacter pylori infection may be important in the etiology of gastric cancer, but major risk factors other than Helicobacter pylori are responsible for the high gastric morbidity in Changle County.

Effects of salvianolic acid-A on NIH/3T3 fibroblast proliferation, collagen synthesis and gene expression

AIM: To investigate the mechanisms of salvianolic acid A (SA-A) against liver fibrosis in vitro.

METHODS: NIH/3T3 fibroblasts were cultured routinely, and incubated with 10^-4 mol/L-10^-7 mol/L SA-A for 22 h. The cell viability was assayed by [³H]proline incorporation, cell proliferation by [³H]TdR incorporation, cell collagen synthetic rate was measured with [³H]proline impulse and collagenase digestion method. The total RNA was prepared from the control cells and the drug treated cells respectively, and α (1) I pro-collagen mRNA expression was semi-quantitatively analyzed with RT-PCR.

RESULTS: 10^-4 mol/L SA-A decreased cell viability and exerted some cytotoxiciy, while 10^-5 mol/L-10^-7 mol/L SA-A did not affect cell viability, but inhibited cell proliferation significantly, and 10^-6 mol/L SA-A had the best effect on cell viability among these concentrations of drugs. 10^-5 mol/L-10^-6 mol/L SA-A inhibited intracellular collagen synthetic rate, but no significant influence on extracellular collagen secretion. Both 10^-5 mol/L and 10^-6 mol/L SA-A could decrease α (1) I pro-collagen mRNA expression remarkably.

CONCLUSION: SA-A had potent action against liver fibrosis. It inhibited NIH/3T3 fibroblast proliferation, intracellular collagen synthetic rate and type I pro-collagen gene expression, which may be one of the main mechanisms of the drug.

Construction of HBV-specific ribozyme and its recombinant with HDV and their cleavage activity in vitro

AIM: To construct the recombinant of HDV cDNA and HBV-specific ribozyme gene by recombinant PCR in order to use HDV as a transporting vector carrying HBV-specific ribozyme into liver cells for inhibiting the replication of HBV.

METHODS: We separately cloned the ribozyme (RZ) gene and recombinant DVRZ (comprising HDV cDNA and HBV-specific ribozyme gene) into the downstream of T7 promoter of pTAdv-T vector and studied the in vitro cleavage activity of their transcripts (rRZ, rDVRZ) on target RNA (rBVCF) from in vitro transcription of HBV C gene fragment(BVCF).

RESULTS: Both the simple (rRZ) and the recombinant ribozyme rDVRZ could efficiently catalyze the cleavage of target RNA (rBVCF) under different temperatures (37 °C, 42 °C and 55 °C) and Mg²⁺ concentrations (10 mmol/L, 15 mmol/L and 20 mmol/L) and their catalytic activity tended to increase as the temperature was rising. But the activity of rRZ was evidently higher than that of rDVRZ.

CONCLUSION: The recombinant of HDV cDNA and ribozyme gene had the potential of being further explored and used in gene therapy of HBV infection.

Effect of intestinal ischemia-reperfusion on expressions of endogenous basic fibroblast growth factor and transforming growth factor β in lung and its relation with lung repair

AIM: To study the changes of endogenous transforming growth factor β (TGF-β) and basic fibroblast growth factor (bFGF) in lung following intestinal ischemia and reperfusion injury and their effects on lung injury and repair.

METHODS: Sixty Wistar rats were divided into five groups, which underwent sham-operation, ischemia (45 min), and reperfusion (6, 24 and 48 h, respectively) after ischemia (45 min). Immunohistochemical method was used to observe the localization and amounts of both growth factors.

RESULTS: Positive signals of both growth factors could be found in normal lung, mainly in alveolar cells and endothelial cells of vein. After ischemia and reperfusion insult, expressions of both growth factors were increased and their amounts at 6 h were larger than those of normal control or of 24 and 48 h after insult.

CONCLUSION: The endogenous bFGF and TGF-βexpression appears to be up-regulated in the lung following intestinal ischemia and reperfusion, suggesting that both growth factors may be involved in the process of lung injury and repair.

Analysis of in vivo patterns of caspase 3 gene expression in primary hepatocellular carcinoma and its relationship to p21WAF1 expression and hepatic apoptosis

AIM: To detect the expression of caspase 3 gene in primary huma n hepatocellular carcinoma (HCC) and investigate its relationship to p21^WAF1 gene expression and HCC apoptosis.

METHODS: In situ hybridization was employed to determine caspase 3 and p21^WAF1 expression in HCC. In situ end-labeling was used to detect hepatocytic apoptosis in HCC.

RESULTS: Twenty-one of 39 (53.8%) cases of HCC were found to express caspase 3 transcripts, while 46.2% of HCC failed to express caspase 3. Non-cancerous adjacent liver tissues showed more positive caspase 3 (87.5%, 7/8) as compared with HCC (P < 0.05). The expression of caspase 3 is correlated with HCC differentiation, 72.2% (13/18) of moderately to highly differentiated HCC showed caspase 3 transcripts positive, while only 38.1% of poorly differentiated HCC harbored caspase 3 transcripts (P < 0.05). No relationship was found between caspase 3 expression and tumor size or grade or metastasis, although 62.5% (5/8) of HCC with metastasis were caspase 3 positive and a little higher than that with no metastasis (51.6%, P > 0.05). Expression of caspase 3 alone did not affect the apoptosis index (AI) of HCC. The AI was 7.12‰ in caspase 3-positive tumors (n = 21), while in caspase 3-negative cases (n = 18) 6.59‰ (P > 0.05). Expression of caspase 3 clearly segregated with p21^WAF1 positive tumors as compared with p21^WAF1 negative cases (16 of 23, 69.6% vs 5 of 16, 31.3%) with statistical significance(P = 0.017). In the cases with positive caspase 3 and negative p21^WAF1, the AI was found slightly higher, but with no statistical significance, than that with expression of p21^WAF1 and caspase 3 (7.21‰vs 6.98‰, P > 0.05).

CONCLUSION: Loss of caspase 3 expression may contribute to HCC carcinogenesis, although the expression of caspase 3 does not correlate well with cell apoptosis in HCC. p21^WAF1 may be merely one of the inhibitors which can reduce caspase 3 mediated cell apoptosis in HCCs.

Zonula occludin toxin, a microtubule binding protein

AIM: To investigate the interaction of Zot with microtubule.

METHODS: Zot affinity column was applied to purify Zot-binding protein(s) from crude intestinal cell lysates. After incubation at room temperature, the column was washed and the proteins bound to the Zot affinity column we re eluted by step gradient with NaCl (0.3-0.5 mol·L^-1). The fractions were subjected to 6.0%-15.0% (w/v) gradient SDS-PAGE and then transferred to PVDF membrane for N-terminal sequencing. Purified Zot and tau protein were blotted by using anti-Zot or anti-tau antibodies. Finally, purified Zot was tested in an in vitro tubulin binding assay.

RESULTS: Fractions from Zot affinity column yielded two protein bands with a M_r of 60 kU and 45 kU respectively. The N-terminal sequence of the 60 kU band resulted identical to β-tubulin. Zot also cross-reacts with anti-tau antibodies. In the in vitro tubulin binding assay, Zot co-precipitate with Mt, further suggesting that Zot possesses tubulin-b inding properties.

CONCLUSION: Taken together, these results suggest that Zot regulates the permeability of intestinal tight junctions by binding to intracellular Mt, with the subsequent activation of the intracellular signaling leading to the permeabilization of intercellular tight junctions.