Modulation of human telomerase reverse transcriptase in hepatocellular carcinoma

AIM:Most cancer cells acquire immortal capability by telornerase activation. The human telornerase reverse transcriptase gene (hTERT) is considered to be the major determinant of the enzymatic activity of human telomerase,and the hTERTpromoter contains several c-lylyc binding sites that mediate hTERTtranscriptional activation. Few studies have examined the role of hTERTin hepatocarcinogenesis,and the relationship between c-Myc and telomerase in human hepatocellular carcinoma tissue is unknown.METHODS:We measured hTERTmRNA levels and c-Myc oncoprotein expression in 57 patients with hepatocellular carcinoma using in situhybridization and immunohistochemistry,respectively. The transcription regulation of hTERT was evaluated by transient transfection of pGL3-1375 into the human hepatocellular carcinoma cell line J5. To determine the relationship between c-Myc and the hTERTpromoter, a 1375-bp DNA fragment encompassing the promoter was placed upstream of the luciferase reporter gene and transiently transfected into the cell line. Two additional hTERT promoter constructs (-776 and -100 bp region) and an hTERT promoter-LUC construct containing 2 c-Myc mutations (pGL3-181 MycMT) were also used for luciferase assays.RESULTS:In 30 of 57 cases (52%), hTERTmRNA expression was associated with c-Myc protein expression. However,16 of 57 cases (28%) showed strong hTERTmRNA detection without c-Myc protein expression, and 11 cases (19%) showed weak hTERTmRNA expression and strong c-Myc expression.Although luciferase activity was decreased between upstream 1375 bp and 776 bp, there was no significant difference between upstream 776 bp and 100 bp. Finally, there was no significant decrease in activity after transfection of the hTERT promoter-LUC construct.CONCLUSION:The results indicate that c-Myc does not play a major role in gene regulation of the catalytic subunit of telomerase (hTERT) in human hepatocellular carcinoma.Other regulatory elements or epigenetic phenomena should be further investigated to understand hTERTgene regulation in human hepatocellular carcinoma.

Comparison of transcatheter arterial chemoembolization,laparoscopic radiofrequency ablation,and conservative treatment for decompensated cirrhotic patients with hepatocellular carcinoma

AIM:To compare the therapeutic effect of transcatheter arterial chemoembolization （TACE), laparoscopic radiofrequency ablation (LRFA), and conservative treatment for the therapy of decompensated liver cirrhosis patients with hepatocellular carcinomas (HCC).METHODS:Between October 2000 and July 2003, one hundred patients with histologically proven primary HCC and clinical decompensated liver cirrhosis (Child classification B or C) were included in this study. Forty patients received LRFA (LRFA group), twenty received TACE (TACE group),and forty received conservative treatment (control group).We compared the survival, recurrence, and complication rates in these three groups, making adjustment using the tumor metastastic node staging system.RESULTS:The major complication rate in the TACE group (9/20) was significantly higher than that in the LRFA group (7/40). For patients with TMN stage Ⅱ HCC, the survival rate of the LRFA group was better than that of the TACE and control groups (P=0.003) but the recurrence rates befween the LRFA and TACE groups did not differ.CONCLUSION: The LRFA group of patients had betterclinical outcomes in terms of survival and complication rates in comparison with the TACE group or conservative treatment in patients with decompensated liver cirrhosis, especially in TMN patients with stage Ⅱ HCC. LRFA is thus an appropriate alternative treatment for poor liver function among patientswith HCC.

Giant malignant gastrointestinal stromal tumors: Recurrence and effects of treatment with STI-571

AIM: Malignant gastrointestinal stromal tumors (GISTs)are rare. Tumors larger than 10 cm tend to recur earlier:the larger the volume of the tumor, the worse the prognosis.We hypothesized that treatment with imatinib mesylate (Gleevec; STI-571), a c-kittyrosine kinase inhibitor, as palliative therapy would prolong the survival of patients with recurrent giant malignant GISTs after resection.METHODS: We performed a retrospective analysis of the effects of resection on patients with giant GISTs (＞10 cm in diameter) to determine the overall survival and recurrence rates. Twenty-three patients diagnosed with giant GISTs were included from June 1996 to December 2003. STI571 was not available until January 2000. After that time,9 patients received this drug. The factors of age, sex, tumor location, histological surgical margin, and STI-571, tumor size changes and drug side effects were reviewed. We compared the survival rate to determine the prognostic factors and the effects of STI-571 on patients with recurrent malignant gastrointestinal stromal tumor.RESULTS: The positive surgical margin group had a significantly higher recurrence rate than the negative margin group (P = 0.012). A negative surgical margin and palliative treatment with STI-571 were significant prognostic variables (Log-rank test,P＜0.05). Age, sex and tumor location were not significant prognostic variables. The 5-year survival rate of the surgical margin free patients was 80%and the 2-year survival rate of the surgical margin positive patients was 28%. The 5-year survival rate was 80% for the patients given STI-571 and 30% for the patients not given STI-571. The use of STI-571 gave a significant tumor shrinkage (6/9) rate in patients with giant GIST recurrence after resection.CONCLUSION: A negative surgical margin and the use of STI-571 after surgical resection were good prognostic indicators. Achieving a tumor-free surgical margin is still the best primary treatment for patients with such tumors.If STI-571 is used immediately when the surgical margin is positive and the tumor recurs after resection, then the prognosis of patients with giant GISTs can be improved.

Gallbladder contractility and volume characteristics in gallstone dyspepsia

AIM:It is difficult to differentiate gallstone dyspepsia and functional dyspepsia by clinical symptoms and signs. We hypothesized that gallstone dyspepsia was related to abnormal gallbladder motility. We aimed to differentiate gallstone dyspepsia from functional dyspepsia by measuring gallbladder motility.METHODS: We measured gallbladder volume changes in response to gastric distension (saline 500mL) and fatty meal in 10normal volunteers (controls) and 62 patients with gallstones and dyspepsia before cholecystectomy. Forty cholecystectomized patients were symptom free or had improvement (group I), while the remaining 22 patients had persistent dyspepsia (group Ⅱ). Gallbladder volume change and ejection fraction were analyzed and compared among the three groups.RESULTS:In group I, there were significant decreases in gallbladder volumes 5-25 rain after gastric distension,compared to fasting volumes. Compared to normal volunteers and group Ⅱ, group I had significantly decreased gallbladder volumes 10-20min after drinking 500mL of normal saline and 10 to 50min after eating fatty meal.CONCLUSION:Our results support the hypothesis that increased gallbladder contraction after gastric distension or fatty meal may be related to dyspeptic symptoms in uncomplicated gallstone disease. These findings may be useful in differentiating functional dyspepsia from gallstone dyspepsia, patients with the latter disease may benefit from laparoscopic cholecystectomy.

Decreased expression of type Ⅱ tumor suppressor gene RARRES3 in tissues of hepatocellular carcinoma and cholangiocarcinoma

AIM: To analyze the expression of retinoic acid receptor responder 3 (RARRES3) protein in paraffin-embedded tissues of hepatocellular carcinoma (HCC) and cholangiocarcinoma(CC), and the correlation of RARRES3 production with tumor differentiation.METHODS: Expression of RARRES3 in tissues from 21CC (10 well-, 7 moderately- and 4 poorly-differentiated)and 32 HCC was determined by immunohistochemistry.RESULTS: Among 21 CC tissues, RARRES3 was detected in 8 (80%) of 10 well-differentiated tumors. Only 2 (18.2%)out of 11 tumors with moderate or poor differentiation showed positive RARRES3 expression. RARRES3 expression in well-differentiated CC was significantly higher than that in tumors with moderate or poor differentiation (Fisher exact test, P＜0.01). Expression of RARRES3 was not different between early (Ⅰ and Ⅱ) and late (Ⅲ and Ⅳ) stages of CC.Among 30 HCC tissues, 17 (56.7%) weakly expressed RARRES3 in HCC cells, and 25 (83.3%) normal tissues adjacent to HCC expressed the protein. RARRES3 expression was significantly decreased in HCC tissues compared to that in adjacent normal tissues (logistic regression analysis, OR = 0.27, 95% CI (0.11-0.62), P＜0.01).CONCLUSION: Expression of RARRES3 is positively correlated to well-differentiated CC, which supports the role of RARRES3 in malignant epithelial differentiation of the tumor. The decrease in RARRES3 expression in tissues of HCC and CC with moderate and poor differentiation suggests that altered RARRES3 expression may play a role in the carcinogenesis of the liver and biliary tract.

Effect of water-soluble contrast in colorectal surgery: A prospective randomized trial

AIM: Postoperative gastrointestinal-tract motility is normally delayed. Early feeding after colorectal surgery has been reported recently, but late feeding is common. Gastrografin not only enhances bowel peristalsis, but also decreases bowel-wall edema. Whether contrast medium allows early oral feeding and reduces the duration of hospitalization requires clarification. METHODS: Fifty patients underwent elective colorectal surgery In a regional medical center. Patients were prosp-ectively randomized into a Gastrografin group or control group (n=25 each). Patients in the Gastrografin group began their feeding schedule with 100 mL of 5% dextrose water with 100 mL of Gastrografin on postoperative d 3 and were advanced to a full liquid diet when the contrast reached the colon in 4 h. Patients in the control group began their feeding schedule with 200 mL of 5% dextrose water on postoperative d 3 and were advanced to a full liquid diet after the passage of flatus and stool. Nasogastric tubes were inserted for persistent postoperative vomiting. Fullness, nausea, vomiting, complications, time of anesthesia, time of operation, time of mobilization, time of oral feeding, and duration of hospital stay were recorded and analyzed with Student's t-test. RESULTS: In the Gastrografin group, one patient had aspiration pneumonia and one patient had anastomotic leakage resulting in sepsis and eventual death. This mortality was excluded from the subsequent statistical analysis. In the control group, two patients had wound infections. There was no significant difference between the two groups at the time of anesthesia, time of operation, or time of mobilization. There were significant differences between the two groups in the time of oral feeding (3.3±0.3 d in the Gastrografin group VS 4.8±0.4 d in the control group; P=odds ratio--, 95%CI [-0.5 to +0.7 d]) and in the length of hospital stay (7.6±1.1 d in the Gastrografin group VS 10.2±1.3 d in the control group; P=odds ratio--, 95% CI [-1.2 to +1.4 d]). CONCLUSION: Gastrografin not only allowed early oral feeding but also reduced the duration of hospitalization after elective colorectal surgery.