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The microcell mediated transfer of human chromosome 8 into highly metastatic rat liver cancer cell line C5F

AIM: Our previous research on the surgical samples of primary liver cancer with CGH showed that the loss of human chromosome 8p had correlation with the metastatic phenotype of liver cancer. In order to seek the functional evidence that there could be a metastatsis suppressor gene (s) for liver cancer on human chromosome 8, we tried to transfer normal human chromosome 8 into rat liver cancer cell line C5F, which had high metastatic potential to lung.

METHODS: Human chromosome 8 randomly marked with neo gene was introduced into C5F cell line by MMCT and positive microcell hybrids were screened by double selections of G418 and HAT. Single cell isolation cloning was applied to clone microcell hybrids. Finally, STS-PCR and WCP-FISH were used to confirm the introduction.

RESULTS: Microcell hybrids resistant to HAT and G418 were obtained and 15 clones were obtained by single-cell isolation cloning. STS-PCR and WCP-FISH proved that human chromosome 8 had been successfully introduced into rat liver cancer cell line C5F. STS-PCR detected a random loss in the chromosome introduced and WCP-FISH found a consistent recombination of the introduced human chromosome with the rat chromosome.

CONCLUSION: The successful introduction of human chromosome 8 into highly metastatic rat liver cancer cell line builds the basis for seeking functional evidence of a metastasis suppressor gene for liver cancer harboring on human chromosome 8 and its subsequent cloning.

Decision making in right-sided diverticulitis

AIM: To evaluate systematically our nine-year experience in treating right-sided diverticulitis of the colon, and to explore its clinical and radiological relationship.

METHODS: The clinical and radiological data of 40 patients with colonic diverticulitis treated in Mackay Memorial Hospital, Taipei, from 1993 through 2002 were reviewed retrospectively.

RESULTS: The average age of the patients with right-sided diverticulitis was 53.1 years, which was 11.6 years younger than that of the patients with left-sided diverticulitis. The preoperative diagnosis of appendicitis was made in 8 of 13 right-sided diverticulitis patients. Nine (69%) had right lower quadrant abdominal pain for more than 48 hours, and ten patients (77%) presented with fever. CT findings suggesting acute right-sided diverticulitis including thickening of the intestinal wall and pericolonic inflammation were present in five patients.

CONCLUSION: Right-sided diverticulitis is easily confused with acute appendicitis because it occurs at a somewhat younger age than that in left-sided diverticulitis. Barium enema and CT are helpful for the early diagnosis of right-sided diverticulitis. While clearly not required in the majority of patients with right lower quadrant abdominal pain, barium enema and CT may be helpful in making the decision with a clinical history or physical examinations atypical of acute appendicitis.

Crohn’s disease and risk of fracture: does thyroid disease play a role?

AIM: To assess the role of thyroid disease as a risk for fractures in Crohn’s patients.

METHODS: A cross-sectional study was conducted from 1998 to 2000. The study group consisted of 210 patients with Crohn’s disease. A group of 206 patients without inflammatory bowel disease served as controls. Primary outcome was thyroid disorder. Secondary outcomes included use of steroids, immunosuppressive medications, surgery and incidence of fracture.

RESULTS: The prevalence of hyperthyroidism was similar in both groups. However, the prevalence of hypothyroidism was lower in Crohn’s patients (3.8% vs 8.2%, P = 0.05). Within the Crohn’s group, the use of immunosuppressive agents (0% vs 11%), steroid usage (12.5% vs 37%), small bowel surgery (12.5% vs 28%) and large bowel surgery (12.5% vs 27%) were lower in the hypothyroid subset as compared to the euthyroid subset. Seven (3.4%) Crohn’s patients suffered fracture, all of whom were euthyroid.

CONCLUSION: Thyroid disorder was not found to be associated with Crohn’s disease and was not found to increase the risk for fractures. Therefore, screening for thyroid disease is not a necessary component in the management of Crohn’s disease.

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Relationship between the expression of human telomerase reverse transcriptase gene and cell cycle regulators in gastric cancer and its significance

AIM: To investigate the expression of human telomerase reverse transcriptase gene (hTRT) in gastric cancer (GC) and its relevance with cell cycle regulators including P16INK4, cyclin and P53.

METHODS: In situ hybridization (ISH) for hTRT mRNA was performed in 53 cases of gastric cancer and adjacent cancerous tissues. Immunohistochemical staining (S-P method) for hTRT protein, P16INK4, cyclinD1 and P53 was performed in 53 cases of GC and adjacent cancerous tissues.

RESULTS: Of 53 cases of GC, the expression of hTRT mRNA and hTRT protein was significantly higher than the expression of hTRT mRNA and hTRT protein in adjacent canerous tissues (P < 0.01), the positive rates of hTRTmRNA and hTRT protein were 79.2% and 88.6%. There was a stastical difference of the expression of hTRT protein among well differentiated adenocarcinoma, poorly differentiated adenocarcinoma and mucoid carcinoma. And there was a highly significant positive correlation between the expression of hTRT mRNA and hTRT protein (r = 0.625, P < 0.01). However, the expression of hTRT mRNA and its protein in GC were not related with other clinicopathological parameters including gender, age, location and size of neoplasm, invasion depth, lymph node metastasis and clinical stage. There was a significant positive correlation between the expression of hTRT mRNA and cyclinD1 protein (r = 0.350, P < 0.01). There was a significant positive correlation between the expression of cyclinD1 protein and hTRT protein (r = 0.549, P < 0.01), so was between P53 and hTRT protein (r = 0.319, P < 0.05).

CONCLUSION: The expression of hTRT gene is correlated significantly to the specific defects of cell cycle on G1/S check point ; telomerase activity may depend on cell cycle in gastric cancer and it is available to clarify the molecular mechanism of telomerase activity regulation. The expression of hTRT mRNA and hTRT protein in GC is significantly different from the expression of hTRT mRNA and hTRT protein in adjacent cancerous tissue which indicates that these targets are correlated closely to the occurrence of GC and can provide important morphologic index for diagnosis of GC.

L-forms of H. pylori

AIM: To study the occurrence of L-forms of H. pylori infection in patients with peptic ulcers and its association with possible changes of cellular immune function in the patients.

METHODS: Endoscopic biopsy specimens of gastric antrum and gastric corpus were taken from 228 patients with peptic ulcers and inoculated into Skirrow selective medium for H. pylori vegetative forms and special medium for H. pylori L-forms, followed by bacterial isolation and identification. And peripheral venous blood of the patients was taken to detect the percentage of CD3⁺, CD4⁺ and CD8⁺ with biotin-streptavidin (BSA) and the level of IL-2, IL-6 and IL-8 with ELISA.

RESULTS: (1) The detection rates of H. pylori L-forms and vegetative forms in the patients were 50.88% (116/228) and 64.91% (148/228) respectively, and the co-infection rate of H. pylori L-forms and vegetative forms was 78.38% (116/148). To be more exact, the detection rates of H. pylori L-forms in male and female patients were 57.04% (77/135) and 41.94% (39/93) respectively, and statistics found significant difference between them (P < 0.05). Furthermore, the detection rates of H. pylori L-forms in patients aged 14 years-, 30 years-, 40 years- and 50 years- were 31.91% (15/47), 42.86% (24/56), 56.94% (41/72) and 67.92% (36/53) respectively, and there was significant difference between them (P < 0.01). (2) The percentages of CD3⁺, CD4⁺, CD8⁺, the ratio of CD4⁺/CD8⁺, and the level of IL-2, IL-6, IL-8 in H. pylori-positive patients were (52.59 ± 5.44)%, (35.51 ± 5.74)%, (27.77 ± 8.64)%, (1.56 ± 0.51), (2.66 ± 0.47) mg/L, (108.62 ± 5.85) ng/L and (115.79 ± 7.18) ng/L respectively, compared with those in H. pylori-negative patients, the percentages of CD3⁺, CD4⁺ and the ratio of CD4⁺/CD8⁺ decreased, but the level of IL-2, IL-6 increased, and the difference was significant (P < 0.001-P < 0.01). Moreover, the percentages of CD3⁺, CD4⁺, CD8⁺, the ratio of CD4⁺/CD8⁺, and the level of IL-2, IL-6, IL-8 in the patients with mixed infection of both H. pylori L-forms and vegetative forms were (51.69±5.28)%, (34.75 ± 5.89)%, (27.15 ± 7.45)%, (1.48 ± 0.47), (2.16 ± 0.38) mg/L, (119.45 ± 5.44) ng/L and (123.64 ± 6.24) ng/L respectively, compared with those in patients with simple infection of H. pylori vegetative forms, the percentage of CD4⁺, the ratio of CD4⁺/CD8 ⁺ and the level of IL-2 increased, but the level of IL-6 and IL-8 decreased, statistical difference was found between them (P < 0.001-P < 0.05).

CONCLUSION: L-forms variation often occurs in patients with peptic ulcers who are infected by H. pylori, which is commonly found in male patients and related to ages. The L-forms variation of H. pylori can be an important factor causing disorder of cellular immune function in the patients with peptic ulcers who are infected by H. pylori.

Successful rescuing a pregnant woman with severe hepatitis E infection and postpartum massive hemorrhage

AIM: To sum up the experience of the successful therapy for the severe hepatitis of pregnant woman with postpartum massive hemorrhage.

METHODS: The advanced therapeutic methods including the bilateral uterine artery embolism, hemodialysis and artificial liver support therapy were performed with comprehensive medical treatments and the course of the successful rescuing the patient was analyzed.

RESULTS: Through the hospitalization of about two mouths the patient and her neonatus had gotten the best of care in our department and pediatric department separately. Both of them were discharged in good condition.

CONCLUSION: The key points for a successful therapy of the pregnant woman with severe hepatitis are termination of the pregnancy and the control of their various complications. It was suggested that the proper combination of these measures of modern therapy would race against time for renewing of hepatic and renal functions.

Detection of HBV, PCNA and GST-π in hepatocellular carcinoma and chronic liver diseases

AIM: To investigate the change of HBV DNA, PCNA and GST-π in chronic liver disease and hepatocellular carcinoma (HCC).

METHODS: Hepatitis B surface antigen (HBsAg), proliferating cell nuclear antigen (PCNA) and glutathione S-transferases (GST-π) were detected by immunohistochemical staining and HBV DNA was detected by in situ hybridization (ISH) in formalin-fixed and paraffin-embedded sections with a total of 111 specimens of chronic hepatitis, liver cirrhosis, paratumorous tissue, HCC and normal liver tissue.

RESULTS: The positive rates of HBsAg and HBVDNA were 62.5%(15/24) and 75.0%(12/16) in chronic hepatitis, 64.0%(16/25) and 83.3%(15/18) in liver cirrhosis, 72.7% (16/22) and 85.7%(12/14) in the paratumorous tissu and 45.0%(14/31) and 64.3%(9/14) in HCC. The positive HBVDNA granules in chronic hepatitis, liver cirrhosis and the paratumorous tissue were more intense than that in HCC. The positive rates of PCNA and GST-π were 34.8%(8/23) and 25.0%(4/16) in chronic hepatitis, 73.7%(14/19) and 17.6%(3/17) in liver cirrhosis, 86.7%(13/15) and 53.3% (8/15) in the paratumorous tissue, 100%(15/15) and 60.0% (9/15) in HCC, respectively, and the positive rate of GST-π in the paratumorous tissue was significantly higher than that in the liver cirrhosis without tumor (P < 0.05), but same as that in HCC(P > 0.05).

CONCLUSION: The HBV infection may increase expression of PCNA and GST-π. The paratumor cirrhosis may be a sequential lesion of precancerous cirrhosis around HCC.

Application of autologous tumor cell vaccine and NDV vaccine in treatment of tumors of digestive traet

AIM: To treat patients with stage I-IV malignant tumors of digestive tract using autologous tumor cell vaccine and NDV (Newcastle disease virus) vaccine, and observe the survival period and curative effect.

METHODS: 335 patients with malignant tumors of digestive tract were treated with autologous tumor cell vaccine and NDV vaccine. The autologous tumor cell vaccine received were assigned for long-term survival observation. While these failed to obtain the autologous tumor tissue were given with NDV vaccine for a received short-term observation on curative effect.

RESULTS: The colorectal cancer patients treated with autologous tumor cell vaccine were divided into two groups: the controlled group (subjected to resection alone) (n = 257), the vaccine group (subjected to both resection and immunotherapy) (n = 310). 25 patients treated with NDV immunotherapy were all at stage IV without having resection. In postoperation adjuvant therapy patients, the 5, 6 and 7-year survival rates were 66.51%, 60.52%, 56.50% respectively; whereas in patients with resection alone, only 45.57%, 44.76% and 43.42% respectively. The average survival period was 5.13 years (resection alone group 4.15 years), the median survival period was over 7 years (resection alone group 4.46 years). There were significant differences between the two groups. The patients treated with resection plus vaccine were measured delayed-type hypersensitivity (DTH) reactions after vaccination, (indurative scope > 5 mm). The magnitude of DTH was related to the prognosis. The 5-year survival rate was 80% for those with indurations greater than 5 mm, compared with 30% for those with indurations less than 5 mm. The 1-year survival rate was 96% for 25 patients treated with NDV immunotherapy. The total effective rate (CR+PR) was 24.00% in NDV immunotherapy; complete remission (CR) in 1 case (4.00%), partial remission (PR) in 5 cases (20.00%), stabilizedin in 16 cases (64.00%), progression (PD) in 1 case (4.00%). After NDV vaccine immunotherapy, the number of NK cell increased and immune function imporved obviously.

CONCLUSION: The autologous tumor cell vaccine and NDV vaccine can prolong the patients’ life. NDV vaccine is notably effective for short-term with promotion of quality of life and can be used whenever necessary with good prospects.

HLA-DRB1 allele polymorphisms in genetic susceptibility to esophageal carcinoma

AIM: To probe into the genetic susceptibility of HLA-DRB1 alleles to esophageal carcinoma in Han Chinese in Hubei Province.

METHODS: HLA-DRB1 allele polymorphisms were typed by polymerase chain reaction with sequence-specific primers (PCR-SSP) in 42 unrelated patients with esophageal cancer and 136 unrelated normal control subjects and the associated HLA-DRB1 allele was measured by nucleotide sequence analysis with PCR.SAS software was used in statistics.

RESULTS: Allele frequency (AF) of HLA-DRB1*0901 was significantly higher in esophageal carcinoma patients than that in the normal controls (0.2500 vs 0.1397, P = 0.028, the odds ratio 2.053, etiologic fraction 0.1282). After analyzed the allele nucleotide sequence of HLA-DRB1*0901 which approachs to the corresponded exon 2 sequence of the allele in genebank. There was no association between patients and controls in the rested HLA-DRB1 alleles.

CONCLUSION: HLA-DRB1*0901 allele is more common in the patients with esophageal carcinoma than in the healthy controls, which is positively associated with the patients of Hubei Han Chinese. Individuals carrying HLA-DRB1*0901 may be susceptible to esophageal carcinoma.

Effect of arsenic trioxide on expression of telomerase and induction of apoptosis of human hepatoma cell

AIM: To investigate the effect of arsenic trioxide on expression of telomerase and induction of apoptosis of hepatoma cells in vitro.

METHODS: The human hepatoma cells were incubated with variety concentration of arsenic trioxide. The cell growth and proliferation were detected by MTT assay. DNA distribution in cell was analyzed with flow cytometry. The expression of telomerase was studied by in situ hybridization, and induction of apoptosis was observed with terminal deoxynucleotidy transferase nick and labeling (TUNEL).

RESULTS: Inhibitory rate of proliferation of hepatoma cell with arsenic trioxide at 24, 48, 72 hours was 22.0%, 25.7%, 32.0%, respectively (P < 0.05). Flow cytometry study indicated that ratio of G0/G1 phase cell was decreased and the portion of S phase cell increased following treatment with arsenic trioxide. The expression of telomerase was decreased and the number of apoptotic cells increased with the increment of arsenic trioxide dosage.

CONCLUSION: Arsenic trioxide may inhibit the proliferation of hepatoma cells in a time-and concentration-dependent manner, and suppress the expression of telomerase and induce apoptosis of human hepatoma cells.

Adhesive small bowel obstruction: How long can patients tolerate conservative treatment?

AIM: To evaluate how long patients with small bowel obstruction caused by postoperative adhesions can tolerate conservative treatment.

METHODS: The records of patients with small bowel obstruction due to postoperative adhesions were retrospectively reviewed. Data collected included the number of admissions, type of management for each admission, duration of conservative treatment, number of repeat laparotomies, and operative findings.

RESULTS: One hundred fifty-five patients with this condition from January 1999 to December 2001, for a total of 293 admissions were enrolled in this study. Medical treatment alone was given in 220 admissions, and repeat laparotomy was performed in 73 admissions. The period of observation in patients managed medically ranged from 2 to 12 days (average: 6.9 days), while for those who underwent surgery, the range was 1 to 14 days (average 5.4 days). At surgery, adhesions were the only finding in 46 cases, while there were intestinal complications in 27, or 9.2% of all 293 admissions. Fever and leukocytosis greater than 15000/mm³ were prediction of intestinal complications.

CONCLUSION: With closely monitoring, most patients with small bowel obstruction due to postoperative adhesions could tolerate supportive treatment and recover well averagely within 1 week, although some patients require more than 10 days of observation.

Effect of CAO released from MS-CAO on human hepatoma cell line SMMC-7721

AIM: To explore the inhibitory effects and mechanisms of CAO released from CAO-MS on the growth of human hepatoma cell line SMMC-7721.

METHODS: Inhibitory effects of CAO and CAO-MS on the growth of human hepatoma cell line SMMC-7721 in vitro were determined with MTT assay. The cell cycles of SMMC-7721 treated with CAO and CAO-MS were analyzed with flow cytometry. The apoptosis of human hepatoma cell line was tested with cellular DNA quantitative analysis, AnnexinⅤ labeling and morphological study. The expressions of p21^WAF1/CIP1 protein and mRNA were detected, respectively, with immunocytochemistry staining (ICC) and reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS: The inhibitory effects of CAO and CAO-MS on the growth of human hepatoma cell line were dose- and time- dependent (P < 0.01). The IC₅₀s of CAO and CAO-MS on SMMC-7721 were 50 mg/L and 100 mg/L, respectively. The propoertion of SMMC-7721 in G₀/G₁ phase increased and that in S and G₂+M phase decreased after exposure with 50mg/L CAO and 100mg/L CAO-MS for 72 hours. ICC and RT-PCR analysis showed that both CAO and CAO-MS incresaed the level of p21^WAF1/CIP1 protein and mRNA. The effect of CAO was superior to that of CAO-MS with the same dosage of CAO and CAO-MS.

CONCLUSION: Dose-dependent inhibitory effects of CAO and CAO-MS on the growth of human hepatoma cell line are remarkable. Both CAO and CAO-MS could induce apoptosis of human hepatoma cell and keep the cell cycle at G₀/G₁ phase from up-regulating expression of ^p21WAF1/CIP1 protein and mRNA.

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Hepatocellular carcinoma with obstructive jaundice: diagnosis, treatment and prognosis

Obstructive jaundice as the main clinical feature is uncommon in patients with hepatocellular carcinoma (HCC). Only 1%-12% of HCC patients manifest obstructive jaundice as the initial complaint. Such cases are clinically classified as “icteric type hepatoma”, or “cholestatic type of HCC”. Identification of this group of patients is important, because surgical treatment may be beneficial. HCC may involve the biliary tract in several different ways: tumor thrombosis, hemobilia, tumor compression, and diffuse tumor infiltration. Bile duct thrombosis (BDT) is one of the main causes for obstructive jaundice, and the previously reported incidence is 1.2%-9%. BDT might be benign, malignant, or a combination of both. Benign thrombi could be blood clots, pus, or sludge. Malignant thrombi could be primary intrabiliary malignant tumors, HCC with invasion to bile ducts, or metastatic cancer with bile duct invasion. The common clinical features of this type of HCC include: high level of serum AFP; history of cholangitis with dilation of intrahepatic bile duct; aggravating jaundice and rapidly developing into liver dysfunction. It is usually difficult to make diagnosis before operation, because of the low incidence rate, ignorant of this disease, and the difficulty for the imaging diagnosis to find the BDT preoperatively. Despite recent remarkable improvements in the imaging tools for diagnosis of HCC, such cases are still incorrectly diagnosed as cholangiocarcinoma or choledocholithiases. Ultrasonography (US) and CT are helpful in showing hepatic tumors and dilated intrahepatic and /or extrahepatic ducts containing dense material corresponding to tumor debris. Direct cholangiography including percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) remains the standard procedure to delineate the presence and level of biliary obstruction. Magnetic resonance cholangiopancreatography (MRCP) is superior to ERCP in interpreting the cause and depicting the anatomical extent of the perihilar obstructive jaundice, and is particularly distinctive in cases associated with tight biliary stenosis and along segmental biliary stricture. Choledochoscopy and bile duct brushing cytology could be alternative useful techniques in the differentiating obstructions due to intraluminal mass, infiltrating ductal lesions or extrinsic mass compression applicable before and after duct exploration. Jaundice is not necessarily a contraindication for surgery. Most patients will have satisfactory palliation and occasional cure if appropriate procedures are selected and carried out safely, which can result in long-term resolution of symptoms and occasional long-term survival. However, the prognosis of icteric type HCC is generally dismal, but is better than those HCC patients who have jaundice caused by hepatic insufficiency.

Comparative study in the effect of C-type natriuretic peptide on gastric motility in various animals

AIM

To investigate the effect of natriuretic peptides on gastric motility in various animals, and the effect of C-type natriuretic peptide (CNP) on spontaneous contraction of gastric smooth muscle in rat, guinea-pig and human in vitro was compared.

METHODS

Spontaneous contraction of gastric smooth muscle was recorded by four channel physiograph.

RESULTS

In the guinea-pig and rat gastric antral circular smooth muscle, CNP markedly decreased the amplitude of spontaneous contraction but it didn't affect the frequency, however, the contractile activity was completely inhibited by CNP in gastric antral longitudinal smooth muscle. In the human gastric antral circular and longitudinal smooth musle, CNP completely inhibited spontaneous contraction. In the circular smooth muscle of guinea-pig and rat gastric fundus, CNP obviously decreased the amplitude of spontaneous contraction but it didn't affect the frequency, however, the contractile activity was completely inhibited by CNP in smooth muscle of fundus longitudinal. In the circular and longitudinal smooth muscle of guinea-pig gastric body, CNP at first induced a relaxation and then an increase in amplitude of spontaneous contraction (rebound contraction), but the frequency was not changed. After the circular smooth muscle of gastric body was pretreated with atropine, an M receptor blocker, the rebound contraction was abolished; In circular and longitudinal smooth muscle of rat gastric body, CNP induced a transient and slight relaxation and successively followed by the recovery in amplitude of spontaneous contraction but it also didn't affect the frequency. After the smooth muscle was pretreated with atropine, the transient and slight relaxation was replaced by long term and complete inhibition; The percentage of CNP-induced inhibition was 76.77+/-6.21 % (fundus), 67.21+/-5.32 % (body) and 58.23+/- 6.21 % (antral) in the gastric circular muscle, however, the inhibitory percentage was 100+/-0.00 % (fundus), 68.66+/- 3.55 % (body) and 100+/-0.00 % (antrum) in the gastric longitudinal smooth muscle of guinea-pigs; In the rat, the percentage of CNP-induced inhibition was 95.87+/-4.12 % (fundus), 94.91+/-5.08 % (body) and 66.32+/-7.32 % (antrum)in the gastric circular smooth muscle, but in the longitudinal smooth muscle, CNP completely inhibited the spontaneous contraction. Using LY83583, a guanylate cyclase inhibitor, and zaparinast as a phosphoesterase inhibitor to inhibit the generation of cGMP, the effect of CNP on the spontaneous contraction was markedly weakened by LY83583, however, the inhibitory effect was enhanced by zaparinast.

CONCLUSION

(1) CNP can obviously inhibit the spontaneous contraction of gastric antral circular and longitudinal smooth muscle in the rat, guinea-pig and human. The order of inhibitory potency is human >rat> guinea-pig. (2) In the same animals, the inhibitory effect of CNP on spontaneous contraction is the most powerful in fundus and the weakest in antrum, in the same position, the inhibitory effect on the circular smooth muscle is more powerful than that on longitudinal smooth muscle. (3) The inhibitory effect of CNP on spontaneous contraction in the gastric smooth muscle is mediated by a cGMP dependent pathway.

Protective effect of ascorbic acid in experimental gastric cancer: reduction of oxidative stress

AIM

Oxidative stress participates in the cell carcinogenesis by inducing DNA mutations. Our aim was to assess whether ascorbic acid, an antioxidant, could have a role in preventing ROS (Reactive Oxygen Species) generation in experimental gastric carcinoma in a rat model.

METHODS

Experimental gastric cancer was induced in twelve Wistar male rats (weighting 250-350 g) by profound duodeno-gastric reflux throught split gastrojenunostomy. The rats were allocated to the following groups: Group I (n=6) was the control; Group II (n=6) which was mantained with daily intake of tape water with Vitamin C (30 mg/Kg). After 6 or 12 months, samples of gastric tumor or non tumor mucosa were taken from the anastomosis of both groups. Oxidative stress was measured by superoxide quantification through lucigenin-amplified chemiluminescence base and by staining with Nitrobluetetrazolium. The histopathologic confirmation of adenocarcinoma was made by eosin-hemathoxilin method.

RESULTS

The intestinal type of gastric adenocarcinoma was microscopically identified in all animals of group I whereas only 3 rats of group II showed an adenocarcinoma without macroscopic evidence of them. The cancers were located in the anastomosis in all cases. Basal luminescence from tumor gastric tissue generated 38.4+/-6.8 count per minute/mg/X10(6) (mean+/-SD) and 14.9+/-4.0 count per minute/mg/X10(6), respectively, in group I and II animals (P<0.05). The Nitrobluetetrazolium method showed intense staining in tumor tissues but not in non neoplasic mucosa.

CONCLUSION

Experimental gastric tumors seem to produce more reactive oxygen species than non neoplasic gastric tissue. The reduction of oxidative stress and gastric tumor incidence in rats were induced by the intake of ascorbic acid. Therefore, it may have a role in the prevention of gastric carcinoma.

Effects of tachyplesin on the regulation of cell cycle in human hepatocarcinoma SMMC-7721 cells

AIM

To investigate the effects of tachyplesin on the cell cycle regulation in human hepatcarcinoma cells.

METHODS

Effects of tachyplesin on the cell cycle in human hepatocarcinoma SMMC-7721 cells were assayed with flow cytometry. The protein levels of p53, p16, cyclin D1 and CDK4 were assayed by immunocytochemistry. The mRNA levels of p21(WAF1/CIP1) and c-myc genes were examined with in situ hybridization assay.

RESULTS

After tachyplesin treatment, the cell cycle arrested at G0/G1 phase, the protein levels of mutant p53, cyclin D1 and CDK4 and the mRNA level of c-myc gene were decreased, whereas the levels of p16 protein and p21(WAF1/CIP1) mRNA increased.

CONCLUSION

Tachyplesin might arrest the cell at G0/G1 phase by upregulating the levels of p16 protein and p21(WAF1/CIP1) mRNA and downregulating the levels of mutant p53, cyclin D1 and CDK4 proteins and c-myc mRNA, and induce the differentiation of human hepatocacinoma cells.

Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

AIM

To investigate the effect of pinaverium bromide, a L-type calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.

METHODS

Cold-restraint stress was conducted on rats to increase fecal pellets output. Each isolated colonic circular muscle strip was suspended in a tissue chamber containing warm oxygenated Tyrode-Ringer solution. The contractile response to ACh or KCl was measured isometrically on ink-writing recorder. Incubated muscle in different concentrations of pinaverium and the effects of pinaverium were investigated on ACh or KCl-induced contraction. Colon smooth muscle cells were cultured from rats and (Ca(2+))(i) was measured in cell suspension using the Ca(2+) fluorescent dye fura-2/AM.

RESULTS

During stress, rats fecal pellet output increased 61 % (P<0.01). Stimulated with ACh or KCl, the muscle contractility was higher in stress than that in control. Pinaverium inhibited the increment of (Ca(2+))(i) and the muscle contraction in response to ACh or KCl in a dose dependent manner. A significant inhibition of pinaverium to ACh or KCl induced (Ca(2+))(i) increment was observed at 10(-6) mol/L. The IC(50) values for inhibition of ACh induced contraction for the stress and control group were 1.66X10(-6) mol/L and 0.91X10(-6) mol/L, respectively. The IC(50) values for inhibition of KCl induced contraction for the stress and control group were 8.13X10(-7) mol/L and 3.80X10(-7) mol/L, respectively.

CONCLUSION

Increase in (Ca(2+))(i) of smooth muscle cells is directly related to the generation of contraction force in colon. L-type Ca(2+) channels represent the main route of Ca(2+) entry. Pinaverium inhibits the calcium influx through L-type channels; decreases the contractile response to many kinds of agonists and regulates the stress-induced colon hypermotility.

A novel HBV antisense RNA gene delivery system targeting hepatocellular carcinoma

AIM

To construct a novel HBV antisense RNA delivery system targeting hapatocellular carcinoma and study its inhibitory effect in vitro and in vivo.

METHODS

GE7,a 16-peptide specific to EGFR, and HA20,a homologue of N-terminus of haemagglutinin of influenza viral envelope protein, were synthesized and conjugated with polylysin. The above conjugates were organized into the pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system, named AFP-enhancing 4-element complex. Hepatocelluar carcinoma HepG2.2.15 cells was used to assay the in vitro inhibition of the complex on HBV. Expression of HBV antigen was assayed by ELISA. BALB/c nude mice bearing HepG2.2.15 cells were injected with AFP-enhancing 4-element complex. The expression of HBV antisense RNA was examined by RT-PCR and the size of tumor in nude mice were measured.

RESULTS

The AFP-enhancing 4-element complex was constructed and DNA was completely trapped at the slot with no DNA migration when the ratio of polypeptide to plasmid was 1:1. The expression of HBsAg and HBeAg of HepG2.2.15 cells was greatly decreased after being transfected by AFP-enhancing 4-element complex. The inhibitory rates were 33.4 % and 58.5 % respectively. RT-PCR showed HBV antisense RNA expressed specifically in liver tumor cells of tumor-bearing nude mice. After 4 injections of AFP-enhancing 4-element complex containing 0.2 micro g DNA, the diameter of the tumor was 0.995 cm+/-0.35, which was significantly smaller than that of the control groups(2.215 cm+/-0.25, P<0.05).

CONCLUSION

AFP-enhancing 4-element complex could deliver HBV antisense RNA targeting on hepatocarcinoma and inhibit both HBV and liver tumor cells in vitro and in vivo.

Intracellular immunization by hammerhead ribozyme against HCV

AIM: To evaluate the effect of hammerhead ribozyme 213 (Rz 213) against hepatitis C virus (HCV) infection.

METHODS: Rz213 cleaving 5'oncoding region (5'CR) of HCV was beforehand transfected in a human hepatic carcinoma cell (HHCC) line and selected for G418 resistance. Cells stably expressing Rz213 were retransfected with pCMVNCRluc containing 5扤CR-luc fusion genes by lipofectAMINE; luciferase activity in lysate of transfactant was measured in scintillation counter.

RESULTS: HHCC cells stably expressing Rz213 exhibited significant resistance to retransfection of targeting gene.

CONCLUSION: Stably transfected cells with Rz213 were selected and expressed in HHCC, and thus exerted the intracellular immunity against infection of HCV.

Interaction between hepatitis C virus core protein and translin protein- a possible molecular mechanism for hepatocellular carcinoma and lymphoma caused by hepatitis C virus

AIM: To investigate the interaction between hepatitis C virus core protein and translin protein and its role in the pathogenensis of hepatocellular carcinoma and lymphoma.

METHODS: With the components of the yeast two hybrid system 3,“ bait” plasmids of HCV core the gene was constructed. After proving that hepatitis C virus core protein could be firmly expressed in AH109 yeast strains, yeast two- hybrid screening was performed by mating AH109 with Y187 that transformed with liver cDNA library plasmids - pACT2 and then plated on quadrople dropout (QDO) medium and then assayed for α-gal activity. Sequencing analysis of the genes of library plasmids in yeast colonies that could grow on QDO with α-gal activity was performed. The interaction between HCV core protein and the protein we obtained from positive colony was further confirmed by repeating yeast two - hybrid analysis and coimmunoprecipitation in vitro.

RESULTS: A gene from a positive colony was the gene of translin, a recombination hotspot binding protein. The interaction between HCV core protein and translin protein could be proved not only in yeast, but also in vitro.

CONCLUSION: The core protein of HCV can interact with translin protein. This can partly explain the molecular mechanism for hepatocellular carcinoma and lymphoma caused by HCV.

Potent inhibition of angiogenesis and liver tumor growth by administration of an aerosol containing a transferrin-liposome-endostatin complex

AIM: To obtain an efficient delivery system for transporting endostatin gene to mouse liver tumor xenografts by administration of aerosol.

METHODS: Recombinant plasmid pcDNA3.0/endostatin containing human endostatin gene together with signal peptide from alkaline phosphatase were transferred into human umbilical vein endothelial cell (HUVEC) by transferrin (TF)-liposome-endostatin complex. Western blot was used to detect the expression of human endostatin in transfected HUVEC cells and its medium. After the tumor-bearing mice were administrated with TF-liposome-endostatin complex, the lung tissue was analyzed by immunohistochemical method for expression of endostatin and the tumors were treated with CD-31 antibody to detect the density of microvesseles in tumor tissues. The inhibition of tumor growth was estimated by the weight of tumors from groups treated with different doses of TF-liposome-endostatin complex. DNA fragmentation assay was used to detect the apoptosis of the cells from primary liver tumor.

RESULTS: Western blot analysis and immunohistochemical method confirmed the expression of endostatin protein in vitro and in vivo. After the tumor sections were treated with CD-31 antibody, the positive reaction cells appeared brown while the negative cells were colorless. The positively stained area of the TF-liposome-endostatin treated group was significantly smaller (P < 0.01, 645.8 ± 5.2 μm²) than that of the control group (1325.4 ± 98.5 μm²). The data showed a significant inhibition of angiogenesis. After administration of TF-liposome-endostatin, comparing with the control group administrated with TF-liposome-pcDNA3.0, liver tumor growth in the mice treated with 50, 250 and 500 mg DNA/kg was inhibited by 36.6%, 40.8%, and 72.8%, respectively (P < 0.01). And a typical DNA fragmentation of apoptosis was found in the cells from tumor tissues of the mice treated with TF-liposome-endostatin but none in the control group.

CONCLUSION: Endostatin gene could be efficiently transported into the mice with TF-liposome-DNA delivery system by administration of aerosol. TF-liposome-mediated endostatin gene therapy strongly inhibited angiogenesis and the growth of mouse xenograft liver tumors. It also could promote the development of apoptosis of tumors without direct influence on tumor cells.

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-II serum level was measured by ELISA. Immunohistochemistry and electron microscopic immunohistochemistry were used to 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 endoplasmic 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.