[Construction of a RU486 inducible recombinant adenoviral vector carrying murine interleukin-12 gene and experimental treatment of colonic carcinoma].

OBJECTIVE: To construct a RU486 inducible recombinant adenovirus of murine IL-12 protein and study its effect and safety on colonic cancer. METHODS: The replication-defective recombinant adenovirus were produced after cotransfection of shutter vector pDC-RUmIL-12 and adenovirus DNA helper plasmid pBHGloxDeltaE1, 3Cre into HEK293 cells. The recombined adenovirus was purified by CsCl density gradient centrifugation and its titer was determined by end point dilution assay. Expression of this regulatable recombinant adenovirus vector in infected C26 colonic carcinoma cells was tested by ELISA kit in vitro. The tumor model was established by hypodermic inoculation of C26 cells. Sixty tumor-bearing mice were randomly divided into 4 groups: Ad-buffer group; Ad-RUmIL-12 group; Ad-RUmIL-12 + RU486 group and Ad-mIL-12 group, and the treatment effects and side effects were evaluated. RESULTS: The adenoviral vector containing murine IL-12 gene was identify by PCR. The viral titer of Ad-RUmIL-12 was 4.62 x 10(10) pfu/ml. The expression of IL-12 protein was induced by the RU486 and the highest expression (516 +/- 43) pg/ml whereas no significant IL-12 protein was detected without inducer or getting rid of the inducer [(38 +/- 3) pg/ml and (42 +/- 5) pg/ml respectively]. The tumor size increased rapidly in group Ad-buffer and group Ad-RUmIL-12 (P > 0.05). Administration of Ad-RUmIL-12 + RU486 and Ad-mIL-12 were showed to delay markedly the growth of transplanted C26 tumor (P > 0.05). Significantly necrosis was observed in both Ad-mIL-12 and Ad-RUmIL-12 + RU486 experimental groups, but the level of the serum alanine transaminase and the rate of side effect was higher in Ad-mIL-12 group (4/15 and 10/15 respectively, P < 0.05). CONCLUSION: A RU486 regulatable recombinant adenoviral vector containing IL-12 gene was successfully constructed. The expression of vector Ad-RUmIL-12, regulated by inducer RU486 in vivo, can obviously improve safety in tumor treatment and provide a good primer for further researches on in vivo gene therapy.

[The expression of P120 catenin in pancreatic carcinoma and the relationship between the T755G polymorphism of P120 catenin gene and pancreatic carcinoma].

OBJECTIVES: To investigate the expression of P120 catenin in pancreatic carcinoma and to explore the association between P120 catenin gene polymorphism at T755G position and pancreatic carcinoma. METHODS: The expression of P120 catenin in 52 cases of pancreatic carcinoma and normal pancreatic tissues on the mRNA and protein levels were evaluated by RT-PCR and Western Blot methods respectively. P120 catenin gene polymorphism at T755G position of in 52 patients and 60 healthy controls were examined by PCR-restriction fragment length polymorphism (PCR-RFLP) technique. RESULTS: The mRNA and protein expressions of P120 catenin in pancreatic carcinoma tissues were significantly lower than normal pancreatic tissues (P=0.000, P=0.002). Reduced expression of P120 catenin mRNA was significantly correlated with differentiated (P=0.033), lymph node metastasis (P=0.004), vascular invasion (P=0.022), and pTNM stage (P=0.003). Additionally, there were significant difference of P120 catenin gene polymorphism genotypes and alleles at T755G position between patients and healthy controls (P=0.008, P=0.016). The GG genotype of P120 catenin gene was associated with higher risk of incidence for pancreatic carcinoma compared with the TT genotype (OR=2.765, 95%CI=1.312-3.958). CONCLUSIONS: The reduced expressions of both P120 catenin mRNA and protein in pancreatic carcinoma suggest its association with pancreatic carcinoma development. Polymorphism of P120 catenin gene at T755G situation might be a risk factor for pancreatic carcinoma, and it may be used to diagnosis and prevent pancreatic carcinoma early.

[Surgical treatment result of hilar cholangiocarcinoma: report of 84 patients].

OBJECTIVE: To analyze the surgical treatment result and clinical characteristics of hilar cholangiocarcinoma in order to improve the rate of early diagnosis and radical resection. METHODS: Between 1986 and 2004,84 hilar cholangiocarcinoma patients underwent surgery, and their data were retrospectively reviewed. RESULTS: According to the Bismuth-Corlette staging system, 7 were type I, 18 type II, 22 type II a, 12 type IlI b, 20 type IV and 5 unclassified. 32 patients (38.1%) had had the history of operation for cholelithiasis before or were found to have cholelithiasis simultaneously at the time of diagnosis. The rate of making correct diagnosis by ultrasound, CT and MRCP was 71.4% , 84.0% and 91.4% , respectively. Of these 84 patients, 24 (28.6%) underwent radical resection, 14 (16.7%) palliative resection and 30 (35.7%) only internal or external drainage, while 16 patients was found to have contraindication for any further surgical intervention. The overall operation rate was 81.0% (68/84) with a radical resection rate of 35.3% (24/68). The 1-, 3- and 5-year survival rates was 70.8%, 50.0% and 20.8% in the radical resection group, and 50.0%, 21.4% and 0 in the palliative resection group, respectively. There was a statistically significant difference in the survival between two groups. Whereas in the internal or external drainage group, the 1-, 3- and 5-year survival rates was 20.0% ,10.0% and 0. All of the patients who did not undergo surgical intervention died within one year. CONCLUSION: Cholelithiasis may play an important role in the pathogenesis of hilar cholangiocarcinoma. Early diagnosis and radical resection are two important factors to improve the prognosis of hilar cholangiocarcinoma. Skeletonization of hepatoduodenal ligament with partial liver resection can improve the rate of radical resection for hilar cholangiocarcinoma.