ObjectiveTo build a lentiviral expression vector regulated by two targets 5 copies of HREs and hTERTp, express the target gene CDX2, and to test the activity of hTERT promoter by using LoVo cells for transfection. MethodsAfter the primer sets were designed, the hTERT promoter was cloned by PCR amplification from the genome of colon cancer. The CEA promoter was removed from the original vector pLEGFP-5HRE-CEAp by double digestion and PCR method, and then the hTERTp was introduced into the vector to construct the recombinant plasmid pLEGFP-5HRE-hTERTp. 5HRE-hTERTp was obtained by PCR, while the CMV promoter was removed from the original vector pLVX-EGFP-3FLAG by double digestion and PCR method, and then the 5HRE-hTERTp was introduced into the vector to construct the recombinant plasmid pLVX-5HRE-hTERTp-EGFP-3FLAG. The CDX2 was cloned by PCR amplification from GV230-CDX2-EGFP, and the EGFP was removed from the vector pLVX-5HRE-hTERTp-EGFP-3FLAG by double digestion, and then the CDX2 was introduced into the vector to construct the recombinant plasmid pLVX-5HRE-hTERTp-CDX2-3FLAG. LoVo cells ex vivo was transiently transfected by pLVX-5HRE-hTERTp-EGFP-3FLAG to evaluate the activity of hTERTp by detecting the expression of green fluorescence protein EGFP. ResultsPCR and sequencing analyzing showed that pLEGFP-5HRE-hTERTp, pLVX-5HRE-hTERTp-EGFP-3FLAG, and pLVX-5HRE-hTERTp-CDX2-3FLAG were sequenced correctly and the same as our designed. pLVX-5HRE-hTERTp-EGFP-3FLAG was successfully transfected into LoVo cells ex vivo and expressed green fluorescence protein EGFP, which showed that hTERTp was activated and promoted the expression of downstream gene. ConclusionThe lentiviral expression vector, pLVX-5HREhTERTp-EGFP-3FLAG and pLVX-5HRE-hTERTp-CDX2-3FLAG are successfully constructed, which lays the foundation of further research. But the function of dual-target regulation needs further proof.
ObjectiveTo explore risk factors of gastric paralysis following gastrectomy of gastric cancer and analyze its causes. MethodsThe clinical data of 116 patients with gastric cancer for hospitalization time more than 21 days following gastrectomy were retrospectively analyzed from October 2011 to October 2013 in this hospital, in which 16 patients with gastric paralysis and 116 patients without gastric paralysis. The factors relevant gastric paralysis were analyzed by logistic regression analysis. ResultsThe results of single factor analysis showed that the preoperative body mass index, history of diabetes, operative time, postoperative cardiovascular complications, albumin and hemoglobin levels within 3 d after operation, time to get out of bed after surgery, extubation time of gastric tube, the first drinking time and the first feeding time were associated with the gastric paralysis (P < 0.05), but the gender, age, time of diabetes history, life mode, smoking history, hypertension history, pylorus preserving or not, laparoscopy or not, intraoperative blood loss, intraoperative blood transfusion, uses of postoperative intraperitoneal chemotherapy drugs and postoperative analgesic drugs, and indwelling time of jejunum nutrition tube were not associated with gastric paralysis (P > 0.05). The results of logistic regression analysis showed that the preoperative body mass index, history of diabetes, operative time, time to get out of bed after surgery, and postoperative cardiovascular complications were the independent risk factors of gastric paralysis (P < 0.05). ConclusionsThere are many factors that affect occurrence of gastric paralysis following gastrectomy of gastric cancer. Preoperative or intraoperative positive prevention measures could be taken according to the factors that might affect occurrence of gastric paralysis, which might be reduce gastric paralysis following gastrectomy of gastric cancer.
ObjectiveTo explore the effect of five copies hypoxia-responsive element (5HRE) and carcinoembryonic antigen promoter (CEAp) element, and to explore the inhibition effect of lentiviral vectors targeted Ras association domain family 1 isoform A (RASSF1A) gene on SGC7901 human gastric cancer cells. Methods①Expressions of carcinoembryonic antigen (CEA) mRNA and its protein, and RASSF1A protein in SGC7901, MKN28, and MCF-10A cells were detect by real time-PCR (qRT-PCR), immunocytochemistry, and Western blot, to confirm the experimental and negative control cells.②The recombinant vectors of pGL4.20-5HRE-CEAp-Luc were constructed through molecular cloning technique to transfected SGC7901, MKN28, and MCF-10A cells. Each kind of cell was divided into 2 groups:one of them didn't add CoCl2 (normoxia group), and another group added CoCl2 (hypoxia group). Comparison of the fold of activation was performed.③SGC7901 cells were infected by lentiviral vectors of pLV-5HRE-CEAp-RASSF1A (infection group) and negative virus (negative control group), SGC7901 cells without any treatment as blank control group. Then SGC7901 cells of 3 groups were divided into 2 groups:one of them didn't add CoCl2 (normoxia group), and another group added CoCl2 (hypoxia group). The expression of RASSF1A protein was tested by Western blot, and the growth inhibition rate was confirmed by cell counting kit-8 (CCK-8) assay. Comparisons of expression of RASSF1A protein and growth inhibition rate of each group were performed. Results①Results of qRT-PCR, immunocytochemistry and Western blot showed that, SGC7901 cells showed higher expression of CEA mRNA and positive expression of RASSF1A protein than corresponding index of MKN28 cells and MCF-10A cells (P < 0.05), which were assigned as experimental cells; but MKN28 cells showed lower expression of CEA mRNA and negative expression of RASSF1A protein, which were assigned as negative control cells.②In SGC7901 and MKN28 cells transfected recombinant vectors of pGL4.20-5HRECEAp-Luc, compared with normoxia group in the same kind of cell group, the folds of activation in hypoxia group were higher (P < 0.01), but there was no significant difference between the normoxia group and hypoxia group in MCF-10A cells (P > 0.05). In the condition of with or without CoCl2, compared with SGC7901 cells in the same condition, the folds of activation in MCF-10A and MKN28 cells were both lower (P < 0.05); compared with MKN28 cells, the fold of activation in MCF-10A cells was lower (P < 0.05).③Western blot results showed that, in the condition with and without CoCl2, expressions of RASSF1A protein decreased in SGC7901 cells of blank control group and negative control group; weak expressions of RASSF1A protein was observed in SGC7901 cells of infection group when in condition of without CoCl2, but increased when adding CoCl2. But RASSF1A protein didn't expressed in MKN28 cells of blank control group, negative control group, and infection group, whether adding CoCl2 or not. CCK-8 assay result showed that, in SGC7901 cells, the growth inhibition rate of infection group which added CoCl2 was higher than those of other 5 groups (P < 0.05); in MKN28 cells, the growth inhibition rates of infection group and negative group were all higher than those of blank control group, whether adding CoCl2 or not (P < 0.05), but there was no significant difference among the infection group and negative group, whether adding CoCl2 or not (P > 0.05). ConclusionsA new hypoxia inducible and cea-positive tumor-targeting transcriptional regulatory element of 5HRE-CEAp is established successfully, and lentivirus vector of pLV-5HRE-CEAp-RASSF1A can significant inhibit the growth of SGC7901 cells under hypoxia condition.