The effect of human papilloma virus type 16 E7 protein expression on growth of RMA cells in vitro and in vivo

Objective： The aim of this study was to study the effect of human papilloma virus （HPV） type 16 E7 protein ex- pression on growth of RMA cells in vitro and in vivo. Methods： The recombination vector pcDNA3.1-E7 carrying wild type HPV 16 E7 was identified by sequencing. The recombination vector pcDNA3.1-E7 was transfected into mouse lymphadenoma cell line RMA by liposome, and the monoclonal cells transfected stably were obtained by antibiotics G418 sieving and limiting dilution assay. RT-PCR method was used to detect the expression of HPV 16 E7 mRNA in RMA-E7 cells. The growth of RMA cells and RMA-E7 cells cultured in vitro was tested by Cell Count Kit-8. RMA-E7 cells and RMA cells were subcutaneously inoculated in syngeneic mice respectively, the tumor size was measured by sliding caliper twice a week, and the E7 protein expression in tumor tissue of mice was detected by Western blot after tumor formation. The kinetics of cytolytic activity of E7 specific T cells in tumor-bearing mice was measured by LDH kit. Results： Sequencing of recombination vector showed the target gene which was inserted into the recombinant was correct, and RMA-E7 cells expressing E7 protein stably were obtained by limited dilution assay. There were no obvious differences in morphous and growth velocity between RMA cells and RMA-E7 cells in vitro. RMA-E7 cells grew in syngeneic mice were significantly slower than RMA cells. The E7 protein was ex- pressed stronger in RMA-E7 cells in vivo than in vitro. The cytolytic ability of ET-specific CTL was activated at the early stage, reached the maximum at the middle stage, and lost at the end stage. RMA-E7 cells isolated from the tumor-bearing mice were more resistant to E7-specific CTL killing than RMA-E7 cells cultured in vitro. Conclusion： The E7 protein expression has no obvious influence on growth of RMA-E7 cells in vitro, and can suppress growth of RMA-E7 cells in vivo. The activity curve of E7 specific CTL approximately presents ＂bell＂ shape. The RMA-E7 cells grew in vivo had a high expression levels of E7 protein, and more resistant to E7-specific CTL killing than those cultured in vitro. The E7 protein expression in vivo not only initiates immune activation, but also induces immune tolerance.

Differences in the primary culture, purification and biological characteristics between endothelial cells and smooth muscle cells from rat aorta

Objective： To investigate the differences of primary culture, purification and biological characteristics between endothelial cells and smooth muscle cells from rat aorta. Methods： Endothelial cells were obtained using the vascular ring adherence, collagenase digestion method and an improved vascular ring adherence method, while smooth muscle cells were separated from tissue sections of rat aorta. Clones of endothelial cells were selected by limiting dilution assay. Both cell types were identified using specific cell immunofluorescent markers, and phase contrast microscopy was used to observe the morphological disparity between endothelial cells and smooth muscle cells at the single cell and colony level. Cell proliferation was determined by the cell counting kit-8. Differences between endothelial cells and smooth muscle cells were evaluated in trypsin digestion time, attachment time and recovery after cryopreservation. Results： Endothelial cells were obtained by all three methods. The improved vascular ring method provided the most reproducible results. Cells were in good condition, and of high purity. Smooth muscle cells were cultured successfully by the tissue fragment culture method. Clonal expansion of single endothelial cells was attained. The two cell types expressed their respective specific markers, and the rate of proliferation of smooth muscle cells exceeded that of endothelial cells. Endothelial cells were more sensitive to trypsin digestion than smooth muscle cells. In addition, they had a shorter adherence time and better recovery following cryopreservation than smooth muscle cells. Conclusion： The improved vascular ring method was optimal for yielding endothelial cells. Limiting dilution is a novel and valid method for purifying primary endothelial cells from rat aorta. Primary rat endothelial cell and vascular smooth muscle cell cultures exhibited different morphological characteristics, proliferation rate, adherence time, susceptibility to trypsin digestion and recovery after cryopreservation. Our research can be a good foundation for further application in the regeneration of blood vessel.

Rupture of hepatocellular carcinoma following transarterial embolization/chemoembolization: two cases report and systematic review

Objective: Rupture of hepatocellular carcinoma (HCC) following transarterial embolization/chemoembolization (TAE/TACE) is a rare but life-threatening complication. The aim of the study was to explore the incidence, risk factors, clinical characteristics, treatment, and outcomes of this complication. Methods: We described two cases and reviewed all cases of ruptured HCC after TAE/TACE reported in the literature. Results: Our search yielded 32 cases of ruptured HCC after TAE/TACE. The overall incidences were 0.45% per patient and 0.21% per session. The mean age of the patients was 57.4 years (range 28-90 years, n=26, No. of cases with available information). Males accounted for 81% of cases (21/26). The 50% of the cases had histories of primary hypertension, diabetes or peripheral artery disease (6/12). Mean diameter of the tumors was 11.4 cm (range 3-20 cm, n=27). The 100% of cases had superficial or exophytic tumors (23/23). Portal vein thrombosis was presented in 61.5% of patients (8/13). The median interval between TAE/TACE and rupture was 2 days (range 0 hour-30 days, n=31). Management choices included emergency TAE, surgery, and conservative treatment. The overall median survival time was 7 days (n=19). Conclusion: Rupture of HCC following TAE/TACE is relatively rare but potentially life-threatening. The management is difficult and prognosis is poor. Large tumor size, superficial or exophytic tumors as well as portal vein thrombosis and comorbidities such as primary hypertension, diabetes or peripheral artery disease may be predisposing factors for rupture.

Gastrointestinal stromal tumor of duodenum:a cause of upper gastrointestinal hemorrhage

Objective:The aim of the study was to report an anemia patient with melena for five years caused by duodenal gastrointestinal stromal tumor (GIST), who required surgical treatment. Methods: A 44-year old man present with anemia appearance was admitted to our center (Department of Hepatobiliary Surgery, Union Hospital, Huazhong University of Science and Technology, China) due to sustaining melena for five years. Endoscopy found no special mucosal abnormalities in the duodenal lumen. Computed Tomography showed a well-demarcated mass, 7.4 cm in diameter, located between the C loop of duodenum and pancreatic head. Pylorus-preserving pancreaticoduodenectomy and right hemicolectomy were performed when the patient's general conditions were improved. He recuperated successfully and was discharged on the 21st postoperative day. No complications happened during the period of hospital stay. Results: Histological and immunohistochemical study revealed a high risk invasive duodenal GIST which was positive for CD117, CD34, α-smooth muscle actin and negative for S-100. Conclusion: Duodenal GIST can be a source of upper gastrointestinal hemorrhage; surgical treatment is still a reasonable choice for the patients with invasive duodenal GIST.

Nicotinamide N-methyltransferase and liver diseases

Cellular metabolism-induced epigenetic regulation is essential for the maintenance of cellular homeostasis.Nicotinamide N-methyltransferase(NNMT)is emerging as a key point of intersection between cellular metabolism and epigenetic regulation and has a central role in various physiological and pathological processes.NNMT catalyzes the methylation of nicotinamide(NAM)using the universal methyl donor S-adenosyl methionine(SAM)to yield S-adeno-syl-L-homocysteine(SAH)and N1-methylnicotinamide(MNAM),directly linking methylation balance with nicotinamide adenosine dinucleotide(NAD+)contents.NNMT acts on either the SAM-methylation balance or both NAD+metabolism,depending on the tissue involved or pathological settings where metabolic demand is increased.Under physiological conditions,the liver act as an essential metabolic organ with abundant NNMT expression,while NNMT hepatic function is not mediated by its methyltransferase activity due to other major methyltransferases such as glycine N-methyltransferase(GNMT)in the liver.However,hepatic NNMT,as well as its metabolite is improperly regulated and linked to the worse pathological states in liver diseases,including alcoholic liver disease,non-alcoholic fatty liver disease(NAFLD),liver cirrhosis,and hepatocellular carcinoma(HCC),suggesting a potential role in the process of liver diseases.In this review,we summarize how NNMT regulates cell methylation balance and NAD metabolism,and extensively outline the current knowledge concerning the functions of NNMT in hepatic metabolism including glucose,lipid and energy,with a specific focus on the contribution of NNMT to the pathophysiology of liver-related diseases.NNMT is involved in the development and progression of liver diseases.Understanding the complex NNMT regulatory network and its effects on pathogenesis could provide new therapeutic strategies in the context of liver diseases.