RNA methyltransferase NSUN2 promotes gastric cancer cell proliferation by repressing p57Kip2 by an m5C-dependent manner.

The RNA methyltransferase NSUN2 has been involved in the cell proliferation and senescence, and is upregulated in various types of cancers. However, the role and potential mechanism of NSUN2 in gastric cancer remains to be determined. Our study showed that NSUN2 was significantly upregulated in gastric cancers, compared to adjacent normal gastric tissues. Moreover, NSUN2 could promote gastric cancer cell proliferation both in vitro and in vivo. Further study demonstrated that CDKN1C (p57Kip2) was the potential downstream gene of regulated by NSUN2 in gastric cancer. NSUN2 could promote gastric cancer cell proliferation through repressing p57Kip2 in an m5C-dependent manner. Our findings suggested that NSUN2 acted as an oncogene through promoting gastric cancer development by repressing p57Kip2 in an m5C-dependent manner, which may provide a novel therapeutic target against gastric cancer.

The optimum marker for the detection of lymphatic vessels.

Podoplanin, lymphatic vessel endothelial hyaluronic acid receptor-1, prospero-related homeobox-1 and vascular endothelial growth factor receptor 3 have been demonstrated to have crucial roles in the development of the lymphatic system and lymphangiogenesis process by combining with their corresponding receptors. Thus, the four markers have been widely used in labelling lymphatic vessels for the detection of lymphangiogenesis and lymphatic vessel invasion. Numerous authors have aimed to identify the roles of these four markers in the lymphatic system and the mechanisms have been partly clarified at the molecular level. The aim of the present review was to comprehensively clarify the characteristics and latent action modes of the four markers in order to determine which is the best one for the detection of lymphangiogenesis and lymphatic vessel invasion.

[Experimental study on early pulmonary injury induced by severe acute pancreatitis in rats].

OBJECTIVE: To investigate the injury to pulmonary tissue induced by severe acute pancreatitis (SAP) during its early period. METHODS: Forty adult male Sprague-Dawley (SD) rats weighing 300-400 g were randomly divided into 4 groups with 8 animals in each group: sham operation group and 30, 60, 120 and 360 minutes after SAP groups. The model of SAP was reproduced by retrograde injection of 5% sodium taurocholate into the pancreatic duct of rats. Rats were sacrificed at different time points, and blood gas analysis, pulmonary pathological changes and wet dry weight ratio (W/D) of the lung were conducted. RESULTS: A large amount of polymorphonuclear neutrophils were observed in pulmonary tissue within 360 minutes after reproduction of SAP with obvious changes, and water content of pulmonary tissue was increased significantly, while base excess (BE) decreased significantly in rats with SAP (P<0.05 or P<0.01 ). But no obvious change was observed in arterial partial pressure of oxygen (PaO(2)) and partial pressure of carbon dioxide (PaCO(2), both P>0.05). CONCLUSION: SAP causes significant inflammation in rat lung with injury to pulmonary tissue in its early period.

Expression of insulin-like growth factor binding protein-2 in gastric carcinoma and its relationship with cell proliferation.

AIM: To investigate the expression of insulin-like growth factor binding protein-2 (IGFBP-2) in gastric carcinoma and its clinical significance and to explore its relationship with cell proliferation. METHODS: Expressions of IGFBP-2 and Ki-67 in 118 cases of gastric carcinoma and 40 cases of normal gastric mucosa were detected by EnVision immunohistochemical technique. RESULTS: Expression of IGFBP-2 in gastric carcinoma was higher than that in normal gastric mucosa (P < 0.01). There was no difference between high- and low-grade gastric carcinoma (P > 0.05). Expression of IGFBP-2 in advanced gastric carcinoma was higher than that in early gastric carcinoma (P < 0.05). Expression of IGFBP-2 in gastric carcinoma with lymph node metastasis was higher than that without lymph node metastasis (P < 0.01). IGFBP-2 expression was a positively related to the clinical stage of gastric carcinoma (P < 0.01). There was a positive correlation between IGFBP-2 and Ki-67 (P < 0.05). CONCLUSION: IGFBP-2 may be involved in carcino-genesis and progression of gastric carcinoma by promoting cell proliferation.

Relationship between inactivation of p16 gene and gastric carcinoma.

AIM: To investigate the relationship between inactivation of p16 gene and gastric carcinoma, and the mechanism of inactivation of p16 gene in gastric carcinogenesis. METHODS: 40 fresh tumor tissue specimens were taken from primary gastric cancer patients. Expression of P16 protein was detected by immunohistochemical method. Deletion and point mutation of p16 gene were analyzed by polymerase chain reaction (PCR) and DNA sequencing, respectively. RESULTS: The frequency of loss of P16 protein expression in the gastric cancer tissue, adjacent nontumor tissue, and distal normal tissue was 77.5 % (31/40), 55.0 % (22/40), and 17.5 % (7/40), respectively (P<0.005). Homozygous deletion of exon 1 and exon 3 was observed in two and three cases, respectively, giving an overall frequency of homozygous deletion of 12.5 %. All five cases had diffuse type gastric carcinoma. No p16 gene point mutation was detected. CONCLUSION: These findings suggest a close correlation between inactivation of p16 gene and gastric carcinoma. Further investigations are needed to testify the mechanism of inactivation of p16 gene in gastric carcinogenesis.

A ten-year study on non-surgical treatment of postoperative bile leakage.

AIM: To summarize systematically our ten-year experience in non-surgical treatment of postoperative bile leakage, and explore its methods and indications. METHODS: The clinical data of 57 patients with postoperative bile leakage treated non-surgically from January 1991 to December 2000 were reviewed retrospectively. RESULTS: The site of the leakage was mainly the disrupted or damaged fistulous tracts of T tube in 25 patients (43.9 %), the fossae of gallbladder in 14 cases (24.6 %), the cut surface of liver in 7 cases(12.3 %), and it was undetectable in the other 2 cases. Besides bile leakage, the wrong ligation of bile ducts was found in 3 patients, residual stones of the distal bile duct in 5 patients, benign papillary strictures in 3, and biloma resulting from bile collections in 2. The diagnoses were made according to the history of surgery, clinical situation, abdominal paracentesis, ultrasonography, ERCP, PTC, MRI/MRCP, gastroscopy and percutaneous fistulography. All 57 patients were treated non-surgically at the beginning of bile leakage. The non-surgical methods included keeping original drainage unobstructed, percutaneous abdominal paracentesis or drainage, percutaneous transhepatic cholangial/biliary drainage (PTCD/PTBD),endoscopic management, traditional Chinese medicine and so on. Of the 57 patients,2 patients died,5 were converted to reoperation later, the other 50 were directly cured by non-surgical methods without any complication. The cure rate of the non-surgery was 82.5 %(50/57). CONCLUSION: Many nonoperative methods are available to treat postoperative bile leakage. Non-surgical treatment may serve as the first choice for the treatment of bile leakage for its advantages in higher cure rate, convenience and safety in practice. It is important to choose the specific non-surgical method according to the volume, site of bile leakage and patient's condition.