Uracil-DNA Glycosylase UNG Promotes Tet-mediated DNA Demethylation.

In mammals, active DNA demethylation involves oxidation of 5-methylcytosine (5mC) into 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) by Tet dioxygenases and excision of these two oxidized bases by thymine DNA glycosylase (TDG). Although TDG is essential for active demethylation in embryonic stem cells and induced pluripotent stem cells, it is hardly expressed in mouse zygotes and dispensable in pronuclear DNA demethylation. To search for other factors that might contribute to demethylation in mammalian cells, we performed a functional genomics screen based on a methylated luciferase reporter assay. UNG2, one of the glycosylases known to excise uracil residues from DNA, was found to reduce DNA methylation, thus activating transcription of a methylation-silenced reporter gene when co-transfected with Tet2 into HEK293T cells. Interestingly, UNG2 could decrease 5caC from the genomic DNA and a reporter plasmid in transfected cells, like TDG. Furthermore, deficiency in Ung partially impaired DNA demethylation in mouse zygotes. Our results suggest that UNG might be involved in Tet-mediated DNA demethylation.

The role of Tet3 DNA dioxygenase in epigenetic reprogramming by oocytes.

Sperm and eggs carry distinctive epigenetic modifications that are adjusted by reprogramming after fertilization. The paternal genome in a zygote undergoes active DNA demethylation before the first mitosis. The biological significance and mechanisms of this paternal epigenome remodelling have remained unclear. Here we report that, within mouse zygotes, oxidation of 5-methylcytosine (5mC) occurs on the paternal genome, changing 5mC into 5-hydroxymethylcytosine (5hmC). Furthermore, we demonstrate that the dioxygenase Tet3 (ref. 5) is enriched specifically in the male pronucleus. In Tet3-deficient zygotes from conditional knockout mice, paternal-genome conversion of 5mC into 5hmC fails to occur and the level of 5mC remains constant. Deficiency of Tet3 also impedes the demethylation process of the paternal Oct4 and Nanog genes and delays the subsequent activation of a paternally derived Oct4 transgene in early embryos. Female mice depleted of Tet3 in the germ line show severely reduced fecundity and their heterozygous mutant offspring lacking maternal Tet3 suffer an increased incidence of developmental failure. Oocytes lacking Tet3 also seem to have a reduced ability to reprogram the injected nuclei from somatic cells. Therefore, Tet3-mediated DNA hydroxylation is involved in epigenetic reprogramming of the zygotic paternal DNA following natural fertilization and may also contribute to somatic cell nuclear reprogramming during animal cloning.

Treatment of gallbladder stone with common bile duct stones in the laparoscopic era.

BACKGROUND: Laparoscopic common bile duct exploration (LCBDE) for stone can be carried out by either laparoscopic transcystic stone extraction (LTSE) or laparoscopic choledochotomy (LC). It remains unknown as to which approach is optimal for management of gallbladder stone with common bile duct stones (CBDS) in Chinese patients. METHODS: From May 2000 to February 2009, we prospective treated 346 consecutive patients with gallbladder stones and CBDS with laparoscopic cholecystectomy and LCBDE. Intraoperative findings, postoperative complications, postoperative hospital stay and costs were analyzed. RESULTS: Because of LCBDE failure,16 cases (4.6%) required open surgery. Of 330 successful LCBDE-treated patients, 237 underwent LTSE and 93 required LC. No mortality occurred in either group. The bile duct stone clearance rate was similar in both groups. Patients in the LTSE group were significantly younger and had fewer complications with smaller, fewer stones, shorter operative time and postoperative hospital stays, and lower costs, compared to those in the LC group. Compared with patients with T-tube insertion, patients in the LC group with primary closure had shorter operative time, shorter postoperative hospital stay, and lower costs. CONCLUSIONS: In cases requiring LCBDE, LTSE should be the first choice, whereas LC may be restricted to large, multiple stones. LC with primary closure without external drainage of the CBDS is as effective and safe as the T-tube insertion approach.

Combined epithelial-mesenchymal transition with cancer stem cell-like marker as predictors of recurrence after radical resection for gastric cancer.

BACKGROUND: The aim of the study was to identify the incidence and the predictors of recurrence after curative resection and the clinical significance of epithelial-mesenchymal transition (EMT) and stem cell-like phenotypes in gastric cancer. METHODS: In a total of 1,463 patients that underwent curative resection for gastric cancer between January 2001 and January 2008 at Drum Tower Hospital, 402 (27.5%) experienced recurrence. They were divided into early recurrence (within two years) and late recurrence (more than two years). The clinicopathological characteristics, including five EMT-related proteins (Snail-1, ZEB-1, E-cadherin, vimentin, and ß-catenin) and the gastric cancer stem cell markers CD44 and CD54, therapeutic modalities, survival time after recurrence, and recurrence patterns were compared between the two groups. RESULTS: Loss of E-cadherin expression and aberrant expression of vimentin and the known gastric cancer stem cell maker CD44 were significantly associated with aggressive clinicopathologic features. Multivariate analysis showed that stage III gastric cancer patients with early recurrence had larger tumors and more lymph node metastasis, coupled with aberrant expression EMT and cancer stem cell marker, than patients with late recurrence. Early recurrence was associated with more distant metastasis than late recurrence and patients tended to die within two years of recurrence. CONCLUSIONS: Combined EMT with cancer stem cell-like marker is a predictor of recurrence after radical resection for gastric cancer. Advanced TNM stage was associated with early cancer death after recurrence.

Clinical manifestation, lifestyle, and treatment patterns of chronic erosive gastritis: A multicenter real-world study in China.

BACKGROUND: Although chronic erosive gastritis (CEG) is common, its clinical characteristics have not been fully elucidated. The lack of consensus regarding its treatment has resulted in varied treatment regimens. AIM: To explore the clinical characteristics, treatment patterns, and short-term outcomes in CEG patients in China. METHODS: We recruited patients with chronic non-atrophic or mild-to-moderate atrophic gastritis with erosion based on endoscopy and pathology. Patients and treating physicians completed a questionnaire regarding history, endoscopic findings, and treatment plans as well as a follow-up questionnaire to investigate changes in symptoms after 4 wk of treatment. RESULTS: Three thousand five hundred sixty-three patients from 42 centers across 24 cities in China were included. Epigastric pain (68.0%), abdominal distension (62.6%), and postprandial fullness (47.5%) were the most common presenting symptoms. Gastritis was classified as chronic non-atrophic in 69.9% of patients. Among those with erosive lesions, 72.1% of patients had lesions in the antrum, 51.0% had multiple lesions, and 67.3% had superficial flat lesions. In patients with epigastric pain, the combination of a mucosal protective agent (MPA) and proton pump inhibitor was more effective. For those with postprandial fullness, acid regurgitation, early satiety, or nausea, a MPA appeared more promising. CONCLUSION: CEG is a multifactorial disease which is common in Asian patients and has non-specific symptoms. Gastroscopy may play a major role in its detection and diagnosis. Treatment should be individualized based on symptom profile.

Safety and efficacy of endoscopic ultrasound-guided gastroenterostomy for gastric outlet obstruction in different sites: A single-center retrospective study.

OBJECTIVES: Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) has recently been employed as a novel treatment for gastric outlet obstruction (GOO). The aim of this study was to evaluate the safety and efficacy of EUS-GE for GOO at different sites. METHODS: Consecutive hospitalized patients who underwent EUS-GE for GOO at the Department of Gastroenterology, Nanjing Drum Tower Hospital from March 2017 to April 2020 were recruited in this retrospective study. Patients were divided into three groups depending on the obstruction site. The primary outcomes included technical success and clinical success. The secondary outcomes were operation time, post-procedure length of stay (LOS), hospitalization cost, and complications such as peritonitis, bleeding, pneumoperitoneum, abdominal pain, and infection. RESULTS: A total of 51 patients were included. Technical success achieved in 100% patients with proximal GOO and in 88.9% with distal GOO (P = 0.176). Clinical success declined from the oral side to the anal side (P = 0.510). Operation time, hospitalization costs, and post-procedural LOS were similar among groups (P = 0.532, 0.520, and 0.144, respectively). Complications were observed in 28 (54.9%) patients. In approaching the mature phase of the endosopist, clinical success improved, while the secondary outcomes showed no statistically significant difference compared with the initial phase. CONCLUSIONS: EUS-GE may be challenging for distal GOO; however, it is safe and effective when carried out by experienced endoscopists. A complete preoperative evaluation to assess the difficulty of the procedure is necessary. Prospective studies with large sample size are needed to further validate our findings.

[Determination of mineral elements utilization of Paeonia lactiflora Pall by ICP-AES].

The contents of K, Ca, Na, Mg, Fe, Cu and so on in the roots of Paeonia lactiflora Pall and in the soil in which they grew were determined by ICP-AES technique to study the mineral elements utilization of P. lactiflora Pall. The results indicate that the elements utilization rate of P. lactiflora Pall is different in different locations, so the contents of mineral elements in the roots of P. lactiflora Pall and even the quality of medicinal materials coming from them in different locations are different. The contents of Ca, Fe, Zn and so on in Chi Shao in Heilongjiang and Inner Mongolia are relatively high. The contents of mineral elements in soil influence not only themselves' utilization but also other mineral elements utilization of P. lactiflora Pall.

A strain of Phoma species improves drought tolerance of Pinus tabulaeformis.

Global warming has led to frequent droughts, posing challenges for afforestation in arid and semiarid regions. In search of labor-saving and money-saving methods to improve the survival and growth rates of trees in these regions, we isolated and identified fungal endophytes that can potentially enhance the drought-resistance abilities of seedlings. We isolated 93 endophytic strains from the roots of Pinus tabulaeformis trees grown on an arid cliff. Three isolates increased the drought resistance of the tree seedlings. Using morphological, molecular, and physiological-biochemical methods, we identified three isolates as different clones of a strain of Phoma spp. and studied the strain's effect on stress resistance-related substances in the seedlings. The results showed that the strain improved drought tolerance and increased the seedlings' proline levels and antioxidant enzyme activities. The strain also secreted abundant extracellular abscisic acid, which likely triggered the seedlings' protective mechanisms. This endophytic strain may provide a cheaper labor-saving, sustainable alternative to traditional methods of enhancing drought resistance.

Distribution Dynamics and Roles of Starch in Non-photosynthetic Vegetative Organs of Santalum album Linn., a Hemiparasitic Tree.

Allocation dynamics of stored starch plays essential roles in the development and growth of trees. Previous studies focused on the dynamics and the characteristics of starch in autotrophic trees. However, although starch granules have been detected in the organs or tissues of some parasitic plants, studies on the allocation dynamics and roles of storage starch in them are limited. Therefore, we determined and estimated the allocation dynamics and roles of starch in Santalum album Linn., a hemiparasitic tree, using morphological and physiological methods. Our findings showed abundant starch in the stem and root of S. album at the early seedling stage. Although S. album seedlings attached to the host showed no significant changes in starch levels throughout the experiment, unattached and host-removed seedlings exhibited a gradual decrease in the starch content over time. When the starch content of unattached seedlings was less than 1%, they started to die. Starch accumulated to high levels in developing and active haustoria; however, starch levels were low in the inactive haustoria. The present study suggests that starch may provide energy to seedlings that have no host, allowing them to survive during the unattached phase, thus increasing their chance to attach to host roots by extending their survival duration. In addition, we speculate that storage starch is potentially involved in the development of haustoria and in the physiological processes of S. album related to the absorption and transportation of water and nutrients from its host.

R-spondin2 Suppresses the Progression of Hepatocellular Carcinoma via MAPK Signaling Pathway.

The R-spondin family plays important roles in embryonic development, including in humans. However, information on the relationship between R-spondin2 and hepatocellular carcinoma (HCC) is lacking. This study aimed was to explore the mechanisms of R-spondin2 action in the progression of HCC. By analyzing R-spondin2 expression levels in HCC tissues by IHC and database, we identified that HCC tissues had lower expression levels of R-spondin2, correlated with a poor prognosis. We also established R-spondin2-overexpressing and knockdown cell lines and measured their viabilities and invasion abilities in vitro and their oncogenic capacity in vivo. Human mRNA microarray analysis was performed to screen for mRNAs that were differentially expressed between R-spondin2-overexpressing and control HCC cells. Microarray and Western blot analyses showed significant changes in the MAPK signaling pathway after transfection. Furthermore, in vivo experiments indicated that R-spondin2 knockdown increased the tumorigenicity of HCC cells after subcutaneous implantation in mice. Altogether, our results indicate that the R-spondin2, which might be a novel tumor suppressor gene, were responsible for inhibiting the proliferation and invasion of HCC via the MAPK signaling pathway. IMPLICATIONS: R-spondin2 gene might be a novel tumor suppressor gene providing new clues to clarify the biological behavior of HCC and thus reduce patient mortality and prolong survival.

Factors affecting the accuracy of endoscopic ultrasound-guided fine needle aspiration for the diagnosis of small (≤20 mm) pancreatic lesions.

To explore the diagnostic value of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for small, solid or semi-solid pancreatic lesions (≤20 mm) and the factors affecting its accuracy. METHODS: Altogether 92 patients with small, solid or semi-solid pancreatic lesions who underwent EUS-FNA at the Nanjing Drum Tower Hospital from November 2009 to January 2019 were retrospectively analyzed. Univariate and multivariate analyses were used to determine the factors affecting the accuracy of EUS-FNA for detecting these lesions. RESULTS: Among the 92 cases, 56 (60.9%) were diagnosed as having malignant lesions and 36 (39.1%) as benign lesions, respectively. The overall sensitivity, specificity and accuracy of EUS-FNA for the diagnosis of small, solid or semi-solid pancreatic lesions were 71.4%, 100% and 82.6%, respectively. When considering the impact of the presence of a tissue core on the diagnosis, the sensitivity, specificity, and accuracy of EUS-FNA with tissue core compared with those based on cytology alone were 77.3% vs 50.0%; 100% vs 100%; and 86.8% vs 62.5%, respectively. The multivariate analysis showed that larger tumor size (>15-20 mm) (odds ratio [OR] 4.200, 95% confidence interval [CI] 1.21-14.53, P = 0.023) and histologic diagnosis based on tissue core (OR 4.593, 95% CI 1.03-20.47, P = 0.046) were related to a higher accuracy of EUS-FNA. Adverse events were observed in three patients, all were treated conservatively and recovered within 3 days. CONCLUSIONS: EUS-FNA is effective and safe for diagnosing small pancreatic lesions. Tumor size and presence of tissue core are related to higher accuracy of the EUS-FNA.

Marked thickening of muscularis mucosae and submucosa in the gastric cardia: A histopathological study of 110 surgical resection cases.

OBJECTIVE: To investigate histopathologic changes of muscularis mucosae (MM) and submucosa in the gastric cardia. METHODS: We performed a histopathology study of 50 distal esophagectomies with proximal gastrectomies for esophageal squamous cell carcinoma as the study (non-cancerous cardiac) group and 60 gastrectomies for early gastric cardiac carcinoma as the cancer group. The gastroesophageal junction was defined as the distal end of squamous epithelium, multilayered epithelium, or deep esophageal glands or ducts. Gastric cardia (n = 110) was defined as the presence of cardiac and cardio-oxyntic mucosae distal to the gastroesophageal junction. RESULTS: The average thickness of MM and submucosa in the cardia was 1.04 and 1.41 mm, respectively, which was significantly thicker than that in distal stomach (n = 34) (0.22 and 0.99 mm) or distal esophagus (n = 92) (0.60 and 1.15 mm). In the cardia, thickened MM displayed frayed muscle fibers (93.3%) with a significantly higher prevalence of entrapped glands, cysts, and lymphoid follicles than in the distal stomach or distal esophagus. In the submucosa fatty changes, cysts, and abnormal arteries were significantly more common in the cardia than in the distal stomach or distal esophagus. Compared with the study group, the cardia in the cancer group showed significantly thicker MM (average 1.31 vs 0.72 mm) and submucosa (average 1.61 vs 1.16 mm), more frequent frayed MM (93.3% vs 60.0%), prolapse-like changes (50.0% vs 2.0%), and cysts (26.7% vs 4.0%). CONCLUSION: MM and submucosa of the cardia were significantly thickened, especially in early gastric cardiac carcinomas.

Laparoscopic exploration of common bile duct with primary closure versus T-tube drainage: a randomized clinical trial.

BACKGROUND: Traditionally, the common bile duct (CBD) is closed with T-tube drainage after choledochotomy and removal of CBD stones. However, the insertion of a T-tube is not without complication and the patients have to carry it for several weeks before removal. In the laparoscopic era, surgery is performed with minimally invasive techniques in order to reduce the trauma, hasten recovery, and reduce the hospital stay of patients. T-tube insertion seems to negate these benefits. This randomized study was designed to compare the two methods applied after LCBDE and to determine whether primary closure can be as safe as closure with T-tube drainage. METHODS: From May 2000 to January 2008, 93 consecutive patients with common bile duct stones (CBDS) and gallbladder in situ were enrolled in this randomized study to undergo laparoscopic cholecystectomy with laparoscopic common bile duct exploration (LCBDE). Intraoperative findings, postoperative complications, postoperative stay, and hospital expenses were recorded and analyzed. RESULTS: There was no mortality in both groups. A T-tube was inserted in 46 patients and the CBD was closed primarily in 47. There were no differences in the demographic characteristics or clinical presentations between the two groups. Compared with the T-tube group, the operative time and postoperative stay were significantly shorter, the hospital expenses were significantly lower, and the incidences of overall postoperative complications and biliary complications were statistically and insignificantly lower in the primary closure group. CONCLUSION: LCBDE with primary closure without external drainage after laparoscopic choledochotomy is feasible and as safe as T-tube insertion.

Incidental gallbladder carcinoma diagnosed during or after laparoscopic cholecystectomy.

BACKGROUND: Gallbladder carcinoma (GC) is a highly lethal neoplasm. With the increase of cholecystectomies since the wide acceptance of laparoscopic cholecystectomy (LC), the incidental diagnosis of gallbladder carcinoma is more frequent. The aim of the present study was to report our experience with GC diagnosed during or after the performance of LC. METHODS: A total of 10,466 LCs were carried out from January 1999 to December 2007 in our hospital. Records of patients with incidental carcinoma were collected and analyzed retrospectively. RESULTS: Of all the patients, 20 (0.19%) were histopathologically diagnosed as having a GC. There were 4 men and 16 women; the median age in this group was 65.7 years (range: 37-81 years).The depth of cancer invasion was: pTis (4 cases), pT1a (2 cases), pT1b (2 cases), pT2 (6 cases), pT3 (4 cases), and pT4 (2 cases). The sensitivity and specificity of intraoperatively frozen section examination were 83.3 and 100%, respectively. Patients with in situ, pT1a and pT1b tumors underwent LC only, and there were no recurrences. The survival rate between patients with GC diagnosed during or after LC showed no difference; it was dependent on the depth of cancer invasion. CONCLUSIONS: The survival with incidental GC is related to stage, and it validates that a carefully performed LC is adequate treatment for carcinoma in situ, and stage 1a and b cancer. A frozen section examination was helpful but did not provide a definitive diagnosis. Meticulous techniques during LC, including retrieval of the gallbladder in a retrieval bag, may prevent port-site recurrence and intraperitoneal dissemination.

Clinical outcomes of endoscopic submucosal dissection for laterally spreading tumors involving the dentate line.

OBJECTIVE: Endoscopic submucosal dissection (ESD) for laterally spreading tumors (LST) involving the dentate line (LST-DL) is challenging because of the specific anatomical features of the anorectum. This study aimed to evaluate the efficacy and safety of ESD for LST-DL. METHODS: Consecutive patients with LST-DL who had undergone ESD at our hospital between January 2010 and December 2015 were retrospectively enrolled in this study. Rates of en bloc resection, R0 resection, and complications, pathological characteristics, and tumor recurrence were analyzed and compared with those of LST in the rectum not involving the dentate line (LST-NDL). RESULTS: Altogether 49 patients with LST-DL (median age 63 years; 39 women; median lesion size 57 mm; median follow-up period of 24 months) and 96 patients with LST-NDL (median age 67 years; 31 women; median lesion size 47 mm; median follow-up period of 31 months) were enrolled. En bloc resection (93.9% [46/49] vs 94.8% [91/96]) and en bloc R0 resection rates (83.7% [41/49] vs 88.5% [85/96]), respectively, for LST-DL and LST-NDL, with no significant differences. However, ESD for LST-DL had a longer procedure time (77 min vs 54 min, P = 0.02), a greater postprocedural perianal pain rate (28.6% vs 0%, P < 0.001), and more anal strictures (4.1% vs 0%, P = 0.04). The complication rates of perforation, bleeding and fever, recurrence rate, and pathological characteristics did not differ between the two groups. CONCLUSIONS: ESD is a safe and effective therapeutic modality for LST-DL. However, this procedure should be performed by experienced endoscopists and the difficulty needs to be fully considered.

Emerging evidence supports grouping by location of early gastric carcinoma for appropriate clinical management in Chinese patients.

Gastric cancer is common in China. At present, early detection with prompt resection of early gastric carcinoma (EGC) is crucial for improving patient's survival. Because of high heterogeneity of EGC in Chinese patients we reviewed recent clinicopathological and molecular evidence and proposed a grouping EGC in three subgroups according to their location for appropriate management. In group 1 (cardia), most patients with EGC in this small location were elderly men. The tumors originated in the cardiac mucosa with a high proportion of cases with slightly elevated gross patterns and intestinal adenocarcinoma histology with moderate to well differentiation. Poorly cohesive carcinoma was infrequent. As the risk for lymph node metastasis in this kind of tumor was significantly lower than that in the distal stomach, endoscopic therapy is preferred. Group 2 (fundus-corpus), many patients with EGC in this large location were young women. The EGCs originated in the oxyntic mucosa with pure and mixed poorly cohesive carcinomas that are more commonly present in this area than in any other. Most tumors were poorly differentiated with a high risk for lymph node metastasis. Thus, endoscopic therapy may be appropriate for intramucosal, but not for submucosal, carcinoma. Group 3 (antrum-pylorus). EGC tumors arose from the antral mucosa, primarily because of Helicobacter pylori infection, following the Correa gastric cancer tumorigenetic pathway. Erosive and ulcerated gross patterns were most frequently observed. While most EGCs in this location were mainly intestinal adenocarcinomas, poorly differentiated EGCs were substantial in number. Because the risk of lymph node metastasis remains to be illustrated, clinical management requires an individualized approach. This preliminary observation requires verification in large nationwide multicenter studies.

Differential analysis of lymph node metastasis in histological mixed-type early gastric carcinoma in the mucosa and submucosa.

AIM: To investigate the relationship between histological mixed-type of early gastric cancer (EGC) in the mucosa and submucosa and lymph node metastasis (LNM). METHODS: This study included 298 patients who underwent gastrectomy for EGC between 2005 and 2012. Enrolled lesions were divided into groups of pure differentiated (pure D), pure undifferentiated (pure U), and mixed-type according to the proportion of the differentiated and undifferentiated components observed under a microscope. We reviewed the clinicopathological features, including age, sex, location, size, gross type, lymphovascular invasion, ulceration, and LNM, among the three groups. Furthermore, we evaluated the predictors of LNM in the mucosa-confined EGC. RESULTS: Of the 298 patients, 165 (55.4%) had mucosa-confined EGC and 133 (44.6%) had submucosa-invasive EGC. Only 13 (7.9%) cases of mucosa-confined EGC and 30 (22.6%) cases of submucosa-invasive EGC were observed to have LNM. The submucosal invasion (OR = 4.58, 95%CI: 1.23-16.97, P = 0.023), pure U type (OR = 4.97, 95%CI: 1.21-20.39, P = 0.026), and mixed-type (OR = 5.84, 95%CI: 1.05-32.61, P = 0.044) were independent risk factors for LNM in EGC. The rate of LNM in mucosa-confined EGC was higher in the mixed-type group (P = 0.012) and pure U group (P = 0.010) than in the pure D group, but no significant difference was found between the mixed-type group and pure U group (P = 0.739). Similarly, the rate of LNM in the submucosa-invasive EGC was higher in the mixed-type (P = 0.012) and pure U group (P = 0.009) than in the pure D group but was not significantly different between the mixed-type and pure U group (P = 0.375). Multivariate logistic analysis showed that only female sex (OR = 5.83, 95%CI: 1.64-20.70, P = 0.028) and presence of lymphovascular invasion (OR = 13.18, 95%CI: 1.39-125.30, P = 0.020) were independent risk factors for LNM in mucosa-confined EGC, while histological type was not an independent risk factor for LNM in mucosa-confined EGC (P = 0.106). CONCLUSION: For mucosal EGC, histological mixed-type is not an independent risk factor for LNM and could be managed in the same way as the undifferentiated type.

Regulation of CD44v6 expression in gastric carcinoma by the IL-6/STAT3 signaling pathway and its clinical significance.

As a cancer stem cell marker, CD44 variant 6 (CD44v6) has been implicated in carcinogenesis, tumor progression, and metastasis in a variety of human carcinomas. However, little is known about the expression of CD44v6 in Gastric Carcinoma (GC). Therefore we investigated CD44v6 expression in clinical specimen and further explore the underlying molecular mechanisms.In this study, we systemically investigated CD44v6 expression by immunohistochemistry in normal, premalignant gastric mucosa (low and high grade intraepithelial neoplasia), and GC at various stages. The correlation of CD44v6 expression with clinicopathological characteristics, and prognosis in GC was also analyzed. Next, we investigated cell proliferation, migration and invasion in GC cell lines. Furthermore, we explored a novel mechanism by which CD44V6 was upregulated in GC cell.The immunohistochemistry results showed that enhanced expression of CD44v6 was closely associated with tumor differentiation, lymph node metastasis, TNM stage and poor prognosis in GC patients. In gastric cancer cell lines, CD44v6 involved in cell proliferation, invasion and metastasis in Next, report on a novel mechanism by which interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling up-regulates expression of CD44v6. RNA interference silencing of STAT3 resulted in decrease of CD44v6 levels. We also found that STAT3 inhibitor AG490 decrease expression of CD44v6 by blocking activation of STAT3, even in the presence of IL-6. Targeting STAT3-mediated CD44v6 up-regulation may represent a novel, effective treatment by eradicating the stomach tumor microenvironment.

Hypoxia-inducible factor-1 alpha Correlates with Tumor-Associated Macrophages Infiltration, Influences Survival of Gastric Cancer Patients.

Background: Hypoxia was a common feature for accelerating tumor metastasis by both inducting epithelial-mesenchymal transition (EMT) of tumor cells and polarization of tumor-associated macrophages (TAMs). The association and roles between hypoxia, EMT and TAMs in the biological behavior of gastric cancer (GC) for the time being recurrence is unclear. Material and methods: hypoixa by expression of hypoxia-inducible factor-1 alpha (HIF-1α), polarized functional status of infiltrated TAMs by immunohistochemical staining of CD68 and CD163, and the expression of E-cadherin as EMT property had been evaluated in 236 patients consecutive with histologically confirmed GC. Clinical significance was assessed for all these patients. Results: High expression of HIF-1α was found in patients with aggressive features, especially for recurrent patients. High infiltration of TAMs and abnormal expression of EMT-marker were also related to aggressive characteristics and predicted poor prognosis in GC. Meanwwhile, there existed a significant correlation among expression of HIF-1α, infiltration of TAMs and EMT marker in GC tissues. Multivariate Cox analysis revealed that high expression of HIF-1α combined TAMs infiltration were independent prognostic factors for disease-specific survival rate. Conclusion: HIF-1α is an unfavorable indicator for prognosis, may promote tumor progression through the induction of EMT and establishment of a pro-tumor immunosuppressive microenvironment. Further investigation into the therapeutic effects of blocking hypoxia is possible a potential strategy for GC treatment.

High Infiltration of Polarized CD163+ Tumor-Associated Macrophages Correlates with Aberrant Expressions of CSCs Markers, and Predicts Prognosis in Patients with Recurrent Gastric Cancer.

Background: As the most predominant tumor-infiltrating immune cells, tumor-associated macrophages (TAMs) are associated with poor outcome in multiple solid cancers and play important roles in cancer progression. Cancer stem cells (CSCs) may account for metastasis and recurrence after cancer therapy. However, the association between TAMs and CSCs is not clarified in gastric cancer (GC). The aim of the present study was to evaluate the effects of TAMs on CSCs in GC and find out the risk factors to predict recurrence and prognosis. Material and methods: This study included consecutive 236 patients with histologically confirmed primary GC. TAMs marker CD163 and CSCs-related proteins were detected by immunohistochemistry (IHC) in GC tissues and their prognostic values were all investigated. Results: High expression of CD163+ TAMs was found in patents with aggressive characteristics, especially for patents with recurrence. There existed a significant correlation between high expression of CD163 and CSCs-related markers in GC tissues. In patients with recurrence, high-expression of CD163 TAMs was an independent worse prognostic factor. Conclusion: High infiltration of TAMs was related to aggressive behavior, associated with aberrant expression of CSC markers, and an independent worse prognostic factor in GC. Targeting TAMs may be a potential treatment strategy for GC, including patients with recurrence.