Activated leukocyte cell adhesion molecule regulates the interaction between pancreatic cancer cells and stellate cells.

Activated leukocyte cell adhesion molecule (ALCAM/CD166) is a transmembrane glycoprotein that is involved in tumor progression and metastasis. In the present study, the expression and functional role of ALCAM in pancreatic cancer cells and pancreatic stellate cells (PSCs) was investigated. Tissue specimens were obtained from patients with pancreatic ductal adenocarcinoma (n=56) or chronic pancreatitis (CP; n=10), who underwent pancreatic resection, and from normal pancreatic tissue samples (n=10). Immunohistochemistry was used to analyze the localization and expression of ALCAM in pancreatic tissues. Subsequently, reverse transcription­quantitative polymerase chain reaction and immunoblotting were applied to assess the expression of ALCAM in pancreatic cancer Panc­1 and T3M4 cells, as well as in PSCs. An enzyme­linked immunosorbent assay was used to measure ALCAM levels in cell culture medium stimulated by hypoxia, tumor necrosis factor (TNF)­α and transforming growth factor­ß. Silencing of ALCAM was performed using ALCAM small interfering (si)RNA and immunocytochemistry was used to analyze the inhibition efficiency. An invasion assay and a cell interaction assay were performed to assess the invasive ability and co­cultured adhesive potential of Panc­1 and T3M4 cells, as well as PSCs. Histologically, ALCAM expression was generally weak or absent in pancreatic cancer cells, but was markedly upregulated in PSCs in pancreatic cancer tissues. ALCAM was highly expressed in PSCs from CP tissues and PSCs surrounding pancreatic intraepithelial neoplasias, as well as in pancreatic cancer cells. ALCAM mRNA was highly expressed in PSCs, with a low to moderate expression in T3M4 and Panc­1 cells. Similar to the mRNA expression, immunoblotting demonstrated that ALCAM protein levels were high in PSCs and T3M4 cells, but low in Panc­1 cells. The expression of TNF­α increased, while hypoxia decreased the secretion of ALCAM in pancreatic cancer Panc­1 and T3M4 cells, and also in PSCs. Silencing of ALCAM by siRNA revealed no significant alteration in the invasion of pancreatic cancer cells, however, it inhibited the invasive ability of PSCs, and decreased the interaction between Panc­1 cells and PSCs. In conclusion, ALCAM is upregulated in PSCs of pancreatic cancer tissues, suggesting a potential role of ALCAM in regulating pancreatic cancer cell­PSC interactions.

Clinicopathological and prognostic significance of programmed cell death ligand 1 (PD-L1) expression in patients with esophageal squamous cell carcinoma: a meta-analysis.

BACKGROUND: The clinicopathological and prognostic significance of programmed cell death ligand 1 (PD-L1) expression in patients with esophageal squamous cell carcinoma (ESCC) remains controversial. To investigate this question, we conducted a meta-analysis. METHODS: A comprehensive literature search of electronic databases (up to July 10, 2016) was performed for relevant studies using multiple search strategies. Correlation between PD-L1 expression and clinicopathological features/overall survival (OS) was analyzed. RESULTS: A total of 1,350 ESCC patients from eight studies were included. The pooled odds ratios (ORs) indicated that none of the clinicopathological characteristics was correlated with PD-L1 expression, including gender [OR =0.84; 95% confidence interval (CI): 0.59-1.18; P=0.31], histological differentiation (OR =1.33; 95% CI: 0.95-1.85; P=0.09), tumor depth (OR =0.66; 95% CI: 0.33-1.35; P=0.26), status of lymph node metastasis (OR =0.67; 95% CI: 0.30-1.52; P=0.34), distal metastasis (OR =0.66; 95% CI: 0.40-1.09; P=0.10) and tumor node metastasis (TNM) stage (OR =0.93; 95% CI: 0.49-1.75; P=0.82). The combined hazard ratio (HR) for OS showed a trend that overexpression of PD-L1 might be associated with the survival outcome of ESCC, though the difference was not statistically significant (HR =1.65; 95% CI 0.95-2.85; P=0.07). CONCLUSIONS: Based on the published studies, PD-L1 overexpression in ESCC was not associated with common clinicopathological characteristics. PD-L1 might be a poor prognostic biomarker for ESCC. Further large-scale research should be performed to reveal the precise clinicopathological and prognostic significance of PD-L1 in ESCC by unified testing standard.

Bacterial overgrowth and diversification of microbiota in gastric cancer.

OBJECTIVE: Microbiota is potentially linked to the development of cancer. However, the features of microbiota in gastric cancer remain unclear. The aim of this study was to characterize the gastric microbiota in cancer. METHODS: A total of 315 patients, including 212 patients with chronic gastritis and 103 patients with gastric cancer, were enrolled in the study. The bacterial load of gastric mucosa was determined using quantitative PCR. To analyze the biodiversity, structure, and composition of microbiota, amplicons of the 16S rRNA gene from 12 patients were pyrosequenced. The sequences were processed and subsequently analyzed. RESULTS: The amount of bacteria in gastric mucosa was estimated to be 6.9×10 per gram tissue on average. It was higher in Helicobacter pylori-infected patients (7.80±0.71) compared with those uninfected (7.59±0.57, P=0.005). An increased bacterial load up to 7.85±0.70 was detected in gastric cancer compared with chronic gastritis (P=0.001). The unweighted principal coordinate analysis showed that the structure of microbiota in gastric cancer was more diversified. Five genera of bacteria with potential cancer-promoting activities were enriched in gastric cancer. The weighted principal coordinate analysis showed that the presence of Helicobacter pylori markedly altered the structure of microbiota, but had little influence on the relative proportions of the other members in the microbiota. CONCLUSION: Findings from this study indicated an altered microbiota in gastric cancer with increased quantity of bacteria, diversified microbial communities, and enrichment of bacteria with potential cancer-promoting activities. These alterations could contribute toward the gastric carcinogenesis.

Rare case of upper gastrointestinal bleeding in achalasia.

Achalasia is a prototypic esophageal motility disorder with complications including aspiration-pneumonia, esophagitis, esophageal-tracheal fistula, spontaneous rupture of the esophagus, and squamous cell carcinoma. However, achalasia is rarely associated with esophageal stones and ulcer formation that lead to upper gastrointestinal bleeding. Here, we report the case of a 61-year-old woman who was admitted to our department after vomiting blood for six hours. Physical examination revealed that the patient had severe anemia and mild palpitation in the upper abdomen. CT revealed lower esophageal dilatation and esophageal wall thickening, and an emergency upper endoscopy showed that the esophagus was substantially expanded by a dark round stone, with multiple ulcers on the esophageal wall and a slit in the cardiac mucosa with a large clot attached. The patient's history included ingestion of 1 kg hawthorn three days prior. The acute upper gastrointestinal bleeding was caused by Mallory-Weiss syndrome associated with achalasia and an esophageal stone. For patients with achalasia, preventing excessive ingestion of tannins is crucial to avoid complications such as bleeding and rupture.

The altered tight junctions: an important gateway of bacterial translocation in cachexia patients with advanced gastric cancer.

UNLABELLED: Tight junctions (TJs) are the structural basis for the intestinal epithelium barrier. Increased intestinal permeability caused by variations in TJ proteins may result in bacterial translocation (BT). There is increasing evidence that BT might contribute to the occurrence and development of cancer cachexia, but the details are not known. Aims, we undertook further investigations into the pathway of BT in cancer cachexia. RESULTS: BT-positive patients had a higher level of claudins-2 (CL-2, P=0.035) and a lower level of occludin (P=0.038) and Zonula occluden-1 (P=0.01) than BT-negative patients. Moreover, the levels of IL-6, TNF-α, and IFN-γ in BT-positive cachexia patients were higher compared with BT-negative cachexia patients (P<0.001, P=0.01, P<0.001) and BT-positive noncachexia patients (P<0.001, P=0.025, P<0.001). In the BT-positive cachexia patients, the local concentration of IL-6, TNF-α, and IFN-γ, in the middle colic vein, was higher than in the peripheral venous (P=0.04, P=0.03, P=0.038). In addition, endotoxin was detected within the small intestinal wall, and the concentration of endotoxin decreased from the mucosal side to the serosal side gradually in BT-positive patients. This study suggests that the altered TJs could be an important gateway of BT in gastric cancer cachexia and local cytokines could play a more important role than systemic cytokines in the process.

Docetaxel shows radiosensitization in human hepatocellular carcinoma cells.

AIM: To determine the radiosensitizing potential of docetaxel in human hepatocellular carcinoma SMMC-7721 cells and its mechanisms. METHODS: SMMC-7721 cells were incubated with docetaxel at 0.125, 0.25, and 0.5 nmoL/L for 24 h and at 0.125 and 0.25 nmol/L for 48 h before irradiation. Radiation doses were given from 0 to 10 Gy. Cell survival was measured by a standard clonogenic assay after a 9-d incubation. The reactive oxygen species (ROS) and glutathione (GSH) are detected after being given the same dose of docetaxel for the same time. RESULTS: The sensitization enhancement ratios (SER) for SMMC-7721 cells determined at the 50% survival level were 1.15, 1.21 and 1.49 at 0.125, 0.25, and 0.5 nmol/L for pre-incubation of 24 h, respectively; the SER were 1.42, 1.67 at 0.125 and 0.25 nmol/L, for pre-incubation of 48 h, respectively. The ROS of SMMC-7721 cells increased and GSH decreased after pretreatment with the same doses of docetaxel for 24 or 48 h. CONCLUSION: A radiosensitizing effect of docetaxel could be demonstrated unambiguously in this cell line used. In addition, our data showed that the mechanism of radiopotentiation by docetaxel probably does not involve a G2/M block in SMMC-7721 cells, and ROS generation and GSH deletion may play a key role in the radiosensitizing effect of docetaxel.

Docetaxel inhibits SMMC-7721 human hepatocellular carcinoma cells growth and induces apoptosis.

AIM: To investigate the in vitro anti-hepatocellular carcinoma (HCC) activity of docetaxel against SMMC-7721 HCC cells and its possible mechanism. METHODS: The HCC cells were given different concentrations of docetaxel and their growth was measured by colony forming assay. Cell cycle and apoptosis were analyzed by flow cytometry and fluorescence microscopy (acridine orange/ethidium bromide double staining, AO/EB), as well as electronic microscopy. The SMMC-7721 HCC cell reactive oxygen species (ROS) and glutathione (GSH) were measured after given docetaxel. RESULTS: Docetaxel inhibited the hepatocellular carcinoma cells growth in a concentration dependent manner with IC(50) 5 x 10(-10)M. Marked cell apoptosis and G2/M phase arrest were observed after treatment with docetaxel >=10(-8)M. Docetaxel promoted SMMC-7721 HCC cells ROS generation and GSH deletion. CONCLUSION: Docetaxel suppressed the growth of SMMC-7721 HCC cells in vitro by causing apoptosis and G2/M phase arrest of the human hepatoma cells, and ROS and GSH may play a key role in the inhibition of growth and induction of apoptosis.