A research of STEAP1 regulated gastric cancer cell proliferation, migration and invasion in vitro and in vivos.

Six-Transmembrane Epithelial Antigene of the Prostate 1 (STEAP1) is associated with the occurrence and development of cancer. This study aimed to clarify the role of STEAP1 in gastric cancer tumour growth and metastasis, as well as its molecular mechanism of action.Statistical methods were used for clinical data analysis. Protein expression was detected using immunohistochemistry(IHC). The mRNA and protein expression in the cell cultures were detected using reverse transcription-polymerase chain reaction(RT-PCR) and western blot analysis. Overexpression and silencing models were constructed using plasmid and lentivirus transfection. To detect cell proliferation in vitro, Cell Counting Kit-8(CCK-8), flow cytometry and colony formation assays were used; transwell and wound healing assays were used to detect cell migration and invasion;For in vivo experiments, nude BALB/c mice were used for detecting subcutaneous tumorigenesis and intraperitoneal implantation. In the results,we found STEAP1 was overexpressed in gastric cancer tissues and cell lines. Single-factor and Cox analyses showed that STEAP1 gene expression level correlated with poor prognosis. Up-regulation of STEAP1 increased cell proliferation, migration and invasion, which decreased after STEAP1 was knocked down. These changes were achieved via the activation of the AKT/FoxO1 pathway and epithelial-mesenchymal transformation (EMT). The in vivo animal experiments showed that STEAP1 knock down, resulted in a decrease in the subcutaneous tumour and peritoneal tumour formation.

Efficacy and safety of modified endoscopic mucosal resection for rectal neuroendocrine tumors: a meta-analysis.

PURPOSE: Rectal neuroendocrine tumors are rare with good prognosis. Several endoscopic methods such as endoscopic polypectomy, endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR), and modified endoscopic mucosal resection (m-EMR) are used in the treatment of rectal neuroendocrine tumors. Although m-EMR is derived from traditional EMR, it has not been widely used in clinical practice. In this study, we compared the efficacy and safety of EMR and m-EMR in the treatment of rectal neuroendocrine tumors by performing a meta-analysis. MATERIALS AND METHODS: We searched PubMed, Web of Science, and EMBASE index up to the end of January 2017 for all published literature about EMR and m-EMR in the treatment of rectal neuroendocrine tumors. RESULTS: A total of 11 studies involving 811 patients were included. The pooled data suggested that there was a significantly higher rate of histologic complete resection and endoscopic complete resection among patients treated with m-EMR than those treated with EMR (histologic complete resection: OR = 0.23, 95 % CI = 0.10-0.51, p < 0.01; endoscopic complete resection: OR = 0.13, 95 % CI = 0.02-0.74, p = 0.02). The procedure time of EMR was longer than m-EMR (MD = 2.40, 95 % CI = 0.33-4.46, p = 0.02). There was a significantly higher rate of vertical margin involvement among patients treated with EMR than those treated with m-EMR; whereas, there was no significant difference of lateral margin involvement between the m-EMR and EMR groups (vertical margin involvement: OR = 5.00, 95 % CI = 2.67-9.33, p < 0.01; lateral margin involvement: OR = 1.44, 95 % CI = 0.48-4.37, p = 0.52). There was no significant difference in mean tumor size among patients treated with m-EMR versus those treated with EMR (MD = -0.30, 95 % CI = -0.75-0.14, p = 0.18); further, there was no significant difference in endoscopic mean sizes of the tumor and pathological mean sizes of the tumor between the m-EMR and EMR groups (endoscopic mean sizes of the tumor: MD = 0.20, 95 % CI = -0.44-0.84, p = 0.43; pathological mean sizes of the tumor: MD = 0.62, 95 % CI = -0.68-1.92, p = 0.05). No significant differences were detected among the treatment groups with regard to complications (bleeding: OR = 0.87, 95 % CI = 0.39-1.95, p = 0.73; complications (bleeding and perforation): OR = 0.87, 95 % CI = 0.40-1.88, p = 0.73). CONCLUSION: The efficacy of m-EMR are better than EMR among patients undergoing endoscopic treatment of rectal neuroendocrine tumors, and the safety of m-EMR is equivalent to EMR treatment.

Smoking status and subsequent gastric cancer risk in men compared with women: a meta-analysis of prospective observational studies.

BACKGROUND: Smoking is one of the well-established risk factors for gastric cancer incidence, yet whether men are more or equally susceptible to gastric cancer due to smoking compared with women is a matter of controversy. The aim of this study was to investigate and compare the effect of sex on gastric cancer risk associated with smoking. METHODS: We conducted a systemic literature search in MEDLINE, EMBASE, and the Cochrane CENTRAL databases to identify studies published from inception to December 2018. We included prospective observational studies which reported effect estimates with 95% confidence intervals (CIs) for associations of current or former smokers with the incidence of gastric cancer by sex. We calculated the ratio of relative risk (RRR) with corresponding 95% CI based on sex-specific effect estimates for current or former smokers versus non-smokers on the risk of gastric cancer. RESULTS: We included 10 prospective studies with 3,381,345 participants in our analysis. Overall, the summary RRR (male to female) for gastric cancer risk in current smokers was significantly increased compared with non-smokers (RRR: 1.30; 95% CI: 1.05-1.63; P = 0.019). Furthermore, there was no significant sex difference for the association between former smokers and gastric cancer risk (RRR: 1.20; 95% CI: 0.92-1.55; P = 0.178). However, the result of sensitivity analysis indicated the pooled result was not stable, which was altered by excluding a nested case-control study (RRR: 1.31; 95% CI: 1.10-1.57; P = 0.002). CONCLUSION: This systematic review showed a potential sex difference association between current smokers and the risk of gastric cancer. The sex differential in smokers can give important clues for the etiology of gastric cancers and should be examined in further studies.

The role of EGFR mutation as a prognostic factor in survival after diagnosis of brain metastasis in non-small cell lung cancer: a systematic review and meta-analysis.

BACKGROUND: The brain is a common site for metastasis in non-small-cell lung cancer (NSCLC). This study was designed to evaluate the relationship between the mutational of the epidermal growth factor receptor (EGFR) and overall survival (OS) in NSCLC patients with brain metastases. METHODS: Searches were performed in PubMed, EmBase, and the Cochrane Library to identify studies evaluating the association of EGFR mutation with OS in NSCLC patients through September 2017. RESULTS: 4373 NSCLC patients with brain metastases in 18 studies were involved. Mutated EGFR associated with significantly improved OS compared with wild type. Subgroup analyses suggested that this relationship persisted in studies conducted in Eastern, with retrospective design, with sample size ≥500, mean age of patients ≥65.0 years, percentage male < 50.0%, percentage of patients receiving tyrosine kinase inhibitor ≥30.0%. Finally, although significant publication bias was observed using the Egger test, the results were not changed after adjustment using the trim and fill method. CONCLUSIONS: This meta-analysis suggests that EGFR mutation is an important predictive factor linked to improved OS for NSCLC patients with brain metastases. It can serve as a useful index in the prognostic assessment of NSCLC patients with brain metastases.

Effect of neoadjuvant chemotherapy in patients with gastric cancer: a PRISMA-compliant systematic review and meta-analysis.

BACKGROUND: Neoadjuvant chemotherapy (NAC) is extensively used in the treatment of patients with gastric cancer (GC), particularly in high risk, advanced gastric cancer. Previous trials testing the efficacy of NAC have reported inconsistent results. METHODS: This study compares the combined use of NAC and surgery with surgery alone for GC by using a meta-analytic approach. We performed an electronic search of PubMed, EmBase, and the Cochrane Library to identify randomized controlled trials (RCTs) on NAC published before Oct 2015. The primary outcome of the studies was data on survival rates for patients with GC. The summary results were pooled using the random-effects model. We included 12 prospective RCTs reporting data on 1538 GC patients. RESULTS: Patients who received NAC were associated with significant improvement of OS (P = 0.001) and PFS (P < 0.001). Furthermore, NAC therapy significantly increased the incidence of 1-year survival rate (SR) (P = 0.020), 3-year SR (P = 0.011), and 4-year SR (P = 0.001). Similarly, NAC therapy was associated with a lower incidence of 1-year (P < 0.001), 2-year (P < 0.001), 3-year (P < 0.001), 4-year (P = 0.001), and 5-year recurrence rate (P = 0.002). Conversely, patients who received NAC also experienced a significantly increased risk of lymphocytopenia (P = 0.003), and hemoglobinopathy (P = 0.021). CONCLUSIONS: The findings of this study suggested that NAC is associated with significant improvement in the outcomes of survival and disease progression for GC patients while also increasing some toxicity.

The efficacy and safety of targeted therapy with or without chemotherapy in advanced gastric cancer treatment: a network meta-analysis of well-designed randomized controlled trials.

BACKGROUND: Advanced gastric cancer (AGC) is a severe malignant tumor associated with high mortality. Targeted therapy is an important approach for improving the therapeutic effects of AGC treatment. This study evaluates the efficacy and safety of targeted agents for AGC patients. METHODS: PubMed, EmBase, and the Cochrane Library were searched for double-blind randomized controlled trials (RCTs) of AGC treatments published prior to July 2017. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and severe adverse effects (AEs) were evaluated to determine the efficacy and safety of targeted agents. A network meta-analysis with a frequentist framework was performed to assess the effects of various targeted agents for AGC treatment. RESULTS: Our analysis included 16 articles involving 5371 patients and 11 types of agents. The network meta-analysis showed that apatinib (97.5%) was most likely to improve PFS, followed by regorafenib (86.3%) and rilotumumab (65.4%). Apatinib was similarly best for OS outcome, (95.5%) followed by rilotumumab (74.7%) and regorafenib (70%). Apatinib (89.6%) also had the best improvement on ORR, followed by rilotumumab (75.4%) and everolimus (68.4%). Bevacizumab (85.5%) was likely to get the lowest severe AEs, followed by sunitinib (63%). CONCLUSIONS: Apatinib, regorafenib, and rilotumumab improved patient PFS and OS. When combined with chemotherapy, ramucirumab and rilotumumab had high efficacy but low tolerability, and bevacizumab had moderate efficacy and tolerability for PFS. Without chemotherapy, ramucirumab and regorafenib had relatively high therapeutic efficacy tolerability for PFS.

The clinicopathological parameters and prognostic significance of HER2 expression in gastric cancer patients: a meta-analysis of literature.

BACKGROUND: Human epidermal growth factor receptor-2 (HER2) is regarded as an important and promising target in the treatment of HER2-positive breast cancers. However, the correlation of clinicopathological characteristics and prognostic significance of HER2 overexpression in gastric cancer patients remains unclear. Our aim was to clarify this issue. METHODS: Embase, PubMed, and the Cochrane Library were searched for relevant articles published up to May 2016. Outcomes of interest contained sex, age, tumor size, tumor site, tumor node metastasis (TNM) stage, distant metastasis, lymph node metastasis, Lauren's classification, differentiation grade, lymphovascular invasion, neural invasion, and multivariate analysis data for overall survival. RESULTS: A total of 41 studies of 17,494 gastric cancer patients were identified with HER2 test. HER2 positive rate was 19.07% (95% CI = 9.16, 28.98). There existed statistical significance between HER2 overexpression and patients' prognosis (RR = 1.47, 95% CI = 1.09, 1.98). Male patients (OR = 1.48, 95% CI = 1.34, 1.65), proximal tumors (OR = 1.25, 95% CI = 1.07, 1.47), intestinal-type tumors (OR = 3.37, 95% CI = 2.54, 4.47), advanced stage cancers (OR = 1.35, 95% CI = 1.10, 1.66), lymph node metastasis (OR = 1.26, 95% CI = 1.14, 1.41), well-differentiated cancers (OR = 1.79, 95% CI = 1.15, 2.76), and distant metastasis (OR = 1.91, 95% CI = 1.08, 3.38) were correlated with higher HER2 expression rates. However, no statistical differences existed in age, tumor size, lymphovascular invasion, or neural invasion. Subgroup analysis revealed that HER2 expression rates reported in articles from Asian (19.52%) countries were quantitatively higher than those from European (16.91%) areas. Results were consistent with those reports that define HER2 status according to trastuzumab for gastric cancer (ToGA) criteria. CONCLUSION: This study showed that HER2 overexpression was associated with poor prognosis in gastric cancer patients. HER2 positive rates may be associated with sex, tumor site, TNM staging system, distant metastasis, lymph node metastasis, Lauren's classification, and differentiation grade in gastric cancer patients. The HER2 expression rate in Asians may be higher than that in Europeans. This study offers a convenient way for doctors to select patients for relevant HER2 detection and following treatment.

Macroscopic Serosal Classification as a Prognostic Index in Radically Resected Stage pT3-pT4b Gastric Cancer.

BACKGROUND: Macroscopic serosal classification (MSC) is an important clinicopathologic index of gastric cancer (GC). To investigate the prognostic significance of MSC status in patients with radically resected stage pT3-pT4b GC, we examined the relationship between MSC type and pT stage. METHODS: Clinicopathologic and survival data of 1613 patients with stage pT3-pT4b GC were studied retrospectively, in the aftermath of radical surgery. RESULTS: MSC types, including reactive, nodular, tendonoid, and color-diffused type, correlated significantly with overall survival (OS) in this cohort, but prognosis was similar for all stages of color-diffused type GC. We proposed a revised pT stage in which color-diffused type cancers at pT3 or pT4a stage were reclassified into pT4b stage. In two-step multivariate analysis, revised pT stage (stage pT4b for all color-diffused types) proved more suitable for determining prognosis, surpassing both Union for International Cancer Control/American Joint Committee on Cancer pT stage and MSC type as an independent prognostic index. CONCLUSIONS: MSC type is a significant and independent prognostic index of OS in patients with radically resected stage pT3-pT4b GC. For prognostic purposes, tumors of color-diffused type at pT3 or pT4a stage should be considered stage pT4b disease.

Borrmann type IV gastric cancer should be classified as pT4b disease.

BACKGROUND: The impact of macroscopic pathologic features of primary tumor that could be obtained preoperatively on pT classification has not been reported so far. The aim of this study was to investigate the feasibility of incorporation of Borrmann type IV gastric cancer into the pT classification. MATERIALS AND METHODS: Clinicopathologic and prognostic data of 1622 patients with advanced gastric cancer who underwent radical surgery were retrospectively studied. RESULTS: Of 1622 patients, 135 (8.32%) patients were classified as having Borrmann type IV gastric cancer. We first confirmed that Borrmann type IV gastric cancer was one of the independent prognostic factors for patients with advanced gastric cancer who underwent radical surgery. Interestingly, we found that overall survival of patients with Borrmann type IV gastric cancer could be clearly distinguished by pN classification and pathological TNM stage but not by pT classification. Importantly, further analysis demonstrated that the prognosis of Borrmann type IV gastric cancers was homogeneous with that of pT4b cancers but poorer than pT2, pT3, pT4a cancers. Therefore, we proposed a novel pT classification in which pT4b disease was defined as cancers that were Borrmann type IV or those that had invaded adjacent structures. Two-step multivariate analysis demonstrated that the novel pT classification was more suitable for prognostic assessment than the original classification. CONCLUSIONS: Classifying Borrmann type IV gastric cancer as pT4b disease improves pT classification prediction of prognosis in patients with advanced gastric cancer after radical surgery.

Meta-analysis of the laparoscopic versus open colorectal surgery within fast track surgery.

BACKGROUND: Laparoscopic methods and fast-track surgery (FTS) can enhance recovery and reduce postoperative hospital stay. However, whether laparoscopic surgery can provide short-term benefits within FTS is controversial. Thus, we conducted a meta-analysis of published studies to evaluate the effect of laparoscopic colorectal surgery within FTS. METHODS: We searched PubMed, EMBASE, Cochrane Library, and Ovid databases for eligible studies. Endpoints were duration of postoperative hospital stay, time to first bowel movement, total postoperative complication rate, readmission rate, mortality within 30 days after surgery, and conversation rate of laparoscopic surgery. RESULTS: Four randomized controlled trials and six clinical controlled trials (1510 patients) were eligible for analyses. Duration of postoperative hospital stay (weighted mean difference, -1.65 days; p < 0.001), time to first bowel movement (-1.13 days; p < 0.001), total postoperative complication rate (risk ratio [RR], 0.65; p < 0.001), readmission rate (0.46; p < 0.001), and mortality (0.45; p < 0.001) were significantly reduced in the laparoscopic surgery group. Overall conversion rate of laparoscopic surgery was 11.1%. Subgroup analyses based on each FT element demonstrated that studies without the element "prevention of hypothermia," "no bowel preparation," or "no routine use of drains" did not show significant differences between two groups with regard to duration of postoperative hospital stay or total prevalence of postoperative complications. CONCLUSION: Within FTS, laparoscopic methods can significantly shorten postoperative hospital stay, accelerate postoperative recovery, and enhance safety in colorectal surgery. The FT elements "prevention of hypothermia," "no bowel preparation," and "no routine use of drains" may play important parts in the combined effect of these two methods.

Aspirin and nonsteroidal anti-inflammatory drugs after but not before diagnosis are associated with improved breast cancer survival: a meta-analysis.

PURPOSE: The association between nonsteroidal anti-inflammatory drugs (NSAIDs) and breast cancer survival is still controversial. The aim of our meta-analysis was to assess the survival benefit of NSAIDs. METHODS: A literature search was conducted in PubMed and EMBASE (to September 2014). A meta-analysis was performed with hazard ratios (HRs) and 95% confidence intervals (CIs) as the effect measures. Subgroup analyses were based on time of NSAID use (before and after diagnosis), medication type (aspirin and other nonaspirin NSAIDs), and study design (cohort and case-control studies). RESULTS: There were 16 eligible studies. Use of NSAIDs after diagnosis was significantly inversely associated with relapse/metastasis (HR 0.69, 95% CI 0.59-0.80) and tended toward potentially protective effects on all-cause mortality, although significance was not reached (HR 0.79, 95% CI 0.61-1.02). In cohort studies, the association between post-diagnostic use of NSAIDs and breast cancer survival was stronger with reduced heterogeneity (breast-cancer-specific mortality: HR 0.65, 95% CI 0.48-0.89, I(2) = 65.3%; all-cause mortality: HR 0.73, 95% CI 0.57-0.92, I(2) = 83.2%; relapse/metastasis: HR 0.73, 95% CI 0.61-0.86, I(2) = 48.3%). Aspirin use after diagnosis was significantly associated with breast-cancer-specific mortality (HR 0.69, 95% CI 0.50-0.96) and relapse/metastasis (HR 0.75, 95% CI 0.56-1.00), and tended toward a protective effect on all-cause mortality, although significance was not reached (HR 0.79, 95% CI 0.60-1.03). Including cohort studies only, we obtained similar results and post-diagnostic use of aspirin was significantly associated with all-cause mortality (HR 0.72, 95% CI 0.56-0.93). CONCLUSIONS: NSAIDs and aspirin after but not before diagnosis were associated with improved breast cancer survival, including breast-cancer-specific mortality, all-cause mortality, and relapse/metastasis.

Lung cancer cells induce senescence and apoptosis of pleural mesothelial cells via transforming growth factor-beta1.

Pleural dissemination is commonly associated with metastatic advanced lung cancer. The injury of pleural mesothelial cells (PMCs) by soluble factors, such as transforming growth factor-beta1 (TGF-ß1), is a major driver of lung cancer pleural dissemination (LCPD). In this study, we examine the effects of TGF-ß1 on PMC injury and the ability of TGF-ß1 inhibition to alleviate this effect both in vitro and in vivo. PMCs were co-cultured with the high TGF-ß1-expressing lung cancer cell line A549 and with various TGF-ß1 signaling inhibitors. Expression of cleaved-caspase 3, cleaved-caspase 9, p21, and p16 were evaluated by Western blot and immunofluorescent confocal imaging. Apoptosis was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltrazoliumbromide assay and AnnexinV-propidium iodide (PI) staining. PMC senescence was assessed by staining for senescence-associated ß-galactosidase (SA-ß-Gal). The ability of lung cancer cells (LCCs) to adhere to injured PMCs was investigated using an LCC-PMC adhesion assay. In our mouse model, PMC injury status was monitored by hematoxylin-eosin (H&E) and Masson's trichrome staining. LCCs expressing high levels of TGF-ß1 induce apoptosis and senescence of PMCs in a co-culture system. Injured PMCs adhere to LCCs, which may further promote LCPD. Importantly, PMC monolayer injury could be reversed with TGF-ß1 inhibitors. This was consistent with our in vivo data showing that the TGF-ß1 inhibitor SB-431542 attenuated PMC barrier injury induced by A549 culture medium in our mouse model. Our study highlights the importance of TGF-ß1 signaling in LCPD and establishes this signaling pathway as a potential therapeutic target in the disease.

Peritoneal milky spots serve as a hypoxic niche and favor gastric cancer stem/progenitor cell peritoneal dissemination through hypoxia-inducible factor 1α.

Peritoneal dissemination is the most common cause of death in gastric cancer patients. The hypoxic microenvironment plays a major role in controlling the tumor stem cell phenotype and is associated with patients' prognosis through hypoxia-inducible factor-1α (HIF-1α), a key transcriptional factor that responds to hypoxic stimuli. During the peritoneal dissemination process, gastric cancer stem/progenitor cells (GCSPCs) are thought to enter into and maintained in peritoneal milky spots (PMSs), which have hypoxic microenvironments. However, the mechanism through which the hypoxic environment of PMSs regulated GCSPC maintenance is still poorly understood. Here, we investigated whether hypoxic PMSs were an ideal cancer stem cell niche suitable for GCSPC engraftment. We also evaluated the mechanisms through which the HIF-1α-mediated hypoxic microenvironment regulated GCSPC fate. We observed a positive correlation between HIF-1α expression and gastric cancer peritoneal dissemination (GCPD) in gastric cancer patients. Furthermore, the GCSPC population expanded in primary gastric cancer cells under hypoxic condition in vitro, and hypoxic GCSPCs showed enhanced self-renewal ability, but reduced differentiation capacity, mediated by HIF-1α. In an animal model, GCSPCs preferentially resided in the hypoxic zone of PMSs; moreover, when the hypoxic microenvironment in PMSs was destroyed, GCPD was significantly alleviated. In conclusion, our results demonstrated that PMSs served as a hypoxic niche and favored GCSPCs peritoneal dissemination through HIF-1α both in vitro and in vivo. These results provided new insights into the GCPD process and may lead to advancements in the clinical treatment of gastric cancer.

Surgery for gastric cancer in a patient with non-cirrhotic hyperammonemia: a case report.

We report a case of gastric cancer in a patient with non-cirrhotic hyperammonemia secondary to a spontaneous portacaval shunt. The patient, a 69-year-old male, had more than 40 years of abdominal discomfort. On gastroscopy, 2.0 × 1.5-cm irregular uplift ulcers were seen on the lesser curvature of the stomach, and tissue biopsy revealed poorly differentiated adenocarcinoma. His hyperammonemia was found on celiac angiography to be due to the formation of a spontaneous portacaval shunt. Imaging revealed no evidence of cirrhosis or portal hypertension. The patient ultimately underwent a distal gastrectomy and gastroduodenal anastomosis; the spontaneous portacaval shunt was left untreated. Postoperatively, there were no short-term complications such as anastomotic leakage, stricture, or bleeding, and the patient's blood ammonia level decreased to within the normal range. Radical gastrectomy without splenectomy or closure of the abnormal shunt was feasible for the treatment of gastric cancer in a patient with non-cirrhotic hyperammonemia.

ILEI: a novel marker for epithelial-mesenchymal transition and poor prognosis in colorectal cancer.

AIMS: Accumulating evidence over the past decade has shown that abnormal activation of epithelial to mesenchymal transition (EMT) contributes to tumour progression and metastasis in colorectal cancer (CRC). In this study, we investigated the expression of interleukin-like EMT inducer (ILEI) and EMT-associated markers (E-cadherin, vimentin) in CRC tissues and determined the correlations between ILEI expression and clinicopathological characteristics, prognosis and EMT in CRC. METHODS AND RESULTS: In total, 194 patients diagnosed with CRC based on histopathological evaluation and those subjected to surgical resection at the First Hospital of China Medical University between 2003 and 2005 were examined. Immunohistochemical staining for ILEI, vimentin and E-cadherin was performed for each specimen. Cytoplasmic overexpression of ILEI usually accompanied down-regulation of E-cadherin and positive expression of vimentin. Conversely, ILEI was simultaneously down-regulated with overexpression of E-cadherin and negative expression of vimentin. ILEI overexpression was associated significantly with T-stage, N-stage, TNM stage and EMT phenotype (P = 0.024, <0.001, <0.001 and <0.001, respectively). Multivariate analysis revealed that ILEI expression was an independent prognostic factor for patient survival. CONCLUSIONS: Our findings indicate that cytoplasmic ILEI expression is a potential marker of EMT and tumour progression in CRC. ILEI is an independent predictive factor associated with poor prognosis in CRC.

Tumor-associated mesothelial cells are negative prognostic factors in gastric cancer and promote peritoneal dissemination of adherent gastric cancer cells by chemotaxis.

Peritoneal dissemination is highly frequent in gastric cancer. Damage to human peritoneal mesothelial cell (HPMC) barriers provokes gastric cancer peritoneal dissemination (GCPD), the key events during GCPD, is characterized by fibroblastic development. In this study, we have studied the association between fibroblast activation protein (FAP) expression in peritoneum and the pathological features of the primary tumor. The clinical prognosis of gastric cancer patients was evaluated according to FAP expression. In a gastric cancer cell-HPMC co-culture system, expression of E-cadherin, α-smooth muscle actin, and FAP were evaluated by Western blotting. Gastric cancer cell migration and adhesion to HPMC were also assayed. Our results showed positive peritoneal staining of FAP in 36/86 cases (41.9 %), which was associated with a higher TNM stage in primary gastric cancer and higher incidence of GCPD (both p<0.05). Survival analysis showed FAP expression was an independent prognostic factor of poor survival (p=0.02). Peritoneum of FAP-positive expression exhibited a distinct fibrotic development and expressed higher level of the mesenchymal marker α-SMA, which was confirmed by the in vitro Western blot assay. In HPMC and gastric cancer cell adherence assay, SGC-7901 cells preferentially adhered to TA-HPMC at different cell densities (both p<0.05). Additionally, SGC-7901 cells were more prone to chemotaxis by FAP-expressed tumor-associated-human peritoneal mesothelial cells (TA-HPMC) compared with HPMC co-cultured with normal gastric glandular epithelial cells in a time-dependent manner (both p<0.05). Our study indicated a positive correlation between peritoneum FAP expression and GCPD. FAP-expressed TA-HPMC might be an important cellular component and instigator of GCPD.

Induction of apoptosis in human peritoneal mesothelial cells by gastric cancer cell supernatant promotes peritoneal carcinomatosis.

This study was carried out to evaluate the effects of gastric cancer cell supernatant on human peritoneal mesothelial cell viability and apoptosis and to investigate the mechanism of action of gastric cancer in a mesothelial cell line (HMrSV5). Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide (MTT) assay. Mesothelial cells treated with gastric cancer cell supernatant were stained with acridine orange/ethidium bromide and subjected to fluorescence microscopy. C57BL/6 mice were used to establish a cancer invasion model. Morphological changes and exfoliation occurred, and naked areas appeared in both cultured mesothelial cells and the parietal peritoneum after treatment with gastric cancer cell supernatant. Cell supernatant from gastric cancer cells induced apoptosis of mesothelial cells in a time-dependent manner. Obvious morphological changes of cell apoptosis were detected, such as condensation of chromatin, nuclear fragmentations, and apoptotic ladders. These findings demonstrate that gastric cancer cells induce apoptosis of human peritoneal mesothelial cells through supernatants in early peritoneal metastasis.

Transforming growth factor-beta1 signaling blockade attenuates gastric cancer cell-induced peritoneal mesothelial cell fibrosis and alleviates peritoneal dissemination both in vitro and in vivo.

Peritoneal dissemination is the most frequent metastatic pattern of advanced gastric cancer and the main cause of death in gastric cancer patients. Transforming growth factor-beta1 (TGF- ß1), one of the most potent fibrotic stimuli for human peritoneal mesothelial cells, has been shown to play an important role in this process. In this study, we investigated the effect of TGF- ß1 signaling blockade in gastric cancer cell (GCC)-induced human peritoneal mesothelial cell (HPMC) fibrosis. HPMCs were cocultured with the high TGF- ß1 expressing GCC line SGC-7901 and various TGF- ß1 signaling inhibitors or SGC-7901 transfected with TGF-ß1-specific siRNA. HPMC fibrosis was monitored on the basis of morphology. Expression of the epithelial cell marker, E-cadherin, and the mesenchymal marker, α-smooth muscle actin (α-SMA), was evaluated by Western blotting and immunofluorescence confocal imaging. GCC adhesion to HPMC was also assayed. In nude mouse tumor model, the peritoneal fibrotic status was monitored by immunofluorescent confocal imaging and Masson's trichrome staining; formation of metastatic nodular and ascites fluid was also evaluated. Our study demonstrated that GCC expressing high levels of TGF-ß1 induced HMPC fibrosis, which is characterized by both upregulation of E-cadherin and downregulation of α-SMA. Furthermore, HPMC monolayers fibrosis was reversed by TGF- ß1 signaling blockade. In vivo, the TGF- ß1 receptor inhibitor SB-431542 partially attenuated early-stage gastric cancer peritoneal dissemination (GCPD). In conclusion, our study confirms the significance of TGFß1 signaling blockade in attenuating GCPD and may provide a therapeutic target for clinical therapy.

The mannose-sensitive hemagglutination pilus strain of Pseudomonas aeruginosa shift peritoneal milky spot macrophages towards an M1 phenotype to dampen peritoneal dissemination.

Peritoneal dissemination (PD) of tumor cells is the most frequent pattern of gastric cancer recurrence and the leading cause of death. Peritoneal milky spots are deemed as the site of origin of gastric cancer PD wherein the main cellular components are macrophages. A vaccine derived from the mannose-sensitive hemagglutination pilus strain of Pseudomonas aeruginosa (PA-MSHA) has exhibit strong immune modulatory properties. In the present study, we tested the hypothesis whether the PA-MSHA vaccine activated peritoneal milky spot macrophages (PMSM) in a manner that would attenuate PD. It was observed that PA-MSHA activated PMSM towards a classical activation phenotype via a toll-like receptor4/9-dependent mechanism, which increased interleukin-12 levels and promoted the expression of co-stimulatory and antigen-presenting molecules like CD80, CD86, and MHC-II (P < 0.05). In addition, PA-MSHA-treated PMSM exhibited strong nonspecific antitumor effects in both contact-dependent and contact-independent modes of action (P < 0.05). In mice treated with PA-MSHA before inoculating gastric cancer cells, we noted alleviated PD toward the untreated mice. In conclusion, our findings demonstrated that PA-MSHA can stimulate PMSM towards an M1 phenotype and that activated PMSM inhibit gastric cancer growth and PD both in vitro and in vivo. The results of the current study provide a mechanistic insight that is relevant to the potential application of PA-MSHA in the treatment of gastric cancer-mediated PD.