Tumor-associated macrophages regulate gastric cancer cell invasion and metastasis through TGFβ2/NF-κB/Kindlin-2 axis

Objective: Recent studies have shown that tumor-associated macrophages(TAMs) play an important role in cancer invasion and metastasis. Our previous studies have reported that TAMs promote the invasion and metastasis of gastric cancer(GC) cells through the Kindlin-2 pathway. However, the mechanism needs to be clarified.Methods: THP-1 monocytes were induced by PMA/interleukin(IL)-4/IL-13 to establish an efficient TAM model in vitro and M2 macrophages were isolated via flow cytometry. A dual luciferase reporter system and chromatin immunoprecipitation(Ch IP) assay were used to investigate the mechanism of transforming growth factor β2(TGFβ2) regulating Kindlin-2 expression. Immunohistochemistry was used to study the relationships among TAM infiltration in human GC tissues, Kindlin-2 protein expression, clinicopathological parameters and prognosis in human GC tissues. A nude mouse oncogenesis model was used to verify the invasion and metastasis mechanisms in vivo.Results: We found that Kindlin-2 expression was upregulated at both m RNA and protein levels in GC cells cocultured with TAMs, associated with higher invasion rate. Kindlin-2 knockdown reduced the invasion rate of GC cells under coculture condition. TGFβ2 secreted by TAMs regulated the expression of Kindlin-2 through the transcription factor NF-кB. TAMs thus participated in the progression of GC through the TGFβ2/NF-κB/Kindlin-2 axis. Kindlin-2 expression and TAM infiltration were significantly positively correlated with TNM stage, and patients with high Kindlin-2 expression had significantly poorer overall survival than patients with low Kindlin-2 expression. Furthermore, Kindlin-2 promoted the invasion of GC cells in vivo.Conclusions: This study elucidates the mechanism of TAMs participating in GC cell invasion and metastasis through the TGFβ2/NF-κB/Kindlin-2 axis, providing a possibility for new treatment options and approaches.

Impact of preoperative chemoradiotherapy on survival in patients with resectable pancreatic cancer

AIM:To explore whether preoperative chemoradiation therapy improves survival of patients with pancreatic cancer undergoing resectional surgery. METHODS:Forty-seven patients with a malignant pancreatic tumor localized in the head or uncinate process of the pancreas underwent radical pancreaticoduodenectomy. Twenty-two received chemoradiation therapy (gemcitabine and radiation dose 50.4 Gy) before surgery (CRR) and 25 patients underwent surgery only (RO). The study was non-randomised. Patients were identified from a prospective database. RESULTS:The median survival time was 30.2 mo in the CRR group and 35.9 mo in the RO group. No statistically significant differences were found in subclasses according to lymph node involvement,TNM stages,tumor size,or perineural invasion. The one,three and five year survival rates were 81%,33% and 33%,respectively,in the CRR group and 72%,47% and 23%,respectively,in the RO group. In ductal adenocarcinoma,the median survival time was 27 mo in the CRR group and 20 mo in the RO group. No statistically significant differences were found in the above subclasses. The one,three and five year survival rates were 79%,21% and 21%,respectively,in the CRR group and 64%,50% and 14%,respectively,in the RO group. The overall hospital mortality rate was 2%. The morbidity rate was 45% in the CRR group and 32% (NS) in the RO group. CONCLUSION:Major multicenter randomized studies are needed to conclusively assess the impact of neoadjuvant treatment in the management of pancreatic cancer.

Carbonic anhydrase enzymes Ⅱ, Ⅶ, Ⅸ and Ⅻ in colorectal carcinomas

AIM To investigate expression of four alpha-carbonic anhydrases(CAs) in colorectal carcinomas(CRC) and compare the results with patients' survival.METHODS Colorectal carcinoma samples from 539 CRC patients and control tissues were arranged as tissue microarrays and analyzed with antibodies against CA Ⅱ, CA Ⅶ, CA Ⅸ, and CA Ⅻ. Intensity and extent of staining were both scored from 0 to 3 in each sample. These enzyme expression levels were then correlated to patients' survival and clinicopathological parameters, which were tumor differentiation grade and stage, site of tumor, patients' age, and gender. Kaplan-Meier analysis and Cox regression hazard ratio model were used to analyze survival data. RESULTS CA Ⅱ and CA Ⅻ staining intensities correlated with patients' survival in that higher expression indicated poorer prognosis. In Cox regression analysis one unit increase in the CA Ⅱ intensity increased the hazard ratio to 1.19 fold(CI: 1.04-1.37, P = 0.009). A significant correlation was also found when comparing CA Ⅻ staining intensity with survival of CRC patients(HR = 1.18, 95%CI: 1.01-1.38, P = 0.036). The extent of CA Ⅻ immunostaining did not correlate to the patients' survival(P = 0.242, Kaplan-Meier analysis). A significant interaction between age group and extent of the CA Ⅱ staining was found. Increased extent of CA Ⅱ had a significant hazard ratio among patients 65 years and older(1.42, 95%CI: 1.16-1.73, P = 0.0006). No correlations were found between CA Ⅶ(intensity P = 0.566, extent P = 0.495, Kaplan-Meier analysis), or CA Ⅸ(intensity P = 0.879, extent P = 0.315, KaplanMeier analysis) immunostaining results and survival, or the other parameters. CONCLUSION The present findings indicate that CA Ⅱ and CA Ⅻ could be useful in predicting survival in CRC.

Effect of the ulcerogenic agents ethanol, acetylsalicylic acid and taurocholate on actin cytoskeleton and cell motility in cultured rat gastric mucosal cells

AIM: To assess the effects of ulcerogenic agents on actin cytoskeleton and cell motility and the contribution of oxidative stress.METHODS: Rat gastric mucosal cell monolayers were cultured on coverslips. The cells were exposed, with or without allopurinol (2 mmol/L), for 15 min to ethanol (10-150 mL/L), ASA (1-20 mmol/L) or taurocholate (1-20 mmol/L), then the cells were processed for actin and vinculin staining. Cell migration after wounding was also measured.RESULTS: Exposure to 10 mL/L ethanol caused divergence of zonula adherens-associated actin bundles of adjacent cells and decreased rate of migration. These actions were opposed by xanthine oxidase inhibitor allopurinol. Exposure to 50 mL/L ethanol induced degradation and divergence of zonula adherens-associated vinculin from adjacent cells,which was, again, partially reverted by allopurinol. With 1 mmol/L ASA actin filaments became shorter and thicker.However, higher concentrations (10, 20 mmol/L) of ASA returned microfilaments thinner and longer, and decreased rate of migration. Zonula adherens-associated actin bundles were moderately distorted with 10 mmol/L ASA and with 10 mmol/L taurocholate. Exposure to taurocholate provoked changes resembling those of ASA. Taurocholate 5-20 mmol/L decreased the rate of migration dose dependently. The effects of ASA and taurocholate were not prevented by allopurinol.CONCLUSION: All ulcerogenic agents decreased the rate of migration dose dependently and induced divergence of zonula adherens-associated actin bundles of adjacent cells.In addition, ethanol and ASA caused degradation of actin cytoskeleton. Oxidative stress seems to underlie ethanol,but not ASA or taurocholate, induced cytoskeletal damage.