A ZBP1 isoform blocks ZBP1-mediated cell death.

ZBP1 is an interferon (IFN)-induced nucleic acid (NA) sensor that senses unusual Z-form NA (Z-NA) to promote cell death and inflammation. However, the mechanisms that dampen ZBP1 activation to fine-tune inflammatory responses are unclear. Here, we characterize a short isoform of ZBP1 (referred to as ZBP1-S) as an intrinsic suppressor of the inflammatory signaling mediated by full-length ZBP1. Mechanistically, ZBP1-S depresses ZBP1-mediated cell death by competitive binding with Z-NA for Zα domains of ZBP1. Cells from mice (Ripk1D325A/D325A) with cleavage-resistant RIPK1-induced autoinflammatory (CRIA) syndrome are alive but sensitive to IFN-induced and ZBP1-dependent cell death. Intriguingly, Ripk1D325A/D325A cells die spontaneously when ZBP1-S is deleted, indicating that cell death driven by ZBP1 is under the control of ZBP1-S. Thus, our findings reveal that alternative splicing of Zbp1 represents autogenic inhibition for regulating ZBP1 signaling and indicate that uncoupling of Z-NA with ZBP1 could be an effective strategy against autoinflammations.

Assessing the predictive value of clinical factors to pathological complete response for locally advanced rectal cancer: An analysis of 124 patients.

Purpose: To investigate the clinical factors affecting pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). Methods: Clinical data of 124 LARC patients treated with nCRT and surgery in the fourth Hospital of Hebei Medical University from 2014 to 2019 were retrospectively analyzed. In this study, univariate analysis and logistic dichotomous multivariate regression analysis were used to study the clinical factors affecting pCR, and the receiver operator characteristic curve (ROC) analysis was used to further verify the accuracy of partial indexes in predicting pCR. Results: Of the 124 enrolled patients, 19 patients (15.32%) achieved pCR. Univariate analysis showed that the number of cycles of consolidation chemotherapy, serum carcino-embryonic antigen (CEA) level before treatment, MRI longitudinal length of tumor, and extramural vascular invasion (EMVI) were statistically correlated with pCR. ROC analysis of the longitudinal length of tumor measured by MRI showed that the area under the curve (AUC) value, sensitivity and specificity were 0.735, 89.47% and 48.57% respectively, and the optimal cut-off value was 5.5cm. The ROC analysis showed that the AUC value, sensitivity and specificity of pCR prediction using CEA were 0.741, 63.16% and 90.48%, respectively, and the optimal cut-off value was 3.1ng/ml. Multivariate results showed that the number of cycles of consolidation chemotherapy, serum CEA level before treatment, and EMVI were independent predictors of pCR. Conclusion: The number of cycles of consolidation chemotherapy, serum CEA level before treatment, and EMVI may be important determinants of LARC patients to reach pCR after nCRT.

Chemically stable piperidinium cations for anion exchange membranes.

The chemical stability of the anion exchange membranes (AEMs) is determinative towards the engineering applications of anion exchange membrane fuel cells (AEMFCs) and other AEM-based electrochemical devices, yet remains a challenge due to deficiencies in the structural design of cations. In this work, an effective design strategy for ultra-stable piperidinium cations is presented based on the systematic investigation of the chemical stability of piperidinium in harsh alkaline media. Firstly, benzyl-substituted piperidinium was degraded by about 23% in a 7 M KOH solution at 100 °C after 1436 h, which was much more stable than pyrrolidinium due to its lower ring strain. The introduction of substituent effects at the α-C position was proved to be an effective strategy for enhancing the chemical stability of the piperidinium functional group. As a result, the butyl-substituted piperidinium cation showed no obvious structural changes after being treated in the 7 M KOH solution at 100 °C for 1050 h. Afterwards, GC-MS and NMR analysis indicated that the α-C atoms in the substituents of piperidinium are fragile to the nucleophilic attack of OH-. Based on the above results, the electronic and steric effects of different alkyl substitutions were analyzed. This work provides critical insights into the structural design of chemically stable piperidinium functional groups for the AEM and boosts its application in electrochemical devices, such as fuel cells and alkaline water electrolysis.

Spermidine Ameliorates Nonalcoholic Steatohepatitis through Thyroid Hormone-Responsive Protein Signaling and the Gut Microbiota-Mediated Metabolism of Bile Acids.

Spermidine, a natural polyamine and physiological autophagy inducer, is involved in various physiological processes. However, the impact and mechanism of spermidine on nonalcoholic steatohepatitis (NASH) remains unclarified. We found that daily spermidine intake was significantly lower in volunteers with liver dysfunction than the healthy controls, and the serum and fecal spermidine levels were negatively correlated with the NASH phenotypes. Spermidine supplementation significantly attenuated hepatic lipid accumulation, insulin resistance, hepatic inflammation, and fibrosis in NASH mice induced by a western diet. The ameliorating effect of spermidine on lipid accumulation might be partly regulated by thyroid hormone-responsive protein (THRSP) signaling and autophagy. Moreover, spermidine altered the profile of hepatic bile acids (BAs) and microbial composition and function. Furthermore, spermidine reversed the progression of hepatic steatosis, inflammation, and fibrosis in mice with preexisting NASH. Therefore, spermidine ameliorates NASH partly through the THRSP signaling and the gut microbiota-mediated metabolism of BAs, suggesting that spermidine might be a viable therapy for NASH.

The reduction of 18F-FDG uptake ability of tumor tissue after neoadjuvant chemoradiotherapy in locally advanced rectal cancer can effectively reflect the degree of tumor regression.

Introduction: To evaluate the predictive value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) imaging parameters for the response to neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). Methods: From January 2016 to March 2020, 52 LARC patients who underwent 18F-FDG PET-CT scans within 1 week before and 8-9 weeks after nCRT, were enrolled in this study according to a pre-designed screening criteria. After total mesorectal excision (TME) surgery, we assessed tumor response to treatment and analyzed the correlation between imaging parameters obtained from two PET-CT scans and tumor regression status. Results: Tumor response assessment showed that 13 of 52 patients received good response (GR), including 9 cases with pathological complete regression (pCR) and 4 cases with near-pathological complete regression (near-pCR). We also found that the maximum standard uptake value after nCRT (post-SUVmax), the response index (RI), the mean standard uptake values after nCRT (post-SUVmean), and the ratio of tumor SUVmean to liver SUVmean after nCRT (post-Ratio), were correlated with GR and pCR. Among these parameters, post-SUVmax and RI had a near-strong correlation with pCR (rs= -0.58 and 0.59, respectively), and also had a strong correlation with GR (rs = -0.7 and 0.63, respectively). Further ROC analysis showed that post-SUVmax and RI had higher values in predicting whether patients could achieve GR and pCR after nCRT, and the area under the curve (AUC) of both were greater than 0.9. The positive predictive values (PPVs) and negative predictive values (NPVs) of post-SUVmax for GR were 80.01% and 97.3%, and for pCR were 66.68% and 97.5%, respectively. The PPVs and NPVs of the RI values for GR were 84.61% and 94.87%, and for pCR were 69.24% and 100%, respectively. Conclusion: For LARC patients, the analysis of imaging parameters such as post-SUVmax and RI, which can reflect the changes of 18F-FDG uptake capacity of tumor tissues before and after nCRT, is of great value for predicting the response of patients to neoadjuvant therapy and guiding the selection of subsequent treatment strategies.

Screening of MicroRNA Related to Irradiation Response and the Regulation Mechanism of miRNA-96-5p in Rectal Cancer Cells.

Neoadjuvant chemoradiotherapy has been widely used in the treatment of locally advanced rectal cancer due to the excellent advantages of irradiation in cancer therapy. Unfortunately, not every patient can benefit from this treatment, therefore, it is of great significance to explore biomarkers that can predict irradiation sensitivity. In this study, we screened microRNAs (miRNAs) which were positively correlated with irradiation resistance and found that miRNA-552 and miRNA-183 families were positively correlated with the irradiation resistance of rectal cancer, and found that high expression of miRNA-96-5p enhanced the irradiation resistance of rectal cancer cells through direct regulation of the GPC3 gene and abnormal activation of the canonical Wnt signal transduction pathway. Based on the radioreactivity results of patient-derived xenograft models, this is the first screening report for radio-resistant biomarkers in rectal cancer. Our results suggest that miRNA-96-5p expression is an important factor affecting the radiation response of colorectal cancer cells.

Analysis of influencing factors of no/low response to preoperative concurrent chemoradiotherapy in locally advanced rectal cancer.

The aim of this study is to investigate the influencing factors associated with no/low response to preoperative concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer (LARC) patients. A total of 79 patients were included in this prospective study. Fifteen factors that might affect the resistance to CCRT were included in this logistic regression analysis, these factors include the general clinical data of patients, the expression status of tumor stem cell marker CD44v6 and the volumetric imaging parameters of primary tumor lesions. We found that the no/low response status to preoperative CCRT was positively correlated with the real tumor volume (RTV), the total surface area of tumor (TSA), and CD44v6 expression, whereas negatively correlated with the tumor compactness (TC). According to the results of logistic regression analysis, two formulas that could predict whether or not no/low response to preoperative CCRT were established. The Area Under Curve (AUC) of the two formulas and those significant measurement data (RTV, TC, TSA) were 0.900, 0.858, 0.771, 0.754, 0.859, the sensitivity were 95.8%, 79.17%, 62.50%, 95.83%, 62.5%, the specificity were 70.9%, 74.55%, 83.64%,47.27%, 96.36%, the positive predictive values were 58.96%, 57.58%, 62.51%,44.23%, 88.23%, the negative predictive values were 97.48%, 89.13%, 83.64%, 96.29%, and 85.48%, respectively.

Volumetric imaging parameters are significant for predicting the pathological complete response of preoperative concurrent chemoradiotherapy in local advanced rectal cancer.

Preoperative concurrent chemoradiotherapy (CCRT) as the standard treatment for locally advanced rectal cancer (LARC) has been widely used in clinic. Its efficiency influences the prognosis and the selection of subsequent treatment. The current criteria for evaluating the prognosis of patients with extremely sensitive preoperative CCRT include the clinical complete remission response (cCR) and pathological complete response (pCR), but those with cCR may not necessarily achieve pCR, and the pCR can be confirmed only after surgery. Some scholars believe that patients with pCR after CCRT can be categorized as 'watch and wait'. Therefore, it is extremely important to find a way to predict the pCR status of patients before therapy. In this study, we examined the expression of stem cell markers and obtained direct and derivative volumetric imaging parameters before treatment. Subsequently, these factors and the general clinical data were adopted into a regression model, and the correlation between them and the pCR was analyzed. We found that the pCR of LARC was positively correlated with tumor compactness (TC), whereas it was negatively correlated with approximate tumor volume (ATV), real tumor volume (RTV), total surface area of the tumor (TSA) and tumor maximum longitudinal length (TML). In these meaningful predictors, the positive predictive values and the negative predictive values of TC were 74.73% and 94.61%, respectively. Compared with other possible predictors, TC is the most encouraging predictor of pCR. Our findings provide a way for clinicians to predict the sensitivity of preoperative CCRT and will help to select individualized treatment options for LARC patients.

ADAMTS8 targets ERK to suppress cell proliferation, invasion, and metastasis of hepatocellular carcinoma.

INTRODUCTION: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors of the digestive system. A disintegrin and metallopeptidase with thrombospondin motif (ADAMTS) has been identified as a secreted metalloproteinase that participates in the inhibition of tumor cell growth and invasion. The aims of the present study were to investigate the clinical significance of ADAMTS8 in patients with HCC and to determine the effect of ADAMTS8 on HCC cell biological activity in vitro and in vivo. METHODS: The tumor tissues and matched adjacent non-tumor tissues were collected from 61 patients with HCC, and ADAMTS8 expression was detected with immunohistochemistry. Flow cytometry and MTT assays were used to assess cell apoptosis and cell viability, respectively, and ERK, p-ERK, Stat3, p-Stat3, Akt, and p-Akt protein expressions were measured by Western blot. RESULTS: The results showed that ADAMTS8 expression was significantly lower in HCC tissues than that in adjacent non-tumor tissues. Moreover, ADAMTS8 expression was inversely associated with clinical stages and metastasis in patients with HCC. Furthermore, we found that transfection with exogenous ADAMTS8 inhibited proliferation and migration and induced apoptosis in HepG2 cells. In the in vivo study, tumor growth of upregulated HepG2 cells in nude mice was significantly slower. Moreover, decreased ERK activity was detected after transfection with ADAMTS8. CONCLUSION: These results indicate that low ADAMTS8 expression is a predictor of a poor prognosis in patients with HCC and that ADAMTS8 plays an important role in regulating HCC growth, invasion, and apoptosis by modulating the ERK signaling pathway. ADAMTS8 maybe a new target in HCC treatment.

Comparison of elective nodal irradiation and involved-field irradiation in esophageal squamous cell carcinoma: a meta-analysis.

It remains controversial whether radical radiotherapy in patients with esophageal squamous cell carcinoma (ESCC) still requires elective nodal irradiation (ENI), or only involved-field irradiation (IFI). In this study, a meta-analysis was conducted to compare ENI and IFI in the treatment of ESCC, in order to provide guidance for clinical practice. Literature on the use of ENI and IFI in the treatment of ESCC was retrieved, and the last access date was 31 December 2017. A meta-analysis was performed to evaluate the relative advantages and disadvantages of using ENI and IFI. Ten studies, involving a total of 1348 patients, were included in this analysis; of these, 605 patients underwent radiotherapy only, and 743 underwent radiochemotherapy. There was no significant difference in the 1-, 2- or 3-year local control rates between ENI and IFI, or in the 1-, 2- or 3-year overall survival rates. However, the incidences of ≥Grade 3 acute esophagitis and pneumonia were significantly lower in the IFI group. There were no differences in the rates of ≥Grade 3 myelosuppression or of out-field recurrence or metastasis between these two groups. Thus, neither local control rates nor overall survival rates differed significantly between the ENI and IFI groups, but in the latter group, incidences of severe radiation esophagitis and pneumonia were significantly lower. IFI was not associated with an increase in out-field recurrence or metastasis.

[Lymph node metastasis patterns and influencing factors in patients with limited esophageal small cell carcinoma].

OBJECTIVE: To explore the patterns and influencing factors of lymph node metastasis in limited esophageal small cell carcinoma (PESCC). METHODS: A total of 98 limited stage PESCC patients who underwent surgery were selected for this study. The lymph node metastasis ratio at different sites, depth of invasion, tumor length and other factors were analyzed to assess their influence on lymph node metastasis. RESULTS: Among the 98 PESCC cases, 46 cases had lymph node metastasis (46.9%). 100 out of 833 lymph nodes had metastasis, with a metastasis ratio of 12.0%. For upper thoracic esophageal small cell carcinomas, lymph node metastasis ratios were 42.9%, 12.5%, 0 and 0 in the superior mediastinum, middle mediastinum, inferior mediastinum and abdominal cavity, respectively. In the middle thoracic PESCCs, the lymph node metastasis ratios were 18.8%, 7.7%, 15.7%, and 15.3%, respectively. In the lower thoracic PESCCs, the lymph node metastasis ratios were 0, 0, 27.3% and 23.5%, respectively. Lymph node metastasis rates in PESCCs at stages T1, T2, T3, T4 were 15.4%, 42.3%, 63.9%, and 80.0%, respectively. The lymph node metastasis ratios in PESCCs at stages T1, T2, T3, T4 were 2.0%, 8.3%, 17.8% and 25.0%, respectively. Lymph node metastasis rate and lymph node metastasis ratio at different T stages were of significant difference (P<0.05 for all). Lymph node metastasis rates in patients with tumor <3 cm, 3-5 cm, and >5 cm were 30.6%, 46.9% and 66.7%, respectively, and lymph node metastasis ratios were 5.4%, 11.0% and 21.1%, respectively. Lymph node metastasis rate and lymph node metastasis ratio in patients with different tumor length had significant differences (P<0.05 for all). Lymph node metastasis ratio was 11.6% in the Chr-A negative and weak positive group, much higher than 4.3% in the Chr-A positive group (P=0.013). There was a tendency that lymph node metastasis ratio of NSE-positive group was higher than that of NSE-negative and weak positive group (P=0.069). The logistic univariate analysis did not find high risk factors of distant lymph node metastasis (all P>0.05). Logistic multivariate analysis found that only depth of invasion was a risk factor of lymph node metastasis in limited PESCC (P=0.002). CONCLUSIONS: Esophagus small cell carcinomas sometimes have early lymph node metastases in many sites and distant range. The middle thoracic PESCCs tend to have extensive metastasis quite common in the upper mediastinal lymph nodes. Lower mediastinal and abdominal lymph node metastases are often seen in lower thoracic PESCCs. The depth of invasion and tumor length are main factors influencing mediastinal lymph node metastasis. The depth of invasion is an independent risk factor for lymph node metastasis.

[Relationship between hypoxia inducible factor-1α and esophageal squamous cell carcinoma: a meta analysis].

OBJECTIVE: To explore the expression of hypoxia inducible factor-1α(HIF-1α) in esophageal squamous cell carcinoma and its correlation with clinicopathological features. METHODS: Original literatures in foreign languages regarding correlation between HIF-1α and esophageal squamous cell carcinoma were identified from Cochrane Library, PubMed, EMbase database, and Chinese original literatures were from CBM, CNKI. All analyses were performed by Stata 11.0 software. Histological grade, degree of differentiation, T stage, lymph node metastasis, tumor stage, lymphatic invasion and vascular invasion were analyzed using pooled odds ratio (OR) with 95% confidence interval (CI). RESULTS: A total of 14 studies including 1 121 patients were enrolled in this meta analysis. Comparing with normal tissue, the expression of HIF-1α in esophageal squamous cell carcinoma was significantly enhanced (OR = 0.088, 95% CI: 0.061-0.129, P = 0.000); HIF-1α was significantly associated with T stage and lymph node metastasis (OR = 0.421, 95% CI: 0.222-0.798, P = 0.008; OR = 0.387, 95% CI: 0.207-0.725, P = 0.003). High expression of HIF-1α was correlated with an increased depth of tumor invasion, more lymph node metastasis and advanced tumor stage, whereas there was no relation to the degree of differentiation, histological grade, tumor stage, lymphatic invasion and vascular invasion. CONCLUSIONS: High expression of HIF-1α protein correlates with an increased risk of esophageal squamous cell carcinoma. HIF-1α may be an indicator for T stage, lymph node metastasis and tumor stage, but further studies are needed.

miR­210 regulates esophageal cancer cell proliferation by inducing G2/M phase cell cycle arrest through targeting PLK1.

micro (mi)RNAs are short regulatory RNAs that negatively modulate protein expression at the post­transcriptional level, and are being considered as novel therapeutic targets for the treatment of cancer. In the present study, an elevated expression level of circulating miR­210 was observed in patients with esophageal squamous cell carcinoma (ESCC) for the first time, to the best of our knowledge, and the induction of miR­210 under hypoxic conditions in ESCC was confirmed. Cell counting kit­8 assay and bromodeoxyuridine incorporation assay indicated that miR­210 markedly inhibited the proliferation of ESCC cells. In addition, the effect of miR­210 on the cell cycle was examined. Transfection of miR­210 resulted in a significant increase in the proportion of cells in G2/M phase. Polo­like kinase 1 (PLK1) was investigated as a candidate target of miR­210, which is a critical regulator of cell cycle transmission at multiple levels. It was demonstrated that miR­210 reduced the levels of PLK1 protein by binding the 3' untranslated region of its mRNA. The results of the present study demonstrated that miR­210 inhibited the proliferation of ESCC cells by inducing G2/M phase cell cycle arrest, and these effects of miR­210 were mediated by the targeting of PLK1.

Association of EMP1 with gastric carcinoma invasion, survival and prognosis.

The aim of this study was to determine the expression and function of epithelial membrane protein 1 (EMP1) in gastric carcinoma. Gastric samples were taken from cancer lesions and adjacent normal tissue in gastric cancer patients immediately after endoscopic biopsy. A portion of the sample was either fixed in 4% paraformaldehyde and embedded in paraffin for immunohistochemistry or stored in liquid nitrogen for western blotting. In order to determine protein expression of EMP1 in gastric cancer (n=65) and normal tissue (n=27), semi-quantitative immunohistochemistry and western blotting were utilized. For in vitro studies, the human gastric cancer cell line SGC-7901 was maintained in RPMI-1640 medium supplemented with 10% fetal bovine serum. Recombinant lentivirus mediated overexpression of EMP1 in SGC-7901 cells was quantified with quantitative polymerase chain reaction (qPCR) and western blotting. Control SGC-7901 cells were transfected with an empty vector. To further study the effect of EMP1 overexpression in SGC-7901 cells, cell proliferation, cell apoptosis and migration and invasion assays were conducted. The expression of EMP1 was significantly lower in gastric cancer tissue compared to normal tissue using both immunohistochemistry (41.5 vs. 70.4% of tissues, P<0.05) and western blotting (0.153 ± 0.012 vs. 0.626 ± 0.058, P<0.05). Decreased expression of EMP1 was significantly correlated with tumor invasion, lymph node metastasis, clinical stage and histological grade of patients with gastric cancer (P<0.05). According to Kaplan-Meier analysis, low EMP1 expression correlated significantly with poor overall 5-year survival (47.4 vs. 70.3% survival, P<0.05). SGC-7901 cells transfected with EMP1 had a lower survival fraction, higher cell apoptosis (13.2 ± 1.5% vs. 2.2 ± 0.5%, P<0.05), significant decrease in migration and invasion (157.0 ± 16.0 and 112.0 ± 12.0, respectively vs. 243.0 ± 21.0 and 203.0 ± 19.0, respectively, P<0.05), higher caspase-9 (0.501 ± 0.050 vs. 0.114 ± 0.010, P<0.05) and lower VEGFC protein expression 0.135 ± 0.011 vs. 0.619 ± 0.074, P<0.05) relative to cells not transfected with EMP1. Low EMP1 expression in gastric cancer is associated with increased disease severity, suggesting that EMP1 may be a negative regulator of gastric cancer.

Inhibiting UHRF1 expression enhances radiosensitivity in human esophageal squamous cell carcinoma.

Radiotherapy is an effective treatment for some esophageal cancers, but the molecular mechanisms of radiosensitivity remain unknown. Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) is a novel nuclear protein which is overexpressed in various cancers but not yet examined in esophageal squamous cell carcinoma (ESCC). The correlation between UHRF1 and the radioresistance in ESCC is still unclear. In the present study, the expression of UHRF1 was examined by immunohistochemistry in specimens of ESCC patients treated with radiotherapy. The results showed that UHRF1 was significantly overexpressed in ESCC specimens. Overexpression of UHRF1 correlated significantly with advanced T-stage, positive lymph node metastasis and poor differentiation. In addition, UHRF1 was associated with radiotherapy response, in which overexpression of UHRF1 was observed more frequently in the radioresistant group than in the effective group. At the molecular level, inhibition of UHRF1 by lentivirus-mediated shRNA targeting UHRF1 increased the radiosensitivity and apoptosis, while decreased radiation-induced G2/M phase arrest in TE-1 cells. Moreover, inhibition of UHRF1 resulted in higher residual γH2AX expression after irradiation, but not initial γH2AX. Further study showed that inhibition of UHRF1 down-regulated the endogenous expressions of DNA repair protein Ku70 and Ku80 in TE-1 cells, and significantly inhibited the increase of these proteins after irradiation. Above all, our data suggested that UHRF1 might play an important role in radioresistance of ESCC, and inhibition of UHRF1 can increase the radiosensitivity of TE-1 cells by altering cell cycle progression, enhancing apoptosis, and decreasing DNA damage repair capacity.

Effect of nitric oxide on esophageal cancer cell line TE-1.

OBJECTIVE: To investigate the radiosensitizing effect of nitric oxide (NO) combined with radiation on esophageal cancer cell line TE-1. METHODS: Methyl thiazolyl tetrazolium (MTT) assay was used to assess the effects of NO and radiation on TE-1 cells regarding inhibition of cell proliferation. Flow cytometry was used to examine the effect of NO and radiation on cell apoptosis and cycle. Reverse transcription polymerase chine reaction and Western blot were used to evaluete the effect of NO on mRNA and protein expression of manganese superoxide dismutase (MnSOD). RESULTS: NO inhibited the proliferation of TE-1 cells while significantly enhancing their radiosensitivity. The application of NO combined with radiation significantly increased the apoptosis rate and G2/M phase proportion of TE-1 cells, with substantial decreases in the MnSOD mRNA and protein expression levels. CONCLUSIONS: NO reduces the MnSOD mRNA and protein expression levels by affecting TE-1 cell cycle, further inhibiting the apoptosis of esophageal cancer cells and enhancing the killing effect of radiation on esophageal cancer cells.

Characteristics of recurrence after radical esophagectomy with two-field lymph node dissection for thoracic esophageal cancer.

Postoperative radiotherapy has shown positive efficacy in lowering the recurrence rate and improving the survival rate in cases involving lymph node (LN) metastasis. However, the radiotherapy target volume remains controversial. Certain published studies have paid more attention to LNs found to be affected during surgery, while little effort has been made to study the LN metastatic pattern following surgery and its influence on the determination of the target volume of postoperative radiotherapy. In this study, the locoregional recurrence of esophageal squamous cell cancer was examined in 134 patients receiving radical surgery with two-field lymph node dissection from 2004 to 2009. In the 134 cases of recurrence, LN metastasis occurred in 126 patients (94.0%) while 13 patients (9.7%) developed anastomotic recurrence and 5 patients (3.7%) experienced tumor bed recurrence. The difference among the groups was statistically significant (P= 0.000). In the 126 cases with lymph node metastasis, the mediastinal metastasis rate (80.2%) was significantly higher compared with the rate of supraclavicular metastasis and abdominal metastasis (P= 0.000). A significant difference was identified between right and left supraclavicular LN metastasis (31.7% vs 16.7%, P= 0.005). Furthermore, the difference between the metastatic rates in the upper (73.8%), middle (39.7%) and lower mediastinum (1.6%) was statistically significant (P=0.000). Nevertheless, no significant correlation between the rate of LN metastasis was observed in the supraclavicular, mediastinal and abdominal regions for upper, middle and lower thoracic carcinomas (P= 0.404, P= 0.718 and P= 0.169, respectively). Based on our data, LN metastasis is the major locoregional recurrence pattern for esophageal squamous cell cancer following radical surgery. The high-risk lymphatic drainage areas include the supraclavicular nodes, recurrent laryngeal nerve nodes, azygos nodes and subcarinal nodes.

HIF-1α contributes to hypoxia-induced invasion and metastasis of esophageal carcinoma via inhibiting E-cadherin and promoting MMP-2 expression.

Hypoxia-inducible factor-1α (HIF-1α) has been found to enhance tumor invasion and metastasis, but no study has reported its action in esophageal carcinoma. The goal of this study was to explore the probable mechanism of HIF-1α in the invasion and metastasis of esophageal carcinoma Eca109 cells in vitro and in vivo. mRNA and protein expression of HIF-1α, E-cadherin and matrix metalloproteinase-2 (MMP-2) under hypoxia were detected by RT-PCR and Western blotting. The effects of silencing HIF-1α on E-cadherin, MMP-2 mRNA and protein expression under hypoxia or normoxia were detected by RT-PCR and Western blotting, respectively. The invasive ability of Eca109 cells was tested using a transwell chambers. We established an Eca109-implanted tumor model and observed tumor growth and lymph node metastasis. The expression of HIF-1α, E-cadherin and MMP-2 in xenograft tumors was detected by Western blotting. After exposure to hypoxia, HIF-1α protein was up-regulated, both mRNA and protein levels of E-cadherin were down-regulated and MMP-2 was up-regulated, while HIF-1α mRNA showed no significant change. SiRNA could block HIF-1α effectively, increase E-cadherin expression and inhibit MMP-2 expression. The number of invading cells decreased after HIF-1α was silenced. Meanwhile, the tumor volume was much smaller, and the metastatic rate of lymph nodes and the positive rate were lower in vivo. Our observations suggest that HIF-1α inhibition might be an effective strategy to weaken invasion and metastasis in the esophageal carcinoma Eca109 cell line.

Bidirectional regulation of manganese superoxide dismutase (MnSOD) on the radiosensitivity of esophageal cancer cells.

The mitochondrial antioxidant protein manganese superoxide dismutase (MnSOD) may represent a new type of tumor suppressor protein. Overexpression of the cDNA of this gene by plasmid or recombinant lentiviral transfection in various types of cancer leads to growth suppression both in vitro and in vivo. We previously determined that changes in MnSOD expression had bidirectional effects on adriamycin (ADR) when combined with nitric oxide (NO). Radiation induces free radicals in a manner similar to ADR, so we speculated that MnSOD combined with NO would also have a bidirectional effect on cellular radiosensitivity. To examine this hypothesis, TE-1 human esophageal squamous carcinoma cells were stably transfected using lipofectamine with a pLenti6-DEST plasmid containing human MnSOD cDNA at moderate to high overexpression levels or with no MnSOD insert. Blastidicin-resistant colonies were isolated, grown, and maintained in culture. We found that moderate overexpression of MnSOD decreased growth rates, plating efficiency, and increased apoptosis. However, high overexpression increased growth rates, plating efficiency, and decreased apoptosis. When combined with NO, moderate overexpression of MnSOD increased the radiosensitivity of esophageal cancer cells, whereas high MnSOD overexpression had the opposite effect. This finding suggests a potential new method to kill certain radioresistant tumors and to provide radioresistance to normal cells.

[Effect of HIF-1α and its mechanism on invasion and metastasis of esophageal carcinoma Eca109 cells in vitro and in vivo].

AIM: To investigate the effects of HIF-1α by RNAi on invasion and metastasis of esophageal carcinoma Eca109 cells in vitro and in vivo, in order to explore its probable mechanism. METHODS: CoCl(2); was used to mimic tumor hypoxic microenvironment. mRNA and protein levels of HIF-1α, E-cadherin and MMP-2 under hypoxia were detected by RT-PCR and immunohistochemistry. The effects of silencing HIF-1α by RNAi on HIF-1α, E-cadherin and MMP-2 mRNA were detected by RT-PCR. The effect of RNAi on invasion and metastasis were tested by cell scratch assay and transwell chambers. The Eca109-implanted nude mouse model was established, and the effects of HIF-1αon tumor growth and lymphoid node metastasis were observed. The expressions of HIF-1α, E-cadherin and MMP-2 in transplanted tumors were detected by Western blot, and the effects of HIF-1α on tumor growth, invasion and metastasis in vitro and in vivo were analyzed. RESULTS: Hypoxia up-regulated HIF-1α protein, mRNA and protein levels of E-cadherin down-regulated, and MMP-2 up-regulated, while had no effect on HIF-1α mRNA . RNAi could silencing HIF-1α effectively, and inhibited E-cadherin or MMP-2 decreased or increased, respectively. The migration and the number of invading cells decreased (P<0.05) after silencing HIF-1α by RNAi. The tumor volume was much smaller, lymph node metastasis rate lower as well in vivo (P<0.05). CONCLUSION: Via its effects on E-cadherin and MMP-2, HIF-1α regulate the growth, invasion and metastasis of Eca109 cells in vitro and in vivo.