Manganese Superoxide Dismutase Gene-Modified Mesenchymal Stem Cells Attenuate Acute Radiation-Induced Lung Injury.

Radiation-induced lung injury (RILI) is a major clinical complication for radiotherapy in thoracic tumors. An immediate effect of lung irradiation is the generation of reactive oxygen that can produce oxidative damage to DNA, lipids, and proteins resulting in lung cell injury or death. Currently, the medical management of RILI remains supportive. Therefore, there is an urgent need for the development of countermeasures. The present study aimed to evaluate the protective effect of manganese superoxide dismutase (MnSOD) gene-modified mesenchymal stem cells (MSCs) to facilitate the improved recovery of RILI. Here, nonobese diabetic/severe combined immunodeficiency mice received a 13 Gy dose of whole-thorax irradiation, and were then transfused intravenously with MnSOD-MSCs and monitored for 30 days. Lung histopathologic analysis, plasma levels of inflammatory cytokines (interleukin [IL]-1, IL-6, IL-10, and tumor necrosis factor-α), profibrotic factor transforming growth factor-ß1, and the oxidative stress factor (hydroxyproline) were evaluated after MnSOD-MSC transplant. Apoptotic rates were evaluated by terminal deoxynucleotidyl transferase-mediated nick-end labeling immunohistochemical method. Colonization and differentiation of MnSOD-MSCs in the irradiated lung were analyzed by immunofluorescence staining. Consequently, systemic administration of MnSOD-MSCs significantly attenuated lung inflammation, ameliorated lung damage, and protected the lung cells from apoptosis. MnSOD-MSCs could differentiate into epithelial-like cells in vivo. MnSOD-MSCs were effective in modulating RILI in mice and had great potential for accelerating from bench to bedside.

Classification, clinicopathologic features and treatment of gastric neuroendocrine tumors.

Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor types of varying pathogenesis, histomorphologic characteristics, and biological behavior. A classification system has been proposed that distinguishes four types of GNETs; the clinicopathological features of the tumor, its prognosis, and the patient's survival strictly depend on this classification. Thus, correct management of patients with GNETs can only be proposed when the tumor has been classified by an accurate pathological and clinical evaluation of the patient. Recently developed cancer therapies such as inhibition of angiogenesis or molecular targeting of growth factor receptors have been used to treat GNETs, but the only definitive therapy is the complete resection of the tumor. Here we review the literature on GNETs, and summarize the classification, clinicopathological features (especially prognosis), clinical presentations and current practice of management of GNETs. We also present the latest findings on new gene markers for GNETs, and discuss the effective drugs developed for the diagnosis, prognosis and treatment of GNETs.

[Expression of Foxa2 and its early alarm value of cancerous in gastric polyps].

OBJECTIVE: To explore the expression of Foxa2 in different pathological types of gastric polyps and examine the correlation with cancerous risk. METHODS: According to computerize random number, a total of 2000 patients were selected to receive endoscopic biopsy during November 2011 to October 2012. Tissues were harvested from 170 with gastric polyps and suspicious cancerous lesions and their histological types detected. There were hyperplastic polyps(n = 35), adenomatous polyps(n = 31), fundic gland polyps(n = 42), advanced gastric cancer tissues (n = 32)and normal gastric mucosa tissues (n = 30). ABC immunohistochemical staining and reverse transcription(RT)-PCR were employed to detect the expression of Foxa2 in these different types of tissues. Imagepro plus was used for quantitative and statistical analyses. RESULTS: A low-level expression of Foxa2 was 3.6% ± 1.3% in normal gastric mucosa group. And its expreesion gradually higher in proliferative inflammatory polyp group(33.1% ± 8.0%), adenomatous polyp group (71.4% ± 1.7%) and gastric cancer group(96.3% ± 0.9%, all P < 0.05). Its expression was 35.6% ± 5.6% in fundic gland polyps, similar to that of proliferative inflammatory polyp group (P > 0.05), it was markedly lower than the gastric cancer group (P < 0.05) and higher than the normal gastric mucosa group (P < 0.05). Correlation analyses of clinicopathological parameters showed that no significant correlation existed between its expression and patient gender, age, predilection, Helicobacter. pylori infection or proton pump inhibitor used (all P > 0.05). However, the size of polyps was correlated with Foxa2 (rs = 0.69, P < 0.05). CONCLUSION: The expression level of Foxa2 in different types of gastric polyps may be used as a clinical predicator of polyps risk.

Manganese superoxide dismutase gene therapy protects against irradiation- induced intestinal injury.

Radiation-induced intestinal injury is a common complication in radiotherapy for solid organ malignancies in abdomen or pelvis. However, currently there are no approved medical countermeasures for radiation-induced intestinal injury. Therefore, it is urgent to develop new treatments for radiation-induced intestinal injury. In the present study, we demonstrated that bone marrow derived mesenchymal stem cells (MSCs) and overexpression of human manganese superoxide dismutase (MnSOD) could ameliorate radiation-induced intestinal syndrome. NOD/SCID mice received abdominal irradiation at a selected dose of 5 Gy, and then infused intravenously with MnSOD-MSCs. Mice body weight, survival and diarrhea were monitored for 30-days. Colonization and differentiation of MnSOD-MSCs in the irradiated intestine were analyzed by histological and immunohistochemical methods. Consequently, our data demonstrated that intravenous administration of MnSOD-MSCs improved survival, decreased diarrhea occurrence and protected the small intestinal structural integrity of irradiated mice. Moreover, intravenously transplanted MnSOD-MSCs could colonize the irradiated intestine and repair injured sites. These findings suggested that MnSOD-MSCs may be an attractive and potential option for radiation-induced intestinal injury.

[Differential proteomic analysis of rat hepatic stellate cells treated by oxymatrine liposomes using two-dimensional electrophoresis].

OBJECTIVE: To analyze differentially expressed proteins of hepatic stellate cells (HSCs) treated with oxymatrine (OMT) liposomes, thus further exploring the molecular mechanism of OMT liposomes for treating liver fibrosis. METHODS: A rat model of CCl4 induced chronic liver fibrosis was established. HSCs were perfusion isolated from modeled SD rats and cultured in vitro . Passage 2 HSCs were divided into the model group (Group A), the OMT-liposome-treated group (Group B), and the liposome-treated control group (Group C). HSCs from normal rats were taken as the normal control group (Group D). The total proteins of HSCs cells were extracted from Group B and D after 7 days of treatment, and separated with isoelectrofocusing two-dimensional electrophoresis (2-DE). A 2-DE system was established to analyze the differences in the protein profile between Group B and Group C. Tow protein dots with most obvious difference were selected to determine the structures and functions of different proteins using peptide mass fingerprinting (PMF). RESULTS: (1) The total number bf proteins decreased after treated with OMT liposomes, with 864 spots before treatment and 756 spots after treatment, and the matching rate was 63%. (2) According to 2-DE results, 10 differential protein spots were found by image analysis of magnifying images in local regions. (3) Two most differently expressed proteins were identified to be ATM (46. 236 kD) and Miz1 (54. 051 kD) by PMF and SWISS-PROT protein database retrieval. CONCLUSION: Action of OMT liposomes on HSCs of rats with chronic liver fibrosis caused different protein expressions, which might be involved in the signaling pathways of inducing the apoptosis of HSCs.

[Oxymatrine could promote mesenchymal stem cell therapy in hepatic fibrosis rats: an experimental research].

OBJECTIVE: To investigate whether oxymatrine (OM) could promote mesenchymal stem cell (MSC) therapy in CCl4-induced hepatic fibrosis (HF) in rats and to initially explore its mechanisms. METHODS: Totally 50 male SD rats were randomly divided into five groups,i.e., the normal control group, the model group, the MSC therapy group, the OM therapy group, and the MSC combined OM therapy group, 10 in each group. Except the normal control group, the HF model was duplicated by CCl4 induction. After successful modeling, rats in the MSC therapy group received 5 x10(6) MSCs by intravenous injection via caudal vein, once a week. Rats in the OM therapy group received 50 mg/kg OM by intramuscular injection, three times a week. Rats in MSC combined OM therapy group received 5 x 10(6) MSCs by intravenous injection via caudal vein, once a week and 50 mg/kg OM by intramuscular injection three times a week. Equal volume of normal saline was given to those in the normal control group and the model group. All medication lasted for 8 weeks. Serum levels of ALT and AST were detected 8 weeks later. The hepatic histopathological injury and extracellular matrix deposit were assessed using HE and Masson staining. Expressions of serum interleukin-4 (IL-4) and interleukin-10 (IL-10) were detected using enzyme linked immunosorbent assay (ELISA). RESULTS: (1) Compared with the normal control group, serum levels of ALT and AST significantly increased in the model group (P < 0.05). Compared with the model group, serum levels of ALT and AST significantly decreased in the OM therapy group, the MSC therapy group, and the MSC combined OM therapy group at the end of 8 weeks of treatment (P < 0.05). But serum levels of ALT and AST were significantly lower in the MSC combined OM therapy group than in the OM therapy group and the MSC therapy group (P < 0.05). (2) Compared with the model group, the hepatic injury was significantly lessened and the area of extracellular matrix deposit was significantly reduced in the OM therapy group, the MSC therapy group, and the MSC combined OM therapy group (P < 0.05). Besides, they wer more significant in the MSC combined OM therapy group (P < 0.05). (3) Compared with the model group, the serum IL-4 level was significantly higher in the MSC therapy group and the MSC combined MO group (P < 0.05). It was higher in the MSC combined MO group (P < 0.05). Although the serum IL-4 level also increased in the OM therapy group, but with no statistical difference (P > 0.05). (4) The serum IL-10 level significantly increased in the OM therapy group, the MSC therapy group, and the MSC combined OM therapy group (P < 0.05), and it was the highest in the MSC combined OM therapy group among the three groups (P < 0.05). (5) Two-photon fluorescence imaging showed no signals of MSCs in liver with or without OM injection. CONCLUSION: OM could promote mesenchymal stem cell therapy in hepatic fibrosis rats, which might be involved in increasing serum levels of IL-4 and IL-10.

Suppression of CB1 cannabinoid receptor by lentivirus mediated small interfering RNA ameliorates hepatic fibrosis in rats.

It is recognized that endogenous cannabinoids, which signal through CB1 receptors in hepatic stellate cells (HSCs), exert a profibrotic effect on chronic liver diseases. In this study, we suppressed CB1 expression by lentivirus mediated small interfering RNA (CB1-RNAi-LV) and investigated its effect on hepatic fibrosis in vitro and in vivo. Our results demonstrated that CB1-RNAi-LV significantly inhibited CB1 expression, and suppressed proliferation and extracellular matrix production in HSCs. Furthermore, CB1-RNAi-LV ameliorated dimethylnitrosamine induced hepatic fibrosis markedly, which was associated with the decreased expression of mesenchymal cell markers smooth muscle α-actin, vimentin and snail, and the increased expression of epithelial cell marker E-cadherin. The mechanism lies on the blockage of Smad signaling transduction induced by transforming growth factor ß1 and its receptor TGF-ß RII. Our study firstly provides the evidence that CB1-RNAi-LV might ameliorate hepatic fibrosis through the reversal of epithelial-to-mesenchymal transition (EMT), while the CB1 antagonists AM251 had no effect on epithelial-mesenchymal transitions of HSCs. This suggests that CB1 is implicated in hepatic fibrosis and selective suppression of CB1 by small interfering RNA may present a powerful tool for hepatic fibrosis treatment.

[The value of serum intestinal fatty acid binding protein measurement in discriminating intestinal ischemia in patients with acute abdomen].

OBJECTIVE: To assess the differential diagnostic value of serum intestinal fatty acid binding protein (I-FABP) in distinguishing intestinal ischemia patients from acute abdomen patients. METHODS: A total of 151 patients with acute abdomen and 17 healthy controls from the PLA General Hospital were enrolled from November, 2009 to August, 2011. Serum I-FABP levels were measured by ELISA. According to the ROC curve, the cut-off value, sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: Of the 151 acute abdomen patients, there were 24 intestinal ischemia patients and 127 without intestinal ischemia. Serum I-FABP level in intestinal ischemia group [(109.67 ± 48.82) µg/L] was significantly higher than those in patients without intestinal ischemia [(36.78 ± 11.25) µg/L] and healthy controls[(8.33 ± 6.25) µg/L](all P values < 0.01). The serum I-FABP cut-off value for the diagnosis of intestinal ischemia was 87.52 µg/L. Serum I-FABP was efficient in terms of sensitivity (0.762), NPV(0.963), PLR(3.05) and NLR (0.24) in the diagnosis of intestinal ischemia. CONCLUSION: I-FABP is potentially useful for discriminating intestinal ischemia from acute abdomen.

Oxymatrine liposome attenuates hepatic fibrosis via targeting hepatic stellate cells.

AIM: To investigate the potential mechanism of Arg-Gly-Asp (RGD) peptide-labeled liposome loading oxymatrine (OM) therapy in CCl4-induced hepatic fibrosis in rats. METHODS: We constructed a rat model of CCl4-induced hepatic fibrosis and treated the rats with different formulations of OM. To evaluate the antifibrotic effect of OM, we detected levels of alkaline phosphatase, hepatic histopathology (hematoxylin and eosin stain and Masson staining) and fibrosis-related gene expression of matrix metallopeptidase (MMP)-2, tissue inhibitor of metalloproteinase (TIMP)-1 as well as type I procollagen via quantitative real-time polymerase chain reaction. To detect cell viability and apoptosis of hepatic stellate cells (HSCs), we performed 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay and flow cytometry. To reinforce the combination of oxymatrine with HSCs, we constructed fluorescein-isothiocyanate-conjugated Arg-Gly-Asp peptide-labeled liposomes loading OM, and its targeting of HSCs was examined by fluorescent microscopy. RESULTS: OM attenuated CCl4-induced hepatic fibrosis, as defined by reducing serum alkaline phosphatase (344.47 ± 27.52 U/L vs 550.69 ± 43.78 U/L, P < 0.05), attenuating liver injury and improving collagen deposits (2.36% ± 0.09% vs 7.70% ± 0.60%, P < 0.05) and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen (P < 0.05). OM inhibited cell viability and induced apoptosis of HSCs in vitro. RGD promoted OM targeting of HSCs and enhanced the therapeutic effect of OM in terms of serum alkaline phosphatase (272.51 ± 19.55 U/L vs 344.47 ± 27.52 U/L, P < 0.05), liver injury, collagen deposits (0.26% ± 0.09% vs 2.36% ± 0.09%, P < 0.05) and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen (P < 0.05). Moreover, in vitro assay demonstrated that RGD enhanced the effect of OM on HSC viability and apoptosis. CONCLUSION: OM attenuated hepatic fibrosis by inhibiting viability and inducing apoptosis of HSCs. The RGD-labeled formulation enhanced the targeting efficiency for HSCs and the therapeutic effect.

In vivo transplantation of bone marrow mesenchymal stem cells accelerates repair of injured gastric mucosa in rats.

BACKGROUND: Adult stem cells provide a promising alternative for the treatment of injured tissues. We aimed to investigate the effect of in vivo transplantation of bone marrow mesenchymal stem cells (BMMSCs) on injured gastric mucosa in rats. METHODS: The gastric ulcer in rats was induced by indomethacin. BMMSCs from male rats, labeled with the fluorescent cell linker 5,6-carboxyfluorescein diacetate succinimidyl ester (CFDA SE), were transplanted into the female rats via tail vein injection. The healing process of gastric ulcers was monitored by HE staining. The protein levels of vascular endothelial growth factor (VEGF) and the epidermal growth factor receptor (EGFR) in the injured gastric mucosa were determined by immunohistochemistry. RESULTS: At 48 and 72 hours after BMMSCs transplantation, the CFDA SE labeled cells were found scattered in the injured gastric mucosa, but not in the gastric mucosa of control rats. At 72 hours after BMMSCs transplantation, the mean ulcer index was 12.67 ± 2.16 in the BMMSCs transplanted group and 17.33 ± 1.97 in vehicle-treated controls (P < 0.01). Both VEGF and EGFR protein expression levels were significantly higher in the gastric section from the rats that received BMMSCs transplantation as compared to rats without BMMSCs transplantation. CONCLUSION: Autologous BMMSCs transplantation can accelerate gastric ulcer healing in injured gastric mucosa in a rodent model.

Magnifying endoscopy in upper gastroenterology for assessing lesions before completing endoscopic removal.

Any prognosis of gastrointestinal (GI) cancer is closely related to the stage of the disease at diagnosis. Endoscopic submucosal dissection (ESD) and en bloc endoscopic mucosal resection (EMR) have been performed as curative treatments for many early-stage GI lesions in recent years. The technologies have been widely accepted in many Asian countries because they are minimally invasive and supply thorough histopathologic evaluation of the specimens. However, before engaging in endoscopic therapy, an accurate diagnosis is a precondition to effecting the complete cure of the underlying malignancy or carcinoma in situ. For the past few years, many new types of endoscopic techniques, including magnifying endoscopy with narrow-band imaging (ME-NBI), have emerged in many countries because these methods provide a strong indication of early lesions and are very useful in determining treatment options before ESD or EMR. However, to date, there is no comparable classification equivalent to "Kudo's Pit Pattern Classification in the colon", for the upper GI, there is still no clear internationally accepted classification system of magnifying endoscopy. Therefore, in order to help unify some viewpoints, here we will review the defining optical imaging characteristics and the current representative classifications of microvascular and microsurface patterns in the upper GI tract under ME-NBI, describe the accurate relationship between them and the pathological diagnosis, and their clinical applications prior to ESD or en bloc EMR. We will also discuss assessing the differentiation and depth of invasion, defying the lateral spread of involvement and targeting biopsy in real time.

[Preparation and identification of monoclonal antibody against human GCRG213].

AIM: To prepare and characterize the monoclonal antibody against human GCRG213. METHODS: The HIS-GCRG213 fusion protein was expressed in E.coli. Mice were immunized with the purified HIS-GCRG213 protein. Hybridoma cell lines secreting monoclonal antibodies against GCRG213 were screened by regular cell fusion and subcloning approach. The titer and specificity of the antibody was characterized by ELISA and Western blot, respectively. The expression of GCRG213 was determined using immunohistochemistry technique on paraffin-embedded tissue sections from normal gastric mucosal tissues and advanced gastric cancer. RESULTS: The HIS-GCRG213 fusion protein with relative molecular mass of 20 800 was over expressed in E.coli. Two hybridoma cell lines which secreted monoclonal antibody specifically against human GCRG213 fusion protein were successfully obtained. The ascite titers of this monoclonal antibody reached 1:10(6);. Western blot analysis showed that the monoclonal antibody could bind to the recombinant HIS-GCRG213 protein specifically.The immunohistochemistry showed that GCRG213 were expressed higher in gastric cancer tissues than in normal ones. CONCLUSION: The monoclonal antibody against human GCRG213 with high titer and specificity has been successfully prepared, which could be utilized as a useful reagent for further studying the biological function of the GCRG213.

Integrin alphavbeta6 promotes tumor tolerance in colorectal cancer.

Tumor immune tolerance plays a critical role in tumor cell survival; the establishment of tumor immune tolerance is incompletely understood yet. Integrin alphavbeta6 (avb6) is involved in tumor growth and metastasis. This study aimed to observe the effect of avb6 on the development of tumor tolerance in colorectal cancer (CRC). In this study, 28 CRC patients were recruited. The frequencies of tolerogenic dendritic cells (TolDC), regulatory T cells (Treg), and CD8+ T cells in surgically removed CRC tissue were assessed by flow cytometry. The levels of avb6 in CRC tissue were measured by enzyme-linked immunoassay (ELISA). The effect of avb6 on inducing TolDCs and Tregs was evaluated with the cell culture model. The results showed that in surgically removed CRC tissue, we detected higher frequencies of TolDC and Tregs, lower frequency CD8+ T cells and high levels of avb6 as compared with non-CRC tissue. CRC protein extracts could induce TolDC development that could be blocked by anti-avb6 antibody. CRC-derived DCs could convert naïve CD4+ T cells to Tregs. Peripheral CD8+ T cells from CRC patients still retained the ability to produce granzyme B and to proliferate in response to CRC tumor antigen in culture that was abolished by the presence of CRC-derived Tregs. We conclude that CRC-derived avb6 is involved in the establishment of tumor immune tolerance in local tissues.

Th17 cells are increased with severity of liver inflammation in patients with chronic hepatitis C.

BACKGROUND AND AIM: As a newly identified subset of T helper cells, T-helper 17 cells (Th17) are major mediators of inflammation-associated disease. Some reports have revealed significantly increased Th17 cells in hepatitis B virus-infected patients, and a recent study has demonstrated that hepatitis C virus (HCV)-specific Th17 cells can be induced in vitro and regulated by transforming growth factor-ß. This study attempted to characterize the role of Th17 cells in the disease progression of chronic hepatitis C (CHC). METHODS: The current study enrolled 53 patients with CHC and 23 healthy controls, in which the circulating and liver-infiltrating Th17 cells were monitored. RESULTS: We found that CHC patients had increased proportions of both circulating and liver-infiltrating Th17 cells compared to healthy individuals, and both measures of Th17 cells were correlated with severity of liver inflammation. We further demonstrated that the HCV-specific Th17 cells were correlated with liver damage but not HCV viral replication. CONCLUSIONS: Such a correlation between the severity of liver damage of CHC and Th17 cells illustrated in this study sheds some light on the understanding of the pathogenesis of CHC.

[A retrospective analysis of clinical characteristics and mortality of gastrointestinal bleeding in 414 elderly patients].

OBJECTIVE: To analyze clinical characteristics of patients with gastrointestinal bleeding (GIB) and the death-related risk factors. METHODS: A retrospective analysis was conducted in 414 patients hospitalized for GIB during a 16-year period of 1994 to 2009. Logistic regression analysis identified predictors of mortality. RESULTS: The mean age of the 414 patients is 83.5 years old, ranging from 65 to 96 years old. The main causes of GIB were peptic ulcer (33.1%, 137/414), gastroduodenal mucosal erosion (28.5%, 118/414) and tumor (21.0%, 87/414). The main symptom was melena (71.0%, 294/414). Drugs that induced GIB were mainly non-steroidal anti-inflammatory drugs, including aspirin (11.1%, 46/414), acetaminophen (8.9%, 37/414) and indomethacin (1.9%, 8/414). 14% of patients (58/414) died of GIB in 30 days. The proportion of drug-induced GIB and gastroduodenal mucosal erosion caused GIB had increased significantly during the period of 2004 to 2009 (P < 0.05). Analysis of 30-day mortality risk showed advanced age, low diastolic blood pressure, high heart rate, low hemoglobin levels at presentation and hemorrhage volume in dead GIB elderly patients were significantly different compared with GIB elderly patients alive. Presence of severe comorbidity (heart failure and renal failure) and caused by cirrhosis and portal hypertension in GIB elderly patients were the only independent predictors of 30-day mortality (P < 0.001). CONCLUSIONS: Death of GIB patients occurred predominantly in elderly patients with severe comorbidities and systemic conditions at presentation.

[Factors for the recurrence after endoscopic resection of early gastric cancer].

OBJECTIVE: To investigate the related factors of recurrence of early gastric cancer (EGC) after endoscopic resection. METHODS: Clinicopathologic data of 169 patients with EGC who underwent endoscopic resection and periodically followed up by the Chinese PLA General hospital were analyzed retrospectively. RESULTS: During a follow-up of 13 - 57 months (median time 24.5 months), 12 patients had gastric cancer again and the recurrence rate was 7.1% (12/169). The recurrence time varied from 3 to 36 (28 ± 23) months and the median time was 18 months. The recurrence rates of 0.5 year, 1(st) year, 2(nd) year and 3(rd) year were 1.18% (2/169), 3.55% (6/169), 9.91% (11/111) and 12.24% (12/98), respectively. Eleven patients had gastric cancer again within 2 years after resection. Undifferentiated histology (including poorly differentiated carcinoma and signet ring cell carcinoma), submucosal infiltration and lymphovascular invasion of the primary lesion of EGC were related to the postsurgical recurrence (all P < 0.05). CONCLUSION: Most recurrence of EGC occurred within 2 years after endoscopic resection and is related with undifferentiated histology, submucosal infiltration and lymphovascular invasion. It is important for these patients to receive endoscopy follow up.

Immunoglobulin kappa and immunoglobulin lambda are required for expression of the anti-apoptotic molecule Bcl-xL in human colorectal cancer tissue.

OBJECTIVE: Aberrant expression of immunoglobulin (Ig) by cancer cells has been documented in a number of malignant tumors but its biological significance is unclear. Cancer cells overexpress anti-apoptotic molecules such as Bcl-xL. The present study aimed to examine the role of expression of Ig light-chain Igk and Iglambda in maintaining the high levels of Bcl-xL in colorectal cancer cells. MATERIAL AND METHODS: Thirty patients with colorectal cancer were recruited to this study. Expression of Igk, Iglambda and Bcl-xL in surgically removed cancer tissue was examined by immunohistochemistry and/or flow cytometry. Using the HT29 cell line as a study platform, RNA interference (RNAi) was employed to knock out the genes of Igk and Iglambda in the cancer cell line; the expression of Bcl-xL in HT29 cells was subsequently analyzed. RESULTS: Human colorectal cancer cells, but not normal colorectal tissue, expressed both Igk and Iglambda in the cytoplasm. High levels of Bcl-xL were detected in cancer cells. Using RNAi to knock out the genes of Igk and/or Iglambda, Bcl-xL expression in HT29 cells was significantly suppressed and the cells became apoptotic. CONCLUSION: The results suggest that expression of Igk and Iglambda is required to stabilize Bcl-xL expression in cancer cells.

[Preparation, identification and preliminary application of the polyclonal antibody against gastric cancer-related protein GCRG224].

AIM: To prepare the polyclonal antibody against gastric cancer-related protein GCRG224. METHODS: The thioredoxin/GCRG224 fusion protein was expressed in E.coli. The polyclonal antibody against GCRG224 was obtained by immunizing a rabbit with the purified GCRG224 protein. The titer and specificity of the antibody were determined by ELISA and Western blot, respectively. The expression of GCRG224 in paraffin-embedded tissue sections from normal gastric mucosal tissues and advanced gastric cancer was determined using immunohistochemistry technique. RESULTS: The thioredoxin/GCRG224 fusion protein with relative molecular mass of 16.8 kDa was over-expressed in E.coli. The purity of the expressed product directly purified from a denaturing polyacrylamide gel was about 100%. The polyclonal antibody against GCRG224 was prepared. ELISA detection proved the titer of antiserum against GCRG224 was about 1:256,000. Western blot analysis showed that the antiserum could bind to the expressed fusion protein specifically. GCRG224 was found to have higher expression in gastric cancer tissues than in normal ones by immunohistochemistry. CONCLUSION: The successful preparation of the polyclonal antibody against GCRG224 lays a foundation for further study of the biological function and the possible role of GCRG224 in the development of gastric carcinoma.

[Expression of S100A6 in primary and metastatic human gastric cancer].

OBJECTIVE: Some members of the S100 gene family have been suggested to be associated with cancer development and metastasis. Our previous cDNA micro-array studies have showed S100A6 expression is elevated in gastric cancer compared with that in paired normal mucosa. To validate our previous results and further investigate the possible role of S100A6 gene in gastric cancer, we carried out this detailed S100A6 expression analysis in more matched gastric cancer samples. METHODS: S100A6 expression was detected in 20 paired fresh surgical samples of gastric tumor tissue and matched non-cancerous mucosa by QRT-PCR. A gastric cancer tissue microarray (TMA) containing 1020 duplicate matched normal mucosa, gastric cancer tissue and metastatic lymph node tissue cores from 208 gastric cancer patients was constructed. S100A6 expression was detected by immunohistochemistry and the correlation between S100A6 expression with clinicopathological factors and survival was analyzed. RESULTS: As quantitated by QRT-PCR, S100A6 transcript level was elevated in 73.7% of the primary cancer lesions with an average 2.25-fold up-regulation than that in matched non-neoplastic mucosa. As displayed by immunohistochemistry, the positive rate of S100A6 in non-neoplastic mucosa, tumor lesions and metastatic lymph nodes was 34.3%, 84.1% and 90.9%, respectively. S100A6 expression level in cancer and metastatic lymph node was significantly higher than their matched non-neoplastic mucosa (P < 0.05). 65.5% of patients showed an increased S100A6 expression in cancer tissue compared with that in matched normal mucosa. S100A6 overexpression was associated with larger tumor size and deeper invasion (P = 0.022 and P = 0.009). No evidence was found for an association between S100A6 expression level and other variables, including tumor grade, nodal metastases, and TNM stage. There was no association between S100A6 expression level and survival. But compared with paired non-neoplastic mucosa, an increased S100A6 expression in tumor lesion predicated a decreasing suvival if compared with a decreased S100A6 expression, though the difference was statistically not significant. CONCLUSION: Elevated expression of S100A6 gene may be an early event in the development and progression of gastric cancer. Further study of this gene may be helpful for understanding the nature of gastric carcinoma.

LINE-1 family member GCRG123 gene is up-regulated in human gastric signet-ring cell carcinoma.

AIM: To analyze the expression profiles of a human gastric-cancer-related gene, GCRG123, in human gastric signet-ring cell carcinoma tissues, and to perform bioinformatics analysis on GCRG123. METHODS: In situ hybridization was used to explore the GCRG123 expression pattern in paraffin-embedded gastric tissues, including 15 cases of signet-ring cell carcinoma, 15 of intestinal-type adenocarcinoma, and 15 of normal gastric mucosa. Northern blotting was used to analyze the differences in GCRG123 expression between stomach signet-ring cell carcinoma and intestinal-type adenocarcinoma tissues. Online software, including BLAST, Multalin and BLAT, were applied for bioinformatics analysis. National Center for Biotechnology Information (NCBI) and the University of California Santa Cruz (UCSC) databases were used for the analyses. RESULTS: The in situ hybridization signal appeared as blue precipitates restricted to the cytoplasm. Ten out of 15 cases of gastric signet ring cell carcinoma, normal gastric mucosal epithelium and pyloric glands showed high GCRG123 expression. Low GCRG123 expression was observed in gastric intestinal-type adenocarcinoma and normal gastric glands. Northern blotting revealed that GCRG123 was up-regulated in signet-ring cell carcinoma tissue but down-regulated in intestinal-type adenocarcinoma tissue. BLAST and Multalin analyses revealed that the GCRG123 sequence had 92% similarity with the ORF2 sequence of human long interspersed nuclear element retrotransposons (LINE-1, L1). BLAT analysis indicated that GCRG123 mapped to all chromosomes. GCRG123 was found to integrate in the intron-17 and -23 of Rb, 5' flanking region of IL-2 and clotting factor IX genes. CONCLUSION: GCRG123, an active member of the L1 family, was up-regulated in human gastric signet-ring cell carcinoma.