Cerebral Gray Matter Volume Changes in Patients with Neuropathic Pain from Total Brachial Plexus Injury.

INTRODUCTION: Total brachial plexus injury not only significantly affects the motor and sensory function of the affected upper limbs but also causes further physical and mental damage to patients with long-term intractable pain. Previous studies mainly focused on the surgical treatment, while only a few paid attention to the intractable neuropathic pain caused by this injury. Changes in the volume of gray matter in the brain are thought to be associated with chronic neuropathic pain. METHODS: Voxel-based morphometry analysis was used to compare the difference in cerebral gray matter volume between total brachial plexus injury patients with neuropathic pain and healthy controls. Correlations between pain duration, pain severity, and GM changes were analyzed. RESULTS: The volume of cerebral gray matter in the patient group was decreased significantly in multiple regions, including the parahippocampal gyrus, paracentric lobule, inferior frontal gyrus, auxiliary motor cortex, middle occipital gyrus, right middle temporal gyrus, while it was increased in the insular, pons, middle frontal gyrus, cingulate gyrus, inferior parietal lobule, bilateral thalamus, and globus pallidus. There were no significant correlations between pain duration and rGMV changes, while a positive correlation was observed between pain severity and rGMV changes in one specific region, involving the anterior cingulate cortex. CONCLUSION: Total brachial plexus injury patients with chronic pain have widespread regions of gray matter atrophy and hypertrophy. The only positive correlation was observed between pain severity and rGMV changes in one specific region, suggesting that nociceptive stimuli trigger a variety of nonpain-specific processes, which confirms the multidimensional nature of pain.

STAT3 signaling drives EZH2 transcriptional activation and mediates poor prognosis in gastric cancer.

BACKGROUND: STAT3 signaling plays the pivotal role in tumorigenesis through EZH2 epigenetic modification, which enhanced STAT3 activity by increased tyrosine phosphorylation of STAT3. Here, another possible feedback mechanism and clinical significance of EZH2 and STAT3 were investigated in gastric cancer (GC). METHODS: STAT3, p-STAT3 (Tyr 705) and EZH2 expression were examined in 63 GC specimens with matched normal tissues by IHC staining. EZH2 and STAT3 were also identified in five GC cell lines using RT-PCR and western blot analyses. p-STAT3 protein was detected by western blotting. In order to investigate whether EZH2 expression was directly regulated by STAT3, EZH2 expression was further detected using siRNA for STAT3 or IL-6 stimulation, with dual luciferase reporter analyses, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays. The clinical significance of STAT3, p-STAT3 and EZH2 expression was evaluated by multi-factor COX regression and Kaplan-Meier analyses. RESULTS: Hyper-activation of STAT3, p-STAT3 and EZH2 expression were observed in GC cells and tissues. STAT3 signaling was correlated with EZH2 expression in GC (R = 0.373, P = 0.003), which was consistent with our data showing that STAT3 as the transcriptional factor enhanced EZH2 transcriptional activity by binding the relative promoter region (-214 ~ -206). STAT3 was an independent signature for poor survival (P = 0.002). Patients with STAT3+/EZH2+ or p-STAT3+/EZH2+ had a worse outcome than others (P < 0.001); Besides, high levels of STAT3 and EZH2 was associated with advanced TNM staging (P = 0.017). Moreover, treatment with a combination of siSTAT3 and EZH2-specific inhibitor, 3-deazaneplanocin A (DZNEP), increased the apoptotic ratio of cells. It is benefit for targeting STAT3-EZH2 interplay in GC treatment. CONCLUSIONS: Our results indicate that STAT3 status mediated EZH2 upregulation, associated with advanced TNM stage and poor prognosis, suggesting that combination with knockdown of STAT3 and EZH2 inhibitor might be a novel therapy in GC treatment. Collectively, STAT3, p-STAT3 and EZH2 expression were provided for the precision medicine in GC patients.

Occurrence of low frequency PIK3CA and AKT2 mutations in gastric cancer.

The PI3K/AKT signal transduction pathway has distinct functional roles in tumor progression. PIK3CA was reported to harbor the hot-spot in many types of tumor. Akt, the downstream of PI3K, its family members especially AKT2 activation in human cancer has been extensively studied, but its activation by mutation was less reported. The occurrence of PIK3CA and AKT2 mutations in a variety of cancers indicates their important involvement in carcinogenesis. Therefore, we investigated their mutation frequencies in gastric cancer (GC) in China. In our study, we selected hot-spot related exons 9, 18 and 20 of PIK3CA and kinase domain exons 6-14 of AKT2 genes were screened in 10 GC cell lines, 100 advanced primary GC and matched normal tissues. Denaturing high performance liquid chromatography (DHPLC) and DNA sequencing were used to analyze the mutations in the two genes. Two point mutations in the PIK3CA gene were identified in 4 of 10 GC cell lines and in 4 of 100 GC primary tumors. Two polymorphisms in AKT2 were detected in 19 of 100 GC primary tumors. One point mutation in AKT2 was detected in 1 of 10 GC cell lines and 3 of 100 GC primary tumors but no hot spot variation was detected. Our results indicate that PIK3CA and AKT2 mutations occurred at low frequency in GC, and suggest that the PIK3CA/AKT2 pathway might engage other events during gastric carcinogenesis.

Clinicopathological significance of altered metallothionein 2A expression in gastric cancer according to Lauren's classification.

BACKGROUND: Dysregulated metallothionein 2A (MT2A) has been implicated in carcinogenesis. The purpose of this study was to investigate the expression of MT2A in gastric cancer (GC) and its correlation with prognosis. METHODS: Reverse transcription-polymerase chain reaction and real-time polymerase chain reaction were used to detect the mRNA expression of MT2A in 12 GC cell lines, normal gastric epithelial GES-1 cells, and 36 GC and adjacent normal tissues. MT2A protein expression was determined in 258 GC tissues and 171 adjacent normal tissues by immunohistochemistry. RESULTS: MT2A mRNA expression was lower in GC cells and primary tumors than in GES-1 cells and adjacent normal tissues, respectively. High protein expression of MT2A was present in 130 of 171 normal tissues (76.0%) and in 56 of 258 GC tissues (21.7%; P < 0.001). MT2A protein expression was higher in well/moderately differentiated GC (22/54; 40.7%) than in poorly differentiated GC (34/204; 16.7%; P < 0.001). Moreover, the protein expression of MT2A was lower in diffuse-type GC (6/82; 7.3%) than in intestinal-type GC (50/176; 28.4%; P = 0.0001). Importantly, MT2A expression was an independent prognostic factor for GC, and decreased MT2A expression was associated with poor clinical outcome (P < 0.001). The expression status of MT2A could predict prognosis in intestinal and diffuse-type GCs. CONCLUSION: Expression status of MT2A might be a useful prognostic biomarker for GC, especially when used in combination with Lauren's classification.

MAWBP and MAWD inhibit proliferation and invasion in gastric cancer.

AIM: To investigate role of putative mitogen-activated protein kinase activator with WD40 repeats (MAWD)/MAWD binding protein (MAWBP) in gastric cancer (GC). METHODS: MAWBP and MAWD mRNA expression level was examined by real-time reverse transcriptase-polymerase chain reaction and semi-quantitative polymerase chain reaction in six GC cell lines. Western blotting was used to examine the protein expression levels. We developed GC cells that stably overexpressed MAWBP and MAWD, and downregulated expression by RNA interference assay. Proliferation and migration of these GC cells were analyzed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT), soft agar, tumorigenicity, migration and transwell assays. The effect of expression of MAWBP and MAWD on transforming growth factor (TGF)-ß1-induced epithelial-mesenchymal transition (EMT) was examined by transfection of MAWBP and MAWD into GC cells. We detected the levels of EMT markers E-cadherin, N-cadherin and Snail in GC cells overexpressing MAWBP and MAWD by Western blotting. The effect of MAWBP and MAWD on TGF-ß signal was detected by analysis of phosphorylation level and nuclear translocation of Smad3 using Western blotting and immunofluorescence. RESULTS: Among the GC cell lines, expression of endogenous MAWBP and MAWD was lowest in SGC7901 cells and highest in BGC823 cells. MAWBP and MAWD were stably overexpressed in SGC7901 cells and knocked down in BGC823 cells. MAWBP and MAWD inhibited GC cell proliferation in vitro and in vivo. MTT assay showed that overexpression of MAWBP and MAWD suppressed growth of SGC7901 cells (P < 0.001), while knockdown of these genes promoted growth of BGC823 cells (P < 0.001). Soft agar colony formation experiments showed that overexpression of MAWBP and MAWD alone or together reduced colony formation compared with vector group in SGC7901 (86.25 ± 8.43, 12.75 ± 4.49, 30 ± 6.41 vs 336.75 ± 22.55, P < 0.001), and knocked-down MAWBP and MAWD demonstrated opposite effects (131.25 ± 16.54, 88.75 ± 11.12, 341.75 ± 22.23 vs 30.25 ± 8.07, P < 0.001). Tumorigenicity experiments revealed that overexpressed MAWBP and MAWD inhibited GC cell proliferation in vivo (P < 0.001). MAWBP and MAWD also inhibited GC cell invasion. Transwell assay showed that the number of traverse cells of MAWBP, MAWD and coexpression group were more than that in vector group (84 ± 16.57, 98.33 ± 9.8, 29 ± 16.39 vs 298 ± 11.86, P < 0.001). Coexpression of MAWBP and MAWD significantly decreased the cells traversing the matrix membrane. Conversely, knocked-down MAWBP and MAWD correspondingly promoted invasion of GC cells (100.67 ± 14.57, 72.66 ± 8.51, 330.67 ± 20.55 vs 27 ± 11.53, P < 0.001). More importantly, coexpression of MAWBP and MAWD promoted EMT. Cells that coexpressed MAWBP and MAWD displayed a pebble-like shape and tight cell-cell adhesion, while vector cells showed a classical mesenchymal phenotype. Western blotting showed that expression of E-cadherin was increased, and expression of N-cadherin and Snail was decreased when cells coexpressed MAWBP and MAWD and were treated with TGF-ß1. Nuclear translocation of p-Smad3 was reduced by attenuating its phosphorylation. CONCLUSION: Coexpression of MAWBP and MAWD inhibited EMT, and EMT-aided malignant cell progression was suppressed.

Overexpression of p42.3 promotes cell growth and tumorigenicity in hepatocellular carcinoma.

AIM: To investigate the association of p42.3 expression with clinicopathological characteristics and the biological function of p42.3 in human hepatocellular carcinoma (HCC). METHODS: We used reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time RT-PCR and western blotting to detect p42.3 mRNA and protein expression in hepatic cell lines. We examined primary HCC samples and matched adjacent normal tissue by immunohistochemistry to investigate the correlation between p42.3 expression and clinicopathological features. HepG2 cells were transfected with a pIRES2-EGFP-p42.3 expression vector to examine the function of the p42.3 gene. Transfected cells were analyzed for their viability and malignant transformation abilities by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony formation assay, and tumorigenicity assay in nude mice. RESULTS: p42.3 is differentially expressed in primary HCC tumors and cell lines. Approximately 69.6% (96/138) of cells were p42.3-positive in hepatic tumor tissues, while 30.7% (35/114) were p42.3-positive in tumor-adjacent normal tissues. Clinicopathological characteristics of the HCC specimens revealed a significant correlation between p42.3 expression and tumor differentiation (P = 0.031). However, p42.3 positivity was not related to tumor tumor-node-metastasis classification, hepatitis B virus status, or hepatoma type. Regarding p42.3 overexpression in stably transfected HepG2 cells, we discovered significant enhancement of cancer cell growth and colony formation in vitro, and significantly enhanced tumorigenicity in nude mice. Western blot analysis of cell cycle proteins revealed that enhanced p42.3 levels promote upregulation of proliferating cell nuclear antigen, cyclin B1 and mitotic arrest deficient 2. CONCLUSION: p42.3 promotes tumorigenicity and tumor growth in HCC and may be a potential target for future clinical cancer therapeutics.

Differential expression of Rab27A/B correlates with clinical outcome in hepatocellular carcinoma.

AIM: To investigate the association of Rab27A and Rab27B expression with clinicopathological characteristics and prognosis of hepatocellular carcinoma (HCC). METHODS: We used reverse transcription polymerase chain reaction (RT-PCR), real-time PCR, and Western blotting to detect Rab27A and Rab27B mRNA and protein expression in 5 human HCC lines and the immortalized hepatic HL-7702 cell line. We further examined 148 primary HCC samples matched with adjacent normal tissue and 80 non-HCC specimens by immunohistochemistry to evaluate the correlation of Rab27A and Rab27B expression with clinicopathological features and prognosis. RESULTS: Our data showed that Rab27A and Rab27B were differentially expressed in cell lines and primary HCC tumors. Rab27A mRNA and protein were detected in 67% (4/6) of human cell lines and 80% (4/5) of HCC cell lines, while Rab27B was found in 50% (3/6) of human lines and 40% (2/5) of HCC lines. Rab27A expression was higher in primary HCC (46.2%, 66/143) than in matched adjacent tissue (24.3%, 33/136, P < 0.001), whereas immunopositivity for Rab27B was lower in primary HCC (57.4%, 81/141) than in matched adjacent tissue (87.5%, 119/136, P < 0.001). Analysis of clinicopathological characteristics of 148 HCC specimens revealed significant correlations between Rab27A and Rab27B expression and tumor tumor-node-metastasis (TNM) classification (P = 0.046 and P = 0.027, respectively), and between strong Rab27A expression and tumor differentiation grade (P = 0.008). Survival analyses revealed that patients with Rab27A(+) or Rab27B(+) tumors had significantly reduced overall survival compared with that of patients with Rab27A(-) or Rab27B(-) tumors (P = 0.015 and P = 0.005, respectively). Risk analyses revealed that Rab27B(+) and TNM III-IV were independent poor prognosis factors associated with a 3.36- and 3.37-fold higher relative risk of death, respectively. CONCLUSION: Rab27A and Rab27B expression were closely correlated with tumor progression and can be valuable prognostic indicators for HCC patients.

Prognostic significance of PTEN, Ki-67 and CD44s expression patterns in gastrointestinal stromal tumors.

AIM: To develop a prognostic approach for gastrointestinal stromal tumors (GISTs) using a cluster of indicators and follow-up information. METHODS: One hundred and four GISTs that had not been subjected to targeted therapies were collected and classified by NIH risk assessment and anatomic location. By immunohistochemistry, the expressions of PTEN, Ki-67, CD44s matrix metalloproteinase (MMP)-9 and TIMP-1 were detected on tissue microarray. Univariate and multimarker survival analyses were performed and then a COX hazard proportion model was constructed to evaluate a cluster of predictors of GIST. RESULTS: Our data showed small intestinal GIST are more aggressive than gastric GIST. The NIH risk assessment correlated with disease-free survival for either gastric GIST or small intestinal GIST. Immunohistochemical analysis revealed that Ki-67 labeling indexes (LIs) < 5% predicted higher disease-specific survival (DSS) in gastric and small intestinal GIST. CD44s positivity and PTEN LIs ≥ 50% correlated with higher DSS in gastric GIST. MMP-9 and TIMP-1 had no correlation with survival. Multimarker analysis revealed that the expression pattern of PTEN LIs ≥ 50% combined with Ki-67 LIs < 5% and CD44s positivity reliably predicted favorable outcomes for gastric GIST (P = 0.009), as did the combination of PTEN LIs ≥ 50% and Ki-67 LIs < 5% for small intestinal GIST (P = 0.011). Authors also found that high NIH risk grade was correlated with DSS in patients with gastric GIST and disease-free survival in patients with small intestinal GIST. CONCLUSION: PTEN LIs ≥ 50%, Ki-67 LIs < 5% and CD44s positivity provides an accurate, favorable prognosis for gastric GIST. PTEN LIs ≥ 50% and Ki-67 LIs < 5% does the same for small intestinal GIST. Ki-67 LIs enhances the NIH assessment.

In vivo measurement of brain GABA concentrations by magnetic resonance spectroscopy in smelters occupationally exposed to manganese.

BACKGROUND: Exposure to excessive levels of manganese (Mn) is known to induce psychiatric and motor disorders, including parkinsonian symptoms. Therefore, finding a reliable means for early detection of Mn neurotoxicity is desirable. OBJECTIVES: Our goal was to determine whether in vivo brain levels of γ-aminobutyric acid (GABA), N-acetylaspartate (NAA), and other brain metabolites in male smelters were altered as a consequence of Mn exposure. METHODS: We used T1-weighted magnetic resonance imaging (MRI) to visualize Mn deposition in the brain. Magnetic resonance spectroscopy (MRS) was used to quantify concentrations of NAA, glutamate, and other brain metabolites in globus pallidus, putamen, thalamus, and frontal cortex from a well-established cohort of 10 male Mn-exposed smelters and 10 male age-matched control subjects. We used the MEGA-PRESS MRS sequence to determine GABA levels in a region encompassing the thalamus and adjacent parts of the basal ganglia [GABA-VOI (volume of interest)]. RESULTS: Seven of 10 exposed subjects showed clear T1-hyperintense signals in the globus pallidus indicating Mn accumulation. We found a significant increase (82%; p = 0.014) in the ratio of GABA to total creatine (GABA/tCr) in the GABA-VOI of Mn-exposed subjects, as well as a distinct decrease (9%; p = 0.04) of NAA/tCr in frontal cortex that strongly correlated with cumulative Mn exposure (R = -0.93; p < 0.001). CONCLUSIONS: We demonstrated elevated GABA levels in the thalamus and adjacent basal ganglia and decreased NAA levels in the frontal cortex, indicating neuronal dysfunction in a brain area not primarily targeted by Mn. Therefore, the noninvasive in vivo MRS measurement of GABA and NAA may prove to be a powerful tool for detecting presymptomatic effects of Mn neurotoxicity.

Expression status of S100A14 and S100A4 correlates with metastatic potential and clinical outcome in colorectal cancer after surgery.

To investigate whether S100A14 and S100A4 expression correlates with metastatic potential and prognosis in colorectal cancer (CRC), we firstly used RT-PCR analysis to detect mRNA expression of S100A14 and S100A4 in 40 pairs of fresh tumor samples matched with adjacent normal tissues. We then evaluated the clinical significance of our findings with immunohistochemistry on 115 samples of formalin-fixed and paraffin-embedded tumors on tissue microarrays. Typically, we identified decreased S100A14 mRNA levels (52.5%, 21/40), and increased S100A4 mRNA levels (70.0%, 28/40) in primary CRC samples. In addition, down-regulated or absent S100A14 expression was detected in 56.5% of samples (65/115) and was correlated with poor differentiation (P=0.010). In contrast, overexpressed S100A4 was detected in 57.4% of samples (66/115) and was associated with lymph node metastasis (P=0.001). Simultaneous S100A14 low-expression and S100A4 high-expression was correlated with high CRC metastatic potential (P<0.001). Taken together, the signature derived from the combined expression status of S100A14 and S100A4 could be a valuable prognostic indicator in CRC.

[Identification of biomarkers for early detection in gastric cancer and its clinical biological significance.].

OBJECTIVE: To systematically understand the cellular and molecular mechanism of gastric cancer (GC) development and to discover early diagnosis and predictive biomarkers, which will be used for early diagnosis and novel treatment targets. METHODS: 70 mer 22 K-oligonucleotide microarrays and bioinformatic analysis were conducted to recognize gene expression profiles in GC and normal appearing tissue (NAT). The control group was collected from non-tumor patients including 20 specimen mixture as a common reference (CR) and 5 individuals as additional control. Our results showed that 837 different expression genes (DEGs) were identified in GC while 570 DEGs were in NATs by Bayesian analysis (P<0.001, Fold change>2.0) as compared respectively with CR. An interesting finding is that we identified 67 over-expressed genes in both GC and NAT tissues, and these gene expression alterations could not be detected by comparison of GC with NATs, which were normally used in routine experiment design. Most of these genes were involved in the control of cell proliferation, metabolism and differentiation. RESULTS: These differential expressed genes were confirmed at mRNA and protein levels in primary tumors using RT-PCR and immunohistochemistry (IHC). The results showed that three genes, EGR1, CYR61 and ADAMTS1 were over expressed in both GC and NATs at mRNA level. These results were consistent with oligo microarray data. Another interesting finding is that these three genes were also over-expressed in intestinal metaplasia (IM) and dysplasia (DYS), which indicated that these three genes might be potential biomakers for early detection of GC. CONCLUSION: Through the systematic analysis of gene expression profiles in GC tissues, NAT and CR normal tissues, we identified a group of genes over-expressed both in GC and precancerous lesions, which might be potential biomarkers for early GC diagnosis.

Identification of matrix metalloproteinase 11 as a predictive tumor marker in serum based on gene expression profiling.

PURPOSE: Prognostic markers discovery is a strategy for early diagnosis and individualization therapy for human cancer. In this study, we focus to integrate different methods to identify specific biomarker and elucidate its clinical significance. EXPERIMENTAL DESIGN: A powerful tool named Digital Gene Expression Display online was applied to isolate differentially expressed genes correlated with gastric cancer. Matrix metalloproteinase 11 (MMP11) was selected and confirmed at both mRNA and protein level in 10 cell lines, 123 cases of tumor tissues, and 305 cases of gastric cancer serum specimen by semiquantitative PCR, immunohistochemistry staining, and ELISA techniques, respectively. RESULTS: Our data showed that overexpression of MMP11 at mRNA and protein level was consistently detected in cell lines and primary tumors compared with matched normal tissues. Importantly, serum MMP11 levels were also significantly elevated in gastric cancer patients compared with those of the control subjects (P < 0.001), and the positive expression was well correlated with metastasis in gastric cancer patients (P = 0.009). Furthermore, we have shown that overexpression of MMP11 was associated with the malignant proliferation of AGS cells. CONCLUSIONS: Combination of gene expression profiling and specific clinical resource is a promising approach to validate gene expression patterns associated with malignant phenotype. As a secreted protein, MMP11 may play an important role in carcinogenesis and has potential implication as a biomarker for the diagnosis and prognosis of human cancers including gastric cancer.

[Prognostic significance of clinicopathologic parameters in gastrointestinal stromal tumor: a study of 156 cases].

OBJECTIVE: To evaluate the prognostic significance of various clinicopathologic parameters in gastrointestinal stromal tumor (GIST), and to study the frequency of c-kit exon 11 mutations in this tumor. METHODS: One hundred and fifty-six cases of gastric or small intestinal GIST were retrieved from the archival files of the Department of Pathology, Chinese PLA General Hospital. The clinical features, site of occurrence, tumor diameter, mitotic index, coagulative tumor necrosis, and risk grade were studied and analyzed statistically. Tumor DNA was extracted and c-kit exon 11 was amplified. Upon detection by denaturing high-performance liquid chromatography, the amplified exon 11 was sequenced. RESULTS: For the 83 cases of gastric GIST studied, the mean age of patients was 55.4 years. Follow-up information was available in 62 cases, with 17 cases having local recurrence or distant metastasis. The 5-year survival rate was 66.5% +/- 17.1%. For the 73 cases of small intestinal GIST studied, the mean age of patients was 50.6 years. Follow-up information was available in 43 cases, with 22 cases having local recurrence or distant metastasis. The 5-year survival rate was 61.8% +/- 18.3%. In general, for gastric GIST, age younger than 50 years (P = 0.046), advanced clinical stage (P = 0.0001), large tumor size (P = 0.0001), high mitotic index (P = 0.0001), presence of coagulative tumor necrosis (P = 0.0001), and high risk grade (P = 0.004) were associated with lower survival rate. COX hazard proportional model revealed that advanced clinical stage (P = 0.001), large tumor size (P = 0.001), high mitotic index (P = 0.002) and high risk grade (P = 0.018) indicated worse prognosi. For small intestinal GIST, advanced clinical stage (P = 0.010) and presence of coagulative tumor necrosis (P = 0.036) were associated with lower survival rate. Advanced clinical stage was an independent prognostic factor. A total of 25 cases harbored c-kit mutations. The frequency of c-kit mutations was 32% and 22.5% for gastric and small intestinal GIST respectively. For gastric GIST, c-kit mutations occurred mainly in patients older than 50 years. In contrast, c-kit mutations in small intestinal GIST occurred in the age group of 40 to 49 years. CONCLUSIONS: For gastric GIST, advanced clinical stage, tumor diameter, mitotic index and risk grade are the main prognostic indicators. For small intestinal GIST, advanced clinical stage and presence of coagulative tumor necrosis indicate poor prognosis. In general, small intestinal GIST is more frequently associated with metastasis and tumor relapse than gastric GIST. The occurrence of c-kit mutations also correlates with age of patients.

Soluble expression of active human beta-defensin-3 in Escherichia coli and its effects on the growth of host cells.

BACKGROUND: Human beta-defensin-3 (HBD(3)) is an epithelial peptide that has been demonstrated to have a salt-insensitive broad spectrum of potent antimicrobial activity. Expressing antimicrobial peptides in Escherichia coli (E. coli) is very difficult for it can result in death of the bacterial host cells. Our aim was to establish a prokaryotic system expressing soluble HBD(3) protein and demonstrate the antimicrobial activity of the expressed protein. We then studied whether the host cells would activate the suicide pathways. METHODS: We first cloned the complementary DNA coding for the mature chain of HBD(3), inserted it into the vector PGEX-KG then transformed E. coli BL21 (DE3) with the appropriate recombinant plasmid. After induction with 0.5 mmol/L isopropyl-1-thio-beta-D-galactopyranoside (IPTG) the transformed E. coli produced a recombinant glutathione S-transferase and HBD(3) (GST-HBD(3)) fusion protein. The fusion protein was treated with thrombin to produce pure HBD(3) protein then the antimicrobial activity of HBD(3) was evaluated in a liquid microdilution assay. RESULTS: The fusion protein GST-HBD(3) was efficiently cleaved by thrombin and yielded HBD(3) that had anti-staphylococcus aureus activity with a minimal inhibitory concentration level of 12.5 microg/ml. The E. coli strain expressing the recombinant protein did not grow slower than the empty vector strain. CONCLUSION: Active HBD(3) in E. coli by expressing the recombinant protein GST-HBD(3) could be produced, and suicide did not occur in the E. coli strain expressing the recombinant protein.

ATM-Chk2-p53 activation prevents tumorigenesis at an expense of organ homeostasis upon Brca1 deficiency.

BRCA1 is a checkpoint and DNA damage repair gene that secures genome integrity. We have previously shown that mice lacking full-length Brca1 (Brca1(delta11/delta11)) die during embryonic development. Haploid loss of p53 completely rescues embryonic lethality, and adult Brca1(delta11/delta11)p53+/- mice display cancer susceptibility and premature aging. Here, we show that reduced expression and/or the absence of Chk2 allow Brca1(delta11/delta11) mice to escape from embryonic lethality. Compared to Brca1(delta11/delta11)p53+/- mice, lifespan of Brca1(delta11/delta11)Chk2-/- mice was remarkably extended. Analysis of Brca1(delta11/delta11)Chk2-/- mice revealed that p53-dependent apoptosis and growth defect caused by Brca1 deficiency are significantly attenuated in rapidly proliferating organs. However, in later life, Brca1(delta11/delta11)Chk2-/- female mice developed multiple tumors. Furthermore, haploid loss of ATM also rescued Brca1 deficiency-associated embryonic lethality and premature aging. Thus, in response to Brca1 deficiency, the activation of the ATM-Chk2-p53 signaling pathway contributes to the suppression of neoplastic transformation, while leading to compromised organismal homeostasis. Our data highlight how accurate maintenance of genomic integrity is critical for the suppression of both aging and malignancy, and provide a further link between aging and cancer.

Dominant expression of 85-kDa form of cortactin in colorectal cancer.

PURPOSE: Cortactin is commonly expressed in several human cancers, which may alter their invasive or metastatic properties. Eighty five kilodalton form (p85) and 80-kDa form (p80) of cortactin are two separate bands in SDS-PAGE representing different conformational states. The objective of this study was to investigate cortactin expression in colorectal cancer (CRC). EXPERIMENTAL DESIGN: Cortactin expression was studied in an eight paired laser capture microdissection (LCM) CRC tissues and matched non-cancerous epithelia by immunoblotting. The expression in 58 CRC and two cell lines, HCT8 and HCT116, was studied respectively by immunohistochemistry and confocal laser scanning immunofluorescence. RESULTS: Dominant expression of p85 was identified in LCM-procured CRC tissues compared with equal intensity of p85 and p80 forms in non-cancerous tissues, while the amount of total cortactin was approximate. Immunohistochemistry analysis demonstrated that cortactin located in the cytoplasm of tumor cells and adjacent non-cancerous cells, and its expression was negatively correlated with TNM staging and lymphatic invasion status. However, the invasion fronts in 3 of 58 primary tumors and 28 of 39 available lymph node metastases were intensively stained. Further, immunofluorescence analysis showed that cortactin was distributed in cytoplasm and enriched in the front of the extending lamellipodia at adhering side of cultured cancer cells. CONCLUSIONS: Our results demonstrated the dominant expression of p85 form of cortactin in CRC for the first time. The enrichment of cortactin in the invasion front of some tumor cells and in the extending lamellipodia of cultured cancer cells suggests that cortactin may help cancer cell movement.

[Relations of transforming growth factor-beta1 expression to differentiation and prognosis of advanced gastric cancer].

OBJECTIVE: To clarify the correlation of transforming growth factor-beta1 (TGF-beta1) expression with the differentiation and prognosis of advanced gastric cancer (GC). METHODS: Whole genome expression chip hybridization, was used to detect the expression of TGF-beta1 and TGF-betaR1 in 20 specimens of intestinal-type GC and para-cancer tissues. RT-PCR and immunohistochemistry (IHC) analysis were used to detect the mRNA and protein expression of TGF-beta1 and TGF-betaR1 in 30 specimens of intestinal-type GC tissue and para-cancer tissues. The mixture of gastric mucosa tissues from 20 non-tumor patients was used as common reference. RESULTS: The expression level of TGF-beta1 and TGF-betaR-1 genes was higher in the GC tissues than in the para-cancer tissues. However, the expression of Smad gene family was not significantly different between the GC tissues and para-tumor normal tissues. TGF-beta1 gene expression and TGF-betaR1 gene expression were higher in the GC tissues. RT-PCR showed that both TGF-beta1 and TGF-betaR-1 genes were highly expressed in the mRNA level in 21 of the 30 CC patients IHC showed that TGF-beta1 protein was expressed mainly in the cytoplasm. 32 of the 90 specimens of GC tissue were highly positive in TGF-beta1 protein (64%), in comparison with the positive rate of 5% (1/20) in the para-cancer normal tissues. The TGF-beta1 protein expression rate of the highly and moderately differentiated GC tissues was 59% (59%, 23/39), significantly higher than that of the lowly differentiated GC tissues (18%, 9/51, P < 0.01). IHC showed that the TGF-beta R-I rate was 57% (42/74) in the well differentiated specimens, particularly 68% (26/38) in the highly differentiated specimens, and was 44% in the poorly differentiated GC (6/20, P < 0.05). Log rank test showed that the prognosis of the patients positive in TGF-beta1 was significantly better than those negative in TGF-beta1 (P = 0.0058). However, the survival rate did not differ significantly according to TGF-beta R-I expression (P = 0.8453). CONCLUSION: TGF-beta1 expression is significantly correlated with the differentiation degree of GC. Moreover, positive expression of TGF-beta1 is a favorable prognostic factor in advanced GC. Expression of TGF-beta1 may be an important preoperative prognostic variable for advanced GC.

Matrix metalloproteinase 11 depletion inhibits cell proliferation in gastric cancer cells.

Our previous study has shown that matrix metalloproteinase 11 (MMP11) is highly expressed in tumor cell lines and primary tumor of gastric cancer (GC). In order to reveal the correlation between expression of MMP11 and biological features of GC cell, we have constructed the recombinant plasmids producing hairpin small interfering RNA (siRNA) to target MMP11 mRNA using a vector-based RNA interference technology. Stable transfection of recombinants into GC cell line BGC823 specifically depleted the mRNA and protein of MMP11 as demonstrated by RT-PCR and Western blotting analysis. The siRNA-treated cells exhibited significantly decreased growth ability compared with mock transfectants and parental BGC823 cells. Furthermore, colony formation of MMP11 deficient cells was dramatically inhibited in soft agar and tumorigenicity was reduced in nude mice, respectively. These results provide new insights into the function of MMP11 and suggest that MMP11 may play an important role in the control of cell proliferation and tumor development in GC.

[Cardiopulmonary bypass of orthotopic heart transplantation].

OBJECTIVE: To summarize the extracorporeal circulation(ECC) management experiences on 4 cases of orthotopic heart transplantation. METHODS: All patients received moderate hypothermia and high flow rate perfusion. Many strategies were taken to maximize the protection of myocardium, lung, kidney and blood conservation. The donor hearts were arrested with aorto perfusion using modified St. Thomas solution at 4 degrees C. After being flushed with 5,000 mL cold saline, the donor hearts were perfused with 1,000 mL UW solution in 4 degrees C and preserved in ice saline. Ice mud was covered on the donor heart and cold saline was dripped into left atrium in the period of anastomosis. RESULTS: The ECC time was 133.3+/-13.1 min, and the warm and cold ischemia time was respectively 1-3 min and 142.0+/-28.2 min. All the cases recovered heart beats automatically. Left ventricular ejection fractions were 60%-65% a month postoperatively. One patient died of acute rejection 150 days postoperatively. 3 cases survived. CONCLUSION: Proper ECC management, importment organs and donor heart protection are the key to success in heart transplant operations.

Alteration of the ATM gene occurs in gastric cancer cell lines and primary tumors associated with cellular response to DNA damage.

Ataxia telangiectasia mutated (ATM) is the gene mutated in the genetic disorder ataxia telangiectasia (AT), the symptoms of which include sensitivity to radiation and an increased risk of cancer. ATM is a kinase involved in activating the appropriate damage-response pathway, leading to either cell-cycle arrest or apoptosis, and is therefore a key checkpoint molecule in regulating cell-cycle response to DNA damage and responsible for maintenance of genome integrity. However, little is known about the association of ATM mutations with human gastric cancer (HGC). In order to determine the mutation and mRNA expression changes of the ATM gene in HGC, we performed analyses by denaturing high-performance liquid chromatography (DHPLC), DNA sequencing and RT-PCR technique on 13 human gastric tumor cell lines and 30 cases of fresh tumor specimens matched normal tissue. We compared the potential effect of the ATM gene mutation and cell behavior including cell-cycle arrest and induction of apoptosis in the tumor cell lines MGC803 and BGC823 with and without ionizing radiation (IR) exposure. Our data show that frequent variations were observed at 10 exons and 2 cDNA fragments which covered 8 other exons of the ATM gene as 5 out of 13 on the cell lines (38.5%) and 2 out of 30 cases in the tissue specimens (6.7%). All point mutations were confirmed as base substitutions (5982T-C; 6620A-G; 8684G-G/A; 9389C-G) and deletions (1079delC) by use of DNA sequencing. Among the mutations, one was reported previously in breast cancer, the other five have not yet been reported. The expression of ATM was significantly lower in five cell lines (MGC803; MKN45; SGC7901; GES and SUN-1) than in two others (BGC823 and RF48). G2/M cell-cycle arrest and apoptosis were observed in ATM-deficient MGC803 cells challenged with IR. A transient up-regulation of p53 occurred 1h post-IR in BGC823 cells but not in MGC803 cells. Our findings suggest that ATM mutations might be a pathogenic factor for an increased risk of gastric cancer, and the dysfunction of ATM may lead to a hypersensitivity to ionizing radiation in gastric cancer cells, possibly by a p53-dependent pathway.