Clinicopathological significance of altered metallothionein 2A expression in gastric cancer according to Lauren's classification / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Expression status of MT2A might be a useful prognostic biomarker for GC, especially when used in combination with Lauren's classification.</p>

Prediction of recurrence risk in early breast cancer using human epidermal growth factor 2 and cyclin A2 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Human epidermal growth factor 2 (HER2) is one of the most important prediction factors, but only 25% - 30% of breast cancer patients HER2 are positive. It is unknown whether there are other molecular markers that could be used to predict prognosis and recurrence in HER2 negative patients. This study investigated correlations of cyclin A2 and HER2 levels with clinical outcomes in 281 patients with invasive breast cancer in order to identify whether cyclin A2 can serve as a prognostic factor in HER2 negative patients.</p><p><b>METHODS</b>Immunohistochemical staining was used to detect cyclin A2 and HER2 expression in 281 patients. Cyclin A2 and HER2 gene amplifications were analyzed using gene analysis and RT-PCR in 12 patients. Risk and survival estimates were analyzed using Log-rank, Kaplan-Meier, and Cox regression analysis; cyclin A2 and HER2 consistency with survival were analyzed using Kappa analysis.</p><p><b>RESULTS</b>Patients with higher cyclin A2 and HER2 expressions had significantly shorter disease-free survival periods (P = 0.047 and P = 0.05, respectively). Kappa analysis performed that cyclin A2 and HER2 showed a low Kappa index (kappa = 0.37), allowing us to conclude that cyclin A2 and HER2 detect different pathologies. Gene analysis and RT-PCR showed that cyclin A2 was upregulated in patients with early relapse; the average increase was 3.69 - 2.74 fold.</p><p><b>CONCLUSIONS</b>Cyclin A2 and HER2 are associated with proliferation and high recurrence, particularly when combined. Cyclin A2 is easily detected by nuclear staining and might be a useful biomarker for recurrence risk in HER2 negative patients.</p>

Mitochondrial DNA 4977-bp deletion correlated with reactive oxygen species production and manganese superoxidedismutase expression in gastric tumor cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mitochondrial DNA 4977-bp deletion (DeltamtDNA(4977)) was reported in many human neoplasia. However, its biological significance remains to be evaluated and the molecular mechanism needs to be investigated. In this study, we analyzed the frequency of DeltamtDNA(4977) in gastric cancer (GC) cell lines and tissues, as well as reactive oxygen species (ROS) contents and manganese superoxide dismutase (MnSOD) expression levels in GC cell lines to explore its biological significance and molecular mechanism.</p><p><b>METHODS</b>Semi-quantitative PCR and real-time PCR were used to detect the incidence of DeltamtDNA(4977) in 13 GC cell lines and 272 human gastric tissues (108 GC specimens and the respective adjacent normal tissues, and 56 normal gastric mucosa from non-cancer patients). We further identified intracellular ROS production by flow cytometry and MnSOD expression by semi-quantitative reverse transcription-PCR (RT-PCR) and Western blotting. Statistical analyses were carried out using the Logistic regression analysis and Kaplan-Meier method.</p><p><b>RESULTS</b>Based on our earlier study, we optimized the PCR amplification condition by reducing the cycle number. In this study, we systematically documented the high incidence of DeltamtDNA(4977) in GC cell lines (10/13, 76.9%), GC tissues (86/108, 79.6%), matched normal tissues (73/108, 67.6%), and normal gastric mucosa of non-cancer patients (29/56, 51.8%). A significantly higher incidence of mutated DeltamtDNA(4977) was observed in GC tissues with respect to the adjacent normal tissues (79.6% vs 67.6%, P = 0.045), and they were both higher than that in normal controls (P < 0.05). Most importantly, we linked the DeltamtDNA(4977) mutations with the expression level of MnSOD and ROS contents. The cell lines containing lower expression level of MnSOD was found to have generally higher frequent DeltamtDNA(4977) and more ROS.</p><p><b>CONCLUSION</b>The decreased anti-oxidative ability, which leads to increased ROS contents, is correlated with the mtDNA damage during gastric carcinogenesis.</p>

Soluble expression of active human beta-defensin-3 in Escherichia coli and its effects on the growth of host cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Prognostic significance of clinicopathologic parameters in gastrointestinal stromal tumor: a study of 156 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>