Efficient isolation and proteomic analysis of cell plasma membrane proteins in gastric cancer reveal a novel differentiation and progression related cell surface marker, R-cadherin.

Cell plasma membrane proteins, playing a crucial role in cell malignant transformation and development, were the main targets of tumor detection and therapy. In this study, CyDye/biotin double-labeling proteomic approach was adopted to profile the membrane proteome of gastric cancer cell line BGC-823 and paired immortalized gastric epithelial cell GES-1. Real-time PCR, Western blotting, and immunohistochemical staining were used to validate the differential expression of a novel identified cell surface marker R-cadherin in gastric cancer cells and tissues. Clinicopathological study and survival analysis were performed to estimate its roles in tumor progression and outcome prediction. Real-time PCR and Western blotting showed that the expression level of R-cadherin in gastric cancer were significantly lower than non-cancerous epithelial cell and tissues. Clinicopathological study indicated that R-cadherin was dominantly expressed on cell surface of normal gastric epithelium, and its expression deletion in gastric cancer tissues was associated with tumor site, differentiation, lymph node metastasis, and pTNM (chi-square test, P < 0.05). Those patients with R-cadherin positive expression displayed better overall survivals than negative expression group (log-rank test, P = 0.000). Cox multivariate survival analysis revealed lacking the expression of R-cadherin was a main independent predictor for poor clinical outcome in gastric cancer (RR = 5.680, 95 % CI 2.250-14.341, P < 0.01). We have established a fundamental membrane proteome database for gastric cancer and identified R-cadherin as a tumor differentiation and progression-related cell surface marker of gastric cancer. Lacking the expression of R-cadherin indicates poor prognosis in patients with gastric cancer.

[Microscopic Raman spectral characteristics and diagnostic value of pathological lip minor salivary glands affected in primary Sjögren's syndrome].

OBJECTIVE: To investigate the Raman spectral characteristics of the pathological lip minor salivary glands affected in primary Sjögren's syndrome. METHODS: Thirty pathological samples and 30 normal samples were collected in this study. The samples were examined by Raman microscope.Support vector machine(SVM) was employed to analyze the data and establish the classification model. RESULTS: The spectra of pathological tissues was different from the controls in proteins, nucleic acids, lipids and glycogen skeleton. The sensitivity, specificity and accuracy of the model established by SVM on the training sets were all 92.0% (92/100), but the sensitivity, specificity and accuracy of the model established by SVM on the testing sets were 69.2% (37/53), 100.0% (37/37) and 82.0% (73/89) respectively. CONCLUSIONS: There was significant difference in Raman spectra between the pathological and normal lip salivary glands, and the classification model established by SVM could discriminate the pathological glands from the normal ones.

[Detection of EML4-ALK fusion gene in non-small cell lung cancer and its clinicopathologic correlation].

OBJECTIVE: To investigate the frequency of EML4-ALK fusion gene in non-small-cell lung cancer (NSCLC) patients, and its correlation with clinicopathologic features. METHODS: Real-time PCR was used to detect the presence of EML4-ALK fusion gene in 268 cases of NSCLCs using paraffin-embedded tissue samples(among which 164 samples were re-validated by Sanger sequencing). Related clinicopathological correlation was analyzed. RESULTS: EML4-ALK fusion gene was found in 4.1% (11/268) of the cases. One hundred and sixty four samples were verified by Sanger sequencing, and the overall coincidence of the results of two methods (Sanger sequencing and Real-time PCR) was 100%. Female patients (5.9%, 5/85), ≤ 60 years of age (4.3%, 6/140), non-smokers (6.8%, 8/118) and adenocarcinomas (7.6%, 10/132) had a higher mutation rate than that in male patients (3.3%, 6/183), > 60 years of age (4.0%, 5/124), smokers (1.6%, 2/132) and squamous cell carcinomas (1.3%, 1/79), although no statistical significance in age (P = 0.918), gender (P = 0.503), smoking history (P = 0.092) and histological type (P = 0.094). CONCLUSIONS: Chinese NSCLC patients have a 4.1% detection rate of EML4-ALK fusion gene in the tumor tissues. Female, non-smoker and adenocarcinoma histological subtype tend to be associated with a higher rate of EML4-ALK gene fusion.

[The effect of 5-fluorouracil on enriching cancer stem cells of hepatoma cell line BEL-7402].

OBJECTIVE: To investigate the effect of 5-FU (5-fluorouracil) on enriching cancer stem cells of HCC cell line BEL-7402 and the biological characteristics of enriched cells. METHODS: The enriching concentration of 5-FU was determined by CCK-8 (cell counting kit-8). Flow Cytometry was used to determine the changes in cell cycle and positive expression ratio of surface marker CD56, CD54, EpCAM and CD133. The self-renewal and differentiation of positive cells were tested by colony formation assay, and were compared with the control group. RESULTS: Enriching concentration of 5-FU was determined as 10 µg/ml with 48 h incubation. After enrichment, G0/G1 phase cells increased from 57.50 %+/-0.98% to 68.70%+/-3.41% (P<0.05). Whereas S phase cells decreased from 40.26%+/-4.12% to 31.80%+/-4.15% (P<0.01); G2/M phase cells disappeared in experimental group, and was 5.80%+/-1.87% in control group (P<0.01). The proportion of the cell cycle changed with significant statistical differences. Meanwhile, positive rate of cell surface makers CD56, CD54, EpCAM and CD133 increased from 0.57%+/-0.12%, 8.10%+/-6.79%, 0.3%+/-0.01% and 3.20%+/-0.99% to 4.13%+/-0.06%, 50.08%+/-1.69%, 0.55%+/-0.07% and 10.51%+/-1.13%, respectively. The difference was significant (P<0.05). The colony forming ratio of CD56, CD54, EpCAM and CD133 negative cells and positive cells were 2.11%+/-0.21%, 3.32%+/-0.31%; 0.86%+/-0.101%, 2.40%+/-0.52 %; 7.19%+/-0.56%, 7.73%+/-0.71%; 2.70%+/-0.26%, 5.75%+/-0.81%, respectively, and significant differences were found between (P<0.05). CONCLUSION: 5-fluorouracil enriched the cancer stem cell population in HCC cell line BEL-7402. CD56 and CD54 can be used as important surface markers in research of liver cancer stem cells.

[Screening for K-ras mutations in colorectal and lung cancers by using a novel real-time PCR with ADx-K-ras kit and Sanger DNA sequencing].

OBJECTIVE: to map out the frequency and types of K-ras gene mutations present in colorectal and lung cancer patients; to evaluate the clinical applicability of a novel real-time double-loop probe PCR using the ADx-K-ras kit, and to compare its performance with the result by using traditional Sanger DNA sequencing in detection of somatic mutations of the tumor genes. METHODS: a total of 827 formalin-fixed paraffin-embedded (FFPE) blocks including 583 from the colorectal and 244 from the lung cancer patients were assayed. Genomic DNA of the sample tissues was extracted, purified and subjected to PCR amplification of K-ras gene codon 12 and 13 and DNA sequencing was carried on using both the traditional Sanger sequencing method and the ADx's K-ras mutation detection kit, respectively. The mutation rates for K-ras gene at codon 12 and 13, and the mutation frequencies detected by using both methods were analyzed. RESULTS: 533 out of 583 (91.4%) colorectal cancer samples and 144 out of 244 lung cancer samples (59.0%) were detected using the traditional Sanger DNA sequencing technique, and 583 out of 583 (100.0%) colorectal plus 244 out of 244(100.0%) lung cancers were detected, respectively by using the ADx-K-ras kit. Of the 583 colorectal cancer samples, 192 (32.9%) showed mutations by using the ADx-K-ras kit in comparing with a result of 160 samples (27.4%) with K-ras gene mutation by using the traditional Sanger DNA sequencing technique. Of the 244 lung cancer samples, 26 (10.7%) showed K-ras gene mutations by using ADx-K-ras kit, while in 144 samples detected by using the traditional Sanger DNA sequencing technique, only 12 samples (8.3%) showed K-ras gene mutations. In colorectal cancer analyzed, GGT→GAT at codon 12 was the most common event with 35.1% (66/188) mutations, followed by GGC→GAC at codon 13 with 26.6% (50/188) and GGT→GTT at codon 12 with 18.6% (35/188), while GGT→GCT at codon12 was the most rare with only 1.6% (3/188) of the total mutation cases. In patients with lung cancer analyzed, GGT→GTT at codon 12 was the most common mutation, accounting for 40.9% (9/22), and GGT→GCT at codon 12 the most rare with only about 4.5% (1/22) of the total mutation cases. CONCLUSIONS: K-ras gene mutations were present in colorectal cases, and significantly more frequent than that in lung cancer. There were significant statistical differences between the two methods. ADx-K-ras real-time PCR showed much higher successful detection rates and mutation ratios compared to Sanger sequencing. As a result, the real-time PCR with ADx-K-ras kit proves to have a good clinical applicability and a strong advantage over the traditional Sanger DNA sequencing. It is a effective and reliable tool for clinical screening of somatic gene mutations in tumors.

[Evaluation of Chai Shao Liu Jun Tang for the treatment of chronic hepatitis B].

OBJECTIVE: To evaluate the effect of Chai Shao Liu Jun Tang in combination with Lamivudine for the treatment chronic hepatitis B (CHB) patients. METHODS: 405 CHB patients in Guangdong Provincial Hospital were randomly divided into 2 groups, 220 in the treated group, and 185 in the control group. The control group was treated with Lamivudine for 18 months. The treated group was treated with Lamivudine in combination with Chai Shao Liu Jun Tang for 18months. At the 3rd, 6th, 9th, 12th and 18th month during the treatment, the clinical symptoms, ALT normalization rate, HBeAg seroconversion rate, the proportion of patients with undetectable serum HBV DNA, and YMDD mutation rate were observed. RESULTS: ALT normalization rates at the 3rd, 6th, 12th, 18th month of the treatment group (69.5%, 85.9%, 90.5%, 82.7%) were higher than those in the control group (50.3%, 65.4%, 78.4%, 69.7%; P < 0.01). HBeAg seroconversion rate, rate of HBV DNA undetectable, and YMDD mutation rate at he 12th and18th month are 77.7%, 57.7%, 25.5%, 6.8%; 86.8%, 74.1%, 33.2%, 8.6% in the treatment group, and 54.6%, 36.8%, 13.0%, 14.6%; 69.2%, 37.3%, 19.5%, 20.5% in the control group (P < 0.01, or P < 0.05). CONCLUSION: Compared to lamivudine alone, Cai Shao Liu Ju Tang in combination with lamivudine is more effective and induces less YMDD mutation rate in CHB patients.

[Expression of PTEN protein and its correlation with p27kip1 and cyclin D1 expression in primary breast cancer].

OBJECTIVE: To study the expression of phosphatase and tensin homology deleted on chromosometen ten (PTEN) protein, a tumor suppressor gene in breast cancer and its correlation with p27(kip1) and cyclin D1 expression. METHODS: PTEN protein expression, p27(kip1) and cyclin D1 protein expression were detected by immunohistochemical method in paraffin sections from 61 women with primary breast cancer. PTEN protein expression was compared with clinico-pathologic parameters as related to p27(kip1) and cyclin D1. RESULTS: PTEN, being shown in the cytoplasm, was negative in 6.6% (4/61), reduced in 41.0% (25/61) and positive in 52.5% (32/61) samples. PTEN expression level was correlated with axillary lymph node status, loss of estrogen receptor stain, recurrence and metastasis. On univariate analysis, the disease-free survival rate of patients with higher PTEN expression (> 50% cells stained) was better than those with lower expression (P = 0.0101). However, there was no correlation between p27(kip1), cyclin D1 expression or PTEN expression. CONCLUSION: PTEN, its lower expression being correlated with poor outcome of breast cancer patients, plays a prominent role in breast cancer. p27(kip1) or cyclin D1 may not be the primary downstream genes of PTEN in breast cancer.