Amplification and clinicopathological significance of HER-2 in Kazakh esophageal squamous cell carcinoma.

Amplification and overexpression of the human epidermal growth factor receptor-2 (HER-2) gene accelerates cell division and proliferation, and promotes tumor growth and metastasis in various malignant tumors. However, there are few reports on its influence and mechanism in esophageal cancer. The aim of the present study was to investigate the gene amplification and clinicopathological significance of HER-2 in Kazakh esophageal squamous cell carcinoma (ESCC). HER-2 gene amplification was detected in 70 esophageal cancer tissues using fluorescence in situ hybridization. The association between the HER-2 gene amplification and the clinicopathological characteristics of patients with esophageal cancer was also analyzed. The amplification rate of the HER-2 gene in patients with esophageal cancer was 54.2% (38/70). The results also revealed a positive association between the amplification rate of the HER-2 gene in esophageal squamous cell carcinomas and the level of tissue differentiation, increasing gradually and significantly among the highly, moderately and poorly differentiated tissues (P<0.05). The amplification rate of the HER-2 gene in patients with lymph node metastasis was higher than those without (P<0.05). There was no significant association between the amplification rate of the HER-2 gene and any of the clinic pathological parameters, such as sex, age, depth of invasion and 3-year survival, among patients (P>0.05). In conclusion, the amplification rate of the HER-2 gene in patients with Kazakh ESCC was high. There was an association with various prognostic factors, including cancer differentiation and lymph node metastasis. HER-2 gene expression levels may be considered as an indicator of poor prognosis in patients with ESCC in the clinical setting, and this may provide a basis of treatment for individualized targeted therapies.

Association between TP53 gene deletion and protein expression in esophageal squamous cell carcinoma and its prognostic significance.

The aim of the present study was to investigate the association between tumor protein 53 (TP53) gene deletion and protein expression and clinical features in esophageal squamous cell carcinoma (ESCC), and to evaluate the predictive value of these two characteristics in the prognosis of ESCC. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were performed to detect the expression of p53 protein and gene deletion in ESCC tissue samples from different ethnic groups in Xinjiang, in order to analyze their association with clinicopathological characteristics and patient prognosis, as well as the sensitivity and specificity of the two methods. In addition, the results were further validated by tissue microarray from a different region. The positive rate of p53 protein expression was 54.5% (201/369) in the multi-ethnic group, and was significantly different between sex (P=0.026) and between tumor differentiation groups (P=0.032). FISH demonstrated that the TP53 gene deletion rate was 31.8% (68/214), which was significantly different between different tumor differentiation (P=0.002), lymph node metastasis (P=0.005) and vascular invasion (P<0.001) groups. The survival rate of patients with TP53 gene deletion was significantly lower than those without TP53 gene deletion (P<0.05). The positive rate of p53 protein expression in the tissue microarray was 58.1% (68/117), which was significantly different between the depth of invasion groups (P=0.011). The TP53 gene deletion rate was 47.9% (56/117), which significantly differed according to lymph node metastasis (P=0.003) and TNM stage (P=0.01). In addition, the total concordance rates of the two methods were 60.3 and 64.1%, respectively. There were also significant differences in the positive rate of TP53 gene deletion and protein expression in different stages of ESCC (P<0.05), which increased gradually with the progression of ESCC. The deletion of the TP53 gene in esophageal cancer was associated with poor prognosis and may be an important biomarker for evaluating the prognosis of patients with ESCC. The combination of FISH and IHC methods could significantly improve the detection rate of TP53 gene abnormalities and the accuracy of prognostic assessment of ESCC.

Epidermal growth factor receptor gene mutation status and its association with clinical characteristics and tumor markers in non-small-cell lung cancer patients in Northwest China.

This study was conducted to investigate the mutation status of epidermal growth factor receptor (EGFR) and its association with clinical characteristics and tumor markers in non-small-cell lung cancer (NSCLC) patients from the Xinjiang Uygur Autonomous Region in China. We enrolled 51 cases of NSCLC patients who received radical surgical treatment in the First Affiliated Hospital of Xinjiang Medical University. Quantitative polymerase chain reaction was applied to detect exons 18, 19, 20 and 21 of the EGFR gene in tumor tissues. Multiple tumor markers, including carcinoembryonic antigen (CEA), were assessed preoperatively. The EGFR-positive rate was 49.02% (25/51), with a mutation rate of 8% (2/25) in exon 18, 52% (13/51) in exon 19, 40% (10/51) in exon 21 and no mutations in exon 20. The positive mutation rate in men and women was 37.5% (12/32) and 68.42%, respectively (13/19), with a statistically significantly higher rate in women (P<0.05). There were also statistically significant differences among adenocarcinoma, adenosquamous carcinoma and squamous cell carcinoma cases (P<0.05), while no statistically significant differences were observed in adenocarcinoma cases regarding degree of differentiation, lymph node metastasis and TNM stage (P>0.05). There was a statistically significant association between the EGFR gene mutation status and the preoperative serum CEA level (P<0.05). The mutation rate of the EGFR gene was 68.42% in female lung adenocarcinoma patients, which supports the application of targeted therapy in such cases. However, whether it is possible to obtain information regarding targeted therapy through measuring the level of serum CEA for NSCLC patients with unknown EGFR mutation status requires further investigation through related studies including a higher number of cases.

LMP gene promoter hypermethylation is a mechanism for its down regulation in Kazak's esophageal squamous cell carcinomas.

Abnormal hypermethylation of CpG islands not only associated with tumor suppressor genes can lead to repression of gene expression, but also contribute to escape of the tumor from immune surveillance and contribute significantly to tumorigenesis. In the present study, we studied the hypermethylation of low molecular-weight protein (LMP) gene and its regulation on protein expression in biopsies from resected tissues from Kazak's esophageal squamous cell carcinoma (ESCC) patients and their neighboring normal tissues. LMP2 and LMP7 genes promoter region methylation sequences were maped in esophageal cancer cell line Eca109 by bisulfite-sequencing PCR and quantitative detection of methylated DNA from 30 pairs of Kazak's ESCC and adjacent normal tissues by MassARRAY (Sequenom, San Diego, CA, USA) and LMP2 and LMP7 protein expression were analyzed with immunohistochemistry. In Eca109, we identified 6 CG sites methylated from all of 22 CpG sites of LMP7 gene. However, no methylation was found for LMP2. The analysis of the data resulted from the quantitative analysis of single CpG site methylation by Sequenom MassARRAY platform, has shown that the methylation level between two groups CpG sites (CpG_5, CpG_9, CpG_20, CpG_21 and CpG_20) from CpG_1, CpG_2, CpG_3, CpG_4, CpG_5, CpG_6, CpG_7, CpG_8, CpG_9, CpG_10.11, CpG_12.13.14, CpG_15.16.17.18, CpG_19, CpG_20, CpG_21 and CpG_22 significant differences between ESCC and neighboring normal tissues. The analysis of methylation level of whole target CpG fragment indicated that the methylation level of LMP7 was significant higher in ESCC (0.0517 ± 0.0357) than in neighboring normal tissues (0.0380 ± 0.0214, P < 0.05). there was a tendency of decreasing the LMP7 proteins expression as the increasing the methylation level of LMP7 gene promoter regions (F = 7.69, P = 0.041). The LMP7 gene promoter methylation and protein downregulation were correlated at high extent in Kazakh's ESCC patients, and may explain the epigenetic regulation on gene expression.

TP53 gene deletion in esophageal cancer tissues of patients and its clinical significance.

The aim of this study was to examine TP53 gene deletion in esophageal cancer (EC) tissues obtained from patients and to evaluate its clinical significance. Forty surgical specimens from patients with esophageal squamous cell carcinoma were examined for TP53 gene deletion using the fluorescence in situ hybridization (FISH) technique. Thirty-two male and 8 female patients were enrolled, with an average age of 56 years. TP53 gene deletion was significantly higher in poorly-differentiated EC cases compared to well-differentiated cases (P=0.028). The TP53 gene deletion rate was also significantly higher in the group with lymph node metastasis compared to the group without lymph node metastasis (P=0.0313). The TP53 gene deletion rate was shown to be correlated with the level of differentiation and lymph node metastasis in EC; it may therefore be an important molecular marker for evaluating the condition of EC in patients.

Molecular pathological diagnosis for early esophageal cancer in Kazakh patients.

Chromosome abnormalities in cancer cells occur early in carcinogenesis. We employed DNA probes for the detection of cancer cells in surgical specimens in Kazakh patients with suspected esophageal carcinoma, to analyze the application of this technique during the early diagnosis of esophageal cancer. Comparative analysis was used to compare the results of pathological diagnosis with the results of FISH. We performed esophagofiberscopic biopsy examinations in 50 Kazakh patients with suspected esophageal carcinoma, including 40 males and 10 females, with an average age of 56.8 years. The final diagnosis was esophageal squamous cell carcinoma in 47 patients, and adenocarcinoma, mucinous carcinoma and small cell carcinoma in one patient each. The pathological findings of the biopsy were positive in 45 cases, and false-negative in 5. The sensitivity and specificity of pathological diagnosis were 87.2 and 100%, respectively. Using FISH to examine the same tissues, we found that 48 cases showed aberrant copy numbers in either chromosome 3 or 17, and 2 cases were false-negative, with a sensitivity and specificity of 94.8 and 100%, respectively. The copy numbers of centromeres in chromosome 3 were significantly higher than the copy numbers of centromeres in chromosome 17 (P=0.0001). Compared with biopsy pathology, the FISH test was more sensitive. Being an objective and qualitative method, the technology of molecular pathological diagnosis may effectively increase the early diagnostic rate of esophageal cancer. In addition, the centromere probe in chromosome 3 may be the most sensitive probe for the diagnosis of esophageal cancer in Kazakh patients.

Revealing the metabonomic variation of EC using ¹H-NMR spectroscopy and its association with the clinicopathological characteristics.

In this study, (1)H NMR-based metabonomics has been applied to investigate esophageal cancer metabolic signatures in plasma and urine, purpose of assessing the diagnostic potential of this approach and gaining novel insights into esophageal cancer metabolism and systemic effects. Plasma and urine samples from esophageal cancer patients (n = 108) and a control healthy group (n = 40) were analyzed by Nuclear Magnetic Resonance (NMR) spectroscopy (600 MHz), and their spectral profiles subjected to Orthogonal Projections to Latent Structures (OPLS-DA) for multivariate statistics. Potential metabolic biomarkers were identified using data base comparisons used for examining the significance of metabolites. Compared to healthy controls, esophageal cancer plasma had higher levels of dimethylamine, α-glucose, ß-glucose, citric acid, together with lower levels of Leucine, alanine, isoleucine, valine, glycoprotein, lactate, acetone, acetate, choline, isobutyrate, unsaturated lipid, VLDL, LDL, 1-methylhistidine; Compared to healthy controls, esophageal cancer urine had higher levels of Mannitol, glutamate, γ-propalanine, phenylalanine, acetate, allantoin, pyruvate, tyrosine, ß-glucose and guinolinate, together with lower levels of N-acetylcysteine, valine, dihydrothymine, hippurate, methylguanidine, 1-methylnicotin- amide and Citric acid; Very good discrimination between cancer and control groups was achieved by multivariate modeling of plasma and urinary profiles. (1)H NMR-based metabolite profiling analysis was shown to be an effective approach to differentiating between patients with EC and healthy subjects. Good sensitivity and selectivity were shown by using the metabolite markers discovered to predict the classification of samples from the healthy control group and the patients with the disease. Plasma and urine metabolic profiling may have potential for early diagnosis of EC and may enhance our understanding of its mechanisms.

Genetic diagnosis of patients with esophageal cancer using FISH.

This study aimed to the clarify the diagnostic efficacy of fluorescence in situ hybridization (FISH) in Kazakh patients with esophageal cancer (EC). FISH was compared with the pathological examination of biopsy specimens with DNA probes. We enrolled 20 patients, of which 15 were males and 5 females, with an average age of 58.3 years, who had abnormal esophaguses on barium radiological digital imaging. Touch preparations were performed on biopsy specimens from all of the patients and were examined using FISH for chromosomal abnormalities. We compared the FISH results with the pathology slides stained with hematoxylin and eosin. Classification, according to pathology, identified 2 cases of class II, 3 cases of IIIa, 1 case of IIIb, 2 cases of IV, 12 cases of class V and no cases of class I. The cases classified as class IIIb or higher were considered to be positive for cancer. Using histopathology, 10 cases were diagnosed with squamous cell carcinoma and 5 were diagnosed as adenocarcinoma, with one case being false-negative. Thus, the sensitivity of the pathological examination was 93% and the specificity was 100%. Using FISH, 16 cases showed aberrant copy numbers in either chromosome 3 or 17. By comparison, pathology did not reveal any false-positive or false-negative cases with a sensitivity and specificity of 100%. The centromeres of chromosome 3 copy numbers was significantly higher (p=0.035) than the centromeres of chromosome 17. Our study compared FISH to diagnose aneusomic esophageal cancer cells with the pathology of biopsied tissue. Our findings suggest that FISH is a useful and objective assay for the detection of malignant cells of esophageal cancer. In our study, the centromeres of chromosome 3 was the more sensitive probe for the diagnosis of esophageal cancer in Kazakh patients.