Abstract Objective To study the esophageal MGMT, survivin protein expression and its clinical significance. Methods immunohistochemistry (EnVision two-step) detected 56 cases of esophageal squamous cell carcinoma, 20 cases of adenoid structure of esophageal and 9 cases of small cell carcinoma of MGMT, survivin protein expression, and analysis with clinicopathological factors relationship. Results of small cell carcinoma and squamous cell carcinoma and adenoid structure esophageal MGMT protein expression showed a significant difference (P <0.01); poorly differentiated squamous cell carcinoma MGMT protein expression was 45.45%, lower than the high in differentiation squamous cell carcinoma, the positive rate (84.44%, P <0.05). Esophageal squamous cell carcinoma survivin positive expression rate was significantly higher than the the adenoid structure esophageal (P <0.05). Conclusion of MGMT survivin protein expression with esophageal cancer closely related to histological type, can be used as the reference index of esophageal cancer prognosis.
Key words esophageal MGMT survivin immune staining
6 oxygen of methylguanine DNA methyl transferase (O6 methylguanine DNA methytransferase, MGMT) is an efficient DNA repair enzymes protect cells from alkylating agents damage, prevent cell cancer and death has extremely important role. survivin is a new member of the inhibitor of apoptosis protein family, play a role in apoptosis inhibition and cell cycle. At present, domestic and foreign literature of MGMT expression of survivin gene in esophageal reported very little between the adenoid structure esophageal tissues has not been reported. In this paper, immunohistochemistry EnVision method, the detection of MGMT in esophageal carcinoma, the expression of survivin, and to investigate the clinical significance of the expression.
1 Materials and methods
Collects and examines the collection of the Department of Pathology of our hospital esophageal surgical resection specimens of 85 cases, including 56 cases of squamous cell carcinoma (including 24 cases of well-differentiated, in differentiation 21 cases, 11 cases of poorly differentiated), the adenoid structure esophageal cancer 20 cases (including eight cases of adenocarcinoma in 2 cases, 10 cases of mucoepidermoid carcinoma, adenosquamous carcinoma) and 9 patients with small cell carcinoma. 85 cases of esophageal carcinoma infiltrating the submucosa, 22 cases of myometrial invasion, are infiltrating into the outer film; 40 patients with regional lymph node metastasis.
1.2.1 Reagents MGMT mouse anti-human monoclonal antibody (concentration
Figure 1MGMT protein positive expression in esophageal squamous cell carcinoma (EnVision × 200)
The Figure 2survivin protein positive expression of adenosquamous carcinoma (EnVision × 400)
Degree to 1:50) and of survivin rabbit anti-human antiserum (working concentration of 1:100) antibody diagnostic companies from the United States.
1.2.2 Immunohistochemical staining the EnVision method for immunohistochemical staining. Staining procedure was carried out according to the instructions, using microwave antigen retrieval, primary antibody overnight at 4 ℃, DAB color hematoxylin. Known positive sections as a positive control, PBS instead of primary antibody as a negative control.
1.3 The results of determination
MGMT, survivin cytoplasm / nucleus brown particles appeared positive. 75%为(＋＋＋)。">The percentage of positive cells accounted for tumor cells of divided: positive cells ≤ 5% to 6% to 25% (-), as a positive (+), 26% to 75% for the (+ +),> 75% (+ + +).
1.4 statistical treatment
SPSS13.0 statistical software for statistical analysis, using χ2 test, Fisher’s exact test and non-parametric tests.
2.1MGMT, survivin protein in esophageal carcinoma positioning
After 85 cases of esophageal cancer by immunohistochemical staining of MGMT and survivin protein positive expression showed brown positive cells in cancer tissue was multifocal / diffuse distribution, as shown in Figure 1, 2. The MGMT protein positive particles located in the nucleus and (or) the cytoplasm, but the center of the cancer nests mainly in the cytoplasm around the nucleus. Expression and localization of survivin protein MGMT protein is basically the same.
2.2MGMT, survivin protein expression in different types of esophageal cancer tissues.
0.05″>MGMT expression of small cell carcinoma and squamous cell carcinoma and adenoid structure esophageal expression showed a significant difference (P <0.01), while no significant difference (P> 0.05 between squamous cell carcinoma and adenoid structure cancer ). Esophageal squamous cell survivin protein expression was significantly higher than the the adenoid structure cancerous tissue (P <0.05) There was no difference between the two I, as shown in Table 1.
2.3 esophageal of MGMT, the relationship between survivin protein expression and clinicopathological characteristics.
MGMT protein expression in esophageal squamous cell carcinoma is closely related to the degree of differentiation (χ2 = 5.510, P <0.05), with gender, age, location, depth of invasion and lymph node metastasis. survivin protein expression and gender, age, location, depth of invasion, degree of differentiation, and lymph node metastasis, as shown in Table 2.
2.4MGMT survivin protein expression in esophageal carcinoma.
To investigate the relationship between of MGMT with survivin protein expression in esophageal carcinoma, the experiment using Spearman correlation analysis. 0.05）,见表3。">The results showed no correlation (r = 0.059, P> 0.05) between MGMT and survivin protein expression, as shown in Table 3.
Esophageal cancer is a common malignancy, nitrosamines and other alkylating agent with esophageal cancer is closely related to the occurrence of. Alkylating agent acting on guanine in DNA, the formation of O6 mG, the latter paired with T in the process of DNA replication, DNA G: C pairs converted to A: T pairs, leading to tumor formation. MGMT is an important DNA repair enzyme, able to transfer the methylation of DNA, O6 mG own cysteine residues, thereby repairing the DNA methylation. MGMT expression in normal cells, but about 1/5 of the tumor cells and 1/3 of the human lymphocytes is not expression. The detection table herein MGMT, survivin protein expression in different types of esophageal cancer tissues Note: Compared with small cell carcinoma, a χ2 = 0.00, P <0.01; bχ2 = 0.00, P <0.01; Comparison with adenoid structure cancer , c χ2 = 0.035, P <0.01 Table 2 MGMT, survivin protein in the relationship between the expression of esophageal cancer and its clinical and pathological features Note: compared with poorly differentiated squamous cell carcinoma, a χ 2 = 5.510, P <0.05 85 different types of patients with esophageal cancer tissues, and found that MGMT protein in esophageal squamous cell carcinoma, adenoid structure cancer and small cell carcinoma, the positive expression rate of 78.57%, 90.00%, 11.11%. MGMT significantly lower than squamous cell carcinoma and adenoid carcinoma (P <0.01), poorly differentiated squamous cell carcinoma rate was significantly lower than the high, moderately differentiated squamous cell carcinoma (P <0.05), suggesting that MGMT protein expression in small cell carcinoma different expression in different types of esophageal cancer, loss of MGMT protein expression and tumor related to the degree of malignancy. In addition, studies have shown that age and gender also affect the expression of the MGMT gene, as Rolhion  glial cell tumors found MGMT gene expression with age was negatively correlated; MGMT protein expression but this study shows gender, age, regardless This Lvjia Chun et al.  is consistent. Table 3 MGMT survivin protein
survivin inhibitor of apoptosis was isolated and identified in 1997 a new member of the family of proteins expressed in the embryonic development organizations and the majority of mankind tumor expression, but not in normal adult tissues (thymus, gonads except). survivin protein with esophageal cancer histological type, degree of differentiation, and lymph node metastasis reported are not consistent. Some studies suggest that the survivin protein expression with tumor differentiation , lymph node metastasis-related, but there are contrary reports . Survivin protein in esophageal cancer, mostly confined in esophageal squamous cell carcinoma, and other types of esophageal cancer has rarely been reported. This article by the detection of the 85 patients with esophageal cancer survivin protein expression esophageal tissue types are closely related. Esophageal small cell carcinoma cancer of survivin protein expression than squamous cell carcinoma and adenoid structure, prompts comparison with squamous cell carcinoma and adenocarcinoma, small cell carcinoma of the esophagus is the differentiation of the worst, the most malignant tumor.
Studies have shown that MGMT gene over-methylation is significantly associated with p53 gene mutation , and survivin protein expression and p53 was positively correlated . To understand that the MGMT and survivin protein expression whether there is a relationship, the two proteins expression correlation analysis found that there is no correlation between MGMT and survivin protein expression. Our results show that, missing esophageal MGMT protein expression of survivin protein expression is a vicious high performance. Detection of esophageal cancer MGMT and survivin protein expression, can be used as reference for esophageal cancer prognosis.