Expression Of Cancer-testis Antigen MAEL In Colorectal Cancer And Its Clinical Significance

[Objects] To detect the expression of MAEL in colorectal cancer and discuss the relationship between clinical features of colorectal cancer.[Methods] Firstly, mouse spermatogonia cell GC-1、human colon cancer cells SW480、 human normal colorectal mucosa cells FHC were cultured, and the MAEL protein expression was detected respectively by Western-blot to verify the cancer-testis antigen characteristics. Then,80 cases of colorectal carcinoma tissues and the corresponding normal colorectal tissues were collected, and MAEL expression in colorectal carcinoma and normal colorectal tissues were detected by Real-time qPCR, and the MAEL expression differences between tumor tissues and normal tissues were compared. At the same time, the clinical and pathological features of patients such as gender, age, tumor location, dukes staging, histologic differentiation, histological type, tumor metastasis degree, tumor size were collected, and the relationship between MAEL expression in colorectal cancer and the pathological features of patients were analysed.[Results]1. The results of Western-blot showed that MAEL was expressed signally in GC-1 cells and SW480 cells, and didn’t express in FHC cells. The expression of MAEL protein in SW480 cells and FHC cells was significantly different.2. MAEL was not expressed or was expressed weakly in 80 cases of normal colorectal tissue, the average value of the relative expression ratio of MAEL was 1.353±0.537. And in 80 cases of colorectal cancer tissues, MAEL expressed abnormally highly, the average value of the relative expression ratio of MAEL was 4.449±2.466. The average value of the relative expression of MAEL gene in colorectal cancer tissue was 3.288 (±0.237) times that of normal colorectal tissue.3. By comparing the relative expression ratio of MAEL gene between colorectal cancer tissues and corresponding normal colorectal tissues, it was found that compared with normal colorectal tissues, the changes folds of MAEL expression of 42 cases accounting for 52.50% was greater than 2, ranged from 1.5 to 2 with 33 cases, accounting for 41.25%; less than 1.5 with 5 cases, accounting for 6.25%. It showed that the expression level of MAEL in colorectal cancer tissues was significantly higher than that in normal colorectal tissues.4. There was no significant correlation between the expression level of MAEL in colorectal cancer and gender, age, tumor location, histological differentiation, tumor size of patients (P> 0.05), however the expression level of MAEL in colorectal cancer was closely related with Dukes stage, tumor metastasis, tumor tissue type of patients (P<0.05) The more the Dukes stage was, the more obvious the tumor metastasis was, the higher the expression of MAEL gene was. The expression of MAEL was higher in adenocarcinoma in mucinous carcinoma tissues and was relatively low in in mucinous carcinoma tissues. Compared with normal colorectal tissues, the expression of MAEL in adenocarcinoma tissues was increased more obviously than mucinous carcinoma tissues.[Conclusions]1. MAEL abnormally high expression in colorectal cancer tissue, and no expression in normal colorectal tissues or weak expression of MAEL in the tissue of colorectal cancer expression levels higher than normal colorectal tissues.2. MAEL gene expression level in colorectal cancer tissues and the patient’s gender, age, tumor location, the histopathologic differentiation, tumor size, clinical pathologic features such as no significant correlation, and in patients with colorectal cancer Dukes staging, tumor type is closely related to the credits.