The Initial Study On CRC Differentiation-related Gene MAGEA3 And Differentiation-related CRC-EST1

Colorectal cancer (CRC) is one of the most frequent cancers in human beings. The incidence has an increasing tendency worldwide in recent years. With the development of molecular biology, tumor has been identified as a kind of genic disease. The intrinsical properties of tumor are activation of oncogene and inactivation of antioncogene. With the post genomic era arriving, there have been many researches on colorectal genes by microarray technique with the character of high-throughput, high-flux, miniaturization and automation. As a result, colorectal genic data-bank is becoming more and more abundant. However, there are no systemic researches based on the strategy "data mining of gene profiles→ screening candidated genes→investigating function of these genes".This study is the extension of Hong-Min Xu's research, "Gene expression profiling of human colorectal cancer with different differentiation grades". Hong-Min Xu et al firstly used Affymetrix GenecChip HG-U133 to monitor gene expression of about 19308 known genes and 12956 ESTs (altogether 32264) on 9 single samples of CRC with different differentiation grades (3 well differentiated, 3 moderately and 3 poorly ) paired normal mucosa tissue (9 samples in one pools), and 1 most important CRC differentiation-related genes MAGEA3 and important differentiation-related CRC-EST1 (temporary name whose Affymetrix number is 233399_x_at and Representative Public ID is AU145662 ) were obtained.In order to investigate the importance of MAGEA3 and the important CRC-EST1, such methods were applied as following:① Immunohistochemistry with MAGEA3 was firstly used in CRC tissues to conform the genechip results.? The relationships between the expression of MAGEA3 and clinical and pathological data were analyzed. The factors that affect the survival rate of CRC were analyzed.? CRC-ESTl expression was detected in CRC and paired normal colorectal mucosa, lung, endometrium tissues by RT-PCR.? 3'RACE technique was used to obtain the complete 3' sequence of the important CRC differentiation-related EST.The results were as follows:? MAGEA3 was only expressed in tumor tissues with the totally positive rate 31.7%. The rate and intensity of MAGEA3 in poor differentiated group was higher than that of the well group (p<0. 05) which was in coincidence with the genechip results.? Clinical data showed that there was no significant relationship between MAGEA3 expression and Dukes stage of CRC , lymph node metastasis, the size and the site of the tumor, the sex and age of CRC patients (p>0.05). Multiple factor COX risk model show that the Dukes stage of CRC and lymph node metastasis could be the dependent prognosis factor (p<0.05 ) .? The EST expression was conformed in CRC and paired normal colorectal mucosa, lung, endometrium tissues, The complete 3' region sequence of the important differentiation-related CRC-ESTl was obtained by means of 3'RACE.The contribution of our study may be as follows:? Immunohistochemistry with MAGEA3 hasn't been reported in CRC tissue before.? The differentiation-related CRC-ESTl was firstly cloned in the world.