Early Experience with a cDNA Microarray in Colorectal Cancer

Keum, Chung Su; Lee, Ryung Ah; Hong, Young Joon; Hong, Seok Il; Hwang, Dae Yong

Abstract

PURPOSE: A cDNA microarray is a systematic method to identify key molecules for prognosis and for treatment response by profiling thousands of genes expressed in a single cancer. The clinical value of cDNA microarray is still being investigated in various fields. This technique could be used in detecting molecules important for cancer to develop, to monitor the effect of new cancer therapeutics, and to give a prognosis for cancer patients. We now report the results of our initial cDNA microarray data to analyze the genome pattern of colorectal cancer tissues and to evaluate the possibility of using cDNA microarrays in a clinical setting for cancer patients.
METHODS
We used the general cDNA microarray technique with a 2.4 K cDNA chip provided by Macrogene company. RNA extracted from seven colorectal cancer tissues was amplified by using RT-PCR (reverse transcriptase-polymerase chain reaction), and applied to a cDNA chip to produce an antigen-antibody reaction. The results were analyzed individually and hierarchically.
RESULTS
All seven tested cancer tissues were harvested from operative specimens at the Korea Cancer Center Hospital. The male-to-female ratio was 4 to 3. Five patients were TNM stage II, and two patients were stage III. Eighteen genes were upregulated in stage II patients, and 51 in stage III patients. The number of genes discriminating stage was 69, including 8 control genes, 4 ribosomal genes, 5 EST genes, 10 known non-functional genes, 23 genesof unknown function, and 19 possible cancer-related genes. A hierarchial graph showed similar patterns within a stage, which suggests that genetic patterns might affect clinical characteristics.
CONCLUSIONS
Seven colorectal cancer tissues were analyzed with the cDNA microarray technique using 2.4 K cDNA chip. Authors could identify 69 genes that showed the significant change of expression. Although our reports presented the preliminary results, we think that the cDNA microarray will be able to offer an informative results to predict cancer development and progression in colorectal cancer.