Objective: To study the method of preparing cDNA microarray of tumor metastasis-associated genes and its application in the investigation of gene expression profile.
Methods: After amplification and purification by PCR, 400 tumor metastasis-associated gene clones were obtained and dotted onto the slides coated by poly-lysine. Total RNA from specimens of human colorectal carcinoma, lung carcinoma, and normal tissue samples were extracted and labeled by fluorescent staining. The labeled probes were then hybridized with the cDNA microarray.
Results: Uniform background and clear signal of the microarray were demonstrated by ScanArrayTM 4000. Specific mRNA expression profiles in association with colorectal cancer and lung cancer were subsequently obtained, showing that 30 genes were consistently up-regulated or down-regulated in the tissue samples examined, including motility factors, adhesion molecules, extracellular matrix-degrading enzymes, oncogenes, tumor-suppressor genes, apoptosis and anti-apoptosis genes, tumor angiogenesis factors and signal transduction factors, etc.
Conclusion: The optimized method is highly sensitive and applicable in examining gene expression profile. The two cancers investigated in this study do not obviously differ in light of tumor metastasis-associated gene expression profiles, indicating similar molecular mechanism accounting for the infiltration and metastatic behavior of different types of cancers.