Methylation Changes of Primary Tumors, Monolayer, and Spheroid Tissue Culture Environments in Malignant Melanoma and Breast Carcinoma
Epigenetic changes have major role in the normal development and programming of gene expression. Aberrant methylation results in carcinogenesis. The primary objective of our study is to determine whether primary tumor tissue and cultured tumor cells in 2D and 3D tissue culture systems have the same methylation signature forPAX5,TMPRSS2, andSBDS. These findings will play an important role in developing in vitro model system to understand the effect of methylation inhibitors on primary tumor tissue. In a previous studyPAX5,TMPRSS2, andSBDSgenes that we are investigating were reported to be methylated more than 60% in breast cancer and malignant melanoma cell lines. However, these genes have never been studied in primary tumor tissues. Thus, primary tumor tissues of breast cancer and malignant melanoma were first grown in 2D and 3D cultures. Then these two types of tumor tissues and their 2D and 3D cultures were investigated for changes considering methylation levels inPAX5,TMPRSS2, andSBDSgenes using real-time polymerase chain reaction. No differences were observed in the primary tissues and culture systems for bothPAX5andTMPRSS2in malignant melanoma tissues. We found thatPAX5gene was an efficient marker to measure the effects of methylation inhibitors for in vitro systems for malignant melanoma tissue.