Biobanking of Fresh-Frozen Cancer Tissue: RNA Is Stable Independent of Tissue Type with Less Than 1 Hour of Cold Ischemia.

Background: The effects of preanalytical variables in tissue processing and storage periods on RNA quality of tissues have been well documented in each type of cancer. However, few studies have been performed on a comparative assessment of the impacts across different cancer tissues, even though it is well known that RNase activity is highly variable in various tissue types and RNase-rich tissues have been found to yield low-quality RNA.

Methods: We investigated the impacts of cold ischemia times and long-term storage on RNA integrity in various types of cancer tissue, which had been fresh-frozen and collected at the Samsung Medical Center Biobank.

Association of the SUV39H1 histone methyltransferase with the DNA methyltransferase 1 at mRNA expression level in primary colorectal cancer.

This study was aimed at investigating the involvement of the SUV39H1 histone methyltransferase on the epigenetic change of euchromatic promoter in colorectal cancer. We retrospectively analyzed the mRNA levels of SUV39H1 and the promoter methylation of the p14(ARF), p16(INK4a) and HLTF genes as well as the mRNA levels of DNA methyltransferase 1 (DNMT1) in fresh frozen tissues from 219 colorectal cancer patients. The mRNA levels of the SUV39H1 and DNMT1 were assessed via quantitative real-time PCR and the methylation profiles of the CpG islands were determined using methylation-specific PCR.