A Preliminary Study On Expression Of Histone Modification Genes In IPSC And Conlon Caner Stem Cells

Objectives:We aimed to detect the mRNA expression profile of histone modification genes in iPSC (induced pluripotent stem cell) and hES cell (human embryonic stem cell), and screen the histone modification genes that might be critical in the "reprogramming" process from adult cell to the pluripotent state. And we will further detect the m RNA expression of selected genes in colon cancer stem cells to explore the potential novel prognostic markers and therapeutic targets for malignant tumors.Methods and Results:Human foreskin fibroblasts, human iPSC and hES cell line H9were cultured under identical standard conditions and total RNA were isolated. MRNA Expression levels of58histone modification genes in each cell line were determined by quantitative realtime RT-PCR. We found3genes had elevated mRNA expression level in iPSC and hES cells (>5fold change), which are Jarid2,KMT5C and PRMT8;3genes had decreased mRNA expression in iPSC and hES cells (>5fold change), which are Mina, Phf2and KMT7. We speculated that these6histone modification genes may play key roles in the "reprogramming" process and searched for their backgrounds and functions in GenBank database.We obtained cancer stem cell-enriched sample from colon cancer cell line SW480by spheroid culture and detected the mRNA expression level of above-mentioned6genes in normal colon epithelial tissue, SW480cell line and SW480derived tumor sphere by quantitative realtime RT-PCR. We found that Jarid2, Mina and Phf2show-comparable expression levels in all3types of cells. KMT5C had a slight increase (1.7fold) in SW480cell line (p<0.05) and a3.3fold increase in SW480-sphere (p<0.05). KMT7had a3.1fold increase in SW480cell line (p<0.05) but a neglectable increase (1.7fold) in SW480-sphere (p<0.05). Remarkably, PRMT8showed a1.6fold increase in SW480cell line and a7fold increase (p<0.05) in SW480-sphere p<0.05).Conclusions:The selected58histone modification genes had indistinguishable mRNA expression profile in human iPSC and hES cells. Jarid2, KMT5C, PRMT8, Mina, Phf2and KMT7had significant changed expression levels (increase/decrease) in iPSC and hES cell compared with foreskin fibroblast, which suggest their important roles in the "reprogramming" process, PRMT had a remarkable increase in cancer stem cell-enriched colon cancer sample relative to normal colon epithelial tissue and its parental bulk cell line. Its roles in the carcinogenesis are to be further investigated and might be used as a potential novel prognostic markers and therapeutic targets for colon cancer.