Genome-scale DNA methylation pattern profiling of human bone marrow mesenchymal stem cells in long-term culture
EXPERIMENTAL AND MOLECULAR MEDICINE
Authors: Choi, Mi Ran; In, Yong-Ho; Park, Jungsun; Park, Taesung; Jung, Kyoung Hwa; Chai, Jin Choul; Chung, Mi Kyung; Lee, Young Seek; Chai, Young Gyu
Abstract
Human bone marrow mesenchymal stem cells (MSCs) expanded in vitro exhibit not only a tendency to lose their proliferative potential, homing ability and telomere length but also genetic or epigenetic modifications, resulting in senescence. We compared differential methylation patterns of genes and miRNAs between early-passage [passage 5 (P5)] and late-passage (P15) cells and estimated the relationship between senescence and DNA methylation patterns. When we examined hypermethylated genes (methylation peak >= 2) at P5 or P15, 2,739 genes, including those related to fructose and mannose metabolism and calcium signaling pathways, and 2,587 genes, including those related to DNA replication, cell cycle and the PPAR signaling pathway, were hypermethylated at P5 and P15, respectively. There was common hypermethylation of 1,205 genes at both P5 and P15. In addition, genes that were hypermethylated at P5 (CPEB1, GMPPA, CDKN1A, TBX2, SMAD9 and MCM2) showed lower mRNA expression than did those hypermethylated at P15, whereas genes that were hypermethylated at P15 (MAML2, FEN1 and CDK4) showed lower mRNA expression than did those that were hypermethylated at P5, demonstrating that hypermethylation at DNA promoter regions inhibited gene expression and that hypomethylation increased gene expression. In the case of hypermethylation on miRNA, 27 miRNAs were hypermethylated at P5, whereas 44 miRNAs were hypermethylated at P15. These results show that hypermethylation increases at genes related to DNA replication, cell cycle and adipogenic differentiation due to long-term culture, which may in part affect MSC senescence.
Genomic and GeneChip expression profiling reveals the inhibitory effects of Amorphophalli Rhizoma in TNBC cells
JOURNAL OF ETHNOPHARMACOLOGY
Authors: Wu, Chunyu; Chen, Mingcang; Zhang, Qiuhua; Yu, Linghong; Zhu, Jiayan; Gao, Xiufei
Abstract
Ethnopharmacological relevance: Amorphophalli Rhizoma has been widely used as an adjuvant treatment for advanced or metastatic breast cancer, pancreatic cancer, hepatoma, and malignant lymphoma, but its molecular mechanism of action for treatment of metastatic triple-negative breast cancer (TNBC) is generally poorly understood. Aim of the study: To investigate genomic changes related to the inhibitory effect of Amorphophalli Rhizoma and to elucidate the molecular mechanism of this inhibition in MDA-MB-231 TNBC cells. Materials and methods: Gene chip analysis was employed to explore genomic changes caused by Amorphophalli Rhizoma in TNBC cells. Potential classical signaling pathways, upstream regulators, functions, regulatory effects and gene interaction networks were analyzed by Ingenuity Pathway Analysis (IPA). Real-time quantitative PCR (RT-qPCR) and RNA interference (RNAi) assays were used to clarify the roles of potential target genes. Results: In total, 536 significantly upregulated and 648 significantly downregulated genes were identified between the group treated with Amorphophalli Rhizoma extract and that treated with vehicle. Many of these differentially expressed genes (DEGs) in TNBC cells are involved in DNA replication, recombination and repair, the cell cycle, and cellular assembly and organization. Attenuation of KNL1, OLFML2A, RTKN2 and SGO1 gene expression by Amorphophalli Rhizoma significantly induced cell cycle arrest and suppressed cell proliferation and migration. Conclusions: The inhibitory effects of Amorphophalli Rhizoma in TNBC cells likely occur through regulation of the spindle checkpoint, chromosomal and centrosomal instability, and cell membrane stability.