DNA Hypomethylation Affects Cancer-Related Biological Functions and Genes Relevant in Neuroblastoma Pathogenesis
PLOS ONE
Authors: Mayol, Gemma; Martin-Subero, Jose I.; Rios, Jose; Queiros, Ana; Kulis, Marta; Sunol, Mariona; Esteller, Manel; Gomez, Soledad; Garcia, Idoia; de Torres, Carmen; Rodriguez, Eva; Galvan, Patricia; Mora, Jaume; Lavarino, Cinzia
Abstract
Neuroblastoma (NB) pathogenesis has been reported to be closely associated with numerous genetic alterations. However, underlying DNA methylation patterns have not been extensively studied in this developmental malignancy. Here, we generated microarray-based DNA methylation profiles of primary neuroblastic tumors. Stringent supervised differential methylation analyses allowed us to identify epigenetic changes characteristic for NB tumors as well as for clinical and biological subtypes of NB. We observed that gene-specific loss of DNA methylation is more prevalent than promoter hypermethylation. Remarkably, such hypomethylation affected cancer-related biological functions and genes relevant to NB pathogenesis such as CCND1, SPRR3, BTC, EGF and FGF6. In particular, differential methylation in CCND1 affected mostly an evolutionary conserved functionally relevant 3' untranslated region, suggesting that hypomethylation outside promoter regions may play a role in NB pathogenesis. Hypermethylation targeted genes involved in cell development and proliferation such as RASSF1A, POU2F2 or HOXD3, among others. The results derived from this study provide new candidate epigenetic biomarkers associated with NB as well as insights into the molecular pathogenesis of this tumor, which involves a marked gene-specific hypomethylation.
Bone Repair by Transplantation of hTERT-Immortalized Human Mesenchymal Stem Cells in Mice
TRANSPLANTATION
Authors: Nakahara, Hiroyuki; Misawa, Haruo; Hayashi, Takahiro; Kondo, Eisaku; Yuasa, Takeshi; Kubota, Yasuhiro; Seita, Masayuki; Kawamoto, Hironobu; Hassan, Wael A. R. A.; Hassan, Reham A. R. A.; Javed, Shahid M.; Tanaka, Masato; Endo, Hirosuke; Noguchi, Hirofumi; Matsumoto, Shinichi; Takata, Katsuyoshi; Tashiro, Yuichi; Nakaji, Shuhei; Ozaki, Toshifumi; Kobayashi, Naoya
Abstract
Background. Human mesenchymal stem cells (hMSCs) are multipotent stem cells found in the adult bone marrow that have the capacity to differentiate into various mesenchymal cell types. The hMSCs may provide a potential therapy to restore damaged tissues or organs of mesenchymal origin; however, a drawback is their limited life span in vitro. Methods. We immortalized normal hMSCs with retrovirally transmitted human telomerase reverse transcriptase cDNA. One of the immortalized clones (YKNK-12) was established, and the biological characteristics were investigated in vitro and in vivo. Results. YKNK-12 cells were capable of differentiating adipocytes, osetoblasts, and chondrocytes. Osteogenically differentiated YKNK-12 cells produced significant levels of growth factors BMP4, BMP6, FGF6, FGF7, transforming growth factor-beta 1, and transforming growth factor-beta 3..Microcomputer tomography T and soft X-ray assays showed an excellent calvarial bone healing in mice after transplantation of osteogenically differentiated YKNK-12 cells. These cells expressed human-specific osteocalcin and increased the gene expression of runt-related transcription factor 2, alkaline phosphatase, osteocalcin, and osterix in the bone regenerating area. YKNK-12 cell transplant corrected the bone defect without inducing any adverse effects. Conclusions. We conclude that hMSCs immortalized by transduction with human telomerase reverse transcriptase may provide an unlimited source of cells for therapeutic use in bone regeneration.