TY - JOUR
T1 - Patterned CpG methylation of silenced B cell gene promoters in classical hodgkin lymphoma-derived and primary effusion lymphoma cell lines
AU - Doerr, Jeanette R.
AU - Malone, Cindy S.
AU - Fike, Francesca M.
AU - Gordon, Melinda S.
AU - Soghomonian, Shahe V.
AU - Thomas, Roman K.
AU - Tao, Qian
AU - Murray, Paul G.
AU - Diehl, Volker
AU - Teitell, Michael A.
AU - Wall, Randolph
PY - 2005/7/22
Y1 - 2005/7/22
N2 - Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) and primary effusion lymphoma (PEL) are derived from germinal center (GC) and post-GC B cells, respectively. Neither express many of the B cell genes or surface markers typically expressed by other GC-derived B cell lymphomas or normal B cells. This loss of B cell gene expression is not due to a lack of essential transcription factors, as studies have shown that the ectopic expression of missing transcription factors failed to reactivate endogenous target genes. These results implicate epigenetic mechanisms extinguishing B cell gene expression. Silenced endogenous B cell genes representing a surface receptor, B29 (Igβ, CD79b), a signaling molecule, TCL1, and a transcription factor, Bob1 (OCA-B, OBF-1), were reactivated by 5-aza-2′-deoxycytidine, indicating that gene silencing in HRS and PEL cells is due to DNA methylation. Genomic bisulfite sequencing corroborated this prediction and revealed three distinct patterns of methylation for the silenced B29 and TCL1 promoters. These distinct patterns consisted of 5′ promoter CpG methylation alone, 5′ and 3′ promoter CpG methylation sparing sites in the central cores, and complete CpG methylation throughout the promoter regions. The silenced Bob1 promoter showed one pattern of dense CpG methylation at essentially all sites. These consistent patterns predict that, although gene silencing in many HRS and PEL cells mimics appropriate gene silencing, in some cases of complete CpG methylation throughout entire promoters both the activation and targeting of methylation is abnormal.
AB - Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) and primary effusion lymphoma (PEL) are derived from germinal center (GC) and post-GC B cells, respectively. Neither express many of the B cell genes or surface markers typically expressed by other GC-derived B cell lymphomas or normal B cells. This loss of B cell gene expression is not due to a lack of essential transcription factors, as studies have shown that the ectopic expression of missing transcription factors failed to reactivate endogenous target genes. These results implicate epigenetic mechanisms extinguishing B cell gene expression. Silenced endogenous B cell genes representing a surface receptor, B29 (Igβ, CD79b), a signaling molecule, TCL1, and a transcription factor, Bob1 (OCA-B, OBF-1), were reactivated by 5-aza-2′-deoxycytidine, indicating that gene silencing in HRS and PEL cells is due to DNA methylation. Genomic bisulfite sequencing corroborated this prediction and revealed three distinct patterns of methylation for the silenced B29 and TCL1 promoters. These distinct patterns consisted of 5′ promoter CpG methylation alone, 5′ and 3′ promoter CpG methylation sparing sites in the central cores, and complete CpG methylation throughout the promoter regions. The silenced Bob1 promoter showed one pattern of dense CpG methylation at essentially all sites. These consistent patterns predict that, although gene silencing in many HRS and PEL cells mimics appropriate gene silencing, in some cases of complete CpG methylation throughout entire promoters both the activation and targeting of methylation is abnormal.
KW - Classical Hodgkin lymphoma
KW - CpG DNA methylation
KW - Gene reactivation
KW - Gene silencing
KW - Primary effusion lymphoma
UR - http://www.scopus.com/inward/record.url?scp=20544472803&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2005.05.032
DO - 10.1016/j.jmb.2005.05.032
M3 - Article
C2 - 15967459
AN - SCOPUS:20544472803
SN - 0022-2836
VL - 350
SP - 631
EP - 640
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 4
ER -