Assistant Professor of Oncology
Department of Molecular and Cellular Biology

Roswell Park Cancer Institute
Elm and Carlton Streets
Buffalo, NY 14263
Tel: (716) 845-3582
Fax:(716) 845-1698
E-mail: Michael.Higgins@RoswellPark.org

General Research Interest

Molecular genetics of Beckwith-Wiedemann syndrome (BWS); epigenetic imprinting and cancer.

Current Program

• Analysis of patients with BWS for abormalities in genomic imprinting
• Functional analysis of the putative imprinting control region, KvDMR1, by targeted deletion in the mouse
• Characterization of KvDMR1 as a chromatin insulator or silencer element
• Positional cloning of genes involved in Wilms' tumor
  

Laboratory Personnel

Galina Fitzpatrick PhD
Jong-Yeon Shin PhD

Description of Research

It is well established that germline and somatic mutations contribute to the transformation of a normal cell to a cancer cell. In addition to these genetic insults to the genome, a rapidly increasing body of evidence has demonstrated that alterations in DNA methylation and chromatin structure can contribute to carcinogenesis by changing the expression level of otherwise normal, mutation-free genes. The mechanisms by which one such "epigenetic" phenomenon, genomic imprinting, is involved in the development of cancer represent a major effort in our laboratory. Genomic imprinting results from epigenetic modification in the germ line of a small number of mammalian genes and is manifested as preferential expression of one of the two parental alleles in a parent-of-origin manner. Most recently we have focussed on elucidating the function of the KvDMR1 locus in human chromosome 11p15.5 (mouse distal chromosome 7) which has characteristics of other cis-acting regulatory sequence elements known as imprinting control regions (ICRs) including differential maternal-specific methylation. Importantly, KvDMR1 suffers an epimutation (i.e. the absence of DNA methylation on the maternal allele) in a large proportion of patients with Beckwith-Wiedemann syndrome (BWS), an overgrowth and cancer predisposition condition (Smilinich et al., 1999; Engel et al., 2000). As a first step in defining its function, we have deleted KvDMR1 in mice and found that following paternal inheritance of this mutation, several imprinted genes (including Cdkn1c, a putative tumor suppressor gene) that are normally expressed only from maternal alleles are also expressed from the paternal chromosome and the affected animals are 20% smaller than their wild type littermates (Fitzpatrick et al., 2002). These finding suggest that KvDMR1 normally functions to silence the paternal alleles of maternal-specific imprinted genes in this chromosome region. We have also demonstrated this putative repressive activity of KvDMR1 in cell culture using two independent enhancer-blocking assays. These experiments show that KvDMR1 can suppress reporter gene expression by functioning as a chromatin insulator, and that this repressive activity appears to modulated by DNA methylation (Kanduri et al., 2002). These results support the model that loss of methylation at KvDMR1 in BWS patients and tumors activates its chromatin insulator/silencer function inappropriately on the maternal chromosome which represses the expression of potential growth regulating genes such as CDKN1C which can lead to overgrowth and malignancy. Currently we are carrying on several projects to elucidate the mechanism by which KvDMR1 promotes gene silencing. These studies include identifying functionally important components and the proteins that bind to them, determining whether the anti-sense RNA associated with this locus has a function, and characterizing differences in chromatin structure between maternal and paternal alleles of genes controlled by KvDMR1. Another ongoing project concerns the identification of genes disrupted by a constitutional translocation in a patient with Wilms' tumor, a pediatric malignancy of the kidney. Once identified, the affected gene(s) will be studied to determine the mechanism by which their disruption contributes to tumorigenesis.

• Smith JF, Mahmood S, Song F, Morrow A, Smiraglia D, Zhang X, Rajput A, Higgins MJ, Krumm A, Petrelli NJ, Costello J, Nagase H, Plass C, Held W.  CpG island methylation in colorectal cancer:  identification of genomic regions of DNA methylation associated with up-regulation of gene expression.  Epigenetics, In press.
• Oh R, Ho R, Gertesenstein M, Paderova J, Hsien J, Squire J, Higgins MJ, Nagy A, Lefebvre L.  Epigenetic and phenotypic consequences of a site-specific truncation in the dital chromosome 7 imprinted domain in mice.  Mol Cell Biol, In press.
• Fitzpatrick GB, Pugacheva EM, Shin J-Y, Abdullayev Z, Yang Y, Khatod K, Lobanenkov V, Higgins, MJ.  Allele-specific binding of CFCF to the mulipartite imprinting control region Kvdmr1.  Mol Cell Biol 2007; 27(7):2636-2647.
• Diaz-Meyer N, Yang Y, Sait SN, Maher ER, Higgins MJ. Alternative mechanisms associated with silencing of CDKN1C in Beckwith-Wiedemann syndrome. J Med Genet 2005; 42:648-655.
• Salas M, John R, Saxena A, Barton S, Frank D, Fitzpatrick G, Higgins MJ, Tycko B. Placental growth retardation due to loss of imprinting of Phlda2. Mech Dev 2004; 121: 1199-1210.
• Reik W, Murrell A, Lewis A, Mitsuya K, Umlauf D, Dean W, Higgins M, Feil R. Chromosome loops, insultators, and histone methylation: New insights into regulation of imprinting in clusters. Cold Spring Harb Symp Quantit Biol 2004; 69:29-37.
• Lewis A, Mitsuya K, Umlauf D, Smith P, Dean W, Walter J, Higgins M, Feil R, Reik W. Imprinting on distal chromosome 7 in the placenta involves repressive histone methylation independent of DNA methylation. Nat Genet 2004; 12:1291-1295.
• Diaz-Meyer N, Day CD, Khatod K, Maher ER, Cooper W, Reik W, Junien C, Graham G, Algar E, Der Kaloustian VM, Higgins MJ. Silencing of CDKN1C (P57^KIP2) is associated with hypomethylation at KVDMR1 in Beckwith-Wiedemann. J Med Genet 2003; 40:797-801.
• Fitzpatrick CV, Soloway PD, Higgins M. Regional loss of imprinting and growth deficiency in mice with a targeted deletion of KvDMR1. Nat Genet 2002; 32:426-431.
• Kanduri C, Fitzpatrick G, Mukhopadhyay R, Kanduri M, Lobanenkov V, Higgins M, Ohlsson RA. differentially methylated imprinting control region with the Kcnq1 locus harbours a methylation-sensitive chromatin insulator. J Biol Chem 2002;277:18106-18110.
• Prawitt D, Enklaar T, Klemm G, Gaertner B, Spangenberg C, Winterpacht A, Higgins MJ, Pelletier J, Zabel B. Identification and characterization of MTR1, a novel gene from the BWS-WT2 critical region on chromosome 11p15.5 with homology to melastatin (MLSN1) and the trp gene family. Hum Mol Genet 2000; 9:203-216.
• Engel JR, Smallwood A, Harper A, Higgins MJ, Oshimura M, Reik W, Schofield PN, Maher ER. Epigenotype-phenotype correlations in Beckwith-Wiedemann syndrome. J Med Genet 2000; 37:921-926.
• Smilinich NJ, Day CD, Fitzpatrick GV, Caldwell G, Lossie A, Cooper PR, Smallwood AC, Joyce JA, Schofield PN, Reik W, Nicholls RD, Driscoll, DJ, Maher ER, Shows TB, Higgins MJ. A maternally methylated CpG-island in KvLQT1 is associated with an antisense paternal transcript and loss of imprinting in Beckwith-Wiedemann syndrome. Proc Natl Acad Sci USA 1999; 96:8064-8069.
• Cooper PR, Smilinich NJ, Day CD, Nowak NJ, Reid LH, Pearsall RS, Reece M, Prawitt D, Landers J, Housman DE, Winterpacht A, Zabel BU, Pelletier J, Weissman BE, Shows TB, Higgins MJ. Divergently transcribed overlapping genes expressed in liver and kidney and located in the 11p15.5 imprinted domain. Genomics 1998; 49: 38-51.
• Reid LH, Davies C, Cooper PR, Crider-Miller SJ, Sait SNJ, Nowak NJ, Evans G, Stanbridge EJ, de Jong P, Shows TB, Weissman BE, Higgins MJ. A 1-Mb physical map and PAC contig of the imprinted domain in 11p15.5 that contains the TAPA1 and the BWSCR1/WT2 region. Genomics 1997; 43: 366-375.

Selected Publications (please click here for a complete PubMed list for Dr. Higgins).