Skip Navigation


Annals of Oncology Advance Access originally published online on October 25, 2005
Annals of Oncology 2006 17(1):43-49; doi:10.1093/annonc/mdj017
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
17/1/43    most recent
mdj017v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (2)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Orita, H.
Right arrow Articles by Fujii, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Orita, H.
Right arrow Articles by Fujii, H.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2005 European Society for Medical Oncology

Allelic loss analysis of early-stage flat-type colorectal tumors

H. Orita1, N. Sakamoto2, Y. Ajioka3, T. Terai2, O. Hino4, N. Sato2, T. Shimoda5, T. Kamano1, M. Tsurumaru1 and H. Fujii4,*

Departments of 1 Surgery (I), 2 Gastroenterology and 4 Pathology (II), Juntendo University, Tokyo; 3 Division of Molecular & Cellular Medicine, Department of Molecular Genetics, Course for Molecular & Cellular Medicine, Niigata University, Graduate School of Medical & Dental Science, Niigata City; 5 Pathology and Clinical Laboratory Divisions, National Cancer Center Research Institute and Hospital, Tokyo, Japan

* Correspondence to: Dr H. Fujii, Department of Pathology (II), Juntendo University School of Medicine, 2-1-1 Hongo, Tokyo 113-8421, Japan. Tel: +81-3-5802-1039; Fax: +81-3-5684-1646; E-mail: hfujii{at}med.juntendo.ac.jp

Background: Flat-type colorectal tumors are rare, but are known for their unusual flat morphology and aggressive clinical behavior despite their small size. To identify distinct genetic alterations, loss of heterozygosity (LOH) analysis was performed on microdissected tissues.

Materials and methods: DNA was extracted from multiple microdissected foci in 43 cases of early-stage flat-type colorectal tumors and LOH analysis was performed on 2q, 4q, 5q, 12q, 14q, 15q, 17p, 18q, 18p and 22q.

Results: LOH patterns were detected in one of two forms: (i) homogeneous LOH throughout the microdissected foci, which indicated the early acquisition of LOH; and (ii) heterogeneous LOH, which were detected in a part of analyzed foci. Homogeneous and heterogeneous LOH were most frequently detected on 17p (92%) followed by 18q (81%), 18p (81%), 5q (61%), 22q (51%), 14q (44%), 15q (41%), 2q (39%), 12q (36%) and 4q (32%). Homogeneous LOH was detected most frequently on 17p (68%) followed by 18p (53%), 18q (53%), 22q (34%) and 12q (27%). The average fractional allelic loss (FAL) for heterogeneous and homogeneous LOH was 0.57 and the average FAL for homogeneous LOH was 0.37.

Conclusions: Early flat-type colorectal tumors frequently shows the early occurrence of multiple LOH including 17p, 18p, 18q and 22q, which is coupled with additional LOH of other loci either simultaneously or in the early clonal progression phase. The extent and sequences of LOH may be the mechanisms responsible for the aggressive clinical behaviors of these tumors.

Key words: flat-type colorectal tumor, fractional allelic loss, loss of heterozygosity, tumor suppressor gene, 17p, 18p, 18q, 22q


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.