Loss of heterozygosity of chromosome 16q in gallbladder carcinoma.
BACKGROUND
The present study was planned to investigate cumulative genetic changes during development and progression of gallbladder carcinoma (GBC) in clinical patients.


METHODS
We examined GBC DNA from resected tissue isolated from 56 cases of GBC for loss of heterozygosity (LOH) at six loci on five chromosomal arms (1p36, 9p21, 13q14, 16q24, 17p13), using highly polymorphic microsatellite markers.


RESULTS
High incidences of LOH at 1p36 (19/36: 53%), 9p21 (12/32: 38%), 13q14 (20/36: 56%), 16q24 (31/54: 61%), and 17p13 (15/36: 42%) were detected. When comparing genetic features with clinicopathological stages of these tumors, it appeared that only LOH at 16q24 had a high incidence (5/6: 83%) at an early stage (T1a: tumor invades lamina propria) of the disease, although large numbers of LOH were found on all chromosomal arms in tumors of more advanced stages (T1b, T2, T3, and T4).


CONCLUSIONS
These results suggested that the putative tumor suppressor gene on 16q24 may be strongly related to an early step of carcinogenesis in GBC and that GBC acquires a high malignant potential when the tumor invades the muscle layer.
Matsuo
Kei
K
Department of Surgery II, Nagasaki University School of Medicine, Nagasaki 852-8501, Japan. matsk@mebe.sphere.ne.jp
Kuroki
Tamotsu
T
Kitaoka
Fumio
F
Tajima
Yoshitsugu
Y
Kanematsu
Takashi
T
D002277:Carcinoma / Q000235:genetics* / Q000556:secondary; D002885:Chromosomes, Human, Pair 16; D004273:DNA, Neoplasm / Q000032:analysis; D005706:Gallbladder Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D019656:Loss of Heterozygosity; D018895:Microsatellite Repeats; D019042:Muscle Neoplasms / Q000235:genetics / Q000556:secondary
D004273:DNA, Neoplasm