Expression of APITD1 is not related to copy number changes of chromosomal region 1p36 or the prognosis of uveal melanoma.
OBJECTIVE
Concurrent loss of chromosome arm 1p, region 36, and chromosome 3 leads to decreased disease-free survival in patients with uveal melanoma. A candidate tumor-suppressor gene APITD1 is located on the critical region on chromosome arm 1p, and it was therefore hypothesized that lower expression levels of this gene could lead to decreased survival in patients, with concurrent loss of a region on chromosome arm 1p and chromosome 3. Using neuroblastoma cells, which, like uveal melanoma, originate from neural crest cells, a former study showed that APITD1 has cell growth and/or cell death properties. In this study, APITD1 expression was analyzed to determine whether it corresponds with the DNA copy number and is related to survival in uveal melanoma.


METHODS
To detect whether loss in the copy number of APITD1 results in lowered mRNA expression of the gene, FISH analysis was combined with real-time PCR. In addition, the effect of APITD1 expression on survival was studied by using Kaplan-Meier survival analysis.


RESULTS
Expression of APITD1 mRNA was not related to DNA copy number (P = 0.956) or chromosome 3 status (P = 0.958). Kaplan-Meier survival analysis showed very similar survival curves for tumors with high and low APITD1 expression, with a log-rank significance value of P = 0.9682.


CONCLUSIONS
These results indicate that APITD1 is not the tumor suppressor gene on 1p36 responsible for the negative prognostic effect in uveal melanoma with concurrent loss of chromosome arm 1p, region 36, and chromosome 3.
van Gils
Walter
W
Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands.
Mensink
Hanneke W
HW
Kilic
Emine
E
Vaarwater
Jolanda
J
Verbiest
Michael M
MM
Paridaens
Dion
D
Luyten
Gregorius P
GP
de Klein
Annelies
A
Brüggenwirth
Hennie T
HT
D017209:Apoptosis / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D018628:Gene Dosage / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008545:Melanoma / Q000235:genetics* / Q000401:mortality; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D014604:Uveal Neoplasms / Q000235:genetics* / Q000401:mortality
D051017:Apoptosis Regulatory Proteins; C493243:CENPS protein, human; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins