Melanoma inhibitor of apoptosis protein is expressed differentially in melanoma and melanocytic naevus, but similarly in primary and metastatic melanomas.
BACKGROUND
Malignant melanoma is highly resistant to current treatments. The inhibitor of apoptosis protein (IAP) family member, melanoma IAP (ML-IAP), is overexpressed in some melanoma cell lines, rendering them resistant to apoptotic signals. Targeting ML-IAP is a promising approach to treating melanoma. However, the status of ML-IAP expression in human melanoma tissues and the difference in expression between melanoma and melanocytic naevus are not known.


OBJECTIVE
To investigate these issues.


METHODS
ML-IAP expression in 48 archived patient samples (34 melanomas and 14 dermal naevi) was assessed by immunohistochemistry and by in situ hybridisation and reverse transcription polymerase chain reaction (RT-PCR) assays developed for the study.


RESULTS
Expression of ML-IAP was detected in 47.6-70.6% (10 of 21 to 24 of 34) of the melanomas, varying with detection methods. The expression rate in melanoma was much higher than that in melanocytic naevus (10.0-21.4%; one of 10 to three of 14). No significant difference was seen between primary and secondary melanomas. ML-IAP expression rates assessed by the three methods were in agreement.


CONCLUSIONS
The ML-IAP expression rate in archived melanoma tissues is around 50-70%, with no difference between primary and secondary melanomas. A small number of dermal naevi ( approximately 20%) also expressed ML-IAP.
Gong
J
J
Pathology Department, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610041, China.
Chen
N
N
Zhou
Q
Q
Yang
B
B
Wang
Y
Y
Wang
X
X
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D005260:Female; D015870:Gene Expression; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization / Q000379:methods; D051034:Inhibitor of Apoptosis Proteins; D008297:Male; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology / Q000556:secondary; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009508:Nevus, Pigmented / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology
D048868:Adaptor Proteins, Signal Transducing; C419866:BIRC7 protein, human; D051034:Inhibitor of Apoptosis Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm