MAGE1 is expressed by a subset of pancreatic endocrine neoplasms and associated lymph node and liver metastases.
BACKGROUND
MAGE1 was originally isolated from human melanoma cells as a target antigen for autologous cytotoxic T lymphocytes. Expression of MAGE1 has subsequently been identified in a number of neoplastic cell types, including testicular germ cell and breast cancer cells, which has led to the development of antitumor MAGE1 vaccines.


OBJECTIVE
To determine if Mage-1 is expressed in pancreatic endocrine neoplasms (PENs) and PEN metastases.


METHODS
We utilized immunolabeling analysis for Mage-1 on 49 primary PENs, 11 liver metastases, and 6 lymph node metastases. A semiquantitative labeling index (LI) of 0 (no expression), 1, 2 (moderate expression), and 3 (intense expression, correlating with internal control markers) was used to determine relative amounts of MAGE1 expression in these lesions.


RESULTS
We have identified MAGE1 expression in a subset (42 of 49; 86%) of PENs. Normal pancreatic ducts, present in tissue adjacent to PENs, were utilized as a positive control for Mage-1 immunolabeling (index score 3); no other detectable labeling for Mage-1 was evident in normal pancreatic tissue. Primary PENs, with or without metastases (mean LI score 1.2 vs 1.0, respectively), did not demonstrate a significant difference in Mage-1 LI, although intratumoral heterogeneity was apparent in some, but not all, of these lesions. Lymph node metastases (mean score 2.0) demonstrated a significant increase in Mage-1 LI as compared to primary, non-metastatic lesions (p = 0.04984) and primary metastatic lesions (p = 0.02351). In contrast, six patients with a survival of less than one year demonstrated a low Mage-1 LI (mean score, 0.58).


CONCLUSIONS
MAGE1 expression is present in a subset of primary PENs and in lymph node metastases, and may therefore serve as a useful marker and potential therapeutic target in PENs. Furthermore, the absence of Mage-1 expression in a subset of primary PENs may indicate a worsened prognosis.
Hansel
Donna E
DE
Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. dhansel@jhmi.edu
House
Michael G
MG
Ashfaq
Raheela
R
Rahman
Ayman
A
Yeo
Charles J
CJ
Maitra
Anirban
A
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D015408:Gastrinoma / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007340:Insulinoma / Q000276:immunology* / Q000473:pathology; D008113:Liver Neoplasms / Q000276:immunology / Q000556:secondary*; D008207:Lymphatic Metastasis; D008297:Male; D058950:Melanoma-Specific Antigens; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis*; D010190:Pancreatic Neoplasms / Q000276:immunology* / Q000473:pathology
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C072011:MAGEA1 protein, human; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins