Immunolocalization of lactoferrin in cartilage-forming neoplasms.
BACKGROUND
Lactoferrin (Lf) is an 80-kDa basic glycoprotein, a member of the transferrin family of iron-binding proteins. Lf immunoreactivity has been extensively investigated in many neoplastic tissues. Recently, Lf expression was documented in the osteoblastic lineage of bone-forming tumors as well as in osteoblasts of fetal bone.


METHODS
Lactoferrin (Lf) immunoexpression was investigated in 30 human cartilage-forming tumors [15 enchondromas, 6 osteochondromas, 3 chondroblastomas (CBL), 3 chondrosarcomas, and 3 chondromyxoid fibromas (CMF)] as well as in human normal bone specimens and cartilaginous tissues obtained at autopsy from 5 adults and 3 fetuses.In addition, the immunohistochemical expression of Ki-67 antigen was analyzed on parallel sections from the same specimens. Quantification of Lf immunoreactivity was performed by using an intensity distribution (ID) score.


RESULTS
Lf immunoexpression with a variable ID score was encountered exclusively in 3 of 3 chondroblastomas and in 3 of 3 chondromyxoid fibromas. Lf immunoreactivity in these tumors, in clear contrast with the Lf absence in enchondromas, osteochondromas, and chondrosarcomas, may suggest a different histogenesis of the former. In agreement with this histogenetic origin, we detected Lf in the chondroblasts and osteoblasts within the fetal tissue, whereas no immunoreactivity was found in the corresponding adult cells. No significant associations were found between the Lf immunoexpression and the Ki 67 LI of the tumors of our series.


CONCLUSIONS
The presence of Lf in neoplastic cells of CBL and CMF, as well as in fetal cartilaginous tissue, may reflect a less mature phenotype of these tumors.
Ieni
Antonio
A
Department of Human Pathology, Policlinico Universitario G Martino, Pad D, Via Consolare Valeria, 98125 Messina, Italy.
Barresi
Valeria
V
Grosso
Maddacena
M
Rosa
Michele Attilio
MA
Tuccari
Giovanni
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000378:metabolism*; D001842:Bone and Bones / Q000196:embryology; D002356:Cartilage / Q000378:metabolism*; D016022:Case-Control Studies; D002648:Child; D002804:Chondroblastoma / Q000378:metabolism*; D005260:Female; D005350:Fibroma / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D007781:Lactoferrin / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
D019394:Ki-67 Antigen; D007781:Lactoferrin