Characterization of insulin-like growth factor 1 in human primary brain tumors.
Insulin-like growth factor 1 (IGF-1) is involved in the regulation of brain development and has been suggested as an autocrine stimulator of brain tumor cell proliferation. This study demonstrates the expression of IGF-1 in tumor tissue from human gliomas and one esthesioneuroblastoma. Using immunohistochemistry, expression of an IGF-1-like peptide was localized in tumor cells of 6 of the 9 gliomas examined as well as the esthesioneuroblastoma. From one anaplastic oligodendroglioma (which showed strong IGF-1 immunostaining) the IGF-1 transcripts were characterized after isolation of mRNA followed by amplification using the reverse transcriptase-polymerase chain reaction. Two IGF-1 complementary DNAs resulting from alternative splicing of the IGF-1 primary transcript were identified. These transcripts encode two different precursor proteins which correspond to Ea IGF-1 and Eb IGF-1. The significance of IGF-1 alternative mRNA splicing pathways remains to be determined.
Department of Pathology, Karolinska Hospital, Stockholm, Sweden.
A C
AC
Sandberg-Nordqvist
P A
PA
Ståhlbom
M
M
Reinecke
V P
VP
Collins
H
H
von Holst
V
V
Sara
D000595:Amino Acid Sequence; D001483:Base Sequence; D001932:Brain Neoplasms / Q000737:chemistry*; D005910:Glioma / Q000737:chemistry*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis* / Q000737:chemistry; D012334:RNA, Neoplasm / Q000032:analysis* / Q000737:chemistry
D012333:RNA, Messenger; D012334:RNA, Neoplasm; D007334:Insulin-Like Growth Factor I