Cytokine expression in human anterior pituitary adenomas.
OBJECTIVE
There is increasing evidence for the role of cytokines in pituitary differentiated function and tumorigenesis, but the spectrum of cytokines found in the pituitary is unknown. Therefore profiles of cytokine expression were determined in different human anterior pituitary adenoma sub-types.


METHODS
The reverse transcriptase-linked polymerase chain reaction (PCR) was used to identify the presence of cytokine mRNA within human pituitary adenomas.


METHODS
Seventeen pituitary adenoma biopsies removed at transsphenoidal surgery were examined: 4 somatotrophinomas, 7 non-functional adenomas, 4 prolactinomas, one case of Cushing's disease and one case of Nelson's syndrome.


METHODS
RNA was extracted from each adenoma biopsy and reverse transcribed into cDNA. This was specifically amplified in a PCR using oligonucleotide primers complementary to each cytokine. The cytokines investigated were interleukin (IL)-I alpha, IL-I beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, tumour necrosis factor (TNF)-alpha, TNF-beta and transforming growth factor (TGF)-beta 1, beta 2 and beta 3. The products of each PCR were visualized using agarose gel electrophoresis.


RESULTS
All 17 adenomas expressed IL-8 transcripts, but no expression of IL-2, IL-5 or IL-7 was found. IL-6 was expressed in all 4 somatotrophinomas, 3 of 7 non-functional tumours, 2 of 4 prolactinomas and in the single case of Nelson's syndrome. At least one of the 3 isoforms of TGF-beta was found in all but 2 tumours; one prolactinoma and one non-functional adenoma. IL-1 alpha, IL-beta, IL-4, TNF-alpha and TNF-beta were expressed sporadically by individual adenomas.


CONCLUSIONS
These data suggest that whilst IL-8 may be important, the local expression of the cytokines IL-2, IL-5 and IL-7 is not important in human anterior pituitary tumorigenesis.
Green
V L
VL
Department of Medicine, University of Hull, Liverpool, UK.
Atkin
S L
SL
Speirs
V
V
Jeffreys
R V
RV
Landolt
A M
AM
Mathew
B
B
Hipkin
L
L
White
M C
MC
D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D000368:Aged; D001483:Base Sequence; D003480:Cushing Syndrome / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009347:Nelson Syndrome / Q000378:metabolism; D010903:Pituitary Gland, Anterior; D010911:Pituitary Neoplasms / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D015175:Prolactinoma / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
D016207:Cytokines; D017931:DNA Primers; D015850:Interleukin-6; D016209:Interleukin-8; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D013006:Growth Hormone