Increased expression of stromelysin 3 mRNA in leiomyomas (uterine fibroids) compared with myometrium.
OBJECTIVE
To determine the level of expression of selected matrix metalloproteinases in uterine leiomyoma compared with unaffected myometrium in an effort to explain the abnormal accumulation of extracellular matrix in the leiomyoma.


METHODS
The levels of matrix metalloproteinase (MMP) mRNA in leiomyoma and myometrium were measured in samples from 22 patients during either proliferative (n = 6) or secretory phases (n = 16) of the menstrual cycle. Relative amounts of collagenase (MMP-1) and stromelysin (MMP-3) mRNAs were measured by Northern blot analysis, and amounts of stromelysin 3 (MMP-11) and matrilysin (MMP-7) mRNA from each sample were determined by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and normalized to beta-actin mRNA.


RESULTS
The levels of MMP-1 and MMP-3 mRNAs were similar in both leiomyoma and unaffected myometrium. The levels of MMP-11 mRNA were twofold greater in leiomyoma compared with myometrium throughout the menstrual cycle, and the differences in the levels of MMP-11 were significantly different during the secretory phase. The level of MMP-7 mRNA expression was similar in leiomyoma, myometrium, and endometrium.


CONCLUSIONS
Among the metalloproteinases examined in this study, only the levels of MMP-11 mRNA were elevated in leiomyoma compared with myometrium. The increased expression of MMP-11 in uterine leiomyoma compared with myometrium is analagous to previously reported elevations of MMP-11 mRNA in dermatofibromas compared with unaffected skin. The increased expression of MMP-11 mRNA in fibroid tumors suggests that this MMP may be involved in the formation of a more fibrous extracellular matrix in leiomyoma relative to unaffected myometrium.
Robert Wood Johnson Pharmaceutical Research Institute, Raritan, New Jersey 08559, USA. spalmer@prius.jnj.com
S S
SS
Palmer
D
D
Haynes-Johnson
T
T
Diehl
R A
RA
Nowak
D017364:Collagenases / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D007889:Leiomyoma / Q000201:enzymology*; D020781:Matrix Metalloproteinase 1; D053507:Matrix Metalloproteinase 11; D020783:Matrix Metalloproteinase 7; D008666:Metalloendopeptidases / Q000235:genetics*; D009215:Myometrium / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D017697:Premenopause; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D012194:RNA-Directed DNA Polymerase; D014594:Uterine Neoplasms / Q000201:enzymology*
D012333:RNA, Messenger; D012194:RNA-Directed DNA Polymerase; D017364:Collagenases; D053507:Matrix Metalloproteinase 11; D008666:Metalloendopeptidases; D020783:Matrix Metalloproteinase 7; D020781:Matrix Metalloproteinase 1