Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been proposed that the biosynthesis of estrogens by the human endometrium may be of physiological significance during the menstrual cycle. Local estrogen production was also suggested to be important in the development of endometrial cancer; however, the presence or absence of aromatase enzyme activity in normal human endometrium is controversial. To address this issue, we used a sensitive technique capable of detecting mRNA transcripts present in only very low copy number. The polymerase chain reaction linked to reverse transcription (RT-PCR) was used to evaluate the presence or absence of aromatase cytochrome P450 (P450arom) transcripts in endometrial tissues (n = 7) and endometrial stromal cells (n = 9) under various culture conditions. RNA was isolated from four proliferative and three secretory tissue samples and from cultured endometrial stromal cells isolated from seven proliferative and two secretory endometria. Five sets of cultures were treated with medroxyprogesterone acetate (MPA), estradiol (E2), and forskolin. Additionally, RNA was isolated from decidualized endometrium obtained from a patient with tubal pregnancy. A single stranded cDNA was synthesized from total RNA using Moloney murine leukemia virus reverse transcriptase and a P450arom-specific oligonucleotide. The single stranded cDNA was used as a template for PCR and was amplified for 20-35 cycles using P450arom-specific primers. RNA from adipose tissue and placenta was amplified to provide positive controls, whereas myometrial RNA was used as a negative control. In two experiments involving two endometrial tissues and three sets of cells in culture, a rat P450arom cRNA was coamplified in each sample as an internal control to demonstrate that the remote possibility of RT-PCR failures in individual test samples cannot account for our negative results. By Southern or slot blot hybridization of the amplified fragments using human and rat P450arom-specific probes, we found no evidence for the presence of P450arom transcripts in normal endometrium, decidualized endometrium, or endometrial stromal cells in culture. In our hands, assay of aromatase activity using [3H]water release from [3H]androstenedione by endometrial stromal cells in culture treated with MPA and E2, did not reveal any detectable aromatase activity. The same cells responded to MPA plus E2 treatment by a significant increase in PRL secretion into the culture medium. Presently, RT-PCR is the most sensitive method available for the detection of specific mRNA species in low copy numbers. These findings are indicative of the absence of P450arom transcripts in normal human endometrium.
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PMID:Polymerase chain reaction amplification fails to detect aromatase cytochrome P450 transcripts in normal human endometrium or decidua. 768 41

Generally, estrogens are considered to be involved in the neoplastic transformation of endometrium. After the menopause these estrogens mainly originate from conversion of adrenal androgens by aromatization in body fat. However, in case of stromal hyperplasia of the ovaries, it cannot be excluded that production of aromatizable androgens by postmenopausal ovaries leads to increased availability of androgen precursors for intratumoral estrogen synthesis in the endometrial tissue as well. The local presence of androgens and the local expression and activity of aromatase is considered important for this steroidogenesis. In this review, we will discuss the available evidence that androgens, produced in hyperplastic ovarian stroma or body fat tissues, play a role in the development of endometrial cancer through conversion into estrogens, a reaction catalyzed in the endometrium by the enzyme aromatase cytochrome P450. As the presence of aromatase appeared to be a pathophysiological factor in the formation of breast cancer, the latter will be evaluated in relation to the development of endometrioid endometrial cancer as well, since both disorders appear partly estrogen dependent. As treatment with aromatase inhibitors appeared feasible in breast cancer, current knowledge of comparable treatment modalities in hormone dependent endometrial cancer will be reviewed.
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PMID:Aromatase in the context of breast and endometrial cancer. A review. 1649 63