Localization and quantification of vascular endothelial growth factor messenger ribonucleic acid in human myometrium and leiomyomata

Vascular endothelial growth factor (VEGF) messenger RNA (mRNA) and VEGF peptide were studied in human myometrium and leiomyomata. Amplification of complementary DNA from myometrium and leiomyomata by the polymerase chain reaction revealed three species of mRNA encoding VEGF: VEGF189, VEGF165, and VEGF121. In situ hybridization demonstrated VEGF mRNA expression throughout the smooth muscle cells of myometrium and leiomyomata. VEGF-like immunoreactivity was also detected in these tissues by immunocytochemistry. Quantification of VEGF mRNA using an RNAse protection assay demonstrated that in normal myometrium, levels of VEGF mRNA are significantly higher in the secretory phase than in the proliferative phase of the cycle. Leiomyomata did not have significantly different levels of VEGF mRNA compared with normal myometrium. In untreated leiomyomata, there was no significant difference between VEGF mRNA levels in the proliferative and secretory phases of the cycle. Leiomyomata from women treated with a GnRH anlog did not have significantly different levels of VEGF mRNA from untreated leiomyomata.

Quantification of mRNA in human tissue using fluorescent nested reverse-transcriptase polymerase chain reaction

We report the development of a quantitative nested reverse-transcriptase polymerase chain reaction which utilizes a fluorescence detection system. Using specific primer pairs to study mRNA for endothelin receptors in the human kidney, we synthesized a cRNA construct containing the same sequences but yielding a PCR product some 300 base pairs larger than native mRNA. Inclusion of a known amount of construct as internal standard with tissue RNA prior to cDNA synthesis allowed all reactions to occur under the same conditions in the same tube. In the nested PCR reaction, serial dilutions made before the second round enabled construction of a standard curve for each assay, and confirmation that standard and sample curves remained parallel. This indicates that both cDNAs amplified at the same rate. One internal primer was fluorescently labeled. Quantification of products using an ABI 373A sequencer with Genescan software gave sensitive and reproducible results. Analysis of a needle biopsy (10 mg) of histologically normal cortex gave 0.4 amol ETA mRNA and 1.6 amol ETB mRNA/micrograms total RNA. In medulla these values were 0.46 and 1.16 amol/micrograms, respectively. Ratios of ETB to ETA message were 74:26 in cortex and 77:23 in medulla, agreeing with previous ligand binding studies of receptor protein. Intra- and interassay coefficients of variation were 4.5 and 5.3%. This new method has potential for widespread application to the study of low copy-number mRNA or where only very small amounts of tissue are available, such as biopsy specimens.

Quantification of messenger ribonucleic acid for epidermal growth factor in human myometrium and leiomyomata using reverse transcriptase polymerase chain reaction

Epidermal growth factor (EGF) mRNA was quantified in samples of human myometrium, untreated leiomyomata, and leiomyomata from patients treated with a GnRH analog. Quantitative reverse transcriptase-polymerase chain reaction, using a synthetic internal standard, was applied to determine levels of EGF mRNA. In myometrium from uteri with no leiomyomata, levels of EGF mRNA did not differ between the proliferative and secretory phase of the cycle. Leiomyomata from women who had received no drug therapy had significantly higher amounts of EGF mRNA than myometrium from a normal uterus, but only in the secretory phase of the cycle. In the proliferative phase, leiomyomata did not have different amounts of EGF mRNA compared to normal myometrium. Untreated leiomyomata in the secretory phase of the cycle, but not those in the proliferative phase, had significantly more EGF mRNA than leiomyomata from women who had received treatment with a GnRH analog. These findings suggest that EGF is important in leiomyomata development, but imply that its production is only increased during the secretory phase of the cycle. This challenges the hypothesis that EGF production in leiomyomata is mediated by estrogen and raises the possibility that progesterone may be the more important hormone in fibroid growth.