Characterization of the prolactin receptor in human prostate

Leake, A.; Chisholm, G. D.; Habib, F. K.

doi:10.1677/joe.0.0990321

Cited by 22 publications

(6 citation statements)

References 10 publications

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“…Unless speci¬ fied otherwise this particulate membrane fraction was used in all subsequent incubations. Subcellular fractionation of the tissue was per¬ formed according to the method of Leake, Chisholm & Habib (1983).…”

Section: Buffersmentioning

confidence: 99%

Localization and characterization of epidermal growth factor receptors on human testicular tissue by biochemical and immunohistochemical techniques

Stubbs

Hargreave²,

Habib³

1990

Journal of Endocrinology

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In the present study attempts were made to characterize the epidermal growth factor (EGF) receptor on human testicular tissue. A radioligand exchange assay with 125I-labelled EGF was used to detect a high affinity, low capacity, single binding site in the 105,000 g particulate fraction of human testicular tissue. Binding was optimal at 32 degrees C following a 40-min incubation with a mean (+/- S.D.) dissociation constant of 327 +/- 59 pmol/l (d.f.9). The number of binding sites ranged from 0.07 to 0.21 pmol/mg protein. Competition studies with other peptide hormones including LH, FSH, prolactin, insulin-like growth factor-I, fibroblast growth factor and nerve growth factor have confirmed the specificity of EGF for its receptor. The receptor was also found to be heat-labile and sensitive to trypsinization. Cross-linking experiments using disuccinimidyl suberate revealed major binding species at the 125 kDa region and this is thought to represent a proteolysed form of the receptor. Immunohistochemical localization of the receptors demonstrated their presence in the interstitial tissue and not within the seminiferous tubules. The presence of specific EGF binding in the interstitial tissue suggests that EGF may play some role in testicular steroidogenesis.

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Section: Buffersmentioning

confidence: 99%

Localization and characterization of epidermal growth factor receptors on human testicular tissue by biochemical and immunohistochemical techniques

Stubbs

Hargreave²,

Habib³

1990

Journal of Endocrinology

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“…The protein concentration of the final total particulate fraction was adjusted to 1 mg/ml and this was used for all subsequent studies except where indicated otherwise. For experiments designed to determine the subcellular distribution of the specific EGF binding protein, the subcellular fractions were prepared according to the method of Leake, Chisholm & Habib (1983) to provide a crude heavy pellet (800 g), the mitochondrial pellet (15 000 g), the microsomal pellet (105 000 g) and the 105 000 # supernatant fraction (cytosol). Briefly, homogenate samples were incubated with 6-0 nmol/1 (200 000 c.p.m.)…”

Section: Other Chemicalsmentioning

confidence: 99%

“…Pretreatments with MgCl2 and dextran-coated charcoal Membrane suspension was mixed with 2 ml buffer C at room temperature for 10 min as detailed by Leake et al (1983). The membrane suspensions were subse¬ quently centrifuged at the appropriate g force and the resultant pellets reconstituted in buffer A.…”

Section: Other Chemicalsmentioning

confidence: 99%

Localization of epidermal growth factor receptors in the human prostate by biochemical and immunocytochemical methods

Maddy¹,

Chisholm²,

Hawkins³

et al. 1987

Journal of Endocrinology

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The receptor for epidermal growth factor (EGF) was characterized in the particulate fraction from human benign prostatic hyperplasia (BPH) and was present in 85% of tissues analysed. The uptake of 125I-labelled EGF by BPH was dependent on both time and temperature, with maximum specific uptake achieved after incubation for 90 min at 37 degrees C. Binding characteristics revealed two classes of binding sites of higher (mean dissociation constant (Kd) +/- S.D. = 0.8 +/- 0.2 nmol/l) and lower (Kd = 7.6 +/- 2.8 nmol/l) affinities. Competition studies demonstrated the specificity of the receptor assay since the binding of labelled EGF was abolished with excess unlabelled EGF but not with excess unlabelled human GH, human insulin, venom nerve growth factor, human FSH, human LH and human prolactin. There was a complex biphasic relationship between specific binding and protein concentration in the range 0.1-8 mg/ml. Subcellular fractionation of BPH homogenates demonstrated that the bulk of the specific binding was confined to the 800 g (crude heavy pellet) and 15,000 g (mitochondrial pellet) fractions. The 105,000 g (microsomal pellet) and the 105,000 g (cytosol fraction) exhibited low and variable binding capacities for the growth factor. The presence of EGF receptor was also confirmed by immunocytochemical staining of frozen sections from BPH using monoclonal antibody specific for EGF receptors. A positive correlation between 125I-labelled EGF binding and the intensity of staining was found. The presence of a specific EGF-binding receptor protein in human BPH tissues suggests that EGF may play a role in the pathogenesis of human BPH.

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“…3,12,13 Moreover, patients with prostate cancer have been reported to have higher levels of plasma PRL than did age-matched controls, 3,12,13 and high affinity PRL binding sites have been detected in normal, BPH, and neoplastic human prostate. 3,11,14 PRL, along with growth hormone, belongs to a superfamily of growth factors. 15,16 The peptide hormone is known to have highly pleiotropic actions including those related to regulation of growth and differentiation.…”

mentioning

confidence: 99%

Prolactin Receptor Expression in the Developing Human Prostate and in Hyperplastic, Dysplastic, and Neoplastic Lesions

Leav

Merk

Lee

et al. 1999

The American Journal of Pathology

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In situ hybridization and immunohistochemistry were used to localize and compare the expression of the long form of the human prolactin receptor in fetal, prepubertal, and adult prostate. Results were then compared with hyperplastic, dysplastic, and neoplastic lesions. Both receptor message and protein were predominately localized in epithelial cells of the fetal, neonatal, prepubertal, and normal adult prostate. In hyperplastic lesions the expression of the receptor was unchanged with respect to normal epithelial cells. Irrespective of grade, markedly enhanced expression of the receptor was evident in dysplastic lesions. In lower Gleason grade carcinomas the intensity of receptor signal at the message and protein levels approximated that found in normal prostatic epithelium. However, in foci within higher grade cancers, receptor expression appeared diminished. Results from our study suggest that prolactin action plays a role in the development and maintenance of the human prostate and may also participate in early neoplastic transformation of the gland. Diminution of receptor expression in high grade neoplasms could reflect the emergence of a population of cells that are no longer responsive to the peptide hormone.

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Characterization of the prolactin receptor in human prostate

Cited by 22 publications

References 10 publications

Localization and characterization of epidermal growth factor receptors on human testicular tissue by biochemical and immunohistochemical techniques

Localization and characterization of epidermal growth factor receptors on human testicular tissue by biochemical and immunohistochemical techniques

Localization of epidermal growth factor receptors in the human prostate by biochemical and immunocytochemical methods

Prolactin Receptor Expression in the Developing Human Prostate and in Hyperplastic, Dysplastic, and Neoplastic Lesions

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