Estramustine-binding protein in meningioma.
The presence of estramustine-binding protein has been suggested to positively correlate with the effect of the cytotoxic drug estramustine, a combination of estradiol and nornitrogen mustard used in the treatment of prostatic carcinoma. This study demonstrates expression of estramustine-binding protein in a series of meningioma using different ligand-based and immunological techniques. Scatchard plot analysis showed specific binding sites for [3H]lestramustine in meningioma tissue with a dissociation constant of 22-26 nM. Immunohistochemistry revealed an immunoreactivity in meningioma comparable to that demonstrated in prostatic carcinoma. The mean concentration (n = 6) of estramustine-binding protein in meningioma, as determined by radioimmunoassay was 159 ng/g tissue (range 18-274 ng/g). Moreover, partial characterization using size exclusion chromatography of [3H]estramustine-labeled tumor extracts and Western blot analysis of immunoprecipitated samples indicated that the structure of the estramustine-binding protein in meningioma is similar to that in rat prostate, with three polypeptide components of 10, 14, and 16 kDa, as compared to 8, 10-11, and 12 kDa in rat prostate. In conclusion, the novel observation of estramustine-binding protein and specific binding of estramustine in meningioma justify further evaluation regarding the role of estramustine-binding protein in the growth behavior of meningioma and the potential for estramustine and similar hormone-related drugs in the treatment of relapsing meningioma.
Karlsson
A E
AE
Department of Oncology, Umeå University, Sweden. Anna.Karlsson@onkologi.umu.se
Bergenheim
A T
AT
Björk
P
P
Henriksson
R
R
D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007150:Immunohistochemistry; D008577:Meningeal Neoplasms / Q000378:metabolism*; D008579:Meningioma / Q000378:metabolism*; D029584:Prostatic Secretory Proteins; D011863:Radioimmunoassay
D002352:Carrier Proteins; D029584:Prostatic Secretory Proteins; C028321:estramustine-binding protein