AA Peters

AC Wolff

American Cancer Society

CY Lin

D Romagnolo

EM Jarvis

G Dorner

H Iwase

JA Duncan

K Kashima

K Yoshida

LA Martin

LL Brunton

LM McShane

ME Hammond

MJ Ellis

N Fujiki

N Tulchin

NA Hatcher RA

R Jeselsohn

RD Rubens

RW Carlson

S Kansra

SR Johnston

T Sorlie

TW Callaway

V Panet-Raymond

VC Jordan

SpringerPlus

Abstract
          
            Background
            Estrogen receptor (ER) positive breast cancer can often be treated by hormone therapy; however a certain population of ER-positive patients become resistant to hormone therapy after long-term hormone treatment. Ethinylestradiol (EE2) is a derivative of estrogen, which has shown promising effects in these patients.
          
          
            Methods
            We successfully obtained tissue samples from 6 patients undergoing EE2 treatment and examined 13 well-known breast cancer-related factors by immunohistochemistry. Of the 6 patients, 5 responded but one patient did not.
          
          
            Results
            Before EE2 treatment, staining for both ER and androgen receptor (AR) was strong in the nucleus, and the progesterone receptor (PgR) was almost no staining. EE2 treatment significantly down-regulated ER and up-regulated PgR while nuclear and cytosolic AR were oppositely down- and up-regulated, respectively. Cytosolic staining of BRCA1 was significantly up-regulated by EE2 whereas nuclear staining tended to decrease. Individual comparisons suggested less induction of PgR and decreasing AKT but increasing pAKT in the non-responder following EE2 treatment.
          
          
            Conclusions
            Our observations revealed that EE2 activated ER downstream genes; however it did not stimulate cell growth. This suggests that hormone resistant cells might receive growth signals from a non-genomic pathway and this may be reflected in their sensitivity to EE2 treatment.
          </jats:sec

Yoko Omoto

Takashi Takeshita

Yutaka Yamamoto

Mutsuko Yamamoto-Ibusuki

Mitsuhiro Hayashi

Aiko Sueta

Saori Fujiwara

Tetsuya Taguchi

Hirotaka Iwase

Crossref

Immunohistochemical analysis in ethinylestradiol-treated breast cancers after prior long-term estrogen-deprivation therapy

https://springerplus.springeropen.com/track/pdf/10.1186/s40064-015-0851-8?site=springerplus.springeropen.com

Immunohistochemical analysis in ethinylestradiol-treated breast cancers after prior long-term estrogen-deprivation therapy

Abstract

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