孕激素对人乳腺组织雌激素受体、孕激素受体、增殖细胞核抗原、bcl-2及c-myc、c-fos、表皮生长因子受体表达的影响

Effect of progesterone on expression of ER, PR, PCNA, bcl-2, c-myc, c-fos, and EGFR in normal breast tissue implanted into nude mice

目的探讨孕激素对人正常乳腺组织癌变的影响。方法取良性乳腺病变患者手术的旁侧正常乳腺组织10例，移植入40只雌性裸鼠皮下，将每例标本分成4份，分别移植人4只裸鼠后随机分至4组：（1）雌激素组：苯甲酸雌二醇20μg（0．1ml，1mg／kg）；（2）孕激素组：60μg（0．1ml，3mg／kg）；（3）雌激素加孕激素组：苯甲酸雌二醇20μg（0．1ml，1mg／kg）和孕激素60μg（0．1ml，3mg／kg）；（4）对照组：生理盐水0．1ml；给药方法为隔天肌内注射。给药4周，取出植入的乳腺组织固定、切片，采用免疫组化检测雌激素受体（ER），孕激素受体（PR）、增殖细胞核抗原（PCNA）和bcl-2的蛋白表达，原位杂交检测c—myc、c-fos和表皮生长因子受体（EGFR）的分子表达。结果雌激素组、雌激素加孕激素组的ER表达比对照组降低，PR表达比对照组增高（P〈0．05）；孕激素组的ER、PR表达与对照组比较差异无统计学意义（P〉0．05）；雌激素组PCNA和bcl-2的表达比对照组增高（P〈0．01，P〈0．05）；其他两给药组与对照组比较，差异均无统计学意义（P〉0．05）。雌激素组、雌激素加孕激素组c-myc、c-los、EGFR的表达（吸光度值）均高于对照组（两组c-myc分别为534±19、623±78比较417±39，均P〈0．01；c-fos分别为265．7±5．3、236．1±3．6比较198．6±10．8，均P〈0．01；EGFR分别为294±6、257±28比较149±10，均P〈0．01）。孕激素组c-myc表达高于对照组（986±98比较417±39，P〈0．01），孕激素组的c-fos、EGFR表达与对照组比较差异无统计学意义（P〉0．05）。结论孕激素不影响人正常乳腺组织的增生和凋亡，但与雌激素合用可能拮抗雌激素的促增生和抑制凋亡作用。孕激素上调c-myc的表达，且并不抑制雌激素对c—myc、c-fos、EGFR的上调作用。

Objective To investigate the effect of progesterone on estrogen receptor （ER）, progesterone receptor （PR）, proliferating cell nuclear antigen （PCNA） , bcl-2 , c-myc, c-fos, and epidermal growth factor receptor （ EGFR ） expression in normal human breast tissues implanted into nude mice. Methods A xenograft-model, pieces of normal human breast tissue implanted subcutaneously into 9-10-week-old atbymic nude mice, was established. The tissue of each case was divided into 4 parts, and were transplanted into 4 nude mice. These mice were randomly divided into 4 groups, namely control group： normal saline 0. 1 ml; estrogen group：estradiol benzoate 20μg （0. 1 ml, 1 mg/kg） ; progesterone group： 60μg （0. 1 ml, 3 mg/kg） ; estrogen plus progestin group：estradiol benzoate 20μg （0. 1 ml, 1 mg/kg） and progesterone （0. 1 ml, 3 mg/kg） 60μg. Treatment was given every other day, and human breast tissues were removed for experiments after treatment for 4 weeks. The implanted breast tissue were fixed and sliced. The expression of ER, PR PCNA and bcl-2 were assayed by immunohistochemical, c-myc, c-los,and EGFR mRNAs were determined by in situ hybridization. Results In estrogen group, and estrogen plus progestin group, the positive expression of ER was lower and PR was higher than those of the control group （P 〈 0. 05 ） ; the expression of ER and PR in progesterone group had no differences compared with the control group （P 〉 0. 05） ; the expression of PCNA and bcl-2 in estrogen group were higher than that of the control group （P 〈 0. 01, P 〈 0. 05 ） , while they showed no significant difference in the other two drug groups compared with the control group （P 〉 0. 05 ）. The expression of c-myc, c-fos and EGFR in estrogen group and estrogen plus progestin group were higher than those in control group （P 〈 0. 01 ）. The expression of c-myc in the progesterone group was higher than that in the control group （P 〈 0. 01 ）, and the expression of c-fos and EGFR in the estrogen and progesterone groups were not significantly different compared with those in the control group （P 〉 0. 05 ）. Conclusions Progesterone did not affect the proliferation and apoptosis of human normal breast tissue, but may have anti-proliferative and pro-apoptosis effects when coupled with estrogen. And it can up-regulate the expression of c-myc.