绝经后服用他莫西芬的乳腺癌患者子宫内膜中PTEN的表达

目的探讨他莫西芬对绝经后妇女子宫内膜腺细胞PTEN表达的影响,从分子生物学上研究绝经后乳腺癌术后妇女应用他莫西芬有否引起子宫内膜癌的可能。方法应用免疫组织化学LSAB二步法,检测PTEN在绝经后妇女服用2年他莫西芬后子宫内膜中及绝经后子宫内膜腺癌中的表达,以脱垂子宫的子宫内膜为对照。结果他莫西芬组与对照脱垂组、子宫内膜腺癌组与对照脱垂组之间差异具有统计学意义(P<0.01);他莫西芬组与子宫内膜癌组之间差异无统计学意义(P>0.05)。结论绝经后每日服用他莫西芬40mg延续2年以上的患者,由于他莫西芬对低雌激素水平的子宫内膜起到弱雌激素样作用,导致子宫内膜腺细胞中PTEN存在严重减少或缺失,可能是他莫西芬导致子宫内膜癌的早期的分子学水平的重要事件。

Expression of Tumor Suppressor Gene PTEN in Endometrium of Postmenoposal Women with Breast Cancer Treated with Tamoxifen

Objective To investigate the influence of tamoxifen on the post menopausal women, and test a hypothesis whether tamoxifen can cause endometrial cancer in the postmenopausal women. Methods Using immunohistochemistry(LSAB) on formalin fixed paraffin embedded endometrium sections to study the phosphatase and tension homology deleted on chromosome ten(PTEN) in endometrium of postmenopausal patients with breast carcinoma who took tamoxifen 40 mg/day for over 2 years and in endometral adenocarcioma, with prolapse uterine endometrium as normal controls. Results There was significant difference among Group tamoxifen, Group carcinoma of endometrium and Group normal endometrium(P<0.05). The differences between the groups of tamoxifen and normal endometrium were significant, the same was seen between carcinoma of endometrium and normal endometrium groups. But no significant difference was found between tamoxifen and carcinoma of endometrium groups. Conclusion The PTEN expression of the breast cancer patients who took tamoxifen 40 mg/day for over 2 years was lower than that in the normal people, and was almost the same as that in the patients of carcinoma of endometrium. Because tamoxifen stimulated postmenopause endometrium in the proliferative phase for a long time, thus made the expression of the PTEN decreased. Loss of PTEN expression is an early event in carcinoma of endometrium. Detection of PTEN protein may be a diagnostic biomarker for the earliest endometrial precancers and carcinoma.