metallothionein and Endometrial-Hyperplasia

To investigate whether regression of endometrial hyperplasia observed after 3 months of treatment with levonorgestrel impregnated intrauterine system device (LNG-IUS) was sustained after 6 months and whether these effects were still occurring synchronously with extinguished expression of progesterone receptors and increased apoptosis.. Retrospective population-based observational study.. Six local hospitals and one university hospital in northern Norway.. Patients (n = 41) with low and medium risk endometrial hyperplasia.. Histopathological treatment response comparing LNG-IUS (n = 25) and standard per oral medroxyprogesterone (n = 16). Expression of progesterone receptor A (PR-A), progesterone receptor B (PR-B), ER-alpha, ER-beta, Bcl-2, BAX, Caspase-3 and metallothionein (MT) were investigated by immunohistochemistry; results were evaluated by a semi-quantitative H-score.. Response to progestin treatment.. All the LNG-IUS treated patients had therapy response after 6 months. PR-A and PR-B in glands were almost extinguished for IUD users compared to the oral group. Estrogen receptors were also reduced. Co-existent changes in apoptosis were differently modulated in glands and stroma in the two treatment groups. Bcl-2 was different in glands and stroma in responders and non-responders to oral therapy.. The study confirms that LNG-IUS can be safely used for 6 months as treatment for endometrial hyperplasia. The clinical effect is accompanied by almost extinguished PR-receptors in glands coinciding with modulation of apoptosis. The results strongly indicate that progestins activate non-classical initiated signaling pathways.

Topics: Adult; bcl-2-Associated X Protein; Caspase 2; Contraceptives, Oral, Synthetic; Down-Regulation; Endometrial Hyperplasia; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Humans; Immunohistochemistry; Intrauterine Devices, Medicated; Levonorgestrel; Metallothionein; Middle Aged; Norway; Proto-Oncogene Proteins c-bcl-2; Receptors, Progesterone; Retrospective Studies; Statistics, Nonparametric

Metallothioneins (MTs) are a group of ubiquitous low-molecular-weight proteins essential for the protection of cells against heavy metal ion toxicity. The immunohistochemical expression of MT was studied by immunohistochemistry using a monoclonal antibody (E9) against a conserved epitope of I and II isoforms in a series of 89 endometrial carcinomas, 34 cases of hyperplasia, and 32 samples of normal endometrium. In secretory phase endometrium, extensive MT expression was detected in most cases (92.4%). In contrast, MT immunoreactivity was confined to small foci in 22.2% of proliferative phase cases. The MT values in normal endometrium were inversely correlated with oestrogen receptor (ER) content (p<0.0001), progesterone receptor (PgR) content and with PCNA (p<0.0001) and MIB1 (p=0.001) scores. In hyperplastic lesions, MT expression was detected only in 3.3% of cases, while in the group of carcinomas it was observed in 23.1%. A statistically significant difference of MT expression was observed between carcinomas and simple hyperplasias (p=0.03). In carcinomas, MT expression was positively correlated with grade (p=0.0065), MIB1 (p=0.022), and p53 (p=0.006) expression, and inversely with PgR (p=0.03). A trend of inverse correlation between MT and ER receptor was also detected (p=0.07). These data suggest that MT expression seems to be under hormonal control in normal endometrium; that it may modify p53 expression; and that it could be used as an additional biological marker indicating aggressive behaviour in endometrial lesions.

Topics: Adult; Biomarkers, Tumor; Endometrial Hyperplasia; Endometrial Neoplasms; Endometrium; Female; Humans; Immunoenzyme Techniques; Metallothionein; Middle Aged; Neoplasm Proteins; Prognosis