Correlation between PTEN expression and PI3K/Akt signal pathway in endometrial carcinoma.
ABSTRACT In order to investigate the role of the PTEN expression in carcinogenesis and development of endometrial carcinoma and clarify whether and how PTEN and PI3K/Akt pathway relate to endometrial carcinoma, the expression of PTEN and phospho-Akt was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) methods and Western-blot from 24 cases of endometrial carcinoma, 10 cases of endometrial atypical hyperplasia, 10 cases of endometrial hyperplasia, and 10 cases of normal endometrium. SP immunohistochemical methods were used to measure levels of PTEN protein expression in following 5 study groups: 31 cases of endometrium in proliferative phase, 30 cases of endometrium in secretory phase, 71 cases of endometrial hyperplasia, 25 cases of atypical hyperplasia and 73 cases of endometrial carcinoma. Immunostaining score of PTEN was 3.39+/-0.15 in proliferative phase, 1.90+/-0.21 in secretory phase, 3.34+/-0.29 in endometrial hyperplasia, 0.62+/-0.11 in atypical hyperplasia, and 0.74+/-0.19 in endometrial carcinoma, respectively. PTEN mRNA relative value in normal endometrium, endometrial hyperplasia, endometrial atypical hyperplasia, and endometrial carcinoma was 2.45+/-0.51, 2.32+/-0.32, 0.46+/-0.11, and 0.35+/-0.13 respectively. The expression levels of PTEN mRNA and protein in patients with endometrial carcinoma and atypical hyperplasia were significantly lower than in those of proliferative phase and with endometrial hyperplasia. The level of PTEN expression in patients with endometrial carcinoma was significantly related to tissue type (P<0.005), differentiation (P<0.05) and clinical stage (P<0.05), but not to depth of myometrium invasion (P>0.05). Western blot analysis revealed that Phospho-Akt level in PTEN negative cases was significantly higher, and there was a negative correlation between PTEN and phospho-Akt (r=-0.8973, P<0.0001). It was suggested that loss of PTEN expression was an early event in endometrial tumorigenesis. The phosphorylation of Akt induced by the loss of PTEN took part in the tumorigenesis and development of endometrial carcinoma.
Article: The effect of overweight and obesity on proliferation and activation of AKT and ERK in human endometria.[show abstract] [hide abstract]
ABSTRACT: To examine whether overweight and obesity could lead to increased endometrial proliferation and activation of AKT and ERK1,2 in cycling premenopausal women. Endometrial and blood samples were obtained from women with normal endometrial histology, and allocated into three groups-normal-weight, overweight and obese-according to the subject's body mass index (BMI). Samples from obese patients with type-I endometrial cancer (EC) were included as a control. Cell proliferation was measured by immunohistochemical detection of Ki67 and phosphorylated histone H3 (p-H3). AKT and ERK1,2 activation was assessed by Western blot. Circulating steroids, leptin and insulin were measured by immunoassays. In endometrial samples with normal histology, epithelial cell proliferation was higher in the overweight and obese groups versus the normal-weight set (P<0.05). Proliferation indexes were positively correlated with the subject's BMI and serum levels of estrogen, leptin and insulin (P<0.05). Increased phosphorylated AKT (pAKT) (1.6-fold) and ERK1,2 (pERK1,2) (8.7-fold) were observed in endometria from obese with respect to normal-weight subjects (P<0.05). Similarly, increased phosphorylation of AKT (0.7-fold) and ERK1,2 (2.3-fold) was detected in endometria from overweight as compared with the normal-weight group (P<0.05). In women with EC, we found a significant increase in endometrial proliferation, and in pAKT and pERK1,2 expression levels when compared to patients with normal endometrial histology. These results show correlation between obesity (and overweight) and increased endometrial cell proliferation, and the activation of AKT and ERK1,2. These features could be related with the higher risk to develop type-I EC in overweight and obese women.Gynecologic Oncology 04/2010; 117(1):96-102. · 3.89 Impact Factor