Ovarian pten expression

Testosterone improves the transition of primary oocytes into secondary growth in artificial maturation eel (Anguilla japonica) by altering ovarian PTEN expression


Yung-Sen Huang*, Ya-Mei Chen, Yan-Horn Lee , Jin-Chywan Gwo, Ming-Chyuan Chen

Direct involvement of androgens in female reproduction is controversial, Androgens appear to enhance follicle development. PI3K (phosphoinositide-3-kinases) pathway is recognized as one critical pathways in early follicular development, roles of the PI3K were revealed by deletion of PTEN (Phosphatase and Tensin homolog on chromosome 10). PTEN plays a vital role in antagonizing the growth-promoting effects of growth factors. PTEN may function through the oocyte pathway in the early stage of follicle development. Two forms of PTEN have been cloned from the Japanese eel, but it still did not know what different roles between them on the development of early ovarian follicles. The natural blockage and inducible of ovarian development in the eel was a benefit to study roles of PTEN on the transition of primary oocytes into secondary growth. Testosterone (T) ameliorates the eel early artificial ovarian development. The aims of this report were to elucidate the two forms of PTEN under cellular and physiological criteria, to investigate the expression pattern of PTEN in the stimulated ovaries, and to study the effects of T on the ovarian PTEN production in the exogenous pituitary extracts stimulated eel. Our data suggested that two forms of PTEN are existing in the eel, and progress of ovarian development corresponded to the decrease of ovarian PTEN expression, vice versa. T on eel ovarian development can be attributed to its PTEN-inhibitor role.


Key words: Anguilla japonica, IGF1, ovary, PPARs, PTEN, testosterone

(看開學前 能不能投兩篇...)
 
 
(from http://baike.baidu.com/view/598777.htm)
 
PTEN(phosphatase and tensin homolog deleted on chromosome ten) 　　PTEN(即MMAC1, mutated in multiple advanced cancers 1)为一新发现的抑癌基因，位于10q23.3，转录产物为515kb mRNA。其蛋白产物含有一酪蛋白磷酸酶的功能区和约175个氨基酸左右的与骨架蛋白tenasin、auxilin同源的区域。PTEN的磷酸酶功能区包括(I/V)-H-C-X-A-G-X-X-R-(S/T)-G模体，后者也存在于酪氨酸和双重特异性(dual-specifity)磷酸酶中。双重特异性磷酸酶能使磷酸化的Tyr、Ser、Thr都去磷酸化。PTEN的磷酸酶活性区和CDC14、PRL-1、BVP等双重特异性磷酸酶的序列同源性最高。PRL-1和CDC14均参与细胞生长，且CDC14还能起始DNA复制。所以PTEN可能通过去磷酸化参与细胞调控。磷酸化和去磷酸化是调节细胞活动的重要方式，许多癌基因的产物都是通过磷酸化而刺激细胞生长。因此，PTEN可能与酪氨酸激酶竞争共同的底物，在肿瘤的发生、发展中起重要作用。10q23LOH常发生在肿瘤晚期［45］，约70%的恶性胶质瘤和60%的晚期膀胱癌可出现LOH，但它却很少出现在低度恶性的胶质瘤和早期膀胱癌中。tenasin通过粘着斑连接肌动蛋白轴丝。粘着斑是包括整合蛋白、粘着斑激酶、Src和生长因子受体的复合物。整合蛋白参与细胞生长调节、瘤浸润、血管生成和转移，所以，推测PTEN也可能是通过参与调节该过程影响肿瘤转移。 　　抑癌基因PTEN于1997年首次被报道之后即成为研究热点。磷酸酶基因（PTEN）是迄今发现的第一个具有双特异磷酸酶活性的抑癌基因,也是继p53基因后另一个较为广泛地与肿瘤发生关系密切的基因.PTEN蛋白在细胞生长、凋亡、粘附、迁移、浸润等方面具有重要作用.PTEN基因是众多肿瘤预后的评价指标,研究其作用机制对肿瘤的诊断及其基因治疗具有重要意义.