2008 Summer Meeting - Leeds - The Pathological Society of Great ...

P91Immunohistochemical study on cell cycle related proteins(PTEN, p27, p53, cyclin D1, cyclin E) of ovarian cancersA Horita 1 , A Sakamoto 11 Kyorin University School of MedicineThe PI3K (phosphatidylinositol 3-kinase) / pAkt pathway is an importantregulator of cell cycle progression and cell survival.?PTEN (phosphatase andtensin homologue deleted on chromosome 10) with phosphatase activityregulates this PI3K / pAkt pathway, thereby functioning as a tumoursuppressor.This study was conducted to clarify the significance of PTEN and itsdown-stream proteins, such as p27, p53, cyclin D1 and cyclin E, that relate tothe cell cycle,with a special focus on the relationship among these proteins inovarian carcinomas. We examined among immunohistochemical expression in64 cases of primary ovarian carcinomas comprised of 17 serous, 8 mucinous, 21endometrioid, and 18 clear cell carcinomas. Immunohistochemical date wereanalized with a co-relation of histologic subtypes, nuclear grades and clinicalstages.Significant differences of PTEN expression were identified in differenthistological subtypes.Percentage of positive staining of PTEN was lower inendometrioid carcinoma (38.1%) than those of other histologic subtypes (55.6-82.4%). PTEN expression did not correlate statistically with expression of p27,p53, cyclin D1 and cyclin E in Fisher’s exact probability test.In all histologicsubtypes of ovarian carcinoma except for clear cell carcinoma, high-level cyclinD1 expression was more frequently found in stage I, II tumours than in stageIII, IV tumours (p