Decreased level of the cell cycle regulator p27 and increased level of its ubiquitin ligase Skp2 in endometrial carcinoma but not in normal secretory or in hyperstimulated endometrium.

p27 is a cyclin-dependent kinase (CDK) inhibitor whose specific late G(1) destruction allows progression of the cell across the G(1)/S boundary. The protein is ubiquitinated by S-phase kinase-interacting protein-2 (Skp2) following its specific phosphorylation, and is subsequently degraded by the 26s proteasome. There is a direct relationship between low level of p27 and rapid proliferation occurring in several benign states and in many malignancies. In the glandular cells of the normal endometrium, the level of p27 is exceedingly low during the proliferative phase, whereas it is markedly increased during the secretory phase. The expression of p27 in endometrial carcinoma is very low but has been found to increase following treatment with progesterone. However, estrogen exposure is considered as a major risk factor in developing endometrial cancer. The implications of the high dose of estrogen and progesterone induced during IVF treatment are still unknown. We have examined the expression of p27 and Skp2 as well as of Ki67 proliferation marker by using endometrial extracts and cells from normal endometrium, from ovarian hyperstimulated patients, and from endometrial carcinoma patients. The expression of p27, Skp2 and Ki67 was found to be similar in both normal secretory endometrium and endometrium from ovarian hyperstimulated patients. In striking contrast, p27 is significantly lower while Skp2 and Ki67 are significantly higher in the endometrial carcinoma and in endometrium from the proliferative phase compared with their normal secretory counterpart tissue.

Expression of HER2 and C-KIT in nasopharyngeal carcinoma: implications for a new therapeutic approach.

We sought to determine the expression and prognostic significance of HER2 and c-KIT proteins in nasopharyngeal carcinoma (NPC). In this retrospective study, immunohistochemical stains for HER2 and c-KIT were performed on formalin-fixed paraffin-embedded sections from 49 patients with NPC who were treated at our hospital from 1971 to 2000. The clinical and immunohistochemical data were correlated, including gender, ethnic origin, age, histological type, EBV status (EBER in situ hybridization), stage, and overall survival. HER2 expression was not found in the tested samples. C-KIT overexpression was found in 33% (16/49) of the patients. Nine of the 16 samples (56%) were strongly positive for c-KIT protein (staining of >50% of the tumor cells). C-KIT expression was associated with younger age. C-KIT was not found in patients with squamous carcinoma or in those with negative EBV status, although these two groups consisted of only five patients each. Although c-KIT-positive cases tended to be associated with slightly better survival, this was not statistically significant. C-KIT protein was expressed in one third of the NPC patients in this study, only in EBV-positive, undifferentiated, or nonkeratinizing carcinoma patients. Further study is needed to check whether c-KIT expression is correlated with c-KIT DNA mutations and to test the possibility of treatment with imatinib mesylate (Gleevec). HER2 protein was negative in the same tested specimens.

Splenic littoral cell haemangioendothelioma: a new low-grade variant of malignant littoral cell tumour.

AIMS: Littoral cell angioma is a recently described splenic vascular tumour of splenic sinus lining cells. Almost all cases of splenic littoral cell tumours hitherto described were benign. METHODS AND RESULTS: A splenic littoral cell tumour recurred 8 years after splenectomy, with an abdominal mass and multiple liver metastases, resulting in the patient's death. Histologically, the original splenic tumour showed solid areas with small necrotic foci in addition to large areas of typical littoral cell angioma. The recurrent tumours showed increased solid architecture and slightly increased nuclear atypia. The tumours showed an immunohistochemical profile positive for factor VIII, CD31, CD68, cathepsin D, and CD21 and negative for CD34 and CD8, consistent with the immunophenotype of classic littoral cell angioma. Ki67 index in the recurrent tumours was higher than in the primary tumour. CONCLUSIONS: The mildly atypical, but not frankly malignant, histological features as well as the protracted clinical course support definition of the tumour as 'littoral cell haemangioendothelioma'. Low rate of Ki67 staining and diploid DNA histogram with low S-phase fraction of the tumours are in accordance with a low-grade malignancy. Literature review revealed two other cases of littoral cell tumours with disseminated disease that may be other examples of littoral cell haemangioendothelioma. Littoral cell haemangioendothelioma should be distinguished from the overtly malignant splenic angiosarcomas, of which a few may show splenic lining cell differentiation with some immunohistochemical features of littoral cells. Due to difficulties in predicting biological behaviour based on histological features of splenic littoral cell tumours, a long-term follow-up for these patients, especially for those with atypical histology, is recommended.