Intercellular contacts, mediated by E-cadherin, are essential for germ cell migration and maturation. Furthermore, it has been suggested that decrease or loss of E-cadherin correlates with tumour progression and invasive behaviour. beta-catenin is involved in a number of different processes, including cell--cell interaction when bound to cadherins, and determination of cell fate in pluripotent cells when activated via the Wnt signal-transduction pathway. To shed more light on the role of these factors in normal fetal germ cell development and the pathogenesis of germ cell tumours (GCTs), the present study investigated the presence and localization of E-cadherin and beta-catenin by immunohistochemistry. E-cadherin was only weakly expressed in or absent from fetal germ cells of the second and third trimesters, and was not expressed in carcinoma in situ/intratubular germ cell neoplasia unclassified (CIS/ITGCNU) and gonadoblastoma, the precursor of an invasive GCT in dysgenetic gonads. In GCTs, it was generally not expressed in seminoma and dysgerminoma, but was found in the vast majority of non-seminoma cells. beta-catenin was found in the cytoplasm of fetal germ cells at all gestational ages and in spermatogenesis in post-pubertal testes. It was also present in CIS/ITGCNU and gonadoblastoma. Whereas seminomas and dysgerminoma were negative, non-seminoma cells were frequently found to express beta-catenin. Expression of both factors therefore reflects the degree of differentiation of these tumours. No differences for either E-cadherin or beta-catenin were observed between samples of tumours resistant or sensitive to chemotherapy, and E-cadherin expression did not correlate with vascular invasion. E-cadherin and beta-catenin therefore play a role in both normal and malignant germ cell development and differentiation that warrants further investigation, but they seem to be of limited value as predictive or prognostic factors in GCTs. 相似文献
Summary A posterior fossa tumour in a 3 year old child is presented with characteristic histological, ultrastructural and immunohistochemical features of rhabdoid tumour. Many tumour cells contained cytoplasmic eosinophilic hyaline inclusions. Ultrastructurally concentric whorls of 10 nm intermediate filaments were identified. Immunohistochemical staining disclosed vimentin, cytokeratin and epithelial membrane antigen positivity. Renal and extrarenal rhabdoid tumours have been well documented but a primary rhabdoid tumour of the brain is extremely rare. Additional ultrastructural features seen were tubular crystalline inclusions in endoplasmic reticulum and abnormal large mitochondria. 相似文献
The aim of this study was to assess the expression of IGF-I and IGF-II in phyllodes tumours and fibroadenomas and to see if there is any correlation between nuclear beta-catenin expression and IGF-I and IGF-II expression in these tumours. In a previous study, it has been shown that Wnt signalling is important in the pathogenesis of phyllodes tumours of the breast. Epithelial Wnt5a overexpression and stromal Wnt2 overexpression were associated with abnormal, nuclear localization of beta-catenin in the stromal cells of these tumours. However, not all tumours with beta-catenin accumulation showed Wnt overexpression. One other possible cause of beta-catenin accumulation is overexpression of insulin-like growth factors (IGFs), as both IGF-I and IGF-II have been shown to stabilize beta-catenin. In this study, 30 fibroadenomas of the breast were assessed for beta-catenin expression using immunohistochemistry and the results were compared with previous data from 119 phyllodes tumours. In situ hybridization was used to assess IGF-I and IGF-II expression in 23 phyllodes tumours and 16 fibroadenomas. Nineteen phyllodes tumours (83%) showed widespread overexpression of IGF-II and 5/23 (22%) showed widespread overexpression of IGF-I. IGF-I expression correlated with nuclear beta-catenin staining in phyllodes tumours. Malignant phyllodes tumours showed no or little IGF-I expression. There was a degree of nuclear beta-catenin expression in the stroma (weak in 33%, moderate in 27%, and strong in 40%) in all fibroadenomas and nuclear beta-catenin staining correlated with IGF-I overexpression. Extensive IGF-II overexpression was also found in the majority of fibroadenomas (12/16). These results support the hypothesis that IGF-I and IGF-II overexpression may be important in the pathogenesis of fibroepithelial neoplasms of the breast and that IGF-I overexpression is likely to be contributing to the nuclear beta-catenin localization observed in the tumours. 相似文献
We describe three cases of solitary fibrous tumour (SFT) arising from thyroid stroma. Grossly, the tumours were clearly delimited but only partly encapsulated. The following histomorphological growth patterns were observed: bundles of cells in storiform configuration; non-structured bundles; prevalence of fibrous matrix; highly cellular, non-structured; prevalence of loose, non-structured extracellular substance; cellular proliferation and vascular spaces in a haemangiopericytic configuration and a lipomatous component. Immunohistochemical investigation demonstrated intense, diffuse vimentin positivity and focal, less intense actin positivity in all three cases. At electron microscopy we observed a primitive cell of mesenchymal type, with cytoplasm poor in organelles and rich in filaments; this cell sometimes presented differentiation characteristics. SFT is at present the most correct term for the lesions presented here despite some morphological characteristics which differ from cases reported in the literature. 相似文献
The aim of the present study was to investigate immunohistochemically the distribution of chromogranin A, chromogranin B, and secretogranin II in a series of 152 neuroendocrine tumours of the gastrointestinal tract. Tumour tissues from 25 argyrophil gastric carcinoids, 18 gastrin and 5 somatostatin-producing tumours, 4 gangliocytic paragangliomas, 49 classical argentaffin and 2 L cell appendiceal carcinoids, 27 classical ileal carcinoids, 17 rectal carcinoids, and 5 poorly differentiated neuroendocrine tumours of the stomach and rectum were immunostained with antibodies against chromogranin A, chromogranin B, and secretogranin II. Chromogranin A was the major granin expressed in gastric carcinoids and in serotonin-producing carcinoids of the appendix and the ileum. In contrast, strong chromogranin B and secretogranin II immunoreactivity was found in rectal carcinoids, in which chromogranin A was rarely expressed. Since chromogranin A is a widely used marker for neuroendocrine differentiation, it is of diagnostic importance that some gastrin-producing tumours, gangliocytic paragangliomas, poorly differentiated neuroendocrine carcinomas, and appendiceal L cell carcinoids completely lacked chromogranin A positivity. It is concluded that the various neuroendocrine tumours of the gastrointestinal tract show distinctly different patterns of granin expression, probably reflecting their histogenetical origin. 相似文献
Infertility represents a major medical, economic, and psychological problem. Stem cells therapy for infertility has a great interest nowadays especially for cancer survivors at pre-reproductive and reproductive age.
Thirty-two adult male albino rats were used, divided equally into four groups; Group I (Control group) received isotonic saline intraperitoneally (i.p.) as vehicle. Group II (Cisplatin-treated group) received Cisplatin (i.p.) at a single dose of 7 mg/kg, and then were sacrificed after 5 days. Group III (Stem-cell-treated group) received Cisplatin (i.p.) at a single dose of 7 mg/kg, then after 5 days received adipose-derived mesenchymal stem cells (ADMSCs) (1 × 106). Cells were injected in the rete testis, then after 60 days, the animals were sacrificed. Group IV (Auto healing group) received Cisplatin (i.p.) at a single dose of 7 mg/kg, and then left for 65 days then the animals were sacrificed. Cisplatin administration resulted in degenerative changes in the testicular architecture in the form of thickened irregular BM of seminiferous tubules. The germinal epithelium showed disorganization and marked reduction in the thickness, associated with Sertoli cells preservation. Features of apoptosis assured by elevated caspase-3 expression were noticed. The interstitium showed cellular infiltration and distorted Leydig cells. Injection of (ADMSCs) resulted in great improvement of testicular architecture and increase in the testosterone level associated with strong immune reaction of the CD-44. ADMSCs are recommended as a new treatment modality for male infertility.