Loss of inhibitor of growth (ING-4) is implicated in the pathogenesis and progression of human astrocytomas

Inhibitor of growth 4 (ING-4) is a tumor suppressor gene that interacts with nuclear factor-kappaB (NF-kappaB) and represses its transcriptional activity. Several lines of evidence suggest that the tumor suppressor gene ING-4, the transcription factor NF-kappaB and its target genes matrix metalloproteases MMP-2, MMP-9 and urokinase plasminogen activator (u-PA) are critically involved in tumor invasion. The aim of the present study was to investigate immunohistochemically the expression pattern of ING-4, NF-kappaB and the NF-kappaB downstream targets MMP-2, MMP-9 and u-PA in human astrocytomas from 101 patients. We found that ING-4 expression was significantly decreased in astrocytomas, and ING-4 loss was associated with tumor grade progression. Expression of p65, a NF-kappaB subunit, was significantly higher in grade IV than in grade III and grade I/II tumors, and a statistical significant negative correlation between expression of ING-4 and expression of nuclear p65 was noticed. MMP-9, MMP-2 and u-PA were overexpressed in human astrocytomas. Of note, astrocytomas of advanced histologic grades (grade III, IV) displayed significantly higher expression levels of these proteins compared to tumors of lower grades (grade I, II). Collectively, our data suggest an essential role for ING-4 in human astrocytoma development and progression possibly through regulation of the NF-kappaB-dependent expression of genes involved in tumor invasion.

Esophageal squamous cell carcinomas and expression of p53, Bcl-2, and Bcl-X(L)

p53 protein promotes apoptosis, whereas Bcl-2 family proteins have an antiapoptotic function. This study determines the predictive value of selected clinical and histopathological factors in correlation with the expression of p53, Bcl-2, and Bcl-X(L) proteins in esophageal squamous cell carcinomas (SCCs). Paraffin-embedded sections from 19 surgically resected primary esophageal SCCs were examined by immunohistochemistry. p53 expression was related to degree of tumor differentiation (P = 0.044). Bcl-2 expression was associated with regional lymph node metastasis (P = 0.053), whereas Bcl-X(L) expression was correlated with distant metastasis (P = 0.060) and with the expression of Bcl-2 protein (P = 0.068). p53 and Bcl-2 family proteins may help to estimate the properties of esophageal SCCs and provide useful information to the oncologist for the selection of patients for intensive combined therapy modalities with curative intention or for palliative therapy.

Fas and WAF1 expression in esophageal squamous cell carcinomas

The Fas/FasL system plays an important role in the regulation of tumor apoptosis. This study examined the correlation between the expression levels of Fas and WAF1 with the clinicopathological characteristics of esophageal squamous cell carcinoma (SCC) tumors. Paraffin-embedded sections from 19 surgically resected primary esophageal squamous cell carcinomas were examined by immunohistochemistry. At low expression levels (5% to 24%), a 4-fold higher expression of Fas relative to WAF1 expression was observed. High expression levels (50% to 74%) of Fas were not recorded, whereas such levels of expression for WAF1 were retained in a proportion of cells > 20%. Proteins WAF1 and Fas were both expressed in all lesions of SCCs. Lesions showing high expression levels of WAF1 have a high degree of differentiation, but a sample that expresses WAF1 and belongs to the morphology I category probably has a medium degree of differentiation.

Assessment of proliferating cell nuclear antigen (PCNA) immunoreactivity in exocrine pancreatic carcinomas

Twenty patients with exocrine pancreatic carcinomas were studied immunohistochemically, using a monoclonal antibody against PCNA. The percentage of tumor cells with positive staining was defined as PCNA Labelling Index (L.I.), and ranged from 13.8% to 92.8%. PCNA LI was found to correlate significantly with grading and more specifically with mitotic activity and degree of nuclear anaplasia. No correlation was found with glandular differentiation or with vessel invasion, lymphatic vessel invasion, lymph node metastasis, perineural invasion or size of tumor. Our results indicate that mitotic activity and degree of nuclear anaplasia might be the most important parameters to take into consideration, when studying the role of PCNA in exocrine pancreatic carcinomas.