EGFR expression is linked to osteopontin and Nf-κB signaling in clear cell renal cell carcinoma.

AIM AND BACKGROUND: Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase involved in many important aspects of cell biology that are related to tumorigenesis. There are opposite evidences of the role of EGFR in renal cancer and the outcome of EGFR-targeted therapies, suggesting the complexity of EGFR signaling pathways. In vitro, osteopontin (OPN) and nuclear factor kappa B (NF-κB) are thought to be involved in specific ligand-independent EGFR activation that could have a role in resistance to EGFR mAb therapy. Aim of this study was to analyze the relationship between EGFR and OPN at the protein and mRNA level, as well as their relation to NF-κB in clear cell renal cell carcinoma (CCRCC). MATERIALS AND METHODS: Expression of EGFR, OPN, and p65 NF-κB protein was analyzed using immunohistochemistry and compared mutually in 88 CCRCC samples. Expression of EGFR and OPN mRNAs was analyzed using quantitative Real-time PCR in 22 CCRCC samples and compared mutually and with NF-κB protein expression. RESULTS: Epidermal growth factor receptor mRNA level was higher in CCRCC samples in comparison with normal renal tissue (p = 0.012) and was associated with high OPN mRNA level, and with NF-κB activation (p < 0.001 and p = 0.045, respectively). Immunohistochemical staining showed the inverse association; high EGFR protein expression was related with low OPN and NF-κB protein expression (p < 0.001 and p = 0.047, respectively). CONCLUSION: Epidermal growth factor receptor gene is upregulated in CRCC and associated with OPN gene expression and NF-kB signaling. The inverse relation between OPN and EGFR at the protein level could probably reflect dynamic changes that EGFR undergoes following activation.

Comparison of microvessel density with tumor associated macrophages in invasive breast carcinoma.

Neovascularization, the growth and formation of capillary blood vessels, is an essential component of solid tumor growth and a critical step in metastasis. Tumor associated macrophages (TAMs) have several functions related to tumor biology including growth, proliferative rate, stroma formation and dissolution, and neovascularization. The aim of this study was to define the TAM and microvessel density (MD) in human invasive breast carcinoma NOS and to correlate their values with lymph node status, tumor size, tumor grade and mitotic activity index (MAI), and, finally, to determine whether MD is connected with TAMs. A total number of 57 invasive breast carcinomas NOS were processed for immunohistochemical analysis using mAb to F-VIII to visualize endothelial cells and mAb to CD68 antigens for macrophages. Statistical analysis showed only a positive correlation between TAMs and MAI (p = 0.004). These results support the notion that intensity of tumor angiogenesis does not provide additional prognostic significance, while TAMs may play a positive role in breast cancer micro system since they regulate tumor proliferation.

Expression of monocyte chemotactic protein-1 in human invasive ductal breast cancer.

Monocyte chemotactic protein-1 (MCP-1) is a chemokine involved in the macrophage infiltration of tumor tissue. Tumor associated macrophages (TAMs) are a population of mononuclear-phagocytic cells, which can express complex functions related to tumor biology. The present study was designed to analyse the expression of MCP-1 in parenchymal and stromal elements on frozen sections of 27 breast invasive ductal carcinomas not otherwise specified (NOS) by immunohistochemistry. The expression of MCP-1 in tumor parenchyma and the degree of tumor differentiation were assessed. MCP-1 was detected in the parenchyma in 15 of 27 ductal carcinomas. Positive immunoreactivity manifested as diffuse, homogeneous, moderate or strong, cytoplasmic staining, confined to tumor epithelium. Generally, MCP-1-negative tumors tended to be well differentiated, while chemokine-positive tumors exhibited a low level of differentiation. MCP-1 immunoreactivity was also present in TAMs (CD68 positive cells) in 23 of 27 tumors, and in endothelial cells in 11 of 27 tumors. These results indicate that parenchymal and, more variably, stromal elements of human invasive ductal carcinomas NOS can express MCP-1 in vivo. Additionally, these findings suggest that MCP-1 expression in tumor parenchyma is correlated with the histological grade of ductal invasive breast carcinoma.

Prognostic significance of T-cell infiltrates, expression of beta 2-microglobulin and HLA-DR antigens in breast carcinoma.

In this study immunohistological staining was used to assess the presence of T-cell infiltrates and the expression of beta 2-microglobulin (beta 2-m) and HLA-DR antigens on tumor cells of 75 ductal invasive carcinomas. The results were compared with the morphometric prognostic index (MPI) that seems to be the most accurate prognostic predictor. The extent of T-cell infiltrates differed widely between tumors, but statistically significant correlation was found only with the lymph node status, namely, tumors with a high degree of infiltration had predominantly negative lymph nodes and vice versa (p < 0.05). Only 19 (25.3%) out of 75 carcinomas were beta 2-m+, 34 cases (45.3%) showed heterogeneous staining pattern and 22 tumors (29.3%) were completely negative. We could not find any significant correlation between beta 2-m expression and MPI or T-cell content. While normal breast epithelium was always HLA-DR negative, tumor cells displayed positivity in 25 cases (33.3%), 5 tumors (6.7%) were completely positive and 20 tumors (26.7%) displayed only focal expression of class II antigens. This expression did not correlate with any single prognostic parameter, nor with MPI. The results suggest that T-cell infiltrates and the expression of histocompatibility antigens can not be accepted as prognostic indicators in breast carcinoma.

Expression of beta-1 integrins on tumor cells of invasive ductal breast carcinoma.

The integrins are transmembrane alfabeta heterodimers mediating cell-cell as well as cell-extracellular matrix interactions. The present study was designed to analyse the expression of beta-1 integrins on cryostat sections of invasive ductal carcinomas not otherwise specified by avidin-biotin complex immunoperoxidase technique, and to compare it with the morphometric prognostic index (MPI). The results show that the expression of beta-1 integrins is heterogeneous in the tumors. This heterogeneity was observed in quantitative and qualitative staining pattern. There was an absent expression of beta-1 integrins in 22 out of 55 tumors while 33 showed staining, weak on 23 cases and strong on 10 infiltrative ductal carcinomas. Statistical analysis pointed to some correlation of beta-1 integrins with some morphometric parameters. Low or absent expression of beta-1 integrins correlated significantly with tumors exceeding 2 cm (p < 0.0245). Moreover, a larger proportion of tumors with positive lymph nodes showed absence of beta-1 expression compared with negative lymph node, and this was also statistically significant (p < 0.0076). Correlation between mitotic activity index and staining intensity for beta-1 integrins was not found (p < 0.372). When tumors with different beta-1 expression were subdivided according to MPI values into two groups, one group with a low-risk, < 0.6, and second with a high risk, > 0.6, concordance in prognostic value was shown between MPI and beta-1 expression (p < 0.0193). These results support the idea that loss of beta-1 integrins correlates with the invasive and metastatic potential of tumor cells.