Bcl6/p53 expression, macrophages/mast cells infiltration and microvascular density in invasive breast carcinoma

To better understand the breast cancer progression and therapeutic resistance is crucial deepen the molecular mechanisms related to regulation of cells behavior in the tumor microenvironment. Inappropriate expression or activation of transcription factors in tumor breast microenvironment can lead to the malignant behavior of breast cancer cells. Bcl6 is a transcriptional factor that may play a role in the pathogenesis of breast cancer. Moreover, cells surrounding tumor cells, including macrophages and mast cells play an important role during tumor progression enhancing angiogenesis. We have demonstrated: 1) An increase of the BCL6 translocation and Bcl6 positive cells in G3 degree of disease; 2) A reduction of the expression of p53 in G3 breast cancer samples as compared to G1/G2 specimens; 3) Macrophages CD68⁺ and CD163⁺ in interstitial and periglandular position, increase in G3 specimens as compared to G1/G2 and control samples; 4) Tryptase-positive mast cells in periglandular position are more numerous in G3 tumor specimens as compared to G1/G2 and control samples. Overall, these data confirm the important role played by epigenetic events, including BCL6 translocation, p53 expression, and microenvironment components, including macrophage and mast cell infiltration and microvascular density involved in the regulation of breast cancer progression.