Morphological and quantitative analysis of BCL6 expression in human colorectal carcinogenesis

Abstract

Abstract. The aim of the present study was to determine whether BCL6 is expressed during malignant transformation of the large bowel and to assess whether, and to what extent, immunoreactivity is related to the different stages of neoplastic progression. Samples of normal colorectal mucosa (n=22), microadenomas (n=22) and colorectal cancer (n=22), were analyzed by immunohistochemistry, immunofluorescence coupled with confocal microscopy and western blotting. Our results clearly outlined the marked increase occurring in both intensity and density of BCL6 protein expression in the normal mucosa-microadenoma-carcinoma sequence. Immunohistochemistry and immunofluorescence analyses showed that BCL6 is expressed at low levels in normal mucosa and increases in microadenoma and in cancer with statistical significance. These results were confirmed by western blotting data. The increasing expression of BCL6 in human colorectal cancer development suggests the involvement of BCL6 in tumor progression, from the earliest stages of carcinogenesis with significant increase in cancer. The enhanced understanding of the biological role of BCL6, previously shown to exert a key role in lymphomagenesis, may lead to a re-evaluation of this protein and may highlight the importance of performing further studies in order to identify novel therapeutic targets for colorectal cancer.

Osteoclastic expression of higher-level regulators NFATc1 and BCL6 in medication-related osteonecrosis of the jaw secondary to bisphosphonate therapy: a comparison with osteoradionecrosis and osteomyelitis

“…2a). The occurrence of BCL6 in both cell compartments was also observed in microadenoma and colorectal cancer cells [32]. In general, protein translation takes place predominantly in the extranuclear cell compartment [33].…”

The oncogene BCL6 is up-regulated in glioblastoma in response to DNA damage, and drives survival after therapy

“…Increasingly BCL6 protein has been found in solid malignancies, including squamous cell carcinoma [6] colorectal [7] gallbladder [8], and breast cancer [9]. In most cases, BCL6 expression is associated with poor prognosis and worse outcome, although not always-BCL6 can suppress tumorigenesis in medulloblastoma [10] and is associated with a better prognosis in a subset of gastric lymphoma [11].…”

High expressions of BCL6 and Lewis y antigen are correlated with high tumor burden and poor prognosis in epithelial ovarian cancer

“…B-cell CLL/lymphoma 6 (BCL6), a highly conserved zinc finger (ZF) transcriptional factor, was first identified as an oncogene by gene expression profile in non-Hodgkin's lymphoma in 2000; 3 it exhibits pivotal roles in germinal center formation and regulation of lymphocyte function, differentiation, and survival. 4 In recent years, more and more studies identified that BCL6 was overexpressed not only in B-cell lymphoma 5 but also in gastric cancer, 6 gallbladder cancer, 7 breast cancer, 8 colorectal cancer, 9 head and neck cancer, 10 and so on. However, there are quite a few studies on the function of BCL6 in ovarian cancer, and it remains unclear whether BCL6 may aberrantly express or be a potential prognosis marker in ovarian cancer.…”