The Bcl6 gene has been identified from the chromosomal translocation breakpoint in B cell lymphomas, and its products are expressed highly in germinal center (GC) B cells. To investigate the function of Bcl6 in lymphocytes, we have generated RAG1-deficient mice reconstituted with bone marrow cells from Bcl6-deficient mice (Bcl6−/−RM). Lymphogenesis in primary lymphoid tissues of Bcl6−/−RM is normal, and Bcl6−/−RM produced control levels of primary IgG1 antibodies specific to T cell–dependent antigens. However, GCs were not found in these mice. This defect was mainly due to the abnormalities of B cells. Therefore, Bcl6 is essential for the differentiation of GC B cells.

No abstract

Background: The present study aimed to assess the efficacy and safety of lenvatinib and verify the possibility of lenvatinib for the expanded indication from the REFLECT trial in patients with advanced hepatocellular carcinoma (HCC) in real-world practice, primarily focusing on the population that was excluded in the REFLECT trial. Methods: We retrospectively collected data on patients with advanced HCC who were administered lenvatinib in 7 institutions

No abstract

The BCL6 gene, which has been identified from the chromosomal translocation breakpoint in B-cell lymphomas, functions as a sequence-specific transcriptional repressor. We cloned a novel Bcl6-homologous gene, BAZF (encoding Bcl6-associated zinc finger protein). The predicted amino acid sequence of BAZF indicated that the BTB/POZ domain and the five repeats of the Krüppel-like zinc finger motif are located in the NH 2 -terminal region and the COOH-terminal region, respectively. BAZF associated with Bcl6 at the BTB/POZ domain and localized in the nucleus. Since zinc finger motifs of BAZF were 94% identical to those of Bcl6 at the amino acid level, BAZF bound specifically to the DNA-binding sequence of Bcl6 and functioned as a transcriptional repressor. The repressor activity was associated with both the BTB/POZ domain and the middle portion of BAZF. The 17-amino-acid sequence in the middle portion was completely conserved between BAZF and Bcl6, and the conserved region was critical for the repressor activity. Expression of BAZF mRNA, like that of Bcl6 mRNA, was induced in activated lymphocytes as an immediate-early gene. Therefore, the biochemical character of BAZF is similar to that of Bcl6 although the tissue expression pattern of BAZF differs from that of Bcl6. This is apparently the first report of a gene family whose members encode zinc finger proteins with the BTB/POZ domain.Chromosomal translocations involving 3q27 have been identified in some non-Hodgkin's lymphomas, particularly in diffuse large B-cell lymphomas (5, 35). The human proto-oncogene BCL6 has been identified from chromosomal breakpoints (25,30,43). Translocations lead to deregulation of the BCL6 gene as a result of the juxtaposition of the BCL6-coding region to heterologous promoters (44) and may be related to lymphomagenesis. The BCL6 gene encodes a 92-to 98-kDa nuclear phosphoprotein (6, 36) that contains the BTB/POZ domain in the NH 2 -terminal region and six Krüppel-type zinc finger motifs in the COOH-terminal region (17,25,30,43).