NAC1, a POZ/BTB protein present in the adult mammalian brain, triggers apoptosis after adenovirus-mediated overexpression in PC-12 cells

An overview of the co-transcription factor NACC1: Beyond its pro-tumor effects

Nucleus accumbens-associated protein 1 (NACC1) is a member of the broad complex, tramtrack, bric-a-brac/poxvirus and zinc finger (BTB/POZ) protein families, mainly exerting its biological functions as a transcription co-regulator. NACC1 forms homo- or hetero-dimers through the BTB/POZ or BANP, E5R, and NACC1 (BEN) domain with other transcriptional regulators to regulate downstream signals. Recently, the overexpression of NACC1 has been observed in various tumors and is positively associated with tumor progression, high recurrence rate, indicating poor prognosis. NACC1 also regulates biological processes such as embryonic development, stem cell pluripotency, innate immunity, and related diseases. Our review combines recent research to summarize advancements in the structure, biological functions, and relative molecular mechanisms of NACC1. The future development of NACC1 clinical appliances is also discussed.

Identification and Expression Profiling of the BTB Domain-Containing Protein Gene Family in the Silkworm, Bombyx mori

The BTB domain is a conserved protein-protein interaction motif. In this study, we identified 56 BTB domain-containing protein genes in the silkworm, in addition to 46 in the honey bee, 55 in the red flour beetle, and 53 in the monarch butterfly. Silkworm BTB protein genes were classified into nine subfamilies according to their domain architecture, and most of them could be mapped on the different chromosomes. Phylogenetic analysis suggests that silkworm BTB protein genes may have undergone a duplication event in three subfamilies: BTB-BACK-Kelch, BTB-BACK-PHR, and BTB-FLYWCH. Comparative analysis demonstrated that the orthologs of each of 13 BTB protein genes present a rigorous orthologous relationship in the silkworm and other surveyed insects, indicating conserved functions of these genes during insect evolution. Furthermore, several silkworm BTB protein genes exhibited sex-specific expression in larval tissues or at different stages during metamorphosis. These findings not only contribute to a better understanding of the evolution of insect BTB protein gene families but also provide a basis for further investigation of the functions of BTB protein genes in the silkworm.

Zinc finger protein ZBTB20 expression is increased in hepatocellular carcinoma and associated with poor prognosis

Background

Our previous studies showed that ZBTB20, a new BTB/POZ-domain gene, could negatively regulate α feto-protein and other liver-specific genes, concerning such as bio-transformation, glucose metabolism and the regulation of the somatotropic hormonal axis. The aim of this study is to determine the potential clinical implications of ZBTB20 in hepatocellular carcinoma (HCC).

Methods

Quantitative real-time RT-PCR and Western blot analyses were used to detect expression levels of ZBTB20 in 50 paired HCC tumorous and nontumorous tissues and in 20 normal liver tissues. Moreover, expression of ZBTB20 was assessed by immunohistochemistry of paired tumor and peritumoral liver tissue from 102 patients who had undergone hepatectomy for histologically proven HCC. And its relationship with clinicopathological parameters and prognosis was investigated.

Results

Both messenger RNA and protein expression levels of ZBTB20 were elevated significantly in HCC tissues compared with the paired non-tumor tissues and normal liver tissues. Overexpressed ZBTB20 protein in HCC was significantly associated with vein invasion (P = 0.016). Importantly, the recurrence or metastasis rates of HCCs with higher ZBTB20 expression were markedly greater than those of HCCs with lower expression (P = 0.003, P = 0.00015, respectively). Univariate and multivariate analyses revealed that ZBTB20 overexpression was an independent prognostic factor for HCC. The disease-free survival period and over-all survival period in patients with overexpressed ZBTB20 in HCC was significantly reduced.

Conclusions

The expression of ZBTB20 is increased in HCC and associated with poor prognosis in patients with HCC, implicating ZBTB20 as a candidate prognostic marker in HCC.

POZ for effect--POZ-ZF transcription factors in cancer and development

The BTB/POZ-ZF [Broad complex, Tramtrack, Bric à brac (BTB) or poxvirus and zinc finger (POZ)-zinc finger] protein family comprises a diverse group of transcription factors. POZ-ZF proteins have been implicated in many biological processes, including B cell fate determination, DNA damage responses, cell cycle progression and a multitude of developmental events, including gastrulation, limb formation and hematopoietic stem cell fate determination. Consequently, dysfunction of vertebrate POZ-ZF proteins, such as promyelocytic leukemia zinc finger (PLZF), B cell lymphoma 6 (Bcl-6), hypermethylated in cancer 1 (HIC-1), Kaiso, ZBTB7 and Fanconi anemia zinc finger (FAZF), has been linked directly or indirectly to tumorigenesis and developmental disorders. Here, we discuss recent advances in the POZ-ZF field and the implications for the design of future studies to elucidate the biological roles of these unique transcription factors.

Genomic profiling of cortical neurons following exposure to beta-amyloid

In vitro and in vivo studies have shown that beta-amyloid peptide induces neuronal cell death. To explore the molecular basis underlying beta-amyloid-induced toxicity, we analyzed gene expression profiles of cultured rat cortical neurons treated for 24 and 48 h with synthetic beta-amyloid peptide. From the 8740 genes interrogated by oligonucleotide microarray analysis, 241 genes were found to be differentially expressed and segregated into distinct clusters. Functional clustering based on gene ontologies showed coordinated expression of genes with common biological functions and metabolic pathways. The comparison with genes differentially expressed in cerebellar granule neurons following serum and potassium deprivation indicates the existence of common regulatory mechanisms underlying neuronal cell death. Our results offer a genomic view of the changes that accompany beta-amyloid-induced neurodegeneration.