ABSTRACT
Tripartite motif containing protein 7 (TRIM7), as a member of the E3 ubiquitin ligase TRIM family, plays an important regulatory role in immune regulation, metabolism and other physiological processes. The aberrant expression of TRIM7 is closely related to the development and progression of hepatocellular carcinoma (HCC) and it shows a complex regulatory role. However, the regulatory mechanism for the expression of TRIM7 in HCC remains unknown. In this study, multiple online databases were used to analyze the expression of TRIM7 in HCC and data indicated that TRIM7 expression was upregulated in HCC and correlated to poor prognosis. Subsequently, the transcription factor binding sites in the TRIM7 promoter region were analyzed using UCSC and JASPAR databases, and the results showed that TRIM7 promoter contains four SP1 binding sites. In this work, we demonstrated that SP1 could directly bind to its binding sites in TRIM7 promoter and positively regulate the transcriptional activity driven by the TRIM7 promoter using dual luciferase reporter experiments and the ChIP-PCR method. Moreover, our results also showed SP1 overexpression upregulated the expression of TRIM7 at both mRNA and protein levels (P<0. 01),and SP1 inhibitor, mithramycin A, could reverse the activated effect of SP1 on TRIM7 expression (P<0. 01). In conclusion, this study preliminarily reveals the regulatory mechanism of TRIM7 upregulation in HCC, which provides an important theoretical basis for further study of the gene function, early diagnosis and targeted therapy.
ABSTRACT
<p><b>OBJECTIVE</b>To study the function of ZNF300 in the megakaryocytes differentiation and proliferation.</p><p><b>METHODS</b>Public data analysis of ZNF300 expression and megakaryocyte culture were used to reveal the correlation of ZNF300 expression with leukemia and megakaryocyte differetniation; ZNF300 overexpression was mediated by lentiviral or retroviral infection, and the differentiation and proliferation of K562 cells and primary mouse bone marrow cells to magekaryocytes were measured by flow cytometry, MTT assay and colony-forming test; the ZNF300 subcellular localization was tested by separating cytosolic and nuclear extracts combined with Western blotting. The dual-luciferase assay and ChIP-qPCR were used to study ZNF300 target gene.</p><p><b>RESULTS</b>ZNF300 expression upregulation correlated with megakaryoyte differentiation; over-expression of ZNF300 promoted CD41 and CD61 expression, inhibited cell cycle progress, and could reduce colony-forming unit. The ZNF300 locolized in nuclear and regulated C-MYC expression.</p><p><b>CONCLUSION</b>ZNF300 promotes megakaryocyte differentiation.</p>