The Colon, Expression And Bioactivities Research Of Lampetra Japonica HBP1

HMG-box transcription factor1(HBP1) is a homologous member of transcriptionalfactor family of the sequence-specific high mobility group (HMG). HBP1comprised of513amino acids and was previously isolated as a retinoblastoma (Rb) partner.As a transcriptionalrepressor,HBP1is serving as a proliferation regulator to suppress oncogenic pathways.Recentstudies showed that HBP1participated in the G1regulatory network together with p38MAPK signaling pathway members,and involved in cell senescence and tumor growthinhibition.Meanwhile,HBP1was also shown to suppress Wnt signaling.The understanding ofHBP1in tumor suppressor networks may contribute to the improvement of cancer diagnosisand treatment.This review outlined the studies in HBP1transcriptional repressor regardingcell cycle control and tumor growth.As one of the most ancient jawless vertebrate, the Lamprey (Lampetra japonica), whichbelongs to the Cyclostomata, living typical migration life between the river and the sea, and ithas crucial place in the evolution of species. In the recent period, the genes of lampreys arebecoming focuses, wishing to find new ways to against tumors.Cells of lamprey hasinteresting character that the cell cycle of lamprey is longer than others. This phenomenonshows that there are genes that inhibit cell cycle in lamprey cells.In the present research, through gene cloning, the full-length cDNA (3277bp) ofJapanese lamprey HBP1(HBP1for shot) are obtained. And the open reading frame length ofHBP1is1584bp, which can encod527amino acids. Semi-quantitative RT-PCR shows thatthe HBP1is widely distributed in the lamprey liver, kidney, heart, intestine, leukocyte cells,muscle, gills and gonads, and the expression level of HBP1in Japanese lamprey do not haveobvious differences. By bioinformatics analysis shows that the HBP1amino acid sequence donot contain signal peptide, meanwhile membrane spaning domain do not exist also.There aretwo functional domain in HBP1, these are AXH domain and HMG domain, which is the samewith the human HBP1. Subcellular localization prediction shows that HBP1located at cellnucleus mainly, which is also similar with the human HBP1. Random coils (50%) composethe main secondary structure of HBP1. Through phylogenetic tree analysis, HBP1located thebottom of phylogenetic tree and had near relation of fishes such as Ictalurus punctatus.A recombinant plasmid pET32a-HBP1had been established, and then transformed intothe BL21，which universal used as a prokaryotic protein expression system. The recombinant protein of HBP1had been obtained, as it was inclusion body. This was a obstacle to futureresearches. In order to settle the inclusion body expression, a recombinant adenovirus vectorwere objected, which contains HBP1gene. Virus degree test and cell CPE phenomenon testshowed that the recombinant adenovirus were achieved. Raji cells were transfected withrecombinant adenovirus, and cell growth curve and cell colony assay results were bothshowing that the expression of HBP1could repress Raji cells proliferation. These resultsindicate that HBP1has important research value in the inhibition of tumor growth, andprovide a new way for the treatment of tumor.