Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Doppel (Dpl) is a newly identified PrP-associated protein. In this study, specific primers for human PRND gene were designed based on the human PRND cDNA sequence encoding human Dpl protein reported in the GenBank. The full-length PRND gene sequence with 531 bp long was obtained from DNA of human peripheral leucocytes as the template by polymerase chain reaction (PCR). After verified by sequence analysis, the PCR product was inserted into a prokaryotic-expressing vector and then transformed into E. coli JM109. The recombinant human Doppel protein (rhDpl) was expressed as inclusion bodies after IPTG induction, with the yield of more than 60% of total bacterial proteins. The rhDpl protein was purified by Ni2+ affinity chromatography and cleaved by hydroxylamine. SDS-PAGE revealed the molecular weight of the purified rhDpl protein was about 15 kD. Trypan blue and MTT assays identified that rhDpl in vitro inhibited the growth of human neuroblastoma cell line SH-SY5Y at concentrations > or =50 microg/mL and human cervical cancer cell line HeLa at concentrations > or =100 microg/mL, showing remarkably dose-and time-dependant manners. Hoechst33342-staining of SH-SY5Y cells treated with rhDpl showed massive apoptosis under fluorescent microscope. These results indicate that Dpl protein possesses cytotoxic activity in vitro, with obvious tissue-specific characteristics. This study provides the foundation for further study of Dpl biological functions in vitro and in vivo.
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PMID:[Expression of recombinant human doppel protein and analysis of its cytotoxic activities]. 1789 27

Doppel (Dpl) is a prion (PrP)-like protein due to the structural and biochemical similarities; however, the natural functions of Dpl and PrP remain unclear. In this study, a 531-bp human PRND gene sequence encoding Dpl protein was amplified from human peripheral blood leucocytes. Full-length and various truncated human Dpl and PrP proteins were expressed and purified from Escherichia coli. Supplement of the full-length Dpl onto human neuroblastoma cell SH-SY5Y induced remarkable cytotoxicity, and the region responsible for its cytotoxicity was mapped at the middle segment of Dpl [amino acids (aa) 81-122]. Interestingly, Dpl-induced cytotoxicity was antagonized by the presence of fulllength wild-type PrP. Analysis on fragments of PrP mutants showed that the N-terminal fragment (aa 23- 90) of PrP was responsible for the protective activity. A truncated PrP (PrPdelta32-121) with similar secondary structure as Dpl induced Dpl-like cytotoxicity on SHSY5Y cells. Furthermore, binding of copper ion could enhance the antagonizing effect of PrP on Dpl-induced cytotoxicity. Apoptosis assays revealed that cytotoxicity induced by Dpl occurred through an apoptotic mechanism. These results suggested that the function of Dpl is antagonistic to PrP rather than synergistic.
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PMID:Doppel-induced cytotoxicity in human neuronal SH-SY5Y cells is antagonized by the prion protein. 1912 49

Doppel (Dpl) is a recently identified prion (PrP)-like protein due to the structural and biochemical similarities, however, its natural function and pathogenic role in neurodegenerative diseases remains unclear. To investigate the possible pathogenic pathway of Dpl and its structural analog for cell apoptosis, mammalian expressing recombinant plasmids containing human PRND gene encoding the full-length Dpl and a truncated human PRNP gene deleting the sequences encoding the peptide from aa 32 to 121 (PrPDelta32-121) were generated. MTT assays showed the cell viabilities of the human neuroblastoma cell line SH-SY5Y receiving Dpl and PrPDelta32-121 expressing plasmids were remarkably lower. Obvious apoptosis phenomena were observed to be associated with the cells transient expressing Dpl and PrPDelta32-121, including reduced mitochondrial transmembrane potential (psim), decreased pro-caspase-3 quantity, more numbers of annexin V- and annexin V/PI-double-stained cells and depressed Bcl-2 level. Moreover, we also found that the Dpl- and PrPDelta32-121-induced cytotoxicities and relevant apoptotic events in SH-SY5Y cells could be fully antagonized by co-expression of the human full-length PrP. These data highly indicate that cytotoxicity induced by the expression of Dpl and truncated PrP in neural derived cells are closely related with the apoptosis process, probably triggering the mitochondrial pathway. It also implies that the cell-benefit activity of the full-length PrP may result from its anti-apoptosis capacity.
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PMID:Transient expressions of doppel and its structural analog prionDelta32-121 in SH-SY5Y cells caused cytotoxicity possibly by triggering similar apoptosis pathway. 1972 51