A human-specific insertion promotes cell proliferation and migration by enhancing TBC1D8B expression.

Human-specific insertions play important roles in human phenotypes and diseases. Here we reported a 446-bp insertion (Insert-446) in intron 11 of the TBC1D8B gene, located on chromosome X, and traced its origin to a portion of intron 6 of the EBF1 gene on chromosome 5. Interestingly, Insert-446 was present in the human Neanderthal and Denisovans genomes, and was fixed in humans after human-chimpanzee divergence. We have demonstrated that Insert-446 acts as an enhancer through binding transcript factors that promotes a higher expression of human TBC1D8B gene as compared with orthologs in macaques. In addition, over-expression TBC1D8B promoted cell proliferation and migration through "a dual finger" catalytic mechanism (Arg538 and Gln573) in the TBC domain in vitro and knockdown of TBC1D8B attenuated tumorigenesis in vivo. Knockout of Insert-446 prevented cell proliferation and migration in cancer and normal cells. Our results reveal that the human-specific Insert-446 promotes cell proliferation and migration by upregulating the expression of TBC1D8B gene. These findings provide a significant insight into the effects of human-specific insertions on evolution.

Pharmacokinetic and pharmacodynamic study of LFA3Ig fusion protein in healthy volunteers and patients with psoriasis.

AIM: To evaluate the pharmacokinetics (PK) and pharmacodynamics of the LFA3Ig fusion protein (LFA3IgFP) in healthy volunteers and patients with chronic plaque psoriasis. METHODS: The clinical trials included 2 phase I open studies. Study 1 was an open-label dose escalation study in 24 healthy volunteers, and study 2 was a single-group, open-label study in 12 patients with chronic plaque psoriasis. The serum drug concentrations were measured, and the concentration-time data were analyzed by compartmental analysis using the Practical Pharmacokinetic Program. RESULTS: In study 1, after intramuscular (im) administration at a dosage of 5, 15, and 25 mg, the concentration-time curves of LFA3IgFP fitted well to a 1 compartment open model. Areas under the concentration-time curves increased linearly with dose. Clearance rates (Cls/ F) and elimination half-lives (T1/2ke) had no significant difference between different dose groups. A transient, slight decline of CD(4+) and CD(8+) T-cell subsets was observed after administration. In study 2, after im administration at a dosage of 15 mg weekly for 8 weeks, the concentration-time curve was best fitted to a 1 compartment open model, with a T(1/2ke ) of 307.9+/-32.7 h. The steady state was attained after the fifth administration. CONCLUSION: The PK behaviors of LFA3IgFP in healthy volunteers and patients with chronic plaque psoriasis complied with linear kinetics within the examined dose range. A significant accumulation was observed after repeated administration at a dose of 15 mg weekly for 8 weeks.

Construction of pGFP-FL plasmid and its application in preparing FL-secreting tumor vaccine.

OBJECTIVE: To construct a plasmid containing a green fluorescent protein (GFP) reporter gene as the effective vector for preparing fms-like tyrosine kinase receptor-3 ligand (FL)-secreting tumor vaccines. METHODS: A pGFP-FL plasmid, harboring a FL gene and a GFP gene, was designed and constructed by routine molecular cloning techniques. In this plasmid, FL gene was under the control of cytomegalovirus promoter, while EF-1a promoter acted to drive GFP gene. A prokaryotic/eukaryotic selective gene Kan(R)/neo was also introduced into the plasmid. After structure identification by restriction analysis, pGFP-FL plasmid was further transferred into Hepa1-6 cells, and the expression of GFP and FL genes was examined by way of fluorescent microscopy and reverse transcriptase-PCR respectively. RESULTS: Restriction analysis showed that the structure of pGFP-FL plasmid was exactly the same as anticipated. Further results indicated that both GFP and FL genes were simultaneously expressed in Hepa1-6 cells. CONCLUSION: A new plasmid has been established as the vector for studying the FL-secreting tumor vaccines, in which GFP gene can serve as a reporter gene reflecting the expression of FL gene.