Tree shrews get more and more concerns due to many of its physiological , biochemical and anatomical characteristics similar to those of human beings .Therefore, tree shrews models of human diseases such as viral diseases , neurological diseases and tumors attract more and more attention of researchers .In this article we will review the recent ad-vances in application of tree shrew models in research on human viral diseases .

Objective:To screen and characterize aptamers against BCR-ABL fusion protein.Methods:A 90bp single stranded DNA( ssDNA) random library was subjected to 13 rounds of selection against BCR-ABL fusion protein by systematic evolution of ligands by expotential enrichment ( SELEX ) method, the selected aptamers were cloned and sequenced.The primary sequences and structure of aptamers were analyzed by Clustal W and DNA Folding Sever and the percentage of the ssDNA pool bound to BCR-ABL core protein were determinated.Results: after 13 rounds selection, the percentage of ssDNA pool bound to BCR-ABL fusion protein increased from 0.3%to 47.1%,the results showed that affinities of the Aptamers were different,the second structure analysis revealed possible stem-loops for binding to BCR-ABL fusion protein,the affinity of aptamer A2 to BCR-ABL fusion protein was highest with Kd values as low as 72 nmol/L.Conclusion:Aptamers against BCR-ABL fusion protein has been identified by SELEX methods from a 90 bp single stranded DNA library.And provide certain reference for the clinical treatment of chronic myelogenous.

AIM:To establish and characterize the patient-derived esophageal squamous-cell carcinoma xeno-graft (PDECX) in mice.METHODS:The samples of human esophageal cancer were grafted into severe combined immu-nodeficient ( SCID) mice.The xenografts were transferred to SCID mice when the first passage of xenografts grew up .The growth of tumors in the first, second and third passages was observed .HE staining was performed.The expression of CK5/6, p63 and p40 in the patient samples , and the first and third passages of the xenografts were detected by immunohisto-chemical analysis.The expression of mTOR, p-mTOR, p70S6K, p-p70S6K, Akt1, p-Akt (Ser473), Erk1/2 and p-Erk1/2 were determined by Western blot .RESULTS:The PDECX was successfully established .The positive expression of CK5/6, p63 and p40 in the xenografts was consistent with that in the patients ’ samples.The levels of phosphorylated and total proteins of proliferation-related signaling pathways were different in the xenografts from different patients .CONCLU-SION:The PDECX model adequately reflects the tumal heterogeneity that is observed in the patients .