Screening of specific binding peptide targeting blood vessel of @entity1 XXXX in vivo in @entity19 .

@entity1 @entity72526 @entity5 @entity19 @entity10391 @entity418
BACKGROUND: @entity5 remains a @entity5 with poor prognosis. Rapid progresses were made in chemotherapeutic agents and the development of molecular markers allowed better identification of candidates for targeted therapy. This study aimed to identify the candidate peptides used for anti-angiogenic therapy of @entity418 by in vivo screening C7C peptide library for peptides binding specifically to blood vessels of @entity1 @entity418 . METHODS: The phage displayed C7C peptide library was injected intravenously into @entity19 bearing @entity1 @entity5 xenografts under renal capsule. After 5 rounds of screening, 13 clones were picked up individually and sequenced. During each round of screening, titers of phage recovery were calculated from @entity5 xenograft and control tissues. Homing of these 9 peptides to @entity5 vessel was detected by calculating phage titers in the @entity5 xenograft and control tissues (lung and spleen) after each phage was injected into @entity19 model, and compared with the distribution of @entity10391 and @entity72526 -related antigen in @entity5 xenograft by immunohistochemical staining. Comparisons among groups of data were made using one-way analysis of variance (ANOVA), followed by the Bonferroni multiple comparisons test. RESULTS: The number of phage recovered from @entity5 tissue of each round increased gradually in @entity5 group while decreased in control groups (P < 0.01 in @entity5 and spleen, P < 0.05 in lung). Immunohistochemical staining showed similar staining pattern with @entity10391 antibody or @entity72526 -related antigen antibody, suggesting that phages displaying the selected peptides could home to blood vessel of @entity1 @entity418 . According to their DNA, 9 corresponding peptide sequences were deduced. And the homing ability to blood vessel of phages displaying the selected peptides was confirmed by comparing with their recovery in @entity5 and control tissues. Two motifs, YSXNXW and PXNXXN, were also obtained by analyzing the homology of these peptide sequences. The staining distribution of phage with the sequence of PNPNNST was similar to that of the blood vessel marker factor @entity72526 -related antigen staining. After sequencing, each phage with the selected peptide of PNPNNST with 1.0   10(11) pfu/ml was injected intravenously into @entity19 . The homing ability to @entity5 vessel of these 9 kinds of peptides in the xenograft was higher than control tissues (lung and spleen). CONCLUSION: Nine peptides obtained from in vivo screening homed to the blood vessel of @entity1 @entity418 , and the two motifs of YSXNXW and PXNXXN are the possible biochemical recognition units binding to vascular endothelial cells of @entity418 .
