The RT PCR employed specific
The RT-PCR employed specific primer pairs (CXCL8F1 and CXCL8R2 for CXCL8, CXCR1FA2 and CXCR1RA for CXCR1 short transcript, CXCR1FA1 and CXCR1RB for CXCR1 long transcript, and CXCR2F1 and CXCR2R1 for CXCR2, ) and dna alkylating agents for 30 cycles, except for the CXCR1 long transcript which was amplified for 40 cycles. Expression of CXCL8 in the fugu was primarily limited to PBL as well as the thymus, head kidney, trunk kidney and spleen (), tissues that normally contain large numbers of lymphocytes, neutrophils, and macrophages, implying the involvement of CXCL8 in the immune system of fugu. Expression of this chemokine was also seen in the heart and gill, though not in the other tissues examined. Though the expression of CXCR2 was similar to that of CXCL8, neither the short nor long transcripts of CXCR1 were observed in the thymus and gill. The results indicate tissue specific expression of CXCRs.
Introduction Angiogenesis, the process of endothelial sprouting then inducing the formation of new blood vessels, which is important for pregnancy, wound healing. Nevertheless, angiogenesis is essential for tumour growth and metastasis . Using anti-angiogenesis targeting drugs such as humanized antibody Avastin, tyrosine kinase inhibitor sorafenib, sunitnib has great potential in cancer therapy , however, the use of inhibitors of one growth factor or siganling intermediate only partly work in clinic. Worse, these drugs always enhance tumour hypoxia and then induce poor prognosis . As we all known, hypoxia is a hallmark of tumour microenvironment, which is a key regulator of tumour growth and metastasis . Hypoxia meditates a series of cellular responses including angiogenesis by activating transcriptional factor hypoxia inducible factor (HIF), which is consist of an obligate dimer of HIF-1α and HIF-1βsubunits, 2 isoforms (HIF-1α and HIF-2α). HIF-1αoverexpression is associated with tumour invasion, liver metastasis  as well as poor prognosis  in colorectal cancer (CRC), which upregualtes several angiogenic genes, and then induces angiogenesis , , . However, whether exsist other genes that been regulated by HIF-1α need to be verified, then provide new targets for cancer therapy.
Materials and methods
Discussion Hypoxia is a common feature in human cancers, when tumour grow beyound 2–3 mm3 in size, the tumour growth would be restricted due to without neo-vasculation  and the tumour would be in hypoxia microenvironment. Under the condition, the tumour would trigger the angiogenesis switch for survival, and increase the ability of cancer cells to invade and metastasis. However, hypoxia regulated genes that invovled angiogenesis in CRC have not been explored in detail. Therefore, the identification of vascular genes in hypoxia condition could provide new targets for therapeutic intervention. In the present study, we found that chronic hypoxia could increase the ability of HUVEC tube formation and promote colorctal cancer cells invasion. Using microarrays and the DAVID bioinformatics database and validated by RT-qPCR, we identified several genes and pathways that associated with angiogenesis, these results might identify more reasonable target candidates for colorectal cancer anti-angiogeneic therapy in the future.