Abstract: ABSTRACT Objective: Study the mechanism of action of hypoxia inducible factor-1α(HIF-1α), signal transducers and activators of transcription 3(STAT3) in lymphatic metastasis of colorectal carcinoma. Methods: The levels of HIF-1α, STAT3 and VEGF-Ｃ mRNA transcription and protein expression of adenocarcinoma and surgical margin tissues gotten from 60 cases with CRC were determined by real-time quantitative PCR using fluorescence and immunohistochemistry, as well as lymph vessel density was counted using anti-podoplanin monoclonal antibody. And correlations of above indexes and lymphatic metastasis of colorectal carcinoma were analyzed. Results: The levels of HIF-1α, STAT3 and VEGF-Ｃ of tumor tissues were significant higher than that of surgical margin in either mRNA transcription or protein expression(P＜0.05). The levels of HIF-1α, STAT3 and VEGF-Ｃ of tumor tissues were more significant relative not only in either mRNA transcription or protein expression but also in lymphatic metastasis group(P＜0.05). Conclusion: The expression of lymphatic vessels system in colorectal carcinoma is higher than that in surgical marginal tissue. HIF-1α,STAT3 and VEGF-C are the key regulators in lymphatic vessel formation of colorectal carcinoma,and are closely related to lymphatic metastasis.

Key words: colorectal carcinoma, microlymphatics, HIF-1α, STAT3, VEGF-C, podoplanin