Colorectal cancer （CRC） is a leading cause of cancer-related deaths worldwide. We aimed to find novel molecules as potential biomarkers for the early diagnosis of CRC. A serum-free conditioned medium was successfull...Colorectal cancer （CRC） is a leading cause of cancer-related deaths worldwide. We aimed to find novel molecules as potential biomarkers for the early diagnosis of CRC. A serum-free conditioned medium was successfully collected from three pairs of CRC tissue and adjacent normal tissue, iTRAQ-based quantitative proteomic analysis was applied to compare the differences in secretome between primary CRC mucosa and adjacent normal mucosa. A total of 145 kinds of proteins were identified. Of these proteins, 29 were significantly different between CRC and normal tissue. Tropomyosin 2 p （TPM2） exhibited the most significant differences; as such, this protein was selected for further validation. Quantitative real-time PCR indicated that the mRNA expression of TPM2 significantly decreased in the CRC tissue compared with the paired adjacent normal tissue. Immunohistochemical analysis also confirmed that TPM2 was barely detected at protein levels in the CRC tissue. In summary, this study revealed potential molecules for future biomarker applications and provided an efficient approach for the differential analysis of cancer-associated secretome. TPM2 may be valuable for the early diagnosis of CRC.展开更多
基金This work was financially supported by National Basic Research Program of China （973 Program, No. 2011CB910700） and National Natural Science Foundation of China （No. 81201966）.
文摘Colorectal cancer （CRC） is a leading cause of cancer-related deaths worldwide. We aimed to find novel molecules as potential biomarkers for the early diagnosis of CRC. A serum-free conditioned medium was successfully collected from three pairs of CRC tissue and adjacent normal tissue, iTRAQ-based quantitative proteomic analysis was applied to compare the differences in secretome between primary CRC mucosa and adjacent normal mucosa. A total of 145 kinds of proteins were identified. Of these proteins, 29 were significantly different between CRC and normal tissue. Tropomyosin 2 p （TPM2） exhibited the most significant differences; as such, this protein was selected for further validation. Quantitative real-time PCR indicated that the mRNA expression of TPM2 significantly decreased in the CRC tissue compared with the paired adjacent normal tissue. Immunohistochemical analysis also confirmed that TPM2 was barely detected at protein levels in the CRC tissue. In summary, this study revealed potential molecules for future biomarker applications and provided an efficient approach for the differential analysis of cancer-associated secretome. TPM2 may be valuable for the early diagnosis of CRC.
