Changes in serum IGF-1 level and tumor VEGF expression in mice with colorectal cancer under hyperglycemic conditions

The present study aimed to observe the growth of transplanted tumors in mice with colorectal cancer (CRC) under hyperglycemic conditions and to detect the expression of vascular endothelial growth factor (VEGF) in these tumors. The study also aimed to observe the changes in serum insulin-like growth factor-1 (IGF-1) levels and to determine whether type 2 diabetes mellitus (T2DM) was a risk factor for the progression and development of CRC. A mouse model of a transplanted colorectal tumor with T2DM was established to observe the changes in volume and size of the transplanted tumor. Mice were sacrificed at the end of the 5th week to determine the serum IGF-1 level and VEGF expression in the tumor tissues. The tumor volume (1628.5 ± 882 mm3) in the CRC-DM group was larger than that in the CRC group (1950.2 ± 726 mm3; P<0.05). The serum IGF-1 level (105.33 ± 32.32 ng/ml) was higher than that in the normal (69.83 ± 25.57 ng/ml) and CRC groups (70.17 ± 25.27 ng/ml; P<0.05). The VEGF expression in the tumor tissues of the CRC-DM group(70.0 ± 11.5%) was higher than that in the CRC group (42.9 ± 7.5%; P<0.05). T2DM may be one of the causes for the promotion of CRC growth and its mechanism may be correlated with the increased IGF-1 action observed in the blood that induces VEGF gene transcription, upregulates VEGF expression, causes tumor angiogenesis and thus leads to the occurrence and metastasis of tumors.