The Expression of YKL-40 in The Peripheral Blood of Colorectal Cancer Patients and its Effect on The Proliferation and Angiogenesis of Colorectal Cancer Cells

Objective: To observe the expression of YKL-40 in the serum of patients with colorectal cancer and to study the effect of the YKL-40 gene on the proliferation and angiogenesis of colon cancer cell lines. Methods: Serum samples of 79 patients with colorectal cancer before and 7 days after surgery, 13 patients with precancerous lesions and 21 healthy controls were collected, and the expression of YKL-40 was detected by enzyme-linked immunosorbent assays (ELISAs). The HCT116 cell line with high expression of YKL-40 was selected from the colon cancer cell lines HCT-15, HCT116 and SW480, and then, HCT116 cells were divided into an experimental group and a control group. The expression of the YKL-40 gene in the experimental group was inhibited by small interfering RNA (siRNA), and the high expression of YKL-40 in the control group was maintained. Then, the cells in the two groups were cocultured with bevacizumab. Cell proliferation was detected by CCK-8 assays, and angiogenesis was detected by cell formation assays. Results: The mean values of serum YKL-40 in the colorectal cancer group (preoperative), the precancerous lesion group and the control group were 178.50±71.91 μg/L, 95.18±33.56 μg/L and 85.47±24.97 μg/L, respectively. The colorectal cancer group (preoperative) had a significantly higher value than the precancerous lesion group and the control group ( P <0.01). The precancerous lesion group had a higher value than the control group, but the difference between the two was not significant ( P = 0.265). The expression of YKL-40 was positively correlated with the stage of colorectal cancer ( P <0.05). There was no significant difference in the expression of serum YKL-40 before and after surgery ( P =0.07). HCT116 is a cell line with high YKL-40 expression. After the expression of this gene was inhibited, the survival rate of the experimental group was 78.75%, which was significantly lower than that of the control group ( P <0.05). The angiogenesis test was used to detect the angiogenic ability. Both siRNA targeting the YKL-40 gene and the addition of bevacizumab inhibited angiogenesis in vitro. Moreover, the vascular inhibitory effect of bevacizumab in the group with low expression of YKL-40 was stronger than that in the group with high expression of YKL-40. Conclusion: YKL-40 is highly expressed in the peripheral blood of patients with colorectal cancer and is related to tumour stage. The HCT116 colon cancer cell line highly expresses YKL-40. Interfering with the expression of YKL-40 can inhibit cell proliferation and angiogenesis. This finding suggests that YKL-40 plays an important role in the occurrence and development of colorectal cancer.