Colorectal cancer prognosis marker, expression evaluation method, kit and applications

[0034] Example 1 SLC12A5 expression up-regulation test in colorectal cancer

[0035] The immunohistochemical method of the embodiment of the present invention was used to detect the expression level of SLC12A5 in colorectal cancer and normal intestinal mucosa respectively, and it was found that the expression level of SLC12A5 was silenced in normal intestinal mucosa and up-regulated in colorectal cancer. The result is as figure 1 as shown, figure 1 It is the result of the expression level of SLC12A5 in colorectal cancer and normal intestinal mucosa according to Example 1 of the present invention. Among them, figure (a) represents colorectal cancer tissues (CRCtumortissues), and figure (b) represents adjacent normal tissues (Adjacentnormaltissues).

[0036] Based on the upregulation of SLC12A5 in colorectal cancer, 15 pairs of colorectal cancer tissue samples were selected, and the expression of SLC12A5 was analyzed by immunohistochemistry. The result is as figure 2 as shown,

[0037] Example 2 In vivo test of the effect of knocking down the expression of SLC12A5 on tumor growth in nude mice

[0038] The control cell lines HCT116 / control or HCT116 / shSLC12A5 were randomly injected into the dorsal side of nude mice, and the tumor growth patterns were compared. Tumor volumes were measured every 3 days for approximately three weeks. Calculate the tumor volume (mm) by measuring the longest and shortest tumor diameter lengths (volume formula = 0.5 × length × 2 × width) 3 ). Twenty-two days after inoculation, the experiment was terminated and the mice were sacrificed. Tumor growth curves in nude mice Figure 4 As shown, wherein, C represents the growth curve of the tumor injected with HCT116 / control, and S represents the growth curve of the tumor injected with HCT116 / shSLC12A5. The average tumor size of nude mice injected with HCT116 / shSLC12A5 was significantly lower than that of control nude mice injected with HCT116 / control (P Figure 5 As sho

[0059] Example 3 Evaluation of the Expression Level of SLC12A5 in Colorectal Cancer Tissue

[0060] In Example 3, the expression level of SLC12A5 in colorectal cancer tissue was evaluated using the method for evaluating the expression of colorectal cancer prognosis markers of the present invention. In this method, the method for detecting the expression level of SLC12A5 is an immunohistochemical method. The specific evaluation process is as follows:

[0061] S10: Obtain 195 colorectal cancer wax block specimens.

[0062] S20: cutting the embedded wax block into slices with a thickness of 5 micrometers.

[0063] S30: Perform immunohistochemical detection on the section. The specific process of this step is shown in steps S31-S37 mentioned above.

[0064] S40, the expression levels of colorectal cancer markers were evaluated according to the percentage of positive cell staining of SLC12A5. Using the scoring standard of the present invention, the level of SLC12A5 was detected b