ABSTRACT
Objective: To study the role of Hippo signaling pathway using mouse liver metastasis and semi-spleen model of colorectal cancer in vivo. Methods: Twenty BALB/c mice were randomly divided into sham operated group and experimental group. In the sham operation group, the abdomen of mouse was opened and closed. In the experimental group, the mouse colonic adenocarcinoma CT26 cells were injected into the lower pole of spleen, and excised to establish a liver metastasis model. After 7 days, the mice were sacrificed and dissected. The expression levels of epinephrine (EPI), glucagon (GC), lysobisphosphatidic acids (LPA) and sphingosine-1 phosphate (S1P) in plasma collected from the eyeballs of mice were detected by ELISA. The successful semi-spleen liver metastasis modeling of colorectal cancer was determined by HE staining. The yes-associated protein 1 (YAP1) and phospho-YAP1 (p-YAP1) were localizated by immunohistochemistry. The expression levels of YAP1 and p-YAP1 proteins in the liver tissues of mice were detected by Western blotting. Results: The liver metastasis rate was 100% after 7 days of spleen hemisection model establishment. The levels of plasma EPI and GC in the sham operated group were significantly higher than those in the experimental group (both P< 0.01). The levels of plasma LPA and S1P in the experimental group were significantly higher than those in the sham operated group (both P< 0.01). The HE staining result of experimental group showed typical features of poorly differentiated adenocarcinoma with mitotic division. In the normal liver tissues of sham operated group, YAP1 protein expressed in the cytoplasm [nuclear YAP (-) and cytoplasmic YAP (+)], p-YAP1 protein expressed in the cytoplasm and nuclei [nuclear p-YAP1 (+) and cytoplasmic p-YAP1 (+)]; In the tumor liver tissues of experimental group, YAP1 protein expressed in the cytoplasm and nuclei [nuclear YAP1 (+) and cytoplasmic YAP1 (+)], p-YAP1 protein was not expressed in the cytoplasm or nuclei [nuclear p-YAP1 (-) and cytoplasmic p-YAP1 (-)]. The expression level of YAP1 protein in the liver of experimental group was significantly higher than that in the sham operated group (P< 0.01), while the expression level of p-YAP1 in the liver of experimental group was significantly lower than that in the sham operated group (P < 0.01). Conclusion: The liver metastasis model of colorectal cancer is successfully established. The expressions of EPI and GC are negatively correlated with YAP1, and positively correlated with p-YAP1. The expressions of LPA and S1P are positively correlated with YAP1, and negatively correlated with p-YAP1. It is expected to develop a targeted therapeutic study for Hippo signaling pathway-related blood factor modulators.
ABSTRACT
Hippo signaling pathway plays a significant role in the development of colorectal cancer,and acts as an important regulatory pathway which regulates cell proliferation and cell differentiation.Multiple proteins and genes in Hippo signaling pathway,especially the downstream YAP protein,play important roles in the occurrence,metastasis,drug resistance and recurrence of colorectal cancer.YAP and other related genes can be used as targeted markers for predicting drug resistance to colorectal cancer.Hippo signaling pathway gene network can be used as targeted therapy or combination therapy,thus providing new ideas for the treatment of colorectal cancer.