Expression of KRT81 in breast cancer tissues and its inhibitory effect on proliferation of breast cancer cells by affecting glucose metabolism through regulating AKT/mTOR pathway

ObjectiveTo investigate the expression of KRT81 in breast cancer tissues and its inhibitory effect on proliferation of breast cancer cells by affecting glucose metabolism through regulating AKT/mTOR pathway.

MethodsThe pathological sections of 100 patients with breast cancer were collected, the expression of KRT81 in breast cancer was detected by immunohistochemistry, and the correlation between KRT81 expression level and clinical pathological characteristics was analyzed.Simultaneously, overexpression plasmids, control plasmids, control knockdown plasmids, and knockdown plasmids were transfected into MCF-7 cells, which were recorded as oeKRT81 group, NC group, Control group, and si-KRT81 group.The cell proliferation was detected by colony formation assay, apoptosis was determined by flow cytometry, and the expression of AKT/mTOR pathway-related proteins and apoptosis-related proteins were detected by Western blotting.

ResultsThe results of immunohistochemistry showed that the positive expression of KRT81 protein in cancer tissues was significantly lower than that in normal adjacent tissues (P < 0.01).The expression level of KRT81 was correlated with Her2, TNM staging, distant metastasis, and tissue grading (P < 0.05 to P < 0.01).The results of the colony formation assay showed that the number of MCF-7 cell colonies in the oeKRT81 group was significantly lower than that in the NC group, while the number of MCF-7 cell colonies in the siKRT81 group was significantly higher than that in the Control group (P < 0.01).The results of flow cytometry showed that compared with the NC group, the apoptosis rate of MCF-7 cells in the oeKRT81 group was significantly increased (P < 0.01); compared with the Control group, the apoptosis rate of MCF-7 cells in the si-KRT81 group was significantly reduced (P < 0.01).The results of Western blotting indicated that the level of Bax protein in MCF-7 cells in the oeKRT81 group were significantly higher than that in the NC group, while the levels of Bcl2, GLUT1, LDH, p-AKT, and p-mTOR proteins were significantly lower than those in the NC group (P < 0.01);the level of Bax protein in the si-KRT81 group was significantly lower than that in the Control group, while the levels of Bcl2, GLUT1, LDH, p-AKT, and p-mTOR proteins were significantly higher than those in the Control group (P < 0.01).

ConclusionsThe low expression of KRT81 is related to poor prognosis of breast cancer, which may inhibit the proliferation of breast cancer cells by affecting glucose metabolism through inhibiting AKT/mTOR pathway.