Tongxie Yaofang regulates tumor-associated macrophage polarization in colorectal cancer under chronic stress / 中国中药杂志

ABSTRACT

This study aims to investigate the intervention effect and mechanism of Tongxie Yaofang in regulating tumor-associated macrophage polarization on colorectal cancer under chronic stress. BALB/C mice were randomized into blank, control, model, mifepristone, and low-, medium-, and high-dose Tongxie Yaofang groups. The other groups except the blank and model groups were subjected to chronic restraint stress and subcutaneous implantation of colon cancer cells for the modeling of colon cancer under stress. Du-ring this period, the body mass and tumor size of each group of mice were recorded. The degree of depression in mice was assessed by behavioral changes. Enzyme-linked immunosorbent assay was employed to determine the levels of cortisol(CORT), 5-hydroxytryptamine(5-HT), norepinephrine(NE), M1-associated inflammatory cytokines [interleukin(IL)-1β, IL-12, and tumor necrosis factor(TNF)-α], and M2-associated inflammatory cytokines(IL-4 and IL-10) in the serum. The tumor growth of mice in each group was regularly monitored by in vivo imaging. The histopathological changes of tumors in each group of mice were observed by hematoxylin-eosin staining. The proportions of CD86 and CD206 in the tumor tissue were detected by flow cytometry and immunofluorescence staining. Western blot was employed to determine the protein levels of Janus kinase(JAK)1, JAK2, JAK3, signal transducer and activator of transcription(STAT)3, and STAT6 in the tumor tissue. The results showed that chronic stress increased the immobility time of mice, elevated the serum levels of CORT, IL-4, and IL-10, lowered the levels of 5-HT, NE, IL-1β, IL-12, and TNF-α, and promoted the growth of subcutaneous tumors. The tumor cells in the tumor tissue grew actively, with obvious atypia and up-regulated protein levels of CD206, JAK1, JAK2, JAK3, STAT3, and STAT6, and down-regulated protein level of CD86. The treatment with Tongxie Yaofang shortened the immobility time of mice, lowered the serum levels of CORT, IL-4, and IL-10, elevated the serum levels of 5-HT, NE, IL-1β, IL-12, and TNF-α, and inhibited the growth of subcutaneous tumors in mice. Moreover, the treatment caused different degrees of necrosis in the tumor tissues, down-regulated the protein levels of CD206, JAK1, JAK2, JAK3, STAT3, and STAT6, and up-regulated the protein level of CD86. In summary, Tongxie Yaofang can promote the transformation of M2 macrophages to M1 macrophages and change the tumor microenvironment under chronic stress to inhibit the development of colorectal cancer, which may be related to the JAK/STAT signaling pathway.