Glucocorticoids promote the development of azoxymethane and dextran sulfate sodium-induced colorectal carcinoma in mice

Tong-Xie-Yao-Fang promotes dendritic cells maturation and retards tumor growth in colorectal cancer mice with chronic restraint stress

ETHNOPHARMACOLOGICAL RELEVANCE

Depression is one of the important risk factors that accelerate the progression of colorectal cancer (CRC). Tong-Xie-Yao-Fang (TXYF) is a widely used classical formula for treating psychiatric-related intestinal diseases in traditional Chinese medicine, that is composed of four different herbs: Atractylodes macrocephala Koidz. (Baizhu), Paeonia lactiflora Pall. (Baishaoyao), Citrus reticulata Blanco (Chenpi), Saposhnikovia divaricata (Turcz.) Schischk (Fangfeng). TXYF has over a hundred years of history and can significantly improve depression and reduce intestinal symptoms. However, the intervention effect and mechanism of TXYF on colorectal cancer accompanied by psychological stress are not still clear.

AIM OF STUDY

This study investigated the therapeutic effect of TXYF on CRC mice with chronic restraint stress (CRS) and to explore its mechanism.

MATERIALS AND METHODS

We constructed a mouse model of chronic stress by CRS and subcutaneous injection of CT26-Luc cells, and administered TXYF by gavage. We measured the body weight, tumor size, and tumor weight of each group of mice. The tumor growth was monitored dynamically of by vivo bioluminescence analysis. The depressive state of each group of mice were evaluated by tail suspension test, forced swimming test, and hormone level changes. We used flow cytometry to detect the ratio of CD4+ T cells, CD8+ T cells, Th1 cells, Th2 cells, and dendritic cells (DCs) phenotype (MHC II, CD80, and CD86) and chemotaxis ability (CXCR4 and CCR7) of in peripheral blood and tumor tissue. the levels of IL-12, IL-18, Th1 cytokines, and Th2 cytokines in the serum of each group of mice were determined by ELISA.

RESULTS

TXYF can improve the body weight of CRC mice with CRS, inhibit tumor volume and weight, alleviate depressive state, upregulate 5-HT levels, and inhibit HPA axis hormone secretion. The results of flow cytometry showed that TXYF can promote the maturation of DCs phenotype and function, enhance antigen presentation ability, increase the ratio of CD4+ T cells and CD4+/CD8+ T cells, and shift Th1/Th2 balance towards Th1 cells, thus increasing serum levels of IFN-γ, IL-18, IL-2, and IL-12, while decreasing serum levels of IL-4 and IL-10, and effectively triggering T cell-mediated immune response.

CONCLUSIONS

This study shows that TXYF inhibits the growth of tumors in CRC mice with CRS by stimulating immune response. The mechanism may be inhibiting the HPA axis and promoting DCs maturation, thus activating T cells and enhancing anti-tumor immune response, ultimately preventing the progression of CRC.

MAdCAM-1 targeting strategy can prevent colitic cancer carcinogenesis and progression via suppression of immune cell infiltration and inflammatory signals

Chronic inflammation caused by infiltrating immune cells can promote colitis-associated dysplasia/colitic cancer in ulcerative colitis (UC) by activating inflammatory cytokine signalling through the IL-6/p-STAT3 and TNFα/NF-κB pathways. Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) expressed on high endothelial venules promotes the migration of immune cells from the bloodstream to the gut via interaction with α4β7 integrin expressed on the immune cells. MAdCAM-1, has therefore drawn interest as a novel therapeutic target for treating active UC. However, the role of MAdCAM-1-positive endothelial cells in immune cell infiltration in dysplasia/colitic cancers remains unclear. We evaluated the expression of MAdCAM-1, CD31 and immune cell markers (CD8, CD68, CD163 and FOXP3) in samples surgically resected from 11 UC patients with dysplasia/colitic cancer and 17 patients with sporadic colorectal cancer (SCRC), using immunohistochemical staining. We used an azoxymethane/dextran sodium sulphate mouse model (AOM/DSS mouse) to evaluate whether dysplasia/colitic cancer could be suppressed with an anti-MAdCAM-1 blocking antibody by preventing immune cell infiltration. The number of MAdCAM-1-positive vessels and infiltrating CD8+ , CD68+ and CD163+ immune cells was significantly higher in dysplasia/colitic cancer than in normal, SCRC and UC mucosa. In AOM/DSS mice, the anti-MAdCAM-1 antibody reduced the number, mean diameter, depth of tumours, Ki67 positivity, number of CD8+ , CD68+ and CD163+ immune cells and the IL-6/p-STAT3 and TNF-α/NF-κB signalling. Our results indicate that targeting MAdCAM-1 is a promising strategy for controlling not only UC severity but also carcinogenesis and tumour progression by regulating inflammation/immune cell infiltration in patients with UC.

Impact of glucocorticoids on the efficacy of neoadjuvant chemoradiotherapy and survival of patients with locally advanced rectal cancer: a retrospective study

BACKGROUND

Preclinical studies suggest that glucocorticoids (GCs) promote the proliferation and development of colorectal cancer. Because GCs are broadly prescribed for treatment-related adverse events in patients with locally advanced rectal cancer (LARC) receiving neoadjuvant chemoradiotherapy (NCRT), it's essential to assess the effect of GCs on clinical outcomes.

METHODS

LARC cases treated with NCRT followed by surgery were assessed retrospectively. Evaluation of the relationship between GCs use (GCs vs. non-GCs) and neoadjuvant rectal (NAR) score (as a three-level categorical dependent variable) was performed using multivariable multinomial logistic regression (MLR). We also examined the relationship between the accumulated dose of GCs and NAR using multivariate MLR. Survival analysis of disease-free survival (DFS) and overall survival (OS) was performed using the Kaplan-Meier method. Multivariate Cox regression was used to assess confounding factors that could influence OS and DFS.

RESULTS

This retrospective cohort study included 790 patients with newly diagnosed non-metastatic LARC (T3-4/N + M0) who received NCRT followed by surgery between January 2012 and April 2017. The end of the follow-up period was May 11, 2022. Among the 790 patients with LARC, 342 (43.2%) received GCs treatment and 448 (56.8%) did not during the NCRT-to-surgery period. GCs medication was significantly different between mid-NAR (8-16) and low-NAR (< 8) (odds ratio [OR], 0.615; 95% CI, 0.420-0.901; P = 0.013), and the high-NAR (> 16) and low-NAR (0.563; 0.352-0.900; 0.016). Patients exposed to GCs, had a decreased 5-year OS (GCs vs. non-GCs = 80.01% (95% CI, 75.87%-84.37%) vs. 85.30% (82.06%-88.67%), P = 0.023) and poorer 5-year DFS (73.99% (69.45%-78.82%) vs. 78.7% (75.14%-82.78%), P = 0.045). The accumulated dose of GCs was an independent risk factor for OS (hazard ratio [HR], 1.007 [1.001-1.014], 0.036) and DFS (1.010 [1.004-1.017], 0.001).

CONCLUSIONS AND RELEVANCE

Our study revealed that GCs were associated with reduced efficacy of NCRT and worse clinical outcomes in patients with LARC during the NCRT-to-surgery period.

Tanshinone IIA attenuates AOM/DSS-induced colorectal tumorigenesis in mice via inhibition of intestinal inflammation

CONTEXT

Tanshinone IIA is a natural extract derived from a Chinese medicinal herb with multiple bioactivities; however, whether and how tanshinone IIA protects against colorectal cancer (CRC) are uncertain.

OBJECTIVE

We investigated the potential beneficial effects of tanshinone IIA in a colitis-associated colorectal tumorigenesis mouse model and its underlying mechanisms.

MATERIALS AND METHODS

Male C57BL/6 mice were treated with azoxymethane (AOM) 10 mg/kg body weight and dextran sulphate sodium (2.5% DSS) to induce a colitis-associated cancer model. Tanshinone IIA (200 mg/kg body weight) was given to the mice intraperitoneally. After 12 weeks, all mice were sacrificed to measure tumour formation, intestinal permeability, neutrophil infiltration, and colonic inflammation. In addition, whether tanshinone IIA has inhibitory effects on neutrophil activation was determined through in vitro investigations.

RESULTS

We observed that tanshinone IIA significantly decreased tumour formation in AOM/DSS-treated mice compared to AOM/DSS-treated alone mice (0.266 ± 0.057 vs. 0.78 ± 0.153, p = 0.013). Tanshinone IIA also decreased intestinal permeability compared to that in AOM/DSS-treated alone mice (3.12 ± 0.369 vs. 5.06 ± 0.597, p = 0.034) and consequently reduced neutrophil infiltration of the colonic mucosa (53.25 ± 8.85 vs. 107.6 ± 13.09, p = 0.014) as well as intestinal inflammation in mice. Mechanistically, tanshinone IIA downregulated the NF-κB signalling pathway in the colonic tumours of AOM/DSS-treated mice. In vitro assays further validated that tanshinone IIA suppressed LPS-induced neutrophil activation.

CONCLUSION

These data suggest that tanshinone IIA alleviates colorectal tumorigenesis through inhibition of intestinal inflammation. Tanshinone IIA may have a therapeutic potential for CRC in clinical practice.

Therapeutic potential and deleterious effect of glucocorticoids on azoxymethane/dextran sulfate sodium-induced colorectal cancer in mice

Glucocorticoids (GCs) are widely used in the treatment of various autoimmune and inflammatory diseases, including inflammatory bowel disease (IBD). However, the effect of GCs on the progression of colitis-associated colorectal cancer (CAC) has not been well explored. In this study, we first established a colorectal cancer model induced by azoxymethane and dextran sulfate sodium (AOM/DSS) and a colitis model induced by DSS in mice. Dexamethasone (DEX) was then administered at different periods of time to determine its effect on tumorigenesis and tumor progression. Meanwhile, body weight, stool property and fecal blood of mice were recorded. At the end of this study, the number and load of tumors were evaluated, and the expression of proteins associated with cell proliferation was analyzed. To evaluate the inflammation in colon, we detected the level of pro-inflammatory cytokine TNFα, and the mucosal infiltration of inflammatory cells. Our results revealed that AOM injection followed by three cycles of drinking water containing 1.5% DSS successfully induced multiple tumor formation in mouse colon and rectum. Both early and late DEX intervention suppressed tumor growth in mouse colorectum, and downregulated the expression of PCNA and cyclin D1. Moreover, DEX treatment significantly inhibited TNFα production, mucosal infiltration of inflammatory cells, and the activity of MAPK/JNK pathway, particularly early DEX intervention. However, we also found that DEX treatment deteriorated the general state of mouse manifested by greater loss of body weight and rectal bleeding. In summary, both early and late DEX interventions significantly ameliorate colonic inflammation and inhibit the progression of AOM/DSS-induced colorectal cancer, at least partly due to the inhibition of MAPK/JNK pathway. It is noteworthy that the deleterious effect on the general condition of mouse may limit the duration of GCs treatment.

Carcinogenesis: Failure of resolution of inflammation?

Inflammation in the tumor microenvironment is a hallmark of cancer and is recognized as a key characteristic of carcinogens. However, the failure of resolution of inflammation in cancer is only recently being understood. Products of arachidonic acid and related fatty acid metabolism called eicosanoids, including prostaglandins, leukotrienes, lipoxins, and epoxyeicosanoids, critically regulate inflammation, as well as its resolution. The resolution of inflammation is now appreciated to be an active biochemical process regulated by endogenous specialized pro-resolving lipid autacoid mediators which combat infections and stimulate tissue repair/regeneration. Environmental and chemical human carcinogens, including aflatoxins, asbestos, nitrosamines, alcohol, and tobacco, induce tumor-promoting inflammation and can disrupt the resolution of inflammation contributing to a devastating global cancer burden. While mechanisms of carcinogenesis have focused on genotoxic activity to induce mutations, nongenotoxic mechanisms such as inflammation and oxidative stress promote genotoxicity, proliferation, and mutations. Moreover, carcinogens initiate oxidative stress to synergize with inflammation and DNA damage to fuel a vicious feedback loop of cell death, tissue damage, and carcinogenesis. In contrast, stimulation of resolution of inflammation may prevent carcinogenesis by clearance of cellular debris via macrophage phagocytosis and inhibition of an eicosanoid/cytokine storm of pro-inflammatory mediators. Controlling the host inflammatory response and its resolution in carcinogen-induced cancers will be critical to reducing carcinogen-induced morbidity and mortality. Here we review the recent evidence that stimulation of resolution of inflammation, including pro-resolution lipid mediators and soluble epoxide hydrolase inhibitors, may be a new chemopreventive approach to prevent carcinogen-induced cancer that should be evaluated in humans.

Dexamethasone induces aberrant macrophage immune function and apoptosis

Glucocorticoids (GCs) are known potent clinical drugs, however, their mode of action is still complex and debatable. Macrophages are the most important target of GCs and play a key role in tumor immunity in vivo, but their relationship is also controversial. In the present study, the lentivirus system was used to overexpress and knock down the level of transcription factor Krüppel-like factor 9 (KLF9). The results revealed that dexamethasone (Dex) induced ROS generation and mitochondria-dependent apoptosis in RAW 264.7 cells via the KLF9. In addition, overexpression of KLF9 significantly increased apoptosis of RAW 264.7 cells. Notably, ELISA assay revealed that increased expression of KLF9 inhibited LPS-induced COX-2 expression and reduced COX-2-derived prostaglandin E2 and pro-inflammatory cytokine secretion. Furthermore, a co-culture system was used to reveal that overexpression of KLF9 in RAW 264.7 cells promoted HepG2 cell survival. In summary, it is reported that KLF9 promoted apoptosis of proinflammatory macrophages, and suppressed the antitumor effects, which can be selectively targeted by GCs as a novel mechanism to suppress antineoplastic activity.