Factors such as red meat consumption, physical inactivity, and obesity greatly increase the incidence of colon cancer. Colon cancer has slowly developed into one of the most common malignant gastrointestinal tumors in the world for decades.
National Cancer Institute and World Cancer Research Fund release:Epidemiological evidence suggests that regular physical activity Can prevent colon cancer.colon cancer. Current research shows thata reasonable level of physical activity can reduce the relative risk of colon cancer by 12% to 28%. Moderate physical activity is associated with a reduced risk of cancer-specific mortality and recurrence after colon cancer diagnosis.
In a new study, researchers collected human serum stimuli before and after acute exercise. The effects of colon cancer cell line (LoVo) and non-exercise control serum on the proliferation of cancer cells were observed.The changes of serum cytokines and intracellular protein expressions induced by exercise were observed. Furtherexplore the potential mechanism of exercise inhibiting colon cancer cell proliferation.
The researchers first incubated LoVo cells (human colon cancer cell line) for 48 hours with media containing 10% human serum collected before and after acute exercise. ), and performed non-motor control experiments. Stimulation of LoVo cells with post-exercise serum decreased cell proliferation compared with pre-exercise serum (-4.2%, 95% CI -6.8 to -1.5%; P = .006; Figure 1A), and compared with pre-control serum, Control serum resulted in increased cell proliferation (5.4%, 95% CI 2.2 to 8.6%; P = .003). After controlling for pre-value, post-exercise serum reduced cell proliferation compared with controls (-5.7%, 95% CI -8.8 to -2.6%; P = .002; Figure 1B).
Figure 1. Effects of serum on colon cancer cell growth under acute aerobic exercise conditions. (A) Viability of LoVo cells 48 h after culture medium containing 10% human serum was collected before and after acute aerobic exercise and non-exercise control experiments. (B) Changes in serum-stimulated cell viability in exercise and control experiments (mean ±95% confidence interval). **P < .01
researchers assessed whether exercise modulated the concentrations of seven humoral factors in serum , to identify humoral factors that may contribute to exercise-induced inhibition of cell proliferation and DNA damage. Experiments showed that exercisepost-exerciseserum IL-6 increased (24.6%, 95%CI 11.2 to 37.9%; P = .002; Figure 2A), while there was no evidence of an effect of exercise on serum IL-8, TNF-α, ON, or OSM (all .05; Figure 2B-E). IL-10 and irisin were not detectable in serum samples.
<600"> Effects of aerobic exercise on serum cytokine concentrations. (A-E) Concentrations of interleukin-6 (IL-6), IL-8, TNF-α, ON, and OSM in serum before and after exercise (mean ± SEM). **P < .01
In order to explore whether IL-6 can directly regulate the proliferation of LoVo cells and affect the expression of γ-H2AX. We stimulated LoVo cells with recombinant IL-6 and showed a dose-dependent effect (Fig. 3A). Specifically, IL-6 doses of 10 pg/mL and 100 pg/mL decreased γ-H2AX expression compared with 1 pg/mL (Fig. 3B). 0.1 pg/mL, 1 pg/mL, 10 pg/mL and 100 pg/mL also reduced LoVo cell proliferation compared to the control group. In addition,there was evidence of a linear trend in cell proliferation and γ-H2AX expression, suggesting that LoVo cell proliferation and γ-H2AX levels decreased proportionally with increasing doses of IL-6.
Fig. Influence of IL-6 on LoVo cell proliferation and intracellular γ-H2AXDa’s influence. (A) Representative immunoblots of γ-H2AX expression in LoVo cells after 45 min at 0, 10 and 100 pg/ml of actin and recombinant IL-6. (B) Quantification of γ-H2AX expression in LoVo cells that exhibited a dose-response effect of IL-6 (mean ± SEM of five replicate experiments). (C) Quantification of LoVo cell proliferation after 48 hours of direct stimulation with recombinant IL-6, showing a dose-response effect (mean ± SEM of 8 replicate control experiments and 4 replicates of IL-6 dose). Bonferroni correction was applied to adjust for multiple comparisons. *P < .05; **P < .01; ***P < .001
The results showed that Acute exercise increased serum IL-6 levels, and serum under acute aerobic exercise conditions reduced colon cancer cell proliferation in vitro. Meanwhile, intracellular levels of γ-H2AX decreased, indicating reduced DNA damage. The researchers stimulated colon cancer cells with recombinant IL-6 to reduce intracellular γ-H2AX expression and cell proliferation in a dose-dependent manner, mimicking the effects of exercise. Thus, experimental findings suggest that the inhibitory effect of exercise on colon cancer cell proliferation may be driven in part by IL-6-induced regulation of DNA damage and repair.
By studying the mechanisms of motility and cell proliferation in colon cancer cells exposed to human serum collected before and after acute exercise. Serum obtained after exercise reduced cancer cell proliferation compared to non-exercise control serum. This effect was accompanied by reduced expression of the DNA damage marker γ-H2AX. Reduced DNA damage was associated with exercise-induced increases in serum IL-6. The newly discovered mechanism may be in part the link between physical activity and a reduced risk of colon cancer.
References:
https://onlinelibrary .wiley.com/doi/10.1002/ijc.33982?af=R