Acute high intensity interval exercise reduces colon cancer cell growth

Abstract

Key points Physical activity is associated with reduced mortality rates for survivors of colorectal cancer. Acute high intensity interval exercise (HIIE) reduced colon cancer cell number in vitro and promoted increases in inflammatory cytokines immediately following exercise. This acute suppression of colon cancer cell number was transient and not observed at 120 minutes post-acute HIIE. The acute effects of exercise may constitute an important mechanism by which exercise can influence colorectal cancer outcomes. Abstract Physical activity is associated with significant reductions in colorectal cancer mortality. However, the mechanisms by which exercise mediates this anti‐oncogenic effect are not clear. In the present study, colorectal cancer survivors completed acute (n = 10) or chronic (n = 10) exercise regimes. An acute high intensity interval exercise session (HIIE; 4 × 4 min at 85–95% peak heart rate) was completed with serum samples collected at baseline, as well as 0 and 120 min post‐exercise. For the ‘chronic’ intervention, resting serum was sampled before and after 4 weeks (12 sessions) of HIIE. The effect of serum on colon cancer cell growth was evaluated by incubating cells (CaCo‐2 and LoVo) for up to 72 h and assessing cell number. Serum obtained immediately following HIIE, but not 120 min post‐HIIE, significantly reduced colon cancer cell number. Significant increases in serum interleukin‐6 (P = 0.023), interleukin‐8 (P = 0.036) and tumour necrosis factor‐α (P = 0.003) were found immediately following acute HIIE. At rest, short‐term HIIE training did not promote any changes in cellular growth or cytokine concentrations. The acute effects of HIIE and the cytokine flux may be important mediators of reducing colon cancer cell progression. Repetitive exposure to these acute effects may contribute to the relationship between exercise and improved colorectal cancer survival.

Physical activity‐related suppression of cancer growth: is a transient increase in cytokine production required for tumour angiogenesis?

“…Devin et al . () observed transient (≤2 h post‐exercise) inhibition of colon cancer growth in two colon cancer cell lines (CaCo‐2 and LoVo) along with increases in cytokine concentrations immediately following HIIE. Interestingly, but consistent with previous findings, this increase was not observed in the short‐term training group.…”

“…While multiple studies reiterate the importance of chronic exercise in mitigating the risk of developing cancer, new data suggest that acute bouts of high intensity exercise can be beneficial as well (Devin et al . ).…”

“…However, as the authors state, ‘the precise mechanisms by which these factors may influence cellular growth in vivo currently remain unknown’ (Devin et al . ).…”

“…In a recent study published in The Journal of Physiology , Devin et al . () investigated the effect of high intensity interval exercise (HIIE) on colorectal cancer cell growth, in vitro . Investigators recruited 20 colorectal cancer survivors who were ≥1 month removed from their radiation therapy, chemotherapy, or surgical treatment; ≥40 years old; not receiving any insulin or insulin‐sensitizing agents; and were free of any ailments that would prevent them from completing the exercise regimens.…”

“…If IL‐6 is a required cytokine to stimulate angiogenesis, the rise in inflammatory cytokines observed by Devin et al . () may be a compensatory mechanism; an acute increase in IL‐6 may be required to establish mature vessels and promote infiltration of immune cells, ultimately reducing the hypoxic, tumour microenvironment.…”