How Exercise May Impact Natural Killer Cells in Patients With Prostate Cancer
Posted: Tuesday, September 29, 2020
Although prostate cancer treatments may alter the maturity and degranulation status of natural killer cells, the addition of moderate-intensity exercise to androgen-deprivation therapy (ADT) does not appear to adversely affect immune function. Alan Hayes, PhD, of the Victoria University in Melbourne, Australia, and colleagues reported their findings in Experimental Physiology.
“While this is an initial step examining how immune function responds to acute exercise and supports current guidelines, larger trials that examine repeated acute exercise bouts and include direct measures of natural killer cell function are required,” concluded the authors.
The team recruited 33 men to participate in the study: 11 prostate cancer survivors treated with ADT, 14 with prostate cancer not on ADT, and 8 healthy men as the control group. These groups were instructed to complete a session of moderate-intensity cycling for 45 minutes. Natural killer cells were phenotyped via flow cytometry before patients completed the exercise, immediately after, 2 hours after, and 24 hours after.
Immediately after exercise, the proportion of CD56-positive natural killer cells increased by an average of 6.2% across all patient groups and decreased 2.5% below baseline by 2 hours after exercise. This trend was seen in both the control group and in those receiving ADT, suggesting prostate cancer survivors may be able to effectively mobilize their immune system. By 24 hours, the natural killer cell population returned to baseline in all patients.
It was also found that patients undergoing ADT had nearly twofold higher expression of interferon-γ, which is expressed during natural killer cell activation, as compared with their control counterparts—independent of exercise. Patients with prostate cancer who were untreated had an 11.4% reduction in expression of perforin compared with the control group, suggesting these cells may be more prone to degranulation. CD75-negative natural killer cells expressed perforin and interferon-γ more frequently after exercise, with no changes observed in the CD57-positive (mature natural killer cells) populations.
Disclosure: The authors reported no conflicts of interest.
