A study from 2020 has explored the potential of exercise as a complementary therapy for patients battling advanced cancer. The research, published in the Journal of Physiology, focuses on the impact of a specific resistance exercise method called whole-body electromyostimulation (WB-EMS) on the growth and survival of cancer cells.
The study involved advanced-stage cancer patients diagnosed with either prostate or colorectal cancer. These patients participated in a 12-week WB-EMS training program consisting of 20-minute sessions twice a week. WB-EMS utilizes low-frequency electrical impulses to stimulate muscle contractions, offering a less strenuous alternative to traditional resistance training with weights. This is particularly beneficial for patients experiencing physical limitations due to their advanced disease stage.

The core finding of the study is that serum collected from these patients after the WB-EMS training program exhibited a significant ability to inhibit the growth and promote the death of human prostate and colon cancer cells in vitro. These effects were consistently observed across different types of prostate cancer cells, including hormone-sensitive and hormone-insensitive ones. Notably, the serum did not negatively impact the growth of non-malignant cells, emphasizing the potential of WB-EMS to selectively target cancer cells.
To further understand the mechanisms behind these observations, the researchers conducted additional experiments using electric pulse stimulation (EPS) on cultured human skeletal muscle cells. EPS simulates the effects of exercise in an in vitro setting. The results showed that EPS-conditioned medium, similar to the serum from WB-EMS trained patients, effectively reduced the viability of both prostate and colon cancer cells. This important finding strengthens the link between muscle stimulation, be it in vivo through WB-EMS or in vitro via EPS, and the inhibition of cancer cell growth.

The researchers propose that myokines, signaling molecules released by skeletal muscles during exercise, might play a crucial role in mediating these anti-cancer effects. Indeed, analysis of the EPS-conditioned medium revealed increased levels of several established myokines, such as BDNF, CCL-2, IGFBP-3, IL-5, IL-6, IL-7, IL-8, and VEGF. The role of these specific myokines in the observed cancer cell growth inhibition warrants further investigation.

To gain deeper insights into the molecular changes induced by exercise, the researchers analyzed the gene expression profiles of prostate cancer cells treated with either WB-EMS patient serum or EPS-conditioned medium. The analysis highlighted several genes involved in cancer cell proliferation and apoptosis that were similarly regulated by both treatments.

Among these genes, several findings stand out:
● CCNE1, a gene promoting cell cycle progression, was downregulated, potentially leading to cell cycle arrest and reduced proliferation.
● GHR, the receptor for growth hormone often associated with tumor progression, was also downregulated, possibly disrupting growth-promoting signals.
● WNT10A, a gene frequently implicated in cancer development, was significantly suppressed, further supporting the anti-cancer potential of exercise.
● Conversely, CDKN1B, a gene that inhibits cell cycle progression, was upregulated, contributing to the suppression of cancer cell growth.
● CASP3 and CASP7, genes encoding enzymes crucial for apoptosis, were upregulated.
● This upregulation was corroborated by increased cleavage of PARP, a protein targeted by these enzymes during apoptosis.

These findings point towards a complex interplay of genetic and molecular events triggered by exercise that ultimately culminates in the inhibition of cancer cell growth and the promotion of their death.

The study concludes that exercise, particularly WB-EMS, holds promise as an adjunctive therapy for cancer patients. The researchers emphasize that regular exercise, apart from its established benefits for physical and mental well-being, might actively contribute to combating cancer development and progression. Future research focusing on identifying the specific myokines involved and further elucidating the molecular mechanisms underlying these effects is crucial for translating these findings into effective clinical applications.

Source.