Conclusion
Twelve weeks of resistance training increased mRNA expression of MuRF-1 in skeletal muscle of PCS on ADT. Elevations in resting mRNA expression of IGF-1, myogenin and PGC-1α4, and reduction in mRNA expression of myostatin that are typically expected following resistance training were not observed.
Methods
PCS on ADT (n = 17) were randomized to 12 weeks of supervised resistance training (EXE, n = 9) or home-based stretching (STRETCH, n = 8) 3 days per week. Outcomes were assessed at baseline and post-intervention. Muscle biopsies were analyzed by RT-PCR for mRNA expression. Body composition was assessed through dual-energy X-ray absorptiometry, and physical function through muscular strength, timed up and go, stair climb, and 400 m walk.
Purpose
Prostate cancer survivors (PCS) receive androgen deprivation therapy (ADT) as treatment for recurrent cancer, yet ADT is associated with loss of skeletal muscle and physical function. Resistance training can counter both muscle and physical function loss; however, an understanding of the molecular responses of skeletal muscle to resistance training during ADT is still undefined. This sub-analysis of the original randomized, controlled pilot trial investigated effects of 12 weeks of periodized resistance training on mRNA expression of the anabolic genes IGF-1, myogenin, PGC-1α4 and the catabolic genes myostatin and MuRF-1 in skeletal muscle of PCS on ADT. Secondary aims investigated if changes in lean mass and physical function correlated with changes in mRNA expression.
Results
MuRF-1 mRNA expression was significantly greater in EXE compared to STRETCH post-intervention (P = .005). Change in MuRF-1 mRNA expression significantly correlated with improvements in strength and physical function (P < .05), while change in IGF-1 expression correlated with change in lean mass (P = .015).
Trial registration
ClinicalTrials.gov NCT01909440.