PREVENTIVE EFFECT OF 8 WEEKS MODERATE TRAINING ON SUSCEPTIBLE COLON CANCER FACTOR (INSULIN GROWTH FACTOR I AND INSULIN GROWTH FACTOR BINDING PROTEIN 3 AND I) IN RATS

Malignant neoplasm of the colon wall or colon cancer (or colorectal cancer) is
the fourth and third most common cancer in men and women worldwide, respectively. Risk factors for
colon cancer are complex and the drug therapies did not have a great survival chance. Regarding the
probable role of the physical activity in preventing the incidence and severity of cancer, the present
study examined insulin-like growth factor-1 (IGF-I) and insulin-like growth factor binding protein 3
(IGFBP3) in an animal model of colon cancer.
Material & Methods: Male Wistar rats were selected based on approved protocols undergoing treadmill
exercise training at moderate intensity. Groups consisted of healthy controls and trained; and cancerous
control and trained. In each group, at least 7 mice were used alternatively. Animals first underwent eight
weeks of moderate-intensity training and then, through intraperitoneal injection of 1,2-
Dimethylhydrazine (DMH), changes in the predisposing factors for colon cancer were investigated. In
non-experimental groups, the experience of drug-carrier injection and treadmill adaptation was also
performed. Four weeks after DMH injection, IGF-I and IGFBP3 levels were measured in animal serum.
Anatomical evidence was provided to confirm colon cancer.
Results: Besides anatomical evidence of colon cancer, assessing the IGF-I and IGFBP3 values using
quantitative ELISA kits showed that serum levels of IGF-I in animals were significantly reduced with
moderate intensity pre-training but serum levels of IGFBP3 increased significantly compared to their
values in untrained animals.
Conclusion: Considering the findings of longitudinal studies, the underlying factors of increasing the
incidence and severity of cancer and its relation with hyperinsulinemia were considered. The Increase
in IGF-I and decrease in IGFBP3 following hyperinsulinemia is likely to be a factor for increasing the
susceptibility to colorectal cancer in these patients. The findings of this study, as well as other studies,
suggest that physical activity by reducing IGF-I and increasing IGFBP3 can be effective in preventing
colon cancer. Physical activity can be important as a non-pharmacological approach to reducing the
severity and development of colon cancer