Lack of Association between Angiogenin (AGN) KO Mice with Improvement in Muscle Strength, Resistance,but Decreased in Chances of Tumorigenesis: Observational Study

Abstract

Background: For quite a while, there has been controversy over whether or not angiogenin is associated with amyotrophic lateral sclerosis (ALS) risk. A lot of meta-analysis has been done in the last few years to support the fact that angiogenin has no relationship in improving the outcome and muscle strength in ALS. In the other hand, for about 3 decades angiogenin has been thought to play an important role in cell survival, growth, and proliferation. Evidence suggests that the expression and activity of ANG increases the odds of developing a variety of human cancers. We present the results of an observational study done in wild type (WT) and angiogenin knock out (ANG -/- KO) mice in order to determine phenotype and different features as explained below. Methods: We used 2 population of mice, 5 WT and 5 ANG -/- KO were involved in the study. They all were old, each 12 weeks old. These 2 populations were studied for a total of 8 weeks. We invested about 4 hours per day, 5 out 7 days per week. We had the mice running at different speeds on a treadmill in cycles of 300 seconds each, repeating these between 7-10 cycles per population. We used different speeds, being anywhere between 1 MPH to 7 MPH at the highest. We tested our theory that mice ANG -/- KO will have better strength and resistance by observing whether the mice looked stronger compared to the other population. Also by observation, we looked for physical abnormalities as well as evident malignancies in the ANG -/- KO vs. WT mice. Results: After conducting this study for 8 weeks, we found that ANG -/- KO mice did not have any statistical significant (p=0.36) muscle strength or resistance improvement compared to the WT mice. Also, at the end of our study we could conclude that ANG -/- KO did have less alopecia, skin cancer (basal cell carcinomas; squamous cell carcinomas), benign lesions of the skin, and malignant development of lymph nodes compared to WT mice. All 5 mice in the WT population did have skin lesions consistent with skin cancer and lymphadenopathy consistent with malignant lymph nodes of either lymphomas or metastatic disease. Discussion: At the end of the study, we could conclude that there was no statistical significance while evaluating both WT and KO mice as they had equal muscle strength and resistance. Conversely, we did see an increase in the number of benign and malignant proliferations in WT mice vs. KO mice.