Determining the role of tumor-derived leukemia inhibitory factor in cancer cachexia using a genetic approach

Abstract

Cachexia is a multifactorial metabolic wasting syndrome that affects a large percentage of cancer patients and results in the involuntary loss of skeletal muscle and adipose tissue. The consequences of this condition include metabolic imbalances and fatigue, which are strongly associated with poor prognosis. While the specific mechanism for skeletal muscle wasting is still undefined, LIF secreted by C26 colon carcinoma cells has recently be found to induce atrophy in treated myotubes. The purpose of this study is to determine the necessity of LIF for inducing atrophy in mouse myotubes by producing a knockout of Lif in C26 cells using CRIPSR-Cas9. Media was collected from these cells and used to treat myotubes. Measurements of myotube diameters were made and atrophy was compared between myotubes that received medium from C26 and C26Lif-/- cells. A dosage of recombinant mouse LIF was also added to LIF-deficient medium in order to determine if LIF alone was sufficient to induce atrophy. At study endpoint, myotubes that were treated with media taken from C26 cells showed significant signs of atrophy compared to myotubes that were treated C26Lif-/- media. LIF was also shown to be sufficient to induce myotube atrophy on its own, with atrophy being rescued in myotubes that received a dosage of LIF added to C26Lif-/- media. These results demonstrate that LIF is required for atrophy to be induced in mouse myotubes treated with media taken from cancer cells, and can do so independent of other secreted factors.