Figure 3. PatA suppresses tumour-induced muscle wasting in BALB/c mice injected with C26 adenocarcinoma cells.

(a–e) Injection of mice with 20 μg kg⁻¹ PatA 6 days post-injection of C26 adenocarinoma cells prevents muscle wasting without affecting tumour growth. Mice were treated with or without 20 μg kg⁻¹ of PatA starting at 6 days post-injection of C26 cells and every second day thereafter. Mice were subsequently killed 19 days after the injection of C26 cells. (a) Photographs of the tumours are representative of n=3 mice per sample group. Bars, 5 mm. Tumour volume (b) and weight (c)±s.e.m. were measured for 3 mice per group. NS refers to non-significance. (d) Photograph and (e) weight of gastrocnemius muscles isolated from mice described above. Photographs in d are representative of n=3 mice, Bars, 5 mm. Weights in e are presented±s.e.m. from n=3 mice per group. *P<0.05, **P<0.01 (Student's t-test). (f–j) Injection of 20 μg kg⁻¹ PatA in C26 tumour-bearing mice prevents muscle atrophy. (f) Effect of 20 μg kg⁻¹ PatA or 50 mg kg⁻¹ AMG on the growth of C26 tumours. Tumour volumes were calculated over a 3-week period. PatA or AMG was only injected into mice on day 13 (indicated on graph by a black arrow) when tumours became palpable and every second day thereafter. The mice were killed on day 22 after the injection of C26 cells. Volumes are presented as ±s.e.m. from n=3 mice. (g) Weight of tumours and (h) gastrocnemius muscles isolated from mice 22 days post-C26 injection treated or not with 20 μg kg⁻¹ of PatA or 50 mg kg⁻¹ AMG, as described above. Weights are presented ±s.e.m. from n=3 mice per group. (h) *P<0.05 (Student's t-test). (i) Immunohistochemical staining of gastrocnemius muscle fibres isolated from saline as well as C26 tumour-bearing mice treated with or without PatA, as described above. Bars, 20 μm. (j) The cross-sectional area of muscle fibres described in i are represented as a frequency histogram from n=2 mice. The mean cross-sectional area of the fibres is indicated in the histogram±s.e.m.