Growth of subcutaneous MC38 colorectal cancer triggers mild cachexia

Colorectal cancer (CRC) frequently manifests with cancer cachexia. To model CRC‑associated cachexia, we implanted MC38 murine CRC cells subcutaneously into mice and evaluated skeletal muscle responses. Tumor‑bearing mice showed mild but significant wasting of both the quadriceps and gastrocnemius muscles (p < 0.05). Quadriceps RNA was profiled using poly(A)‑selected, stranded RNA‑seq. Differential expression analysis (DESeq2) identified 616 significantly altered genes (|log2FC| ≥ 1, FDR < 0.05). Pathway enrichment revealed marked upregulation of neutrophil degranulation and inflammatory response programs, accompanied by downregulation of voltage‑gated potassium channel activity and potassium ion transport pathways. Together, these findings implicate heightened inflammatory/neutrophil‑associated signaling and reduced ion‑channel gene expression as key molecular features of skeletal muscle wasting in this CRC cachexia model. Raw FASTQ files and processed gene‑level counts are provided to support reuse and secondary analyses.