Genetic alterations and epigenetic alterations of cancer-associated fibroblasts

Cancer-associated fibroblasts (CAFs) are one major type of component identified in the tumor microenvironment. Studies have focused on the genetic and epigenetic status of CAFs, since they are critical in tumor progression and differ phenotypically and functionally from normal fibroblasts. The present review summarizes the recent achievements in understanding the gene profiles of CAFs and pays special attention to their possible epigenetic alterations. A total of 7 possible genetic alterations and epigenetic changes in CAFs are discussed, including gene differential expression, karyotype analysis, gene copy number variation, loss of heterozygosis, allelic imbalance, microsatellite instability, post-transcriptional control and DNA methylation. These genetic and epigenetic characteristics are hypothesized to provide a deep understanding of CAFs and a perspective on their clinical significance.