Loss of exosomal miR-34c-5p in cancer-associated fibroblast for the maintenance of stem-like phenotypes of laryngeal cancer cells.

Background: Cancer-associated fibroblasts (CAFs) reconstitute cancer stemness. This study aims to investigate whether the loss of CAF-derived exosomal miR-34c-5p contributes to the maintenance of stem-like properties of laryngeal squamous cell carcinoma (LSCC).

Methods: Exosomes from primarily cultured CAFs and paired normal fibroblasts (NFs) were collected and identified. The differential expression of exosomal miR-34c-5p between CAFs and NFs was detected by next-generation sequencing. In vitro and in vivo assays were performed to examine the effects of miR-34c-5p on the maintenance of stem-like properties.

Results: MiR-34c-5p expression is significantly reduced in CAF-derived exosomes. In vitro and in vivo assays revealed that exosomal miR-34c-5p can regulate the stem-like properties of LSCC cells, such as proliferation, invasion, sphere and plate colony formation, chemoresistance, tumorigenicity in nude mice, as well as the expression of cancer stem cell genes.

Conclusions: Loss of miR-34c-5p in CAF-derived exosomes contributes to the maintenance of stem-like phenotypes of LSCC.