Contrasting Localization of c-Myc with Other Myc Superfamily Transcription Factors in the Human Hair Follicle and During the Hair Growth Cycle

The study investigated the expression patterns of the Myc superfamily of transcription factors—c-Myc, N-Myc, Max, and Mad1-4—within the human hair follicle at different stages of the hair growth cycle using immunohistochemistry. It was found that N-Myc, Max, Mad1, and Mad3 were present in the epidermis and epithelium of hair follicles in both growth (anagen) and rest (telogen) phases. However, c-Myc showed three distinct patterns: in the infundibulum, it was mainly in the basal layers; in the follicle bulb, it was in both proliferating and differentiating cells; and intense c-Myc activity was observed in the bulge region of the outer root sheath, which is associated with the putative stem cell compartment and was consistent regardless of the hair cycle stage. These findings suggest that members of the Myc family have different roles in various parts of the hair follicle and may influence cell fate in the stem cell compartment.