KRT17 Gene

KRT17 (keratin 17) is a protein-coding gene located on chromosome 17q21.2. This gene encodes a 48 KDa type I intermediate filament that is mainly found in epithelial basal cells.

Mutations in this gene lead to:

• Pachyonychia congenita type I and type II and
• Steatocystoma multiplex (Zhang B et al. 2020; Wang Jet al. 2018)

Associated metabolic pathways include developmental biology and keratinization. An important paralog of this gene is KRT14.

Type I keratin is involved in the formation and maintenance of various skin appendages, particularly in determining the shape and alignment of hair. It is necessary for the correct growth of hair follicles, especially for the maintenance of the anagen (growth) state.

Modulates the function of TNF-alpha in the specific context of the hair cycle.

Regulates protein synthesis and growth of epithelial cells by binding to the adapter protein SFN and by stimulating the Akt/mTOR signaling pathway.

Participates in tissue repair.

The encoded protein could be a marker for basal cell differentiation in complex epithelia and therefore indicate a certain type of epithelial "stem cell".

KRT17 acts as a promoter of epithelial proliferation by acting as a regulator of the immune response in the skin: promotes a Th1/Th17-dominated immune milieu.

May act as an autoantigen in the immunopathogenesis of psoriasis, with certain peptide regions being a major target for autoreactive T cells, causing their proliferation.

KRT17 and carcinomas: KRT17 has been shown to be overexpressed in many malignant tumors and plays an important role in tumorigenesis and development, including non-small cell lung cancer (NSCLC ) and colorectal carcinoma (Wang Z et al. 2019).

Ujiie D et al. (2020) were able to demonstrate that high expression of KRT17 transcripts is significantly associated with poor recurrence-free survival (RFS) in colorectal carcinoma. An analogous finding can be established in non-small cell lung cancer (NSCLC) (Wang Z et al. 2019).

1. Alotaibi L et al (2019) Steatocystoma Multiplex Suppurativa: A Case with Unusual Giant Cysts over the Scalp and Neck. Case Rep Dermatol 11:71-76.
2. Antal AS et al (2012) Steatocystoma multiplex: keratin 17 - the key player? Br J Dermatol 167:1395-1397.
3. Ujiie D et al (2020) KRT17 as a prognostic biomarker for stage II colorectal cancer. Carcinogenesis 41: 591-599.
4. Wang J et al. (2018) A recurrent mutation in the KRT17 gene responsible for severe steatocystoma multiplex in a large Chinese family. Clin Exp Dermatol 43: 205-208.
5. Wang Z et al (2019) Overexpression of KRT17 promotes proliferation and invasion of non-small cell lung cancer and indicates poor prognosis. Cancer Manag Res 11:7485-7497.
6. Zhang B et al (2020) Mutation analysis of the KRT17 gene in steatocystoma multiplex and a brief literature review. Clin Exp Dermatol 45:132-134.