Biomarker: Human kallikrein 6 (hK6)

Histology type: rare type

Country: USA

Region: Arkansas

Study type: Comparative Study

Followed up time :

Subgroup 1 name : mean copy number in USPC

Subgroup 1 number: 1927

Subgroup 2 name: mean copy number in EEC

Conclusion: hK6 is highly expressed in USPC and is released in the plasma and serum of USPC patients. hK6 may represent a novel biomarker for USPC for monitoring early disease recurrence and response to therapy.

Sample type : plasma

Sample method: ELISA,real-time PCR

Expression pattern : expression

Subgroup 2 age: 59.2;37–76

Funtion Uniprot: Serine protease which exhibits a preference for Arg over Lys in the substrate P1 position and for Ser or Pro in the P2 position. Shows activity against amyloid precursor protein, myelin basic protein, gelatin, casein and extracellular matrix proteins such as fibronectin, laminin, vitronectin and collagen. Degrades alpha-synuclein and prevents its polymerization, indicating that it may be involved in the pathogenesis of Parkinson disease and other synucleinopathies. May be involved in regulation of axon outgrowth following spinal cord injury. Tumor cells treated with a neutralizing KLK6 antibody migrate less than control cells, suggesting a role in invasion and metastasis

UniProt ID: Q92876

UniProt Link: https://www.uniprot.org/uniprotkb/Q92876/entry

Molecular function from UniProt:

Tissue specificity from UniProt: In fluids, highest levels found in milk of lactating women followed by cerebrospinal fluid, nipple aspirate fluid and breast cyst fluid. Also found in serum, seminal plasma and some amniotic fluids and breast tumor cytosolic extracts. Not detected in urine. At the tissue level, highest concentrations found in glandular tissues such as salivary glands followed by lung, colon, fallopian tube, placenta, breast, pituitary and kidney. Not detected in skin, spleen, bone, thyroid, heart, ureter, liver, muscle, endometrium, testis, pancreas, seminal vesicle, ovary, adrenals and prostate. In brain, detected in gray matter neurons (at protein level). Colocalizes with pathological inclusions such as Lewy bodies and glial cytoplasmic inclusions. Overexpressed in primary breast tumors but not expressed in metastatic tumors.

Subcellular UniProt: Philippe Le Mercier Keywords Cellular component #Cytoplasm #Endoplasmic reticulum #Microsome #Mitochondrion #Nucleus #Secreted

Alternative name from UniProt:

Activity regulation: Inhibited by a range of serine protease inhibitors including soybean trypsin inhibitor, benzamidine and serpins. Activated by a range of glycosaminoglycans including chondroitin sulfate, dermatan sulfate, heparan sulfate and heparin.

Recommended name: Kallikrein-6

Gene name from HGNC: KLK6 (Bssp, Klk7, neurosin, PRSS18, PRSS9)

HPA class: Cancer-related genes Enzymes Plasma proteins

AlphaFold DB: Q92876

AlphaFold Link: https://alphafold.ebi.ac.uk/entry/Q92876

Induction: By spinal cord injury. This effect is particularly prominent in macrophages, microglia and reactive astrocytes.

HPA link: https://www.proteinatlas.org/ENSG00000167755-KLK6

Tissue specificity RNA from HPA: Tissue enhanced (brain, esophagus)

Tissue expression from HPA: Cancer-related genes Enzymes Plasma proteins

Single cell type specificity Cell type enhanced (Oligodendrocytes, Breast glandular cells, Breast myoepithelial cells, Collecting duct cells

Immune cell specificity: Not detected in immune cells

Subcellular summary HPA Located in Nucleoplasm, Nuclear membrane, Cytokinetic bridge (Single cell variability, CCD Protein)

Cancer prognostic summary HPA Prognostic marker in endometrial cancer (unfavorable), urothelial cancer (unfavorable), pancreatic cancer (unfavorable) and lung cancer (unfavorable)

Pathology link: https://www.proteinatlas.org/ENSG00000167755-KLK6/pathology

Pathology endo: https://www.proteinatlas.org/ENSG00000167755-KLK6/pathology/endometrial+cancer

OMIM: 602652

OMIM link2: https://www.omim.org/entry/602652

HGNC ID: HGNC:6367

HGNC link: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6367