Gene: the genes for keratins 13, 14, 15, 16, 17, and 19 are contained in less than 150 kb of genomic DNA in the region 17q21-q22 (Ceratto N. et al., 1997).
mRNA: size: 1.3 kb.
Protein: a 40-kda acidic keratin, component of
intermediate filaments.
Cell lines:
- The phenotypic characteristics of 2 tumor cell lines (BC-H1 and BC-K1) established from bone marrow of patients with breast cancer were studied by immunocytochemistry, flow cytometry, and RT-PCR. Both cell lines expressed
E-cadherin,
vimentin, cytokeratins, alpha 5-,
alpha V-,
beta 1-, and
beta 3- integrin subunits,
ICAM-1,
MCAM, LFA-3 (CD58), and
CD44s (but not
CD44v5,
v6,
v7/8). BC-H1 also expressed
ErbB2 (not found in BC-K1), and
MAGE-4 (but not MAGE-1, -2, -3/6, -12; BC-K1 was not tested). In both cell lines, the mesenchymal cytoskeleton protein
vimentin was coexpressed with cytokeratins CK8/18 and CK8/19, indicating an epithelial to mesenchymal transition of these micrometastatic cells. The expressed molecules might be potential candidates for novel therapeutic targets (Putz E. et al., 1999).
Tumors:
- Keratin 19 was found non-suitable for RT-PCR detection of submicroscopic lymph node metastases in breast cancer, as its transcript was also detected in the great majority of control (from non-cancer patients) lymph nodes tested (Merrie AEH et al., 1999).
- A cytokeratin 19 pseudogene has been described. It shows a high degree (84.7%) of identity with the cytokeratin 19 gene sequence, except for differences caused by 3 small deletions and a number of point mutations, resulting in termination codons and frameshifts. The gene has therefore no coding potential, but could interfere with the CK19 RT-PCR assays for micrometastasis detection (Ruud P. et al., 1999).
