p16 INK4a is a tumor suppressor protein involved in the pathogenesis of a variety of malignancies. p16 INK4a is a 16.5 kDa protein expressed in the nucleoplasm of proliferating cells, functioning as an inhibitor of CDK4. Recent analyses of the p16 INK4a gene revealed homozygous deletions, nonsense, missense, or frameshift mutations in several human cancers (1).
The Ki-67 nuclear antigen is associated with cell proliferation. It is found throughout the cell cycle in the G1, S, G2, and M phases; but not the (G0) phase. It is commonly used to grade proliferation rates of tumors.
An optimized antibody cocktail for p16 INK4a and Ki-67 may aid in the identification of cells co-expressing markers for both tumor suppression and cell proliferation, an indicator of cell-cycle deregulation (2). Coexpression of p16 and Ki-67 has been observed in cervical intraepithelial neoplasia (CIN) lesions associated with high-risk HPV infection, presenting potential utility in the classification of CIN lesions (3).
p16 + Ki-67 Antibody is Not Available in Germany.
1. LaPak KM, Burd CE. The molecular balancing act of p16(INK4a) in cancer and aging. Mol Cancer Res. 2014 Feb;12(2):167-83.
2. Ikenberg H, et al. Screening for cervical cancer precursors with p16/Ki-67 dual-stained cytology: results of the PALMS study. J Natl Cancer Inst. 2013;105:1550–7.
3. Rossi P, et al. A population of 1136 HPV DNA-HR positive women: expression of p16(INK4a)/Ki67 Dual-Stain Cytology and cytological diagnosis. Histological correlations and cytological follow up. Pathologica. 2015;107:185–91.
4. Center for Disease Control Manual. Guide: Safety Management, NO. CDC-22, Atlanta, GA. April 30, 1976 “Decontamination of Laboratory Sink Drains to Remove Azide Salts.”
5. Clinical and Laboratory Standards Institute (CLSI). Protection of Laboratory Workers from Occupationally Acquired Infections; Approved Guideline-Fourth Edition CLSI document M29-A4 Wayne, PA 2014.