KB Cells

The KB cell line is an adherent epithelial cell line initially believed to be derived from an epidermal carcinoma of the mouth. However, subsequent analyses, including isoenzyme assays, HeLa marker chromosome identification, and DNA fingerprinting, revealed that the KB cell line was actually established through contamination with HeLa cells. This misidentification underscores the importance of rigorous cell line authentication in research. KB cells express keratin, a key structural protein in epithelial cells, as confirmed by immunoperoxidase staining. Additionally, they have been found to contain sequences from human papillomavirus 18 (HPV-18), which may be of interest in studies related to viral oncology. The isoenzyme profile of KB cells includes glucose-6-phosphate dehydrogenase (G6PD) type A, consistent with the characteristics of HeLa cells. Given these findings, it is critical to recognize that KB cells share many biological properties with HeLa cells, including the presence of HeLa-specific marker chromosomes. As a result, KB cells should be used with caution, particularly in experiments where the exact cellular origin is crucial. Despite this, they remain a useful model for studying epithelial cell behavior, cancer biology, and the mechanisms of viral integration and expression. As with all cell lines, KB cells are intended strictly for in vitro research and are not suitable for therapeutic or in vivo applications.