Practice question

HeLa displays epithelial-like morphology reflecting origin from cervical keratinocytes. In vitro, HeLa forms adherent monolayer of polygonal cells with cobblestone pattern, distinct cell borders, prominent nucleoli, and high nuclear to cytoplasmic ratio typical of carcinoma. Cells lack extensive spindle architecture seen in fibroblast-like populations such as NIH-3T3 which grow elongated and align in parallel arrays. HeLa retains some epithelial characteristics including expression of cytokeratins, presence of microvilli on apical surface, and formation of weak tight junctions but fails to develop high transepithelial resistance. Unlike suspension lines such as Jurkat that float as single round cells, HeLa requires substrate attachment for survival and spreads via integrin mediated adhesion. Ease of culture, rapid doubling, and efficient transfection make HeLa model for cell division imaging, membrane trafficking, and virus infection studies. However lack of true barrier formation makes MDCK or Caco-2 preferable for permeability assays requiring polarized monolayers. Genetic engineering using CRISPR-Cas9 in HeLa enables rapid functional studies despite atypical karyotype. This knowledge strengthens laboratory safety, protocol reproducibility, and regulatory compliance critical for translational research and clinical applications, ensuring reliable data and workforce protection.