CAL-33 Cells

The CAL-33 cell line is a human squamous cell carcinoma line derived from a primary tumor of the tongue. Established from a male patient with moderately differentiated squamous cell carcinoma, CAL-33 cells are known for their robust growth in vitro and tumorigenic capacity when injected into immunocompromised mice. These cells display polygonal epithelial morphology, with a doubling time of approximately 43 hours. Given its origin, CAL-33 serves as an effective model for studying oral and head and neck squamous cell carcinoma (HNSCC) biology, specifically in contexts where HPV-negative carcinoma models are necessary.
CAL-33 is particularly valuable in radiation oncology research due to its well-characterized subclones with varying degrees of radioresistance and radiosensitivity. Studies on these subclones have shown distinct genomic and transcriptomic profiles, which contribute to differential radiation responses. Pathways associated with radioresistance in CAL-33 include DNA repair, senescence, apoptosis, and PI3K/AKT signaling, with additional involvement of genes linked to the senescence-associated secretory phenotype (SASP). These features make CAL-33 a significant tool for investigating radiation-induced cellular responses and identifying potential therapeutic targets aimed at overcoming radioresistance in HNSCC.
Moreover, the CAL-33 cell line is also used for drug sensitivity studies, as it exhibits sensitivity to various chemotherapeutic agents. This versatility in applications-ranging from basic oncogenic pathway elucidation to applied therapeutics and radiation studies-has solidified CAL-33 as a prominent cell line in cancer research focused on aggressive squamous cell carcinomas of the oral cavity.