SCLC-21H Cells

The SCLC-21H cell line was derived from the pleural effusion of a patient with small cell lung cancer (SCLC) of the oat cell subtype. This cell line, along with SCLC-22H, was established during a period of chemotherapy, with SCLC-21H being the second to be derived after an additional 15 days of treatment. While both cell lines originated from the same patient, they display significantly different biochemical, morphological, and kinetic properties. SCLC-21H, for example, has a faster population doubling time and a higher colony-forming efficiency compared to SCLC-22H. These differences make SCLC-21H a distinct tool for studying certain variant forms of SCLC. Biochemically, SCLC-21H differs from SCLC-22H in its low or undetectable levels of key neuroendocrine markers such as L-Dopa decarboxylase, bombesin, and carcinoembryonic antigen. However, both cell lines express high levels of neuron-specific enolase and creatine kinase isoenzyme BB, which are characteristic markers of SCLC. Moreover, while both cell lines exhibit c-myc amplification, SCLC-21H contains an additional rearranged and amplified EcoRI c-myc fragment, further highlighting its genetic uniqueness. Structurally, SCLC-21H exhibits loose growth in culture and features prominent nucleoli and abundant cytoplasm, contrasting with the more tightly packed morphology of SCLC-22H. The presence of ultrastructurally dense core granules in SCLC-21H confirms its neuroendocrine origin, and it is classified as representing a variant form of SCLC. These distinct features make SCLC-21H a valuable model for exploring the variant forms of small cell lung cancer and understanding their response to chemotherapy.