A continuous tumor‐cell line from a human lung carcinoma with properties of type II alveolar epithelial cells

TLDR

The A549 tumor‑cell line, derived from a human alveolar cell carcinoma, has been maintained in vitro for over three years, exceeding 1,000 cell generations. This cell line was established to enable in‑vitro analysis of human surfactant synthesis and secretion and to serve as a potential source of therapeutic surfactant for pulmonary diseases marked by surfactant deficiency. A549 cells possess a human karyotype, originate from a single progenitor, exhibit type II alveolar epithelial characteristics—including multilamellar cytoplasmic inclusions—and synthesize lecithin rich in disaturated fatty acids via the CDP‑choline pathway, mirroring surfactant‑producing cells.

Abstract

The A549 tumor-cell line, initiated from a human alveolar cell carcinoma, has been continuously propagated in vitro for more than 3 years (more than 1,000 cell generations). These cells have a human karyotype and appear to have been derived from a single parent cell. All A549 cells examined by electron microscopy at both early and late passage levels contain multilamellar cytoplasmic inclusion bodies typical of those found in type II alveolar epithelial cells of the lung. At early and late passage levels, the cells synthesize lecithin with a high percentage of disaturated fatty acids utilizing the cytidine diphosphocholine pathway; such a pattern of phospholipid synthesis is expected for cells believed to be responsible for pulmonary surfactant synthesis. The A549 cell line should permit in vitro analysis of human surfactant synthesis and secretion and possibly provide a source of human surfactant for therapeutic intervention in pulmonary disease states characterized by surfactant deficiency.