Molecular alterations in a new cell line (KU-Lu-MPPt3) established from a human lung adenocarcinoma with a micropapillary pattern.

PURPOSE: Lung adenocarcinomas with a micropapillary pattern (MPP) are characterized by more frequent and pronounced vascular invasion, higher incidence and more advanced lymph node involvement and poorer prognosis than papillary adenocarcinomas without an MPP. Here we established a new lung cancer cell line featuring micropapillary structure.

METHODS: A 73-year-old never-smoker Japanese female, presenting with an abnormal chest shadow, was diagnosed with a clinical T2aN0M0 Stage IB lung adenocarcinoma and underwent left upper lobectomy with mediastinal lymph node dissection. Pathological study demonstrated a T2aN2M0 Stage IIIA micropapillary adenocarcinoma. Tumor cells were obtained from freshly resected lung material and used to establish the KU-Lu-MPPt3 cell line.

RESULTS: The KU-Lu-MPPt3 cells featured adherent monolayers, adherent tufts, and suspended tufts without adhesion under the same culture conditions. The cells were positive for cytokeratin, epithelial cell-adhesion molecules, E-cadherin, mucin-1, thyroid transcription factor-1, vimentin, and anti-programmed death ligand 1. Xenograft tumors clearly demonstrated micropapillary structures. Sequencing and fragment analysis of the epidermal growth factor receptor in the primary tumor tissue and KU-Lu-MPPt3 cells revealed an in-frame deletion E746-A750 in exon 19.

CONCLUSIONS: This cell line represents a new model system for molecular studies of lung adenocarcinoma which may be suitable for investigation of cancer spread and also for development of molecular-targeting and immunotherapies, both in vitro and in vivo.