Establishment and characterization of a new xenograft-derived human esophageal squamous cell carcinoma cell line HKESC-4 of Chinese origin

A new human esophageal cancer cell line, HKESC-4, was established from a nude-mouse xenograft of a moderately differentiated esophageal squamous cell carcinoma (ESCC) developed from a 65-year-old Hong Kong Chinese man. The cellular characteristics (morphological, electron microscopic, and immunohistochemical studies), tumorigenicity in athymic nude mice, cytogenetic features, and DNA ploidy of the cell line were investigated. The cell line was maintained in vitro for 17 months and passaged 80 times. HKESC-4 grew as a monolayer, with a doubling time of 63 hours. The epithelial nature of HKESC-4 included the presence of cytokeratin intermediate filaments, as shown by antibodies (AE1/AF3, CAM5.2, and MAK 6), and the presence of the tonofilaments, as seen under electron microscopy. HKESC-4 was tumorigenic in nude mice and had DNA aneuploidy. The cytogenetic abnormalities of HKESC-4 included −1, −2, −3, −4, −5, −6, −7, −8, −9, −10, −11, −12, −15, −16, −17, −18, −19, +20, −21, −22, +del(11)(p11), +i(11)(q10), and +21 marker chromosomes. Comparative genomic hybridization analysis demonstrated chromosomal gains at 1p36.13, 3q23∼q28, 5p15.33∼p15.1, 6p25.1∼p22.3, 7p21.3∼p11.2, 7q11.21∼q21.13, 8q23.3∼q23.3, 11p11.2, 11q12.1∼q13.2, 14q21.3∼q32.2, 17p13.3, 18p11.32∼p11.31, and 20p13∼p12.2 and chromosomal losses at 1q12, 2p25.1∼p24.3, 13p13∼p11.2, 21p, 22p13∼p11.2, and Y. The newly established cell line HKESC-4 promises to be a useful tool in future studies of molecular pathogenesis and therapeutics in ESCC.