The multiple tumor suppressor 1 (MTS1) gene is homozygously deleted fr
equently in cell lines derived from a wide variety of tumors. We inves
tigated the deletion of the MTS1 gene in esophageal cancer cell lines
and primary esophageal squamous carcinomas using the polymerase chain
reaction. Sixteen and 15 of 23 esophageal cancer cell lines showed hom
ozygous deletion of MTS1 exon 1 and exon 2, respectively, while none o
f 21 primary esophageal carcinomas showed the deletion. An analysis of
MTS1 gene mutations was carried out by direct DNA sequencing in 8 cel
l lines and 21 primary carcinomas showing no homozygous deletion. In c
ontrast to previous reports of esophageal carcinoma, there were no mut
ations recognized in the region sequenced. Our study suggests that the
inactivation of the MTS 1 gene may play an important role in esophage
al carcinoma cell lines but may be less important in primary carcinoma
s of the human esophagus.