Chromosome analysis of hepatocellular carcinoma 7777 and correlation with alpha-fetoprotein production.

The Morris hepatocellular carcinoma 7777 is productive of extraordinarily high levels of the oncofetal protein, alpha-fetoprotein. Its chromosome composition was examined in detail since it represents the only near-diploid tumor of such productivity and has been reported to demonstrate a single unusual chromosomal alteration. The major finding is the presence of a submetacentric marker chromosome, composed of a No. 7 chromosome and a short arm that demonstrated a poorly defined banding pattern on Giemsa staining. This marker is unique to 7777 and is of particular interest in view of recent reports of an association between such unbanded chromosome arms and supraproduction of cell products.