Isolation of Inoue-Melnick virus from human colorectal carcinoma cell lines

Inoue-Melnick virus (IMV) was isolated from five of six human colorectal carcinoma cell lines, whereas the virus was not isolated from three normal colon-derived cell lines, three pancreas carcinoma cell lines, two bladder carcinoma cell lines, one kidney adenocarcinoma cell line, and one cervical carcinoma cell line. IMV synthesis was remarkably enhanced in the colorectal carcinoma cell lines by treatment with 5-bromodeoxyuridine (BUDR). However, virus was not detected in any of the other cell lines in spite of BUDR treatment. Five strains of virus isolated from colorectal carcinoma cell lines were subsequently identified by the neutralization test as intermediate-type IMV.