[Establishment of alpha-fetoprotein producing human rectal cancer cell line (RKK-YK) and its features]

We succeeded in establishing a rectal cancer cell line RKK-YK from the primary lesion in a patient with rectal cancer. It took 36.2 hours for duplication. We were able to transplant the RKK-YK cell line to nude mice at a transplantation rate of 50%. The transplanted tumor exhibited histological features similar to those of the primary lesion. Cancer cells with two different degrees of differentiation, in which features of moderately differentiated adenocarcinoma and well-differentiated adenocarcinoma were observed together, were established. The levels of the tumor markers (CEA, CA19-9 and AFP) were elevated in the supernatant of the culture solution and the serum of the nude mice over time course. In the immunohistological examination of the transplanted tumor, anti-CEA, anti-CA19-9 and anti-AFP antibodies were positively stained. Molecular biological analysis revealed nor point mutation or deletion in K-ras gene exon 1 and 2, p53 gene exon 5 to 11 or MCC.