Establishment of two distinct human hepatocellular carcinoma cell lines from a single nodule showing clonal dedifferentiation of cancer cells

Abstract

Hepatocellular carcinomas often contain tumor cells of more than one histological grade. The clonal relationship and biological behavior of hepatocellular carcinoma cells in histologically heterogeneous areas have not been fully explored. We established two distinct human hepatocellular carcinoma cell lines (HAK-1A and 1B) from a single nodule showing a three-layered structure with a different histological grade in each layer. Morphologically, HAK-1A and 1B resembled well-differentiated hepatocellular carcinoma cells in the outer layer of the original tumor and poorly differentiated ones in the inner layer, respectively. HAK-1B appeared less differentiated morphologically and more aggressive biologically than HAK-1A; HAK-1B had a shorter doubling time, higher tumorigenicity and an aneuploid DNA index. Chromosome analysis revealed many different abnormalities in the two cell lines, in which, however, two identical structural abnormalities (2q+ and 17p+) were identified. Moreover, sequence analysis of the p53 gene showed identical mutations at codon 242 in both cell lines. These findings suggest that the two cell lines are of clonal origin and that hepatocellular carcinomas consisting of cancerous tissues of more than one histological grade may reflect clonal dedifferentiation in the tumor. Furthermore, we predict that a clonal, morphologically less differentiated subpopulation such as HAK-1B is more aggressive in proliferation and may be closely related to subsequent tumor progression in hepatocellular carcinoma.

Troglitazone induces p27Kip1-associated cell-cycle arrest through down-regulating Skp2 in human hepatoma cells

“…8C). Of interest, a lower expression level in Skp2 was found in HAK-1A, in comparison with that in HAK-1B, which has been the aggressive and clonally dedifferentiated sister cell line of HAK-1A, 24 suggesting that Skp2 was involved in the later stages of hepatocarcinogenesis. Indeed, Skp2 overexpression in vivo was found in moderately differentiated HCCs and poorly differentiated HCCs but not in welldifferentiated HCCs or the noncancerous counterpart liver tissues (Fig.…”

“…HAK-1B has been identified as a clonally dedifferentiated sister cell line of HAK-1A, using point-mutation analysis of p53. 24 Taken together, targeting Skp2 and realizing p27 Kip1 accumulation may theoretically be a new cell-cycle-based strategy for the treatment of advanced HCCs. Troglitazone provided deep insights into this concept, opening the door to create sharp and potent agents, which pharmacologically target Skp2.…”

“…We used 6 human hepatoma cell lines: HLF, HLE, HepG2, Hep3B, HAK-1A, 24 and HAK-1B. 24 HLF and HLE were obtained from the Japanese Cancer Research Resources Bank (Tokyo, Japan). HepG2 and Hep3B were from the Cancer Cell Repository, Tohoku University (Sendai, Japan).…”

“…HAK-1B is presumed to be derived from HAK-1A through its clonal dedifferentiation, judging from p53 mutation analysis. 24 The colon cancer cell line HCT-116 was purchased from American Type Culture Collection (Rockville, MD).…”

High expression of insulin‐like growth factor binding protein‐3 is correlated with lower portal invasion and better prognosis in human hepatocellular carcinoma

“…HAK-1A, HAK-1B, KIM-1, KYN-1, KYN-2 and KYN-3 were established at Kurume University (Kurume, Japan) as described previously. (17)(18)(19)(20)(21) HepG2 was purchased from American Type Culture Collection (Manassas, VA, USA). These cell lines were grown in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum.…”