Metastatic human hepatoblastoma cells exhibit enhanced tumorigenicity, invasiveness and a stem cell-like phenotype

PIM Kinase Inhibition Attenuates the Malignant Progression of Metastatic Hepatoblastoma

“…PIM kinases have been demonstrated to play a role in a number of pediatric solid tumors and have been shown to be of particular importance in hepatoblastoma [ 8 , 9 , 10 ]. We first used immunoblotting to confirm the expression of each of the individual PIM kinases in the metastatic hepatoblastoma cell line ( Figure S1A ), providing evidence for the presence of a druggable target for the pan-PIM inhibitor, AZD1208, which was employed in the remainder of our studies.…”

“…Prior studies have demonstrated that PIM kinases support the stem cell-like cancer cell (SCLCC) phenotype in primary hepatoblastoma which may play an important role in the progression of metastatic disease [ 10 ]. We noted that the metastatic hepatoblastoma cell line, HLM_2, had higher levels of mRNA abundance of stemness markers Oct4 , Nanog , Nestin , and Sox2 compared to the parent cell line, HuH6 [ 9 ], so we sought to explore the effects of PIM kinase inhibition on metastatic hepatoblastoma stemness. Using qPCR, we evaluated the change in mRNA abundance of known stemness markers Nanog , Sox2 , Nestin , and Oct4.…”

“…In primary hepatoblastoma, we have found PIM kinase inhibition resulted in decreased migration and invasion [ 8 ]. Additionally, we have found the HLM_2 cells to be more metastatic than primary hepatoblastoma cells [ 9 ] so we sought to investigate the effects of PIM inhibition on HLM_2 cell migration and invasion. Our investigations demonstrated no significant difference in HLM_2 cell migration after treatment with 20 µM AZD1208 (cell count 3146 ± 1679 v. 3560 ± 1204, p = 0.17) ( Supplemental Figure S1C ).…”

“…The current study is not without limitations. The use of a tail vein model of metastases to generate the HLM_2 cell line comes with the disadvantage of allowing the cells to bypass the initial steps of the metastatic cascade [ 9 ]. However, the ability to more quickly generate metastatic disease, compared to the development of spontaneous metastasis, does hasten the pace at which experiments may be conducted.…”

“…We utilized the metastatic human hepatoblastoma cell line, HLM_2, which was previously established through a series of tail vein injections to create pulmonary metastases from the human long-term passaged hepatoblastoma cell line, HuH6 [ 9 ]. Briefly, HuH6 Luc cells were generously provided by the Hjelmeland laboratory (Anita Hjelmeland, University of Alabama at Birmingham (UAB), Birmingham, AL, USA) and were established by stable transfection of HuH6 cells with the luciferase reporter cloned into the pCDH-CMV-MCS-EF1a-Puro lentiviral vector (System Biosciences, Palo Alto, CA, USA).…”