Scientific Publications and Presentations

DNAJB1-PRKACA in HEK293T cells induces LINC00473 overexpression that depends on PKA signaling

February 15, 2022

Kim, Kycia, Karski, Ma, Bordt, Kwan, ..., Sethupathy, & Vakili
Journal article published in PLOS ONE

While FLC in almost all patients is caused by the DNAJB1-PRKACA gene fusion, the mechanism by which that fusion causes the cancer is still unclear. In order to get insight into that question, this team engineered the DNAJB1-PRKACADP fusion gene into “immortalized” liver cells and measured the impact that the change had on the functions of those cells. These cells, called HEK293T cells, HEK293T cells have been widely used in cell biology research for many years because of their reliable growth characteristics.

The team used the gene editing technology CRISPR/Cas9 to engineer HEK293T clones (called HEK-DP) to express the FLC fusion gene. Following the successful editing of the fusion gene, the team noted some interesting findings that resembled FLC and therefore proceeded with further characterization of the HEK-DP cell lines. They performed a series of transcriptomic (changes in the RNA), proteomic (changes in the proteins), and mitochondrial studies to characterize this new cellular model. Mitochondria are the “energy factories” of cells.

Key findings discussed in the paper include that HEK-DP cells demonstrated significantly elevated mitochondrial fission, which suggests a role for the fusion gene in altering mitochondrial dynamics. Importantly, the transcriptomic analysis of HEK-DP cells revealed a significant increase in the level of LINC00473 expression. LINC00473 is a type of long non-coding RNA (lincRNA) that is not translated into protein. The function of lincRNAs includes regulating other genes through several different mechanisms. Because the change in LINC00473 expression is also observed in actual human FLC samples, the study suggested that LINC00473 could be a potential marker for FLC’s fusion gene activity. This means that it could be useful in diagnosis or understanding exactly how the fusion protein causes the disease.

The full text of the article can be read here.

Thank you to the patients and families who have contributed biospecimens to the FCF biobank! Several of those samples were used in this study.