Novel Immortalized Pulmonary Artery Endothelial Cell Line Recapitulates the Characteristics of Primary Cells

Background

Primary endothelial cells have been used as in vitro models to study cardiovascular diseases and cancer development. However, cellular senescence and donor availability restrict the potential usefulness of primary endothelial cells. Cell immortalization technology enables the development of new cell models that represent normal physiology while gaining the capability of an extensive lifespan. The objective of this study is to develop an immortalized pulmonary artery endothelial cell line that retains the functional characteristics of primary cells.

Methods

In this study, we generated a clonal cell line that was immortalized by stably expressing the human BMI1 gene in normal human primary pulmonary artery endothelial cells. Cell morphology, growth rate, cell surface biomarkers, and bio-functions were analyzed to compare the parental primary cell line and the immortalized cell line. 

Results

The newly established HPAEC-BMI1 (ATCC CRL-4065) cell line has a similar cell growth profile and cell doubling time as the parental primary cells. The cell line had been cultured for over 200 days to ensure it is fully immortalized. In addition, this cell line has been cultured continuously for additional 38 population doublings after master cell banking.  There’s no signs of replicative senescence or growth rate change. The HPAEC-BMI1 cells have a near-diploid karyotype and an endothelial-like morphology. CD31 expression and AcLDL uptake features were maintained. HPAEC-BMI1 cells also form capillary-like tubes on a basement membrane matrix (ATCC ACS-3035). To test if the cell line can be a predictive model, we used a well-known angiogenesis inhibitor in cell-based assays. We found sunitinib could suppress HPAEC-BMI1 cells tube formation and migration in a dose-dependent manner.

Conclusions

The fully immortalized HPAEC-BMI1 cell line presents a novel cell model that avoids the limitations of primary cells while still retaining the functional characteristics of primary pulmonary artery endothelial cells. It provides a valuable tool for angiogenesis research, drug screening, and toxicology studies.