Effects of interferons α/β on the proliferation of human micro- and macrovascular endothelial cells

Area of Science:

• Endocrinology
• Cell Biology
• Oncology

Background:

• Synthetic interferons (IFNs) are utilized in cancer therapy and exhibit antiangiogenic properties.
• Understanding the specific effects of different IFN types on endothelial cells is crucial for optimizing cancer treatments.

Purpose of the Study:

• To investigate the in vitro effects of Interferon-alpha (IFN-α) and Interferon-beta (IFN-β) on human microvascular lung endothelial cells (HMVEC-L) and human umbilical cord endothelial cells (HUVEC).
• To analyze the impact of these IFNs on endothelial cell proliferation, apoptosis, and cell cycle distribution.

Main Methods:

• Immunohistochemical staining and quantitative reverse transcriptase (RT)-polymerase chain reaction were used to assess type I IFN receptor expression.
• Endothelial cell proliferation was measured by DNA content.
• Apoptosis was evaluated using DNA fragmentation assays (ELISA).
• Cell cycle distribution was analyzed via flow cytometry.

Main Results:

• Both HUVEC and HMVEC-L cells expressed comparable levels of distinct IFN receptor subtypes.
• IFN-β significantly inhibited the proliferation of both HMVEC-L and HUVEC (IC50 values of 60 and 90 IU/mL, respectively).
• IFN-α did not inhibit proliferation at doses up to 1,000 IU/mL.
• IFN-β unexpectedly inhibited apoptosis in endothelial cells after 72 hours of treatment.
• Cell cycle arrest in the late S-phase was observed in both cell lines treated with IFN-β.

Conclusions:

• IFN-β demonstrates inhibitory activity on endothelial cell proliferation, while IFN-α does not at the tested concentrations.
• The anti-proliferative effect of IFN-β is attributed to cell cycle arrest in late S-phase.
• IFN-β's unexpected role in decreasing apoptosis warrants further investigation regarding its antiangiogenic mechanisms.