Article Abstract

Acute hypoxia induces apoptosis in serum-deprived prostate cancer LNCaP cells

Authors: Weiyong Liu, Yunkai Zhu, Jun Jiang, Xuechao Jiang, Yaqing Chen


Background: Human prostate cancer LNCaP cells can develop an androgen-sensitive prostate cancer animal model that closely mimic clinical disease. However, implantation of LNCaP cells yields a low take rate when subcutaneously xenografted in immunodeficient mice. Given that LNCaP cells are sensitive to hypoxia, we hypothesized that LNCaP cells might undergo substantial apoptosis in response to acute hypoxia under conditions of serum deprivation.
Methods: Serum-deprived LNCaP cells were cultured and exposed to either normoxic (21.0% O2) or hypoxic (1.0% O2) conditions. Morphological changes in nuclei were evaluated with Hoechst 33258 staining under fluorescence microscopy. Cell viability and migration were assayed by Cell Counting Kit-8 (CCK-8) and wound healing assay, respectively. The production of intracellular reactive oxygen species (ROS) was measured by a fluorescent probe assay. Apoptosis, mitochondrial membrane potential (ΔΨm), and the cell cycle of LNCaP cells were analyzed by flow cytometry.
Results: Serum-deprived LNCaP cells tended to form multicellular aggregates, and the viability and migration of LNCaP cells were markedly suppressed under acute hypoxia. Acute hypoxia exposure for 24 hours induced significant ROS production, which was distributed heterogeneously among cells. LNCaP cells exhibited a time-dependent increase in apoptosis under acute hypoxia by flow cytometric analysis. Furthermore, acute hypoxia induced the collapse of the ΔΨm of LNCaP cells, and it also increased cell cycle arrest at the G0/G1 phases in a time-dependent manner.
Conclusions: Acute hypoxia induces substantial apoptosis in LNCaP cells under conditions of serum deprivation. The findings may provide valuable information for improving the tumor-formation method of LNCaP subcutaneous xenografts in nude mice.