Molecular oxygen regulates MHC class I expression transcriptionally.

Abstract

<p><b>(A)</b> Mice bearing MCA205 pulmonary tumors were exposed to either respiratory hypoxia (10% O₂), normoxia (21% O₂), or respiratory hyperoxia (60% O₂) for 48h. <b>(B)</b> MCA205 tumors grown <i>in vitro</i> in 3D spheroids under hypoxia (1% O₂), normoxia (21% O₂), or hyperoxia (60% O₂) for 48h. Hypoxia significantly downregulated whereas hyperoxia significantly upregulated MHC class I transcripts as compared normoxic controls both <i>in vivo</i> and <i>in vitro</i>. RT-qPCR was used to analyze MHC class I (H-2Kb) transcript levels. Ribosomal protein L32 was used as internal control. Y- axis represents transcript levels relative to normoxic controls. n = 4. The significance of differences was analyzed by the Student’s t-test (two-sided); p values are as indicated in the figure. Error bars indicate SD.</p