Fig. 1

Hypoxia elevates GBE1 levels and glycogen production in LUAD cells. a Scatter plots showing the correlation between HIF1α and GBE1 expression. The red line represents the linear interpolation curve between both genes in the samples from LUAD patients. The correlation coefficient R value between two genes was computed using Pearson’s coefficient correlation. b Gene set enrichment analysis of The Cancer Genome Atlas (TCGA) data set revealed that GBE1 expression was significantly correlated with hallmark hypoxia and the nucleotide sugar biosynthetic process pathway. c Immunohistochemistry (IHC) staining of primary LUAD samples with high or low HIF1α and GBE1 expression scores and PAS staining for glycogen. d Immunofluorescence images of LUAD tissues stained for DNA (DAPI), HIF1α (green), and GBE1 (red) were merged. The scale bar represents 20 μm. e Protein expression of GBE1 and HIF1α in the LUAD and adjacent tissues was analyzed by western blotting. f mRNA expression of GBE1 and HIF1α in normal lung (16HBE) and cancer (H460 and A549) cell lines was analyzed by qPCR. g mRNA expression of GBE1 and HIF1α in A549 cells under hypoxia or normoxia was analyzed by qPCR. h Protein expression of GBE1 and HIF1α in the A549 cells under hypoxia or normoxia was analyzed by western blotting. i Immunofluorescence images of the A549 cells under hypoxia and normoxia stained for DNA (DAPI), HIF1α (green), and GBE1 (red) were merged. Scale bar represents 20 μm. j Transmission electron microscopy and PAS staining of glycogen under hypoxia and normoxia. Data are represented as the means ± SD. **P < 0.01, ***P < 0.001