Inhibition of HIST1H2AB suppresses the proliferation of lung adenocarcinoma

Abstract

Background Lung adenocarcinoma is one of the common causes of cancer‐related deaths worldwide. Histone cluster 1 H2A family member b (HIST1H2AB) is a member of the histone H2A family. Bioinformatic analyses have revealed that HIST1H2AB is highly expressed in some cancers and might be an oncogene. However, information on the function of HIST1H2AB in lung adenocarcinoma is limited. Methods The expression of HIST1H2AB was analyzed in normal lung, lung adenocarcinoma and paracancerous tissues from The Cancer Genome Atlas (TCGA) database and immunohistochemistry staining. It was further verified in the relative cell lines using real‐time quantitative polymerase chain reaction (RT‐qPCR). When the adenocarcinoma cells lines (A549 and H1299) were successfully transfected with shHIST1H2AB or an empty plasmid packaged into a lentivirus, cell proliferation was detected using Celigo fluorescence cell‐counting, colony formation and annexin V‐allophycocyanin assays. Twenty nude mice were subcutaneously injected with A549 cells transfected with shHIST1H2AB or empty plasmid; the tumor size was recorded on day 25 and then measured every 3 days thereafter. The final tumor weight was measured on day 37. Significantly differentially expressed genes were analyzed using a human gene expression array. Furthermore, the potentially relevant genes were verified using RT‐qPCR and western blotting. Results HIST1H2AB was highly expressed in lung adenocarcinoma tissues from TCGA database and immunohistochemistry staining. Similar results were seen in the lung adenocarcinoma cells. When the cells were successfully transfected with shHIST1H2AB or an empty plasmid, downregulation of HIST1H2AB inhibited the growth and promoted the apoptosis of lung adenocarcinoma cells. The xenograft results suggested that HIST1H2AB downregulation delayed tumor growth and reduced tumor weight. Moreover, interferon signaling pathway and four genes (HMGB1, FOXM1, F2RL1 and SLC4A7) might be regulated by HIST1H2AB in the development of lung adenocarcinoma as indicated through gene expression array, RT‐qPCR and western blotting analyses. Conclusions HIST1H2AB acts as an oncogenic protein and HIST1H2AB inhibition suppresses the proliferation of lung adenocarcinoma cells. It may be a novel target for lung adenocarcinoma therapy.