Impact of the Epigenetically Regulated Hoxa-5 Gene in Neural Differentiation from Human Adipose-Derived Stem Cells

The circular RNA Rap1b promotes Hoxa5 transcription by recruiting Kat7 and leading to increased Fam3a expression, which inhibits neuronal apoptosis in acute ischemic stroke

Circular RNAs can regulate the development and progression of ischemic cerebral disease. However, it remains unclear whether they play a role in acute ischemic stroke. To investigate the role of the circular RNA Rap1b (circRap1b) in acute ischemic stroke, in this study we established an in vitro model of acute ischemia and hypoxia by subjecting HT22 cells to oxygen and glucose deprivation and a mouse model of acute ischemia and hypoxia by occluding the right carotid artery. We found that circRap1b expression was remarkably down-regulated in the hippocampal tissue of the mouse model and in the HT22 cell model. In addition, Hoxa5 expression was strongly up-regulated in response to circRap1b overexpression. Hoxa5 expression was low in the hippocampus of a mouse model of acute ischemia and in HT22-AIS cells, and inhibited HT22-AIS cell apoptosis. Importantly, we found that circRap1b promoted Hoxa5 transcription by recruiting the acetyltransferase Kat7 to induce H3K14ac modification in the Hoxa5 promoter region. Hoxa5 regulated neuronal apoptosis by activating transcription of Fam3a, a neuronal apoptosis-related protein. These results suggest that circRap1b regulates Hoxa5 transcription and expression, and subsequently Fam3a expression, ultimately inhibiting cell apoptosis. Lastly, we explored the potential clinical relevance of circRap1b and Hoxa5 in vivo. Taken together, these findings demonstrate the mechanism by which circRap1b inhibits neuronal apoptosis in acute ischemic stroke.

Comprehensive Landscape of HOXA2, HOXA9, and HOXA10 as Potential Biomarkers for Predicting Progression and Prognosis in Prostate Cancer

Prostate cancer (PCa) is recognized as a common malignancy in male patients. The homeobox A cluster (HOXA) family members have been confirmed to be implicated in the development of several types of tumors. However, the expression pattern and prognostic values of HOXA genes in PCa have not been investigated. In this study, we analyzed TCGA datasets and identified six HOXA family members which showed a dysregulated expression in PCa specimens compared with nontumor specimens. We also explored the potential mechanisms involved in the dysregulation of HOXA family members in PCa, and the results of Pearson's correlation revealed that most HOXA members were negatively related to the methylation degree. Moreover, we explored the prognostic values of HOXA family members and identified six survival-related HOXA members. Importantly, HOXA2, HOXA9, and HOXA10 were identified as critical PCa-related genes which were abnormally expressed in PCa and associated with clinical outcomes of PCa patients. Then, we explored the association between the above three genes and immune cell infiltration. We observed that the levels of HOXA2, HOXA9, and HOXA10 were associated with the levels of immune infiltration of several kinds of immune cells. Overall, our findings identified the potential values of the HOXA family for outcome prediction in PCa, which might facilitate personalized counselling and treatment in PCa.