The expression of heat shock protein A12B (HSPA12B) in non-Hodgkin's lymphomas

Background

Heat shock protein A12B (HSPA12B) plays a considerable protective role for cells, tissues, and organs against various noxious conditions. However, the expression of HSPA12B in cancer biology remains controversial. This study aimed to investigate the expression of HSPA12B and its role in cell adhesion mediated drug resistance (CAM-DR) of non-Hodgkin’s lymphoma (NHL).

Methods

In this study, the expression of HSPA12B in NHL was determined by immunohistochemical, and the effect of HSPA12B expression on the prognosis of NHL was analyzed by Kaplan–Meier curves. Then, the transfection technique was used to research the effect of HSPA12B in cell apoptosis. The most important was to study the expression changes of HSPA12B in the adhesion model and the effect of overexpression of HSPA12B on CAM-DR.

Results

We analyzed the relationship between the expression levels of HSPA12B and clinical parameters in NHL. The expression of HSPA12B was directly related to the different NHL variants. We overexpressed HSPA12B in 2 NHL cell lines and found a subsequent reduction in apoptosis. More specifically, we used an adhesion assay to demonstrate that HSPA12B expression was induced in NHL cells when they adhered to fibronectin (FN) or bone marrow stroma cells (BMSCs). Finally, it was revealed that HSPA12B overexpression enhances CAM-DR.

Conclusions

Our data suggest that HSPA12B may play a functional role in CAM-DR and is thus a potential novel target for NHL treatment.

Downregulation of miRNA-134 protects neural cells against ischemic injury in N2A cells and mouse brain with ischemic stroke by targeting HSPA12B

MicroRNAs (miRNAs) have emerged as a major regulator in neurological diseases, and understanding their molecular mechanism in modulating cerebral ischemic injury may provide potential therapeutic targets for ischemic stroke. However, as one of 19 differentially expressed miRNAs in mouse brain with middle cerebral artery occlusion (MCAO), the role of miR-134 in ischemic injury is not well understood. In this study, the miR-134 expression level was manipulated both in oxygen-glucose deprivation (OGD)-treated N2A neuroblastoma cells in vitro and mouse brain with MCAO-induced ischemic stroke in vivo, and its possible targets of heat shock protein A5 (HSPA5) and HSPA12B were determined by bioinformatics analysis and dual luciferase assay. The results showed that overexpression of miR-134 exacerbated cell death and apoptosis both in vitro and in vivo. Conversely, downregulating miR-134 levels reduced cell death and apoptosis. Furthermore, non-expression of miR-134 enhanced HSPA12B protein levels in OGD-treated N2A cells as well as in the ischemic region. It could attenuate brain infarction size and neural cell damage, and improve neurological outcomes in mice with ischemic stroke, whereas upregulation of miR-134 had the opposite effect. In addition, HSPA12B was validated to be a target of miR-134 and its short interfering RNAs (siRNAs) could block miR-134 inhibitor-induced neuroprotection in OGD-treated N2A cells. In conclusion, downregulation of miR-134 could induce neuroprotection against ischemic injury in vitro and in vivo by negatively upregulating HSPA12B protein expression.