HSPB8 facilitates prostate cancer progression via activating the JAK/STAT3 signaling pathway

Molecular panorama of therapy resistance in prostate cancer: a pre-clinical and bioinformatics analysis for clinical translation

Prostate cancer (PCa) is a malignant disorder of prostate gland being asymptomatic in early stages and high metastatic potential in advanced stages. The chemotherapy and surgical resection have provided favourable prognosis of PCa patients, but advanced and aggressive forms of PCa including CRPC and AVPC lack response to therapy properly, and therefore, prognosis of patients is deteriorated. At the advanced stages, PCa cells do not respond to chemotherapy and radiotherapy in a satisfactory level, and therefore, therapy resistance is emerged. Molecular profile analysis of PCa cells reveals the apoptosis suppression, pro-survival autophagy induction, and EMT induction as factors in escalating malignant of cancer cells and development of therapy resistance. The dysregulation in molecular profile of PCa including upregulation of STAT3 and PI3K/Akt, downregulation of STAT3, and aberrant expression of non-coding RNAs are determining factor for response of cancer cells to chemotherapy. Because of prevalence of drug resistance in PCa, combination therapy including co-utilization of anti-cancer drugs and nanotherapeutic approaches has been suggested in PCa therapy. As a result of increase in DNA damage repair, PCa cells induce radioresistance and RelB overexpression prevents irradiation-mediated cell death. Similar to chemotherapy, nanomaterials are promising for promoting radiosensitivity through delivery of cargo, improving accumulation in PCa cells, and targeting survival-related pathways. In respect to emergence of immunotherapy as a new tool in PCa suppression, tumour cells are able to increase PD-L1 expression and inactivate NK cells in mediating immune evasion. The bioinformatics analysis for evaluation of drug resistance-related genes has been performed.

HSPB8 binding to c-Myc alleviates hypoxia/reoxygenation-induced trophoblast cell dysfunction

Preeclampsia (PE) is a pregnancy-specific syndrome with complex pathogenesis. The present study aimed to explore the role of heat shock protein B8 (HSPB8) and c-Myc in trophoblast cell dysfunction using a hypoxia/reoxygenation (H/R)-treated HTR8/SVneo cell model. HSPB8 expression in tissues of patients with PE was analyzed using the Gene Expression Omnibus database. Following detection of HSPB8 expression in H/R-stimulated HTR8/SVneo cells, HSPB8 was overexpressed by transfection of the gene with a HSPB8-specific plasmid. Cell Counting Kit-8, wound healing and Transwell assays were used to evaluate the proliferation, migration and invasion of HTR8/SVneo cells exposed to H/R conditions. Reactive oxygen species (ROS) were determined by 2,7-dichlorodihydrofluorescein diacetate staining. 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbo-cyanine iodide (JC-1) staining was applied to assess mitochondrial membrane potential. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were detected using the corresponding commercial kits. In addition, the induction of apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Moreover, the Biogrid database predicted that HSPB8 was bound to c-Myc, and a co-immunoprecipitation (Co-IP) assay was used to verify this interaction. Subsequently, c-Myc expression was silenced to conduct rescue experiments in HTR8/SVneo cells exposed to H/R conditions and upregulated HSPB8 expression. Notably, reduced HSPB8 expression was noted in PE tissues and H/R-stimulated HTR8/SVneo cells. HSPB8 enforced expression promoted the proliferation, migration and invasion of HTR8/SVneo cells. Moreover, H/R caused an increase in ROS and MDA levels as well as in TUNEL staining and a decrease in aggregated JC-1 fluorescence and SOD activity levels, which were restored following HSPB8 overexpression. Co-IP confirmed the interaction between HSPB8 and c-Myc. Moreover, knockdown of c-Myc expression compromised the effects of HSPB8 upregulation on trophoblast cell dysfunction following induction of H/R. Collectively, the data indicated that HSPB8 could improve mitochondrial oxidative stress by binding to c-Myc to alleviate trophoblast cell dysfunction. The findings may provide new insights into the pathogenesis of PE and highlight the role of HSPB8/c-Myc in the prevention and treatment of PE in the future.