Exosomal PTEN as a Predictive Marker of Aggressive Gliomas.

Background: Liquid biopsies have emerged as convenient alternative diagnostic methods to invasive biopsies, by evaluating disease-specific biomarkers and monitoring the disease risk noninvasively. Phosphatase and tensin homolog deleted in chromosome 10 (PTEN) is a potent tumor suppressor, and its deletion/mutations are common in gliomas. Objective: Evaluate the feasibility of non-invasive detection of PTEN and its downstream genes in serum exosomes of glioma patients. Materials and methods: PTEN, Yes-associated-protein 1 (YAP1), and lysyl oxidase (LOX) transcript expression were monitored through polymerase chain reaction (PCR) in serum exosomes and their paired tumor tissues. The impact of PTEN and its axis genes expression on the overall survival (OS) was monitored. Results: Out of the 106 glioma serum samples evaluated, PTEN was retained/lost in 65.4%/34.6% of the tumor samples while it was retained/lost in 67.1%/32.9% of their paired exosomal fractions. PTEN expression in both tissue and paired exosomal fractions was observed in 48.11% of the samples. Sanger sequencing detected three mutations (Chr10: 89720791(A>G), Chr10:89720749(C>T), and Chr10:89720850(A>G). Both PTEN-responsive downstream genes (YAP1) and LOX axis were upregulated in the PTEN-deficient samples. PTEN loss was associated with poor survival in the glioma patients (hazard ratio (HR) 0.68, confidence interval (CI): 0.35-1.31, P = 0.28). The OS of the exosomal PTEN cohort coincided with the tumor-tissue PTEN devoid group (HR 1.08, CI: 0.49-2.36, P = 0.85). While, old age yielded the worst prognosis; gender, location, and grade were not prognostic of OS in the multivariate analysis. Conclusions: PTEN and its responsive genes YAP1 and LOX can be detected in serum exosomes and can serve as essential tools for the non-invasive evaluation/identification of aggressive gliomas.

Expression of NF-κB and PTEN in osteosarcoma and its clinical significance.

We investigated the role of nuclear factor-κB (NF-κB) and phosphatase and tensin homolog deleted in chromosome 10 (PTEN) in the pathogenesis of osteosarcoma and its relationship with prognosis. Immunohistochemical method was used to detect the expression of NF-κB and PTEN in osteosarcoma and adjacent tissues. RT-PCR was used to detect the expression of NF-κB and PTEN mRNA in osteosarcoma and adjacent tissues. Western blotting was used to detect the expression of NF-κB and PTEN in osteosarcoma and adjacent tissues and compare their differences. The expression of NF-κB and PTEN was detected in osteosarcoma and adjacent tissues. The positive rate of NF-κB was 75.3 and 32.9%, respectively; while the positive rate of PTEN was 67.1 and 90.4%, respectively. The positive expression of NF-κB and PTEN was statistically significant. There was a negative correlation between NF-κB and PTEN expression (r=-0.502, p<0.05). The positive and negative expression of NF-κB and PTEN was statistically significant for the five-year survival (p<0.05). At gene and protein level, osteosarcoma tissues had higher expression of NF-κB, and lower expression of PTEN, which was significantly different from the adjacent tissues. In osteosarcoma, NF-κB is highly expressed, but PTEN is expressed at low level, and the two are negatively correlated. This is of great significance for the early diagnosis of osteosarcoma and prognosis.

Neuroprotective effect of phosphatase and tensin homolog allele activity deleted in chromosome 10 inhibition on neuronal apoptosis after hypoxia-ischemia / 中华实用儿科临床杂志

Objective To investigate the mechanisms of neuroprotective roles of phosphatase and tensin homolog allele activity deleted in chromosome 10 (PTEN) inhibition on neuronal apoptosis after hypoxia-ischemia (HI)damage.Methods The cerebral cortical neurons of newbom Sprague-Dawley rats were cultured in vitro.Oxygen and glucose deprivation (OGD) model was established to imitate HI environment in vivo.Neurons were divided randomly into 3 groups:control group:neurons were treated with normal medium ; OGD group:neurons were treated with OGD for 3 h followed by reperfusion at 0.5,3.0,6.0,12.0,24.0,48.0 h ; PTEN inhibition group:before OGD treatment,neurons were pretreated with PTEN inhibitor,and then the neurons were collected at 24 h after reperfusion.Terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling staining was used to detect the apoptotic cells.Western blot was used to detect the expression of PTEN,p-PTEN,protein kinase B(Akt),p-Akt,synthesis of glucose kinase-3 betal (GSK-3β),p-GSK-3β and myeloid cell ceukemia-1 (Mcl-1).Results 1.As compared with control group,TUNEL positive cells increased after OGD observed by TUNEL staining (P ＜ 0.05).The expression of PTEN was increased,the expressions of p-PTEN,p-Akt,p-GSK-3 β,and Mcl-1 were significantly decreased after OGD (all P ＜ 0.05).However,Akt and GSK-3β remained unchanged at different time points after OGD(all P ＞ 0.05).2.As compared with OGD group,TUNEL positive cells were obviously reduced at 24 h after OGD in PTEN group (P ＜ 0.05).Although total PTEN,Akt,and GSK-3 β were not obviously changed in PTEN group(all P ＞ 0.05),the expressions of p-PTEN,p-Akt,p-GSK-3β,and Mcl-1 were significantly increased after OGD (all P ＜ 0.05).Conclusions HI can induce neuronal apoptosis,and the mechanisms of apoptosis may involve PTEN/Akt/GSK-3β/Mcl-1 pathway.The phosphorylation of Akt and GSK-3β can be increased via PTEN activity inhibition,while the ubiquitination of Mcl-1 would be decreased,and thus reduce the neuronal apoptosis.