Overexpression of long noncoding RNA PTPRG-AS1 is associated with poor prognosis in epithelial ovarian cancer

SUMMARY OBJECTIVE Long noncoding RNAs (lncRNAs) have been shown to play a critical role in tumor progression. Abnormal expression of LncRNA PTPRG antisense RNA 1 (PTPRG-AS1) has been reported in several tumors. Hence, we aimed to determine the expression and clinical significance of PTPRG-AS1 in epithelial ovarian cancer (EOC) patients. METHODS The expressions of PTPRG-AS1 were assessed in 184 pairs of EOC tumor specimens and adjacent normal tissues. The levels of target lncRNAs and GAPDH were examined using standard SYBR-Green methods. The relationships between the expressions of PTPRG-AS1 and the clinicopathological features were analyzed using the chi-square test. Multivariate analysis using the Cox proportional hazards model was performed to assess the prognostic value of PTPRG-AS1 in EOC patients. RESULTS We confirmed that the expressions of PTPRG-AS1 were distinctly higher in the EOC tissue compared with the adjacent non-tumor specimens (p < 0.01). Higher levels of PTPRG-AS1 in EOC patients were associated with advanced FIGO stage (p = 0.005), grade (p = 0.006), and distant metastasis (p = 0.005). Survival analyses revealed that patients with high expressions of PTPRG-AS1 had a distinctly decreased overall survival (p = 0.0029) and disease-free survival (p = 0.0009) compared with those with low expressions of PTPRG-AS1. Multivariate assays indicated that PTPRG-AS1 expression was an independent prognostic factor for both overall survival and disease-free survival in EOC (Both p < 0.05). CONCLUSIONS Our study suggests that PTPRG-AS1 may serve as a novel prognostic biomarker for EOC patients.

RESUMO OBJETIVO Sabe-se que RNAs longos não codificantes (lncRNAs) desempenham um papel crítico na progressão tumoral. A expressão anormal do RNA 1 anti-senso LncRNA PTPRG (PTPRG-AS1) já foi relatada em diversos tumores. Assim, buscamos determinar a expressão e significância clínica do PTPRG-AS1 em pacientes com câncer de ovário epitelial (COE). METODOLOGIA As expressões do PTPRG-AS1 foram avaliadas em 184 pares de amostras tumorais de COE e tecidos normais adjacentes. Os níveis de lncRNAs e GAPDH alvo foram examinados usando o método padrão de SYBR Green. As relações entre as expressões do PTPRG-AS1 e as características clínico-patológicas foram analisadas através do teste qui-quadrado. Uma análise multivariada utilizando o modelo de riscos proporcionais de Cox foi realizada para avaliar o valor prognóstico do PTPRG-AS1 em pacientes com COE. RESULTADOS Constatou-se que as expressões do PTPRG-AS1 foram nitidamente maiores nos tecidos de COE em relação aos espécimes adjacentes não tumorosos (p<0,01). Níveis mais elevados do PTPRG-AS1 em pacientes com COE foram associados a um estágio avançado de FIGO (p = 0,005), grau (p = 0,006) e metástases à distância (p = 0,005). As análises de sobrevida revelaram que pacientes com expressões elevadas do PTPRG-AS1 tiveram uma diminuição significativa da sobrevida global (p = 0,0029) e da sobrevida livre de doença (p = 0,0009) em relação àqueles com baixas expressões do PTPRG-AS1. As análises multivariadas indicaram que a expressão do PTPRG-AS1 foi um fator de prognóstico independente tanto para a sobrevida global quanto para a sobrevida livre de doença em pacientes com EOC (p < 0,05). CONCLUSÃO Nosso estudo sugere que o PTPRG-AS1 pode ser um novo biomarcador prognóstico para pacientes com COE.

Methylation of PTPRG gene and its regulation in gastric cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the difference in methylation of PTPRG gene between gastric primary cancer and its lymph node metastases, and its regulation by 5-Aza-2'-deoxycytidin in a gastric cancer cell line SGC7901.</p><p><b>METHODS</b>Methylation-specific polymerase chain reaction (MSP) and RT-PCR were applied to identify the difference between gastric primary cancer and lymph node metastases and assess the changes of methylation in gastric cancer cell line SGC7901 treated by 5-Aza-2'-deoxycytidin.</p><p><b>RESULTS</b>There were significant differences of PTPRG gene methylation and PTPRG mRNA expression between gastric primary cancer and lymph node metastases: a linear regression analysis revealed a significant association between the quantity of metastatic lymph nodes and their methylation rate. A statistied relationship between methylation of PTPRG gene and loss of PTPRG mRNA expression was detected. PTPRG gene methylation in the gastric cancer cell line changed into negative and PTPRG mRNA expression in the cell line was recovered after 5-Aza-2'-deoxycytidin treatment.</p><p><b>CONCLUSION</b>There is a difference of PTPRG gene methylation in gastric primary cancer and metastatic lymph nodes. 5-Aza-2'-deoxycytidin, an inhibitor of DNA methylation, can recovery the expression of PTPRG gene.</p>

Effects of androgen on phosphacan and NG2 proteoglycan expression and neurite regeneration in neonatal rats with hypoxic-ischemic brain damage / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of androgen on the expression of phosphacan and NG2 proteoglycan (NG2) and neurite regeneration in neonatal rats with hypoxic-ischemic brain damage (HIBD) and the potential mechanism underlying the protective effect of androgen against HIBD.</p><p><b>METHODS</b>One hundred and twenty neonatal Sprague-Dawley rats were randomly divided into three groups: sham-operated, HIBD and androgen treatment. HIBD was induced by the ligation of left common carotid artery and hypoxia exposure. The androgen treatment group rats were injected with testosterone propionate (25 mg/kg) immediately after HIBD. Phosphacan and NG2 expression in the cortex and the hippocampus was detected with the immunohistochemical method 24 and 72 hrs and 7 and 10 days after hypoxia-ischemia (HI). The ultrastructure and neurite regeneration of neurons in the cortex and the hippocampus were observed under a transmission electron microscope.</p><p><b>RESULTS</b>The neurite regeneration was obvious in the sham-operated group, but seldom in the HIBD group. The androgen treatment group showed increased neurite regeneration compared with the HIBD group. There were fewer phosphacan and NG2 positive cells in the cortex and the hippocampus in the sham-operated group. Phosphacan and NG2 expression in the cortex and the hippocampus was observed at 24 hrs, increased at 72 hrs, and peaked at 7 days after HI in the HIBD group and remained at a higher expression 10 days after HI than in the sham-operated group. The levels of phosphacan and NG2 expression in the cortex and the hippocampus in the androgen treatment group were significantly reduced compared with those in the HIBD group 24 and 72 hrs and 7 and 10 days after HI (P<0.01).</p><p><b>CONCLUSIONS</b>Phosphacan and NG2 may be important inhibitory factors for neurite regeneration following HIBD in neonatal rats. The neuroprotection of androgen against neonatal HIBD is produced possibly through an inhibition of phosphacan and NG2 expression.</p>