Expression of microRNA 210 associates with poor survival and age of tumor onset of soft-tissue sarcoma patients.

Expression of microRNAs can affect age of tumor onset and prognosis of cancer patients. However, nothing is known about the effects of microRNAs on altered age of cancer onset and disease-specific survival of soft-tissue sarcoma (STS) patients. The levels of miR-210, also known as hypoxia-regulated microRNA, were analyzed by quantitative real-time (RT)-PCR in the tumors of 78 STS patients. The patients were stratified according to their microRNA levels with low, intermediate and high expression levels and the association of microRNA expression and patients' survival was analyzed using multivariate Cox's regression hazard analyses. A significant correlation between an intermediate miR-210 expression and disease-specific death of STS patients [relative risk (RR) = 3.19; p = 0.018] was observed compared with patients with high expression levels in their tumors. Interestingly, the association between an intermediate expression of miR-210 and a poor prognosis was only significant in female STS patients (RR = 11.28; p = 0.010), but not observed in male individuals. Furthermore, the expression of miR-210 showed a significant association with the age of tumor onset in a gender-specific manner. Specifically, male patients with an intermediate expression of miR-210 associated with a 9.6-year later age of tumor onset (p = 0.017) compared with males with a low expression of miR-210 in their tumors. However, no significant differences in the female patients were observed. This study provides the first evidence of a correlation of expression levels of a single microRNA (miR-210) with the prognosis and age of tumor onset in a gender-specific manner in STS patients.

Co-detection of members of the urokinase plasminogen activator system in tumour tissue and serum correlates with a poor prognosis for soft-tissue sarcoma patients.

BACKGROUND: The urokinase plasminogen activator (uPA) system is one of the best-investigated protease systems, both under physiological and pathological conditions, including various types of cancer. However, effects of co-expression of members of the uPA system in soft-tissue sarcoma (STS) patients at the protein level in both tumour tissue and serum have not been investigated yet. METHODS: We examined 82 STS patients for protein levels of uPA, PAI-1and uPAR in tumour tissue and serum by ELISA. RESULTS: A significant correlation between high antigen levels of uPA, PAI-1 or uPAR in tumour tissue, and of uPAR in serum, with poor outcome of STS patients was found for the first time. Most strikingly, we observed an additive effect of combined uPA, PAI-1 or uPAR levels in tumour tissue extracts with uPAR levels in serum on patients' prognosis. High uPA/uPAR, PAI-1/uPAR and uPAR/uPAR antigen levels in tumour tissue/serum were associated with a 5.9-fold, 5.8-fold and 6.2-fold increased risk of tumour-related death (P=0.003, 0.001 and 0.002, respectively) compared with those patients who displayed low levels of the respective marker combination. CONCLUSION: As expression of members of the uPA system in tumour tissue and serum is additively correlated with prognosis of STS patients, our results suggest that combinations of these biomarkers can identify STS patients with a higher risk of tumour-related death.

The stem cell-associated Hiwi gene in human adenocarcinoma of the pancreas: expression and risk of tumour-related death.

Piwi proteins and their interaction with piRNAs have rapidly emerged as important contributors to gene regulation, indicating their crucial function in germline and stem cell development. However, data on the Hiwi 1 (Hiwi) gene, one of the four human Piwi homologues, are still scarce. Therefore, we investigated the Hiwi mRNA expression in microdissected PDAC tissues from patients with ductal adenocarcinoma of the pancreas (PDAC) by quantitative real-time PCR and the protein expression by immunohistochemistry. Elevated levels of Hiwi mRNA transcripts were measured in 40 out of 56 tissues and a positive immunostaining of Hiwi was detected in tumours of 21 out of 78 patients. There was no general impact of elevated Hiwi mRNA transcript levels or protein expression on survival, as tested by multivariate Cox regression and Kaplan-Meier analysis. However, men showed a significantly increased risk for tumour-related death in case of down- or upregulated expression of Hiwi mRNA (relative risk (RR)=2.78; P=0.034). In summary, we report the first analysis of Hiwi expression in PDAC and its impact on prognosis. We suggest that alterations in mRNA expression of Hiwi can increase the risk of tumour-related death in male PDAC patients.

The effects of knockdown of wild-type survivin, survivin-2B or survivin-delta3 on the radiosensitization in a soft tissue sarcoma cells in vitro under different oxygen conditions.

The inhibitor of apoptosis wild-type survivin is a multifunctional protein that suppresses apoptosis and regulates cell cycle progression. An association between wild-type survivin expression and radiosensitivity has been described in different tumor cells. The effects of siRNA-induced knockdown of wild-type survivin and survivin-splice variants survivin-2B and survivin-Delta3 were investigated under normoxic and hypoxic conditions in the human sarcoma cell line US 8-93 (mutant p53). Inhibition of the survivin isoforms by siRNA resulted in a decrease of target mRNA down to 14-70% compared to cells treated with control siRNA independent of the oxygen level. The mRNA expression of survivin isoforms was decreased by the factor of 1-12 when the cells were cultivated under hypoxic conditions. Moreover, the knockdown of wild-type survivin reduced colony formation independent of oxygen concentration down to 70% and induced formation of polyploid cells. Less reduction of plating efficiency was observed after specific knockdown of survivin-2B and survivin-Delta3 under hypoxic or normoxic conditions. A knockdown of wild-type survivin, survivin-Delta3 and survivin-2B isoforms in combination with irradiation caused no radiosensitization in cell line US 8-93, neither under hypoxic nor under normoxic conditions tested in the colony-forming assay. However, knockdown of wild-type survivin caused radiosensitization in the megacolony assay.

Stem cell-associated genes are extremely poor prognostic factors for soft-tissue sarcoma patients.

Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it is still difficult to detect and isolate cancer stem cells. An alternative approach is to analyse stem cell-associated gene expression. We investigated the coexpression of three stem cell-associated genes, Hiwi, hTERT and survivin, by quantitative real-time-PCR in 104 primary soft-tissue sarcomas (STS). Multivariate Cox's proportional hazards regression analyses allowed correlating gene expression with overall survival for STS patients. Coexpression of all three stem cell-associated genes resulted in a significantly increased risk of tumor-related death. Importantly, tumors of patients with the poorest prognosis were of all four tumor stages, suggesting that their risk is based upon coexpression of stem cell-associated genes rather than on tumor stage.

Expression of the stem cell self-renewal gene Hiwi and risk of tumour-related death in patients with soft-tissue sarcoma.

Self-renewal is considered as a common property of stem cells. Dysregulation of stem cell self-renewal is likely a requirement for the development of cancer. Hiwi, the human Piwi gene, encodes a protein responsible for stem cell self-renewal. In this study, we investigated the expression of Hiwi at the RNA level by real-time quantitative PCR in 65 primary soft-tissue sarcomas (STS) and ascertained its impact on prognosis for STS patients. In a multivariate Cox's proportional hazards regression model, we found that an increased expression of Hiwi mRNA is a significant negative prognostic factor for patients with STS (P=0.017; relative risk 4.6, 95% confidence interval (CI) 1.3-16.1) compared to medium expression of Hiwi transcript. However, a low expression of Hiwi transcript is correlated with a 2.4-fold (CI 0.7-8.0) increased risk, but this effect was not significant (P=0.17). Altogether, high-level expression of Hiwi mRNA identifies STS patients at high risk of tumour-related death. This is the first report showing a correlation between expression of a gene involved in stem cell self-renewal and prognosis of cancer patients.