Expression of human Piwi-like genes is associated with prognosis for soft tissue sarcoma patients
- Equal contributors
1 Center for Reproductive Medicine and Andrology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
2 Department of Oral and Maxillofacial Plastic Surgery, Martin-Luther-University Halle-Wittenberg, Halle, Germany
3 Department of Radiotherapy, Martin-Luther-University Halle-Wittenberg, Halle, Germany
4 Institute of Medical Biometry and Informatics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
5 Institute of Transfusion Medicine, Martin-Luther-University Halle-Wittenberg, Halle, Germany
6 Institute of Pathology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
7 Div. Molecular Urology, FAU Erlangen-Nürnberg, University Clinic of Urology, Erlangen, Germany
8 Nikolaus-Fiebiger-Center for Molecular Medicine, FAU Erlangen-Nürnberg, Erlangen, Germany
9 Department of General and Visceral Surgery, Diakoniekrankenhaus Halle, Halle, Germany
10 Klinik für Urologie und NFZ, FAU Erlangen, Glückstr. 6, D-91054, Erlangen, Germany
BMC Cancer 2012, 12:272 doi:10.1186/1471-2407-12-272Published: 29 June 2012
Argonaute genes are essential for RNA interference, stem cell maintenance and differentiation. The Piwi-like genes, a subclass of the Argonaute genes, are expressed mainly in the germline. These genes may be re-expressed in tumors, and expression of the Piwi-like genes is associated with prognosis in several types of tumors.
We measured the expression of Piwi-like mRNAs (Piwi-like 2–4) in 125 soft tissue sarcoma (STS) samples by qPCRs. Statistical tests were applied to study the correlation of expression levels with tumor-specific survival for STS patients.
In multivariate Cox’s regression analyses, we showed that low Piwi-like 2 and Piwi-like 4 mRNA expression were significantly associated with a worse prognosis (RR = 1.87; p = 0.032 and RR = 1.82; p = 0.039). Low expression of both genes was associated with a 2.58-fold increased risk of tumor-related death (p = 0.01). Piwi-like 4 and combined Piwi-like 2 and 4 mRNA levels correlated significantly with prognosis (RR = 3.53; p = 0.002 and RR = 5.23; p = 0.004) only for female but not for male patients. However, combined low Piwi-like 2 and 3 transcript levels were associated with worse survival (RR = 5.90; p = 0.02) for male patients.
In this study, we identified a significant association between the expression of Piwi-like 2 and 4 mRNAs and the tumor-specific survival of soft tissue sarcoma patients. Furthermore, a connection between sex and the impact of Piwi-like mRNA expressions on STS patients’ prognosis was shown for the first time.