Open Access Research article

Sperm protein 17 is expressed in human nervous system tumours

Fabio Grizzi14, Paolo Gaetani2, Barbara Franceschini14, Antonio Di Ieva2, Piergiuseppe Colombo3, Giorgia Ceva-Grimaldi14, Angelo Bollati5, Eldo E Frezza6, E Cobos7, Riccardo Rodriguez y Baena2, Nicola Dioguardi14 and Maurizio Chiriva-Internati8*

Author Affiliations

1 Scientific Direction, Istituto Clinico Humanitas, IRCCS, 20089 Rozzano, Milan, Italy

2 Department of Neurosurgery, Istituto Clinico Humanitas, IRCCS, 20089 Rozzano, Milan, Italy

3 Department of Pathology, Istituto Clinico Humanitas, IRCCS, 20089 Rozzano, Milan, Italy

4 "Michele Rodriguez" Foundation. Scientific Institute for Quantitative Measures in Medicine, 20100 Milan, Italy

5 Department of Neurosurgery, University of Brescia, Spedali Civili, Italy

6 Department of Surgery, Texas Tech University Health Sciences Center and Southwest Cancer Treatment and Research Center, 79430 Lubbock, Texas, USA

7 Department of Internal Medicine, Texas Tech University Health Sciences Center and Southwest Cancer Treatment and Research Center, 79430 Lubbock, Texas, USA

8 Department of Microbiology and Immunology, Texas Tech University Health Sciences Center and Southwest Cancer Treatment and Research Center, 79430 Lubbock, Texas, USA

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BMC Cancer 2006, 6:23  doi:10.1186/1471-2407-6-23

Published: 26 January 2006

Abstract

Background

Human sperm protein 17 (Sp17) is a highly conserved protein that was originally isolated from a rabbit epididymal sperm membrane and testis membrane pellet. It has recently been included in the cancer/testis (CT) antigen family, and shown to be expressed in multiple myeloma and ovarian cancer. We investigated its immunolocalisation in specimens of nervous system (NS) malignancies, in order to establish its usefulness as a target for tumour-vaccine strategies.

Methods

The expression of Sp17 was assessed by means of a standardised immunohistochemical procedure [(mAb/antigen) MF1/Sp17] in formalin-fixed and paraffin embedded surgical specimens of NS malignancies, including 28 neuroectodermal primary tumours (6 astrocytomas, 16 glioblastoma multiforme, 5 oligodendrogliomas, and 1 ependymoma), 25 meningeal tumours, and five peripheral nerve sheath tumours (4 schwannomas, and 1 neurofibroma),.

Results

A number of neuroectodermal (21%) and meningeal tumours (4%) were found heterogeneously immunopositive for Sp17. None of the peripheral nerve sheath tumours was immunopositive for Sp17. The expression pattern was heterogeneous in all of the positive samples, and did not correlate with the degree of malignancy.

Conclusion

The frequency of expression and non-uniform cell distribution of Sp17 suggest that it cannot be used as a unique immunotherapeutic target in NS cancer. However, our results do show the immunolocalisation of Sp17 in a proportion of NS tumour cells, but not in their non-pathological counterparts. The emerging complex function of Sp17 makes further studies necessary to clarify the link between it and immunopositive cells.