Expression of dentin sialophosphoprotein in human prostate cancer and its correlation with tumor aggressiveness.

Abstract

Recent studies have demonstrated that two SIBLING family members, bone sialoprotein (BSP) and osteopontin (OPN), are overexpressed in human prostate cancer. The expression of these proteins is associated with the acquisition of a metastatic phenotype by cancer cells and a poor prognosis for the patient. Dentin sialophosphoprotein (DSPP) shares several structural and genetic features with OPN and BSP. The presence of DSPP has been recently established in salivary glands, indicating that its expression is not restricted to mineralized tissues. However, its potential expression in human tumors has not been addressed yet. In this study, we sought to evaluate the expression of DSPP in human prostate cancer. Immunohistochemistry was performed on 69 prostate cancer specimens using LFMb-21 anti-DSPP monoclonal antibody. All of the prostate cancer lesions examined expressed detectable levels of DSPP, as compared with no or low level of expression in adjacent normal glands (p < 0.0001). High grade prostatic intraepithelial neoplasia (HGPIN) glands generally displayed DSPP expression levels that were similar to those found in neighboring cancer glands. DSPP expression was significantly associated with the pathological stage (p = 0.0087) and the Gleason score (p = 0.0176) of the tumors. Western Blot was performed on 5 representative prostate tumor extracts and 3 prostatic tumor cell lines (PC3, LNCaP and DU145). All tumor extracts and cell lines analyzed have been found to express DSPP. In addition, in situ hybridization was used to assess the presence of DSPP mRNA. DSPP was detected at the RNA level in both HGPIN and tumoral glands. This study shows for the first time that DSPP is ectopically expressed in human prostate cancer. The expression of this SIBLING protein strongly correlates with conventional histopathological prognostic indicators of prostate cancer progression.

• Authors: Michaël Chaplet, David Waltregny, Cédric Detry, Larry W Fisher, Vincent Castronovo, Akeila Bellahcène
• Journal: International journal of cancer (Int J Cancer) Vol. 118 Issue 4 Pg. 850-6 (Feb 15 2006) ISSN: 0020-7136 [Print] United States
• PMID: 16108038 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Extracellular Matrix Proteins
• Phosphoproteins
• Protein Precursors
• Sialoglycoproteins
• dentin sialophosphoprotein

Topics

• Aged
• Disease Progression
• Extracellular Matrix Proteins
• Humans
• Immunohistochemistry
• In Situ Hybridization
• Male
• Middle Aged
• Neoplasm Invasiveness
• Neoplasm Metastasis
• Neoplasm Staging
• Phosphoproteins
• Prognosis
• Prostatic Intraepithelial Neoplasia (genetics, pathology)
• Prostatic Neoplasms (genetics, physiopathology)
• Protein Precursors (biosynthesis, physiology)
• Sialoglycoproteins