PTOV-1 overexpression in neuroendocrine tumors: a new molecular marker

#79

Introduction: PTOV-1 (Prostate Tumor Overexpressed-1) is a novel protein encoded by 12-exon gene localized in chromosome 19q.13.3. Recently identified as an androgen-induced gene, it is involved in prostate cell proliferation and in prostate human cancer. PTOV-1 expression has been demonstrated in neuroendocrine cells of normal prostate tissue. Preliminary data indicate that PTOV-1 can be related to flotilin, integrins and other cellular factors involved in cancer progression.

Aim(s): As PTOV-1 has not yet been studied in neuroendocrine tumors (NETs), the aim of this research was to carry out an immunohistochemical study on a large cohort of neuroendocrine tumors of different origin, in order to evaluate this novel oncogenic factor in NETs.

Materials and methods: Eighty NETs of distinctive origin were selected: 12 medullary thyroid carcinomas, five Merckel carcinomas (four skin, one vulva), 21 small cell carcinomas (two bladder, one ovary, 18 lung), one large cell neuroendocrine carcinoma (lung), 11 pheocromocytomes, 25 GEP-NET (10 appendix, four small bowel, 11 pancreas) and five NET lymph nodal metastases. Immunohistochemical assay with PTOV-1 (home-made polyclonal 1:40 dilution) and chromogranin A (monoclonal, Dako; 1:50 dilution) with Envision method was performed on formalin-fixed paraffin-embedded sections. Intensity and percentage of immunostaining was evaluated by the HScore (scale 1 to 300), considering overexpression > 100. Data were analyzed with SPSS16.0, using U Mann-Whitney and Spearman tests.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Landolfi S

Authors: de Torres I, Castellvi J, Landolfi S, Fernandez S, Alaña L,

Keywords: PTOV-1, chromogranin A, NETs, inmunohistochemistry,

To read the full abstract, please log into your ENETS Member account.