The expression of prostate stem cell antigen in human clear cell renal cell carcinoma: a quantitative reverse transcriptase-polymerase chain reaction analysis

Authors

  • ESSAM M. ELSAMMAN,

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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  • TOMOHARU FUKUMORI,

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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  • SHUJI TANIMOTO,

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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  • RYOICHI NAKANISHI,

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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  • MASAYUKI TAKAHASHI,

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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  • KAZUNORI TOIDA,

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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  • HIRO-OMI KANAYAMA

    1. Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan
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Hiro-omi Kanayama, Department of Urology, The University of Tokushima Graduate School Institute of Health Biosciences, 3-18-15 Kuramoto, Tokushima 770–8503, Japan. e-mail: kanahiro@clin.med.tokushima-u.ac.jp

Abstract

OBJECTIVES

To analyse the gene expression level of prostate stem cell antigen (PSCA) in human clear cell renal cell carcinoma (CC-RCC) and its relationship with conventional clinicopathological manifestations, to evaluate its prognostic value for patient outcome, and to determine the effect of PSCA on the progression of CC-RCC.

PATIENTS AND METHODS

We quantified PSCA mRNA level in human RCC cell lines (ACHN, A704, KPK-1, Caki-1, and Caki-2) and in 154 surgical tissue samples (81 from CC-RCC, 73 from normal kidney) using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The findings were analysed in relation to clinicopathological factors. Immunohistochemical expression was examined using confocal laser scanning light-microscopy.

RESULTS

PSCA was overexpressed in all RCC cell lines. PSCA mRNA levels were significantly higher in CC-RCC than in normal kidney tissue samples (P < 0.001), in G2-G3 than in G1 tumours (P = 0.028), and in advanced disease (T3-T4) than in organ-confined (T1-T2) tumours (P = 0.016). There was significantly higher PSCA mRNA expression in patients with M1 than in those with M0 disease (P = 0.029). Patients in whom the lesions had high PSCA expression levels had a significantly worse prognosis than those with low PSCA expression levels (P = 0.044). Using immunohistochemical analysis there was markedly greater PSCA expression in CC-RCC than in normal kidney, and in advanced-disease high-grade tumours than in organ-confined low-grade tumours.

CONCLUSIONS

A significant correlation was detected in the gene expression level of PSCA with histological grade, clinicopathological stage and prognosis in CC-RCC. Our data indicate that PSCA is associated with carcinogenesis and progression of CC-RCC.

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