Absence of PIWIL2 (HILI) expression in human bladder cancer cell lines and tissues

Department of Genetics, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran.
Cancer epidemiology 08/2009; 33(3-4):271-5. DOI: 10.1016/j.canep.2009.06.011
Source: PubMed

ABSTRACT PIWIL2, a member of Argonaute family of proteins, is exclusively expressed in testis and functions in development and maintenance of germline stem cells. Recently, ectopic expression of PIWIL2 has been reported in a variety of human and mouse tumors. To investigate a potential involvement of PIWIL2 in human bladder cancer, we examined its expression in several human bladder cancer cell lines, normal uroepithelial cell cultures, and some bladder tissues.
Relative expression of PIWIL2 was determined by real-time quantitative RT-PCR in fifteen bladder carcinoma cell lines, six normal uroepithelial cell cultures and seventy tissue specimens of tumor, tumor margins and morphologically normal tissues of bladder. Specific primers for PIWIL2, TBP and GAPDH (as two internal controls) were used for reverse transcription polymerase chain reaction technique.
Real-time qRT-PCR demonstrated high PIWIL2 expression in testis tissue, but at least 240-fold lower expression in all examined cell lines. The highest expression outside testis was observed in one of six primary cultures of normal uroepithelial cells, but even lower expression of PIWIL2 was detected in any of the examined tumor and non-tumor tissues.
Lack of PIWIL2 expression in most tissues along with its aberrant expression in some tumors candidate the gene as an attractive tumor marker for some neoplasms. However, our study indicates that PIWIL2 does not play a role in carcinogenesis of human bladder carcinoma.

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Available from: Parvaneh Nikpour, Sep 26, 2015
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    • "Among them, PIWIL4 might play unique roles in tumorigenesis and exhibit a ubiquitous expression pattern in various types of cancers, including colon and breast cancers [14] [15] [16]. However, the expression and function of PIWIL4 in cervical cancer remain unclear. "
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    ABSTRACT: Recently, PIWIL4 has been identified as a functional protein involved in tumorigenesis. Cervical cancer is the second most prevalent form of cancer worldwide. The relationship between PIWIL4 and cervical cancer is still unknown. Here, we found that PIWIL4 is up-regulated in human cervical cancer tissues in comparison to adjacent normal tissues, and it promotes cell growth and proliferation by inhibiting apoptosis through the p14ARF/p53 pathway. PIWIL4 can also promote the invasion of cervical cancer cells. These results suggest that PIWIL4 might play an oncogenic role in cervical cancer and be useful as a new therapeutic target in the future.
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    • "The results reveal that PL2L60 rather than Piwil2 are constitutively and widely expressed in various types of cancers without the restriction of tissue origin. The notion is also supported by the fact that Piwil2 transcripts were undetectable in the bladder cancers by real-time RT-PCR with the primers amplifying first 6 exons of PIWIL2 [51], which are absent in PL2L genes. Therefore, the “Piwil2” transcripts amplified by primers within PL2L genes and the translated proteins detected by mAbs Kao2/3, de facto represent PL2L genes and PL2L proteins in cancer cell lines or in the tissues of primary and metastatic cancers. "
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