Article

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.

0 Bookmarks
 · 
197 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PIWI family proteins have recently emerged as essential contributors in numerous biological processes including germ cell development, stem cell maintenance and epigenetic reprogramming. Expression of some of the family members has been shown to be elevated in tumors. In particular, PIWIL2 has been probed as a potential neoplasia biomarker in many cancers in humans. Previously, PIWIL2 was shown to be expressed in most tumours as a set of its shorter isoforms. In this work, we demonstrated the presence of its 60 kDa (PL2L60A) and 80 kDa (PL2L80A) isoforms in testicular cancer cell lines. We also ascertained the transcriptional boundaries of mRNAs and alternative promoter regions for these PIWIL2 isoforms. Further, we probed a range of testicular germ cell tumor (TGCT) samples and found PIWIL2 to be predominantly expressed as PL2L60A in most of them. Importantly, the levels of both PL2L60A mRNA and protein products were found to vary depending on the differentiation subtype of TGCTs, i.e., PL2L60A expression is significantly higher in undifferentiated seminomas and appears to be substantially decreased in mixed and nonseminomatous TGCTs. The higher level of PL2L60A expression in undifferentiated TGCTs was further validated in the model system of retinoic acid induced differentiation in NT2/D1 cell line. Therefore, both PL2L60A mRNA and protein abundance could serve as an additional marker distinguishing between seminomas and nonseminomatous tumors with different prognosis and therapy approaches.
    PLoS ONE 01/2014; 9(11):e112528. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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.
    FEBS letters 03/2012; 586(9):1356-62. · 3.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Piwi-like gene family members (Piwil 1–4) are considered stem cell-associated genes/proteins. These are expressed predominantly in germline cells, but are re-expressed in different tumors. Piwil 1–4 gene expression has not previously been studied and correlated with clinicopathological parameters in renal cell carcinomas (RCC). The Piwil 1–4 transcript levels were analyzed by quantitative real-time PCR in 73 clear cell RCC (ccRCC) tissues and corresponding normal tissues. The transcript levels of Piwil 1, 2 and 4 were strongly and significantly correlated with each other, in both the tumor tissues and the normal tissues (P < 0.001; Spearman’s rank test). Piwil 4 gene expression was significantly higher in the ccRCC tissues than in the corresponding normal renal tissues (P < 0.001; Wilcoxon signed-rank test). When the ccRCC patient cohort was divided according to the median Piwil 1–4 expression into low and high-expression groups and according to age into younger (≤ 64 years) and older patient groups (> 64 years), the younger patients displayed significantly higher levels of Piwil 1 mRNA in comparison to the older patients (P = 0.010; Fisher’s exact test). Interestingly, Piwil 1 expression was left-right polarized in the normal tissues but not in the tumor tissues (P = 0.004; Fisher’s exact test). Altogether, associations were determined between the Piwi-like family member expression levels and clinicopathological parameters of ccRCC, suggesting a potential role for these genes/proteins in ccRCC diagnostics and tumorigenesis, as well as in renal tissue embryology.
    Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease 01/2014; · 4.91 Impact Factor

Full-text

Download
93 Downloads
Available from
May 20, 2014