Piwi-Interacting RNAs Are Differentially Expressed in Renal Cell Carcinoma and Its Metastasis
Yuping Li, Xiwei Wu, Hanlin Gao, Xuejun Li, Jennifer M Jin, Frances Wang, Bing Mu, Jinhui Wang, Young S Kim, Lawrence M Weiss, Huiqing Wu. City of Hope National Medical Center and Beckman Research Institute, Duarte, CA; Third Military Medical University, Chongqing, China
Background: Piwi-interacting RNAs (piRNAs) are a distinct group of abundant small non-coding RNAs (smRNAs) of ∼24-30 nucleotides in length. They form the piRNA-induced silencing complex (piRISC) with Piwi family proteins in the germ line across animal species and protect genome integrity by transposable elements (TEs) silencing. Owing to their limited expression in gonads and sequence diversity, piRNAs remain the most mysterious class of smRNAs. Recent pilot studies have shown that piRNAs are present in somatic tissues including some human cancers. However, the functional significance of piRNA in somatic cells or human cancers is still not clear. Here, we report the study to profile piRNA expression in renal cell carcinoma (RCC) and its metastasis.
Design: Using a publically available piRNA database (RNAdb: http://Research.imb.uq.edu.au/), we investigated whether piRNAs are present in our whole genome smRNA deep sequencing data from an RCC tissue cohort including benign kidney tissue, localized and metastatic RCC specimens (n = 24). Using the same tissue cohort, we profiled the piRNA expression between benign kidney tissue and RCCs. We further characterized the piRNA differential expression in localized and metastatic RCCs.
Results: (1) 530 piRNAs have been found to be present in at least 3 out of 24 tissue specimens (≥10 copies/reads in at least 1 specimen). (2) 80 piRNAs have been found to be dysregulated in tumors (≥1-log2 ratio, p <0.05), including 19 up-regulated and 61 down-regulated. (3) 34 piRNAs have been found to be dysregulated (all up-regulated) in metastatic RCCs compared to the localized ones (≥1-log2 ratio, p <0.05).
Conclusions: We are the first to show that piRNAs are present in benign and malignant kidney tissues. We have shown the altered expression of piRNAs in RCCs compared to their benign counterparts. We have further characterized the differential expression of piRNAs in localized and metastatic RCCs. These findings may indicate the biological significance of piRNAs in tumorigenesis and metastasis.
Category: Special Category - Pan-genomic/Pan-proteomic approaches to Cancer
Tuesday, March 20, 2012 9:30 AM
Poster Session III # 275, Tuesday Morning