BioProject

Background/Objective: MicroRNAs (miRNAs) play a pivotal role in cancerogenesis and cancer progression, but their specific role in metastasis of clear cell renal cell carcinomas (ccRCCs) as so-called metastamirs is still limited. More...

Background/Objective: MicroRNAs (miRNAs) play a pivotal role in cancerogenesis and cancer progression, but their specific role in metastasis of clear cell renal cell carcinomas (ccRCCs) as so-called metastamirs is still limited. Based on microRNA microarray analyses from normal (n=12) and cancerous (n=12) samples of ccRCC specimens and from bone metastases (n=9) of ccRCC patients, we identified a set of 57 differentially expressed microRNAs between those three sample groups of ccRCC. A selected panel of 33 miRNAs, including miRNAs reported in the literature as differentially expressed in non-metastatic RCC, was validated by RT-qPCR on 57 clinical samples. 30 of the 33 examined miRNAs were confirmed to be deregulated. A stepwise down-regulated miRNA expression from normal over primary tumor to metastatic tissue samples was found to be typical. 23 miRNAs (miR-10b/-19a/-19b/-20a/-29a/-29b/-29c/-100/-101/-126/-127/-130/-141/-143/-145/-148a/-192/-194/-200c/-210/-215/-370/-514) were down-regulated in metastatic tissue samples in comparison to normal tissue. This down-regulated expression in metastatic tissue was also present in 21 miRNAs except for miR-127 and miR-370. The altered miRNA profiles including the newly identified metastasis-associated miRNAs, the compiled predicted miRNA-target interactions, and the significant correlations of miRNAs which were either lost or newly appeared in the studied sample groups afford a solid basis for further functional analyses of individual miRNAs. Overall design: In this study, microarray-based profiling was performed from 9 bone metastatic tissue samples from 9 patients with clear cell renal cell carcinoma (ccRCC). For controls, 2 bone metastatic samples from two patients with prostate carcinoma and 5 total RNA pools (2 different pools of total RNAs isolated from malignant renal tissue samples derived from different ccRCC patients; 1 pool from non-malignant renal tissue of ccRCC patients; 2 pools of total RNA both from malignant and non-malignant prostate cancer tissue) were used. In addition, matched malignant (e.g., malignant NC2) and non-malignant (e.g., non-malignant NN1) samples from two independent 12 ccRCC sets were profiled (these samples were previously analyzed on a different Platform in GSE12105). The 2002 TNM System and the 2004 WHO classification was used for staging and grading. Less...