Jiří Šána

Expression levels of transcribed ultraconserved regions uc.73 and uc.388 are altered in colorectal cancer.

Objectives: The development of colorectal cancer (CRC) is characterized by multiple genetic alterations. Transcribed ultraconserved regions (T-UCRs) are a subset of 481 sequenc es longer than 200 bp, which are absolutely conserved between orthologous regions of human, rat and mouse genomes, and are actively transcribed. It has recently been proven in cancer systems that differentially expressed T-UCRs could alter the functional characteristics of malignant cells. Genome-wide profiling revealed that T-UCRs have distinct signatures in human leukemia and carcinoma. Methods: In our study, we examined the expression levels of uc.43, uc.73, uc.134, uc.230, uc.339, uc.388 and uc.399 in 54 samples of primary colorectal carcinomas and 15 samples of non-tumoral adjacent tissues by real-time PCR. T-UCR expression levels were also correlated with commonly used clinicopathological features of CRC. Results: Expression levels of uc.73 (p = 0.0139) and uc.388 (p = 0.0325) were significantly decreased in CRC tissue, and uc.73 indicated a positive correlation with overall survival (p = 0.0315). The lower expression of uc.388 was associated with the distal location of CRC (p = 0.0183), but no correlation of any evaluated T-UCR with clinical stage, grade and tumor diameter was observed. Conclusion: Our preliminary results suggest that uc.73 and uc.388 could be potential diagnostic and prognostic biomarkers in CRC patients.

MicroRNA and Glial Tumors: Tiny Relation with Great Potential

MicroRNAs (miRNAs) are endogenously expressed small non-coding RNAs that act as post-transcriptional regulators of gene expression. Dysregulation of these molecules has been observed in many types of cancers. Altered expression levels of several miRNAs were identified also in gliomas. It was many times showed that miRNAs are involved in core signaling pathways, which play roles in crucial cellular processes, such as proliferation, apoptosis, cell cycle regulation, invasion, angiogenesis and stem cell behaviour. Therefore, miRNAs have a great potential for oncodiagnostic as well as could be promising therapeutic targets in gliomas.