No abstract

Background: In recent years, tRFs(transfer RNA-Derived Fragments) and transfer RNADerived Stress-induced RNAs (or tRNA halves) have been shown to have vital roles in cancer biology. We aimed to reveal the expression profile of tRNA-derived fragments in breast cancer tissues in the study, and to explore their potential as biomarkers of breast cancer. Methods: We characterized the tRNA-derived fragments expression profile from 6 paired clinical breast cancer tissues and adjacent normal samples. Then we selected 6 significantly expressed tRNAderived fragments and screened the genes for validation by using Quantitative Real-time PCR. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes biological pathway were finally analyzed. Results: We found 30 differentially expressed tRNA-derived fragments across our dataset, out of which 17 were up-regulated, and 13 were down-regulated. Compared with 16 clinical breast cancer tissues and adjacent normal tissues by qPCR, the results demonstrated that tRF-32-Q99P9P9NH57SJ (FC = -2.6476, p = 0.0189), tRF-17-79MP9PP (FC = -4.8984, p = 0.0276) and tRF-32- XSXMSL73VL4YK (FC = 6.5781, p = 0.0226) were significantly expressed in breast cancer tissues (p < 0.001). tRF-32-XSXMSL73VL4YK was significantly up-regulated, and tRF-32- Q99P9P9NH57SJ and tRF-17-79MP9PP were significantly down-regulated in which the expression patterns were similar to the sequencing results. The top ten significant results of GO and KEGG pathways enrichment analysis were presented. Conclusion: Our studies have demonstrated that there were significantly expressed tRNA-derived fragments in breast cancer tissues. They are hopefully to become biomarkers and would be valuable researches in this area.

Recent studies have shown that expression of metastasis-associated in colon cancer-1(MACC1) is observed in different types of cancer and plays an important role in tumor metastasis. However, the expression of MACC1 and its possible role in esophageal cancer remains unknown. In this study, we determined the expression of MACC1 in esophageal cancer by utilizing immunohistochemistry and analyzed the relationship between the expression and esophageal cancer prognosis. Immunohistochemistry results showed that 47 of 85 cancer lesions (55.2 %) were stained positive, and high expression of MACC1 was correlated with the node metastasis and TNM stage (P < 0.05). The Kaplan-Meier survival curve showed that patients with high MACC1 expression had significantly reduced overall 5-year survival rates (P = 0.004). Cox regression analysis revealed that high expression of MACC1 was associated with increased risk of death (hazard ratio [HR] =2.25) in patients with esophageal cancer. These findings suggested that high expression of MACC1 was correlated with progression and metastasis of esophageal cancer and might serve as a novel prognostic marker for patients with esophageal cancer.