Abstract
Abnormal expression of Aurora-A and epidermal growth factor receptor (EGFR) is observed in different kinds of cancer and associated with poor prognosis in cancer patients. However, the relationship between Aurora-A and EGFR in tumour development was not clear. In previous reports, we found that EGFR translocates to nucleus to activate Aurora-A expression after EGF treatment in EGFR-overexpressed cells. However, we also observed that not all the EGFR-overexpressed cells have the nuclear EGFR pathway to mediate the Aurora-A expression. In this study, we demonstrated that EGF signalling increased the Aurora-A protein expression in EGFR-overexpressed colorectal cancer cell lines via increasing the translational efficiency. In addition, the overexpression of EGFR was also associated with higher expression of Aurora-A in clinical colorectal samples. Activation of the PI3K/Akt/mTOR and MEK/ERK pathways mediated the effect of EGF-induced translational up-regulation. Besides, only the splicing variants containing exon 2 of Aurora-A mRNA showed increased interaction with the translational complex to synthesize Aurora-A protein under EGF stimulus. Besides, the exon 2 containing splicing variants were the major Aurora-A splicing forms expressed in human colorectal cancers. Taken together, our results propose a novel regulatory mechanism for the abnormal expression of Aurora-A in EGFR-overexpressed cancers, and highlight the importance of alternative 5'-UTR splicing variants in regulating Aurora-A expression. Furthermore, the specific expression of exon 2 containing splicing variants in cancer tissues may serve as a potential target for cancer therapy in the future.
Original language | English |
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Pages (from-to) | 1520-1531 |
Number of pages | 12 |
Journal | Journal of Cellular and Molecular Medicine |
Volume | 14 |
Issue number | 6 B |
DOIs | |
Publication status | Published - Jun 2010 |
Keywords
- 5'UTR
- Alternative splicing
- Aurora-A
- Colorectal cancer
- EGF
- Translation
ASJC Scopus subject areas
- Molecular Medicine
- Cell Biology