Epidermal growth factor receptor-regulated miR-125a-5p--a metastatic inhibitor of lung cancer - PubMed (original) (raw)

Epidermal growth factor receptor-regulated miR-125a-5p--a metastatic inhibitor of lung cancer

Guofu Wang et al. FEBS J. 2009 Oct.

Free PMC article

Abstract

Both the epidermal growth factor receptor signaling pathway and microRNA (miRNA) play an important role in lung cancer development and progression. To address the potential role of miRNA in epidermal growth factor receptor signaling, we identified miR-125a-5p as a downstream target, using an miRNA array. We further demonstrated that miR-125a-5p inhibited migration and invasion of lung cancer cells. Moreover, miR-125a-5p regulated the expression of several downstream genes of epidermal growth factor receptor signaling. Importantly, examination of lung cancer samples revealed a significant correlation of miR-125a-5p repression with lung carcinogenesis. Taken together, our results provide compelling evidence that miR-125a-5p, an epidermal growth factor-signaling-regulated miRNA, may function as a metastatic suppressor.

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Figures

Fig. 1

Gefitinib inhibited EGF-induced EGFR, ERK1/2 and Akt phosphorylation and reversed EGF-stimulated miRNA expression in lung cancer cells. (A) Western blot showed that, after EGF (20 ng·mL−1) stimulation, phosphorylation of EGFR, ERK1/2 and Akt occurred in PC9, A549 and H1299 lung cancer cells, and that this could be almost completely abolished by gefitinib at different concentrations. (B) After EGF stimulation, miRNA microarray analysis revealed that the expression of 39 miRNAs was significantly altered (P < 0.01). Among these, five miRNAs, let-7i, miR-24, miR-25, miR-29b, and miR-125a-5p, were further confirmed as EGFR-regulated miRNAs by gefitinib treatment. **P < 0.01 as compared with the serum-starved medium group. (C) Quantitative RT-PCR showed that the mir-125a-5p level was significantly reduced after EGF (20 ng·mL−1) stimulation in all three cell lines, and that this effect was reversed by gefitinib. The value for miR-125a-5p in the EGF group was set at 1, and the relative amounts of miR-125a-5p in the other groups were plotted as fold induction.

Fig. 2

Promotional effects of antisense miR-125a-5p on migration and invasion of PC9 cells. (A) Assay of migration and invasion of antisense miR-125a-5p across 8 μm porous membranes relative to negative control. (B) Confluent cell monolayers were wounded with a pipette tip. Wound closure was monitored by microscopy at the indicated times. Data are given as closed width/scratched width (%). (C) Representative photomicrographs of migration, invasion and wound-healing in PC9 cells were taken with a Nikon ECLIPSETS 100 microscope. **P < 0.001 and *P < 0.005, as compared with the negative control. Magnification: for migration and invasion, ×200; for wound-healing, ×100.

Fig. 3

Antisense miR-125a-5p facilitated the growth of PC9 cells and tube formation of ECV304 cells. (A) PC9 cells (5 × 103) cells were plated on 96-well plates. Forty-eight hours later, MTT was added to each well for 3 h at 37 °C, and then replaced by dimethylsulfoxide. Absorbance was read at 570 nmol·L−1. The data are presented as percentage of growth relative to the negative control. (B) ECV304 cells were cultured in a 12-well plate coated with ECM gel. Photographs of tube formation were taken using a Nikon ECLIPSETS 100 microscope (under ×200 magnification). (C) Total tube length was measured with

image analysis

software. **P < 0.001, and P < 0.005, as compared with the negative control.

References

1. Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics 2007. CA Cancer J Clin. 2007;57:43–66. - PubMed
1. Zhang S, Chen W, Kong L, Li L, Lu F, Li G, Meng J, Zhao P. An analysis of cancer incidence and mortality from 30 cancer registries in China, 1998–2002. Bull Chin Cancer. 2006;5:430–448.
1. Nesbitt JC, Putnam JB, Jr, Walsh GL, Roth JA, Mountain CF. Survival in early-stage non-small cell lung cancer. Ann Thorac Surg. 1995;60:466–472. - PubMed
1. Muller WJ, Sinn E, Pattengale PK, Wallace R, Leder P. Single-step induction of mammary adenocarcinoma in transgenic mice bearing the activated c-neu oncogene. Cell. 1988;54:105–115. - PubMed
1. Hermeking H. p53 enters the microRNA world. Cancer Cell. 2007;12:414–418. - PubMed

Epidermal growth factor receptor-regulated miR-125a-5p--a metastatic inhibitor of lung cancer - PubMed (original) (raw)