Inclusion of hnRNP L Alternative Exon 7 Is Associated with Good Prognosis and Inhibited by Oncogene SRSF3 in Head and Neck Squamous Cell Carcinoma

Figure 3

SRSF3 inhibits the inclusion of hnRNP L exon 7. (a) HEK 293, CAL 27, or SCC-9 cells were transfected by SRSF3 expression or vector control plasmid. The alternative splicing of exon 7 was analyzed by RT-PCR. The L/S ratio represents the ratio of exon 7 inclusion versus exclusion isoform. (b) The histogram summarized the effects of SRSF3 overexpression on the alternative splicing of hnRNP L exon 7 in HEK 293, CAL 27, and SCC-9 cells. Data are the means ± SD, n = 3. (c) Knockdown of SRSF3 promotes the inclusion of hnRNP L exon 7 in HEK 293, CAL 27, and SCC-9 cells. Cells were transfected with anti-SRSF3 siRNA (si#1 or si#2) or nonspecific control siRNA (NC). The alternative splicing of exon 7 was analyzed by RT-PCR. : , : . (d) The histogram summarized the effects of SRSF3 knockdown on the alternative splicing of hnRNP L exon 7 in HEK 293, CAL 27, and SCC-9 cells. Data are the means ± SD, n = 3. (e-f) The overexpression of T7-tagged SRSF3 (e) or knockdown efficiency of SRSF3 (f) was confirmed by Western blot. The expression of hnRNP L full-length protein was also analyzed by Western blot. “Relative hnRNP L” represents the relative expression level of hnRNP L normalized by β-actin and controls.

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