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 1

The inclusion of hnRNP L exon 7 in head and neck cancer is significantly changed. (a) Schematic diagram of the alternative splicing of hnRNP L exon 7. Human hnRNP L pre-mRNA has an alternative exon 7, which contains an in-frame stop codon. Exon 7-included transcripts are degraded by NMD or encode truncated hnRNP L protein. Exon 7-excluded transcripts can encode full-length hnRNP L. hnRNP L can promote the inclusion of exon 7 and autoregulate its expression. Boxes and lines represent exons or introns in the pre-mRNA, respectively. Dashed lines above or below introns indicate RNA splicing direction. (b-e) The alternative splicing of hnRNP L exon 7 in the TCGA head and neck cancer patients. Normalized expression levels of exon 7-excluded or exon 7-included isoforms were obtained from an online program, TSVdb. (b) The ratios of hnRNP L exon 7 inclusion versus exclusion isoform were compared between normal (44 cases) and tumor (520 cases) tissues. (c) Kaplan-Meier curves of overall survival for patients with low ratio (84 cases) or high ratio (356 cases) of exon 7 inclusion versus exclusion isoform. Low ratio was defined as less than mean-0.8 SD (standard deviation). (d) The ratios of hnRNP L exon 7 exclusion versus inclusion isoform in stages I-II (101 cases), stage III (81 cases), or stage IV (265 cases). (e) Normalized total hnRNP L transcriptional levels were compared between normal and tumor tissues.

(a)

(b)

(c)

(d)

(e)