Fig 2: Regulatory mechanism: LINC00894 was downregulated in thyroid cancer tissues and inhibited cancer cell proliferation, migration, and invasion by acting as a sponge of let-7e-5p to regulate TIA-1 expression. LINC00984 and the 3'-UTR of TIA-1 have a ceRNA regulatory relationship by binding the same miRNA, let-7e-5p. In cell homeostasis, the let-7e-5p bound by LINC00984 and those bound by the 3'-UTR of TIA-1 are balanced. In thyroid cancer. Upon reduced LINC00984 expression, low let-7e-5p bind to LINC00894, resulting in more let-7e-5p bound to TIA-1 3'-UTR and decreased TIA-1 expression; Upon increased LINC00984 expression, more let-7e-5p bind to LINC00894, resulting in fewer let-7e-5p bound to TIA-1 3’-UTR and increased TIA-1 expression

Fig 3: TIA-1 is the gene target of let-7e-5p. A Potential target genes bound by let-7e-5p were identified using starBase 3.0, TargetScan 8.0, and GEPIA2. B TIA-1 expression in thyroid cancer tissues (n = 512) include follicular thyroid cancer (n = 106), papillary thyroid cancer (n = 397), and other thyroid cancer (n = 9) and normal tissues (n = 712) was investigated. C The prognostic value of TIA-1 in thyroid cancer was analyzed using Kaplan–Meier plotter. D The binding sites between let-7e-5p and the 3'-UTR of TIA-1 are shown. E The binding between let-7e-5p and the 3'-UTR of TIA-1 was determined using a luciferase assay. F TIA-1 expression in CAL-62 and TPC-1 cells was analyzed by western blotting 24 h after transfection. *p < 0.05

Fig 4: Increase genome instability and cell dead in the absence of TIA1 and TIAL1(A) Comet assay for analysis of double-strand DNA breaks in pro-B cells. Cells were FACS sorted prior to DNA staining with EtBr. Comet score of each cell is quantified. Data from one of the two independent experiments performed with n = 2 mice/genotype. Each point is data from one cell. Scale bar, 100 µm.(B) Analysis of pSer139-H2A.X in B cell progenitors from control and double Tia1 Tial1 cKO mice. MFI is shown corrected by an isotype antibody. From one of four independent experiments (n = 3–7 mice/genotype and experiment).(C) p53 protein expression in cells shown in (B).(D) Cell-cycle analysis in pro-B cells from control and double Tia1 Tial1 cKO mice. Representative dot plots showing EdU incorporation and DAPI staining and the percentage of cells in each phase is shown. Quantitation from two independent experiments performed with n = 3–5 mice/genotype.(E) FACS plots showing caspase activation and cell viability of B cell progenitors in control and double Tia1 Tial1 cKO mice. From one of three independent experiments performed with at least n = 4 mice/genotype.(F) Percentage of dead cells in (E).Mann-Whitney tests in (A)–(F). In (B)–(F), each point is data from one mouse. See also Figure S6.

Fig 5: TIA1 and TIAL1 are required for the expression of DNA damage genes(A) Heatmap showing the expression of AS and DE DNA damage genes in control and double Tia1 Tial1 cKO pro-B cells. In back, TIAL1 targets.(B) TIAL1 crosslink sites annotated within the exon-intron junctions of DNA damage genes.(C) Alternative splicing of Chk2 exon 5 visualized as a sashimi plot. TIAL1 crosslink sites are shown. The left scale indicates the number of unique TIAL1 iCLIP cDNA counts detected or annotated RNA-seq reads in Chk2 exons.(D) Xrcc5, Xrcc6, Atm, Chek1, Chek2, Trp53, Trp53bp1, and Rif1a mRNA expression in pro-B cells from control and double Tia1 Tial1 cKO mice (mRNAseq data generated with n = 4 samples/genoptype, adjusted p values are calculated with DESeq2 using BH correction).(E) Representative FACS histograms showing protein expression of CHK2, ATM, Ku70, and Ku80. Bottom, MFI of CHK2, ATM, Ku70, and Ku80 corrected by the MFI of an isotype antibody control. Data shown relative to the expression in control pro-B cells. Data from three independent experiments performed each with n = 3–4 mice/genotype. Each point is data from one mouse. Two-tailed unpaired t test.See also Figure S5.