Fig. 4

Identification of the direct interaction between circMTCL1 and C1QBP protein in LSCC cells. a, Schematic diagram of binding manner for circMTCL1 and C1QBP. b, Co-localization of circMTCL1 with C1QBP protein detected by ISH and IF assays in TU212 and LCC cells. Scale bars = 5 μm. c, Bioinformatics online software predicting the specific binding sequence and sites of circMTCL1 secondary structure and C1QBP protein (http://www.tartaglialab.com/). d, The probe information of circMTCL1 in pull-down assay. e, RNA pull-down followed by Western blot was conducted to examine the direct interaction of the circMTCL1-WT, circMTCL1-Mut and antisense RNA probes with C1QBP protein after circMTCL1 knockdown in TU212 cells. f, RIP assay was performed to verify the combination of circMTCL1 and C1QBP in TU212 cell. g, ISH and IHC methods were used to determine the cell localization and expression levels of circMTCL1 and C1QBP in our included clinical LSCC tissues and matched adjacent-tumor controls (n = 140). Scale bars = 100 μm. h, Violin charts displaying the expression scores of circMTCL1 and C1QBP between LSCC tissues and matched paired adjacent normal tissues (n = 140). Nonparametric tests and median and 95%CIs were shown. i, Linear correlation pattern representing a positive association of circMTCL1 expression with C1QBP expression