Table 1.

Selection of 18 circRNAs involved in cancer-related and/or epithelial polarity pathways for RT-qPCR validation.

(a) Ten up-regulated (of 75 significantly up-regulated) and eight down-regulated (of 46 significantly down-regulated) circRNAs in Cx43-KO-S1 as compared to S1 cells were chosen for further validation based on whether the genes from which they originate were involved in cancer-related and/or epithelial polarity pathways. (b) The three isoforms of circRNAs that originate from Cx43 (GJA1) mRNAs were also chosen due to their relevance to the 3D risk-progression culture model. One Cx43 circRNA isoform, hsa_circ_0077754, was not detected by the microarray due to its short size of 93 bp, since library size-selections usually excludes circRNAs < 200 nt long⁵⁸. Alias represents the circRNAs probe name as annotated by CircBAse⁵⁹. Gene Symbol denotes the gene of the transcript from which this circRNAs originate. Primers were designed using CircularRNA Interactome in silico tool⁶⁰ and purchased from Eurofins (Canada). The circRNA fragment size represents the size of the resulting amplified PCR fragment. The circRNAs highlighted in red font were significantly dysregulated in Cx43-KO-S1 as compared to S1 cells in 3D, as validated through RT-qPCR (shown in Fig. 4).