Clinical significance and diagnostic value of QPCT, SCEL and TNFRSF12A in papillary thyroid cancer

To identify specific novel genes that could be used as diagnostic and prognostic factors in papillary thyroid carcinoma (PTC). Screening of differential genes by RNA sequencing (RNA-Seq) in normal thyroid, Hashimoto's thyroiditis, PTC combined with Hashimoto's thyroiditis and PTC tissues. The genes QPCT, SCEL and TNFRSF12A were selected by qRT-PCR and immunohistochemical pre-experiments. The GEPIA2 database, qRT-PCR, and immunohistochemical studies were used to confirm the target genes QPCT, SCEL, and TNFRSF12A. ROC curves were used to assess the diagnostic usefulness of these 3 genes for PTC in more detail. Functional enrichment analysis showed that QPCT, SCEL and TNFRSF12A were enriched in the pathways for peptidyl-pyroglutamic acid biosynthesis, keratinocyte differentiation, WNT signaling, apoptosis. GEPIA2 database analysis revealed that QPCT, SCEL and TNFRSF12A were high in thyroid cancer, and TC patients with lower TNFRSF12A levels had short survival. QPCT, SCEL and TNFRSF12A were elevated in PTC and thyroid adenoma. The mRNA diagnostic values were as follows: for QPCT, AUROC = 0.891, 95% CI, 0.835–0.947; for SCEL, AUROC = 0.921, 95% CI, 0.869–0.974; for TNFRSF12A, AUROC = 0.884, 95% CI, 0.809–0.958. Immunohistochemical results showed that QPCT, SCEL, and TNFRSF12A differed to varying degrees between subgroups of thyroid tissue. SCEL was associated with BRAF V600E mutation status and stratification of recurrence risk, while TNFRSF12A was associated with Cyclin D1. The protein diagnostic values were as follows: for QPCT, AUROC = 0.752, 95% CI, 0.685–0.819; for SCEL, AUROC = 0.715, 95% CI, 0.645–0.784; for TNFRSF12A, AUROC = 0.660, 95% CI, 0.587–0.734. QPCT, SCEL and TNFRSF12A are expected to be diagnostic markers for PTC.