Correlation of SALL1 with CEUS Parameters and Immune Escape in Thyroid Carcinoma

Background: Contrast-enhanced ultrasonography (CEUS) is widely used to diagnose thyroid carcinoma (TC), though its accuracy in differentiating malignant nodules is limited. We identified TC-associated differentially expressed genes (DEGs) and examined the impact of these genes, particularly SALL1, on immune escape mechanisms within TC cells.

Methods and materials: DEG analysis was conducted on GSE65144 dataset to identify genes associated with TC. Functional enrichment analysis focused on genes related to pituitary function, with SALL1 identified as a key candidate. Clinical data from TC cases were used to assess the diagnostic impact of combining SALL1 expression with CEUS parameters. Additionally, TCP-1 cell lines with manipulated SALL1 expression were used to investigate cellular behaviors in vitro, while in vivo studies in nude mice evaluated tumor growth and immune microenvironment changes linked to SALL1 expression.

Results: We identified 152 DEGs, including NKX2-1, CDH1, and SALL1, which are associated with pituitary function. TIMER database analysis revealed SALL1's correlation with immune cell infiltration in TC. Clinically, SALL1 was downregulated in TC and showed a significant correlation with CEUS parameters, and combining SALL1 expression with CEUS markedly enhanced diagnostic accuracy for TC. In vitro, low SALL1 expression increased cell proliferation, TC progression, and immune escape, whereas upregulation led to reduced cell activity, increased apoptosis, and activation of autophagy and pyroptosis. In vivo, nude mouse models demonstrated that silencing SALL1 enhanced tumor growth, while overexpression inhibited tumor progression and modulated immune microenvironment.

Conclusions: Combining SALL1 with CEUS improves TC diagnostic accuracy, highlighting SALL1 as a potential biomarker in TC.