Suppression of Elk1 inhibits thyroid cancer progression by mediating PTEN expression.

ETS‑domain containing protein (Elk1) is reported to be a member of the ETS oncogene family, and promotes tumorigenesis in cancer such as bladder, prostate and ovarian. Nevertheless, the role of Elk1 in thyroid cancer progression remains unclear. In the present study, we aimed to investigate the role and underlying molecular mechanism of Elk1 in thyroid cancer. The results indicated that Elk1 was significantly upregulated in thyroid cancer tissues and cells. We found that loss of Elk1 function obviously induced the expression of early growth response‑1 (Egr‑1) and PTEN, promoted apoptosis and constrained the proliferation of thyroid cancer cells. Furthermore, Egr‑1 inhibition obviously abrogated the induction of PTEN induced by Elk1 reduction. Moreover, Egr‑1 suppression prevented the promotion of apoptosis and the inhibition of cell proliferation caused by Elk1 reduction. In conclusion, Elk1 inhibition induced thyroid cancer cell apoptosis and restrained their proliferation by regulating Egr‑1/PTEN, indicating a potential role for Elk1 in thyroid cancer treatment.