Fig. 7.

DDX3X and metastasis. a In HNSCC, DDX3X cooperates with the CBC-eIF3 complex to enhance the translation of ATF4 mRNA. Increased ATF4 expression results in upregulated expression of ACTA2, CDH2 (N-cadherin), FAP, SNAI2 (Slug), and VIM (vimentin) and downregulated expression of CHD1 (E-cadherin), thus triggering EMT. b DDX3X interacts with SP1 to promote MDM2 transcription. In E6-positive lung cancer, P53 inactivation leads to downregulation of DDX3X expression, which suppresses MDM2 expression. MDM2 promotes E-cadherin expression by mediating proteasomal degradation of Slug. Therefore, loss of DDX3X downregulates MDM2 expression, stabilizes Slug and suppresses E-cadherin expression, which eventually promotes tumour metastasis