Figure 4.

Schematic of the dysregulated LIN28/let-7 axis in malignant germ cell tumours (GCT)s. Let-7 down-regulation in malignant GCTs is attributable to abundant LIN28 expression (Murray et al., ²⁰¹³). In turn, this leads to over-expression of let-7 targets (e.g. MYCN) and increased cellular proliferation. Loss of direct negative feedback from let-7 maintains high LIN28 levels and let-7 repression. Other contributions to abundant LIN28 expression include other microRNAs that bind to the 3′UTR of LIN28 transcripts, but which are down-regulated in malignant GCTs (Palmer et al., ²⁰¹⁰). Taken together, these findings highlight the LIN28/let-7 axis as a novel therapeutic target in malignant GCTs.