We observe that uPA interacts directly with transcription factors LIM homeobox-2 (Lhx2), homeobox transcription factor A5 (HOXA5), and Hey to possibly promote cancer stemness. uPA regulates Lhx2 expression by suppressing expression of miR-124 and p53 expression by repressing its promoter by inactivating HOXA5.
Furthermore, we discovered that Lhx2 promoted cancer cell proliferation in vitro/vivo and elevated β-catenin levels correlated with Lhx2 expression in PDA while the Lhx2 simulated β-catenin activation was required for LMO1's oncogenic effects.
In addition, examination of transcriptome and DNA methylation databases indicated that methylation at three non-promoter regions (far-upstream EN1 and PITX2 and intronic LHX2) was associated with higher gene expression, unlike the inverse associations between cancer DNA hypermethylation and cancer-altered gene expression usually reported.
In this study, we confirm that LHX2 is up-regulated in osteosarcoma, and that its silencing inhibits OS malignancy and induces autophagy via mTOR signaling.