Figure 4.

RARα expression is inversely related to the levels of E2F1 in osteosarcoma tissues and cells. (A) Correlation analysis of E2F1 with RARα in osteosarcoma tumor tissues. The immunoreactivities of E2F1 and RARα in osteosarcoma tumor tissues were illustrated (left) and the analyzed results as presented (right). (B) Inverse correlation between E2F1 and RARα expression levels in primary osteosarcoma cultures. The protein levels of E2F1 and RARα in primary osteosarcoma cultures were determined. (C) E2F1 inversely regulates RARα. U2OS cells were transfected with E2F1 plasmid (left) or E2F1 siRNA (right) along with corresponding control groups, and the protein levels of RARα and E2F1 were detected.