Have Tumor Suppressor PDCD4 and its Counteragent Oncogenic miR-21 Gone Rogue?

TLR4 signaling: The MyD88-dependent pathway through PDCD4. LPS activates TLR4 and stimulates activation of the MyD88-dependent early-phase activation of NF-κB, which leads to an increase in miR-21 expression. miR-21 inhibits PDCD4 expression via translational regulation. PDCD4 regulates IL-10 expression by post-transcriptional regulation, possibly by inhibiting translation. PDCD4 appears to positively regulate NF-κB activity and consequent IL-6 expression.