The present study aimed to determine whether actinomycin X2 (AX2) intercepted the mTOR/PTEN/PI3K/Akt signaling pathway to inhibit human prostate cancer cells (PC-3) in vitro. The effects of AX2 on mTOR, PTEN, PI3K, and Akt at the protein level and mRNA were determined by western blotting and real-time reverse transcription-PCR (RT-PCR), respectively. Concurrently, the effects of AX2 on expression levels of MiRNA144 and MiRNA126 in PC-3 were measured by real-time RT-PCR. The association of MiRNA144 with 3′-UTR of mTOR was identified using the Dual-Luciferase Reporter Gene System. The direct effect of MIRNA144 on the mTOR/PTEN/PI3K/Akt pathway was determined by real-time RT-PCR and western blotting. Apoptosis of PC-3 cells induced by AX2 was determined by MTT and flow cytometry. The results indicated that mTOR/PTEN/PI3K/Akt were decreased and PTEN was increased by AX (1, 10 µmol/l) at protein and mRNA levels in a dose-dependent manner. MiRNA144 was decreased, whereas MiRNA126 was increased by AX2. MiRNA144 associated with 3′-UTR of mTOR was corroborated. Overexpression of MiRNA144 decreased mTOR, but did not affect PTEN, PI3K, or Akt. The proliferation rates of AX2 on PC-3 cells were decreased. It suggests that AX2 induces apoptosis of PC-3 cells via meddling in the mTOR/PTEN/PI3K/Akt signaling pathway, but those effects are compounded by MiRNA144. Both AX2 and MiRNA144 intercept the signaling in different ways but cross on mTOR.