Targeted regulation of PI3K/Akt/mTOR/NF-κB signaling by indole compounds and their derivatives: mechanistic details and biological implications for cancer therapy

Abstract

Indole compounds, found in cruciferous vegetables, are potent anti-cancer agents. Studies with indole-3-carbinol (I3C) and its dimeric product, 3,3'-diindolylmethane (DIM) suggest that these compounds have the ability to deregulate multiple cellular signaling pathways, including PI3K/Akt/mTOR signaling pathway. These natural compounds are also effective modulators of downstream transcription factor NF-κB signaling which might help explain their ability to inhibit invasion and angiogenesis, and the reversal of epithelial-to-mesenchymal transition (EMT) phenotype and drug resistance. Signaling through PI3K/Akt/mTOR and NF-κB pathway is increasingly being realized to play important role in EMT through the regulation of novel miRNAs which further validates the importance of this signaling network and its regulations by indole compounds. Here we will review the available literature on the modulation of PI3K/Akt/mTOR/NF-κB signaling by both parental I3C and DIM, as well as their analogs/derivatives, in an attempt to catalog their anticancer activity.

Fig. (1)

Structures of glucobrassicin, I3C and DIM.

Fig. (2)

Structures of I3C analogues with AKT-modulatory activity.

Fig. (3)

Structures of indole derivatives with AKT/mTOR-modulatory activity.

Fig. (4)

Structures of DIM analogues with AKT/mTOR-modulatory activity.

Fig. (5)

Structures of heterocycle-connected indole derivatives with AKT/mTOR-modulatory activity.

Fig. (6)

Schematic representation of inhibition of PI3K/Akt/mTOR/NF-κB signaling by indole compounds I3C and DIM.