Advances in the Understanding of Akt Signaling in Cancers and the Potential of Inhibiting Akt-Driven Tumors Using Small Molecule Inhibitors: An Overview

The phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway is a central regulator of cellular metabolism, survival, and proliferation and is frequently dysregulated in cancer. Since the identification of protein kinase B (Akt) in 1996, extensive research has established its critical role in tumor initiation, progression, and therapeutic resistance, making Akt an attractive target for anticancer drug development. Although numerous inhibitors targeting the PI3K/Akt pathway have been developed, their clinical success has been limited due to inadequate isoform specificity and unfavorable toxicity profiles. These limitations have prompted increasing interest in identifying Akt-selective inhibitors from natural sources, particularly microbial metabolites. Recent in vitro and in vivo studies demonstrate that several microbial-derived compounds effectively modulate PI3K/Akt signaling and suppress key cancer hallmarks, including proliferation, angiogenesis, and metastatic potential. Nevertheless, further studies are required to define Akt isoform specificity, evaluate selectivity against closely related kinases, and validate therapeutic efficacy in relevant preclinical models, including patient-derived xenografts. In addition, the development of robust purification and optimization strategies remains essential to enable the reliable isolation and translational advancement of these bioactive metabolites. This review summarizes Akt structure, function, and key regulatory motifs relevant to pharmacological targeting and critically examines microbial-derived inhibitors of the PI3K/Akt pathway and their mechanisms of action. Representative compounds discussed include Bostrycin, Anthracycline analogs, Wentilactone A, Thiocoraline, Iturin A, SZ-685C, Isebromoamide B, Xyloketal B, and Demethoxyfumitremorgin C. Collectively, this review highlights the therapeutic potential of microbial natural products while outlining current challenges and future directions for developing selective Akt-targeted anticancer therapies.