Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/ AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

The fact that the phosphatidylinositol 3 kinase (PI3K) signaling pathway is one of the most frequently deregulated signaling networks has triggered intensive efforts in the development of PI3K pathway inhibitors. However, recent clinical trial data have shown only limited activity of PI3K inhibitors at tolerated doses. Thus, there is an urgent need to identify rational combination therapy to improve the efficacy of PI3K-targeted cancer treatment. In this study, we investigated if dietary compound ellagic acid (EA) could improve the therapeutic efficacy of PI3K inhibitor GDC-0941 in breast cancer. Specifically, using a panel of breast cancer cell lines, we showed that combined use of EA and GDC-0941 significantly inhibited cell growth under attached and detached conditions, blocked migration and invasion in vitro as well as tumor initiation and metastasis in vivo. Furthermore, we found that EA promoted apoptosis and further reduced AKT/mTOR activation in GDC-0941- treated breast cancer cells. Together, our data suggest that EA may be a safe and effective agent to boost the efficacy of PI3K-directed breast cancer therapy and that such drug combination may merit further clinical investigation.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Imatinib mesylate was considered to be a breakthrough drug in clinical treatment of GIST, but GIST patients showed resistance against it. We aimed to identify critical microRNAs (miRNAs) related to imatinib resistance in imatinib-treated GIST patients. Microarray datasets under the accession number of GSE63159 and GSE45901 were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed miRNAs (DEMs) that are related to imatinib resistance were identified. GO function and KEGG pathway enrichment analyses were performed, and lncRNA-miRNA-target gene regulatory networks were constructed. Finally, the critical miRNAs and their target genes that are related to imatinib resistance or sensitivity were identified. In total, 20 DEMs in the GSE63159 dataset (7 significantly up-regulated and 13 down-regulated) and 23 DEMs in the GSE45901 dataset (8 up-regulated and 15 down-regulated) were identified. In lncRNA-miRNA-target gene regulatory networks, five critical miRNAs and 109 target genes were identified. GO function and KEGG pathway enrichment analysis showed that the target genes of DEMs were mainly involved in several signaling pathways, such as focal adhesion and the GnRH signaling pathway. Among the five miRNAs, the overexpression of hsa-miR-28-5p and hsa-miR-125a-5p had significant correlation to imatinib resistance or imatinib sensitivity in GIST patients. Hsa-miR-28-5p and hsa-miR-125a-5p may be involved in the development and progression of GIST, and they may be able to serve as prognostic markers for imatinib-response in GIST patients.

Given that 3-phosphoinositide-dependent kinase 1 (PDK1) plays a crucial role in the malignant biological behaviors of a wide range of cancers, we review the influence of PDK1 in breast cancer (BC). First, we describe the power of PDK1 in cellular behaviors and characterize the interaction networks of PDK1. Then, we establish the roles of PDK1 in carcinogenesis, growth and survival, metastasis, and chemoresistance in BC cells. More importantly, we sort the current preclinical or clinical trials of PDK1-targeted therapy in BC and find that, even though no selective PDK1 inhibitor is currently available for BC therapy, the combination trials of PDK1-targeted therapy and other agents have provided some benefit. Thus, there is increasing anticipation that PDK1-targeted therapy will have its space in future therapeutic approaches related to BC, and we hope the novel approaches of targeted therapy will be conducive to ameliorating the dismal prognosis of BC patients.

Given that 3-Phosphoinositide-dependent kinase 1 (PDK1) plays a crucial role in malignant biological behaviors of a wide-range of cancers, we further review the influence of PDK1 in breast cancer (BC). First, we describe the power of PDK1 in cellular behaviors and extensively demonstrate the interacting networks of PDK1 via PI3K-dependent/ PI3K-independent pathway. Then we enlighten the roles of PDK1 in carcinogenesis, growth and survival, metastasis, and chemoresistance in BC cells. More important, we sort the current preclinical or clinical trials of PDK1 targeted therapy in BC and find that even though at present no selective PDK1 inhibitor is available for BC therapy, but the combination trials of PDK1 targeted therapy and other agents have demonstrated some benefit. Thus, there is increasing anticipations that PDK1 targeted therapy will have its space in future therapeutic concepts of BC, and we hope to feature PDK1 in BC to the clinic and bring the new promising to patients for targeted therapies.