Characterization of AKT Somatic Mutations in Chinese Breast Cancer Patients

Crosstalk between circRNAs and the PI3K/AKT signaling pathway in cancer progression

Circular RNAs (circRNAs), covalently closed noncoding RNAs, are widely expressed in eukaryotes and viruses. They can function by regulating target gene expression, linear RNA transcription and protein generation. The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays key roles in many biological and cellular processes, such as cell proliferation, growth, invasion, migration, and angiogenesis. It also plays a pivotal role in cancer progression. Emerging data suggest that the circRNA/PI3K/AKT axis modulates the expression of cancer-associated genes and thus regulates tumor progression. Aberrant regulation of the expression of circRNAs in the circRNA/PI3K/AKT axis is significantly associated with clinicopathological characteristics and plays an important role in the regulation of biological functions. In this review, we summarized the expression and biological functions of PI3K-AKT-related circRNAs in vitro and in vivo and assessed their associations with clinicopathological characteristics. We also further discussed the important role of circRNAs in the diagnosis, prognostication, and treatment of cancers.

Hotspot mutation profiles of AKT1 in Asian women with breast and endometrial cancers

BACKGROUND

The V-Akt murine thymoma viral oncogene (AKT) 1 (E17K) is a subfamily of serine/threonine protein kinases that affects the survival, proliferation, and invasion of cancer cells. The clinicopathological features and frequencies in Asian populations with AKT1 mutations in breast and endometrial cancers are unclear. Hence, we aimed to determine the frequencies and relationships between clinicopathological features and AKT1 mutations in Asian women with cancer.

METHODS

We extracted DNA from 311 and 143 samples derived from patients with breast and endometrial cancers to detect the AKT1 point mutation (hotspot), E17K. We examined correlations between clinicopathological features and AKT1 mutation status.

RESULTS

The frequency of AKT1 mutations in breast cancer was 7.4%, and they were found more frequently in human epidermal growth factor receptor 2 (HER2)-negative breast cancer subtypes, although this was not statistically significant (P = 0.08). The frequency of AKT1 mutations in endometrial cancer was 4.1%, and the mutations were histologically detected only in endometrioid types. However, AKT1 mutations did not correlate with relapse-free or overall survival of patients with breast or endometrial cancer.

CONCLUSIONS

AKT1 mutations are associated with HER2-negative subtype in breast cancer and in endometrial cancer with endometrioid histology. The frequencies of AKT1 mutations in breast and endometrial cancers were similar between Asian and other regional women. The frequency of mutations is too low in both tumor types to talk about predictive significance.

Targeting Akt in cancer for precision therapy

Biomarkers-guided precision therapeutics has revolutionized the clinical development and administration of molecular-targeted anticancer agents. Tailored precision cancer therapy exhibits better response rate compared to unselective treatment. Protein kinases have critical roles in cell signaling, metabolism, proliferation, survival and migration. Aberrant activation of protein kinases is critical for tumor growth and progression. Hence, protein kinases are key targets for molecular targeted cancer therapy. The serine/threonine kinase Akt is frequently activated in various types of cancer. Activation of Akt promotes tumor progression and drug resistance. Since the first Akt inhibitor was reported in 2000, many Akt inhibitors have been developed and evaluated in either early or late stage of clinical trials, which take advantage of liquid biopsy and genomic or molecular profiling to realize personalized cancer therapy. Two inhibitors, capivasertib and ipatasertib, are being tested in phase III clinical trials for cancer therapy. Here, we highlight recent progress of Akt signaling pathway, review the up-to-date data from clinical studies of Akt inhibitors and discuss the potential biomarkers that may help personalized treatment of cancer with Akt inhibitors. In addition, we also discuss how Akt may confer the vulnerability of cancer cells to some kinds of anticancer agents.