Whereas in AC the expression and amplification of EGFR were linked to AKT activation (P< or =0.050), in SCC its expression was correlated with pSTAT3 (P=0.024).
We therefore analyzed 102 large-cell carcinomas by immunohistochemistry for TTF-1 and ΔNp63/p40 as classifiers for adenocarcinoma and squamous cell carcinoma, respectively, and correlated the resulting subtypes with nine therapeutically relevant genetic alterations characteristic of adenocarcinoma (EGFR, KRAS, BRAF, MAP2K1/MEK1, NRAS, ERBB2/HER2 mutations and ALK rearrangements) or more common in squamous cell carcinoma (PIK3CA and AKT1 mutations).
We divided our OSCC patients into non-metastasizing (PNM) and metastasizing (PM) groups, and the expression of total AKT, pAKT1<sup>Thr308</sup>, pAKT<sup>Ser473</sup>, GSK3β, pGSK3β<sup>Ser9</sup>, and pmTOR<sup>Ser2448</sup> was analyzed by immunohistochemistry.
Tissue microarrays (TMAs) were used to evaluate pAKT(Ser473)/(Thr308), total protein kinase B (AKT)(pan) and phosphatase and tensin homolog (PTEN) expression in primary tumors and corresponding nodal disease in oropharyngeal SCC.
The screen of 95 biomarker-verified SQCCs revealed no EGFR/KRAS [0%; 95% confidence interval (CI), 0%-3.8%], four PIK3CA (4%; 95% CI, 1%-10%), and one AKT1 (1%; 95% CI, 0%-5.7%) mutations.
Specifically, we found that KRAS/LKB1-mutant lung adenocarcinomas responded strongly to phenformin + MLN0128 treatment, but the response of SCCs to single or combined treatment with MLN0128 was more attenuated due to acquired resistance to mTOR inhibition through modulation of the AKT-GSK signaling axis.
Our data suggest that the PI3K/AKT pathway is related to cell survival and proliferation in oral squamous cell carcinoma through its interaction with Bcl-2 family members.<br />.
Moreover, since the PI3K/AKT/mTOR pathway is considered to be a promising target for anticancer therapy, we discuss clinical implications for the treatment of HPV-positive cervical and head and neck squamous cell carcinomas.
Moreover, blocking the whole PI3K-AKT-mTOR pathway with the PI3K/mTOR dual inhibitor BEZ235 also showed efficacy in treating this subtype of lung SqCC.
Liposome-encapsulated curcumin suppresses growth of head and neck squamous cell carcinoma in vitro and in xenografts through the inhibition of nuclear factor kappaB by an AKT-independent pathway.
Increased expression of lncRNA CASC9 promotes tumor progression by suppressing autophagy-mediated cell apoptosis via the AKT/mTOR pathway in oral squamous cell carcinoma.
In sum, our data provide compelling evidence that miR-194 functions as a potential tumor suppressor by inhibiting the PI3K/AKT/FoxO3a signaling pathway and might sever as a potential therapeutic target for OSCC patients.
In conclusion, our date indicate 1) epigenetic regulation is associated with <i>CSTA</i> gene silencing; 2) CSTA exerts tumor suppressive function through inhibiting MAPK and AKT pathways; 3) Overexpression of CSTA leads to MET and prevents TGF-β1-induced EMT by modulating the MAPK pathway; 4) CSTA may be a potential biomarker for lung SCC and tumor differentiation.
Expression of total Akt, Akt2 and Akt3 were frequently observed in small cell carcinoma, but phosphorylated Akt and Akt1 were more frequently observed in squamous cell carcinoma.