Targeting mTOR and AREG with everolimus, sunitinib and sorafenib in HPV-positive and -negative SCC.

Head and neck squamous cell carcinoma (HNSCC) is an aggressive epithelial malignancy. It is the most common neoplasm appearing in the upper aerodigestive tract and the sixth most common cancer worldwide. The five-year survival rate remains poor despite advances in surgery, radiation and chemotherapy. Furthermore, the incidence of human papillomavirus (HPV)-associated oropharyngeal cancer is rising. Thus, innovative therapy approaches are imperative in order to improve the situation. Everolimus, an inhibitor of the mammalian target of rapamycin (mTOR) and sorafenib and sunitinib, multityrosine kinase inhibitors, have been notably effective in the therapy of different tumor entities. The modest side-effects and oral application of the drugs might improve patient compliance. Expression levels of mTOR and Amphiregulin (AREG) in p16-positive and -negative SCC (squamous cell carcinoma) and the effect of everolimus, sorafenib or sunitinib on the expression levels of these target proteins were assessed. As far as we are aware of, this is one of the first in vitro studies to evaluate the effect of these small-molecule drugs with regard to the p16 status of SCC cells. p16-negative HNSCC 11A and 14C cells and p16-positive CERV196 cells were exposed to different concentrations of everolimus, sorafenib and sunitinib for 2-8 days. Expression levels of mTOR and AREG were determined by enzyme-linked immunosorbent assay (ELISA) and compared against a chemonaïve control. AREG and mTOR were expressed in all tested cell lines. CERV196 displayed a remarkable increase of mTOR expression compared to p16-negative HNSCC. On the contrary, AREG levels were reduced by 50% in CERV196. Everolimus, sorafenib and sunitinib significantly reduced mTOR expression. Everolimus significantly decreased AREG expression independently of the HPV status. Sunitinib and sorafenib increased AREG expression in HNSCC 11A and 14C but not in CERV196. The applied drugs showed remarkable suppression of mTOR expression, which might delay tumor progression. Interestingly, sorafenib and sunitinib increased AREG in HNSCC 11A and 14C, which could be a possible evasive mechanism following incubation with these drugs. On the contrary, p16-positive CERV196 showed increased susceptibility to sorafenib and sunitinib concerning suppression of AREG expression. Further studies are required to evaluate the HPV-dependent differences of therapy response and the possible consequences for treatment options.

Aderhold C ，Faber A ，Umbreit C ，Birk R ，Weiss C ，Sommer JU ，Hörmann K ，Schultz JD ... -  《-》

Small molecules alter VEGFR and PTEN expression in HPV-positive and -negative SCC: new hope for targeted-therapy.

Prognosis for patients with head and neck squamous cell carcinoma (HNSCC) is poor in most cases and has not improved despite advances in therapy. Novel therapeutic approaches are mandatory in order to improve the situation. Everolimus, an inhibitor of mammalian target of rapamycin, as well as the multi-tyrosine kinase inhibitors sorafenib and sunitinib, has demonstrated a substantial therapeutic effect in various types of human cancer with moderate side-effects. Expression of vascular endothelial growth factor receptor (VEGFR) 1 and 2, and of the tumor-suppressor protein phosphatase and tensin homolog deleted on chromosome 10 (PTEN) were evaluated in chemonaïve human papillomavirus (HPV)-positive and -negative squamous cell carcinoma (SCC) and after exposure to everolimus, sorafenib or sunitinib. p16-positive CERV196 and p16-negative HNSCC 11A and 14C cells were incubated with different drug concentrations for 48-192 h. Expression of VEGFR1 and -2 as well as PTEN were determined by enzyme-linked immunosorbent assay and was compared to a chemonaïve control. VEGFR1 and -2, as well as PTEN, were expressed in all three cell lines. Sunitinib, sorafenib and everolimus significantly reduced the expression of VEGFR1 and -2, especially in p16-positive CERV196 cells. Sunitinib appeared to be more effective in reducing VEGFR1 and -2 expression than sorafenib and everolimus. PTEN levels were remarkably lower in HPV-positive CERV196 cells. PTEN expression increased significantly under sunitinib and sorafenib in HNSCC 11A and CERV196 cells. Everolimus, on the other hand, led to a significant decrease of PTEN expression in these cell lines. The tested drugs displayed a remarkable anti-angiogenic effect by inhibition of VEGFR1 and -2 expression. Sunitinib and sorafenib were able to increase PTEN expression, which might induce apoptosis of cancer cells. HPV-positive CERV196 cells were characterized by an increased susceptibility to these small-molecule drugs. Further studies are imperative to scrutinize HPV status-dependent differences in drug response and possible implications for future treatment options.

Aderhold C ，Faber A ，Umbreit C ，Chakraborty A ，Bockmayer A ，Birk R ，Sommer JU ，Hörmann K ，Schultz JD ... -  《-》

Small molecule-based chemotherapeutic approach in p16-positive and -negative HNSCC in vitro.

Aderhold C ，Faber A ，Grobschmidt GM ，Chakraborty A ，Bockmayer A ，Umbreit C ，Birk R ，Stern-Straeter J ，Hörmann K ，Schultz JD ... -  《-》

FGF Expression in HPV16-positive and -negative SCC After Treatment With Small-molecule Tyrosine Kinase Inhibitors and Everolimus.

Targeted therapies in the treatment of head and neck squamous cell carcinoma (HNSCC) are subject to extensive research. Different mutations of genes belonging to the fibroblast growth factor (FGF) family have been detected in HNSCC. In this study, we examined the expression of FGF1 and FGF2 after treatment with small-molecule tyrosine kinase inhibitors (TKIs) and an inhibitor of mechanistic target of rapamycin (mTOR) in vitro using human papillomavirus (HPV)-positive and -negative SCC lines. Cells of two human HPV-negative cell lines (UMSCC-11A/-14C) and one HPV-positive cell line (CERV196) were incubated with 20 μmol/l of erlotinib, gefitinib, nilotinib, dasatinib, or everolimus for 24-96 h. Cell proliferation was assessed by proliferation assay and the protein concentrations of FGF1 and FGF2 by sandwich enzyme-linked immunosorbent assay. For statistical analysis, the results were compared with those for untreated HPV-negative SCC cells. FGF1 and FGF2 were detected in all three tested cell lines. The tested TKIs significantly (p<0.05 reduced) FGF1 expression in the UMSCC-11A cell line within the first 24 h. At later time points, the tested TKIs and everolimus significantly (p<0.05) increased FGF1 and FGF2 expression in HPV-negative and -positive cancer cell lines. The effect was stronger in the HPV-positive cell line. Alterations in FGF signalling are considered to be relevant drivers of tumourigenesis in some HNSCCs. Our results show that the expression of FGF1 and -2 can be influenced effectively by small-molecule TKIs and everolimus. Based on our data, future research should include combinations of specific FGF inhibitors, mTOR inhibitors and other TKIs in the treatment of HNSCC and research on FGF-mediated drug escape mechanisms.

Huber L ，Birk R ，Knuettel M ，Rotter N ，Aderhold C ，Scherl C ，Lammert A ，Jungbauer F ，Kramer B ... -  《-》

Chemotherapeutic alteration of VEGF-/PDGF- and PDGF-Rα/β expression by imatinib in HPV-transformed squamous cell carcinoma compared to HPV-negative HNSCC in vitro.

Schultz JD ，Mühlheim K ，Erben P ，Hofheinz RD ，Faber A ，Thorn C ，Sommer JU ，Hörmann K ，Sauter A ... -  《-》