Targeted therapy in head and neck cancer. Tumour Biol. 2012;33:707-721. [PMID: 22373581 DOI: 10.1007/s13277-012-0350-2]

Synergistic effect of cannabidiol with dasatinib on lung cancer by SRC/PI3K/AKT signal pathway

Dasatinib-related resistance frequently occurs and may lead to the failure of chemotherapy; thus, dose interruptions are necessary. Cannabidiol (CBD) has potential for integration with orthodox cancer care. In this study, we explored the combination effect of CBD and dasatinib on A549 cells. CBD in combination with dasatinib could induce significant synergistic apoptosis in vitro (ZIP > 10) and in vivo. The combination of CBD and low-dose dasatinib exhibited antiproliferative and proapoptotic effects through up-regulation of caspase-3 and Bax, and down-regulation of Bcl-2 in A549 cells. The xenograft mouse model suggested that the combination was more efficient and safer. In short, CBD and low-dose dasatinib exhibited a synergistic effect on anticancer by targeting the SRC/PI3K/AKT signaling pathway, suggesting a potential therapeutic option for the treatment of lung cancer.

Uncovering the role of aquaporin and chromobox family members as potential biomarkers in head and neck squamous cell carcinoma via integrative multiomics and in silico approach

Head and neck squamous cell carcinoma (HNSC) is a diverse group of tumors arising from oral cavity, oropharynx, larynx, and hypopharynx squamous epithelium, posing significant morbidity. Aquaporins (AQPs) are membrane proteins forming water channels, some associated with carcinomas. Chromobox (CBX) family is known to modulate physiological and oncological processes. In our study, we analyzed AQPs and CBXs having significant expression followed by their prognostic and mutational assessment. Next, we performed enrichment and tumor infiltration analysis followed by HPA validation. Lastly, we established a 3-node miRNA-TF-mRNA regulatory network and performed protein-protein docking of the highest-degree subnetwork motif between TF and mRNA. Significant upregulation of CBX3/2 and downregulation of AQP3/5/7 correlated with poor overall survival (OS) in HNSC patients. The most significant pathway, GO-BP, GO-MF, and GO-CC terms associated with AQP3 and CBX3 were passive transport by aquaporins, response to vitamin, glycerol channel activity, and condensed chromosome, centromeric region. AQP3 negatively correlated with [Formula: see text] T cells, positively with [Formula: see text] T cells and B cells, and negatively with tumor purity, whereas CBX3 positively correlated with [Formula: see text] T cells, negatively with [Formula: see text] T cells and B cells, and positively with tumor purity. Three-node miRNA-TF-mRNA regulatory network revealed a highest-degree subnetwork motif comprising one TF (SMAD3), one miRNA (miR-423-5p), and one mRNA (AQP3). Protein-protein interaction studies suggested a direct interaction between AQP3 and Smad3 proteins. We concluded that AQP3 and CBX3 hold potential as treatment strategies and individual prognostic biomarkers, while further protein-protein interaction studies of AQP3 could offer insights into its interactions with Smad3 proteins.

Current Insights and Progress in the Clinical Management of Head and Neck Cancer

Head and neck cancer (HNC), also known as the cancer that can affect the structures between the dura mater and the pleura, is the 6th most common type of cancer. This heterogeneous group of malignancies is usually treated with a combination of surgery and radio- and chemotherapy, depending on if the disease is localized or at an advanced stage. However, most HNC patients are diagnosed at an advanced stage, resulting in the death of half of these patients. Thus, the prognosis of advanced or recurrent/metastatic HNC, especially HNC squamous cell carcinoma (HNSCC), is notably poorer than the prognosis of patients diagnosed with localized HNC. This review explores the epidemiology and etiologic factors of HNC, the histopathology of this heterogeneous cancer, and the diagnosis methods and treatment approaches currently available. Moreover, special interest is given to the novel therapies used to treat HNC subtypes with worse prognosis, exploring immunotherapies and targeted/multi-targeted drugs undergoing clinical trials, as well as light-based therapies (i.e., photodynamic and photothermal therapies).

Arctigenin induces caspase-dependent apoptosis in FaDu human pharyngeal carcinoma cells

The present study was carried out to investigate the effect of Arctigenin on cell growth and the mechanism of cell death elicited by Arctigenin were examined in FaDu human pharyngeal carcinoma cells. To determine the apoptotic activity of Arctigenin in FaDu human pharyngeal carcinoma cells, cell viability assay, DAPI staining, caspase activation analysis, and immunoblotting were performed. Arctigenin inhibited the growth of cells in a dose-dependent manner and induced nuclear condensation and fragmentation. Arctigenin-treated cells showed caspase-3/7 activation and increased apoptosis versus control cells. FasL, a death ligand associated with extrinsic apoptotic signaling pathways, was up-regulated by Arctigenin treatment. Moreover, caspase-8, a part of the extrinsic apoptotic pathway, was activated by Arctigenin treatments. Expressions of anti-apoptotic factors such as Bcl-2 and Bcl-xL, components of the mitochondria-dependent intrinsic apoptosis pathway, significantly decreased following Arctigenin treatment. The expressions of pro-apoptotic factors such as BAX, BAD and caspase-9, and tumor suppressor -53 increased by Arctigenin treatments. In addition, Arctigenin activated caspase-3 and poly (ADP-ribose) polymerase (PARP) induced cell death. Arctigenin also inhibited the proliferation of FaDu cells by the suppression of p38, NF-κB, and Akt signaling pathways. These results suggest that Arctigenin may inhibit cell proliferation and induce apoptotic cell death in FaDu human pharyngeal carcinoma cells through both the mitochondria-mediated intrinsic pathway and the death receptor-mediated extrinsic pathway.

Characterization of Recurrent Relevant Genes Reveals a Novel Role of RPL36A in Radioresistant Oral Squamous Cell Carcinoma

Simple Summary

Radioresistance is one of the major factors contributing to radiotherapy failure in OSCC. By systematically comparing the prognostic values of all genes in TCGA-OSCC patients with and without radiotherapy, radioresistance-associated genes were identified. Higher RPL36A transcript levels were found to be associated with a poor prognosis only in OSCC patients with radiotherapy in the cohort of TCGA and another independent Taiwanese cohort. RPL36A was then shown to be involved in the regulation of DNA damage, cell cycle and apoptosis, leading to radioresistance. Thus, such integrated studies are expected to be greatly beneficial for the development of new therapeutic interventions for radioresistant OSCC in the future.

Abstract

Radioresistance is one of the major factors that contributes to radiotherapy failure in oral cavity squamous cell carcinoma (OSCC). By comparing the prognostic values of 20,502 genes expressed in patients in The Cancer Genome Atlas (TCGA)-OSCC cohort with (n = 162) and without radiotherapy (n = 118), herein identified 297 genes positively correlated with poor disease-free survival in OSCC patients with radiotherapy as the potential radioresistance-associated genes. Among the potential radioresistance-associated genes, 36 genes were upregulated in cancerous tissues relative to normal tissues. The bioinformatics analysis revealed that 60S ribosomal protein L36a (RPL36A) was the most frequently detected gene involved in radioresistance-associated gene-mediated biological pathways. Then, two independent cohorts (n = 162 and n = 136) were assessed to confirm that higher RPL36A transcript levels were significantly associated with a poor prognosis only in OSCC patients with radiotherapy. Mechanistically, we found that knockdown of RPL36A increased radiosensitivity via sensitizing cells to DNA damage and promoted G2/M cell cycle arrest followed by augmenting the irradiation-induced apoptosis pathway in OSCC cells. Taken together, our study supports the use of large-scale genomic data for identifying specific radioresistance-associated genes and suggests a regulatory role for RPL36A in the development of radioresistance in OSCC.

Antitumor Activity of Nanoparticles Loaded with PHT-427, a Novel AKT/PDK1 Inhibitor, for the Treatment of Head and Neck Squamous Cell Carcinoma

Currently, new treatments are required to supplement the current standard of care for head and neck squamous cell carcinoma (HNSCC). The phosphatidylinositol3-kinase (PI3K) signaling pathway is commonly altered and activated in HNSCC. PHT-427 is a dual PI3K-mammalian target of the AKT/PDK1 inhibitor; however, to the best of our knowledge, the effect of the PHT-427 inhibitor on HNSCC has not been investigated. This study aims to evaluate the antitumoral effect of PHT-427-loaded polymeric nanoparticles based on α-tocopheryl succinate (α-TOS). The in vitro activity of PHT-427 was tested in hypopharynx carcinoma squamous cells (FaDu) to measure the cell viability, PI3KCA/AKT/PDK1 gene expression, and PI3KCA/AKT/PDK1 levels. Apoptosis, epidermal growth factor receptor (EGFR), and reactive oxygen species (ROS) were also measured. The presence of PHT-427 significantly enhances its antiproliferative and proapoptotic activity by inactivating the PI3K/AKT/PDK1 pathway. Nanoparticles (NPs) effectively suppress AKT/PDK1 expression. Additionally, NPs loaded with PHT-427 produce high oxidative stress levels that induce apoptosis. In conclusion, these results are promising in the use of this nanoformulation as a PHT-427 delivery system for effective HNSCC treatment.

A chemical genetic screen identifies Aurora kinases as a therapeutic target in EGFR T790M negative, gefitinib-resistant head and neck squamous cell carcinoma (HNSCC)

BACKGROUND

Overexpression of epidermal growth factor receptor (EGFR), and downstream pathway activation appears to be a common oncogenic driver in the majority of head and neck squamous cell cancers (HNSCCs); yet targeting EGFR for the treatment of HNSCC has met with limited success. Apart from the anti-EGFR antibody cetuximab, no small molecule EGFR/tyrosine kinase inhibitors (TKIs) have progressed to routine clinical use. The aim of this study was to determine factors contributing to the lack of response to TKIs and identify alternative therapeutic vulnerabilities.

METHODS

Genomic and transcriptomic sequencing, high-throughput compound screens, overexpression and siRNA knockdown, western blot, in vivo xenograft studies.

FINDINGS

We derived three pairs of isogenic gefitinib (TKI)-sensitive and resistant patient-derived HNSCC cell lines. Genomic sequencing of gefitinib-resistant cell lines identified a lack of activating and resistance-associated EGFR mutations. Instead, transcriptomic sequencing showed upregulated EMT gene signature in the gefitinib-resistant cells with a corresponding increase in their migratory phenotype. Additionally, the resistant cell displayed reduced growth rate. Surprisingly, while gefitinib-resistant cells were independent of EGFR for survival, they nonetheless displayed activation of downstream ERK and AKT signalling. High-throughput screening (HTS) of druggable, small molecule libraries revealed that the gefitinib-resistant cells were particularly sensitive to inhibitors of genes involved in cell cycle and mitosis, such as Aurora kinase inhibitors (AKIs), cyclin-dependent kinase (CDK) inhibitors, and microtubule inhibitors. Notably our results showed that in the EGFR inhibited state, Aurora kinases are essential for cell survival.

INTERPRETATION

Our study demonstrates that in the absence of activating EGFR mutations, HNSCCs may gain resistance to gefitinib through decreased cell proliferation, which makes them exceptionally vulnerable to cell-cycle inhibitors.

FUNDING

Agency for Science, Technology, and Research (A*STAR), National Medical Research Council (NMRC), and the National Institutes of Health (NIH)/National Cancer Institute (NCI).

Inhibition of IKKβ/NF-κB signaling pathway to improve Dasatinib efficacy in suppression of cisplatin-resistant head and neck squamous cell carcinoma

Proto-oncogene tyrosine-protein kinase Src plays an important role in Head and Neck Squamous Cell Carcinoma (HNSCC). However, the FDA-approved SRC inhibitor Dasatinib shows very limited efficacy in HNSCC clinical trials, even though Dasatinib can completely inhibit SRC in the laboratory setting. These results suggest that SRC inhibition can cause compensatory up-regulation and/or activation of other survival pathways, which suggests that co-targeting of SRC and the potential signaling pathways may improve the Dasatinib efficacy. In this study, we investigated the role of IKKβ/NF-κB in regulation of the sensitivity of cisplatin-resistant HNSCC to Dasatinib. Additionally, we wished to determine whether inhibition of the IKKβ/NF-κB signaling pathway could enhance Dasatinib efficacy to inhibit cisplatin-resistant HNSCC without the use of cisplatin. Previous studies have shown that ETS-1 is a crucial SRC effector protein that regulates cancer cell proliferation, anti-apoptosis, and metastasis. We found that SRC kinase inhibition by Dasatinib decreased ETS-1 expression but caused elevation of IKKβ/NF-κB signaling in multiple cisplatin-resistant HNSCC. Interestingly, inhibition of IKKβ/NF-κB by CmpdA (Bay65-1942), a recently identified IKKβ inhibitor, also led to a decrease in ETS-1 levels. Moreover, the knockdown of IKK, but not NF-κB, dramatically decreased ETS-1 expression. In addition, IKKβ and ETS-1 interacted in cisplatin-resistant HNSCC. These data demonstrated cross-talk between SRC and IKK to regulate NF-κB and ETS-1. Furthermore, we found that simultaneous inhibition of SRC and IKKβ through a Dasatinib and CmpdA combination synergistically inhibited NF-κB activation and ETS-1expression, suppressed cell proliferation, and induced apoptosis. Taken together, our data indicate that SRC and IKKβ play crucial roles in cisplatin-resistant HNSCCC and co-targeting SRC and IKKβ could be an effective strategy to treat cisplatin-resistant HNSCC.

Synergistic Anti-Tumour Effect of Syk Inhibitor and Olaparib in Squamous Cell Carcinoma: Roles of Syk in EGFR Signalling and PARP1 Activation

Syk is a non-receptor tyrosine kinase involved in the signalling of immunoreceptors and growth factor receptors. Previously, we reported that Syk mediates epidermal growth factor receptor (EGFR) signalling and plays a negative role in the terminal differentiation of keratinocytes. To understand whether Syk is a potential therapeutic target of cancer cells, we further elucidated the role of Syk in disease progression of squamous cell carcinoma (SCC), which is highly associated with EGFR overactivation, and determined the combined effects of Syk and PARP1 inhibitors on SCC viability. We found that pharmacological inhibition of Syk could attenuate the EGF-induced phosphorylation of EGFR, JNK, p38 MAPK, STAT1, and STAT3 in A431, CAL27 and SAS cells. In addition, EGF could induce a Syk-dependent IL-8 gene and protein expression in SCC. Confocal microscopic data demonstrated the ability of the Syk inhibitor to change the subcellular distribution patterns of EGFR after EGF treatment in A431 and SAS cells. Moreover, according to Kaplan-Meier survival curve analysis, higher Syk expression is correlated with poorer patient survival rate and prognosis. Notably, both Syk and EGFR inhibitors could induce PARP activation, and synergistic cytotoxic actions were observed in SCC cells upon the combined treatment of the PARP1 inhibitor olaparib with Syk or the EGFR inhibitor. Collectively, we reported Syk as an important signalling molecule downstream of EGFR that plays crucial roles in SCC development. Combining Syk and PARP inhibition may represent an alternative therapeutic strategy for treating SCC.

Co-targeting PI3K/Akt and MAPK/ERK pathways leads to an enhanced antitumor effect on human hypopharyngeal squamous cell carcinoma

PURPOSE

The present study aims to determine whether co-targeting PI3K/Akt and MAPK/ERK pathways in human hypopharyngeal squamous cell carcinoma (HSCC) is a potential anticancer strategy.

METHODS

We retrospectively analyzed the clinical data of HSCC patients, and the phosphorylation status of Akt and Erk in HSCC and tumor adjacent tissues was evaluated by immunohistochemistry. MTT and colony formation assay were performed to determine the anti-proliferative effect of PI3K/mTOR inhibitor GDC-0980 and MEK inhibitor Refametinib on HSCC cell line Fadu. Wound-healing and Transwell migration assay were used to analyze the anti-migrative capability of the two drugs. The involved anti-tumor mechanism was explored by flow cytometry, qRT-PCR and western blot. The combinational anticancer effect of GDC-0980 and Refametinib was evaluated according to Chou and Talalay's method.

RESULTS

The levels of p-Akt and p-Erk were increased significantly with the progression of clinical stage of HSCC, suggesting PI3K/Akt and MAPK/ERK pathways might be associated with HSCC occurrence and progression. Furthermore, both GDC-0980 and Refametinib showed obvious antitumor effects on FaDu cells. Treatment by the two drugs arrested FaDu cell cycle progression in G1 phase, with reduction of cyclin D1 and p-Rb, in contrast to enhancement of p27. GDC-0980 inhibited FaDu cell migration and reduced metastasis related proteins including p-PKCζ, p-Integrin β1 and uPA. Combination use of GDC-0980 and Refametinib exhibited strong synergistic anti-tumor effect.

CONCLUSION

Dual inhibition of PI3K/Akt and MAPK/ERK pathway by GDC-0980 and Refametinib might be a promising treatment strategy for HSCC patients.

Analysis of oncogenic activities of protein kinase D1 in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer death in the US. The protein kinase D (PKD) family has emerged as a promising target for cancer therapy with PKD1 being most intensively studied; however, its role in HNSCC has not been investigated.

METHODS

The expression of PKD was evaluated in human HNSCC by quantitative RT-PCR, Western blot and immunohistochemistry. Cell proliferation, wound healing, and matrigel invasion assays were performed upon siRNA-mediated knockdown of PKD1 in HNSCC cells, and subcutaneous xenograft mouse model was established by implantation of the stable doxycycline (Dox)-inducible PKD1 expression cell lines for analysis of tumorigenic activity in vivo.

RESULTS

PKD1 was frequently downregulated in HNSCC cell lines at both transcript and protein levels. In human HNSCC tissues, PKD1 was significantly down-regulated in localized tumors and metastases, and in patient-paired tumor tissues as compared to their normal counterparts, which was in part due to epigenetic modification of the PRKD1 gene. The function of PKD1 in HNSCC was analyzed using stable doxycycline-inducible cell lines that express native or constitutive-active PKD1. Upon induction, the rate of proliferation, survival, migration and invasion of HNSCC cells did not differ significantly between the control and PKD1 overexpressing cells in the basal state, and depletion of endogenous PKD1 did not impact the proliferation of HNSCC cells. However, the median growth rate of the subcutaneous HNSCC tumor xenografts over time was elevated with PKD1 induction, and the final tumor weight was significantly increased in Dox-induced vs. the non-induced tumors. Moreover, induced expression of PKD1 promoted bombesin-induced cell proliferation of HNSCC and resulted in sustained ERK1/2 activation in response to gastrin-releasing peptide or bombesin stimulation, suggesting that PKD1 potentiates GRP/bombesin-induced mitogenic response through the activation of ERK1/2 in HSNCC cells.

CONCLUSIONS

Our study has identified PKD1 as a frequently downregulated gene in HNSCC, and functionally, under certain cellular context, may play a role in GRP/bombesin-induced oncogenesis in HNSCC.

Effects of ionizing radiation and HPSE1 inhibition on the invasion of oral tongue carcinoma cells on human extracellular matrices in vitro

Chemoradiation is an established approach in the treatment of advanced oral tongue squamous cell carcinoma (OTSCC), but therapy may cause severe side-effects due to signal interchanges between carcinoma and the tumour microenvironment (TME). In this study, we examined the potential use of our human 3D myoma disc and Myogel models in in vitro chemoradiation studies by analysing the effects of ionizing radiation (IR) and the combined effect of heparanase I (HPSE1) inhibitors and IR on OTSCC cell proliferation, invasion and MMP-2 and - 9 production. Finally, we analysed the long-term effects of IR by studying clones of previously irradiated and invaded HSC-3 cells. We found that in both human uterine leiomyoma-based extracellular matrix models IR inhibited the invasion of HSC-3 cells, but blocking HPSE1 activity combined with IR induced their invasion. Low doses of IR increased MMP expression and initiated epithelial-mesenchymal transition in cells cultured on myoma discs. We conclude that myoma models offer consistent methods for testing human carcinoma cell invasion and phenotypic changes during chemoradiation treatment. In addition, we showed that IR had long-term effects on MMP-2 and - 9, which might elicit different HSC-3 invasion responses when cells were under the challenge of HPSE1 inhibitors and IR.

Efficacy and safety of anti-EGFR agents administered concurrently with standard therapies for patients with head and neck squamous cell carcinoma: a systematic review and meta-analysis of randomized controlled trials

Agents targeting epidermal growth factor receptor (EGFR) are used to treat head and neck squamous cell carcinoma (HNSCC); however, their efficacy and safety is poorly understood. Here we evaluated the efficacy and safety of anti-EGFR agents administered concurrently with standard therapies for HNSCC. Randomized controlled trials that evaluated addition of EGFR targeted therapy versus standard therapy alone were included. The primary outcome was overall survival (OS). Secondary outcomes were progression-free survival (PFS), overall response rate (ORR), locoregional control, and severe adverse events (SAEs, grade ≥ 3). Sixteen eligible trials with 4031 patients were included. Addition of anti-EGFR regimens to standard therapy significantly improved OS of patients with HNSCC (HR = 0.89; 95% CI, 0.82-0.96), with a moderately elevated rate of SAEs (RR = 1.08; 95% CI, 1.03-1.13). Subgroup analysis indicated that the survival benefit was observed when cetuximab was administered concurrently with radiotherapy (RT) for stage III/IV patients (HR = 0.76; 95% CI, 0.61-0.94; p = 0.01), or with chemotherapy for recurrent or metastatic (R/M) HNSCC (HR = 0.86; 95% CI, 0.78-0.95; p = 0.005). Significantly increased ORR (RR = 1.51; 95% CI 1.05-2.18) and PFS (HR = 0.72; 95% CI, 0.59-0.88) were found in R/M HNSCC patients treated with anti-EGFR plus chemotherapy, while no significant improvements were found in stage III/IV patients treated with anti-EGFR plus standard therapy. In conclusion, addition of cetuximab to standard therapy may improve outcomes for R/M HNSCC patients, while causing a moderate increase in SAEs. For stage III/IV patients, anti-EGFR mAb plus RT can improve OS compared with RT alone, while replacement of chemotherapy with EGFR mAb or adding EGFR mAb to combined chemotherapy and RT did not improve outcomes.

Targeted therapy of chronic liver diseases with the inhibitors of angiogenesis

Angiogenesis appears to be intrinsically associated with the progression of chronic liver diseases, which eventually leads to the development of cirrhosis and related complications, including hepatocellular carcinoma. Several studies have suggested that this association is relevant for chronic liver disease (CLD) progression, with angiogenesis. The fact that angiogenesis plays a pivotal role in CLDs gives rise to new opportunities for treating CLDs. Inhibitor of angiogenesis has proved effective for the treatment of patients suffering from CLD. However, it is limited in diagnosis. The last decade has witnessed a plethora of publications which elucidate the potential of angiogenesis inhibitors for the therapy of CLD. The close relationship between the progression of CLDs and angiogenesis emphasizes the need for anti-angiogenic therapy to block/slow down CLD progression. The present review summarizes all these discussions, the results of the related studies carried out to date and the future prospects in this field. We discuss liver angiogenesis in normal and pathophysiologic conditions with a focus on the role and future use of angiogenic factors as second-line treatment of CLD. This review compiles relevant findings and offers opinions that have emerged in last few years relating liver angiogenesis and its treatment using anti-angiogenic factors.

Severe Pain Due to Paraspinal Abscess Formation in Two Patients with Squamous-Cell Carcinoma of the Head and Neck after Multimodal Treatment Including Cetuximab

BACKGROUND

Patients with squamous-cell carcinoma of the head and neck (SCCHN) on palliative therapy usually have a bad prognosis and suffer from various symptoms. With increasing use of targeted agents in cancer patients at the end of life, the correct assignment of therapy-related symptoms becomes increasingly difficult as cancer-related symptoms usually increase as well.

CASE REPORT

We report on 2 cases of patients with SCCHN who received multimodal treatment including palliative therapy with cetuximab. Both patients developed severe thoracic and cervicothoracic pain following treatment. In both cases, extensive paraspinal abscess formation proved to be the underlying cause. One patient was treated conservatively; the other one had to undergo surgical intervention.

CONCLUSIONS

Awareness of multifaceted therapy-related complications is mandatory when patients receive multimodal treatment including targeted therapies. Unexplained pain syndromes in this context should raise suspicions concerning possible infectious complications and should lead to early use of magnetic resonance imaging.

Toward the use of precision medicine for the treatment of head and neck squamous cell carcinoma

Precision medicine is a new strategy that aims at preventing and treating human diseases by focusing on individual variations in people's genes, environment and lifestyle. Precision medicine has been used for cancer diagnosis and treatment and shows evident clinical efficacy. Rapid developments in molecular biology, genetics and sequencing technologies, as well as computational technology, has enabled the establishment of "big data", such as the Human Genome Project, which provides a basis for precision medicine. Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with a high incidence rate and low survival rate. Current therapies are often aggressive and carry considerable side effects. Much research now indicates that precision medicine can be used for HNSCC and may achieve improved results. From this perspective, we present an overview of the current status, potential strategies, and challenges of precision medicine in HNSCC. We focus on targeted therapy based on cell the surface signaling receptors epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and human epidermal growth factor receptor-2 (HER2), and on the PI3K/AKT/mTOR, JAK/STAT3 and RAS/RAF/MEK/ERK cellular signaling pathways. Gene therapy for the treatment of HNSCC is also discussed.

ON 01910.Na (rigosertib) inhibits PI3K/Akt pathway and activates oxidative stress signals in head and neck cancer cell lines

Squamous cell carcinoma of the head and neck (HNSCC) is characterized by high morbidity and mortality. Treatment failure, drug resistance and chemoradiation toxicity have necessitated the development of alternative treatment strategies. Styryl benzyl sulfones, a family of novel small molecule inhibitors, are being evaluated as anti-neoplastic agents in multiple clinical trials. The activity of these compounds has been well characterized in several preclinical tumor studies, but their activity has yet to be fully examined in HNSCC. We tested ON 01910.Na (rigosertib), a styryl benzyl sulfone in late-stage development, in HNSCC preclinical models. Rigosertib induced cytotoxicity in both HPV(+) and HPV(−) HNSCC cells in a dose-dependent manner. Characterization of the underlying molecular mechanism indicated that rigosertib induced inhibition of the PI3K/Akt/mTOR pathway, induced oxidative stress resulting in increased generation of reactive oxygen species (ROS), and activated extracellular signal-regulated kinases (ERK1/2) and c-Jun NH2-terminal kinase (JNK). Increased phosphorylation and cytoplasmic translocation of ATF-2 were also observed following rigosertib treatment. These changes in cell signaling led us to consider combining rigosertib with HNSCC standard-of-care therapies, such as cisplatin and radiation. Our study highlights the promising preclinical activity of rigosertib in HNSCC irrespective of HPV status and provides a molecular basis for rigosertib in combination with standard of care agents for HNSCC.

Adenosine induces intrinsic apoptosis via the PI3K/Akt/mTOR signaling pathway in human pharyngeal squamous carcinoma FaDu cells

Adenosine has been identified to occur abundantly intra-and extracellularly, and to exert diverse biological functions, including the suppression of cell proliferation and the induction of apoptosis. Adenosine has been reported to induce apoptosis in several cancer cell lines; however, to the best of our knowledge, the effect of adenosine on head and neck cancer cells has not been investigated. Therefore, the purpose of the present study was to evaluate whether adenosine exerts any anticancer effect via induction of apoptosis in human pharyngeal squamous carcinoma FaDu cells. An MTT assay demonstrated that adenosine-treated FaDu cells inhibited a dose-dependent rate of cell growth, whereas human oral keratinocytes cells were unaffected by adenosine treatment. In addition, A₁ and A_2a adenosine receptor mRNA was detected in FaDu cells by reverse transcription-polymerase chain reaction, and adenosine-induced FaDu cell death was significantly suppressed by treatment with ATL-444, an antagonist of these receptors. Furthermore, adenosine-induced cell growth inhibition was exerted via apoptosis, as confirmed by the analysis of DNA fragmentation, Hoechst nuclear staining and flow cytometry with Annexin V-fluorescein isothiocyanate and propidium iodide staining. Adenosine was also demonstrated to induce an increase in Bcl-associated X expression, a decrease in B-cell lymphoma 2 expression, the release of cytochrome c from mitochondria, and the activation of caspase-3, -9 and poly(ADP-ribose) polymerase in FaDu cells. Finally, phosphoinositide 3-kinase (PI3K), RAC serine/threonine-protein kinase (Akt) and mechanistic target of rapamycin (mTOR) phosphorylation was found to be significantly inhibited in adenosine-treated FaDu cells, as was phosphorylation of the mTOR downregulators, S6 kinase β1, eukaryotic translation initiation factor 4E-binding protein 1, and eukaryotic translation initiation factor 4 γ1. Taken together, these results indicate that adenosine induces apoptosis via the mitochondrial intrinsic pathway, and activates caspase-3 and -9 activity via the PI3K/Akt/mTOR signaling pathway.

Effects of Cetuximab and Erlotinib on the behaviour of cancer stem cells in head and neck squamous cell carcinoma

The therapeutic responses of many solid tumours to chemo- and radio-therapies are far from fully effective but therapies targeting malignancy-related cellular changes show promise for further control. In head and neck squamous cell carcinoma, the epidermal growth factor receptor (EGFR) is commonly overexpressed and investigation of agents that block this receptor indicate a limited response when used alone but an ability to enhance the actions of other drugs. The hierarchical stem cell patterns present in tumours generate cellular heterogeneity and this is further complicated by cancer stem cells (CSC) shifting between epithelial (Epi-CSC) and mesenchymal (EMT-CSC) states. To clarify how such heterogeneity influences responses to EGFR blocking, we examined the effects of Cetuximab and Erlotinib on the cell sub-populations in HNSCC cell lines. These agents reduced cell proliferation for all subpopulations but induced little cell death. They did however induce large shifts of cells between the EMT-CSC, Epi-CSC and differentiating cell compartments. Loss of EMT-CSCs reduced cell motility and is expected to reduce invasion and metastasis. EGFR blocking also induced shifts of Epi-CSCs into the differentiating cell compartment which typically has greater sensitivity to chemo/radiation, an effect expected to enhance the overall response of tumour cell populations to adjunctive therapies.

Natural Killer Group 2D Ligand Depletion Reconstitutes Natural Killer Cell Immunosurveillance of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous and aggressive tumor originating from the epithelial lining of the upper aero-digestive tract accounting for 300,000 annual deaths worldwide due to failure of current therapies. The natural killer group 2D (NKG2D) receptors on natural killer (NK) cells and several T cell subsets play an important role for immunosurveillance of HNSCC and are thus targeted by tumor immune evasion strategies in particular by shedding of various NKG2D ligands (NKG2DLs). Based on plasma and tumor samples of 44 HNSCC patients, we found that despite compositional heterogeneity the total plasma level of NKG2DLs correlates with NK cell inhibition and disease progression. Strikingly, based on tumor spheroids and primary tumors of HNSCC patients, we found that NK cells failed to infiltrate HNSCC tumors in the presence of high levels of NKG2DLs, demonstrating a novel mechanism of NKG2DL-dependent tumor immune escape. Therefore, the diagnostic acquisition of the plasma level of all NKG2DLs might be instrumental for prognosis and to decipher a patient cohort, which could benefit from restoration of NKG2D-dependent tumor immunosurveillance. Along these lines, we could show that removal of shed NKG2DLs (sNKG2DLs) from HNSCC patients’ plasma restored NK cell function in vitro and in individual patients following surgical removal of the primary tumor. In order to translate these findings into a therapeutic setting, we performed a proof-of-concept study to test the efficacy of adsorption apheresis of sNKG2DLs from plasma after infusion of human MICA in rhesus monkeys. Complete removal of MICA was achieved after three plasma volume exchanges. Therefore, we propose adsorption apheresis of sNKG2DLs as a future preconditioning strategy to improve the efficacy of autologous and adoptively transferred immune cells in cellular cancer immunotherapy.

Oral mucosal changes induced by anticancer targeted therapies and immune checkpoint inhibitors

Development of biological targeted therapies and immune checkpoint inhibitors has redefined the treatment for many cancers; however, the increasing use of new protocols has led to physicians observing a new spectrum of toxicities. To date, oral adverse events induced by these new anticancer therapies have been mainly reported using nonspecific terminology ("stomatitis," "mucosal inflammation," "mucositis") and remain poorly characterized, with the exception of mammalian target of rapamycin (mTOR) inhibitor-associated stomatitis. Oral toxicities of targeted therapies often display very characteristic features which clearly differ from classic oral injuries observed with cytotoxic chemotherapy and/or radiotherapy. In addition, they frequently affect more than 20% of treated patients and can lead to a significant morbidity or permanent treatment discontinuation. Oral mucosal toxicities described in this review include mTOR inhibitor-associated stomatitis (mIAS); stomatitis, benign migratory glossitis, and osteonecrosis of the jaw associated with multi-targeted kinase inhibitors of the VEGF and PDGF receptors; mucositis induced by EGFR inhibitors (in monotherapy or in combination with head and neck radiotherapy and/or chemotherapy); hyperkeratotic lesions with BRAF inhibitors; pigmentary changes and lichenoid reactions secondary to imatinib; and more recent data on the "Osler-Weber-Rendu-like syndrome" described with the antibody-drug conjugate, TDM-1. Finally, we provide, to our knowledge, the first available structured data on oral toxicities induced by the new recently FDA- and EMA-approved monoclonal antibodies targeting PD-1. Clinical management of these targeted therapy-related oral changes is also discussed.

Anti-tumor effects of metformin on head and neck carcinoma cell lines: A systematic review

Metformin is commonly used for treating type 2 diabetes, and may also reduce cancer risk. Previous studies have demonstrated the association between metformin use and a decreased risk of head and neck cancer. Therefore, the aim of the present systematic review was to summarize the available literature on the in vitro anti-tumor effects of metformin on head and neck squamous cell carcinoma (HNSCC). Research studies were obtained from Cochrane Library, Embase, LILACS, MEDLINE and PubMed databases, without time or language restrictions. Only in vitro studies analyzing the effects of metformin on HNSCC cell lines were included. The authors methodically appraised all the selected studies according to the Grading of Recommendations Assessment, Development and Evaluation method to make a judgment of the evidence quality. Of the 388 identified reports, 11 studies met the inclusion criteria and were used for qualitative analysis. These studies demonstrated that metformin is important in inhibiting cell proliferation, inducing G0/G1 cell cycle arrest and apoptosis, and in regulating proteins involved in carcinogenesis pathways, which corroborates its potential in vitro anti-tumor effects. The present systematic review highlights the biological mechanisms of metformin used alone or together with traditional therapies for cancer. Though very limited, currently available preclinical evidence shows that metformin exerts a potential effect on head and neck carcinoma.

Pharmacokinetics and derivation of an anticancer dosing regimen for the novel anti-cancer agent isobutyl-deoxynyboquinone (IB-DNQ), a NQO1 bioactivatable molecule, in the domestic felid species

Isobutyl-deoxynyboquinone (IB-DNQ) is a selective substrate for NAD(P)H:quinone oxidoreductase (NQO1), an enzyme overexpressed in many solid tumors. Following activation by NQO1, IB-DNQ participates in a catalytic futile reduction/reoxidation cycle with consequent toxic reactive oxygen species generation within the tumor microenvironment. To elucidate the potential of IB-DNQ to serve as a novel anticancer agent, in vitro studies coupled with in vivo pharmacokinetic and toxicologic investigations in the domestic felid species were conducted to investigate the tractability of IB-DNQ as a translationally applicable anticancer agent. First, using feline oral squamous cell carcinoma (OSCC) as a comparative cancer model, expressions of NQO1 were characterized in not only human, but also feline OSCC tissue microarrays. Second, IB-DNQ mediated cytotoxicity in three immortalized feline OSCC cell lines were studied under dose-dependent and sequential exposure conditions. Third, the feasibility of administering IB-DNQ at doses predicted to achieve cytotoxic plasma concentrations and biologically relevant durations of exposure were investigated through pharmacokinetic and tolerability studies in healthy research felines. Intravenous administration of IB-DNQ at 1.0-2.0 mg/kg achieved peak plasma concentrations and durations of exposure reaching or exceeding predicted in vitro cytotoxic concentrations. Clinical adverse side effects including ptyalism and tachypnea exhibited during and post-IV infusion of IB-DNQ were transient and tolerable. Additionally, IB-DNQ administration did not produce acute or delayed-onset unacceptable hematologic, non-hematologic, or off-target oxidative toxicities. Collectively, the findings reported here within provide important safety and pharmacokinetic data to support the continued development of IB-DNQ as a novel anticancer strategy for NQO1 expressing cancers.

Genomic amplification of Fanconi anemia complementation group A (FancA) in head and neck squamous cell carcinoma (HNSCC): Cellular mechanisms of radioresistance and clinical relevance

Radio (chemo) therapy is a crucial treatment modality for head and neck squamous cell carcinoma (HNSCC), but relapse is frequent, and the underlying mechanisms remain largely elusive. Therefore, novel biomarkers are urgently needed. Previously, we identified gains on 16q23-24 to be associated with amplification of the Fanconi anemia A (FancA) gene and to correlate with reduced progression-free survival after radiotherapy. Here, we analyzed the effects of FancA on radiation sensitivity in vitro, characterized the underlying mechanisms, and evaluated their clinical relevance. Silencing of FancA expression in HNSCC cell lines with genomic gains on 16q23-24 resulted in significantly impaired clonogenic survival upon irradiation. Conversely, overexpression of FancA in immortalized keratinocytes conferred increased survival accompanied by improved DNA repair, reduced accumulation of chromosomal translocations, but no hyperactivation of the FA/BRCA-pathway. Downregulation of interferon signaling as identified by microarray analyses, enforced irradiation-induced senescence, and elevated production of the senescence-associated secretory phenotype (SASP) appeared to be candidate mechanisms contributing to FancA-mediated radioresistance. Data of the TCGA HNSCC cohort confirmed the association of gains on 16q24.3 with FancA overexpression and impaired overall survival. Importantly, transcriptomic alterations similar to those observed upon FancA overexpression in vitro strengthened the clinical relevance. Overall, FancA amplification and overexpression appear to be crucial for radiotherapeutic failure in HNSCC.

Growth factor expression mediates resistance to EGFR inhibitors in head and neck squamous cell carcinomas

OBJECTIVES

Epidermal growth factor receptor (EGFR)-targeted therapy is frequently used in the treatment of advanced head and neck squamous cell carcinoma (HNSCC). However, constitutive or acquired resistance is common and underlying resistance mechanisms remain poorly understood. We investigated the expression levels of growth factors (GF) in tumor-associated stroma and tumor from HNSCC patients and determined the influence of GFs on EGFR inhibitor efficacy in vitro.

MATERIALS AND METHODS

The Chicago HNC Genomic Cohort (CHGC) was queried for GF and receptor tyrosine kinase (RTK) expression. Viability assays were used to evaluate the effect of EGFR inhibition (gefitinib), GF treatment, or both in HNSCC cell lines. Caspase-based assays were used to measure apoptotic activity. Expression of RTKs was determined and correlated with GF treatment effects.

RESULTS

Amphiregulin (AREG), transforming growth factor (TGFβ1), insulin like growth factor (IGF1), fibroblast growth factors (FGF1/FGF2) and the corresponding RTKs were highly expressed in 30-50% of HNSCC, and expression was usually concurrent. While EGFR inhibition was markedly efficacious in HNC cell lines (HN5/HN13/H400/SCC61), co-treatment with most GFs increased viability up to 100%. Only TGFβ1 treatment was additive to EGFR inhibition. GFs also reduced apoptotic effects of EGFR inhibition. RTK expression showed strong positive correlation with respective GF treatment effect for IGF1-IGF1R, less strong for HGF-MET/AREG-EGFR and a moderate negative correlation for TGFβ1-TGFBR1/2.

CONCLUSION

High expression of GFs/RTKs occurs in HNSCC. Co-expression is common. GF expression contributes to EGFR inhibition resistance in our model system, and may be a common mechanism of constitutive or acquired resistance to EGFR inhibition in HNSCC.

Interventions for the treatment of oral and oropharyngeal cancers: targeted therapy and immunotherapy

BACKGROUND

Oral cancers are the sixth most common cancer worldwide, yet the prognosis following a diagnosis of oral cavity or oropharyngeal cancers remains poor, with approximately 50% survival at five years. Despite a sharp increase in research into molecularly targeted therapies and a rapid expansion in the number of clinical trials assessing new targeted therapies, their value for treating oral cancers is unclear. Therefore, it is important to summarise the evidence to determine the efficacy and toxicity of targeted therapies and immunotherapies for the treatment of these cancers.

OBJECTIVES

To assess the effects of molecularly targeted therapies and immunotherapies, in addition to standard therapies, for the treatment of oral cavity or oropharyngeal cancers.

SEARCH METHODS

We searched the following electronic databases: Cochrane Oral Health Group Trials Register (to 3 February 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2015, Issue 1), MEDLINE via Ovid (1946 to 3 February 2015) and EMBASE via Ovid (1980 to 3 February 2015). We searched the US National Institutes of Health Trials Register (clinicaltrials.gov), the World Health Organization Clinical Trials Registry Platform, the American Society of Clinical Oncology conference abstracts and the Radiation Therapy Oncology Group clinical trials protocols for ongoing trials. We placed no restrictions on the language or date of publication.

SELECTION CRITERIA

We included randomised controlled trials where more than 50% of participants had primary tumours of the oral cavity or oropharynx, and which compared targeted therapy or immunotherapy, plus standard therapy, with standard therapy alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. We attempted to contact study authors for missing data or clarification where necessary. We combined sufficiently similar studies in meta-analyses using random-effects models when there were at least four studies and fixed-effect models when fewer than four studies. We obtained or calculated a hazard ratio (HR) and 95% confidence interval (CI) for the primary outcomes where possible. For dichotomous outcomes, we reported risk ratios (RR) and 95% CIs.

MAIN RESULTS

Twelve trials (2488 participants) satisfied the inclusion criteria. In the included trials, 12% of participants (298 participants) had tumours of the oral cavity and 59% (1468 participants) had oropharyngeal tumours. The remaining 29% had tumours of the larynx or hypopharynx and less than 1% had tumours at other sites.No included trial was at low risk of bias; seven had an unclear risk of bias, and five had a high risk of bias. We grouped trials by intervention type into three main comparisons: standard therapy plus epidermal growth factor receptor monoclonal antibody (EGFR mAb) therapy (follow-up period 24 to 70 months); standard therapy plus tyrosine kinase inhibitors (TKIs) (follow-up period 40 to 60 months) and standard therapy plus immunotherapy (follow-up period 24 to 70 months), all versus standard therapy alone.Moderate quality evidence showed that EGFR mAb therapy may result in 18% fewer deaths when added to standard therapy (HR of mortality 0.82; 95% CI 0.69 to 0.97; 1421 participants, three studies, 67% oropharyngeal tumours, 2% oral cavity tumours).There was also moderate quality evidence that EGFR mAb may result in 32% fewer locoregional failures when added to radiotherapy (RT) (HR 0.68; 95% CI 0.52 to 0.89; 424 participants, one study, 60% oropharyngeal tumours).A subgroup analysis separating studies by type of standard therapy (radiotherapy (RT) or chemoradiotherapy (CRT)) showed some evidence that adding EGFR mAb therapy to RT may result in a 30% reduction in the number of people whose disease progresses (HR 0.70; 95% CI 0.54 to 0.91; 424 participants, one study, 60% oropharyngeal tumours, unclear risk of bias). For the subgroup comparing EGFR mAb plus CRT with CRT alone there was insufficient evidence to determine whether adding EGFR mAb therapy to CRT impacts on progression-free survival (HR 1.08; 95% CI 0.89 to 1.32; 891 participants, one study, 70% oropharyngeal tumours, high risk of bias). The high subgroup heterogeneity meant that we were unable to pool these subgroups.There was evidence that adding cetuximab to standard therapy may result in increased skin toxicity and rash (RR 6.56; 95% CI 5.35 to 8.03; 1311 participants, two studies), but insufficient evidence to determine any difference in skin toxicity and rash in the case of nimotuzumab (RR 1.06; 95% CI 0.85 to 1.31; 92 participants, one study).There was insufficient evidence to determine whether TKIs added to standard therapy impacts on overall survival (HR 0.99; 95% CI 0.62 to 1.57; 271 participants, two studies; very low quality evidence), locoregional control (HR 0.89; 95% CI 0.53 to 1.49; 271 participants, two studies; very low quality evidence), disease-free survival (HR 1.51; 95% CI 0.61 to 3.71; 60 participants, one study; very low quality evidence) or progression-free survival (HR 0.80; 95% CI 0.51 to 1.28; 271 participants, two studies; very low quality evidence). We did find evidence of an increase in skin rash (erlotinib: RR 6.57; 95% CI 3.60 to 12.00; 191 participants, one study; lapatinib: RR 2.02; 95% CI 1.23 to 3.32; 67 participants, one study) and gastrointestinal complaints (lapatinib: RR 15.53; 95% CI 2.18 to 110.55; 67 participants, one study).We found very low quality evidence from one small trial that adding recombinant interleukin (rIL-2) to surgery may increase overall survival (HR 0.52; 95% CI 0.31 to 0.87; 201 participants, 62% oral cavity tumours, 38% oropharyngeal tumours) and there was insufficient evidence to determine whether rIL-2 impacts on adverse effects.

AUTHORS' CONCLUSIONS

We found some evidence that adding EGFR mAb to standard therapy may increase overall survival, progression-free survival and locoregional control, while resulting in an increase in skin toxicity for some mAb (cetuximab).There is insufficient evidence to determine whether adding TKIs to standard therapies changes any of our primary outcomes.Very low quality evidence from a single study suggests that rIL-2 combined with surgery may increase overall survival compared with surgery alone.

Molecular imaging of EGFR and CD44v6 for prediction and response monitoring of HSP90 inhibition in an in vivo squamous cell carcinoma model

Purpose

Heat shock protein 90 (HSP90) is essential for the activation and stabilization of numerous oncogenic client proteins. AT13387 is a novel HSP90 inhibitor promoting degradation of oncogenic proteins upon binding, and may also act as a radiosensitizer. For optimal treatment there is, however, the need for identification of biomarkers for patient stratification and therapeutic response monitoring, and to find suitable targets for combination treatments. The aim of this study was to assess the response of surface antigens commonly expressed in squamous cell carcinoma to AT13387 treatment, and to find suitable biomarkers for molecular imaging and radioimmunotherapy in combination with HSP90 inhibition.

Methods

Cancer cell proliferation and radioimmunoassays were used to evaluate the effect of AT13387 on target antigen expression in vitro. Inhibitor effects were then assessed in vivo in mice-xenografts. Animals were treated with AT13387 (5 × 50 mg/kg), and were imaged with PET using either ¹⁸F-FDG or ¹²⁴I-labelled tracers for EGFR and CD44v6, and this was followed by ex-vivo biodistribution analysis and immunohistochemical staining.

Results

AT13387 exposure resulted in high cytotoxicity and possible radiosensitization with IC₅₀ values below 4 nM. Both in vitro and in vivo AT13387 effectively downregulated HSP90 client proteins. PET imaging with ¹²⁴I-cetuximab showed a significant decrease of EGFR in AT13387-treated animals compared with untreated animals. In contrast, the squamous cell carcinoma-associated biomarker CD44v6, visualized with ¹²⁴I-AbD19384 as well as ¹⁸F-FDG uptake, were not significantly altered by AT13387 treatment.

Conclusion

We conclude that AT13387 downregulates HSP90 client proteins, and that molecular imaging of these proteins may be a suitable approach for assessing treatment response. Furthermore, radioimmunotherapy targeting CD44v6 in combination with AT13387 may potentiate the radioimmunotherapy outcome due to radiosensitizing effects of the drug, and could potentially lead to a lower dose to normal tissues.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-015-3260-x) contains supplementary material, which is available to authorized users.

Activation of MET pathway predicts poor outcome to cetuximab in patients with recurrent or metastatic head and neck cancer

BACKGROUND

Activation of the MET oncogene promotes tumor growth, invasion and metastasis in several tumor types. Additionally, MET is activated as a compensatory pathway in the presence of EGFR blockade, thus resulting in a mechanism of resistance to EGFR inhibitors.

METHODS

We have investigated the impact of HGF and MET expression, MET activation (phosphorylation), MET gene status, and MET-activating mutations on cetuximab sensitivity in recurrent or metastatic squamous cell carcinoma of the head and neck (HNSCC) patients.

RESULTS

A single-institution retrospective analysis was performed in 57 patients. MET overexpression was detected in 58% patients, MET amplification in 39% and MET activation (p-MET) in 30%. Amplification was associated with MET overexpression. Log-rank testing showed significantly worse outcomes in recurrent/metastatic, MET overexpressing patients for progression-free survival and overall survival. Activation of MET was correlated with worse PFS and OS. In multivariate logistic regression analysis, p-MET was an independent prognostic factor for PFS. HGF overexpression was observed in 58% patients and was associated with MET phosphorylation, suggesting a paracrine activation of the receptor.

CONCLUSIONS

HGF/MET pathway activation correlated with worse outcome in recurrent/metastatic HNSCC patients. When treated with a cetuximab-based regimen, these patients correlated with worse outcome. This supports a dual blocking strategy of HGF/MET and EGFR pathways for the treatment of patients with recurrent/metastatic HNSCC.

In vitro Anti-Tumor Effects of Statins on Head and Neck Squamous Cell Carcinoma: A Systematic Review

BACKGROUND

Statins are commonly used against arteriosclerotic disease, but recent retrospective analyses have suggested that statins also prevent cancer. The aim of this systematic review is to verify the vitro anti-tumor effects of statins on head and neck squamous cell carcinoma.

METHODS

Studies were gathered by searching Cochrane, MEDLINE, EMBASE, LILACS, and PubMed, up until May 9, 2015, with no time or language restrictions. Only in vitro studies that discuss the effect of statins on head and neck carcinoma were selected.

RESULTS

Of 153 identified papers, 14 studies met the inclusion criteria. These studies demonstrated that statins had a significant effect on head and neck squamous cell carcinoma cell lines and influenced cell viability, cell cycle, cell death, and protein expression levels involved in pathways of carcinogenesis, which corroborates with the potential in vitro anti-tumor effects. It provides highlights about the biological mechanisms of statins used alone or associated with traditional therapy for cancer.

CONCLUSIONS

Though there are few studies on the topic, currently available evidence suggests that statins shows that preclinical experiments supports the potentiality of statin as an adjuvant agent in chemotherapy and/or radiotherapy approaches routinely used in the management of HNSCC and should undergo further clinical assessment.

Hepatitis C virus-mediated angiogenesis: Molecular mechanisms and therapeutic strategies

Angiogenesis is an essential process for organ growth and repair. Thus, an imbalance in this process can lead to several diseases including malignancy. Angiogenesis is a critical step in vascular remodeling, tissue damage and wound healing besides being required for invasive tumor growth and metastasis. Because angiogenesis sets an important point in the control of tumor progression, its inhibition is considered a valuable therapeutic approach for tumor treatment. Chronic liver disease including hepatitis C virus (HCV) infection is one of the main cause for the development of hepatic angiogenesis and thereby plays a critical role in the modulation of hepatic angiogenesis that finally leads to hepatocellular carcinoma progression and invasion. Thus, understanding of the molecular mechanisms of HCV-mediated hepatic angiogenesis will help design a therapeutic protocol for the intervention of HCV-mediated angiogenesis and subsequently its outcome. In this review, we will focus on the molecular mechanisms of HCV-mediated hepatic angiogenesis and the related signaling pathways that can be target for current and under development therapeutic approaches.

Radiation oncology in vitro: trends to improve radiotherapy through molecular targets

Much has been investigated to improve the beneficial effects of radiotherapy especially in that case where radioresistant behavior is observed. Beyond simple identification of resistant phenotype the discovery and development of specific molecular targets have demonstrated therapeutic potential in cancer treatment including radiotherapy. Alterations on transduction signaling pathway related with MAPK cascade are the main axis in cancer cellular proliferation even as cell migration and invasiveness in irradiated tumor cell lines; then, for that reason, more studies are in course focusing on, among others, DNA damage enhancement, apoptosis stimulation, and growth factors receptor blockages, showing promising in vitro results highlighting molecular targets associated with ionizing radiation as a new radiotherapy strategy to improve clinical outcome. In this review we discuss some of the main molecular targets related with tumor cell proliferation and migration as well as their potential contributions to radiation oncology improvements.

Characterization of CD44 variant expression in head and neck squamous cell carcinomas

CD44 is a complex family of molecules, associated with aggressive malignancies and cancer stem cells. However, the role of CD44 variants in tumor progression and treatment resistance is not clear. In this study, the expression of CD44 and its variants was assessed in head and neck squamous cell carcinomas (HNSCC). Furthermore, subpopulations of cells expressing high amounts of CD44 variants were identified and characterized, for e.g., cell cycle phase and radioresistance. Results revealed high and homogenous CD44 and CD44v7 expression in four cell lines and CD44v4 and CD44v6 in three cell lines. CD44v3 was highly expressed in two cell lines, whereas CD44v5, CD44v7/8, CD44v10, CD133, and CD24 demonstrated no or moderate expression. Moreover, a subpopulation of very high CD44v4 expression was identified, which is independent of cell phase, demonstrating increased proliferation and radioresistance. In cell starvation experiments designed to enrich for cancer stem cells, a large population with dramatically increased expression of CD44, CD44v3, CD44v6, and CD44v7 was formed. Expression was independent of cell phase, and cells demonstrated increased radioresistance and migration rate. Our results demonstrate that the heterogeneity of tumor cells has important clinical implications for the treatment of HNSCC and that some of the CD44 variants may be associated with increased radioresistance. Highly expressed CD44 variants could make interesting candidates for selective cancer targeting.

Role of EGFR as a prognostic factor for survival in head and neck cancer: a meta-analysis

The prognostic role of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) remains controversial. The goal of this study was to summarize existing evidence regarding whether EGFR overexpression is a prognostic factor in HNSCC. Relevant studies were identified using Pubmed, Ovid, and Web of Science databases. A meta-analysis was conducted on the prognostic value of EGFR expression for overall survival (OS) and disease-free survival (DFS). Thirty-seven studies were included. Primary analysis indicated that EGFR overexpression was associated with reduced OS (hazard ratio [HR]: 1.694, 95% confidence interval [CI]: 1.432–2.004). DFS, on the other hand, was not associated with EGFR expression after adjusting for publication bias (HR: 1.084, 95% CI: 0.910–1.290). Subgroup analysis gave a statistically significant pooled HR for OS in laryngeal carcinoma (HR: 2.519, 95% CI: 1.615–3.928) and in oropharyngeal carcinoma (HR: 2.078, 95% CI: 1.605–2.690). The pooled HR was statistically significant for DFS with respect to oropharyngeal carcinoma (HR: 1.055, 95% CI: 1.020–1.092), but not laryngeal carcinoma (HR: 1.750, 95% CI: 0.911–3.360). When dividing studies based on the immunohistochemistry (IHC) scoring system, only the group that evaluated EGFR expression according to the intensity and extent of staining showed no between-study heterogeneity for both OS and DFS. Overall, EGFR overexpression was associated with shortened OS, but not DFS. Future studies are needed that stratify patients by specific tumor sites. Furthermore, when estimating protein level by the IHC method, it is advisable to consider both intensity and extent of staining.

Clinical application of genetics to guide prevention and treatment of oral diseases

Dental care costs in the United States exceed $100 billion annually. Personalized medicine efforts in dentistry are driven by potentially compelling clinical utility and cost-effectiveness prospects in the major diseases of periodontitis, caries, and oral cancers. This review discusses progress and challenges identifying genetic markers and showing clinical utility in dentistry. Genome-wide association studies (GWAS) of chronic periodontitis (CP) identified no significant variants, but CDKN2BAS variants on chromosome 9 were significantly associated with aggressive periodontitis. Stratifying patients by interleukin (IL)-1 gene variants, smoking and diabetes differentiated CP prevention outcomes. Dental caries' GWAS identified significant signals in LYZL2, AJAp1, and KPNA4; and efforts are ongoing to identify genetic factors for multiple caries phenotypes. Trials of molecularly targeted therapies are in progress for oral, head, and neck squamous cell carcinomas (OHNSCC) and results have been promising but limited in their effectiveness. Current opportunities and challenges for molecular targeting for OHNSCC are discussed.

Optical metabolic imaging of treatment response in human head and neck squamous cell carcinoma

Optical metabolic imaging measures fluorescence intensity and lifetimes from metabolic cofactors nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD). These molecular level measurements provide unique biomarkers for early cellular responses to cancer treatments. Head and neck squamous cell carcinoma (HNSCC) is an attractive target for optical imaging because of easy access to the site using fiber optic probes. Two HNSCC cell lines, SCC25 and SCC61, were treated with Cetuximab (anti-EGFR antibody), BGT226 (PI3K/mTOR inhibitor), or cisplatin (chemotherapy) for 24 hours. Results show increased redox ratio, NADH α1 (contribution from free NADH), and FAD α1 (contribution from protein-bound FAD) for malignant cells compared with the nonmalignant cell line OKF6 (p<0.05). In SCC25 and SCC61 cells, the redox ratio is unaffected by cetuximab treatment and decreases with BGT226 and cisplatin treatment (p<0.05), and these results agree with standard measurements of proliferation rates after treatment. For SCC25, NADH α1 is reduced with BGT226 and cisplatin treatment. For SCC61, NADH α1 is reduced with cetuximab, BGT226, and cisplatin treatment. Trends in NADH α1 are statistically similar to changes in standard measurements of glycolytic rates after treatment. FAD α1 is reduced with cisplatin treatment (p<0.05). These shifts in optical endpoints reflect early metabolic changes induced by drug treatment. Overall, these results indicate that optical metabolic imaging has potential to detect early response to cancer treatment in HNSCC, enabling optimal treatment regimens and improved patient outcomes.

Hazards and risks in oncology: radiation oncology

Adverse effects and hazards which have their origin from radiation using conventional techniques like 3-D conformal radiotherapy and total radiation doses are well known. However little is known about the sprectum of especially late toxicity after radiation using new technologies like intensity modulated radiotherapy (IMRT) combined with novel target volume and dose concepts. Since IMRT allows for selective protection of the large salivary glands this technique improves the intermediate term quality of life and is the standard of care despite many details need further prospective evaluation. Combining cytotoxic drugs and radiotherapy yield improved survival in well-defined high risk patients. However morbidity and mortality of these protocols are high and deserve special expertise and supportive therapy. EGF-receptor antibodies have gained well defined indications, albeit specific toxicities in combination with irradiation deserve prospective studies and special attention.

Choice of labeling and cell line influences interactions between the Fab fragment AbD15179 and its target antigen CD44v6

Medical imaging by use of immunotargeting generally relies on a labeled molecule binding to a specific target on the cell surface. It is important to utilize both cell-based and time-resolved binding assays in order to understand the properties of such molecular interactions in a relevant setting. In this report we describe the detailed characterization of the interaction properties for AbD15179, a promising CD44v6-targeting antibody fragment for radio-immunotargeting. Influence of labeling and cell-line model on the protein interaction kinetics was assessed using three different labeling approaches ((111)In, (125)I and FITC) on three different squamous carcinoma cell lines. Interactions were measured using time-resolved assays on living cells, and further analyzed with Interaction Map®. Results demonstrated a general biphasic appearance of a high- and a low-affinity binding event in all cases. The relative contribution from these two interactions differed between conjugates. For (125)I-Fab, the population of low-affinity binders could be significantly increased by extending the chloramine T exposure during labeling, whereas the (111)In-labeling predominantly resulted in a high-affinity interaction. Interactions were also shown to be cell line dependent, with e.g. SCC-25 cells generally mediating a faster dissociation of conjugates compared to the other cell lines. In conclusion, we report both cell line dependent and labeling associated variations in interaction kinetics for AbD15179 binding to CD44v6. This has implications for cell-based kinetic assays and applications based on labeled conjugates in general, as well as in a clinical setting, where each individual tumor may create different kinetic profiles for the same conjugate.

Combination antiangiogenic therapy and radiation in head and neck cancers

Tumor angiogenesis is a hallmark of advanced cancers and promotes invasion and metastasis. Over 90% of head and neck squamous cell carcinomas (HNSCC) express angiogenic factors such as vascular endothelial growth factor (VEGF). Several preclinical studies support the prognostic implications of angiogenic markers for HNSCC and currently this is an attractive treatment target in solid tumors. Since radiotherapy is one of the most commonly used treatments for HNSCC, it is imperative to identify the interactions between antiangiogenic therapy and radiotherapy, and to develop combination therapy to improve clinical outcome. The mechanisms between antiangiogenic agents and ionizing radiation are complicated and involve many interactions between the vasculature, tumor stroma and tumor cells. The proliferation and metastasis of tumor cells rely on angiogenesis/blood vessel formation. Rapid growing tumors will cause hypoxia, which up-regulates tumor cell survival factors, such as hypoxia-inducing factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), giving rise to more tumor proliferation, angiogenesis and increased radioresistance. Thus, agents that target tumor vasculature and new tumor vessel formation can modulate the tumor microenvironment to improve tumor blood flow and oxygenation, leading to enhanced radiosensitivity. In this review, we discuss the mechanisms of how antiangiogenic therapies improve tumor response to radiation and data that support this combination strategy as a promising method for the treatment of HNSCC in the future.

Immunotherapy for head and neck cancer patients: shifting the balance

Head and neck squamous cell carcinoma is the sixth most common cancer in the western world. Over the last few decades little improvement has been made to increase the relatively low 5-year survival rate. This calls for novel and improved therapies. Here, we describe opportunities in immunotherapy for head and neck cancer patients and hurdles yet to be overcome. Viruses are involved in a subset of head and neck squamous cell carcinoma cases. The incidence of HPV-related head and neck cancer is increasing and is a distinctly different disease from other head and neck carcinomas. Virus-induced tumors express viral antigens that are good targets for immunotherapeutic treatment options. The type of immunotherapeutic treatment, either active or passive, should be selected depending on the HPV status of the tumor and the immune status of the patient.

Use of panitumumab-IRDye800 to image cutaneous head and neck cancer in mice

OBJECTIVE

To assess the feasibility of panitumumab in real-time fluorescent imaging and histologic processing of cutaneous squamous cell carcinoma (cSCC) in mice.

DESIGN

A near-infrared (NIR) fluorescent probe (IRDye800CW) was covalently linked to a monoclonal antibody-targeting epidermal growth factor receptor (panitumumab) or nonspecific IgG and injected into mice bearing flank xenografts from a cSCC cell line (SCC-13 or SRB-12; n = 7), human split-thickness skin grafts (STSGs; n = 3), or a human tumor explant (n = 1). The tumor and lymph nodes were imaged and dissected using fluorescence guidance with the SPY imaging system and verified with a charge-coupled NIR system. An NIR scanning device (Odyssey) was used to measure fluorescence intensity in histological sections.

SUBJECTS

Immunodeficient mice.

SETTING

In vivo and in vitro imaging lab.

RESULTS

Tumor tissue could be delineated from the human STSG with tumor-to-background ratios of 4.5 (Pearl) and 3.4 (SPY). Tumor detection was substantially improved with panitumumab-IRDye800 compared with IgG-IRDye800. Biopsies positive for fluorescence were assessed by histology and immunohistochemistry (n = 18/18) to confirm the presence of tumor, yielding a 100% sensitivity. Biopsies of nonfluorescent tissue negative for malignancy (n = 18/18) yielded a specificity of 100%. Furthermore, the SPY system was able to detect residual disease as small as 200 µm in diameter. In addition, the Odyssey confirmed fluorescence of microscopic disease (in tumor samples of frozen and paraffin-embedded histologic specimens) but not in adjacent noncancerous tissue.

CONCLUSIONS

These data suggest panitumumab-IRDye800 may have clinical utility in detection and removal of subclinical cSCC using Food and Drug Administration-approved imaging hardware.

Mechanisms of resistance to EGFR targeted therapies

EGFR is a validated therapeutic target in many human cancers. EGFR targeted therapies are in widespread clinical use in patients with non-small cell lung cancer and other tumor types. Despite the clinical success of EGFR targeted therapy, resistance to treatment is a significant barrier to the optimized use of EGFR inhibitors to cure patients with lung and other cancers. Here, we review established and emerging mechanisms of resistance to EGFR targeted therapy and highlight strategies that could overcome treatment resistance and therefore enhance clinical outcomes.

mTOR Pathway and mTOR Inhibitors in Head and Neck Cancer

Head and neck cancer is the sixth most common type of Cancer worldwide. Since conventional treatment regimens are nonselective and are associated with systemic toxicities, intense investigations focus on molecular targeted therapy with high selectivity and low adverse effects. mTOR signaling pathway has been found to be activated in head and neck cancer, making it attractive for targeted therapy. In addition, expression levels of mTOR and downstream targets eIF4E, 4EBP1, S6K1, and S6 are potential diagnostic and prognostic biomarkers for head and neck cancer. mTOR inhibitors, such as rapamycin and its derivatives temsirolimus and everolimus, exhibit inhibitory effects on head and neck cancer in both in vitro cell line model and in vivo xenograft model. A large number of clinical trials have been initiated to evaluate the therapeutic effects of mTOR inhibitors on patients with head and neck cancer. mTOR inhibitor has potential as a single therapeutic agent or in combination with radiation, chemotherapeutic agents, or other targeted therapeutic agents to obtain synergistic repression on head and neck cancer.

Selection and in vitro characterization of human CD44v6-binding antibody fragments

The cluster of differentiation (CD) 44v6 antigen has been suggested to be involved in tumor formation, invasion, and metastasis formation, and has been observed in a majority of primary and metastatic squamous cell carcinomas of the head and neck. Probes specifically binding to this region may be utilized as tools for the challenging tasks of early detection and targeted treatments of small residual disease. In this project, an epitope-guided phage display selection of human fragment antigen-binding (Fab) fragments with affinity to the v6 sequence was performed. A selected set of Fab fragments was shown to specifically recognize increasingly complex forms of the target sequence, both in the form of a short synthetic or recombinant peptide and in the context of a purified extracellular domain of CD44. The binding was independent of known v6-sequence variation and posttranslational modifications that are common in the CD44 protein family. Furthermore, real-time interaction measurements on antibody fragments labeled with ¹²⁵I showed specific and high-affinity binding to the antigen present on cultured head and neck squamous cell carcinoma cells. There was no cross-reactivity toward cells that lack the target protein. As hypothesized, characterization of the interaction between Fab fragments and the targets using the mathematical tool Interaction Map revealed more heterogeneous interactions on cells than with pure proteins analyzed by surface plasmon resonance. One main candidate Fab fragment with optimal affinity for all forms of the target sequence was identified. The flexible recombinant source of the Fab fragments might aid the development of tailored molecules adapted for therapeutic or diagnostic applications in the future.