Molecular targeted therapy of head and neck cancer: Review and clinical development challenges

Natural killer cell-based signature: Prognostic analysis in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSC) is a challenging cancer with significant clinical implications. Natural killer (NK) cells have emerged as important players in tumor immunosurveillance, yet their role and potential as prognostic biomarkers in HNSC remain unclear.

METHODS

Quantitative analysis using multiple algorithms identified FCRL1, KIR3DL2 and ZNF541 as molecules significantly associated with local NK cell infiltration and patient survival. A prognostic model based on these molecules demonstrated robust predictive performance.

RESULTS

Analysis of high- and low-risk patient groups revealed distinct differences in the tumor microenvironment, indicating an inhibitory immune microenvironment in high-risk patients. Notably, low-risk patients exhibited potential sensitivity to immunotherapy and showed favorable responses to specific drugs such as axitinib, methotrexate, rapamycin and vorinostat. NK cells, important effectors of the innate immune response, were found to play a crucial role in HNSC immunity. The present study provides valuable insights into the correlation between FCRL1, KIR3DL2, ZNF541 and NK cell infiltration, paving the way for future investigations into their roles in HNSC. Activation of NOTCH signaling, MYC targets, DNA repair, E2F targets, epithelial-mesenchymal transition, G2M checkpoint and mitotic spindle pathways in high-risk patients suggests their involvement in disease progression and poor prognosis.

CONCLUSIONS

The present study reveals the significance of NK cells in HNSC and their potential as prognostic biomarkers. The CFKZ score offers a promising approach for predicting patient outcomes and guiding personalized treatment decisions in HNSC. These findings contribute to our understanding of HNSC immunobiology and hold implications for precision medicine in HNSC management.

Molecular targeted therapy, advanced treatment for cancers of the head-and-neck region: A systematic review

Introduction

The foundation of oncology treatment as a single modality approach as well as the "multimodality" concept has been studied by statistical evaluation pre, during, and posttreatment to rule out their efficacy, expected prognosis, toxicity reactions, and overall survival for the patient. Such studies have also provided an appreciable amount of data for future custom utility. "Targeted therapy" is a cancer treatment that uses drugs but is different from traditional chemotherapy. It works by targeting cancer-specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. Researchers are developing drugs that target specific molecular changes. The drugs can block or turn off signals that tell cancer cells to grow and divide, keep cells from living longer than usual, and destroy the cancer cells.

Aim

The aim of the study is to carry out a systematic review of clinical trials of molecular targeted therapy in the treatment of cancer.

Objective

The objective of the study is to evaluate the efficacy of molecular targeted therapy in the treatment of head-and-neck cancers.

Materials and Methods

A group of keywords was preselected to search for scientific articles on a web-based database of PubMed. Only completed randomized controlled trials published in the past 5 years in the English language were included with open access. All the selected articles were subjected to the Cochrane bias tool and PRISMA guidelines to extract results.

Results

Among 4 studies specifying the progression-free survival (PFS) for comparing the groups treated either using targeted therapy or other modality/placebo, 50% of studies show a slight increase in PFS in the group treated with TT and other 50% show PFS increase in the non-TT group. Thus, insufficient evidence is furnished to provide a statement and acknowledged the expectancy of a disease-free period with or without the use of TT in the treatment of head-and-neck cancer.

Conclusion

Considering very little information on enhanced effect and presence of evidence supporting an increased risk of adverse events, the addition of TT to treatment is a question to the dilemma. A systematic review intends advantageous in providing foresight for oncologists concerning patient assessment and evaluation to defend inclination proceeding toward the treatment defined.

Precision Medicine Approaches to Overcome Resistance to Therapy in Head and Neck Cancers

Head and neck squamous cell carcinoma (HNSCC) is the sixth most incident cancer worldwide. More than half of HNSCC patients experience locoregional or distant relapse to treatment despite aggressive multimodal therapeutic approaches that include surgical resection, radiation therapy, and adjuvant chemotherapy. Before the arrival of immunotherapy, systemic chemotherapy was previously employed as the standard first-line protocol with an association of cisplatin or carboplatin plus 5-fluorouracil plus cetuximab (anti-EFGR antibody). Unfortunately, acquisition of therapy resistance is common in patients with HNSCC and often results in local and distant failure. Despite our better understanding of HNSCC biology, no other molecular-targeted agent has been approved for HNSCC. In this review, we outline the mechanisms of resistance to the therapeutic strategies currently used in HNSCC, discuss combination treatment strategies to overcome them, and summarize the therapeutic regimens that are presently being evaluated in early- and late-phase clinical trials.

Adaptive Responses to Monotherapy in Head and Neck Cancer: Interventions for Rationale-Based Therapeutic Combinations

Most Phase II and III clinical trials in head and neck cancer (HNC) combine two or more treatment modalities, which are based, in part, on knowledge of the molecular mechanisms of innate and acquired resistance to monotherapy. In this review, we describe the range of tumor-cell autonomously derived (intrinsic) and tumor-microenvironment-derived (extrinsic) acquired-resistance mechanisms to various FDA-approved monotherapies for HNC. Specifically, we describe how tumor cells and the tumor microenvironment (TME) respond to radiation, chemotherapy, targeted therapy (cetuximab), and immunotherapies [programmed cell death 1 (PD-1) inhibitors] and adapt to the selective pressure of these monotherapies. Due to the diversity of adaptive responses to monotherapy, monitoring the response to treatment in patients is critical to understand the path that leads to resistance and to guide the optimal therapeutic drug combinations in the clinical setting. We envisage that applying such a rationale-based therapeutic strategy will improve treatment efficacy in HNC patients.

High expression of ACTL8 is poor prognosis and accelerates cell progression in head and neck squamous cell carcinoma

Actin‑like protein 8 (ACTL8) is a member of the cancer‑testis antigens (CTA) family, which is mainly localized in the cytoplasm and generally expressed in the testis. The association between ACTL8 and various types of cancer, including glioblastoma and breast cancer, has previously been demonstrated. However, whether ACTL8 is involved in the development of head and neck squamous cell carcinoma (HNSCC) remains unknown. In the present study, the expression of ACTL8 in patients with HNSCC was analyzed in The Cancer Genome Atlas (TCGA) dataset, clinical tissues and cell lines. Correlations between the expression levels of ACTL8 and HNSCC clinical outcomes were analyzed with the Kaplan‑Meier method and the Cox proportional hazards model. Cell Counting Kit‑8, plate colony formation and Transwell assays were used to assess the effects of ACTL8 interference on the proliferation, migration and invasion of HNSCC PCI‑13 cells. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to evaluate the expression levels of ACTL8 in PCI‑13 cells. Furthermore, alterations in the expression levels of key proteins in the phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K)/RAC‑α protein kinase B (AKT) signaling pathway were determined by western blotting. Increased expression of ACTL8 in HNSCC was observed in TCGA dataset, cancerous tissue samples and HNSCC cell line. Cox regression analysis indicated that ACTL8 expression could be regarded as an independent prognostic factor for HNSCC, since increased expression of ACTL8 was associated with a poor prognosis. Knocking down ACTL8 markedly inhibited the proliferation, invasion and migration of PCI‑13 cells. Additionally, activation of the PI3K/AKT signaling pathway was suppressed by reduced expression levels of certain key proteins in this pathway. The present data indicate that ACTL8 serves a role in the progression and clinical prognosis of HNSCC. Therefore, ACTL8 may be a potential prognostic marker and novel therapeutic target for HNSCC.

C6 ceramide motivates the anticancer sensibility induced by PKC412 in preclinical head and neck squamous cell carcinoma models

The purpose of this study was to evaluate the anti-head and neck squamous cell carcinoma (anti-HNSCC) cell activity by C6 ceramide and multikinase inhibitor PKC412. Experiments were performed on HNSCC cell lines (SQ20B and SCC-9) and primary human oral carcinoma cells. Results showed that PKC412 inhibited HNSCC cell proliferation without provoking apoptosis activation. Cotreatment of C6 ceramide significantly augmented PKC412-induced lethality in HNSCC cells. PKC412 decreased Akt-mammalian target of rapamycin (mTOR) activation in HNSCC cells, facilitated with cotreatment of C6 ceramide. In contrast, exogenous expression of a constitutively active Akt restored Akt-mTOR activation and attenuated lethality by the cotreatment. We propose that Mcl-1 is a primary resistance factor of PKC412. The cytotoxicity of PKC412 in HNSCC cells was potentiated with Mcl-1 short hairpin RNA knockdown, but was attenuated with Mcl-1 overexpression. Intriguingly, C6 ceramide downregulated Mcl-1 in HNSCC cells. In vivo, PKC412 oral administration inhibited SQ20B xenograft tumor growth in severe combined immunodeficient mice. The antitumor activity of PKC412 was further sensitized with coadministration of liposomal C6 ceramide. Together, we suggest that PKC412 could be further studied as a promising anti-HNSCC strategy, alone or in combination with C6 ceramide.

Radiochemotherapy with Cisplatin and Oral Tegafur in Advanced Head and Neck Cancer: Long-Term Results of a Phase II Study

Aims and Background

To evaluate the tolerance and efficacy of an original concurrent radiochemotherapy regimen in locally advanced head and neck cancer.

Methods

Sixty-four patients with stage III or IV squamous cell carcinoma arising from a head and neck mucosal site were eligible. Simultaneous radiochemotherapy consisted of two courses of continuous infusional cisplatin (20 mg/m2/d, days 1–4 and 29–32) and oral tegafur (1200 mg/d, days 1–14 and 29–43), together with conventional radiation therapy up to a total dose of 70–75 Gy over nine weeks.

Results

All the patients were evaluated for toxicity and response. Acute mucositis was the most prevalent complication. Grade 3 toxicities were mucositis (44%), skin toxicity (10%), leukopenia (8%), and thrombocytopenia (1%). No toxic death was observed. Complete response to treatment was observed in 72% of patients. With a median follow-up of 48.5 months (range, 27–84), 5-year actuarial rate of local-regional control, disease-free survival, overall survival and disease-specific survival were 60% (95% confidence interval [CI], 40–70%), 55% (95% CI, 45–65%), 51% (95% CI, 43–59%) and 61% (95% CI, 53–69%), respectively.

Conclusions

Response, local-regional control and survival rates are equivalent to those reported from other concomitant radiochemotherapy combinations. However, the regimen offers the advantage of its tolerance and toxicity profile.

Inhibition of Bcl-2 potentiates AZD-2014-induced anti-head and neck squamous cell carcinoma cell activity

Mammalian target of rapamycin (mTOR) is a therapeutic target for head and neck squamous cell carcinoma (HNSCC). Here, we evaluated the activity of AZD-2014, a potent mTOR complex 1/2 (mTORC1/2) dual inhibitor, against HNSCC cells. We showed that AZD-2014 blocked mTORC1/2 activation in established and primary human HNSCC cells, where it was anti-proliferative and pro-apoptotic. Yet, AZD-2014 was non-cytotoxic to the human oral epithelial cells with low basal mTORC1/2 activation. In an effect to identify possible AZD-2014 resistance factors, we showed that the anti-apoptosis protein Bcl-2 was upregulated in AZD-2014-resistant SQ20B HNSCC cells. Inhibition of Bcl-2 by ABT-737 (a known Bcl-2 inhibitor) or Bcl-2 shRNA dramatically potentiated AZD-2014 lethality against HNSCC cells. On the other hand, exogenous overexpression of Bcl-2 largely attenuated AZD-2014's activity against HNSCC cells. For the in vivo studies, we showed that oral gavage of AZD-2014 suppressed SQ20B xenograft growth in severe combined immunodeficient (SCID) mice. It also significantly improved mice survival. Importantly, AZD-2014's anti-HNSCC activity in vivo was potentiated with co-administration of ABT-737. The preclinical results of this study suggest that AZD-2014 could be further tested as a valuable anti-HNSCC agent, either alone or in combination with Bcl-2 inhibitors.

Electrochemistry-based approaches to low cost, high sensitivity, automated, multiplexed protein immunoassays for cancer diagnostics

Early detection and reliable diagnostics are keys to effectively design cancer therapies with better prognoses. The simultaneous detection of panels of biomarker proteins holds great promise as a general tool for reliable cancer diagnostics. A major challenge in designing such a panel is to decide upon a coherent group of biomarkers which have higher specificity for a given type of cancer. The second big challenge is to develop test devices to measure these biomarkers quantitatively with high sensitivity and specificity, such that there are no interferences from the complex serum or tissue matrices. Lastly, integrating all these tests into a technology that does not require exclusive training to operate, and can be used at point-of-care (POC) is another potential bottleneck in futuristic cancer diagnostics. In this article, we review electrochemistry-based tools and technologies developed and/or used in our laboratories to construct low-cost microfluidic protein arrays for the highly sensitive detection of a panel of cancer-specific biomarkers with high specificity which at the same time has the potential to be translated into POC applications.

Role of ubiquitin-specific peptidase 22 in carcinogenesis of human pharyngeal squamous cell carcinoma

Human pharyngeal squamous cell carcinoma (HNSCC) are highly invasive and proliferative and exhibit a poor five-year survival rate, mainly due to poor understanding of HNSCC pathogenesis mechanisms, preventing efficient treatment. Ubiquitin‑specific peptidase 22 (USP22) is an important component of cell cycle regulation, as it indirectly affects chromatin structure via histone ubiquitination and regulates activation of gene transcription. In previous studies, silencing of USP22 significantly inhibited tumor cell proliferation. To investigate the expression levels and the role of USP22 in the carcinogenesis of human pharyngeal squamous cell carcinoma, pharyngeal squamous cell carcinoma and adjacent normal tissue samples were collected from four patients. Six pharyngeal squamous cell carcinoma cell lines (SAS, CAL-33, FaDu, HSC-4, UTSCC-5 and UTSCC-8) were also included in this study. The USP22 mRNA and protein expression levels in the patient and cell‑line samples were evaluated using quantitative polymerase chain reaction and western blotting analyses. Subsequently, stable USP22 gene silencing in cells was achieved using lentiviral-delivered small interfering RNA (siRNA), and an MTT assay was used to evaluate tumor cell proliferation. Expression levels of cell cycle-associated proteins following USP22 knockdown were assessed using western blot analysis. The results revealed that USP22 was upregulated in pharyngeal squamous cell carcinoma. USP22 knockdown, using lentivirus‑delivered siRNA, increased the expression levels of cell cycle proteins P21 and P27, but reduced the levels of phosphorylated retinoblastoma protein, resulting in the inhibition of FaDu cell growth and proliferation. In conclusion, USP22 is involved in the carcinogenesis of human pharyngeal squamous cell carcinoma through regulating tumor cell growth and proliferation.

Rapamycin inhibits Toll-like receptor 4-induced pro-oncogenic function in head and neck squamous cell carcinoma

Toll-like receptor 4 (TLR4) is expressed in head and neck squamous cell carcinoma (HNSCC) cells and is associated with HNSCC cancer progression. Rapamycin has been proven to be efficient for the treatment of HNSCC in vivo, yet the mechanism is not understood and rapamycin demonstrates little effect in vitro. In the present study, the HNSCC cell lines CAL27 and SCC4 were pre-treated with rapamycin then stimulated with a TLR4 ligand lipopolysaccharide (LPS). Cell proliferation, migration, invasion, resistance to TRAIL-induced apoptosis, cytokine production, NF-κB and p65 activation were determined. The results indicated that LPS significantly stimulated HNSCC cell proliferation, cytokine production, migration, invasion and resistance to apoptosis induced by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). Pretreatment with rapamycin significantly attenuated LPS-induced pro-oncogenic effects by inhibiting the activation of NF-κB by LPS. siRNA knockdown of TLR4 in HNSCC cells demonstrated that rapamycin attenuated LPS-induced pro-oncogenic effects via TLR4. Hence, this study suggests rapamycin may be efficient for the treatment of HNSCC by attenuating TLR4-induced pro-oncogenic effects.

Synthesis and anti-proliferative activity evaluation of N3-acyl-N5-aryl-3,5-diaminoindazole analogues as anti-head and neck cancer agent

Background

Head and neck squamous cell carcinoma (HNSCC) is the 11th leading cancer by incidence worldwide. Surgery and radiotherapy have been the major treatment for patients with HNSCC while chemotherapy has become an important treatment option for locally advanced HNSCC. Understanding of the molecular mechanisms underlying HNSCC impelled the development of targeted therapeutic agents. The development and combinations of targeted therapies in different cellular pathways may be needed to fulfill the unmet needs of current HNSCC chemotherapy.

Results

A series of N3-acyl-N5-aryl-3,5-diaminoindazoles were synthesized and their anti-proliferative activities were evaluated against human cancer cell lines, Caki, A549, AMC-HN1, AMC-HN3, AMC-HN4, AMC-HN6, and SNU449. The cellular selectivity of compound was obtained by the modification of substituent at N5-aryl group of 3,5-diaminoindazole. Compound 9a and 9b showed more than 7-fold selectivity for AMC-HN4 and AMC-HN3, respectively.

Conclusions

N3-acyl-N5-aryl-3,5-diaminoindazole analogues can be used as hits in the development of anticancer drug for HNSCC.

TGM3, a candidate tumor suppressor gene, contributes to human head and neck cancer

BACKGROUND

In our previous study using oligonucleotide microarrays, we revealed that transglutaminase 3 (TGM3) was remarkably down-regulated in head and neck cancer (HNC). However, the potential of TGM3 as a useful biomarker or molecular target for HNC is unclear.

METHODS

The transcriptional and post-translational status of TGM3 in HNC cell lines and specimens was detected using real-time PCR and western blot analysis. Bisulfate-treated DNA sequencing was used to analyze the molecular mechanism of TGM3 gene silencing. In addition, the effects of TGM3 on the proliferation, colony formation and induction of apoptosis in vitro and tumorigenicity in vivo were investigated through exogenous expression of TGM3 in HNC cells. Immunohistochemistry was used to evaluate TGM3 expression in large HNC samples.

RESULTS

TGM3 was down-regulated in HNC samples and cell lines (P < 0.0001). The hypermethylation of a promoter CpG island was one of the mechanisms of silencing the TGM3 gene in HNC. Exogenous expression of TGM3 in HNC cells could inhibit the proliferation and enhance the apoptosis of HNC cells in vitro and suppress tumor growth in vivo. In addition, TGM3 protein levels were strongly associated with the pathological differentiation of HNC tissues (P = 0.0037). Survival analysis revealed that low TGM3 expression was associated with worse overall survival (P = 0.0002), and TGM3 expression level was an independent predictor in patients with HNC.

CONCLUSIONS

The studies prove that TGM3, as a candidate tumor suppressor, contributes to the carcinogenesis and development of HNC and may serve as a useful biomarker for patients with HNC.

Sensitive detection of protein and miRNA cancer biomarkers using silicon-based photonic crystals and a resonance coupling laser scanning platform

Enhancement of the fluorescent output of surface-based fluorescence assays by performing them upon nanostructured photonic crystal (PC) surfaces has been demonstrated to increase signal intensities by >8000×. Using the multiplicative effects of optical resonant coupling to the PC in increasing the electric field intensity experienced by fluorescent labels ("enhanced excitation") and the spatially biased funneling of fluorophore emissions through coupling to PC resonances ("enhanced extraction"), PC enhanced fluorescence (PCEF) can be adapted to reduce the limits of detection of disease biomarker assays, and to reduce the size and cost of high sensitivity detection instrumentation. In this work, we demonstrate the first silicon-based PCEF detection platform for multiplexed biomarker assay. The sensor in this platform is a silicon-based PC structure, comprised of a SiO2 grating that is overcoated with a thin film of high refractive index TiO2 and is produced in a semiconductor foundry for low cost, uniform, and reproducible manufacturing. The compact detection instrument that completes this platform was designed to efficiently couple fluorescence excitation from a semiconductor laser to the resonant optical modes of the PC, resulting in elevated electric field strength that is highly concentrated within the region <100 nm from the PC surface. This instrument utilizes a cylindrically focused line to scan a microarray in <1 min. To demonstrate the capabilities of this sensor-detector platform, microspot fluorescent sandwich immunoassays using secondary antibodies labeled with Cy5 for two cancer biomarkers (TNF-α and IL-3) were performed. Biomarkers were detected at concentrations as low as 0.1 pM. In a fluorescent microarray for detection of a breast cancer miRNA biomarker miR-21, the miRNA was detectable at a concentration of 0.6 pM.

Targeted therapy in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) of multi-factorial etiopathogenesis is rising worldwide. Treatment-associated toxicity problems and treatment failure in advanced disease stages with conventional therapies have necessitated a focus on alternative strategies. Molecular targeted therapy, with the potential for increased selectivity and fewer adverse effects, hold promise in the treatment of HNSCC. In an attempt to improve outcomes in HNSCC, targeted therapeutic strategies have been developed. These strategies are focusing on the molecular biology of HNSCC in an attempt to target selected pathways involved in carcinogenesis. Inhibiting tumor growth and metastasis by focusing on specific protein or signal transduction pathways or by targeting the tumor microenvironment or vasculature are some of the new approaches. Targeted agents for HNSCC expected to improve the effectiveness of current therapy include EGFR inhibitors (Cetuximab, Panitumumab, Zalutumumab), EGFR tyrosine kinase inhibitors (Gefitinib, Erloitinib), VEGFR inhibitors (Bevacizumab, Vandetanib), and various inhibitors of, e.g., Src-family kinase, PARP, proteasome, mTOR, COX, and heat shock protein. Moreover, targeted molecular therapy can also act as a complement to other existing cancer therapies. Several studies have demonstrated that the combination of targeting techniques with conventional current treatment protocols may improve the treatment outcome and disease control, without exacerbating the treatment related toxicities. Some of the targeted approaches have been proved as promising therapeutic potentials and are already in use, whereas remainder exhibits mixed result and necessitates further studies. Identification of predictive biomarkers of resistance or sensitivity to these therapies remains a fundamental challenge in the optimal selection of patients most likely to benefit from targeted treatment.

Activation of EGFR promotes squamous carcinoma SCC10A cell migration and invasion via inducing EMT-like phenotype change and MMP-9-mediated degradation of E-cadherin

EGFR is a potent stimulator of invasion and metastasis in head and neck squamous cell carcinomas (HNSCC). However, the mechanism by which EGFR may stimulate tumor cell invasion and metastasis still need to be elucidated. In this study, we showed that activation of EGFR by EGF in HNSCC cell line SCC10A enhanced cell migration and invasion, and induced loss of epitheloid phenotype in parallel with downregulation of E-cadherin and upregulation of N-cadherin and vimentin, indicating that EGFR promoted SCC10A cell migration and invasion possibly by an epithelial to mesenchymal transition (EMT)-like phenotype change. Interestingly, activation of EGFR by EGF induced production of matrix metalloproteinase-9 (MMP-9) and soluble E-cadherin (sE-cad), and knockdown of MMP-9 by siRNA inhibited sE-cad production induced by EGF in SCC10A. Moreover, both MMP-9 knockdown and E-cadherin overexpression inhibited cell migration and invasion induced by EGF in SCC10A. The results indicate that EGFR activation promoted cell migration and invasion through inducing MMP-9-mediated degradation of E-cadherin into sE-cad. Pharmacologic inhibition of EGFR, MEK, and PI3K kinase activity in SCC10A reduced phosphorylated levels of ERK-1/2 and AKT, production of MMP-9 and sE-cad, cell migration and invasion, and expressional changes of EMT markers (E-cadherin and N-cadherin) induced by EGF, indicating that EGFR activation promotes cell migration and invasion via ERK-1/2 and PI3K-regulated MMP-9/E-cadherin signaling pathways. Taken together, the data suggest that EGFR activation promotes HNSCC SCC10A cell migration and invasion by inducing EMT-like phenotype change and MMP-9-mediated degradation of E-cadherin into sE-cad related to activation of ERK-1/2 and PI3K signaling pathways.

Measurement of biomarker proteins for point-of-care early detection and monitoring of cancer

This critical review evaluates progress toward viable point-of-care protein biomarker measurements for cancer detection and diagnostics. The ability to measure panels of specific, selective cancer biomarker proteins in physicians' surgeries and clinics has the potential to revolutionize cancer detection, monitoring, and therapy. The dream envisions reliable, cheap, automated, technically undemanding devices that can analyze a patient's serum or saliva in a clinical setting, allowing on-the-spot diagnosis. Existing commercial products for protein assays are reliable in laboratory settings, but have limitations for point-of-care applications. A number of ultrasensitive immunosensors and some arrays have been developed, many based on nanotechnology. Multilabel detection coupled with high capture molecule density in immunosensors and arrays seems to be capable of detecting a wide range of protein concentrations with sensitivity ranging into the sub pg mL(-1) level. Multilabel arrays can be designed to detect both high and ultralow abundance proteins in the same sample. However, only a few of the newer ultrasensitive methods have been evaluated with real patient samples, which is key to establishing clinical sensitivity and selectivity.

Simultaneous over activation of EGFR, telomerase (h TERT), and cyclin D1 correlates with advanced disease in larynx squamous cell carcinoma: a tissue microarray analysis

Overexpression of Epidermal Growth Factor Receptor (EGFR) and also of cell cycle control proteins, such as cyclin D1 is a frequent event in squamous cell carcinoma of the larynx (LSSC). Our aim was to correlate their protein levels with telomerase catalytic subunit (h-TERT) expression. Using tissue microarray technology, fifty-five paraffin embedded histologically confirmed primary LSSCs and also ten dysplastic lesions were cored at a diameter of 1.5 mm. Immunohistochemistry (IHC) was performed by the use of anti-EGFR, anti-cyclin D1, and anti-h TERT monoclonal antibodies. Chromogenic in situ hybridization (CISH) analysis was also applied using EGFR gene and chromosome 7 probes, respectively. EGFR, cyclin D1 and h-TERT protein overexpression was observed in 48/55 (87.2%), 19/55 (34.5%) and 21/55 (38.1%) carcinoma cases, respectively. EGFR protein expression was statistically associated with grade (P=0.01), and also with stage (P=0.001) of the examined tumors. Borderline statistical significance was assessed correlating overall cyclin D1 expression to h TERT expression (P=0.06). Simultaneous up regulation of the three proteins was established in 7/55 (12.7%) cases, correlated to the stage of the tumors (P=0.05). EGFR gene amplification was observed in 7/65 (10.7%) carcinomas and dysplasias, whereas chromosome 7 aneuploidy was detected in 4/65 (6.1%) of those cases.Simultaneous up regulation of EGFR, cyclin D1 and h TERT proteins correlates with advanced stage in LSCC. EGFR gene amplification and not only protein over expression maybe is the eligible criterion for targeted therapeutic strategies in those patients.

Pharmacological retention of oral mucosa progenitor/stem cells

Oral mucosa progenitor/stem cells reside as a small-sized cell population that eventually differentiates concurrently with an increase in cell size. Activation of the mammalian target of rapamycin (mTOR) leads to an increase in cell size. We hypothesized that rapamycin, a specific inhibitor of mTOR, will maintain primary human oral keratinocytes as a small-sized, undifferentiated cell population capable of retaining their proliferative capacity. Primary, rapamycin-treated (2 nM, 20 nM) oral keratinocytes showed a diminished cell size that correlated with a higher clonogenicity, a longer-term proliferative potential, and a slower cycling cell population concurrent with decreased expression of a differentiation marker when compared with untreated cells. Only the 2-nM rapamycin-treated oral keratinocytes maintained their ability to regenerate oral mucosa in vitro after 15 weeks of culture. Rapamycin, a Food and Drug Administration-approved drug, may have applicability for use in creating a highly proliferative cell population for use in regenerative medicine.

Designing nanomaterial-enhanced electrochemical immunosensors for cancer biomarker proteins

Detection of multiple cancer biomarker proteins in human serum and tissue at point-of-care is a viable approach for early cancer detection, but presents a major challenge to bioanalytical device development. This article reviews recent approaches developed in our laboratories combining nanoparticle decorated electrodes and multilabeled secondary antibody labeled particles to achieve high sensitivity for the detection of cancer biomarker proteins. Two nanomaterial-based sensor platforms were used: (a) upright single wall carbon nanotube forests and (b) layers of densely packed 5 nm gold nanoparticles. Both platforms feature pendant carboxylate groups for easy attachment of enzymes or antibodies by amidization. In quality performance tests, the biocatalytic responses for determination of hydrogen peroxide of AuNP layers with attached horseradish peroxidase (HRP) on electrodes gave somewhat better detection limit and sensitivity than single wall carbon nanotube (SWNT) forest platforms with HRP attached. Evaluation of these sensors as platforms for sandwich immunoassays for cancer biomarker prostate specific antigen (PSA) in serum showed that both approaches gave accurate results for human serum samples from cancer patients. The best detection limit (0.5 pg mL(-1)) and sensitivity were obtained by combining the AuNP immunosensors with binding of 1 mum diameter magnetic particles decorated with secondary antibodies and 7500 HRP labels.

Overview of current and future biologically based targeted therapies in head and neck squamous cell carcinoma

Recent advances in genomics, proteomics, bioinformatics and systems biology have unraveled the complex aberrant signaling networks in cancer. The knowledge accrued has dramatically increased the opportunities for discovery of novel molecular targets for drug development. Major emphasis is being laid on designing new therapeutic strategies targeting multiple signaling pathways for more effective disease management. However, the translation of in vitro findings to patient management often poses major challenges that limit their clinical efficacy. Here we will discuss how understanding the dysregulated signaling networks can explain the pitfalls in translating the laboratory findings from the bench-to-bedside and suggest novel approaches to overcome these problems using head and neck cancer as a prototype. The five year survival rates of HNSCC patients (about 50% at 5 years) have not improved significantly despite advancements in multimodality therapy including surgery, radiation and chemotherapy. Molecular targeted therapies with inhibitors of EGFR and VEGF either alone, or in combination with conventional treatments have shown limited improved efficacy. The key deregulated signaling pathways in head and neck squamous cell carcinoma (HNSCC) include EGFR, Ras, TGFβ, NFκB, Stat, Wnt/β-catenin and PI3-K/AKT/mTOR. The aberrant activities of these interrelated signaling pathways contribute to HNSCC development. In depth understanding of the cross-talks between these pathways and networks will form the basis of developing novel strategies for targeting multiple molecular components for more effective prevention and treatment of HNSCC.

Molecularly targeted agents in the treatment of recurrent or metastatic squamous cell carcinomas of the head and neck

Proof of principle that molecularly targeted therapy is a valid therapeutic approach for squamous cell carcinoma of the head and neck (SCCHN) has emerged with epidermal growth factor receptor targeting agents. Other interesting targets, such as Src, insulin-like growth factor 1 receptor, and the proteasome, have been shown in vitro to play key roles in SCCHN, and their inhibition is currently being studied in phase II trials. Identification of predictive biomarkers of resistance or sensitivity to these therapies remains one of the main challenges in the optimal selection of patients most likely to benefit from them. However, clinical trials with these novel agents need to be designed rationally to improve the overall outcome of patients. Given the emerging evidence that human papilloma virus-related SCCHN is a distinct disease, it should be studied in specific trials.

A phase I clinical study of VB4-845: weekly intratumoral administration of an anti-EpCAM recombinant fusion protein in patients with squamous cell carcinoma of the head and neck

VB4-845 is a scFv-Pseudomonas exotoxin A fusion construct that targets epithelial cell adhesion molecule (EpCAM). A phase I trial was conducted to determine the maximum tolerated dose (MTD) of VB4-845 when administered as weekly intratumoral (IT) injections to patients with squamous cell carcinoma of the head and neck (SCCHN). Secondary objectives included the evaluation of the safety, tolerability, pharmacokinetic profile, and immunogenicity, and a preliminary assessment of tumor response. Twenty patients with advanced, recurrent SCCHN were treated weekly for four weeks in ascending dose cohorts of 100, 200, 330, 500, 700, and 930 microg. The MTD was established as 930 microg with a dose limiting toxicity of elevated liver enzymes in two of five patients. VB4-845 therapy was well tolerated with common treatment-related adverse events of injection site reactions, fever, gastrointestinal disorders, and elevated liver enzyme levels. All patients developed antibodies to VB4-845 by the end of the study, but only seven patients had neutralizing antibodies. Preliminary efficacy data found 87.5% of EpCAM-positive patients had a positive response to VB4-845 therapy. Noninjected dermal metastases were also resolved in one patient. VB4-845 IT therapy is safe and feasible and warrants further clinical evaluation for the treatment of SCCHN.

Hypoxia-induced energy stress inhibits the mTOR pathway by activating an AMPK/REDD1 signaling axis in head and neck squamous cell carcinoma

The mammalian target of rapamycin (mTOR) signaling network is frequently hyperactivated in patients with head and neck squamous cell carcinoma (HNSCC). Recent studies suggest that hypoxia, a common microenvironmental stress found in tumors, blocks this mitogenic pathway. Here, we demonstrate that in HNSCC cell lines, the expression of the phosphorylated forms of the mTOR downstream targets S6 kinase and S6 (pS6) decreased after hypoxia. These events were associated with a marked up-regulation of the regulated in development and DNA damage 1 (REDD1), a recently characterized hypoxia-induced protein that negatively controls mTOR activity. Conversely, pS6 levels were retained under hypoxia in REDD1 knock-down cells and in HNSCC cells lacking endogenous REDD1 expression. Furthermore, we observed that prolonged hypoxia induced an energy-depleting response as evidenced by decreased cellular ATP levels and AMP-activated protein kinase (AMPK) activation. Interestingly, AMPK inhibition before prolonged hypoxia prevented REDD1 expression, thereby sustaining mTOR activity. These results suggest a novel mechanism by which AMPK activation after hypoxia-induced energy stress may be crucial in regulating REDD1 expression to control the mTOR pathway in HNSCC. Furthermore, we found that, in some HNSCC cells, the reduced mTOR activity in response to hypoxia through AMPK/REDD1 was deregulated, which hence might contribute to the persistent activation of the mTOR pathway in this cancer type.

Molecular pathogenesis of oral squamous cell carcinoma: implications for therapy

The development of oral squamous cell carcinoma (OSCC) is a multistep process requiring the accumulation of multiple genetic alterations, influenced by a patient's genetic predisposition as well as by environmental influences, including tobacco, alcohol, chronic inflammation, and viral infection. Tumorigenic genetic alterations consist of two major types: tumor suppressor genes, which promote tumor development when inactivated; and oncogenes, which promote tumor development when activated. Tumor suppressor genes can be inactivated through genetic events such as mutation, loss of heterozygosity, or deletion, or by epigenetic modifications such as DNA methylation or chromatin remodeling. Oncogenes can be activated through overexpression due to gene amplification, increased transcription, or changes in structure due to mutations that lead to increased transforming activity. This review focuses on the molecular mechanisms of oral carcinogenesis and the use of biologic therapy to specifically target molecules altered in OSCC. The rapid progress that has been made in our understanding of the molecular alterations contributing to the development of OSCC is leading to improvements in the early diagnosis of tumors and the refinement of biologic treatments individualized to the specific characteristics of a patient's tumor.

Gene expression profiles in mouse liver cells after exposure to different types of radiation

The liver is one of the target organs of radiation-induced cancers by internal exposures. In order to elucidate radiation-induced liver cancers including Thorotrast, we present a new approach to investigate in vivo effects of internal exposure to alpha-particles. Adopting boron neutron capture, we separately irradiated Kupffer cells and endothelial cells in mouse liver in vivo and analyzed the changes in gene transcriptions by an oligonucleotide microarray. Differential expression was defined as more than 3-fold for up-regulation and less than 1/3 for under-regulation, compared with non-irradiated controls. Of 6,050 genes examined, 68 showed differential expression compared with non-irradiated mice. Real-time polymerase chain reaction validated the results of the microarray analysis. Exposure to alpha-particles and gamma-rays produced different patterns of altered gene expression. Gene expression profiles revealed that the liver was in an inflammatory state characterized by up-regulation of positive acute phase protein genes, irrespective of the target cells exposed to radiation. In comparison with chemical and biological hepatotoxicants, inductions of Metallothionein 1 and Hemopexin, and suppressions of cytochrome P450s are characteristic of radiation exposure. Anti-inflammatory treatment could be helpful for the prevention and protection of radiation-induced hepatic injury.