Nuclear factor-kappa B pathway and response in a phase II trial of bortezomib and docetaxel in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

Inhibition of USP14 promotes TNFα-induced cell death in head and neck squamous cell carcinoma (HNSCC)

TNFα is a key mediator of immune, chemotherapy and radiotherapy-induced cytotoxicity, but several cancers, including head and neck squamous cell carcinomas (HNSCC), display resistance to TNFα due to activation of the canonical NFκB pro-survival pathway. However, direct targeting of this pathway is associated with significant toxicity; thus, it is vital to identify novel mechanism(s) contributing to NFκB activation and TNFα resistance in cancer cells. Here, we demonstrate that the expression of proteasome-associated deubiquitinase USP14 is significantly increased in HNSCC and correlates with worse progression free survival in Human Papillomavirus (HPV)- HNSCC. Inhibition or depletion of USP14 inhibited the proliferation and survival of HNSCC cells. Further, USP14 inhibition reduced both basal and TNFα-inducible NFκB activity, NFκB-dependent gene expression and the nuclear translocation of the NFκB subunit RELA. Mechanistically, USP14 bound to both RELA and IκBα and reduced IκBα K48-ubiquitination leading to the degradation of IκBα, a critical inhibitor of the canonical NFκB pathway. Furthermore, we demonstrated that b-AP15, an inhibitor of USP14 and UCHL5, sensitized HNSCC cells to TNFα-mediated cell death, as well as radiation-induced cell death in vitro. Finally, b-AP15 delayed tumor growth and enhanced survival, both as a monotherapy and in combination with radiation, in HNSCC tumor xenograft models in vivo, which could be significantly attenuated by TNFα depletion. These data offer new insights into the activation of NFκB signaling in HNSCC and demonstrate that small molecule inhibitors targeting the ubiquitin pathway warrant further investigation as a novel therapeutic avenue to sensitize these cancers to TNFα- and radiation-induced cytotoxicity.

Pescadillo ribosomal biogenesis factor 1 reduction suppresses tumour growth and renders chemosensitivity of head and neck squamous cell carcinoma

BACKGROUND

As one of the most devastating cancers, head and neck squamous cell carcinoma (HNSCC) has a short survival time and poor prognosis. Pescadillo ribosomal biogenesis factor 1 (PES1) plays a critical role in the progression of numerous cancers. However, its role and underlying mechanisms in HNSCC remain unclear.

METHODS

A variety of bioinformatic approaches were used to identify the expressions, prognostic and diagnostic value of PES1 in HNSCC. qRT-PCR, immunofluorescence (IF) assay, western blotting and immunohistochemical (IHC) were used to evaluate the expression of PES1 in HNSCC cell lines and clinical tissues. PES1 was knocked down in TU177 and FaDu cells which have high PES1 expression. The effects of PES1 on cell proliferation and tumour growth in HNSCC were elevated by colony formation, CCK8 assays and tumorigenicity assay in nude mice. The effects on cisplatin (CDDP) sensitivity upon silencing of PES1 were assessed using a patient-derived xenograft (PDX) model.

RESULTS

PES1 expression was an independent prognostic factor for HNSCC and negatively associated with the overall survival rate. Silencing of PES1 reduces HNSCC cell proliferation and tumour growth. Moreover, PES1 inhibition significantly sensitises HNSCC cells to cisplatin. Furthermore, we found a PES1 has a high correlation with c-Myc and plays an essential role in the tumour immune microenvironment.

CONCLUSION

Our findings suggest that PES1 is associated with tumour growth and drug resistance and served as a potential cancer marker for diagnosis and a putative therapeutic target for HNSCC.

Proteasome inhibition by bortezomib parallels a reduction in head and neck cancer cells growth, and an increase in tumor-infiltrating immune cells

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy. Thus, the use of innovative therapeutic drugs is being assessed. Bortezomib is a proteasome inhibitor with anticancer effects. In vitro antitumoral activity of Bortezomib was investigated employing human tongue (SCC-15, CAL-27), pharynx (FaDu), salivary gland (A-253) cancer cell lines and a murine cell line (SALTO-5) originated from a salivary gland adenocarcinoma arising in BALB-neuT male mice transgenic for the oncogene neu. Bortezomib inhibited cell proliferation, triggered apoptosis, modulated the expression and activation of pro-survival signaling transduction pathways proteins activated by ErbB receptors and inhibited proteasome activity in vitro. Intraperitoneal administration of Bortezomib delayed tumor growth of SALTO-5 cells transplanted in BALB-neuT mice, protracted mice survival and adjusted tumor microenvironment by increasing tumor-infiltrating immune cells (CD4⁺ and CD8⁺ T cells, B lymphocytes, macrophages, and Natural Killer cells) and by decreasing vessels density. In addition, Bortezomib modified the expression of proteasome structural subunits in transplanted SALTO-5 cells. Our findings further support the use of Bortezomib for the treatment of HNC and reveal its ineffectiveness in counteracting the activation of deregulated specific signaling pathways in HNC cell lines when resistance to proteasome inhibition is developed.

Remimazolan inhibits glioma cell growth and induces apoptosis through down-regulation of NF-κB pathway

Glioma alone accounts for 30% of various kinds of primary brain tumors and is the highest cause of mortality associated with intracranial malignant cancers. In the present study, Suzuki-coupling products of remimazolan were synthesized and investigated for anti-neoplastic property against glioma cells. RFMSP treatment for 48 hr suppressed viabilities of U-118MG and U87MG cells in dose dependent manner. Exposure of primary astrocytes to RFMSP at 2-20 μM concentration range minimally affected viabilities. RFMSP treatment at 5 μM doses raised apoptotic cell count to 53.8 ± 2.3% and 48.2 ± 1.8%, respectively in U-118MG and U87MG cells. Treatment of the cells with RFMSP induced nuclear condensation and subsequent fragmentation. In RFMSP treated U-118MG and U87MG cells, NF-κB p65 expression was markedly suppressed compared to the control cells. Additionally, RFMSP treatment decreased the ratio of nuclear to total NF-κB p65 level in both the cell lines. Treatment of U-118MG and U87MG cells with 5 μM RFMSP for 48 hr caused a marked down-regulation in survivin and XIAP levels. Treatment with RFMSP promoted Bax expression and suppressed Bcl-2 level. The caspase-9 and -3 activation was markedly induced by RFMSP treatment in U-118MG and U87MG cells compared to the control cells. In summary, the RFMSP synthesized by Suzuki-coupling of RFMSP inhibited glioma cell survival via DNA damage mediated apoptosis. The anti-glioma potential of RFMSP involved down-regulation of NF-κB expression, targeted survivin & XIAP levels and induced caspase activation in glioma cells. Therefore, RFMSP may be studied further as therapeutic agent for the treatment of glioma.

Regulation of NFκB Signalling by Ubiquitination: A Potential Therapeutic Target in Head and Neck Squamous Cell Carcinoma?

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with over 600,000 cases per year. The primary causes for HNSCC include smoking and alcohol consumption, with an increasing number of cases attributed to infection with Human Papillomavirus (HPV). The treatment options for HNSCC currently include surgery, radiotherapy, and/or platinum-based chemotherapeutics. Cetuximab (targeting EGFR) and Pembrolizumab (targeting PD-1) have been approved for advanced stage, recurrent, and/or metastatic HNSCC. Despite these advances, whilst HPV+ HNSCC has a 3-year overall survival (OS) rate of around 80%, the 3-year OS for HPV- HNSCC is still around 55%. Aberrant signal activation of transcription factor NFκB plays an important role in the pathogenesis and therapeutic resistance of HNSCC. As an important mediator of inflammatory signalling and the immune response to pathogens, the NFκB pathway is tightly regulated to prevent chronic inflammation, a key driver of tumorigenesis. Here, we discuss how NFκB signalling is regulated by the ubiquitin pathway and how this pathway is deregulated in HNSCC. Finally, we discuss the current strategies available to target the ubiquitin pathway and how this may offer a potential therapeutic benefit in HNSCC.

Clinical Development of Molecular Targeted Therapy in Head and Neck Squamous Cell Carcinoma

A better understanding of cancer biology has led to the development of molecular targeted therapy, which has dramatically improved the outcome of some cancer patients, especially when a biomarker of efficacy has been used for patients' selection. In head and neck oncology, cetuximab that targets epidermal growth factor receptor is the only targeted therapy that demonstrated a survival benefit, both in the recurrent and in the locally advanced settings, yet without prior patients' selection. We herein review the clinical development of targeted therapy in head and neck squamous cell carcinoma in light of the molecular landscape and give insights in on how innovative clinical trial designs may speed up biomarker discovery and deployment of new molecular targeted therapies. Given the recent approval of immune checkpoint inhibitors targeting programmed cell death-1 in head and neck squamous cell carcinoma, it remains to be determined how targeted therapy will be incorporated into a global drug development strategy that will inevitably incorporate immunotherapy.

Target therapies in recurrent or metastatic head and neck cancer: state of the art and novel perspectives. A systematic review

Recurrent or metastatic head and neck squamous-cell carcinomas (R/M HNSCC) are a group of cancers with a very poor prognosis. Many clinical trials testing novel target therapies in this setting are currently ongoing. We performed a systematic review focusing our attention on all clinical trials, ongoing or already published, concerning the use of novel drugs for treatment of R/M HNSCC. We found that the research of novel molecules effective in treatment of R/M HNSCC has been intense during last decade, and nowadays it is still very active. Unfortunately, the results in this setting have been, overall, disappointing: until now, only cetuximab and, recently, nivolumab and pembrolizumab received authorization for treatment of R/M HNSCC. Nevertheless, the promising results showed by some novel drugs may lead to continue the research in this field, with the aim of producing more evidence and finding new therapeutic indication.

Optimizing treatments for recurrent or metastatic head and neck squamous cell carcinoma

INTRODUCTION

The majority of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) will recur. The treatment of patients with recurrent/metastatic (R/M HNSCC) is rapidly evolving. Areas covered: This article will comprehensively review the current systemic treatment of R/M HNSCC. Expert commentary: For the time being, the EXTREME regimen (cetuximab in combination with platinum and 5-fluorouracil) still remains standard of care in previously untreated R/M HNSCC patients who are candidates for combination chemotherapy. Single agents with well documented activity in HNSCC include methotrexate, cisplatin, 5-FU, docetaxel, and paclitaxel. The anti-PD-1 monoclonal antibody nivolumab can be considered the current standard of care in patients with R/M HNSCC progressing after platinum-based therapy based on the results of CheckMate 141 showing a survival benefit over standard of care drugs, such as single agent weekly cetuximab, methotrexate, or docetaxel. Multiple randomized phase III trials comparing anti-PD(L)-antibodies either as single agent or in combination with chemotherapy or an anti-CTLA-4 with the EXTREME as fist line treatment are ongoing or planned. The outcome of these trials might change the current treatment paradigm in previously untreated R/M HNSCC. Immunotherapeutic agents under active investigation include Toll-like receptor 8 agonists and inhibitors of IDO1.

A novel and effective inhibitor combination involving bortezomib and OTSSP167 for breast cancer cells in light of label-free proteomic analysis

PURPOSE

The 26S proteasome plays important roles in many intracellular processes and is therefore a critical intracellular cellular target for anticancer treatments. The primary aim of the current study was to identify critical proteins that may play roles in opposing the antisurvival effect of the proteasome inhibitor bortezomib together with the calcium-chelator BAPTA-AM in cancer cells using label-free LC-MS/MS. In addition, based on the results of the proteomic technique, a novel and more effective inhibitor combination involving bortezomib as well as OTSSP167 was developed for breast cancer cells.

METHODS AND RESULTS

Using label-free LC-MS/MS, it was found that expressions of 1266 proteins were significantly changed between the experimental groups. Among these proteins were cell division cycle 5-like (Cdc5L) and drebrin-like (DBNL). We then hypothesized that inhibition of the activities of these two proteins may lead to more effective anticancer inhibitor combinations in the presence of proteasomal inhibition. In fact, as presented in the current study, Cdc5L phosphorylation inhibitor CVT-313 and DBNL phosphorylation inhibitor OTSSP167 were highly cytotoxic in 4T1 breast cancer cells and their IC₅₀ values were 20.1 and 43 nM, respectively. Under the same experimental conditions, the IC₅₀ value of BAPTA-AM was found 19.9 μM. Using WST 1 cytotoxicity assay, it was determined that 10 nM bortezomib + 10 nM CVT-313 was more effective than the control, the single treatments, or than 5 nM bortezomib + 5 nM CVT-313. Similarly, 10 nM bortezomib + 10 nM OTSSP167 was more cytotoxic than the control, the monotherapies, 5 nM bortezomib + 5 nM OTSSP167, or than 5 nM bortezomib + 10 nM OTSSP167, indicating that bortezomib + OTSSP167 was also more effective than bortezomib + CVT-313 in a dose-dependent manner. Furthermore, the 3D spheroid model proved that bortezomib + OTSSP167 was more effective than the monotherapies as well as bortezomib + CVT-313 and bortezomib + BAPTA-AM combinations. Finally, the effect of bortezomib + OTSSP167 combination was tested on MDA-MB-231 breast cancer cells, and it similarly determined that 20 nM bortezomib +40 nM OTSSP167 combination completely blocked the formation of 3D spheroids.

CONCLUSIONS

Altogether, the results presented here indicate that bortezomib + OTSSP167 is a novel and effective combination and may be tested further for cancer treatment in vivo and in clinical settings.

Application of molecular targeted therapies in the treatment of head and neck squamous cell carcinoma

Despite the development of standard therapies, including surgery, radiotherapy and chemotherapy, survival rates for head and neck squamous cell carcinoma (HNSCC) have not changed significantly over the past three decades. Complete recovery is achieved in <50% of patients. The treatment of advanced HNSCC frequently requires multimodality therapy and involves significant toxicity. The promising, novel treatment option for patients with HNSCC is molecular-targeted therapies. The best known targeted therapies include: Epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab, panitumumab, zalutumumab and nimotuzumab), EGFR tyrosine kinase inhibitors (gefitinib, erlotinib, lapatinib, afatinib and dacomitinib), vascular endothelial growth factor (VEGF) inhibitor (bevacizumab) or vascular endothelial growth factor receptor (VEGFR) inhibitors (sorafenib, sunitinib and vandetanib) and inhibitors of phosphatidylinositol 3-kinase/serine/threonine-specific protein kinase/mammalian target of rapamycin. There are also various inhibitors of other pathways and targets, which are promising and require evaluation in further studies.

A versatile nanoplatform for synergistic combination therapy to treat human esophageal cancer

One of the major goals of precision oncology is to promote combination therapy to improve efficacy and reduce side effects of anti-cancer drugs based on their molecular mechanisms. In this study, we aimed to develop and validate new nanoformulations of docetaxel (DTX) and bortezomib (BTZ) for targeted combination therapy to treat human esophageal cancer. By leveraging our versatile disulfide cross-linked micelles (DCMs) platform, we developed nanoformulations of DTX and BTZ (named DTX-DCMs and BTZ-DCMs). Their physical properties were characterized; their anti-cancer efficacies and mechanisms of action were investigated in a human esophageal cancer cell line in vitro. Furthermore, the in vitro anti-tumor activities of combination therapies (concurrent drug treatment, sequential drug treatment, and treatment using different ratios of the drugs) were examined in comparison with the single drug treatment and free drug strategies. These drug-loaded nanoparticles were spherical in shape and relatively small in size of approximately 20-22 nm. The entrapment efficiencies of DTX and BTZ into nanoparticles were 82.4% and 84.1%, respectively. The drug release rates of DTX-DCMs and BTZ-DCMs were sustained, and greatly increased in the presence of GSH. These nanodrugs were effectively internalized by KYSE30 esophageal cancer cells, and dose-dependently induced cell apoptosis. We further revealed a strong synergistic effect between DTX-DCMs and BTZ-DCMs against KYSE30 esophageal cancer cells. Sequential combination therapy with DTX-DCMs followed by BTZ-DCMs exhibited the best anti-tumor efficacy in vitro. This study demonstrates that DTX and BTZ could be successfully nanoformulated into disulfide cross-linked micelles. The nanoformulations of DTX and BTZ demonstrate an immense potential for synergistic combination therapy to treat human esophageal cancer.

Molecular mechanisms for synergistic effect of proteasome inhibitors with platinum-based therapy in solid tumors

The successful development of the proteasome inhibitor bortezomib as an anticancer drug has improved survival in patients with multiple myeloma. With the emergence of the newly US Food and Drug Administration-approved proteasome inhibitor carfilzomib, ongoing trials are investigating this compound and other proteasome inhibitors either alone or in combination with other chemotherapy drugs. However, in solid tumors, the efficacy of proteasome inhibitors has not lived up to expectations. Results regarding the potential clinical efficacy of bortezomib combined with other agents in the treatment of solid tumors are eagerly awaited. Recent identification of the molecular mechanisms (involving apoptosis and autophagy) by which bortezomib and cisplatin can overcome chemotherapy resistance and sensitize tumor cells to anticancer therapy can provide insights into the development of novel therapeutic strategies for patients with solid malignancies.

Visualizing the antivascular effect of bortezomib on the hypoxic tumor microenvironment

Bortezomib, a novel proteasome inhibitor, has been approved for treating multiple myeloma and mantle cell lymphoma and studied pre-clinically and clinically for solid tumors. Preferential cytotoxicity of bortezomib was found toward hypoxic tumor cells and endothelial cells in vitro. The purpose of this study is to investigate the role of a pretreatment hypoxic tumor microenvironment on the effects of bortezomib in vitro and ex vivo, and explore the feasibility of dynamic contrast enhanced magnetic resonance imaging (DCE MRI) to noninvasively evaluate the biological effects of bortezomib. It was shown in vitro by Western blot, flow cytometry, and ELISA that bortezomib accumulated HIF-1α in non-functional forms and blocks its hypoxia response in human colorectal cancer cell lines. Ex vivo experiments were performed with fluorescent immunohistochemical staining techniques using multiple endogenous and exogenous markers to identify hypoxia (pimonidazole, HRE-TKeGFP), blood flow/permeability (Hoechst 33342), micro-vessels (CD31 and SMA), apoptosis (cleaved caspase 3) and hypoxia response (CA9). After bortezomib administration, overall apoptosis index was significantly increased and blood perfusion was dramatically decreased in tumor xenografts. More importantly, apoptosis signals were found preferentially located in moderate and severe pretreatment hypoxic regions in both tumor and endothelial cells. Meanwhile, DCE MRI examinations showed that the tumor blood flow and permeability decreased significantly after bortezomib administration. The present study revealed that bortezomib reduces tumor hypoxia response and blood perfusion, thus, presenting antivascular properties. It will be important to determine the hypoxic/perfusion status pre- and during treatment at further translational studies.

Inhibition of HDAC6 Protein Enhances Bortezomib-induced Apoptosis in Head and Neck Squamous Cell Carcinoma (HNSCC) by Reducing Autophagy

Chemoresistance is a major barrier to effective chemotherapy of solid tumors, including head and neck squamous cell carcinoma (HNSCC). Recently, autophagy, a highly conservative intracellular recycling system, has shown to be associated with chemoresistance in cancer cells. However, little is known about how autophagy plays a role in the development of chemoresistance in HNSCC and how autophagy is initiated when HNSCC cells undergo cytotoxic stress. Here, we report that autophagy was activated when HNSCC cells are treated with the proteasome inhibitor bortezomib, proposed as an alternative chemotherapeutic agent for both primary and cisplatin-resistant HNSCC cells. Ablation of histone deacetylase 6 (HDAC6) expression and its activity in HNSCC cells significantly inhibited autophagy induction by altering the phosphorylation status of mammalian target of rapamycin and enhanced the bortezomib cytotoxicity. Similarly, a combination regimen of bortezomib and the histone deacetylase inhibitor trichostatin A abolished HDAC6 activity and decreased autophagy induction while significantly enhancing bortezomib-induced apoptosis in HNSCC cells. These data uncover a novel molecular mechanism indicating that HDAC6 may serve as a critical causal link between autophagy, apoptosis, and the cell survival response in HNSCC. A combination regimen resulting in regression of autophagy improves chemotherapeutic efficacy, thereby providing a new strategy to overcome chemoresistance and to improve the treatment and survival of HNSCC patients.

Garcinol sensitizes human head and neck carcinoma to cisplatin in a xenograft mouse model despite downregulation of proliferative biomarkers

Platinum compounds such as cisplatin and carboplatin are frequently used as the first-line chemotherapy for the treatment of the head and neck squamous cell carcinoma (HNSCC). In the present study, we investigated whether garcinol, a polyisoprenylated benzophenone can chemosensitize HNSCC to cisplatin. We found that garcinol inhibited the viability of a panel of diverse HNSCC cell lines, enhanced the apoptotic effect of cisplatin, suppressed constitutive as well as cisplatin-induced NF-κB activation, and downregulated the expression of various oncogenic gene products (cyclin D1, Bcl-2, survivin and VEGF). In vivo study showed that administration of garcinol alone (0.5 mg/kg body weight, i.p. five times/week) significantly suppressed the growth of the tumor, and this effect was further increased by cisplatin. Both the markers of proliferation index (Ki-67) and microvessel density (CD31) were downregulated in tumor tissues by the combination of cisplatin and garcinol. The pharmacokinetic results of garcinol indicated that good systemic exposure was achievable after i.p. administration of garcinol at 0.5 mg/kg and 2 mg/kg with mean peak concentration (Cmax) of 1825.4 and 6635.7 nM in the mouse serum, respectively. Overall, our results suggest that garcinol can indeed potentiate the effects of cisplatin by negative regulation of various inflammatory and proliferative biomarkers.

Efficacy of therapy with bortezomib in solid tumors: a review based on 32 clinical trials

The ubiquitin-proteasome system is a major pathway for protein degradation, so that proteasome is now considered as an important target for drug discovery. Bortezomib, the first US FDA-approved proteasome inhibitor now used as a front-line treatment for multiple myeloma. To better understand the effects of bortezomib in cancer treatment, we carried out a review based on 32 published clinical trials to determine whether bortezomib will benefit patients with solid tumors. Information of complete response, partial response, stable disease and objective response rate was collected to assess clinical outcomes. A lack of therapeutic effects was observed when bortezomib was used as a single agent. Meanwhile, when bortezomib treatment was combined with other agents, bortezomib offered no statistically significant response versus these agents alone. High-quality studies are required to better understand the clinically effects of bortezomib and the development of a new generation of proteasome inhibitors is absolutely necessary.

The ubiquitin-proteasome system: opportunities for therapeutic intervention in solid tumors

The destruction of proteins via the ubiquitin-proteasome system is a multi-step, complex process involving polyubiquitination of substrate proteins, followed by proteolytic degradation by the macromolecular 26S proteasome complex. Inhibitors of the proteasome promote the accumulation of proteins that are deleterious to cell survival, and represent promising anti-cancer agents. In multiple myeloma and mantle cell lymphoma, treatment with the first-generation proteasome inhibitor, bortezomib, or the second-generation inhibitor, carfilzomib, has demonstrated significant therapeutic benefit in humans. This has prompted United States Food and Drug Administration (US FDA) approval of these agents and development of additional second-generation compounds with improved properties. There is considerable interest in extending the benefits of proteasome inhibitors to the treatment of solid tumor malignancies. Herein, we review progress that has been made in the preclinical development and clinical evaluation of different proteasome inhibitors in solid tumors. In addition, we describe several novel approaches that are currently being pursued for the treatment of solid tumors, including drug combinatorial strategies incorporating proteasome inhibitors and the targeting of components of the ubiquitin-proteasome system that are distinct from the 26S proteasome complex.

Molecular pathways: linking tumor microenvironment to epithelial-mesenchymal transition in metastasis

During tumor development, tumor cells constantly communicate with the surrounding microenvironment through both biochemical and biophysical cues. In particular, the tumor microenvironment can instruct carcinoma cells to undergo a morphogenesis program termed epithelial-to-mesenchymal transition (EMT) to facilitate local invasion and metastatic dissemination. Growing evidence uncovered a plethora of microenvironmental factors in promoting EMT, including proinflammatory cytokines secreted by locally activated stromal cells, hypoxia conditions, extracellular matrix components, and mechanical properties. Here, we review various biochemical and biophysical factors in the tumor microenvironment that directly impinge upon the EMT program. Specifically, cytokines such as TGFβ, TNFα, and IL6 and hypoxia are capable of inducing EMT in various tumors. Several extracellular matrix (ECM) proteins, including collagen-I, fibronectin, and hyaluronan, and ECM remodeling via extracellular lysyl oxidase are also implicated in regulating EMT. In preclinical studies and ongoing clinical trials, targeting these tumor microenvironmental signals has shown promises in halting tumor progression in various human cancers.

A 3'-UTR KRAS-variant is associated with cisplatin resistance in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

BACKGROUND

A germline mutation in the 3'-untranslated region of KRAS (rs61764370, KRAS-variant: TG/GG) has previously been associated with altered patient outcome and drug resistance/sensitivity in various cancers. We examined the prognostic and predictive significance of this variant in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

PATIENTS AND METHODS

We conducted a retrospective study of 103 HNSCCs collected from three completed clinical trials. KRAS-variant genotyping was conducted for these samples and 8 HNSCC cell lines. p16 expression was determined in a subset of 26 oropharynx tumors by immunohistochemistry. Microarray analysis was also utilized to elucidate differentially expressed genes between KRAS-variant and non-variant tumors. Drug sensitivity in cell lines was evaluated to confirm clinical findings.

RESULTS

KRAS-variant status was determined in 95/103 (92%) of the HNSCC tumor samples and the allelic frequency of TG/GG was 32% (30/95). Three of the HNSCC cell lines (3/8) studied had the KRAS-variant. No association between KRAS-variant status and p16 expression was observed in the oropharynx subset (Fisher's exact test, P = 1.0). With respect to patient outcome, patients with the KRAS-variant had poor progression-free survival when treated with cisplatin (log-rank P = 0.002). Conversely, KRAS-variant patients appeared to experience some improvement in disease control when cetuximab was added to their platinum-based regimen (log-rank P = 0.04).

CONCLUSIONS

The TG/GG rs61764370 KRAS-variant is a potential predictive biomarker for poor platinum response in R/M HNSCC patients.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT00503997, NCT00425750, NCT00003809.

Carfilzomib and oprozomib synergize with histone deacetylase inhibitors in head and neck squamous cell carcinoma models of acquired resistance to proteasome inhibitors

Acquired resistance to proteasome inhibitors represents a considerable impediment to their effective clinical application. Carfilzomib and its orally bioavailable structural analog oprozomib are second-generation, highly-selective, proteasome inhibitors. However, the mechanisms of acquired resistance to carfilzomib and oprozomib are incompletely understood, and effective strategies for overcoming this resistance are needed. Here, we developed models of acquired resistance to carfilzomib in two head and neck squamous cell carcinoma cell lines, UMSCC-1 and Cal33, through gradual exposure to increasing drug concentrations. The resistant lines R-UMSCC-1 and R-Cal33 demonstrated 205- and 64-fold resistance, respectively, relative to the parental lines. Similarly, a high level of cross-resistance to oprozomib, as well as paclitaxel, was observed, whereas only moderate resistance to bortezomib (8- to 29-fold), and low level resistance to cisplatin (1.5- to 5-fold) was seen. Synergistic induction of apoptosis signaling and cell death, and inhibition of colony formation followed co-treatment of acquired resistance models with carfilzomib and the histone deacetylase inhibitor (HDACi) vorinostat. Synergism was also seen with other combinations, including oprozomib plus vorinostat, or carfilzomib plus the HDACi entinostat. Synergism was accompanied by upregulation of proapoptotic Bik, and suppression of Bik attenuated the synergy. The acquired resistance models also exhibited elevated levels of MDR-1/P-gp. Inhibition of MDR-1/P-gp with reversin 121 partially overcame carfilzomib resistance in R-UMSCC-1 and R-Cal33 cells. Collectively, these studies indicate that combining carfilzomib or oprozomib with HDAC or MDR-1/P-gp inhibitors may be a useful strategy for overcoming acquired resistance to these proteasome inhibitors.

Preserving biological heterogeneity with a permuted surrogate variable analysis for genomics batch correction

MOTIVATION

Sample source, procurement process and other technical variations introduce batch effects into genomics data. Algorithms to remove these artifacts enhance differences between known biological covariates, but also carry potential concern of removing intragroup biological heterogeneity and thus any personalized genomic signatures. As a result, accurate identification of novel subtypes from batch-corrected genomics data is challenging using standard algorithms designed to remove batch effects for class comparison analyses. Nor can batch effects be corrected reliably in future applications of genomics-based clinical tests, in which the biological groups are by definition unknown a priori.

RESULTS

Therefore, we assess the extent to which various batch correction algorithms remove true biological heterogeneity. We also introduce an algorithm, permuted-SVA (pSVA), using a new statistical model that is blind to biological covariates to correct for technical artifacts while retaining biological heterogeneity in genomic data. This algorithm facilitated accurate subtype identification in head and neck cancer from gene expression data in both formalin-fixed and frozen samples. When applied to predict Human Papillomavirus (HPV) status, pSVA improved cross-study validation even if the sample batches were highly confounded with HPV status in the training set.

AVAILABILITY AND IMPLEMENTATION

All analyses were performed using R version 2.15.0. The code and data used to generate the results of this manuscript is available from https://sourceforge.net/projects/psva.

Genetic alterations in head and neck squamous cell carcinoma: The next-gen sequencing era

Head and neck squamous cell carcinoma is the sixth most common cancer in the world with approximately 650000 new cases diagnosed annually. Next-generation molecular techniques and results from phase 2 of the Cancer Genome Atlas becoming available have drastically improved our current knowledge on the genetics basis of head and neck squamous cell carcinoma. New insights and new perspectives on the mutational landscape implicated in head and neck squamous cell carcinoma provide improved tools for prognostication. More importantly, depend on the patient’s tumor subtypes and prognosis, deescalated or more aggressive therapy maybe chosen to achieve greater potency while minimizing the toxicity of therapy. This paper aims to review our current knowledge on the genetic mutations and altered molecular pathways in head and neck squamous cell carcinoma. Some of the most common mutations in head and neck squamous cell carcinoma reported by the cancer genome atlas including TP53, NOTCH1, Rb, CDKN2A, Ras, PIK3CA and EGFR are described here. Additionally, the emerging role of epigenetics and the role of human papilloma virus in head and neck squamous cell carcinoma are also discussed in this review. The molecular pathways, clinical applications, actionable molecular targets and potential therapeutic strategies are highlighted and discussed in details.

Saponin 1 induces apoptosis and suppresses NF-κB-mediated survival signaling in glioblastoma multiforme (GBM)

Saponin 1 is a triterpeniod saponin extracted from Anemone taipaiensis, a traditional Chinese medicine against rheumatism and phlebitis. It has also been shown to exhibit significant anti-tumor activity against human leukemia (HL-60 cells) and human hepatocellular carcinoma (Hep-G2 cells). Herein we investigated the effect of saponin 1 in human glioblastoma multiforme (GBM) U251MG and U87MG cells. Saponin 1 induced significant growth inhibition in both glioblastoma cell lines, with a 50% inhibitory concentration at 24 h of 7.4 µg/ml in U251MG cells and 8.6 µg/ml in U87MG cells, respectively. Nuclear fluorescent staining and electron microscopy showed that saponin 1 caused characteristic apoptotic morphological changes in the GBM cell lines. Saponin 1-induced apoptosis was also verified by DNA ladder electrophoresis and flow cytometry. Additionally, immunocytochemistry and western blotting analyses revealed a time-dependent decrease in the expression and nuclear location of NF-κB following saponin 1 treatment. Western blotting data indicated a significant decreased expression of inhibitors of apoptosis (IAP) family members,(e.g., survivin and XIAP) by saponin 1. Moreover, saponin 1 caused a decrease in the Bcl-2/Bax ratio and initiated apoptosis by activating caspase-9 and caspase-3 in the GBM cell lines. These findings indicate that saponin 1 inhibits cell growth of GBM cells at least partially by inducing apoptosis and inhibiting survival signaling mediated by NF-κB. In addition, in vivo study also demonstrated an obvious inhibition of saponin 1 treatment on the tumor growth of U251MG and U87MG cells-produced xenograft tumors in nude mice. Given the minimal toxicities of saponin 1 in non-neoplastic astrocytes, our results suggest that saponin 1 exhibits significant in vitro and in vivo anti-tumor efficacy and merits further investigation as a potential therapeutic agent for GBM.

Targeted therapies for squamous cell carcinoma of the head and neck: current knowledge and future directions

Despite progress in the therapeutic management of patients with squamous cell carcinoma of the head and neck (SCCHN), the mortality rate of patients presenting with advanced disease remains high. One approach to improve treatment efficacy is to add novel molecular targeted agents to the classical treatment regimens. Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) have shown clinical benefits in palliative and curative settings. However, only a minority of patients presenting with recurrent or metastatic (R/M) SCCHN have meaningful tumor regression with these agents and virtually all who do develop acquired tumor resistance after a few months of treatment. For these reasons, other inhibitors of EGFR or molecules that interfere with known molecular pathways activated in SCCHN are of considerable interest, either as single agents or in combination with other treatment modalities. In this review, we discuss the different molecular therapeutic approaches explored in SCCHN. We also briefly outline new trial designs that could be used to accelerate the investigation of emerging therapeutic agents in this disease.

Can medical herbs stimulate regeneration or neuroprotection and treat neuropathic pain in chemotherapy-induced peripheral neuropathy?

Chemotherapy-induced neuropathy (CIPN) has a relevant impact on the quality of life of cancer patients. There are no curative conventional treatments, so further options have to be investigated. We conducted a systematic review in English and Chinese language databases to illuminate the role of medical herbs. 26 relevant studies on 5 single herbs, one extract, one receptor-agonist, and 8 combinations of herbs were identified focusing on the single herbs Acorus calamus rhizoma, Cannabis sativa fructus, Chamomilla matricaria, Ginkgo biloba, Salvia officinalis, Sweet bee venom, Fritillaria cirrhosae bulbus, and the herbal combinations Bu Yang Huan Wu, modified Bu Yang Huan Wu plus Liuwei Di Huang, modified Chai Hu Long Gu Mu Li Wan, Geranii herba plus Aconiti lateralis praeparata radix , Niu Che Sen Qi Wan (Goshajinkigan), Gui Zhi Jia Shu Fu Tang (Keishikajutsubuto), Huang Qi Wu Wu Tang (Ogikeishigomotsuto), and Shao Yao Gan Cao Tang (Shakuyakukanzoto). The knowledge of mechanism of action is still limited, the quality of clinical trials needs further improvement, and studies have not yielded enough evidence to establish a standard practice, but a lot of promising substances have been identified. While CIPN has multiple mechanisms of neuronal degeneration, a combination of herbs or substances might deal with multiple targets for the aim of neuroprotection or neuroregeneration in CIPN.

A phase II study of temsirolimus and erlotinib in patients with recurrent and/or metastatic, platinum-refractory head and neck squamous cell carcinoma

OBJECTIVES

The epidermal growth factor receptor (EGFR) is a validated target in head and neck squamous cell carcinoma (HNSCC). In recurrent and/or metastatic (R/M) HNSCC, resistance to anti-EGFR therapy inevitably occurs. Downstream activation of the PI3K/Akt/mTOR pathway is an established resistance mechanism. Concurrent mTOR blockade may improve efficacy of anti-EGFR therapy.

MATERIALS AND METHODS

Erlotinib 150 mg daily and temsirolimus 15 mg weekly were administered to patients with platinum-refractory R/M HNSCC and ECOG performance status 0-2. The primary endpoint was progression-free survival (PFS). Correlative studies determined PIK3CA and HRAS mutation status; p16, EGFR, pS6K, pAkt and PTEN expression; and pre- and post-treatment plasma levels of 20 immunomodulatory cytokines.

RESULTS

Twelve patients enrolled; six withdrew within 6 weeks due to toxicity or death, prompting early closure of the trial. Grade ≥ 3 toxicities included fatigue, diarrhea, gastrostomy tube infection, peritonitis, pneumonia, dyspnea, and HN edema. Median PFS was 1.9 months. Median overall survival was 4.0 months. Six/12 tumors were p16(+), 9/11 lacked measurable PTEN expression, and 1/12 harbored a PIK3CA mutation. On exploratory analysis, high baseline plasma VEGF and interferon-gamma levels marginally associated with tumor progression.

CONCLUSIONS

The combination of erlotinib and temsirolimus was poorly tolerated. Low prevalence of PTEN expression and 8% incidence of PIK3CA mutations indicate biological relevance of this pathway in R/M disease. Investigation of more tolerable combinations of EGFR and PI3K/Akt/mTOR pathway inhibitors in selected HNSCC patients is warranted.

Future directions and treatment strategies for head and neck squamous cell carcinomas

Head and neck cancer is a devastating disease that afflicts many individuals worldwide. Conventional therapies are successful in only a limited subgroup and often leave the patient with disfigurement and long lasting adverse effects on normal physiologic functions. The field is in dire need of new therapies. Oncolytic viral as well as targeted therapies have shown some success in other malignancies and are attractive for the treatment of head and neck cancer. Recently, it has been shown that a subset of head and neck cancers is human papillomavirus (HPV) positive and that this subset of cancers is biologically distinct and more sensitive to chemoradiation therapies although the underlying mechanism is unclear. However, chemoresistance remains a general problem. One candidate mediator of therapeutic response, which is of interest for the targeting of both HPV-positive and -negative tumors is the human DEK proto-oncogene. DEK is upregulated in numerous tumors including head and neck cancers regardless of their HPV status. Depletion of DEK in tumor cells in culture results in sensitivity to genotoxic agents, particularly in rapidly proliferating cells. This suggests that tumors with high DEK protein expression may be correlated with poor clinical response to clastogenic therapies. Targeting molecules such as DEK in combination with new and/or conventional therapies, holds promise for novel future therapeutics for head and neck cancer.

Autophagic action of new targeting agents in head and neck oncology

The survival rates of patients with squamous cell carcinoma of the head and neck (HNSCC) have not improved significantly despite multi-modality therapy, including surgery, radiation therapy, and chemotherapy. Recently, molecular targeted agents have shown significant improvement in clinical outcomes; for example, in chronic myelogeneous leukemia with imatinib, breast cancer with trastuzumab, colon cancer with bevacizumab and cetuximab, and renal cell cancer with sorafenib and sunitinib. In HNSCC, the epidermal growth factor receptor antibody cetuximab has shown promising results in combination with radiation. Targeted agents including cetuximab induce stresses to activate prosurvival autophagy. Combining autophagy inhibitors with agents that induce autophagy as a prosurvival response may therefore increase their therapeutic efficacy. Whether autophagy contributes to the prosurvival response or to the antitumor effect of chemotherapeutic drugs is largely unknown. This review will discuss the possible role of autophagy as a novel target for anticancer therapy agents in HNSCC.

Phase II 2-arm trial of the proteasome inhibitor, PS-341 (bortezomib) in combination with irinotecan or PS-341 alone followed by the addition of irinotecan at time of progression in patients with locally recurrent or metastatic squamous cell carcinoma of the head and neck (E1304): a trial of the Eastern Cooperative Oncology Group

BACKGROUND

Constitutive activation of nuclear factor κB (NF-κB) is associated with poor prognosis. Irinotecan demonstrates single-agent activity in head and neck cancer but activates NF-κB, promoting cell survival and resistance. Bortezomib is a proteasome inhibitor that inactivates NF-κB.

PATIENTS AND METHODS

We performed a randomized phase II trial of bortezomib on days 1, 4, 8, and 11 and irinotecan on days 1 and 8 of each 21-day cycle or single-agent bortezomib on days 1, 4, 8, and 11 on a 21-day cycle. The addition of irinotecan to bortezomib was allowed in patients who progressed on bortezomib alone.

RESULTS

The response rate of bortezomib and irinotecan was 13%. One patient had a partial response to bortezomib alone (response rate 3%). No responses were seen in patients with addition of irinotecan at time of progression on bortezomib.

CONCLUSIONS

The bortezomib-based regimens evaluated in this study have minimal activity in recurrent or metastatic head and neck cancer.

New promising molecular targets in head and neck squamous cell carcinoma

PURPOSE OF REVIEW

Despite advances in multimodality therapy, the overall 5-year survival rate is 40-50% in patients with head and neck squamous cell carcinoma (HNSCC) and current multimodality approaches impart significant toxicities. This review highlights promising targets with the potential to improve clinical outcomes in HNSCC.

RECENT FINDINGS

In addition to mutagenic exposure to tobacco and alcohol as risk factors, recent studies have shown that human papillomavirus is one of the main causes of HNSCC and as such is being investigated as a therapeutic target. Furthermore, recent data generated from whole exome sequencing of HNSCC, new insights into the biology of DNA damage repair, and increased understanding of tumor hypoxia responses are pointing to new therapeutic possibilities for treating HNSCC.

SUMMARY

HNSCC is a heterogeneous disease. Improved treatment will require a rapid translation of basic science research, and the simultaneous development of novel therapeutics and corresponding biomarkers to guide their application.

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.

Novel targeted therapies in head and neck cancer

INTRODUCTION

Molecularly targeted therapy, with the potential for increased selectivity and fewer adverse effects, hold promise in the treatment of HNSCC.

AREAS COVERED

Targeted agents for HNSCC expected to improve the effectiveness of current therapy including HER family, Src-family kinase, cell cycle, MET, AKT, HDAC, PARP, COX inhibitors and antiangiogenesis.

EXPERT OPINION

Epidermal growth factor receptor inhibitors are established in HNSCC and the need now is to find biomarkers for sensitivity to better select patients. Moreover, other pathway inhibitors hold significant promise and are being tested in clinical trials. Angiogenesis inhibition is likely to yield only modest efficacy alone but may augment existing standards. Lastly, one clinical arena where targeted therapies may find secure purchase is in the adjuvant or prevention setting where minimal or preneoplastic disease can be affected by inhibition of a single or few targets.

Results of a phase II trial of gemcitabine plus doxorubicin in patients with recurrent head and neck cancers: serum C₁₈-ceramide as a novel biomarker for monitoring response

PURPOSE

Here we report a phase II clinical trial, which was designed to test a novel hypothesis that treatment with gemcitabine (GEM)/doxorubicin (DOX) would be efficacious via reconstitution of C(18)-ceramide signaling in head and neck squamous cell carcinoma (HNSCC) patients for whom first-line platinum-based therapy failed.

EXPERIMENTAL DESIGN

Patients received GEM (1,000 mg/m²) and DOX (25 mg/m²) on days 1 and 8, every 21 days, until disease progression. After completion of 2 treatment cycles, patients were assessed radiographically, and serum samples were taken for sphingolipid measurements.

RESULTS

We enrolled 18 patients in the trial, who were evaluable for toxicity, and 17 for response. The most common toxicity was neutropenia, observed in 9 of 18 patients, and there were no major nonhematologic toxicities. Of the 17 patients, 5 patients had progressive disease (PD), 1 had complete response (CR), 3 exhibited partial response (PR), and 8 had stable disease (SD). The median progression-free survival was 1.6 months (95% CI: 1.4-4.2) with a median survival of 5.6 months (95% CI: 3.8-18.2). Remarkably, serum sphingolipid analysis revealed significant differences in patterns of C₁₈-ceramide elevation in patients with CR/PR/SD in comparison with patients with PD, indicating the reconstitution of tumor suppressor ceramide generation by GEM/DOX treatment.

CONCLUSIONS

Our data suggest that the GEM/DOX combination could represent an effective treatment for some patients with recurrent or metastatic HNSCC, and that serum C₁₈-ceramide elevation might be a novel serum biomarker of chemotherapy response.

Early tumor progression associated with enhanced EGFR signaling with bortezomib, cetuximab, and radiotherapy for head and neck cancer

PURPOSE

A phase I clinical trial and molecular correlative studies were conducted to evaluate preclinical evidence for combinatorial activity of the proteasome inhibitor bortezomib, the epidermal growth factor receptor (EGFR) inhibitor cetuximab, and radiation therapy.

EXPERIMENTAL DESIGN

Patients with radiotherapy-naive stage IV or recurrent squamous cell carcinoma of the head and neck (SCCHN) were studied. Escalating doses of bortezomib (0.7, 1.0, and 1.3 mg/m²) were given intravenously twice weekly on days 1, 4, 8, and 11, every 21 days, with weekly cetuximab beginning 1 week prior and concurrently with intensity-modulated radiotherapy, delivered in 2 Gy fractions to 70 to 74 Gy. Molecular effects were examined in serial serum and SCCHN tumor specimens and the cell line UMSCC-1.

RESULTS

Seven patients were accrued before the study was terminated when five of six previously untreated patients with favorable prognosis oropharyngeal SCCHN progressed within 1 year (progression-free survival = 4.8 months; 95% CI, 2.6-6.9). Three patients each received bortezomib 0.7 or 1.0 mg/m², without dose-limiting toxicities; one patient treated at 1.3 mg/m² was taken off study due to recurring cetuximab infusion reaction and progressive disease (PD). Expected grade 3 toxicities included radiation mucositis (n = 4), dermatitis (n = 4), and rash (n = 1). SCCHN-related cytokines increased in serial serum specimens of patients developing PD (P = 0.029). Bortezomib antagonized cetuximab- and radiation-induced cytotoxicity, degradation of EGFR, and enhanced prosurvival signal pathway activation in SCCHN tumor biopsies and UMSCC-1.

CONCLUSIONS

Combining bortezomib with cetuximab and radiation therapy showed unexpected early progression, evidence for EGFR stabilization, increased prosurvival signaling, and SCCHN cytokine expression, warranting avoidance of this combination.

Development of targeted therapy for squamous cell carcinomas of the head and neck

Targeted therapy is a very exciting era in the treatment of squamous cell carcinomas of the head and neck. After adding cetuximab to conventional chemotherapy and radiation therapy, we are strongly considering the role of induction chemotherapy with the addition of docetaxel. At the same time, other new treatments, especially targeted agents and novel combined regimens, are being evaluated in ongoing clinical trials. For example, several trials are attempting to combine docetaxel and cetuximab in chemoradiation or induction settings. However, in the near future we are likely to see a strong presence of targeted agents that have been found to be not only effective, but also less toxic than conventional chemotherapeutic agents. Their toxicity profiles make them eligible for addition to radiation treatment strategies, as well as other chemotherapy agents, or even for replacing these chemotherapy agents. In this article, we are going to review the indications and current role of cetuximab, tyrosine kinase inhibitors (gefitinib and erlotinib), dual inhibitors, IGF receptor inhibitors, as well as other agents that are in development for treatment of head and neck squamous cell carcinomas.

Pharmacotherapy for squamous-cell carcinoma of the head and neck

INTRODUCTION

squamous-cell carcinoma of the head and neck (HNSCC) is one of the most common malignancies, the treatment of which constitutes a therapeutic challenge.

AREAS COVERED

the purpose of this review is to provide an update on the pharmacotherapy for the treatment of HNSCC focusing mainly on molecular-targeted therapies. An overview of the different novel therapeutic agents that can selectively inhibit signaling pathways and receptors that are involved in the development and progression of cancer especially in HNSCC is presented.

EXPERT OPINION

the treatment of HNSCC is traditionally based on surgery and radiotherapy for early-stage HNSCC; however, chemotherapy is no longer used only for palliation, and individualized patient treatment assisted by molecular-targeted therapies represents a future therapeutic challenge.

Virus reactivation: a panoramic view in human infections

Viruses are obligate intracellular parasites, relying to a major extent on the host cell for replication. An active replication of the viral genome results in a lytic infection characterized by the release of new progeny virus particles, often upon the lysis of the host cell. Another mode of virus infection is the latent phase, where the virus is 'quiescent' (a state in which the virus is not replicating). A combination of these stages, where virus replication involves stages of both silent and productive infection without rapidly killing or even producing excessive damage to the host cells, falls under the umbrella of a persistent infection. Reactivation is the process by which a latent virus switches to a lytic phase of replication. Reactivation may be provoked by a combination of external and/or internal cellular stimuli. Understanding this mechanism is essential in developing future therapeutic agents against viral infection and subsequent disease. This article examines the published literature and current knowledge regarding the viral and cellular proteins that may play a role in viral reactivation. The focus of the article is on those viruses known to cause latent infections, which include herpes simplex virus, varicella zoster virus, Epstein-Barr virus, human cytomegalovirus, human herpesvirus 6, human herpesvirus 7, Kaposi's sarcoma-associated herpesvirus, JC virus, BK virus, parvovirus and adenovirus.

Curcumin: A review of anti-cancer properties and therapeutic activity in head and neck squamous cell carcinoma

Curcumin (diferuloylmethane) is a polyphenol derived from the Curcuma longa plant, commonly known as turmeric. Curcumin has been used extensively in Ayurvedic medicine for centuries, as it is nontoxic and has a variety of therapeutic properties including anti-oxidant, analgesic, anti-inflammatory and antiseptic activity. More recently curcumin has been found to possess anti-cancer activities via its effect on a variety of biological pathways involved in mutagenesis, oncogene expression, cell cycle regulation, apoptosis, tumorigenesis and metastasis. Curcumin has shown anti-proliferative effect in multiple cancers, and is an inhibitor of the transcription factor NF-κB and downstream gene products (including c-myc, Bcl-2, COX-2, NOS, Cyclin D1, TNF-α, interleukins and MMP-9). In addition, curcumin affects a variety of growth factor receptors and cell adhesion molecules involved in tumor growth, angiogenesis and metastasis. Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and treatment protocols include disfiguring surgery, platinum-based chemotherapy and radiation, all of which may result in tremendous patient morbidity. As a result, there is significant interest in developing adjuvant chemotherapies to augment currently available treatment protocols, which may allow decreased side effects and toxicity without compromising therapeutic efficacy. Curcumin is one such potential candidate, and this review presents an overview of the current in vitro and in vivo data supporting its therapeutic activity in head and neck cancer as well as some of the challenges concerning its development as an adjuvant chemotherapeutic agent.

Gene expression profiling of RNA extracted from FFPE tissues: NuGEN technologies' whole-transcriptome amplification system

Gene expression profiling of RNA isolated from formalin fixed, paraffin-embedded (FFPE) tissue samples has been historically challenging. Yet FFPE samples are sought-after because of the in-depth retrospective records typically associated with them rendering these samples a valuable resource for translational medicine studies. Extensive degradation, chemical modifications, and cross-linking have made it difficult to isolate RNA of sufficient quality required for large-scale gene expression profiling studies. NuGEN Technologies' WT-Ovation™ FFPE System linearly amplifies RNA from FFPE samples through a robust and simple whole-transcriptome approach using as little as 50 ng total RNA isolated from FFPE samples. The amplified material may be labeled with validated kits and/or protocols from NuGEN for analysis on any of the major gene expression microarray platforms, including: Affymetrix, Agilent, and Illumina gene expression arrays. Results compare well with those obtained using RNA from fresh-frozen samples. RNA quality from FFPE samples varies significantly and neither sample age nor sample size analysis via gel electrophoresis or the Agilent Bioanalyzer system accurately predict materials suitable for amplification. Therefore, NuGEN has validated a correlative qPCR-based analytical method for the RNA derived from FFPE samples which effectively predicts array results. The NuGEN approach enables fast and successful analysis of samples previously thought to be too degraded for gene expression analysis.

Chemotherapy and signaling: How can targeted therapies supercharge cytotoxic agents?

In recent years, oncologists have begun to conclude that chemotherapy has reached a plateau of efficacy as a primary treatment modality, even if toxicity can be effectively controlled. Emerging specific inhibitors of signaling and metabolic pathways (i.e., targeted agents) contrast with traditional chemotherapy drugs in that the latter primarily interfere with the DNA biosynthesis and the cell replication machinery. In an attempt to improve on the efficacy, combination of targeted drugs with conventional chemotherapeutics has become a routine way of testing multiple new agents in early phase clinical trials. This review discusses the recent advances including integrative systematic biology and RNAi approaches to counteract the chemotherapy resistance and to buttress the selectivity, efficacy and personalization of anti-cancer drug therapy.

Molecular targeted therapies in head and neck cancer--an update of recent developments-

Targeted therapies have made their way into clinical practice during the past decade. They have caused a major impact on the survival of cancer patients in many areas of clinical oncology and hematology. Indeed, in some hematologic malignancies, such as chronic myelogenous leukemia or non-Hodgkin's lymphomas, biologicals and antibodies specifically designed to target tumour-specific proteins have revolutionized treatment standards. In solid tumours, new drugs targeting EGF- or VEGF- receptors are now approved and are entering clinical practise for treatment of colon, lung, kidney and other cancers, either alone or in combination with conventional treatment approaches. Recent data have now shown that molecular targeted therapy might display efficacy in patients with head and neck squamous cell carcinoma (HNSCC) as well. The evaluated biologicals are generally well tolerated from HNSCC patients, who usually have the burden of multiple co-morbidities that interfere with conventional systemic treatment options. Therefore, molecular targeted therapies offer new treatment options even for heavily pretreated and seriously ill patients usually unable to tolerate chemotherapy or radiation therapy. The two most promising and advanced strategies are the blockage of growth-factor based cellular signalling and interference with angiogenesis-related pathways. But inhibitors of alternative targets, such as Scr and proteasomes, have already been evaluated in early clinical trials with HNSCC patients.