Topical polyethylene glycol as a novel chemopreventive agent for oral cancer via targeting of epidermal growth factor response

Combination Treatment of TRPV4 Agonist with Cisplatin Promotes Vessel Normalization in an Animal Model of Oral Squamous Cell Carcinoma

Background and Objectives: Oral squamous cell carcinoma (OSCC) is the sixth most common malignancy in the world. Transient receptor potential vanilloid 4 (TRPV4) channel has been shown to be involved in angiogenesis in multiple types of tumors. However, not much is known about TRPV4′s involvement in OSCC. Thus, in this study, we investigate the effect of administering a TRPV4 agonist on angiogenesis in OSCC. Materials and Methods: Thirty-six Sprague Dawley (SD) rats were used in this study. 4-nitroquinoline 1-oxide (4NQO) was used to induce OSCC. Cisplatin (an anticancer drug), and GSK1016790A (an agonist for TRPV4) was used in this study. Immunohistochemistry was employed to examine the TRPV4 expression. An RT2 Profiler PCR Array was performed for gene expression analysis of TRPV4, vascular growth factors that correspond directly with angiogenesis, such as angiopoietin (Ang-1 and Ang-2), and tyrosine kinase (Tie-1 and Tie-2) receptors. Tumor vessel maturity was assessed by microvessel density and microvessel-pericyte-coverage index. Results: RT2 profiler PCR array showed significant elevated levels of Ang-1 (2.1-fold change; p < 0.05) and Tie-2 (4.5-fold change; p < 0.05) in OSCC following the administration of a combination of GSK1016790A and cisplatin. Additionally, the combination treatment significantly reduced the microvessel density (p < 0.01) and significantly increased the percentage of microvessels covered with pericytes (p < 0.01) in OSCC. Furthermore, tumor size was significantly reduced (p < 0.05) in rats that received cisplatin alone. The combination treatment also greatly reduced the tumor size; however, the data were not statistically significant. Conclusions: The findings suggest that combining a TRPV4 agonist with cisplatin for treatment of OSCC promote vessels normalization via modulation of Ang-1/Tie-2 pathway.

4-nitroquinoline-1-oxide (4NQO) induced oral carcinogenesis: A systematic literature review

OBJECTIVE

Based on a critical review of published studies, we aimed to develop a good practice guide for using 4-nitroquinoline-1-oxide (4NQO) as an inducer of oral carcinogenesis in Wistar rats.

DESIGN

A systematic search was performed on Medline Ovid, PubMed, Embase, Web of Science, and Scopus databases. The SYRCLE's risk of bias tool was used to assess the quality of the studies.

RESULTS

Thirty-five articles met the selection criteria; 22 (62.9%) of them administered 4NQO systemically in drinking water, with a mean concentration of 30.2 ppm (SD±15.9) and during a mean period of 20.8 (SD±7.8) weeks. The other 13 (37.1%) studies performed topical applications of 4NQO painting the oral mucosa of the animals three times a week (100%) with a mean period of administration of 16.8 (SD±7.0) weeks. Different 4NQO concentrations used for other periods achieved significant tumor development. Most studies didn't perform quantitative clinical analysis, and the histopathological diagnosis/grading criteria varied considerably.

CONCLUSIONS

A poor description of solution care, adverse effects, and the number of losses were observed, and the reporting of these features needs to be improved. Suggestions to guide the development of future research are provided.

Oral squamous cell carcinoma-released brain-derived neurotrophic factor contributes to oral cancer pain by peripheral tropomyosin receptor kinase B activation

ABSTRACT

Oral cancer pain is debilitating and understanding mechanisms for it is critical to develop novel treatment strategies treatment strategies. Brain-derived neurotrophic factor (BDNF) signaling is elevated in oral tumor biopsies and is involved with tumor progression. Whether BDNF signaling in oral tumors contributes to cancer-induced pain is not known. The current study evaluates a novel peripheral role of BDNF-tropomyosin receptor kinase B (TrkB) signaling in oral cancer pain. Using human oral squamous cell carcinoma (OSCC) cells and an orthotopic mouse tongue cancer pain model, we found that BDNF levels were upregulated in superfusates and lysates of tumor tongues and that BDNF was expressed by OSCC cells themselves. Moreover, neutralization of BDNF or inhibition of TrkB activity by ANA12, within the tumor-bearing tongue reversed tumor-induced pain-like behaviors in a sex-dependent manner. Oral squamous cell carcinoma conditioned media also produced pain-like behaviors in naïve male mice that was reversed by local injection of ANA12. On a physiological level, using single-fiber tongue-nerve electrophysiology, we found that acutely blocking TrkB receptors reversed tumor-induced mechanical sensitivity of A-slow high threshold mechanoreceptors. Furthermore, single-cell reverse transcription polymerase chain reaction data of retrogradely labeled lingual neurons demonstrated expression of full-form TrkB and truncated TrkB in distinct neuronal subtypes. Last but not the least, intra-TG siRNA for TrkB also reversed tumor-induced orofacial pain behaviors. Our data suggest that TrkB activities on lingual sensory afferents are partly controlled by local release of OSCC-derived BDNF, thereby contributing to oral cancer pain. This is a novel finding and the first demonstration of a peripheral role for BDNF signaling in oral cancer pain.

Chemopreventive activity of Tualang honey against oral squamous cell carcinoma-in vivo

OBJECTIVE

The aim of this study was to evaluate the chemopreventive activity of Malaysian jungle Tualang honey (TH) after oral carcinogenesis induced with 4-nitroquinoline 1-oxide (4 NQO).

STUDY DESIGN

A total of 28 male Sprague-Dawley (SD) rats were distributed into 4 groups as follows: group 1 (nontreated group); group 2 (control), which received 4 NQO during 8 weeks in drinking water only; and groups 3 and 4, which received 4 NQO for 8 weeks in drinking water and treated with TH 1000 mg/kg and 2000 mg/kg by oral gavage for 10 weeks. All rats from all experiments were sacrificed after 22 weeks, and the incidence of oral neoplasms and histopathologic changes were microscopically evaluated. Moreover, immunohistochemical expression was analyzed in tongue specimens by using image analysis software. The expression of particular genes associated with oral cancer were assessed by using RT² Profiler PCR Array (Qiagen, Germantown, MD).

RESULTS

TH significantly reduced the incidence of oral squamous cell carcinoma (OSCC) and suppressed cancer cell proliferation via diminishing the expression of CCND1, EGFR, and COX-2. Furthermore, TH preserved cellular adhesion (epithelial polarity) through overexpression of β-catenin and e-cadherin and inhibited the OSCC aggressiveness by downregulating TWIST1 and RAC1.

CONCLUSIONS

Our data suggest that TH exerts chemopreventive activity in an animal model in which oral cancer was induced by using 4 NQO.

Antitumor Activity of Ficus deltoidea Extract on Oral Cancer: An In Vivo Study

Background

The aim of this study is to evaluate the chemopreventive and chemotherapeutic activities of Ficus deltoidea (FD) in an animal model induced for oral cancer using 4-nitroquinoline-1-oxide (4NQO).

Methods

Male Sprague-Dawley (SD) rats were randomized into six groups (n = 7 per group): Group 1 (untreated group); Group 2 (control cancer group) received 4NQO only for 8 weeks in their drinking water; Groups 3 and 4 (chemopreventive) received 4NQO for 8 weeks and were simultaneously treated with FD extract at 250 and 500 mg/kg, respectively, by oral gavage; Groups 5 and 6 (chemotherapeutic) received 4NQO for 8 weeks followed by the administration of FD extract at 250 and 500 mg/kg, respectively, for another 10 weeks. The incidence of oral cancer was microscopically evaluated. Moreover, immunohistochemical expression was analysed in tongue specimens using an image analyser computer system, while the RT² profiler PCR array method was employed for gene expression analysis.

Results

The results of the present study showed a beneficial regression effect of the FD extract on tumor progression. The FD extract significantly reduced the incidence of oral squamous cell carcinoma (OSCC) from 100% to 14.3% in the high-dose groups. The immunohistochemical analysis showed that the FD extract had significantly decreased the expression of the key tumor marker cyclin D1 and had significantly increased the expression of the β-catenin and e-cadherin antibodies that are associated with enhanced cellular adhesion. Based on the gene expression analysis, FD extract had reduced the expression of the TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.β-catenin and e-cadherin antibodies that are associated with enhanced cellular adhesion. Based on the gene expression analysis, FD extract had reduced the expression of the TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.

Prevention of oral carcinogenesis in rats by Dracaena cinnabari resin extracts

OBJECTIVES

In vivo study was performed to determine the chemopreventive efficacy of the DC resin methanol extract on a 4-nitroquinoline-1-oxide (4NQO) oral cancer animal model.

MATERIALS AND METHODS

This study involves administration of 4NQO solution for 8 weeks alone (cancer induction) or with Dracaena cinnabari (DC) extract at 100, 500, and 1000 mg/kg. DC extract administration started 1 week before exposure until 1 week after the carcinogen exposure was stopped. All rats were sacrificed after 22 weeks, and histological analysis was performed to assess any incidence of pathological changes. Immunohistochemical expressions of selected tumor marker antibodies were analyzed using an image analyzer computer system, and the expression of selected genes involved in apoptosis and proliferative mechanism related to oral cancer were evaluated using RT²-PCR.

RESULTS

The incidence of OSCC decreased with the administration of DC extract at 100, 500, and 1000 mg/kg compared to the induced cancer group. The developed tumor was also observed to be smaller when compared to the induced cancer group. The DC 1000 mg/kg group inhibits the expression of Cyclin D1, Ki-67, Bcl-2, and p53 proteins. It was observed that DC 1000 mg/kg induced apoptosis by upregulation of Bax and Casp3 genes and downregulation of Tp53, Bcl-2, Cox-2, Cyclin D1, and EGFR genes when compared to the induced cancer group.

CONCLUSIONS

The data indicated that systemic administration of the DC resin methanol extract has anticarcinogenic potency on oral carcinogenesis.

CLINICAL RELEVANCE

Chemoprevention with DC resin methanol extract may significantly reduce morbidity and possibly mortality from OSCC.

Prevention of colonic neoplasia with polyethylene glycol: A short term randomized placebo-controlled double-blinded trial

Chemoprevention represents an attractive modality against colorectal cancer (CRC) although widespread clinical implementation of promising agents (e.g. aspirin/NSAIDS) have been stymied by both suboptimal efficacy and concerns over toxicity. This highlights the need for better agents. Several groups, including our own, have reported that the over-the-counter laxative polyethylene glycol (PEG) has remarkable efficacy in rodent models of colon carcinogenesis. In this study, we undertook the first randomized human trial to address the role of PEG in prevention of human colonic neoplasia. This was a double-blind, placebo-controlled, three-arm trial where eligible subjects were randomized to 8g PEG-3350 (n = 27) or 17g PEG-3350 (n = 24), or placebo (n = 24; maltodextrin) orally for a duration of six months. Our initial primary endpoint was rectal aberrant crypt foci (ACF) but this was changed during protocol period to rectal mucosal epidermal growth factor receptor (EGFR). Of the 87 patients randomized, 48 completed study primary endpoints and rectal EGFR unchanged PEG treatment. Rectal ACF had a trend suggesting potentially reduction with PEG treatment (pre-post change 1.7 in placebo versus -0.3 in PEG 8+ 17g doses, p = 0.108). Other endpoints (proliferation, apoptosis, expression of SNAIL and E-cadherin), previously noted to be modulated in rodent models, appeared unchanged with PEG treatment in this clinical trial. We conclude that PEG was generally well tolerated with the trial failing to meet primary efficacy endpoints. However, rectal ACFs demonstrated a trend (albeit statistically insignificant) for suppression with PEG. Moreover, all molecular assays including EGFR were unaltered with PEG underscoring issues with lack of translatability of biomarkers from preclinical to clinical trials. This data may provide the impetus for future clinical trials on PEG using more robust biomarkers of chemoprevention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00828984.

The dynamics of gene expression changes in a mouse model of oral tumorigenesis may help refine prevention and treatment strategies in patients with oral cancer

A better understanding of the dynamics of molecular changes occurring during the early stages of oral tumorigenesis may help refine prevention and treatment strategies. We generated genome-wide expression profiles of microdissected normal mucosa, hyperplasia, dysplasia and tumors derived from the 4-NQO mouse model of oral tumorigenesis. Genes differentially expressed between tumor and normal mucosa defined the “tumor gene set” (TGS), including 4 non-overlapping gene subsets that characterize the dynamics of gene expression changes through different stages of disease progression. The majority of gene expression changes occurred early or progressively. The relevance of these mouse gene sets to human disease was tested in multiple datasets including the TCGA and the Genomics of Drug Sensitivity in Cancer project. The TGS was able to discriminate oral squamous cell carcinoma (OSCC) from normal oral mucosa in 3 independent datasets. The OSCC samples enriched in the mouse TGS displayed high frequency of CASP8 mutations, 11q13.3 amplifications and low frequency of PIK3CA mutations. Early changes observed in the 4-NQO model were associated with a trend toward a shorter oral cancer-free survival in patients with oral preneoplasia that was not seen in multivariate analysis. Progressive changes observed in the 4-NQO model were associated with an increased sensitivity to 4 different MEK inhibitors in a panel of 51 squamous cell carcinoma cell lines of the aerodigestive tract. In conclusion, the dynamics of molecular changes in the 4-NQO model reveal that MEK inhibition may be relevant to prevention and treatment of a specific molecularly-defined subgroup of OSCC.

A Way Forward for Cancer Chemoprevention: Think Local

As cells progress through carcinogenesis, the associated exponential expansion of genetic and molecular aberrations and resultant heterogeneity make therapeutic success increasingly unattainable. Therapeutic intervention at early stages of carcinogenesis that occurs within the primary organ and in the face of a lower burden of molecular aberrations, constitutes a basic tenet of cancer chemoprevention, and provides a situation that favors a greater degree of therapeutic efficacy compared with that of advanced cancer. A longstanding barrier to chemoprevention relates to the requirement for essentially no systemic toxicity, and the fact that when large numbers of people are treated, the emergence of systemic toxicity is almost universal. A rational means to address this in fact relates to a second basic tenet of the chemopreventive strategy: the focus of therapeutic intervention is to disrupt a process that is in essence localized to a single organ. Based upon this consideration, a strategy which is based upon local delivery of therapeutics to an at-risk organ will achieve therapeutic efficacy while avoiding systemic delivery and its associated toxicity. This article will review the rationale for undertaking such an approach, describe successful clinical achievements based on this strategy, describe ongoing efforts to expand the impact of this approach, and together will highlight the high impact that this approach has already had on the field as well as its extremely high potential for future impact. Cancer Prev Res; 10(1); 14-35. ©2016 AACR.

Extracellular signal-regulated kinase (ERK) expression and activation in mobile tongue squamous cell carcinoma: associations with clinicopathological parameters and patients survival

Extracellular signal-regulated kinase (ERK) has been considered as a critical regulator of diverse cellular processes such as proliferation, survival and motility, being implicated in the malignant transformation in several tissue types. The present study aimed to evaluate the clinical significance of total ERK1 (t-ERK1) and phosphorylated ERK1/2 (p-ERK1/2) protein expression in mobile tongue squamous cell carcinoma (SCC). t-ERK1 and p-ERK1/2 protein expression in tumour cells and infiltrating the tumour microenvironment lymphoid cells was assessed immunohistochemically on 47 mobile tongue SCC tissue samples and was analyzed in relation with clinicopathological characteristics, overall and disease-free patients' survival. Enhanced nuclear t-ERK1 and p-ERK1/2 expression in tumour cells was associated with the absence of perineural invasion (p = 0.043) and shorter overall patients' survival (log-rank test, p = 0.028), respectively. Enhanced t-ERK1 expression in infiltrating lymphoid cells was significantly associated with female gender, absence of vascular and perineural invasion, lymph node metastases and early depth of invasion (p = 0.008, p = 0.019, p = 0.011, p = 0.036 and p = 0.001, respectively), as well as with longer disease-free survival times (log-rank test, p = 0.038). Enhanced p-ERK1/2 expression in infiltrating lymphoid cells was significantly associated with the presence of vascular invasion and lymph node metastases (p = 0.019 and p = 0.004, respectively) and shorter overall patients' survival (log-rank test, p = 0.013). In multivariate analysis, p-ERK1/2 expression in tumour cells and infiltrating lymphoid cells was identified as independent prognostic factors of overall survival (Cox regression analysis, p = 0.045 and p = 0.032, respectively). The present study supported evidence that ERK signalling pathway may exert a potential role in the pathophysiological aspects of the mobile tongue SCC, presenting also potential utility as a biomarker for patients' survival and reinforcing the development of novel anti-cancer therapies targeting ERK signalling cascade in this type of human malignancy.

Biomarkers and chemopreventives in oral carcinogenesis and its prevention

Squamous cell carcinoma is the predominant type of oral malignancy and is a result of oral carcinogenesis. Oral carcinogenesis is a mutifactorial and complex process related to the sequential occurrence of alterations in genetic structures, promoting inhibitory or excitatory effects of the tumor oncogenes and gene suppressors, compromising the histophysiology of the division, differentiation and cell death; and therefore, methods to prevent, detect, or treat it in the best way is constantly being searched for. Biomarkers reveal the genetic and molecular changes related to early, intermediate and late endpoints in the process of oral carcinogenesis. Thereby, they are likely to not only refine our ability to predict the biologic course of oral cancer and distinguish individuals at high and/or low risk of oral cancer development; but, also they will also reveal the genetic and molecular changes related to various endpoints of oral carcinogenesis. Chemopreventives are chemicals of natural or synthetic origin, which reduce the incidence of fatal diseases such as cancer before clinical symptoms occur. Chemopreventives are agents whose curative capacity is defined with help of biomarkers, as the later determine the effectiveness and safety of chemopreventives.

Cetuximab inhibits oral squamous cell carcinoma invasion and metastasis via degradation of epidermal growth factor receptor

Cetuximab (Erbitux, C225) is a chimeric monoclonal antibody that binds to the extracellular domain of epidermal growth factor receptor (EGFR), inhibiting tumor growth, invasion, angiogenesis and metastasis. However, the mechanisms underlying the effect of Cetuximab in human oral squamous cell carcinoma (OSCC) remain unclear. Here, we report that Cetuximab modulates EGFR protein stability through the ubiquitin/proteasome pathway, resulting in the inhibition of human OSCC growth. Cetuximab significantly inhibited the migration and invasion of human OSCC cells by blocking epithelial/mesenchymal transition (EMT) and the AKT and ERK pathways. Furthermore, Cetuximab-inhibited cell growth by modulating the expression of integrin β5. Taken together, these results provide novel insights into the mechanism of Cetuximab action and suggest potential therapeutic strategies for OSCC.

Bioinformatics and systems biology analysis of genes network involved in OLP (Oral Lichen Planus) pathogenesis

BACKGROUND

Genes involved in different biological processes form complex interaction networks. However, only few of them have a high number of interactions with the other genes in the network and therefore they may play a major role. In previous bioinformatics and experimental studies, these genes were identified and termed as "leader genes". In the current ab initio theoretical study, genes involved in human OLP (Oral Lichen Planus) pathogenesis are identified and ranked according to their number of interactions, in order to obtain a broader view of its molecular mechanisms and to plan targeted experimentations.

METHODS

Genes involved or potentially involved in OLP were identified by systematically querying several databases until the identification of a final set of genes. Interactions among these genes were mapped and given a significance score using STRING database. For each gene, significance scores were summed to obtain a weighted number of links (WNL) and subsequently genes were clustered according to this parameter. The genes in the highest cluster were termed as leader genes; the other ones were ranked as class B genes, class C genes, and so on. This study was complemented by a topological analysis of the network, carried out using Cytoscape, BinGO and FANMOD software.

RESULTS

The interactions in the obtained network showed power law behaviour, in agreement with the scale-free topology theory of the biological graphs. 132 genes were identified and five of them (namely, JUN, EGFR, FOS, IL2, ITGB4) were classified as leaders. Interestingly, all of them but EGFR were up-regulated and were widely distributed in the network (in term of topological parameters such as stress, eccentricity and radiality) and showed higher topological coefficients than the other genes.

CONCLUSIONS

Even with the limitations of any ab initio analysis, this study can suggest targeted experimentation, focused on the leader genes and therefore simpler to be analysed than mass scale molecular genomics. Moreover, it may suggest new potential risk factors and therapeutic targets.

The clinical evaluation of novel imaging methods for cancer management

The National Cancer Institute (NCI) has a long-standing interest in evaluating and using the known advantages of molecular and functional imaging, as well as assessing the potential of novel imaging agents and modalities, to improve clinical cancer research and cancer care. In this Perspectives article, I discuss the strategies and resources being used by the NCI to foster and enhance these evaluations. Although resource and logistical challenges abound in successfully mounting these trials, many examples exist of real and potential solutions to improve the clinical evaluation process for imaging agents and modalities in the USA and in international collaborations.