Role of inflammation in oral carcinogenesis (Part II): CD8, FOXP3, TNF-α, TGF-β and NF-κB expression

Chinese herbal medicine compound of flavonoids adjunctive treatment for oral cancer

Oral cancer is a prevalent global issue, with oral squamous cell carcinoma constituting the majority of cases. Standard treatments like surgery, radiotherapy, and chemotherapy are available but may have adverse effects. Molecular gene therapy, focusing on genetic mutations linked to oral cancer, presents a promising alternative.In this study, we evaluated 27 chemotherapeutic drugs and 63 Chinese herbal medicines for their effectiveness, categorized them by their cellular mechanisms, and identified potential adjuvant therapy candidates for oral cancer. Our findings highlight the impact of natural flavonoids on oral cancer cells, inducing apoptosis, and confirming their potential in molecular genetic analysis. In conclusion, the natural compounds present in Chinese herbal medicine, particularly flavonoids, offer a promising avenue to target specific genetic mutations in oral cancer cells. This approach may reduce the risks associated with oral cancer treatment and pave the way for innovative adjuvant therapies.

The stromal immunoexpression of CLIC4 may be related to the difference in the biological behavior between oral squamous cell carcinoma and oral verrucous carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) has high morbidity and mortality rates while oral verrucous carcinoma (OVC), an uncommon variant of OSCC, exhibits a distinct biological behavior. CLIC4 protein plays a role in the cell cycle and apoptosis regulation and participates in the myofibroblasts transdifferentiation process, which are the main cells of the tumor stroma. This study analyzed the immunoexpression of CLIC4 and α-SMA in 20 OSCC cases and 15 OVC cases.

MATERIAL AND METHODS

A semiquantitative analysis of CLIC4 and α-SMA immunoexpression was performed in the parenchyma and stroma. Nuclear and cytoplasmic reactivity was analyzed separately for the CLIC4 immunostaining. The data were submitted to Pearson's chi-square and Spearman's correlation tests (p ≤ 0.05).

RESULTS

In the CLIC4 analysis, there was a significant difference in the immunoexpression of this protein between OSCC and OVC stroma (p < 0.001). It was observed a higher expression of α-SMA in the OSCC stroma. There was a positive and significant correlation between CLIC4 and α-SMA immunoexpression in the OVC stroma (r = 0,612; p = 0,015).

CONCLUSIONS

The decrease or absence of nuclear CLIC4 immunoexpression in the neoplastic epithelial cells and the increase of its expression in the stroma may influence the difference in biological behavior between OSCC and OVC.

Precancerous Lesions of the Head and Neck Region and Their Stromal Aberrations: Piecemeal Data

Head and neck squamous cell carcinomas (HNSCCs) develop through a series of precancerous stages from a pool of potentially malignant disorders (PMDs). Although we understand the genetic changes that lead to HNSCC, our understanding of the role of the stroma in the progression from precancer to cancer is limited. The stroma is the primary battleground between the forces that prevent and promote cancer growth. Targeting the stroma has yielded promising cancer therapies. However, the stroma at the precancerous stage of HNSCCs is poorly defined, and we may miss opportunities for chemopreventive interventions. PMDs already exhibit many features of the HNSCC stroma, such as inflammation, neovascularization, and immune suppression. Still, they do not induce cancer-associated fibroblasts or destroy the basal lamina, the stroma's initial structure. Our review aims to summarize the current understanding of the transition from precancer to cancer stroma and how this knowledge can reveal opportunities and limitations for diagnostic, prognostic, and therapeutic decisions to benefit patients. We will discuss what may be needed to fulfill the promise of the precancerous stroma as a target to prevent progression to cancer.

Inflammation and Invasion in Oral Squamous Cell Carcinoma Cells Exposed to Electronic Cigarette Vapor Extract

Electronic cigarettes (eCig) represent a new avenue of tobacco exposure that involves heating oil-based liquids and the delivery of aerosolized flavors with or without nicotine, yet little is known about their overall health impact. The oral cavity is an anatomic gateway for exposure that can be compromised by activating myriad of signaling networks. Oral squamous cell carcinoma (OSSC) is a common malignancy affecting 30,000 people in the United States each year. Our objective was to determine the impact of eCig and nicotine on gingival OSSC invasion and their secretion of pro-inflammatory molecules. Gingiva-derived Ca9-22 cells and tongue-derived Cal27 cells were exposed to eCig vapor extract (EVE) generated from Red Hot or Green Apple (Apple) flavored eCig solution +/- nicotine for 6 hours. Isolation of protein lysates and collection conditioned media was done after treatment. Real-time cellular invasion was assessed using a RTCA DP instrument. Protein expression was determined using western blot. Compared to controls, we observed: elevated NF-kB, TNF-α, ERK, JNK, MMP-13 and cell invasion by Ca9-22 treated with Apple EVE; increased TNF-α and JNK by Ca9-22 treated with Red Hot EVE; and increased TNF-α and JNK by Cal27 cells treated with both Apple and Red Hot EVE. We conclude that eCig flavoring and nicotine orchestrated differential cell invasion and inflammatory effects. This study provides an important initial step in dissecting mechanisms of cancerous invasion and molecular avenues employed by OSCC.

Characterization of Oral Squamous Cell Carcinoma Associated Inflammation: A Pilot Study

Background: Oral squamous cell carcinoma (OSCC) is a devastating disease that is usually associated with a dense associated inflammatory infiltrate. Characterizing tumor-associated inflammation is critical to understand the pathogenies of tumor development and progression.

Methods: We have tested a protocol to analyze tissue and salivary immune cells and mediators of 37 patients with OSCC at different stages and compared to eight chronic periodontitis patients and 24 healthy controls. Tissue analysis was based on fluorescent immunohistochemistry (FIHC) and inflammatory mediators were analyzed using a Luminex-based 30-Plex panel. Immune cells were analyzed using multichannel flow cytometry including CD45, CD66b, CD3, CD4, CD8, CD25, CD56, CD68, CD138, PD-1, and PD-L1.

Results: We show an increase in OSCC-associated inflammation characterized by increased pro-inflammatory cytokines including IL-6, IL-8, TNFα, and GMCSF and increased salivary immune cells.

Conclusion: We described a new method to analyze salivary inflammatory markers that can be used in future studies to monitor disease progression and prognosis.

Immunological Network in Head and Neck Squamous Cell Carcinoma-A Prognostic Tool Beyond HPV Status

Head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous disease that affects more than 800,000 patients worldwide each year. The variability of HNSCC is associated with differences in the carcinogenesis processes that are caused by two major etiological agents, namely, alcohol/tobacco, and human papillomavirus (HPV). Compared to non-virally induced carcinomas, the oropharyngeal tumors associated with HPV infection show markedly better clinical outcomes and are characterized by an immunologically “hot” landscape with high levels of tumor-infiltrating lymphocytes. However, the standard of care remains the same for both HPV-positive and HPV-negative HNSCC. Surprisingly, treatment de-escalation trials have not shown any clinical benefit in patients with HPV-positive tumors to date, most likely due to insufficient patient stratification. The in-depth analysis of the immune response, which places an emphasis on tumor-infiltrating immune cells, is a widely accepted prognostic tool that might significantly improve both the stratification of HNSCC patients in de-escalation trials and the development of novel immunotherapeutic approaches.

Modification in CLIC4 Expression is Associated with P53, TGF-β, TNF-α and Myofibroblasts in Lip Carcinogenesis

Chloride intracellular channel-4 (CLIC4) is regulated by p53 and tumor necrosis factor-α (TNF-α), it is linked to the increase of transforming growth factor-β (TGF-β), and myofibroblastic differentiation in skin carcinogenesis. This study analyzed the immunoexpression of CLIC4, p53, TGF-β, TNF-α, and α-SMA in 50 actinic cheilitis (AC) and 50 lower lip squamous cell carcinoma (LLSCC). AC and LLSCC immunoexpression were categorized as score 1 (<5% positive cells), 2 (5-50%) or 3 (>50%). For CLIC4, nuclear and cytoplasmic immunostaining of epithelial cells was considered individually. For morphologic analysis, the World Health Organization criteria were used to epithelial dysplasia grade of ACs, and Bryne grading of malignancy system was applied for LLSCC. Higher nuclear CLIC4 (CLIC4n) and TGF-β were observed in ACs with low-risk of transformation, while cytoplasmic CLIC4 (CLIC4c), p53 and TNF-α were higher in the high-risk cases (p<0.05). In LLSCCs, CLIC4c was higher in cases with lymph node metastasis, advanced clinical stages, and histological high-grade malignancy. p53 expression was higher in high-grade LLSCCs, whereas TGF-β decreased as the clinical stage and morphological grade progressed (p<0.05). ACs showed an increased expression of CLIC4n and TGF-β, while CLIC4c and α-SMA were higher in LLSCCs (p<0.0001). Both lesions showed negative correlation between CLIC4n and CLIC4c, while in LLSCCs, negative correlation was also verified between CLIC4c and p53, as well as CLIC4c and TGF-β (p<0.05). Change of CLIC4 from the nucleus to cytoplasm and alterations in p53, TGF-β, TNF-α, and α-SMA expression are involved in lip carcinogenesis.

Evaluation of Proinflammatory, NF-kappaB Dependent Cytokines: IL-1α, IL-6, IL-8, and TNF-α in Tissue Specimens and Saliva of Patients with Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders

Background: Oral squamous cell carcinoma (OSCC) is a life-threatening disease. It could be preceded by oral potentially malignant disorders (OPMDs). It was confirmed that chronic inflammation can promote carcinogenesis. Cytokines play a crucial role in this process. The aim of the study was to evaluate interleukin-1alpha (IL-1α), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-α) in tissue specimens and saliva of patients with OSCC and OPMDs. Methods: Cytokines were evaluated in 60 tissue specimens of pathological lesions (OSCCs or OPMDs) and in 7 controls (normal oral mucosa, NOM) by immunohistochemistry and in saliva of 45 patients with OSCC or OPMDs and 9 controls (healthy volunteers) by enzyme-linked immunosorbent assays. Results: Immunohistochemical analysis revealed significantly higher expression of IL-8 in OSCC specimens and TNF-α in OSCCs and OPMDs with dysplasia as compared to NOM. Moreover, expression of TNF-α was significantly higher in oral leukoplakia and oral lichen planus without dysplasia, whereas expression of IL-8 only in oral leukoplakia without dysplasia in comparison with NOM. Salivary concentrations of all evaluated cytokines were significantly higher in patients with OSCC than in controls. Moreover, levels of IL-8 were significantly higher in saliva of patients with OPMDs with dysplasia as compared to controls and in OSCC patients as compared to patients with dysplastic lesions. There was also significant increase in salivary concentrations of IL-6, IL-8 and TNF-α in patients with OSCC as compared to patients with OPMDs without dysplasia. Conclusion: The study confirmed that proinflammatory, NF-kappaB dependent cytokines are involved in pathogenesis of OPMDs and OSCC. The most important biomarker of malignant transformation process within oral mucosa among all assessed cytokines seems to be IL-8. Further studies on a larger sample size are needed to corroborate these results.

Role of Inflammatory Markers in Prognosis of Oral Squamous Cell Carcinoma

BACKGROUND

This estudie evaluated the immunostaining of cytokines in oral carcinoma, in tissue of margin of surgical resecate (MSR) and metastatic lymph nodes, as well as their role in patient prognosis.

METHODS

A retrospective study was carried out in patients with oral squamous cell carcinomas, and sociodemographic and clinical-pathological data were evaluated. In addition, surgical site analysis of the patients was conducted by immunohistochemistry, using a tissue microarray for inflammatory (Tumor Necrosis Factor-alpha, Interleukin-1beta, Interleukin-6, interleukin-10), transcription NF-kappa B and CD68 markers. Immunoexpression was assessed qualitatively and quantitatively using ImageJ software, and data were correlated with the prognostic factors and patient survival rates.

RESULTS

There was a greater immunoexpression of inflammatory and CD68 cytokines in primary tumour and lymph node metastasis than in MSR. In a multinomial logistic regression model, patients with low education (p = 0.041) and a high histoscore for TNF-α (p = 0.021) showed a survival rate of 15.64 (95% CI = 1.13-217.24) and 6.81 (95% CI = 1.02-105.96).

CONCLUSION

Therefore, despite there is an increased immunoexpression of cytokines in the primary tumour, only TNF-α was the inflammatory cytokine that influenced the survival of patients with oral cancer.

Mediators of Inflammation - A Potential Source of Biomarkers in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common tumour of the oral cavity, associated with significant morbidity and mortality. It is a multifactorial condition, both genetic and environmental factors being involved in its development and progression. Its pathogenesis is not fully elucidated, but a pivotal role has been attributed to inflammation, strong evidence supporting the association between chronic inflammation and carcinogenesis. Moreover, an increasing number of studies have investigated the role of different mediators of inflammation in the early detection of OSCC. In this review, we have summarized the main markers of inflammation that could be useful in diagnosis and shed some light in OSCC pathogenesis.

Subsite-specific association of DEAD box RNA helicase DDX60 with the development and prognosis of oral squamous cell carcinoma

The clinical significance and biological function of DEXD/H box helicase 60 (DDX60) in oral cancer remains unknown. Herein, we evaluated the association of DDX60 expression with tumorigenesis and the prognosis of oral squamous cell carcinoma (OSCC). DDX60 expression was examined by immunohistochemistry on tissue microarray slides of 494 OSCC patients, including 180 buccal mucosal SCC (BMSCC), 241 tongue SCC (TSCC), and 73 lip SCC (LSCC) patients. DDX60 expression was significantly increased in all three subsites of OSCC compared to its expression in tumor adjacent normal tissues. However, its association with tumorigenesis was specific to the oral cavity subsite after the stratification of betel quid chewing, smoking, and drinking. Among OSCC patients, higher levels of DDX60 expression were associated with the male gender, a well-differentiated tumor, advanced stage of disease, and a large tumor size with subsite specific features. LSCC patients with high DDX60 expression levels showed shorter disease-specific survival, particularly those with moderately or poorly differentiated tumors. Additionally, TSCC or OSCC patients with high DDX60 expression showed a poor disease-free survival (DFS), particularly those with moderately or poorly differentiated tumors. Therefore, DDX60 is a novel and unfavorable biomarker for tumorigenesis and prognosis of OSCC in a subsite-specific manner.

Microenvironmental regulation of the progression of oral potentially malignant disorders towards malignancy

Oral potentially malignant disorders (OPMD) develop in a complex tissue microenvironment where they grow sustainably, acquiring oral squamous cell carcinoma (OSCC) characteristics. The malignant tumor depends on interactions with the surrounding microenvironment to achieve loco-regional invasion and distant metastases. Unlike abnormal cells, the multiple cell types in the tissue microenvironment are relatively stable at the genomic level and, thus, become therapeutic targets with lower risk of resistance, decreasing the risk of OPMD acquiring cancer characteristics and carcinoma recurrence. However, deciding how to disrupt the OPMD and OSCC microenvironments is itself a daunting challenge, since their microenvironments present opposite capacities, resulting in diverse consequences. Furthermore, recent studies revealed that tumor-associated immune cells also participate in the process of differentiation from OPMD to OSCC, suggesting that reeducating stromal cells may be a new strategy to prevent OPMD from acquiring OSCC characteristics and to treat OSCC. In this review, we discuss the characteristics of the microenvironment of OPMD and OSCC as well as new therapeutic strategies.

Genistein inhibited ammonia induced astrocyte swelling by inhibiting NF-κB activation-mediated nitric oxide formation

Our previous study has indicated the involvement of epidermal growth factor receptor (EGFR) transactivation in ammonia-induced astrocyte swelling, which represents a major pathogenesis of brain edema in hepatic encephalopathy. In this study, we examined the effect of genistein, a naturally occurred broad-spectrum protein tyrosine kinase (PTK) inhibitor, on ammonia-induced cell swelling. We found that genistein pretreatment significantly prevented ammonia-induced astrocyte swelling. Mechanistically, ammonia triggered EGFR/extracellular signal-regulated kinase (ERK) association and subsequent ERK phosphorylation were alleviated by genistein pretreatment. Moreover, ammonia-induced NF-κB nuclear location, iNOS expression, and consequent NO production were all prevented by AG1478 and genistein pretreatment. This study suggested that genistein could alleviate ammonia-induced astrocyte swelling, which may be, at least partly, related to its PTK-inhibiting activity and repression of NF-κB mediated iNOS-derived NO accumulation.

Proteomics investigation of OSCC-specific salivary biomarkers in a Hungarian population highlights the importance of identification of population-tailored biomarkers

Oral squamous cell carcinoma (OSCC) accounting for about 90% of malignant oral lesions is the 6th most common malignancy worldwide. Diagnostic delay may contribute to dismal survival rate therefore, there is a need for developing specific and sensitive biomarkers to improve early detection. Hungarian population occupies the top places of statistics regarding OSCC incidence and mortality figures therefore, we aimed at finding potential salivary protein biomarkers suitable for the Hungarian population. In this study we investigated 14 proteins which were previously reported as significantly elevated in saliva of patients with OSCC. In case of IL-1α, IL-1β, IL-6, IL-8, TNF-α and VEGF a Luminex-based multiplex kit was utilized and the salivary concentrations were determined. In case of catalase, profilin-1, S100A9, CD59, galectin-3-bindig protein, CD44, thioredoxin and keratin-19, SRM-based targeted proteomic method was developed and the relative amount of the proteins was determined in the saliva of patients with OSCC and controls. After several rounds of optimization and using stable isotope-containing peptides, we developed an SRM-based method for rapid salivary protein detection. The validation of the selected potential biomarkers by ELISA revealed salivary protein S100A9 and IL-6 as useful protein biomarkers for OSCC detection improving the diagnostic accuracy for OSCC in the Hungarian population.A noninvasive diagnostic method to detect biomarkers useful for the early diagnosis of OSCC was developed. This can be an attractive strategy in screening saliva samples collected in a nation-wide multi-centric study in order to decrease morbidity, mortality, to enhance survival rate and to improve quality of life. The heterogeneity of protein biomarkers found in different ethnic groups presented in the literature highlights the importance of identification of population-tailored protein biomarkers.

A novel environmental exposure index and its interaction with familial susceptibility on oral cancer in non-smokers and non-drinkers: a case-control study

The objective of this study was to explore the collective effect of environmental factors and its interaction with familial susceptibility on oral cancer among non-smokers and non-drinkers (NSND). A hospital-based case-control study, including 319 oral cancer patients and 994 frequency-matched controls, was conducted in Fujian, China. We raised a weighed environmental exposure index according to nine significant environmental factors obtained from multivariable logistic regression model. And then, the index was classified into three categories according to the tertiles of controls (<1.34, 1.34-2.43, and >2.43). Multiplicative and additive interactions were evaluated between environmental exposure index and family cancer history. Our results showed that environmental exposure index was associated with an increased risk of oral cancer especially for those with family cancer history. Compared to subjects with low environmental exposure index and without family cancer history, those with high index and family cancer history showed the highest magnitude of OR in oral cancer risk (OR 10.40, 95% CI 5.46-19.80). Moreover, there was a multiplicative interaction between environmental exposure index and family cancer history for the risk of oral cancer (P < 0.001). This study puts forward a novel environmental exposure index, which enables a comprehensive evaluation on the overall effect of environmental risk factors on oral cancer among NSND and may interact with family cancer history. Further studies are warranted to explore the underlying mechanisms.

Salivary and serum IL-10, TNF-α, TGF-β, VEGF levels in oropharyngeal squamous cell carcinoma and correlation with HPV and EBV infections

Background

Each year approximately 6,000 new cases of head and neck cancer are registered in Poland. Human papillomavirus (HPV) and Epstein-Barr virus (EBV) have been associated with tumour formation. Cytokines have been shown to play an important role both in inflammation and carcinogenesis and they can be detected in saliva and serum with ELISA assays. Salivary biomarkers may be used as markers of early cancer detection.

The aim of this study was the analysis of the serum and salivary levels of IL-10, TNF-α, TGF-β and VEGF in patients with oropharyngeal cancer and in healthy individuals. The level of these biomarkers was also analyzed in HPV- and EBV-related cases.

Methods

The study involved 78 patients with histopathologically confirmed oropharyngeal squamous cell carcinoma and 40 healthy controls. Serum and salivary levels of IL-10, TNF-α, TGF-β and VEGF were analyzed both in patients and in healthy individuals by ELISA method using Diaclone SAS commercially available kits (France). EBV DNA was detected by the nested PCR for amplification of EBNA-2. HPV detection and genotyping was performed using the INNO-LiPA HPV Genotyping Extraassay (Innogenetics N. V, Gent, Belgium). The obtained results were subjected to statistical analysis using Mann–Whitney and Kruskal Wallis tests. Test values of p < 0.05 were considered statistically significant.

Results

The level of tested cytokines was higher in patients than in controls both in serum (IL-10: 2.3 pg/ml vs 1.65 pg/ml, p = 0.0003; TGF-β: 11.3 ng/ml vs 7.8 ng/ml, p = 0.0005; VEGF: 614 pg/ml vs 210 pg/ml, p = 0.0004; TNF-α: 15.0 ng/ml vs 12.90 ng/ml, p = 0.1397) as well as in saliva (IL-10: 5.9 pg/ml vs 2.5 pg/ml, p = 0.00002; TGF-β: 24.1 ng/ml vs 14.8 ng/ml, p = 0.00002; VEGF: 4321 pg/ml vs 280 pg/ml, p = 0.0000; TNF-α: 23.1 ng/ml vs 11.3 ng/ml, p = 0.00002).

EBV DNA was detected in 51.3 % of patients and 20 % of controls, HPV DNA was present in 30.8 % of patients and 2,5 % of controls.

The level of IL-10 was statistically higher in patients infected with EBV, HPV and co-infected with EBV/HPV. The level of TNF-α was significantly higher in patients infected with EBV, while TGF-β in patients with HPV infection and EBV/HPV co-infection.

Conclusion

Detection of salivary cytokines may be very helpful in early diagnosis, treatment and prognosis of OSCC.

Up-regulation of miR-455-5p by the TGF-β-SMAD signalling axis promotes the proliferation of oral squamous cancer cells by targeting UBE2B

MicroRNAs (miRNAs) are involved in the tumourigenesis of various cancers by regulating their downstream targets. To identify the changes of miRNAs in oral squamous cell carcinoma (OSCC), we investigated the expression profiles of miRNAs in 40 pairs of OSCC specimens and their matched non-tumour epithelial tissues. Our data revealed higher miR-455-5p expression in the tumour tissues than in the normal tissues; the expression was also higher in oral cancer cell lines than in normal keratinocyte cell lines. MiR-455-5p knockdown reduced both the anchorage-independent growth and the proliferative ability of oral cancer cells, and these factors increased in miR-455-5p-overexpressing cells. Furthermore, by analysing the array data of patients with cancer and cell lines, we identified ubiquitin-conjugating enzyme E2B (UBE2B) as a target of miR-455-5p, and further validated this using 3'-untranslated region luciferase reporter assays and western blot analysis. We also demonstrated that UBE2B suppression rescued the impaired growth ability of miR-455-5p-knockdown cells. Furthermore, we observed that miR-455-5p expression was regulated, at least in part, by the transforming growth factor-β (TGF-β) pathway through the binding of SMAD3 to specific promoter regions. Notably, miR-455-5p expression was associated with the nodal status, stage, and overall survival in our patients, suggesting that miR-455-5p is a potential marker for predicting the prognosis of patients with oral cancer. In conclusion, we reveal that miR-455-5p expression is regulated by the TGF-β-dependent pathway, which subsequently leads to UBE2B down-regulation and contributes to oral cancer tumourigenesis. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Human Head and Neck Squamous Cell Carcinoma-Associated Semaphorin 4D Induces Expansion of Myeloid-Derived Suppressor Cells

One of the mechanisms by which malignancies can induce immune suppression is through the production of cytokines that affect the maturation and differentiation of inflammatory cells in the tumor microenvironment. Semaphorin 4D (Sema4D) is a proangiogenic cytokine produced by several malignancies, which has been described in the regulation of the immune system. In the present study, we examined the role of human head and neck squamous cell carcinoma (HNSCC)-secreted Sema4D on myeloid cell differentiation. CD33(+) cells cultured in HNSCC cell line-derived conditioned medium differentiated into myeloid derived suppressor cells (MDSC) (CD33(+)CD11b(+)HLA-DR(-/low)). The addition of anti-Sema4D Ab to HNSCC conditioned medium significantly reduced the expansion of the MDSC population. Similarly, knockdown of Sema4D in an HNSCC cell line resulted in a loss of MDSC function as shown by a decrease in the production of the immune-suppressive cytokines arginase-1, TGF-β, and IL-10 by MDSC, concomitant with recovery of T cell proliferation and IFN-γ production following stimulation of CD3/CD28. Importantly, CD33(+) myeloid and T cells cultured in conditioned medium of HNSCC cells in which Sema4D was knocked down promoted antitumor inflammatory profile, through recovery of the effector T cells (CD4(+)T-bet(+) and CD8(+)T-bet(+)), as well as a decrease in regulatory T cells (CD4(+)CD25(+)FOXP3(+)). We also showed that Sema4D was comparable to GM-CSF in its induction of MDSC. Collectively, this study describes a novel immunosuppressive role for Sema4D in HNSCC through induction of MDSC, and it highlights Sema4D as a therapeutic target for future studies to enhance the antitumorigenic inflammatory response in HNSCC and other epithelial malignancies.

Proinflammatory cytokine levels in oral lichen planus, oral leukoplakia, and oral submucous fibrosis

OBJECTIVES

The objective of this study was to identify salivary and serum concentrations of interleukin (IL)-8, IL-6, and tumor necrosis factor alpha (TNF-α) in patients with oral lichen planus, oral leukoplakia, oral submucous fibrosis, and healthy controls.

MATERIALS AND METHODS

Patients selected included 54 oral lichen planus (41 to 65 years), 50 oral leukoplakia (42 to 65 years), 51 oral submucous fibrosis (41 to 65 years), and 50 healthy controls (42 to 65 years). Oral lichen planus, oral leukoplakia, and oral submucous fibrosis cases were diagnosed using histopathological analysis. Salivary and serum cytokine concentrations were measured using enzyme-linked immunoassay kits in all subjects.

RESULTS

The levels of serum and salivary TNF-α, IL-6, and IL-8 were statistically significantly increased in oral leukoplakia, submucous fibrosis, and lichen planus in contrast to normal healthy subjects (P<0.05). Serum and salivary correlation analysis revealed strong and highly significant correlations for TNF-α, IL-6, and IL-8 in all groups (r=0.72-0.82, P<0.05).

CONCLUSION

Salivary and serum cytokines were also elevated when analyzed in oral precancerous lesions. Thus, salivary and serum IL-8, IL-6, and TNF-α levels might act as diagnostic markers for detection of oral precancer.

Tissue invasion and metastasis: Molecular, biological and clinical perspectives

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.

Type 2 diabetes mellitus and risk of oral cancer and precancerous lesions: a meta-analysis of observational studies

OBJECTIVE

Associations between type 2 diabetes mellitus (type 2 DM) and risk of oral cancer and precancerous lesions have been reported with controversial findings. We performed a meta-analysis to explore these associations.

METHODS

We identified studies by a literature search of MEDLINE and EMBASE through May 31, 2014, and by searching the reference lists of pertinent articles. Summary relative risk (SRR) with 95% confidence interval (CI) was calculated with a random-effects model. Between- study heterogeneity was assessed using the Cochran's Q and I(2) statistics.

RESULTS

A total of 13 studies (4 case-control and 9 cohort studies) on the association between type 2 DM and oral cancer were included. Overall analysis found that compared with non-diabetic individuals, individuals with type 2 DM had a significantly elevated incidence of oral cancer (SRR=1.15, 95% CI: 1.02-1.29; Pheterogeneity=0.277, I(2)=15.4%; 10 studies). Subgroup analyses found that duration of follow-up (⩾11years) significantly altered this positive association. Type 2 DM was associated with increased oral cancer mortality (SRR=1.41, 95% CI: 1.16-1.72; 4 studies). Meta-analysis of the four case-control studies showed a positive association between type 2 DM and risk of oral precancerous lesions (SRR=1.85, 95%CI: 1.23-2.80; Pheterogeneity=0.038, I(2)=57.5%). No significant public bias was found across these studies.

CONCLUSIONS

These findings of this meta-analysis indicate that compared with non-diabetic individuals, individuals with type 2 DM have an elevated risk of oral cancer and precancerous lesions development.

Regulatory T-cell infiltration in tongue squamous cell carcinoma

CONCLUSION

In tongue squamous cell carcinoma (SCC), high levels of regulatory T-cell (Treg) infiltration in tumor nests are observed in the cases with poor prognosis.

OBJECTIVES

The role of Tregs in head and neck cancers remains unclear. The aim of this study was to observe the distribution of Tregs in different stages of tongue SCC and estimate the effects on prognosis.

METHODS

Thirty-four cases with tongue SCC were examined immunohistochemically for CD4, CD8, and Forkhead box P3 (Foxp3). Immunoreactive cells were counted in cancer stroma and nest regions, and relationships between cell numbers and disease-free survival rates were analyzed.

RESULTS

In the 34 cases, univariate analysis for disease-free survival indicated high-level infiltration of Tregs (CD4(+)Foxp3+) into both cancer nests and stroma and presence of helper T (CD4(+)Foxp3-) cells in cancer stroma as potential predictors of significantly worse prognosis. In early-stage cases (stage I/II), high-level infiltration of Tregs in cancer nests correlated significantly with poor disease-free survival rate. Multivariate analysis for disease-free survival found no independent variables.

1α,25-dihydroxyvitamin D3 modulates CYP2R1 gene expression in human oral squamous cell carcinoma tumor cells

Oral squamous cell carcinomas (OSCC) are the most common malignant neoplasms associated with mucosal surfaces of the oral cavity and oropharynx. 1α,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is implicated as an anticancer agent. Cytochrome P450 2R1 (CYP2R1) is a microsomal vitamin D 25-hydroxylase which plays an important role in converting dietary vitamin D to active metabolite, 25-(OH)D3. We identified high levels of CYP2R1 expression using tissue microarray of human OSCC tumor specimens compared to normal adjacent tissue. Therefore, we hypothesize that 1,25(OH)2D3 regulates CYP2R1 gene expression in OSCC tumor cells. Interestingly, real-time RT-PCR analysis of total RNA isolated from OSCC cells (SCC1, SCC11B, and SCC14a) treated with 1,25(OH)2D3 showed a significant increase in CYP2R1 and vitamin D receptor (VDR) mRNA expression. Also, Western blot analysis demonstrated that 1,25(OH)2D3 treatment time-dependently increased CYP2R1 expression in these cells. 1,25(OH)2D3 stimulation of OSCC cells transiently transfected with the hCYP2R1 promoter (-2 kb)-luciferase reporter plasmid demonstrated a 4.3-fold increase in promoter activity. In addition, 1,25(OH)2D3 significantly increased c-Fos, p-c-Jun expression, and c-Jun N-terminal kinase (JNK) activity in these cells. The JNK inhibitor suppresses 1,25(OH)2D3, inducing CYP2R1 mRNA expression and gene promoter activity in OSCC cells. Furthermore, JNK inhibitor significantly decreased 1,25(OH)2D3 inhibition of OSCC tumor cell proliferation. Taken together, our results suggest that AP-1 is a downstream effector of 1,25(OH)2D3 signaling to modulate CYP2R1 gene expression in OSCC tumor cells, and vitamin D analogs could be potential therapeutic agents to control OSCC tumor progression.

Risk genes in head and neck cancer: a systematic review and meta-analysis of last 5 years

The aim of this work was to identify risk genes related to the development and progression of squamous cell carcinoma head and neck (SCCHN) and do a meta-analysis of available estimates. Eligible gene/polymorphism studies were identified by electronic searches. Individual participant data of 8540 patients with HNC and 9844 controls from 19 genetic studies were analyzed, yielding adjusted (tobacco, gender, age and alcohol) odds ratios (OR) and 95% confidence intervals (CIs) comparing cases with controls. A meta-analysis was done on the studies that applied fixed and random models. People have an increase of polymorphism expression related to inflammation (NFKB1-294-ATTG, TNFα308-A2A2/A2A1, and TNFβ252- B2B2/B2B1) or carcinogenic metabolism (GSTM1 null, and CYP1A1 m1/m1), representative of malignancy development. Furthermore, the increased expression of genes associated with the stabilization and repair of the cellular (OGG1-Asp267Asn, Ser279Gly Ile253Phe, 1578A>T, 1582C>T Ala399Glu (1542C>A) 1582insG 1543_1544delCT), and genes associated with the regulation of proliferation, apoptosis or tumor survival (miRNA499-CT/CC, CRYABC802G-CG/GG) are considered as risk factors. In this scheme, only the polymorphisms of ADH7A92G-GG and DEC1606-T/C genes are protective against malignancy transformation. The TP53, GSTM1 and CYPA1genes have been evaluated in more than one study and analyzed for homogeneity in each genotype. The meta-analysis showed no significant association between different allelic variants of Arg72Pro rs1042522 and SCCHN risk. In a model of tumorigenesis, an increased risk of SCCHN is associated with DNA repair and DNA stabilization genes. In addition, the polymorphisms involved in inflammation and carcinogenic metabolism processes represent an increased risk of SCCHN.

Chemokines and cytokines as salivary biomarkers for the early diagnosis of oral cancer

Chemokines have been shown to be important in both inflammation and carcinogenesis and are able to be measured in saliva with relatively robust methods including enzyme-linked immunosorbent assays (ELISA). Thus it has been hypothesized that patients with oral cancer and oral potentially malignant lesions will have elevated levels of specific chemokines in oral fluids and that this may be used as a marker of both the early detection of malignant disease and progression to malignancy. The concept that salivary biomarkers can be easily measured and indicate disease states has profound consequences for clinical practice and may open up new strategies for the diagnosis, prognosis, and potential therapy of oral squamous cell carcinoma (OSCC). This review focuses on our understanding of cytokines and chemokines and the potential role that they may have in clinical practice.