Oral cancer: reviewing the present understanding of its molecular mechanism and exploring the future directions for its effective management

A Comparative Study of Morphometric Analysis of Nucleolar Organizer Regions in Oral Leukoplakia and Oral Squamous Cell Carcinoma and Significance of AgNOR as a Diagnostic Tool

Background Silver stainable nucleolar organizer regions (AgNORs) have proven to exhibit utmost importance due to their higher occurrence in the nucleus especially in malignant cells than in normal. Thus, they assist in the examination of nucleolar structures and variations in nucleolar activity. Aim Quantitative and qualitative analysis in relation to the number and area of AgNOR in tissue sections of the normal oral mucosa (NOM), oral leukoplakia (OL), and oral squamous cell carcinoma (OSCC) was the main aim of the study. Materials & method A total of 50 cases comprising 20 OL with dysplasia, 20 OSCC cases, and 10 samples of normal oral mucosa were taken. Silver nitrate (Sol A) & gelatin (Sol B) solutions were freshly prepared for staining the lesional slides. Results The mean value of nuclear profile area (A Nuc) was comparatively higher in oral leukoplakia i.e. 41.97 and in oral squamous cell carcinoma i.e. 62.36 in comparison to the control group where it was 36.19. The mean value of a single AgNOR profile area per nucleus (A NOR) was found to be comparatively lower in both study groups i.e. oral leukoplakia (2.76) and oral squamous cell carcinoma (1.61) in comparison to the control group (3.45) . The mean value of total AgNOR profile area per nucleus (TA NOR) and the number of profiles of AgNORs per nucleus (n NOR) were found higher in both study groups (oral leukoplakia and oral squamous cell carcinoma) as compared to normal oral mucosa of the control group. However, the findings of all four parameters of morphometric analysis were found to be significantly associated with disorder of oral mucosa i.e. cases of oral leukoplakia and oral squamous cell carcinoma (P value <0.01). Conclusion It can thus be suggested that the mean AgNOR count displayed a higher value in OSCC. Hence, the number of AgNORs in nuclei increases as epithelial cells undergo malignant transformation which is designated that mean AgNOR count may contribute to establishing the prognosis of a lesion.

Potential use of heat shock protein 90 as a biomarker for the diagnosis of human diseases

INTRODUCTION

The heat shock protein 90 (Hsp90) is a protein involved in many different biological processes and especially in cell survival. Some of these functions require the participation of other biological molecules, so Hsp90 is a chaperone that takes part in many protein-protein interactions working as a critical signaling hub protein. As a member of the heat shock protein family, Hsp90 expression is regulated under certain environmental and/or stressful situations, therefore Hsp90 concentration can be monitored and linked to these effects.

AREAS COVERED

This review discusses the Hsp90 expression in samples from individuals affected by different diseases (from infectious to cancer origin), and the biological consequences of these disorders, including the potential use of Hsp90 as a biomarker for the diagnosis of human diseases.

EXPERT OPINION

The potential of Hsp90 as a biomarker disease has been demonstrated in several studies in relation to infectious diseases and especially cancer. However, further research in this field is still needed, mainly to validate in statistically significant clinical studies that the detection of Hsp90 protein allows the diagnosis of some cancers at an early stage and also that it can act as a biomarker for monitoring the efficacy of their therapies.

Quality of Life of Oral Squamous Cell Carcinoma Patients before and after Primary Treatment

Background

HNSCC (head and neck squamous cell carcinoma) is a serious global health problem, with estimated more than 550,000 new cases and 300,000 deaths annually. More than 90% of these malignancies are oral squamous cell carcinoma (OSCC).

Materials and Methods

Patients selected were asked to fill the detailed structured case history proforma and thorough clinical examination, structured, pre-designed, pre-evaluated (UW-QOL) UW Questionnaire version 4 on quality of life (QOL) of oral squamous cell carcinoma patients containing thirteen subjective questionnaires and three global questionnaires. All the patients of OSCC after one month (1 month) of radiation and chemotherapy were assessed for quality of life by questionnaire.

Result

Post-treatment QOL assessment of OSCC patients reveals a number of problems such as chewing, swallowing, saliva, lack of activity, and mood disturbances. Preoperative clinical features including tumor site, tumor stage, and extent of mouth opening have a significant impact on post-treatment problems in different ways.

Conclusion

The need to balance clinician's need and use of health-related quality of life (HRQOL) data against patient's burden should be considered in the selection process.

Cathepsins in oral diseases: mechanisms and therapeutic implications

Cathepsins are a type of lysosomal globulin hydrolase and are crucial for many physiological processes, including the resorption of bone matrix, innate immunity, apoptosis, proliferation, metastasis, autophagy, and angiogenesis. Findings regarding their functions in human physiological processes and disorders have drawn extensive attention. In this review, we will focus on the relationship between cathepsins and oral diseases. We highlight the structural and functional properties of cathepsins related to oral diseases, as well as the regulatory mechanisms in tissue and cells and their therapeutic uses. Elucidating the associated mechanism between cathepsins and oral diseases is thought to be a promising strategy for the treatment of oral diseases and may be a starting point for further studies at the molecular level.

Evaluation of the Role of Toluidine Blue Paint as an Adjunctive Method to Biopsy in Suspicious Oral Lesion: A Hospital Based Study

Early detection is a major step in the success of cancer therapy. Histopathology report is considered as the gold standard in the formulation of management protocol of any malignancy worldwide. But unfortunately, there is a delay in the detection of oral cancer very often due to inconclusive histopathology reports. The main reason behind it is obtaining a biopsy specimen from the non-representative area of the lesion. A hospital-based evaluation of the role of Toluidine Blue dye, used as an adjunctive method prior to biopsy was conducted in a tertiary care hospital on 200 patients presenting with oral lesions persistent for more than 3 weeks. The participants were divided into two equal groups by alternate sampling. In one group biopsy was taken by clinical judgment and in others, Toluidine Blue was used prior to obtaining a biopsy to decide the area to be biopsied. Data was collected using a predesigned proforma and was analyzed with the help of SPSS version 20. Results in two groups were compared with respect to sensitivity, specificity, positive and negative predictive values, false positive and false negative percentages. The Sensitivity, Specificity, Positive Predictive Value and Negative Predictive Value of wedge biopsy without staining were 73.68, 58.14, 70.00, and 62.50% respectively. These values were 95.08, 82.05, 89.23, and 91.43% respectively when Toluidine Blue staining was done as an adjunctive before the biopsy procedure. These results indicate the promising role of Toluidine blue staining before the biopsy to diagnose oral malignancy more efficiently than obtaining biopsy specimens on clinical assessment only and in avoiding the delay in initiating the treatment in case of oral malignant lesions.

Altered expression of junctional proteins as a potential biomarker in oral precancerous and cancerous patients

Due to a lower survival rate in patients with advanced clinical stages of oral cancer, discovering a biomarker that could diagnose and predict disease progression is vital. Cell-cell junctional proteins play a crucial role in the maintenance of tissue architecture but are often deregulated in different cancer. The present study investigates the expression of cell-cell junctional proteins viz: e-cadherin (E-cad) and zonula occludens-1 (ZO-1) in oral precancerous (OED) and cancerous (OSCC) patients to monitor if they can serve as practicable molecular markers. The ultrastructural junctional complex was studied by transmission electron microscopy, and the expression of proteins was performed by immunohistochemistry. The relationship between the expression of protein and clinicopathological features of the patients was checked by Pearson's correlation test. Furthermore, the survival curve of the follow-up data was estimated by the Kaplan-Meier method. We observed a disrupted junctional complex and a significantly decreased immunoexpression of E-cad and ZO-1 in OED and OSCC when compared to the adjacent non-cancerous tissues. The expression of ZO-1 was associated with TNM stages, whereas E-cad was associated with histological grades as well as TNM stages. A positive correlation was observed between the expression of ZO-1 and E-cad proteins in OED and OSCC. Further, follow-up studies revealed that high ZO-1 and E-cad expressing patients survived longer than their low expressed counterparts. The present study shows disruption of junctional complex and alteration of junctional proteins expression that could draw the attention of health professionals to explore junctional proteins as a possible therapeutic target in oral cancer.

Accuracy of autofluorescence and chemiluminescence in the diagnosis of oral Dysplasia and Carcinoma: A systematic review and Meta-analysis

OBJECTIVES

To define the accuracy of autofluorescence-based (AF) and chemiluminescence-based (CL) systems in the diagnosis of oral dysplastic and malignant lesions in addition to the Conventional Oral Examination (COE).

MATERIALS AND METHODS

The study was performed according to the PRISMA-DTA guidelines.

RESULTS

A total of 2631 oral cavity lesions (AF, n = 2076; CL, n = 555) from 26 studies (AF = 17; CL = 9) was used for calculation of diagnostic accuracy parameters. The overall pooled sensitivity and specificity of the AF were 81.3% (95% CI: 74.3% - 87.5%) and 52.1% (95% CI: 36.9% - 67.1%), respectively. Cumulative diagnostic odds ratio (DOR) was 5.44 (95% CI: 2.29 - 10.56) with a significant heterogeneity between studies (I² = 80.7%, 95% CI: 70.0% - 86.7%; p < .05). The overall pooled sensitivity and specificity for the CL were 84.9% (95% CI: 66.7% - 96.7%) and 51.8% (95% CI: 37.3% - 65.9%), respectively. The overall pooled DOR was 8.59 (95% CI: 2.11 - 22.38) with a significant heterogeneity between studies (I² = 65.4%, 95% CI: 29.6% - 83.0%; p < .05).

CONCLUSIONS

AF and CL present a high sensitivity in the diagnosis of dysplastic and malignant oral cavity lesions, demonstrating that diagnostic biopsies may be avoided in case of a negative test result. Both tests have a low specificity, and the reduction of the false positive rate compared to the COE alone remains poor.

Evaluation of aryl hydrocarbon receptor expression in oral squamous cell carcinoma and normal oral mucosa using western blot

Background

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that acts as a binding site for toxic chemicals, particularly the dioxin group of chemicals. Elevated levels of AHR have been observed in various human cancers, including lung carcinomas, hepatic carcinomas and in mammary tumors. However, the expression of AHR in oral squamous cell carcinoma (OSCC) patients who are tobacco users are less explored.

Aims and Objectives

The aim of the present study is to evaluate and compare AHR levels in OSSC patients and in normals using Western blot technique in an attempt to explore the possible role of AHR in oral carcinogenesis.

Materials and Methods

The study sample consisted of ten oral squamous cell carcinoma cases which were diagnosed clinically and confirmed histopathologically as OSCC and four samples of the normal oral mucosa. AHR protein expression was evaluated using Western blot technique and chemiluminescence detection kit. The densitometry was performed on a Microtek scan maker MSP flatbed scanner and quantified using Image J software. Mean AHR protein levels were calculated and compared between OSCC and normal oral mucosa using Student's t-test.

Results

The mean AHR protein level in OSCC samples (n = 10) was 2878.90 ± 1231.27 and 975.75 ± 227.27 in the normal oral mucosa (n = 4). The OSCC samples showed significantly higher levels of AHR protein compared to the normal oral mucosa (P = 0.008).

Conclusion

The study showed a significantly higher expression of AHR in oral squamous cell carcinoma samples when compared to the normal oral mucosa, suggesting a possible role of AHR in the initiation, promotion and progression of oral squamous cell carcinoma.

Comprehending the crosstalk between Notch, Wnt and Hedgehog signaling pathways in oral squamous cell carcinoma - clinical implications

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a malignant oral cavity neoplasm that affects many people, especially in developing countries. Despite several advances that have been made in diagnosis and treatment, the morbidity and mortality rates due to OSCC remain high. Accumulating evidence indicates that aberrant activation of cellular signaling pathways, such as the Notch, Wnt and Hedgehog pathways, occurs during the development and metastasis of OSCC. In this review, we have articulated the roles of the Notch, Wnt and Hedgehog signaling pathways in OSCC and their crosstalk during tumor development and progression. We have also examined possible interactions and associations between these pathways and treatment regimens that could be employed to effectively tackle OSCC and/or prevent its recurrence.

CONCLUSIONS

Activation of the Notch signaling pathway upregulates the expression of several genes, including c-Myc, β-catenin, NF-κB and Shh. Associations between the Notch signaling pathway and other pathways have been shown to enhance OSCC tumor aggressiveness. Crosstalk between these pathways supports the maintenance of cancer stem cells (CSCs) and regulates OSCC cell motility. Thus, application of compounds that block these pathways may be a valid strategy to treat OSCC. Such compounds have already been employed in other types of cancer and could be repurposed for OSCC.

Molecular Alterations in Oral Carcinogenesis: Significant Risk Predictors in Malignant Transformation and Tumor Progression

In this study an attempt was made to establish the significance of a battery of molecular alterations and thereby identify risk predictors in oral carcinogenesis. For this purpose, EGFR, Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67 and Bcl-2 were localized immunohistochemically in normal mucosa (n=12), hyperplasia (n=35), dysplasia (n=25), early stage carcinoma (n=65) and advanced stage carcinoma (n=70). Deregulation occurred at an early stage and the number of alterations increased with disease progression. Using multivariate logistic regression analysis, the significant risk predictor for hyperplasia from normal mucosa was Ki-67 (OR=5.75, p=0.021); the significant risk predictors for dysplasia from hyperplasia were EGFR (OR=12.96, p=0.002), Stat3 (OR=17.16, p=0.0001), p16 (OR=5.50, p=0.039) and c-myc (OR=5.99, p=0.052); the significant risk predictors for early stage carcinoma from dysplasia were p53 (OR=6.63, p=0.0001) and Rb (OR=3.81, p=0.056); and the significant risk predictors for further progression were EGFR (OR=5.50, p=0.0001), Stat3 (OR=4.49, p=0.0001), H-ras (OR=4.05, p=0.001) and c-myc (OR=2.99, p=0.015). Cyclin D1 holds a key position linking upstream signaling pathways to cell cycle regulation. Gene products of the mitogenic signaling pathway play an equally significant role as cell cycle regulatory proteins in the hyperplasia-dysplasia-early-advanced-carcinoma sequence and together may provide a reference panel of markers for use in defining premalignant lesions and predicting the risk of malignant transformation and tumor progression.

Evaluation of mast cells in oral premalignant and malignant lesions: A histochemical study

Introduction:

Oral leukoplakia, oral submucous fibrosis, and oral lichen planus are the precancerous or potentially malignant lesions and conditions whereas oral squamous cell carcinoma (OSCC) is a cancerous or malignant lesion of the oral cavity. They have characteristic clinical and histopathological features. These diseases not only originate from epithelium but also associated with chronic inflammation juxta-epithellialy. Mast cells present in the connective tissue stroma and release pro-inflammatory and mitogenic cytokines. These functions of mast cells contribute and enhance the pathogenesis translation of diseases.

Aim:

The study was done to histologically evaluate the number of mast cells in oral epithelial dysplasia and OSCC and compare it with normal oral mucosa (NOM).

Materials and Methods:

Forty-five cases each of oral dysplasia, OSCC and ten cases of NOM were studied for mast cell number using toluidine blue.

Results:

There was a highly significant increase of mast cells in oral epithelial dysplasia on comparison with OSCC whereas there was only a significant increase in mast cells in OSCC on comparison with NOM.

Conclusion:

The literature has proven that mast cells can be an indicator of increased angiogenesis and hence can help in the prediction of carcinogenesis, its progression, and also the prognosis of the malignant lesions.

Low level laser therapy induces increased viability and proliferation in isolated cancer cells

OBJECTIVES

Low level laser therapy (LLLT), which stimulates natural biological processes in the application region, is frequently used in dental treatments. The aim of our study was to evaluate the effects of LLLT which could activate precancerous cells or increase existing cancerous tissue in case of clinically undetectable situations.

MATERIALS AND METHODS

Saos-2 osteoblast-like osteosarcoma cells and A549 human lung carcinoma cells were used. Twenty-four hours after preparation of cell culture plates, laser irradiation was performed 1, 2 and 3 times according to the test groups using Nd:YAG laser with the power output 0.5, 1, 2 and 3 W. Cell proliferation analysis was performed by MTT assay at the 24th hour following the last laser applications.

RESULTS

Generally, it was observed that the proliferation rates increased as the number of applications increased, when compared to the controls, especially in those cases in which the irradiation was performed 2 or 3 times more.

CONCLUSION

The findings of this study have led to the conclusion that LLLT increases cancer cell proliferation, depending on the power output level of the laser and the number of applications. In addition to the proliferation and mitotic activity of the cancer tissue cells, we concluded that LLLT, which is frequently used in dental practice, could activate precancerous cells or increase existing cancerous tissue.

Survivin expression, HPV positivity and microvessel density in oropharyngeal carcinomas and relationship with survival time

INTRODUCTION

Among head and neck cancers, those of the oral cavity and oropharynx are the second most prevalent following the larynx. This study aimed to research immunohistochemical expression of survivin, HPV positivity and microvessel density in tumors and their relationships with prognosis.

MATERIAL AND METHODS

Pathological materials and demographic properties of 46 patients were retrospectively evaluated. Survivin, HPV and CD34 (for microvessel density evaluation) antibodies were applied tumoral tissues. Survival times, clinical stage and differentiation were evaluated.

RESULTS

In univariate analysis, we observed that survivin, microvessel density and stage were significantly associated with survival time (p < 0.05). In multivariate analysis, only survivin and microvessel density were associated with survival time (p < 0.05). But we did not find significant correlation between neither tumor differentiation nor HPV positivity and survival (p > 0.05).

CONCLUSIONS

Survivin levels and microvessel density were found to be effective prognostic factors and were related to survival in oral cavity and oropharyngeal cancers. Treatments targeting survivin expression and angiogenesis might be employed against these tumor groups.

Changes in cell junctions induced by inhibition of epidermal growth factor receptor in oral squamous cell carcinoma cells

The benefits of epidermal growth factor receptor (EGFR) targeting in the treatment of head and neck cancer, have been documented. However, a minority of patients with head and neck cancer are unresponsive to EGFR targeting therapies. The present study evaluated the effects and limitations of an EGFR inhibitor on oral squamous cell carcinoma cells, particularly on cell-cell junctions mediated by epithelial (E)-cadherin. HSC-3 oral squamous cell carcinoma cells were treated with the EGFR inhibitor, AG1478 (0, 0.5, 2, 10 and 50 µM), and the effects of EGFR inhibition in HSC-3 cells were evaluated by wound healing assays, E-cadherin immunostaining and measurement of transepithelial electrical resistance in vitro. It was observed that treatment of oral squamous cell carcinoma cells with AG1478 suppressed cell motility, altered cell morphology and increased the number of cell-cell junctions compared with untreated control cells. Knockdown of EGFR induced a similar phenotype to that observed by the inhibition of EGFR. Furthermore, in oral squamous cell carcinoma cells treated with high-dose EGFR inhibitor (50 µM), the small number of cells that survived formed cell-cell junctions that were positive for E-cadherin expression. In cells treated with low concentrations of EGFR inhibitor (2 µM), recovery of epithelial properties was observed. The retention of E-cadherin expression in cells that survived high-dose EGFR inhibitor treatment may be a survival mechanism of cancer cells.

Polymeric drug delivery systems for intraoral site-specific chemoprevention of oral cancer

Oral cancer is among the most prevalent cancers in the world. Moreover, it is one of the major health problems and causes of death in many regions of the world. The traditional treatment modalities include surgical removal, radiation therapy, systemic chemotherapy, or a combination of these methods. In recent decades, there has been significant interest in intraoral site-specific chemoprevention via local drug delivery using polymeric systems. Because of its easy accessibility and clear visibility, the oral mucosa is amenable for local drug delivery. A variety of polymeric systems-such as gels, tablets, films, patches, injectable systems (e.g., millicylindrical implants, microparticles, and in situ-forming depots), and nanosized carriers (e.g., polymeric nanoparticles, nanofibers, polymer-drug conjugates, polymeric micelles, nanoliposomes, nanoemulsions, and polymersomes)-have been developed and evaluated for the local delivery of natural and synthetic chemopreventive agents. The findings of in vitro, ex vivo, and in vivo studies and the positive outcome of clinical trials demonstrate that intraoral site-specific drug delivery is an attractive, highly effective and patient-friendly strategy for the management of oral cancer. Intraoral site-specific drug delivery provides unique therapeutic advantages when compared to systemic chemotherapy. Moreover, intraoral drug delivery systems are self-administrable and can be removed when needed, increasing patient compliance. This article covers important aspects and advances related to the design, development, and efficacy of polymeric systems for intraoral site-specific drug delivery. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1383-1413, 2018.

Predictive value of pre-treatment apparent diffusion coefficient (ADC) in radio-chemiotherapy treated head and neck squamous cell carcinoma

OBJECTIVE

This study aimed at evaluating the role of "baseline" apparent diffusion coefficent (ADC), in patients affected by head and neck cancer treated with radio-chemotherapy, as a potential marker of response to therapy.

METHODS

Fifty-seven patients underwent pretreatment ADC maps. Minimum, maximum, and medium ADC were computed. Age, dose, treatment time, and ADC values were compared between the two groups (Group 1: local control; Group 2: relapse/persistence of disease) using the Student t test two-tailed unpaired. Two-tailed Fischer exact test was used to compare T stage, N stage, grading and type of treatment between two groups. We have analyzed the receiver operating characteristic (ROC) of statistically significant variables.

RESULTS

In patients with local control, values of pre-treatment medium and minimum ADC were lower than ADC values of patients with persistent or recurrent disease, with values, respectively, of 0.83 ± 0.02 × 10^-3 mm²/s and 0.59 ± 0.02 × 10^-3 mm²/s (vs 0.94 ± 0.05 × 10^-3 mm²/s and 0.70 ± 0.05 × 10^-3 mm²/s). ROC curve analysis displayed statistical significance as regarding the medium ADC value, showing a sensitivity of 50% and a specificity of 84.8%. ROC analysis of the values minimum ADC showed a sensitivity of 42.9% and specificity of 87.9%.

CONCLUSION

The value of the ADC pre-treatment of patients with local control of the disease is lower than that of patients with persistent disease or recurrence.

Potential Role of PET/MRI for Imaging Metastatic Lymph Nodes in Head and Neck Cancer

OBJECTIVE

This article explores recent developments in PET and MRI, separately or combined, for assessing metastatic lymph nodes in patients with head and neck cancer.

CONCLUSION

The synergistic role of PET and MRI for imaging metastatic lymph nodes has not been fully explored. To facilitate the understanding of the areas that need further investigation, we discuss potential mechanisms and evidence reported so far, as well as future directions and challenges for continued development and clinical research.

Dynamic changes in the gene expression profile during rat oral carcinogenesis induced by 4-nitroquinoline 1-oxide

The typical progression of oral cancer is from hyperplastic epithelial lesions through dysplasia to invasive carcinoma. It is important to investigate malignant oral cancer progression and development in order to determine useful approaches of prevention of dysplastic lesions. The present study aimed to gain insights into the underlying molecular mechanism of oral carcinogenesis by establishing a rat model of oral carcinogenesis using 4-nitroquino-line 1-oxide. Subsequently, transcription profile analysis using an integrating microarray was performed. The dynamic gene expression changes of the six stages of rat oral carcinogenesis (normal, mild epithelial dysplasia, moderate dysplasia, severe dysplasia, carcinoma in situ and oral squamous cell carcinomas) were analyzed using component plane presentations (CPP)-self-organizing map (SOM). Six genes were verified by quantitative polymerase chain reaction, immunohistochemistry and succinate dehydrogenase (SDH) activity assay kit. Numerous differentially expressed genes (DEGs) were identified during rat oral carcinogenesis. CPP-SOM determined that these DEGs were primarily enriched during cell cycle, apoptosis, inflammatory response and tricarboxylic acid cycle, indicating the coordinated regulation of molecular networks. In addition, the expression of specific DEGs, such as janus kinase 3, cyclin-dependent kinase A-1, B-cell chronic lymphocytic leukaemia/lymphoma 2-like 2, nuclear factor-κB, tumor necrosis factor receptor superfamily member 1A, cyclin D1 and SDH were identified to have high concordance with the results from microarray data. The current study demonstrated that oral carcinogenesis is a multi-step and multi-gene process, with a distinct pattern alteration along a continuum of malignant transformation. In addition, this comprehensive investigation provided a theoretical basis for the understanding of the molecular alterations associated with oral carcinogenesis.

C-deletion in exon 4 codon 63 of p53 gene as a molecular marker for oral squamous cell carcinoma: A preliminary study

BACKGROUND

Exfoliated oral cancer cells in saliva samples from patients with oral squamous cell carcinoma (OSCC) can be used to determine the incidence and type of mutations of the p53 tumor suppressor gene. The purpose of this study was to identify C-deletion mutation in exon 4 codon 63 of p53 gene in the saliva of OSCC patients by polymerase chain reaction (PCR).

MATERIALS AND METHODS

Saliva samples of 20 newly histopathologically diagnosed OSCC patients and 5 healthy volunteers were subjected to isolation of the total genomic DNA and PCR amplification for C-deletion on exon 4 of p53 gene. The resulting products were resolved by agarose gel electrophoresis, viewed and photographed on ultraviolet-transilluminator.

RESULTS

The relationship between the frequencies of genetic alterations was assessed by Chi-square test. Differences with values of P < 0.05 were statistically significant.

CONCLUSION

The study concluded a 100% presence of C-deletion mutation in exon 4 codon 63 of p53 in the saliva of OSCC patients. This study suggests that detection of mutation in exon 4 codon 63 of p53 by PCR is a fast, reliable, accurate, and sensitive molecular method for OSCC diagnosis.

Squamous Cell Carcinoma of the Head and Neck: Comparison of Diffusion-weighted MRI at b-values of 1,000 and 2,000 s/mm(2) to Predict Response to Induction Chemotherapy

PURPOSE

Recent publications have reported contradictory results of pretreatment diffusion-weighted magnetic resonance imaging (DWI) for the prediction of chemoradiotherapeutic response in primary squamous cell carcinomas of the head and neck (HNSCC). Therefore, we evaluated the diagnostic performance of DWI obtained with both standard (b = 0 and 1,000 s/mm²) and high (b = 0 and 2,000 s/mm²) b-values for predicting response to induction chemotherapy in HNSCCs.

METHODS

For 25 patients with primary HNSCC who underwent DWI with both standard and high b-values prior to treatment, we calculated corresponding apparent diffusion coefficient (ADC) maps. Regions of interest containing the tumor were drawn on every section of ADC maps and summated to make volume-based data of the entire tumor. Histogram parameters (mean ADC, kurtosis, and skewness) were correlated with treatment response using unpaired Student t test. Univariate and multivariate analysis of the ADC parameters, patient age, sex, whole tumor volume, and T stage were also performed to predict tumor response to induction chemotherapy.

RESULTS

Response to induction chemotherapy was good in 13 of the 25 patients and poor in 12. The mean ADC values of good responders at standard b-value (ADC1000), 1.23 ± 0.34 (× 10⁻³ mm²/s), and high b-value (ADC2000), 0.62 ± 0.14 (× 10⁻³ mm²/s), were lower than those of poor responders (ADC1000, 1.32 ± 0.28 [× 10⁻³ mm²/s]; ADC2000, 0.76 ± 0.15 [× 10⁻³ mm²/s]), but significant difference was achieved only at the ADC2000 map (P = 0.02). In addition, mean tumor volume prior to treatment of good responders was smaller than that of poor responders. However, at multiple logistic regression analysis, only the mean ADC2000 value remained as a significant predictor of response to induction chemotherapy.

CONCLUSION

DWI with high b-values (b = 0 and 2,000 s/mm²) as an assessment of ADC values may help predict tumor response to neoadjuvant chemotherapy for primary HNSCCs.

Silver binding nucleolar organizer regions dots in oral leukoplakia with epithelial dysplasia and oral squamous cell carcinoma: an in vivo study

Silver binding nucleolar organizer regions (AgNOR) in normal oral mucosa (NOM), oral leukoplakia with epithelial dysplasia (ED), and oral squamous cell carcinoma (OSCC) were studied. The mean AgNOR count per nucleus increased from NOM to ED to OSCC. Tissue showing ED in oral leukoplakia and OSCC cases showed higher counts, wider scatter, and smaller size of AgNOR dots in the nuclei. The study seems to suggest that time method has some potential in distinguishing between NOM and oral leukoplakia with ED and OSCC. Studies of larger numbers are needed to arrive at more substantial conclusions.

Clinicobiological progression and prognosis of oral squamous cell carcinoma in relation to the tumor invasive front: impact on prognosis

CONCLUSION

There are several factors that influence the final outcome when treating oral squamous cell carcinoma (OSCC). Invasive front phenomena and more importantly their clinicopathological translation can have a direct impact on survival, and subsequently on the decision for an adjuvant treatment.

OBJECTIVES

In recent years, the concept of tumor-host interaction has been the subject of substantial efforts in cancer research. Tumoral behavior may be better understood when studying the changes occurring at the tumor-host interface. This study evaluated the influence of several clinicopathological features on the outcome of OSCCs.

METHODS

The clinical records and pathology specimens of 54 patients with OSCC treated by primary resection were reviewed retrospectively. The pathologic features reviewed were: invasive front grading (IFG), stromal reaction, lymphovascular invasion (LVI), perineural invasion (PNI), margin status, and depth of invasion.

RESULTS

High IFGs had a significant relationship with pT status and pN status. High IFGs were strongly correlated with nodal metastases (odds ratio (OR) = 4.77; confidence interaval (CI) = 1.37-16.64). Concerning survival, IFG had a strong impact on disease-free survival in patients treated unimodally, as did the depth of invasion in the same group. Lymphovascular involvement was found to have a negative impact on overall survival in patients treated multimodally.

Oxygen metabolism in oral cancer: HIF and GLUTs (Review)

Oral cancer is a significant cause of morbidity and mortality, and has a poor prognosis. This has encouraged additional studies into factors that may affect the development of this disease. The biological behavior of malignant neoplasms is complex. Studies have investigated the energy metabolism of tumor cells, in an endeavor to elucidate the tumor biology. The identification of molecular signatures and mechanisms, in order to understand tumor progression, may facilitate the identification of novel predictive and prognostic markers. Pathways that influence tumor progression, such as those involving hypoxia-inducible factor (HIF) and glucose transporter (GLUT) proteins, have been the targets of recent studies.

Nitric oxide and cancer: a review

Nitric oxide (NO), is a ubiquitous, water soluble, free radical gas, which plays key role in various physiological as well as pathological processes. Over past decades, NO has emerged as a molecule of interest in carcinogenesis and tumor growth progression. However, there is considerable controversy and confusion in understanding its role in cancer biology. It is said to have both tumoricidal as well as tumor promoting effects which depend on its timing, location, and concentration. NO has been suggested to modulate different cancer-related events including angiogenesis, apoptosis, cell cycle, invasion, and metastasis. On the other hand, it is also emerging as a potential anti-oncogenic agent. Strategies for manipulating in vivo production and exogenous delivery of this molecule for therapeutic gain are being investigated. However, further validation and experimental/clinical trials are required for development of novel strategies based on NO for cancer treatment and prevention. This review discusses the range of actions of NO in cancer by performing an online MEDLINE search using relevant search terms and a review of the literature. Various mechanisms by which NO acts in different cancers such as breast, cervical, gastric,colorectal, and head and neck cancers are addressed. It also offers an insight into the dichotomous nature of NO and discusses its novel therapeutic applications for cancer prevention and treatment.

Epigenetic deregulation of the anaplastic lymphoma kinase gene modulates mesenchymal characteristics of oral squamous cell carcinomas

DNA hypermethylation of promoter CpG islands is associated with epigenetic silencing of tumor suppressor genes in oral squamous cell carcinomas (OSCCs). We used a methyl-CpG-binding domain protein capture method coupled with next-generation sequencing (MBDCap-seq) to survey global DNA methylation patterns in OSCCs with and without nodal metastasis and normal mucosa (total n = 58). Of 1462 differentially methylated CpG islands identified in OSCCs relative to normal controls, MBDCap-seq profiling uncovered 359 loci linked to lymph node metastasis. Interactive network analysis revealed a subset of these loci (n = 23), including the anaplastic lymphoma kinase (ALK) gene, are potential regulators and effectors of invasiveness and metastatic progression. Promoter methylation of ALK was preferentially observed in OSCCs without node metastasis, whereas relatively lower methylation levels were present in metastatic tumors, implicating an active state of ALK transcription in the latter group. The OSCC cell line, SCC4, displayed reduced ALK expression that corresponded to extensive promoter CpG island methylation. SCC4 treatment with demethylating agents induced ALK expression and increased invasion and migration characteristics. Inhibition of ALK activity in OSCC cells with high ALK expression (CAL27, HSC3 and SCC25), decreased cell growth and resulted in changes in invasive potential and mesenchymal marker expression that were cell-line dependent. Although ALK is susceptible to epigenetic silencing during oral tumorigenesis, overwriting this default state may be necessary for modulating invasive processes involved in nodal metastases. Given the complex response of OSCC cells to ALK inhibition, future studies are required to assess the feasibility of targeting ALK to treat invasive OSCCs.

Therapeutic and preventive effects of an epidermal growth factor receptor inhibitor on oral squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is the sixth most common human neoplasm worldwide. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is highly expressed in human OSCC and is a target for cancer therapy and prevention. This study investigated the therapeutic and preventive effects of an inhibitor of EGFR (PD153035) on OSCC.

METHODS

The effects of PD153035 were examined in human cancer cell lines in vitro, in an athymic nude mouse xenograft model in vivo, and in the 7,12-dimethyl benz[a]anthracene (DMBA)-induced hamster cheek pouch tumour model in vivo.

RESULTS

PD153035 significantly inhibited cell growth, delayed cell cycle progression and induced apoptosis in human OSCC cells in vitro. In vivo, PD153035 inhibited xenograft tumour growth in nude mice in a dose-dependent manner and prevented the development of OSCC at the postinitiation stage in the DMBA-induced hamster cheek pouch tumour model. PD153035 inhibited the DMBA-induced increases in cell proliferation and in levels of phosphorylated EGFR and phosphorylated signal transducer and activator of transcription 3 (STAT3) protein in the hamster cheek pouch.

CONCLUSIONS

Inhibitors of EGFR, such as PD153035, have potential value in the treatment and prevention of OSCC.

Positive and negative regulation of podoplanin expression by TGF-β and histone deacetylase inhibitors in oral and pharyngeal squamous cell carcinoma cell lines

OBJECTIVES

Podoplanin, a transmembrane sialomucin-like glycoprotein, is known to express at high frequency in oral squamous cell carcinomas (OSCC) and possess metastasis-promoting activity such as increased invasion and platelet-aggregating activity. However, the regulatory mechanism of podoplanin expression in OSCC remains unknown.

MATERIALS AND METHODS

In the present study, we investigated the podoplanin expression in both clinical specimens from total 80 patients (50 OSCC and 30 pharyngeal SCC) and in 4 OSCC cell lines in vitro.

RESULTS

Immunohistochemical analysis of surgically resected specimens of OSCC revealed podoplanin expression in 70% of OSCC cases with localization primarily in the basal layer of squamous cancer nest and the expression was inversely correlated with squamous cell differentiation. In vitro analysis of OSCC cell lines revealed 36 that podoplanin expression was decreased in response to the squamous cell differentiation (Cytokeratin 10 expression as a marker) induced by treatment with histone deacetylase (HDAC) inhibitors such as sodium butyrate and trichostatin. Furthermore, transforming growth factor-β (TGF-β) significantly enhanced podoplanin expression in OSCC cell lines in line with increased phosphorylation of Smad2. A TGF-β type I receptor inhibitor (SB431542) significantly inhibited such induction of podoplanin expression by TGF-β at both the protein and mRNA level. However, in a subset of OSCC cell line, its expression was only weakly dependent on TGF-β and squamous differentiation.

CONCLUSION

These results suggest that regulation of podoplanin is not simple, but in the majority of OSCC cell lines, its expression is positively and negatively regulated by TGF-β receptor/Smad signaling pathway and epigenetic mechanism leading to squamous differentiation, respectively.

Heparanase and cyclooxygenase-2 gene and protein expressions during progression of oral epithelial dysplasia to carcinoma

Heparanase and cyclooxygenase-2 (COX-2) are 2 key enzymes that modulate diverse physiological processes during embryonic development and in adult life. Their deregulations have been implicated in the growth and progression of many cancer types. To date, comparatively little is known about the roles of these molecules during oral carcinogenesis. The aim of this study was to investigate the expression patterns of heparanase and COX-2 during progression of oral epithelial dysplasia (OED) to carcinoma. In situ hybridization and immunohistochemistry were performed on 5 cases of normal mucosa, 15 cases of OED, 5 cases of carcinoma in situ and/or microinvasive carcinoma, and 40 cases of oral squamous cell carcinoma (OSCC). Results demonstrated that heparanase and COX-2 messenger RNA and protein were absent in normal oral mucosa but were coexpressed in increasing intensity as OED progressed to OSCC. Concomitant heparanase- and COX-2-positive staining in the stromal cells suggests that OED/OSCC progression may be modulated by stromal-cancer cell interactions. Diffuse intense staining of poorly differentiated OSCC compared with staining localized to tumor nest periphery in well- and moderately differentiated OSCC suggests that heparanase and COX-2 overexpressions correlated with tumor grade. Strong expression of these enzymes in tumor cells at the advancing front suggests a role in local tumor spread. These results, taken together, suggest that heparanase and COX-2 might play complementary roles in the stepwise progression of OED to carcinoma.

Integrating multiple microarray datasets on oral squamous cell carcinoma to reveal dysregulated networks

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the sixth most common type of carcinoma worldwide. The pathogenic pathways involved in this cancer are mostly unknown; therefore, a better characterization of the OSCC gene expression profile would represent a considerable advance. The public availability of gene expression datasets was meant to obtain new insights on biological processes.

METHODS

We integrated 4 public microarray datasets on OSCC to evaluate the degree of consistency among the biological results obtained in these different studies and to identify common regulatory pathways that could be responsible for tumor growth.

RESULTS

Twelve altered cellular pathways implicated in OSCC and 4 genes altered in the extracellular matrix (ECM) receptor pathway were validated by quantitative real-time polymerase chain reaction (qRT-PCR).

CONCLUSION

Using 4 expression array datasets, we have developed a robust method for analyzing pathways altered in OSCC.

Podoplanin expression predicts prognosis in patients with oral squamous cell carcinoma treated with neoadjuvant radiochemotherapy

Despite new therapeutic approaches patients with advanced oral squamous cell carcinoma still have a dismal prognosis. The main factor contributing to this problem is locoregional failure due to a lack of response to treatment. Several trials have proven the effect of neoadjuvant radiochemotherapy followed by radical surgery in comparison to primary surgery followed by adjuvant radiochemotherapy. No reliable parameters have been identified so far to predict response to radiochemotherapy. The aim of our study was to assess whether podoplanin expression in pretreatment biopsies could serve as a biomarker to predict the host response to neoadjuvant radiochemotherapy. In this retrospective study, podoplanin expression was examined in a set of 63 patients with oral squamous cell carcinoma by immunohistochemistry. We analyzed associations between the level of podoplanin expression and various clinicopathologic parameters, including response to radiochemotherapy, clinical and histological N-status. Furthermore we evaluated the effects of these parameters on overall survival and on locoregional control in univariate and multivariate analysis. The χ(2)-test revealed that high expression of podoplanin in pretreatment biopsy material was associated with non-regression of the tumor (p=0.013) and poor overall survival (p<0.001). Five-year survival rates of 92.9% for patients with weak expression and 15.0% for high expression were revealed. Podoplanin expression was also significantly associated with ypN status (p=0.004) and ypUICC status (p<0.001). We concluded that podoplanin might serve as a factor to predict treatment response in oral squamous cell carcinoma treated with neoadjuvant platin-based radiochemotherapy as well as a prognostic factor for overall survival and locoregional control.

Gene expression profiling of oral squamous cell carcinoma by differential display rt-PCR and identification of tumor biomarkers

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide. Despite progress in therapeutic and surgical treatments, its survival period at 5 years is the lowest among major cancers, and remains unchanged in the last two decades. The growing epidemiological relevance of oral cancer emphasizes the need to better understand the molecular mechanisms underlying this disease and identify predictive tumor markers and therapeutic targets. To this end, we have used the DDRT-PCR analysis to profile the oral tumor transcriptome and identify differentially regulated genes that may be used as potential biomarkers and therapeutic targets. Our DDRT-PCR analysis identified 51 differentially expressed fragments, of which 25 were revalidated by reverse Northern analysis. Northern blot analysis further corroborated these findings for a few genes. In order to ascertain the utility of some of the identified genes as molecular markers and therapeutic targets, semi-quantitative RT-PCR analysis was carried out in a panel of matched oral normal and tumor samples, that confirmed GLTP, PCNA, RBM28, C17orf75 and DIAPH1 as significantly upregulated, whereas TNKS2, PAM and TUBB2C showed significant downregulation in tumor samples. Taken together, our DDRT-PCR analysis has revealed several genes, belonging to diverse cellular pathways, that have been associated with OSCC for the first time. Thus, these genes could be investigated as biomarkers and therapeutic targets for OSCC.

Immunohistochemical expression of p16(INK4A) protein as a helpful marker of a subset of potentially malignant oral epithelial lesions: study on a series with long-term follow-up

AIM

  To examine a group of lesions that progressed to oral squamous cell carcinoma (OSCC) to determine whether p16(INK4A) expression is an early finding during malignant transformation, and whether immunohistochemical evaluation of p16(INK4A) is an appropriate prognostic marker.

METHODS AND RESULTS

  Twenty cases of OSCC were investigated. All cases had had a biopsy on the same site as OSCC performed at least 1year before OSCC (range 1-11years; mean 3.15±3.1years). Twenty specimens from normal oral mucosa served as controls. p16(INK4A) expression was evaluated by immunohistochemical analysis and cases showing >5% of stained cells were defined as 'positive'. All 20 control cases were negative for p16(INK4A) . Oral lesions were p16(INK4A) -positive in nine cases and negative in 11. No significant relationship was found between p16(INK4A) positivity and the presence/absence of dysplasia. Among OSCC, nine tumours showed p16(INK4A) positivity and 11 showed negativity. A significant relationship (χ(2)=7.1; P<0.01) was found between the presence/absence of p16(INK4A) staining in OSCC and the presence/absence of p16(INK4A) staining in lesions preceding OSCC.

CONCLUSIONS

  p16(INK4A) immunohistochemistry has a potential role in detecting a subset of p16(INK4A) -positive lesions with malignant potential.

Salivary transcriptome biomarkers in oral squamous cell cancer detection

In all, 350,000 new cases of oral cancer are reported annually worldwide, 35,000 of these occur in the United States. For decades, the 5-year survival rate has remained low at only 60%, which is mainly due to cancer diagnosis at late and progressed stage. Using saliva as a diagnostic medium could be the key for early detection and thus improved survival rates. Among all salivary constituents, the transcriptome has turned out to be a highly promising biomarker source. So far, seven mRNA and two microRNA markers were found to be discriminatory in saliva of oral cancer patients. This review will give an overview on the field of salivary transcriptome research with focus on oral cancer detection as well as the translation of salivary diagnostics into clinical reality.

Analysis of differentially expressed proteins in oral squamous cell carcinoma by MALDI-TOF MS

PURPOSE

To explore the presence of differentially expressed proteins in OSCC for discrimination of tumour and normal mucosa to establish potential biomarkers and therapeutic targets.

EXPERIMENTAL DESIGN

Paired protein samples of 12 individuals (tongue cancer and non-cancerous mucosa) were separated by two-dimensional polyacrylamid gel electrophoresis. The protein patterns were compared pairwise and protein spots were quantified. We identified about 70 regulated proteins which we subsequently identified by MALDI-TOF mass spectrometry.

RESULTS

Cancerous and non-cancerous tissues could be most precisely distinguished by a panel of proteins. They include the heat shock proteins (hsp)70 and 90, keratins (ck) 5, 6, 13, 14, 16, 17 and 19, beta globin, alpha-2-actin, stratifin, tropomyosin, calreticulin precursor, beta-2-tubulin, galectin7, thioredoxin, involucrin, adenylyl-cyclase-associated protein, disulfide isomerase-associated protein, thyrosine 3-monooxygenase, MYL2 and the s100 calcium binding protein. MYL3, cardiac muscle alpha actin 1 proprotein and transferrin were under-represented in OSCC. Six biomarkers, ck6 und ck13, beta globin, alpha-2-actin, hsp70 and hsp90 discriminated best between cancerous and non-cancerous oral tissues. All over-expressed proteins were analysed by STRING-analysis to highlight experimentally determined and computationally predicted interactions between the proteins. Especially involucrin, hsp70, calreticulin precursor, stratifin, (ck) 5, 6, 14, 19, tyrosine 3-monooxygenase, beta-2-tubulin and disulfide isomerase associated protein showed multiple relations.

CONCLUSION

We identified six proteins which are differentially expressed in most OSCC compared to healthy tissues. Of those, by string analysis, multiple interaction partners are assumed for hsp70. This protein is supposed to be the most promising candidate as marker molecule and target for OSCC therapy.

C-deletion mutation of the p53 gene at exon 4 of codon 63 in the saliva of oral squamous cell carcinoma in central India: a preliminary study

AIM

The purpose of this study was to detect the C-deletion mutation of the p53 gene at exon 4 of codon 63 in the saliva of oral squamous cell carcinoma in central India.

METHODS

The study was carried out in 30 oral squamous cell carcinoma cases and five healthy controls with no habit of betel nut and tobacco chewing. The C-deletion mutation of the p53 gene at exon 4 of codon 63 was detected in the saliva samples by using polymerase chain reaction.

RESULTS

In this study, C-deletion at exon 4 of codon 63 was detected in 28 of 30 oral squamous cell carcinoma cases (93.33%), but was negative in all five healthy controls and two oral squamous cell carcinoma cases.

CONCLUSIONS

The results indicated that C-deletion mutation at exon 4 of codon 63 of the p53 gene in the saliva might be a plausible molecular marker for oral squamous cell carcinoma patients with a habit of betel nut and tobacco lime quid chewing. The results further emphasize the presence of p53 gene mutation in patients with oral squamous cell carcinoma, which can be detected in the saliva through polymerase chain reaction.

Molecular diagnostics for head and neck pathology

Molecular diagnostic techniques are quickly finding a role in the detection and diagnosis of tumors, and in predicting their behavior. They may also prove useful in developing new therapeutic approaches to head and neck cancer. The surgeon working in the craniomaxillofacial region should have an understanding of these technologies, their availability in various settings, and how they affect various aspects of treatment, particularly in the detection and treatment of malignancies. This article offers an overview of recent advances in molecular diagnostic techniques, with their implications for diagnosis and management of head and neck tumors.

Clinical, pathological and molecular determinants in squamous cell carcinoma of the oral cavity

Squamous cell carcinoma of the oral cavity (OCSCC) is the most frequently observed form of head-and-neck cancer in Southeast Asia and is the sixth most common cancer worldwide. Most cases of this preventable disease are caused by alcohol consumption, smoking and betel nut chewing. The survival rates of patients with advanced OCSCC have not increased significantly in recent years. While treatments for OCSCC are similar worldwide, survival rates differ by geographical area. The various genetic profiles and individual genetic susceptibility for carcinogens may account for this discrepancy. In some respects, molecular alteration or accumulation affects tumor progression and the clinical outcomes among patients with OCSCC. Clarifying the tumor behavior of oral cancer, with regard to pathological features or molecular aspects, could help clinicians to judge, tailor and adopt more effective therapeutic strategies to treat oral cancer.

Prognostic significance of molecular markers in oral squamous cell carcinoma: a multivariate analysis

BACKGROUND

Multiple marker accumulation impacts tumor progression and biologic phenotypes affect clinical outcome of patients with head and neck cancer. Hence, this study investigated a battery of molecular markers that may help to reflect biologic aggressiveness and predict prognosis.

METHODS

Epidermal growth factor receptor (EGFR), Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67, and Bcl-2 were localized immunohistochemically in 135 oral squamous cell carcinoma patients to assess prognostic value.

RESULTS

In univariate analysis of total patients, p53, Stat3, and p16 predicted both relapse-free survival (RFS) and overall survival (OS). In Cox multivariate analysis, after adjusting for tumor size, nodal status, and lymphatic permeation, p53 was independently associated with RFS and OS, and p16 with RFS only. In only early-stage patients, in univariate analysis, nuclear Stat3 was significant for RFS and OS.

CONCLUSION

Immunostaining of p53, p16, and Stat3 might serve as potential adjuncts in pathologic evaluation of oral tumors to predict risk of relapse.

Oxidant-antioxidant status in blood and tumor tissue of oral squamous cell carcinoma patients

BACKGROUND AND OBJECTIVE

Increased oxidative and nitrosative stress associated with disturbances in antioxidant defense system have been implicated in the pathogenesis of several diseases, most notably oral cancer. The aim of this study was to evaluate the oxidant-antioxidant status in blood samples and tumor tissue in oral squamous cell carcinoma (OSCC) patients in comparison with the healthy controls.

METHODS

Blood and tumor tissue samples from the diseased individuals and the normal controls were analyzed for malondialdehyde (MDA) and nitric oxide (NO) as indicators of oxidative stress and nitrosative stress respectively; superoxide dismutase (SOD) and catalase enzymes as indicators of antioxidant defense by UV visible spectrophotometer.

RESULTS

Malondialdehyde and NO levels were significantly elevated in the blood and tissue samples of OSCC patients as compared with the healthy controls. The antioxidant enzymes SOD and catalase were significantly reduced in tissue samples of OSCC group than in the control group while in the erythrocytes, catalase levels were significantly reduced and the SOD levels were higher in OSCC group in comparison with the healthy controls.

INTERPRETATION AND CONCLUSION

Increased levels of MDA and NO indicate an increase in the oxidative stress in OSCC patients associated with a deficient antioxidant defense mechanism. This oxidant-antioxidant imbalance may be considered as one of the factors responsible for pathogenesis of cancer. Future studies regarding assessment of oxidant-antioxidant status in OSCC patients in view of selecting appropriate mode of therapy and the effectiveness of such therapy in limiting the tumor progression and recurrence is to be carried out.

Proteomic profiling of cancer of the gingivo-buccal complex: Identification of new differentially expressed markers

Tobacco-related oral cancer is the most common cancer among Indian males, gingivo-buccal complex (GBC) being the most affected subsite due to the habit of chewing tobacco. Proteins from the lysates of microdissected normal and transformed epithelium from clinically well-characterized tissue samples of the GBC were separated by two-dimensional gel electrophoresis to identify differentially expressed proteins. Eleven protein spots showed differential expression, which could withstand the stringency of statistical evaluation. The observations were confirmed with additional tissues. Nine of these differentiators were identified by MS as lactate dehydrogenase B, α-enolase, prohibitin, cathepsin D, apolipoprotein A-I, tumor protein translationally controlled-1, an SFN family protein, 14-3-3σ and tropomyosin. Cluster analysis indicated that these proteins, as a coexpressed set, could distinguish normal and transformed epithelium. Functionally, these differentiator molecules are relevant to the pathways and processes that have been previously implicated in oral carcinogenesis and could therefore be investigated further as a panel of markers for management of cancer of the GBC.

Oral carcinoma epidemiology in Paraná State, Southern Brazil

Oral carcinoma is the sixth most frequent type of cancer in the world and the seventh most common in Brazil (the country with the highest incidence in Latin America). Mean five-year survival remains one of the lowest among the main cancers, thus justifying studies that contribute to the development of preventive strategies. The aim of this study was to compare the epidemiological, clinical, and histological characteristics of 91 patients with oral carcinoma. Mean age was 58.62 +/- 10.46 years, and male-to-female ratio was 6.6:1.0 (79 men and 12 women). European descendants predominated with 79 patients (86.8%). Eighty-five individuals (93.4%) smoked and 70 (76.9%) consumed alcohol regularly. Anatomical distribution of tumors was: 27 (29.7%) tongue; 18 (19.8%) floor of mouth; 11 (12.1%) oropharynx; and 11 (12.1%) oral mucosa. Fifty-seven patients (62.6%) presented lymph node involvement and three (3.3%) had distant metastases. Surgery and radiotherapy were used in 43.2% of patients. With the exception of the male/female ratio (which was higher), our data are consistent with previous studies on oral carcinoma patients.

The adjunctive role of toluidine blue in detection of oral premalignant and malignant lesions

PURPOSE OF REVIEW

To review the literature on toluidine blue (TBlue) and to discuss the utility of TBlue in assessing and in clinical management of patients with oral mucosal lesions. The literature search was conducted using key word search including oral cancer, oral premalignant lesions, and TBlue and by selecting references from the articles reviewed.

RECENT FINDINGS

The findings of this review show that TBlue has utility as an adjunct in the detection of premalignant and malignant oral mucosal lesions and in identifying high-risk areas of lesions for biopsy in patients at increased risk of cancer when evaluated by experienced healthcare workers.

SUMMARY

TBlue positive lesions, whether histologically benign or with dysplasia, predict molecular change and behavior of oral premalignant lesions. TBlue may provide information regarding lesion margins, accelerate the decision to biopsy, guide biopsy site selection and treatment of oral premalignant and malignant lesions. These findings support the utility of TBlue as a clinical adjunct in assessment of oral mucosal lesions.

Proteomic analysis of protein expression in human tonsillar cancer: differentially expressed proteins characterize human tonsillar cancer

BACKGROUND

Head and neck cancer continues to be one of the most common tumor entities worldwide. Within this group of malignancies, tonsillar squamous cell carcinoma represent approximately 15-20% of all intraoral and oropharyngeal carcinomas in the United States. Accurate and early stage diagnosis still remains a major challenge, as patients are often presented at an advanced stage of disease, causing a low overall survival rate. Thus, new diagnostic markers are highly desirable and could allow for a more reliable diagnosis, with further insights into carcinogenesis and tumor biology. Furthermore, these markers could be the basis for new therapeutic targets and early disease detection. To address these issues, we decided to use a global proteomic approach to characterize tonsillar squamous cell carcinoma.

MATERIALS AND METHODS

A total of 19 tonsillar carcinoma samples and 12 benign controls acquired from the corresponding normal epithelium were analyzed by 2-D gel electrophoresis. 2-DE gels were silver stained and analyzed using the PDQuest analysis software (BioRad). Tumor specific spots were detected and identified by consecutive MALDI-TOF-MS or MS/MS polypeptide identification.

RESULTS

In total, 70 proteins showed significant quantitative differences in protein expression, with 50 polypeptides accessible for identification. Of those 50 polypeptides, we were able to identify a total of 27 proteins and protein isoforms, significantly up- or down-regulated in tonsillar cancer samples. In addition to previously reported polypeptides in head and neck cancers, we were able to identify several new potential marker proteins in this study.

CONCLUSION

Our results show that a combination of tonsillar cancer specific proteins can be used for histopathological diagnosis and may serve as a basis for discovering further biomarkers for early detection and prediction of response to treatment in the future.