NADPH oxidase and uncoupled nitric oxide synthase are major sources of reactive oxygen species in oral squamous cell carcinoma. Potential implications for immune regulation in high oxidative stress conditions

The development of cancer is associated with high oxidative stress and at the same time with immune system activation. Tumors develop efficient mechanisms of protection against the immune response, which allow them to escape the immune surveillance. Simultaneously, key events in the process of carcinogenesis are related to oxidative stress. The relationship between the two remains unknown. Novel understanding of oxidative stress shows that discrete changes of activities of certain enzyme systems such as NADPH oxidases or nitric oxide synthases may be more important than the overall balance of production and removal of reactive oxygen species. Such imbalance of nitric oxide and superoxide production could modify inflammation and immune regulation. We studied superoxide anion production (by lucigenin enhanced chemiluminescence - 5 microM), NADPH oxidase activity and nitric oxide synthase (NOS) dysfunction. In parallel mRNA expression of immunomodulatory markers such as FoxP3 (T regulatory cell marker), CCR6 (mucosal homing effector T cell marker) and CD85j (NK cell/CD8 T cell Ig-like MHC class I inhibitory receptor) was determined. Basal superoxide production and NADPH oxidase activity are increased in oral squamous cell carcinoma. Tumor superoxide production was inhibited by NADPH oxidase inhibitor apocynin and by NOS inhibitor L-NAME. This indicates, for the first time, that oral squamous cell carcinoma is characterized by dysregulated nitric oxide synthase, which apart from increased NADPH oxidase activity contributes to oxidative stress and may be related to the immuno-pathology of these tumors. Studied tumors were infiltrated by CCR6+, but showed lower expression of both CD85j and FoxP3 mRNA. Finally, the CD85j mRNA expression was inversely correlated to oxidative stress parameters. These preliminary studies indicate that tumor oxidative stress, related to NADPH oxidase activity and NOS activity could be related to immune responses to cancer, thus therapeutic modification of oxidative stress, which could include the correction of NOS dysfunction, could facilitate immune surveillance.

[The study on oral carcinoma-associated fibroblast promoting the proliferation of lingual carcinoma cell line]

OBJECTIVE

The aim of this study was in vitro to investigate the effects of oral carcinoma-associated fibroblasts (CAFs) on the proliferation of lingual carcinoma cells.

METHODS

The interaction model between primary oral CAFs and a lingual carcinoma cell line Tca8113 was established for this study project. The effects of CAFs on the viability and cell cycle of Tca8113 were investigated through morphological observation, MTT assay and flow cytometry.

RESULTS

After oral CAFs interacted with Tca8113 directly, Tca8113 showed the cellular shape changes in morphology; compared with normal fibroblasts (NFs), CAFs enhanced the viability of Tca8113 (P<0.05), and increased the percentage of carcinoma cells in S phase and G2 phase (48.1% vs 40.0%).

CONCLUSION

Oral CAFs can promote the proliferation of the lingual carcinoma cell line Tca8113 in vitro, and may play a key role in the progression of oral squamous cell carcinoma (OSCC).

Adenosquamous carcinoma of oral cavity: a case report

An elderly man presented with a pair of soft tissue swelling, one on upper and another on lower gums, with chest pain and respiratory distress. Histopathological examination of the biopsied material showed features suggestive of adenosquamous carcinoma, but CT-guided fine needle aspiration cytology from lung mass showed evidence of non-keratinising squamous cell carcinoma. This histologic dissimilarity between primary and metastatic tumour is a characteristic feature of the lesion. Palliative radiation was given as the patient was unfit for surgery, but his condition deteriorated rapidly and treatment had to be withdrawn.

Analysis of formant frequencies in patients with oral or oropharyngeal cancers treated by glossectomy

AIMS

To compare voice quality as defined by formant analysis using a sustained vowel in patients who have undergone a partial glossectomy with a group of normal subjects.

METHODS & PROCEDURES

The design consisted of a single centre, cross-sectional cohort study. The setting was an Adult Tertiary Referral Unit. A total of 26 patients (19 males) who underwent partial glossectomy and 31 normal volunteers (18 males) participated in the study. Group comparisons using the first three formant frequencies (F1, F2 and F3) using linear predictive coding (Laryngograph Ltd, London, UK) were performed. The existence of any significant difference of F1, F2 and F3 between the two groups using the sustained vowel /i/ and the effects of other factors, namely age, first presentation versus recurrence, site (oral cavity, oropharynx), subsite (anterior two-thirds of the tongue, tongue base), stage, radiation, complication, and neck dissection, were analysed.

OUTCOMES & RESULTS

Formant frequencies F1, F2 and F3 were normally distributed. F1 and F2 were significantly different in normal males versus females. F1, F2 and F3 were not different statistically between male and female glossectomees. Comparison of only women showed significant differences between normal subjects and patients in F2 and F3, but none in F1. This was the opposite in men where F1 was significantly different. Age, tumour presentation, site, subsite, radiation and neck dissection showed no significant difference. Postoperative complications significantly affected the F1 formant frequency.

CONCLUSIONS

The study found that the formant values in patients following a partial glossectomy were altered significantly as compared with the normal control subjects. Only gender and complications and not the age, site, subsite, radiation and neck dissection were seen to influence the formant scores.

Swallowing Function Following Extensive Resection of Oral or Oropharyngeal Cancer With Laryngeal Suspension and Cricopharyngeal Myotomy

OBJECTIVE

To investigate factors that influence postoperative swallowing function in patients who underwent tongue and oropharynx resection.

METHODS

Sixty-two subjects who had undergone extensive resection of oral or oropharyngeal cancer between 1993 and 2005 participated in this study. All surgical procedures involved excision of the bilateral suprahyoid muscles or of >or=50% of the tongue base. Laryngeal suspension and cricopharyngeal myotomy were performed on all subjects. A multivariate analysis of the effects of extensive tongue and oropharynx resection on swallowing function was performed.

RESULTS

A total of 53 (85.5%) of the 62 subjects achieved independent oral intake and no longer required tube feeding. Six months after surgery, better eating capabilities had been attained by younger patients as compared with older patients; patients with less extensive tongue base resections; patients who had not undergone radiotherapy; and patients reconstructed with free flaps rather than pedicled flaps.

CONCLUSIONS

Age was found to be the most important factor in determining whether a patient could achieve independent oral intake after extensive oral or oropharyngeal resection. The main factors in determining the quality of diet attained by the patient were found to be age, the percentage of tongue base resection, and the method of postoperative reconstruction.

Nutritional status in head and neck cancer patients

OBJECTIVE

Patients suffering from cancer of head and neck are at risk of nutritional depletion. The aim of our study was to investigate the role of type, location and stage of tumors in nutritional status.

PATIENTS AND METHODS

A population of 230 consecutive patients with head and neck cancer was enrolled. A nutritional evaluation was realized.

RESULTS

The distribution of tumour sites was: oral cavity (77 patients), pharynx (30 patients) and larynx (123 patients). Subjective Global Assessment (SGA) test showed significant differences. Midly malnourished frequency is higher in larynx site than others. Severely malnourished is higher in larynx and oral cavity than pharynx. In pharynx, larynx and oral cavity tumours is more frequent to be well nourished than severely malnourished. In pharynx and larynx tumours is more frequent to be mildly malnourished than severely malnourished. In stages II, III and IV are more frequent to be well nourished than severely malnourished and in stages II and III is more frequent to be mildly malnourished than severely malnourished.

CONCLUSIONS

SGA test shows a good nutritional status in patients with head and neck tumours. However, SGA test shows statistical differences in some categories of tumours stages or sites.

Oxidative stress in lymphocytes, neutrophils, and serum of oral cavity cancer patients: modulatory array of L-glutamine

OBJECTIVES

Our aim was to assess the oxidative stress and ameliorative effect of L-glutamine in serum, neutrophils, and lymphocytes of oral cancer patients by measuring the levels of malondialdehyde (MDA) and antioxidants.

MATERIALS AND METHODS

This study has been conducted on serum and specific blood cells in adult, male oral cancer patients (stage III-6, stage IV-42) and normal subjects of an equal number of age and sex-matched disease-free healthy subjects. The levels of lipid peroxidation and antioxidant enzymes were assayed using spectrophotometric methods.

RESULTS

MDA levels were elevated, and antioxidant enzyme status was decreased significantly in all groups of cancer patients simultaneously, but after supplementation of "glutammune" (66.66% L-glutamine), oxidative stress has been alleviated to some extent; especially, it has repaired the glutathione cascade system.

CONCLUSION

We conclude that oxidative stress is due to the enhanced lipid peroxidation and decrease in antioxidant enzymes, and it can be restored with dietary supplementation of L-glutamine related drug.

Repression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) but not its receptors during oral cancer progression

Background

TRAIL plays an important role in host immunosurveillance against tumor progression, as it induces apoptosis of tumor cells but not normal cells, and thus has great therapeutic potential for cancer treatment. TRAIL binds to two cell-death-inducing (DR4 and DR5) and two decoy (DcR1, and DcR2) receptors. Here, we compare the expression levels of TRAIL and its receptors in normal oral mucosa (NOM), oral premalignancies (OPM), and primary and metastatic oral squamous cell carcinomas (OSCC) in order to characterize the changes in their expression patterns during OSCC initiation and progression.

Methods

DNA microarray, immunoblotting and immunohistochemical analyses were used to examine the expression levels of TRAIL and its receptors in oral epithelial cell lines and in archival tissues of NOM, OPM, primary and metastatic OSCC. Apoptotic rates of tumor cells and tumor-infiltrating lymphocytes (TIL) in OSCC specimens were determined by cleaved caspase 3 immunohistochemistry.

Results

Normal oral epithelia constitutively expressed TRAIL, but expression was progressively lost in OPM and OSCC. Reduction in DcR2 expression levels was noted frequently in OPM and OSCC compared to respective patient-matched uninvolved oral mucosa. OSCC frequently expressed DR4, DR5 and DcR1 but less frequently DcR2. Expression levels of DR4, DR5 and DcR1 receptors were not significantly altered in OPM, primary OSCC and metastatic OSCC compared to patient-matched normal oral mucosa. Expression of proapoptotic TRAIL-receptors DR4 and DR5 in OSCC seemed to depend, at least in part, on whether or not these receptors were expressed in their parental oral epithelia. High DR5 expression in primary OSCC correlated significantly with larger tumor size. There was no significant association between TRAIL-R expression and OSSC histology grade, nodal status or apoptosis rates of tumor cells and TIL.

Conclusion

Loss of TRAIL expression is an early event during oral carcinogenesis and may be involved in dysregulation of apoptosis and contribute to the molecular carcinogenesis of OSCC. Differential expressions of TRAIL receptors in OSCC do not appear to play a crucial role in their apoptotic rate or metastatic progression.

Long-term functional outcome and satisfaction after radial forearm free flap reconstructions of intraoral malignancy resections

PURPOSE

Evaluation of objective and subjective functional follow-up results of intraoral radial forearm free flap reconstructions.

METHODS

A total of 149 patients had received radial forearm free flaps between January 1996 and December 2005. Seventy-two patients completed a European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-H&N35 (EORTC H&N35) in the follow-up study. Patients were divided according to location of defect (anterior or posterior) or irradiation. Thirty-nine patients with anterior positioned flaps received standardised physical examinations.

RESULTS

Flap survival was 99.3%. Complications were divided in early (<2 weeks; 23%) and late complications (20%). Most common complications were dehiscence or fistula, responding well to conservative treatment. Analysis of questionnaire subscales showed no statistically significant differences between anterior and posterior defects. Irradiation showed significant impairment for the ability to smell and taste. No important donor site impairment was found.

CONCLUSION

The radial forearm free flap is an adequate method for reconstructions after resection of intraoral malignancies. Subjective functional outcome seemed to be defined by adjuvant radiotherapy, patient coping and, to a lesser extent, flap bulk for anterior defects.

Free anterolateral thigh flap versus free forearm flap: Functional results in oral reconstruction

Nowadays, microsurgery performed for oral reconstruction of cancer patients, has become the standard treatment in restoring oral functions. The free radial forearm flap (FRFF) is still apparently the first reconstructive choice in oral cavity cancers. Recently the anterolateral thigh flap (ALTF) seemed to challenge the superiority of FRFF. The lack of functional data on which to base this recent supposition is the reason for this new research. Twenty reconstructed patients were enrolled for this study. Speech, swallowing, and donor site complications were studied to assess differences between the two techniques. Results show that difference in function between ALTF and FRFF groups is statistically insignificant. Donor site risks and complications seem to be the only variables among groups. These variables may be used as indicators when making a surgical choice.

A comprehensive salivary analysis for oral cancer diagnosis

PURPOSE

This study utilized comprehensive salivary analysis to evaluate biochemical and immunological parameters in the saliva of oral squamous cell carcinoma (OSCC) patients.

METHODS

Whole saliva was collected from 25 otherwise healthy OSCC patients and compared to 25 healthy, age- and gender-matched individuals. All OSCC lesions were located at the lateral aspect of the mobile tongue. The salivary parameters analyzed included: sodium (Na), potassium (K), calcium (Ca), inorganic phosphate (P), magnesium (Mg), total protein (TP), albumin (Alb), lactate dehydrogenase (LDH), amylase (Amy), total immunoglobulin G (IgG), secretory immunoglobulin A (Sec. IgA), epidermal growth factor, insulin growth factor I (IGF-I) and metalloproteinases MMP-2 and MMP-9.

RESULTS

In cancer patients, salivary median total protein concentration was significantly higher by 26% (P = 0.01), as were concentrations of Na, Ca, P and Mg by 14% (P = 0.05), 59% (P = 0.05), 39% (P = 0.08) and 28% (P = 0.12), respectively. Amy and K concentrations were lower by 25% (P = 0.12) and 15% (P = 0.03), respectively. Alb was 108% higher (P = 0.0007), as were salivary LDH (88%, P = 0.002) and total IgG (125%, P = 0.01), while Sec. IgA was lower by 45% (P = 0.001). Concentrations of IGF, MMP-2 and MMP-9 were significantly higher by 117% (P = 0.03), 75% (P = 0.0003) and 35% (P = 0.05), respectively.

CONCLUSIONS

Comprehensive salivary analysis revealed an overall altered salivary composition in OSCC, indicating a compromised oral environment in these patients and suggesting salivary analysis as a new diagnostic tool for oral cancer. Local therapeutic agents can be easily applied to the oral mucosa, altering its "bathing medium"-the saliva.

Abundance and localization of skeletal muscle-related erbB2 may stimulate tumour growth during initial stages of oral oncogenesis

ErbB2 and erbB3 transmembrane receptors, known to be associated with neuronal and skeletal muscle developmental function, seem to play an important role in human oral oncogenesis. This study was designed to determine gradual erbB2 and erbB3 expression in an experimental animal system of induced oral carcinogenesis in Syrian golden hamsters. Thirty-seven animals were divided into one control group (N=7) and three experimental groups (N=10 each one), which were treated with carcinogen 9,10-dimethyl-1,2-benzanthracene and sacrificed at 10, 14 and 19 weeks after treatment. The histological status of observed lesions in the three experimental groups corresponded well with tumour advancement (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma). Tissue sections ranging from normal mucosa to squamous cell carcinoma were studied using monoclonal antibodies against erbB2 and erbB3 proteins. Cytoplasmic erbB2 expression was gradually increased in pre-cancerous stages, remained stable in initial tumour stages and substantially decreased in moderately-differentiated carcinomas, suggesting that it may be useful as an early prognostic factor. On the contrary, erbB3 was not expressed at all either in normal or tumour tissue.

Establishment of a murine model of bone invasion by oral squamous cell carcinoma

This study examines the establishment an animal model of bone invasion by oral squamous cell carcinoma to clarify the mechanisms of osteoclast-mediated bone invasion. C(3)H/HeN mice were inoculated with SCCVII cells into the masseter region. At the end of week 3, all surviving mice were sacrificed and analyzed by three-dimensional imaging using micro-computed tomography, histopathological observation using Hematoxylin-Eosin staining and Tartrate-Resistant Acid Phosphatase staining, and confirmation of mRNA expression of the osteoclast-related cytokines IL-6, TNF-alpha, and PTHrP. SCCVII cells rapidly multiplied in the masseter muscle of the mice. Bone invasion was evident only in the SCCVII transplanted group on micro-computed tomography. The histopathologic findings obtained with H-E and TRAP staining indicated that the tumor cells in the mandible of all animals of the SCCVII transplanted group exhibited funicular invasion and presented a serrated pattern of bone resorption. The mRNA expression of IL-6, PTHrP, and TNF-alpha increased as the control decreased. SCCVII cells were highly invasive into mandibular bone in C(3)H/HeN mice. This model was similar to the invasion of human oral cancer into maxillary and mandibular bone. Our mandibular invasion model may provide a powerful new modality for the diagnosis and treatment of oral cancer with bone invasion.

Quality of life and functional status in patients with cancer of the oral cavity and oropharynx: pretreatment values of a prospective study

We assessed the pretreatment health-related quality of life (HRQOL) and functional status of patients with advanced oral and oropharyngeal cancer. Eighty patients were investigated. HRQOL was assessed by EORTC QLQ-C30/QLQ-H&N35 questionnaires. Functional status assessment comprised speech and oral function tests. The results revealed a wide range of HRQOL and functional deficits before treatment. HRQOL appeared to be related to some extent to tumor site (patients with oral tumors reported more pain compared to patients with oropharyngeal tumors) and tumor classification (patients with T3–T4 tumors reported more trouble opening the mouth and felt more ill compared to patients with T2 tumors). Comorbidity appeared to have a major impact. Patients with comorbidity had significantly worse scores on several scales/items on both the EORTC questionnaires. Functional deficits were related to tumor site, classification and comorbidity. Patients with oral cavity tumors (versus oropharyngeal tumors), patients with T3–T4 tumors (versus T2 tumors), and patients with comorbidity (versus without comorbidity) scored significantly worse on several speech and oral function tests. Impaired speech and oral function appeared to be clearly related to global quality of life (QLQ-C30) and self-reported speech (QLQ-H&N35). Many patients with advanced oral and oropharyngeal cancer have compromised HRQOL and functional status before the start of treatment. In addition to tumor site and tumor classification, comorbidity appears to have a major impact on HRQOL and functional status. Knowledge of pretreatment HRQOL and functional status levels is useful for better understanding the impact of treatment on these outcomes over time.

Advances in the biology of oral cancer

The incidence of oral cancer remains high and is associated with many deaths in both Western and Asian countries. Several risk factors for the development of oral cancer are now well known, including smoking, drinking and consumption of smokeless tobacco products. Genetic predisposition to oral cancer has been found in certain cases but its components are not yet entirely clear. In accordance with the multi-step theory of carcinogenesis, the natural history of oral cancer seems to gradually evolve through transitional precursor lesions from normal epithelium to a full-blown metastatic phenotype. A number of genomic lesions accompany this transformation and a wealth of related results has appeared in recent literature and is being summarized here. Furthermore, several key genes have been implicated, especially well-known tumor suppressors like the cyclin-dependent kinase inhibitors, TP53 and RB1 and oncogenes like the cyclin family, EGFR and ras. Viral infections, particularly with oncogenic HPV subtypes and EBV, can have a tumorigenic effect on oral epithelia and their role is discussed, along with potential therapeutic interventions. A brief explanatory theoretical model of oral carcinogenesis is provided and potential avenues for further research are highlighted.

Application of lateral arm free flap in oral and maxillofacial reconstruction following tumor surgery

OBJECTIVE

To describe the application of lateral arm free flap (LAFF) in reconstruction of defects in the oral and maxillofacial regions following ablative oncological surgery.

SUBJECTS AND METHODS

The study included 16 patients (13 male, 3 female, mean age 56, range 35-69 years). Sixteen LAFF were harvested to reconstruct defects caused by the dissection of malignant tumors of the oral and maxillofacial regions. The tumor was squamous cell carcinoma of the tongue (6 cases), floor of the mouth (4), retromolar area (3), inner cheek (2), and lower gingival (1). Flap sizes ranging from 5 x 7 to 6 x 9 cm were harvested using a sterile tourniquet for bloodless technique. The anastomoses were carried out using a magnifier or microscope. All donor defects were closed primarily.

RESULTS

Fourteen flaps healed without venous insufficiency. One flap, in a female patient, survived with mild local microcirculatory obstruction but that of another female patient developed necrosis. There was no significant complication at the donor sites. The advantages of this flap include anatomically reliable vascular supply, accessible donor site, and the aesthetic quality of donor tissue is good. Compared with the radial artery, the posterior radial collateral artery is a nonessential vessel of the arm. The disadvantages are the relatively smaller vessel size for anastomosis and thicker subcutaneous tissue.

CONCLUSIONS

For the repair of moderate-sized defects of the maxillofacial area, especially in male patients, the LAFF can be recommended.

Evaluation of the quality of life of patients with oral cancer in Brazil

This study performed a field trial of a Portuguese version of the University of Washington quality of life questionnaire (UW-QOL, 3rd version), aiming at appraising its ability to identify different patterns of health-related quality of life of patients with oral cancer in Brazil. Patients (N = 100) were interviewed as they were undergoing treatment for oral squamous cell carcinoma at a large Brazilian hospital ("Hospital das Clínicas", School of Medicine, University of São Paulo). The results were compared based on categories of socio-demographic and clinical characteristics of the patients. At a one-year follow-up, 20 patients had died, and 24 were considered dropouts. The remaining patients accounted for the longitudinal assessment of modifications in the self report of quality of life. Patients with larger tumours and neoplasms in the posterior part of the mouth presented significantly (p < 0.05) poorer indications of quality of life. Chewing was the poorest rated domain (35.0/100.0), and presented the highest proportion of complaints both at the baseline and at the follow-up assessments. The questionnaire allowed the identification of important contrasts (while comparing clinical characteristics) and similarities (while comparing socio-demographic status) among subsets of respondents, and it can contribute to reduce the impact of treatments and improve subsequent patient management.

Mechanical allodynia and thermal hyperalgesia induced by experimental squamous cell carcinoma of the lower gingiva in rats

We developed a rat model of oral cancer pain by inoculating cancer cells into the lower gingiva. A squamous cell carcinoma (SCC) derived from Fisher rats, SCC-158, was inoculated into the subperiosteal tissue on the lateral side of the lower gingiva in male Fisher rats. Inoculation of cancer cells induced marked mechanical allodynia and thermal hyperalgesia in the ipsilateral maxillary and mandibular nerve area. Infiltration of the tumor cells into the mandible and the completely encompassed inferior alveolar nerve was observed. Calcitonin gene-related peptide (CGRP)-, substance P (SP)-, ATP receptor (P2X(3))-, and capsaicin receptor (TRPV1)-immunoreactive cells strikingly increased in the small-cell group of trigeminal ganglia (TGs) after tumor cell inoculation. The TRPV1-immunoreactive cells also increased in the medium- and large-cell groups. Retrograde tracing combined with immunofluorescence techniques revealed the increased expression of peptides and the receptors in maxillary nerve afferent neurons. These results suggest that inoculation of SCC cells into the lower gingiva produces mechanical allodynia and thermal hyperalgesia, indicating the establishment of a novel rat model of oral cancer pain. Increased expression of CGRP, SP, P2X(3), and TRPV1 in the TG may be involved in the behavioral changes in this model.

PERSPECTIVE

To clarify the mechanisms of oral cancer pain, we examined the expression of calcitonin gene-related peptide, substance P, ATP receptor P2X(3), and capsaicin receptor TRPV1 in trigeminal ganglia. Characterizations of these molecular systems which mediate pain perception are important to develop novel clinical tools for promoting relief of oral cancer pain.

FGFR-2 and -3 play an important role in initial stages of oral oncogenesis

BACKGROUND

FGFR-2 and FGFR-3 (fibroblast growth factor receptors) have been shown to play an important role in several processes including carcinogenesis. This study was designed to determine gradual FGFR-2 and FGFR-3 expression in sequential stages of oral carcinogenesis in an experimental animal system of Syrian golden hamsters.

MATERIALS AND METHODS

Tissue sections ranging from normal mucosa to squamous cell carcinoma were studied using monoclonal antibodies against FGFR-2 and FGFR-3 proteins.

RESULTS

A significant elevation was revealed in both FGFR-2 and FGFR-3 expression during the stages of dysplasia and early invasion, while in the later stages of oral carcinogenesis the expression of both FGFR-2 and FGFR-3 decreased although not significantly.

CONCLUSION

Our findings indicate that FGFR-2 and FGFR-3 seem to play an important role in the initial stages of oral cancer progression.

Photodynamic therapy down-regulates the invasion promoting factors in human oral cancer

Squamous cell carcinomas of the head and neck are characterized by their high tendency for invasion and metastasis. Several studies have identified the roles of matrix metalloproteinases (MMPs), vascular endothelial growth factors (VEGF) and urokinase plasminogen activators (uPA) in this process. Photodynamic Therapy (PDT) is an emerging treatment currently in clinical practice for the treatment of early cancer. Here we evaluate, in vitro, the influence of PDT on the expression of these molecules. A series of human keratinocyte cell lines derived from human oral squamous cell carcinomas (OSCC) were used as the PDT 'targets' in this study. Each cell line was subjected to sublethal dose of PDT. Activity of MMP-2, MMP-9, MMP-13, uPA and VEGF were evaluated at protein levels using zymography and ELISA on culture medium. For uPA, a chromogenic assay was performed. Gelatin zymography results revealed that, in control medium, MMP-9 and MMP-2 were secreted in proform. MMP-2 was highly expressed by H376 cells while VB6 and UP cells relatively show similar MMP-2 with comparatively low expression. For MMP-9, the latent type was highly expressed by VB6 cells and only slightly by H376, while active-MMP-9 was expressed by VB6 cell line only. Following PDT, both active and latent MMP-2 and MMP-9 were down regulated by UP and VB6 cells (p<0.001), while H376 showed an increase in active-MMP-2. These observations were supported by ELISA. This study has demonstrated that, PDT causes the suppression of factors responsible for tumour invasion which may be of therapeutic value.

The functional intraoral Glasgow scale (FIGS) in retromolar trigone cancer patients

BACKGROUND

Surgical incisions in the retromolar trigone (RMT) cause injury to underlying structures. The functional intraoral Glasgow scale (FIGS) is used to determine the ability of patients to speak, chew and swallow. FIGS could be used to investigate whether there is a correlation between clinical tumour stage and the function of the oral cavity following surgery in the RMT.

MATERIALS AND METHODS

FIGS scores for 58 patients speech, chewing and swallowing collected pre-operatively, then at 3 and 20 weeks post-operatively, were used to calculate a total 'Global Oral Disability' value and compared with the clinical tumour size using the TMN staging method.

RESULTS

Patients with RMT cancer who undergo surgical resection can expect a degree of functional impairment which is proportional to the clinical tumour size.

DISCUSSION

FIGS is a simple and reproducible way of assessing a patient's functional impairment following surgery in the RMT, especially when using the new global oral disability value.

Oxidative and nitrative DNA damage in animals and patients with inflammatory diseases in relation to inflammation-related carcinogenesis

Infection and chronic inflammation are proposed to contribute to carcinogenesis through inflammation-related mechanisms. Infection with hepatitis C virus, Helicobacter pylori and the liver fluke, Opisthorchis viverrini (OV), are important risk factors for hepatocellular carcinoma (HCC), gastric cancer and cholangiocarcinoma, respectively. Inflammatory bowel diseases (IBDs) and oral diseases, such as oral lichen planus (OLP) and leukoplakia, are associated with colon carcinogenesis and oral squamous cell carcinoma (OSCC), respectively. We performed a double immunofluorescence labeling study and found that nitrative and oxidative DNA lesion products, 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), were formed and inducible nitric oxide synthase (iNOS) was expressed in epithelial cells and inflammatory cells at the site of carcinogenesis in humans and animal models. Antibacterial, antiviral and antiparasitic drugs dramatically diminished the formation of these DNA lesion markers and iNOS expression. These results suggest that oxidative and nitrative DNA damage occurs at the sites of carcinogenesis, regardless of etiology. Therefore, it is considered that excessive amounts of reactive nitrogen species produced via iNOS during chronic inflammation may play a key role in carcinogenesis by causing DNA damage. On the basis of our results, we propose that 8-nitroguanine is a promising biomarker to evaluate the potential risk of inflammation-mediated carcinogenesis.

Heterogeneous Nuclear Ribonucleoprotein G Shows Tumor Suppressive Effect against Oral Squamous Cell Carcinoma Cells

PURPOSE

Heterogeneous nuclear ribonucleoproteins (hnRNP) are nucleic acid binding proteins involved in RNA processing. We found that hnRNP G is expressed in normal human oral epithelial cells while frequently not found in the cells derived from human oral squamous cell carcinomas (HOSCC). The current study was designed to test the hypothesis that hnRNP G is a tumor suppressor.

EXPERIMENTAL DESIGN

We investigated the expression levels of hnRNP G protein in normal, precancerous, and malignant oral tissues by in situ immunohistochemistry. In addition, wild-type or mutant hnRNP G was ectopically overexpressed in HOSCC cells and their effects on cellular replication kinetics, colonogenic efficiency, anchorage-independent growth, and in vivo tumorigenicity were determined.

RESULTS

In situ immunohistochemical staining showed robust presence of hnRNP G in the basal cell layers of normal oral epithelium but the level of its staining was markedly reduced in dysplastic or cancerous tissues. Ectopic expression of wild-type hnRNP G in cancer cells lacking hnRNP G expression or containing mutant hnRNP G resulted in severe retardation of proliferation, reduction of colonogenic efficiency, loss of anchorage-independent growth, and reduction of in vivo tumorigenicity in immunocompromised mice. In addition, hnRNP G overexpression led to up-regulation of the expression of TXNIP, a cell cycle inhibitory gene, and significantly reduced the expression of the genes that promote cellular proliferation, such as EGR1, JUND, JUNB, FOS, FOSL1, ROS, and KIT.

CONCLUSIONS

These results indicate that hnRNP G is a tumor suppressor against HOSCC but its mechanisms of action remain to be further investigated.