Squamous cell carcinomas arising from different types of oral epithelia differ in their tumor and patient characteristics and survival

Evidence for etiologic field changes in tongue distant from tumor in patients with squamous cell carcinoma of the oral tongue

Oral cancer is a paradigm of Slaughter's concept of field cancerization, where tumors are thought to originate within an area of cells containing genetic alterations that predispose to cancer development. The field size is unclear but may represent a large area of tissue, and the origin of mutations is also unclear. Here, we analyzed whole exome and transcriptome features in contralateral tumor-distal tongue (i.e. distant from the tumor, not tumor-adjacent) and corresponding tumor tissues of 15 patients with squamous cell carcinoma of the oral tongue. The number of point mutations ranged from 41 to 237 in tumors and from one to 78 in tumor-distal samples. Tumor-distal samples showed mainly clock-like (associated with aging) or tobacco smoking mutational signatures. Tumors additionally showed mutations that associate with cytidine deaminase AID/APOBEC enzyme activities or a UV-like signature. Importantly, no point mutations were shared between a tumor and the matched tumor-distal sample in any patient. TP53 was the most frequently mutated gene in tumors (67%), whereas a TP53 mutation was detected in only one tumor-distal sample, and this mutation was not shared with the matched tumor. Arm-level copy number variation (CNV) was found in 12 tumors, with loss of chromosome (Chr) 8p or gain of 8q being the most frequent events. Two tumor-distal samples showed a gain of Chr8, which was associated with increased expression of Chr8-located genes in these samples, although gene ontology did not show a role for these genes in oncogenic processes. In situ hybridization revealed a mixed pattern of Chr8 gain and neutral copy number in both tumor cells and adjacent nontumor epithelium in one patient. We conclude that distant field cancerization exists but does not present as tumor-related mutational events. The data are compatible with etiologic field effects, rather than classical monoclonal field cancerization theory. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Preoperative Prediction of the Aggressiveness of Oral Tongue Squamous Cell Carcinoma with Quantitative Parameters from Dual-Energy Computed Tomography

Objectives

To determine whether quantitative parameters derived from dual-energy computed tomography (DECT) were predictive of the aggressiveness of oral tongue squamous cell carcinoma (OTSCC) including the pathologic stages, histologic differentiation, lymph node status, and perineural invasion (PNI).

Methods

Between August 2019 and March 2021, 93 patients (mean age, 54.6 ± 13.8 years; 66 men) with pathologically diagnosed OTSCC were enrolled in this prospective study. Preoperative DECT was performed and quantitative parameters (e.g., slope of the spectral Hounsfield unit curve [λ_Hu], normalized iodine concentration [nIC], normalized effective atomic number [nZ_eff], and normalized electron density [nRho]) were measured on arterial phase (AP) and venous phase (VP) DECT imaging. Quantitative parameters from DECT were compared between patients with different pathologic stages, histologic differentiation, lymph node statuses, and perineural invasion statuses. Logistic regression analysis was utilized to assess independent parameters and the diagnostic performance was analyzed by the receiver operating characteristic curves (ROC).

Results

λ_Hu and nIC in AP and λ_Hu, nZ_eff, and nIC in VP were significantly lower in stage III–IV lesions than in stage I–II lesions (p < 0.001 to 0.024). λ_Hu in VP was an independent predictor of tumor stage with an odds ratio (OR) of 0.29, and area under the curve (AUC) of 0.80. λ_Hu and nIC were higher in well-differentiated lesions than in poorly differentiated lesions (p < 0.001 to 0.021). The nIC in VP was an independent predictor of histologic differentiation with OR of 0.31, and AUC of 0.78. λ_Hu and nIC in VP were lower in OTSCCs with lymph node metastasis than those without metastasis (p < 0.001 to 0.005). λ_Hu in VP was the independent predictor of lymph node status with OR of 0.42, and AUC of 0.74. No significant difference was found between OTSCCs without PNI and those with PNI in terms of the quantitative DECT parameters.

Conclusion

DECT can be a complementary means for the preoperative prediction of the aggressiveness of OTSCC.

Quantitative analysis of KLF4 and SOX2 expression in oral carcinomas reveals independent association with oral tongue subsite location and histological grade

BACKGROUND

Stemness factors associated with tumorigenesis in different types of cancers have not been specifically studied in oral tongue SCC (OTSSC). Here, we aimed to quantify expression levels and distribution of KLF4 and SOX2, two relevant stemness factors, in oral SCC including OTSCC samples from different subsites.

METHODS AND RESULTS

We determined KLF4 and SOX2 expression levels by immunostaining 35 biopsies of OSCC. Stained wholeslide images were digitized and subjected to automatic cell detection and unbiased quantification using Qupath software. We found statistically significant reduction in KLF4 positive cells density (p= 0.024), and fraction (p= 0.022) in OTSCC from tongue borders compared with other tongue subsites. Instead, quantitative SOX2 analysis did not show differences in expression levels between OTSCC from the borders versus OTSCC developed in others subsites. Notably SOX2 expression was revealed increased in moderately and poorly differentiated OSCC compared with well differentiated ones (positive cells density p= 0.025, fraction p= 0.006). No significant correlation between KLF4 and SOX2 expression was observed, neither in OSCC nor in OTSCC.

CONCLUSIONS

KLF4 and SOX2 exhibit opposite expression profiles regarding subsite localization and differentiation level in OSCC. Our study prompts future OTSCC prospective studies looking for clinical prognosis to incorporate detailed subsite information in the analysis.

A Retrospective Cohort Study of Oral Leukoplakia in Female Patients-Analysis of Risk Factors Related to Treatment Outcomes

Background: The aim of this study was to make a comparison of clinicopathological characteristics of oral leukoplakia between male and female patients following carbon dioxide laser excision for oral leukoplakia and analyze the factors associated with the treatment outcomes in female patients. Methods: Medical records of patients with oral leukoplakia receiving laser surgery from 2002 to 2020 were retrospectively reviewed and analyzed statistically. Results: A total of 485 patients were enrolled, including 412 male (84.95%) and 73 female (15.05%). Regarding the locations, the predilection site of oral leukoplakia in male patients was buccal mucosa (p = 0.0001) and that for women patients was tongue (p = 0.033). The differences of recurrence and malignant transformation between both sexes were not significant (p > 0.05). Among female patients, area of oral leukoplakia was the risk factor related to recurrence (p < 0.05). Clinical morphology and postoperative recurrence were the risk factors related to malignant transformation (p < 0.05). Conclusions: In comparison with male patients, there was no significant difference of the postoperative recurrence and malignant transformation of oral leukoplakia in female patients. Among the female patients, clinicians should pay more attention to large-sized and non-homogeneous leukoplakia, and postoperative recurrent lesions.

Lateral skull base surgery for posterior oral cavity cancer

The aim of this study was to better understand posterior oral cavity cancer (POCC) and its surgical treatment. This was a retrospective study of 76 patients who were diagnosed with POCC and underwent surgical treatment. Twenty-eight patients were treated with anatomical unit resection surgery (AURS) and 48 patients with conventional surgery. After initial treatment with curative intent, the patients were followed-up regularly with clinical examinations and imaging; the median duration of follow-up was 30.9 months (range 2-67 months). The 3-year overall survival was 64.3% in the experimental AURS group and 39.6% in the conventional surgery control group (hazard ratio 0.49, 95% confidence interval 0.26-0.93; P=0.031). The 3-year disease-free survival was 64.3% in the experimental group and 37.5% in the control group (hazard ratio 0.53, 95% confidence interval 0.27-1.02; P=0.114). In conclusion, AURS is an effective surgical treatment for POCC that can considerably improve patient survival rates.

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.

An anatomical perspective on clinicopathological characteristics and treatment outcomes of dorsal and ventrolateral tongue leukoplakia after carbon dioxide laser surgery

Background

The tongue has been identified as a high-risk site for malignant transformation of oral leukoplakia. The purpose of this study was to investigate the clinicopathological characteristics and treatment outcomes of the dorsal and ventrolateral tongue leukoplakia.

Methods

Demographic data and pathological results of patients who underwent carbon dioxide laser surgery for tongue leukoplakia from 2002 to 2019 were retrospectively reviewed and analyzed statistically.

Results

Of the 111 patients enrolled, 80 were males and 31 females, with a mean age of 51.86 ± 11.84 years. The follow-up time was 3.74 ± 4.19 years. Fifteen patients had a postoperative recurrence (13.51%). Four (3.6%) patients developed malignant transformation. Annual transformation rate was 4.03%. There were no differences in the time to develop carcinoma (3.19 ± 1.94 vs. 3.51 ± 2.12 years, P = 0.83), overall cumulative malignant transformation rates (7.41% vs. 2.25%, P = 0.12), and annual transformation rates (2.32% vs. 0.64%, P = 0.099). The prevalence of the ventrolateral tongue leukoplakia was higher than that of the dorsal tongue leukoplakia (P < 0.001). The results of multivariate logistic regression analysis showed that the degree of pathology was the only independent prognostic factor related to postoperative malignant transformation (P = 0.045).

Conclusions

Dorsal tongue leukoplakia is not as frequently encountered clinically as ventrolateral tongue leukoplakia. The response of the dorsal tongue and ventrolateral tongue leukoplakia to laser therapy of are comparable in postoperative recurrence and postoperative malignant transformation. Clinicians should take a more aggressive attitude toward oral tongue leukoplakia with higher grade of dysplasia.

Assessment of Anti-carcinogenic Effect of Pomegranate in Oral Squamous Cell Carcinoma (Pre-clinical Study)

BACKGROUND AND OBJECTIVE

The survival portion of patients treated from oral cancer isn't in progress. This is why researchers are continuously looking for new anti-cancer drugs either natural product or natural product derivatives. Studies have shown that pomegranate and its constituents might have an anti-tumorigenic effect. So the aim of this study was to assess the anticarcinogenic roles of pomegranate on oral squamous cell carcinoma as an adjuvant of chemotherapy.

MATERIALS AND METHODS

The Hep-2 cells were propagated and maintained under basic culture media. Cells were grouped according to culture media and each group was tested for cell proliferation as well as VEGF expression and caspase-3 expressions using ELISA and RT-PCR, respectively.

RESULTS

Regarding cell proliferation and VEGF expression, a higher mean value was recorded in group 1 in comparison to group 3 with a significant difference (p = 0.001) and in group 2 in comparison to group 4, with a significant difference (p = 0.049). While concerning caspase-3 expression, a higher mean value was recorded in group 3 in comparison to group 1 with a significant difference (p = 0.045) and in group 4 in comparison to group 2, with a significant difference (p = 0.00).

CONCLUSION

Pomegranate can be an adjuvant, natural product for oral cancer treatment in combination with 5-fluorouracil to reduce its dose and nullify its toxic side effects on normal body organs.

Effects of flavonoids on tongue squamous cell carcinoma

Squamous cell carcinoma (SCC) of the tongue is associated with tobacco use, alcohol abuse, and human papillomavirus (HPV) infections. While clinical outcomes have recently improved for HPV-positive patients in general, 50% of patients suffering from tongue cancer die within 5 years of being diagnosed. Flavonoids are secondary plant metabolites with a wide range of biological activities including antioxidant, anti-inflammatory, and anticancer activities. Flavonoids have generated high interest as therapeutic agents owing to their low toxicity and their effects on a large variety of cancer cell types. In this literature review, we evaluate the actions of flavonoids on SCC of the tongue demonstrated in both in vivo and in vitro models.

Non-plaque-induced gingival diseases

While plaque-induced gingivitis is one of the most common human inflammatory diseases, several non-plaque-induced gingival diseases are less common but often of major significance for patients. The non-plaque-induced gingival lesions are often manifestations of systemic conditions, but they may also represent pathologic changes limited to gingival tissues. A classification is proposed, based on the etiology of the lesions and includes: Genetic/Developmental disorders; Specific infections; Inflammatory and immune conditions and lesions; Reactive processes; Neoplasms; Endocrine, Nutritional and metabolic diseases; Traumatic lesions; and Gingival pigmentation.

Non-plaque-induced gingival diseases

While plaque-induced gingivitis is one of the most common human inflammatory diseases, several non-plaque-induced gingival diseases are less common but often of major significance for patients. The non-plaque-induced gingival lesions are often manifestations of systemic conditions, but they may also represent pathologic changes limited to gingival tissues. A classification is proposed, based on the etiology of the lesions and includes: Genetic/Developmental disorders; Specific infections; Inflammatory and immune conditions and lesions; Reactive processes; Neoplasms; Endocrine, Nutritional and metabolic diseases; Traumatic lesions; and Gingival pigmentation.

Cisplatin based induction chemotherapy modified by ERCC1 improved the outcome of young adults with locally advanced oral squamous cell carcinoma

Objective: To evaluate the efficacy of induction chemotherapy in young adults with locally advanced oral squamous cell carcinoma (OSCC) and the usefulness of ERCC1 as a prognostic indicator.

Methods: A total of 156 young adults with locally advanced OSCC were retrospectively analyzed from May 2007 to May 2017. Cisplatin based induction chemotherapy followed by surgery and upfront surgery were the primary treatment options for locally advanced OSCC. ERCC1 was evaluated by immunohistochemistry. Multivariate analysis was performed to identify significant prognostic factors for the overall survival (OS) in young adults with locally advanced OSCC.

Results: Extracapsular spread (ECS) (p<0.0001) and UICC staging (p<0.0001) were critical prognostic factors for OS in young adults with locally advanced OSCC. The 5-year OS was 83.2% in N0 patients received induction chemotherapy and 61.7% in N0 patients received upfront surgery (p<0.05). Patients with a low ERCC1 expression were more likely to benefit from induction chemotherapy, as the 5-year OS was 22.4% in patients with a high ERCC1 expression and 84.7% in patients with a low ERCC1 expression, respectively (p<0.0001). However, induction chemotherapy resulted in a higher 5-year OS (84.7%) than upfront surgery (59.1%) in patients with a low ERCC1 expression (p=0.03).

Conclusions: Induction chemotherapy can improve the outcome of N0 patients. However, the ERCC1 expression should be determined in young patients with locally advanced OSCC prior to induction chemotherapy, as it is a useful biomarker for predicting the outcome after induction chemotherapy.

Oral lichen planus and other confounding factors in narrow band imaging (NBI) during routine inspection of oral cavity for early detection of oral squamous cell carcinoma: a retrospective pilot study

Background

Narrow Band Imaging is a noninvasive optical diagnostic tool. It allows the visualization of sub-mucosal vasculature; four patterns of shapes of submucosal capillaries can be recognized, increasingly associated with neoplastic transformation. With such characteristics, it has showed high effectiveness for detection of Oral Squamous Cell Carcinoma. Still, scientific literature highlights several bias/confounding factors, such as Oral Lichen Planus. We performed a retrospective observational study on patients routinely examined with Narrow Band Imaging, investigating for bias, confounding factors and conditions that may limit its applicability.

Methods

Age, sex, smoking, use of dentures, history of head & neck radiotherapy, history of Oral Squamous Cell Carcinoma, site of the lesion and thickness of the epithelium of origin were statistically evaluated as possible bias/confounding factors. Pearson’s Chi-squared test, multivariate logistic regression, Positive Predictive Value, Negative Predictive Value, Sensitivity, Specificity, Positive Likelihood Ratio, Negative Likelihood Ratio and accuracy were calculated, normalizing the cohort with/without patients affected by Oral Lichen Planus, to acknowledge its role as bias/confounding factor.

Results

Five hundred fifty-six inspections were performed on 106 oral cavity lesions from 98 patients. Age, sex, smoking, use of dentures and anamnesis of Oral Squamous Cell Carcinoma were not found to influence Narrow Band Imaging. History of head & neck radiotherapy was not assessed due to insufficient sample. Epithelium thickness does not seem to interfere with feasibility. Presence of Oral Lichen Planus patients in the cohort led to false positives but not to false negatives. Among capillary patterns, number IV was the most significantly associated to Oral Squamous Cell Carcinoma (p < 0.001), not impaired by the presence of Oral Lichen Planus patients in the cohort (accuracy: 94.3, 95% confidence interval: 88.1–97.9%; odds ratio: 261.7, 95% confidence interval: 37.7–1815.5).

Conclusion

Narrow Band Imaging showed high reliability in detection of Oral Squamous Cell Carcinoma in a cohort of patients with oral cavity lesions not normalized for bias/confounding factors. Still, Oral Lichen Planus may lead to false positives. Narrow Band Imaging could help in the follow-up of patients with multiple lesions through detection of capillary pattern IV, which seems to be the most significantly associated to neoplastic epithelium.

The maintenance of an oral epithelial barrier

Oral epithelial barrier consists of closely controlled structure of the stratified squamous epithelium, which is the gateway to human bodies and encounters a huge burden of microbial, airborne and dietary antigens, as well as masticatory damage. Once this barrier is destroyed, it will trigger bone loss, tissue damage and microbial dysbiosis and lead to diseases, such as periodontitis, oral mucosal diseases and oral cancer. Recently, increasing evidences showed that different factors including microorganism, saliva, proteins and immune components have been considered to play a critical role in the disruption of oral epithelial barrier. Herein, we discussed mechanisms governing the maintenance of oral epithelial barrier. Besides, the role of oral epithelial barrier failure in oral carcinogenesis will also be talked about.

Distinct Expression and Clinical Significance of Zinc Finger AN-1-Type Containing 4 in Oral Squamous Cell Carcinomas

Zinc finger AN1-type containing 4 (ZFAND4) has emerged as a promising prognostic marker and predictor of metastasis for patients with oral squamous cell carcinoma (OSCC). However, further validation is fundamental before clinical implementation. Hence, this study evaluated the expression pattern of ZFAND4 protein expression by immunohistochemistry using an independent cohort of 125 patients with OSCC, and correlations with the clinicopathologic parameters and disease outcome. Remarkably, ZFAND4 expression, while negligible in normal epithelium, exhibited two distinct expression patterns in tumors that did not overlap. A gross granular staining was characteristic of the undifferentiated cells at the invasive front of tumors, whereas the most differentiated cells located at the center of the tumor nests showed diffuse non-granular staining. ZFAND4 staining was higher in undifferentiated than in differentiated areas of tumors. High ZFAND4 expression in differentiated cells was significantly associated to well-differentiated (p = 0.04) and non-recurrent tumors (p = 0.04), whereas ZFAND4 expression in undifferentiated cells correlated with tumor location (p = 0.005). No correlations between the ZFAND4 expression and patient survival were found. These data question the clinical relevance of ZFAND4 expression as a prognostic biomarker in OSCC, and also reveal distinct ZFAND4 expression patterns depending on the differentiation areas of tumors that should be evaluated separately.

PD-L1 Expression in Tumor Cells Is an Independent Unfavorable Prognostic Factor in Oral Squamous Cell Carcinoma

BACKGROUND

The immune checkpoint PD-1 and its ligand PD-L1 are involved in the induction of immunological tolerance of solid tumors including oral squamous cell carcinoma (OSCC). The aim of the study was to establish the clinical and prognostic significance of PD-L1 in OSCC.

METHODS

Tissue microarrays of 125 resected OSCC were stained with two different commercially available PD-L1 antibodies (clones E1L3N and 22C3), alongside PD-1 immunostaining.

RESULTS

PD-L1 expression in more than 10% of tumor cells was associated with poorer survival, and established as a clinically relevant cut-off point. This relevant PD-L1 expression was detected in 10% to 15% OSCC specimens depending on the anti-PD-L1 antibody, and showed an inverse correlation with tobacco and alcohol consumption. We consistently found that PD-L1 expression was associated with tumor recurrence and lower disease-specific survival. Multivariate analysis further revealed that neck node metastasis (HR 2.304; P = 0.009) and tumor PD-L1 expression (HR 2.571; P = 0.01) were significant independent factors for poor prognosis.

CONCLUSIONS

PD-L1 expression in more than 10% of tumor cells was a significant and independent factor of poor prognosis in OSCC.

IMPACT

PD-L1 expression in more than 10% of tumor cells was consistently established as a clinically relevant cut-off point by using two different antibodies. Remarkably, PD-L1 expression emerges as an independent poor prognosis marker in patients with OSCC.

Prognostic significance of FOXM1 in oral squamous cell carcinoma patients treated by docetaxel-containing regimens

Forkhead box protein M1 (FOXM1) is an oncoprotein that is involved in cell proliferation, differentiation and aging, and overexpression of FOXM1 is thought to be associated with the development and progression of various types of cancer. The expression of FOXM1 was retrospectively examined in tumor tissues taken from 56 oral squamous cell carcinoma (OSCC) patients by immunohistochemical staining. All of these patients received docetaxel (Doc)-containing regimens as treatments against OSCC. The association between FOXM1 expression and the clinicopathological characteristics and prognosis of these patients was then examined. FOXM1 was expressed in the nucleus and cytoplasm of OSCC tissues samples. There was a significant association between FOXM1 expression in tumor tissues and N classification (P=0.0395), stage (P=0.004), therapeutic efficacy (P=0.0113) and outcome (P=0.0134) of patients. However, FOXM1 expression had no association with patients' sex, age or T classification. Additionally, high expression of FOXM1 in tumor cells was associated with a shorter overall survival (P=0.0257) of patients. Multivariate analysis also revealed that elevated expression of FOXM1 was a predictor of patients' poor survival (P=0.0327). The results suggested that high expression of FOXM1 in OSCC tumors may result in reduced therapeutic effects and poor clinical outcomes of patients receiving Doc-based treatment regimens.

Elucidating the mechanism of miRNA-214 in the regulation of gingival carcinoma

The aim of the present study was to evaluate the expression levels of microRNA (miRNA)-214 in tumor tissue, blood and saliva of patients with gingival carcinoma, and to investigate the mechanisms underlying the infiltration and invasion of gingival carcinoma. Between January 2013 and March 2015, blood and saliva samples, gingival carcinoma tumor specimens and peritumoral tumor tissues were harvested from 56 patients with gingival carcinoma. Blood and saliva samples were also harvested from 33 control patients without gingival carcinoma. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to detect miRNA-214 and protein tyrosine phosphatase gene (PTEN) mRNA levels. Western blotting and ELISA were performed to detect PTEN protein levels. The results of RT-qPCR demonstrated that the expression of PTEN mRNA in tumor tissues, blood and saliva of patients with gingival carcinoma were significantly decreased compared with that of the control group (P<0.05). These findings were consistent were consistent with the results of PTEN protein expression detected via western blotting and ELISA in these samples (P<0.05). Conversely, the expression levels of miRNA-214 in these samples were significantly increased (P<0.05) in patients with gingival carcinoma compared with the control group. The decreased expression of PTEN may be associated with the expression of miRNA-214. miRNA-214 may regulate infiltration and invasion of gingival carcinoma via PTEN. These results suggest that miRNA-214 may be used as a marker of gingival carcinoma.

miR-448 downregulates MPPED2 to promote cancer proliferation and inhibit apoptosis in oral squamous cell carcinoma

The incidence of oral squamous cell carcinoma (OSCC) is continuously increasing while its survival rate has not notably improved. There is a pressing need for improved understanding of the genetic regulation of OSCC tumorigenesis and progression. In this study, the function of miR-448 in the regulation of OSCC growth and its putative target were thoroughly analyzed in vitro. The expression of miR-448 was detected in human OSCC specimens and OSCC cell lines (Cal-27 and Scc-9) by reverse transcription-quantitative polymerase chain reaction. The function of miR-448 was investigated in Cal-27 cells transfected with miR-448 inhibitor, and its putative target determined using a luciferase reporter assay. MTT and wound healing assays and flow cytometry were used to evaluate the effects of miR-448 on OSCC proliferation, metastasis and apoptosis. The level of miR-448 was significantly elevated in human OSCC tissues and the Cal-27 cell line. Suppression of miR-448 expression attenuated cell proliferation and migration, and induced apoptosis of Cal-27 cells. Furthermore, miR-448 bound with the 3'-untranslated region of metallophosphoesterase domain containing 2 (MPPED2) mRNA, thereby reducing the MPPED2 protein level. Thus, it appears that miR-448 acts as a tumor inducer, causing OSCC growth by inhibiting the expression of its target MPPED2. These results demonstrate that miR-448 plays a critical role in OSCC tumorigenesis, and is a potential therapeutic target.

Prevalence of human papillomavirus in oral squamous cell carcinomas in northern Spain

The aim of this study was to analyze the prevalence of high-risk HPV in oral squamous cell carcinoma (OSCC) in a northern Spanish population, as well as to ascertain the prognostic role of p16^INK4a expression. The examination samples were collected from paraffin tissue blocks, from 125 patients surgically treated between 1996 and 2007. All cases were histologically evaluated, and the presence of HPV was assessed by p16 and p53immunohistochemistry followed by DNA detection by in situ hybridization (ISH) and polymerase chain reaction (PCR) amplification using the combination of consensus primers MY11/GP6 + . Fourteen cases (11 %) were p16-immunopositive, and p53 was scored positive in 73 cases (58 %). Five cases (4 %) showed a simultaneous p16-positive and p53-negative immunostaining. ISH was negative in all the cases. Among the p16INK4a-immunopositive cases, PCR amplification failed to reveal HPV DNA in any tumor samples. There were no statistically significant differences in any clinical or pathological characteristics of the patients regarding p16^INK4a expression. T classification, neck-node metastasis, and clinical stage showed outcome relevance. However, no significant differences in cause-specific survival based on p16INK4a were observed. We did not find any high-risk HPV types in our patients, thus, are unlikely that HPV has an important role in the etiology of OSCC. p16INK4a protein was neither an accurate marker of HPV infection nor a prognosis marker in OSCC.

Demographic risk factors, affected anatomical sites and clinicopathological profile for oral squamous cell carcinoma in a north Indian population

BACKGROUND

Oral cancer is a common form of cancer in India, particularly among men. About 95% are squamous cell carcinomas. Tobacco along with alcohol are regarded as the major risk factors.

OBJECTIVES

(i) To determine associations of oral squamous cell carcinoma (OSCC) with respect to gender, age group, socioeconomic status and risk habits; (ii) To observe the distribution of affected oral anatomical sites and clinico-pathological profile in OSCC patients.

MATERIALS AND METHODS

This is an unmatched case-control study during period January 2012 to December 2013. Total of 471 confirmed OSCC patients and 556 control subjects were enrolled. Data on socio-demography, risk habits with duration and medical history were recorded.

RESULTS

There were significant associations between OSCC with middle age (41-50years; unadjusted OR=1.63, 95%CI=1.05-2.52, p=0.02) (51-60 years; unadjusted OR=1.79, 95%CI=1.15-2.79, p=0.009) and male subjects (unadjusted OR=2.49, 95%CI=1.89-3.27, p=0.0001). Cases with both habits of tobacco chewing and smoking were at a higher risk for OSCC than tobacco chewing alone (unadjusted OR=0.52, 95%CI=0.38-0.72, p=0.0001), duration of risk habits also emerged as a responsible factor for the development of carcinoma. The majority of patients were presented in well-differentiated carcinomas (39.9%). Prevalence of advance stages (TNM stage III, IV) was 23.4% and 18.3% respectively. The buccal mucosa was the most common (35.5%) affected oral site.

CONCLUSIONS

In most Asian countries, especially India, there is an important need to initiate the national level public awareness programs to control and prevent oral cancer by screening for early diagnosis and support a tobacco free environment.

Prognostic value of matrix metalloproteinases in oral squamous cell carcinoma

The aim of this study was to investigate whether there is a correlation between the expressions of four matrix metalloproteinases (MMPs): MMP-2, MMP-7, MMP-9 and MMP-13, and the TNM (tumour–node–metastasis) stages of oral squamous cell carcinoma (OSCC); and to explore the implication of these MMPs in OSCC dissemination. Samples from 61 patients diagnosed with oropharyngeal tumour were studied by immunohistochemistry against MMP-2, MMP-7, MMP-9 and MMP-13. The assessment of immunoreactivity was semi-quantitative. The results showed that MMP-2 and MMP-9 had similar expression patterns in the tumour cells with no changes in the immunoreactivity during tumour progression. MMP-9 always had the highest expression, whereas that of MMP-2 was moderate. MMP-7 showed a significant decrease in expression levels during tumour evolution. MMP-13 had constant expression levels within stage T2 and T3, but showed a remarkable decline in immunoreactivity in stage T4. No significant differences in the MMPs immunoreactivity between tumour cells and stroma were observed. Although strong evidence for the application of MMPs as reliable predictive markers for node metastasis was not acquired, we believe that combining patients’ MMPs expression intensity and clinical features may improve the diagnosis and prognosis. Strong evidence for the application of MMPs as reliable predictive markers for node metastasis was not acquired. Application of MMPs as prognostic indicators for the malignancy potential of OSCC might be considered in every case of tumour examination. We believe that combining patients’ MMPs expression intensity and clinical features may improve the process of making diagnosis and prognosis.

Upregulation of GRIM-19 suppresses the growth of oral squamous cell carcinoma in vitro and in vivo

Constitutive activation of the signal transducer and activator of transcription 3 (STAT3) and its upregulation contribute to the progression and metastasis of several different tumor types. The gene associated with retinoid‑interferon‑induced mortality-19 (GRIM-19) is known to functionally interact with STAT3 and inhibit its transcriptional activity. It has been reported that upregulation of genes associated with GRIM-19 can significantly reduce the tumor growth of several types of tumors. However, little is known in regards to its role in oral squamous cell carcinoma (OSCC). In the present study, a recombinant eukaryotic expression plasmid carrying GRIM-19 was constructed to evaluate its effects on OSCC cancer growth. Upregulation of GRIM-19 in OSCC cells significantly inhibited cell proliferation, migration and invasion in vitro and suppressed tumor growth in vivo. Moreover, we found that upregulation of GRIM-19 reduced cyclin D1, Bcl-2, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) expression whose protein is involved in STAT3 activation. Taken together, these findings suggest that GRIM-19 plays an inhibitory role in the progression of OSCC, and contribute to the future development of STAT3-based gene therapeutic approaches for OSCC.

Establishment of 5-fluorouracil-resistant oral squamous cell carcinoma cell lines with epithelial to mesenchymal transition changes

5-Fluorouracil (5-FU) has been used for oral squamous cell carcinoma (OSCC) treatments, and the acquisition of resistance is the major problem to successful OSCC treatment. It has been reported that the epithelial to mesenchymal transition (EMT) is associated with chemoresistance in several types of cancers. In the present study, we established 5-FU-resistant OSCC cell lines (HSC2/FU and HSC4/FU), and aimed to elucidate the mechanism(s) involved in resistance in association with its EMT characteristics. MTT assay revealed that HSC2/FU is about 14-fold more resistant compared to HSC2, and HSC4/FU is 5-fold more resistant compared to HSC4. TUNEL assay also showed a dramatically decreased number of apoptotic cells in the 5-FU-resistant OSCC cell lines compared to each parental cell after treatment with 5-FU. Moreover, the 5-FU-resistant OSCC cell lines had typical morphologic phenotypes of EMT; loss of cell-cell adhesion, increased formation of pseudopodia and spindle-shaped morphology. Western blot analysis showed downregulated E-cadherin, and upregulated N-cadherin and Twist in the 5-FU-resistant OSCC cell lines. Results of our tumor xenograft studies coincide with our in vitro study data that confirmed the 5-FU resistant nature of HSC2/FU and HSC4/FU tumors. Moreover, immunohistochemistry showed that EMT changes (downregulated E-cadherin, and upregulated Twist and N-cadherin) occurred in the 5-FU-resistant xenografted tumor cells. These results suggest that EMT has important roles in the 5-FU-resistant OSCC cells, and that these resistant cells may be considered as useful tools for understanding the mechanisms involved in 5-FU resistance in OSCC.

MicroRNA-29a upregulates MMP2 in oral squamous cell carcinoma to promote cancer invasion and anti-apoptosis

Abnormal microRNA expression is a common and important feature of human malignancies. Matrix metalloproteinase 2 (MMP2), which has been reported in several cancers, plays important roles in cancer progression. However, the microRNA regulatory mechanism on MMP2 expression remains unclear. In this study, we first detected MMP2 and microRNA-29a (miR-29a) expression in oral squamous carcinoma (OSCC) specimens, which showed that MMP2 was higher in OSCC cancer tissues than adjacent tissues but that miR-29a was lower in OSCC cancer tissues than adjacent tissues. Then, we confirmed that miR-29a, which directly targeted 3'-UTR of MMP2 gene, negatively regulated MMP2 expression by miR-29a transfection and luciferase reporter assay. Exogenous overexpression of miR-29a inhibited OSCC cell invasion and anti-apoptosis significantly in vitro. Whereas, knockdown of miR-29a promoted OSCC cell invasion and induced drug-resistance in vitro. This study suggests that miR-29a plays an inhibiting role in the progression of OSCC, which may be a potentially therapeutic approach in the future.

The clinical and histologic presentation of gingival squamous cell carcinoma: a study of 519 cases

OBJECTIVES

Gingival squamous cell carcinoma (SCCA) often presents with benign features, which may lead to delay in treatment. This study describes the clinical and histologic characteristics of a series of gingival SCCA cases.

STUDY DESIGN

A retrospective consecutive case review was performed using the University of Florida College of Dentistry Biopsy service's database, which yielded clinical and histologic information on 519 cases of gingival SCCA.

RESULTS

The average age of affected patients was 72.3 years. The most common site was the mandibular posterior gingiva. Approximately 72% of lesions were present for >2 months at biopsy. The majority of clinicians considered a malignancy in their differential diagnosis (64%), although 15% considered only reactive lesions. Most of the carcinomas presented as exophytic masses and, histologically, were moderately differentiated.

CONCLUSIONS

Gingival SCCA may present with varied clinical and histologic appearances and should be considered in the differential diagnosis of benign appearing lesions of the gingiva.

Role of viruses in oral squamous cell carcinoma

The etiology of oral squamous cell carcinoma (OSCC) is complex and involves many factors. The most clearly defined risk factors are smoking and alcohol, which substantially increase the risk of oral SCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on co-factors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC.

Identification of novel transcripts deregulated in buccal cancer by RNA-seq

The differential transcriptome analysis provides better understanding of molecular pathways leading to cancer, which in turn allows designing the effective strategies for diagnosis, therapeutic intervention and prediction of therapeutic outcome. This study describes the transcriptome analysis of buccal cancer and normal tissue by CLC Genomics Workbench from the data generated by Roche's 454 sequencing platform, which identified total of 1797 and 2655 genes uniquely expressed in normal and cancer tissues, respectively with 2466 genes expressed in both tissues. Among the genes expressed in both tissues, 1842 were up-regulated whereas 624 were down-regulated in cancer tissue. Besides transcripts known to be involved in cancer, this study led to the identification of novel transcripts, with significantly altered expression in buccal cancer tissue, providing potential targets for diagnosis and cancer therapeutics. The functional categorization by the KEGG pathway and gene ontology analysis revealed enrichment of differentially expressed transcripts to various pathways leading to cancer, including the p53 signaling pathway. Moreover, the gene ontology analysis unfolded suppression of transcripts involved in actin mediated cell contraction process. The down-regulation of four of these transcripts MYL1, ACTA1, TCAP and DESMIN in buccal cancer were further supported by quantitative PCR signifying its possible implication in the cancer progression.

Transcriptional profiling of formalin fixed paraffin embedded tissue: pitfalls and recommendations for identifying biologically relevant changes

Expression profiling techniques have been used to study the biology of many types of cancer but have been limited to some extent by the requirement for collection of fresh tissue. In contrast, formalin fixed paraffin embedded (FFPE) samples are widely available and represent a vast resource of potential material. The techniques used to handle the degraded and modified RNA from these samples are relatively new and all the pitfalls and limitations of this material for whole genome expression profiling are not yet clarified. Here, we analyzed 70 FFPE tongue carcinoma samples and 17 controls using the whole genome DASL array covering nearly 21000 genes. We identified that sample age is related to quality of extracted RNA and that sample quality influences apparent expression levels in a non-random manner related to gene probe sequence, leading to spurious results. However, by removing sub-standard samples and analysing only those 28 cancers and 15 controls that had similar quality we were able to generate a list of 934 genes significantly altered in tongue cancer compared to control samples of tongue. This list contained previously identified changes and was enriched for genes involved in many cancer-related processes such as tissue remodelling, inflammation, differentiation and apoptosis. Four novel genes of potential importance in tongue cancer development and maintenance, SH3BGL2, SLC2A6, SLC16A3 and CXCL10, were independently confirmed, validating our data. Hence, gene expression profiling can be performed usefully on archival material if appropriate quality assurance steps are taken to ensure sample consistency and we present some recommendations for the use of FFPE material based on our findings.

Human papillomavirus infections in the oral mucosa

BACKGROUND

Public awareness of human papillomavirus (HPV) as the causal agent of cervical cancer and of the availability of HPV vaccines has increased. As a result, more patients are asking their dentists about oral HPV infection and its prevention by means of vaccination. Parents of pediatric dental patients also may be concerned when their children have HPV-associated oral lesions, because HPV infection still often is considered a purely sexually transmitted disease. In this review, the authors provide the latest information for dental professionals about HPV infection in the oral mucosa and in general.

TYPES OF STUDIES REVIEWED

The authors searched PubMed for all studies regarding HPV infection in the oral mucosa, and they reviewed relevant publications focusing exclusively on HPV infections of the oral cavity. In selecting studies for review, the authors made a clear distinction between studies regarding HPV infections in the mouth and those regarding HPV infection in the oropharynx or in other head and neck sites.

RESULTS

HPV can infect oral mucosa. A subgroup of oral cancer clearly is associated with HPV. Oral HPV infection is transmitted sexually but also can be transmitted from mouth to mouth and vertically from an infected mother during delivery.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Persistent HPV infection in the oral mucosa might increase the risk of developing oral cancer. Regular and meticulous clinical examination is the dentist's most important tool in detecting HPV-associated changes in the oral mucosae. HPV-associated oral cancer may affect a population younger than that typically affected by HPV-independent oral cancer. Alcohol and tobacco use increase the risk of developing oral cancer, so good practice includes encouraging patients to avoid these habits. The available HPV vaccines cover the HPV genotypes found most commonly in the oral mucosa, but their protective effect against oral cancer remains to be elucidated.

Low prevalence of high risk genotypes of human papilloma virus in normal oral mucosa, oral leukoplakia and verrucous carcinoma

OBJECTIVE

Squamous Cell Carcinoma (SCC) is the most common malignancy of the oral cavity and Verrucous Carcinoma (VC) is its least invasive form with no metastasis potential. Leukoplakia (clinical term for hyperkeratosis and acanthosis with and without dysplasia) is the most common pre-malignant lesion of the oral cavity. Human Papilloma Virus (HPV) has been recognized as an etiologic factor for mentioned lesions. In this study the relationship between high risk types of this virus (HPV(HR)) with VC and Leukoplakia is investigated.

MATERIALS AND METHOD

Forty-one paraffin-embedded blocks including 21 VC, 20 leukoplakias in addition to 18 normal oral mucosal tissues as the control group were studied by Polymerase Chain Reaction (PCR) to detect HPV 16, 18, 31 and 33.

RESULTS

In three specimens of VCs (14.3%) HPV(HR) was detected. Each of these contained both HPV 16 and 18. All three positive specimens belonged to women older than 65 and were obtained from the vestibule of the mandible. Neither Leukoplakia nor normal mucosa showed HPV presence. No significant relationship between HPV and VC was found compared with the control group (p = 0.23).

CONCLUSION

This study did not show relationship between HPV and leukoplakia. Although no statistically significant relationship was found between HPV and VC, but considering sample size limitation for such uncommon cases, its presence in three cases of 14 makes more investigations to overcome the controversies necessary.

Oral soft tissue alterations in patients with neurofibromatosis

Our aim was to characterize the type and frequency of oral soft tissue alterations in neurofibromatosis. A total of 103 patients with neurofibromatosis 1 (NF1) and three patients with neurofibromatosis 2 (NF2) were clinically evaluated for their oral soft tissue alterations. Disturbing growths were removed from nine patients with NF1 and from one patient with NF2. The specimens were analyzed using routine histological methods and with immunohistochemistry using antibodies to S100, type IV collagen, CD34, neurofilament, and neuron-specific tubulin (TUBB3). Alterations including oral tumors, overgrowths of gingival soft tissue, and enlarged papillae of the tongue were discovered in 74% of NF1 patients. The results showed that three tumors clinically classified as plexiform neurofibromas and five out of six discrete mucosal tumors displayed histology and immunohistology consistent with that of neurofibroma. The histology of one palatal lesion resembled that of a scar, and the lesion removed from the patient with NF2 was classified as an amyloid tumor. To conclude, oral soft tissue growths are common findings in NF1, but most lesions do not require treatment and the patients may even not be aware of these alterations. Collagen IV, S100, and CD34 are useful biomarkers in the analysis of NF1-related oral soft tissue tumors. The clinicians should recognize that oral soft tissue alterations are relatively common in NF1. Some of the growths are disturbing, and plexiform neurofibromas may bear a risk of malignant transformation.

Gingival carcinoma: retrospective analysis of 72 patients and indications for elective neck dissection

Gingival squamous cell carcinoma (SCC) is relatively uncommon, and little is known about its metastatic pattern. We retrospectively reviewed 864 consecutive patients with oral SCC who were seen at the University of Maryland Department of Oral and Maxillofacial Surgery (1991-2005), and identified 111 cases of gingival SCC. Inclusion criteria were fulfilled in 72 patients (mean duration of follow up 49 (1-153) months). Mean (range) age was 72 (45-93) years; 41 patients were women and 31 men. Distribution was almost equal: mandible 35 and maxilla 37. Forty (56%) were in the early stages (pI/II) and 32 (44%) in the later stages (pIII/IV). Twenty-nine patients had primary neck dissections, of whom 7/21 had clear, and 6/8 invaded, cervical nodes. The total number of occult nodal metastases was 9/29 (31%) in the mandible and 14/35 in the maxilla (one patient with initially clear nodes had both invaded nodes at neck dissection and a recurrence in the neck). The number of early compared with late stage occult metastases was 4 of 20 patients (20% T1/T2) and 5 of 9 patients (55% T3/T4) in the mandible and 2 of 22 patients (9% T1/T2) and 2 of 13 patients (15% T3/T4) in the maxilla. Two of 9 patients developed occult nodes within T2 maxillary gingival SCC. Bony invasion was identified in 17 patients (24%) occurring in 8 of 19 patients (42%) with invaded nodes compared with 9 of 53 patients (17%) with clear nodes. Overall survival at 2 and 5 years was 53 of 72 patients (74%) and 27 of 72 patients (38%) respectively. Elective neck dissection is indicated for all stages of mandibular gingival tumours and T3/T4 carcinomas of the maxillary gingiva. T2 maxillary SCC should be considered for elective neck dissection. Overall disease-free survival was worse among those with cervical metastases (p=0.004) and those who had had marginal resections (p=0.04).

Tubulin α-6 chain is a stably expressed reference gene in archival samples of normal oral tissue and oral squamous cell carcinoma

One of the most critical factors in gene expression studies using quantitative real-time PCR is the choice of reference gene. Many of the commonly used reference genes have been shown to vary during a number of biological processes as well as between tissues. It is therefore important to always verify the stability of the gene of choice for all new tissues and experimental conditions. Here, we used two publicly available computer software packages (GeNorm and NormFinder) to investigate the stability of eight potential reference genes in formalin-fixed paraffin-embedded (FFPE) samples from normal oral tissue of different origin as well as from oral squamous cell carcinomas. Both programs found the tubulin α-6 chain (TUBA6) and ribosomal protein S13 (RPS13) to have the most stable expression between malignant and non-malignant tissue. NormFinder also found TUBA6 to be the most stable gene when samples were grouped according to tissue origin. FFPE samples constitute a large research resource, which considerably increases the number of samples available for analysis, leading to more reliable conclusions. Verification of a proper reference gene in oral FFPE tissue is therefore of great importance for future studies.

p63 contributes to cell invasion and migration in squamous cell carcinoma of the head and neck

The transcription factor p63 is commonly over-expressed in squamous cell carcinomas of the head and neck (SCCHN). By microarray analysis of p63-siRNA-treated SCCHN cells we identified 127 genes whose expression relies on over-expression of p63. More than 20% of these genes are involved in cell motility. Chromatin immunoprecipitation and reporter assay revealed PAI-1 and AQP3 as direct p63 transcriptional targets. In addition to PAI-1, most of the key cell motility-related molecules are up-regulated by p63, such as MMP14 and LGALS1. Our findings indicate a contribution by p63 in cell invasion and migration, supporting an oncogenic role for p63 in SCCHN.