Focal adhesion kinases in head and neck squamous cell carcinoma.

BACKGROUND: Focal adhesion kinase (FAK) phosphorylation contributes to the regulation of growth factors that promote cellular adhesion, mobility, and survival, being a key factor in tumor development. The objective of this study was to evaluate the immunohistochemical expression patterns of FAK and its phosphorylated forms, FAK Tyr-576 and FAK Tyr-925, in head and neck squamous cell carcinoma and non-neoplastic adjacent epithelial tissue (AE). METHODS: The percentage of immunohistochemistry stained cells and its correlation with clinicopathological variables and prognosis were determined using samples from 54 patients. RESULTS: FAK, FAK Tyr-576, and FAK Tyr-925 overexpression was observed in tumor zones and AE. FAK Tyr-576 immunostaining showed a relationship with tumor clinicopathological parameters. Moreover, positive immunostaining of FAK Tyr-576 in AEsue was associated with patients prognoses. CONCLUSIONS: Increased expression of FAK Tyr-576 could enable identification of tumors with a more aggressive behavior and epithelial alterations before the appearance of clinical or histological manifestations.

Angina bullosa hemorrhagica: report of 7 cases and analysis of 199 cases from the literature.

Angina bullosa hemorrhagica (ABH) is a condition characterized by blood blisters in the oral or oropharyngeal mucosa. Typically, the first presentation of ABH is acute, and rupture of the blisters occurs after a few hours or days. Although its etiology is unclear, ABH is assumed to be associated with predisposing factors such as local trauma or chronic use of inhaled steroids. The diagnosis is defined clinically, based on the presentation and evolution of the lesions. The recommended treatment is symptomatic, but extensive lesions may present a risk of airway obstruction and may require surgical excision. This case series reports 7 cases of ABH and reviews 199 cases published in the English-language literature. The possible etiologic factors, predisposing factors, and differential diagnoses are discussed.

The importance of histopathologic analysis of pericoronal follicles for the early identification of ameloblastomas.

The objective of this study was to discuss the importance of performing histopathological examination of pericoronal follicles as a routine procedure, so as to enable the early identification of odontogenic lesions. We describe two clinical cases with histopathological diagnoses of ameloblastomas who did not show clinical or radiographic signs of disease before microscopic examination.

Relationship between the positions of impacted third molars and the presence of dentigerous cysts.

The objective of this study was to assess the association between the histopathological diagnoses of dentigerous cysts and pericoronal follicles and the positions of impacted third molars. The sample comprised 151 cases, diagnosed as dentigerous cysts and pericoronal follicles. Most patients were female (70.9%), white (90.1%), and age 20 years or older (63.6%). Ninety-eight cases (64.9%) were diagnosed as pericoronal follicles and 53 (35.1%) as dentigerous cysts. Teeth that developed dentigerous cysts were predominantly located in the mandible (84.9%), in a mesioangular position (49.1%), and in the 20- to 29-year age group (66.0%). The mandible seems to be the most frequent location of impacted teeth, probably because mandibular tooth eruption is more difficult, as well as dentigerous cysts, probably because the long duration of impaction increases the exposure to inflammatory stimuli and, thus, the potential for formation of dentigerous cysts. The findings also suggest that the incidence of dentigerous cysts tends to increase with age, especially for mandibular teeth in mesioangular positions.

Spatial distribution of cancer stem cells in head and neck squamous cell carcinomas.

BACKGROUND: CD44 and aldehyde dehydrogenase 1 (ALDH1) are considered putative markers of highly tumorigenic cells (i.e., cancer stem-like cells) in head and neck squamous cell carcinomas. This small subset of cells is believed to be the primary responsible for tumor initiation and progression. The objectives of this study were (i) to evaluate the patterns of CD44 and ALDH1 expression in the tumor center and in the invasive front, as well as in adjacent non-tumor epithelium, and (ii) to correlate these findings with clinical parameters. MATERIALS AND METHODS: The sample comprised 44 patients with primary head and neck squamous cell carcinomas. Hematoxylin and eosin (HE) staining was used for histopathological tumor grading and for morphological analysis of adjacent non-tumor epithelium. Semiquantitative analysis was performed in histological sections immunostained for CD44 and ALDH1. RESULTS: ALDH1 immunostaining in the invasive front showed positive association with tumor size, regional metastasis, tumor histopathological grading, and disease progression. Moreover, expression of this marker in both tumor invasive front and adjacent non-tumor epithelium was related with more aggressive tumors. CD44 immunostaining was heterogeneous in all areas evaluated and did not show association with clinical data. CONCLUSION: Collectively, these data suggest that ALDH1 immunostaining in the invasive front and in adjacent non-tumor epithelium may help identify tumors with a more aggressive behavior, potentially contributing to improving treatment customization and the monitoring of patients with head and neck cancer.

Analysis of the proliferative potential of odontogenic epithelial cells of pericoronal follicles.

AIM: To evaluate the proliferative potential and the cell proliferation rate of odontogenic epithelial cells. MATERIALS AND METHODS: Forty-two cases of pericoronal follicles of impacted third molars were submitted to silver impregnation technique for quantification of argyrophilic nucleolar organizer regions (AgNOR) and immunohistochemical staining for EGFR and Ki-67. For AgNOR quantification, the mean number of active nucleolar organizer regions per nucleus (mAgNOR) and the percentage of cells with 1, 2, 3 and 4 or more AgNORs per nucleus (pAgNOR) were quantified. Ki-67 immunolabeling was quantified, whereas for EGFR, a descriptive analysis of staining patterns (membrane, cytoplasm or membrane + cytoplasm positivity) was performed. We evaluated the reduced epithelium of the enamel organ and/or islands of odontogenic epithelium present in the entire connective tissue. RESULTS: mAgNOR were 1.43 (1.0-2.42) and were significantly different among pericoronary follicles from upper and lower teeth (p = 0.041). Immunostaining of Ki-67 was negative in all cases. EGFR immunolabeling was found mainly in the cytoplasm and was more intense in islands and cords when compared to reduced epithelium of the enamel organ. CONCLUSION: Odontogenic epithelial cells of some pericoronal follicles have proliferative potential, suggesting their association with the development of odontogenic lesions. CLINICAL SIGNIFICANCE: The authors suggest that nonerupted, especially of the lower teeth, should be monitored and if necessary removed.

Exploring the mechanisms of alcohol-related damage in oral mucosa - is oxidative stress associated with the increase in cell proliferation in rat tongue epithelium?

CONTEXT: Alcohol consumption has been related to a cell proliferation increase in oral epithelium but its mechanism remains unclear. OBJECTIVE: The aim of this study was to investigate whether oxidative stress parameters are implicated in the induction of cell proliferation in rat tongue epithelium after different times of chronic alcohol consumption. MATERIALS AND METHODS: Cell proliferation was assessed in tongue epithelium using AgNOR (argyrophilic proteins related to active nucleolar organizer regions) quantification. Oxidative stress parameters [lipid peroxidation, protein carbonyls, superoxide dismutase activity and catalase (CAT) activity and immunocontent] and Nrf2 immunocontent were quantified in tongue homogenates. RESULTS AND DISCUSSION: Mean AgNOR numbers (mAgNOR) per nucleus was 2.22 ± 0.30 in ventral tongue epithelium after 120 days of alcohol consumption (vs. 1.87 ± 0.18 for control animals and 1.91 ± 0.23 for animals treated with alcohol for 60 days) indicating cell proliferation increase (p < 0.05, ANOVA followed by Tukey post hoc). Interestingly, 60 days of alcohol consumption induced changes in oxidative stress parameters, but no alteration in cell proliferation. Vitamin E co-treatment was conduced in order to evaluate its possible protective effects. The 120 day Tween + vitamin E + alcohol treatment induced an increase in mAgNORs when compared to the Tween + vitamin E treated group (respectively 2.10 ± 0.30 vs. 1.77 ± 0.11, p < 0.05, ANOVA followed by Tukey post hoc), showing that vitamin E co-treatment had no protective effects. In addition, an inverse association was observed between CAT activity and AgNORs quantity (R = -0.32; p < 0.05, Person's correlation) as well as the possible involvement of Nrf2 in alcohol-related damage. CONCLUSIONS: Our findings suggest that the increase in cell proliferation associated with alcohol-related damage has no direct relation with an imbalance in oxidative parameters. In contrast, our results indicate that hydrogen peroxide may be implicated in cellular signaling during proliferation in the oral mucosa.

Leishmaniasis with oral mucosa involvement.

INTRODUCTION: The term leishmaniasis comprises a group of diseases caused by different protozoan species of the genus Leishmania. There are three main clinical forms of leishmaniasis: visceral, cutaneous and mucocutaneous. Exclusive involvement of the mucosa is very rare. OBJECTIVES: To present a case of mucocutaneous leishmaniasis in an elderly patient, discuss the clinical presentation, diagnostic process and treatment emphasizing the distinctions from other granulomatous lesions. CASE REPORT: A 71-year-old male presenting with a symptomatic lesion on the hard and soft palate, which had developed over a period of 6 months was evaluated. The oral exam revealed a lesion with multiple ulcerated nodules on the hard and soft palate extending to the oropharynx. The diagnostic hypothesis was chronic infectious disease (paracoccidioidomycose, tuberculosis and leishmaniasis) or squamous cell carcinoma. Histopathological, histochemical and immunohistochemical analysis were performed. A chest x-ray revealed a normal pulmonary pattern. The Montenegro skin test was positive. The definitive diagnosis was leishmaniasis with exclusive oral manifestation and the patient was treated with liposomal amphotericin. CONCLUSIONS: Localized oral mucosa leishmaniasis is an uncommon event in an immunocompetent patient. Dentists play an important role in the diagnosis of oral leishmaniasis, which has systemic repercussions.

Healing action of topical chamomile on 5-fluoracil induced oral mucositis in hamster.

BACKGROUND: Oral mucositis is a common complication in the treatment of cancer. Its management and prevention are seen as high priority in cancer patient care. The aim of the present study was to investigate the effect of topical chamomile in the treatment of oral mucositis induced by 5-fluoracil (5-FU) in hamsters. MATERIALS AND METHODS: One hundred five hamsters were randomly separated into three groups (35 animals each): group I--without treatment (control); group II--treatment with chamomile (Ad-Muc®); and group III--treatment with corticoid (betamethasone elixir--Celestone®). The animals received an intraperitoneal injection of 5-FU on days 0 and 2. On days 3 and 4, the buccal mucosa was scratched and therapy was initiated on day 5. Three animals were sacrificed on days 0, 2, 5, 8, 10, 12, 14, and 16, weighed, and the buccal mucosa removed for clinical and histopathological analysis. RESULTS: The animals that developed mucositis and were treated with chamomile or the corticoid agent weighed significantly less than those in the control group. The group treated with the corticoid agent exhibited a more severe clinical condition, whereas the group treated with chamomile exhibited mild mucositis throughout the experiment. The group treated with chamomile had a 12-fold greater chance of scoring zero (absence of mucositis) than the control group. Analysis of the histopathological results demonstrated that the group treated with chamomile exhibited a lesser degree of mucositis throughout the evaluation period in comparison to the control and corticoid groups. CONCLUSION: Chamomile proved effective in the treatment of oral mucositis in a hamster model. However, well-designed clinical studies are needed to confirm the clinical efficacy of this medicine in humans.

Enucleation and liquid nitrogen cryotherapy in the treatment of keratocystic odontogenic tumors: a case series.

PURPOSE: This study describes the technique of lesion enucleation without capsule disruption combined with liquid nitrogen cryotherapy in the surgical treatment of keratocystic odontogenic tumors (KOTs). PATIENTS AND METHODS: Eight patients (9 KOTs) were included in the study. After enucleation, liquid nitrogen was applied twice for 1 minute, with 5-minute intervals between applications. The patients were followed up for 3 to 9 years. RESULTS: There were no recurrences during the follow-up of 9 KOTs for up to 9 years. Only 1 patient had temporary reversible loss of lip sensation after treatment. There were no pathologic fractures. In all cases bone height at the surgical site was restored, and no patients needed bone reconstruction for post-treatment rehabilitation. CONCLUSIONS: This study confirmed the efficiency of KOT treatment enucleation without fragmentation combined with liquid nitrogen cryotherapy at the surgical site.

Evaluation of cell proliferation rate in non-dysplastic leukoplakias.

OBJECTIVE: Analyze whether the most frequent cases of non-dysplastic leukoplakias, hyperkeratosis (H), acanthosis (A), and hyperkeratosis with acanthosis (HA) have similar cell proliferation rates and to compare them with epithelial dysplastic (ED) leukoplakias and normal oral epithelium (NOE). STUDY DESIGN: The sample comprised 10 cases of normal oral epithelium, 10 cases of hyperkeratosis, 10 cases of acanthosis, 10 cases of hyperkeratosis with acanthosis and 10 cases of epithelial dysplasia. The mean number of AgNORs per nucleus (mAgNOR) and the mean percentage of cells with 1, 2, 3 and 4 or more AgNORs per nucleus (pAgNOR) were recorded. RESULTS: The results of mAgNOR showed differences between disorders in the evaluation of the basal layer, of the parabasal layer, and in the overall evaluation. mAgNOR and pAgNOR=2 increased progressively from normal oral epithelium to hyperkeratosis with acanthosis, hyperkeratosis, acanthosis and epithelial dysplasia (p<0.05). Cell proliferation rate was different between different subtypes of non-dysplastic leukoplakias and this group presented a higher proliferative behavior when compared to normal oral epithelium. CONCLUSION: It may be suggested that non-dysplastic leukoplakias had different characteristics regarding cell proliferation rates and sometimes showed a proliferative behavior similar to that found in epithelial dysplasia. More studies should be conduced to increase knowledge about the biological profile of non-dysplastic leukoplakias, especially as it pertains to acanthosis.

Immunohistochemical analysis of the patterns of p53 and PCNA expression in odontogenic cystic lesions.

OBJECTIVE: the role of p53 expression in odontogenic lesions has not been fully determined, but has been associated with cell proliferation. The purpose of this study was to analyze p53 and proliferating cell nuclear antigen (PCNA) expression in 4 different odontogenic lesions. DESIGN: expression of p53 and PCNA was analyzed in radicular and dentigerous cysts, odontogenic keratocysts, and calcifying odontogenic cysts (Gorlin cysts) using monoclonal antibodies for detection of p53 and PCNA. RESULTS: PCNA expression was significantly greater in the basal layer of radicular cysts and in the suprabasal layer of odontogenic keratocysts; the percentage of p53 positive cells was significantly greater in the suprabasal layer of odontogenic keratocysts. CONCLUSIONS: The patterns of p53 and PCNA expression in dentigerous and radicular cysts were similar although the two lesions are of different origin. In odontogenic keratocysts and Gorlin cysts, results indicate a different pattern of tumor growth.

Effects of aging on mouse tongue epithelium focusing on cell proliferation rate and morphological aspects.

The aim of this study was to investigate cell proliferation rate and certain morphological features of mouse epithelium as aging progresses. Tongue biopsies were performed on female mice (Mus domesticus domesticus) at 2, 8, 14 and 20 months of age as indicative of adolescence, adulthood, early senescence and senescence, respectively. Histological sections of tongue were stained with hematoxylin-eosin and subjected to silver staining for active nucleolar organizer region counting. Cell proliferation rate and epithelial thickness analysis were carried out. Analysis of variance detected no differences between the groups in terms of numbers of silver-stained dots associated with nucleolar proteins. There was an increase in mean epithelial thickness in adult animals, followed by a gradual reduction until senescence. Mean keratin thickness presented an increase at 8 and 20 months of age. This difference is probably related to puberty, growth or dietary habits. Aging has no influence on oral epithelial proliferation rate in mice. A gradual reduction in epithelial thickness is a feature of aging in mammals. A conspicuous increase in the keratin layer was observed in senescence as an adaptative response to the reduction in epithelial thickness. These results suggest that aging affects the oral epithelium maturation process through a mechanism that is not related to cell proliferation.

Giant cell lesions with a Noonan-like phenotype: a case report.

AIM: The purpose of this article is to describe a case of multiple giant cell lesions of the mandible that occurred in a 14-year-old girl with phenotypic characteristics associated with Noonan Syndrome (NS). BACKGROUND: NS is a dysmorphic disorder characterized by hypertelorism, short stature, congenital heart defects, short and webbed neck, skeletal anomalies, and bleeding diathesis. REPORT: A 14-year-old girl with a previous diagnosis of NS (sporadic case) presented with multiple radiolucent lesions in the body and ramus of her mandible. SUMMARY: In terms of clinical behavior and the described radiographic characteristics, giant cells lesions with Noonan-like phenotype can be considered a form of cherubism. Therefore, surgical intervention is not necessary, but radiographic follow-up and observation is very important during the control and gradual regression of the lesions.

Bone tissue microscopic findings related to the use of diode laser (830 nm) in ovine mandible submitted to distraction osteogenesis.

PURPOSE: To analyze the microscopic characteristics of the effect of Gallium-Aluminum Arsenid diode laser (GaAlAs - 830etam) applied during the activation and consolidation period to ovine mandibles submitted to distraction osteogenesis. METHODS: Eighteen sheep underwent surgery in order to have bone distractors implanted in the left side of the jaw area. They were divided into three groups: 1 - Control; 2 - Laser irradiation during the activation period; 3 - Laser irradiation during the fixation period. The irradiation was carried out in five sessions, on every other day, with 4,0J/cm(2) doses applied to four pre-established areas, totaling 16J per session. After four days of latency under post-operative care, ten days of distractor activation (at 1mm/day) and twenty-one days of fixation the animals were sacrificed and the devices removed for microscopic analysis. RESULTS: The groups that received laser irradiation (GaAlAs) presented a greater amount of mineralized bone trabeculae when compared to the Control Group. Despite that, cartilaginous tissues were also found in Group 2. CONCLUSION: The laser has been more favorable when used in the consolidation period, after bone elongation.

Predictive value of p63, ki-67, and survivin expression in oral leukoplakia: A tissue microarray study.

The aim of this study was to analyze the immunohistochemical expression of survivin, ki-67, and p63 in oral leukoplakic lesions, histopathologically differentiated into dysplastic and nondysplastic. A tissue microarray containing 57 samples of biopsies from clinically classified lesions, such as leukoplakia, was immunolabeled for survivin, ki-67, and p63. Samples were scored for percentage of positively stained. Scores were designated as follows: low = less than 25% of positive cells; and high = more than 25% of positive cells. On performing histopathological diagnosis, 20 dysplastic lesions and 37 nondysplastic lesions were seen, in which female patients (56.1%) were predominant with an average age of 58.27 years. The study showed a high expression of 37.5% for survivin, 43.7% for ki-67, and 88.2% for p63 in dysplastic lesions. However, there was a high expression of 16.7% for survivin, 16.7% for ki-67, and 92% for p63 in nondysplastic lesions. There is a positive correlation of expression among the three antibodies. In the association of immunoreactivity, in both dysplastic and nondysplastic lesions, increased expression of survivin reflects on the increased expression of ki-67, and there is an overexpression of p63. In leukoplakia, the expression of survivin associated with that of ki-67 reinforces the assumption that all these lesions are potentially malignant, regardless of histopathology; and the overexpression of p63 may indicate carcinogenic potential. These findings may help in the treatment of patients with this type of lesion.

Therapeutic Inhibition of the MDM2-p53 Interaction Prevents Recurrence of Adenoid Cystic Carcinomas.

Purpose: Conventional chemotherapy has modest efficacy in advanced adenoid cystic carcinomas (ACC). Tumor recurrence is a major challenge in the management of ACC patients. Here, we evaluated the antitumor effect of a novel small-molecule inhibitor of the MDM2-p53 interaction (MI-773) combined with cisplatin in patient-derived xenograft (PDX) ACC tumors.Experimental Design: Therapeutic strategies with MI-773 and/or cisplatin were evaluated in SCID mice harboring PDX ACC tumors (UM-PDX-HACC-5) and in low passage primary human ACC cells (UM-HACC-2A, -2B, -5, -6) in vitro The effect of therapy on the fraction of cancer stem cells (CSC) was determined by flow cytometry for ALDH activity and CD44 expression.Results: Combined therapy with MI-773 with cisplatin caused p53 activation, induction of apoptosis, and regression of ACC PDX tumors. Western blots revealed induction of MDM2, p53 and downstream p21 expression, and regulation of apoptosis-related proteins PUMA, BAX, Bcl-2, Bcl-xL, and active caspase-9 upon MI-773 treatment. Both single-agent MI-773 and MI-773 combined with cisplatin decreased the fraction of CSCs in PDX ACC tumors. Notably, neoadjuvant MI-773 and surgery eliminated tumor recurrences during a postsurgical follow-up of more than 300 days. In contrast, 62.5% of mice that received vehicle control presented with palpable tumor recurrences within this time period (P = 0.0097).Conclusions: Collectively, these data demonstrate that therapeutic inhibition of MDM2-p53 interaction by MI-773 decreased the CSC fraction, sensitized ACC xenograft tumors to cisplatin, and eliminated tumor recurrence. These results suggest that patients with ACC might benefit from the therapeutic inhibition of the MDM2-p53 interaction. Clin Cancer Res; 23(4); 1036-48. ©2016 AACR.

Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma.

Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization.

Ameloblastic neoplasia spectrum: a cross-sectional study of MMPS expression and proliferative activity.

OBJECTIVE: To compare the proliferation and the expression of matrix metalloproteinases (MMPs; MMP-2 and MMP-9) in solid and unicystic ameloblastomas with ameloblastic carcinomas. STUDY DESIGN: Five cases of ameloblastic carcinoma (AC), 18 cases of solid ameloblastoma (SA), and seven of unicystic ameloblastoma (UA) were selected. The immunohistochemical expression of MMPs was assessed by the percentage of positive tumor cells and stained stroma. The mean argyrophilic nucleolar organizer region (AgNOR) and the percentage of cells with more than one AgNOR per nucleus were evaluated. RESULTS: Statistically significant higher mean AgNOR was observed in AC than in SA and UA. MMP-2 was expressed similarly in tumor and stroma among groups. MMP-9 was higher in the stroma of SA than that of UA (P = .0484). CONCLUSIONS: The cell proliferation was related to the greater aggressiveness of AC. High expression of MMP-2 and MMP-9 in all lesions highlighted the importance of these enzymes in the biology of ameloblastic tumors.