Different expression patterns of carbonic anhydrase IX in oral lichen planus and leukoplakia.

Tumor hypoxia is an important indicator of cancer prognosis. Among the different genes that are upregulated by hypoxia is carbonic anhydrase IX, which combines carbon dioxide and water to form bicarbonate and hydrogen. Although expression of this enzyme is very low in normal tissues, carbonic anhydrase IX is overexpressed in several types of cancer. The aim of the present work was to analyze carbonic anhydrase IX expression in the two most frequent potentially malignant oral disorders: oral lichen planus and oral leukoplakia. Immunohistochemical analysis of oral lichen planus and oral leukoplakia biopsies was performed using anticarbonic anhydrase IX antibody. Samples of normal mucosa served as controls. Statistical analysis was performed by Fischer's exact test. The enzyme was detected in the epithelium of both lesions. The staining was more intense in the basal layer and decreased towards the surface in oral lichen planus. Conversely, the most intense reaction was observed in the superficial layers in leukoplakia, and staining intensity decreased towards the basal membrane. No carbonic anhydrase IX expression was seen in normal mucosa samples. Carbon anhydrase IX expression in lichen and leukoplakia epithelia shows that hypoxia plays a role in the pathogenesis of both lesions. The different distribution patterns provides further evidence of the different biological behavior of these two entities, which under certain circumstances can have similar clinical and histological features.

La hipoxia tumoral es un importante indicador de pronóstico en cáncer. Entre los distintos genes que son activados por hipoxia, uno de los principales es la anhidrasa carbónica IX (CAIX), que combina CO2 con H2O para sintetizar HCO3 y H+. Aunque la expresión de esta enzima es muy baja en tejidos normales, se sobreexpresa en varios tipos de cáncer. La finalidad del presente trabajo fue analizar la expresión de CAIX en las dos lesiones orales potencialmente malignas más frecuentes: el liquen plano y la leucoplasia. Se utilizó una técnica inmuno histoquímica con un anticuerpo específico contra CAIX, en biopsias de liquen plano oral y leucoplasia oral. Se utilizaron mucosas normales como controles. Se realizaron análisis estadísticos utilizando test exacto de Fischer. La identificación de la enzima fue positiva en el epitelio de ambas lesiones. En los líquenes la reacción es más intensa en los estratos basales, disminuyendo hacia la superficie. Inversamente, las leucoplasias mostraron marcación más intensa en estratos superficiales, con disminución hacia la membrana basal. Las mucosas normales resultaron negativas. La expresión de CAIX en el epitelio de líquenes y leucoplasias indica que la hipoxia juega algún papel en la patogenia de ambas lesiones. El diferente patrón de distribución es una evidencia más del diferente comportamiento biológico de dos entidades las cuales en ciertas circunstancias pueden manifestar cuadros clínicos e histológicos semejantes.

Different expression patterns of carbonic anhydrase IX in oral lichen planus and leukoplakia

Tumor hypoxia is an important indicator of cancer prognosis. Among the different genes that are upregulated by hypoxia is carbonic anhydrase IX, which combines carbon dioxide and water to form bicarbonate and hydrogen. Although expression of this enzyme is very low in normal tissues, carbonic anhydrase IX is overexpressed in several types of cancer. The aim of the present work was to analyze carbonic anhydrase IX expression in the two most frequent potentially malignant oral disorders: oral lichen planus and oral leukoplakia. Immunohistochemical analysis of oral lichen planus and oral leukoplakia biopsies was performed using anticarbonic anhydrase IX antibody. Samples of normal mucosa served as controls. Statistical analysis was performed by Fischer's exact test. The enzyme was detected in the epithelium of both lesions. The staining was more intense in the basal layer and decreased towards the surface in oral lichen planus. Conversely, the most intense reaction was observed in the superficial layers in leukoplakia, and staining intensity decreased towards the basal membrane. No carbonic anhydrase IX expression was seen in normal mucosa samples. Carbon anhydrase IX expression in lichen and leukoplakia epithelia shows that hypoxia plays a role in the pathogenesis of both lesions. The different distribution patterns provides further evidence of the different biological behavior of these two entities, which under certain circumstances can have similar clinical and histological features (AU)

La hipoxia tumoral es un importante indicador de pronóstico en cáncer. Entre los distintos genes que son activados por hipoxia, uno de los principales es la anhidrasa carbónica IX (CAIX), que combina CO2 con H2O para sintetizar HCO3 y H+. Aunque la expresión de esta enzima es muy baja en tejidos normales, se sobreexpresa en varios tipos de cáncer. La finalidad del presente trabajo fue analizar la expresión de CAIX en las dos lesiones orales potencialmente malignas más frecuentes: el liquen plano y la leucoplasia. Se utilizó una técnica inmuno histoquímica con un anticuerpo específico contra CAIX, en biopsias de liquen plano oral y leucoplasia oral. Se utilizaron mucosas normales como controles. Se realizaron análisis estadísticos utilizando test exacto de Fischer. La identificación de la enzima fue positiva en el epitelio de ambas lesiones. En los líquenes la reacción es más intensa en los estratos basales, disminuyendo hacia la superficie. Inversamente, las leucoplasias mostraron marcación más intensa en estratos superficiales, con disminución hacia la membrana basal. Las mucosas normales resultaron negativas. La expresión de CAIX en el epitelio de líquenes y leucoplasias indica que la hipoxia juega algún papel en la patogenia de ambas lesiones. El diferente patrón de distribución es una evidencia más del diferente comportamiento biológico de dos entidades las cuales en ciertas circunstancias pueden manifestar cuadros clínicos e histológicos semejantes (AU)

Immunohistochemical expression of GLUT-1, GLUT-3, and carbonic anhydrase IX in benign odontogenic lesions.

BACKGROUND: Some benign odontogenic lesions have a distinct biological behavior with high recurrence rates and local aggressive behavior. To determine whether glucose transporters proteins (GLUT-1 and GLUT-3) and carbonic anhydrase IX (CA IX) are associated with the development of as dentigerous cyst (DC), odontogenic keratocyst (OK), and ameloblastoma (AM), we evaluated the immunohistochemical expression of these proteins in these lesions. MATERIALS AND METHODS: Immunoexpression of GLUT-1, GLUT-3, and CA IX was evaluated semiquantitative fields in each of the 20 cases of OK, AM, and DC. The cases were classified according to the scores: 0 (0% positive cells), 1 (<10% of positive cells), 2 (10-50% of positive cells), and 3 (>50% of positive cells). The statistical analysis was performed using Pearson's chi-square, Kruskal-Wallis and Mann-Whitney tests. RESULTS: All cases were positive for GLUT-1 and 65% of OK showed scored 3. Staining was diffuse in 90% of OK and 85% of DC cases (P < 0.001). In 50% of OK and AM, staining was only observed in the membrane (P = 0.01). Most of the samples (66.7%) were negative for GLUT-3. Staining intensity for anhydrase was higher in the epithelium of DC when compared to OK (P = 0.01). Strong staining was observed in 55% of DC and 20% of OK samples (P = 0.01). CONCLUSIONS: These results suggest that GLUT-1 may be involved in the metabolic regulation of glucose in odontogenic lesions studied. In addition, CA IX appears to influence the development of AM, OK, and DC which can explain the differences their biological behavior.

Novel predictive biomarkers for cervical cancer prognosis.

High hypoxic, glycolytic and acidosis metabolisms characterize cervical cancer tumors and have been described to be involved in chemoradioresistance mechanisms. Based on these observations, the present study assessed four selected novel biomarkers on the prognosis of locally advanced cervical carcinoma. A total of 66 patients with stage IIB/IIIB cervical cancer were retrospectively included. The protein expression levels of glucose transporter 1 (GLUT1), carbonic anhydrase 9 (CAIX) and hexokinase 1 (HKII) were investigated by immunohistochemistry on tumor biopsies, hemoglobin was measured and the disease outcome was monitored. A total of 53 patients (80.3%) presented a complete response. For these patients, the protein expression levels of GLUT1, CAIX and HKII were overexpressed. A significant difference was observed (P=0.0127) for hemoglobin levels (≤11 g/dl) in responsive compared with non-responsive patients. The expression of GLUT1 is associated with a lower rate of both overall and disease-free survival, with a trend of decreased risk of 1.1x and 1.5x, respectively. Co-expression of GLUT1 and HKII is associated with a decreased trend risk of 1.6x for overall survival. Patients with hemoglobin levels ≤11 g/dl had a 4.3-fold risk (P=0.02) in decreasing both to the rate of overall and disease-free survival. The presence of anemic hypoxia (hemoglobin ≤11 g/dl) and the expression of GLUT1 and/or HKII influence treatment response and are associated with a lower overall and disease-free survival. The present results demonstrated that these biomarkers may be used as predictive markers and suggested that these metabolic pathways can be used as potential novel therapeutic targets.

Prognostic and predictive biomarkers for hypoxic regions on breast cancer: advances and challenges / Biomarcadores preditivos e prognósticos em regiões hipóxicas do câncer de mama: avanços e desafios

Hypoxia has been extensively studied in solid tumors mainly in breast cancers and it is commonly associated with chemotherapy and radiotherapy resistance. Hypoxia inducible factor (HIF)-1α is responsible for hypoxia in the tumor microenvironment and its molecular mechanisms as well as its therapeutic strategies have been described. However, a few investigations in the literature deal with its role in the hypoxic environment at diagnosis with the aim to guide therapeutic approaches. This study alerts researchers in pathology and oncology to the importance of assessing area extension as well as specific biomarkers, inasmuch as molecules reactive to hypoxia may indicate response to antiangiogenic therapy. The extension of hypoxic areas may alter the choice of therapeutic approach, insofar as some antiangiogenic treatments may considerably aggravate patient's clinical course since they create a hypoxic environment.

A hipóxia vem sendo bastante estudada nos tumores sólidos, principalmente nos de mama, os quais são frequentemente responsáveis pela resistência a quimioterapia e radioterapia. O hypoxia inducible factor (HIF)-1α é o principal responsável pela hipóxia no microambiente tumoral e seus mecanismos moleculares têm sido descritos, além de estratégias terapêuticas desenhadas para essa molécula. Porém, poucos estudos na literatura tratam do papel do microambiente hipóxico no momento do diagnóstico para colaborar com a conduta dos oncologistas. Este artigo alerta os pesquisadores em patologia e oncologia para que eles observem a importância da avaliação da extensão da área, bem como dos biomarcadores específicos para esse ambiente, já que moléculas responsivas à hipóxia podem ser indicativas de resposta à terapia antiangiogênica. A extensão das áreas hipóxicas pode mudar a decisão do oncologista na escolha da conduta terapêutica, visto que alguns tratamentos antiangiogênicos podem piorar consideravelmente a evolução clínica do paciente por criar um ambiente hipóxico.