Downregulation of CD9 protein expression is associated with aggressive behavior of oral squamous cell carcinoma

Squamous cell carcinoma of the oral cavity (OSCC) is a malignancy characterized by a high degree of local aggression and metastasis to cervical lymph nodes. Tetraspanins are proteins with functional roles in a wide array of cellular processes and are reported to be associated with tumor progression. The present study investigated the expression of the CD9, CD37, CD63, CD81 and CD82 tetraspanins in OSCC using immunohistochemistry (IHC) and quantitative Real Time-PCR (qRT-PCR). Tissue microarray (TMA) analysis of samples from 179 cases of OSCC and 10 normal samples oral mucosa were evaluated immunomorphologically. We analyzed CD9 and CD82 expression by qRT-PCR in 66 OSCC cases and 4 normal samples of oral mucosa. Expression of CD63, CD37 and CD81 was not detected in the samples studied. CD82 was downregulated or negative in 127 of 179 (80%) specimens; no correlation was observed between CD82 expression, clinicopathological parameters, disease-free survival and 5-year overall survival. CD9 expression was downregulated or negative in 75 of 129 (42%) OSCC samples. Loss of CD9 expression in OSCC samples correlated with the incidence of lymph node metastasis (p = 0.017). Disease-free survival and the 5-year overall survival of patients with downregulated or negative CD9 expression were significantly lower than in patients with positive CD9 expression (p = 0.010 and p = 0.071, respectively). No correlation was found between CD9 or CD82 expression and clinicopathological parameters by qRT-PCR. Our results suggest that the downregulation or lack of expression of the CD9 protein might indicate a more aggressive of OSCC. (C) 2009 Elsevier Ltd. All rights reserved.

CDKN2A is not the principal target of deletions on the short arm of chromosome 9 in neuroendocrine (Merkel cell) carcinoma of the skin

The majority of small-cell lung cancers (SCLCs) express p16 but not pRb, Given our previous study showing loss of pRb in Merkel cell carcinoma (MCC)/neuroendocrine carcinoma of the skin and the clinicopathological similarities between SCLC acid MCC, we wished to determine if this was also the case in MCC, Twenty-nine MCC specimens from 23 patients were examined for deletions at 10 loci on 9p and I on 9p. No loss of heterozygosity (LO H) was peen in 9 patients including 2 for which tumour and cell line DNAs were examined. Four patients had LOH for all informative loci on 9p, Ten tumours showed more limited regions of loss on 9p, and from these 2 common regions of deletion were determined, Half of all informative cases had LOH at D95168, the most telomeric marker examined, and 3 specimens showed loss of only D9S168, A second region (InFNA-D9S126) showed L0H in 10(44%) cases, and case MCC26 showed LOH for only D9S126, implicating genes centromeric of the CDKN2A locus. No mutations in the coding regions of p16 were seen in 7 cell lines tested, and reactivity to anti-p16 antibody was seen in all Il tumour specimens examined and in 6 of 7 cell lines from 6 patients. Furthermore, all cell lines examined reacted with anti-p 14' antibody, These results suggest that neither transcript of the CDKN2A locus is the target of deletions on 9p in MCC and imply the existence of tumour-suppressor genes mapping both centromeric and telomeric of this locus. (C) 2001 Wiley-Liss, Inc.

Saturable dose-response relationships for melphalan in melanoma treatment by isolated limb infusion in the nude rat

Nude rats bearing melanomas on their hindlimbs were treated by isolated limb infusion (ILI) with increasing doses (7.5-400 mug/ml) of melphalan. The response of tumours to treatment at the end of the observation period was graded, according to diameter, as complete response (CR), partial response (PR), no change (NC) or progressive disease (PD). No linear relationship between the dose of melphalan and the tumour response was observed. All doses above a threshold of 15 mug/ml achieved a PR or CR. The achievement of CR was not related to increased dose. Two major implications arise from this work. Firstly, the typically two-to three-fold increase in cytotoxic drug concentration given in high dose chemotherapy compared with standard drug concentration may not be sufficient to produce the expected increase in tumour response and possibly survival, and the controversial results of high dose chemotherapy in different studies may thus be explained. Secondly, since an increase in melphalan dose above a certain threshold does not greatly increase tumour response, the use of combination therapies would seem to be more likely to be effective than increased chemotherapeutic drug doses in achieving better tumour responses.

Role of myofibroblasts in tumour encapsulation of hepatocellular carcinoma in haemochromatosis

Background/Aims: Hepatocellular carcinoma is a carcinoma malignancy and a major complication of untreated haemochromatosis. Encapsulation of liver tumours has been associated with a better prognosis and longer disease-free periods following resection, This study investigated the source of the tumour capsule in patients with haemochromatosis and coexisting hepatocellular carcinoma and examined potential factors influencing development. Methods: Five haemochromatosis patients with encapsulated hepatocellular carcinoma were studied. Myofibroblasts were identified using combined immunohistochemistry and in situ hybridisation for a-smooth muscle actin and procollagen alpha (1)(I) mRNA, respectively. Immunohistochemistry was also performed for transforming growth factor (TGF)-beta (1), platelet-derived growth factor (PDGF)-beta receptor and malondialdehyde. Results. Procollagen alpha (1)(I) mRNA co-localised to alpha -smooth muscle actin positive myofibroblasts. The number of myofibroblasts was maximal within the capsule and decreased away from the tumour. TGF-beta (1) protein was expressed in iron-loaded cells in non-tumour liver at the interface of tumour capsule. PDGF-beta receptor expression was observed in mesenchymal cells in the tumour capsule and in portal tracts. Malondialdehyde adducts were observed in the tumour, non-tumour tissue and in the capsule. Conclusions: This study provides evidence that myofibroblasts are the cell type responsible for collagen production within the tumour capsule surrounding hepatocellular carcinoma in haemochromatosis, The production of TGF-beta (1) by iron-loaded hepatic cells at the tumour capsule interface may perpetuate the myofibroblastic phenotype, resulting in, the formation of the tumour capsule.

Metabolic activation of polycyclic aromatic hydrocarbons and other procarcinogens by cytochromes P450 1A1 and P4501B1 allelic variants and other human cytochromes P450 in Salmonella typhimurium NM2009

A variety of polycyclic aromatic hydrocarbons and their dihydrodiol derivatives, arylamines, heterocyclic amines, and nitroarenes, were incubated with cDNA-based recombinant (Escherichia coli or Trichoplusia ni) systems expressing different forms of human cytochrome P450 (P450 or CYP) and NADPH-P450 reductase using Salmonella typhimurium, tester strain NM2009, and the resultant DNA damage caused by the reactive metabolites was detected by measuring expression of umu gene in the cells. Recombinant (bacterial) CYP1A1 was slightly more active than any of four CYP1B1 allelic variants, CYP1B1*1, CYP1B1*2, CYP1B1*3, and CYP1B1*6, in catalyzing activation of chrysene-1,2-diol, benz[a]anthracene-trans-1,2-, 3,4-, 5,6-, and 8,9-diol, fluoranthene-2,3-diol, dibenzo[a]pyrene, benzo[c]phenanthrene, and dibenz[a,h]anthracene and several arylamines and heterocyclic amines, whereas CYP1A1 and CYP1B1 enzymes had essentially similar catalytic specificities toward other procarcinogens, such as (+)-, (-)-, and (+/-)-benzo[a]pyrene-7,8-diol, 5-methylchrysene-1,2-diol, 7,12-dimethylbenz[a]anthracene-3,4-diol, dibenzo[a,l]pyrene-11,12-diol, benzo[b]fluoranthene-9,10-diol, benzo[c]chrysene, 5,6-dimethylchrysene-1,2-diol, benzo[c]phenanthrene-3,4-diol, 7,12-dimethylbenz[a]anthracene, benzo[a]pyrene, 5-methylchrysene, and benz[a]anthracene. We also determined activation of these procarcinogens by recombinant (T. ni) human P450 enzymes in S. typhimurium NM2009. There were good correlations between activities of procarcinogen activation by CYP1A1 preparations expressed in E. coli and T. ni cells, although basal activities with three lots of CYP1B1 in T. ni cells were very high without substrates and NADPH in our assay system. Using 14 forms of human P450S (but not CYP1B1) (in T. ni cells), we found that CY1P1A2, 2C9, 3A4, and 2C19 catalyzed activation of several of polycyclic aromatic hydrocarbons at much slower rates than those catalyzed by CYP1A1 and that other enzymes, including CYP2A6, 2B6, 2C8, 2C18, 2D6, 2E1, 3A5, 3A7, and 4A11, were almost inactive in the activation of polycyclic aromatic hydrocarbons examined here.

alpha-melanocyte stimulating hormone potentiates p16/CDKN2A expression in human skin after ultraviolet irradiation

The contribution of the UV component of sunlight to the development of skin cancer is widely acknowledged, although the molecular mechanisms that are disrupted by UV radiation (UVR) resulting in the loss of normal growth controls of the epidermal stem cell keratinocytes and melanocytes is still poorly understood. alpha-Melanocyte stimulating hormone (alpha-MSH), acting via its receptor MC1, has a key role in skin pigmentation and the melanizing response after exposure to UVR. The cell cycle inhibitor p16/CDKN2A also appears to have an important function in a cell cycle checkpoint response in skin after exposure to UVR. Both of these genes have been identified as risk factors in skin cancer, MC1R variants are associated with increased risk to both melanoma and nonmelanoma skin cancers, and p16/CDKN2A with increased risk of melanoma. Here we demonstrate that the increased expression of p16 after exposure to sub-erythemal doses of UVR is potentiated by alpha-MSH, a ligand for MC1R, and this effect is mimicked by cAMP, the intracellular mediator of alpha-MSH signaling via the MC1 receptor. This link between p16 and MC1R may provide a molecular basis for the increased skin cancer risk associated with MC1R polymorphisms.

Oral lichen planus: Causes, diagnosis and management

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology. In this paper we review the clinical and histological features of OLP, process of OLP diagnosis, causes of OLP, management of OLP patients and medical treatment of OLP lesions. Approximately 0.2 per cent OLP patients develop intra-oral carcinoma each year compared with approximately 0.005 per cent Australian adults. Possible mechanisms of increased oral cancer risk in OLP patients are presented. The aims of current OLP therapy are to eliminate mucosal erythema and ulceration, alleviate symptoms and reduce the risk of oral cancer. Patient education may improve the outcomes of OLP therapy and further reduce the risk of oral cancer in OLP patients. Although OLP may be diagnosed clinically, appropriate specialist referral is required for: (i) histological diagnosis; (ii) assessment of causative/exacerbating factors, associated diseases and oral cancer risk; (iii) patient education and management; (iv) medical treatment; and (v) long-term review and re-biopsy as required.

Variation in coumarin 7-hydroxylase activity associated with genetic polymorphism of cytochrome P450 2A6 and the body status of iron stores in adult Thai males and females

The relationships between catalytic activity of cytochrome P450 2A6 (CYP2A6), polymorphism of CYP2A6 gene, gender and levels of body iron stores were analysed in a sample group of 202 apparently healthy Thais, aged 1947 years. Eleven individuals were found to have high activity of CYP2A6, judged by the relatively large amounts (11.2-14.6 mg) of 7-hydroyxcoumarin (7-OHC) excreted 3 h following administration of 15 mg of coumarin. Ten individuals, however, did not excrete any 7-OHC. Of these 10, four were found to have no CYP2A6 gene (whole gene deletion; CYP2A6*4 allele). The frequency of the CYP2A6 alleles; *1A, *1B and *4 in the whole sample group was 52, 40 and 8% while the frequency of the CYP2A6 gene types; *1A/* 1A, *1A/* 1B, *1B/* 1B, *1A/* 4, *1BI* 4, *4/* 4 was 29, 41, 16, 7, 5 and 2%. Subjects having CYP2A6* 1A/* 1B gene-type group were found to have higher rates of coumarin 7-hydroxylation compared with those of the CYP2A6* 1B/* 1B and CYP2A6* 1A/* 4 gene types. The inter-individual variability in CYP2A6 catalytic activity was therefore attributed in part to the CYP2A6 genetic polymorphism. Variation in CYP2A6 activity in this sample group was not associated with gender but, interestingly, it did show an inverse association with plasma ferritin; an indicator of body iron stores. Higher rates of coumarin 7-hydroxylation were found in individuals with low body iron stores (plasma ferritin < 20 μg/l) compared with subjects having normal body iron store status. Subjects (n = 16) with iron overload (plasma ferritin > 300 mug/l) also tended to have elevated rates of coumarin 7-hydroxylation. These results suggest an increased CYP2A6 expression in subjects who have excessive body iron stores. Further investigations into the underlying factors that may lead to increased expression of CYP2A6 in association with abnormal body iron stores are currently in progress in our laboratory. Pharmacogenetics 12:241-249 (C) 2002 Lippincott Williams Wilkins.

Long-term trends in sunshine duration and its association with schizophrenia birth rates and age at first registration - data from Australia and the Netherlands

Back ground. Based on the well-described excess of schizophrenia births in winter and spring, we hypothesised that individuals with schizophrenia (a) would be more likely to be born during periods of decreased perinatal sunshine, and (b) those born during periods of less sunshine would have an earlier age of first registration. Methods. We undertook an ecological analysis of long-term trends in perinatal sunshine duration and schizophrenia birth rates based on two mental health registers (Queensland. Australia n = 6630; The Netherlands n = 24, 474). For each of the 480 months between 1931 and 1970, the agreement between slopes of the trends in psychosis and long-term sunshine duration series were assessed. Age at first registration was assessed by quartiles of long-term trends in perinatal sunshine duration, Males and females were assessed separately. Results. Both the Dutch and Australian data showed a statistically significant association between falling long-term trends in sunshine duration around the time of birth and rising schizophrenia birth rates for males only. In both the Dutch and Australian data there were significant associations between earlier age of first registration and reduced long-term trends in sunshine duration around the time of birth for both males and females, Conclusions. A measure of long-term trends in perinatal sunshine duration was associated with two epidemiological features of schizophrenia in two separate data sets. Exposures related to sunshine duration warrant further consideration in schizophrenia research. (C) 2002 Elsevier Science B.V. All rights reserved.

Linkage and Association Analysis of Radiation Damage Repair Genes XRCC3 and XRCC5 with Nevus Density in Adolescent Twins

Previous studies have shown that a deficiency in DNA damage repair is associated with increased cancer risk, and exposure to UV radiation is a major risk factor for the development of malignant melanoma. High density of common nevi (moles) is a major risk factor for cutaneous melanoma. A nevus may result from a mutation in a single UV-exposed melanocyte which failed to repair DNA damage in one or more critical genes. XRCC3 and XRCC5 may have an effect on nevus count through their function as components of DNA repair processes that may be involved directly or indirectly in the repair of DNA damage due to UV radiation. This study aims to test the hypothesis that the frequency of flat or raised moles is associated with polymorphism at or near these DNA repair genes, and that certain alleles are associated with less efficient DNA repair, and greater nevus density. Twins were recruited from schools in south eastern Queensland and were examined close to their 12th birthday. Nurses examined each individual and counted all moles on the entire body surface. A 10cM genome scan of 274 families (642 individuals) was performed and microsatellite polymorphisms in XRCC3 and adjacent to XRCC5 were also typed. Linkage and association of nevus count to these loci were tested simultaneously using a structural-equation modeling approach implemented in MX. There is weak evidence for linkage of XRCC5 to a QTL influencing raised mole count, and also weak association. There is also weak evidence for association between flat mole count and XRCC3. No tests were significant after correction for testing multiple alleles, nor were any of the tests for total association significant. If variation in XRCC3 or XRCC5 influences UV sensitivity, and indirectly affects nevus density, then the effects are small.

Evaluation of staining techniques on the results of micronucleus in exfoliated oral mucosa cells

Micronuclei (MN) in exfoliated epithelial cells are widely used as biomarkers of cancer risk in humans. MN are classified as biomarkers of the break age and loss of chromosomes. They are small, extra nuclear bodies that arise in dividing cells from centric chromosome/chromatid fragments or whole chromosomes/chromatids that lag behind in anaphase and are not included in the daughter nuclei in telophase. Buccal mucosa cells have been used in biomonitoring exposed populations because these cells are in the direct route of exposure to ingested pollutant, are capable of metabolizing proximate carcinogens to reactive chemicals, and are easily and rapidly collected by brushing the buccal mucosa. The objective of the present study was to further investigate if, and to what extent, different stains have an effect on the results of micronuclei studies in exfoliated cells. These techniques are: Papanicolaou (PAP), Modified Papanicolaou, May-Grünwald Giemsa (MGG), Giemsa, Harris’s Hematoxylin, Feulgen with Fast Green counterstain and Feulgen without counterstain.

Geographical patterns of proportionate mortality for the most common causes of death in Brazil

Mortality due to chronic diseases has been increasing in all regions of Brazil with corresponding decreases in mortality from infectious diseases. The geographical variation in proportionate mortality for chronic diseases for 17 Brazilian state capitals for the year 1985 and their association with socio-economic variables and infectious disease was studied. Calculations were made of correlation coefficients of proportionate mortality for adults of 30 years or above due to ischaemic heart disease, stroke and cancer of the lung, the breast and stomach with 3 socio-economic variables, race, and mortality due to infectious disease. Linear regression analysis included as independent variables the % of illiteracy, % of whites, % of houses with piped water, mean income, age group, sex, and % of deaths caused by infectious disease. The dependent variables were the % of deaths due to each one of the chronic diseases studied by age-sex group. Chronic diseases were an important cause of death in all regions of Brazil. Ischaemic heart diseases, stroke and malignant neoplasms accounted for more than 34% of the mortality in each of the 17 capitals studied. Proportionate cause-specific mortality varied markedly among state capitals. Ranges were 6.3-19.5% for ischaemic heart diseases, 8.3-25.4% for stroke, 2.3-10.4% for infections and 12.2-21.5% for malignant neoplasm. Infectious disease mortality had the highest (p < 0.001) correlation with all the four socio-economic variables studied and ischaemic heart disease showed the second highest correlation (p < 0.05). Higher socio-economic level was related to a lower % of infectious diseases and a higher % of ischaemic heart diseases. Mortality due to breast cancer and stroke was not associated with socio-economic variables. Multivariate linear regression models explained 59% of the variance among state capitals for mortality due to ischaemic heart disease, 50% for stroke, 28% for lung cancer, 24% for breast cancer and 40% for stomach cancer. There were major differences in the proportionate mortality due to chronic diseases among the capitals which could not be accounted for by the social and environmental factors and by the mortality due to infectious disease.

Genotoxicity biomarkers: application in histopathology laboratories

Most cancers results from man-made and natural environmental exposures (such as tobacco smoke; chemical pollutants in air, water, food, drugs; radon; and infectious agents) acting in concert with both genetic and acquired characteristics. It has been estimated that without these environmental factors, cancer incidence would be dramatically reduced, by as much as 80%-90%. The modulation of environmental factors by host susceptibility was rarely evaluated. However, within the past few years, the interaction between environmental factors and host susceptibility factors has become a very active area of research. Molecular biology as a tool for use in epidemiological studies has significant potential in strengthening the identification of cancers associated with environmental exposures related to lifestyle, occupation, or ambient pollution. In molecular epidemiology, laboratory methods are employed to document the molecular basis and preclinical effects of environmental carcinogenesis. Molecular epidemiology has become a major field of research and considerable progress has been made in validation and application of biomarkers and its greatest contribution has been the insights provided into interindividual variation in human cancer risk and the complex interactions between environmental factors and host susceptibility factors, both inherited and acquired, in the multistage process of carcinogenesis.

Alimentação, composição corporal e cancro da mama

Introdução – A nível mundial, o cancro da mama é o tipo de cancro mais frequente nas mulheres. Estudos têm sugerido que os fatores de estilo de vida (alimentação, consumo de álcool, atividade física) e a adiposidade corporal estão implicados na sua etiologia, sobretudo nos tumores diagnosticados após a menopausa. O objetivo deste artigo foi o de identificar quais os fatores nutricionais e de composição corporal implicados na etiologia da doença e qual a sua relação. Metodologia – Foi realizada uma revisão da literatura referente a estudos de revisão, de coorte e experimentais, de acordo com a temática em estudo. Resultados – As mulheres obesas têm maior risco de desenvolver cancro da mama após a menopausa e a adiposidade corporal, localizada na região abdominal, é também fator de risco. A obesidade, além de fator promotor, relaciona-se inversamente com o prognóstico da doença. Relativamente ao padrão alimentar, a ingestão de ácidos gordos saturados confere risco, ainda que com uma associação fraca e, com uma associação modesta, a dieta mediterrânica parece estar associada a um menor risco de cancro da mama pós-menopausa. Conclusão – A adoção de um estilo de vida saudável (alimentação e atividade física) e a obtenção/manutenção de um peso corporal saudável devem ser encorajados para prevenir o cancro da mama. Mais estudos devem ser realizados no futuro para consolidar a associação com outras variáveis dietéticas. ABSTRACT - Background – Breast cancer is worldwide the most common cancer in women. Studies have suggested that lifestyle such as nutrition, alcohol intake and physical activity are enrolled in aetiology, especially in postmenopausal tumours. This review aimed to investigate the relationship between nutritional factors and body composition with the disease. Methods – A selective review of the literature for recent studies and meta-analyses on this topic. Results – Obese women have higher risk to develop breast cancer after menopause. Abdominal adiposity is also a risk factor. Obesity, beside of promote the disease, is also a negative factor of prognoses. In respect to dietary pattern, the intake of saturated fatty acids seems to attribute risk, even if with a weak association. Although with a modest association, Mediterranean diet may be associated with lower breast cancer risk among postmenopausal women. Conclusion – Adopt a healthy lifestyle (nutrition and physical activity) and maintain a healthy body weight should be encouraged to prevent breast cancer. Future research should focus other dietary variables already investigated but still with no clear evidence.

Exercício físico e cancro da mama: uma revisão

Introdução – Os efeitos fisiológicos da atividade física e do treino são atualmente motivo de extensa investigação cujos resultados mostraram já de forma incontroversa os seus benefícios em diferentes condições clínicas. Diferentes estudos mostraram já os efeitos benéficos do exercício regular de intensidade leve a moderada na diminuição do risco de cancro, bem como na aptidão física de indivíduos portadores de cancro, submetidos ou não a cirurgia. A prescrição do exercício mais adequado para a sua maior eficácia na melhoria da aptidão física e para a diminuição da fadiga não é, no entanto, ainda consensual. O objetivo deste estudo foi o de rever o conhecimento atual sobre os benefícios do exercício físico em sobreviventes de cancro da mama, bem como sistematizar as linhas orientadoras atuais para a prescrição do exercício físico na referida população. Metodologia – Recorreu-se a uma revisão da literatura, tendo como base as palavras-chave: cancro da mama, sobreviventes de cancro da mama, risco de cancro, exercício físico, atividade física e treino, dando preferência a estudos que, na classificação de Oxford, correspondessem aos níveis I (ensaios clínicos randomizados e revisões sistemáticas) e II de evidência científica (ensaios clínicos não randomizados). Conclusão – Embora se reconheça que o exercício físico é benéfico para a população em geral e existam linhas orientadoras para a prescrição do exercício físico em indivíduos com cancro, estas não são ainda absolutamente consensuais, necessitando sempre de individualização no treino. A investigação em torno das questões que envolvem a adequada prescrição do exercício físico em indivíduos com ou em risco de desenvolver cancro é primordial. ABSTRACT - Introduction – Physiological effects of physical activity and training are currently subject of extensive research which has already showed uncontroversial benefits in different clinical conditions. Different studies have already shown the beneficial effects of mild to moderate regular exercise in decreasing cancer risk and increasing physical fitness of individuals suffering from cancer, undergoing surgery or not. However, the appropriate exercise prescription for greater efficacy in improving physical fitness and decreasing fatigue is not yet consensus. The aim of this study was to review current knowledge about the benefits of exercise on breast cancer survivors and systematize the existing guidelines for prescribing exercise in this population. Methodology – A literature review was conducted based on the keywords: breast cancer, breast cancer survivors, cancer risk, physical exercise, physical activity and training, giving preference to studies in the classification of Oxford corresponded to level I (randomized clinical trials and systematic reviews) and II (no randomized clinical trials) scientific evidence. Conclusion – Although it is recognized that exercise is beneficial for general population and that there are guidelines for exercise prescription for individuals with cancer, there is no absolute agreement and they constantly require individual adaptations in training. Research on issues involving the correct prescription of exercise for individuals with or at risk of developing cancer is vital.