RESUMO
AIMS: RAD51 participates in homologous recombination repair (HRR) of double-stranded DNA breaks (DSBs) which may cause genomic instability and cancer. The aim of this study was to investigate RAD51 gene expression at transcriptional and translational levels to measure mRNA and protein level and to correlate its relationship with proliferation marker, Ki67 in thyroid cancer patients. This study also explored correlation of these genes with different clinicopathological parameters of the study cohort by Spearman's rank correlation coefficient. METHODS: Quantitative real time polymerase chain reaction (qRT-PCR) and immunohistochemistry were used to detect mRNA transcript levels and protein expression of RAD51 and Ki67 in 102 cases of thyroid cancer tissues and equal number of uninvolved healthy thyroid tissue controls. RESULTS: Data showed that expression for both RAD51 and Ki67 was significantly increased in thyroid cancer (p<0.001). High RAD51 and Ki67 expression was associated with later stages, poor tissue differentiation, large tumor size, positive lymph node metastasis and distant metastasis. The correlation analysis demonstrated a strong positive correlation (r=0.461) between RAD51 and Ki67 on mRNA level and on protein level (r=0.866). Strong correlation was observed between clinicopathological characteristics and selected molecules. CONCLUSION: The present study concluded that upregulation of RAD51 and overexpression of Ki67 may be associated with the progression of thyroid cancer.
Assuntos
Regulação Neoplásica da Expressão Gênica , Antígeno Ki-67/metabolismo , Rad51 Recombinase/metabolismo , Neoplasias da Glândula Tireoide/genética , Progressão da Doença , Feminino , Marcadores Genéticos , Humanos , Imuno-Histoquímica , Antígeno Ki-67/genética , Metástase Linfática/genética , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Rad51 Recombinase/genética , Regulação para CimaRESUMO
AIMS: Differential attainment (DA) in post graduate medical training is a recognised challenge and refers to unexplained variation across groups when split by several protected characteristics. The Royal College of Radiology is committed to fostering diversity, inclusivity, and equality with the goal of narrowing existing gaps and improving training outcomes. MATERIALS AND METHODS: This was a mixed methods study aiming to understand the causes of DA with view to helping the RCR develop strategies to address this. A cross-sectional survey was completed by 140 clinical oncology trainees in September 2022. Trainees and trainers (17 and 6 respectively) from across England, Scotland, Wales and Northern Ireland, took part in focus group and interviews from August to December 2022. Quantitative and qualitative data merged and interpreted. RESULT: Results showed international medical graduates and trainees from ethnic minority backgrounds were more likely to encounter challenges. The qualitative findings were used to identify three themes through which these problems could be framed. The trainee as a "space invader," the hidden curriculum of clinical oncology training and the process of navigating and tacking the training journey. CONCLUSION: Differential attainment is the product of a complex interplay between the trainee, trainer, and the training environment. Therefore, interventions must be tailored to different people and contexts. At a national level, the RCR can adopt general policies to promote this such as mentorship programmes, protected time for supervision and cultural competency training. Efficacy of proposed interventions for trial and their impact on DA should be evaluated to drive evidence-based changes.
Assuntos
Educação de Pós-Graduação em Medicina , Oncologia , Humanos , Oncologia/educação , Estudos Transversais , Masculino , Feminino , Reino Unido , AdultoRESUMO
The use of 17-beta-oestradiol, testosterone, progesterone, zearanol, trenbolone acetate and melengesterol acetate in animal feed as growth promoters has been banned in the European Union since 1989. However, the data available on their genotoxicity is limited. To bridge this gap the present study was carried out with the aim of evaluating these hormones for their ability to induce aneuploidy. Aneuploidy has been recently considered sufficiently important to be included in the routine testing of chemicals and radiation. These types of numerical chromosomal aberrations may arise by at least two mechanisms, chromosome loss and non-disjunction. Over the past few years, the cytokinesis blocked micronucleus (CBMN) technique has evolved into a robust assay for the detection of aneuploidy induction. At the present time, it is the only assay which can reliably detect both chromosome loss and non-disjunction when the basic methodology is coupled with appropriate molecular probing techniques such as immunoflourescent labelling of kinetochores and Fluorescence in situ Hybridisation. In this present study, aneuploidy induction by three groups of hormones was studied using CBMN assay coupled with Fluorescence in situ Hybridisation. The results from the present study demonstrate that 17-beta-oestradiol, diethylstilboestrol, progesterone and testosterone are genotoxic and induce aneuploidy by non-disjunctional mechanism, whereas trenbolone is also genotoxic by a clastogenic mechanism. However, melengesterol acetate and zearanol proved to be non-genotoxic in vitro.
Assuntos
Androgênios/farmacologia , Citocinese/efeitos dos fármacos , Estrogênios/farmacologia , Progestinas/farmacologia , Aneugênicos/farmacologia , Aneuploidia , Linhagem Celular , Citocinese/genética , Humanos , Testes para Micronúcleos/métodosRESUMO
BACKGROUND: Spleen Tyrosine Kinase (SYK) belongs to non-receptor tyrosine Kinase family, which normally expresses in epithelial breast tissues and acts as a tumor suppressor gene. OBJECTIVE: Analysis of mutations in the SYK gene and deregulation of SYK transcripts by miRNA in breast cancer was studied. METHODS: All exons and exon/intron boundaries of SYK gene were amplified and sequenced in blood samples of 207 breast cancer cases and 200 matched controls using PCR-single stranded conformational polymorphism method. RESULTS: Sequence analysis revealed 10 novel mutations in breast cancer patients. Among these 6 mutations (Ala 161Pro, His162Tyr, Phe191Tyr, Val 535Gly, Ser 556lIe and Lys536Gln) were found in exonic region and 4 (26249 T>A, 63941 G>A, 63981G>C and 86548T>A) were found in intronic region. All of these mutations are associated with â¼ 5 folds (p< 0.0001) increase in breast cancer risk in present study cohort. Regulation of SYK transcripts by miRNA was also analyzed using in silico bioinformatics tools, exon 6's mutation (Phe191Tyr) was found to have altered interaction with miR-873. CONCLUSION: Overall novel mutations in SYK gene and in silico analysis revealed that these mutations are crucial and might be responsible for altered expression of SYK.
Assuntos
Neoplasias da Mama/genética , MicroRNAs/genética , Mutação de Sentido Incorreto/genética , Quinase Syk/genética , Adolescente , Adulto , Idoso , Sequência de Bases , Sítios de Ligação , Feminino , Humanos , Pessoa de Meia-Idade , Polimorfismo Conformacional de Fita Simples/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Adulto JovemRESUMO
Aneuploidy plays a major role in the production of human birth defects and is becoming increasingly recognised as a critical event in the etiology of a wide range of human cancers. Thus, the detection of aneuploidy and the characterisation of the mechanisms which lead to chromosome malsegregation is an important area of genotoxicological research. As an aid to aneuploidy research, methods have been developed to analyse the mechanisms of chromosome malsegregation and to investigate the role of aneuploidy in tumour progression. The presence of aneuploid cells is a common characteristic of many of tumour cell types as illustrated by the wide range of chromosome number changes detected in post-menopausal breast tumours. To investigate the time of occurrence of aneuploidy during tumour progression, we have studied the chromosome number status of Syrian hamster dermal (SHD) cells cultures progressing to morphological transformation. The production of both polyploid and aneuploid cells is a common feature of progressing cells in this model. The elevation of both progression to morphological transformation and aneuploid frequencies can be produced by exposure to a diverse range of carcinogens and tumour promoters. Analysis of the genotoxic activity of the hormone 17-beta oestradiol demonstrated its ability to induce both chromosome loss and non-disjunction in human lymphoblastoid cells implicating aneugenic activity in hormone related cancers. Mutations in the p53 tumour suppressor gene introduced into human fibroblasts produced modifications in chromosome separation at mitosis which may lead to the production of both aneuploidy and polyploid cells. Our studies indicate that the production of aneuploid cells can be influenced by both endogenous and exogenous factors and occur throughout the progression of normal cells to a malignant phenotype.
Assuntos
Aneuploidia , Segregação de Cromossomos/genética , Alquilantes/farmacologia , Animais , Animais Recém-Nascidos , Linhagem Celular Transformada , Células Cultivadas , Segregação de Cromossomos/efeitos dos fármacos , Cricetinae , Relação Dose-Resposta a Droga , Estradiol/farmacologia , Feminino , Genoma Humano , Humanos , Mesocricetus , Testes para Micronúcleos , Mutação , Hibridização de Ácido Nucleico/métodos , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologiaRESUMO
The activity of Rb proteins is controlled by post-translational modifications, especially through phosphorylation. Acetylation of Rb2/p130 was reported recently in NIH3T3 cells but its physiological relevance in cell cycle control and tumorigenesis is still unknown. Efforts are underway to investigate possible interplay between Rb2/p130 phosphorylation and acetylation. Here we hypothesized that Rb2/p130 acetylation, like p53 acetylation, may play a role in development of the tumor phenotype. The proposed hypothesis regarding acetylation of Rb2/p130 in tumor VS normal cells was found to be true in our case study of 36 tumor samples. Statistical analysis of results suggest strong correlation among Rb2/p130 acetylation and cancer phenotype.
Assuntos
Processamento de Proteína Pós-Traducional , Proteína p130 Retinoblastoma-Like/metabolismo , Retinoblastoma/metabolismo , Retinoblastoma/patologia , Acetilação , Estudos de Casos e Controles , Seguimentos , Humanos , Imunoprecipitação , Gradação de Tumores , PrognósticoRESUMO
Glutathione S-transferases constitute the phase II detoxification enzymes involved in the metabolism and detoxification of a wide range of potential environmental carcinogens. GSTM1 and GSTT1 are polymorphic and their deletions have been found to be associated with breast cancer risk in some of the world populations. The current study was aimed at evaluation of GSTM1 and GSTT1 gene deletions in 150 unrelated breast cancer patients and 150 healthy controls from Pakistani population. Multiplex PCR assay along with CYP1A1 exon 7 as an internal control was used. Our sampled patients and controls had a mean age of 48 (+11.8) and 45 (+7.9) years respectively. The analysis suggested that only 2% breast cancer patient and 8% controls had homozygous GSTM1 gene deletions (OR 0.23, 95% CI 0.06-0.85). A total of 8.7% patients and 18.6% controls had homozygous GSTT1 deletion (OR 0.41, 95% CI 0.25-0.83). The statistical analysis suggest that a non significant number (P>0.05) of individuals compared to controls have GSTM1 and GSTT1 gene deletions. Deletion in both genes was not observed in any of the patients or controls. The present case control study suggests no association of GSTM1 and GSTT1 gene deletions with sporadic form of breast cancer in Pakistani population.
Assuntos
Neoplasias da Mama/genética , Glutationa Transferase/genética , Adulto , Neoplasias da Mama/enzimologia , Estudos de Casos e Controles , Citocromo P-450 CYP1A1/genética , Feminino , Deleção de Genes , Predisposição Genética para Doença , Genótipo , Homozigoto , Humanos , Pessoa de Meia-Idade , PaquistãoRESUMO
BACKGROUND: Head and neck cancer is included among the top five most commonly prevailing cancers worldwide. Abnormalities of either genetic or epigenetic factors are found responsible for the development and progression of head and neck cancer. Metastasis is the leading cause of death in patients with head and neck cancer. Down regulation of metastasis suppressor genes (MSGs) expression have been frequently observed in advanced tumours. METHODOLOGY: The present study was designed to screen two of the most frequently down-regulated MSGs (KISS1 and KAI1) for mutations in 120 diagnosed head and neck cancer affected Pakistani patients. The questionnaire was filled for basic information about age, gender, smoking habits and area of cancer affected and other relevant details. Primers for both genes were designed using "Primer 3" software in such a way that both intron exon boundaries were included in this region. DNA isolation and estimation was done by using organic method and agarose gel electrophoresis. Single Strand conformational polymorphism technique was used after amplification of the respective genes. Mobility patterns were analyzed using BioDoc Analyzer. RESULTS: Data of patients were analyzed on the basis of age, sex and type of cancer as variables. The mean age of patients and controls was 44 years. There were 53% females and 47% males in this group of study, 63% nonsmokers and 37% smokers and larynx cancer was found to be most frequent type of cancer with a percentage of 64. Lack of germ line mutation was observed in the entire coding region in both coding regions as well as splice sites of the respective genes. CONCLUSION: Germ line mutations in KISS1 and KAI1 are thus considered to be a less frequent event in head and neck cancer patients. However, two polymorphisms in intronic region of exon 3 and exon 9 of KAI1 gene were observed in 1% of patients. In non coding region downstream of exon 3 (KAI1), there was a C 29166 T substitution and in intronic region upstream exon 9 of KAI1 gene, a C 52840 A substitution was observed. Both patients were females with ages 47 and 50 years respectively. A detailed analysis of regulatory mechanism is required to explore the genetic basis of down regulation of these MSGs for a better understanding of head and neck cancer progression.
Assuntos
Genes Supressores de Tumor , Mutação em Linhagem Germinativa , Neoplasias de Cabeça e Pescoço/genética , Proteína Kangai-1/genética , Kisspeptinas/genética , Adolescente , Adulto , Sequência de Bases , Criança , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Paquistão , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: Metastasis suppressor genes are involved in the inhibition of a cancer cell's ability to metastasize. Down expression of such genes may contribute to pathogenesis of breast cancer. The aim of current study was firstly to evaluate expression of two examples, KAI1 and KISS1, and then to determine relationships with stages of breast cancer in a Pakistani population. METHODOLOGY: Fresh biopsy tissues were collected from different hospitals and oncology research institutes. The semi quantitative reverse transcriptase polymerase chain reaction was used to investigate KAI1 and KISS1 expression in 25 breast tumor tissues and 25 normal tissues. Statistical analysis was performed to explore its association with breast cancer risk. RESULTS: The present study revealed that KAI1 and KISS1 mRNA expression was markedly reduced in tissues of breast cancer compared to adjacent normal tissue. In present study a splice variant of KAI1 during a screen for its expression analysis was also observed. This splice variant has not been reported previously. CONCLUSIONS: Metastasis suppressor genes demonstrate reduced expression in breast cancers in Pakistan.
Assuntos
Neoplasias da Mama/genética , Proteína Kangai-1/genética , Kisspeptinas/genética , Sequência de Bases , Biópsia , Regulação para Baixo , Feminino , Genes Supressores de Tumor , Humanos , Dados de Sequência Molecular , Paquistão , Isoformas de Proteínas/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNARESUMO
Ability of ethanol to produce chromosomal changes has been controversial in past many years; nevertheless many recent studies have shown that ethanol itself produces genotoxic effects like acetaldehyde. This study was carried out to evaluate the ability of ethanol and its metabolite acetaldehyde to induce chromosomal changes using in vitro CBMN assay (Cytokinesis Blocked Micronucleus assay) in conjunction with immunofluorescent labeling of kinetochores. Kinetochore staining was used with a view to differentiate, between the genotoxic effects of both chemicals, and ascertain the mechanisms of genotoxicity induction by ethanol and acetaldehyde. Both ethanol and acetaldehyde produced statistically significant (P<0.05) dose dependent increase in MN induction as compared with the controls over the dose range tested. Kinetochore analysis proved that the MN induced in ethanol were originated by an aneugenic mechanism, whereas in the case of acetaldehyde most of the MN had originated by a clastogenic mechanism. This not only confirms the ability of ethanol to produce DNA damage in vitro but it also establishes the efficacy of CBMN assay to detect and differentiate between the genotoxic effects of different genotoxins. Here we report that ethanol is itself genotoxic, at least in vitro, and produces genotoxic effects mainly through an aneugenic mechanism whereas its metabolite acetaldehyde is a clastogen.
Assuntos
Acetaldeído/toxicidade , Depressores do Sistema Nervoso Central/toxicidade , Etanol/toxicidade , Mutagênicos , Aneuploidia , Apoptose/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Aberrações Cromossômicas/efeitos dos fármacos , Indicadores e Reagentes , Cinetocoros/metabolismo , Testes para Micronúcleos , Testes de Mutagenicidade , Necrose/patologiaRESUMO
Polymorphic deletions of GSTM1 and GSTT1 genes involved in the detoxification of potentially carcinogenic agents may be risk factors for various cancers, including head and neck cancer (HNC). In the present case-control study we aimed to access possible associations of HNC with GSTM1 and GSTT1 null genotypes in a Pakistani population. DNA was extracted from leukocytes of 388 cancer patients and 150 healthy controls by phenol-chloroform procedure. GSTM1 and GSTT1 deletion variants were genotyped by multiplex PCR assay with CYP1A1 as an internal control and further analyzed by primer specific PCR assay and sequencing. Mean age of cases and controls was 48 (±16.6) years with a male to female ratio of 1:1. Cancer of the oral cavity (57%) was most prevalent in the sampled population followed by pharynx and larynx (30% and 13% respectively). A statistically significant (P<0.05) association was observed for both null genotypes in contribution to HNC as compared with the controls. The odds ratio (OR) for the GSTM1 null genotype was 2.3 with a 95% CI of 1.5-5.5 and for GSTT1 OR was 2.04 with 95% CI of 1.3-3.1. These results suggest that the GSTM1 and GSTT1 null genotypes are risk factors for HNC development among the Pakistani population.
Assuntos
Deleção de Genes , Glutationa Transferase/genética , Neoplasias Laríngeas/genética , Neoplasias Bucais/genética , Neoplasias Faríngeas/genética , Adulto , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Neoplasias Laríngeas/etiologia , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/etiologia , Razão de Chances , Paquistão , Neoplasias Faríngeas/etiologiaRESUMO
PIP: Data on children ever born from surveys conducted between 1984 and 1988 provide evidence for fertility decline in Pakistan and little evidence for a "zig zag" pattern of variations in the levels of the birth rate reported in surveys conducted between 1962 and 1988. This study is concerned with the indirect estimation of the crude birth rate (CBR). Input data is available on age specific mortality and the age distribution of the population. CBR was calculated on the basis of the life table method. The estimation of CBR from 1962-65 to 1979 revealed a declining trend, which also appeared in estimations based on survey data after 1979. Estimation of CBR based on infant and child mortality risks showed declining trends through 1979, a slight elevation in infant mortality in 1984, and then decline followed by a higher increase in 1988. The increased risk of infant mortality was interpreted as an artifact of the data. Further analysis of the correlation between infant and child mortality risks in the ordinary least squares equations indicated that 50% of the variation in infant mortality risk was explained by child mortality risk variation between 1962 and 1979. The adjusted values were then used to estimate mortality between 1984 and 1988, which indicated similar values (91/1000 births) as the 1990-91 survey data. In the ordinary least squares examination of the association between child mortality risks and the estimates of crude birth rates between 1962 and 1979, the finding was that 70% of the variation in the values of CBR were explained by variations in child mortality risks. The indirect estimation for 1984 to 1988 however showed elevated CBR, which was construed to be due to increased infant mortality risks, which may be in error. When CBR was estimated using the proportions in the population aged 0-4 years and mortality risk, the life table estimates showed a reduced rate by 3.3 for 1984 and by 1.1 for 1988, and with other substitutions, lower CBR. The conclusion from the exploration of different methods of calculating was that CBR may be even lower that 37/1000, and the rate of natural increase may be lower than 2.7%.^ieng
Assuntos
Coeficiente de Natalidade , Tábuas de Vida , Projetos de Pesquisa , Estatística como Assunto , Ásia , Demografia , Países em Desenvolvimento , Fertilidade , Paquistão , População , Dinâmica Populacional , PesquisaRESUMO
A comprehensive evaluation of the genotoxic potential of chemicals requires the assessment of the ability to induce gene mutations and structural chromosome (clastogenic activity) and numerical chromosome (aneugenic activity) aberrations. Aneuploidy is a major cause of human reproductive failure and an important contributor to cancer and it is therefore important that any increase in its frequency due to chemical exposures should be recognized and controlled. The in vitro binucleate cell micronucleus assay provides a powerful tool to determine the ability of a chemical to induce chromosome damage. The application of an anti-kinetochore antibody to micronuclei allows their classification into kinetochore-positive and kinetochore-negative, indicating their origin by aneugenic or clastogenic mechanisms, respectively. The availability of chromosome-specific centromere probes allows the analysis of the segregation of chromosomes into the daughter nuclei of binucleate cells to evaluate chromosome non-disjunction. Quantitative relationships between the two major causes of aneuploidy, chromosome loss and non-disjunction, can be determined. The mechanisms leading to chromosome loss and non-disjunction can be investigated by the analysis of morphological and structural changes in the cell division apparatus by the application of specific stains and antibodies for various cell division components. We illustrate such analyses by the demonstration of the interaction of the monomer bisphenol-A with the centrosome of the mitotic spindle and the folic acid antagonist pyrimethamine with the centromeres of chromosomes. Both types of modifications lead to the induction of aneuploidy in exposed cells. Our studies also implicate the products of the p53 and XPD genes in the regulation of the fidelity of chromosome segregation at mitosis.