The Fragile Histidine Triad Gene: A Molecular Link Between Cigarette Smoking and Cervical Cancer

Modelling metastatic colonization of cholangiocarcinoma organoids in decellularized lung and lymph nodes

Cholangiocarcinoma (CCA) is a type of liver cancer with an aggressive phenotype and dismal outcome in patients. The metastasis of CCA cancer cells to distant organs, commonly lung and lymph nodes, drastically reduces overall survival. However, mechanistic insight how CCA invades these metastatic sites is still lacking. This is partly because currently available models fail to mimic the complexity of tissue-specific environments for metastatic CCA. To create an in vitro model in which interactions between epithelial tumor cells and their surrounding extracellular matrix (ECM) can be studied in a metastatic setting, we combined patient-derived CCA organoids (CCAOs) (n=3) with decellularized human lung (n=3) and decellularized human lymph node (n=13). Decellularization resulted in removal of cells while preserving ECM structure and retaining important characteristics of the tissue origin. Proteomic analyses showed a tissue-specific ECM protein signature reflecting tissue functioning aspects. The macro and micro-scale mechanical properties, as determined by rheology and micro-indentation, revealed the local heterogeneity of the ECM. When growing CCAOs in decellularized lung and lymph nodes genes related to metastatic processes, including epithelial-to-mesenchymal transition and cancer stem cell plasticity, were significantly influenced by the ECM in an organ-specific manner. Furthermore, CCAOs exhibit significant differences in migration and proliferation dynamics dependent on the original patient tumor and donor of the target organ. In conclusion, CCA metastatic outgrowth is dictated both by the tumor itself as well as by the ECM of the target organ. Convergence of CCAOs with the ECM of its metastatic organs provide a new platform for mechanistic study of cancer metastasis.

Stop smoking advice by practice assistants after routine cervical screening in general practice: A qualitative exploration of potential barriers and enablers

Background

Cervical screening could be an appropriate routine moment to provide female smokers with tailored stop smoking advice. In Dutch general practice, cervical smears are performed by practice assistants.

Objectives

This study was performed in preparation for a randomised trial to identify potential barriers and enablers for a brief stop smoking strategy performed by trained practice assistants after routine cervical screening.

Methods

Between December 2016 and March 2017 three focus group meetings were held with ten practice assistants, three nurses, and six general practitioners to explore their views and expectations towards the proposed approach. We analysed data using thematic analysis. Identified factors are presented within the framework of the Social-Ecological Model.

Results

Potential barriers and enablers were identified at individual, interpersonal, and workplace levels. Practice assistants, nurses and GPs did not consider assistants to have a role in stop smoking care. They believed it is feasible to register smoking status but had reservations towards providing advice by assistants, for which knowledge and skills are needed. Practice assistants’ own beliefs about smokers and smokers’ response to stop smoking advice might influence how assistants and smokers interact. An explanation of why advice is given could help, provided assistants have enough time and experience with the smear. The nurses’ availability and general practitioners’ view on prevention might affect the delivery of the strategy by the assistant.

Conclusion

At individual, interpersonal, and workplace levels, several factors could influence the provision of a stop smoking strategy by a practice assistant.

Smoking cessation strategy in the national cervical cancer screening program (SUCCESS): study protocol for a pragmatic cluster randomised trial and process evaluation in Dutch general practice

INTRODUCTION

Cervical cancer screening in general practice could be a routine moment to provide female smokers with stop smoking advice and support. The aim of this study is to assess the effect of a stop smoking strategy delivered by trained practice assistants after the cervical smear, and to evaluate the implementation process.

METHODS AND ANALYSIS

The study is a two-arm, pragmatic cluster randomised trial, in Dutch general practice. Randomisation takes place 1:1 at the level of the general practice. Practices either deliver the SUCCESS stop smoking strategy or the usual care condition. The strategy consists of brief stop smoking advice based on the Ask-Advise-Connect method and is conducted by trained practice assistants after routine cervical cancer screening. The primary outcome is the performance of a serious quit attempt in the 6 months after screening. Secondary outcomes are 7-day point prevalence abstinence, reduction in the number of cigarettes per day and transition in motivation to quit smoking. Follow-up for these measurements takes place after 6 months. Analysis on the primary outcome aims to detect a 10% difference between treatment arms (0.80 power, p=0.05, using a one-sided test), and will be performed according to the intention to treat principle. The process evaluation will assess feasibility, acceptability and barriers or enablers to the strategy's implementation. For this purpose, both qualitative and quantitative data will be collected via questionnaires and in-depth interviews, respectively, in both individual study participants and involved staff.

ETHICS AND DISSEMINATION

The Dutch Ministry of Health, Welfare and Sport approved of the trial after an advisory report from the Health Council (Nr. 2018/17). A licence was provided to conduct the study under the Population Screening Act. Study results will be disseminated through publications in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NL5052 (NTR7451).

Smoking cessation advice after cervical screening: a qualitative interview study of acceptability in Dutch primary care

BACKGROUND

Cervical cancer screening in general practice could be a routine and opportune moment to advise females who smoke to stop smoking.

AIM

The aims of this study were to investigate the attitudes of females who smoke to receiving advice about stopping smoking after cervical screening and to identify factors associated with the acceptability of this advice.

DESIGN AND SETTING

This qualitative interview study was conducted with Dutch females who smoked, had undergone cervical screening, and were aged 30 to 60 years. Interviews were performed between December 2016 and September 2017.

METHOD

In this study 15 participants were interviewed and transcripts were analysed using thematic analysis.

RESULTS

Females who smoke were ambivalent (positive or sceptical) about being advised to stop smoking after they had undergone cervical screening. An explanation of why smoking behaviour is addressed by the practice assistant performing the smear, and making females feel at ease during the smear test, were found to be factors that might influence acceptability of such advice. Although a personal and non-judgemental approach to discussing smoking was considered essential, participants expressed different preferences regarding the form and content of cessation support. This was reflected by the variations in knowledge about smoking cessation support, previous experiences of cessation attempts, and received cessation advice or support.

CONCLUSION

Study participants had mixed opinions about being given advice about smoking cessation after their cervical smear test and differed in their preferences for the type of support for smoking cessation. An interactive approach might improve how well a smoking cessation intervention is received by females who smoke and cater to their individual needs and preferences.

Disturbance of Bcl-2, Bax, Caspase-3, Ki-67 and C-myc expression in acute and subchronic exposure to benzo(a)pyrene in cervix

Epidemiological studies have demonstrated that cigarette smoking is an important cofactor or an independent risk factor for the development of cervical cancer. Benzo(a)pyrene (BaP) is one of the most potent tobacco smoke carcinogens in tobacco smoke. BaP induced DNA damage and over expression in p53 cervical tissue of mice as demonstrated in our previous study. Here we present the findings of exposure to BaP on the expression of Bcl-2, C-myc, Ki-67, Caspase-3 and Bax genes in mouse cervix. Acute intraperitoneal administration of BaP (12.5, 25, 50, 100mg/kg body weight) to ICR female mice induced a significant increase in Bcl-2, C-myc, Ki-67 mRNA and protein level till 72h except in Bcl-2 at 24h with 12.5, 25, 50mg/kg as well as at 48h with 12.5mg/kg body weight post treatment. A significant increase was also seen in Caspase-3 and Bax mRNA and protein level with peak level at 24h and gradual decrease till 72h, however, the expression of caspase-3 increased while that of Bax decreased with increasing dose of Bap after 24h. In sub chronic intraperitoneal and oral gavage administration of BaP (2.5, 5, 10mg/kg body weight), similar significant increase was observed for all the examined genes as compared to the control and vehicle groups, however the expression of Bax decreased in a dose dependent manner. The findings of this study will help in further understanding the molecular mechanism of BaP induced carcinogenesis of cervical cancer.

A knockdown with smoke model reveals FHIT as a repressor of Heme oxygenase 1

Fragile histidine triad (FHIT) gene deletions are among the earliest and most frequent events in carcinogenesis, particularly in carcinogen-exposed tissues. Though FHIT has been established as an authentic tumor suppressor, the mechanism underlying tumor suppression remains opaque. Most experiments designed to clarify FHIT function have analyzed the consequence of re-expressing FHIT in FHIT-negative cells. However, carcinogenesis occurs in cells that transition from FHIT-positive to FHIT-negative. To better understand cancer development, we induced FHIT loss in human bronchial epithelial cells with RNA interference. Because FHIT is a demonstrated target of carcinogens in cigarette smoke, we combined FHIT silencing with cigarette smoke extract (CSE) exposure and measured gene expression consequences by RNA microarray. The data indicate that FHIT loss enhances the expression of a set of oxidative stress response genes after exposure to CSE, including the cytoprotective enzyme heme oxygenase 1 (HMOX1) at the RNA and protein levels. Data are consistent with a mechanism in which Fhit protein is required for accumulation of the transcriptional repressor of HMOX1, Bach1 protein. We posit that by allowing superinduction of oxidative stress response genes, loss of FHIT creates a survival advantage that promotes carcinogenesis.

WWOX, large common fragile site genes, and cancer

WWOX is a gene that spans an extremely large chromosomal region. It is derived from within chromosomal band 16q23.2 which is a region with frequent deletions and other alterations in a variety of different cancers. This chromosomal band also contains the FRA16D common fragile site (CFS). CFSs are chromosomal regions found in all individuals which are highly unstable. WWOX has also been demonstrated to function as a tumor suppressor that is involved in the development of many cancers. Two other highly unstable CFSs, FRA3B (3p14.2) and FRA6E (6q26), also span extremely large genes, FHIT and PARK2, respectively, and these two genes are also found to be important tumor suppressors. There are a number of interesting similarities between these three large CFS genes. In spite of the fact that they are derived from some of the most unstable chromosomal regions in the genome, they are found to be highly evolutionarily conserved and the chromosomal region spanning the mouse homologs of both WWOX and FHIT are also CFSs in mice. Many of the other CFSs also span extremely large genes and many of these are very attractive tumor suppressor candidates. WWOX is therefore a member of a very interesting family of very large CFS genes.

Very large common fragile site genes and their potential role in cancer development

Common fragile sites (CFSs) are large chromosomal regions that are hot-spots for alterations especially within cancer cells. The three most frequently expressed CFS regions (FRA3B, FRA16D and FRA6E) contain genes that span extremely large genomic regions (FHIT, WWOX and PARK2, respectively), and these genes were found to function as important tumor suppressors. Many other CFS regions contain extremely large genes that are also targets of alterations in multiple cancers, but none have yet been demonstrated to function as tumor suppressors. The loss of expression of just FHIT or WWOX has been found to be associated with a worse overall clinical outcome. Studies in different cancers have revealed that some cancers have decreased expression of multiple large CFS genes. This loss of expression could have a profound phenotypic effect on these cells. In this review, we will summarize the known large common fragile site genes and discuss their potential relationship to cancer development.

Molecular profiling of cervical neoplasia

Cervical cancer, a potentially preventable disease, remains the second most common malignancy in women worldwide. Human papillomavirus is the single most important etiological agent in cervical cancer, contributing to neoplastic progression through the action of viral oncoproteins, mainly E6 and E7, which interfere with critical cell cycle pathways, p53 and retinoblastoma. However, evidence suggests that human papillomavirus infection alone is insufficient to induce malignant changes and that other host genetic variations are important in the development of cervical cancer. This article will discuss the latest molecular profiling techniques available and review the published literature relating to their role in the diagnosis and management of cervical dysplasia and cancer. It is hoped that these techniques will allow the detection of novel biomarkers at DNA, RNA, microRNA and protein levels, which may ultimately play a role in facilitating early disease diagnosis and in predicting response to therapies, thus allowing the development of personalized treatment strategies.

Multiple Patterns of FHIT Gene Homozygous Deletion in Egyptian Breast Cancer Patients

Fragile histidine triad (FHIT) gene encodes a putative tumour suppressor protein. Loss of Fhit protein in cancer is attributed to different genetic alterations that affect the FHIT gene structure. In this study, we investigated the pattern of homozygous deletion that target the FHIT gene exons 3 to 9 genomic structure in Egyptian breast cancer patients. We have found that 65% (40 out of 62) of the cases exhibited homozygous deletion in at least one FHIT exon. The incidence of homozygous deletion was not associated with patients' clinicopathological parameters including patients' age, tumour grade, tumour type, and lymph node involvement. Using correlation analysis, we have observed a strong correlation between homozygous deletions of exon 3 and exon 4 (P < 0.0001). Deletions in exon 5 were positively correlated with deletions in exon 7 (P < 0.0001), Exon 8 (P < 0.027), and exon 9 (P = 0.04). Additionally, a strong correlation was observed between exons 8 and exon 9 (P < 0.0001).We conclude that FHIT gene exons are homozygously deleted at high frequency in Egyptian women population diagnosed with breast cancer. Three different patterns of homozygous deletion were observed in this population indicating different mechanisms of targeting FHIT gene genomic structure.

A common carcinogen benzo[a]pyrene causes p53 overexpression in mouse cervix via DNA damage

Benzo[a]pyrene (BaP) is cytotoxic and/or genotoxic to lung, stomach and skin tissue in the body. However, the effect of BaP on cervical tissue remains unclear. The present study detected DNA damage and the expression of the p53 gene in BaP-induced cervical tissue in female mice. Animals were intraperitoneally injected and orally gavaged with BaP at the doses of 2.5, 5, and 10mg/kg twice a week for 14 weeks. The single-cell gel electrophoresis (SCGE) assay was used to detect the DNA damage. Immunohistochemistry (IHC) and in situ hybridization (ISH) were used to detect the expression of p53 protein and p53 mRNA, respectively. The results showed that BaP induced a significant and dose-dependent increase of the number of cells with DNA damaged and the tail length as well as Comet tail moment in cervical tissue. The expression level of p53 protein and mRNA was increased. The results demonstrate that BaP may show toxic effect on the cervix by increasing DNA damage and the expression of the p53 gene.

Overcoming Barriers to Cervical Cancer Screening Among Asian American Women

Significant disparities in cervical cancer incidence and mortality exist among ethnic minority women, and in particular, among Asian American women. These disparities have been attributed primarily to differences in screening rates across ethnic/racial groups. Asian American women have one of the lowest rates of screening compared to other ethnic/racial groups. Yet Asian Americans, who comprise one of the fastest growing populations in the United States, have received the least attention in cancer control research. Studies suggest that various factors, including lack of knowledge, psychosocial and cultural beliefs, and access barriers, are associated with cervical cancer screening behaviors among Asian American women. Indeed, the few interventions that have been developed for Asian American women demonstrate that targeting these factors can yield significant increases in screening rates. It is important to note, however, that the effectiveness of educational interventions is often attenuated if access barriers are not adequately addressed. Hence, interventions that include key essential components, such as the use of community individuals as lay health workers, culturally-tailored and linguistically-appropriate educational materials, and navigation assistance to overcome access barriers, are more likely to be successful in enhancing screening rates. As the benefits of community-based cervical cancer prevention programs become more apparent, it will be essential to identify effective approaches for disseminating such programs more broadly. In conclusion, community-based cervical cancer screening programs have demonstrated promise in addressing existing cervical cancer disparities by increasing awareness and knowledge and promoting recommended screening behaviors. These findings will be instrumental in guiding future community-based programs to reduce cervical cancer health disparities among Asian American women.

Tissue tumor marker expression in smokers, including serum cotinine concentrations, in women with cervical intraepithelial neoplasia or normal squamous cervical epithelium

OBJECTIVE

The purpose of this study was to investigate correlations between smoking and serum cotinine, respectively, and tumor marker expression in cervical intraepithelial neoplasia (CIN) and normal epithelium.

STUDY DESIGN

Women (n = 228) with cervical biopsy specimens that ranged histologically from normal to carcinoma in situ (CIN III) were included. Expression of 11 tumor markers with possible relevance in cervical neoplasms was studied. Smoking habits were recorded, and serum was assessed for cotinine concentrations.

RESULTS

No differences were found in tumor marker expression in normal epithelium between smokers and nonsmokers. The tumor suppressors p53 and fragile histidine triad and the immunologic marker interleukin-10 were underexpressed, and the tumor markers cyclooxygenase-2 and Ki-67 were overexpressed in smoking, compared with nonsmoking, women with CIN and particularly in all fertile women.

CONCLUSION

The molecular pattern indicates that smoking exerts unfavorable effects in cervical neoplasia. This provides biologic evidence of smoking being a true cofactor in cervical neoplasia.

Fragile histidine triad protein: structure, function, and its association with tumorogenesis

BACKGROUND

The human fragile histidine triad (FHIT) gene is a putative tumor suppressor gene, which is located at chromosome region 3p14.2. It was suggested that the loss of heterozygosity (LOH), homozygous deletions, and abnormal expression of the FHIT gene were involved in several types of human malignancies.

MATERIALS AND METHODS

To determine the role of FHIT in various cancers, we have performed structural and functional analysis of FHIT in detail.

RESULTS AND DISCUSSION

The protein FHIT catalyzes the Mg(2+) dependent hydrolysis of P1-5 cent-O-adenosine-P3-5 cent-O-adenosine triphosphate, Ap3A, to AMP, and ADP. The reaction is thought to follow a two-step mechanism. Histidine triad proteins, named for a motif related to the sequence H-cent-H-cent-H-cent-cent- (cent, a hydrophobic amino acid), belong to superfamily of nucleotide hydrolases and transferases. This enzyme acts on the R-phosphate of ribonucleotides, and contain a approximately 30-kDa domain that is typically a homodimer of approximately 15 kDa polypeptides with catalytic site.

CONCLUSION

Here we have gathered information is known about biological activities of FHIT, the structural and biochemical bases for their functions. Our approach may provide a comparative framework for further investigation of FHIT.

Inequalities in the incidence of cervical cancer in South East England 2001-2005: an investigation of population risk factors

BACKGROUND

The incidence of cervical cancer varies dramatically, both globally and within individual countries. The age-standardised incidence of cervical cancer was compared across primary care trusts (PCTs) in South East England, taking into account the prevalence of known behavioural risk factors, screening coverage and the deprivation of the area.

METHODS

Data on 2,231 cases diagnosed between 2001 and 2005 were extracted from the Thames Cancer Registry, and data on risk factors and screening coverage were collated from publicly available sources. Age-standardised incidence rates were calculated for each PCT using cases of squamous cell carcinoma in the screening age group (25-64 years).

RESULTS

The age-standardised incidence rate for cervical cancer in South East England was 6.7 per 100,000 population (European standard) but varied 3.1 fold between individual PCTs. Correlations between the age-standardised incidence rate and smoking prevalence, teenage conception rates, and deprivation were highly significant at the PCT level (p < 0.001). However, screening coverage was not associated with the incidence of cervical cancer at the PCT level. Poisson regression indicated that these variables were all highly correlated and could not determine the level of independent contribution at a population level.

CONCLUSION

There is excess disease burden within South East England. Significant public health gains can be made by reducing exposure to known risk factors at a population level.

Gene discovery in cervical cancer : towards diagnostic and therapeutic biomarkers

Cervical cancer is a potentially preventable disease; however, it remains the second most common malignancy in women worldwide. The human papillomavirus (HPV) is the single most important etiological agent in cervical cancer. HPV contributes to neoplastic progression through the action of two viral oncoproteins E6 and E7, which interfere with critical cell cycle pathways, tumor protein p53, and retinoblastoma protein. However, evidence suggests that HPV infection alone is insufficient to induce malignant changes, and other host genetic variations are important in the development of cervical cancer. Advances in molecular biology and high throughput technologies have heralded a new era in biomarker discovery and identification of molecular targets related to carcinogenesis. These advancements have improved our understanding of carcinogenesis and will facilitate screening, early detection, management, and personalized targeted therapy. A number of these developments and molecular targets associated with cervical cancer will be addressed in this review.

3p microsatellite signature in exhaled breath condensate and tumor tissue of patients with lung cancer

RATIONALE

Our group has recently demonstrated the possibility of studying microsatellite alterations (MAs) of 3p in the DNA of exhaled breath condensate (EBC) of patients with non-small cell lung cancer (NSCLC).

OBJECTIVES

To verify whether MAs analyzed in DNA from EBC reflect a profile of alterations present in tumor tissue of NSCLC.

METHODS

Fifty-nine subjects undergoing histologic diagnosis for clinical suspicion of lung cancer entered the study: 41 were found to have NSCLC and 18 to have nonneoplastic diseases. All subjects underwent allelotyping on DNA from whole blood, EBC, and lung tissue removed for histologic diagnosis by analyzing a panel of five microsatellites located in chromosomal region 3p. Results obtained from DNA of the three biological sites and nonneoplastic tissues from controls were compared.

MEASUREMENTS AND MAIN RESULTS

MAs in DNA from tumor tissues and EBC of each patient with cancer presented an overlapping profile of loss of heterozygosity and microsatellite instability. An MA profile of DNA of lung tissue reflecting the DNA of EBC profile from controls was also confirmed. Smoking status was associated with the presence of MAs in patients with NSCLC and in control subjects.

CONCLUSIONS

We demonstrated that MAs in DNA from EBC of patients with NSCLC are significantly more frequent than in control subjects. More interesting, the MA profile of DNA from EBC corresponds to that from lung cancer tissue of each patient with NSCLC.

The association of p16(INK4A) and fragile histidine triad gene expression and cervical lesions

OBJECTIVE

This cross-sectional study was intended to assess the association between immunohistochemical analysis of p16 and fragile histidine triad (FHIT) and the presence of precancerous cervical lesions.

MATERIALS AND METHODS

Women seen at Pérola Byington Hospital, São Paulo, Brazil, with histologically confirmed cervicitis (n = 31), cervical intraepithelial neoplasia (CIN) 1 (n = 30), CIN 2,3 (n = 30), and cervical cancer (n = 7) had also cervical material collected for liquid-based cytology, human papillomavirus Hybrid Capture 2 (HC2) test, and p16 and FHIT immunohistochemical reactions.

RESULTS

p16 and FHIT reactions were scored as the following: <1%, 1% to 5%, >5% to 25%, and >25%. Receiver operating curve analysis was used to select p16 and FHIT score cutoffs for further categorical analyses. All but one of the 37 CIN 2,3/cancer cases had a p16 score of greater than 1% to 5%. Among the 61 cervicitis/CIN 1 cases, 46 (75%) had a p16 score lower than 1% to 5%. In contrast, no association of FHIT expression and severity of cervical lesions could be demonstrated in this data set. Receiver operating curve analyses suggested the score of 1% to 5% for p16 as the cutoff that best discriminates CIN 2,3/cancer from cervicitis/CIN 1. No cutoff for FHIT scores could be suggested with data set.

CONCLUSIONS

p16, but not FHIT expression, has the potential to be used as complementary diagnostic tool to investigate human papillomavirus-induced cervical lesions, if these results are confirmed in larger studies.

Fragile Histidine Triad Expression in Oral Squamous Cell Carcinoma and Precursor Lesions

PURPOSE

Fragile histidine triad (FHIT) expression in precursor oral lesions (POL) and oral squamous cell carcinomas (OSCC) was studied with regard to (a) the frequency of loss of FHIT expression, (b) whether loss of FHIT expression correlates with degree of dysplasia in POLs, (c) whether FHIT loss predicts high-risk POLs that are more likely to transform, and (d) whether FHIT loss in OSCCs correlates with survival.

EXPERIMENTAL DESIGN

Ninety-four POLs and 86 OSCCs were immunostained for FHIT. Survival analysis was done for cases with validated clinical outcomes.

RESULTS

By optimizing the immunostaining protocol, we found that FHIT is expressed in a distinctive strong nuclear and weak cytoplasmic pattern in oral tissues. Loss of FHIT expression was found in 42 of 94 (45%) POLs and in 66 of 86 (77%) OSCCs. We observed a statistically significant positive correlation between frequency of FHIT loss and increasing grade of dysplasia (chi2=13.8; degrees of freedom=4; P=0.008). Loss of FHIT expression in POLs that progressed to malignancy was more frequent than in those that did not [17 of 25 (68%) versus 12 of 29 (41.4%), respectively]. This difference was statistically significant (chi2=3.8; degrees of freedom=1; P=0.046). In OSCCs, loss of FHIT staining indicated a worse prognosis (survival rate, 36.2%) than when positive FHIT staining was observed (survival rate, 50%), but the difference was not statistically significant (P=0.546, Kaplan-Meier, log-rank).

CONCLUSIONS

FHIT seems to localize to both nuclear and cytoplasmic domains. FHIT inactivation occurs early in oral carcinogenesis and may be useful molecular marker for progressive dysplastic oral lesions.

Genomic mechanisms and measurement of structural and numerical instability in cancer cells

The progression to cancer is often associated with instability and the acquisition of genomic heterogeneity, generating both clonal and non-clonal populations. Chromosomal instability (CIN) describes the excessive rate of numerical and structural genomic change in tumors. Mitotic segregation errors strongly influences copy number, while structural aberrations can occur at unstable genomic regions, or through aberrant DNA repair or methylation. Combined molecular cytogenetic analyses can evaluate cell-to-cell variation, and define the complexity of numerical and structural alterations. Because structural change may occur independently of numerical alteration, we propose the term structural chromosomal instability [(S)-CIN] to distinguish numerical from structural CIN.

Fatores associados ao câncer do colo uterino em Propriá, Sergipe, Brasil

O câncer do colo uterino apresenta uma alta incidência nas regiões pobres dos países em desenvolvimento. Relaciona-se a fatores ligados ao estilo de vida que levam à infecção pelo Papilomavirus humano (HPV). O objetivo do estudo foi avaliar quais os fatores que favoreciam a infecção pelo HPV e ao desenvolvimento do carcinoma do colo uterino no Município de Própria, Sergipe, Brasil. Para o desenvolvimento da pesquisa, realizou-se um estudo de caso-controle, pareando-se quatro controles para cada caso quanto à idade, procedência e condição sócio-econômica. Foram identificadas vinte mulheres portadoras de carcinoma do colo uterino e oitenta controles. As mulheres do grupo casos apresentaram maior número de gestações e freqüência menor de realização de exame preventivo de rotina. Verificou-se também que as mulheres nos dois grupos tinham conhecimento pobre sobre o câncer e as suas formas de prevenção, alto índice de analfabetismo e os seus companheiros tinham múltiplas parceiras sexuais. O estudo concluiu que no Município de Própria, o maior número de gestações e a não realização de exames preventivos de rotina associaram-se à ocorrência de carcinoma do colo uterino.