Prevalência dos genótipos do papilomavírus humano: comparação entre três métodos de detecção em pacientes de Pernambuco, Brasil Prevalence of human papillomavirus genotypes: comparison between three detection methods in patients of Pernambuco, Brazil

OBJETIVO: comparar três métodos para detecção do HPV e determinar a prevalência dos genótipos encontrados. MÉTODOS: um total de 120 amostras de raspagem da região cervical de mulheres portadoras de neoplasia intraepitelial cervical foram analisadas pela reação em cadeia da polimerase convencional, usando os sistemas de primers MY09/11, GP05+/06+ e pela Nested-PCR. As amostras foram submetidas à extração de DNA e, logo após, amplificadas com os primers GH20 e PC04 (&#946;-globina) para verificação da qualidade do DNA obtido e pela reação em cadeia da polimerase convencional e Nested-PCR. Os fragmentos amplificados foram visualizados em gel de agarose a 1,2%, corados com Blue Green Loading Dye I. As amostras positivas foram sequenciadas usando o sequenciador automático de DNA "MegaBACE 1000". Para análise estatística foram utilizados os teste do &#935;2 e o de Fisher com nível de significância de 5%. RESULTADOS: quinze amostras não se amplificaram para os primers de &#946;-globina, sendo eliminadas do estudo. Das amostras restantes, 40% (42/105) foram positivas para os primers MY09/11, 98% (103/105) para os primers GP05+/06+ e 92% (97/105) para Nested-PCR. Considerado as técnicas MY09/11 e GP05+/06+, foi possível observar 100% de amostras positivas para o HPV. Neste estudo, a prevalência dos genótipos foi de 58, 23, 5, 4 e 3% para HPVs 16, 18, 31, 33 e 56, respectivamente. Os HPV 67 e 83 apresentaram 2% e os HPV 6, 11, 58 e candHPV85, 1% cada. A prevalência dos genótipos neste estudo está de acordo com o reportado em todo o mundo (IC95%=0,4657-0,8976). CONCLUSÕES: para obter resultados mais confiáveis, é necessário o uso de mais que um sistema de primers para detecção do HPV. Acredita-se que as três técnicas estudadas são importantes e adequadas para o diagnóstico clínico do HPV quando apropriadamente combinadas.<br>PURPOSE: to compare three methods for the detection of HPV infection and to determine the prevalence of the genotypes found. METHODS: a total of 120 cervical scrape samples from patients with cervical intraepithelial neoplasia were analyzed by the conventional polymerase chain reaction using the MY09/11 and GP05+/06+ primers, and by the Nested polymerase chain reaction. The samples were subjected to DNA amplification with the GH20 and PC04 primers (&#946;-globin) to verify DNA quality and also by polymerase chain reaction and Nested polymerase chain reaction. The amplicons were visualized in 1.2% agarose gel stained with Blue Green Loading Dye I. Positive samples also were sequenced using the automatic DNA sequencer "MegaBACE 1000". The &#935;2 and Fisher tests were used for statistical analysis with the level of significance set at 5%. RESULTS: fifteen samples were eliminated from the study because they failed to amplify the &#946;-globin gene. Of the remaining samples, 40% (42/105) were positive using primers MY09/11, 98% (103/105) using primers GP05+/06+, and 92% (97/105) using Nested-PCR. With the MY09/11 and GP05+/06+ techniques, it was possible to obtain 100% HPV-positive samples. In this study, the prevalence of the genotypes found was 57, 23, 5, 4 and 3% for HPV genotypes 16, 18, 31, 33 and 56, respectively. HPVs 67 and 83 were present in 2%, and genotypes 6, 11, 58 and candHPV85 were present in 1% each. The prevalence of the more common genotypes (HPV 16 and 18) in this study agrees with that reported worldwide (IC95%=0.4657-0.8976). CONCLUSIONS: to obtain more reliable results, it is necessary the use of more than one primer system to detect HPV infections. We believe that the three techniques studied are important and suitable for the clinical diagnosis of HPV, when they are appropriately combined

CCR2 and CCR5 genes polymorphisms in women with cervical lesions from Pernambuco, Northeast Region of Brazil: a case-control study

Polymorphisms in chemokine receptors play an important role in the progression of cervical intraepithelial neoplasia (CIN) to cervical cancer (CC). Our study examined the association of CCR2-64I (rs1799864) and CCR5-&#916;32 (rs333) polymorphisms with susceptibility to develop cervical lesion (CIN and CC) in a Brazilian population. The genotyping of 139 women with cervical lesions and 151 women without cervical lesions for the CCR2-64I and CCR5-&#916;32 polymorphisms were performed using polymerase chain reaction-restriction fragment length polymorphism. The individuals carrying heterozygous or homozygous genotypes (GA+AA) for CCR2-64I polymorphisms seem to be at lower risk for cervical lesion [odds ratio (OR) = 0.37, p = 0.0008)]. The same was observed for the A allele (OR = 0.39, p = 0.0002), while no association was detected (p > 0.05) with CCR5-&#916;32 polymorphism. Regarding the human papillomavirus (HPV) type, patients carrying the CCR2-64I polymorphism were protected against infection by HPV type 16 (OR = 0.35, p = 0.0184). In summary, our study showed a protective effect of CCR2-64I rs1799864 polymorphism against the development of cervical lesions (CIN and CC) and in the susceptibility of HPV 16 infection

Quantifying mRNA and MicroRNA with qPCR in Cervical Carcinogenesis: A Validation of Reference Genes to Ensure Accurate Data

<div><p>A number of recent studies have catalogued global gene expression patterns in a panel of normal, tumoral cervical tissues so that potential biomarkers can be identified. The qPCR has been one of the most widely used technologies for detecting these potential biomarkers. However, few studies have investigated a correct strategy for the normalization of data in qPCR assays for cervical tissues. The aim of this study was to validate reference genes in cervical tissues to ensure accurate quantification of mRNA and miRNA levels in cervical carcinogenesis. For this purpose, some issues for obtaining reliable qPCR data were evaluated such as the following: geNorm analysis with a set of samples which meet all of the cervical tissue conditions (Normal + CIN1 + CIN2 + CIN3 + Cancer); the use of individual Ct values versus pooled Ct values; and the use of a single (or multiple) reference genes to quantify mRNA and miRNA expression levels. Two different data sets were put on the geNorm to assess the expression stability of the candidate reference genes: the first dataset comprised the quantities of the individual Ct values; and the second dataset comprised the quantities of the pooled Ct values. Moreover, in this study, all the candidate reference genes were analyzed as a single “normalizer”. The normalization strategies were assessed by measuring p16^INK4a and miR-203 transcripts in qPCR assays. We found that the use of pooled Ct values, can lead to a misinterpretation of the results, which suggests that the maintenance of inter-individual variability is a key factor in ensuring the reliability of the qPCR data. In addition, it should be stressed that a proper validation of the suitability of the reference genes is required for each experimental setting, since the indiscriminate use of a reference gene can also lead to discrepant results.</p></div

Effect of normalization options on miR-203 expression in cervical tissues.

<p>In a), it is shown that there is no significant effect on normalization between the use of the two most stable genes and the three genes. The differences in the expression levels of miR-203 were statistically significant with ANOVA when the use of the two and three most stable genes were compared with the use of each gene as a single normalizer. Graph b), shows the relative quantification of miR-203 in cervical tissues using a combination of <i>miR-191</i> and <i>miR-23a</i> (from an analysis involving individual Ct values) as the normalizer. The error bars indicate a 95% confidence interval; **, p<0.01; ****, p<0.0001.</p

Influence of IL-6, IL-8, and TGF-β1 gene polymorphisms on the risk of human papillomavirus-infection in women from Pernambuco, Brazil

Human papillomavirus (HPV) infections are strongly associated with the development of cervical intraepithelial neoplasias and invasive cervical cancer. Polymorphisms in cytokine-encoding genes and behavioural cofactors could play an important role in protecting an individual against viral infections and cancer. Here, we investigated whether IL-6 -174 G>C, IL-8 +396 G>T, and TGF-β1 +869 G>C and +915 G>C polymorphisms were associated with susceptibility to HPV infection in women from north-east (Pernambuco) Brazil. We analysed 108 healthy uninfected women (HC) and 108 HPV-positive women with cervical lesions. Genetic polymorphisms were assessed using Sanger sequencing and polymerase chain reaction-restriction fragment length polymorphism. Comparison of the distribution of the genotypic and allelic frequencies of the IL-18 +396 T>G polymorphism between HPV infected woman an uninfected controls showed that the GG genotype and G allele were both more frequent in the HC group, and were associated with protection from HPV infection (p = 0.0015; OR = 0.29 CI95% = 0.13-0.61; p = 0.0005; OR = 0.45 CI95% 0.29-0.7, respectively). Individuals from the control group could have previously had HPV infection that was spontaneously eliminated; however, it was undetectable at the time of sample collection. Based on our findings, we hypothesize that the IL-8 +396 G>T polymorphism could interfere with susceptibility to HPV infection, by modulating the ability of immune system to fight the virus

Ranking and best combination of candidate genes determined from the analysis of individual Ct values, by geNorm.

<p>Ranking and best combination of candidate genes determined from the analysis of individual Ct values, by geNorm.</p

Ct values of candidate npcRNA reference genes in cervical tissues.

<p>Boxplots shows interquartile range box, median and range whiskers, from the raw Ct values obtained from the amplification curves. All the npcRNA genes showed a normal distribution pattern across all the cervical tissue conditions as confirmed by the D′Agostino–Pearson normality test.</p