Prevalence of human papillomavirus infection in pregnant versus non-pregnant women in Brazil.

PURPOSE: To investigate the prevalence of human papillomavirus (HPV) in cervical samples of pregnant and non-pregnant women in South-Brazil. METHODS: A prospective study of 91 pregnant and 92 non-pregnant women with no previous history of cervical dysplasia or cancer was carried out. Cervical samples for HPV testing and cytology were collected in each trimester of pregnancy and in the puerperium for pregnant women and at matched intervals for the non-pregnant women. All samples were analyzed through PCR with consensus primers GP5+/GP6+. Genotyping was performed using specific primers. To control for confounding factors, the analysis of multivariate logistic regression was applied. The measure of odds ratio (OR) and the 95 % confidence interval (95 % CI) were used. The level of statistical significance was set at 5 % (P ≤ 0.05). RESULTS: HPV DNA was detected in 23/91 (25.3 %) cervical samples from the pregnant women and in 12/92 (13 %) cervical samples from non-pregnant women (P = 0.035). There was a significant association among cervical HPV infection and young age, number of lifetime sexual partners, and the presence of abnormal cervical cytology. HPV16 and HPV18 were the viral types more frequently detected. Out of the 23 HPV-positive pregnant women, 17 (73.9 %) had normal cervical cytology. CONCLUSION: Our results suggest a higher prevalence of HPV infection in pregnant vs. non-pregnant women. This finding may be related to the relative immunosuppression observed in pregnant women, outlining the importance of the appropriate monitoring of the viral infection in this specific population.

TWIST1 promoter methylation in primary colorectal carcinoma.

TWIST1 gene, a transcription factor that belongs to the family of basic helix-loop-helix proteins, has been related to tumor progression and metastasis in different cancers. The aim of our study was to investigate TWIST1 promoter methylation in patients with primary colorectal carcinoma and determine its correlation with prognostic factors and disease outcome. Seventy-three patients with primary colorectal adenocarcinoma were studied. From each patient two tissue samples were collected: one sample of the tumor and one sample of normal colorectal tissue from an area located 15 cm away from the tumor. Samples of colorectal mucosa obtained from 30 individuals without malignant disease were also studied as a control group. All tissues were analyzed through methylation-specific PCR. TWIST1 hypermethylation was detected in colorectal specimens of 46 patients with cancer, but in none of the tissues from the nonmalignant control group (p < 0.001). In cancer patients, TWIST1 hypermethylation was found in 38 of 73 tumor samples as compared with 20 of 73 matched samples of non-cancerous colorectal tissue (P = 0.001). TWIST1 hypermethylation was not correlated with prognostic predictors for the disease outcome, patients' overall survival and disease-free survival rates. We concluded that TWIST1 hypermethylation is present in the colon and rectum of most patients with colorectal carcinoma, suggesting this molecular alteration may be involved in the process of colorectal carcinogenesis.

Polimorfismos das isoformas M1, T1 e P1 da glutationa S-transferase e associação com os aspectos clínico-patológicas no carcinoma colorretal / Polymorphism of glutathione S-transferase M1, T1 and P1 and association with clinicopathological aspects in colorectal carcinoma

As variáveis clínico-patológicas são importantes fatores que possam estar associados à progressão da neoplasia e, consequentemente, ao prognóstico da doença. As glutationas S-Transferases GSTM1, GSTT1 e GSTP1 são enzimas da segunda fase de biotransformação que atuam na destoxificação de uma ampla variedade de agentes exógenos incluindo os carcinógenos. Os genes GSTM1, GSTT1 e GSTP1 são polimórficos em humanos e suas variantes têm sido associadas, em algumas populações, ao aumento dos riscos de neoplasia, entre elas o carcinoma colorretal. Neste estudo retrospectivo 50 biópsias de pacientes com carcinoma colorretal do Rio Grande do Sul foram analisadas os polimorfismos nos genes GSTM1, GSTT1 e GSTP1 por PCR multiplex e RFLP, quanto às variáveis clínico-patológicas: localização, estadiamento e diferenciação. Não foram encontrados valores p significativo nas variáveis: estadiamento (p=0,28, p=0,93 e p=0,67), diferenciação (p=0,70 e p=0,37) e localização (p= 0,23. p= 0,58 e p= 0,60 ) respectivamente e o presença do polimorfismos dos genes GSTM1, GSTT1 e GSTP1 nas variáveis estadiamento e localização. A única variável clínico-patológica que apresentou valor significativo na diferenciação do CCR foi o polimorfismo do gene GSTP1 Ile/val e val/val (p= 0,046) entretanto, mais pesquisas são necessárias para confirmar estes achados ,visto que, esses resultados podem ter sido influenciados pelo número reduzido de biópsias analisadas.

The clinical and pathological variables are important factors that may be associated with tumor progression and consequently, the prognoses of the disease. The glutathione S-Transferases GSTM1, GSTT1 and GSTP1 are enzymes from the second phase II of biotransformation that work in the detoxificatin pathways of a wide range of exogen agents including the carcinogens. The GSTM1, GSTT1 and GSTP1 genes are polymorphic in humans and their variants have been related in some populations an increased neoplasia risks, including colorectal cancer. In this retrospective study 50 biopsies of patients with colorectal carcinoma of South Brazilian were analyzed polymorphisms in the genes GSTM1, GSTT1 and GSTP1 by Multiplex PCR and RFLP for the clinical and pathological variables: location, stage and differentiation. There were no significant p values for the variables: stage (p=0,28, p=0,93 e p=0,67), differentiation (p=0,70 e p=0,37) and location (p= 0,23. p= 0,58 e p= 0,60 ) respectively and the presence of polymorphism of GSTM1, GSTT1 and GSTP1 in variables staging and location. The only clinicopathological variable that showed significant value in the differentiation of CCR was the polymorphism GSTP1 ile/val and val/val (p= 0,046), however, more research is needed to confirm these findings, since these results may have been influenced by the reduced number of biopsies analyzed.

Evidence for an association of TP53 codon 72 polymorphism with breast cancer risk.

BACKGROUND: A common Arg/Pro polymorphism at codon 72 of the TP53 gene has been investigated as a risk factor for cancer in different populations. So far, the results have been controversial. Our purpose was to investigate the association of this polymorphism with breast carcinoma in women from Southern Brazil, a high-risk area for breast cancer. METHODS: Blood samples collected from 118 women with primary breast carcinoma and from 202 female blood donors were analyzed through polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. RESULTS: The relative frequency of each allele was 0.75 for Arg and 0.25 for Pro in patients with cancer, and 0.62 for Arg and 0.38 for Pro in normal controls (P < 0.001). The Arg/Arg genotype was significantly associated with an increased risk for breast cancer (OR 2.9; 95% CI 1.43-3.6; P < 0.002). No correlation between the genotype distribution and specific prognostic predictors for the disease outcome was observed. DISCUSSION: TP53 codon 72 polymorphism might be implicated in breast carcinogenesis, with the Arg/Arg genotype being associated with an increased susceptibility for this malignancy.

Evidence for an association of human papillomavirus and breast carcinomas.

Human papillomavirus (HPV) DNA has been detected in breast carcinoma by different laboratorial techniques, suggesting the virus could play a role in the pathogenesis of this tumor. The aim of the present study is to investigate the presence of HPV in patients with breast carcinoma and the correlation of the viral infection with prognostic factors for the disease outcome. Between June 2001 and July 2002, 101 paraffin embedded breast carcinoma specimens were analyzed through polymerase chain reaction (PCR) and sequencing of HPV-E6 gene. Twenty specimens of reduction mammoplasty and 21 specimens of fibroadenomas were also studied as a non-malignant control group. Two different specific primer sets targeting E6 region of the HPVs 16 and 18 were used for the analysis. The HPV DNA was detected in 25 breast carcinomas (24.75%), but in none of the benign breast specimens ( p < 0.001). Out of the 25 positive cases, 14 were HPV-16 positive (56%) and 10 were HPV-18 positive (40%). An original finding was the detection of both HPV-16 and -18 in a single tumor (4%). The amplified viral sequences confirmed the presence of HPV-16 and -18. No correlation between the presence of HPV DNA and specific prognostic predictors for the disease outcome was observed. Our results suggest that the presence in the breast of either HPV-16 or -18 might be related to development of the malignant phenotype. Further studies are warranted.

Intrafamilial transmission of hepatitis C virus in patients with hepatitis C and human immunodeficiency virus coinfection.

OBJECTIVE: The aim of this study was to determine whether hepatitis C virus (HCV)/HIV coinfection of index cases increases intrafamilial transmission (sexual and nonsexual contacts) of HCV. METHODS: We prospectively enrolled 347 subjects, including 87 family members of 53 HCV/HIV-coinfected index cases and 134 family members of 73 HCV-monoinfected index cases, which served as a control group. All index cases and family members were interviewed, and a screening for HCV and HIV using enzyme-linked immunosorbent assays was performed. Positive samples were confirmed by polymerase chain reaction and tested for genotype and HCV RNA viral load. A meta-analysis designed to assess the pooled risk of sexual transmission of HCV among HCV/HIV-coinfected patients was performed. RESULTS: Anti-HCV was detected in 2.2% of family members of HCV-monoinfected index cases and 2.3% of family members of HCV/HIV-coinfected index cases. Viral load was higher in coinfected index cases (7.2 x 10(6) mEq/ml) compared with HCV alone (1.9 x 10(6) mEq/ml), p = 0.01. HCV genotype concordance was observed in three family members of HCV-monoinfected index cases and in two family members of HCV/HIV-coinfected index cases. The pooled OR of the meta-analysis evaluating HIV as a cofactor of sexual transmission of HCV was 1.54 (95% CI = 0.76-3.12). CONCLUSIONS: Our data demonstrate a low prevalence of intrafamilial transmission of HCV, independent of the presence of HCV/HIV coinfection. This finding is supported by meta-analysis, which failed to identify HIV as an important cofactor of sexual transmission in HCV/HIV-coinfected patients.

TP53 mutation pattern of esophageal squamous cell carcinomas in a high risk area (Southern Brazil): role of life style factors.

In an attempt to correlate the TP53 mutation pattern of squamous cell carcinomas of the esophagus (ESCC) and life style factors of patients from the high risk area Rio Grande do Sul, Brazil, 135 ESCC were analyzed, after prescreening by p53 immunohistochemistry, by SSCP and DNA sequencing of TP53, exon 5-9. Forty-nine somatic TP53 mutations (and 1 case with p53 polymorphism) were identified as missense (n = 39), frameshift (n = 6), silent (n = 1), amber (n = 1) or intron border mutations (n = 2) that cause splicing aberrations. They were preferentially found in exon 5 (36.7%) and exon 8 (32.7%). Several mutations were located in the mutation hot spot codons 248, 273 and 282, mainly at CpG sites. Transition mutations were observed in 53.1% (among them 50% G > A), transversion mutations in 34.7% (among them 47.1% G > T) and frameshifts in 12.2%, the latter 2 mainly in smokers and alcohol drinkers. Transitions were more prevalent in females than in males (p < 0.05). TP53 mutations, mainly transversions, were more frequently found in heavy smokers (p = 0.03), with the same tendency after chronic alcohol consumption. Comparison with the worldwide IARC database disclosed differences in the TP53 mutation pattern of the Brazilian tumors, with a higher accumulation of TP53 mutations in exon 8 and a higher prevalence of transition mutations. Mutations at the reported hot spot codon 176 were missing. Although difficult because of the documented coexposure to various life style risk factors in most patients of this series, the hypothesis is proposed that besides smoking and alcohol drinking the commonly consumed hot mate tea in this high risk area for ESCC is responsible for this different pattern of TP53 mutations because of chronic hyperthermic irritation and inflammation in the esophagus with an endogenous formation of radicals or carcinogenic factors that lead to a higher prevalence of transition mutations.