Sérgio Zucoloto

p63 correlates with both BRCA1 and cytokeratin 5 in invasive breast carcinomas: further evidence for the pathogenesis of the basal phenotype of breast cancer

Aims:  To study the expression of p63, cytokeratin (CK) 5 and CK8/18 in invasive ductal carcinomas and their relationship with BRCA1 and other pathological and immunohistochemical features of clinical significance.

The Relationship Between p63 and p53 Expression in Normal and Neoplastic Breast Tissue

CONTEXT p63 is a recently described p53 homologue. Despite structural homology, they have different activities. OBJECTIVES To obtain new insights into the role of p63 in normal and neoplastic breast tissue and to verify the possible association between p63 and p53 in breast carcinomas. DESIGN Immunohistochemistry in 85 breast carcinomas using p63, smooth muscle actin (1A4), p53, estrogen receptor, and progesterone receptor. The p63-positive cases were submitted to a double-immunolabeling study using p63 with 1A4, cytokeratin 7, and 34betaE12. Clinical data were retrieved from medical files. RESULTS p63, like 1A4, stained a single and continuous layer surrounding normal breast ductal and alveolar epithelium. In carcinomas, p53 was expressed in 21.17% of carcinomas, whereas p63 was expressed only in poorly differentiated ductal carcinomas (11.76% of cases). p63-positive cells coexpressed 1A4 and 34betaE12, but not cytokeratin 7. Expression of p63 correlated with pathologic staging, tumor size, histologic grading, nodal metastasis, and estrogen receptor negativity. CONCLUSIONS p63 is a specific myoepithelial cell marker in normal breast tissue and is expressed in a minority of breast carcinomas, being seen only in grade III ductal carcinomas. In ductal carcinomas, malignant p63-positive cells have an immunophenotype similar to that of myoepithelial cells, suggesting that these cells originate from a primary progenitor cell that underwent divergent differentiation to ductal and myoepithelial cells during clonal expansion. Our study argues against a direct role in mammary tumorigenesis. However, p53 is rarely coexpressed with p63, suggesting that p63 could act indirectly as an oncogene by inhibiting p53. This hypothesis could also explain why p63 correlated with several other indicators of poor prognosis.

Are Haemochromatosis Mutations Related to the Severity of Liver Disease in Hepatitis C Virus Infection

It has been proposed that iron overload may adversely affect liver disease outcome. The recent identification of 2 mutations in the HFE gene related to hereditary haemochromatosis (Cys282Tyr and His63Asp) provided an opportunity to test whether they are associated with hepatic iron accumulation and the activity and severity of liver disease in hepatitis C virus (HCV) infection. We investigated the prevalence of HFE mutations in 135 male patients with chronic HCV hepatitis, and correlated genotype distribution with different parameters of iron status and the activity and severity of liver disease. Of these 135 patients, 6 (4.4%) carried Cys282Tyr and 32 (23.7%) carried His63Asp, frequencies which were similar to those observed in healthy controls. Serum iron levels and transferrin saturation (but not ferritin levels or liver iron content) were significantly higher in carriers than in non-carriers of HFE mutations. No difference was observed in serum ALT, AST and GGT levels between carriers and non-carriers. Finally, scores for necroinflammatory activity and fibrosis in the liver were significantly higher in HFE carriers than in non-carriers. Patients with chronic HCV infection carrying HFE mutations tend to present more evident body iron accumulation and a higher degree of necroinflammatory activity and fibrosis in the liver. HFE gene mutations might be an additional factor to be considered among those implicated in the determination of a worse prognosis of the liver disease in chronic HCV infection.

Prognostic factors and survival analysis in a sample of oral squamous cell carcinoma patients.

OBJECTIVES The aims of this report were to describe the 5-year overall survival (OS) in a group of oral squamous cell carcinoma (OSCC) patients and to investigate the effects of age, gender, anatomic localization, tumor evolution time, smoking and alcohol intake, nodal status, tumoral recurrences, histologic classification, p53 and p63 immunoexpression, human papillomavirus DNA presence, and treatment on the prognostic outcome. STUDY DESIGN Survival curves were generated using Kaplan-Meier method, and univariate and multivariate analyses were made using the log rank test and Cox regression, respectively. RESULTS The 5-year OS was 28.6%, and the univariate analysis showed significant results for p53 and p63 immunoexpression, age, and anatomic localization. The Cox regression demonstrated poor OS for tumors with p53 immunoexpression and for patients aged over 60 years. There were also significant differences in survival depending on the anatomic localizations. CONCLUSION These results highlight the influence of p53 immunoexpression, age, and anatomic localization in OSCC evolution.

Hepatic stellate cells in hepatitis C patients: Relationship with liver iron deposits and severity of liver disease

Background and Aim:  To determine the relationship between hepatic stellate cell (HSC) populations and severity of liver disease and liver iron deposits in patients with chronic hepatitis C virus (HCV). We also studied the relationship between iron cellular distribution and HSC population and the role of HFE mutations in the determination of iron deposits.

Porphyria cutanea tarda in Brazilian patients: association with hemochromatosis C282Y mutation and hepatitis C virus infection

OBJECTIVE:Porphyria cutanea tarda (PCT) is commonly associated with iron overload and hepatitis C virus (HCV) infection. Association between hemochromatosis C282Y or H63D mutations and PCT has been observed, although not uniformly, and iron overload is also commonly found in chronic HCV hepatitis. The aim of the present study was to investigate the frequency of C282Y and H63D mutations and HCV infection in Brazilian patients with PCT and their relationship with iron overload.METHODS:Twenty-three patients (19 men) aged 39.6 ± 11.1 yr were studied. All had dermatological lesions of PCT and high levels of urinary uroporphyrin. HCV infection and iron overload were investigated. DNA samples were analyzed for the presence of HFE mutations.RESULTS:The frequency of C282Y was significantly higher in PCT patients than in 278 healthy individuals (17.4% vs 4%, odds ratio = 5.1, 95% confidence interval 1.5–17.6, p= 0.02), whereas no difference was observed regarding the H63D mutation (30.4% vs 31%, odds ratio = 1, 95% confidence interval 0.4–2.4, p= 1). Biochemical tests in PCT patients showed iron overload with transferrin saturation = 47.3 ± 20.7% and ferritin = 566.8 ± 425 ng/ml. Fifteen of 23 (65.2%) patients had HCV infection and alcohol ingestion was observed in 17 of 23 (73.9%).CONCLUSIONS:PCT patients exhibited evidence of iron overload, a high frequency of HCV, and an association with C282Y mutation. These data further support the notion that both acquired and inherited factors contribute to the occurrence of PCT, and indicate that screening for C282Y may be justified in PCT patients.

Liver iron deposits in hepatitis B patients: association with severity of liver disease but not with hemochromatosis gene mutations.

Background and Aims:  Iron deposits in the liver and abnormalities in serum iron biochemistry are frequently observed in patients with chronic liver diseases, but data for patients with hepatitis B virus (HBV) infection are scarce. Moreover, the role of HFE mutations in iron deposits in this condition remains unknown. The aim of the present study was to determine the prevalence of serum iron biochemical abnormalities and iron deposits in the liver of chronic HBV patients, and to evaluate the consequences for the activity and severity of liver disease. Additionally, we studied the role of HFE gene mutations in iron deposits.

Vascular Endothelial Growth Factor Expression in the Basal Subtype of Breast Carcinoma

The recognition of subtypes of breast carcinomas based on their molecular features has brought new perspectives in breast cancer research. Some key regulators of angiogenesis and tumor infiltration were evaluated in breast carcinomas of basal phenotype (cytokeratin [CK]5+). Immunohistochemical analysis with 14 primary antibodies was performed in 100 formalin-fixed, paraffin-embedded samples of invasive ductal carcinomas. CK5 correlated with indicators of poor outcome, including precocious age, high histologic grade, lymph node positivity, advanced pathologic stage, negativity for hormonal receptors, and a high proliferative rate (Ki-67 labeling index). CK5 also correlated with vascular endothelial growth factor (VEGF) expression but not with the microvessel density. Considering that VEGF-overexpressing neoplastic mammary cells display increased proliferative activity in vitro regardless of the angiogenic effect of VEGF, the differential expression of VEGF might contribute to the more aggressive behavior of these neoplasms. CK5 correlated with tissue inhibitor of metalloproteinase (TIMP)-1, but not matrix metalloproteinase (MMP)-1, MMP-2, extracellular matrix metalloproteinase inducer, TIMP-2 or plasminogen activator inhibitor, indicating that antiproteolytic stimuli might be preponderant in these neoplasms.

Liver HLA-G expression is associated with multiple clinical and histopathological forms of chronic hepatitis B virus infection

Summary.  As the mechanisms leading to the persistence of hepatitis B virus (HBV) infection are poorly understood and as the histocompatibility leucocyte antigen (HLA)‐G is well described as a tolerogenic molecule, we evaluated HLA‐G expression in 74 specimens of HBV liver biopsies and in 10 specimens obtained from previously healthy cadaver liver donors. HBV specimens were reviewed and classified by the METAVIR score, and HLA‐G expression was assessed by immunohistochemistry. No HLA‐G expression was observed in control hepatocytes. In contrast, 57 (77%) of 74 HBV specimens showed soluble and membrane‐bound HLA‐G expression in hepatocytes, biliary epithelial cells or both. No associations between the intensity of HLA‐G expression and patient age or gender, HBeAg status, severity of liver fibrosis, and grade of histological findings were observed. Although significance was not reached (P = 0.180), patients exhibiting HLA‐G expression presented a higher median HBV DNA viral load (105 copies/mL) than those who did not express HLA‐G (103.7 copies/mL). These results indicate that HLA‐G is expressed in most cases of chronic HBV infection in all stages and may play a role in the persistency of HBV infection.

Melatonin treatment reduces the severity of experimental Trypanosoma cruzi infection

Abstract:  Prior studies show that melatonin enhances the immune response. This study investigated the possible therapeutic effects of melatonin during the course of Trypanosoma cruzi infection. T. cruzi‐infected male Wistar rats were orally treated with 5 mg/kg body weight/day of melatonin. Animals treated with melatonin showed a significant reduction in the number of blood trypomastigotes during the acute phase of infection compared with untreated animals (P < 0.05). A significant increase in leucocytes numbers during the peak of parasitaemia was also observed (P < 0.05). Moreover, both prior and concomitant treatment with melatonin increased interleukin‐2 levels, especially 9 days postinfection (P < 0.05). Histopathological observations of heart tissue revealed that melatonin administration also resulted in fewer and smaller amastigote burdens, and less inflammatory infiltrate and tissue disorganization, indicating a reduced parasitism of this tissue. These results show that melatonin is effective in controlling parasite replication and suggest that melatonin might serve as an effective therapeutic agent in the treatment of American trypanosomiasis.