Immunocytochemical study of TOP2A and Ki-67 in cervical smears from women under routine gynecological care.

BACKGROUND: Cervical cancer is one of the most common female cancers and is caused by human papillomavirus (HPV). Viral infection leads to cell cycle deregulation by inactivating p53 and retinoblastoma protein by viral oncoproteins E6 and E7, respectively. Then, nuclear proteins such as DNA topoisomerase type IIa (TOP2A) and Ki-67 show increased expression because of increased cell division. These molecules are used as biomarkers for immunohistochemistry analysis of cervical tissue. METHODS: In this cross-sectional study, we recruited 110 women receiving regular gynecological surveillance at public health centers in Olinda - PE, Brazil. Cervicovaginal cells were collected to determine the presence of cytological abnormalities and HPV infection. Pap smear slides were used to evaluate the expression of TOP2A and Ki-67 using immunocytochemistry techniques. RESULTS: Of the 110 women, 75.4 % showed HPV-DNA(+) infection (83/110) and 29.1 % showed cellular abnormalities (32/110). Two atypical cells of undetermined significance, one low-grade squamous intraepithelial lesion, and one high-grade squamous intraepithelial lesion samples showed no HPV-DNA. TOP2A was positive in 71.9 % of samples, while Ki-67 was positive in 81.2 %. Immunocytochemistry results were positive in 4 of 5 atypical cells of undetermined significance samples. In HPV-DNA(+) samples with cytological abnormalities, immunocytochemistry results were positive 96.4 % of samples (p < 0.0001; odds ratio = 28.0). Among the samples infected with HR-HPV, TOP2A(+) was effective in 71 % samples, while and Ki-67(+) was 77.4 %. Ki-67 and TOP2A were positive for all samples infected with HPV6, HPV11, and HPV18. Ki-67 was also positive for all HPV16 samples, except for one negative sample in cytopathology analysis. CONCLUSIONS: TOP2A and Ki-67 antibodies may be used in combination for cervical cancer screening in immunocytochemistry assays.

Association between the genetic polymorphisms of glutathione S-transferase (GSTM1 and GSTT1) and the clinical manifestations in sickle cell anemia.

The hereditary deficiency of antioxidant enzymes when associated with sickle cell anemia (SCA) further contributes to the oxidation of hemoglobin S, which increases the formation of degradation products of this hemoglobin. The glutathione S transferases play an important role in the conjugation of glutathione to endogenous products of peroxidation of lipids and protect cells from the deleterious effects of oxidative stress. We analyzed genomic DNA from 278 patients with sickle cell anemia to correlate the genotypes GSTT1 and/or GSTM1 null (determined by multiplex PCR technique) and the clinical manifestations of the disease. 27% of patients showed absence of the GSTM1 gene and 15% had absence of GSTT1. The GSTM1 and GSTT1 null genotypes were found in 11% of the population. The risk of individuals with the GSTT1 null genotype developing acute chest syndrome and aseptic necrosis of the femoral head were, respectively, 10 and 6.3 times higher when compared with those individuals who had of this gene. Patients with GSTM1 null showed a risk 3.9 times higher to develop stroke and high risk for malleolar ulcers and acute chest syndrome (OR=6.9 and 4.2, respectively). The individuals with the GSTM1 and GSTT1 null genotypes showed a higher chance of developing acute chest syndrome, malleolar ulcer and aseptic necrosis of the femoral head. The absence of GSTT1 and/or GSTM1 was an important risk factor for increasing the morbidity of SCA, especially in regard to acute chest syndrome.