Entendendo o Processo Molecular da Tumorigênese

Diagnostic value of p16 and Ki-67 expression in cervical glandular intraepithelial disease: A review

OBJECTIVES

Cervical adenocarcinoma has been increasing in frequency, particularly among young women. Its diagnosis still presents many challenges. In addition to the difficulty in accessing the lesion, the lack of well-established criterias for cytological and histological diagnosis, and colposcopic images that are often not very clear, there are many benign situations that mimic glandular diseases. Immunohistochemistry has been used to aid this diagnosis. The purpose of this review is to evaluate the data available in the literature related to the use of p16 and Ki-67 as an auxiliary tool in the diagnosis of glandular disease.

METHODS

Original articles were searched in the PUBMED/MEDLINE, EMBASE, SCOPUS and BVS using different combinations of keywords and descriptors.

RESULTS

Of the 83 initial articles, 10 were selected. The criterias used for immunohistochemical interpretation showed many differences. The studies compared benign pathologies to malignant pathologies and some used panels with different immunomarkers while others used only p16. P16 showed an intense staining pattern in malignant pathologies, despite some studies have shown a negative pattern in adenocarcinoma. This can be explained by the histological subtype, not always related to HPV. Some studies have shown immunopositivity for p16 in normal tissues, tubal metaplasia and cervical endometriosis, but the staining pattern was never intense, as in malignant tissues. Ki-67 showed a more intense staining in AIS and adenocarcinoma tissues and was also present in normal tissues, mainly in tubal metaplasia and cervical endometriosis.

CONCLUSIONS

Biomarkers have proved to be important tools in aiding the diagnosis of glandular lesions, either alone or in panels. Standardization in the interpretation of immunochemistry is required.

Genotoxic activity of L-asparaginase produced by Streptomyces ansochromogenes UFPEDA 3420

L-asparaginase is an enzyme capable of hydrolyzing the substrate asparagine in aspartic acid and ammonia. Due to this mechanism of action observed, L-asparaginase is widely used in the treatment of Acute Lymphoblastic Leukemia, since these cells use asparagine for their survival. Because it is frequently used as an antineoplastic, it is necessary to evaluate its genotoxic effects. The aim of the present study was to evaluate cellular DNA damage after exposure to L-asparaginase produced by Streptomyces ansochromogenes UFPEDA 3420. NCIH-292, MCF-7 and MOLT-4 neoplastic cell lines and normal PBMC cells were used. L-Asparaginase used in this study was produced by actinobacteria S. ansochromogenes UFPEDA 3420, isolated and purified by chromatographic methods. L-Asparaginase induced micronucleus formation in PBMC cells and tumor lines when compared to the negative control. These data suggest that L-Asp appears to have a genotoxic effect very close to the positive control in normal cells (p < 0.05). The level of genomic damage measured by DNA breaks in alkaline SCGE assay was detected from the lowest concentration (12.5 µg/mL) to the highest concentration (50 µg/mL) for tumor cell lines and PBMC. In view of the above, new genotoxic studies will be carried out to better elucidate L-Asparaginase and its mutagenic potential, still unknown, enough for this drug to be safely used in conventional antineoplastic therapies.

Histologic correlation of expression of Ki-67 in squamous cell carcinoma of the glottis according to the degree of cell differentiation

Introduction

Squamous cell carcinoma is the most common neoplasm of the larynx and glottis, and its prognosis depends on the size of the lesion, level of local invasion, cervical lymphatic spread, and presence of distant metastases. Ki-67 (MKI67) is a protein present in the core, whose function is related to cell proliferation.

Aim

To evaluate the expression of marker Ki-67 in squamous cell carcinoma of the larynx and glottis and its correlation to pathological findings.

Methods

Experimental study with immunohistochemistry analysis of Ki-67, calculating the percentage of the cell proliferation index in glottic squamous cell carcinomas.

Results

Sixteen cases were analyzed, with six well-differentiated and 10 poorly/moderately differentiated tumors. There was a correlation between cell proliferation index and degree of cell differentiation, with higher proliferation in poorly/moderately differentiated tumors.

Conclusion

The cell proliferation index, as measured by Ki-67, may be useful in the characterization of histological degree in glottic squamous cell tumors.

Tuberous sclerosis complex

Tuberous Sclerosis Complex, also known as Epiloia or Bourneville-Pringle disease is an autosomal dominant neurocutaneous syndrome with variable clinical expression. It is a multisystem disorder that may be associated with hamartomas in multiple organs in an unpredictable manner. The dermatologist plays an essential role in the history of the disease, since skin manifestations represent the most prevalent clinical features, enabling early diagnosis and intervention in its natural course. This article aims to inform the scientific community about advances made in the study of genetics and molecular biology. Recent findings regarding stimulation of tumor growth have been changing the history of this condition, making therapeutic trials with topical and systemic drugs possible. Knowledge of these topics enables better management of the patients affected, since tissue replacement by tumors can result in significant morbidity and mortality.