The immunohistochemical (IHC) detection of MMR proteins is an accurate and rapid method to predict the presence of defective DNA MMR genes. MMR protein expression could also serve as a prognostic indicator of human cancers. The results of many studies demonstrate the usefulness of IHC tests with monoclonal antibodies MSH2 and MLH1 in screening the microsatellite sequence instability within both spontaneous and hereditary malignant neoplasms. The aim of our study was to perform an IHC estimation of the hMLH1 and hMSH2 expression in a subset of vulvar carcinomas according to HPV 16/18 status. The level of MMR proteins was further analyzed in relation to histoclinical features of the disease in either HPV-positive or -negative cancers. We identified archival diagnostic phase tissue specimens from 46 cases of vulvar cancer. From the same paraffin blocks containing material from the margin of surgical section during vulvectomy, normal epithelial tissue fragments were collected and designated as the control group. The characteristic of the lesion was examined in comparison with the presence of HPV DNA. Identification of the HPV 16/18 types was performed using PCR. IgG1 monoclonal antibodies detecting those epitopes characteristic for hMLH1 and hMSH2 were used in the study. In the analyzed cases of vulvar cancer, we have observed increased expression of proteins of both hMSH2 and hMLH1 genes compared to the control group. A comparison of the hMLH1 and hMSH2 protein expression levels showed that hMSH2 expression was higher than that of hMLH1 in the case of vulvar carcinomas. The performed analysis of correlation between individual parameters did not reveal statistically significant relationship with both the gradient and status of HPV 16/18. hMSH2 and hMLH1 were definitely interrelated.
Download full-text PDF |
Source |
---|
Histopathology
April 2024
IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
Aims: The Lynch syndrome (LS) screening algorithm requires BRAF testing as a fundamental step to distinguish sporadic from LS-associated colorectal carcinomas (CRC). BRAF testing by immunohistochemistry (IHC) has shown variable results in the literature. Our aim was to analyse concordance between BRAF IHC and BRAF molecular analysis in a large, mono-institutional CRC whole-slide, case series with laboratory validation.
View Article and Find Full Text PDFCancer Diagn Progn
March 2023
Breast Unit, 1st Department of Obstetrics and Gynaecology, Alexandra Hospital, National and Kapodistrian University of Athens, Athens, Greece.
DNA mismatch repair system (MMR) is considered a leading genetic mechanism in stabilizing DNA structure and maintaining its function. DNA MMR is a highly conserved system in bacteria, prokaryotic, and eukaryotic cells, and provides the highest protection to DNA by repairing micro-structural alterations. DNA MMR proteins are involved in the detection and repair of intra-nucleotide base-to-base errors inside the complementary DNA strand recognizing the recently synthesized strand from the parental template.
View Article and Find Full Text PDFVirchows Arch
June 2023
Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Curr Oncol
August 2022
The Yale Larynx Laboratory, Department of Surgery, Yale School of Medicine, New Haven, CT 06510, USA.
Deregulation of the DNA mismatch repair (MMR) mechanism has been linked to poor prognosis of upper aerodigestive tract cancers. Our recent in vitro data have provided evidence of crosstalk between deregulated miRNAs and MMR genes, caused by tobacco smoke (TS) -Nitrosamines, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in hypopharyngeal cells. Here, we explored whether chronic exposure to TS components can affect MMR mechanism and miRNA profiles in hypopharyngeal mucosa.
View Article and Find Full Text PDFRev Gastroenterol Mex (Engl Ed)
November 2022
Departamento de Patología, Instituto Nacional de Ciencias Médicas y Nutrición «Salvador Zubirán», Mexico City, Mexico. Electronic address:
Introduction And Aims: A frequent task in the study of colorectal carcinomas (CRC) is to identify tumors harboring deficient DNA mismatch repair systems (dMMR), which are associated with microsatellite instability. Given that there is scant information on those tumors in Mexican patients, our aim was to describe their frequency, clinical and pathologic characteristics, and results, which are necessary for future trials.
Materials And Methods: A consecutive series of CRC patients, treated and followed at a tertiary care center was performed.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!