Eliete Neves Silva Guerra

Evaluation of human papillomavirus testing for squamous cell carcinoma of the tonsil in clinical practice

Background Oncogenic human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC) is a subtype of head-and-neck cancer with a distinct clinical and prognostic profile. While there are calls to undertake HPV testing for oropharyngeal SCCs within the diagnostic setting and for clinical trials, there are currently no internationally accepted standards. Methods 142 tonsil SCCs were tested using p16 immunohistochemistry (IHC), high-risk HPV DNA in situ hybridisation (ISH) and HPV DNA polymerase chain reaction (PCR; GP5+/6+ primers). Results There were high levels of agreement between pathologists for p16 IHC and HPV ISH scoring; however, around 10% of HPV ISH cases showed some interobserver discrepancy that was resolved by slide review. The combination of p16 IHC and HPV ISH classified 53% of the samples as HPV-positive, whereas the combination of p16 IHC and HPV PCR classified 61% of the samples as HPV-positive. By employing a three-tiered, staged algorithm (p16 IHC/HPV ISH/HPV PCR), the authors were able to classify 98% of the cases as either HPV-positive (p16 IHC+/HPV DNA+; 62%) or HPV-negative (p16 IHC−/HPV DNA−; 35%). Conclusions The current study suggests that using a combination of p16 IHC/HPV ISH/HPV PCR, in a three-tiered, staged algorithm, in conjunction with consensus reporting of HPV ISH, leads to less equivocal molecular classification. In order to ensure consistent reporting of this emerging disease, it is increasingly important for the head-and-neck oncology community to define the minimum requirements for assigning a diagnosis of ‘HPV-related’ oropharyngeal SCC in order to inform prognosis and for stratification in clinical trials.

Plants from Brazilian Cerrado with Potent Tyrosinase Inhibitory Activity

The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations.

Effects of metformin on head and neck cancer: A systematic review

Conventional therapeutic approaches for head and neck squamous cell carcinoma (HNSCC) are associated with many adverse effects that reduce quality of life. Therefore, identification of new less cytotoxic treatments is highly important. Metformin, which is commonly used for type 2 diabetes, may reduce cancer risk. A few clinical studies have examined the association between HNSCC and metformin. Therefore, the aim of this systematic review was to synthesize the available literature of the potential effect of metformin on HNSCC. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Studies were gathered by searching PubMed, MEDLINE, EMBASE, LILACS, and the Cochrane database before June 28, 2014, with no time or language restrictions. Studies that evaluated individuals of any age that underwent metformin and had HNSCC and compared with patients without treatment or patients that use other kind of treatment for HNSCC (drugs or radiotherapy) were considered. Selected articles were evaluated according to the Critical Appraisal Skills Programs. Of 313 identified citations, 3 studies met the inclusion criteria and were used for qualitative analysis. These studies demonstrated that individuals taking metformin had decreased rates of locoregional recurrence and metastasis and improved overall survival and disease-free survival rates. Individuals taking metformin had a lower incidence of HNSCC than those not taking metformin. Though there are only a few studies on the topic, currently available evidence suggests an association between HNSCC and metformin use. Metformin reportedly improves the overall survival of HNSCC patients.

Extracts of Morus nigra L. Leaves Standardized in Chlorogenic Acid, Rutin and Isoquercitrin: Tyrosinase Inhibition and Cytotoxicity

Melanogenesis is a process responsible for melanin production, which is stored in melanocytes containing tyrosinase. Inhibition of this enzyme is a target in the cosmetics industry, since it controls undesirable skin conditions such as hyperpigmentation due to the overproduction of melanin. Species of the Morus genus are known for the beneficial uses offered in different parts of its plants, including tyrosinase inhibition. Thus, this project aimed to study the inhibitory activity of tyrosinase by extracts from Morus nigra leaves as well as the characterization of its chromatographic profile and cytotoxicity in order to become a new therapeutic option from a natural source. M. nigra leaves were collected, pulverized, equally divided into five batches and the standardized extract was obtained by passive maceration. There was no significant difference between batches for total solids content, yield and moisture content, which shows good reproducibility of the extraction process. Tyrosinase enzymatic activity was determined for each batch, providing the percentage of enzyme inhibition and IC50 values obtained by constructing dose-response curves and compared to kojic acid, a well-known tyrosinase inhibitor. High inhibition of tyrosinase activity was observed (above 90% at 15.625 μg/mL). The obtained IC50 values ranged from 5.00 μg/mL ± 0.23 to 8.49 μg/mL ± 0.59 and were compared to kojic acid (3.37 μg/mL ± 0.65). High Performance Liquid Chromatography analysis revealed the presence of chlorogenic acid, rutin and, its major compound, isoquercitrin. The chromatographic method employed was validated according to ICH guidelines and the extract was standardized using these polyphenols as markers. Cytotoxicity, assessed by MTT assay, was not observed on murine melanomas, human keratinocytes and mouse fibroblasts in tyrosinase IC50 values. This study demonstrated the potential of M. nigra leaf extract as a promising whitening agent of natural source against skin hyperpigmentation.

Human papillomavirus detection in dysplastic and malignant oral verrucous lesions

The role of human papillomaviruses (HPV) in dysplastic and malignant oral verrucous lesions is controversial since there is a wide range in the incidence of virus detection. This study used a multi-tiered method of HPV detection using DNA in-situ hybridisation (ISH) for low- and high-risk subtypes, consensus PCR, and HPV genotype analysis in archival tissue from 20 cases of dysplastic and malignant oral verrucous lesions. The biological significance of HPV DNA detection was assessed by p16 immunohistochemistry (IHC). While 1/7 carcinomas and 5/13 dysplasias contained HPV DNA by consensus PCR and genotype analysis, all specimens were negative for low- and high-risk HPV ISH and negative for p16 IHC. Results show that although high-risk HPV DNA is detectable in a subset of these lesions, the lack of p16 overexpression suggests that the oncogenic process is not driven by HPV oncoproteins.

Copy Number and Loss of Heterozygosity Detected by SNP Array of Formalin-Fixed Tissues Using Whole-Genome Amplification

The requirement for large amounts of good quality DNA for whole-genome applications prohibits their use for small, laser capture micro-dissected (LCM), and/or rare clinical samples, which are also often formalin-fixed and paraffin-embedded (FFPE). Whole-genome amplification of DNA from these samples could, potentially, overcome these limitations. However, little is known about the artefacts introduced by amplification of FFPE-derived DNA with regard to genotyping, and subsequent copy number and loss of heterozygosity (LOH) analyses. Using a ligation adaptor amplification method, we present data from a total of 22 Affymetrix SNP 6.0 experiments, using matched paired amplified and non-amplified DNA from 10 LCM FFPE normal and dysplastic oral epithelial tissues, and an internal method control. An average of 76.5% of SNPs were called in both matched amplified and non-amplified DNA samples, and concordance was a promising 82.4%. Paired analysis for copy number, LOH, and both combined, showed that copy number changes were reduced in amplified DNA, but were 99.5% concordant when detected, amplifications were the changes most likely to be ‘missed’, only 30% of non-amplified LOH changes were identified in amplified pairs, and when copy number and LOH are combined ∼50% of gene changes detected in the unamplified DNA were also detected in the amplified DNA and within these changes, 86.5% were concordant for both copy number and LOH status. However, there are also changes introduced as ∼20% of changes in the amplified DNA are not detected in the non-amplified DNA. An integrative network biology approach revealed that changes in amplified DNA of dysplastic oral epithelium localize to topologically critical regions of the human protein-protein interaction network, suggesting their functional implication in the pathobiology of this disease. Taken together, our results support the use of amplification of FFPE-derived DNA, provided sufficient samples are used to increase power and compensate for increased error rates.

Host-derived salivary biomarkers in diagnosing periodontal disease: systematic review and meta-analysis

AIM To systematically evaluate the accuracy of host-derived salivary biomarkers in the diagnosis of periodontal disease based on the given sensitivity and specificity information. MATERIALS AND METHODS Studies were eligible for inclusion if they had compared the diagnostic application of salivary biomarkers with clinical examination of periodontal disease. A detailed search was performed in five databases without restrictions on subject age, chronology, or language. Additionally, a partial grey-literature search was conducted. The revised Quality Assessment of Diagnostic Accuracy Studies tool and Meta-analysis were used to evaluate the selected studies. RESULTS From the 905 screened studies, four were included in the qualitative and quantitative analysis. One biomarker, macrophage inflammatory protein-1α (MIP-1α), had excellent diagnostic accuracy and two, interleukin-1β (IL-1β) and interleukin-6 (IL-6), showed acceptable diagnostic values. However, the only biomarker considered excellent was evaluated in a single study, which may reduce the robustness of the results. CONCLUSION There is currently limited evidence to confirm the diagnostic capability of salivary biomarkers in the clinical assessment of periodontal disease. Notwithstanding, the summary findings showed the growing importance of salivary biomarker, and can guide larger, well-controlled, diagnostic accuracy studies. Likewise, although not conclusive, MIP-1α, IL-1β, and IL-6 may be promising biomarkers for future studies.

Diagnostic capability of salivary biomarkers in the assessment of head and neck cancer: A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis was to evaluate the diagnostic value of salivary biological markers in the diagnosis of head and neck carcinoma. Studies were gathered by searching Cochrane, EMBASE, LILACS, MEDLINE, and PubMed. The references were also crosschecked and a partial grey literature search was undertaken using Google Scholar. The methodology of selected studies was evaluated using the 14-item Quality Assessment Tool for Diagnostic Accuracy Studies. After a two-step selection process, 15 articles were identified and subjected to qualitative and quantitative analyses. The studies were homogeneous, and all had high methodological quality. Combined biomarkers demonstrated better accuracy with higher sensitivity and specificity than those tested individually. Furthermore, the salivary biomarkers reviewed predicted the early stages of head and neck carcinoma better than the advanced stages. A restricted set of five single biomarkers (interleukin-8, choline, pipecolinic acid, l-phenylalanine, and S-carboxymethyl-l-cysteine) as well as combined biomarkers demonstrated excellent diagnostic test accuracy. The present systematic review confirms the potential value of a selected set of salivary biomarkers as diagnostic tools for head and neck carcinoma.

Salivary biomarkers in the diagnosis of breast cancer: A review

Salivary biomarkers could be helpful to characterize breast cancer. Therefore, this review was performed to evaluate the capability of salivary biological markers in the diagnosis and monitoring of breast cancer. Studies were eligible for inclusion if they assessed the potential diagnostic value or other discriminatory properties of biological markers in saliva of patients with breast cancer. The search was performed in six electronic databases (Cochrane, LILACS, PubMed, Science Direct, Scopus, Web of Science). In addition the biomarkers were classified according to their potential clinical application. We identified 567 pertinent studies, of which 13 met the inclusion criteria. Combined biomarker approaches demonstrated better ability to predict breast cancer patients than individual biomarkers. As single biomarker, namely proline, reported great capacity in both early and late stage breast cancer diagnosis. Taurine showed interesting capability to identify early breast cancer individuals. Furthermore, valine also demonstrated excellent diagnostic test accuracy for advanced stages of breast cancer. Only seven studies reported sensitivity and specificity (Zhang et al., 2010; Streckfus et al., 2000a; Brooks et al., 2008; Cheng et al., 2015; Bigler et al., 2002; Zhong et al., 2016; Streckfus, 2009), which varied considerably from 50% to 100%, and from 51% to 97%, respectively. In general, salivary biomarkers identified advanced stages of breast cancer better than early stages. There is currently limited evidence to confirm the putative implementation of salivary biomarkers as diagnostic tools for breast cancer. However, current review provides new research directions.

Effects of metformin on endometrial cancer: Systematic review and meta-analysis

BACKGROUND Endometrial cancer is one of the most common gynecological cancers, which is frequently preceded by atypical endometrial hyperplasia, a premalignant lesion. Metformin, an antidiabetic drug, has emerged as a new adjunctive strategy for different cancer types, including endometrial cancer. This systematic review and meta-analysis aimed to evaluate the effects of metformin in atypical endometrial hyperplasia and endometrial cancer patients. METHODS The search was conducted on January 2017 and the articles were collected in Cochrane, LILACS, PubMed, Scopus and Web of Science. A grey literature search was undertaken using Google SCHOLAR, ProQuest and Open Grey. Nineteen studies were included, which contained information about the following outcomes: reversal of atypical endometrial hyperplasia, cellular proliferation biomarkers expression and overall survival in metformin-users compared to non-users. RESULTS Metformin was associated with reversion of atypical endometrial hyperplasia to a normal endometrial, and with decreased cell proliferation biomarkers staining, from 51.94% (CI=36.23% to 67.46%) to 34.47% (CI=18.55% to 52.43%). However, there is a high heterogeneity among studies. Metformin-users endometrial cancer patients had a higher overall survival compared to non-metformin users and non-diabetic patients (HR=0.82; CI: 0.70-0.95; p=0.09, I2=40%). CONCLUSION Regardless the high heterogeneity of the analyzed studies, the present review suggests that adjunct metformin treatment may assist in the reversal of atypical endometrial hyperplasia to normal endometrial histology, in the reduction of cell proliferation biomarkers implicated in tumor progression, and in the improvement of overall survival in endometrial cancer. Further work on prospective controlled trials designed to address the effects of adjunct metformin on clinical outcomes is necessary for definite conclusions.