Effects of tobacco on the DNA of smokers and non-smokers affected by OSCC: systematic review and meta-analysis

Abstract Scientific evidence about genetic and molecular changes in oral squamous cell carcinoma (OSCC) among smokers and non-smokers is inconclusive. This systematic review and meta-analysis assessed the effects of tobacco on the DNA of individuals with OSCC based on protein mutations. Electronic searches were conducted on PubMed, Ovid, Web of Science, and Scopus to identify observational studies published up to January/2022. The Joanna Briggs Institute tool was used for the critical appraisal of studies. The certainty of the evidence was evaluated. Twenty-three studies assessing 4,060 individuals (2,967 smokers vs. 1,093 non-smokers) were included in this review. Fifteen groups of proteins/genes were investigated. Analysis of the quality of articles revealed low risk of bias in most studies. The certainty of the evidence was very low. The meta-analysis confirmed no significant difference between smokers and non-smokers with respect to damage to GSTM1 (OR: 0.60; 95%CI: 0.30-1.18), GSTT1 (OR: 1.18; 95%CI:0.49-2.83), hydrolase proteins (Ku70 and Ku80) (OR: 0.74; 95%CI: 0.18-3.05), and transferase proteins (GSTM1, GSTT1, GSTM3) (OR: 0.74; 95%CI: 0.47-1.18). Most of the studies included showed that smokers are more likely to exhibit genetic instability. However, the meta-analysis revealed that smokers do not necessarily have more genetic alterations in the DNA than non-smokers.

DNA damage-related proteins in smokers and non-smokers with oral cancer

Abstract: Tobacco smoking involves a high risk of human malignancies, including oral cancer, because it contains multiple carcinogens that cause genetic instability. Thus, a worse prognosis would be expected for cancer patients who are smokers. The aim of this study was to assess the DNA damage response through the expression of checkpoint kinase 2 (CHK2), H2A histone family member X (H2AX), and P53 among smokers and non-smokers with oral squamous cell carcinoma (OSCC). Associations between immunoexpression of proteins and clinicopathological data and histopathological grading were also analyzed. A total of 35 individuals (18 non-smokers and 17 smokers) with OSCC of the tongue and/or floor of the mouth were included. Immunohistochemistry for H2AX was conducted for the identification of double-strand breaks, CHK2, and P53 to evaluate the expression of this protein in cell cycle regulation. The sample consisted of 22 males and 13 females, with a mean age of 63.9±11.8 years. OSCC of non-smokers were well-differentiated tumors in 50% of the cases, and those of smokers were equally distributed into moderately differentiated and poorly differentiated tumors (35.3% each). Overall, 31 (88.6%) cases were CHK2-positive, 27 (77.1%) were H2AX-positive, and 23 (65.7%) were P53-positive, with no difference between smokers and non-smokers (p > 0.05). No association was found between proteins and clinicopathologic data (p > 0.05). Similarities in CHK2, H2AX, and P53 immunohistochemical staining patterns were observed between smokers and non-smokers, and immunoexpression was not associated with clinicopathological parameters. However, the findings indicated consistent expression of these proteins in OSCC.

Toxicity of Carnoy's solution toward human keratinocytes: an in vitro study

Abstract: The present study aimed to characterize the chemical elements and cytotoxicity of Carnoy's solution (CS) by comparing two different trademarked products (one Brazilian [NCS] and another imported [ICS]) using inductively coupled plasma mass spectrometry (ICP-MS) and human keratinocyte (HaCaT) cultures. For performing ICP-MS, the solutions were diluted according to calibration curves, and the chemical elements were analyzed with a spectrometer. HaCaT cells were exposed to CS concentrations ranging from 0.10% to 20% for 3 or 5 min. Cell viability was evaluated immediately (T0), 24 h (T1), and 7 days (T2) after exposure to CS using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) reduction assay. Data were analyzed using a t-test for ICP-MS and analysis of variance followed by Tukey's post-hoc test for MTT assay, both considering statistical significance at p<0.05. ICP-MS results revealed that ICS presented significantly lower concentrations of 12 chemical elements than NCS. The results of MTT assay revealed that at T0, ICS was more cytotoxic than NCS regardless of the time of exposure (p < 0.05). At T1, the only difference between the groups was at a concentration of 0.10% after 5 min of exposure. At T2, at a concentration of 0.5%, ICS resulted in a significant reduction in cell viability compared to NCS (p < 0.05). Thus, the results showed that ICS was more cytotoxic than NCS. Collectively, our findings suggest that the individual compositions of different CS formulations should be investigated.

DNA Aneuploidy in Malignant Salivary Gland Neoplasms is Independent of USP44 Protein Expression

Chromosomal instability, leading to aneuploidy, is one of the hallmarks of human cancers. USP44 (ubiquitin specific peptidase 44) is an important molecule that plays a regulatory role in the mitotic checkpoint and USP44 loss causes chromosome mis-segregation, aneuploidy and tumorigenesis in vivo. In this study, it was investigated the immunoexpression of USP44 in 28 malignant salivary gland neoplasms and associated the results with DNA ploidy status assessed by image cytometry. USP44 protein was widely expressed in most of the tumor samples and no clear association could be established between its expression and DNA ploidy status or tumor size. On this basis, it may be concluded that the aneuploidy of the salivary gland cancers included in this study was not driven by loss of USP44 protein expression.

Resumo Instabilidade cromossômica acarretando aneuploidia é um dos fatores marcantes de neoplasias malignas humanas. USP44 (peptidase específica de ubiquitina 44) é uma importante molécula que exerce um papel regulador no ciclo celular e sua perda pode acarretar em segregação cromossômica deficiente, aneuploidia e desenvolvimento de tumores in vivo. Neste estudo, investigou-se a expressão imuno-histoquímica da proteína USP44 em 28 neoplasias malignas de glândulas salivares, associando-se os resultados com o estado de ploidia do DNA avaliado por citometria de fluxo. A proteína USP44 apresentou ampla expressão na maioria das amostras avaliadas e não foi observada associação entre a expressão protéica e o estado de ploidia do DNA ou extensão do tumor. Baseando-se nos resultados, concluiu-se que a aneuploidia das neoplasias malignas de glândulas de salivares incluídas neste estudo não foi influenciada pela perda de expressão da proteína USP44.

Wilms tumor 1 protein is not expressed in oral lymphangiomas

Lymphangiomas are benign hamartomatous lesions of lymphatic vessels. Wilms Tumor 1 (WT1) is a transcription factor that is activated in some human neoplasias. WT1 protein expression is observed in endothelial cells during angiogenesis and is a useful marker to distinguish between vascular proliferations and vascular malformations. The purpose of the present study is to report a case series of oral lymphangiomas together with an immunohistochemical investigation of WT1. Seventeen cases of oral lymphangioma were retrieved and reviewed. Immunohistochemical analysis of WT1 protein was performed and pyogenic granuloma samples were used as positive controls. The male/female ratio was 1.125 and most of the lesions occurred in young subjects. While pyogenic granuloma showed positive staining for WT1, the endothelial cells lining the thin-walled dilated lymphatic vessels of lymphangiomas were negative for this protein. The findings strengthen the idea that oral lymphangioma is a vascular malformation characterized by lymphatic dilatation without significant endothelial proliferation.

Os linfangiomas são tumores hamartomatosos benignos dos vasos linfáticos. O Wilms Tumor 1 (WT1) é um fator de transcrição que se encontra ativo em algumas neoplasias humanas. A expressão da proteína WT1 é observada em células endoteliais durante a angiogênese e pode ser um marcador útil para distinguir as proliferações vasculares das malformações vasculares. O objetivo deste estudo foi relatar uma série de casos de linfangiomas orais e avaliar a expressão imunoistoquímica da proteína WT1. Dezessete casos de linfangiomas orais foram recuperados e revisados. A análise imunoistoquímica foi realizada e amostras de granuloma piogênico foram utilizadas como controle positivo. A relação homem/mulher foi de 1,125 e a maioria das lesões acometeram pacientes jovens. Enquanto o granuloma piogênico mostrou uma imunopositividade para WT1, as células endoteliais da fina parede dos vasos linfáticos dilatados apresentaram-se negativas para esta proteína. Tais achados reforçam a idéia de que o linfangioma oral é uma malformação vascular caracterizada por dilatação linfática sem uma proliferação endotelial significativa.

Intraoral mucoepidermoid carcinoma of salivary glands: lack of association among clinicopathological features and immunoexpression of c-erbB-2 in 29 cases

The association among clinicopathological features and c-erbB-2 oncoprotein expression was evaluated in twenty-nine cases of intra-oral mucoepidermoid carcinoma (MEC). MEC was prevalent in the female gender (79.3 percent), tumors were more frequent in ages between 21 and 40 years (48.3 percent), and the palate was the most commonly affected site (72.4 percent). Microscopically, 27 cases (93.1 percent) were classified as low grade of malignancy. The c-erbB-2 expression was considered positive in 9 (31 percent) cases and no significant association (p>0.05) was found among protein expression and gender nor between patient age and site or histological grade of the lesion. c-erbB-2 expression in MEC may reflect intrisinc biologic properties of salivary gland neoplasms and may be linked to histogenesis and cellular differentiaton.

Fueron evaluados 29 casos de carcinoma mucoepidermoide intraoral en sus aspectos clínico-patológicos, además de la expresión de la oncoproteina c-erbB-2. El carcinoma mucoepidermoide fue predominante en las mujeres (79,3 por ciento), siendo más frecuente en individuos entre 21 y 40 años de edad (48,3 por ciento). El paladar fue el sitio más comunmente afectado (72,4 por ciento). Microscópicamente, 27 casos (93,1 por ciento) fueron clasificados como de baja malignidad. La expresión del c-erbB-2 se consideró positiva en 9 (31 por ciento) casos y no fue observada ninguna asociación significativa (p>0,05) entre la expresión de la proteína y género, ni entre la edad de los pacientes y el sitio o el grado histológico de la lesión. La expresión de la c-erbB-2 en el carcinoma mucoepidermoide puede mostrar las propiedades biológicas intrísecas de las neoplasias de las glándulas salivales.