metallothionein and Mouth-Neoplasms

Metallothioneins (MTs) gene polymorphisms have been associated with the ability of free radical scavenging and detoxification of heavy metals leading to cancer development. Our aim was to revisit, in a Brazilian population, single-nucleotide polymorphisms (SNPs) of the MT gene family previously associated with oral squamous cell carcinoma (OSCC).. A case-control investigation with 28 OSCC patients and 45 controls was conducted, using conventional risk factors (tobacco use and alcohol consumption) as covariates. SNPs genotyping for rs8052334 (MT1B), rs964372 (MT1B), and rs1610216 (MT2A) was performed by PCR-RFLP, and SNPs for rs11076161 (MT1A) were analyzed by TaqMan assay.. The only SNP associated with increased risk for OSCC was the MT-1A AA genotype (OR = 4.7; p = 0.01). We have also evidenced for the first time a significant linkage disequilibrium between the SNPs of MT-2A and MT-1A in this population with the highest frequency (30%) of the unfavorable haplotype G/A/C/T (rs1610216 / rs11076161 / rs964372 / rs8052334) of MT gene polymorphisms (OR = 6.2; p = 0.04). Interestingly, after removing the effects of conventional risk factors, we have uncovered the significance of the AA genotype of the rs11076161 with increased odds of 19-fold higher towards OSCC development.. This is the first demonstration that a significant linkage disequilibrium among gene polymorphisms of the MT family may affect susceptibility to oral cancer, which is conditioned by the G/A/C/T haplotype (rs1610216/rs11076161/rs964372/ rs8052334) and the MT-1A gene polymorphism has a potential clinical utility for the OSCC risk assessment.

Topics: Brazil; Carcinoma, Squamous Cell; Case-Control Studies; Genetic Predisposition to Disease; Genotype; Head and Neck Neoplasms; Humans; Metallothionein; Mouth Neoplasms; Polymorphism, Single Nucleotide; Risk Factors; Squamous Cell Carcinoma of Head and Neck

Metallothioneins (MTs) are proteins associated with the carcinogenesis and prognosis of various tumours. Previous studies have shown their potential as biomarkers in oral squamous cell carcinoma (OSCC). Aiming to understand more clearly the function of MTs in OSCC we evaluated, for the first time, the gene expression profile of MTs in this neoplasm.. Tissue samples from 35 cases of tongue and/or floor of mouth OSCC, paired with their corresponding non-neoplastic oral mucosa (NNOM), were retrieved (2007-09). All tissues were analysed for the following genes using TaqMan(®) reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays: MT1A, MT1B, MT1E, MT1F, MT1G, MT1H, MT1X, MT2A, MT3 and MT4. The expression of MT1B and MT1H was seldom detected in both OSCC and NNOM. A significant loss of MT1A, MT1X, MT3 and MT4 expression and gain of MT1F expression was observed in OSCC, compared to NNOM. Cases with MT1G down-regulation exhibited the worst prognoses. The up-regulation of MT1X was restricted to non-metastatic cases, whereas up-regulation of MT3 was related to cases with lymph node metastasis.. Metallothionein mRNA expression is altered significantly in oral squamous cell carcinomas. The expression of MT1G, MT1X and MT3 may aid in the prognostic discrimination of OSCC cases.

Topics: Aged; Biomarkers, Tumor; Carcinoma, Squamous Cell; Down-Regulation; Female; Humans; Male; Matrix Metalloproteinase 16; Metallothionein; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Prognosis; RNA, Messenger; RNA, Neoplasm; Tongue Neoplasms; Up-Regulation

To examine the presence of markers associated with malignancy, including p53, p21 cyclin-dependent kinase inhibitor 1A, murine double minutes-2, and others, in chronic hyperplastic candidiasis.. Immunohistochemical methods were used to examine the expression of p53, murine double minutes-2, p21 cyclin-dependent kinase inhibitor 1A, metallothionein, and proliferating cell nuclear antigen in 42 chronic hyperplastic candidiasis lesions and 11 non-infected control tissues. Terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling was used to examine apoptosis, which was correlated with p53 expression. These markers were measured in lesions of chronic hyperplastic candidiasis that did not show any epithelial dysplasia or histological signs of malignancy.. p53 scores were higher in chronic hyperplastic candidiasis than in controls (P = 0.0046). Murine double-minutes 2 levels were not elevated. p21 cyclin-dependent kinase inhibitor 1A was increased in parabasal (P < 0.0001) and basal epithelial cells. Chronic hyperplastic candidiasis lesions showed a similar basal/parabasal metallothionein staining pattern to that seen in normal squamous epithelium. Proliferating cell nuclear antigen was increased (P = 0.0007), as was apoptosis (P = 0.0033).. Increased p53 in oral chronic hyperplastic candidiasis suggests an increased potential for malignant change in the epithelium, above that of normal tissues. Further functional investigation is required, as well as clinical follow-up studies.

Topics: Biomarkers, Tumor; Candidiasis, Oral; Carcinoma, Squamous Cell; Cyclin-Dependent Kinase Inhibitor p21; Epithelial Cells; Female; Gene Expression; Humans; Hyperplasia; Immunohistochemistry; In Situ Nick-End Labeling; Male; Metallothionein; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-mdm2; Tumor Suppressor Protein p53

We recently reported that TCRP1, a novel multidrug-resistance associated human gene, can mediate cisplatin resistance in OSCC cells. However, the molecular mechanism underlying this role of TCRP1 remained to be elucidated. In this study, by using Human Toxicology and Drug Resistance Microarray, we identified 30 genes with significantly different expression levels between Tca/PYM and TCRP1 knockdown cell lines. Co-immunoprecipitation experiments and GST-pull down assays showed that metallothionein1X (MT1X) and Akt interact with TCRP1. siRNA-mediated knockdown of TCRP1 and MT1X was found to sensitize cells to cisplatin, leading to increased apoptosis and inhibition of cell proliferation. These functions of TCRP1 may be caused at least in part via activation of the PI3K/Akt/NF-κB signaling pathway. Taken together, our findings indicate that TCRP1 may be an important drug target for improvement of the treatment and survival of patients with oral squamous cell carcinoma.

Topics: Antineoplastic Agents; Apoptosis; Base Sequence; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Cisplatin; DNA Primers; Drug Resistance, Neoplasm; Gene Knockdown Techniques; Humans; Metallothionein; Mouth Neoplasms; NF-kappa B; Oligonucleotide Array Sequence Analysis; Proteins; Real-Time Polymerase Chain Reaction

We conducted an independent analysis of metallothionein 1 (MT-1) rs8052394, rs11076161, rs8052334, rs964372, rs7191779, and rs708274 in 587 individuals who were either healthy controls or subjects with oral squamous cell carcinoma (OSCC).. All participants provided a nucleic acid sample (blood) as well as epidemiologic information on covariates or "risk factors" for OSCC, including tobacco, alcohol, and areca quid use. The genotyping result was used in a logistic regression model that examined main effects as well as statistical interactions while controlling for confounders.. MT-1 is involved in regulation of zinc and copper homeostasis. It also is a potent antioxidant and its polymorphisms correlate with the risk for OSCC. Rs11076161 A, rs964372 C, and rs7191779 C alleles were protective against OSCC (adjusted OR = 0.53, 0.49, 0.36, respectively; p < 0.05), whereas rs8052394 A alleles were associated with increased risk. Areca quid chewing and tobacco use were strong risk factors for developing the disease and were associated with 20- and 8-fold increases in adjusted risk (p < 0.05), respectively.. Controlling for the effects of age, gender, areca quid, tobacco, and alcohol use, individuals with inherited the MT-1 rs11076161 AA, rs964372 CC, and rs7191779 GC genotypes may experience significant protection against OSCC, whereas individuals carrying the MT-1 rs8052394 A allele seem exposed to higher risk.

Topics: Alcohol Drinking; Areca; Carcinoma, Squamous Cell; Case-Control Studies; Female; Genotype; Humans; Male; Metallothionein; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Polymerase Chain Reaction; Polymorphism, Genetic; Prognosis; Risk Factors

This study aimed at finding out whether the expression of metallothionein (MT), laminin, Ki-67 antigen and minichromosome maintenance-2 (Mcm-2) protein changes with growing invasiveness of the tumour. The expression of these markers in primary tumours with no metastases to lymph nodes (PT N-) was compared with the expression in primary tumours with metastases in draining lymph nodes (PT N+). The difference in marker expression was also evaluated between metastatic lymph nodes (LN+) and the corresponding primary tumours (PT N+).. The studies were performed on tumour samples from 39 patients with squamous cell carcinoma of the oral cavity floor or of the oral part of the tongue. All the patients had been subjected to radical surgery, accompanied by the removal of lymph nodes. In 20 patients post-operative histopathology disclosed the presence of metastases in the draining lymph nodes (pN+), while in 19 patients the presence of such metastases was excluded (pN0).. The PT N+ group was found to contain a significantly higher percentage of cells with cytoplasmic expression of MT, than the PT N- group. In turn, a significant increase in the intensity of reaction of cytoplasmic MT and an increased percentage of cancer cells demonstrating MT expression in the cell nuclei was demonstrated in the LN+ compared to the PT N+ group. The expression of the remaining parameters did not significantly differ between PT N-, PT N+ and LN+.. A gradual increase in MT expression (both cytoplasmic and nuclear) takes place with progression of the tumour and the increased nuclear expression of MT in LN+ cells may suggest a role of MT in metastasis development in the studied tumours.

Topics: Adult; Aged; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Cycle Proteins; Disease Progression; Female; Humans; Ki-67 Antigen; Lymphatic Metastasis; Male; Metallothionein; Middle Aged; Minichromosome Maintenance Complex Component 2; Mouth Neoplasms; Neoplasm Invasiveness; Nuclear Proteins

Metallothionein and p53 proteins have been associated with tumoral evolution and resistance against therapy. Experimentally, the former may modulate the activity of tumor suppressor protein through zinc exchange. However, there is no information on the relationship of these proteins in oral cancer.. Immunohistochemical detection of metallothionein and p53 antigens was performed in 100 oral squamous cell carcinomas. Results were compared to evaluate possible relationships between them and the disease-specific survival.. Mean cellular indexes of positivity were 66.5% and 52.5% for metallothionein and p53, respectively, and a positive correlation was found between them. Frequent nuclear metallothionein immunolocalization was associated to increased p53 expression. Concomitant overexpression of both antigens predicted shorter survival for patients with advanced disease.. These results corroborate the speculated association between metallothionein and p53 and suggest that simultaneous assessment of these proteins may be useful to evaluate aggressiveness of oral cancer.

Topics: Biomarkers, Tumor; Carcinoma, Squamous Cell; Female; Humans; Immunoenzyme Techniques; Male; Metallothionein; Middle Aged; Mouth Neoplasms; Prognosis; Survival Rate; Tumor Suppressor Protein p53

Oral leukoplakia (OL) is the main potentially malignant lesion of the oral cavity, and oral squamous cell carcinoma (OSCC) accounts for more than 95% of all malignant neoplasms in the oral cavity. Therefore, the aim of this study was to verify the immunoexpression of p-Akt and Metallothionein (MT) proteins in dysplasic and neoplasic oral lesions.. Immunohistochemical studies were carried out on 10 normal epithelium, 30 OL and 15 OSCC paraffin-embedded samples. Immunoperoxidase reaction for p-Akt and MT proteins was applied on the specimens, and the positivity of the reactions was calculated for 1000 epithelial cells.. Using the ANOVA and the Tukey's post hoc statistical analyses, it was observed a significant difference in the immunoexpression for p-Akt and MT when the OSCC samples were compared with normal and dysplasic epithelial groups. In addition, the Pearson's correlation test showed a significant correlation between the proteins' expression.. Based on the data obtained, p-Akt and MT activation may play an important role in the conversion of a potentially malignant oral lesion to a malignant carcinoma since its earlier stages.

Topics: Adult; Analysis of Variance; Carcinoma, Squamous Cell; Case-Control Studies; Female; Humans; Leukoplakia, Oral; Male; Metallothionein; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Precancerous Conditions; Proto-Oncogene Proteins c-akt; Reference Values; Second Messenger Systems; Signal Transduction; Statistics, Nonparametric

Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich, inducible, intracellular proteins that bind heavy metals with high affinity. MT-1 is known as a stress-inducible protein and functions as an antioxidant enzyme. Areca quid chewing is a major risk factor in the development and further progression of oral squamous cell carcinoma (OSCC). The aim of this study was to compare MT-1 expression in normal human oral epithelium and OSCC and further explore the potential mechanism that may lead to induce MT-1 expression. Thirty four OSCC and 10 normal epithelium specimens were examined by immunohistochemistry and analyzed by the clinico-pathological profiles. The oral epithelial cell line GMN cells were challenged with arecoline, a major areca nut alkaloid, by reverse-transcriptase polymerase chain reaction. Furthermore, tobacco smoke carcinogen benzo[a]pyrene (BaP) and glutathione (GSH) precursor N-acetyl-l-cysteine (NAC) were added to find the possible regulatory mechanisms. The results from immunohistochemistry demonstrated that MT-1 expression was significantly higher in OSCC specimens (p<0.05). No significant difference in MT-1 expression was observed with respect to age, sex, T category, and stage (p>0.05). The high MT-1 expression was associated with lymph node metastasis (p=0.012). In addition, arecoline was found to elevate MT-1 mRNA in a dose-dependent manner (p<0.05). Furthermore, the addition of BaP enhanced the arecoline-induced MT-1 expression (p<0.05). The addition of NAC markedly inhibited the arecoline-induced MT-1 expression (p<0.05). These results lead to the conclusion that MT-1 expression is significantly upregulated in areca quid chewing associated-OSCC. The expression profile suggests MT-1 could be used clinically as a marker for tumors possessing the potential for lymph node metastasis. The compounds of tobacco products may act synergistically in the pathogenesis of OSCC in areca quid chewers. The regulation of MT-1 expression induced by arecoline is critically dependent on the intracellular GSH concentration.

Topics: Adult; Aged; Areca; Carcinoma, Squamous Cell; Case-Control Studies; Chi-Square Distribution; Female; Humans; Immunohistochemistry; Male; Metallothionein; Middle Aged; Mouth Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Up-Regulation

Metallothionein (MT), a low-molecular-weight protein with high cysteine content, seems to be related to neoplastic resistance to oncologic treatment and therefore has been studied as a prognostic factor for a variety of human malignant tumors. MT overexpression in neoplasms of ectodermal origin is usually associated with a poor prognosis. MT expression was evaluated in 60 samples of oral squamous cell carcinoma by immunohistochemistry to study its prognostic influence on oral cancer. Possible associations of MT immunoexpression were also investigated with respect to clinical stage (TNM), histological grading, and proliferation index (Ki-67) of the lesions. No significant statistical correlation was observed among these variables. The impact on overall survival was assessed by uni and multivariate statistical tests. Mean MT labeling index was 60%. High MT labeling indexes (over 76%) predicted shorter survival in univariate statistical analysis. In multivariate analysis, MT labeling index and clinical stage were independent prognostic factors. MT overexpression in oral squamous cell carcinoma seems to be related to a worse prognosis for patients.

Topics: Adult; Aged; Carcinoma, Squamous Cell; Cell Division; Female; Humans; Immunoenzyme Techniques; Ki-67 Antigen; Male; Metallothionein; Middle Aged; Mouth Neoplasms; Neoplasm Staging; Survival Analysis; Survival Rate