Leptin acts on neoplastic behavior and expression levels of genes related to hypoxia, angiogenesis, and invasiveness in oral squamous cell carcinoma.

Leptin, one of the main hormones controlling energy homeostasis, has been associated with different cancer types. In oral cancer, its effect is not well understood. We investigated, through in vitro and in vivo assays, whether leptin can affect the neoplastic behavior of oral squamous cell carcinoma. Expression of genes possibly linked to the leptin pathway was assessed in leptin-treated oral squamous cell carcinoma cells and also in tissue samples of oral squamous cell carcinoma and oral mucosa, including leptin, leptin receptor, hypoxia-inducible factor 1-alpha, E-cadherin, matrix metalloproteinase-2, matrix metalloproteinase-9, Col1A1, Ki67, and mir-210. Leptin treatment favored higher rates of cell proliferation and migration, and reduced apoptosis. Accordingly, leptin-treated oral squamous cell carcinoma cells show decreased messenger RNA caspase-3 expression, and increased levels of E-cadherin, Col1A1, matrix metalloproteinase-2, matrix metalloproteinase-9, and mir-210. In tissue samples, hypoxia-inducible factor 1-alpha messenger RNA and protein expression of leptin and leptin receptor were high in oral squamous cell carcinoma cases. Serum leptin levels were increased in first clinical stages of the disease. In animal model, oral squamous cell carcinoma-induced mice show higher leptin receptor expression, and serum leptin level was increased in dysplasia group. Our findings suggest that leptin seems to exert an effect on oral squamous cell carcinoma cells behavior and also on molecular markers related to cell proliferation, migration, and tumor angiogenesis.

Hypoxia reduces the E-cadherin expression and increases OSCC cell migration regardless of the E-cadherin methylation profile.

OBJECTIVE: The purpose of the current study is to investigate the association between E-cadherin methylation status, hypoxia and OSCC. METHODS: HaCat and SCC9 cell lines were submitted to hypoxic treatment, followed by methylation profile analysis (MS-PCR) and analysis of the expression of mRNA gene E-cadherin (RT-PCR). Study group samples comprise individuals affected by potentially malignant lesions Potential Malignant Oral Lesion (PMOL, n=18) and oral squamous cell carcinoma (OSCC, n=28). The control group oral mucosa (OM, n=15) of patients with an oral mucocele. Cell migration ability was evaluated a scratch wound assay in SCC9 and HaCat cell lines RESULTS: E-cadherin mRNA expression in the cell lines SCC9 and HaCat was significantly reduced under hypoxia, regardless of the methylation profile, when compared to the control group. No differences in methylation profile of the E-cadherin were observed among the groups OM, PMOL and OSCC. HaCat and SCC9 presented increases in cell migration rates under hypoxia. CONCLUSION: The current study demonstrates that hypoxia reduces E-cadherin expression and increase cell migration, regardless of the methylation profile. Additionally, no differences in E-cadherin methylation patterns were observed among OM, PMOL and OSCC.

Increasing demonstration of angiogenic markers in skin neoplastic lesions.

BACKGROUND: Skin cancer represents the most common worldwide malignancy. Angiogenesis is an important factor in tumor growth and metastasis. Given these facts, the purpose of the current study was to compare the levels of angiogenic proteins in the context of the most common malignant and premalignant skin lesions. METHODS: Immunohistochemistry of CD31, HIF1A, VEGFR1 and VEGFR2 was performed in basal cell carcinoma (BCC), actinic keratosis (AK) and squamous cell carcinoma of the skin (SCCS). RESULTS: SCCS presented with increased levels of HIF1A, VEGFR1 and VEGFR2 in comparison to AK. In addition, SCCS also demonstrated increased levels of HIF1A to BCCLR or BCCHR. BCC presented with more vessels than AK. However, no correlation was observed among CD31, HIF1A, VEGFR1 and VEGFR2. CONCLUSIONS: SCCS presented with higher levels of HIF1A, VEGFR1 and VEGFR2, while BCC demonstrated an increased number of vessels in relation to AK. These data suggest that antiangiogenic therapy might be useful for skin cancer treatment.

Fuzzy clustering demonstrates that codon 72 SNP rs1042522 of TP53 gene associated with HNSCC but not with prognoses.

It is estimated that 7.6 million people will die as a consequence of head and neck squamous cell carcinoma (HNSCC). Genetic predisposition has emerged as an important risk factor in the development and prognosis of HNSCC. Considering this, the aim of the current study is to assess whether codon 72 SNP of the TP53 gene (rs1042522) is associated with an increased odds ratio of developing HNSCC or with a worse prognosis in patients with HNSCC. Analysis of the rs1042522 in HNSCC patients and in control individuals. Differences between the case and control groups were determined using chi-squared tests. Multivariate analysis was performed to evaluate the odds ratio of HNSCC. Fussy C Means Clustering was to cluster HNSCC patients for survival analyses. Time of survival was calculated using the Kaplan-Meier estimator and comparing this to the log rank test. Statistical significance was set at p < 0.05. A total of 71.4 % of the Arg/Arg genotype were from HNSCC patients, while only 28.6 % of Arg/Arg genotype were found in the control group. Logistic regression demonstrated that the Arg/Arg genotype, smoking, and alcohol consumption increase the odds ratio of HNSCC. No association between TP53 codon 72 polymorphism and P53 expression. No association between rs1042522 and survival or prognoses was observed. This study identified that individuals carrying the arginine allele at rs1042522 have an increased odds ratio of HNSCC. However, no association between codon 72 SNP of the TP53 gene and HNSCC prognosis or P53 expression was observed.

Bioinformatics, interaction network analysis, and neural networks to characterize gene expression of radicular cyst and periapical granuloma.

INTRODUCTION: Bioinformatics has emerged as an important tool to analyze the large amount of data generated by research in different diseases. In this study, gene expression for radicular cysts (RCs) and periapical granulomas (PGs) was characterized based on a leader gene approach. METHODS: A validated bioinformatics algorithm was applied to identify leader genes for RCs and PGs. Genes related to RCs and PGs were first identified in PubMed, GenBank, GeneAtlas, and GeneCards databases. The Web-available STRING software (The European Molecular Biology Laboratory [EMBL], Heidelberg, Baden-Württemberg, Germany) was used in order to build the interaction map among the identified genes by a significance score named weighted number of links. Based on the weighted number of links, genes were clustered using k-means. The genes in the highest cluster were considered leader genes. Multilayer perceptron neural network analysis was used as a complementary supplement for gene classification. RESULTS: For RCs, the suggested leader genes were TP53 and EP300, whereas PGs were associated with IL2RG, CCL2, CCL4, CCL5, CCR1, CCR3, and CCR5 genes. CONCLUSIONS: Our data revealed different gene expression for RCs and PGs, suggesting that not only the inflammatory nature but also other biological processes might differentiate RCs and PGs.

Protein expression of MMP-2 and MT1-MMP in actinic keratosis, squamous cell carcinoma of the skin, and basal cell carcinoma.

Squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are 2 skin neoplasms with distinct potentials to invasion and metastasis. Actinic keratosis (AK) is a precursor lesion of SCC. Immunohistochemistry was performed to evaluate the expression of MMP-2 and MT1-MMP in samples of BCC (n = 29), SCC (n = 12), and AK (n = 13). The ratio of positive cells to total cells was used to quantify the staining. Statistical significance was considered under the level P < .05. We found a higher expression of MMP-2 in tumor stroma and parenchyma of SCC as compared to BCC. The expression of this protein was also similar between SCC and its precursor actinic keratosis, and it was higher in the stroma of high-risk BCC when compared to low-risk BCC. MT1-MMP, which is an activator of MMP-2, was similarly expressed in all groups. Our results suggest that MMP-2 expression may contribute to the distinct invasive patterns seen in SCC and BCC.

p16 (CDKN2A) SNP rs11515 was not associated with head and neck carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is considered a serious public health problem in many countries. Recently, genetic variations have been considered as important factors to cancer susceptibility and prognosis. More specifically, genetic polymorphisms have been associated with the development and prognosis of HNSCC. The purpose of the current study was to investigate an association among p16 (CDKN2A) gene polymorphism at rs11515, age, and HNSCC aggressiveness. PCR-RFLP analysis was used to investigate the p16 (CDKN2A) gene in 96 patients with HNSCC and in 100 individuals without HNSCC. A case group was categorized by age in younger (<60 years) and older (≥ 60 years) patients. Differences between the case and control groups were determined using Fisher and chi-squared tests. Time of survival was calculated from the date of diagnosis to the date of last follow-up visit or to the date of death using the Kaplan-Meier estimator and comparing this to the log-rank test. Statistical significance was set at p<0.05. In the present study, no association was established between HNSCC and rs11515 polymorphism, as indicated in a previous study. We found that HNSCC individuals with large-sized tumors and with metastatic disease presented worse overall survival, consistent with fundamental concepts that establish the effects of tumor size and lymph node metastasis to HNSCC outcomes. This study identified that there is no difference in the distribution of rs11515 between the control and HNSCC groups. In addition, no differences between rs11515 genotypes and clinicopathological parameters were observed.