Alteration of miRNA expression correlates with lifestyle, social and environmental determinants in esophageal carcinoma.

BACKGROUND/AIM: Esophageal cancer (EC) is the eighth most common cancer with a highly aggressive potency. Considering the poor survival of esophageal carcinoma there is a need for useful molecular biomarkers for prevention and early detection. Our aim was to determine the significance of altered microRNA (miRNA) expression in esophageal cancer, in relation to lifestyle, social and environmental factors. MATERIALS AND METHODS: The relative expression levels of the following miRNAs: miR-21, miR-143, miR-196a, miR-203, miR-205 and miR-221 were monitored in control and esophageal squamous-cell carcinoma (ESCC) samples using real-time polymerase chain reaction (RT-PCR). miRNA expression pattern of tumor tissues were evaluated according to patients' social status, living condition, smoking and drinking habits alone and in combinations. RESULTS: miR-21, miR-143, miR-203, miR-205 and miR-221 were over-expressed in esophageal cancer compared with normal tissues. Increased expression of miR-205 was related to smoking, while excessive alcohol consumption showed a correlation with under-expression of miR-143, miR-203 and miR-205 in tumor samples. Significant associations were detected between reduced expression of miR-143, miR-203 and low social status, and combination of smoking and heavy drinking. CONCLUSION: Alterations of miRNA expression in ESCC can be correlated with the presence of common risk factors. The altered expression of certain miRNAs could be used as novel molecular markers of esophageal carcinoma.

MicroRNA expressions in HPV-induced cervical dysplasia and cancer.

BACKGROUND/AIM: The role of oncogenic or high-risk human papillomavirus (HPV) in cervical carcinogenesis is inevitable, yet not fully understood. Detailed analysis of microRNA (miRNA) alterations occurring during high-risk HPV transformation will increase our current understanding over cervical carcinogenesis. The two main aims of the study were: (i) finding association between HPV infection characteristics and socio-demographic variables, (ii) finding an predictors of clinical outcome. MATERIALS AND METHODS: The expression levels of different microRNAs (miR-21, miR-27a, miR-34a, miR-155, miR-196a, miR-203) were determined in formalin-fixed paraffin-embedded (FFPE) human HPV-positive cervical dysplastic and tumorous tissue samples using quantitative real-time PCR (qPCR). Sociodemographic and life-style factors were also analyzed. RESULTS: The expression of miR-27a was significantly higher in cervical intraepithelial neoplasia (CIN)2-3 compared to CIN1 (p=0.023) and in squamous cell carcinoma (SCC) compared to CIN2-3 (p=0.033). Moreover, significantly lower levels of miR-34a were detected in CIN2-3 than in CIN1 (p=0.041) and in SCC than in CIN2-3 (p=0.021). Furthermore, we found significant differences in subjects with multiple HPV in miR-27a (p=0.015) and miR-203 (p=0.025) in CIN2-3 compared to CIN1 and miR-21 (p=0.002), mir-27a (p=0.001) and miR-34a (p=0.001) in SCC/CIN2-3. Expression of miR-27a, showing up-regulation in CIN2-3 compared to CIN1 (p=0.028) and miR-34a (down-regulated), correlated with HPV 16 positivity (CIN2-3/CIN1: p=0.027 and SCC/CIN2-3: p=0.036). MiR-34a expression was also significantly altered in connection to smoking status and presence of HPV 16. CONCLUSION: The demand for additional, alternative molecular biomarkers with prognostic potential is strong. Evaluation of miRNA expression might be helpful to distinguish different cervical lesions and might be able to help in the prediction of HPV infection outcome.

Red sludge-induced mRNA and miRNA expression alterations in vital organs of CBA/Ca mice.

Several studies have investigated the ecological and genotoxic effects of the red mud accident in 2010 in Ajka, Hungary, but none was designed to reveal the early biological effects of red mud exposure at the level of early-responding gene expression. To address relevant questions, in the present study expression alterations of oncogenes (c-myc, K-ras), tumor suppressor genes (Bcl2, p53) and apoptosis-regulatory micro(mi) RNAs (miR-21, miR-27a, miR-93, miR-221) were analized 1, 3, 6 and 24 h after a single intraperitoneal injection of red mud to CBA/Ca mice. We observed changes in the expression of all investigated mRNAs, miR-21 and miR-221 in the liver, spleen, lung, kidney and lymph nodes of mice. An overexpression of the investigated genes was observed, but the level and the peak of the alteration differed according to examined tissue.

Unique microRNA expression profiles in cervical cancer.

Cervical cancer is the second leading cause of death among female patients with cancer in the world. Our aim was to analyze cervical cancer cases, in the Southwestern Transdanubian Region of Hungary, with regard to human papillomavirus (HPV) genotype and histological and clinical grading. After HPV testing and genotyping, the expressions of eight different pre-microRNAs (miR-21, miR-27a, miR-34a, miR-146a, miR-155, miR-196a, miR-203, miR-221) in formalin-fixed paraffin-embedded (FFPE) primary human cervical cancer samples were evaluated with the help of the LightCycler 480 PCR System (Roche). Statistically significant overexpression of miR-21 (p=0.004), miR-27a (p=0.018), miR-34a (p<0.001), miR-155 (p=0.021), miR-196a (p=0.032), miR-203 (p=0.037) and miR-221 (p=0.017) were observed in squamous cell carcinoma, regardless of HPV status and clinical grading. Significant overexpression of miR-21 (p=0.004), miR-27a (p=0.02), miR-34a (p<0.001), miR-196a (p=0.027) and miR-221 (p=0.031) was characteristic of HPV-positive squamous cell carcinomas in contrast to adenocarcinomas of the same HPV status.

Expression of NFkB1, GADD45A and JNK1 in salivary gland carcinomas of different histotypes.

The class of salivary gland tumours is very heterogenous, both in a histopathological and clinical sense. Since they are uncommon lesions, their clinical management is still problematic. Molecular mechanisms underlying the development of these cancer types may be fundamental for the diagnosis, treatment and prognosis of this disease. In this study, the gene expression of nuclear factor-kappa B (NKkB1/p65), c-Jun N-terminal kinase (JNK1) and growth arrest and DNA damage (GADD45A), which all play an important role in inflammatory and cell survival mechanisms, was assessed in benign and malignant neoplasms of the salivary gland. The absolute mRNA content of paraffin embedded samples of salivary gland cancer was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using specific primers for NFkB1, GADD45A and JNK1. Expression values (relative to HPRT) were statistically evaluated. Among the detected alterations in gene expression, the only difference reaching statistical significance was in the case of NFkB1 in adenocystic carcinomas (p=0.05). Given the importance of these signalling mechanisms in the biology of tumorigenesis, these results may be implemented in further research and these genes might become targets for innovative diagnostic and therapeutic strategies.

miRNA expression profiles of oral squamous cell carcinomas.

BACKGROUND: Oral squamous cell carcinoma (OSCC) development involves complex machinery of genomic and epigenetic regulations including microRNA (miRNA) expression changes. We aimed to analyze the expression patterns of a set of miRNAs in human TNM stage I and II OSCC samples in an autologous normal mucosa-controlled experimental design. MATERIALS AND METHODS: Forty samples of OSCC and 40 matched normal tissues were evaluated for miR-21, miR-155, miR-191, miR-146a, miR-221 and miR-222 expression in a LightCycler 480(PCR) system. RESULTS: Our results showed significant overexpression of miR-21, miR-155, miR-191 and miR-221 in paired-sample t-test and the sensitivity/specificity of tests were over 90% in the case of miR-21 and miR-155 on the receiver operating characteristic curve (ROC) analysis. CONCLUSION: Our results underline the role of miR-21 in OSCC and support the possible causal role of miR-155 and miR-221 in oral carcinogenesis. The overexpression of miR-191 is a novel finding in squamous cell carcinoma.

Very early effect of DMBA and MNU on microRNA expression.

BACKGROUND: microRNA expression profile analysis provides evaluation of the early stages of carcinogenesis. This study focuses on early alteration of miRNA expression after treatment with different carcinogens. MATERIALS AND METHODS: Mice were intraperitoneally injected with one dose of 7,12-dimethylbenz(α)anthracene (DMBA) and N-methyl-N-nitrosourea (MNU). The expression of miRNAs were analyzed 3 and 6 hours after the treatment, using quantitative real-time-polymerase chain reaction. RESULTS: Underexpression of miR-34a and miR-155 were detected in the liver, spleen and kidneys at 3 and 6 hours after MNU treatment. In the lungs and kidneys, the expression of miR-21 was significantly elevated 6 hours after DMBA treatment, while in the liver, MNU induced higher expression levels of miR-21 at 3 and 6 hours compared to treatment with DMBA. CONCLUSION: The different response of miRNAs to carcinogens emphasizes their possible role as potential epidemiological biomarkers in early phases of environmental tumorigenesis.

DMBA induces deregulation of miRNA expression of let-7, miR-21 and miR-146a in CBA/CA mice.

BACKGROUND: 7,12-Dimethylbenz(α)anthracene (DMBA) is a carcinogen capable of inducing various types of tumors. MATERIALS AND METHODS: We investigated the effect of DMBA on micro-RNA expression in CBA/CA H2(k) inbred mice after 24 hours and one week from exposure. RESULTS: Expression levels of miR-21, miR-146a and let-7a were significantly higher in the vital organs of the mice 24 hours after DMBA exposure compared to those of the controls. On the other hand, a significant down-regulation of the miRNAs was observed seven days after DMBA administration. CONCLUSION: Based on our data, DMBA has an impact on the expression of miR-21, let-7a and miR-146a genes. The altered micro-RNA expression can be regarded as an early effect of exposure to chemical carcinogens. To our knowledge, this is the first study of miRNA modulation caused by DMBA in non-malignant tissues.

Difficulties in the prevention of cervical cancer: adults' attitudes towards HPV vaccination 3 years after introducing the vaccine in Hungary.

Cervical cancer is one of the most prevalent gynaecological malignancies worldwide. The Hungarian incidence and mortality of this disease take the 4th-5th places within the European Union. A survey including 785 male and female adults was conducted to assess the knowledge and attitudes concerning HPV vaccination. We focused on the difficulties of the primary and secondary prevention of cervical cancer and examined some potential sociodemographic predictors of HPV vaccine acceptability. Our findings have identified some important issues like: incomplete knowledge, intense distrust and financial concerns. Almost half of the college students (45.6%) are unaware of HPV infections. We confirmed previous findings that older age and female gender correlates with better knowledge on STDs, including HPV. We found that greater exposure to health information comes with better knowledge and more positive attitudes towards vaccination. One quarter of survey respondents do not believe that cervical cancer may be prevented by vaccination. More than half of the adults do not trust national health care system and the preparedness of Hungarian doctors. General attitudes towards vaccination are broadly positive, 80% of survey participants had expressed desire towards HPV vaccination, however if there was a need to pay for the vaccination the willingness would decrease by half. Primary prevention through HPV-focused educational programs, clear communication and financial support would be important for public health to reduce the high incidence and mortality of cervical cancer in Hungary in the future.

[Impact of microRNAs on molecular epidemiology]. / Mikro-RNS-ek jelentosége a molekuláris epidemiológiában.

Cancer research concerning short non-coding RNA sequences and functionally linked to RNA interference (RNAi) have reached explosive breakthrough in the past decade. Molecular technology applies microRNA in extremely wide spectrum from molecular tumor prediction, diagnostics, progression monitoring and prevention. Functional analysis of tissue miRNA and cell-free serum miRNA in posttranscription and translation regulation innovated and restructured the knowledge on the field. This review focuses on molecular epidemiology and primary prevention aspects of the small non-coding RNA sequences.