Phosphatase and tensin homologue (PTEN) is a tumour suppressor gene implicated in tumorigenesis of melanoma, with distinct cytoplasmic and nuclear functions. Cytoplasmic PTEN negatively regulates the PI3K/AKT/mTOR signalling pathway, while nuclear PTEN works as a tumour suppressor. Clinical data suggest that the loss of PTEN function in melanoma is associated with aggressive tumour behaviour. We performed a comprehensive analysis of PTEN in 112 primary cutaneous melanomas including immunohistochemical (IHC), fluorescent in situ hybridization (FISH), next-generation sequencing (NGS), and epigenetic analysis. The goal of our study was to: (a) correlate PTEN expression with selected clinico-pathological variables, and assess its prognostic significance; (b) correlate molecular aberrations with PTEN expression to consider the utility of immunohistochemical analysis of PTEN protein expression for screening PTEN genetic alterations; (c) review the literature and evaluate the PTEN expression level in melanoma with respect to possible therapeutic targeting. Our results showed that PTEN molecular alterations were present in 4/20 (20 %) cases with a loss of expression, 3/11 (27 %) cases with clonal-like expression, and 1/81 (1 %) cases with positive PTEN expression. No PTEN promoter methylation was found in any of the cases. Even though the value of our observation is limited by the low number of cases fully evaluated by IHC (112 cases), FISH (19 cases) and NGS (30 cases), our data suggest that IHC is not an appropriate method for the screening of PTEN genetic alterations. Our survival analysis suggests that patients with positive cytoplasmic PTEN expression show better disease-free survival (P < 0.05).
Sinonasal carcinomas are head and neck tumours arising from the nasal cavity and paranasal sinuses characterized by unfavourable outcome, difficult treatment, diagnosis and prognosis. MicroRNAs are key molecules in the regulation of development and progression of cancer and their expression profiles could be used as prognostic biomarkers, to predict the patients’ survival and response to treatment. In this study, we used quantitative real-time PCR with TaqMan® Advanced miRNA Assays to investigate the relative expression values of selected micro-RNAs in a unique set of formalin-fixed paraffin-embedded tissue samples obtained from 46 patients with sinonasal squamous cell carcinoma. Our results showed statistically significant up-regulation of three mature microRNAs: miR-9-5p (fold change: 6.80), miR-9-3p (fold change: 3.07) and let-7d (fold change: 3.93) in sinonasal carcinoma patients. Kaplan-Meier survival analysis and logrank test identified association between higher expression of miR-9-5p and longer survival of the patients (P = 0.0264). Lower expression of let-7d was detected in the patients with impaired survival, and higher expression of miR-137 was linked to shorter survival of the patients., We alsoidentified several correlations between expression of the studied microRNAs and recorded clinico-pathological data. Higher expression of miR-137 and lower expression of let-7d correlated with local recurrence (P = 0.045 and P = 0.025); lower expression of miR-9-5p and higher expression of miR-155-5p correlated with regional recurrence (P = 0.045 and P = 0.036). Higher expression of miR-9-3p correlated with occupational risk (P = 0.031), presence of vascular invasion (P = 0.013) and perineural invasion (P = 0.031). Higher expression of miR-155-5p was present in the samples originating from maxillary sinus (P = 0.011), cN1-3 classified tumours (P = 0.009) and G2-3 classified tumours (P = 0.017). In conclusion, our study supports the hypothesis of future prospect to use expression of miRNAs as prognostic biomarkers of squamous cell sinonasal carcinoma. In particular, miR-9-5p and miR-9-3p seem to be important members of the sinonasal cancer pathogenesis., and Corresponding author: Helena Kovaříková
Hepatocyte nuclear factor 1-β is a transcription factor which plays a crucial role during ontogenesis in the differentiation of visceral endoderm from primitive endoderm, and is especially important for the normal development of the kidney, urogenital tract, gastrointestinal tract, liver, and pancreas. Despite the growing knowledge about the potential involvement of hepatocyte nuclear factor 1-β in the process of carcinogenesis, the exact underlying mechanism that would explain its rather varied effects in different tumours has not been sufficiently investigated. Most of the data regarding the significance of hepatocyte nuclear factor 1-β arise from genome-wide association studies and is concerned with the influence of single-nucleotide polymorphisms of hepatocyte nuclear factor 1-β on either the increased or decreased susceptibility to certain types of cancer. However, the influence of both the germinal and somatic mutations of this gene on the process of carcino-genesis is still poorly understood. According to current data, in some tumours hepatocyte nuclear factor 1-β acts as a protooncogene, while in others as a tumour suppressor gene, although the reasons for this are not clear. The exact incidence of hepatocyte nuclear factor 1-β mutations and the spectrum of
tumours in which they may play a role in the process of carcinogenesis remain unknown. From the practical point of view, immunohistochemical expression of hepatocyte nuclear factor 1-β can be used in differential diagnostics of certain tumours, especially clear cell carcinoma. In our article we review the current knowledge regarding the significance of hepatocyte nuclear factor 1-β in carcinogenesis. and Corresponding author: Michaela Bártů