Deep learning for MYC binding site recognition.

Motivation: The definition of the genome distribution of the Myc transcription factor is extremely important since it may help predict its transcriptional activity particularly in the context of cancer. Myc is among the most powerful oncogenes involved in the occurrence and development of more than 80% of different types of pediatric and adult cancers. Myc regulates thousands of genes which can be in part different, depending on the type of tissues and tumours. Myc distribution along the genome has been determined experimentally through chromatin immunoprecipitation This approach, although powerful, is very time consuming and cannot be routinely applied to tumours of individual patients. Thus, it becomes of paramount importance to develop in silico tools that can effectively and rapidly predict its distribution on a given cell genome. New advanced computational tools (DeeperBind) can then be successfully employed to determine the function of Myc in a specific tumour, and may help to devise new directions and approaches to experiments first and personalized and more effective therapeutic treatments for a single patient later on. Results: The use of DeeperBind with DeepRAM on Colab platform (Google) can effectively predict the binding sites for the MYC factor with an accuracy above 0.96 AUC, when trained with multiple cell lines. The analysis of the filters in DeeperBind trained models shows, besides the consensus sequence CACGTG classically associated to the MYC factor, also the other consensus sequences G/C box or TGGGA, respectively bound by the SP1 and MIZ-1 transcription factors, which are known to mediate the MYC repressive response. Overall, our findings suggest a stronger synergy between the machine learning tools as DeeperBind and biological experiments, which may reduce the time consuming experiments by providing a direction to guide them.

Angiotensin II: immunohistochemical study in Sardinian pterygium.

The angiotensin II (Ang II) is the principal effector peptide of the RAS system. It has a pleiotropic effect and, beside its physiological role, it has the property to stimulate angiogenesis and activate multiple signalling pathways related to cell proliferation. The purpose of the study was to determinate the Ang II expression and localization in Sardinian pterygium and normal conjunctiva by immunohistochemistry, and its possible involvement in the development and progression of the disease. Twenty-three pterygiums and eleven normal conjunctiva specimens obtained from Sardinian patients, were processed for paraffin embedding and assessed for the immunohistochemical revelation of Ang II. Significant Ang II expression was identified in pterygium and conjuntica. Particularly, thirteen pterygium specimens (n=13) displayed exclusively moderate to strong nuclear staining; some specimens (n=5) showed exclusively a moderate cytoplasmatic immunoreactivity, and few specimens (n=2) displayed moderate to strong immunoreactivity in both cytoplasm and nucleus. Statistical significance difference in respect of nuclear and cytoplasmatic localization was observed between normal conjunctiva and pterygium (P=0.038).The results showed a predominant intranuclear localization of Ang II in pterygium epithelial cells, in spite of conjunctiva that mainly showed cytoplasmatic localization. In view of these results, we hypothesized a possible gene expression modulator role played by Ang II in pterygium.

Nestin expression associates with poor prognosis and triple negative phenotype in locally advanced (T4) breast cancer.

Nestin, an intermediate filament protein, has traditionally been noted for its importance as a neural stem cell marker. However, in recent years, expression of nestin has shown to be associated with general proliferation of progenitor cell populations within neoplasms. There is no reported study addressing nestin expression in T4 breast cancer patients. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of nestin in T4 breast cancer, in order to determine its association with clinical and pathological parameters as well as with patients' outcome. Nestin was detectable in tumoral cells and in endothelial cells of blood microvessels, and it is significantly expressed in triple-negative and in inflammatory breast cancer (IBC) subgroups of T4 breast tumours. The Kaplan-Meier analysis showed that the presence of nestin in tumoral cells significantly predicted poor prognosis at 5-years survival (P=0.02) and with borderline significance at 10-years of survival (P=0.05) in T4 breast cancer patients. On the basis of these observations, we speculate that nestin expression may characterize tumours with an aggressive clinical behavior, suggesting that the presence of nestin in tumoral cells and vessels may be considered an important factor that leads to a poor prognosis. Further studies are awaited to define the biological role of nestin in the etiology of these subgroups of breast cancers.

Expression of survivin protein in pterygium and relationship with oxidative DNA damage.

Ultraviolet radiation is known to cause oxidative DNA damage and is thought to be a major factor implicated in the pathogenesis of pterygium. Among all the photo-oxidative DNA products, the 8-hydroxydeoxyguanosine (8-OHdG) is regarded a sensitive and stable biomarker for evaluating the degree of DNA damage. The protein p53 is a major cell stress regulator that acts to integrate signals from a wide range of cellular stresses. UV radiation has a carcinogenic effect resulting in DNA damaged cells with loss of normal growth control. This assumption is supported by the association between UV-B exposure and activation of survivin, a member of the inhibitor of apoptosis protein family (IAP), highly up-regulated in almost all types of human malignancy. In this study we demonstrate, for the first time in pterygium, the immunohistochemical presence of survivin, and investigate the correlation between survivin, p53 and 8-OHdG. Our results demonstrate that oxidative stress could lead to a significant activation of survivin expression, suggesting that this might be an important event in the development of pterygium, inducing and supporting a hyperproliferative condition. Survivin expression in pterygium would counteract UV-B-induced apoptosis and would cooperate with loss of p53. The co-operation between survivin and functional loss of p53 might provide a general mechanism for aberrant inhibition of apoptosis that could be responsible for the development of pterygium and its possible progression to neoplasia.

Receptor modifications in vulvar dystrophies before and after treatment with topical hormones: comparison between the dextran-charcoal technique and immunohistochemical evaluation.

PURPOSE OF INVESTIGATION: The objective of the study was first to quantify estrogen receptors (ERs) and progesterone receptors (PRs) in dystrophic vulvar tissue before and after topical hormone treatment in an attempt to evaluate whether receptor modifications occurred. Second we compared quantitative analysis with immunohistochemical staining of the vulvar specimens. METHODS: We studied 115 vulvar specimens obtained from 75 consenting women ranging from 21 to 78 years of age. Of the patients, 12 had histologically normal vulvar skin, 45 had vulvar dystrophies that were not treated by topical steroid therapy, 28 patients had vulvar dystrophies that were treated by testosterone propionate (TP) 2%, 12 patients had vulvar dystrophies that were treated by progesterone in hydroalcoholic gel and 18 patients had vulvar malignant tumors. For immunohistochemical analysis we considered 25 cases of vulvar dystrophies: 11 cases of squamous hyperplasia (SH) and 14 cases of lichen sclerosus (LS). Among these 25 cases, 15 (5 SH and 10 LS) were treated with TP 2%. RESULTS: After treatment of the vulvar dystrophies with progesterone, the positivity of ERs decreased (58.3% vs 77.8%). After treatment of the vulvar dystrophies with TP 2%, the positivity of PRs significantly decreased (14.3% vs 68.9%) whereas after treatment with progesterone the positivity of PRs increased (83.3%). The immunohistochemical study showed some differences in comparison to the quantitative study. In fact we found low basal positivity especially for PRs (16% vs 68.9% of the quantitative study). This finding was due to the use of a cutoff of at least ++ in order to increase the specificity. After treatment with TP 2%, we observed an increase of immunohistochemical positivity for ERs even in cases that were negative before treatment and a lack of PRs even in cases that were positive before treatment. CONCLUSIONS: These data demonstrate the efficacy of androgen therapy with TP 2% in vulvar dystrophies with increased trophism due to the increase of ERs.