The role of Microenvironment in tumorigenesis. Focus on dendritic cells in human papillomavirus E6, E7-transformed keratinocytes

The inception of tumor microenvironment (TME), a complex and dynamic system constituted by different types of cells engaged by tumor and extracellular matrix surrounding cancer cells, is a way for them to elude the immune surveillance. Dendritic cells (DCs), as a sentinel, are able to recognize alteration in the microenvironment and predispose the immune system response. The relationship between cancer and virus infection is well documented. High-risk Human Papillomavirus (HR-HPV) has a well-characterized transforming property and has been associated with squamous cell carcinoma of the ano-genital and oral tracts. Transforming ability of HR-HPVs is based on the function of E6 and E7 viral oncoproteins, which interact and inactivate p53 and pRb oncosuppressors, respectively. Recently, it was demonstrated that HPV oncoproteins are also able to affect a number of microRNAs (miRNAs) regulating the expression of genes involved in proliferative control. For these reasons DC-based vaccines targeting oncogenic E6 and E7 are ideal candidates to elicit strong immune responses. Here we summarize significant data about the analysis of TME in HPV-induced tumorigenesis. We also report original results produced by cytotoxic T lymphocyte (CTL) in vitro priming against E6 and E7 HPV16 antigens, performed using human monocyte-derived dendritic cells. Dendritic cells, maturated by the exposition to necrotic or apoptotic keratinocytes expressing both oncoproteins of HPV16, show different expression levels of specific maturation markers. Evidence indicating the ability of necrotic keratinocytes to alter the microRNA profile in DCs, macrophages (MΦ) and Langerhans cells (LCs) compared to prototypical stimuli as bacterial lipopolysaccharide was also provided. We can speculate that, based on transformed cells death pathway (i.e. apoptosis versus necrosis), virus-induced immune alterations might show different results in creating an immunotolerogenic microenvironment during the carcinogenesis process

Role of Extracellular Vesicles in Human Papillomavirus-Induced Tumorigenesis

Emerging evidence demonstrates a role of extracellular vesicles (EVs) in a variety of fundamental physiological and pathological processes ranging from antigen presentation to T cell to neurodegenerative diseases. In several types of malignancies, a variety of EVs can be isolated from bodily fluids of cancer patients, and it has been reported that the number of circulating EVs seems to be higher than in healthy subjects. This increase correlates with poor prognosis. Data obtained from different groups clearly point out a role of EVs in the transfer of bioactive molecules such as microRNAs and viral oncoproteins in human papillomavirus-induced malignancies of genital and oral tracts. This study summarizes these data in the context of relevant literature considering the EVs as carriers of oncogenic signatures in human cancer as well as their therapeutic potential in HPV-related tumors

Breg Cells in Celiac Disease Isolated or Associated to Hashimoto's Thyroiditis

Hashimoto's thyroiditis (HT) may occur associated with celiac disease (CD). Regulatory B cells (Breg) subsets have been shown to play a significant role in autoimmune processes. Therefore, we have characterized their distribution in the peripheral blood obtained from 10 patients with isolated HT, 10 patients with HT + CD, 9 patients with isolated CD, and 9 healthy donors (HD). Th17 cells were significantly increased in patients with HT and in patients bearing both HT and CD, while patients with isolated CD exhibited a lower percentage of Th17, as compared with healthy donors. CD24hiCD38hi Breg cells were significantly higher in patients with HT + CD and in patients with isolated CD as compared to both HD patients and patients with isolated HT (p = 0.0010). On the contrary, Breg memory phenotypes (CD24hiCD38- and CD24hiCD27+) significantly decreased in patients with HT + CD as compared with the isolated disorders. Following CpG oligodeoxynucleotide stimulation, IL-10+ CD24hiCD38hi Breg cells were similar in all groups of patients, despite these cells would have been higher in CD patients. In conclusion, celiac disease, isolated and even more when associated with HT, determines a peculiar behavior of Breg cells which are increased in number but possibly functionally defective. Furthermore, the association CD + HT was characterized by a reduction of Breg memory subsets as compared with the isolated disorders. The behavior of Th17 subset in patients with celiac disease associated with HT might have been sensitive to the effect of long-lasting GFD, and it is essentially determined by the presence of thyroid autoimmunity

MicroRNAs differentially expressed in actinic keratosis and healthy skin scrapings

: Actinic keratosis (AK) is a carcinoma in situ precursor of cutaneous squamous cell carcinoma (cSCC), the second most common cancer affecting the Caucasian population. AK is frequently present in the sun-exposed skin of the elderly population, UV radiation being the main cause of this cancer, and other risk factors contributing to AK incidence. The dysregulation of microRNAs (miRNAs) observed in different cancers leads to an improper expression of miRNA targets involved in several cellular pathways. The TaqMan Array Human MicroRNA Card assay for miRNA expression profiling was performed in pooled AK compared to healthy skin scraping samples from the same patients. Forty-three miRNAs were modulated in the AK samples. The expression of miR-19b (p < 0.05), -31, -34a (p < 0.001), -126, -146a (p < 0.01), -193b, and -222 (p < 0.05) was validated by RT-qPCR. The MirPath tool was used for MiRNA target prediction and enriched pathways. The top DIANA-mirPath pathways regulated by the targets of the 43 miRNAs are TGF-beta signaling, Proteoglycans in cancer, Pathways in cancer, and Adherens junction (7.30 × 10-10 < p < 1.84 × 10-8). Selected genes regulating the KEGG pathways, i.e., TP53, MDM2, CDKN1A, CDK6, and CCND1, were analyzed. MiRNAs modulated in AK regulate different pathways involved in tumorigenesis, indicating miRNA regulation as a critical step in keratinocyte cancer

The mitochondrial DNA control region shows genetically correlated levels of heteroplasmy in leukocytes of centenarians and their offspring

<p>Abstract</p> <p>Background</p> <p>Studies on heteroplasmy occurring in the mitochondrial DNA (mtDNA) control region (CR) in leukocytes of centenarians and younger subjects have shown that the C150T somatic transition is over-represented in centenarians. However, whether the occurrence/accumulation of heteroplasmy is a <it>phenotypic consequence </it>of extreme ageing or a <it>genetically controlled event </it>that may favor longevity is a question that deserves further attention. To clarify this point, we set up a Denaturing High Performance Liquid Chromatography (DHPLC) protocol to quantify mtDNA CR heteroplasmy. We then analyzed heteroplasmy in leukocytes of centenarians (100 subjects), their offspring and nieces/nephews (200 subjects, age-range 65–80 years, median age 70 years), and in leukocytes of 114 control subjects sex- and age-matched with the relatives of centenarians.</p> <p>Results</p> <p>The centenarians and their descendants, despite the different ages, showed similar levels of heteroplasmy which were significantly higher than levels in controls. In addition we found that heteroplasmy levels were significantly correlated in parent-offspring pairs (r = 0.263; p = 0.009), but were independent of mtDNA inherited variability (haplogroup and sequence analyses).</p> <p>Conclusion</p> <p>Our findings suggest that the high degree of heteroplasmy observed in centenarians is genetically controlled, and that such genetic control is independent of mtDNA variability and likely due to the nuclear genome.</p

Interferon-beta induces S phase slowing via up-regulated expression of PML in squamous carcinoma cells.

Interferon-β induces S phase slowing via up-regulated expression of PML in squamous carcinoma cell

Mechanisms of acquired BRAF inhibitor resistance in melanoma. A systematic review

This systematic review investigated the literature on acquired v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitor resistance in patients with melanoma. We searched MEDLINE for articles on BRAF inhibitor resistance in patients with melanoma published since January 2010 in the following areas: (1) genetic basis of resistance; (2) epigenetic and transcriptomic mechanisms; (3) influence of the immune system on resistance development; and (4) combination therapy to overcome resistance. Common resistance mutations in melanoma are BRAF splice variants, BRAF amplification, neuroblastoma RAS viral oncogene homolog (NRAS) mutations and mitogen-activated protein kinase kinase 1/2 (MEK1/2) mutations. Genetic and epigenetic changes reactivate previously blocked mitogen-activated protein kinase (MAPK) pathways, activate alternative signaling pathways, and cause epithelial-to-mesenchymal transition. Once BRAF inhibitor resistance develops, the tumor microenvironment reverts to a low immunogenic state secondary to the induction of programmed cell death ligand-1. Combining a BRAF inhibitor with a MEK inhibitor delays resistance development and increases duration of response. Multiple other combinations based on known mechanisms of resistance are being investigated. BRAF inhibitor-resistant cells develop a range of ‘escape routes’, so multiple different treatment targets will probably be required to overcome resistance. In the future, it may be possible to personalize combination therapy towards the specific resistance pathway in individual patients