Association between several immune response-related genes and the effectiveness of biological treatments in patients with moderate-to-severe psoriasis.

Biological therapies are safer and more effective against psoriasis than conventional treatments. Even so, 30-50% of psoriatic patients show an inadequate response, which is associated with individual genetic heterogeneity. Pharmacogenetic studies have identified several single nucleotide polymorphisms (SNPs) as possible predictive and prognostic biomarkers for psoriasis treatment response. The objective of this study was to determine the link between several SNPs and the clinical response to biological therapies in patients with moderate-severe psoriasis. A set of 21 SNPs related to psoriasis and/or other immunological diseases were selected and analysed from salivary samples of patients (n = 88). Treatment effectiveness and patient improvement was assessed clinically through Relative Psoriasis Area and Severity Index (PASI), also called 'PASI response', as well as absolute PASI. Associations between SNPs and PASI factors were assessed at 3 and 12 months for every treatment category of IL-17, IL-23, IL-12&23 and TNF-α inhibitors. Multivariate correlation analysis and Fisher's exact test were used to analyse the relationship between SNPs and therapy outcomes. Several SNPs located in the TLR2, TLR5, TIRAP, HLA-C, IL12B, SLC12A8, TNFAIP3 and PGLYRP4 genes demonstrated association with increased short and long-term therapy-effectiveness rates. Most patients achieved values of PASI response ≥75 or absolute PASI<1, regardless of the biological treatment administered. In conclusion, we demonstrate a relationship between different SNPs and both short- and especially long-term effectiveness of biological treatment in terms of PASI. These polymorphisms may be used as predictive markers of treatment response in patients with moderate-to-severe psoriasis, providing personalized treatment.

Glioblastoma Therapy: Past, Present and Future.

Glioblastoma (GB) stands out as the most prevalent and lethal form of brain cancer. Although great efforts have been made by clinicians and researchers, no significant improvement in survival has been achieved since the Stupp protocol became the standard of care (SOC) in 2005. Despite multimodality treatments, recurrence is almost universal with survival rates under 2 years after diagnosis. Here, we discuss the recent progress in our understanding of GB pathophysiology, in particular, the importance of glioma stem cells (GSCs), the tumor microenvironment conditions, and epigenetic mechanisms involved in GB growth, aggressiveness and recurrence. The discussion on therapeutic strategies first covers the SOC treatment and targeted therapies that have been shown to interfere with different signaling pathways (pRB/CDK4/RB1/P16ink4, TP53/MDM2/P14arf, PI3k/Akt-PTEN, RAS/RAF/MEK, PARP) involved in GB tumorigenesis, pathophysiology, and treatment resistance acquisition. Below, we analyze several immunotherapeutic approaches (i.e., checkpoint inhibitors, vaccines, CAR-modified NK or T cells, oncolytic virotherapy) that have been used in an attempt to enhance the immune response against GB, and thereby avoid recidivism or increase survival of GB patients. Finally, we present treatment attempts made using nanotherapies (nanometric structures having active anti-GB agents such as antibodies, chemotherapeutic/anti-angiogenic drugs or sensitizers, radionuclides, and molecules that target GB cellular receptors or open the blood-brain barrier) and non-ionizing energies (laser interstitial thermal therapy, high/low intensity focused ultrasounds, photodynamic/sonodynamic therapies and electroporation). The aim of this review is to discuss the advances and limitations of the current therapies and to present novel approaches that are under development or following clinical trials.

Genetic variants associated with skin photosensitivity in a southern European population from Spain.

BACKGROUND/PURPOSE: Recent GWAS studies, mostly performed in populations of North European origin, have identified the genetic loci associated with pigmentation, sun sensitivity, freckling and skin cancer susceptibility. Here, we aimed at addressing the genetic determinants of sunlight sensitivity in Spain, a southern European population. METHODS: Nine SNPs located in 8 pigmentation-related genes (IRF4, TYR, ASP, HERC2, OCA2, BNC2, SLC24A4 and SLC45A2) were genotyped in 456 Spaniards. Additionally, the complete sequence of the MC1R gene was obtained, testing each nonsynonymous mutation supported by the classification as R or r alleles. A standardised questionnaire was used to collect demographic characteristics, pigmentation and sun sensitivity traits, as well as sun exposure habits. RESULTS: MC1R R alleles and IRF4 rs12203592 were significantly associated with sunlight sensitivity at the Bonferroni-corrected level (P-value < 4.54 × 10-3 ). Genetic variants in SLC45A2 (rs16891982) and HERC2 (rs12913832) were also found to be significantly associated with skin photosensitivity in our Spanish sample. Interaction analysis using the MDR method revealed epistatic effects when these four variants were considered together. CONCLUSION: MC1R, IRF4, HERC2 and SLC45A2 play a significant role in skin sensitivity to sunlight in the Spanish population. Moreover, interaction among these four loci seems to modulate the ability of the skin to respond to UV radiation.

Genetic 3'UTR variation is associated with human pigmentation characteristics and sensitivity to sunlight.

Sunlight exposure induces signalling pathways leading to the activation of melanin synthesis and tanning response. MicroRNAs (miRNAs) can regulate the expression of genes involved in pigmentation pathways by binding to the complementary sequence in their 3'untranslated regions (3'UTRs). Therefore, 3'UTR SNPs are predicted to modify the ability of miRNAs to target genes, resulting in differential gene expression. In this study, we investigated the role in pigmentation and sun-sensitivity traits, as well as in melanoma susceptibility, of 38 different 3'UTR SNPs from 38 pigmentation-related genes. A total of 869 individuals of Spanish origin (526 melanoma cases and 343 controls) were analysed. The association of genotypic data with pigmentation traits was analysed via logistic regression. Web-based tools for predicting the effect of genetic variants in microRNA-binding sites in 3'UTR gene regions were also used. Seven 3'UTR SNPs showed a potential implication in melanoma risk phenotypes. This association is especially noticeable for two of them, rs2325813 in the MLPH gene and rs752107 in the WNT3A gene. These two SNPs were predicted to disrupt a miRNA-binding site and to impact on miRNA-mRNA interaction. To our knowledge, this is the first time that these two 3'UTR SNPs have been associated with sun-sensitivity traits. We state the potential implication of these SNPs in human pigmentation and sensitivity to sunlight, possibly as a result of changes in the level of gene expression through the disruption of putative miRNA-binding sites.

Simultaneous purifying selection on the ancestral MC1R allele and positive selection on the melanoma-risk allele V60L in south Europeans.

In humans, the geographical apportionment of the coding diversity of the pigmentary locus melanocortin-1 receptor (MC1R) is, unusually, higher in Eurasians than in Africans. This atypical observation has been interpreted as the result of purifying selection due to functional constraint on MC1R in high UV-B radiation environments. By analyzing 3,142 human MC1R alleles from different regions of Spain in the context of additional haplotypic information from the 1000 Genomes (1000G) Project data, we show that purifying selection is also strong in southern Europe, but not so in northern Europe. Furthermore, we show that purifying and positive selection act simultaneously on MC1R. Thus, at least in Spain, regions at opposite ends of the incident UV-B radiation distribution show significantly different frequencies for the melanoma-risk allele V60L (a mutation also associated to red hair and fair skin and even blonde hair), with higher frequency of V60L at those regions of lower incident UV-B radiation. Besides, using the 1000G south European data, we show that the V60L haplogroup is also characterized by an extended haplotype homozygosity (EHH) pattern indicative of positive selection. We, thus, provide evidence for an adaptive value of human skin depigmentation in Europe and illustrate how an adaptive process can simultaneously help to maintain a disease-risk allele. In addition, our data support the hypothesis proposed by Jablonski and Chaplin (Human skin pigmentation as an adaptation to UVB radiation. Proc Natl Acad Sci U S A. 2010;107:8962-8968), which posits that habitation of middle latitudes involved the evolution of partially depigmented phenotypes that are still capable of suitable tanning.

Genetic variants in PARP1 (rs3219090) and IRF4 (rs12203592) genes associated with melanoma susceptibility in a Spanish population.

BACKGROUND: Few high penetrance genes are known in Malignant Melanoma (MM), however, the involvement of low-penetrance genes such as MC1R, OCA2, ASIP, SLC45A2 and TYR has been observed. Lately, genome-wide association studies (GWAS) have been the ideal strategy to identify new common, low-penetrance susceptibility loci. In this case-control study, we try to validate in our population nine melanoma associated markers selected from published GWAS in melanoma predisposition. METHODS: We genotyped the 9 markers corresponding to 8 genes (PARP1, MX2, ATM, CCND1, NADSYN1, CASP8, IRF4 and CYP2R1) in 566 cases and 347 controls from a Spanish population using KASPar probes. Genotypes were analyzed by logistic regression and adjusted by phenotypic characteristics. RESULTS: We confirm the protective role in MM of the rs3219090 located on the PARP1 gene (p-value 0.027). Additionally, this SNP was also associated with eye color (p-value 0.002). A second polymorphism, rs12203592, located on the IRF4 gene was associated with protection to develop MM for the dominant model (p-value 0.037). We have also observed an association of this SNP with both lentigines (p-value 0.014) and light eye color (p-value 3.76 × 10(-4)). Furthermore, we detected a novel association with rs1485993, located on the CCND1 gene, and dark eye color (p-value 4.96 × 10(-4)). Finally, rs1801516, located on the ATM gene, showed a trend towards a protective role in MM similar to the one firstly described in a GWAS study. CONCLUSIONS: To our knowledge, this is the first time that these SNPs have been associated with MM in a Spanish population. We confirmed the proposed role of rs3219090, located on the PARP1 gene, and rs12203592, located on the IRF4 gene, as protective to MM along the same lines as have previous genome-wide associated works. Finally, we have seen associations between IRF4, PARP1, and CCND1 and phenotypic characteristics, confirming previous results for the IRF4 gene and presenting novel data for the last two, suggesting that pigmentation characteristics correlated with eye color are potential mediators between PARP1 and MM protection.

Neural Stem Cells as Potential Glioblastoma Cells of Origin.

Glioblastoma multiforme (GBM) is the most malignant brain tumor in adults and it remains incurable. These tumors are very heterogeneous, resistant to cytotoxic therapies, and they show high rates of invasiveness. Therefore, patients face poor prognosis, and the survival rates remain very low. Previous research states that GBM contains a cell population with stem cell characteristics called glioma stem cells (GSCs). These cells are able to self-renew and regenerate the tumor and, therefore, they are partly responsible for the observed resistance to therapies and tumor recurrence. Recent data indicate that neural stem cells (NSCs) in the subventricular zone (SVZ) are the cells of origin of GBM, that is, the cell type acquiring the initial tumorigenic mutation. The involvement of SVZ-NSCs is also associated with GBM progression and recurrence. Identifying the cellular origin of GBM is important for the development of early detection techniques and the discovery of early disease markers. In this review, we analyze the SVZ-NSC population as a potential GBM cell of origin, and its potential role for GBM therapies.

Enhancing Prostate Tumor Biobanking Reliability with Improved Sampling Technique and Histological Characterization.

Acquiring fresh and well-characterized tumor tissue samples is critical for conducting high-quality "omics" studies. However, it can be particularly challenging in the context of prostate cancer (PC) due to the unique nature of this organ and the high heterogeneity associated with this tumor. On the other hand, histopathologically characterizing samples before their storage without causing significant tissue alterations is also an intriguing challenge. In this context, we present a new method for acquiring, mapping, characterizing, and micro-dissecting resected prostate tissue based on anatomopathological criteria. Unlike previously published protocols, this method reduces the time required for histopathological analysis of the prostate specimen without compromising its structure, which is crucial for assessing surgical margins. Furthermore, it enables the delineation and micro-macro dissection of fresh prostate tissue samples, with a focus on histological tumor areas defined by pathological criteria such as Gleason score, precursor lesions (high-grade prostatic intraepithelial neoplasia - PIN), and inflammatory lesions (prostatitis). These samples are then stored in a Biobank for subsequent research analyses.

The peopling of Europe and the cautionary tale of Y chromosome lineage R-M269.

Recently, the debate on the origins of the major European Y chromosome haplogroup R1b1b2-M269 has reignited, and opinion has moved away from Palaeolithic origins to the notion of a younger Neolithic spread of these chromosomes from the Near East. Here, we address this debate by investigating frequency patterns and diversity in the largest collection of R1b1b2-M269 chromosomes yet assembled. Our analysis reveals no geographical trends in diversity, in contradiction to expectation under the Neolithic hypothesis, and suggests an alternative explanation for the apparent cline in diversity recently described. We further investigate the young, STR-based time to the most recent common ancestor estimates proposed so far for R-M269-related lineages and find evidence for an appreciable effect of microsatellite choice on age estimates. As a consequence, the existing data and tools are insufficient to make credible estimates for the age of this haplogroup, and conclusions about the timing of its origin and dispersal should be viewed with a large degree of caution.

Migration distance rather than migration rate explains genetic diversity in human patrilocal groups.

In patrilocal groups, females preferentially move to join their mate's paternal relatives. The gender-biased gene flow generated by this cultural practice is expected to affect genetic diversity across human populations. Greater female than male migration is predicted to result in a larger decrease in between-group differentiation for mitochondrial DNA (mtDNA) than for the non-recombining part of the Y chromosome (NRY). We address the question of how patrilocality affects the distribution of genetic variation in human populations controlling for confounding factors such as ethno-linguistic heterogeneity and geographic distance which possibly explain the contradictory results observed in previous studies. By combining genetic and bio-demographic data from Lesotho and Spain, we show that preferential female migration over short distances appears to minimize the impact of a generally higher female migration rate in patrilocal communities, suggesting patrilocality might influence genetic variation only at short ranges.

UV-Induced Somatic Mutations Driving Clonal Evolution in Healthy Skin, Nevus, and Cutaneous Melanoma.

INTRODUCTION: Due to its aggressiveness, cutaneous melanoma (CM) is responsible for most skin cancer-related deaths worldwide. The origin of CM is closely linked to the appearance of UV-induced somatic mutations in melanocytes present in normal skin or in CM precursor lesions (nevi or dysplastic nevi). In recent years, new NGS studies performed on CM tissue have increased the understanding of the genetic somatic changes underlying melanomagenesis and CM tumor progression. METHODS: We reviewed the literature using all important scientific databases. All articles related to genomic mutations in CM as well as normal skin and nevi were included, in particular those related to somatic mutations produced by UV radiation. CONCLUSIONS: CM development and progression are strongly associated with exposure to UV radiation, although each melanoma subtype has different characteristic genetic alterations and evolutionary trajectories. While BRAF and NRAS mutations are common in the early stages of tumor development for most CM subtypes, changes in CDKN2A, TP53 and PTEN, together with TERT promoter mutations, are especially common in advanced stages. Additionally, large genome duplications, loss of heterozygosity, and copy number variations are hallmarks of metastatic disease. Finally, the mutations driving melanoma targeted-therapy drug resistance are also summarized. The complete sequential stages of clonal evolution leading to CM onset from normal skin or nevi are still unknown, so further studies are needed in this field to shed light on the molecular pathways involved in CM malignant transformation and in melanoma acquired drug resistance.

Association of TYR SNP rs1042602 with Melanoma Risk and Prognosis.

Cutaneous melanoma is the most aggressive of skin tumors. In order to discover new biomarkers that could help us improve prognostic prediction in melanoma patients, we have searched for germline DNA variants associated with melanoma progression. Thus, after exome sequencing of a set of melanoma patients and healthy control individuals, we identified rs1042602, an SNP within TYR, as a good candidate. After genotyping rs1042602 in 1025 patients and 773 healthy donors, we found that the rs1042602-A allele was significantly associated with susceptibility to melanoma (CATT test: p = 0.0035). Interestingly, we also observed significant differences between patients with good and bad prognosis (5 years of follow-up) (n = 664) (CATT test for all samples p = 0.0384 and for men alone p = 0.0054). Disease-free-survival (DFS) analyses also showed that patients with the A allele had shorter DFS periods. In men, the association remained significant even in a multivariate Cox Proportional-hazards model, which was adjusted for age at diagnosis, Breslow thickness, ulceration and melanoma subtype (HR 0.4; 95% confidence interval (CI) 0.20-0.83; p = 0.0139). Based on our results, we propose that rs1042602-A is a risk allele for melanoma, which also seems to be responsible for a poorer prognosis of the disease, particularly in men.

Malignant melanoma arising from a perianal fistula and harbouring a BRAF gene mutation: a case report.

BACKGROUND: Melanoma of the anal region is a very uncommon disease, accounting for only 0.2-0.3% of all melanoma cases. Mutations of the BRAF gene are usually absent in melanomas occurring in this region as well as in other sun-protected regions. The development of a tumour in a longstanding perianal fistula is also extremely rare. More frequent is the case of a tumour presenting as a fistula, that is, the fistula being a consequence of the cancerous process, although we have found only two cases of fistula-generating melanomas reported in the literature. CASE PRESENTATION: Here we report the case of a 38-year-old male who presented with a perianal fistula of four years of evolution. Histopathological examination of the fistulous tract confirmed the presence of malignant melanoma. Due to the small size and the central location of the melanoma inside the fistulous tract, we believe the melanoma reported here developed in the epithelium of the fistula once the latter was already formed. Resected sentinel lymph nodes were negative and the patient, after going through a wide local excision, remains disease-free nine years after diagnosis. DNA obtained from melanoma tissue was analysed by automated direct sequencing and the V600E (T1799A) mutation was detected in exon 15 of the BRAF gene. CONCLUSION: Since fistulae experience persistent inflammation, the fact that this melanoma harbours a BRAF mutation strengthens the view that oxidative stress caused by inflammatory processes plays an important role in the genesis of BRAF gene mutations.

Genetic determinants of freckle occurrence in the Spanish population: Towards ephelides prediction from human DNA samples.

Prediction of human pigmentation traits, one of the most differentiable externally visible characteristics among individuals, from biological samples represents a useful tool in the field of forensic DNA phenotyping. In spite of freckling being a relatively common pigmentation characteristic in Europeans, little is known about the genetic basis of this largely genetically determined phenotype in southern European populations. In this work, we explored the predictive capacity of eight freckle and sunlight sensitivity-related genes in 458 individuals (266 non-freckled controls and 192 freckled cases) from Spain. Four loci were associated with freckling (MC1R, IRF4, ASIP and BNC2), and female sex was also found to be a predictive factor for having a freckling phenotype in our population. After identifying the most informative genetic variants responsible for human ephelides occurrence in our sample set, we developed a DNA-based freckle prediction model using a multivariate regression approach. Once developed, the capabilities of the prediction model were tested by a repeated 10-fold cross-validation approach. The proportion of correctly predicted individuals using the DNA-based freckle prediction model was 74.13%. The implementation of sex into the DNA-based freckle prediction model slightly improved the overall prediction accuracy by 2.19% (76.32%). Further evaluation of the newly-generated prediction model was performed by assessing the model's performance in a new cohort of 212 Spanish individuals, reaching a classification success rate of 74.61%. Validation of this prediction model may be carried out in larger populations, including samples from different European populations. Further research to validate and improve this newly-generated freckle prediction model will be needed before its forensic application. Together with DNA tests already validated for eye and hair colour prediction, this freckle prediction model may lead to a substantially more detailed physical description of unknown individuals from DNA found at the crime scene.

Sex-specific genetic effects associated with pigmentation, sensitivity to sunlight, and melanoma in a population of Spanish origin.

BACKGROUND: Human pigmentation is a polygenic quantitative trait with high heritability. In addition to genetic factors, it has been shown that pigmentation can be modulated by oestrogens and androgens via up- or down-regulation of melanin synthesis. Our aim was to identify possible sex differences in pigmentation phenotype as well as in melanoma association in a melanoma case-control population of Spanish origin. METHODS: Five hundred and ninety-nine females (316 melanoma cases and 283 controls) and 458 males (234 melanoma cases and 224 controls) were analysed. We genotyped 363 polymorphisms (single nucleotide polymorphisms (SNPs)) from 65 pigmentation gene regions. RESULTS: When samples were stratified by sex, we observed more SNPs associated with dark pigmentation and good sun tolerance in females than in males (107 versus 75; P = 2.32 × 10(-6)), who were instead associated with light pigmentation and poor sun tolerance. Furthermore, six SNPs in TYR, SILV/CDK2, GPR143, and F2RL1 showed strong differences in melanoma risk by sex (P < 0.01). CONCLUSIONS: We demonstrate that these genetic variants are important for pigmentation as well as for melanoma risk, and also provide suggestive evidence for potential differences in genetic effects by sex.

The relationship between surname frequency and Y chromosome variation in Spain.

In most societies, surnames are passed down from fathers to sons, just like the Y chromosome. It follows that, theoretically, men sharing the same surnames would also be expected to share related Y chromosomes. Previous investigations have explored such relationships, but so far, the only detailed studies that have been conducted are on samples from the British Isles. In order to provide additional insights into the correlation between surnames and Y chromosomes, we focused on the Spanish population by analysing Y chromosomes from 2121 male volunteers representing 37 surnames. The results suggest that the degree of coancestry within Spanish surnames is highly dependent on surname frequency, in overall agreement with British but not Irish surname studies. Furthermore, a reanalysis of comparative data for all three populations showed that Irish surnames have much greater and older surname descent clusters than Spanish and British ones, suggesting that Irish surnames may have considerably earlier origins than Spanish or British ones. Overall, despite closer geographical ties between Ireland and Britain, our analysis points to substantial similarities in surname origin and development between Britain and Spain, while possibly hinting at unique demographic or social events shaping Irish surname foundation and development.

Comparison of the Transcriptional Profiles of Melanocytes from Dark and Light Skinned Individuals under Basal Conditions and Following Ultraviolet-B Irradiation.

We analysed the whole-genome transcriptional profile of 6 cell lines of dark melanocytes (DM) and 6 of light melanocytes (LM) at basal conditions and after ultraviolet-B (UVB) radiation at different time points to investigate the mechanisms by which melanocytes protect human skin from the damaging effects of UVB. Further, we assessed the effect of different keratinocyte-conditioned media (KCM+ and KCM-) on melanocytes. Our results suggest that an interaction between ribosomal proteins and the P53 signaling pathway may occur in response to UVB in both DM and LM. We also observed that DM and LM show differentially expressed genes after irradiation, in particular at the first 6h after UVB. These are mainly associated with inflammatory reactions, cell survival or melanoma. Furthermore, the culture with KCM+ compared with KCM- had a noticeable effect on LM. This effect includes the activation of various signaling pathways such as the mTOR pathway, involved in the regulation of cell metabolism, growth, proliferation and survival. Finally, the comparison of the transcriptional profiles between LM and DM under basal conditions, and the application of natural selection tests in human populations allowed us to support the significant evolutionary role of MIF and ATP6V0B in the pigmentary phenotype.

Long telomere length and a TERT-CLPTM1 locus polymorphism association with melanoma risk.

Telomere length has been associated with the development of cancer. Studies have shown that shorter telomere length may be related to a decreased risk of cutaneous melanoma. Furthermore, deregulation of the telomere-maintaining gene complexes, has been related to this oncogenic process. Some variants in these genes seem to be correlated with a change in telomerase expression. We examined the effect of 10 single nucleotide polymorphisms (SNPs) in the TERT gene (encoding telomerase), one SNP in the related TERT-CLPTM1L locus and one SNP in the TRF1 gene with telomere length, and its influence on melanoma risk in 970 Spanish cases and 733 Spanish controls. Genotypes were determined using KASP technology, and telomere length was measured by quantitative polymerase chain reaction (PCR) on DNA extracted from peripheral blood leucocytes. Our results demonstrate that shorter telomere length is associated with a decreased risk of melanoma in our population (global p-value, 2.69×10(-11)), which may be caused by a diminution of proliferative potential of nevi (melanoma precursor cells). We also obtained significant results when we tested the association between rs401681 variant (TERT-CLPTM1L locus) with melanoma risk (Odds ratio, OR; 95% confidence interval, CI=1.24 (1.08-1.43); p-value, 3×10(-3)). This is the largest telomere-related study undertaken in a Spanish population to date. Furthermore, this study represents a comprehensive analysis of some of the most relevant telomere pathway genes in relation to cutaneous melanoma susceptibility.