Association of promoter polymorphism −765G>C in the PTGS2 gene with malignant melanoma in Italian patients and its correlation to gene expression in dermal fibroblasts

Sex-dependent interaction of PTGS2 with miR-146a as risk factor for melanoma and the impact of sex hormones in gene expression in skin cells

Gender disparity in melanoma is a complex issue where sex hormones could be engaged. Differences in genetic variations are important in understanding the mechanisms of sex disparity in melanoma. Post-transcriptional regulation of prostaglandin-endoperoxide synthase (PTGS2) mRNA occurs through a complex interplay of specific trans-acting RNA-binding proteins and microRNAs. MiR-146a is a key player in melanoma, modulating immune responses and tumor microenvironment (TME). Polymorphisms in PTGS2 gene rs20415GC have been associated with an increased risk of melanoma. Epistasis between polymorphisms rs20415GC was investigated by genotyping 453 melanoma patients and 382 control individuals. The effects of testosterone and 17β-estradiol were analyzed in keratinocytes and two melanoma cell lines. The rs2910164GG showed a higher risk in the presence of the genotype rs20417CC in the male population. Testosterone and 17β-estradiol act differently on PTGS2 and miR-146a expression, depending on the cell type. Testosterone augments PTGS2 gene expression in keratinocytes and miR-146a in melanoma cells. While 17β-estradiol only increases miR-146a expression in HaCaT cells. The present study indicates a sex-specific relation between miR-146a and PTGS2 polymorphisms with melanoma cancer risk. Testosterone and 17β-estradiol act differently on the expression of PTGS2 and miR-146a depending on the skin cell type.

The potential impact of dietary choices on melanoma risk: an anti-inflammatory diet

The role of inflammation in the aetiology of cancer is recognized. However, no study yet examined the association between an anti-inflammatory diet and cutaneous melanoma and explored whether it could be modified by genetic variations in cyclooxygenase-2 (COX-2), a key enzyme in inflammation. A case-control study was conducted in the IDI-IRCCS hospital in Rome, Italy with 273 cases of primary cutaneous melanoma and 269 controls frequency matched to cases. Information on socio-demographic and pigmentary characteristics, medical history, sun exposure and dietary habits were collected for all subjects. The - 765G > C polymorphism was identified in DNA extracted from blood samples. An anti-inflammatory diet score was created. Logistic regression models were fitted to obtain odds ratios (ORs) and 95% confidence intervals (CIs). A high anti-inflammatory diet score (≥ 8 anti-inflammatory dietary items) was associated with a decreased risk of cutaneous melanoma (OR: 0.29; 95%CI: 0.17-0.49, Ptrend < 0.0001) after adjusting for sex, age, education, number of common nevi, skin photo-type, solar lentigines and sunburns in childhood. COX-2 -765 G > C polymorphism was not an independent risk factor for cutaneous melanoma. Although interaction between - 765G > C genotypes and anti-inflammatory diet score was not statistically significant (p = 0.25), when stratified by -765 G > C genotypes the effect of the anti-inflammatory diet was slightly more pronounced for participants carrying - 765GG (OR: 0.17; 95%CI: 0.06-0.47, Ptrend < 0.001). Our study findings suggest that adherence to an anti-inflammatory diet is associated with a decreased risk of developing cutaneous melanoma. These results suggest the potential impact of dietary choices on melanoma risk.

The relationship between single nucleotide polymorphisms and skin cancer susceptibility: A systematic review and network meta-analysis

Background

Single nucleotide polymorphisms (SNPs) interfere with the function of certain genes and thus may influence the probability of skin cancer. The correlation between SNPs and skin cancer (SC) lacks statistical power, however. Therefore, the purpose of this study was to identify the gene polymorphisms involved in skin cancer susceptibility using network meta-analysis and to determine the relationship between SNPs and SC risk.

Methods

PubMed, Embase, and Web of Science were searched for articles including "SNP" and different types of SC as keywords between January 2005 and May 2022. The Newcastle-Ottawa Scale was used to assess bias judgments. The odds ratio (ORs) and their 95% confidence intervals (CIs) were determined to estimate heterogeneity within and between studies. Meta-analysis and network meta-analysis were carried out to identify the SNPs associated with SC. The P-score of each SNP was compared to obtain the rank of probability. Subgroup analyses were performed by cancer type.

Results

A total of 275 SNPs from 59 studies were included in the study. Two subgroup SNP networks using the allele model and dominant model were analyzed. The alternative alleles of rs2228570 (FokI) and rs13181 (ERCC2) were the first-ranking SNPs in both subgroups one and two of the allele model, respectively. The homozygous dominant genotype and heterozygous genotype of rs475007 in subgroup one and the homozygous recessive genotype of rs238406 in subgroup two were most likely to be associated with skin cancer based on the dominant model.

Conclusions

According to the allele model, SNPs FokI rs2228570 and ERCC2 rs13181 and, according to the dominant model, SNPs MMP1 rs475007 and ERCC2 rs238406 are closely linked to SC risk.

Molecular classification and subtype-specific characterization of skin cutaneous melanoma by aggregating multiple genomic platform data

PURPOSE

Traditional classification of melanoma is widely utilized with little apparent results making the development of robust classifiers that can guide therapies an urgency. Successful seminal research on classification has provided a wider understanding of cancer from multiple molecular profiles, respectively. However, it may ignore the complementary nature of the information provided by different types of data, which motivated us to subtype melanoma by aggregating multiple genomic platform data.

METHODS

Aggregating three omics data of 328 melanoma samples, melanoma subtyping was performed by three clustering methods. Differences across subtypes were extracted by functional enrichment, epigenetically silencing, gene mutations and clinical features. Subtypes were further distinguished by putative biomarkers.

RESULTS

Functional enrichment of the subtype-specific differential expression genes endowed subtypes new designation: immune, melanin and ion, in which the first subtype was enriched for immune system, the second was characterized by melanin and pigmentation, and the third was enriched for ion-involved transmission process. Subtypes also differed in age, Breslow thickness, tumor site, mutation frequency of BRAF, PTGS2, CDKN2A, CDKN2B and incidence of epigenetically silencing for IL15RA, EPSTI1, LXN, CDKN1B genes.

CONCLUSIONS

Skin cutaneous melanoma can be robustly divided into three subtypes by SNFCC+. Compared with the TCGA classification derived from gene expression, the subtypes we presented share concordance, but new traits are excavated. Such a genomic classification offers insights to further personalize therapeutic decision-making and melanoma management.

Prefrontal activity during working memory is modulated by the interaction of variation in CB1 and COX2 coding genes and correlates with frequency of cannabis use

The CB1 cannabinoid receptor is targeted in the brain by endocannabinoids under physiological conditions as well as by delta9-tetrahydrocannabinol under cannabis use. Furthermore, its signaling appears to affect brain cognitive processing. Recent findings highlight a crucial role of cyclooxygenase-2 (COX-2) in the mechanism of intraneuronal CB1 signaling transduction, while others indicate that two single nucleotide polymorphisms (SNPs) (rs1406977 and rs20417) modulate expression of CB1 (CNR1) and COX-2 (PTGS2) coding genes, respectively. Here, our aim was to use fMRI to investigate in healthy humans whether these SNPs interact in modulating prefrontal activity during working memory processing and if this modulation is linked with cannabis use. We recruited 242 healthy subjects genotyped for CNR1 rs1406977 and PTGS2 rs20417 that performed the N-back working memory task during fMRI and were interviewed using the Cannabis Experience Questionnaire (CEQ). We found that the interaction between CNR1 rs1406977 and PTGS2 rs20417 is associated with dorsolateral prefrontal cortex (DLPFC) activity such that specific genotype configurations (CNR1 C carriers/PTGS2 C carriers and CNR1 TT/PTGS2 GG) predict lower cortical response versus others in spite of similar behavioral accuracy. Furthermore, DLPFC activity in the cluster associated with the CNR1 by PTGS2 interaction was negatively correlated with behavioral efficiency and positively correlated with frequency of cannabis use in cannabis users. These results suggest that a genetically modulated balancing of signaling within the CB1-COX-2 pathway may reflect on more or less efficient patterns of prefrontal activity during working memory. Frequency of cannabis use may be a factor for further modulation of CNR1/PTGS2-mediated cortical processing associated with this cognitive process.

Pharmacogenomics of cyclooxygenases

Cyclooxygenases (COX-1 and COX-2) are key enzymes in several physiopathological processes. Many adverse drugs reactions to NSAIDs are attributable to COX-inhibition. The genes coding for these enzymes (PTGS1 and PTGS2) are highly variable, and variations in these genes may underlie the risk of developing, or the clinical evolution of, several diseases and adverse drug reactions. We analyze major variations in the PTGS1 and PTGS2 genes, allele frequencies, functional consequences and population genetics. The most salient clinical associations of PTGS gene variations are related to colorectal cancer and stroke. In many studies, the SNPs interact with NSAIDs use, dietary or environmental factors. We provide an up-to-date catalog of PTGS clinical associations based on case–control studies and genome-wide association studies, and future research suggestions.