Immunomodulatory properties of bacteriophage derived dsRNA of different size and their use as anticancer vaccine adjuvants.

Dendritic cell (DC) based immunotherapy is one of the strategies to combat cancer invoking a patient's immune system. This form of anticancer immunotherapy employs adjuvants to enhance the immune response, triggering mechanisms of innate immunity and thus increase immunotherapeutic efficiency. A conventional adjuvant for DCs maturation during production of anticancer vaccines is bacterial LPS. Nevertheless, synthetic dsRNAs were also shown to stimulate different receptors on innate immune cells and to activate immune responses through induction of cytokines via toll-like receptors. In our study we investigated the potential of Larifan as dsRNA of natural origin to stimulate maturation of DCs with proinflammatory (possible antitumoral) activity and to compare these immunostimulatory properties between Larifan's fractions with different molecular lengths. To explore the suitability of this product for therapy, it is necessary to study the properties of its different fractions and compare them to standard adjuvants. We investigated the effect of Larifan's fractions on immune system stimulation in vivo by monitoring the survival time of tumor-bearing mice. Murine DCs produced in vitro using Larifan and its fractions together with tumor antigens during production were also characterized. All Larifan fractions resulted in inducing high expression of immunogenic markers CD40, CD80, CD86, CCR7, MHC II and lower secretion of the immunosuppressive cytokine IL-10, compared to the maturation with LPS in mDCs. The lowest expression of tolerogenic gene Ido1 and highest expression of the immunogenic genes Clec7a, Tnf, Icosl, Il12rb2, Cd209a were characteristic to the unfractionated dsRNA and short fraction FR15. In the mouse model the best overall survival rate was observed in mice treated with medium-length FR9 and FR15. We can state that both Larifan and its fractions were superior to LPS as vaccine adjuvants in stimulating phenotype and functional activity of mature DCs. DCs maturation using these factors induces a valuable anticancer immune response.

The Price of Human Evolution: Cancer-Testis Antigens, the Decline in Male Fertility and the Increase in Cancer.

The increasing frequency of general and particularly male cancer coupled with the reduction in male fertility seen worldwide motivated us to seek a potential evolutionary link between these two phenomena, concerning the reproductive transcriptional modules observed in cancer and the expression of cancer-testis antigens (CTA). The phylostratigraphy analysis of the human genome allowed us to link the early evolutionary origin of cancer via the reproductive life cycles of the unicellulars and early multicellulars, potentially driving soma-germ transition, female meiosis, and the parthenogenesis of polyploid giant cancer cells (PGCCs), with the expansion of the CTA multi-families, very late during their evolution. CTA adaptation was aided by retrovirus domestication in the unstable genomes of mammals, for protecting male fertility in stress conditions, particularly that of humans, as compensation for the energy consumption of a large complex brain which also exploited retrotransposition. We found that the early and late evolutionary branches of human cancer are united by the immunity-proto-placental network, which evolved in the Cambrian and shares stress regulators with the finely-tuned sex determination system. We further propose that social stress and endocrine disruption caused by environmental pollution with organic materials, which alter sex determination in male foetuses and further spermatogenesis in adults, bias the development of PGCC-parthenogenetic cancer by default.

The Role of Mitotic Slippage in Creating a "Female Pregnancy-like System" in a Single Polyploid Giant Cancer Cell.

In our recent work, we observed that triple-negative breast cancer MDA-MB-231 cells respond to doxorubicin (DOX) via "mitotic slippage" (MS), discarding cytosolic damaged DNA during the process that provides their resistance to this genotoxic treatment. We also noted two populations of polyploid giant cells: those budding surviving offspring, versus those reaching huge ploidy by repeated MS and persisting for several weeks. Their separate roles in the recovery from treatment remained unclear. The current study was devoted to characterising the origin and relationship of these two sub-populations in the context of MS. MS was hallmarked by the emergence of nuclear YAP1/OCT4A/MOS/EMI2-positivity featuring a soma-germ transition to the meiotic-metaphase-arrested "maternal germ cell". In silico, the link between modules identified in the inflammatory innate immune response to cytosolic DNA and the reproductive module of female pregnancy (upregulating placenta developmental genes) was observed in polyploid giant cells. Asymmetry of the two subnuclei types, one repairing DNA and releasing buds enriched by CDC42/ACTIN/TUBULIN and the other persisting and degrading DNA in a polyploid giant cell, was revealed. We propose that when arrested in MS, a "maternal cancer germ cell" may be parthenogenetically stimulated by the placental proto-oncogene parathyroid-hormone-like-hormone, increasing calcium, thus creating a "female pregnancy-like" system within a single polyploid giant cancer cell.

Effects of BRAF V600E and NRAS mutational status on the progression-free survival and clinicopathological characteristics of patients with melanoma.

Hotspot mutations of the BRAF and NRAS genes are the most common genetic alterations in invasive cutaneous melanoma; however, the prognostic significance of BRAF and NRAS co-mutations remains controversial. The present study aimed to determine the association between NRAS and BRAF mutation status and the clinicopathological characteristics of patients with stage IA-IIC melanoma. A total of 118 patients who underwent surgical treatment for stage IA-IIC melanoma at the Riga East University Hospital between 2012 and 2018 were retrospectively enrolled in the present study. BRAF and NRAS mutation status was assessed by digital droplet PCR using the BRAFV600, NRAS Q61 and NRAS G12/G13 Screening Assays. The association between mutation status and clinicopathological features and progression-free survival (PFS) was then analyzed. The BRAF V600 mutation was detected in 67 out of 118 patients (56.8%). The PFS did not differ between patients with BRAF wild-type and BRAF-mutant melanoma. NRAS mutations were detected in 35 out of 118 patients (29.6%). The NRAS mutational status was associated with Breslow thickness (P=0.035), tumor type (P=0.020; χ2=0.20), mitotic rate (P=0.025) and lymphovascular invasion (P=0.02; χ2=0.20). Patients with NRAS-mutant melanoma had significantly worse PFS compared with NRAS wild-type melanoma (HR=12.30; 95% CI=5.78-26.21, P<0.0001). Furthermore, BRAF and NRAS co-mutant melanoma was associated with a significantly worse PFS compared with BRAF-mutant melanoma (HR=6.30; 95% CI=3.10-12.70, P<0.0001). In conclusion, NRAS-mutant and NRAS/BRAF co-mutant stage IA-IIC melanoma was associated with worse PFS compared with NRAS wild-type and BRAF-mutant melanoma. The assessment of NRAS mutation status in melanoma in routine clinical practice may be beneficial for the risk stratification of disease progression for primary non-metastatic malignant melanoma.

The Transcriptome and Proteome Networks of Malignant Tumours Reveal Atavistic Attractors of Polyploidy-Related Asexual Reproduction.

The expression of gametogenesis-related (GG) genes and proteins, as well as whole genome duplications (WGD), are the hallmarks of cancer related to poor prognosis. Currently, it is not clear if these hallmarks are random processes associated only with genome instability or are programmatically linked. Our goal was to elucidate this via a thorough bioinformatics analysis of 1474 GG genes in the context of WGD. We examined their association in protein-protein interaction and coexpression networks, and their phylostratigraphic profiles from publicly available patient tumour data. The results show that GG genes are upregulated in most WGD-enriched somatic cancers at the transcriptome level and reveal robust GG gene expression at the protein level, as well as the ability to associate into correlation networks and enrich the reproductive modules. GG gene phylostratigraphy displayed in WGD+ cancers an attractor of early eukaryotic origin for DNA recombination and meiosis, and one relative to oocyte maturation and embryogenesis from early multicellular organisms. The upregulation of cancer-testis genes emerging with mammalian placentation was also associated with WGD. In general, the results suggest the role of polyploidy for soma-germ transition accessing latent cancer attractors in the human genome network, which appear as pre-formed along the whole Evolution of Life.

Bacteriophage-Derived Double-Stranded RNA Exerts Anti-SARS-CoV-2 Activity In Vitro and in Golden Syrian Hamsters In Vivo.

Bacteriophage-derived dsRNA, known as Larifan, is a nationally well-known broad-spectrum antiviral medication. This study aimed to ascertain the antiviral activity of Larifan against the novel SARS-CoV-2 virus. Larifan's effect against SARS-CoV-2 in vitro was measured in human lung adenocarcinoma (Calu3) and primary human small airway epithelial cells (HSAEC), and in vivo in the SARS-CoV-2 infection model in golden Syrian hamsters. Larifan inhibited SARS-CoV-2 replication both in vitro and in vivo. Viral RNA copy numbers and titer of infectious virus in the supernatant of Calu3 cells dropped significantly: p = 0.0296 and p = 0.0286, respectively. A reduction in viral RNA copy number was also observed in HSAEC, especially when Larifan was added before infection (p = 0.0218). Larifan markedly reduced virus numbers in infected hamsters' lungs post-infection, with a more pronounced effect after intranasal administration (p = 0.0032). The administration of Larifan also reduced the amount of infections virus titer in the lungs (p = 0.0039). Improvements in the infection-induced pathological lesion severity in the lungs of animals treated with Larifan were also demonstrated. The inhibition of SARS-CoV-2 replication in vitro and the reduction in the viral load in the lungs of infected hamsters treated with Larifan alongside the improved lung histopathology suggests a potential use of Larifan in also controlling the COVID-19 disease in humans.

Role of the Circadian Clock "Death-Loop" in the DNA Damage Response Underpinning Cancer Treatment Resistance.

Here, we review the role of the circadian clock (CC) in the resistance of cancer cells to genotoxic treatments in relation to whole-genome duplication (WGD) and telomere-length regulation. The CC drives the normal cell cycle, tissue differentiation, and reciprocally regulates telomere elongation. However, it is deregulated in embryonic stem cells (ESCs), the early embryo, and cancer. Here, we review the DNA damage response of cancer cells and a similar impact on the cell cycle to that found in ESCs­overcoming G1/S, adapting DNA damage checkpoints, tolerating DNA damage, coupling telomere erosion to accelerated cell senescence, and favouring transition by mitotic slippage into the ploidy cycle (reversible polyploidy). Polyploidy decelerates the CC. We report an intriguing positive correlation between cancer WGD and the deregulation of the CC assessed by bioinformatics on 11 primary cancer datasets (rho = 0.83; p < 0.01). As previously shown, the cancer cells undergoing mitotic slippage cast off telomere fragments with TERT, restore the telomeres by ALT-recombination, and return their depolyploidised offspring to telomerase-dependent regulation. By reversing this polyploidy and the CC "death loop", the mitotic cycle and Hayflick limit count are thus again renewed. Our review and proposed mechanism support a life-cycle concept of cancer and highlight the perspective of cancer treatment by differentiation.

Addressing the importance of melanoma tumor-infiltrating lymphocytes in disease progression and clinicopathological characteristics.

Tumor-infiltrating lymphocytes (TILs) in primary cutaneous melanoma are considered to represent the host's antitumor immunological response; however, whether there are associations between TIL grade and histopathological characteristics and disease survival remains controversial. BRAF mutational status has been established as a routine screening method in advanced malignant melanoma, and worse prognosis rates have been demonstrated in patients harboring BRAF mutations. However, the general impact of BRAF mutational status on survival and histopathological characteristics is still debated. The aim of the present study was to compare the value of the assessment of TIL grade in stages I-II nodular and superficial spreading melanoma and BRAF mutational status, and its influence on clinicopathological characteristics. Altogether, 85 patients at stage IA-IIC who underwent melanoma surgical treatment at the Riga East University Hospital between 2012 and 2017 were retrospectively enrolled in the study. The histopathological characteristics were assessed according to the current World Health Organization and The American Joint Committee on Cancer 8th edition guidelines. The current study showed that patients with melanoma with high TIL grade had significantly better progression-free survival than patients with low TIL grade (hazard ratio, 4.9; 95% CI, 2.3-11.2; P<0.0001). BRAF mutations were observed in 52 patients (61.2%). BRAF mutational status in melanoma was associated with Clark invasion level (P=0.045), patient age (P=0.02) and TIL (P=0.04). The assessment of TIL grade in stage I-II melanoma demonstrated prognostic significance value and may help improve risk assessment in the future.

Birth cohort-specific trends of sun-related behaviors among individuals from an international consortium of melanoma-prone families.

BACKGROUND: Individuals from melanoma-prone families have similar or reduced sun-protective behaviors compared to the general population. Studies on trends in sun-related behaviors have been temporally and geographically limited. METHODS: Individuals from an international consortium of melanoma-prone families (GenoMEL) were retrospectively asked about sunscreen use, sun exposure (time spent outside), sunburns, and sunbed use at several timepoints over their lifetime. Generalized linear mixed models were used to examine the association between these outcomes and birth cohort defined by decade spans, after adjusting for covariates. RESULTS: A total of 2407 participants from 547 families across 17 centers were analyzed. Sunscreen use increased across subsequent birth cohorts, and although the likelihood of sunburns increased until the 1950s birth cohort, it decreased thereafter. Average sun exposure did not change across the birth cohorts, and the likelihood of sunbed use increased in more recent birth cohorts. We generally did not find any differences in sun-related behavior when comparing melanoma cases to non-cases. Melanoma cases had increased sunscreen use, decreased sun exposure, and decreased odds of sunburn and sunbed use after melanoma diagnosis compared to before diagnosis. CONCLUSIONS: Although sunscreen use has increased and the likelihood of sunburns has decreased in more recent birth cohorts, individuals in melanoma-prone families have not reduced their overall sun exposure and had an increased likelihood of sunbed use in more recent birth cohorts. These observations demonstrate partial improvements in melanoma prevention and suggest that additional intervention strategies may be needed to achieve optimal sun-protective behavior in melanoma-prone families.

Association of HERV-K and LINE-1 hypomethylation with reduced disease-free survival in melanoma patients.

Aim: To evaluate CpG methylation of long interspersed nuclear elements 1 (LINE-1) and human endogenous retrovirus K (HERV-K) retroelements as potential prognostic biomarkers in cutaneous melanoma. Materials & methods: Methylation of HERV-K and LINE-1 retroelements was assessed in resected melanoma tissues from 82 patients ranging in age from 14 to 88 years. In addition, nevi from eight patients were included for comparison with nonmalignant melanocytic lesions. Results: Methylation levels were lower in melanomas than in nevi. HERV-K and LINE-1 methylation were decreased in melanoma patients with clinical parameters associated with adverse prognosis, while they were independent of age and gender. Hypomethylation of HERV-K (but not LINE-1) was an independent predictor of reduced disease-free survival. Conclusion: HERV-K hypomethylation can be a potential independent biomarker of melanoma recurrence.

Features associated with melanoma metastasis in Latvia.

Cutaneous melanoma (CM) is the most aggressive form of skin cancer, exhibits an increasing incidence worldwide and has a high potential to develop metastasis. The current study aimed to identify a set of parameters that may aid in predicting the probability and timing of the onset of CM metastasis. A retrospective analysis was performed using the archive data of 2,026 patients with CM that were treated at the Riga East University Hospital Latvian Oncology Centre, which is the largest oncological hospital in the country, between 1998 and 2015. A case-control study design was employed, where patients with metastasis (n=278) were used as the cases and patients without metastasis were used as the controls. The present study examined the associations between metastasis and potential risk factors and constructed multivariate models of features that predicted metastasis using stepwise regression. Time until metastasis was analyzed using negative binomial regression models. The results of the present study indicated an increase in the number of melanomas that developed metastases during 1998-2015. Tumor Breslow thickness was demonstrated to be significantly larger in patients with metastasis compared with those without (P=0.012). The presence of ulceration significantly increased the risk of metastases [odds ratio (OR), 1.66; 95% CI, 1.07-2.59; P=0.033]. The absence of pigment in melanoma tissues was indicated to lead to a greater likelihood of metastasis (OR, 2.14; 95% CI, 1.10-4.19; P=0.035). Shorter times from diagnosis until the onset of metastases were observed in older patients (incident rate ratio (IRR), 6.85; 95% CI, 2.43-19.30; P=2.78×10-4), and a borderline significant association was observed in those with ulcerated tumors (IRR, 1.33; 95% CI, 0.98-1.80; P=0.064). Therefore, the main features associated with the development of melanoma metastasis in Latvia were indicated to be tumor ulceration, absence of pigment and Breslow thickness.

"Mitotic Slippage" and Extranuclear DNA in Cancer Chemoresistance: A Focus on Telomeres.

Mitotic slippage (MS), the incomplete mitosis that results in a doubled genome in interphase, is a typical response of TP53-mutant tumors resistant to genotoxic therapy. These polyploidized cells display premature senescence and sort the damaged DNA into the cytoplasm. In this study, we explored MS in the MDA-MB-231 cell line treated with doxorubicin (DOX). We found selective release into the cytoplasm of telomere fragments enriched in telomerase reverse transcriptase (hTERT), telomere capping protein TRF2, and DNA double-strand breaks marked by γH2AX, in association with ubiquitin-binding protein SQSTM1/p62. This occurs along with the alternative lengthening of telomeres (ALT) and DNA repair by homologous recombination (HR) in the nuclear promyelocytic leukemia (PML) bodies. The cells in repeated MS cycles activate meiotic genes and display holocentric chromosomes characteristic for inverted meiosis (IM). These giant cells acquire an amoeboid phenotype and finally bud the depolyploidized progeny, restarting the mitotic cycling. We suggest the reversible conversion of the telomerase-driven telomere maintenance into ALT coupled with IM at the sub-telomere breakage sites introduced by meiotic nuclease SPO11. All three MS mechanisms converging at telomeres recapitulate the amoeba-like agamic life-cycle, decreasing the mutagenic load and enabling the recovery of recombined, reduced progeny for return into the mitotic cycle.

The complementary effect of rs1042522 in TP53 and rs1805007 in MC1R is associated with an elevated risk of cutaneous melanoma in Latvian population.

Genetic factors serve important roles in melanoma susceptibility. Although much genetic variation has been associated with cutaneous melanoma (CM), little is known about the interactions between genetic variants. The current study investigated the joint effect of rs1042522 in the tumour protein 53 (TP53) gene, rs2279744 in the murine double minute-2 (MDM2) gene and several single nucleotide polymorphisms (SNPs) in the melanocortin 1 receptor (MC1R) gene. All of these genes are interconnected in a single signalling pathway that regulates pigmentation. The current study included 479 individuals, of which, 255 were patients with CM and 224 were controls from the Latvian population. Multifaceted analyses of potential interactions between SNPs were performed, whilst taking into account the pigmentation phenotypes of individuals and tumour characteristics (Breslow thickness and ulceration). Univariate analyses revealed a borderline significant association between rs1042522 in the TP53 gene and CM risk. The results also confirmed a known association with rs1805007 in the MC1R gene. The rs1042522 was also selected as a CM risk factor in multivariate models, suggesting an effect that is independent from and complementary to that of rs1805007. The results indicated that these SNPs need to be taken into account when determining melanoma risk. A strong association between CM and red hair was identified for rs1805007, and rs1805008 in the MC1R gene was mainly associated with red hair. An association was also determined between rs2279744 in the MDM2 gene and brown eye colour. No convincing associations were identified between the analysed SNPs and Breslow thickness of tumours or ulcerations.

Comparison of the effects of bacteriophage-derived dsRNA and poly(I:C) on ex vivo cultivated peripheral blood mononuclear cells.

Double-stranded RNA (dsRNA), regardless of the origin and nucleotide sequence, exhibits multiple biological activities, including the establishment of an antiviral state and modulation of the immune response. Both involve the stimulation of innate immunity primarily via the release of pro-inflammatory cytokines, which in turn shapes the adaptive immune response. In this study, we compared the immune response triggered by two different dsRNAs: 1) a well-known synthetic dsRNA-poly (I:C); and 2) bacteriophage-derived dsRNA (bf-dsRNA) that is a replicative form of ssRNA bacteriophage f2. Human peripheral blood mononuclear cells (PBMCs) from 61 heathy volunteers were stimulated ex vivo with both dsRNAs. Subsequently, activation markers on the main lymphocyte subpopulations were analysed by flow cytometry and the production of 29 different cytokines and chemokines was measured by Luminex xMAP technology. The effect of bf-dsRNA on ex vivo cultivated PBMCs is similar to that induced by poly(I:C), albeit with subtle dissimilarities. Both treatments increased expression of the lymphocyte CD38 marker and intracellular IFN-γ in CD8+ T and natural killer (NK) cells, as well as the CD95 marker on the main lymphocyte subpopulations. Poly(I:C) was a stronger inducer of IL-6, IL-1ß, and CCL4, whereas bf-dsRNA induced higher levels of IFN-α2, CXCL10, and CCL17. These differences might contribute to a distinct clinical manifestation when used as vaccine adjuvants, and bf-dsRNA may have more profound activity against several types of bacteria.

Estimating CDKN2A mutation carrier probability among global familial melanoma cases using GenoMELPREDICT.

BACKGROUND: Although rare in the general population, highly penetrant germline mutations in CDKN2A are responsible for 5%-40% of melanoma cases reported in melanoma-prone families. We sought to determine whether MELPREDICT was generalizable to a global series of families with melanoma and whether performance improvements can be achieved. METHODS: In total, 2116 familial melanoma cases were ascertained by the international GenoMEL Consortium. We recapitulated the MELPREDICT model within our data (GenoMELPREDICT) to assess performance improvements by adding phenotypic risk factors and history of pancreatic cancer. We report areas under the curve (AUC) with 95% confidence intervals (CIs) along with net reclassification indices (NRIs) as performance metrics. RESULTS: MELPREDICT performed well (AUC 0.752, 95% CI 0.730-0.775), and GenoMELPREDICT performance was similar (AUC 0.748, 95% CI 0.726-0.771). Adding a reported history of pancreatic cancer yielded discriminatory improvement (P < .0001) in GenoMELPREDICT (AUC 0.772, 95% CI 0.750-0.793, NRI 0.40). Including phenotypic risk factors did not improve performance. CONCLUSION: The MELPREDICT model functioned well in a global data set of familial melanoma cases. Adding pancreatic cancer history improved model prediction. GenoMELPREDICT is a simple tool for predicting CDKN2A mutational status among melanoma patients from melanoma-prone families and can aid in directing these patients to receive genetic testing or cancer risk counseling.

The Cancer Aneuploidy Paradox: In the Light of Evolution.

Aneuploidy should compromise cellular proliferation but paradoxically favours tumour progression and poor prognosis. Here, we consider this paradox in terms of our most recent observations of chemo/radio-resistant cells undergoing reversible polyploidy. The latter perform the segregation of two parental groups of end-to-end linked dyads by pseudo-mitosis creating tetraploid cells through a dysfunctional spindle. This is followed by autokaryogamy and a homologous pairing preceding a bi-looped endo-prophase. The associated RAD51 and DMC1/γ-H2AX double-strand break repair foci are tandemly situated on the AURKB/REC8/kinetochore doublets along replicated chromosome loops, indicative of recombination events. MOS-associated REC8-positive peri-nucleolar centromere cluster organises a monopolar spindle. The process is completed by reduction divisions (bi-polar or by radial cytotomy including pedogamic exchanges) and by the release of secondary cells and/or the formation of an embryoid. Together this process preserves genomic integrity and chromosome pairing, while tolerating aneuploidy by by-passing the mitotic spindle checkpoint. Concurrently, it reduces the chromosome number and facilitates recombination that decreases the mutation load of aneuploidy and lethality in the chemo-resistant tumour cells. This cancer life-cycle has parallels both within the cycling polyploidy of the asexual life cycles of ancient unicellular protists and cleavage embryos of early multicellulars, supporting the atavistic theory of cancer.

Author Correction: Telomere length and survival in primary cutaneous melanoma patients.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Telomere length and survival in primary cutaneous melanoma patients.

Telomere repeats at chromosomal ends, critical to genomic integrity, undergo age-dependent attrition. Telomere length, a polygenic trait, has been associated with risk of several disorders including cancers. In contrast to association of long telomeres with increased risk of several cancers, including melanoma, emerging reports suggest that short telomeres predict poor survival in patients with different cancers. In this study based on 1019 stage I and II cutaneous melanoma patients, we show an association between the patients with short telomeres and poor melanoma-specific survival (HR 2.05, 95% CI 1.33-3.16) compared to patients with long telomeres. Due to inverse correlation between age and telomere length (r -0.19, P < 0.0001), we stratified the patients into quantiles based on age at diagnosis and also carried out age-matched analysis. The effect of short telomeres on survival was determined by using multivariate Cox regression that included composite genetic risk score computed from genotyping of the patients for telomere-length associated polymorphisms. The effect of decreased telomere length on poor melanoma-specific survival was particularly strong in patients within the age quantile below 30 years (HR 3.82, 95% CI 1.10-13.30) and between 30-40 years (HR 2.69, 95% CI 1.03-7.03). Our study shows that in contrast to increased melanoma risk associated with increased telomere length, decreased telomere length predicts poor survival in melanoma subgroups.

Oncolytic viruses sensitize human tumor cells for NY-ESO-1 tumor antigen recognition by CD4+ effector T cells.

Oncolytic immunotherapy using oncolytic viruses (OV) has been shown to stimulate the antitumor immune response by inducing the release of tumor-associated antigens (TAA) and danger signals from the dying infected tumor cells. In this study, we sought to determine if the lysis of tumor cells induced by different OV: measles virus, vaccinia virus, vesicular stomatitis virus, herpes simplex type I virus, adenovirus or enterovirus, has consequences on the capacity of tumor cells to present TAA, such as NY-ESO-1. We show that the co-culture of NY-ESO-1neg/HLA-DP4pos melanoma cells with NY-ESO-1pos/HLA-DP4neg melanoma cells infected and killed by different OV induces an intercellular transfer of NY-ESO-1 that allows the recognition of NY-ESO-1neg/HLA-DP4pos tumor cells by an HLA-DP4/NY-ESO-1(157-170)-specific CD4+ cytotoxic T cell clone, NY67. We then confirmed this result in a second model with an HLA-DP4+ melanoma cell line that expresses a low amount of NY-ESO-1. Recognition of this cell line by the NY67 clone is largely increased in the presence of OV productive infection. Altogether, our results show for the first time another mechanism of stimulation of the anti-tumor immune response by OV, via the loading of tumor cells with TAA that sensitizes them for direct recognition by specific effector CD4+ T cells, supporting the use of OV for cancer immunotherapy.

Germline Variation at CDKN2A and Associations with Nevus Phenotypes among Members of Melanoma Families.

Germline mutations in CDKN2A are frequently identified among melanoma kindreds and are associated with increased atypical nevus counts. However, a clear relationship between pathogenic CDKN2A mutation carriage and other nevus phenotypes including counts of common acquired nevi has not yet been established. Using data from GenoMEL, we investigated the relationships between CDKN2A mutation carriage and 2-mm, 5-mm, and atypical nevus counts among blood-related members of melanoma families. Compared with individuals without a pathogenic mutation, those who carried one had an overall higher prevalence of atypical (odds ratio = 1.64; 95% confidence interval = 1.18-2.28) nevi but not 2-mm nevi (odds ratio = 1.06; 95% confidence interval = 0.92-1.21) or 5-mm nevi (odds ratio = 1.26; 95% confidence interval = 0.94-1.70). Stratification by case status showed more pronounced positive associations among non-case family members, who were nearly three times (odds ratio = 2.91; 95% confidence interval = 1.75-4.82) as likely to exhibit nevus counts at or above the median in all three nevus categories simultaneously when harboring a pathogenic mutation (vs. not harboring one). Our results support the hypothesis that unidentified nevogenic genes are co-inherited with CDKN2A and may influence carcinogenesis.