Genetic variation in RNASEL and risk for prostate cancer in a population-based case-control study

Racial Differences in Germline Genetic Testing for Prostate Cancer: A Systematic Review

PURPOSE

Testing for pathogenic variants can aid in oncologic risk stratification and identification of targeted therapies. Despite known disparities in access to prostate cancer (PCa) care, little has been written about access to germline genetic testing (GGT) for Black men and other historically marginalized populations. This systematic review sought to delineate racial/ethnic disparities in GGT for PCa.

METHODS

This systematic review identified articles published from January 1996 through May 2021 in PubMed, Web of Science, and Embase. We included studies that reported rates of GGT in men with PCa in the United States by race/ethnicity as reflective of routine clinical care or research. A narrative synthesis was performed.

RESULTS

Of 4,309 unique records, 91 studies examining 50 unique study populations met inclusion criteria. Of these, four populations included men who received GGT through routine clinical care, accounting for 4,415 men (72.6% White and 7.2% Black). The other 46 populations included men who received GGT as part of a research study, accounting for 30,824 men (64.3% White and 21.6% Black). Of these 46 research populations, 19 used targeted methods to increase recruitment from a specific demographic.

CONCLUSION

Most studies that report GGT rates by race/ethnicity are in research settings. Many of these studies used targeted recruitment methods and subsequently have a greater proportion of Black men than clinical and US population-based studies. Other historically marginalized populations are not well represented. There remains a knowledge gap regarding the extent of racial disparities in the use of GGT, particularly in the clinical setting.

Carriage of mutations R462Q (rs 486907) and D541E (rs 627928) of the RNASEL gene and risk factors in patients with prostate cancer in Burkina Faso

Background

Prostate cancer (Pca) is a public health problem that affects men, usually of middle age or older. It is the second most common cancer diagnosed in men and the fifth leading cause of death. The RNASEL gene located in 1q25 and identified as a susceptibility gene to hereditary prostate cancer, has never been studied in relation to prostate cancer in Burkina Faso. The aim of this study was to analyze the carriage of RNASEL R462Q and D541E mutations and risks factors in patients with prostate cancer in the Burkina Faso.

Methods

This case–control study included of 38 histologically diagnosed prostate cancer cases and 53 controls (cases without prostate abnormalities). Real-time PCR genotyping of R462Q and D541E variants using the TaqMan® allelic discrimination technique was used. Correlations between different genotypes and combined genotypes were investigated.

Results

The R462Q variant was present in 5.3% of cases and 7.5% of controls. The D541E variant was present in 50.0% of cases and 35% of controls. There is no association between R462Q variants (OR = 0.60; 95%IC, 0.10–3.51; p = 0.686) and D541E variants (OR = 2.46; 95%IC, 0.78–7.80; p = 0.121) and genotypes combined with prostate cancer. However, there is a statistically significant difference in the distribution of cases according to the PSA rate at diagnosis (p ˂ 0.001). For the Gleason score distribution, only 13.2% of cases have a Gleason score greater than 7. There is a statistically significant difference in the Gleason score distribution of cases (p ˂ 0.001).

Conclusions

These variants, considered in isolation or in combination, are not associated with the risk of prostate cancer.

Activation of the viral sensor oligoadenylate synthetase 2 (Oas2) prevents pregnancy-driven mammary cancer metastases

BACKGROUND

The interferon response can influence the primary and metastatic activity of breast cancers and can interact with checkpoint immunotherapy to modulate its effects. Using N-ethyl-N-nitrosourea mutagenesis, we found a mouse with an activating mutation in oligoadenylate synthetase 2 (Oas2), a sensor of viral double stranded RNA, that resulted in an interferon response and prevented lactation in otherwise healthy mice.

METHODS

To determine if sole activation of Oas2 could alter the course of mammary cancer, we combined the Oas2 mutation with the MMTV-PyMT oncogene model of breast cancer and examined disease progression and the effects of checkpoint immunotherapy using Kaplan-Meier survival analysis with immunohistochemistry and flow cytometry.

RESULTS

Oas2 mutation prevented pregnancy from increasing metastases to lung. Checkpoint immunotherapy with antibodies against programmed death-ligand 1 was more effective when the Oas2 mutation was present.

CONCLUSIONS

These data establish OAS2 as a therapeutic target for agents designed to reduce metastases and increase the effectiveness of checkpoint immunotherapy.

Genomic analyses of the metastasis-derived prostate cancer cell lines LNCaP, VCaP, and PC3-AR

BACKGROUND

The lymph node metastasis-derived LNCaP, the bone metastasis-derived PC3 (skull), and VCaP (vertebral) cell lines are widely used as preclinical models of human prostate cancer (CaP) and have been described in more than 19,000 publications. Here, we report on short-read whole-genome sequencing and genomic analyses of LNCaP, VCaP, and PC3 cells stably transduced with WT AR (PC3-AR).

METHODS

LNCaP, VCaP, and PC3-AR cell lines were sequenced to an average depth of more than 30-fold using Illumina short-read sequencing. Using various computational methods, we identified and compared the single-nucleotide variants, copy-number profiles, and the structural variants observed in the three cell lines.

RESULTS

LNCaP cells are composed of multiple subpopulations, which results in nonintegral copy number states and a high mutational load when the data is analyzed in bulk. All three cell lines contain pathogenic mutations and homozygous deletions in genes involved in DNA mismatch repair, along with deleterious mutations in cell-cycle, Wnt signaling, and other critical cellular processes. PC3-AR cells have a truncating mutation in TP53 and do not express the p53 protein. The VCaP cells contain a homozygous gain-of-function mutation in TP53 (p.R248W) that promotes cancer invasion, metastasis, and progression and has also been observed in prostate adenocarcinomas. In addition, we detect the signatures of chromothripsis of the q arms of chromosome 5 in both PC3-AR and VCaP cells, strengthening the association of TP53 inactivation with chromothripsis reported in other systems.

CONCLUSIONS

Our work provides a resource for genetic, genomic, and biological studies employing these commonly-used prostate cancer cell lines.

RNASEL 1623A>C variant is associated with the risk of prostate cancer in African descendants

Association between ribonuclease L (RNASEL) gene 1623A>C polymorphism and prostate cancer (PCa) susceptibility has been assessed in large quantities of studies but with controversial conclusions. We undertook a pooled analysis containing 7397 PCa cases and 6088 control subjects to assess the correlation between RNASEL 1623A>C polymorphism and PCa risk. Moreover, we used enzyme-linked immunosorbent assay to test the serum RNASEL expression among patients enrolled in our centers and in-silico tools were also utilized. The overall results of our analysis indicated a positive relationship between 1623A>C variant and PCa risk (allelic contrast, odds ratio [OR] = 1.07; 95% confidence interval [CI] = 1.02-1.12; P_{heterogeneity}  = 0.575; CC vs AA, OR = 1.14; 95% CI = 1.03-1.26; P_{heterogeneity}  = 0.217; CC + CA vs AA, OR = 1.10; 95% CI = 1.01-1.19; P_{heterogeneity}  = 0.303; and CC vs CA + AA, OR = 1.08; 95% CI = 1.00-1.17; P_{heterogeneity}  = 0.298). In ethnicity subgroup analysis, similar results were especially indicated in African descendants. In addition, serum RNASEL levels in PCa cases with CC + CA genotypes were higher than those with AA genotypes. Our present study showed evidence that RNASEL 1623A>C polymorphism is related to PCa risk, especially in African descendants.

Identification of a novel microRNA-mRNA regulatory biomodule in human prostate cancer

Our recent study identified a list of differentially expressed microRNAs (miRNAs) in human prostate cancer (PCa) tissues compared to adjacent benign prostate tissues. In the current study, to identify the crucial miRNA-mRNA regulatory biomodule involved into prostate carcinogenesis based on the previous miRNA expression profile in PCa, we proposed an integrated systematic approach which combined miRNA-mediated gene expression regulatory network analysis, experimental validations in vitro and in vivo, as well as clinical significance evaluation. As a result, the CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I axis was identified as a bottleneck in the miRNA-mediated gene expression regulatory network of PCa according to network topological analysis. The direct binding relationship between TP73 and PCa downregulated miR-193a-5p, and the direct binding relationship between UBE2I and PCa upregulated miR-188-5p were both experimentally validated. In addition, miR-193a-5p had a more significant regulatory effect on the tumor promoter isoform of TP73-deltaNp73 than on the tumor suppressive isoform of TP73-TAp73. Importantly, the deregulation of either the miR-193a-5p-TP73 or miR-188-5p-UBE2I axes was significantly associated with aggressive progression and poor prognosis in PCa patients. Gain- and loss-of-function experiments showed that miR-193a-5p efficiently inhibited in vitro PCa cell proliferation, migration, and invasion, and in vivo tumor growth, and markedly induced PCa cell apoptosis via regulating TP73 with a corresponding suppression of the CCND1-RNASEL-CDKN1A-MDM2 axis. In contrast, miR-188-5p exerted its tumor promoter roles through targeting UBE2I with a subsequent activation of the CCND1-RNASEL-CDKN1A-MDM2 axis. Taken together, this integrated analysis revealed the potential roles of the miR-193a-5p/TP73 and miR-188-5p/UBE2i negative regulation pairs in PCa. In addition to the significant clinical relevance, miR-193a-5p- and miR-188-5p-regulated CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I signaling may be a novel regulatory biomodule in prostate carcinogenesis.

RNase L is a negative regulator of cell migration

RNase L is a regulated endoribonuclease that functions in the interferon antiviral response. Activation of RNase L by 2', 5'-oligoadenylates has been linked to apoptosis, autophagy and inflammation. Genetic studies have also suggested the possible involvement of the RNase L gene (RNASEL) on chromosome 1q25.3 in several types of cancer. Here we report that ablation of RNase L in human prostate cancer PC3 cells by CRISPR/Cas9 gene editing technology enhanced cell migration as determined both by transwell assays and scratch wound healing assays. In addition, RNase L knockdown by means of RNAi increased migration of PC3 and DU145 cells in response to either fibronectin or serum stimulation, as did homozygous disruption of the RNase L gene in mouse embryonic fibroblasts. Serum or fibronectin stimulation of focal adhesion kinase (FAK) autophosphorylation on tyrosine-397 was increased by either knockdown or ablation of RNase L. In contrast, a missense mutant RNase L (R667A) lacking catalytic activity failed to suppress cell migration in PC3 cells. However, a nuclease-inactive mutant mouse RNase L (W630A) was able to partially inhibit migration of mouse fibroblasts. Consistent with a role for the catalytic activity of RNase L, transfection of PC3 cells with the RNase L activator, 2', 5'-oligoadenylate, suppressed cell migration. RNase L knockdown in PC3 cells enhanced tumor growth and metastasis following implantation in the mouse prostate. Our results suggest that naturally occurring mutations in the RNase L gene might promote enhanced cell migration and metastasis.

New advances in our understanding of the "unique" RNase L in host pathogen interaction and immune signaling

Ever since the discovery of the existence of an interferon (IFN)-regulated ribonuclease, significant advances have been made in understanding the mechanism and associated regulatory effects of its action. What had been studied initially as a "unique" endoribonuclease is currently known as ribonuclease L (RNase L where "L" stands for latent). Some of the key developments include discovery of the RNase L signaling pathway, its structural characterization, and its molecular cloning. RNase L has been implicated in antiviral and antibacterial defense, as well as in hereditary prostate cancer. RNase L is activated by 2'-5' linked oligoadenylates (2-5A), which are synthesized by the oligoadenylate synthetases (OASs), a family of IFN-regulated pathogen recognition receptors that sense double-stranded RNAs. Activated RNase L cleaves single stranded RNAs, including viral RNAs and cellular RNAs. The catalytic activity of RNase L has been found to lead into the activation of several cellular signaling pathways, including those involved in autophagy, apoptosis, IFN-β production, NLRP3 inflammasome activation leading to IL-1β secretion, inhibition of cell migration, and cell adhesion. In this review, we will highlight the newest advances in our understanding of the catalytic role of RNase L in the context of different cellular pathways and extend the scope of these findings to discussion of potential therapeutic targets for antimicrobial drug development.

Variation in genes involved in the immune response and prostate cancer risk in the placebo arm of the Prostate Cancer Prevention Trial

BACKGROUND

We previously found that inflammation in benign prostate tissue is associated with an increased odds of prostate cancer, especially higher-grade disease. Since part of this link may be due to genetics, we evaluated the association between single nucleotide polymorphisms (SNPs) in immune response genes and prostate cancer in the placebo arm of the Prostate Cancer Prevention Trial.

METHODS

We genotyped 16 candidate SNPs in IL1β, IL2, IL4, IL6, IL8, IL10, IL12(p40), IFNG, MSR1, RNASEL, TLR4, and TNFA and seven tagSNPs in IL10 in 881 prostate cancer cases and 848 controls negative for cancer on an end-of-study biopsy. Cases and controls were non-Hispanic white and frequency matched on age and family history. We classified cases as lower (Gleason sum <7; N = 674) and higher (7-10; N = 172) grade, and used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusting for age and family history.

RESULTS

The minor allele (C) of rs3212227 in IL12(p40) was associated with an increased risk of total (log additive: OR = 1.30, 95%CI 1.10-1.53; P-trend = 0.0017) and lower-grade (OR = 1.36, 95%CI 1.15-1.62; P-trend = 0.0004) prostate cancer. The minor allele (A) of rs4073 in IL8 was possibly associated with a decreased risk of higher-grade (OR = 0.81, 95%CI 0.64-1.02; P-trend = 0.07), but not total disease. None of the other candidates was associated with risk. The minor alleles of IL10 tagSNPs rs1800890 (A; OR = 0.87, 95%CI: 0.75-0.99; P-trend = 0.04) and rs3021094 (C; OR = 1.31, 95%CI 1.03-1.66, P-trend = 0.03) were associated with risk; the latter also with lower- (P-trend = 0.04) and possibly higher- (P-trend = 0.06) grade disease. These patterns were similar among men with PSA <2 ng/ml at biopsy.

CONCLUSION

Variation in some immune response genes may be associated with prostate cancer risk. These associations were not fully explained by PSA-associated detection bias. Our findings generally support the role of inflammation in the etiology of prostate cancer.

RNASEL and MIR146A SNP-SNP interaction as a susceptibility factor for non-melanoma skin cancer

Immunity and inflammatory pathways are important in the genesis of non-melanoma skin cancers (NMSC). Functional genetic variation in immune modulators has the potential to affect disease etiology. We investigated associations between common variants in two key regulators, MIR146A and RNASEL, and their relation to NMSCs. Using a large population-based case-control study of basal cell (BCC) and squamous cell carcinoma (SCC), we investigated the impact of MIR146A SNP rs2910164 on cancer risk, and interaction with a SNP in one of its putative targets (RNASEL, rs486907). To examine associations between genotype and BCC and SCC, occurrence odds ratios (OR) and 95% confidence intervals (95%CI) were calculated using unconditional logistic regression, accounting for multiple confounding factors. We did not observe an overall change in the odds ratios for SCC or BCC among individuals carrying either of the RNASEL or MIR146A variants compared with those who were wild type at these loci. However, there was a sex-specific association between BCC and MIR146A in women (ORGC = 0.73, [95%CI = 0.52-1.03]; ORCC = 0.29, [95% CI = 0.14-0.61], p-trend<0.001), and a reduction in risk, albeit not statistically significant, associated with RNASEL and SCC in men (ORAG = 0.88, [95%CI = 0.65-1.19]; ORAA = 0.68, [95%CI = 0.43-1.08], p-trend = 0.10). Most striking was the strong interaction between the two genes. Among individuals carrying variant alleles of both rs2910164 and rs486907, we observed inverse relationships with SCC (ORSCC = 0.56, [95%CI = 0.38-0.81], p-interaction = 0.012) and BCC (ORBCC = 0.57, [95%CI = 0.40-0.80], p-interaction = 0.005). Our results suggest that genetic variation in immune and inflammatory regulators may influence susceptibility to NMSC, and novel SNP-SNP interaction for a microRNA and its target. These data suggest that RNASEL, an enzyme involved in RNA turnover, is controlled by miR-146a and may be important in NMSC etiology.

A single nucleotide polymorphism in inflammatory gene RNASEL predicts outcome after radiation therapy for localized prostate cancer

PURPOSE

To study associations between single nucleotide polymorphisms (SNP) in Ribonuclease L (RNASEL), a gene implicated in inflammation and prostate cancer risk, and outcomes after radiation therapy.

EXPERIMENTAL DESIGN

We followed participants in the prospective US Health Professionals Follow-Up Study treated with radiation therapy for early-stage prostate cancer. Three SNPs were genotyped based on previously determined functional and biological significance. We used multivariable Cox proportional hazards models to assess per-allele associations with the primary outcome defined as time to a composite endpoint including development of lethal prostate cancer or biochemical recurrence.

RESULTS

We followed 434 patients treated with radiation therapy for a median of 9 years. On multivariate analysis, the rs12757998 variant allele was associated with significantly decreased risk of the composite endpoint [HR: 0.65; 95% confidence interval (CI), 0.45-0.94%; P = 0.02] driven by decreased biochemical recurrence (HR: 0.60; 95% CI, 0.40-0.89%; P = 0.01) and men treated with external beam (HR: 0.58; 95% CI, 0.36-0.93%; P = 0.02). In contrast, in 516 men from the same cohort treated with radical prostatectomy, we found no significant impact of this variant on outcome. Furthermore, the rs12757998 variant allele significantly modified the association between androgen deprivation therapy and outcomes after radiation therapy (p-interaction = 0.02).

CONCLUSION

We show an association between RNASEL SNP rs12757998 and outcome after radiation therapy for prostate cancer. This SNP is associated with increased circulating C-reactive protein and interleukin-6, suggesting a potential role for inflammation in the response to radiation. If validated, genetic predictors of outcome may help inform prostate cancer management.

Analysis of Xq27-28 linkage in the international consortium for prostate cancer genetics (ICPCG) families

BACKGROUND

Genetic variants are likely to contribute to a portion of prostate cancer risk. Full elucidation of the genetic etiology of prostate cancer is difficult because of incomplete penetrance and genetic and phenotypic heterogeneity. Current evidence suggests that genetic linkage to prostate cancer has been found on several chromosomes including the X; however, identification of causative genes has been elusive.

METHODS

Parametric and non-parametric linkage analyses were performed using 26 microsatellite markers in each of 11 groups of multiple-case prostate cancer families from the International Consortium for Prostate Cancer Genetics (ICPCG). Meta-analyses of the resultant family-specific linkage statistics across the entire 1,323 families and in several predefined subsets were then performed.

RESULTS

Meta-analyses of linkage statistics resulted in a maximum parametric heterogeneity lod score (HLOD) of 1.28, and an allele-sharing lod score (LOD) of 2.0 in favor of linkage to Xq27-q28 at 138 cM. In subset analyses, families with average age at onset less than 65 years exhibited a maximum HLOD of 1.8 (at 138 cM) versus a maximum regional HLOD of only 0.32 in families with average age at onset of 65 years or older. Surprisingly, the subset of families with only 2-3 affected men and some evidence of male-to-male transmission of prostate cancer gave the strongest evidence of linkage to the region (HLOD = 3.24, 134 cM). For this subset, the HLOD was slightly increased (HLOD = 3.47 at 134 cM) when families used in the original published report of linkage to Xq27-28 were excluded.

CONCLUSIONS

Although there was not strong support for linkage to the Xq27-28 region in the complete set of families, the subset of families with earlier age at onset exhibited more evidence of linkage than families with later onset of disease. A subset of families with 2-3 affected individuals and with some evidence of male to male disease transmission showed stronger linkage signals. Our results suggest that the genetic basis for prostate cancer in our families is much more complex than a single susceptibility locus on the X chromosome, and that future explorations of the Xq27-28 region should focus on the subset of families identified here with the strongest evidence of linkage to this region.