BACKGROUND & AIMS: DNA mismatch repair deficiency drives microsatellite instability (MSI). Cells with MSI accumulate numerous frameshift mutations. Frameshift mutations affecting cancer-related genes may promote tumorigenesis and, therefore, are shared among independently arising MSI tumors. Consequently, such recurrent frameshift mutations can give rise to shared immunogenic frameshift peptides (FSPs) that represent ideal candidates for a vaccine against MSI cancer. Pathogenic germline variants of mismatch repair genes cause Lynch syndrome (LS), a hereditary cancer syndrome affecting approximately 20-25 million individuals worldwide. Individuals with LS are at high risk of developing MSI cancer. Previously, we demonstrated safety and immunogenicity of an FSP-based vaccine in a phase I/IIa clinical trial in patients with a history of MSI colorectal cancer. However, the cancerpreventive effect of FSP vaccination in the scenario of LS has not yet been demonstrated. METHODS: A genome-wide database of 488,235 mouse coding mononucleotide repeats was established, from which a set of candidates was selected based on repeat length, gene expression, and mutation frequency. In silico prediction, in vivo immunogenicity testing, and epitope mapping was used to identify candidates for FSP vaccination. RESULTS: We identified 4 shared FSP neoantigens (Nacad [FSP-1], Maz [FSP-1], Senp6 [FSP-1], Xirp1 [FSP-1]) that induced CD4/CD8 T cell responses in naïve C57BL/6 mice. Using VCMsh2 mice, which have a conditional knockout of Msh2 in the intestinal tract and develop intestinal cancer, we showed vaccination with a combination of only 4 FSPs significantly
Background
Efficient identification of neoantigen-specific T-cell responses in epithelial ovarian cancer (EOC) remains a challenge. Existing investigations of spontaneous T-cell response to tumor neoepitope in EOC have taken the approach of comprehensive screening all neoantigen candidates, with a validation rate of 0.5–2%.
Methods
Whole-exome and transcriptome sequencing analysis of treatment-naive EOC patients were performed to identify neoantigen candidates, and the immunogenicity of prioritized neoantigens was evaluated by analyzing spontaneous neoantigen-specfic CD4
+
and CD8
+
T-cell responses in the tumor and/or peripheral blood. The biological relevance of neoantigen-specific T-cell lines and clones were analyzed by evaluating the capacity of autologous ovarian tumor recognition. Genetic transfer of T-cell receptor (TCR) from these neoantigen-specific T-cell clones into peripheral blood T-cells was conducted to generate neoepitope-specific T-cells. The molecular signature associated with positive neoantigen T-cell responses was investigated, and the impacts of expression level and lymphocyte source on neoantigen identification were explored.
Results
Using a small subset of prioritized neoantigen candidates, we were able to detect spontaneous CD4
+
and/or CD8
+
T-cell responses against neoepitopes from autologous lymphocytes in half of treatment-naïve EOC patients, with a significantly improved validation rate of 19%. Tumors from patients exhibiting neoantigen-specific T-cell responses exhibited a signature of upregulated antigen processing and presentation machinery, which was also associated with favorable patient survival in the TCGA ovarian cohort. T-cells specific against two mutated cancer-associated genes,
NUP214
and
JAK1
, recognized autologous tumors
.
Gene-engineering with TCR from these neoantigen-specific T-cell clones conferred neoantigen-reactivity to peripheral T-cells.
Conclusions
Our study demonstrated the feasibility of efficiently identifying both CD4
+
and CD8
+
neoantigen-specific T-cells in EOC. Autologous lymphocytes genetically engineered with tumor antigen-specific TCR can be used to generate cells for use in the personalized adoptive T-cell transfer immunotherapy.
Electronic supplementary material
The online version of this article (10.1186/s40425-019-0629-6) contains supplementary material, which is available to authorized users.
Background
Reproductive factors, particularly parity, have differential effects on breast cancer risk according to estrogen receptor (ER) status, especially among African American (AA) women. One mechanism could be through DNA methylation, leading to altered expression levels of genes important in cell fate decisions.
Methods
Using the Illumina 450K BeadChip, we compared DNA methylation levels in paraffin-archived tumor samples from 383 AA and 350 European American (EA) women in the Women’s Circle of Health Study (WCHS). We combined 450K profiles with RNA-seq data and prioritized genes based on differential methylation by race, correlation between methylation and gene expression, and biological function. We measured tumor protein expression and assessed its relationship to DNA methylation. We evaluated associations between reproductive characteristics and DNA methylation using linear regression.
Results
410 loci were differentially methylated by race, with the majority unique to ER− tumors. FOXA1 was hypermethylated in tumors from AA versus EA women with ER− cancer, and increased DNA methylation correlated with reduced RNA and protein expression. Importantly, parity was positively associated with FOXA1 methylation among AA women with ER− tumors (P = 0.022), as was number of births (P = 0.026), particularly among those who did not breastfeed (P = 0.008). These same relationships were not observed among EA women, although statistical power was more limited.
Conclusions
Methylation and expression of FOXA1 is likely impacted by parity and breastfeeding. Because FOXA1 regulates a luminal gene expression signature in progenitor cells and represses the basal phenotype, this could be a mechanism that links these reproductive exposures with ER− breast cancer.
Objective• To validate the Bladder Control Self-Assessment Questionnaire (B-SAQ), a short screener to assess lower urinary tract symptoms (LUTS) and overactive bladder (OAB) in men.
Patients and Methods• This was a prospective, single-centre study including 211 patients in a urology outpatient setting.• All patients completed the B-SAQ and Kings Health Questionnaire (KHQ) before consultation, and the consulting urologist made an independent assessment of LUTS and the need for treatment.• The psychometric properties of the B-SAQ were analysed.
Results• A total of 98% of respondents completed all items correctly in <5 min.• The mean B-SAQ scores were 12 and 3.3, respectively for cases (n = 101) and controls (n = 108) (P < 0.001).• Good correlation was evident between the B-SAQ and the KHQ.• The agreement percentages between the individual B-SAQ items and the KHQ symptom severity scale were 86, 85, 84 and 79% for frequency, urgency, nocturia and urinary incontinence, respectively.• Using a B-SAQ symptom score threshold of ≥4 alone had sensitivity, specificity and positive predictive values for detecting LUTS of 75, 86 and 84%, respectively, with an area under the curve of 0.88; however, in combination with a bother score threshold of ≥1 these values changed to 92, 46 and 86%, respectively.
Conclusions• The B-SAQ is an easy and quick valid case-finding tool for LUTS/OAB in men, but appears to be less specific in men than in women.• The B-SAQ has the potential to raise awareness of LUTS.• Further validation in a community setting is required.
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