Characterization of mismatch-repair/microsatellite instability-discordant endometrial cancers.

BACKGROUND: Mismatch-repair (MMR)/microsatellite instability (MSI) status has therapeutic implications in endometrial cancer (EC). The authors evaluated the concordance of testing and factors contributing to MMR expression heterogeneity. METHODS: Six hundred sixty-six ECs were characterized using immunohistochemistry (IHC), MSI testing, and mut-L homolog 1 (MLH1) methylation. Select samples underwent whole-transcriptome analysis and next-generation sequencing. MMR expression of metastatic/recurrent sites was evaluated. RESULTS: MSI testing identified 27.3% of cases as MSI-high (n = 182), MMR IHC identified 25.1% cases as MMR-deficient (n = 167), and 3.8% of cases (n = 25) demonstrated discordant results. A review of IHC staining explained discordant results in 18 cases, revealing subclonal loss of MLH1/Pms 1 homolog 2 (PMS2) (n = 10) and heterogeneous MMR IHC (mut-S homolog 6 [MSH6], n = 7; MLH1/PMS2, n = 1). MSH6-associated Lynch syndrome was diagnosed in three of six cases with heterogeneous expression. Subclonal or heterogeneous cases had a 38.9% recurrence rate (compared with 16.7% in complete MMR-deficient cases and 9% in MMR-proficient cases) and had abnormal MMR IHC results in all metastatic recurrent sites (n = 7). Tumors with subclonal MLH1/PMS2 demonstrated 74 differentially expressed genes (determined using digital spatial transcriptomics) when stratified by MLH1 expression, including many associated with epithelial-mesenchymal transition. CONCLUSIONS: Subclonal/heterogeneous MMR IHC cases showed epigenetic loss in 66.7%, germline mutations in 16.7%, and somatic mutations in 16.7%. MMR IHC reported as intact/deficient missed 21% of cases of Lynch syndrome. EC with subclonal/heterogeneous MMR expression demonstrated a high recurrence rate, and metastatic/recurrent sites were MMR-deficient. Transcriptional analysis indicated an increased risk for migration/metastasis, suggesting that clonal MMR deficiency may be a driver for tumor aggressiveness. Reporting MMR IHC only as intact/deficient, without reporting subclonal and heterogeneous staining, misses opportunities for biomarker-directed therapy. PLAIN LANGUAGE SUMMARY: Endometrial cancer is the most common gynecologic cancer, and 20%-40% of tumors have a defect in DNA proofreading known as mismatch-repair (MMR) deficiency. These results can be used to guide therapy. Tests for this defect can yield differing results, revealing heterogeneous (mixed) proofreading capabilities. Tumors with discordant testing results and mixed MMR findings can have germline or somatic defects in MMR genes. Cells with deficient DNA proofreading in tumors with mixed MMR findings have DNA expression profiles linked to more aggressive characteristics and cancer spread. These MMR-deficient cells may drive tumor behavior and the risk of spreading cancer.

Association of ESR1 germline variants with TP53 somatic variants in breast tumors in a genome-wide study.

Background: In breast tumors, somatic mutation frequencies in TP53 and PIK3CA vary by tumor subtype and ancestry. HER2 positive and triple negative breast cancers (TNBC) have a higher frequency of TP53 somatic mutations than other subtypes. PIK3CA mutations are more frequently observed in hormone receptor positive tumors. Emerging data suggest tumor mutation status is associated with germline variants and genetic ancestry. We aimed to identify germline variants that are associated with somatic TP53 or PIK3CA mutation status in breast tumors. Methods: A genome-wide association study was conducted using breast cancer mutation status of TP53 and PIK3CA and functional mutation categories including TP53 gain of function (GOF) and loss of function mutations and PIK3CA activating/hotspot mutations. The discovery analysis consisted of 2850 European ancestry women from three datasets. Germline variants showing evidence of association with somatic mutations were selected for validation analyses based on predicted function, allele frequency, and proximity to known cancer genes or risk loci. Candidate variants were assessed for association with mutation status in a multi-ancestry validation study, a Malaysian study, and a study of African American/Black women with TNBC. Results: The discovery Germline x Mutation (GxM) association study found five variants associated with one or more TP53 phenotypes with P values <1×10-6, 33 variants associated with one or more TP53 phenotypes with P values <1×10-5, and 44 variants associated with one or more PIK3CA phenotypes with P values <1×10-5. In the multi-ancestry and Malaysian validation studies, germline ESR1 locus variant, rs9383938, was associated with the presence of TP53 mutations overall (P values 6.8×10-5 and 9.8×10-8, respectively) and TP53 GOF mutations (P value 8.4×10-6). Multiple variants showed suggestive evidence of association with PIK3CA mutation status in the validation studies, but none were significant after correction for multiple comparisons. Conclusions: We found evidence that germline variants were associated with TP53 and PIK3CA mutation status in breast cancers. Variants near the estrogen receptor alpha gene, ESR1, were significantly associated with overall TP53 mutations and GOF mutations. Larger multi-ancestry studies are needed to confirm these findings and determine if these variants contribute to ancestry-specific differences in mutation frequency.

Rare BRIP1 Missense Alleles Confer Risk for Ovarian and Breast Cancer.

Germline loss-of-function mutations in BRCA1 interacting protein C-terminal helicase 1 (BRIP1) are associated with ovarian carcinoma and may also contribute to breast cancer risk, particularly among patients who develop disease at an early age. Normal BRIP1 activity is required for DNA interstrand cross-link (ICL) repair and is thus central to the maintenance of genome stability. Although pathogenic mutations have been identified in BRIP1, genetic testing more often reveals missense variants, for which the impact on molecular function and subsequent roles in cancer risk are uncertain. Next-generation sequencing of germline DNA in 2,160 early-onset breast cancer and 1,199 patients with ovarian cancer revealed nearly 2% of patients carry a very rare missense variant (minor allele frequency < 0.0001) in BRIP1. This is 3-fold higher than the frequency of all rare BRIP1 missense alleles reported in more than 60,000 individuals of the general population (P < 0.0001, χ 2 test). Using CRISPR-Cas9 gene editing technology and rescue assays, we functionally characterized 20 of these missense variants, focusing on the altered protein's ability to repair ICL damage. A total of 75% of the characterized variants rendered the protein hypomorph or null. In a clinical cohort of >117,000 patients with breast and ovarian cancer who underwent panel testing, the combined OR associated with BRIP1 hypomorph or null missense carriers compared with the general population was 2.30 (95% confidence interval, 1.60-3.30; P < 0.0001). These findings suggest that novel missense variants within the helicase domain of BRIP1 may confer risk for both breast and ovarian cancer and highlight the importance of functional testing for additional variants. SIGNIFICANCE: Functional characterization of rare variants of uncertain significance in BRIP1 revealed that 75% demonstrate loss-of-function activity, suggesting rare missense alleles in BRIP1 confer risk for both breast and ovarian cancer.

MAX Mutations in Endometrial Cancer: Clinicopathologic Associations and Recurrent MAX p.His28Arg Functional Characterization.

Background: Genomic studies have revealed that multiple genes are mutated at varying frequency in endometrial cancer (EC); however, the relevance of many of these mutations is poorly understood. An EC-specific recurrent mutation in the MAX transcription factor p.His28Arg was recently discovered. We sought to assess the functional consequences of this hotspot mutation and determine its association with cancer-relevant phenotypes. Methods: MAX was sequenced in 509 endometrioid ECs, and associations between mutation status and clinicopathologic features were assessed. EC cell lines stably expressing MAXH28R were established and used for functional experiments. DNA binding was examined using electrophoretic mobility shift assays and chromatin immunoprecipitation. Transcriptional profiling was performed with microarrays. Murine flank (six to 11 mice per group) and intraperitoneal tumor models were used for in vivo studies. Vascularity of xenografts was assessed by MECA-32 immunohistochemistry. The paracrine pro-angiogenic nature of MAXH28R-expressing EC cells was tested using microfluidic HUVEC sprouting assays and VEGFA enzyme-linked immunosorbent assays. All statistical tests were two-sided. Results: Twenty-two of 509 tumors harbored mutations in MAX, including 12 tumors with the p.His28Arg mutation. Patients with a MAX mutation had statistically significantly reduced recurrence-free survival (hazard ratio = 4.00, 95% confidence interval = 1.15 to 13.91, P = .03). MAXH28R increased affinity for canonical E-box sequences, and MAXH28R-expressing EC cells dramatically altered transcriptional profiles. MAXH28R-derived xenografts statistically significantly increased vascular area compared with MAXWT and empty vector tumors (P = .003 and P = .008, respectively). MAXH28R-expressing EC cells secreted nearly double the levels of VEGFA compared with MAXWT cells (P = .03, .005, and .005 at 24, 48, and 72 hours, respectively), and conditioned media from MAXH28R cells increased sprouting when applied to HUVECs. Conclusion: These data highlight the importance of MAX mutations in EC and point to increased vascularity as one mechanism contributing to clinical aggressiveness of EC.

TGF-ß and CTGF are Mitogenic Output Mediators of Wnt/ß-Catenin Signaling in Desmoid Fibromatosis.

Desmoid fibromatosis is a locally aggressive clonal fibroblastic proliferation with high recurrence rates and no metastatic potential. Implicated molecular aberrations occur within the Wnt/ß-catenin pathway (APC and ß-catenin gene mutations). Transforming growth factor-ß (TGF-ß) and connective tissue growth factor (CTGF) are profibrotic growth factors, downstream from nuclear translocation of ß-catenin, that lead to increased fibrogenesis. CTGF (a downstream effector of TGF-ß) is a matricellular protein that modulates the activity of growth factors, adhesion molecules, integrins, and extracellular matrix thus playing a central role in tissue remodeling and fibrosis. Recently there has been growing interest in use of extracellular matrix inhibitors for treatment of various fibrogenic diseases. Desmoid fibromatosis samples (n=15) were evaluated for expression of ß-catenin, TGF-ß, and CTGF using immunohistochemistry on formalin paraffin-embedded material. A control group comprising scar tissue and adjacent normal skin (n=10) were simultaneously immunostained with above mentioned markers. Real-time polymerase chain reaction was performed on frozen specimens of desmoid fibromatosis (n=6) and normal skin (n=2). All 15 desmoid tumors were positive for ß-catenin (surrogate marker of Wnt/ß-catenin pathway dysregulation) which was negative in control normal skin and scar samples. TGF-ß and CTGF were negative in 9 of 10 normal skin controls. TGF-ß and CTGF were positive in all cases of scar tissue. All 15 cases of desmoid tumors were positive for TGF-ß and CTGF. The real-time polymerase chain reaction showed higher expression levels of TGF-ß and CTGF in desmoid fibromatosis compared with normal skin. The high constitutive expression of ß-catenin downstream effectors; TGF-ß, CTGF has the potential for enabling targeted therapy.

Differential mutation frequencies in metastatic cutaneous squamous cell carcinomas versus primary tumors.

BACKGROUND: Exome and targeted sequencing studies have identified potential driver mutations for a variety of tumor types. Cutaneous squamous cell carcinoma (cSCC) is one of the most highly mutated cancers but typically is associated with low rates of metastasis and high survival rates. Nevertheless, metastatic cSCC is a significant health threat; up to 8800 individuals die each year of this disease. METHODS: Because it is difficult to predict which cSCCs are more likely to metastasize, and because to the best of the authors' knowledge there are no targeted therapies specifically designated for patients with metastatic cSCC, exome and/or targeted sequencing of 18 metastatic and 10 primary cSCCs was performed to identify mutations that were more frequent in metastatic tumors and might be targeted for therapeutic benefit. The authors compared their results with published sequencing results of an additional 223 primary tumors and 68 metastatic cSCCs. RESULTS: The authors identified genes demonstrating higher mutation frequencies in metastatic cSCC compared with primary tumors, including the chromatin remodeling gene lysine methyltransferase 2D (KMT2D) and the classic skin tumor suppressor tumor protein p53 (TP53), which was found to be mutated in 54% of primary tumors compared with 85% of metastatic tumors (P<.0001). CONCLUSIONS: These studies appear to uncover potential pathways that are important in metastatic cSCC and that broaden understanding of the biology contributing to aggressive tumor behavior. These results may lead to new therapeutic strategies. Cancer 2017;123:1184-1193. © 2016 American Cancer Society.

Functional Analysis of BARD1 Missense Variants in Homology-Directed Repair of DNA Double Strand Breaks.

Genes associated with hereditary breast and ovarian cancer (HBOC) are often sequenced in search of mutations that are predictive of susceptibility to these cancer types, but the sequence results are frequently ambiguous because of the detection of missense substitutions for which the clinical impact is unknown. The BARD1 protein is the heterodimeric partner of BRCA1 and is included on clinical gene panels for testing for susceptibility to HBOC. Like BRCA1, it is required for homology-directed DNA repair (HDR). We measured the HDR function of 29 BARD1 missense variants, 27 culled from clinical test results and two synthetic variants. Twenty-three of the assayed variants were functional for HDR; of these, four are known neutral variants. Three variants showed intermediate function, and three others were defective in HDR. When mapped to BARD1 domains, residues crucial for HDR were located in the N- and C- termini of BARD1. In the BARD1 RING domain, critical residues mapped to the zinc-coordinating amino acids and to the BRCA1-BARD1 binding interface, highlighting the importance of interaction between BRCA1 and BARD1 for HDR activity. Based on these results, we propose that the HDR assay is a useful complement to genetic analyses to classify BARD1 variants of unknown clinical significance.

Inhibition of LPS-induced TLR4 signaling products in murine macrophages by phenylmethimazole: an assay methodology for screening potential phenylmethimazole analogs.

Preclinical Research Phenylmethimazole (C10) is an inhibitor of Toll-like receptor (TLR3 and TLR4) expression and signaling. In this study, we carried out a detailed investigation of the effect of C10 on TLR4 and its molecular signaling products in RAW 264.7 macrophages using quantitative real-time polymerase chain reaction (PCR), ELISA and cell toxicity assays, a set of in vitro assays that may be used to screen future C10 analogs. C10 exhibited an inhibitory effect on TLR4 MyD88-dependent and MyD88-independent pathways. Within the TLR4 pathway, C10 inhibited the expression of cytokines, cytokine receptors, kinases, adapter molecules and transcription factors, suggesting a pathway-wide inhibitory effect. We also found that C10 dose-dependently inhibited the expression of TLR4 signaling products, specifically IL-6, inducible nitric oxide (NO) synthase and IFNß. Additionally, pre-treatment of RAW 264.7 cells with C10 resulted in protection from lipopolysaccharide (LPS) insults, suggesting C10 may be bound to the target thus exhibiting activity during/following LPS stimulation. Also, dimethyl sulfoxide, the solvent for C10 exhibited inhibitory effect on TLR4 signaling products independent from the effects of C10. Combined, this study enhances understanding of the actions of C10 on the TLR4 signaling pathway providing a path for the development of new C10 analogs for inhibiting TLR expression and signaling [corrected].

Differential expression of miR-1, a putative tumor suppressing microRNA, in cancer resistant and cancer susceptible mice.

Mus spretus mice are highly resistant to several types of cancer compared to Mus musculus mice. To determine whether differences in microRNA (miRNA) expression account for some of the differences in observed skin cancer susceptibility between the strains, we performed miRNA expression profiling of skin RNA for over 300 miRNAs. Five miRNAs, miR-1, miR-124a-3, miR-133a, miR-134, miR-206, were differentially expressed by array and/or qPCR. miR-1 was previously shown to have tumor suppressing abilities in multiple tumor types. We found miR-1 expression to be lower in mouse cutaneous squamous cell carcinomas (cSCCs) compared to normal skin. Based on the literature and our expression data, we performed detailed studies on predicted miR-1 targets and evaluated the effect of miR-1 expression on two murine cSCC cell lines, A5 and B9. Following transfection of miR-1, we found decreased mRNA expression of three validated miR-1 targets, Met, Twf1 and Ets1 and one novel target Bag4. Decreased expression of Ets1 was confirmed by Western analysis and by 3' reporter luciferase assays containing wildtype and mutated Ets1 3'UTR. We evaluated the effect of miR-1 on multiple tumor phenotypes including apoptosis, proliferation, cell cycle and migration. In A5 cells, expression of miR-1 led to decreased proliferation compared to a control miR. miR-1 expression also led to increased apoptosis at later time points (72 and 96 h) and to a decrease in cells in S-phase. In summary, we identified five miRNAs with differential expression between cancer resistant and cancer susceptible mice and found that miR-1, a candidate tumor suppressor, has targets with defined roles in tumorigenesis.

The efficacy of exercise therapy in reducing shoulder pain related to breast cancer: a systematic review.

PURPOSE: Recent research indicates that physiotherapy interventions, such as exercise and manual therapy, may be effective in decreasing the frequency of side effects linked with breast cancer treatment, including fatigue, pain, nausea, and decreased quality of life. This systematic review aims to determine the efficacy of exercise therapy in reducing shoulder pain related to breast cancer treatment and to identify outcome measures that can be used to assess shoulder pain in this population. METHODS: A systematic review of the current literature was conducted using portals such as the Physiotherapy Evidence Database (PEDro), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Ovid MEDLINE (1996 to April 2011), and Allied and Complementary Medicine (AMED) (1985 to April 2011). Databases were searched for relevant studies published up to April 2011. Participants in relevant studies were adults (≥18 years of age) with a primary diagnosis of breast cancer at any point during the treatment of their disease. RESULTS: Six articles were independently appraised by two blinded reviewers. Six studies met the inclusion criteria, each analyzing different types of exercise-shoulder/arm/scapular strengthening/stabilization, postural exercises, general exercises and conditioning, shoulder range-of-motion exercises, and lymphedema exercises-with respect to their efficacy in reducing shoulder pain related to breast cancer treatment. CONCLUSIONS: RESULTS suggest that exercise targeting shoulder pain related to breast cancer treatment may be effective. However, definitive conclusions cannot be drawn due to the lack of methodological quality and homogeneity of the studies included. Clinicians should use valid outcome measures, such as the visual analogue scale and brief pain inventory, to evaluate the effectiveness of this treatment.

Objectif : Des recherches récentes indiquent que les interventions de physiothérapie comme l'exercice et la thérapie manuelle peuvent être efficaces pour réduire la fréquence des effets secondaires liés au traitement du cancer du sein, y compris la fatigue, la douleur, les nausées et une baisse de la qualité de vie. Cette critique systématique vise à déterminer l'efficacité de la thérapie par l'exercice lorsqu'il s'agit d'atténuer une douleur à l'épaule liée à un traitement du cancer du sein et à déterminer les mesures de résultat qu'il est possible d'utiliser pour évaluer la douleur à l'épaule dans cette population. Méthode : On a procédé à un examen systématique des publications courantes en utilisant des portails comme PEDro, CINAHL, PubMed, Ovid MEDLINE (1996 à avril 2011) et AMED (1985 à avril 2011). On a cherché dans des bases de données des études pertinentes publiées jusqu'en avril 2011. Les participants aux études pertinentes étaient des adultes (≥18 ans) qui avaient reçu un diagnostic primaire de cancer du sein à n'importe quel moment au cours du traitement de leur maladie. Résultats : Six articles ont fait l'objet d'examens à l'aveugle effectués par des examinateurs indépendants. Six études ont satisfait aux critères d'inclusion, chacune analysant des types différents d'exercice­renforcement/stabilisation de l'épaule, du bras ou de l'omoplate, exercices posturaux, exercices généraux et conditionnement, exercices portant sur l'amplitude du mouvement de l'épaule et exercices contre le lymphœdème­en ce qui a trait à leur efficacité pour réduire la douleur à l'épaule liée au traitement du cancer du sein. Conclusions : Les résultats indiquent que les exercices prescrits contre la douleur à l'épaule liée au traitement du cancer du sein peuvent être efficaces. On n'a pu toutefois tirer de conclusions définitives parce que les études incluses manquaient de qualité méthodologique et d'homogénéité. Les cliniciens devraient utiliser des mesures de résultat valables comme l'échelle analogue visuelle et le bref inventaire de la douleur pour évaluer l'efficacité du traitement.

Botox therapy for ischemic digits.

BACKGROUND: Treating patients with Raynaud's phenomenon who have chronic pain and ulcerations is extremely challenging. Unrelenting pain can lead to dysfunction and disuse, rendering the patient debilitated and/or chronically depressed. Pharmacologic vasodilators and surgical sympathectomies offer variable benefits. Outcomes of symptomatic patients treated with botulinum toxin type A (Botox) injections for Raynaud's phenomenon are presented. METHODS: A retrospective study focused on patient outcomes was performed on 19 patients diagnosed with Raynaud's phenomenon. Patients suffered from chronic ischemic hand pain. All patients had vascular studies to rule out occlusive disease. Fifty to 100 units of Botox were injected into the palm around each involved neurovascular bundle. Preinjection and postinjection laser Doppler scanning was performed on most patients to measure blood flow. RESULTS: Sixteen of 19 patients (84 percent) reported pain reduction at rest. Thirteen patients reported immediate relief; three reported more gradual pain reduction over 1 to 2 months. Three patients had no or minimal pain relief. Tissue perfusion results demonstrated a marked change in blood flow (-48.15 percent to 425 percent) to the digits. All patients with chronic finger ulcers healed within 60 days. Most patients [n = 12 (63 percent)] remained pain-free (13 to 59 months) with a single-injection schedule. Four patients (21 percent) required repeated injections because of recurrent pain. CONCLUSIONS: Vascular function is abnormal in patients with Raynaud's phenomenon. Although its mechanism is unknown, Botox yielded a distinct improvement in perfusion and reduction in pain in patients failing conservative management. Continued research may lead to more specific and reliable treatment for Raynaud's patients.