RECQL5: Another DNA helicase potentially involved in hereditary breast cancer susceptibility.

There is still around 50% of the familial breast cancer (BC) cases with an undefined genetic cause, here we have used next-generation sequencing (NGS) technology to identify new BC susceptibility genes. This approach has led to the identification of RECQL5, a member of RECQL-helicases family, as a new BC susceptibility candidate, which deserves further study. We have used a combination of whole exome sequencing in a family negative for mutations in BRCA1/2 throughout (BRCAX), in which we found a probably deleterious variant in RECQL5, and targeted NGS of the complete coding regions and exon-intron boundaries of the candidate gene in 699 BC Spanish BRCAX families and 665 controls. Functional characterization and in silico inference of pathogenicity were performed to evaluate the deleterious effect of detected variants. We found at least seven deleterious or likely deleterious variants among the cases and only one in controls. These results prompt us to propose RECQL5 as a gene that would be worth to analyze in larger studies to explore its possible implication in BC susceptibility.

Therapeutic inertia in anti-platelet therapy in patients with a cardiovascular event attended in an emergency department.

Objective As very few studies have assessed therapeutic inertia (TI) in anti-platelet therapy in patients in secondary cardiovascular prevention, the authors designed a study in their hospital emergency department to quantify its magnitude and its associated factors. Methods This descriptive cross-sectional observational study involved a sample of 223 patients with a history of cardiovascular disease and recommendation for anti-platelet therapy who attended the emergency department in a Spanish region in 2016. The main variable was TI in platelet anti-aggregation (lack of a prescription when recommended by the clinical guidelines). The secondary variables were gender, age, educational level, stable partner, hypertension, dyslipidemia, diabetes, smoking, type and number of cardiovascular events, blood pressure, and glomerular filtration rate. The magnitude of TI was quantified and associated factors were studied using a binary logistic regression model. Results TI was present in 107 patients (48.0%). In the multifactorial analysis, the following factors were associated with a higher proportion of TI: female gender (p = .021), higher cultural level (p = .020), and having no previous diagnosis of hypertension (p = .003) or dyslipidemia (p = .002). Conclusions The magnitude of TI in anti-platelet therapy in patients who had already suffered a cardiovascular event was very high. TI was associated with being a woman, having a high cultural level, and not being diagnosed with hypertension or dyslipidemia. More studies are needed to corroborate these results to take the appropriate measures to reduce TI.

Germline missense pathogenic variants in the BRCA1 BRCT domain, p.Gly1706Glu and p.Ala1708Glu, increase cellular sensitivity to PARP inhibitor olaparib by a dominant negative effect.

BRCA1-deficient cells show defects in DNA repair and rely on other members of the DNA repair machinery, which makes them sensitive to PARP inhibitors (PARPi). Although carrying a germline pathogenic variant in BRCA1/2 is the best determinant of response to PARPi, a significant percentage of the patients do not show sensitivity and/or display increased toxicity to the agent. Considering previously suggested mutation-specific BRCA1 haploinsufficiency, we aimed to investigate whether there are any differences in cellular response to PARPi olaparib depending on the BRCA1 mutation type. Lymphoblastoid cell lines derived from carriers of missense pathogenic variants in the BRCA1 BRCT domain (c.5117G > A, p.Gly1706Glu and c.5123C > A, p.Ala1708Glu) showed higher sensitivity to olaparib than cells with truncating variants or wild types (WT). Response to olaparib depended on a basal PARP enzymatic activity, but did not correlate with PARP1 expression. Interestingly, cellular sensitivity to the agent was associated with the level of BRCA1 recruitment into γH2AX foci, being the lowest in cells with missense variants. Since these variants lead to partially stable protein mutants, we propose a model in which the mutant protein acts in a dominant negative manner on the WT BRCA1, impairing the recruitment of BRCA1 into DNA damage sites and, consequently, increasing cellular sensitivity to PARPi. Taken together, our results indicate that carriers of different BRCA1 mutations could benefit from olaparib in a distinct way and show different toxicities to the agent, which could be especially relevant for a potential future use of PARPi as prophylactic agents in BRCA1 mutation carriers.

DNA repair capacity is impaired in healthy BRCA1 heterozygous mutation carriers.

BRCA1 germline mutations increase the lifetime risk of developing breast and ovarian cancers. However, taking into account the differences in disease manifestation among mutation carriers, it is probable that different BRCA1 mutations have distinct haploinsufficiency effects and lead to the formation of different phenotypes. Using lymphoblastoid cell lines derived from heterozygous BRCA1 mutation carriers and non-carriers, we investigated the haploinsufficiency effects of various mutation types using qPCR, immunofluorescence, and microarray technology. Lymphoblastoid cell lines carrying a truncating mutation showed significantly lower BRCA1 mRNA and protein levels and higher levels of gamma-H2AX than control cells or those harboring a missense mutation, indicating greater spontaneous DNA damage. Cells carrying either BRCA1 mutation type showed impaired RAD51 foci formation, suggesting defective repair in mutated cells. Moreover, compared to controls, cell lines carrying missense mutations displayed a more distinct expression profile than cells with truncating mutations, which is consistent with different mutations giving rise to distinct phenotypes. Alterations in the immune response pathway in cells harboring missense mutations point to possible mechanisms of breast cancer initiation in carriers of these mutations. Our findings offer insight into how various heterozygous mutations in BRCA1 could lead to impairment of BRCA1 function and provide strong evidence of haploinsufficiency in BRCA1 mutation carriers.

Customized treatment in non-small-cell lung cancer based on EGFR mutations and BRCA1 mRNA expression.

BACKGROUND: Median survival is 10 months and 2-year survival is 20% in metastatic non-small-cell lung cancer (NSCLC) treated with platinum-based chemotherapy. A small fraction of non-squamous cell lung cancers harbor EGFR mutations, with improved outcome to gefitinib and erlotinib. Experimental evidence suggests that BRCA1 overexpression enhances sensitivity to docetaxel and resistance to cisplatin. RAP80 and Abraxas are interacting proteins that form complexes with BRCA1 and could modulate the effect of BRCA1. In order to further examine the effect of EGFR mutations and BRCA1 mRNA levels on outcome in advanced NSCLC, we performed a prospective non-randomized phase II clinical trial, testing the hypothesis that customized therapy would confer improved outcome over non-customized therapy. In an exploratory analysis, we also examined the effect of RAP80 and Abraxas mRNA levels. METHODOLOGY/PRINCIPAL FINDINGS: We treated 123 metastatic non-squamous cell lung carcinoma patients using a customized approach. RNA and DNA were isolated from microdissected specimens from paraffin-embedded tumor tissue. Patients with EGFR mutations received erlotinib, and those without EGFR mutations received chemotherapy with or without cisplatin based on their BRCA1 mRNA levels: low, cisplatin plus gemcitabine; intermediate, cisplatin plus docetaxel; high, docetaxel alone. An exploratory analysis examined RAP80 and Abraxas expression. Median survival exceeded 28 months for 12 patients with EGFR mutations, and was 11 months for 38 patients with low BRCA1, 9 months for 40 patients with intermediate BRCA1, and 11 months for 33 patients with high BRCA1. Two-year survival was 73.3%, 41.2%, 15.6% and 0%, respectively. Median survival was influenced by RAP80 expression in the three BRCA1 groups. For example, for patients with both low BRCA1 and low RAP80, median survival exceeded 26 months. RAP80 was a significant factor for survival in patients treated according to BRCA1 levels (hazard ratio, 1.3 [95% CI, 1-1.7]; P = 0.05). CONCLUSIONS/SIGNIFICANCE: Chemotherapy customized according to BRCA1 expression levels is associated with excellent median and 2-year survival for some subsets of NSCLC patients , and RAP80 could play a crucial modulating effect on this model of customized chemotherapy. TRIAL REGISTRATION: (ClinicalTrials.gov) NCT00883480.

5-fluorouracil as a protracted continuous infusion plus irinotecan (CPT-11) in patients with advanced colorectal cancer treated with fluoropyrimidine-based regimens as first line.

We carried out a single-center series with the combination of irinotecan (CPT-11) plus protracted 5-fluorouracil (5-FU) infusion as second-line chemotherapy for patients previously treated with a single-agent fluoropyrimidine as monotherapy or in combination with oxaliplatin. Twenty-five patients diagnosed with advanced colorectal cancer (CRC) received CPT-11 300 mg/m2 every 3 weeks plus 5-FU 250 mg/m2/day as a protracted infusion. Results were as follows. Twenty-four of 25 patients were evaluable for response. Two patients achieved a complete response and five a partial response, resulting in an overall response rate of 28%. Disease stabilization was obtained in 10 patients (40%), resulting in a tumor growth control rate of 68% (17 patients) and disease progression in seven (28%). Median progression-free interval was 6 months and median overall survival was 12 months. Neutropenia and diarrhea appeared as the most frequent adverse events, being grade 3/4 in 12 and 16% of patients, respectively. Mucositis, emesis, and hand and foot syndrome were mild. We conclude that protracted 5-FU infusion plus CPT-11 is an active and safe regimen for patients with advanced CRC. A phase III trial comparing this schedule with conventional CPT-11 monotherapy is warranted.

Utilidad de la linfogammagrafía en el drenaje linfático de melanomas con drenaje ambiguo, en cabeza, cuello y tronco / Radionuclide lymphoscintigraphy to identify lymphatic drainage of cutaneous melanoma at ambiguous sites in the head and neck and trunk

Introducción. La linfogammagrafía fue descrita desde hace más de 20 años y ha demostrado su gran utilidad para la detección del drenaje linfático en melanoma cutáneo, principalmente en los casos localizados en troco hombro o en cabeza y cuello. Con la técnica de detección del ganglio centinela ha aumentado su utilidad, sobre todo en neoplasias con estas localizaciones. Pacientes y métodos: Fueron estudiados 25 pacientes con diagnóstico de melanoma maligno atendidos en la Clínica de Cáncer de Piel y Melanomas, en el Hospital Angeles del Pedregal, México. A todos los sujetos se les practicó linfogammagrafía previa al mapeo linfático, mapeo linfático con estudio del ganglio centinela con hematoxilina y eosina e inmunohistoquímica. A los pacientes que presentaron ganglios centinelas con metástasis se les realizó una linfadenectomía completa. Resultados. Se efectuaron 25 linfogammagrafías y se encontraron 38 zonas de drenaje. Se les practicó mapeo linfático y biopsia del ganglio centinela, con lo que fueron hallados 32 (84.2 por ciento) ganglios centinelas, cinco con metástasis; dos de estos casos con estudio transoperatorio y tres con estudio de inmunohistoquímica. A los pacientes con ganglios centinelas metastásicos se les realizó una linfadenectomía de la zona afectada. A un caso en el que no se encontró el ganglio centinela se le practicó una linfadenectomía y se encontraron tres ganglios con micrometástasis. Conclusiones. El estudio de linfogammagrafía es de gran utilidad para detectar las zonas de drenaje de los melanomas localizados en tronco, hombro, cabeza y cuello