Identification of hereditary breast and ovarian cancer germline variants in Granada (Spain): NGS perspective.

The aim of this study was to assess the prevalence of germline variants in cancer-predisposing genes by either targeted (BRCA1/2) or multigene NGS panel in a high-risk Hereditary Breast and Ovarian Cancer (HBOC) cohort. Samples from 824 Caucasian probands were retrospectively collected and the impact of genetic diagnosis and genetic variants epidemiology in this cohort was evaluated. Performance of risk-reducing prophylactic measures, such as prophylactic mastectomy and/or prophylactic oophorectomy, was assessed through clinical follow-up of patients with a positive genetic result. Pathogenic variants predisposing to HBOC were identified in 11.9% (98/824) individuals at BRCA2 (47/98), BRCA1 (24/98), PALB2 (8/51), ATM (7/51), CHEK2 (6/51) MSH6, (2/51), RAD51C (2/51) and TP53 (2/386). Of them, 11 novel pathogenic variants and 12 VUS were identified, characterized, and submitted to ClinVar. Regarding clinical impact, the risk of developing basal or Her2 breast cancer was increased 15.7 times or 37.5 times for BRCA1 and MSH6 pathogenic variants respectively. On the contrary, the risk of developing basal or luminal A breast cancer was reduced to 81% or 77% for BRCA2 and BRCA1 pathogenic variants, respectively. Finally, 53.2% of individuals testing positive for class IV/V variants underwent prophylactic surgery (mastectomy, oophorectomy or both) being significantly younger at the cancer diagnosis than those undertaking prophylactic measures (p = 0.008). Of them, 8 carried a pathogenic/likely pathogenic variant in other genes different from BRCA1 and BRCA2, and the remaining (46.7%) decided to continue with clinical follow-up. No differences in pathogenicity or risk of developing cancer were found for BRCA1/2 between targeted and multigene sequencing strategies; however, NGS was able to resolve a greater proportion of high-risk patients.

The Relationship between the IC50 Values and the Apparent Inhibition Constant in the Study of Inhibitors of Tyrosinase Diphenolase Activity Helps Confirm the Mechanism of Inhibition.

Tyrosinase is the enzyme involved in melanization and is also responsible for the browning of fruits and vegetables. Control of its activity can be carried out using inhibitors, which is interesting in terms of quantitatively understanding the action of these regulators. In the study of the inhibition of the diphenolase activity of tyrosinase, it is intriguing to know the strength and type of inhibition. The strength is indicated by the value of the inhibition constant(s), and the type can be, in a first approximation: competitive, non-competitive, uncompetitive and mixed. In this work, it is proposed to calculate the degree of inhibition (iD), varying the concentration of inhibitor to a fixed concentration of substrate, L-dopa (D). The non-linear regression adjustment of iD with respect to the initial inhibitor concentration [I]0 allows for the calculation of the inhibitor concentration necessary to inhibit the activity by 50%, at a given substrate concentration (IC50), thus avoiding making interpolations between different values of iD. The analytical expression of the IC50, for the different types of inhibition, are related to the apparent inhibition constant (KIapp). Therefore, this parameter can be used: (a) To classify a series of inhibitors of an enzyme by their power. Determining these values at a fixed substrate concentration, the lower IC50, the more potent the inhibitor. (b) Checking an inhibitor for which the type and the inhibition constant have been determined (using the usual methods), must confirm the IC50 value according to the corresponding analytical expression. (c) The type and strength of an inhibitor can be analysed from the study of the variation in iD and IC50 with substrate concentration. The dependence of IC50 on the substrate concentration allows us to distinguish between non-competitive inhibition (iD does not depend on [D]0) and the rest. In the case of competitive inhibition, this dependence of iD on [D]0 leads to an ambiguity between competitive inhibition and type 1 mixed inhibition. This is solved by adjusting the data to the possible equations; in the case of a competitive inhibitor, the calculation of KI1app is carried out from the IC50 expression. The same occurs with uncompetitive inhibition and type 2 mixed inhibition. The representation of iD vs. n, with n=[D]0/KmD, allows us to distinguish between them. A hyperbolic iD vs. n representation that passes through the origin of coordinates is a characteristic of uncompetitive inhibition; the calculation of KI2app is immediate from the IC50 value. In the case of mixed inhibitors, the values of the apparent inhibition constant of meta-tyrosinase (Em) and oxy-tyrosinase (Eox), KI1app and the apparent inhibition constant of metatyrosinase/Dopa complexes (EmD) and oxytyrosinase/Dopa (EoxD), KI2app are obtained from the dependence of iD vs. n, and the results obtained must comply with the IC50 value.

Exosomal miRNA profile as complementary tool in the diagnostic and prediction of treatment response in localized breast cancer under neoadjuvant chemotherapy.

BACKGROUND: Breast cancer patients under neoadjuvant chemotherapy includes a heterogeneous group of patients who eventually develop distal disease, not detectable by current methods. We propose the use of exosomal miRNAs and circulating tumor cells as diagnostic and predictive biomarkers in these patients. METHODS: Fifty-three breast cancer women initially diagnosed with localized breast cancer under neoadjuvant chemotherapy were prospectively enrolled in this study. However, six of them were later re-evaluated and diagnosed as metastatic breast cancer patients by PET-CT scan. Additionally, eight healthy donors were included. Circulating tumor cells and serum exosomal miRNAs were isolated from blood samples before and at the middle of neoadjuvant therapy and exosomal miRNA levels analyzed by qPCR. RESULTS: Before neoadjuvant therapy, exosomal miRNA-21 and 105 expression levels were higher in metastatic versus non-metastatic patients and healthy donors. Likewise, higher levels of miRNA-222 were observed in basal-like (p = 0.037) and in luminal B versus luminal A (p = 0.0145) tumor subtypes. Exosomal miRNA-222 levels correlated with clinical and pathological variables such as progesterone receptor status (p = 0.017) and Ki67 (p = 0.05). During neoadjuvant treatment, exosomal miRNA-21 expression levels directly correlated with tumor size (p = 0.039) and inversely with Ki67 expression (p = 0.031). Finally, higher levels of exosomal miRNA-21, miRNA-222, and miRNA-155 were significantly associated with the presence of circulating tumor cells. CONCLUSION: Liquid biopsies based on exosomal miRNAs and circulating tumor cells can be a complementary clinical tool for improving breast cancer diagnosis and prognosis.

Circulating tumor cells criteria (CyCAR) versus standard RECIST criteria for treatment response assessment in metastatic colorectal cancer patients.

BACKGROUND: The use of circulating tumor cells (CTCs) as indicators of treatment response in metastatic colorectal cancer (mCRC) needs to be clarified. The objective of this study is to compare the Response Evaluation Criteria in Solid Tumors (RECIST) with the Cytologic Criteria Assessing Response (CyCAR), based on the presence and phenotypic characterization of CTCs, as indicators of FOLFOX-bevacizumab treatment response. METHODS: 77 mCRC blood samples from FOLFOX-bevacizumab treated patients were analyzed to isolate CTCs before and after (12 and 24 weeks) treatment, using an immunomagnetic separation method. VEGFR expression was identified by double immunostaining. RESULTS: We observed a decrease of CTCs (42.8 vs. 18.2%) and VEGFR positivity (69.7% vs. 41.7%) after treatment. According to RECIST, 6.45% of the patients did not show any clinical benefit, whereas 93.55% patients showed a favorable response at 12 weeks. According to CyCAR, 29% had a non-favorable response and 71% patients did not. No significant differences were found between the response assessment by RECIST and CyCAR at 12 or 24 weeks. However, in the multivariate analysis, RECIST at 12 weeks and CyCAR at 24 weeks were independent prognostic factors for OS (HR: 0.1, 95% CI 0.02-0.58 and HR: 0.35, 95% CI 0.12-0.99 respectively). CONCLUSIONS: CyCAR results were comparable to RECIST in evaluating the response in mCRC and can be used as an alternative when the limitation of RECIST requires additional response analysis techniques.

Significance of EGFR Expression in Circulating Tumor Cells.

This chapter focuses on a deep description of the epidermal growth factor receptor (EGFR) expression in circulating tumor cells (CTCs) and its main role in cancer progression, genetic changes related to metastasis , and resistance to treatment. The aberrant behavior of cancer cells is caused by genetic mutations and altered patterns of gene expression. These changes can be responsible for an increase in cell motility but also an ability of CTCs to survival in different microenvironments, as well as developing therapy-resistant clones. Finally, CTCs can acquire the ability to invade distant organs, where metastatic foci can develop.

Initial results of the oesophageal and gastric cancer registry from the Comunidad Valenciana. / Resultados iniciales del registro de carcinomas esófago-gástricos de la Comunidad Valenciana.

AIMS: To evaluate the initial results of the oesophagogastric cancer registry developed for the Sociedad Valenciana de Cirugía and the Health Department of the Comunidad Valenciana (Spain). METHODS: Fourteen of the 24 public hospitals belonging to the Comunidad Valenciana participated. All patients with diagnosis of oesophageal or gastric carcinomas operated from January 2013 to December 2014 were evaluated. Demographic, clinical and pathological data were analysed. RESULTS: Four hundred and thirty-four patients (120 oesophageal carcinomas and 314 gastric carcinomas) were included. Only two hospitals operated more than 10 patients with oesophageal cancer per year. Transthoracic oesophaguectomy was the most frequent approach (84.2%) in tumours localized within the oesophagus. A total gastrectomy was performed in 50.9% patients with gastroesophageal junction (GOJ) carcinomas. Postoperative 30-day and 90-day mortality were 8% and 11.6% in oesophageal carcinoma and 5.9 and 8.6% in gastric carcinoma. Before surgery, middle oesophagus carcinomas were treated mostly (76,5%) with chemoradiotherapy. On the contrary, lower oesophagus and GOJ carcinomas were treated preferably with chemotherapy alone (45.5 and 53.4%). Any neoadjuvant treatment was administered to 73.6% of gastric cancer patients. Half patients with oesophageal carcinoma or gastric carcinoma received no adjuvant treatment. CONCLUSIONS: This registry revealed that half patients with oesophageal cancer were operated in hospitals with less than 10 cases per year at the Comunidad Valenciana. Also, it detected capacity improvement for some clinical outcomes of oesophageal and gastric carcinomas.

4-n-butylresorcinol, a depigmenting agent used in cosmetics, reacts with tyrosinase.

4-n-Butylresorcinol (BR) is considered the most potent inhibitor of tyrosinase, which is why it is used in cosmetics as a depigmenting agent. However, this work demonstrates that BR is a substrate of this enzyme. The Em (met-tyrosinase) form is not active on BR, but Eox (oxy-tyrosinase) can act on this molecule, hydroxylating it to o-diphenol. In turn, this is oxidized to an o-quinone, which isomerizes to a red p-quinone. Thus, for tyrosinase to act on this compound, a mechanism to generate Eox in the medium is required, which can be achieved by means of hydrogen peroxide or ascorbic acid. A kinetic analysis of the proposed mechanism allows its kinetic characterization: catalytic constant kcatBR (8.49 ± 0.20 s(-1) ) and Michaelis-constant KMBR (60.26 ± 8.76 µM). These findings are compared with those for other monophenolic substrates of tyrosinase. Studies of BR docking to the Em form of the enzyme show that the hydroxyl group in C-1 position is oriented toward the copper atom A (CuA), as in it is L-tyrosine. As regards Eox , BR is oriented with the carbon in C-6 position ready to be hydroxylated. The reaction of BR originates o-quinones, which isomerize to p-quinones, which in turn, could react with thiol compounds, a finding that could have important implications for pharmacology and the cosmetic industry. © 2016 IUBMB Life, 68(8):663-672, 2016.

Characterization of the action of tyrosinase on resorcinols.

The action of tyrosinase on resorcinol and some derivatives (4-ethylresorcinol, 2-methylresorcinol and 4-methylresorcinol) was investigated. If the catalytic cycle is completed with a reductant such as ascorbic acid or an o-diphenol such as 4-tert-butylcatechol, these compounds act as substrates of tyrosinase in all cases. The reaction can also be carried out, adding hydrogen peroxide to the medium. All the above compounds were characterized as substrates of the enzyme and their kinetic constants, KM (Michaelis constant) and kcat (catalytic constant) were determined. Measurement of the activity of the enzyme after pre-incubation with resorcinol, 4-ethylresorcinol or 4-methylresorcinol points to an apparent loss of activity at short times, which could correspond to an enzymatic inactivation process. However, if the measurements are extended over longer times, a burst is observed and the enzymatic activity is recovered, demonstrating that these compounds are not suicide substrates of the enzyme. These effects are not observed with 2-methylresorcinol. The docking results indicate that the binding of met-tyrosinase with these resorcinols occurs in the same way, but not with 2-methylresorcinol, due to steric hindrance.

[Syncrhonous carcinosarcoma of the extrahepatic bile duct and gallbladder.] / Carcinosarcoma sincrónico de la vesícula y la via biliar extrahepática.

Carcinosarcoma is a malignant neoplasm characterized for intermingled epithelial and mesenchymal components. CASE REPORT: A preoperative suspected diagnosis will allow a radical therapy avoiding a very bad prognosis. We report on a male patient who was operated in our Service with diagnosis of synchronous carcinosarcoma of gallbladder and extrahepatic bile duct and a review of the Medical Literature. DISCUSSION: A gallblader carcinosarcoma showing extension into common bile duct is very rare, a carcinosarcoma of the bile duct is exceptional, and a synchronous carcinosarcoma ofthe bile duct and gallbladder has not been reported previously.

Long-term follow-up of chronic anal fissure (CAF) on diltiazem 2% using a telephone questionnaire. Do results change?

INTRODUCTION: Calcium channel blockers have an excellent effectiveness in the conservative management of chronic anal fissure (CAF). OBJECTIVES: To assess the long-term results of management with diltiazem 2% ointment using a telephone questionnaire. METHODS: A descriptive, retrospective study from March 2004 to March 2011 in patients with CAF on diltiazem 2%, 3 applications daily for 4-6 weeks. Starting at 12 months a questionnaire was administered over the phone by medical staff outside the surgery department to record socio-demographic data, predominant manifestations, and response to diltiazem on a 5-point scale measuring symptom relief (1 = poorest, 5 = best). Patients with therapy failure were referred to surgery. RESULTS: The study was completed for 166 patients with a mean age of 54.1 years. CAF was posterior in 82.3% of subjects. Diltiazem tolerability was excellent with only 4 adverse event cases (3 skin irritation, 1 hypotension). We obtained symptom relief in 62.1% of patients and CAF healing in 51.2%, and referred 33.7% to surgery. The questionnaire showed that 74.1% of patients had used only 2 applications daily, and that results were better with an increased number of applications, albeit without statistical significance. CONCLUSIONS: The telephone questionnaire showed symptom relief for 62% and healing for 51.2% of patients with CAF on diltiazem 2%, which should be considered first-choice for the conservative management of this condition.

[Prospective study of gluco-lipidic hormone and peptide levels in morbidly obese patients after sleeve gastrectomy]. / Estudio prospectivo de los valores de hormonas y péptidos relacionados con el metabolismo glucolipídico en pacientes obesos mórbidos sometidos a una gastrectomía vertical.

INTRODUCTION: Different hormones and peptides involved in lipid and carbohydrate metabolism have been studied in relation to morbid obesity and its variation after bariatric surgery. The aim of this study is toevaluate variations in different molecules related to glico-lipidic metabolism during the first year after sleeve gastrectomy in morbidly obese patients. MATERIAL AND METHODS: Prospective study in patients undergoing sleeve gastrectomy between November 2009 and January 2011. We analyzed changes in different clinical, anthropometric and analytic parameters related with glico-lipidic metabolism in all patients in the preoperative period, first postoperative day, fifth day, one month, 6 months and one year after surgery. Statistical analysis was performed using SPSS 20.0. RESULTS: We included 20 patients, 60% were women with a median of age of 45 years. Median of body mass index (IMC) was 48,5 kg/m(2) and 70% had obstructive sleep apnea syndrome (SAOS), 65% arterial hypertension (HTA), 45% dyslipidemia and 40% diabetes mellitus. One year after surgery, the percentage of excess of BMI loss was 72% and the rate of cure or improvement of dyslipidemia was 100%, diabetes 87,5%, HTA 84,6% and SAOS 57,1%. At this time, glycemia levels decreased significantly (P<.001), and levels of IGF-1 and HDL-cholesterol increased significantly. Levels of adiponectine increased and leptine (P=.003), insulin (P=.004) and triglycerides (P=.016) decreased significantly one year after the surgery. ACTH levels (that decreased during first 6 months after surgery), glycosilated hemoglobin, total cholesterol and LDL-cholesterol had no changes one year after surgery. CONCLUSIONS: Sleeve gastrectomy is a surgical technique with good results of weight loss and cure of comorbidities. This procedure induces significant modifications in blood levels of glico-lipidic metabolism related peptides and hormones, such as glucose, IGF-1, insulin, leptin, triglycerides and HDL-cholesterol.

Biomarkers characterization of circulating tumour cells in breast cancer patients.

INTRODUCTION: Increasing evidence supports the view that the detection of circulating tumor cells (CTCs) predicts outcomes of nonmetastatic breast cancer patients. CTCs differ genetically from the primary tumor and may contribute to variations in prognosis and response to therapy. As we start to understand more about the biology of CTCs, we can begin to address how best to treat this form of disease. METHODS: Ninety-eight nonmetastatic breast cancer patients were included in this study. CTCs were isolated by immunomagnetic techniques using magnetic beads labelled with a multi-CK-specific antibody (CK3-11D5) and CTC detection through immunocytochemical methods. Estrogen receptor, progesterone receptor and epidermal growth factor receptor (EGFR) were evaluated by immunofluorescence experiments and HER2 and TOP2A by fluorescence in situ hybridization. We aimed to characterize this set of biomarkers in CTCs and correlate it with clinical-pathological characteristics. RESULTS: Baseline detection rate was 46.9% ≥ 1 CTC/30 ml threshold. CTC-positive cells were more frequent in HER2-negative tumors (p = 0.046). In patients younger than 50 years old, HER2-amplified and G1-G2 tumors had a higher possibility of being nondetectable CTCs. Heterogeneous expression of hormonal receptors (HRs) in samples from the same patients was found. Discordances between HR expression, HER2 and TOP2A status in CTCs and their primary tumor were found in the sequential blood samples. Less that 35% of patients switched their CTC status after receiving chemotherapy. EGFR-positive CTCs were associated with Luminal tumors (p = 0.03). CONCLUSIONS: This is the largest exploratory CTC biomarker analysis in nonmetastatic BC patients. Our study suggests that CTC biomarkers profiles might be useful as a surrogate marker for therapeutic selection and monitoring since heterogeneity of the biomarker distribution in CTCs and the lack of correlation with the primary tumor biomarker status were found. Further exploration of the association between EGFR-positive CTCs and Luminal tumors is warranted.

Insights into the treatment of postsleeve gastrectomy leak: analysis of the results of 105 cases on a national register.

BACKGROUND: Many options have been put forward to treat staple line leaks after sleeve gastrectomy (SG) but no clear consensus has emerged concerning a management algorithm. OBJECTIVES: Aiming to establish a pattern to tailor treatment, the Spanish Society of Obesity Surgery (SECO) and the Obesity Section of the Spanish Association of Surgeons (AEC) set up a national register to record treatment of leaks after SG. SETTING: Multiple hospital centers, Spain. METHODS: Between September 2016 and December 2017, cases were entered into an online database. Results were assessed according to the number and type of therapeutic procedures. RESULTS: One hundred and five patients from 27 centers were diagnosed with postSG leak. The mean age was 44 years, and 77 (73%) were women. Mean body mass index (BMI) was 47 kg/m2. Mortality was 7%. The first treatment was effective in 50% of cases with no significant differences between nonoperative management and surgery. We found no significant correlations between appearance of leak, type of treatment (nonoperative management or surgery), and treatment effectiveness. An endoscopic stent was the first nonoperative option in 30% of cases and second option in 50% of cases, with effectiveness of 61% and 50%, respectively. In patients requiring a third treatment option (n = 25), surgery was more effective than nonoperative treatment (75% versus 8%) and the incidence of complications secondary to endoscopic stent placement was high (71%). CONCLUSION: The choice of postSG leak treatment depends on the patient's clinical condition and the site of the leak. Healing may be slow (>2 months) and may require several interventions using different approaches such as nonoperative treatment, endoscopic stents, or surgery. The effectiveness of endoscopic options decreases and the effectiveness of complex resective or derivative surgery increases with leak duration and the number of treatments required.

Enzymatic oxidation of oleuropein and 3-hydroxytyrosol by laccase, peroxidase, and tyrosinase.

The oxidation of oleuropein and 3-hydroxytyrosol by oxidases laccase, tyrosinase, and peroxidase has been studied. The use of a spectrophotometric method and another spectrophotometric chronometric method has made it possible to determine the kinetic parameters Vmax and KM for each enzyme. The highest binding affinity was shown by laccase. The antioxidant capacities of these two molecules have been characterized, finding a very similar primary antioxidant capacity between them. Docking studies revealed the optimal binding position, which was the same for the two molecules and was a catalytically active position. PRACTICAL APPLICATIONS: One of the biggest environmental problems in the food industry comes from olive oil mill wastewater with a quantity of approximately 30 million tons per year worldwide. In addition, olive pomace, the solid residue obtained from the olive oil production, is rich in hydroxytyrosol and oleuropein and the action of enzymatic oxidases can give rise to products in their reactions that can lead to polymerization. This polymerization can have beneficial effects because it can increase the antioxidant capacity with potential application on new functional foods or as feed ingredients. Tyrosinase, peroxidase, and laccase are the enzymes degrading these important polyphenols. The application of a spectrophotometric method for laccase and a chronometric method, for tyrosinase and peroxidase, allowed us to obtain the kinetic information of their reactions on hydroxytyrosol and oleuropein. The kinetic information obtained could advance in the understanding of the mechanism of these important industrial enzymes.

[Local treatment of a chronic anal fissure with diltiazem vs. nitroglycerin. A comparative study]. / Tratamiento local de la fisura anal crónica con diltiazem vs. nitroglicerina. Estudio comparativo.

AIM: To assess the value of using smooth muscle relaxants drugs and assess the results of the topical use of 2% diltiazem as an alternative to 0.2% nitroglycerin in the treatment of chronic anal fissure (CAF). METHODS: Review of the CAF contained in a prospectively collected database of anal fissures including one hundred forty-five patients diagnosed with CAF and treated with standard measures (ST) in two consecutive periods. During the first period they were allocated alternatively to not receive further treatment (ST group) or to be treated with nitroglycerin ointment (NTG group). In the second period all were treated with local diltiazem (DTZ group). One hundred forty-five patients entered the study and 124 completed it. RESULTS: Initially there were significant differences in improvement rates (45% ST, 62.5% NTG and 80% DTZ, p<0.01), but not in the cure rates (27% ST, 40% NTG and 39% DTZ) and the treatment was completed by 124 patients (85.5%). There were more side effects and more dropouts in the NTG group. In the subsequent follow-up for a median period of 25 months there were 25% recurrences and almost all responded to repeated medical treatment. CONCLUSIONS: Smooth muscle relaxant drugs do not achieve a higher cure rate than the traditional measures used in CAF, but offer more symptomatic relief, providing an opportunity to avoid surgery. Topical diltiazem does not have the side effects of the nitroglycerin and is better accepted by patients.

The role of endoprostheses in the treatment of leaks after laparoscopic sleeve gastrectomy. Analysis of a Spanish registry. / Papel de las endoprótesis en el tratamiento de las fistulas posgastrectomía vertical laparoscópica. Análisis de un registro nacional.

It has been suggested that endoprostheses are an effective treatment for fistulae after sleeve gastrectomy, but the results published are very variable. To analyze the effectiveness of stents as treatment of leakage after sleeve gastrectomy, the Spanish Society of Obesity Surgery (SECO) and the Obesity Division of the Spanish Association of Surgeons (AEC) set up a National Registry to record treatments of leaks after sleeve gastrectomy. We have analyzed patients with leaks after sleeve gastrectomy and treated with endoprostheses: 19 medical centers reported the use of endoprostheses, where 51 endoprostheses were used in 42 patients (34 women/8 men, mean age: 43.8 years, BMI: 47.6). Global effectiveness was 45%, with a complication rate of 35%. Uni- and multivariate analyses detected no factors influencing the efficacy of treatment. A larger diameter bouggie used to calibrate the stomach was related to a higher incidence of complications. No factors were found related with better stent efficacy. The effectiveness of a second stent was very low when the previous one had not been effective.

Extracellular vesicle-miRNAs as liquid biopsy biomarkers for disease identification and prognosis in metastatic colorectal cancer patients.

Disseminated disease is present in ≈50% of colorectal cancer patients upon diagnosis, being responsible for most of cancer deaths. Addition of biological drugs, as Bevacizumab, to chemotherapy, has increased progression free survival and overall survival of metastatic colorectal cancer (mCRC) patients. However, these benefits have been only reported in a small proportion of patients. To date, there are not biomarkers that could explain the heterogeneity of this disease and would help in treatment selection. Recent findings demonstrated that microRNAs (miRNAs) play an important role in cancer and they can be encapsulated with high stability into extracellular vesicles (EVs) that are released in biological fluids. EVs can act as cell-to-cell communicators, transferring genetic information, such as miRNAs. In this context, we aimed to investigate serum EV associated miRNAs (EV-miRNAs) as novel non-invasive biomarkers for the diagnosis and prognosis of Bevacizumab-treated mCRC patients. We observed that baseline miRNA-21 and 92a outperformed carcinoembryonic antigen levels in the diagnosis of our 44 mCRC patients, compared to 17 healthy volunteers. In addition, patients who died presented higher levels of miRNA-92a and 222 at 24 weeks. However, in the multivariate Cox analysis, higher levels of miRNA-222 at 24 weeks were associated with lower overall survival. Altogether, these data indicate that EV-miRNAs have a strong potential as liquid biopsy biomarkers for the identification and prognosis of mCRC.

Kinetic characterization of the oxidation of catecolamines and related compounds by laccase.

The pathways of melanization and sclerotization of the cuticle in insects are carried out by the action of laccases on dopamine and related compounds. In this work, the laccase action of Trametes versicolor (TvL) on catecholamines and related compounds has been kinetically characterized. Among them, dopamine, l-dopa, l-epinephrine, l-norepinephrine, dl-isoprenaline, l-isoprenaline, dl-α-methyldopa, l-α-methyldopa and l-dopa methylester. A chronometric method has been used, which is based on measuring the lag period necessary to consume a small amount of ascorbic acid, added to the reaction medium. The use of TvL has allowed docking studies of these molecules to be carried out at the active site of this enzyme. The hydrogen bridge interaction between the hydroxyl oxygen at C-4 with His-458, and with the acid group of Asp-206, would make it possible to transfer the electron to the T1 Cu-(II) copper centre of the enzyme. Furthermore, Phe-265 would facilitate the adaptation of the substrate to the enzyme through Π-Π interactions. To kinetically characterize these compounds, we need to take into consideration that, excluding l-dopa, l-α-methyldopa and dl-α-methyldopa, all compounds are in hydrochloride form. Because of this, first we need to kinetically characterize the inhibition by chloride and, after that, calculate the kinetic parameters KM and VmaxS. From the kinetic data obtained, it appears that the best substrate is dopamine. The presence of an isopropyl group bound to nitrogen (isoprenaline) makes it especially difficult to catalyse. The formation of the ester (l-dopa methyl ester) practically does not affect catalysis. The addition of a methyl group (α-methyl dopa) increases the rate but decreases the affinity for catalysis. l-Epinephrine and l-norepinephrine have an affinity similar to isoprenaline, but faster catalysis, probably due to the greater nucleophilic power of their phenolic hydroxyl.

Cooperative and Escaping Mechanisms between Circulating Tumor Cells and Blood Constituents.

Metastasis is the leading cause of cancer-related deaths and despite measurable progress in the field, underlying mechanisms are still not fully understood. Circulating tumor cells (CTCs) disseminate within the bloodstream, where most of them die due to the attack of the immune system. On the other hand, recent evidence shows active interactions between CTCs and platelets, myeloid cells, macrophages, neutrophils, and other hematopoietic cells that secrete immunosuppressive cytokines, which aid CTCs to evade the immune system and enable metastasis. Platelets, for instance, regulate inflammation, recruit neutrophils, and cause fibrin clots, which may protect CTCs from the attack of Natural Killer cells or macrophages and facilitate extravasation. Recently, a correlation between the commensal microbiota and the inflammatory/immune tone of the organism has been stablished. Thus, the microbiota may affect the development of cancer-promoting conditions. Furthermore, CTCs may suffer phenotypic changes, as those caused by the epithelial-mesenchymal transition, that also contribute to the immune escape and resistance to immunotherapy. In this review, we discuss the findings regarding the collaborative biological events among CTCs, immune cells, and microbiome associated to immune escape and metastatic progression.

Synthesis and Characterization of Specific Reverse Transcriptase Inhibitors for Mammalian LINE-1 Retrotransposons.

Retrotransposons are a type of transposable element (TE) that have amplified to astonishing numbers in mammalian genomes, comprising more than a third of the human and mouse genomes. Long interspersed element class 1 (LINE-1 or L1) retrotransposons are abundant and currently active retroelements in the human and mouse genomes. Similarly, long terminal repeat (LTR)-containing retrotransposons are abundant in both genomes, although only active in mice. LTR- and LINE-1-retroelements use different mechanisms for retrotransposition, although both involve the reverse transcription of an intermediate retroelement-derived RNA. Retrotransposon activity continues to effect the germline and somatic genomes, generating interindividual variability over evolution and potentially influencing cancer and brain physiology, respectively. However, relatively little is known about the functional consequences of retrotransposition. In this study, we have synthesized and characterized reverse transcriptase inhibitors specific for mammalian LINE-1 retrotransposons, which might help deciphering the functional impact of retrotransposition in vivo.