In colon cancer, normal colon tissue and blood cells have altered telomere lengths.

BACKGROUND: Telomere length (TL) shortened occurs in colorectal carcinogenetic process. Our objective is to determine if it is only a local fact or there are alterations in normal colon cells and in other body cells. METHODS: TL of tumoral and normal mucosa and leukocytes of 40 patients operated of colorectal cancer (CRC) and 40 control patients with normal colonoscopy were measured by Southern-blot. Groups were matched by the same localization as tumors, sex, and age. RESULTS: In CRC patients, TRFL (Telomere Repeat Factor Length) leukocytes mean was 8.84 kpb, normal colonic mucosa 7.97 kpb, and tumoral mucosa 7.33 kpb (P < 0.001). In the 40 normal control patients, mean TRFL of colonic mucosa was 7.76 kpb, while in blood cells was 7.01 kpb (P < 0.001). We observed an inverse correlation between leukocytes TRFL and age (r(2) = 0.17, P = 0.008). Mucosa TRFL correlates significantly with patient's age (r(2) = 0.138, P = 0.018). TRFL of controls colonic mucosa correlates with TRFL of their blood cells (r(2) = 0.354, P < 0.001). CONCLUSIONS: Normal colonic mucosa and leukocytes in CCR patients presents telomere altered in respect to normal patients. Telomere length in normal leukocytes could be an initial marker for colorectal cancer.

Reduction of total IgE by targeted coengagement of IgE B-cell receptor and FcγRIIb with Fc-engineered antibody.

BACKGROUND: Sequestration of IgE to prevent its binding to high-affinity IgE receptor FcεRI on basophils and mast cells is an effective therapy for allergic asthma. IgE production requires differentiation of activated IgE(+) B cells into plasma cells upon allergen sensitization. B-cell receptor signaling is suppressed by the inhibitory IgG Fc receptor FcγRIIb; therefore, we reasoned that a therapeutic antibody that coengages FcγRIIb and IgE B-cell receptor would not only sequester IgE but also suppress its production by blocking IgE(+) B-cell activation and differentiation to IgE-secreting plasma cells. OBJECTIVE: To explore the effects of IgE sequestration versus IgE suppression by comparing omalizumab to FcγRIIb-optimized anti-IgE antibodies in humanized mouse models of immunoglobulin production. METHODS: By using a murine anti-IgE antibody as a template, we humanized, increased IgE binding, and modified its Fc domain to increase affinity for FcγRIIb. We next compared effects of this antibody (XmAb7195) versus omalizumab on the secretion of IgE and other isotypes in human PBMC cultures and in PBMC-engrafted severe combined immunodeficiency mice. RESULTS: Relative to omalizumab, XmAb7195 has a 5-fold higher affinity for human IgE and more than 400-fold higher affinity for FcγRIIb. In addition to sequestering soluble IgE, XmAb7195 inhibited plasma cell differentiation and consequent human IgE production through coengagement of IgE B-cell receptor with FcγRIIb. In PBMC-engrafted mice, XmAb7195 reduced total human IgE (but not IgG or IgM) levels by up to 40-fold relative to omalizumab. CONCLUSION: XmAb7195 acts by IgE sequestration coupled with an FcγRIIb-mediated inhibitory mechanism to suppress the formation of IgE-secreting plasma cells and reduce both free and total IgE levels.

Obatoclax Rescues FUS-ALS Phenotypes in iPSC-Derived Neurons by Inducing Autophagy.

Aging is associated with the disruption of protein homeostasis and causally contributes to multiple diseases, including amyotrophic lateral sclerosis (ALS). One strategy for restoring protein homeostasis and protecting neurons against age-dependent diseases such as ALS is to de-repress autophagy. BECN1 is a master regulator of autophagy; however, is repressed by BCL2 via a BH3 domain-mediated interaction. We used an induced pluripotent stem cell model of ALS caused by mutant FUS to identify a small molecule BH3 mimetic that disrupts the BECN1-BCL2 interaction. We identified obatoclax as a brain-penetrant drug candidate that rescued neurons at nanomolar concentrations by reducing cytoplasmic FUS levels, restoring protein homeostasis, and reducing degeneration. Proteomics data suggest that obatoclax protects neurons via multiple mechanisms. Thus, obatoclax is a candidate for repurposing as a possible ALS therapeutic and, potentially, for other age-associated disorders linked to defects in protein homeostasis.

Progress and challenges in directing the differentiation of human iPSCs into spinal motor neurons.

Motor neuron (MN) diseases, including amyotrophic lateral sclerosis, progressive bulbar palsy, primary lateral sclerosis and spinal muscular atrophy, cause progressive paralysis and, in many cases, death. A better understanding of the molecular mechanisms of pathogenesis is urgently needed to identify more effective therapies. However, studying MNs has been extremely difficult because they are inaccessible in the spinal cord. Induced pluripotent stem cells (iPSCs) can generate a theoretically limitless number of MNs from a specific patient, making them powerful tools for studying MN diseases. However, to reach their potential, iPSCs need to be directed to efficiently differentiate into functional MNs. Here, we review the reported differentiation protocols for spinal MNs, including induction with small molecules, expression of lineage-specific transcription factors, 2-dimensional and 3-dimensional cultures, as well as the implementation of microfluidics devices and co-cultures with other cell types, including skeletal muscle. We will summarize the advantages and disadvantages of each strategy. In addition, we will provide insights into how to address some of the remaining challenges, including reproducibly obtaining mature and aged MNs.

An associational study: preschool teachers' acceptance and self-efficacy towards Educational Robotics in a pre-service teacher training program.

PURPOSE: This study explores pre-service preschool teachers' acceptance and self-efficacy towards Educational Robotics (ER) during a university course, and also examines their perceptions of the course. METHODOLOGY: This is a one-group intervention study with an associational research design that includes both quantitative and qualitative research methods: two pre-questionnaires and two post-questionnaires on pre-service teachers' acceptance and self-efficacy towards ER, and participants' training journals. FINDINGS: The results show that pre-service teachers' acceptance and self-efficacy towards ER improved after they completed the ER teacher training course. There was a significant difference between the start and the end of the ER training in the pre-service teachers' acceptance of ER in the areas of perceived ease of use, enjoyment and attitudes, and in their self-efficacy. The findings based on the training journals show that participants positively evaluated the course. The participants also provided suggestions for improving it, such as additional training sessions, resources and time for experimentation. VALUE: Our study reveals the impact of an ER training program and showcases the importance of integrating ER in pre-service teachers' education.

Secundiflorol G isolated from Aeschynomene fascicularis, a Mayan medicinal plant, induces apoptosis in cervical cancer cells.

Secundiflorol G (SG) is an isoflavan isolated from the root bark of Aeschynomene fascicularis, a Mayan medicinal plant used to treat cancer-like symptoms. SG has been shown to have cytotoxic effects on cervical cancer cells (HeLa). Assays were done to identify the mechanisms of SG's cytotoxic effect.HeLa cells treated with SG exhibited early and late apoptosis, and caspase-9, -8 and -3 activities. It also induces generation of reactive oxygen species and disrupted mitochondrial membrane potential.SG isolated from A. fascicularis induces apoptosis through extrinsic and intrinsic pathways on HeLa cells. SG could be a candidate for in vivo studies and a promising natural compound in cervical cancer treatment.

Spectral-domain optical coherence tomography foveal morphology as a prognostic factor for vision performance in congenital aniridia.

BACKGROUND: Patients with congenital aniridia usually have some degree of foveal hypoplasia, thus representing a limiting factor in the final visual acuity achieved by these patients. The purpose of this study was to analyze whether the foveal morphology assessed by spectral-domain optical coherence tomography may serve as a prognostic indicator for best-corrected visual acuity in congenital aniridia patients. METHODS: Observational two-center study performed between January 2012 and March 2017 in the pediatric ophthalmology department at Vissum Alicante and Vissum Madrid, Spain. A total of 31 eyes from 19 patients with congenital aniridia were included. After a complete ophthalmological examination, a high-resolution spectral-domain optical coherence tomography with a three-dimensional scan program macular protocol was used. A morphological grading system of foveal hypoplasia was used varying from grade 1 in which there is a presence of a shallow foveal pit, extrusion of inner retinal layers, outer nuclear layer widening, and a presence of outer segment lengthening to grade 4 in which none of these processes occur. RESULTS: No correlation between central, mid-peripheral, and peripheral macular thickness and logMAR best-corrected visual acuity was found. The presence of outer segment lengthening was associated with better best-corrected visual acuity with a median best-corrected visual acuity, 0.30 logMAR, whereas the absence of this morphologic feature was associated with poorer VA with a median best-corrected visual acuity of 0.61 logMAR (p < 0.001). CONCLUSION: Foveal hypoplasia morphology can predict the best-corrected visual acuity. Specifically, the morphologic optical coherence tomography feature that is related to a better best-corrected visual acuity in congenital aniridia patients is the presence of outer segment lengthening.

Neuroprotective effect of Mayan medicinal plant extracts against glutamate-induced toxicity.

Neurological disorders are a public health problem worldwide for which there is currently no direct treatment of the cause of the disorder. The goal of this study was to investigate the potential in vitro neuroprotective property of plants used in Mayan traditional medicine. Plant ethanolic extracts were prepared and tested on models in which neuronal damage was induced by glutamate, i.e., a human neuroblastoma cell line (SH-SY5Y) and rat cortical neurons. HPLC profiles from active extracts were also obtained. A total of 51 plant species were identified in the literature as plant species used in Mayan traditional medicine for the treatment of symptoms suggestive of neurological disorders, and we studied 34 of these in our analysis. Six extracts had a neuroprotective effect on SH-SY5Y cells, with the most active extract being that from Schwenckia americana roots (half maximal effective concentration [EC50] 11.3 ± 2.9 µg/mL), and three extracts exhibited a neuroprotective effect in the rat neuron cortical model, with the most active extract being that from Elytraria imbricata aerial parts (EC50 6.8 ± 3.1 µg/mL). These results suggest that the active extracts from such plants have the potential to be a great resource. Future studies should be performed that are more extensive and which isolate the active constituents.

hTERT methylation is necessary but not sufficient for telomerase activity in colorectal cells.

Colorectal cancers exhibit a high telomerase activity, usually correlated with the hypermethylation of the promoter of its hTERT catalytic subunit. Although telomerase is not expressed in normal tissue, certain proliferative somatic cells such as intestinal crypt cells have demonstrated telomerase activity. The aim of this study was to determine whether a correlation exists between telomerase activity, levels of hTERT methylation and telomere length in tumoral and normal colorectal tissues. Tumor, transitional and normal tissues were obtained from 11 patients with a colorectal cancer. After bisulfite modification of genomic DNA, hTERT promoter methylation was analyzed by methylation-sensitive single-strand conformation analysis (MS-SSCA). Telomerase activity and telomere length were measured by a fluorescent-telomeric repeat amplification protocol assay and by Southern blotting, respectively. A significant increase of hTERT methylation and telomerase activity, and a reduction of the mean telomere length were observed in the tumor tissues compared to the transitional and normal mucosa. In the transitional and normal mucosa, telomerase activity was significantly lower than that in tumor tissues, even with high levels of hTERT methylation. Nevertheless, hTERT promoter methylation was not linearly correlated to telomerase activity. These data indicate that hTERT promoter methylation is a necessary event for hTERT expression, as is telomerase activity. However, methylation is not sufficient for hTERT activation, particularly in normal colorectal cells.

A novel bispecific antibody format enables simultaneous bivalent and monovalent co-engagement of distinct target antigens.

Bispecific antibodies based on full-length antibody structures are more optimal than fragment-based formats because they benefit from the favorable properties of the Fc region. However, the homodimeric nature of Fc effectively imposes bivalent binding on all current full-length bispecific antibodies, an attribute that can result in nonspecific activation of cross-linked receptors. We engineered a novel bispecific format, referred to as mAb-Fv, that utilizes a heterodimeric Fc region to enable monovalent co-engagement of a second target antigen in a full-length context. mAb-Fv constructs co-targeting CD16 and CD3 were expressed and purified as heterodimeric species, bound selectively to their co-target antigens, and mediated potent cytotoxic activity by NK cells and T cells, respectively. The capacity to co-engage distinct target antigens simultaneously with different valencies is an improved feature for bispecific antibodies with promising therapeutic implications.

Telomerase activity is a prognostic factor for recurrence and survival in rectal cancer.

PURPOSE: This study was designed to determine whether telomerase activity measured in samples of tumoral tissue, transitional mucosa, and normal mucosa from patients with sporadic colorectal cancer is a prognostic factor for recurrence and overall survival. METHODS: Telomerase activity was determined by fluorescence-based telomeric repeat amplification in tissue samples from 108 patients with sporadic colorectal cancer. A telomerase index was determined by using the formula log (telomerase activity of cancer tissue - telomerase activity of normal mucosa). RESULTS: Mean telomerase activity in tumoral tissue was 11.49 (total product generated), in transitional mucosa it was 1.51, and in normal mucosa it was 1.09 (P < 0.001). Telomerase activity and telomerase index were not correlated with clinicopathologic factors. Rectal cancer patients' recurrence-free survival was related to N classification (P = 0.004) and to tumor-node-metastases stage classification (P = 0.023) and telomerase index 0.85 (P = 0.023). Overall survival was associated with N classification (positive/negative) and telomerase index (0.85; P = 0.018 and P = 0.011, respectively). CONCLUSIONS: Measurement of telomerase activity has a diagnostic value in colorectal patients. In rectal cancer, telomerase index is an independent prognostic factor for disease progression. A telomerase index

Evidence for antibody-catalyzed ozone formation in bacterial killing and inflammation.

Recently, we showed that antibodies catalyze the generation of hydrogen peroxide (H2O2) from singlet molecular oxygen (1O2*) and water. Here, we show that this process can lead to efficient killing of bacteria, regardless of the antigen specificity of the antibody. H2O2 production by antibodies alone was found to be not sufficient for bacterial killing. Our studies suggested that the antibody-catalyzed water-oxidation pathway produced an additional molecular species with a chemical signature similar to that of ozone. This species is also generated during the oxidative burst of activated human neutrophils and during inflammation. These observations suggest that alternative pathways may exist for biological killing of bacteria that are mediated by potent oxidants previously unknown to biology.