Autophagy regulator BECN1 suppresses mammary tumorigenesis driven by WNT1 activation and following parity

Earlier studies reported allelic deletion of the essential autophagy regulator BECN1 in breast cancers implicating BECN1 loss, and likely defective autophagy, in tumorigenesis. Recent studies have questioned the tumor suppressive role of autophagy, as autophagy-related gene (Atg) defects generally suppress tumorigenesis in well-characterized mouse tumor models. We now report that, while it delays or does not alter mammary tumorigenesis driven by Palb2 loss or ERBB2 and PyMT overexpression, monoallelic Becn1 loss promotes mammary tumor development in 2 specific contexts, namely following parity and in association with wingless-type MMTV integration site family, member 1 (WNT1) activation. Our studies demonstrate that Becn1 heterozygosity, which results in immature mammary epithelial cell expansion and aberrant TNFRSF11A/TNR11/RANK (tumor necrosis factor receptor superfamily, member 11a, NFKB activator) signaling, promotes mammary tumorigenesis in multiparous FVB/N mice and in cooperation with the progenitor cell-transforming WNT1 oncogene. Similar to our Becn1^+/−;MMTV-Wnt1 mouse model, low BECN1 expression and an activated WNT pathway gene signature correlate with the triple-negative subtype, TNFRSF11A axis activation and poor prognosis in human breast cancers. Our results suggest that BECN1 may have nonautophagy-related roles in mammary development, provide insight in the seemingly paradoxical roles of BECN1 in tumorigenesis, and constitute the basis for further studies on the pathophysiology and treatment of clinically aggressive triple negative breast cancers (TNBCs).     

Structural characterization of the osmosensor ProP

ProP, an osmoprotectant symporter from the major facilitator superfamily was expressed, purified and reconstituted into proteoliposomes that are amenable to structural characterization using infrared spectroscopy. Infrared spectra recorded in both ¹H₂O and ²H₂O buffers reveal amide I band shapes that are characteristic of a predominantly α-helical protein, and that are similar to those recorded from the well-characterized homolog, lactose permease (LacY). Curve-fit analysis shows that ProP and LacY both exhibit a high α-helical content. Both proteins undergo extensive peptide hydrogen-deuterium exchange after exposure to ²H₂O, but are surprisingly thermally stable with denaturation temperatures greater than 60 °C. 25-30% of the peptide hydrogens in both ProP and LacY are resistant to exchange after 72 h in ²H₂O at 4 °C. Surprisingly, these exchange resistant peptide hydrogens exchange completely for deuterium at temperatures below those that lead to denaturation. Our results show that ProP adopts a highly α-helical fold similar to that of LacY, and that both transmembrane folds exhibit unusually high temperature-sensitive solvent accessibility. The results provide direct evidence that ProP adopts a structure consistent with other major facilitator superfamily members.     

Tablet Splitting of a Narrow Therapeutic Index Drug: A Case with Levothyroxine Sodium

Levothyroxine is a narrow therapeutic index, and to avoid adverse effect associated with under or excessive dosage, the dose response is carefully titrated. The tablets are marketed with a score providing an option to split. However, there are no systematic studies evaluating the effect of splitting on dose accuracy, and current study was undertaken to evaluate effects of splitting and potential causes for uniformity failures by measuring assay and content uniformity in whole and split tablets. Stability was evaluated by assaying drug for a period of 8 weeks. Effect of formulation factors on splittability was evaluated by a systematic investigation of formulation factors by preparing levothyroxine tablets in house by varying the type of excipients (binder, diluent, disintegrant, glidant) or by varying the processing factors (granulating liquid, mixing type, compression pressure). The tablets were analyzed using novel analytical tool such as near infrared chemical imaging to visualize the distribution of levothyroxine. Assay was not significantly different for whole versus split tablets irrespective of method of splitting (hand or splitter), and splitting also had no measurable impact on the stability. Split tablets either by hand or splitter showed higher rate of content uniformity failures as compared to whole tablets. Tablet splitter produced more fragmentation and, hence, more content uniformity and friability failures. Chemical imaging data revealed that the distribution of levothyroxine was heterogeneous and was dependent on type of binder and the process used in the manufacture of tablets. Splitting such tablets could prove detrimental if sub- or super-potency becomes an issue.     

Direct influence of serotonin on the larval heart of Drosophila melanogaster

The heart rate (HR) of larval Drosophila is established to be modulated by various neuromodulators. Serotonin (5-HT) showed dose-dependent responses in direct application within semi-intact preparations. At 1 nM, HR decreased by 20% while it increased at 10 nM (10%) and 100 nM (30%). The effects plateaued at 100 nM. The action of 5-HT on the heart was examined with an intact Central Nervous System (CNS) and an ablated CNS. The heart and aorta of dorsal vessel pulsate at different rates at rest and during exposure to 5-HT. Splitting the heart and aorta resulted in a dramatic reduction in pulse rate of both the segments and the addition of 5-HT did not produce regional differences. The split aorta and heart showed a high degree of sensitivity to sham changes of saline but no significant effect to 5-HT. Larvae-fed 5-HT (1 mM) did not show any significant change in HR. Since 3,4-methylenedioxymethamphetamine (MDMA) is known to act as a weak agonist on 5-HT receptors in vertebrates, we tested an exogenous application; however, no significant effect was observed to dosage ranging from 1 nM to 100 μM in larvae with and without an intact CNS. In summary, direct application of 5-HT to the larval heart had significant effects in a dose-dependent manner while MDMA had no effect.     

Modulation of the oxidative stress and inflammatory cytokine response by thymoquinone in the collagen induced arthritis in Wistar rats

Thymoquinone (TQ) is the major active compound derived from Nigella sativa. Our aim of this work was to evaluate the antioxidant and antiarthritic activity of TQ in Wistar rat by collagen induced arthritis (CIA). TQ was administered at a dose of 5mgkg(-1) body weight once daily for 21days. The effects of treatment in the rats were assessed by biochemical (articular elastase, MPO, LPO, GSH, catalase, SOD and NO), inflammatory mediators (IL-1β, IL-6, TNF-α, IL-10, IFN-γ and PGE(2)) and histological studies in joints. TQ was effective in bringing significant changes on all the parameters (articular elastase, MPO, LPO, GSH, catalase, SOD and NO) studied. Oral administration of TQ resulted in significantly reduced the levels of pro-inflammatory mediators (IL-1β, IL-6, TNF-α, IFN-γ and PGE(2)) and increased level of IL-10. The protective effects of TQ against RA were also evident from the decrease in arthritis scoring and bone histology. In conclusion, the fact that TQ abolished a number of factors known to be involved in RA pathogenesis indicates that the administration of thymoquinone may have potential value in the treatment of inflammatory disease.     

Evaluation of a Typhoid/Paratyphoid Diagnostic Assay (TPTest) Detecting Anti-Salmonella IgA in Secretions of Peripheral Blood Lymphocytes in Patients in Dhaka,Bangladesh

Background

Rapid and reliable diagnostic assays for enteric (typhoid and paratyphoid) fever are urgently needed. We report the characterization of novel approach utilizing lymphocyte secretions, for diagnosing patients with enteric fever by the TPTest procedure.

Methodology

TPTest detects Salmonella-specific IgA responses in lymphocyte culture supernatant. We utilized TPTest in patients with suspected enteric fever, patients with other illnesses, and healthy controls. We also evaluated simplified modifications of TPTest for adaptation in laboratories with limited facilities and equipment.

Principal Findings

TPTest was positive in 39 (27 typhoid and 12 paratyphoid A) patients confirmed by blood culture and was negative in 74 healthy individuals. Among 32 individuals with other illnesses, 29 were negative by TPTest. Of 204 individuals with suspected enteric fever who were negative by blood culture, 44 were positive by TPTest and the patients were clinically indistinguishable from patients with confirmed bacteremia, except they were more likely to be under 5 years of age. We evaluated simplifications in TPTest, including showing that lymphocytes could be recovered using lysis buffer or buffy coat method as opposed to centrifugation, that incubation of cells at 37°C did not require supplemental CO₂, and that results were available for majority of samples within 24 hours. Positive results by TPTest are transient and revert to negative during convalescence, supporting use of the test in endemic areas. The results can also be read using immunodot blot approach as opposed to ELISA. Since no true gold standard currently exists, we used a number of definitions of true positives and negatives. TPTest had sensitivity of 100% compared to blood culture, and specificity that ranged from 78–97% (73–100, 95% CI), depending on definition of true negative.

Conclusion

The TPTest is useful for identification of patients with enteric fever in an endemic area, and additional development of simplified TPTest is warranted.     

Nutritional constituents of mulberry and their potential applications in food and pharmaceuticals: A review

Mulberry is a fast growing deciduous plant found in wide variety of climatic, topographical and soil conditions, and is widely distributed from temperate to subtropical regions. Due to presence of valuable phytochemical constituents, mulberry as a whole plant has been utilized as a functional food since long time. Mulberry fruits are difficult to preserve as they have relatively high water content. Therefore for proper utilization, different value-added products like syrups, squashes, teas, pestil sand köme, pekmez (turkuish by-products), yogurts, jams, jellies, wines, vinegar, breads, biscuits, parathas, and many more are made. In overseas, these value-added products are commercially sold and easily available, though in India, this versatile medicinal plant is still missing its identity at commercial and industrial scale. Leaves of mulberry are economically viable due to their important role in the sericulture industry since ancient times. Mulberries or its extracts exhibit excellent anti-microbial, anti-hyperglycaemic, anti-hyperlipidemic, anti-inflammatory, anti-cancer effects and is used to combat different acute and chronic diseases. Different parts of Morus species like fruits, leaves, twigs, and bark exhibit strong anti-tyrosinase inhibition activity that makes it a suitable candidate in cosmetic industries as a whitening agent. The current review provides a comprehensive discussion concerning the phytochemical constituents, functionality and nutraceutical potential of mulberry and as a common ingredient in various cosmetic products.     

The Childhood Leukemia International Consortium

Background: Acute leukemia is the most common cancer in children under 15 years of age; 80% are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood leukemia shows further diversity based on cytogenetic and molecular characteristics, which may relate to distinct etiologies. Case–control studies conducted worldwide, particularly of ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens. There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other complex diseases, is likely to be influenced both by independent and interactive effects of genes and environmental exposures. While some studies have analyzed the role of genetic variants, few have been sufficiently powered to investigate gene–environment interactions. Objectives: The Childhood Leukemia International Consortium (CLIC) was established in 2007 to promote investigations of rarer exposures, gene–environment interactions and subtype-specific associations through the pooling of data from independent studies. Methods: By September 2012, CLIC included 22 studies (recruitment period: 1962–present) from 12 countries, totaling approximately 31 000 cases and 50 000 controls. Of these, 19 case–control studies have collected detailed epidemiologic data, and DNA samples have been collected from children and child–parent trios in 15 and 13 of these studies, respectively. Two registry-based studies and one study comprising hospital records routinely obtained at birth and/or diagnosis have limited interview data or biospecimens. Conclusions: CLIC provides a unique opportunity to fill gaps in knowledge about the role of environmental and genetic risk factors, critical windows of exposure, the effects of gene–environment interactions and associations among specific leukemia subtypes in different ethnic groups.     

Childhood Cancer Incidence in British Indians & Whites in Leicester, 1996–2008

Background

South Asians in England have an increased risk of childhood cancer but incidence by their individual ethnicities using self-assigned ethnicity is unknown. Our objective was to compare the incidence of childhood cancer in British Indians and Whites in Leicester, which has virtually complete, self-assigned, ethnicity data and the largest population of Indians in England.

Methods

We obtained data on all cancer registrations from 1996 to 2008 for Leicester with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Age-standardised incidence rates were calculated for childhood cancers in Indians and Whites as well as rate ratios, adjusted for age.

Results

There were 33 cancers registered among Indian children and 39 among White children. The incidence rate for Indians was greater compared to Whites for all cancers combined (RR 1.82 (95% CI 1.14 to 2.89); p = 0.01), with some evidence of increased risk of leukaemia (RR 2.20 (0.95 to 5.07); p = 0.07), lymphoma (RR 3.96 (0.99 to 15.84); p = 0.04) and central nervous system tumours (RR 2.70 (1.00 to 7.26); p = 0.05). Rates were also higher in British Indian children compared to children in India.

Conclusions

British Indian children in Leicester had an increased risk of developing cancer compared to White children, largely due to a higher incidence of central nervous system and haematological malignancies.