Bax expression is predictive of favorable clinical outcome in chemonaive advanced gastric cancer patients treated with capecitabine, oxaliplatin, and irinotecan regimen

OBJECTIVE: Bax protein is a key mediator of apoptosis, and it might be related to chemosensitivity. The purpose of this study was to evaluate the prognostic role of Bax in patients with advanced gastric cancer treated with triplet chemotherapy COI regimen (capecitabine, oxaliplatin, and irinotecan). METHODS: Pretreatment tissue blocks were available for 23 consecutive patients, selected for good performance status (ECOG ≤ 1) and consenting for treatment with first-line COI at a single institution. Bax levels were classified as positive or negative by immunohistochemistry (bax N20; Santa Cruz Biotechnology) and related to outcome in terms of response rate, progression-free survival, and overall survival. RESULTS: Bax-negative and -positive samples were 26% and 74%, respectively. Bax expression was associated with significantly higher response rate (87% vs 33%), progression-free survival (8.7 vs 4.9 months, P = .016), and overall survival (23.8 vs 12.7 months, P = .025). In multivariate analysis including Bax and performance status, low Bax independently predicted worse outcome, along with suboptimal performance status. CONCLUSIONS: In advanced gastric cancer, Bax expression was related to clinical benefit with COI regimen. Whether Bax is a prognostic or mixed prognostic/predictive factor warrants prospective confirmation. It is to be defined if Bax predicts sensitivity to platinum analogs or to whatever chemotherapy regimen.     

True 3q Chromosomal Amplification in Squamous Cell Lung Carcinoma by FISH and aCGH Molecular Analysis: Impact on Targeted Drugs

Squamous lung carcinoma lacks specific “ad hoc” therapies. Amplification of chromosome 3q is the most common genomic aberration and this region harbours genes having role as novel targets for therapeutics. There is no standard definition on how to score and report 3q amplification. False versus true 3q chromosomal amplification in squamous cell lung carcinoma may have tremendous impact on trials involving drugs which target DNA zones mapping on 3q. Forty squamous lung carcinomas were analyzed by FISH to assess chromosome 3q amplification. aCGH was performed as gold-standard to avoid false positive amplifications. Three clustered patterns of fluorescent signals were observed. Eight cases out of 40 (20%) showed ≥8 3q signals. Twenty out of 40 (50%) showed from 3 to 7 signals. The remaining showed two fluorescent signals (30%). When corrected by whole chromosome 3 signals, only cases with ≥8 signals maintained a LSI 3q/CEP3 ratio >2. Only the cases showing 3q amplification by aCGH (+3q25.3−3q27.3) showed ≥8 fluorescent signals at FISH evidencing a 3q/3 ratio >2. The remaining cases showed flat genomic portrait at aCGH on chromosome 3. We concluded that: 1) absolute copy number of 3q chromosomal region may harbour false positive interpretation of 3q amplification in squamous cell carcinoma; 2) a case results truly “amplified for chromosome 3q” when showing ≥8 fluorescent 3q signals; 3) trials involving drugs targeting loci on chromosome 3q in squamous lung carcinoma therapy have to consider false versus true 3q chromosomal amplification.     

Haplotype affinities resolve a major component of goat (Capra hircus) MtDNA D-loop diversity and reveal specific features of the Sardinian stock

Goat mtDNA haplogroup A is a poorly resolved lineage absorbing most of the overall diversity and is found in locations as distant as Eastern Asia and Southern Africa. Its phylogenetic dissection would cast light on an important portion of the spread of goat breeding. The aims of this work were 1) to provide an operational definition of meaningful mtDNA units within haplogroup A, 2) to investigate the mechanisms underlying the maintenance of diversity by considering the modes of selection operated by breeders and 3) to identify the peculiarities of Sardinian mtDNA types. We sequenced the mtDNA D-loop in a large sample of animals (1,591) which represents a non-trivial quota of the entire goat population of Sardinia. We found that Sardinia mirrors a large quota of mtDNA diversity of Western Eurasia in the number of variable sites, their mutational pattern and allele frequency. By using bayesian analysis, a distance-based tree and a network analysis, we recognized demographically coherent groups of sequences identified by particular subsets of the variable positions. The results showed that this assignment system could be reproduced in other studies, capturing the greatest part of haplotype diversity.We identified haplotype groups overrepresented in Sardinian goats as a result of founder effects. We found that breeders maintain diversity of matrilines most likely through equalization of the reproductive potential. Moreover, the relevant amount of inter-farm mtDNA diversity found does not increase proportionally with distance. Our results illustrate the effects of breeding practices on the composition of maternal gene pool and identify mtDNA types that may be considered in projects aimed at retrieving the maternal component of the oldest breeds of Sardinia.     

The practicability and surgeons' subjective experiences with vaginal danazol before an operative hysteroscopy

This randomized, double blind, placebo-controlled study compared the usefulness of danazol 400mg vaginally versus 600mg orally in women as a preoperative preparation for hysteroscopic surgery. Ninety-one fertile women were randomly allocated to Group A (46 patients received 400mg of danazol placed into the posterior vaginal fornix and three oral tablets of commercially available folic acid as a placebo), and Group B [45 women treated with 600mg of danazol orally (200mg three times daily) and two vaginal tablets of Lactobacillus rhamnosus as a placebo]. The patients underwent an operative hysteroscopy, transvaginal sonography, blood tests, and a histological assay. A visual analog scale (VAS) score to compute the degree of the surgeon's satisfaction was used. The outcome measures were as follows: an evaluation of the changes in the endometrial thickness, the prevalence of endometrial atrophy, changes in the blood tests, any collateral effects, the degree of difficulty and view, the duration of the surgical procedure, any complications during the operative hysteroscopy and associated side effects, and the surgeon's satisfaction with the endometrial preparation. The vaginal administration route was associated with a more pronounced effect on the endometrial thickness. Significantly more patients receiving vaginal danazol (45/46) had a hypotrophic endometrium than those receiving oral danazol (37/45, P<0.01). In addition, the patients receiving danazol vaginally had a shorter operating time, lower infusion volume, fewer side effects, and a higher surgeon satisfaction. Vaginal danazol adequately prepares the endometrium for an operative hysteroscopy by thinning the endometrium effectively with few side effects and little impact on the metabolic parameters.     

Heat-shock protein 70 from plant biofactories of recombinant antigens activate multiepitope-targeted immune responses

Although a physiological role of heat-shock proteins (HSP) in antigen presentation and immune response activation has not been directly demonstrated, their use as vaccine components is under clinical trial. We have previously demonstrated that the structure of plant-derived HSP70 (pHSP70) can be superimposed to the mammalian homologue and similarly to the mammalian counterpart, pHSP70-polypeptide complexes can activate the immune system. It is here shown that pHSP70 purified from plant tissues transiently expressing the influenza virus nucleoprotein are able to induce both the activation of major histocompatibility complex class I-restricted polyclonal T-cell responses and antibody production in mice of different haplotypes without the need of adjuvant co-delivery. These results indicate that pHSP70 derived from plants producing recombinant antigens may be used to formulate multiepitope vaccines.     

Proteomics of β2-microglobulin amyloid fibrils

Knowledge on the chemical structure of β2-microglobulin in natural amyloid fibrils is quite limited because of the difficulty in obtaining tissue samples suitable for biochemical studies. We have reviewed the available information on the chemical modifications and we present new data of β2-microglobulin extracted from non-osteotendinous tissues. β2-microglobulin can accumulate in these compartments after long-term haemodialysis but rarely forms amyloid deposits. We confirm that truncation at the N-terminus is an event specific to β2-microglobulin derived from fibrils but is not observed in the β2-microglobulin from plasma or from the insoluble non-fibrillar material deposited in the heart and spleen. We also confirm the partial deamidation of Asn 17 and Asn 42, as well as the oxidation of Met 99 in fibrillar β2-microglobulin. Other previously reported chemical modifications cannot be excluded, but should involve less than 1–2% of the intact molecule.     

Proliferation versus migration in platelet-derived growth factor signaling: the key role of endocytosis

It is common knowledge that platelet-derived growth factor (PDGF) is a critical regulator of mesenchymal cell migration and proliferation. Nevertheless, these two cellular responses are mutually exclusive. To solve this apparent contradiction, we studied the behavior of NIH3T3 fibroblasts in response to increasing concentrations of PDGF. We found that there is strong cell proliferation induction only with PDGF concentrations >5 ng/ml, whereas the cell migration response arises starting from 1 ng/ml and is negligible at higher PDGF concentrations. According to these phenotypic evidences, our data indicate that cells display a differential activation of the main signaling pathways in response to PDGF as a function of the stimulation dose. At low PDGF concentrations, there is maximal activation of signaling pathways linked to cytoskeleton rearrangement needed for cell motility, whereas high PDGF concentrations activate pathways linked to mitogenesis induction. Our results suggest a mechanism by which cells switch from a migrating to a proliferating phenotype sensing the increasing gradient of PDGF. In addition, we propose that the cell decision to proliferate or migrate relies on different endocytotic routes of the PDGF receptor in response to different PDGF concentrations.     

Are aquatic assemblages from small water bodies more stochastic in dryer climates? An analysis of ostracod spring metacommunities

Metacommunity ecology describes community organisation considering both environmental and spatial processes. We tested the relative importance of environmental and spatial factors on spring ostracod assemblages from four European regions characterised by different climatic conditions (e.g. aridity). Pure and shared effects of environment and space were calculated using redundancy analysis and variation partitioning. Both environmental and spatial variables significantly explain assemblage variation, although with different relevance among areas. The amount of variation explained by environmental factors decreased with increasing climate aridity. The reduced size of spring habitats makes them prone to drying events, which are more frequent in dryer climates. Frequent disturbances may lead to local extinctions followed by colonisations from nearby sites, in a source–sink dynamics. Early recolonisation leads to random assemblages and reduces the match between organisms and environmental conditions. As a consequence, a low amount of community variation can be explained by environmental variables. Conversely, the settled communities from wetter climates best fit the ecological characteristics of sites, and deterministic processes, such as species sorting, dominate the assemblages. In conclusion, in the studied regions, ostracod communities from small water bodies of dryer climates seem to be mainly driven by stochastic dynamics when compared to more continental areas.     

Mitochondrial permeability transition involves dissociation of F1FO ATP synthase dimers and C‐ring conformation

The impact of the mitochondrial permeability transition (MPT) on cellular physiology is well characterized. In contrast, the composition and mode of action of the permeability transition pore complex (PTPC), the supramolecular entity that initiates MPT, remain to be elucidated. Specifically, the precise contribution of the mitochondrial F₁F_O ATP synthase (or subunits thereof) to MPT is a matter of debate. We demonstrate that F₁F_O ATP synthase dimers dissociate as the PTPC opens upon MPT induction. Stabilizing F₁F_O ATP synthase dimers by genetic approaches inhibits PTPC opening and MPT. Specific mutations in the F₁F_O ATP synthase c subunit that alter C‐ring conformation sensitize cells to MPT induction, which can be reverted by stabilizing F₁F_O ATP synthase dimers. Destabilizing F₁F_O ATP synthase dimers fails to trigger PTPC opening in the presence of mutants of the c subunit that inhibit MPT. The current study does not provide direct evidence that the C‐ring is the long‐sought pore‐forming subunit of the PTPC, but reveals that PTPC opening requires the dissociation of F₁F_O ATP synthase dimers and involves the C‐ring.