Risk Factors for Sensitization to Anisakis Simplex: A Multivariate Statistical Evaluation

Anisakis simplex is a nematode belonging to the Anisakidae family. The ingestion of third stage larvae in uncooked or undercooked seafood may cause human diseases known as anisakiasis and anisakidosis. A total of 400 (159 atopic and 241 non-atopic) subjects living in an area of southern Italy (Bari district) were consecutively evaluated to identify the association of some factors (sex, age, atopy, consumption of uncooked seafood and sensitization to dust mites) with the risk of Anisakis simplex sensitization. Patients were investigated on history of atopy and allergic diseases and were skin prick tested with commercial allergen extracts of Anisakis simplex, Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae, Glycyphagus domesticus, Euroglyphus maynei, Dermatophagoides pteronyssinus and Dermatophagoides faunae. Our results suggest that atopic subjects have a lower risk of Anisakis allergy than non-atopic subjects and show the association of Anisakis simplex sensitization with the consumption of uncooked seafood (anchovies and squid), increasing age and sensitization to Glycyphagus domesticus.

Abstract 4327: Nek6 and Hif-1α cooperate with the cytoskeletal gateway of drug resistance to drive outcome in serous ovarian cancer

Hypoxia selects the most aggressive and drug-resistant clones in solid malignancies. One of the pivotal transcription factors induced by hypoxia is Hif-1α. However, in serous ovarian cancer (SEOC), Hif-1α expression is not a prognostic biomarker. This study aims to assess the hypothesis that the serine-threonine kinase Nek6 functions as a downstream effector cooperating with Hif-1α in driving ovarian cancer aggressiveness.

Nek6 was overexpressed and Hif-1α was silenced in A2780 cells. Nek6 was also stably silenced in Hey cells. The dependence of Nek6 expression on Hif-1α was assayed as a function of hypoxic growth conditions. Nek6 interaction with the cytoskeletal gateway of drug resistance was investigated with far western blot. The co-expression of NEK6, HIF1A, TUBB3 and GBP1 transcripts was quantified with qPCR in two cohorts of SEOC patients (346 locally treated patients and 344 from the TCGA dataset).

Nek6 expression is induced by hypoxia in a Hif-1α dependent fashion. Nek6 directly interacts with GBP-1, thus being a component of the cytoskeletal gateway of drug resistance. Nek6 overexpression increases and silencing decreases the anchorage-independent growth of cultured cells. In SEOC patients, NEK6 expression is significantly correlated with HIF1A. Co-expression of NEK6, HIF1A, TUBB3 and GBP1 transcripts identifies a subset of SEOC patients characterized by poor outcome and drug resistance.

This study demonstrates the functional relevance of Nek6 in the context of the adaptive response to hypoxia in SEOC. This finding may help identify a sub-population of patients at high risk of relapse to standard first-line chemotherapy.

Citation Format: Marta De Donato, Mara Fanelli, Marisa Mariani, Giuseppina Raspaglio, Deep Pandya, Shiquan He, Paul Fiedler, Marco Petrillo, Giovanni Scambia, Cristiano Ferlini. Nek6 and Hif-1α cooperate with the cytoskeletal gateway of drug resistance to drive outcome in serous ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4327. doi:10.1158/1538-7445.AM2015-4327

Nek6 and Hif-1α cooperate with the cytoskeletal gateway of drug resistance to drive outcome in serous ovarian cancer

Hypoxia selects the most aggressive and drug-resistant clones in solid malignancies. One of the pivotal transcription factors induced by hypoxia is Hif-1α. However, in serous ovarian cancer (SEOC), Hif-1α expression is not a prognostic biomarker. This study aims to assess the hypothesis that the serine-threonine kinase Nek6 functions as a downstream effector cooperating with Hif-1α in driving ovarian cancer aggressiveness. Nek6 was overexpressed and Hif-1α was silenced in A2780 cells. Nek6 was also stably silenced in Hey cells. The dependence of Nek6 expression on Hif-1α was assayed as a function of hypoxic growth conditions. Nek6 interaction with the cytoskeletal gateway of drug resistance was investigated with far western blot. The co-expression of NEK6, HIF1A, TUBB3 and GBP1 transcripts was quantified with qPCR in two cohorts of SEOC patients (346 locally treated patients and 344 from the TCGA dataset). Nek6 expression is induced by hypoxia in a Hif-1α dependent fashion. Nek6 directly interacts with GBP-1, thus being a component of the cytoskeletal gateway of drug resistance. Nek6 overexpression increases and silencing decreases the anchorage-independent growth of cultured cells. In SEOC patients, NEK6 expression is significantly correlated with HIF1A. Co-expression of NEK6, HIF1A, TUBB3 and GBP1 transcripts identifies a subset of SEOC patients characterized by poor outcome and drug resistance. This study demonstrates the functional relevance of Nek6 in the context of the adaptive response to hypoxia in SEOC. This finding may help identify a sub-population of patients at high risk of relapse to standard first-line chemotherapy.

[Aseptic, simultaneous and bilateral mobilisation due to an acetabular shell fracture in a 43 year-old patient]

The acetabular shell mobilization is the main long-term complication in total hip replacement. Metal-back fracture has also to be considered among the possible causes of shell mobilization. A case is presented of bilateral acetabular shell mobilization due to the trabecular covering de-soldering from the metal-back in a 43 year-old patient, 13-14 years after the first surgery.

Abstract P4-12-26: A phase II randomized study of lapatinib in combination with capecitabine, vinorelbine or gemcitabine as first or second line-therapy in patients with HER2 positive metastatic breast cancer progressing after taxane (LACOG 0801)

Background:

Lapatinib-Capecitabine (LC) is approved for the treatment of advanced or metastatic breast cancer (MBC) whose tumors overexpress HER2 and who have received prior therapy including an anthracycline, a taxane (T), and trastuzumab (H). LACOG 0801 evaluated different L-based chemotherapies as first and second-line treatments in MBC.

Methods:

This is a randomized, open label, multicenter, phase II trial of L 1250 mg BID given continuously in combination with C 2000 mg/m2 d1-14 (LC), or Vinorelbine (V) 25mg/m2 d1 and 8 (LV) or Gemcitabine (G) 1000 mg/m2 d1 and 8 (LG), in 21 days cycles. Primary endpoint was ORR (RECIST). Secondary endpoints included progression free survival (PFS), overall survival, tolerability and safety. Patients with HER2 positive MBC who had failed a T-based treatment and who had ≤1 chemotherapy regimen in the metastatic setting were included. Prior therapy with H was not mandatory. Patients were stratified by the presence of liver metastasis, previous use of H, and T administered in the neo/adjuvant or the metastatic setting. With an expected ORR of 23% in the control arm (LC), we hypothesized an absolute increase of 12% in the experimental arms using Simon's design.

Results:

A total of 142 pts from Argentina, Brazil and Peru were included from 2009-2012. Patient baseline characteristics were well balanced between the three arms. Median age was 51y, 58% postmenopausal, 65% ECOG 1, 49% had visceral disease (32% liver metastasis), 57% hormone receptor negative and only 47% had received prior H. Median number of administered cycles was 6 (LC = 5; LV = 7; LG = 6). ORR was 47.1% (95%CI 38.5; 67.1), 55.6% (95%CI 29.6; 60.0) and 41.3% (95%CI 43.2; 73.0) in LC, LV and LG, respectively. Median PFS was 9.1m (95%CI 6.1; 14.7), 7.0m (95%CI 5.0; 9.9) and 6.8m (95%CI 5.8; 9.9) in LC, LV and LG arms respectively. Survival data will be updated. The proportion of patients with at least one adverse event (AE) was 96% in all arms. Most common all grade AE were diarrhea (76%), hand-foot syndrome (HFS) (45%) and vomiting (39%) in LC; diarrhea (71%), neutropenia (68%) and nausea (43%) in LV; diarrhea (64%), neutropenia (60%), anemia and increased ALT both 44% in LG. The most frequent grade 3 and 4 AEs were HFS (18%), diarrhea (6%) and increased ALT/AST (4%) in LC; neutropenia (36%), diarrhea (9%) and febrile neutropenia (6%) in LV; and neutropenia (47%), ALT/AST elevation (13%) and rash (4%) in LG. Discontinuation due to toxicity occurred in 16%, 7% and 20% of patients in arms LC, LV and LG respectively.

Conclusion:

LV and LG seems to be active combinations in patients with HER2 positive MBC after T failure. The high ORR observed in this study might be explained, among other factors, by the inclusion of patients with less prior treatment exposure. No new safety signals where reported with these two novel Lapatinib/chemotherapy combinations. The different side effect profile may help in selecting the most appropriate regimen for a particular patient.

Sponsor: Latin American Cooperative Oncology Group (LACOG) with support from GlaxoSmithKline.

ClinicalTrials.gov number NCT01050322.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-26.

Preclinical validation of Aurora kinases-targeting drugs in osteosarcoma

Background:

Aurora kinases are key regulators of cell cycle and represent new promising therapeutic targets in several human tumours.

Methods:

Biological relevance of Aurora kinase-A and -B was assessed on osteosarcoma clinical samples and by silencing these genes with specific siRNA in three human osteosarcoma cell lines. In vitro efficacy of two Aurora kinases-targeting drugs (VX-680 and ZM447439) was evaluated on a panel of four drug-sensitive and six drug-resistant human osteosarcoma cell lines.

Results:

Human osteosarcoma cell lines proved to be highly sensitive to both drugs. A decreased drug sensitivity was observed in doxorubicin-resistant cell lines, most probably related to ABCB1/MDR1 overexpression. Both drugs variably induced hyperploidy and apoptosis in the majority of cell lines. VX-680 also reduced in vitro cell motility and soft-agar cloning efficiency. Drug association experiments showed that VX-680 positively interacts with all conventional drugs used in osteosarcoma chemotherapy, overcoming the cross-resistance observed in the single-drug treatments.

Conclusion:

Aurora kinase-A and -B represent new candidate therapeutic targets for osteosarcoma. In vitro analysis of the Aurora kinases inhibitors VX-680 and ZM447439 indicated in VX-680 a new promising drug of potential clinical usefulness in association with conventional osteosarcoma chemotherapeutic agents.

Physical exercise and environment exploration affect synaptogenesis in adult-generated neurons in the rat dentate gyrus: possible role of BDNF

A brief training in a pool maze, with or without cognitive tasks, modifies the synaptogenesis and maturation of newborn neurons in adult rat dentate gyrus. These types of trainings have many aspects, including physical activity and exploration. Therefore, to evaluate whether physical exercise and environment exploration are able to affect synapse formation and the maturation of adult-generated neurons, GFP-retrovirus infusion was performed on rats which, on the fourth day after injection, were housed under running conditions or allowed to explore an enriched environment briefly in the absence of exercise for the following three days. Afterward, at the end of the trainings, electrophysiological and morphological studies were conducted. Considering that neurotrophic factors increase after exercise or environment exploration, hippocampal BDNF levels and TrkB receptor activation were evaluated. In this study, we show that both spontaneous physical activity and enriched environment exploration induced synaptogenesis and T-type voltage-dependent Ca(2+) currents in very immature neurons. Hippocampal BDNF levels and TrkB receptor activation were determined to be increasing following physical activity and exploration. A possible contribution of BDNF signaling in mediating the observed effects was supported by the use of 7-8-dihydroxyflavone, a selective TrkB agonist, and of ANA-12, an inhibitor of TrkB receptors.

An unconventional indication of the Sauve' - Kapandji procedure in a radial shaft pseudoarthrosis and chronic DRUJ dislocation: a case report

We present a 42-years-old male who developed a radial shaft pseudoartrosis and a chronic DRUJ dislocation/instability, following a Galeazzi fracture. He presented to our Office with a severe inability of wrist and forearm motion. A Sauve'-Kapandji procedure was adopted, performing a lateral approach to the ulna and grafting the excised ulnar block to retrieve radial length at the pseudoarthrosis level. Cancellous bone grafts from the iliac crest were also applied and mixed with autologous platelet rich plasma to promote callus formation. The goal was to create an intentional pseudoarthrosis of the distal ulna combined with a DRUJ arthrodesis, in order to resolve instability and regain forearm pronation/supination. We obtained bone healing, an excellent clinical recovery, and the patient returned to all his previous activities six months after surgery. To our knowledge, this is the first reported case of a radial shaft psudoarthrosis treated with the Sauve'-Kapandji technique.

Interleukin-21 (IL-21) synergizes with IL-2 to enhance T-cell receptor-induced human T-cell proliferation and counteracts IL-2/transforming growth factor-β-induced regulatory T-cell development

Interleukin-2 (IL-2) is a mainstay for current immunotherapeutic protocols but its usefulness in patients is reduced by severe toxicities and because IL-2 facilitates regulatory T (Treg) cell development. IL-21 is a type I cytokine acting as a potent T-cell co-mitogen but less efficient than IL-2 in sustaining T-cell proliferation. Using various in vitro models for T-cell receptor (TCR)-dependent human T-cell proliferation, we found that IL-21 synergized with IL-2 to make CD4(+) and CD8(+) T cells attain a level of expansion that was impossible to obtain with IL-2 alone. Synergy was mostly evident in naive CD4(+) cells. IL-2 and tumour-released transforming growth factor-β (TGF-β) are the main environmental cues that cooperate in Treg cell induction in tumour patients. Interleukin-21 hampered Treg cell expansion induced by IL-2/TGF-β combination in naive CD4(+) cells by facilitating non-Treg over Treg cell proliferation from the early phases of cell activation. Conversely, IL-21 did not modulate the conversion of naive activated CD4(+) cells into Treg cells in the absence of cell division. Treg cell reduction was related to persistent activation of Stat3, a negative regulator of Treg cells associated with down-modulation of IL-2/TGF-β-induced phosphorylation of Smad2/3, a positive regulator of Treg cells. In contrast to previous studies, IL-21 was completely ineffective in counteracting the suppressive activity of Treg cells on naive and memory, CD4(+) and CD8(+) T cells. Present data provide proof-of-concept for evaluating a combinatorial approach that would reduce the IL-2 needed to sustain T-cell proliferation efficiently, thereby reducing toxicity and controlling a tolerizing mechanism responsible for the contraction of the T-cell response.

Abstract P4-02-03: FDG PET/CT for early monitoring of response to neoadjuvant chemotherapy in breast cancer patients

Introduction: Neoadjuvant chemotherapy (NAC), initially used only for locally advanced breast cancer, is now commonly used in patients with operable but large breast cancer or unfavorable tumor/breast size index because increases the chances of performing breast conservative surgery (BCS) instead of mastectomy in this group of patients.

Patients and Methods: This is a prospective unicenter trial. FDG PET/CT were performed in 40 patients at baseline and after the second cycle of NAC. The level and relative changes in standardized uptake value (SUV) of FDG uptake were assessed regarding their ability to predict histopathologic response.

Pathologic complete response (pCR) was defined as no malignant cells (no invasive ductal carcinoma and no ductal carcinoma in situ) identifiable in sections from the site of the tumor in the breast and in the axillary lymph node.

Results: This prospectively study analyzed forty patients undergoing NAC, all female, age ranged 27–64 years (mean 41.0 years and median 38 years), all tumors were invasive ductal carcinoma, histological tumor grade 1, 2 and 3 were present respectively at 5%, 38.5% and 100% of the sample and nuclear grade 2 and 3 were present respectively at 12.5% and 87.5%. Estrogen receptor was positive in 60% of patients and the progesterone receptor was positive in 47.5% of patients. Her 2 was overexpressed in 12 patients (30%). Phenotype in this sample had the following distribution: 12.5% luminal A (5 patients), 50% Luminal B (20 patients: 14 patients with Ki-67> 14% and 6 cases with HER 2 overexpression), 15 % HER 2 (6 patients) and cases triple negative 9 (22.5%). size of the primary tumor ranged from 4.10 cm to 12.0 cm (mean 7.10 cm). The size of the primary tumor ranged from had a mean of 6.7 cm and a median of 6.0 cm. This group showed great uniformity in relation to primary chemotherapy. NAC with cyclophosphamide and adriamycin were administered to 38 patients. In this study, pCR was obtained in 12 patients (30%). Baseline FDG SUV referring to pCR group was 11.26 and 7.26 in non-pCR group (p = 0.04). FDG SUV after second cycle was 2.73 in pCR group and 4.64 in non-pCR group (p = 0.048). When analyzing ΔSUV (difference between baseline SUV and SUV after second cycle), pCR group had a mean reduction of 81.58% and non-pCR group had a mean reduction of 81.58% (p = 0.001). Receiver operating curve analyses were performed to deter mine optimal differentiation cut-off values of ΔSUV for differentiation of pCR and non-pCR. After two courses of NAC the optimal cutoff value to early differentiation between pCR from non-pCR were 59,1% in decrease of SUV. The sensitivity and specificity were 64,3% and 100,0%, respectively.

Conclusion: The optimum role of FDG PET in predicting the response of breast cancers to neoadjuvant chemotherapy is still not clearly defined and the SUV cut-off needs to be validated. FDG-PET allows for prediction of treatment response by the level of FDG uptake in terms of SUV at baseline and after two cycles of chemotherapy and FDG-PET may be helpful for individual treatment stratification in breast cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-02-03.

Dexamethasone Affects FAS-and Serum Deprivation-Induced Cell Death of Human Osteoblastic Cells through Survivin Regulation

Glucocorticoid-induced bone loss is the most prevalent form of secondary osteoporosis. Such loss could be due to the alteration of osteoclast and osteoblast lifespan through regulated apoptosis. The current study investigated the effect of dexamethasone on Fas- and starvation-induced apoptosis of mature osteoblasts and their precursors. Using the human osteoblastic hFOB1.19 and the MG63 osteosarcoma cell lines, we found that sub-lethal doses of dexamethasone act on pre-osteoblasts but not on mature cells by increasing their susceptibility to apoptosis. Apoptosis occurs in a caspase-dependent manner as both DNA fragmentation and mitochondrial transmembrane potential dissipation (ΔΨm) are inhibited by the pan-caspase inhibitor zVAD. The increased susceptibility of osteoblast precursors to apoptosis could be due to dexamethasone-mediated down-regulation of survivin expression. Dexamethasone can up-regulate survivin, and to a lesser extent Bcl-2, in mature cells but not in pre-osteoblasts. In addition, it can induce FLIP over-expression in osteosarcoma cells. All these effects are inhibited by the glucocorticoid antagonist RU486, indicating that dexamethasone action is specific and, furthermore, that it depends on glucocorticoid receptor. Finally, we have found that survivin and Bcl-2 are essential for pre- and mature osteoblast survival as their silencing is sufficient to induce spontaneous apoptosis in both cell types. In conclusion, our data outline a new molecular mechanism of glucocorticoid-mediated bone loss due to the enhanced apoptosis of precursors compared to mature osteoblasts. Furthermore, the data suggest a mechanism of dexamethasone-induced resistance of osteosarcoma cells to Fas- and stress-induced apoptosis.

Malten, a new synthetic molecule showing in vitro antiproliferative activity against tumour cells and induction of complex DNA structural alterations

BACKGROUND

Hydroxypyrones represent several classes of molecules known for their high synthetic versatility. This family of molecules shows several interesting pharmaceutical activities and is considered as a promising source of new antineoplastic compounds.

METHODS

In the quest to identify new potential anticancer agents, a new maltol (3-hydroxy-2-methyl-4-pyrone)-derived molecule, named malten (N,N'-bis((3-hydroxy-4-pyron-2-yl)methyl)-N,N'-dimethylethylendiamine), has been synthesised and analysed at both biological and molecular levels for its antiproliferative activity in eight tumour cell lines.

RESULTS

Malten exposure led to a dose-dependent reduction in cell survival in all the neoplastic models studied. Sublethal concentrations of malten induce profound cell cycle changes, particularly affecting the S and/or G2-M phases, whereas exposure to lethal doses causes the induction of programmed cell death. The molecular response to malten was also investigated in JURKAT and U937 cells. It showed the modulation of genes having key roles in cell cycle progression and apoptosis. Finally, as part of the effort to clarify the action mechanism, we showed that malten is able to impair DNA electrophoretic mobility and drastically reduce both PCR amplificability and fragmentation susceptibility of DNA.

CONCLUSION

Taken together, these results show that malten may exert its antiproliferative activity through the induction of complex DNA structural modifications. This evidence, together with the high synthetic versatility of maltol-derived compounds, makes malten an interesting molecular scaffold for the future design of new potential anticancer agents.

Selective changes in the immune profile of tumor-draining lymph nodes after different neoadjuvant chemoradiation regimens for locally advanced cervical cancer

PURPOSE

To assess how neoadjuvant chemoradiation regimens modulate the immune system state in tumor-draining lymph nodes (TDLN), in the setting of advanced cervical cancer.

METHODS AND MATERIALS

Tumor-draining lymph nodes of patients undergoing chemotherapy only (nonirradiated, NI-TDLN) and chemoradiation with lower-dose (39.6 Gy, LD-TDLN) and higher-dose radiation (50 Gy, HD-TDLN) were analyzed by multicolor flow cytometry.

RESULTS

Enlarging our previous data, LD-TDLN showed features overall indicative of an enhanced antitumor response as compared with NI-TDLN, namely a significant Th1 and Tc1 polarization and a lower amount of the potent CD4(+)Foxp3(+)CD25(high) regulatory T cell (Treg) subset identified by neuropilin-1 expression. Conversely, compared with NI-TDLN, HD-TDLN showed features overall indicative of an impaired antitumor response, namely a significantly inverted CD4/CD8 cell ratio, a higher Nrp1(+)Treg frequency, and a higher frequency of CCR4(+)Treg, a Treg subset facilitated in migrating out from TDLN to suppress the immune response against distant cancer cells. Moreover, the Th1 and Tc1 polarization induced by LD radiation was lost, and there was an unfavorable tolerogenic/immunogenic dendritic cell ratio compared with LD-TDLN.

CONCLUSIONS

Even minor differences in radiation dose in neoadjuvant regimens for locally advanced cervical cancer are crucial for determining the balance between a tolerogenic and an efficacious antitumor immune response in TDLN. Because most of the anticancer immune response takes place in TDLN, the present findings also emphasize the importance of chemoradiation protocols in the context of immunotherapeutic trials.

Decitabine, differently from DNMT1 silencing, exerts its antiproliferative activity through p21 upregulation in malignant pleural mesothelioma (MPM) cells

Malignant pleural mesothelioma (MPM) is a locally aggressive neoplasm, principally linked to asbestos fibres exposure. Strong evidences associate this pollutant with induction of DNA breaks, aberrant chromosomes segregation and important chromosomal rearrangements, considered crucial events in malignant transformation. A considerable contribution to cellular transformation in MPM is also given by the presence of high genomic instability, as well as by the increased DNA methylation, and consequent decreased expression, of tumor-suppressor genes. In this study we first demonstrated that MPM cells are characterized by a decreased methylation level of pericentromeric DNA sequences which can justify, at least in part, the genomic instability observed in this neoplasia. Concomitantly, we found a paradoxical increased expression of DNMT1, the most expressed DNA methyltransferases in MPM cells, DNMT3a and all five isoforms of DNMT3b. Thus, we compared two experimental strategies, DNMT1 silencing and usage of a demethylating agent (5-aza-2'-deoxycytidine or Decitabine), both theoretically able to revert the locally hypermethylated phenotype and considered potential future therapeutic approaches for MPM. Interestingly, both strategies substantially decrease cell survival of MPM cells but the antitumor activity of Decitabine, differently from DNMT1 silencing, is mediated, at least in part, by a p53-independent p21 upregulation, and is characterized by the arrest of MPM cells at the G2/M phase of the cell cycle. These results indicate that the two approaches act probably through different mechanisms and, thus, that DNMT1 silencing can be considered an effective alternative to Decitabine for cancer treatment.

Heat shock factor 1 represses estrogen-dependent transcription through association with MTA1

Heat shock factor 1 (HSF1), the transcriptional activator of the heat shock genes, is increasingly implicated in cancer. We have shown that HSF1 binds to the corepressor metastasis-associated protein 1 (MTA1) in vitro and in human breast carcinoma samples. HSF1-MTA1 complex formation was strongly induced by the transforming ligand heregulin and complexes incorporated a number of additional proteins including histone deacetylases (HDAC1 and 2) and Mi2alpha, all components of the NuRD corepressor complex. These complexes were induced to assemble on the chromatin of MCF7 breast carcinoma cells and associated with the promoters of estrogen-responsive genes. Such HSF1 complexes participate in repression of estrogen-dependent transcription in breast carcinoma cells treated with heregulin and this effect was inhibited by MTA1 knockdown. Repression of estrogen-dependent transcription may contribute to the role of HSF1 in cancer.

Mapping the intake of different elements in vegetal tissues by dual-energy X-ray imaging at DaPhine synchrotron light source

This article reports on the first utilization of the soft X-ray beamline at the DaPhine synchrotron light source for mapping the intake of different elements in plant tissues. As a test, the method of dual-energy X-ray microradiography was applied to the investigation of the natural sulfur content in dried leaf and root samples. Our ultimate goal was to monitor the pollutant lead and its intake, which was added in controlled doses to the hydroponic medium of laboratory-controlled samples of vegetal species. The results obtained by the nondestructive X-ray radiographic analysis are compared to the values of concentrations determined by a standard chemical analysis utilizing atomic absorption spectroscopy. From this comparison the validity of the X-ray detection of heavy metals in biological samples has been confirmed. The superposition of the dual energy results on the simple planar radiography shows the representation of the pollutant intake directly on the sample structures. It should be pointed out that this method, developed here for plant root and leaves could be applied to any biological sample of interest, but the preparation and observation conditions necessitate different strategies according to the type of sample under analysis.