Susceptibility-Weighted Angiography for the Follow-Up of Brain Arteriovenous Malformations Treated with Stereotactic Radiosurgery

The criterion standard for assessing brain AVM obliteration postradiosurgery is DSA. To explore the value of susceptibility-weighted angiography, we followed 26 patients with brain AVMs treated by radiosurgery using susceptibility-weighted angiography and DSA. Studies were evaluated by 2 independent readers for residual nidi. Susceptibility-weighted angiography demonstrated good intermodality (κ = 0.71) and interobserver (κ = 0.64) agreement, and good sensitivity (85.7%) and specificity (85.7%). Susceptibility-weighted angiography is a useful radiation- and contrast material-free technique to follow-up brain AVM obliteration postradiosurgery.

Abstract P5-03-11: Sensitivity to cell cycle inhibitors in taxane resistant breast cancer models

Background: The use of anthracycline and taxane chemotherapy has improved overall and disease-free survival in breast cancer. However these agents have significant toxicity. In addition, breast cancers can acquire or possess intrinsic chemoresistance. It is imperative to identify patients who will benefit most from adjuvant taxane treatment and those with resistant tumours who could be spared unnecessary toxicity.

Methods: A panel of in vitro derived cell lines models of taxane resistance were generated by serial culture in escalating doses of either paclitaxel or docetaxel until resistance was achieved. Taxane resistant cells were characterised by 2D growth, cell cycle and apoptosis analyses. Genomic profiling using the NanoString® platform was performed to identify differentially expressed genes. The identification of kinases which target the chemoresistant models was achieved through a small molecule kinase inhibitor screen. Effects of selected target kinases on cell proliferation, cell cycle, apoptosis and protein expression were assessed.

Results:

Resistant cell lines exhibited an IC50 at least 40-fold higher than that of the parental cells and displayed cross-resistance to the non-establishing taxane. Cell cycle analysis revealed taxane treatment failed to induce G2/M arrest in the resistant models. A reduced apoptotic response was demonstrated. Genomic profiling identified pathways associated with the cell cycle as being significantly altered. Dinaciclib, a CDK inhibitor of CDK1, CDK2, CDK5 and CDK9, inhibited taxane resistant cell growth with IC50s comparable to the parental lines. Upon exposure to dinaciclib, cell cycle arrest at G2/M was induced and marked apoptosis demonstrated. A reduction in cyclin B1, PLK1 and pRB was observed by western blotting.

Table 1:Sensitivity of taxane resistant cell lines models to paclitaxel and docetaxelCell line modelPaclitaxel (μM)Docetaxel (μM)MDA-MB-231 Parent0.004 ± 0.0030.002 ± 0.003MDA-MB-231 PACR0.184 ± 0.030.017 ± 0.02MDA-MB-231 DOCR0.414 ± 0.0470.262 ± 0.058MCF7 Parent0.004 ± 0.00050.005 ± 0.001MCF PACR0.769 ± 0.1050.07 ± 0.02

Table 2:Gene ontology enrichment analysis of biological process terms significantly over-represented in MDA-MB-231 PACR cell line modelGO TermP-valueFDRpositive regulation of transcription from RNA polymerase II promoter1.11E-162.44E-13positive regulation of cell proliferation9.99E-161.10E-12activation of cysteine-type endopeptidase activity involved in apoptotic process1.43E-106.27E-08negative regulation of apoptotic process2.13E-095.83E-07extrinsic apoptotic signaling pathway8.33E-091.62E-06cell cycle arrest8.89E-091.62E-06positive regulation of cell migration2.83E-084.42E-06

Conclusion: In this study we identified candidate resistance-associated pathways which were differentially expressed between in vitro derived taxane resistant cell line models and the sensitive parental line. The CDK inhibitor, dinaciclib, demonstrated potent activity against the taxane resistant cell line models. Clinical validation to ascertain the role of dinaciclib as a novel therapeutic in the treatment of chemorefractory breast cancer is required.

Citation Format: Taylor KJ, Lyttle N, Liao L, Gourley C, Cameron DA, Bartlett JM, Spears M. Sensitivity to cell cycle inhibitors in taxane resistant breast cancer models [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-03-11.

Abstract P5-04-24: Molecular stratification of ER+/HER2- breast cancer cell lines to predict sensitivity to targeted agents

Background: Approximately 70% of all breast cancers are estrogen receptor positive (ER+) at diagnosis and are dependent on estrogen signaling for tumour growth and proliferation. Some ER+ breast cancers can be effectively treated with adjuvant endocrine therapies including tamoxifen, but despite favorable improvements in overall survival, resistance to endocrine therapy is common and has been associated with dysregulation of several signaling pathways. These pathways can be targeted with specific inhibitors, many of which are currently under clinical investigation. However currently there is a lack of predictive biomarkers to identify which patients should receive treatment with targeted therapy. The goal of this study was to determine whether alterations in specific signaling pathways can be identified and used to stratify breast cancer cell lines to the most effective experimental treatments.

Methods/Results: Fifteen ER+/HER2- cell lines were characterized using a NanoString PAM50-like assay as well as next generation sequencing and were then stratified according to alterations in three key signaling pathways: CCND/CDK, PI3K/AKT/mTOR and FGFR. High-throughput small-molecule screenings were performed to identify the IC50 values of 24 inhibitors across the strata. Variation in inhibitor sensitivity was observed between cell lines based on molecular alterations. Cell lines with a PIK3CA mutation in combination with a CDK-pathway alteration were more sensitive to CDK inhibitors (50 to 120nM) than cell lines with alterations in the CDK-pathway alone or PIK3CA mutations alone (170nM to >5000nM). In addition, cell lines with the dual alterations demonstrated stronger synergy between CDK and PI3K-pathway inhibitors compared to either alteration alone.

Conclusions: The results suggest that stratification according to molecular alterations in specific signaling pathways may predict sensitivity to targeted inhibitors in a panel of ER+/HER2- luminal breast cancer cell lines. Work is ongoing to identify the optimal synergistic inhibitor combinations for each strata. The ultimate goal is to translate this work into a novel personalized medicine approach, using molecular stratification based on a combination of molecular events in a functional pathway as opposed to single genes.

Citation Format: Bathurst L, Liao L, Crozier C, Lyttle N, Marcellus R, Bayani J, Al-awar R, Bartlett J, Spears M. Molecular stratification of ER+/HER2- breast cancer cell lines to predict sensitivity to targeted agents [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-24.

Abstract P3-11-03: Validation of CIN4 in the DBCG 89D clinical cohort

Background: Chromosome instability (CIN) in solid tumours is associated with poor prognosis and results in numerical and structural chromosomal aberrations. Our group previously have developed the CIN signatures and have demonstrated the CIN signatures as prognostic biomarkers in breast cancer cohorts. Furthermore, our work in the BR9601 and MA.5 clinical cohorts CIN4 provided level IIB evidence that CIN4 was predictive of anthracycline sensitivity. An analysis of the DBCG 89D clinical trial was now performed to validate the role of CIN gene expression signatures as a marker of anthracycline sensitivity.

Methods: RNA was extracted from patients in DBCG 89D clinical trial analysed through NanoString technology. The prognostic and predictive values of the signatures on distant relapse-free survival (DRFS) were explored using Cox proportional hazard models. Multivariate models included menopausal status, tumour size, nodal status, ER and Her2 status, histological type and grade, and treatment regimen.

Results: All of the 594 samples available from the DBCG 89D we successfully analysed. CIN25 and CIN70 gene expression signatures did not associate with any of the clinicopathological characteristics tested. In addition, CIN25 and CIN70 were not prognostic or predictive of distant relapse free or breast cancer specific survival in this clinical cohort. Low CIN4 score was associated with ER negativity (p=0.02), HER2 normal expression (p<0.05).

Conclusion: In this study we demonstrated that CIN4 was associated with aggressive disease. We were however in DBCG 89D unable to validate the predictive value of CIN4 concerning anthracycline sensitivity.

Citation Format: Spears M, Jensen M-B, Lyttle N, Liao L, Laenkholm A-V, Ejitlertsen B, Bartlett JM. Validation of CIN4 in the DBCG 89D clinical cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-11-03.

Observation of a Space-Time Crystal in a Superfluid Quantum Gas

Time crystals are a phase of matter, for which the discrete time symmetry of the driving Hamiltonian is spontaneously broken. The breaking of discrete time symmetry has been observed in several experiments in driven spin systems. Here, we show the observation of a space-time crystal using ultracold atoms, where the periodic structure in both space and time is directly visible in the experimental images. The underlying physics in our superfluid can be described ab initio and allows for a clear identification of the mechanism that causes the spontaneous symmetry breaking. Our results pave the way for the usage of space-time crystals for the discovery of novel nonequilibrium phases of matter.

Abstract P2-10-01: Validation that a histone gene signature predicts anthracycline response in early breast cancer

Background: The use of anthracycline-based chemotherapies has improved overall and disease free survival in breast cancer. However, anthracyclines can have significant toxicities including cardiotoxicity and leukemia. It is, therefore, imperative to identify those patients who will benefit from adjuvant anthracycline treatment and patients who could be spared unnecessary toxicities and be considered for alternative adjuvant therapy. Previous work performed by our laboratory identified a histone gene expression signature as a predictive marker of anthracycline benefit in the BR9601 clinical trial. In this study we validate the 18 histone gene signature in the MA.5 clinical trial and examine the role of the signature in individual intrinsic subtypes of breast cancer.

Methods We analysed the CCTG MA.5 clinical trial in a prospectively planned retrospective biomarker approach to validate this signature and tested the role of intrinsic subtyping as predictive markers of anthracycline benefit. RNA was extracted from patients in the MA.5 adjuvant trial evaluating the addition of epirubicin (E) to CMF and analysed using NanoString technology. Log-rank analyses validated the predictive values of the signature on distant relapse-free survival (DRFS). Cox-regression models tested independent predictive value on DRFS in the presence of treatment, age, tumour size, nodal status, HER2, ER status and grade, and treatment by marker interactions.

Results Analysis of the MA.5 clinical cohort revealed that patients whose tumour had low histone gene signature expression experienced increased DRFS (HR: 0.54, 95% CI 0.38-0.76, p=0.001) when treated with CEF compared with patients treated with CMF alone. Conversely, there was no apparent benefit of CEF vs CMF in patients with high histone gene expression signature (HR: 1.01, 95%CI 0.66-1.55, p=0.963). After multivariate analysis and adjustment for HER2, nodal status, age, grade and ER, the treatment by marker interaction for the gene signature was 0.54 (95%CI 0.31-0.94, p=0.030) for DRFS.

The predictive impact of the histone signature was independent of intrinsic subtype.

Conclusion The histone gene expression signature is an independent predictor of anthracycline benefit and could be a potential candidate diagnostic assay for patients with early breast cancer.

Citation Format: Spears M, Kornaga E, Lyttle N, Liao L, Bayani J, Quintayo M-A, Yao CQ, D'Costa A, Boutros PC, Twelves CJ, Pritchard KI, Levine MN, Nielsen TO, Shepherd L, Bartlett JMS. Validation that a histone gene signature predicts anthracycline response in early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-10-01.

Abstract P2-10-04: Targeted sequencing in early breast cancer: Identification of novel candidate mutations predictive of anthracycline benefit

Background The use of chemotherapies such as anthracyclines and taxanes have improved overall and disease free survival in breast cancer. For all patients, anthracyclines can have significant toxicities including cardiotoxicity and leukemia. It is therefore essential to select the subset of patients who will receive the optimal overall benefit from anthracycline therapy and to identify molecular pathways driving resistance. To fully understand the impact of mutations in the context of current breast cancer therapy, requires a comprehensive mapping of key molecular events in the context of treatment. We sequenced 101 genes, that were prioritized based on not only gene frequency, but also taking into account the importance of amino acid substitution, type of mutation and network connectivity, in 692 primary tumours to both identify driver genes and pathway cassettes and to understand their clinical significance in response to anthracycline treatment.

Methods We performed targeted sequencing in patients from the BR9601 (n=374) and CCTG MA.5 (n=703) clinical trials. The BR9601 and MA.5 clinical trials examined the effectiveness of combination chemotherapy consisting of CMF (cyclophosphamide, methotrexate and 5-fluorouracil) with or without epirubicin. DNA was extracted, samples were sequenced using AmpliSeq Technology adapted to Illumina and somatic mutations were called using a novel mutation calling pipeline (ISOWN). A priori analyses were performed using distant recurrence free survival (DRFS) as the primary endpoint.

Results: In 692 successfully analysed samples 509 (73.6%) samples exhibited at least one single nucleotide mutation (range 0-54). 94/101 genes were mutated in at least one patient. Only variants in PIK3CA, TP53, CDH1, TLE6, MLL3 and USH2A were detected in 5% or more of samples. TSC22D1, RB1 and ZNF565 were associated with increased risk of distant relapse in multivariate analyses corrected for clinic-pathological variables. No single genes were predictive of anthracycline treatment compared to CMF in multivariate analyses corrected for clinic-pathological variables. Signaling cassettes/modules were designed based on the pathway database, Reactome. Within the signaling cassettes one module was predictive of anthracycline failure. Patients with one or more mutations in this module had an increased risk of distant relapse (HR 0.52, 95% CI 0.29-0.95, p=0.034) when treated with an anthracycline containing chemotherapy regimen compared to CMF (HR 1.34 95% CI 1.05-1.72, p=0.019).

Conclusions: We successfully performed a signaling pathway-based targeted sequencing analysis within predefined signaling modules. We identified a single signaling cassette linked to anthracycline resistance in early breast cancer. However, further work to validate this study in a separate clinical trial is warranted.

Citation Format: Spears M, Kalatskaya I, Trinh QM, Liao L, Chong TM, Crozier C, Dion D, Heisler L, Timms L, Stein LD, Pritchard KI, Levine MN, Shepherd L, Twelves CJ, Bartlett JMS. Targeted sequencing in early breast cancer: Identification of novel candidate mutations predictive of anthracycline benefit [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-10-04.

Osteochondral Interface Stiffening in Mandibular Condylar Osteoarthritis

Osteoarthritis (OA) of the temporomandibular joint (TMJ) is associated with dental biomechanics. A major change during OA progression is the ossification of the osteochondral interface. This study investigated the formation, radiological detectability, and mechanical property of the osteochondral interface at an early stage, the pathogenesis significance of which in OA progression is of clinical interest and remains elusive for the TMJ. Unilateral anterior crossbite (UAC) was performed on 6-wk-old rats as we previously reported. TMJs were harvested at 4, 12, and 20 wk. The progression of TMJ OA was evaluated using a modified Osteoarthritis Research Society International (OARSI) score system. Osteochondral interface was investigated by quantifying the thickness via von Kossa staining of histological slices and in vivo calcium deposition by calcein injection. Tissue ossification was imaged by micro-computed tomography (CT). Mechanical properties were measured at nanoscale using dynamic indentation. Time-dependent TMJ cartilage lesions were elicited by UAC treatment. Geometric change of the condyle head and increased value of the OARSI score were evident in UAC TMJs. At the osteochondral interface, there was not only enhanced deep-zone cartilage calcification but also calcium deposition at the osseous boundary. The thickness, density, and stiffness of the osteochondral interface were all significantly increased. The enhanced ossification of the osteochondral interface is a joint outcome of the aberrant deeper cartilage calcification at the superior region and promoted formation of subchondral cortical bone at the inferior region. The micro-CT detectable ossification from an early stage thus is of diagnostic significance. Although the environment of the cartilage and subchondral bone could be changed due to the stiffness of the interface, whether or not the stiffened interface would accelerate OA progress remains to be confirmed. With that evidence, the osteochondral interface could be a new diagnostic and therapeutic target of the mechanically initiated OA in the TMJ.

Shapes and Fissility of Highly Charged and Rapidly Rotating Levitated Liquid Drops

We use diamagnetic levitation to investigate the shapes and the stability of free electrically charged and spinning liquid drops of volume ∼1 ml. In addition to binary fission and Taylor cone-jet fission modes observed at low and high charge density, respectively, we also observe an unusual mode which appears to be a hybrid of the two. Measurements of the angular momentum required to fission a charged drop show that nonrotating drops become unstable to fission at the amount of charge predicted by Lord Rayleigh. This result is in contrast to the observations of most previous experiments on fissioning charged drops, which typically exhibit fission well below Rayleigh's limit.

Steroid receptor coactivator-1 can regulate osteoblastogenesis independently of estrogen

Steroid receptor coactivator-1 (SRC-1), a well-studied coactivator of estrogen receptor (ER), is known to play an important and functional role in the development and maintenance of bone tissue. Previous reports suggest SRC-1 maintains bone mineral density primarily through its interaction with ER. Here we demonstrate that SRC-1 can also affect bone development independent of estrogen signaling as ovariectomized SRC-1 knockout (SRC-1 KO) mouse had decreased bone mineral density. To identify estrogen-independent SRC-1 target genes in osteoblastogenesis, we undertook an integrated analysis utilizing ChIP-Seq and mRNA microarray in transformed osteoblast-like U2OS-ERα cells. We identified critical osteoblast differentiation genes regulated by SRC-1, but not by estrogen including alkaline phosphatase and osteocalcin. Ex vivo primary culture of osteoblasts from SRC-1 wild-type and KO mice confirmed the role of SRC-1 in osteoblastogenesis, associated with altered ALPL levels. Together, these data indicate that SRC-1 can impact osteoblast function in an ER-independent manner.

Improvement in detrusor-sphincter dyssynergia by bladder-wall injection of replication-defective herpes simplex virus vector-mediated gene delivery of kynurenine aminotransferase II in spinal cord injury rats

STUDY DESIGN

An experimental study.

OBJECTIVES

To investigate the effect of replication-defective herpes simplex virus (HSV) vectors encoding the kynurenine aminotransferase II (HSVrd-KATII) gene on detrusor-sphincter dyssynergia (DSD) in spinal cord injury (SCI) rats.

SETTING

Beijing, China.

METHODS

Sprague-Dawley rats (240-265 g) were spinalized with complete transaction at the T10 level of the spinal cord. The rats were randomly divided into the following three groups: sham group (n=12, with normal saline); HSVrd group (n=12, with HSVrd) and HSVrd-KATII group (n=12, with HSVrd-KATII). One week after spinalization normal saline, HSVrd or HSVrd-KATII was injected into the bladder walls of the three groups, respectively. Three weeks after virus injection, the urethral pressure profile (UPP) and continuous cystometry were performed under awake conditions and gene expression was evaluated in all of the SCI rats.

RESULTS

In the HSVrd-KATII group, the maximum urethral closure pressure (Pclo.max), maximum voiding pressure (MVP), and the number and amplitude of non-voiding contraction (NVCs) were significantly decreased (34.7-39.1%, 46.7-56.2% and 31.5-32.5%, respectively), along with an increase in voiding efficiency (49.1-52.1%) compared with the sham and HSVrd groups. In addition, the levels of KATII protein and mRNA were significantly increased in the L6-S1 dorsal root ganglia (DRG) and L6-S1 spinal cord segments in the HSVrd-KATII group compared with the HSVrd group.

CONCLUSIONS

HSVrd vector encoding the KATII gene effectively improved DSD and detrusor overactivity by bladder-wall injection, perhaps by blocking N-methyl-d-aspartate receptors in the L6-S1 dorsal root ganglion and L6-S1 spinal cord.

Twist1 promotes breast cancer invasion and metastasis by silencing Foxa1 expression

The heterogeneous breast cancers can be classified into different subtypes according to their histopathological characteristics and molecular signatures. Foxa1 expression is linked with luminal breast cancer (LBC) with good prognosis, whereas Twist1 expression is associated with basal-like breast cancer (BLBC) with poor prognosis owing to its role in promoting epithelial-to-mesenchymal transition (EMT), invasiveness and metastasis. However, the regulatory and functional relationships between Twist1 and Foxa1 in breast cancer progression are unknown. In this study, we demonstrate that in the estrogen receptor (ERα)-positive LBC cells Twist1 silences Foxa1 expression, which has an essential role in relieving Foxa1-arrested migration, invasion and metastasis of breast cancer cells. Mechanistically, Twist1 binds to Foxa1 proximal promoter and recruits the NuRD transcriptional repressor complex to de-acetylate H3K9 and repress RNA polymerase II recruitment. Twist1 also silences Foxa1 promoter by inhibiting AP-1 recruitment. Twist1 expression in MCF7 cells silenced Foxa1 expression, which was concurrent with the induction of EMT, migration, invasion and metastasis of these cells. Importantly, restored Foxa1 expression in these cells largely inhibited Twist1-promoted migration, invasion and metastasis. Restored Foxa1 expression did not change the Twist1-induced mesenchymal cellular morphology and the expression of Twist1-regulated E-cadherin, β-catenin, vimentin and Slug, but it partially rescued Twist1-silenced ERα and cytokeratin 8 expression and reduced Twist1-induced integrin α5, integrin β1 and MMP9 expression. In a xenografted mouse model, restored Foxa1 also increased Twist1-repressed LBC markers and decreased Twist1-induced BLBC markers. Furthermore, Twist1 expression is negatively correlated with Foxa1 in the human breast tumors. The tumors with high Twist1 and low Foxa1 expressions are associated with poor distant metastasis-free survival. These results demonstrate that Twist1's silencing effect on Foxa1 expression is largely responsible for Twist1-induced migration, invasion and metastasis, but less responsible for Twist1-induced mesenchymal morphogenesis and expression of certain EMT markers.

Oral Food Challenges: A Retrospective Review of A Canadian Paediatric Allergy Clinic

BACKGROUND: Food allergies in children can be life threatening and require prompt treatment with epinephrine. The gold standard for food allergy diagnosis is an Oral Food Challenge (OFC).

OBJECTIVES: To demonstrate the safety of OFCs for diagnosing and monitoring food allergies in a Canadian community paediatric population.

DESIGN/METHODS: Retrospective review of 500 paediatric patients that underwent 684 OFCs to a variety of foods from November 2006 to December 2013. Data collected from the patients includes demographics; the food challenged; reasons for the OFC; reactions experienced during the OFC; medical intervention performed; and whether the patient should continue eating the food challenged (OFC success). Anaphylaxis was defined using the World Allergy Organization criteria – i.e. dermatologic and cardiovascular or respiratory involvement after food ingestion; or two of dermatologic, cardiovascular, respiratory or gastrointestinal involvement after a likely allergen; or cardiovascular involvement after a known allergen. Mild reactions involved only 1 non-cardiovascular system; and moderate reactions involved more than 1 non-cardiovascular system, but did not qualify as anaphylaxis. Systems observed included the dermatologic, upper and lower respiratory, gastrointestinal, cardiovascular, and behavioural systems.

RESULTS: Of the 684 OFCs performed, there were 584 OFCs (85.4%) where the patients were successful at eating the food. Reactions occurred in 274 of 684 OFCs (40.1%), including 161 mild reactions (58.8% of reactions), 56 moderate reactions (20.4% of reactions), and 57 anaphylactic reactions (20.8% of reactions). Medical intervention was required in 74 OFCs (27.0% of reactions). All OFCs with no reaction were successful and all OFCs with anaphylaxis were not successful. OFCs with mild and moderate reactions had equivalent odds of being successful (OR [95% CI] = 0.01 [0.0003, 0.08] and 0.006 [0.0001, 0.04], respectively). Most reactions occurred within six hours of exposure to the food (267 of 274 reactions; 97.4%). The most common foods challenged were peanuts, eggs, and cow’s milk. The reasons for the OFCs were to diagnose an allergy (49.7%), monitor outgrowth of a diagnosed allergy (43.7%), or due to a family member having an allergy (6.6%).

CONCLUSION: In this community practice setting, patients undergoing an OFC were able to eat the food afterwards in 85.4% of the cases. Reactions occurred in 40.1% of OFCs. Anaphylaxis occurred in 8.3% of OFCs (57 of 684 OFCs). Most patients reacted within six hours of exposure. The majority of patients undergoing OFCs did not require treatment. OFCs provide a safe environment to diagnose and monitor food allergies in children.

Effects of grafting on key photosynthetic enzymes and gene expression in the citrus cultivar Huangguogan

Grafting influences scion photosynthetic capacity and fruit quality. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), which strongly affects photosynthetic rate, and Rubisco activase (RCA), which regulates Rubisco activity, are two key photosynthetic enzymes. However, little information is available regarding the effect of grafting on the concentration and expression of Rubisco and RCA in the citrus cultivar Huangguogan. The objective of this study was to investigate the effect of grafting Huangguogan plants onto trifoliate orange, tangerine, and orange on: 1) the concentration of Rubisco and RCA; 2) the mRNA levels of rbcL, rbcS, and rca; and 3) fruit quality. Overall, the results showed that when Huangguogan plants budded on tangerine and orange, they had better fruit quality, while on trifoliate orange they had higher Rubisco concentration. Tangerine and orange are probably the most suitable rootstocks for Huangguogan plants given the environmental conditions of Sichuan Province, China.

Abstract P2-05-23: TWIST1 silences FOXA1 transcription to promote breast cancer progression

TWIST1 promotes epithelial-mesenchymal transition (EMT), invasion and metastasis of breast cancer cells, but the underlying mechanism is still not well understood. We generated mammary gland tumor specific Twist1 knock out mouse model and found that TWIST1 does not affect PyMT-induced mammary tumor initiation and growth but promotes tumor lung metastasis. We identified FOXA1 as a novel direct target of TWIST1 in both mouse and human breast cancer. We further found that TWIST1 inhibits FOXA1 expression through direct binding to its proximal promoter region and recruiting Mi2/nucleosome remodeling and deacetylase (Mi2/NuRD) transcriptional repressor complex. Moreover, TWIST1 also diminished transcriptional activator AP1 binding to FOXA1 promoter. TWIST1 mediated FOXA1 down-regulation is essential for promoting breast cancer migration, invasion and metastasis. FOXA1 significantly inhibits TWIST1 dependent cell migration and invasion capability of MCF7 cells through inhibiting integrin α5, β1 and MMP9 expression. Importantly, TWIST1high FOXA1low correlates with the poorest prognosis in breast cancer patients.

Citation Format: Xu Y, Feng Z, Xu Y, Mo Q, Qin L, Sun T, Wu H, Li Y, Liao L, Xu J. TWIST1 silences FOXA1 transcription to promote breast cancer progression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-23.