Abstract P2-01-13: The splicing factor PHD finger protein 5A inhibits apoptosis to promote breast cancer progression

Background: All the widely accepted hallmarks of cancer are known to be affected by aberrant splicing (AS), and splicing dysregulation itself is considered a valuable therapeutic target. Understanding the AS that promote cancer progression is crucial for the development of effective strategies for treating breast cancer.

Methods: An in vivo CRISPR screen targeting RNA-binding proteins (RBPs) was performed to reveal the key splicing modulator (PHD finger protein 5A, PHF5A) of breast tumor progression. Immunohistochemistry method and survival analysis were performed using a tissue microarray (TMA) containing 450 breast carcinoma. Proliferation, transwell migration and in vivo tumor formation assays were utilized to assess the biological role of PHF5A. RNA sequencing and RT-PCR assay were used to identify PHF5A-regulated AS events in breast cancer cells. Biological functions and molecular pathways of the affected genes were investigated through a gene ontology (GO) analysis. Flow cytometry and Western blot analysis were used for apoptotic assessments. The correlation between PHF5A expression and AS events was further analysed using mRNA-Seq data of 40 paired breast cancer and adjacent normal breast tissues. And the correlation between the levels of PHF5A and cleaved caspase-3 were evaluated in the TMA.

Results: According to RNA sequencing analysis of MCF10 cell series (MCF10A, MCF10AT, MCF10DCIS and MCF10CA1a), 159 RBPs were found to be up-regulated in cancer cells compared with non-cancer cells. And the CRISPR screen targeting these 159 RBPs systematically identified highest-ranking genes including PHF5A. In TMA cohort, high PHF5A expression was correlated with poor disease-free survival. PHF5A is frequently up-regulated in breast cancer and is essential for cancer cell proliferation, migration and tumor formation. Knockdown of PHF5A induces genome-wide AS events. The RT-PCR assay of MCF10CA1a cells showed that splicing changes of nine arbitrarily selected target genes were all modulated by PHF5A. GO analysis showed that PHF5A-regulated AS events were involved in apoptotic and anti-apoptotic pathways, among which FAS-activated serine/threonine kinase (FASTK) AS showed significant PSI (percent spliced in) difference. PHF5A knockdown appeared to switch full-length FASTK (FASTK-L) to an intron 5-retained variant (herein termed FASTK short, FASTK-S) in MCF10CA1a cells. The knockdown of PHF5A resulted in cleavage of caspase-3 and poly-ADP-ribose polymerase and conversion of the FASTK-L (61 kDa) and FASTK-S (42 kDa) proteins. Intriguingly, cells transduced with exogenous FASTK-S showed the most significant apoptotic effect, whereas the FASTK-L group presented a decreased apoptotic effect. The PHF5A ratios of paired non-tumor to tumor tissue were negatively correlated with the FASTK PSI differences between non-tumor and tumor tissues. A strong negative correlation was found between the PHF5A and cleaved caspase-3 levels in TMA.

Conclusions: PHF5A depletion sensitizes cancer cells to apoptotic signaling partially through AS-mediated FASTK isoform conversion. This apoptotic suppressor plays a key role in breast cancer progression and acts as a prognostic indicator, and should be critically considered for optimization of the current therapeutic strategy.

Citation Format: Zheng Y-Z, Xue M-Z, Shen H-J, Li X-G, Ma D, Gong Y, Hu X, Shao Z-M. The splicing factor PHD finger protein 5A inhibits apoptosis to promote breast cancer progression [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 P2-01-13.

Abstract P3-08-11: Multi-omics profiling reveals distinct molecular features in young and elderly triple negative breast cancer

Purpose

Age at breast cancer diagnosis not only predicts clinical outcome, but also indicates distinct molecular features thus we can choose the most appropriate treatment strategies. Yet little is known about the molecular profile of young and elderly triple negative breast cancers (TNBCs).

Methods

Clinical, genomic and transcriptome features of young (<40 year-olds) and elderly (≥65 year-olds) TNBC patients were studied in a cohort of 473 TNBCs from Fudan University Shanghai Cancer Center.

Results

In this study, 50, 354 and 69 patients were <40, 40–64 and ≥65 years of age, respectively. Young TNBCs had more relapse or metastasis within the first 2 years after surgery (P=0.036) which was also significant in the basal-like subgroup (P=0.004), while elderly TNBCs were more likely to be luminal androgen receptor (LAR) subtype (46%) harboring frequent PIK3CA and KMT2C/KMT2D somatic mutations, with more fibrosis or mesenchymal-like (MES) subtype (in the basal-like subgroup) and featured by significantly lower Ki-67 index. Gene set enrichment analyses revealed that young TNBCs showed elevated expression of genes involved in cell cycle, nucleotide metabolism and DNA damage repair. In further discussion on nucleotide metabolism, TYMS, a crucial gene encoding thymidylate synthase while is also the target of fluorouracil and capecitabine, were identified to be enriched in young TNBCs independent of molecular subtype in both our cohort (adjusted P<0.001) and METABRIC (adjusted P=0.027). We next studied DNA damage features and found that while TNBCs of different age groups had comparable somatic mutation load, their mutations had distinct generation mechanism that homologous recombination deficiency (HRD) related signature and Aging related signature tend to be enriched in younger and elder patients, respectively. We also observed higher germline BRCA1 mutation rate in young TNBCs (23%). Interestingly, while germline BRCA2 mutation rate was comparable among the groups, copy number (CN) loss of Chr13q13 (with BRCA2 in the 'peak') was almost exclusively found in young patients (adjusted P<0.05). We also found enriched CN loss at Chr15q13 (with FAN1 in the 'peak') and CN amplification at Chr1p34 (with KDM4A in the 'peak') in young patients. These two events significantly affected the expression levels of FAN1 and KDM4A, respectively, and were both corrected with genomic based HRD indexes.

Conclusions

TNBCs of different age had distinct clinical and molecular features. We should pay attention to that nearly half of the TNBCs diagnosed at 65 years-old or later were not basal-like cancers but a special group with positive AR staining. Taking together with the higher fibrosis/MES proportion in elderly TNBC, we should reconsider the benefit of specific treatment strategies (like neoadjuvant chemotherapy) in these patients. The young TNBCs were characterized by activated cell cycle, elevated nucleotide metabolism (especially TYMS expression and corresponding pyrimidine metabolism) and enhanced DNA damage (especially HRD). These molecular features supported the aggressive phenotypes of young TNBC, while also provide us with potential therapeutic strategies.

Citation Format: Ma D, Jiang Y-Z, Xie M-D, Xiao Y, Zhao S, Shao Z-M. Multi-omics profiling reveals distinct molecular features in young and elderly triple negative breast cancer [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 P3-08-11.

Abstract P3-07-07: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Jiang Y-Z, Ma D, Suo C, Shi J, Xue M, Stover DG, Verschraegen C, Kaklamani V, Wang P, Shi L, Huang W, Shao Z-M. Withdrawn [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 P3-07-07.

Abstract P4-06-24: Microenvironment heterogeneity of triple-negative breast cancer reveals distinct immune escape mechanisms and potential driver events

Background The microenvironment phenotypes strongly affect the immunotherapeutic strategies for triple-negative breast cancer (TNBC). Although the multi-omics profile of TNBC has been comprehensively characterized, few studies have focused on the microenvironment phenotypes of TNBC.

Methods With multi-omics data for the largest single-center TNBC cohort (n=386), we first established a TNBC-specific microenvironment cell signature. We further used single sample gene set enrichment analysis to calculate the relative number of microenvironment cell subsets in each sample. Then, we performed k-means clustering to classify the TNBC microenvironment phenotypes into heterogeneous clusters. Furthermore, we systematically analyzed the extrinsic and intrinsic immune escape mechanisms of different TNBC microenvironment clusters. In addition, we explored genomic alterations that might decrease immune infiltration in certain TNBC microenvironment clusters.

Results We classified the TNBC microenvironment phenotypes into three heterogeneous clusters. Cluster 1 (type 1 “cold tumor”) had low microenvironment cells infiltration. Cluster 2 (type 2 “cold tumor”) was characterized by resting innate immune cells, fibroblasts and endothelial cells infiltration. Cluster 3 (“hot tumor”) was featured by adaptive immune cells infiltration. Analysis of immune escape mechanism revealed that an incapability to attract innate immune cells (resulting in failure of adaptive immunity) led to immune escape of cluster 1. The chemotaxis but inactivation of innate immunity (also leading to failure of adaptive immunity) and low tumor antigen burden resulted in immune escape of cluster 2. High expression of immune checkpoint molecules contributed to immune escape of cluster 3. In addition, we found that tumor infiltrating lymphocytes (TILs) were positively correlated with immune checkpoint molecules expression, while mutation load was negatively correlated with those indicators in triple-negative breast cancer. Analysis of enrichment pathways, mutations and somatic copy number variations between the “cold tumor” and “hot tumor” clusters revealed that amplification of MYC and activation of MYC-related pathways might decrease the immune infiltration of cluster 1. Mutations in PI3K-AKT pathway members and activation of fibroblasts-related pathways might decrease the immune infiltration of cluster 2.

Conclusion Utilizing the largest single-center TNBC cohort with multi-omics data, our study first revealed the heterogeneity of the TNBC microenvironment, with translational significance both clinically and biologically. First, we identified a subtype of “hot tumor” in TNBC (cluster 3), for which immune checkpoint blockers (ICBs) might be effective. TILs and immune checkpoint molecules expression but not mutation load might predict the efficacy of ICBs. Second, we presumed some genomic alterations that might drive “cold tumor” formation in TNBC. Our study represents a step toward personalized immunotherapy for TNBC patients.

Key Words triple-negative breast cancer, multi-omics, microenvironment heterogeneity, immune escape

Citation Format: Xiao Y, Ma D, Zhao S, Jiang Y-Z, Shao Z-M. Microenvironment heterogeneity of triple-negative breast cancer reveals distinct immune escape mechanisms and potential driver events [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 P4-06-24.

Abstract P2-08-33: A novel seven-gene signature predicts prognosis in early-stage triple-negative breast cancer

Purpose:

Chemotherapy remains the only systemic treatment option for patients with triple-negative breast cancer (TNBC). However, due to the heterogeneity of TNBC, not all patients benefit from chemotherapy, especially those with early-stage disease. In order to improve prognostic assessment and reduce unnecessary adjuvant systemic therapy in these patients, we have developed a novel seven-gene signature.

Experimental Design:

With the ComBat method, we integrated the results from 150 transcriptome microarrays samples and 246 RNA-seq samples of early-stage TNBC patients, and identified mRNAs associated with recurrence-free survival (RFS) using Lasso-Cox model, We further analyzed these TNBC samples and compared them with 60 paired normal breast tissues (40 samples from RNA-seq and 20 samples from microarrays) to identify tumor-specific mRNAs. Twenty-one overlapped mRNAs of the RFS-associated mRNAs and the tumor-specific mRNAs are selected as candidate mRNAs. An additional 371 samples of frozen primary tumors were then collected from early-stage TNBC patients (mean follow-up of 45 months) and randomly divided into two sets: a training set (n = 186) and a validation (n = 185) set. Expression level of candidate mRNAs in these samples were measured using RT-qPCR assays, and a seven-gene signature was built through all subset regression in the training set. The prognostic and predictive accuracy of our signature was tested in the validation set and other public databases (GSE5327, GSE2034 and METABRIC).

Results:

Twenty-one candidate mRNAs were identified in early-stage TNBC patients, from which we developed a novel seven-gene signature (recurrence risk score [mRNA signature] = 1.108*TMEM101 - 0.213*KRT5 - 0.315*ACAN - 0.464*LCA5 + 0.446*RPP40 - 0.373*LAGE3 - 0.257*CDKL2). Patients in the training set were classified into high- or low-risk group based on our seven-gene signature and an optimum cut-off score derived from x-tile. The patients in high-risk group were more likely to suffer from recurrence (HR, 2.718; 95% confidence interval [CI], 1.928–3.726, P= 0.001), and a time-dependent receiver operating curve showed that the seven-gene mRNA signature had a better prognostic value than the clinicopathologic risk factors in both training set and validation set. The prognostic and predictive accuracy of the signature was also validated in the METABRIC and two other public GEO databases (GSE5327 and GSE2034). The time-dependent receiver operating curve showed that this signature had an area under the curve (AUC) of 0.742 (95% CI, 0.705-0.773) in METABRIC, 0.716 (95% CI, 0.682-0.739) and 0.723 (95% CI, 0.683-0.756) in GSE5327 and GSE2034 respectively.

Conclusion:

In this study, we developed a novel seven-gene signature which can provide additional prognostic information and may guidance in identifying early-stage TNBC patients eligible for adjuvant therapy or reduction of chemotherapy. To our knowledge, this is the first study investigating the prognostic potential of mRNA signature in early-stage triple-negative breast cancer. Our novel signature may provide an opportunity for de-escalating treatment in early-stage TNBC patients in the future.

Citation Format: Ren Y, Jiang Y, Zuo W, Xu X, Jin X, Ma D, Shao Z. A novel seven-gene signature predicts prognosis in early-stage triple-negative breast cancer [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 P2-08-33.

Dexmedetomidine enhances ropivacaine-induced sciatic nerve injury in diabetic rats

BACKGROUND

Previous studies suggest that dexmedetomidine has a protective effect against local anaesthetic-induced nerve injury in regional nerve blocks. Whether this potentially protective effect exists in the context of diabetes mellitus is unknown.

METHODS

A diabetic state was established in adult male Sprague-Dawley rats with intraperitoneal injection of streptozotocin. Injections of ropivacaine 0.5%, dexmedetomidine 20 μg kg^-1 (alone and in combination), or normal saline (all in 0.2 ml) were made around the sciatic nerve in control and diabetic rats (n=8 per group). The duration of sensory and motor nerve block and the motor nerve conduction velocity (MNCV) were determined. Sciatic nerves were harvested at post-injection day 7 and assessed with light and electron microscopy or used for pro-inflammatory cytokine measurements.

RESULTS

Ropivacaine and dexmedetomidine alone or in combination did not produce nerve fibre damage in control non-diabetic rats. In diabetic rats, ropivacaine induced significant nerve fibre damage, which was enhanced by dexmedetomidine. This manifested with slowed MNCV, decreased axon density, and decreased ratio of inner to outer diameter of the myelin sheath (G ratio). Demyelination, axon disappearance, and empty vacuoles were also found using electron microscopy. An associated increase in nerve interleukin-1β and tumour necrosis factor-α was also seen.

CONCLUSIONS

Ropivacaine 0.5% causes significant sciatic nerve injury in diabetic rats that is greatly potentiated by high-dose dexmedetomidine. Although the dose of dexmedetomidine used in this study is considerably higher than that used in clinical practice, our data suggest that further studies to assess ropivacaine (alone and in combination with dexmedetomidine) use for peripheral nerve blockade in diabetic patients are warranted.

Preoperative vitamin D deficiency increases the risk of postoperative cognitive dysfunction: a predefined exploratory sub-analysis

BACKGROUND

Vitamin D is important for maintaining physiological functions including cognition and its deficiency is associated with the occurrence of cognitive impairment. This study was to explore the association between preoperative vitamin D status and the occurrence of postoperative cognitive dysfunction (POCD) in elderly patients undergoing major surgery.

METHODS

This was a predefined exploratory sub-analysis of one-centre data from a randomized controlled trial. In all, 123 elderly (≥ 65 years) patients who were scheduled to undergo major cancer surgery were recruited. Serum 25-hydroxyvitamin D concentration was measured before surgery. In total, 59 nonsurgical control subjects with comparable age and education level were also enrolled. A battery of neuropsychological tests was administered the day before and the 7th day after surgery in patients or at the same time interval in control subjects. POCD was diagnosed according to the ISPOCD1 definition.

RESULTS

71.5% (88/123) of elderly patients had vitamin D deficiency (serum 25-hydroxyvitamin D concentration < 12 ng/ml) before surgery; 24.4% (30/123) of them developed cognitive dysfunction at 1 week after surgery. After adjusting for confounding factors, high preoperative serum 25-hydroxyvitamine D concentration was related to a decreased risk of POCD (odds ratio [OR]: 0.829, 95% confidence interval [CI]: 0.708-0.971; P = 0.020), whereas preoperative vitamin D deficiency was associated with an increased risk of POCD (OR: 8.427, 95% CI: 1.595-44.511; P = 0.012).

CONCLUSIONS

Vitamin D deficiency is prevalent in elderly patients undergoing major cancer surgery and increases the risk of early POCD development. Whether prophylactic vitamin D supplementation can reduce POCD in the elderly deserves further study.

Antioxidant effect of glutathione on promoting 2-keto-l-gulonic acid production in vitamin C fermentation system

AIMS

Oxidative stress limited the growth of cells and 2-keto-l-gulonic acid (2-KGA) production in vitamin C (Vc) fermentation system. The study aims to investigate the antioxidant effect of glutathione on promoting 2-KGA in Vc fermentation system using Ketogulonicigenium vulgare 25B-1 and Bacillus endophyticus ST-1 as the co-culturing microbes.

METHODS AND RESULTS

The activities of antioxidant-related enzymes and qPCR were used to study the antioxidant effect of glutathione addition in Vc fermentation system. The addition of GSH and GSH/GSSG increased 2-KGA production and decreased fermentation time, and the highest 2-KGA production increased by 40·63% and the lowest fermentation time shortened to 60 h when the addition of optimal concentration ratio of GSH/GSSG was 50 : 1. Moreover, the increased production of 2-KGA was accompanied by up-regulated the activities of total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), catalase (CAT) and over-expressed oxidative stress-related genes sod, gst, gr, zwf, gp, which resulted in scavenging reactive oxygen species to reduce oxidative stress in Vc fermentation system.

CONCLUSIONS

Glutathione showed a significant effect on increasing 2-KGA production and decreasing fermentation time in Vc fermentation system. GSH/GSSG could maintain a dynamic balance with two forms of glutathione and the optimal concentration ratio of GSH/GSSG was 50 : 1.

SIGNIFICANCE AND IMPACT OF THE STUDY

Glutathione is proved to be effective to relieve oxidative stress. The promotion effects of GSSG and GSH on 2-KGA production could help to further explore the optimization of co-culture fermentation process for Vc industrial production.

Copy Number Variations with Isolated Fetal Ventriculomegaly

BACKGROUND

Copy Number Variations (CNVs) are an important genetic cause of a number of neurodevelopmental disorders (NDs). However, the association between CNVs and the development and prognosis of fetal isolated mild ventriculomegaly (IMV) is unclear.

OBJECTIVES

To investigate possible associations between CNVs and the development of fetal IMV.

METHODS

This retrospective study recruited 154 subjects with ultrasound-confirmed fetal IMV and 190 subjects in a control cohort who underwent a high-risk prenatal serum screening program. The exclusion criteria included fetus G-banding chromosomal abnormality or positive fetus TORCH infection. DNA samples from all 344 fetuses were examined by an SNP-array. Developmental outcomes were assessed during postnatal follow-up.

RESULTS

Fourteen pathogenic CNVs (pCNVs) were identified in 13 out of 154 IMV fetuses. Three pCNVs were found in 3 out of 190 subjects in the prenatal screening high-risk cohort, with a significant difference (P value=0.016, X2 test). Notably, the 14 pCNVs detected in the IMV cohort were all associated with neurodevelopmental disorders (NDs), including autism, intellectual disability. Among the 13 IMV fetuses carrying pCNVs, five subjects were found in the postnatal follow-up to manifest NDs, including two with autism and three with mild neurodevelopmental delay. The other 8 subjects consisted of three normal infants younger than 12-months old, two lost in the follow-up, and three with the termination of pregnancy. Out of 141 IMV subjects without detectable pCNVs, 123 subjects showed normal development, 16 were lost in the follow-up, 2 subjects terminated the pregnancy due to fetal hydrocephalus or congenital heart disease in the late fetus development.

CONCLUSIONS

This study suggests an association between pCNVs and fetal IMV. pCNVs may be involved in the pathological process of fetal IMV and postnatal NDs. Identifying specific genomic alterations may provide an insight into pathogenetic mechanism and aid better diagnosis and prognosis of neurodevelopmental outcomes in fetal IMV.

[Analysis of Arsenic Compounds in Blood and Urine by HPLC-ICP-MS]

OBJECTIVES

To establish an analysis method for the detection of 6 arsenic compounds [AsC, AsB, As（Ⅲ）, DMA, MMA and As（V）] in blood and urine by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry （HPLC-ICP-MS）, and apply it to real cases.

METHODS

Triton was used to damage cells, and then EDTA·2Na·2H2O was used to complex arsenic compounds in cells, and sonication and protein deposition by acetonitrile were performed for sample pretreatment. With the mobile phase consisted of ammonium carbonate and ultrapure water, gradient elution was performed for obtaining the arsenic compounds in samples, which were analysed by ICP-MS with Hamilton PRP-X100 column.

RESULTS

The limits of detection in blood were 1.66-10 ng/mL, while the lower limits of quantitation in blood ranged from 5 to 30 ng/mL. The limits of detection in urine were 0.5-10 ng/mL, while the lower limits of quantitation in urine were 5-30 ng/mL. The relative standard deviation of inter-day and intra-day precisions was less than 10%. This method had been successfully applied to 3 cases.

CONCLUSIONS

This study has established an analysis method for detecting 6 common arsenic compounds in blood and urine, which can be used to detect the arsenic compounds in the blood and urine from arsenic poisoning cases as well as the patients under arsenic treatment.

Effects of alendronate and alfacalcidol on bone in patients with myasthenia gravis initiating glucocorticoids treatment

OBJECTIVE

Glucocorticoids (GCs) are the first-line treatment for myasthenia gravis (MG) and act as long-term immunosuppressants. However, GCs can induce osteoporosis and bone fractures. In this study, we evaluate the effects of oral alendronate and alfacalcidol, or alfacalcidol alone on the bone of Chinese patients with MG who will initiate treatment with GCs.

DESIGN AND METHODS

A total of 75 patients were included in this 12-month prospective, open-label, single-centre study. Patients with bone mineral density (BMD) T-score less than -1.0 at baseline were treated with 70 mg of alendronate per week. Patients with BMD T-score greater than -1.0 at baseline were included in the alfacalcidol-alone group. Patients in two groups were treated with 0.25 μg of alfacalcidol every other day and 600 mg of calcium daily.

RESULTS

After 12 months of treatment, the mean BMD of lumbar spine, femoral neck and total hip increased by 3.4% (P = .002), 1.8% (P = .21) and 2.6% (P = .02), respectively, in alendronate group. In alfacalcidol-alone group, the mean BMD of lumbar spine, femoral neck and total hip decreased by 6.1%, 3.2% and 3.3%, respectively (all P < .001 vs baseline).

CONCLUSIONS

We demonstrated for the first time that treatment with alendronate combined with alfacalcidol significantly increased BMD, decreased bone turnover biomarker levels and reduced the occurrence of hypercalciuria in a large cohort of Chinese patients with MG who initiated treatment with glucocorticoids. However, treatment with alfacalcidol alone failed to prevent bone loss in patients with MG receiving glucocorticoid therapy.

CdS nanoparticles of different lengths induce differential responses in some of the liver functions of mice

Cadmium sulfide nanoparticles (CdS NPs) are one of important nanoparticle materials which are widely used in photoelectric production, but their potential health hazard to the liver is not clear. This study is aimed at exploring the possible mechanisms of liver injury induced by CdS NPs. Male mice were treated with nanoparticles of 110-130 nm and 80-100 nm cadmium sulfide. The main methods were based on detecting the vigor of superoxide dismutase (SOD) and glutathione (GSH), and content of malondialdehyde (MDA) in both blood and liver tissues as well as on observing the pathological changes in liver tissue. CdS NPs suppressed the activity of SOD and GSH, and increased the serum MDA content (p < 0.05); both effects were observed together in liver tissues of 80-100 nm group (p < 0.05) and were accompanied by an obviously inflammatory response. CdS NPs induced oxidative damage and inflammatory response in liver tissue, which may be an underlying mechanism for its pulmonary toxicity. Additionally, the toxicity of CdS NPs was closely related to the size of nanoparticles. Pathological results showed that the hepatotoxicity of shorter CdS NPs is greater than that of longer CdS NPs (Tab. 6, Fig. 3, Ref. 20).

Abstract P2-06-03: Clinicopathologic characteristics and genomic essence analyses revealed estrogen receptor positive, progesterone receptor negative and human epidermal growth factor receptor 2 negative breast cancer to be more basal-like and endocrine resistant

Background: Estrogen receptor positive/ progesterone receptor negative/ human epidermal growth factor receptor 2 negative (ER+/PR-/HER2-) tumors define a distinct subtype of ER+ breast cancer, characterized by poor response to endocrine therapy and poor prognosis. The genomic landscape of ER+/PR-/HER2- tumor has yet to be systematically studied,and driver events for tumor progression and endocrine resistance with loss of PR expression are yet to be identified. Methods: We assessed 13,410 ER+/PR-/HER2- patients from Surveillance, Epidemiology, and End Results (SEER), the Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) for clinicopathologic characteristics, survival and genomic analyses. Patients were divided into endocrine-resistant and endocrine-sensitive groups using an endocrine therapy sensitivity score [(0.8*ER+1.2*PGR+BCL2+SCUBE2)/4], and we further explored genomic events enriched in the endocrine-resistant group. Results: Clinicopathologic features and survival outcomes of ER+/PR-/HER2- patients were worse than ER+/PR+/HER2- in SEER and METABRIC cohort. The genomic landscape of ER+/PR-/HER2- tumors revealed them to have more aggressive properties, like a higher percentage of luminal B (29-35%) and basal-like (4-16%) subtypes; more intClust subtypes with high genomic instability (intClust1, 6); more TP53 mutation and less PIK3CA mutation; and more copy number variation events. ER+/PR-/HER2- tumors have more focal amplification events, including 8p11.23 (ZNF703) and 17q23.1 (RPS6KB1) and more focal deletion events, such as 17q21.31 (BRCA1) and 14q24.3 (MLH3). Pathifier pathway analyses showed that up-regulated pathways in ER+/PR-/HER2-tumors included those associated with biosynthesis, metabolism, drug resistance and DNA replications (FDR&lt;0.1). Endocrine sensitivity score for ER+/PR-/HER2- group was significantly lower than ER+/PR+/HER2- group. When split by 1st quartile of endocrine sensitivity score, up to 72.7% of ER+/PR-/HER2- tumors were grouped into the endocrine-resistant group. Mutant-allele tumor heterogeneity (MATH) score is significantly lower in the endocrine-resistant group. Several focal SCNA events were more common in the endocrine-resistant group (P&lt;0.05), including 8q24.21 amplification with only the MYC gene in the “peak” region. Pathways unregulated in the endocrine-resistant group of ER+/PR-/HER2- tumor included MYC pathway and mTORC1 signaling (FDR&lt;0.25). Conclusion: ER+/PR-/HER2- breast cancer was a heterogeneous tumor group and featured more basal-like and luminal B characteristics. The ER+/PR-/HER2- tumors are relatively resistant to endocrine therapy, and MYC pathway enrichment and corresponding 8q24.21 amplification might be one of the drug-resistance mechanisms. Our study provides an overall understanding of the distinct genomic landscape of ER+/PR-/HER2- breast cancer. Further investigations into the pathways activated with the loss of PR expression may provide clues for novel changes in the therapeutic regimens of ER+/PR-/HER2- breast cancer.

Citation Format: Liu X, Ma D, Jiang Y-Z, Liu Y-R, Yu K-D, Shao Z-M. Clinicopathologic characteristics and genomic essence analyses revealed estrogen receptor positive, progesterone receptor negative and human epidermal growth factor receptor 2 negative breast cancer to be more basal-like and endocrine resistant [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 P2-06-03.

Correction to: Gene mutation spectrum and genotype-phenotype correlation in a cohort of Chinese osteogenesis imperfecta patients revealed by targeted next generation sequencing

In Table 2:Family 6 should be c.643-13_662delCTATCTTTTCTAGGGTCCCATGGGTCCCCGAGG instead of c.643-13_662delCTATCTTTTCTAGGGTCCCATGGGTCCCC.Family 33 should be c.271_279dupGCCCTCTCG instead of c.271_279dupGCCCTCT.In the 2nd para. of the Molecular diagnosis, section t(5;8)(q32;q21) should be t(5;7)(q32;q21).

Gene mutation spectrum and genotype-phenotype correlation in a cohort of Chinese osteogenesis imperfecta patients revealed by targeted next generation sequencing

The achievement of more accurate diagnosis would greatly benefit the management of patients with osteogenesis imperfecta (OI). In this study, we present the largest OI sample in China as screened by next generation sequencing. In particular, we successfully identified 81 variants, which included 45 novel variants. We further did a genotype-phenotype analysis, which helps make a better understanding of OI.

INTRODUCTION

This study aims to reveal the gene mutation spectrum and the genotype-phenotype relationship among Chinese OI patients by next generation sequencing (NGS).

METHODS

We developed a NGS-based panel for targeted sequencing of all exons of 14 genes related to OI, and performed diagnostic gene sequencing for a cohort of 103 Chinese OI patients from 101 unrelated families. Mutations identified by NGS were further confirmed by Sanger sequencing and co-segregation analysis.

RESULTS

Of the 103 patients from 101 unrelated OI families, we identified 79 mutations, including 43 novel mutations (11 frameshift, 17 missense, 5 nonsense, 9 splice site, and 1 chromosome translocation) in 90 patients (87.4%). Mutations in genes encoding type I collagen, COL1A1 (n = 37), and COL1A2 (n = 29) accounts for 73.3% of all molecularly diagnosed patients, followed by IFITM5 (n = 9, 10%), SERPINF1 (n = 4, 4.4%), WNT1 (n = 4, 4.4%), FKBP10 (n = 3, 3.3%), TMEM38B (n = 3, 3.3%), and PLOD2 (n = 1, 1.1%). This corresponds to 75 autosomal dominant inherited (AD) OI patients and 15 autosomal recessive (AR) inherited patients. Compared with AD inherited OI patients, AR inherited patients had lower bone mineral density (BMD) at spine (P = 0.05) and less frequent blue sclera (P = 0.001). Patients with type I collagen qualitative defects had lower femoral neck BMD Z-score (P = 0.034) and were shorter compared with patients with type I collagen quantitative defects (P = 0.022).

CONCLUSION

We revealed the gene mutation spectrum in Chinese OI patients, and novel mutations identified here expanded the mutation catalog and genotype and phenotype relationships among OI patients.

Association between bone mineral density, muscle strength, and vitamin D status in patients with myasthenia gravis: a cross-sectional study

Myasthenia gravis (MG) patients had low proximal hip BMD, which could be explained by reduced muscle strength, elevated bone resorption markers, vitamin D deficiency, and increased PTH levels in those with MG compared to controls.

INTRODUCTION

Muscle strength is closely correlated with bone mineral density (BMD) and vitamin D status. Here, we evaluated muscle strength, BMD, and vitamin D status in a large sample of Chinese patients with MG.

METHODS

In this cross-sectional survey, 86 patients with MG without glucocorticoid treatment and 86 healthy controls were included. Serum levels of 25-hydroxyvitamin D [25OHD], parathyroid hormone (PTH), bone turnover markers (BTMs), and BMD were measured and compared between the two groups. Grip strength and one-leg standing time (OLST) were also assessed in MG patients.

RESULTS

Low grip strength and short OLST were found in 11 (12.8%) and 12 (14.0%) MG patients, respectively. There were 3 (3.5%) MG patients with low bone mass for chronological age. Serum beta C-terminal telopeptide and PTH levels were higher (p < 0.001 and p = 0.001, respectively), and BMD at the femoral neck and trochanter were lower in MG patients (p < 0.001 and p < 0.001, respectively) compared to healthy controls. In patients with MG, grip strength was positively correlated with BMD. Serum 25OHD levels were lower in MG patients than in healthy controls (17.36 ± 6.64 vs. 22.11 ± 7.28 ng/ml, p < 0.001).

CONCLUSION

Grip strength was positively correlated with BMD in Chinese patients with MG. MG patients tended to have low proximal hip BMD, which may partially be explained by reduced muscle strength, vitamin D deficiency, increased PTH levels, and elevated bone resorption markers compared to controls.

Modeling the Blood-Brain Barrier in a 3D triple co-culture microfluidic system

The need for a blood-brain barrier (BBB) model that accurately mimics the physiological characteristics of the in-vivo situation is well-recognized by researchers in academia and industry. However, there is currently no in-vitro model allowing studies of neuronal growth and/or function influenced by factors from the blood that cross through the BBB. Therefore, we established a 3D triple co-culture microfluidic system using human umbilical vein endothelial cells (HUVEC) together with primary rat astrocytes and neurons. Immunostaining confirmed the successful triple co-culture system consisting of an intact BBB with tight intercellular junctions in the endothelial monolayer. The BBB selective permeability was determined by a fluorescent-based assay using dextrans of different molecular weights. Finally, neuron functionality was demonstrated by calcium imaging.

Abstract P1-06-07: Clinical and molecular relevance of intra-tumor genetic heterogeneity in breast cancer: Integrative analysis of data from The Cancer Genome Atlas

Background: Intra-tumor heterogeneity (ITH) plays a pivotal role in driving breast cancer progression and therapeutic resistance. Emerging evidence has indicated that the extent of genetic heterogeneity may serve as a clinically useful biomarker. While several studies have suggested the prognostic value of ITH in several cancer types, the clinical significance of genetic ITH and molecular portraits that correlated with different ITH levels were poorly understood in breast cancer. The establishment of algorithms estimating genetic ITH based on sequencing of bulk tumor DNA offered us an opportunity to explore the clinical implication of ITH in large breast cancer cohorts and, for the first time, to use integrative genomic analyses to reveal molecular portraits related to intra-tumor genetic heterogeneity.

Methods: We assessed 916 female breast cancer patients from The Cancer Genome Atlas. Mutant-allele tumor heterogeneity (MATH) values were calculated from whole-exome sequencing data. We used integers nearest to the tertiles of the MATH values as cutoff points to divide the patients into three groups nearly equal in size. The association between MATH value and clinical characteristics was evaluated, followed by survival analyses in these different MATH groups. We then compared the rates of total non-silent somatic mutations among the different MATH groups, and further determined the mutations independently associated with high MATH by logistic regression adjusting for T classification and clinical subtypes. Similar methods, superadding somatic copy number alteration (SCNA) burden in logistic model, were used to evaluate SCNA events that were significantly associated with high MATH level. Gene enrichment between the high and rest MATH groups was analyzed using Gene Set Enrichment Analysis.

Results: The patients were divided into low (MATH value lower than 33), intermediate (MATH between 33 and 46) and high (MATH higher than 46) MATH groups. High T stage, African American race, and triple-negative or basal-like subtype were associated with a higher MATH level (all P&lt;0.001). In hormone receptor-positive and human epidermal growth factor receptor-negative patients, the high MATH group showed a tendency toward a worse overall survival (P=0.052); however, while in triple-negative breast cancer, both high and low MATH indicated a worse outcome (P=0.032). Furthermore, the TP53 mutation rate increased as MATH was elevated (P&lt;0.001), whereas CDH1 mutations were correlated with a lower level of MATH (P=0.002). Several focal and arm-level SCNA events were more common in the high MATH group, including Chr8q24 with only the MYC gene in the “peak” region. Similarly, high MATH was associated with gene set enrichment related to the MYC pathway and proliferation.

Conclusion: Our study extended the knowledge concerning the clinical role of ITH in breast cancer, especially the distinct pattern of prognostic values in different clinical subtypes, which may help promote the clinical utilization of genetic ITH. Our attempt at exploring the molecular features related to ITH might provide clues for the source and consequences of ITH, inspiring subsequent experiments investigating the laws underling tumor heterogeneity.

Citation Format: Ma D, Jiang Y-Z, Liu X-Y, Liu Y-R, Yu K-D, Shao Z-M. Clinical and molecular relevance of intra-tumor genetic heterogeneity in breast cancer: Integrative analysis of data from The Cancer Genome Atlas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-06-07.

Compacting a Single Flow Diverter versus Overlapping Flow Diverters for Intracranial Aneurysms: A Computational Study

BACKGROUND AND PURPOSE

Locally compacting the mesh of a flow diverter by a dynamic push-pull technique can accelerate intracranial aneurysm healing. We asked how this deployment strategy compares with overlapping 2 flow diverters for aneurysmal flow reduction.

MATERIALS AND METHODS

Using a high-fidelity virtual stent placement method, we simulated 3 flow-diverter strategies (single noncompacted, 2 overlapped, and single compacted) in 3 aneurysms (fusiform, large saccular, and medium saccular). Computational fluid dynamics analysis provided posttreatment hemodynamic parameters, including time-averaged inflow rate, aneurysm-averaged velocity, wall shear stress, total absolute circulation, and turnover time. We examined the relationship between the achieved degree of compaction and aneurysm orifice area.

RESULTS

Flow-diverter compaction resulted in a compaction coverage of 57%, 47%, and 22% over the orifice of the fusiform, large, and medium saccular aneurysm, respectively. Compaction coverage increased linearly with orifice area. In the fusiform aneurysm, the single compacted flow diverter accomplished more aneurysmal flow reduction than the other 2 strategies, as indicated by all 5 hemodynamic parameters. In the 2 saccular aneurysms, the overlapped flow diverters achieved the most flow reduction, followed by the single compacted and the noncompacted flow diverter.

CONCLUSIONS

Compacting a single flow diverter can outperform overlapping 2 flow diverters in aneurysmal flow reduction, provided that the compaction produces a mesh denser than 2 overlapped flow diverters and this denser mesh covers a sufficient portion of the aneurysm orifice area, for which we suggest a minimum of 50%. This strategy is most effective for aneurysms with large orifices, especially fusiform aneurysms.

Structural predictions for curli amyloid fibril subunits CsgA and CsgB

CsgA are the building blocks of curli fibrils.

MR Fingerprinting of Adult Brain Tumors: Initial Experience

BACKGROUND AND PURPOSE

MR fingerprinting allows rapid simultaneous quantification of T1 and T2 relaxation times. This study assessed the utility of MR fingerprinting in differentiating common types of adult intra-axial brain tumors.

MATERIALS AND METHODS

MR fingerprinting acquisition was performed in 31 patients with untreated intra-axial brain tumors: 17 glioblastomas, 6 World Health Organization grade II lower grade gliomas, and 8 metastases. T1, T2 of the solid tumor, immediate peritumoral white matter, and contralateral white matter were summarized within each ROI. Statistical comparisons on mean, SD, skewness, and kurtosis were performed by using the univariate Wilcoxon rank sum test across various tumor types. Bonferroni correction was used to correct for multiple-comparison testing. Multivariable logistic regression analysis was performed for discrimination between glioblastomas and metastases, and area under the receiver operator curve was calculated.

RESULTS

Mean T2 values could differentiate solid tumor regions of lower grade gliomas from metastases (mean, 172 ± 53 ms, and 105 ± 27 ms, respectively; P = .004, significant after Bonferroni correction). The mean T1 of peritumoral white matter surrounding lower grade gliomas differed from peritumoral white matter around glioblastomas (mean, 1066 ± 218 ms, and 1578 ± 331 ms, respectively; P = .004, significant after Bonferroni correction). Logistic regression analysis revealed that the mean T2 of solid tumor offered the best separation between glioblastomas and metastases with an area under the curve of 0.86 (95% CI, 0.69-1.00; P < .0001).

CONCLUSIONS

MR fingerprinting allows rapid simultaneous T1 and T2 measurement in brain tumors and surrounding tissues. MR fingerprinting-based relaxometry can identify quantitative differences between solid tumor regions of lower grade gliomas and metastases and between peritumoral regions of glioblastomas and lower grade gliomas.

Development of an opto-electronic fiber device with multiple nano-probes

We present the fabrication and characterization of an opto-electronic fiber device which can allow for both electromechanical functionality and optical waveguiding capability. The air holes of a photonic crystal fiber are selectively sealed and then pumped with molten metal under pressure. The metal filled holes act as electrodes to which individual carbon nanotubes (CNT) are attached precisely by a laser-welding technique or a focused ion beam assisted pick-and-bond technique. The optical modal profile and the group velocity dispersion of the fabricated device are studied both numerically and experimentally. We also present preliminary experimental proof showing the feasibility of electric actuation of a pair of nanotubes by applying up to 40 V potential difference between the filled electrodes. Furthermore, numerical simulations are carried out which agree with the experimentally observed displacement of the CNT upon electric actuation. The unique aspect of our device is that it provides optical waveguiding and electromechanical nano-probing capability in a single package. Such combined functionality can potentially enable simultaneous electrical and optical manipulation and interrogation at the nanoscale.

Conditioned medium from neural stem cells inhibits glioma cell growth

Malignant glioma is one of the most common brain tumors in the central nervous system. Although the significant progress has been made in recent years, the mortality is still high and 5-year survival rate is still very low. One of the leading causes to the high mortality for glioma patients is metastasis and invasion. An efficient method to control the tumor metastasis is a promising way to treat the glioma. Previous reports indicated that neural stem cells (NSCs) were served as a delivery vector to the anti-glioma therapy. Here, we used the conditioned medium from rat NSCs (NSC-CM) to culture the human glioblastoma cell lines. We found that NSC-CM could inhibit the glioma cell growth, invasion and migration in vitro and attenuate the tumor growth in vivo. Furthermore, this anti-glioma effect was mediated by the inactivation of mitogen activated protein kinase (MAPK) pathway. Above all, this study provided the direct evidence to put forward a simple and efficient method in the inhibition of glioma cells/tumor growth, potentially advancing the anti-glioma therapy.