Two new secondary metabolites, saccharochlorines A and B, from a marine bacterium Saccharomonospora sp. KCTC-19160

Two new chlorinated secondary metabolites, saccharochlorines A and B (1 and 2), were isolated from the saline cultivation of a marine-derived bacterium Saccharomonospora sp. (KCTC-19160). The chemical structures of the saccharochlorines were elucidated by 2D NMR and MS spectroscopic data. Saccharochlorines A and B (1 and 2) exhibit weak inhibition of β-secretase (BACE1) in biochemical inhibitory assay, but they induced the release of Aβ (1-40) and Aβ (1-42) in H4-APP neuroglial cells. This discrepancy might be derived from the differences between the cellular and sub-cellular environments or the epigenetic stimulation of BACE1 expression.

An Activatable AIEgen Probe for High-Fidelity Monitoring of Overexpressed Tumor Enzyme Activity and Its Application to Surgical Tumor Excision

Monitoring fluctuations in enzyme overexpression facilitates early tumor detection and excision. An AIEgen probe (DQM-ALP) for the imaging of alkaline phosphatase (ALP) activity was synthesized. The probe consists of a quinoline-malononitrile (QM) core decorated with hydrophilic phosphate groups as ALP-recognition units. The rapid liberation of DQM-OH aggregates in the presence of ALP resulted in aggregation-induced fluorescence. The up-regulation of ALP expression in tumor cells was imaged using DQM-ALP. The probe permeated into 3D cervical and liver tumor spheroids for imaging spatially heterogeneous ALP activity with high spatial resolution on a two-photon microscopy platform, providing the fluorescence-guided recognition of sub-millimeter tumorigenesis. DQM-ALP enabled differentiation between tumor and normal tissue ex vivo and in vivo, suggesting that the probe may serve as a powerful tool to assist surgeons during tumor resection.

Salvianolic Acid B Inhibits Hand-Foot-Mouth Disease Enterovirus 71 Replication through Enhancement of AKT Signaling Pathway

Hand, foot, and mouth disease (HFMD) is caused by enterovirus 71 (EV71) in infants and children under six years of age. HFMD is characterized by fever, mouth ulcers, and vesicular rashes on the palms and feet. EV71 also causes severe neurological manifestations, such as brainstem encephalitis and aseptic meningitis. Recently, frequent outbreaks of EV71 have occurred in the Asia-Pacific region, but currently, no effective antiviral drugs have been developed to treat the disease. In this study, we investigated the antiviral effect of salvianolic acid B (SalB) on EV71. SalB is a major component of the Salvia miltiorrhiza root and has been shown to be an effective treatment for subarachnoid hemorrhages and myocardial infarctions. HeLa cells were cultured in 12-well plates and treated with SalB (100 or 10 µg/ml) and 10⁶ PFU/ml of EV71. SalB treatment (100 µg/ml) significantly decreased the cleavage of the eukaryotic eIF4G1 protein and reduced the expression of the EV71 capsid protein VP1. In addition, SalB treatment showed a dramatic decrease in viral infection, measured by immunofluorescence staining. The Akt signaling pathway, a key component of cell survival and proliferation, was significantly increased in EV71-infected HeLa cells treated with 100 µg/ml SalB. RT-PCR results showed that the mRNA for anti-apoptotic protein Bcl-2 and the cell cycle regulator Cyclin-D1 were significantly increased by SalB treatment. These results indicate that SalB activates Akt/PKB signaling and inhibits apoptosis in infected HeLa cells. Taken together, these results suggest that SalB could be used to develop a new therapeutic drug for EV71-induced HFMD.

Biosynthesis of Nonimmunosuppressive FK506 Analogues with Antifungal Activity

A reduction in the strong immunosuppressive activity of FK506 (1) is essential for developing this compound as an antifungal agent. Seven new FK506 analogues modified at both the FK506-binding protein 12- and the calcineurin-binding regions were biosynthesized. 9-DeoxoFK520 (7) exhibited a >900-fold reduction in the in vitro immunosuppressive activity but maintained significant antifungal activity, indicating that the C-9 and C-21 positions are critical for separation of immunosuppressive and antifungal activities. 7 exhibited robust synergistic antifungal activity with fluconazole. FK506 (1) is a 23-membered macrolide produced by several Streptomyces species and is used as an immunosuppressive drug to prevent the rejection of transplanted organs. FK506 has also exhibited antifungal, neuroprotective, and neuroregenerative activities. In humans, FK506 binds to FK506-binding protein (FKBP) 12, and the resulting FKBP12-FK506 complex interacts with a Ca²⁺-calmodulin-dependent phosphatase, calcineurin (CaN). Inactivation of CaN by forming the FKBP12-FK506-CaN ternary complex prevents the activation of nuclear factor of activated T cells (NF-AT), inhibiting the production of interleukin-2 and subsequent T-cell proliferation. This CaN signaling pathway also plays a critical role in the growth and pathogenesis of major fungal pathogens such as Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus. Therefore, the synthesis of FK506 analogues that can discriminate human FKBP12/CaN from its fungal counterparts may separate antifungal activity from the immunosuppressive activity, thereby allowing the development of a novel antifungal agent.

Mycousfurans A and B, Antibacterial Usnic Acid Congeners from the Fungus Mycosphaerella sp., Isolated from a Marine Sediment

Mycousfurans (1 and 2), two new usnic acid congeners, along with (−)-mycousnine (3), (−)-placodiolic acid (4), and (+)-usnic acid (5), were isolated using high-performance liquid chromatography-ultraviolet (HPLC-UV)-guided fractionation of extracts of Mycosphaerella sp. isolated from a marine sediment. The planar structures of 1 and 2 were elucidated using 1D and 2D NMR spectra. The relative configurations of the stereogenic carbons of 1 and 2 were established via analysis of their nuclear Overhauser spectroscopy (NOESY) spectra, and their absolute configurations were determined using a comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1 and 2 were found to have antibacterial activity, showing moderate activity against Kocuria rhizophila and Staphylococcus aureus.

Meroindenon and Merochlorins E and F, Antibacterial Meroterpenoids from a Marine-Derived Sediment Bacterium of the Genus Streptomyces

Meroterpenoids, meroindenon (1) and merochlorins E (2) and F (3), were isolated from a marine-derived bacterium belonging to the genus Streptomyces. Their chemical structures were established using extensive analysis of MS, UV, ECD, and NMR spectroscopic data. Compounds 1-3 possess a tetrahydroxynaphthalene core and a C₁₅-isoprene unit. Compounds 2 and 3 exhibited strong antibacterial activities against B. subtilis, K. rhizophila, and S. aureus, with a range of MIC values from 1 to 2 μg/mL.

Potent and selective inhibition of human monoamine oxidase-B by 4-dimethylaminochalcone and selected chalcone derivatives

Six synthetic (1-6) and six natural (7-12) chalcones were tested for human monoamine oxidases (hMAOs) and acetylcholinesterase (AChE) inhibitory activities. Compounds 4-dimethylaminochalcone (2), 4'-chloro-4-dimethylaminochalcone (5), and 2,4'-dichloro-4-dimethylaminochalcone (1) potently inhibited hMAO-B with IC₅₀ values of 0.029, 0.061, and 0.075 μM, respectively. 4-Nitrochalcone (4) and 4-chlorochalcone (3) also potently inhibited hMAO-B with IC₅₀ values of 0.066 and 0.082 μM, respectively (2.3- and 2.6-fold less than compound 2). Compound 2 had a high selectivity index (113.1) for hMAO-B over hMAO-A (IC₅₀ = 3.28 μM). Compounds 1 and 2,2'-dihydroxy-4',6'-dimethoxychalcone (12) potently inhibited hMAO-A with IC₅₀ values of 0.18 and 0.39 μM, respectively. In addition, compounds 4 and 2 also effectively inhibited AChE with IC₅₀ values of 1.25 and 6.07 μM, respectively, and thus, exhibited dual-targeting. Compound 2 reversibly and competitively inhibited hMAO-B with a K_i value of 0.0066 μM. Docking simulations showed binding affinities of compounds 1 to 5 for hMAO-B were higher than those for hMAO-A or AChE and suggested these five chalcones form hydrogen bonds with MAO-B at Cys172 but that they do not form hydrogen bonds with hMAO-A or AChE. These findings suggest compound 2 be considered a promising and dual-targeting lead compound for the treatment of Alzheimer's disease.

Abstract P3-08-12: PIK3CA mutations in breast cancer: Mutational landscape and clinical implications in ER+/HER2- subtype

Introduction: PIK3CA mutation is one of the most frequent genomic alterations in breast cancer. We evaluated PIK3CA mutational status including spatial and temporal heterogeneity, clinical characteristics and prognostic impact focused on ER+/HER2- subtype.

Methods: We performed targeted ultra-deep sequencing (CancerSCAN™) of breast cancer tissue in a prospective cohort. Burden of disease was assessed by metabolic tumor volume(MTV) in 18F-FDG-PET scan. Association with clinical characteristics or survival were tested in ER+/HER2- subtype, using Chi square test or Kaplan-Meier method.

Results: PIK3CA analyses were performed in 1274 breast cancer specimens from 1091 patients. 957 patients had early breast cancer. PIK3CA alterations were found in 397 patients(36.3%), and frequency of PIK3CA mutation was significantly lower in triple negative breast cancer(19.0%), compared with 40.4% in ER+/HER2-, 40.9% in ER+/HER2+, and 45.2% in ER-/HER2+ subtype(p<0.0001). 158 patients had more than two biopsies. Among 92 patients with second biopsy within one month, 11%(10/92) had spatial heterogeneity of PIK3CA mutation. After neoadjuvant chemotherapy, 10%(3/30) of patients had change of PIK3CA mutational status. Serial biopsy at time of recurrence revealed loss or gain of PIK3CA mutation in 10 out of 59 patients (17%). In ER+/HER2- subtype, PIK3CA had a trend toward longer distant disease free survival without statistical significance. In patients with stage IV ER+/HER2- disease, PIK3CA hotspot mutations were associated with significant longer overall survival(OS) (71.0 vs. 37.8 months, p=0.048) and better progression free survival(PFS) at 1st line palliative treatment (37.7 vs. 9.4 months, p = 0.0004). Frequency of symptomatic recurrence, recurrence as oligometastases, and specific metastatic sites were not associated with PIK3CA mutational status, except that bone metastases at first distant metastases was less prevalent in patients with PIK3CA hotspot mutations(35.6% vs. 53.8% in PIK3CA wt, p=0.048). Metabolic tumor volume(MTV) at time of first distant metastases was not associated with presence of PIK3CA mutation.

Conclusion: We observed variations in PIK3CA mutational status in more than 10% of patients with >1 repeated biopsy. In stage IV ER+/HER2- disease, PIK3CA hotspot mutation seemed to be associated with longer PFS and OS, however metabolic tumor burden was not associated with PIK3CA alterations.

Citation Format: Ahn HK, Park S, Hyun SH, Park K, Lee E, Kim J-Y, Nam SJ, Kim SW, Lee JE, Lee SK, Yu JH, Ahn JS, Im Y-H, Park YH. PIK3CA mutations in breast cancer: Mutational landscape and clinical implications in ER+/HER2- subtype [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 P3-08-12.

Abstract P1-09-11: Prognostication of genetic alterations of ESR 1 in estrogen receptor positive metastatic breast cancers using targeted ultra-deep sequencing data analysis

Introduction: Genetic alteration of Estrogen Receptor 1(ESR1) gene have been associated with acquired endocrine resistance and occurred in about 20% of endocrine resistant estrogen receptor(ER)-positive metastatic breast cancer(MBC). Mutations in ligand binding domain of ESR1 lead to constitutive activity of the ER without ligand estrogen and stimulated down stream cell growth signal. Therefore, ESR1 ligand binding domain alteration is known resistant mechanism of aromatase inhibitor. Among these ESR1 mutations, Y537S, one of the ligand binding domain mutations, caused ER antagonist, fulvestrant resistance. Therefore, assessment of ESR1 mutation in ER-positive MBC had significant benefit to further precision medicine for MBCs. In this study, we explored to identify the frequency and type of ESR1 genetic alterations of ER-positive MBC.

Methods: We performed targeted ultra-deep sequencing (CancerSCAN™) using BC tissue specimens. This sequencing was covered entire coding area of ESR1 gene and also detected copy number alteration and translocation of ESR1.

Results: Targeted ultra-deep sequencing of ESR1 was performed using 990 BC tissues. Of 990 tissue samples, 341(34.5%) were MBCs. Of MBCs, 112(11.3%) were ER-positive and human epidermal growth factor receptor 2(HER2)-negative BCs. In ER-positive HER2-negative MBCs (N=112), 21 ESR1 genetic alterations were identified in 19 BCs (17.0%). Nineteen were single nucleotide variats (SNVs) and three were copy number (CN) amplification. Most commonly detected single nucleotide variant (SNV) was D538G (6 of 19, 31.6%) followed by Y537N, Y537S, V382I (4, 2 and 2 cases, respectively). Three mutations occurred in non-ligand binding domain (G415V, V392I and P79A). Two BC samples harbored two ESR1 mutations, respectively (Y537S and D538G, L536P and Y537N). In terms of treatment, 11 of 12 patients with ER-positive MBC harboring ESR1 mutation received palliative endocrine therapies. Eight patients received aromatase inhibitor and two patients received tamoxifen. One patient received letrozole plus palbociclib. In 2 MBCs with Y537S mutation, progression free survival (PFS) of endocrine therapy was 1.4 and 5.3 months. MBCs with D538G had 12.3months of PFS (range, 5.3-23.7(months)) and BCs harboring another ligand binding domain mutations (Y537N, L536H and L536P) had 15.7months of PFS of endocrine therapy (range, 8.4-17.3(months)). BC with mutation observed in non-lignand binding domain had short PFS (1.8 (V392I) and 2.7 (P79A) months, respectively). In terms of ESR1 CN amplification, patients could not receive endocrine therapy because their BCs rapidly progressed and extensive distant metastases were occurred within 3 months after curative surgery.

Conclusion: In this exploratory study, ESR1 genetic alterations were detected in about 20% of ER-positive MBC. The type of genetic alterations varied including SNVs, CNAs. Each locus of ESR1 mutation predicted endocrine resistance. In addition, we might suggest that ESR1 CN amplification is prognostic marker of ER-positive BCs.

Citation Format: Kim J-Y, Park KH, Park W-Y, Nam SJ, Kim SW, Lee JE, Lee SK, Yu JH, Ahn JS, Im Y-H, Park YH. Prognostication of genetic alterations of ESR 1 in estrogen receptor positive metastatic breast cancers using targeted ultra-deep sequencing data analysis [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 P1-09-11.

Abstract P4-08-30: Prognostication of immune related gene expression in patients with triple negative breast cancer

Introduction: To date, the role of immunotherapy with check point inhibitors and/or vaccines in the treatment of breast cancer (BC) is still debating, and the main focus of immunotherapy in BC is on triple negative subtype as a target population in many ongoing clinical trials. Translational research into identifying predictive and prognostic immune biomarkers is of particular clinical relevance, but, there are currently no definite prognostic and predictive immune biomarkers in BC, especially in triple negative breast cancer(TNBC). We investigated the expression profiles of immune genes in patients with TNBC to identify the prognostic value of immune genes in search of clinical implications.

Methods : We investigated expression profiles of 770 pan-cancer immune related genes using the nCounter mRNA expression assay (NanoString®) from paraffin-embedded tumor tissues in 200 patients diagnosed as TNBC who received curative surgery at Samsung Medical Center from 2000 to 2004. We analyzed the relationship between stage adjusted level of gene expressions and patients' survival outcomes using Cox regression model.

Results: Of 770 genes, 186 genes were selected from univariate analysis with clinical stage adjustment. In multivariate analysis using Cox regression, expressions of CD1B, CD45, CD53, CT45A1, GTF3C1, IL11RA, IL1RN, LRRN3, MAPK1, NEFL, PRKCE, SPACA3 and RANKL were associated with distant recurrence free survival (p<0.05, respectively). Among these 13 genes, expression of MAPK1, NEFL, CD45, SPACA3 and RANKL were correlated with favorable outcome in terms of distant recurrence free survival (p<0.05, respectively). In terms of overall survival, C3, IL1RL1, IL1RN, IL7 and PRKCE were associated with poor prognosis (p<0.05, respectively) and expression of SAA1 CXCL9 and RANKL resulted in favorable outcome (p<0.05, respectively).

Table 1ParameterParameter EstimateStandard Errorp-valueHazard Ratio95% Confidence Interval(a) distant recurrence free survival     Stage2.487350.680570.000312.0293.169, 45.661CD1B1.141910.2753<.00013.1331.826, 5.374CD531.531650.34851<.00014.6262.336, 9.159CT45A10.426110.134210.00151.5311.177, 1.992GTF3C11.193110.579720.03963.2971.059, 10.271IL11RA1.671120.461750.00035.3182.151, 13.146IL1RN0.980280.24657<.00012.6651.644, 4.321LRRN31.424170.28742<.00014.1542.365, 7.297MAPK1-0.542740.258240.03560.5810.35, 0.964NEFL-1.12170.335610.00080.3260.169, 0.629PRKCE2.378340.49659<.000110.7874.076, 28.549CD45-2.736780.43154<.00010.0650.028, 0.151SPACA3-0.745930.272270.00610.4740.278, 0.809RANKL-1.288920.2976<.00010.2760.154, 0.494(b) overall survival     Stage1.359280.497810.00633.8931.468, 10.329C30.329830.150350.02831.3911.036, 1.867CXCL9-0.379190.100680.00020.6840.562, 0.834IL1RL10.679360.262940.00981.9731.178, 3.303IL1RN0.437130.172370.01121.5481.104, 2.171IL70.507280.206250.01391.6611.109, 2.488PRKCE0.835340.272910.00222.3061.35, 3.936SAA1-0.564250.13449<.00010.5690.437, 0.74RANKL-0.604990.234510.00990.5460.345, 0.865

Conclusion: High expression of IL1RN, PRKCE were associated with short distant recurrence free survival and overall survival in patients with TNBCs who received curative surgery. In contrast, RANKL expression resulted in prolonged distant recurrence free survival and overall survival.

Citation Format: Kim J-Y, Jung HH, Lim JE, Cho EY, Lee SK, Yu JH, Lee JE, Kim SW, Nam SJ, Park YH, Ahn JS, Im Y-H. Prognostication of immune related gene expression in patients with 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 P4-08-30.

Abstract P2-08-52: A predictive model for distant metastasis in breast cancer patients using machine learning

Introduction

Tumor metastasis is a major clinical challenge accounting for the vast majority of cancer related deaths.In previous studies, prediction of distant metastasis was based on subtypes,clinical status and sometimes gene expression were used however clinical application was difficult.

In this study, we develop the easy to use prediction tool for distant metastasis using clinical characteristics and gene profiles which came from CancerSCANTM, Next Generation Sequencing based targeted-sequencing platform designed at Samsung Medical Center(SMC).

Methods

We performed a retrospective chart review of 326 breast cancer patients who underwent surgery and CancerSCAN TM between Jan 2001 and Dec 2014 at SMC. Median follow up period was 83 months (Range 1˜190). Cancer scanTM cover 381 genes but 27 genes and 34 occasions (loss of function, mutation or copy number variation) were selected for analysis through gradient boosting and Wilcoxon Signed rank test. Azure Machine Learning is a cloud service that enables the execution of machine learning processes.This was accomplished using the steps of (1) edit the data, (2) split the data, (3) train the model, (4) score the model, and (5) evaluate the model. We split the modeling data into training and testing sets using a randomized 50–50 split. Two-class Decision Forest method was used. After deploying the Azure ML predictive model as a web service, we used a Representational State Transfer application programming interface to send data and obtained predictions in real-time.

Results

No distant metastasis group and distant metastasis group consisted of 267 and 59 patients, respectively. HR-/HER2+ and 50 years old and over patients were higher in metastasis group (p-value = 0.003 and p-value = 0.000). Nuclear grade 3 and N2,3 were higher in metastasis group (p-value = 0.010 and p-value = 0.000, p-value = 0.001 respectively). Stage III was also higher in metastasis group (p-value = 0.000). Among 59 patients with distantmetastasis, multiple sites metastasis was 21 cases (35.6%) and then lung metastasis was 19 cases (32.2%). In the 21 cases of multiple sites metastasis, triple sites was 6 cases (28.6%) and double sites was 15 cases (71.4%). PIK3CA mutation was the most frequent gene variation in all patients (34.5% of no metastasis group and 27.1% of metastasis group) but there was no difference between two groups(p-value = 0.278). BRCA 1 loss of function and BRCA2 loss of function were more frequent in metastasis group than no metastasis group(p-value = 0.033 and p-value = 0.024, respectively) but total counts was too small. We assessed the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for predictive value. The AUC of ROC curve was 1.000 and also accuracy, precision, recall were 1.000. In addition, we conducted internal validation using 83 patients during 2015. When we applied a 0.5 threshold value with our predictive model, true negative was 81 and true positive was 2 among 83 patients. Finally, the accuracy of validation was 1.000.

Conclusion

Our predicted model could represent a useful and easy-to-access tool for the selection of patients with distant metastasis. After additional evaluation with large data and external validation, worldwide use of our model could be expected.

Citation Format: Kim I, Choi HJ, Ryu JM, Lee SK, Yu JH, Kim SW, Nam SJ, Seo SW, Lee JE. A predictive model for distant metastasis in breast cancer patients using machine learning [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 P2-08-52.

Abstract PD5-08: Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers

Understanding how standard-of-care drug treatments affect tumor intrinsic biology and microenvironment is critical for elucidating drug resistance mechanisms and developing better combination therapies as well as new therapies. To characterize the effects of neoadjuvant chemotherapy (NAC) on the genome, transcriptome and tumor infiltrating leukocytes (TILs), we have conducted whole exome and whole transcriptome sequencing of a large longitudinal breast cancer cohort consisting of 146 cases and 281 paired tumor samples. In total, 52 (38%) patients achieved pathologic complete response (pCR) while 85 patients (62%) had residual disease with standard chemotherapy regimen. Tumor biopsies were collected for each patient at three time points – pre-treatment, three weeks after the first cycle of anthracycline and cyclophosphamide (AC) and at the time of surgery after 3 more cycles of AC followed by 4 cycles of taxane or taxane plus Herceptin in case of HER2+ subtype. We detected 5,955 protein-altering somatic mutations affecting 4,414 genes in pretreatment samples and 502 acquired mutations in surgery samples affecting 477 genes including 19recurrently mutated genes such as TP53 and NOTCH1. Across all subtypes, 4,346 genes were differentially expressed (DE) following NAC treatment and significantly enriched in pathways such as cell cycle, ER signaling, PI3K/mTOR, immune and metabolism. Expression-based virtual microdissection analysis indicated that NAC treatment induced an increase in the fractions of stromal and adjacent normal tissue compartment, consistent with observed reduction in tumor cellularity. To assess the NAC induced changes in the molecular landscape of these tumors, we compared molecular features including gene expression signatures, mutation prevalence and copy number alteration between three time points while adjusting for confounding effects of molecular subtype and tumor cellularity. We found that NAC induced dynamic changes in gene expression signatures associated with proliferation and immunomodulatory treatment response. We further validated the observed pattern of change in TILs through histopathology and digital imaging analyses. In pretreatment tumors, 116 genes were DE between patients with pCR vs. those with residual disease with significant enrichment in immune/inflammatory pathways. Further, pre-treatment TIL levels were found to be significantly associated with pCR, echoing previous reports in breast cancers that implicated anti-tumor immunity in mediating the efficacy of chemotherapies. Our analyses also revealed associations between NAC response and baseline genomic attributes such as genomic alterations that affect DNA damage repair pathways. Taken together, these results suggest that NAC induced a multitude of changes on the genomic landscape and immune microenvironment of breast cancers, some of which point to combination strategies with immunomodulatory therapies and therapies that target DNA damage repair.

Citation Format: Kan Z, Lal S, Ding Y, Lee JE, Lee S-H, Lee SK, Yu JH, Choi Y-l, Kim SW, Nam SJ, Kim J-Y, Ram S, Powell E, Ching K, Cho SY, Bonato V, Deng S, Park W-Y, Rejto P, Bienkowska J, Park Y-H. Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers [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 PD5-08.

Abstract P1-15-18: Not presented

This abstract was not presented at the conference.

Citation Format: Choi HJ, Kim SW, Ryu JM, Kim I, Nam SJ, Yu J, Lee SK, Lee JE. Not presented [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 P1-15-18.

Abstract P4-14-04: Time course changes in serum FSH, estradiol, and menstruation restoration in premenopausal patients with breast cancer taking adjuvant tamoxifen after completing chemotherapy: A report from the ASTRRA study

BACKGROUND

Assessment of restoration of ovarian function after chemotherapy is critical with respect to the initiation of different types of endocrine treatment in young high risk breast cancer patients

METHODS

In total, 1289 women who remained premenopausal or resumed premenopausal status after chemotherapy were randomized to receive 5 years of tamoxifen or 5 years of tamoxifen plus 2 years of ovarian suppression. The patients who did not resume menstruation were followed up for 2 years with tamoxifen treatment after finishing chemotherapy. Prospectively collected consecutive post-chemotherapy hormone and menstruation data were available for 705 breast cancer patients who enrolled tamoxifen-only treatment group or did not resume menstruation during follow up. This analysis evaluated the proportion of patients with pre-menopausal FSH levels (<30 mIU/ml), E2 levels (340 pg/ml), and menstruation at any time point during treatment with tamoxifen.

RESULTS

During 5 years of tamoxifen treatment after chemotherapy for premenopausal breast cancer patients, 62% of patients resumed menstruation. Menstruation returned in 92% of patients under 35 years old but only in 31% of patients over 45 years old. Ovarian function, defined by serum FSH and E2 levels, resumed in 94% and 65% of patients, respectively, over 5 years. Most patients achieved ovarian function restoration during the first 2 years after chemotherapy, with 47.1% resuming menstruation and 86.2% and 50.3% achieving pre-menopausal FSH and E2 levels, respectively, in the first 2 years. Clinical factors related to menstruation restoration were younger age (HR = 6.38, 95% CI 1.33-3.47), 6 month hormone profile after chemotherapy (FSH<30: HR=1.67, 95% CI 1.28-2.17; E2 >40: HR=2.96, 95% CI 2.25-3.89), and anthracycline without taxane chemotherapy (HR=1.63, 95% CI 1.25-2.13).

CONCLUSIONS

During 5 years of tamoxifen treatment after chemotherapy, half of patients experienced menstruation restoration, including most very young patients under 35 years. The majority of patients experienced menstruation restoration in the first 2 years of tamoxifen treatment.

Citation Format: Kim HJ, Noh WC, Nam SJ, Park B-w, Lee ES, Im SA, Jung YS, Yoon JH, Kang SS, Park KH, Lee S-J, Jung J, Lee MH, Cho SH, Kim SY, Kim H-A, Han S-H, Han W, Hur MH, Ahn SH. Time course changes in serum FSH, estradiol, and menstruation restoration in premenopausal patients with breast cancer taking adjuvant tamoxifen after completing chemotherapy: A report from the ASTRRA study [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 P4-14-04.

Abstract P2-08-29: The impact of time interval between diagnosis and surgery in each type and stage of breast cancer

Background: There are many factors that might contribute to the delay of surgery in patients with breast cancer. Previous studies investigate the influence of delay of surgery, but they reported inconsistent results. The purpose of this study was to evaluate the impact of time of surgery on prognosis of breast cancer.

Methods: We performed a retrospective review of the patients with breast cancer, who received surgery between 1992 and 2009, by using data from Korea Breast Cancer Society Registry. Kaplan-Meier survival analysis and Cox regression model were used to evaluate the impact of time to surgery in breast cancer and subgroup analyses were performed for each disease stage and molecular subtype.

Result: A total 14727 patients were included for analysis. Delay of surgery more than 31 days was associated with worse survival for breast cancer [hazard ratio (HR) = 2.16; 95% confidence interval (CI), 1.936-2.408, p<0.001]. Subgroup analyses revealed that over 31 days of surgical delay were significantly associated with worse survival in hormone receptor positive and HER-2 negative (p<0.001), hormone receptor positive and HER-2 positive (p<0.001), hormone receptor negative and HER-2 positive (p<0.001), triple negative (p<0.001) and stage II, III breast cancer patients (p<0.001).

Conclusion: Surgical delay of more than 31 days were independent risk factors for worse outcome of breast cancer in each molecular subtype and breast cancer group except stage 0 and I. Although preoperative evaluation is required, surgical delay should be shortened to enhance survival of breast cancer, especially in patients with tumor size more than 2cm or presence of lymph node metastasis.

Citation Format: Kim J-M, Choi HJ, Kim I, Ryu JM, Yu J, Lee JE, Kim SW, Nam SJ, Lee SK. The impact of time interval between diagnosis and surgery in each type and stage of 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 P2-08-29.

Scalalactams A⁻D, Scalarane Sesterterpenes with a γ-Lactam Moiety from a Korean Spongia Sp. Marine Sponge

Intensive study on the chemical components of a Korean marine sponge, Spongia sp., has led to the isolation of four new scalarane sesterterpenes, scalalactams A–D (1–4). Their chemical structures were elucidated from the analysis of spectroscopic data including 1D-and 2D-NMR as well as MS data. Scalalactams A–D (1–4) possess a scalarane carbon skeleton with a rare structural feature of a γ-lactam moiety within the molecules. Scalalactams A and B (1 and 2) have an extended isopropanyl chain at the lactam ring, and scalalactams C and D (3 and 4) possess a phenethyl group at the lactam ring moiety. Scalalactams A–D (1–4) did not show FXR antagonistic activity nor cytotoxicity up to 100 μM.

Structural and Biochemical Characterization of the Curcumin-Reducing Activity of CurA from Vibrio vulnificus

Curcumin is a yellow-colored ingredient in dietary spice turmeric ( Curcuma longa Linn). This nontoxic polyphenol has antitumor, anti-inflammatory, apoptotic, and antioxidant activities. The ingested curcumin is reduced to multihydrated forms with more potent therapeutic potentials by the curcumin reductase (CurA) from commensal Escherichia coli. In this study, we demonstrated that Vibrio vulnificus CurA ( VvCurA) with 87% sequence similarity to the E. coli CurA exhibits the curcumin-reducing activity through spectrophotometric detection of NADPH oxidation and high performance liquid chromatographic analysis of curcumin consumption and product generation. Afterward, we determined the crystal structures of VvCurA and the VvCurA/NADPH complex, and made the in silico model of the VvCurA/NADPH/curcumin ternary complex through induced fit docking. Based on structural information, active site residues that play critical roles in catalysis have been identified and characterized by mutational and kinetic studies, leading us to propose the reaction mechanism of CurA.

Cholic Acid Attenuates ER Stress-Induced Cell Death in Coxsackievirus-B3 Infection

Coxsackievirus Type B3 (CVB3) is an enterovirus that belongs to the Picornaviridae and causes various diseases such as myocarditis and hand-foot-mouth disease. However, an effective antiviral drug is still not developed. In this study, we looked for potential inhibitors of CVB3 replication by examining the survival of CVB3-infected HeLa cells. We detected an antiviral effect by cholic acid and identified it as a candidate inhibitor of CVB3 replication. Cholic acid circulates in the liver and intestines, and it helps the digestion and absorption of lipids in the small intestine. HeLa cells were cultured in 12-well plates and treated with cholic acid (1 and 10 μg/ml) and 10⁶ PFU/ml of CVB3. After 16 h post-infection, the cells were lysed and subjected to western blot analysis and RT-PCR. The production of the viral capsid protein VP1 was dramatically decreased, and translation initiation factor eIF4G1 cleavage was significantly inhibited by treatment with 10 μg/ml cholic acid. Moreover, cholic acid inhibited ERK signaling in CVB3-infected HeLa cells. RT-PCR showed that the amounts of the CVB3 RNA genome and mRNA for the ER stress-related transcription factor ATF4 were significantly reduced. These results showed that cholic acid strongly reduced ER stress and CVB3 proliferation. This compound can be developed as a safe natural therapeutic agent for enterovirus infections.

A Two-Photon Fluorescent Probe for Imaging Endogenous ONOO- near NMDA Receptors in Neuronal Cells and Hippocampal Tissues

In this study, we developed a two-photon fluorescent probe for detection of peroxynitrite (ONOO^-) near the N-methyl-d-aspartate (NMDA) receptor. This naphthalimide-based probe contains a boronic acid reactive group and an ifenprodil-like tail, which serves as an NMDA receptor targeting unit. The probe displays high sensitivity and selectivity, along with a fast response time in aqueous solution. More importantly, the probe can be employed along with two-photon fluorescence microscopy to detect endogenous ONOO^- near NMDA receptors in neuronal cells as well as in hippocampal tissues. The results suggest that the probe has the potential of serving as a useful imaging tool for studying ONOO^- related diseases in the nervous system.

A New Secondary Metabolite from Korean Traditional Herb Plant Hovenia dulcis

Investigation of chemical compounds from the butanol soluble layer of the traditional herb Hovenia dulcis has led to the isolation of a new compound, identified as 2-methoxybenzoic acid-5- O-α-L-rhamnopyranoside (1), along with three known compounds, syringic acid-4- O-α-L-rhamnopyranoside (2), syringic acid (3), and vanillic acid (4). Their chemical structures were established from the interpretation of 2D NMR spectroscopic and the high-resolution mass data.

Enantioselective Synthesis of a Novel Thiazoline Core as a Potent Peroxisome Proliferator-Activated Receptor δ Agonist

The convergent and enantioselective synthesis of a highly potent human peroxisome proliferator-activated receptor delta agonist is presented. More specifically, the thiazoline structure, which constitutes the biosynthetically distinctive core structure of pulicatin (a secondary metabolite of symbiotic bacteria), was synthesized from a commercially available and inexpensive chiral pool of l-threonine.

Colorimetric and Fluorescent Detecting Phosgene by a Second-Generation Chemosensor

Because of the current shortage of first-generation phosgene sensors, increased attention has been given to the development of fluorescent and colorimetric based methods for detecting this toxic substance. In an effort focusing on this issue, we designed the new, second-generation phosgene chemosensor 1 and demonstrated that it undergoes a ring-opening reaction with phosgene in association with color and fluorescent changes with a detection limit of 3.2 ppb. Notably, in comparison with the first-generation sensor RB-OPD, 1 not only undergoes a much faster response toward phosgene with an overall response time within 2 min, but it also generates no byproducts during the sensing process. Finally, sensor 1 embedded nanofibers were successfully fabricated and used for accurate and sensitive detection of phosgene.

Abstract P6-09-08: Identification of ESR1 mutation in breast cancers using targeted ultra-deep sequencing data analysis

Introduction: Estrogen Receptor 1 (ESR1) gene encodes an estrogen receptor, which regulates cell proliferation and promotes tumor progression in estrogen receptor(ER)-positive breast cancer (BC). Therefore, endocrine therapy that inhibiting ER downstream signal, is the most effective treatment strategy in ER-positive BC. However, about 25% of patients with primary disease and almost all patients with metastases will present with or eventually develop endocrine resistance. And genetic alteration of ESR1 is now identified as the endocrine resistance mechanism. However, a few data from clinical trials or public data base exists and could not reflect real world clinic. Therefore, we aimed to identify the frequency and type of ESR1 genetic alterations in BCs through this large scaled study.

Methods: We performed targeted ultra-deep sequencing (CancerSCAN™) using BC tissue specimens. This sequencing was covered entire coding area of ESR1 gene and also detected copy number alteration and translocation of ESR1.

Results: Targeted ultra-deep sequencing of ESR1 was performed using 618 BC tissues. Of 618 tissue samples, 253(40.9%) were MBCs, 362(58.6%) were early BCs (EBCs) and 3 were not identified. In terms of subtypes, 220 ER-positive BCs, 122 ER-positive and HER2-positive BCs, 119 HER2-positive and 153 triple-negative BCs (TNBCs) were included. BCs from patients under 40 year-old were 277(44.8%)(Median: 43.0, range: 23.5 -75.6). ESR1 genetic alterations were identified in 21 BCs (5 EBCs and 16 MBCs). In EBCs, 3 cases were observed in TNBCs and 2 cases were in ER-positive BCs (2.6% and 1.2%, respectively). All five EBC were treatment naïve status. Of 16 cases of ESR1 alterations in MBCs, 10 cases of ESR1 alterations were detected in ER-positive BCs (17.6%), 5cases in ER and HER2-positive BCs(6.7%) and 1 in HER2-positive BCs (1.2%). All ER-positive MBCs were treated with more than one line of endocrine therapy. Most commonly detected genetic alteration was single nucleotide variant (SNV) (15 of 21, 71.4%). Thirteen were in ligand binding domain and two cases occurred in activation function-1 (AF-1) domain (P79A and G145S). D538G and V392I were most frequently mutated loci followed by Y537N (3, 3 and 2 cases, respectively) and only metastatic ER-positive BCs harbored ESR1 activating mutation. Four copy number (CN) amplification in 2 ER-positive and 2 ER and HER2-positive BCs, one CN deletion in TNBC and one ESR1 fusion in ER and HER2-positive BC were also detected (19.0%, 4.8% and 4.8%, respectively). In frame ESR1 fusion was occurred between ESR1 and NPHS1 genes.

Conclusion: In this experimental study, ESR1 genetic alterations were frequently detected in ER-positive MBC but ER-negative or EBC also harbored. The type of genetic alterations varied including SNVs, CN alterations and translocation and ESR1-NPHS1 fusion is the novel genetic alteration that has not been reported. To identify the role of ESR1 genetic alteration in ER-negative BCs and novel translocation, further functional validation would be warranted (Clinical trials.gov Number :NCT02591966).

Citation Format: Kim J-Y, Park K, Park W-Y, Nam SJ, Kim SW, Lee JE, Lee SK, Jung HH, Yu JH, Ahn JS, Im Y-H, Park YH. Identification of ESR1 mutation in breast cancers using targeted ultra-deep sequencing data analysis [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 P6-09-08.

Abstract P1-07-25: Differences among young breast cancer patients based on subtype: A study from the Korean Breast Cancer Society – Running head: Do breast cancers in 20s have worse prognosis than 30s?

Purpose Numerous studies demonstrated that breast cancer in young women (BCY) has unfavorable prognostic features and unfavorable subtype. However, there were few studies to evaluate the effect on the prognosis of breast cancer according to the subtype disparities by age especially BCY. We analyzed breast cancer mortality stratified tumor subtype according to age among the patients with less than 50 year-old. Patients and Methods Data obtained from the Korean Breast Cancer Society Registry (KBCSR), patients diagnosed with invasive breast cancer were retrospectively between 2003 and 2010. We excluded patients with male breast cancer, underwent neoadjuvant chemotherapy, distant metastasis or inflammatory breast cancer at presentation, and other histopathology except invasive ductal or invasive lobular carcinoma. We also excluded patients with lack of immunohistochemistry data and short-term follow-up duration (<12 months). Results We identified 37,865 patients, and excluded by study protocol. Among those, 30,793 patients with breast cancer for eligible for analysis, 793 (2.6%) were 20-29 years and 8,926 (28.8%) were 30-39 years of age. Median follow-up duration was 84 months. Mean age was 42.4 years old. Younger patients with breast cancer were more likely to have advanced stage, higher nuclear grade, present lymphovascular invasion, and more likely to be unfavorable subtype such as triple negative breast cancer (TNBC)

Table 1. Baseline Characteristics Age at Presentation 20-29, N(%)30-39, N(%)40-49, N(%)P-valueOverall793 (2.6)8,133 (26.4)21,867 (71.0) Pathologic stage   <.0001I295 (37.2)2,928 (36.0)9,288 (42.5) II373 (47.0)3,644 (44.8)9,078 (41.5) III119 (15.0)1,442 (17.7)3,211 (14.7) Family history   <.0001Yes81 (10.2)674 (8.3)1,391 (6.4) No712 (89.8)7,459 (91.7)20,476 (93.6) Nuclear grade   <.0001Low85 (10.2)941 (11.6)3,824 (17.5) Intermediate288 (36.3)3,340 (41.1)9,688 (44.3) High331 (41.7)3,165 (38.9)6,650 (30.4) LVI   <.0001Yes249 (31.4)2,840 (34.9)6,711 (30.7) No433 (54.6)4,367 (53.7)13,005 (59.5) Subtype   <.0001Luminal A314 (39.6)3,529 (43.4)11,716 (53.6) Luminal B190 (24.0)1,895 (23.3)4,775 (21.8) Her-252 (6.6)724 (8.9)1,723 (7.9) TNBC237 (29.8)1,895 (24.4)3,653 (16.7) HER-2, human epidermal growth factor-2; TNBC, triple negative breast cancer

. Patients with younger age group showed worse prognosis than patients with older age patients. In multivariate analysis for overall survival, as patients were younger group, hazard ratio was increased, and the patients with TNBC showed higher HR than HER-2, Luminal B, and Luminal A subtype (P< .0001, P< .0001, P< .0001, and P< .0001, respectively). Stratified by subtype, luminal subtype showed significant worse prognosis as the age group was younger, while as, Her-2 and TNBC subtype showed no significantly difference by the age group. Conclusion Patients with 20s breast cancer showed unfavorable characteristics and worse prognosis than 30s and older aged group. Stratified by tumor subtype, breast cancer in 20s with luminal subtype showed worse prognosis, while as HER-2 and TNBC showed no significantly different compare to breast cancer in 30s.

Citation Format: Ryu JM, Yu J, Nam SJ, Kim I, Lee JE, Lee SK, Kim JM, Choi HJ, Kim SW. Differences among young breast cancer patients based on subtype: A study from the Korean Breast Cancer Society – Running head: Do breast cancers in 20s have worse prognosis than 30s? [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 P1-07-25.

Naphthalene-based fluorescent probes for glutathione and their applications in living cells and patients with sepsis

Rationale: Among the biothiols-related diseases, sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection and can result in severe oxidative stress and damage to multiple organs. In this study, we aimed to develop a fluorescence chemosensor that can both detect GSH and further predict sepsis.

Methods: In this study, two new naphthalene dialdehyde compounds containing different functional groups were synthesized, and the sensing abilities of these compounds towards biothiols and its applications for prediction of sepsis were investigated.

Results: Our study revealed that the newly developed probe 6-methoxynaphthalene-2, 3-dicarbaldehyde (MNDA) has two-photon is capable of detecting GSH in live cells with two-photon microscopy (TPM) under the excitation at a wavelength of 900 nm. Furthermore, two GSH detection probes naphthalene-2,3-dicarboxaldehyde (NDA) and 6-fluoronaphthalene-2,3-dicarbaldehyde (FNDA) not only can detect GSH in living cells, but also showed clinical significance for the diagnosis and prediction of mortality in patients with sepsis.

Conclusions: These results open up a promising direction for further medical diagnostic techniques.

A commensal strain of Staphylococcus epidermidis protects against skin neoplasia

We report the discovery that strains of Staphylococcus epidermidis produce 6-N-hydroxyaminopurine (6-HAP), a molecule that inhibits DNA polymerase activity. In culture, 6-HAP selectively inhibited proliferation of tumor lines but did not inhibit primary keratinocytes. Resistance to 6-HAP was associated with the expression of mitochondrial amidoxime reducing components, enzymes that were not observed in cells sensitive to this compound. Intravenous injection of 6-HAP in mice suppressed the growth of B16F10 melanoma without evidence of systemic toxicity. Colonization of mice with an S. epidermidis strain producing 6-HAP reduced the incidence of ultraviolet-induced tumors compared to mice colonized by a control strain that did not produce 6-HAP. S. epidermidis strains producing 6-HAP were found in the metagenome from multiple healthy human subjects, suggesting that the microbiome of some individuals may confer protection against skin cancer. These findings show a new role for skin commensal bacteria in host defense.

Acetonic extracts of the endolichenic fungus EL002332 isolated from Endocarpon pusillum exhibits anticancer activity in human gastric cancer cells

BACKGROUND

Endolichenic fungi are microbes that inhabit the thalli of lichens and produce various unique chemicals that can be used for pharmaceutical purposes.

PURPOSE

This study screened a library of endolichenic fungal extracts to identify novel anticancer agents capable of suppressing the tumorigenicity of human cancer cells.

METHODS

Active compounds were isolated from extracts of endolichenic fungi by column chromatography and reverse-phase HPLC. The anticancer effects of the extracts on cell viability was assessed with the use of MTT assay, Western blotting, fluorescence labeling of apoptotic cell, and flow cytometric analysis; and cell motility with the use of migration, invasion and soft agar colony-formation assay in vitro; and on skin and intraperitoneal mouse xenograft tumors in vivo were investigated. The therapeutic effects of the extract alone or in combination with the conventional chemoreagent docetaxel were analyzed by sulforhodamine B assay.

RESULTS

Acetone extracts of EL002332, isolated from Endocarpon pusillum collected in the China desert in 2010, showed selective cytotoxicity against AGS human gastric cancer cells and CT26 mouse colon cancer cells. An active pure compound named myC was isolated from mycelium acetone extracts in a liquid culture system and showed more potent cytotoxicity than crude extracts in the AGS cell line. Especially, myC greatly increased the apoptotic cell population at the IC₅₀ concentration and activated apoptotic signaling by regulating Bcl2 family protein expression and caspase pathway activity. EL002332 crude extracts and myC decreased AGS cell motility at sub-lethal concentrations. In vivo skin and intraperitoneal xenograft tumor experiments showed that the size of tumors and the tumor score were significantly smaller in EL002332 crude extract-treated groups than in control groups. EL002332 crude extracts showed synergistic effects with docetaxel on the AGS and TMK1 cell lines.

CONCLUSION

The endolichenic fungus EL002332 has potential anticancer activity in gastric cancer and peritoneal carcinomatosis.

Citreibacter salsisoli gen. nov., sp. nov., a bacterium isolated from marine soil

A Gram-stain-negative, strictly aerobic, yellow-colored, rod-shaped, chemoheterotrophic bacterium, designated SNA426^T, was isolated from marine soil in the Republic of Korea. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel marine isolate was affiliated with the family Flavobacteriaceae of phylum Bacteroidetes and that it shared the highest (96.2%) sequence similarity with Gillisia mitskevichiae KMM 6034^T. The strain could be differentiated phenotypically from related members of the family Flavobacteriaceae. The major fatty acids of strain SNA426^T were iso-C15:0, C16:1 ω7c and/or C16:1 ω6c and iso-C17:0 3-OH. The DNA G+C content of the strain was 39.6 mol% and the major respiratory quinone was menaquinone 6 (MK-6). Strain SNA426^T had phosphatidylethanolamine, phosphatidylcholine, three unidentified aminolipids and nine unidentified lipids as polar lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel genus in the family Flavobacteriaceae, for which the name Citreibacter gen. nov. is proposed. The type species is Citreibacter salsisoli sp. nov., with the type strain SNA426^T (= KCCM 90269^T = CGMCC 1.16129^T).

Identification of Antiangiogenic Potential and Cellular Mechanisms of Napyradiomycin A1 Isolated from the Marine-Derived Streptomyces sp. YP127

Angiogenesis is the process of new blood vessel formation. Excessive angiogenesis is a critical factor in the progression of cancer, macular degeneration, and other chronic inflammatory diseases. When investigating the effects of crude extracts of cultured marine microorganisms, an extract of the cultured Streptomyces sp. YP127 strain was found to inhibit human umbilical vein endothelial cell (HUVEC) tube formation. Bioassay-guided fractionation and spectroscopic data analyses led to the identification of napyradiomycin A1 (1) as an antiangiogenic component of the extract. Compound 1 inhibited HUVEC tube formation in a concentration-dependent manner. It inhibited endothelial cell proliferation but did not affect human dermal fibroblast proliferation. Compound 1 also suppressed migration and invasion of vascular endothelial cells. In addition, compound 1 suppressed vascular endothelial cadherin expression and increased the permeability of the endothelial cell membrane. These results suggested that compound 1 modulates cell permeability and inhibits the angiogenesis of endothelial cells.

Anti-Pigmentary Effect of (-)-4-Hydroxysattabacin from the Marine-Derived Bacterium Bacillus sp

Bioactivity-guided isolation of a crude extract from a culture broth of Bacillus sp. has led to the isolation of (-)-4-hydroxysattabacin (1). The inhibitory effect of (-)-4-hydroxysattabacin (1) was investigated on melanogenesis in the murine melanoma cell line, B16F10, and human melanoma cell line, MNT-1, as well as a pigmented 3D-human skin model. (-)-4-Hydroxysattabacin treatment decreased melanin contents in a dose-dependent manner in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. Quantitative real time PCR (qRT–PCR) demonstrated that treatment with (-)-4-hydroxysattabacin down-regulated several melanogenic genes, including tyrosinase, tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) while their enzymatic activities were unaffected. The anti-melanogenic effects of (-)-4-hydroxysattabacin were further demonstrated in a pigmented 3D human epidermal skin model, Melanoderm^TM, and manifested as whitening and regression of melanocyte activation in the tissue.

Biosynthetic pathways of aminoglycosides and their engineering

Despite decades long clinical usage, aminoglycosides still remain a valuable pharmaceutical source for fighting Gram-negative bacterial pathogens, and their newly identified bioactivities are also renewing interest in this old class of antibiotics. As Nature's gift, some aminoglycosides possess natural defensive structural elements that can circumvent drug resistance mechanisms. Thus, a detailed understanding of aminoglycoside biosynthesis will enable us to apply Nature's biosynthetic strategy towards expanding structural diversity in order to produce novel and more robust aminoglycoside analogs. The engineered biosynthesis of novel aminoglycosides is required not only to develop effective therapeutics against the emerging 'superbugs' but also to reinvigorate antibiotic lead discovery in readiness for the emerging post-antibiotic era.

Abstract P6-09-50: Impact of young age on recurrence and mortality after surgery in breast cancer: 15 years active surveillance

Introduction:Substantial efforts have been made to find factors associated with breast cancer (BC) recurrence and mortality after BC treatment. So far TNM stage, ER, PR, and HER2 status are considered as the major predictive markers of BC recurrence and used for treatment decision. However, most of these factors were evaluated independent from other important confounders such as age, stage, and various anti-cancer treatments because they were mostly derived from clinical trials. In Korea, up to 50% of BC patients are premenopausal women, it is not clear how age at diagnosis affect the progression and outcomes of the disease considering all known prognostic factors including TNM stage, ER, PR, and HER2 status. We aim to evaluate the impact of young age on recurrence and mortality after surgery among Korean women with BC.

Methods: This is a retrospective cohort study conducted using the data from BC registry from 2000 to 2016 at Samsung Medical Cancer, Seoul, Korea. Patients who received curative BC surgery and who had histologically-confirmed invasive BC between 2000 to 2011 were included in the study. Patients who second primary cancer or double primary cancer were excluded. Information local, regional, or distant recurrence and death until May 2016 was collected using electronic medical records and National Health Statistics. Cumulative incidence rates of distant recurrence and morality at 3-years, 5-years and 10-years were calculated using a competing-risk model. Cox proportional hazards analysis were conducted with 3 different models to take into account for potential confounding factors including age, body mass index (BMI), stage and subtype at breast cancer diagnosis, chemotherapy, radiotherapy and hormone therapy.

Results:There were 7360 BC patients with curative BC surgery between 2000 and 2011, and the average follow up duration was 75.4 months. The mean age at diagnosis was 48.4 years old (Standard deviation (SD)=±10), and 6.2% (n=459) was diagnosed younger than 35. Of total, 13.3% were stage III BC and 73.4% of patients had hormone receptor positive BC. The cumulative incidence (95%CI) of recurrence at 3, 5, and 10 years was 4.4% (3.9-4.9), 7.5% (6.8-8.2), and 14.8% (12.9-16.7) respectively. The incidence of mortality at 3, 5, and 10 years was 1.8% (1.5-2.1), 3.8% (3.3-4.3), and 10.2% (9.1-11.5) respectively. Patients who were diagnosed BC under 35 years of age had 2.14 (95% confidence interval (CI):1.74-3.10) and 1.62 (95% CI:1.02-2.56) times higher risk of distant recurrence and mortality compared to patients whose age at diagnosis were between 50 to 60 after adjusting all well-known prognostic factors including stage, subtype, and BMI at diagnosis, chemotherapy, radiotherapy and hormone therapy.

Conclusions: Young age at diagnosis (<35) was the most significant predictor on BC recurrence and mortality independently from BC stage and subtype. Further study is warranted to explain biologic background for the differences in outcomes in young women with BC.

Citation Format: Kim J-Y, Cho J, Kim H, Kang D, Jung HA, Lee S-H, Bae S, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im Y-H, Guallar E, Park YH. Impact of young age on recurrence and mortality after surgery in breast cancer: 15 years active surveillance [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 P6-09-50.

Abstract P1-05-15: Multi-omics and immuno-oncology profiling reveal distinct molecular signatures of young Asian breast cancers

Breast cancers (BC) in younger, premenopausal patients (YBC) tend to be more aggressive with worse prognosis, higher chance of relapse and poorer response to endocrine therapies compared to breast cancers in older patients. The proportion of YBC (age ≤ 40) among BC in East Asia is estimated to be 16-32%, significantly higher than the 7% reported in Western countries. To characterize the molecular bases of Asian YBC, we have performed whole-exome sequencing (WES) and whole-transcriptome sequencing (WTS) on tumor and matched normal samples from 134 Korean BC patients consisting of 74 YBC cases (age ≤ 40) and 60 OBC cases (age > 40). We then performed comparison analyses and integrative analyses with the TCGA BC cohort consisting of 1,116 tumors from primarily Caucasian patients, also grouped by age into YBC (age ≤ 40), IBC (40 < age ≤ 60) and OBC (age > 60).

Somatic mutation prevalence analysis identified 7 significantly mutated genes and the same top three genes – TP53, GATA3 and PIK3CA – were reported by the TCGA BC study. To identify differentially expressed (DE) genes and pathways in YBCs vs. OBCs, we performed logistic regression analyses while controlling for the confounding effects of tumor purity and stage. We were surprised to see a significant overlap in DE pathways between a comparison of adjacent normal tissues in younger vs. older TCGA cohorts and a comparison of YBC vs. OBC tumors, indicating that normal tissue compartment could contribute to observed differences between bulk tumors. To separately examine molecular signatures from tumor, stroma and normal compartments, we used non-negative matrix factorization (NMF) analyses to virtually dissect bulk tumor expression data and identified 14 factors including 3 factors associated with normal tissues, 1 factor associated with stroma and 1 factor associated with tumor infiltrating lymphocytes (TIL). Integrative analyses of tumor associated factors and DE pathways revealed that estrogen response, endocrine therapy resistance, and oxidative phosphorylation pathways are up-regulated in YBCs compared to OBCs while cell cycle and proliferation pathways are up-regulated in Asian OBCs. Interestingly, many immune and inflammation pathways correlated with the TIL factor were significantly upregulated in OBCs vs. YBCs. Using gene expression signatures representing distinct immune cell types, we classified our cohort into four subtypes of varying TIL activities and observed significant enrichment of the TIL-high subtype in OBCs compared to YBCs. These observations were confirmed by IHC analyses of four TIL markers (CD45, CD4, CD8 and CD163) in 120 tumors.

To our knowledge, this is the first large-scale multi-omics study of Asian breast cancer and would significantly contribute to the compendium of molecular data available for studying young breast cancers. The major landmarks in the molecular landscape looked similar across BCs of different ethnicities and ages, however, we have identified a number of distinguishing molecular characteristics associated with Asian YBC. The sources for some signatures were further traced to non-tumor intrinsic compartments, indicating that tumor microenvironment may play potentially important roles in driving the carcinogenesis of young breast cancers.

Citation Format: Kan Z, Ding Y, Cho S, Lee S-H, Powell E, Jung HH, Chung W, Deng S, Choi Y-l, Kim J, Park W-Y, Vizcarra P, Fernandez-Banet J, Nichols T, Ram S, Lee SK, Kim SW, Lee JE, Ching KA, Kim J-Y, Ahn JS, Im Y-H, Nam SJ, Park YH. Multi-omics and immuno-oncology profiling reveal distinct molecular signatures of young Asian breast cancers [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 P1-05-15.

Abstract P1-02-11: Clinical utility of serial monitoring of circulating tumor DNA (ctDNA)in patients with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC)

Introduction: Circulating tumor DNA (ctDNA) is a new biomarker which could guide further treatment. Characterization of tumor mutation profiles is required for informed choice of therapy, given that biological agents target specific pathways and effectiveness may be modulated by specific mutations. It would have clinical utility for neoadjuvant setting also. Thus, we assess the potency of ctDNA to predict tumor response to neoadjuvant chemotherapy(NAC) in locally advanced breast cancer(LABC).

Methods: We performed targeted deep sequencing of 30 plasma DNAs and 10 matched germline DNAs from 10 LABC patients. Serial plasma DNAs were collected at diagnosis, after 1st NAC and curative surgery. For the target enrichment, we designed RNA baits covering a total of ~202kb regions of human genome including a total of 83 cancer-related genes. We constructed the sequencing libraries according to the optimized protocol that we recently reported and sequenced on Illumina HiSeq2500 aiming a mean sequencing depth of ~10,000. After excluding unmapped reads, PCR duplicates and off-target reads, the coverage depths for plasma DNA and germline DNA samples were 2,627x and 4,833x on average, respectively. NAC response was measured by residual cancer burden(RCB) score, calculated as a continuous index combining pathologic measurements of primary tumor and nodal metastases for prediction of distant relapse-free survival.

Results: We analyzed ctDNA and primary tumor tissues from 10 patients with LABC scheduled NAC followed by operation in Samsung Medical Center. Of ten LABCs, one excluded from analysis because of angiosarcoma of breast. Five samples were triple-negative breast cancers (BCs), 2 were HER2 positive BCs and others were ER positive BCs. In tumor response, 1 patient had pathologic complete response (pCR), 1 had RCB class I, 4 and 3 patients did RCB class II and III.

Of 83 genes, in analysis of ctDNA at BC diagnosis, we found 2 to 6 mutations in each samples and 3 mutations were detected averagely. Most common mutation was TP53 (6 patients), followed by PIK3CA mutation. By measuring these mutations in serial ctDNA, we found that ctDNA had disappeared after first cycle of NAC in patient with pCR. In two patients with RCB class I, ctDNA had decreased by more than 10 percent (the level of ctDNA(pg/ml): 455.9 to 30.4, 5.8 to 0.0) of primary plasma sample after first NAC. Two patients increased level of ctDNA had tumor response with RCB class III and one patient had distant tumor recurrence within 3 months after curative surgery. However, correlation between the level of ctDNA and initial stage was not observed.

Patient No.Initial stageSurgical stageRCB scoreRCB classct DNA at diagnosis (pg/5ml)ctDNA after 1st NAG (pg/5ml)Tumor recurrence12A11.3331455.930.4No22B00pCR446.60.0No33B2A1.31515.80.0No42A12.132246.255.4No52B11.7972107.811.6No63B3A4.09033401.15075.5Yes73A2B3.92235088.68536.7No

Conclusions: This preliminary result suggests that serial monitoring of ctDNA would be a potiential surrogate marker to predict tumor response and recurrence during NAC in LABC patients. Further results with long-term outcomes are warranted.

Citation Format: Kim J-Y, Park D, Jung HH, Bae SY, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im Y-H, Park YH. Clinical utility of serial monitoring of circulating tumor DNA (ctDNA)in patients with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC) [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 P1-02-11.

Abstract P6-09-36: Tamoxifen resistance: EGFR expression in hormone receptor-positive and HER2 negative breast cancer

Purpose: Crosstalk between growth factor receptor tyrosine kinases (RTKs) and the estrogen receptor (ER) represents one of the most important mechanisms of endocrine resistance. EGFR and HER2 have been recognized as prominent factors associated with endocrine resistance. Most previous studies did not identify subgroups by HER2 overexpression and/or included breast cancer with HER2 overexpression. Accordingly, we analyzed HR positive (HR+) tumors without HER2 overexpression (HER2-).

Methods: We analyzed the clinical data of 2,166 patients with HR+HER2- breast tumors, between January 2007 and July 2013.We included only patients who had endocrine therapy with tamoxifen. Immunostaining for EGFR was interpreted as positive when at least 10% of the tumor cells showed moderate to strong membrane staining.

Results: EGFR expression (EGFR+) was present in 109 patients (5%). EGFR expression was significantly associated with more advanced stage and higher grades. In the univariate analyses, EGFR+ tumors were associated with poorer prognosis than EGFR- tumors (5-year DFS, EGFR+ vs. EGFR-, 91.2% vs. 96.6%, P <0.001; 5-year OS, EFGR+ vs EGFR-, 93.1 % vs. 99.4%, P < 0.001). In the multivariate analysis, EGFR+ tumors had a hazard ratio of 2.63 (95% CI 1.14 -6.05) for DFS. EGFR+ tumors had a hazard ratio of 8.8 (95% CI 2.68-132.25) for OS.

Conclusion: EGFR expression could be prognostic factor in hormone receptor-positive and HER2 negative breast cancer, for tamoxifen resistance.

Citation Format: Bae SY, Nam SJ, Lee SK, Kim SW, Lee JE, Yu JH. Tamoxifen resistance: EGFR expression in hormone receptor-positive and HER2 negative breast cancer [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 P6-09-36.

A two-photon fluorescent probe for specific detection of hydrogen sulfide based on a familiar ESIPT fluorophore bearing AIE characteristics

A two-photon fluorescent probe based on an ESIPT fluorophore bearing AIE characteristics was utilized to detect H₂S.

An efficient two-photon fluorescent probe for human NAD(P)H:quinone oxidoreductase (hNQO1) detection and imaging in tumor cells

The probe TPQ, which displays high selectivity and anti-interference ability, was successfully applied to endogenous hNQO1 imaging and for the identification of different cancer cells.

Cadiolides J-M, antibacterial polyphenyl butenolides from the Korean tunicate Pseudodistoma antinboja

Activity-guided fractionations of the tunicate Pseudodistoma antinboja yielded four new compounds of the cadiolide class (cadiolides J-M, 1, 3-5) along with a known one (cadiolide H, 2). The structures were defined by spectroscopic methods including X-ray crystallographic analysis. These compounds were evaluated for their antibacterial activity and exhibited potent antibacterial activity against all of the drug resistant strains tested with MICs comparable to those of marketed drugs such as vancomycin and linezolid.

Characterization of the Two Methylation Steps Involved in the Biosynthesis of Mycinose in Tylosin

The S-adenosyl-l-methionine-dependent O-methyltransferases TylE and TylF catalyze the last two methylation reactions in the tylosin biosynthetic pathway of Streptomyces fradiae. It has long been known that the TylE-catalyzed C2‴-O-methylation of the 6-deoxy-d-allose bound to demethylmacrocin or demethyllactenocin precedes the TylF-catalyzed C3‴-O-methylation of the d-javose (C2‴-O-methylated 6-deoxy-d-allose) attached to macrocin or lactenocin. This study reveals the unexpected substrate promiscuity of TylE and TylF responsible for the biosynthesis of d-mycinose (C3‴-O-methylated d-javose) in tylosin through the identification of a new minor intermediate 2‴-O-demethyldesmycosin (2; 3‴-methyl-demethyllactenocin), which lacks a 2‴-O-methyl group on the mycinose moiety of desmycosin, along with 2‴-O-demethyltylosin (1; 3‴-methyl-demethylmacrocin) that was previously detected from the S. fradiae mutant containing a mutation in the tylE gene. These results unveil the unique substrate flexibility of TylE and TylF and demonstrate their potential for the engineered biosynthesis of novel glycosylated macrolide derivatives.

Anti-adipogenic and anti-diabetic effects of cis-3',4'-diisovalerylkhellactone isolated from Peucedanum japonicum Thunb leaves in vitro

Peucedanum japonicum Thunb is a medicinal plant belonging to the family Umbelliferae. This study evaluated the anti-diabetic and anti-obesity effects of cis-3',4'-diisovalerylkhellactone (cDIVK) isolated from Peucedanum japonicum Thunb leaves. cDIVK (30 and 50μM) effectively inhibited adipocyte differentiation and fat accumulation, whereas it stimulated glucose uptake compared with the control in 3T3-L1 cells. cDIVK significantly increased AMPK activation and suppressed protein and mRNA expression of major adipogenic transcriptional factors such as C/EBPα, PPARγ and SREBP-1c in 3T3-L1 cells. In addition, cDIVK had potential α-glucosidase inhibitory activity. These results indicated that cDIVK may act as a natural dual therapeutic agent for diabetes and obesity.

Acredinone C and the Effect of Acredinones on Osteoclastogenic and Osteoblastogenic Activity

A new inhibitor, acredinone C (1), of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation was isolated from the culture broth of the fungus Acremonium sp. (F9A015) along with acredinones A (2) and B (3). The structure of acredinone C (1), which incorporates benzophenone and xanthone moieties, was established by the analyses of combined spectroscopic data including 1D and 2D NMR and MS. All of the acredinones studied efficiently inhibited the RANKL-induced formation of TRAP(+)-MNCs in a dose-dependent manner without any cytotoxicity up to 10 μM. Acredinone A showed dual activity in both osteoclast and osteoblast differentiation in vitro and good efficacy in an animal disease model of bone formation.