Abstract P6-20-10: Role of GPR110 in breast cancer

Our long-term goal is to discover adhesion GPCR targets in breast cancer. Our previous studies have found GPR110 to be overexpressed in tumorigenic cell population as well as in anti-HER2 drug-resistant derivatives of HER2+ breast cancer cells. In subsequent studies, we found that GPR110 knockdown inhibited anchorage-independent cell growth, mammosphere formation, and invasion/migration of HER2+ breast cancer cells. Conversely, overexpression of GPR110 by lentiviral delivery of cDNA enhanced anchorage-independent cell growth, mammosphere formation, and invasion/migration in HER2+ breast cancer cells. In addition, GPR110 overexpression led to increase in the % of Aldefluor-positive tumorigenic cell population, further emphasizing the role of GPR110 as a mediator of tumorigenesis in addition to the metastatic processes in HER2+ breast cancer. Among various subtypes of breast cancer, GPR110 expression was higher in HER2+ and basal subtypes, most of which are triple-negative (negative for ER, PR, and HER2), compared to luminal A and B subtypes. GPR110 was either gene amplified or upregulated in 4% of all breast cancers based on the publicly available TCGA dataset. GPR110 overexpression predicted poorer recurrence-free survival in triple-negative breast cancer. Furthermore, GPR110 was overexpressed in brain metastatic lesions compared to mammary tumors in patient-derived xenograft models of triple-negative breast cancer (WHIM2 and WHIM30). Knocking down GPR110 reduced anchorage-dependent and -independent cell growth, mammosphere formation, and invasion/migration of triple-negative breast cancer cells. Overall, our results suggest that GPR110 may be a potential drug target in HER2+ and triple-negative breast cancer. Drug discovery efforts to identify GPR110 antagonists will provide useful pharmacological tools for validating GPR110 as a drug target in breast cancer. Since GPR110 is also overexpressed in various other types of cancer, understanding the mechanism of GPR110 upregulation and signaling in cancer is an important future direction.

This work was supported by the Department of Defense Grants W81XWH-14-1-0340 and W81XWH-14-1-0341 to Drs. Trivedi and Schiff, respectively.

Citation Format: Bhat R, Qin L, De Angelis C, Sahay D, Bhargava D, Creighton C, Yadav P, Yazdanfard S, Alrawi A, Yadav V, Vasaikar S, Nanda S, Sethunath V, Fu X, Zhang B, Narkar V, Schiff R, Trivedi M. Role of GPR110 in 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 P6-20-10.

Abstract P1-05-05: eEF1A2 facilitates PTEN-GSK3β mediated Aurora-A protein degradation during S-G2 phase inactivated in PTEN-deficient breast cancer

The AURKA gene, encoding Aurora kinase-A (Aurora-A), is frequently amplified and overexpressed across multiple cancer types correlating with poor prognosis. Although the AURKA gene is frequently amplified in human cancers, underlying mechanism(s) for Aurora-A protein stability through different phases of cell cycle are not well elucidated. Inhibiting the kinase activity and promoting protein degradation are two well-validated conceptual strategies for targeting protein kinases in cancers. Here, we demonstrate that Eukaryotic Elongation Factor 1 Alpha 2 (eEF1A2) facilitates PTEN-GSK3β mediated Aurora-A protein degradation through the SCF complex (SKP1-Cul1-FBXW7) during the S/G2 phase of proliferating cells. In contrast, this mechanism is inactivated in cancer cells accompanying PTEN-GSK3β pathway deficiency. Mechanistically, eEF1A2 interacts with Aurora-A, GSK3β, FBXW7 and Cul1-E3 ligase, as the SCF complex, to facilitate Aurora-A polyubiquitination for 26S proteasomal degradation. eEF1A2 promotes PTEN phosphorylation at T366 and stability, inactivates AKT and activates GSK3β which in turn phosphorylates Aurora-A at S283, S284 and S342. The phosphorylation of Aurora-A at S342 is detected during S/G2 phase of cell mitosis in parallel with eEF1A2-SCF complex formation with active form of GSK3β and neddylated Cul1. Conversely, genetic ablation of EEF1A2 and PTEN, activation of AKT, inhibition of GSK3β, expression of Aurora-A phosphodeficient-mutant attenuates the Aurora-A protein degradation which is corroborated in Aurora-A overexpressing mouse mammary carcinomas and human breast carcinomas. This study identifies a novel mechanism of Aurora-A protein degradation mediated eEF1A2-PTEN-GSK3β pathway and provides a framework for the discovery of Aurora-A therapeutic targets in breast cancer that harbors deficiency of PTEN tumor suppressor pathway.

Citation Format: Treekitkarnmongkol W, Solis LM, Kai K, Thompson AM, Tian W, Wistuba II, Sasai K, Jltsumori Y, Sahin AA, Hawke DH, Lee JM, Qin L, Bawa-Khalfe T, Rad R, Wong KK, Abbott CM, Katayama H, Sen S. eEF1A2 facilitates PTEN-GSK3β mediated Aurora-A protein degradation during S-G2 phase inactivated in PTEN-deficient 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 P1-05-05.

Abstract P6-17-12: Neratinib in combination with trastuzumab is superior to each alone and to pertuzumab plus trastuzumab in HER2-positive in vivo breast cancer models

Background: Lapatinib (L) plus trastuzumab (T) alone or with endocrine therapy for HER2+/ER+ tumors but without chemotherapy, yielded complete tumor eradication in xenograft models. In neoadjuvant trials (NCT00548184, 00999804, 01973660), a substantial number of patients achieved pathologic complete response with this same strategy. The irreversible pan-HER inhibitor neratinib (N) has been recently approved by the FDA for early stage HER2+ breast cancer and has shown greater potency compared to L in the preclinical setting. However, the therapeutic efficacy of N in combination with T (N+T) and how it compares to pertuzumab (P) +T (without chemotherapy) has not been well studied.

We hypothesize that dual HER2 inhibition using N+T will be highly efficacious and more effective than P+T due to more complete blockade of the HER pathway. Here, we evaluate the therapeutic efficacy of N, P, and T, either alone or in combination, with a primary focus on comparing N+T vs. P+T in established cell line- and patient-derived xenograft (PDX) models.

Methods: Athymic nude and SCID/Beige mice bearing BT474-AZ cell line (ER+/HER2+), and BCM-3963 PDX tumors (ER-/HER2+, wild-type PIK3CA), respectively were randomized to vehicle, N (20mg/kg, 5 days/week), T (10mg/kg, twice a week), P (6mg/kg, once a week), N+T, or P+T, with simultaneous estrogen (E2) deprivation (ED) in BT474-AZ model. Treatment response was assessed by biweekly tumor measurements. Study endpoints included time to tumor regression (TTR) and progression (TTP) (tumor halving/doubling over baseline, respectively), and the rate and time of complete response (CR and TCR, respectively). Results were analyzed using survival analysis (Kaplan-Meier estimates) and generalized Wilcoxon tests.

Results: In the BT474-AZ model, mice treated with E2+vehicle and ED+vehicle showed steady tumor growth, with a median TTP of 8 and 25 days, respectively. While tumor regression was observed in 100% of mice treated with N, P, T, N+T, and P+T, tumors treated with N+T regressed faster compared to P (p<0.001), T (p=0.004), and P+T (p=0.044). Further, N+T was superior to N (p=0.018) and T (p=0.007) alone in achieving accelerated CR. In the BCM-3963 model, tumors treated with vehicle, T, P, and P+T continued to grow with a median TTP of 11, 16, 19, and 17 days, respectively. In contrast, CR was achieved in 100% of N and N+T treated mice. Importantly, combining N with T accelerated the attainment of CR compared to N alone (p=0.026). Molecular and pathologic analysis of short-term treated tumors in both models to evaluate alterations in HER signaling, cell proliferation, and apoptosis is ongoing.

Model/TreatmentN of miceMedian TTP (Days)Median TTR (Days)Median TCR (Days)CR (%)BT474-AZ     E2+Vehicle98--0ED+Vehicle1025--0ED+N13-214100ED+T12-519100ED+P12-185492ED+N+T13-210100ED+P+T14-414100BCM-3963     Vehicle1511--0N15-417100T1416--0P1319--0N+T19-614100P+T1617--0

Conclusions: Our findings establish the preclinical efficacy of combining N with T for HER2+ breast cancer and warrant further clinical testing to investigate the efficacy of N+T without chemotherapy in the neoadjuvant setting for patients with HER2+ breast cancer.

Citation Format: Veeraraghavan J, Sethunath V, Qin L, Shea MJ, Mitchell T, De Angelis C, Nanda S, Diala I, Lalani AS, Hilsenbeck SG, Rimawi MF, Osborne CK, Schiff R. Neratinib in combination with trastuzumab is superior to each alone and to pertuzumab plus trastuzumab in HER2-positive in vivo breast cancer models [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-12.

[Efficacy and safety of cryotherapy combined with balloon dilatation through electronic bronchoscope in the management of airway occlusion caused by scar stenosis type of tracheobronchial tuberculosis]

Objective: To investigate the efficacy and safety of cryotherapy combined with balloon dilatation through electronic bronchoscope in the management of airway occlusion caused by scar stenosis type of tracheobronchial tuberculosis (TBTB). Methods: From December 2008 to May 2016, 98 cases of airway occlusion caused by scar stenosis of TBTB were diagnosed by microbiology, histopathology, CT (computer tomography), bronchial reconstructions and bronchoscopy. All patients underwent routine anti-tuberculosis chemotherapy and cryotherapy through bronchoscope. The patients whose airways were reopened successfully received balloon dilatation through bronchoscope subsequently. The treatment effects were estimated by indexes including clinical efficacy, modified medical research council (mMRC) dyspnea scale and complications. Results: Among the 98 patients, airway occlusion in 87 cases were reopened successfully by cryotherapy for (10±4) times, and then these patients received balloon dilatation through bronchoscope for (7±3) times subsequently. The total effective rates were 76.53% and 72.45% after 3 and 12 months after the treatments respectively. Analysis of the disease courses of patients with different therapeutic efficacy showed that the median disease course was 3 months in healed cases, 5 months in effective cases and 9 months in ineffective cases. There was a significant difference between the ineffective and the total effective cases in disease courses (t=-15.012, P<0.01). The average of mMRC score changed from (3.8±0.5) before the procedure, to (1.1±0.7), (1.2±0.7) and (1.2±0.7) immediately, 3 and 12 months after the treatments. The difference was significant between the scores before and after therapy (t=30.398-31.058, P<0.01), but not among the 3 scores after treatments. No serious complications were observed in all cases. Conclusions: Cryotherapy combined with balloon dilatation through electronic bronchoscope was a very safe and effective method in the management of airway occlusion caused by scar stenosis of tracheobronchial tuberculosis. A shorter course of disease indicated more benefits for patients.

[Clinical management of 110 cases of polypropylene mesh and sling exposure after reconstructive pelvic floor surgery]

Objective: To explore the clinical management and outcomes of polypropylene mesh and sling exposure after reconstructive pelvic surgery (RPS) . Methods: A total of 110 cases of mesh and sling exposure after RPS were analyzed, who admitted between Jan. 2002 and Oct. 2017 in First Affiliated Hospital of PLA General Hospital, in which 3 cases were referred from other hospitals. Mesh and sling exposures were identified in the outpatient clinic and categorized and managed according to International Continence Society and International Urogynecology Association (ICS-IUGA) classification about category, time and site (CTS) of mesh complication. Outpatient management included observation, topical estrogen use and mesh removal. Management in hospital included surgical removal of exposed mesh and repair of the resulting defects under the anesthesia. Seventy-four cases were managed in the outpatient setting, and 36 cases required inpatient management. Follow-up was consecutively performed from 1 month to 10 years. Objective outcome included the surgeon's assessment of the healing state of the vaginal mucosa. Subjective outcome was evaluated with patient global impression of improvement questionnaire (PGI-I) . Results: One hundred and ten patients with mesh exposure were classified according to the different RPS underwent. There were 95 cases from transvaginal mesh surgery, 5 cases from anti-stress urinary incontinence sling surgery, and 10 cases from sacrocolpopxy. The outpatient group healed at an average of (3.0±1.8) months. Of the 36 patients who required inpatient management, 21 cases healed completely at an average of 7 days after one surgery. The remaining 8 cases required either two or three times surgeries or conservative management. In the outpatient group, the PGI-I scale very much better was found in 65 cases (87.8%) and much better in 9 cases (12.2%) . In the inpatient surgery group, the scale was very much better in 30 cases (83.3%) , and much better in 6 cases (16.7%) . Conclusions: Among patients with mesh exposure after mesh-augmented RPS, 2/3 of patients with a CTS classification 1-3 could be managed in the office, and remaining 1/3 with CTS classification 4-6 need operation under anesthesia in hospital. If the mesh and sling exposure could be scientifically classified, according to the size, site and accompany symptoms, as well as pain, most of the mesh complications after explosure could be resolved. Using the pelvic floor repair and polypropylene mesh sling, the majority of the patients could get a better outcome, without affecting the effect of the original operation.

Volatile flavour components, microbiota and their correlations in different sufu, a Chinese fermented soybean food

AIM

To investigate the volatile flavour components (VFCs), microbiota and their correlations of three categories of sufu, a Chinese fermented soybean food.

METHODS AND RESULTS

The VFCs were analyzed by headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography and mass spectrometry. A total of 141 VFCs were tentatively identified, in which 12 esters, eight aldehydes, five alcohols and nine miscellaneous compounds were recognized as the characteristic VFCs through the relative odour activity value. The complex microbial community was revealed by Illumina MiSeq sequencing. Among the total 202 bacteria and 125 fungi species identified, 16 bacteria and 7 fungi species were revealed as dominant community members. Furthermore, the VFC-microbiota correlation was characterized by Spearman's rank correlation coefficients (ρ). Based on the positive VFC-microbiota correlation, two bacterial species and three fungal species were selected as potential flavour-producing microbiota.

CONCLUSIONS

A variety of VFCs and complicated microbiota were observed in the three categories of sufu. Lactococcus lactis, Sphingobacterium sp., Pichia fermentans, Kodamaea ohmeri and Saccharomyces rouxii were the potential flavour-producing microbiota.

SIGNIFICANCE AND IMPACT OF THE STUDY

The preliminary results would be useful for designing starter cultures to produce sufu with desirable sensory properties, consistent flavour and shorter ripening time. Furthermore, these results will also provide a new insight to improve the flavour quality of traditional fermented soybean food.

Can we assess severity of Guillain-Barré syndrome using absolute monocyte count?

INTRODUCTION

Guillain-Barré syndrome (GBS) is an inflammatory demyelinating autoimmune disease, associated with blood-nerve barrier breakdown, inflammatory cells infiltration, and cytokine leakage in the peripheral nervous system. Currently, it has been revealed that monocytes play key roles in the inflammatory response. Therefore, we aimed to assess the correlation between monocyte count and GBS in this study.

METHODS

Retrospective study was conducted in 114 patients with GBS and 120 age- and gender-matched individuals.

RESULTS

Absolute monocyte count in patients with GBS was higher than that in healthy controls (0.61 ± 0.24 vs 0.41 ± 0.10; P  < .001). Interestingly, monocyte count had significant positive correlations with CRP, ESR, and disease severity of GBS (r = .244, P = .009; r = .269, P = .004; r = .322, P < .001). A cutoff value of 0.515 for monocyte count was observed in patients with GBS (areas under the curve = 0.808, 95% confidence interval = 0.749-0.868, P  < .001). Meanwhile, absolute monocyte count was independently associated with GBS in logistic regression analysis (odds ratio = 2.291, 95% confidence interval = 3.557-27.493, P < .001).

CONCLUSION

Our findings demonstrated that elevated monocyte count is independently associated with GBS patients, and suggested monocyte count is positively associated with disease severity of GBS.

[Blocking effects of serum antibodies against HBGA binding to norovirus GII.4 of population in oyster culture area of Guangdong Province]

Objective: Evaluate GII.4 norovirus infection and blocking effects of serum antibodies against HBGAs binding to GII.4 norovirus of population in oyster culture area, provide references for screening of fully human monoclonal antibody. Methods: Using a random survey method to collect blood and saliva samples in oyster culture area, select serum samples from the inland region of Guangdong as control group. Identification of salivary HBGA receptor phenotype and detection of serum antibody levels between two areas by ELISA. A vitro neutralization model was to determine the efficiency of serum antibodies blocking GII.4 norovirus and HBGA receptors binding. Results: The age were (50.68 ± 15.17), (52.52 ± 15.90) and (51.37 ± 13.32) years old of 2015, 2016 in experimental group, and in control group, respectively. Males accounted for 5.9% (70/195), 36.6%(60/164), 40.8% (69/169) (χ(2)=0.93, P=0.334). The mean value of serum antibodies Absorbance value was 2.521±0.05 of 2015 and was 2.583±0.045 of 2016 in oyster culture area, the mean value was 2.249±0.05 in control group, there was a statistical difference among three group (F=13.28, P<0.001). The antibody prevalence in the three groups was 100%. BT50 geometric mean titer (GMT) of oyster culture area in 2015 was 423.1±40.11, culture group was 248.2±25.63, there was a statistical difference (t=3.73, P<0.001). Conclusion: The population in oyster culture area does have more chance of exposure and infection GII.4 norovirus, Serum antibody of blocking ability in oyster culture areas is better than the general population in inland city. Suggesting that the population is more immunity resistant infected GII.4 norovirus.

[Opportunistic infection in systemic lupus erythematosus patients: the disease spectrum and the characteristics of peripheral lymphocyte subsets]

Objective: To investigate the common opportunistic infections and the characteristics of peripheral lymphocyte subsets in patients with systemic lupus erythematosus (SLE). Methods: From December 2013 to December 2016, peripheral lymphocyte subsets were consecutively detected by flow cytometry in treated SLE patients with or without opportunistic infections (OIs) . The lymphocyte subsets in healthy donors were used as normal control group. Results: A total of 145 treated SLE patients were enrolled including 108 with OIs and 37 without OIs. The common OIs were cytomegalovirus (CMV) diseases (66/108), Pneumocystis jirovecii pneumonia (PJP, 16/108), other fungal infections (16/108), Epstein-Barr virus (EBV, 15/108) and tuberculosis (14/108). Compared with treated SLE without OIs, total lymphocyte, CD(4+) T, and CD(8+) T lymphocyte counts were significantly reduced in SLE with OIs [1 260 (780, 1 810) cells/μl vs. 565 (399, 1 043) cells/μl, P<0.001; 485 (280, 811) cells/μl vs. 173 (95, 327) cells/μl, P<0.001; 464 (339, 764) cells/μl vs. 265 (158, 424) cells/μl, P=0.003, respectively]. Conclusions: The common OIs in treated SLE patients were CMV diseases, PJP, other fungi, EBV and tuberculosis. OIs are prone to develop in SLE patients with severe lymphocytopenia, especially CD(4+) T cell depletion.

Abstract P3-06-03: Dual p38/NLK kinase inhibitor as potential novel therapeutic agent for tamoxifen-resistant luminal breast cancer

Background: Tamoxifen is the most commonly used endocrine agent for estrogen receptor (ER) positive breast cancer (also known as luminal breast cancer). However, approximately half of the patients develop resistance after initial response to tamoxifen. To date, no effective targeted therapy exists to overcome it. We previously identified the role of nemo-like kinase (NLK), a serine-threonine kinase that functions in stress response and neurite outgrowth, in breast endocrine resistance. In addition, activation of p38 MAPK has been reported to modulate ER signaling and promote endocrine resistance. We identified a highly selective dual p38 and NLK kinase inhibitor (PNKI) through analysis of public kinase profiling datasets, and evaluated its therapeutic effect in endocrine-resistant breast cancers using in vitro and in preclinical mouse models. Experimental design and methods: To determine the in vitro therapeutic window of PNKI, we treated an acquired tamoxifen-resistant cell line (MCF7-TamR) and a benign breast epithelial cell line (MCF10A) with gradually increasing doses of PNKI. To determine the effect of PNKI on tamoxifen-resistant breast cancer cells, we treated primary tamoxifen-resistant breast cancer cell line BT483, and MDAMB415, together with acquired tamoxifen-resistant line MCF7 TamR, T47D TamR, and ZR-75-B TamR, with 0.5 uM PNKI in the presence of different doses of Tamoxifen. To evaluate the therapeutic effect of PNKI in a T47D-derived xenograft tumor model with acquired tamoxifen resistance, we administered PNKI alone or in combination with Fulvestrant, the second-line endocrine therapy agent, or with Everolimus, the mTOR inhibitor that could improve patient outcomes in several clinical trials. Mice bearing xenografts were randomized into six treatment groups (Vehicle, PNKI, Fulvestrant, Fulvestrant+PNKI, Everolimus, Everolimus+PNKI). Tumor growth was tracked closely. The tumors harvested two weeks after treatments started were profiled with Reverse Phase Protein Array (RPPA) to assess the early signaling changes after treatments. The therapeutic effect of PNKI were also evaluated in a patient-derived xenograft (PDX) model of de novo endocrine resistant breast cancer. Mice bearing the PDX tumors were randomized to four treatment groups (Vehicle, PNKI, Everolimus, Everolimus+PNKI) and tumor growth curve was measured timely. Results: PNKI showed an in vitro therapeutic window at 0.1-1μM for MCF7-TamR cells. Breast cancer cell lines with either de novo or acquired Tamoxifen resistance became more sensitive to tamoxifen when treated with 0.5uM PNKI. The concomitant treatment of PNKI and Everolimus results in significant decreased tumor burden and prolonged progression free survival in the both T47D-TamR xenograft tumors and re-transplanted de novo endocrine-resistant PDX tumors compared to other treatments. RPPA data of T47D-TamR tumors harvested following 2-week treatments revealed that several key survival signaling in breast cancer are repressed only when PNKI are combined with Everolimus. Conclusion: The dual p38 and NLK inhibitor (PNKI) exhibited potential therapeutic value as adjuvant agent to the mTOR inhibitor everolimus for acquired or de novo tamoxifen-resistant luminal breast cancers.

Citation Format: Wang X, Cao X, Veeraraghavan J, Qin L, Kim J-A, Tan Y, Hilsenbeck SG, Schiff R, Wang X. Dual p38/NLK kinase inhibitor as potential novel therapeutic agent for tamoxifen-resistant luminal breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-06-03.

Abstract P4-03-04: Targeting the mevalonate pathway in HER2-positive breast cancer to overcome resistance to anti-HER2 therapy

Background: Despite the advent of HER2-targeted therapies for HER2+ breast cancer (BC), including the monoclonal antibody trastuzumab (T) either alone or in combinations, resistance still poses a major clinical challenge. Using our broad panel of HER2+ cell lines made resistant (R) to T alone (TR), and to lapatinib plus T (LTR), we observed that in resistant models where HER2 remains inhibited, especially the LTR derivative, the mevalonate (MVA) pathway is activated and provides an alternative proliferative signal, including the activation of mTOR, to drive resistance. While these resistant cell models were hypersensitive to the widely-used cholesterol-lowering statins, the role of other MVA pathway inhibitors such as zoledronic acid (ZA), which is in clinical use to treat bone metastasis, in overcoming resistance to HER2-targeted therapy has not been explored. Based on recent reports and our preliminary data using reverse phase protein array (RPPA) analysis, the YAP/TAZ transcription factor (TF) emerged as a potential mediator of MVA pathway signaling to mTOR. Here, we investigated the therapeutic efficacy of additional MVA pathway inhibitors and the role of YAP/TAZ in mediating resistance to HER2-targeted therapy.

Methods: HER2+ SKBR3 and AU565 BC cells and their LTR derivatives were used. Changes in cell growth upon genetic and pharmacologic inhibition of the MVA pathway were quantified by methylene blue staining. Luciferase reporter assays and western blots (WB) measured changes in total and phosphorylated (S127 and S381/inactive) YAP protein levels to examine activity of the YAP/TAZ TF complex. To validate the function of YAP/TAZ in resistance, we performed YAP/TAZ knockdown (siRNA), overexpression of dominant-active YAP constructs (S381A, S381/127A), and qRT-PCR assessment of YAP/TAZ target gene expression.

Results: ZA, like simvastatin (Sim), selectively inhibited the growth of resistant cells in a dose-dependent manner. This inhibition was rescued by geranyl geranyl pyrophosphate (GGPP), a downstream metabolite, but not by MVA, an upstream metabolite, indicating the on-target effect of ZA. Further, ZA and Sim combination showed a synergistic growth-inhibitory effect in R but not in parental (P) cells. YAP/TAZ luciferase reporter assays and phosphorylated YAP and total TAZ levels by WB, confirmed the increased activity of YAP/TAZ in R models, which was selectively inhibited by Sim or ZA and was rescued by the corresponding downstream metabolites. YAP/TAZ knockdown selectively inhibited resistant cell growth and mTOR signaling in R vs. P cells, and dominant-active YAP/TAZ rescued the mTOR inhibition by Sim. YAP/TAZ inhibition by siRNA or by Sim significantly decreased the expression of YAP/TAZ target gene survivin in R vs. P cells, and the Sim inhibition was rescued by MVA.

Conclusions: The MVA pathway plays a critical role in mediating resistance to anti-HER2 therapy, which was overcome by Sim and ZA either alone or in combination. Given the synergistic effect of Sim and ZA, their combination may offer a therapeutic strategy to overcome HER2-targeted therapy resistance. Our results also reveal the role of YAP/TAZ in MVA pathway-mediated HER2-targeted therapy resistance, which could suggest new biomarkers and therapeutic targets.

Citation Format: Sethunath V, Hu H, De Angelis C, Veeraraghavan J, Qin L, Rimawi MF, Osborne KC, Schiff R. Targeting the mevalonate pathway in HER2-positive breast cancer to overcome resistance to anti-HER2 therapy [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 P4-03-04.

Ectopic Cartilage Formation Induced by Mesenchymal Stem Cells on Porous Gelatin-Chondroitin-Hyaluronate Scaffold Containing Microspheres Loaded with TGF-β1

The study aimed to produce a novel porous gelatin-chondroitin-hyaluronate scaffold in combination with a controlled release of TGF-β1 and to evaluate its potentials in ectopic cartilage formation. The gelatin-chondroitin-hyaluronate scaffold was developed to mimic the natural extra cellular matrix of cartilage. Gelatin microspheres loaded with TGF-β1 (MS-TGFβ1) showed a fast cytokine release at initial phase (37.4%) and the ultimate accumulated release was 83.1% by day 18. Then MS-TGFβ1 were incorporated into scaffold. The MSCs seeded on scaffold with or without MS-TGFβ1 were incubated in vitro or implanted subcutaneously in nude mice. In vitro study showed that, compared to the scaffold, the scaffold/MS-TGFβ1 significantly augmented the proliferation of MSCs and GAG synthesis. Three weeks postoperatively histology observation showed that in MSCs/scaffold/MS-TGFβ1 implantation group, cells of newly formed ectopic cartilage were located within typical lacunae and demonstrated morphological characteristics of chondrocytes. Six weeks later the ectopic cartilage grew more and islands of cartilage were observed. The matrix was extensively metachromatic by safranin-O/Fast green staining. Immunohistochemical staining also indicated ectopic cartilage was intensely stained for type II collagen. Instead, in the MSCs/scaffold implantation group, no cartilage-like tissue formed and matrix showed negative or weak positive staining. The percentage of positive staining area was significantly larger in MSCs/scaffold/MS-TGFβ1 group (p<0.05) at each time point. The results indicated that the novel gelatin-chondroitin-hyaluronate scaffold with MS-TGFβ1 could induce the chondral differentiation of MSCs to form cartilage and might serve as a new way to repair cartilage defects.

Stepwise preconditioning enhances mesenchymal stem cell-based cartilage regeneration through epigenetic modification

OBJECTIVE

This study is to investigate the functions and underlying mechanisms of mesenchymal stem cells (MSCs) underwent stepwise preconditioning in chondrogenic medium before expansion, then further explore their therapeutic effects in a surgically induced osteoarthritis (OA) model.

METHODS

MSCs isolated from the adult rats expressing Green Fluorescence Protein (GFP) were incubated in basal medium or primed in chondrogenic medium before expansion. The multipotency including cell proliferation, differentiation, and survivability was compared between chondrogenic manipulated MSCs (M-MSCs) and untreated MSCs. Methylation modification of Nanog and Oct4 were detected by bisulfite genomic sequencing. Loss-of-function phenotype in M-MSCs induced by shNanog was also observed. Then the therapeutic effect of the cells was evaluated in a surgically induced OA rat model by single intraarticular injection. The injected GFP-labeled cells in the joints were monitored in vivo. These rats were sacrificed and subjected to histological examinations and microstructural analysis after 4 weeks.

RESULTS

We found that cell clonogenicity, proliferation, survivability, and chondrogenic property were enhanced after stepwise preconditioning. We then further found that the expression level of Nanog and Oct4 was temporarily increased in the M-MSCs. Results of epigenetic analysis revealed that demethylation happened in Nanog and Oct4 after the stepwise preconditioning. Results of in vivo imaging showed more GFP-labeled cells in the M-MSCs-injected group. And results of histology and micro-CT analysis also indicated a superior therapeutic effect of M-MSCs on the surgically induced-OA.

CONCLUSION

These findings indicated a feasible method to obtain a cell population with high survivability and chondrogenic commitment for the treatment of OA.

miR-146a rs2910164 polymorphism might be associated with coronary artery disease risk in Asians

Recently, several studies reported the association between miR-146a rs2910164 polymorphism and coronary artery disease (CAD) risk. However, the results were inconclusive. We therefore did a meta-analysis to investigate this association. Electronic databases, including PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) databases, were searched. The strength of association was assessed by calculating odds ratios (OR) and 95% confidence interval (CI). Five eligible studies included in this meta-analysis. The total sample size of this meta-analysis was 1565 cases and 1541 controls. We found that miR-146a rs2910164 polymorphism was significantly associated with an increased CAD risk (OR = 1.19; 95% CI 1.07 - 1.32; P = 0.002). In the subgroup analysis by race, miR-146a rs2910164 polymorphism was significantly associated with an increased CAD risk in Asians (OR = 1.18; 95% CI 1.04 - 1.33; P = 0.008). However, we did not find significant result in Caucasians (OR = 1.22; 95% CI 0.86 - 1.74; P = 0.25). In the subgroup analysis by age, we found that miR-146a rs2910164 polymorphism increased CAD risk in old population (OR = 1.22; 95% CI 1.09 - 1.38; P = 0.0008). In conclusion, this meta-analysis found that miR-146a rs2910164 polymorphism was significantly associated with CAD risk.

Toll-like receptor 2 costimulation potentiates the antitumor efficacy of CAR T Cells

Chimeric antigen receptor (CAR) T-cell immunotherapies have shown unprecedented success in treating leukemia but limited clinical efficacy in solid tumors. Here, we generated 1928zT2 and m28zT2, targeting CD19 and mesothelin, respectively, by introducing the Toll/interleukin-1 receptor domain of Toll-like receptor 2 (TLR2) to 1928z and m28z. T cells expressing 1928zT2 or m28zT2 showed improved expansion, persistency and effector function against CD19⁺ leukemia or mesothelin⁺ solid tumors respectively in vitro and in vivo. In a patient with relapsed B-cell acute lymphoblastic leukemia, a single dose of 5 × 10⁴/kg 1928zT2 T cells resulted in robust expansion and leukemia eradication and led to complete remission. Hence, our results demonstrate that TLR2 signaling can contribute to the efficacy of CAR T cells. Further clinical trials are warranted to establish the safety and efficacy of this approach.

Exosomes from Plasmodium-infected hosts inhibit tumor angiogenesis in a murine Lewis lung cancer model

Previous research to investigate the interaction between malaria infection and tumor progression has revealed that malaria infection can potentiate host immune response against tumor in tumor-bearing mice. Exosomes may play key roles in disseminating pathogenic host-derived molecules during infection because several studies have shown the involvement and roles of extracellular vesicles in cell–cell communication. However, the role of exosomes generated during Plasmodium infection in tumor growth, progression and angiogenesis has not been studied either in animals or in the clinics. To test this hypothesis, we designed an animal model to generate and isolate exosomes from mice which were subsequently used to treat the tumor. Intra-tumor injection of exosomes derived from the plasma of Plasmodium-infected mice provided significantly reduced Lewis lung cancer growth in mice. We further co-cultured the isolated exosomes with endothelial cells and observed significantly reduced expression of VEGFR2 and migration in the endothelial cells. Interestingly, high level of micro-RNA (miRNA) 16/322/497/17 was detected in the exosomes derived from the plasma of mice infected with Plasmodium compared with those from control mice. We observed that overexpression of the miRNA 16/322/497/17 in endothelial cell corresponded with decreased expression of VEGFR2, inhibition of angiogenesis and inhibition of the miRNA 16/322/497/17 significantly alleviated these effects. These data provide novel scientific evidence of the interaction between Plasmodium infection and lung cancer growth and angiogenesis.

[The breast cancer diagnosis accuracy of the digital breast tomosynthesis technique]

Objective: To explore the Digital breast tomosynthesis technique (DBT) in breast cancer diagnosis accuracy. Methods: Choose 263 cases of patients with breast lesions, using DBT combined FFDM (Full field digital mammography) independent FFDM, evaluate the diagnostic accuracy of breast cancer. Results: The ROC curve area (AUC) of two kinds of breast cancer diagnosis methods (DBT combined FFDM and independent FFDM) were 0.954±0.014 and 0.907±0.019, with significant difference (P=0.000 3). In premenopausal patients and breast density ACR3-4 cases, DBT combined FFDM diagnosis accuracy is higher than FFDM alone group, with significant difference (P<0.05). Conclusion: DBT combined FFDM compared with independent FFDM, in a certain extent, improves the accuracy of the diagnosis of breast cancer.

Surface-enrichment with hydroxyapatite nanoparticles in stereolithography-fabricated composite polymer scaffolds promotes bone repair

Fabrication of composite scaffolds using stereolithography (SLA) for bone tissue engineering has shown great promises. However, in order to trigger effective bone formation and implant integration, exogenous growth factors are commonly combined to scaffold materials. In this study, we fabricated biodegradable composite scaffolds using SLA and endowed them with osteopromotive properties in the absence of biologics. First we prepared photo-crosslinkable poly(trimethylene carbonate) (PTMC) resins containing 20 and 40wt% of hydroxyapatite (HA) nanoparticles and fabricated scaffolds with controlled macro-architecture. Then, we conducted experiments to investigate how the incorporation of HA in photo-crosslinked PTMC matrices improved human bone marrow stem cells osteogenic differentiation in vitro and kinetic of bone healing in vivo. We observed that bone regeneration was significantly improved using composite scaffolds containing as low as 20wt% of HA, along with difference in terms of osteogenesis and degree of implant osseointegration. Further investigations revealed that SLA process was responsible for the formation of a rich microscale layer of HA corralling scaffolds. To summarize, this work is of substantial importance as it shows how the fabrication of hierarchical biomaterials via surface-enrichment of functional HA nanoparticles in composite polymer stereolithographic structures could impact in vitro and in vivo osteogenesis.

STATEMENT OF SIGNIFICANCE

This study reports for the first time the enhance osteopromotion of composite biomaterials, with controlled macro-architecture and microscale distribution of hydroxyapatite particles, manufactured by stereolithography. In this process, the hydroxyapatite particles are not only embedded into an erodible polymer matrix, as reported so far in the literature, but concentrated at the surface of the structures. This leads to robust in vivo bone formation at low concentration of hydroxyapatite. The reported 3D self-corralling composite architecture provides significant opportunities to develop functional biomaterials for bone repair and tissue engineering.

Abstract OT1-01-07: A phase 2 study of eribulin followed by doxorubicin and cyclophosphamide as preoperative therapy for HER2-negative inflammatory breast cancer

Background: HER2 negative(neg) inflammatory breast cancer(IBC) exhibits relative resistance to chemotherapy evidenced by pCR(pathologic complete response rate) rates of 12-25% with preoperative taxane/anthracycline regimens. Eribulin(Eisai®) inhibits microtubular function via sequestration of tubulin into nonfunctional aggregates, thus being effective against taxane-resistant cancer. Preclinical data shows 2 mechanisms of action: reversion of EMT(epithelial to mesenchymal transition) and normalization of tumor vascularity. Treatment of triple negative breast cancer(TNBC) cell-lines with eribulin results in downregulation of mesenchymal markers with concomitant increase in expression of classical epithelial markers(Yoshida BJC 2014). In PDX models, eribulin improved blood perfusion in central region of tumors, increased vessel density, reduced vessel diameter, and reduced hypoxia. IBC is highly angiogenic, with increased microvessel density, higher fraction of proliferating endothelial cells and greater expression of pro-angiogenic genes compared with non-IBC(McCarthy CCR 2002). This preoperative study(EAC) exploits the angiogenic properties of IBC with the treatment scheme of eribulin(E) followed by doxorubicin/cyclosphosphamide(AC) in newly diagnosed HER2neg IBC.

Methods: Pts with HER2neg Stage III (cT4d,any N,M0) IBC are eligible if they have not received prior therapy for BC, have adequate organ function, cardiac ejection fraction &gt; 50%, and willing to undergo 2 research biopsies (rbx) of the affected breast. Following baseline rbx, pts receive cycle 1, day(d)1 eribulin 1.4 mg/m2. A 2nd rbx occurs on d8, prior to dosing of E. Following 3 more cycles of E(1.4mg/m2 d1,d8,every 21d), pts receive 4 cycles of dose-dense AC(A-60 mg/m2,C-600mg/m2 every 14d). Pts with adequate disease response undergo mastectomy/axillary lymph node dissection followed by chest wall/regional lymph node radiation. Adjuvant endocrine therapy is used if hormone receptor positive. An imaging sub-study evaluates tumor perfusion via DCE-MRI pre and post 1st dose E.

Correlatives: To investigate whether E induces reversion of EMT in IBC, expression of 10 EMT-related genes are determined in each rbx, and normalization of tumor vessel phenotype are assessed by expression of 15 angiogenesis-related genes in rbx by RT-qPCR. Gene expression will be repeated on residual tumor at mastectomy. An imaging sub-study of DCE-MRI (10 pts) will assess vascular remodeling via changes in Ktrans , ve and vp determination of IBC region of interest, core and rim and changes in the iAUC computed pre and post 1st dose E.

Statistics: The primary endpoint is pCR. A Simon two-stage design is used. If the proportion of pts having pCR is &lt; 0.10 then EAC is considered minimally effective, versus alternative hypothesis that EAC is worthy of further study if proportion pCR &gt; 0.30. In the 1st stage, if &lt; 2/16 pts have pCR, the study is stopped; if &gt; 3 pts have pCR, the study proceeds. In the 2nd stage, EAC is rejected if &lt; 4 of 25 pts have a pCR(α=0.10;β=0.10). Up to 25 pts will be enrolled. Secondary endpoints are residual cancer burden, disease-free survival, time to treatment failure and overall survival. Clinical trial information: NCT02623972.

Citation Format: Overmoyer B, Goel S, Regan M, Hirshfield-Bartek J, Schlosnagel E, Yeh E, Qin L, Bellon J, Nakhlis F, Jacene H, Winer E. A phase 2 study of eribulin followed by doxorubicin and cyclophosphamide as preoperative therapy for HER2-negative inflammatory 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 OT1-01-07.

Cellular and molecular basis for stress-induced depression

Chronic stress has a crucial role in the development of psychiatric diseases, such as anxiety and depression. Dysfunction of the medial prefrontal cortex (mPFC) has been linked to the cognitive and emotional deficits induced by stress. However, little is known about the molecular and cellular determinants in mPFC for stress-associated mental disorders. Here we show that chronic restraint stress induces the selective loss of p11 (also known as annexin II light chain, S100A10), a multifunctional protein binding to 5-HT receptors, in layer II/III neurons of the prelimbic cortex (PrL), as well as depression-like behaviors, both of which are reversed by selective serotonin reuptake inhibitors (SSRIs) and the tricyclic class of antidepressant (TCA) agents. In layer II/III of the PrL, p11 is highly concentrated in dopamine D2 receptor-expressing (D2⁺) glutamatergic neurons. Viral expression of p11 in D2⁺ PrL neurons alleviates the depression-like behaviors exhibited by genetically manipulated mice with D2⁺ neuron-specific or global deletion of p11. In stressed animals, overexpression of p11 in D2⁺ PrL neurons rescues depression-like behaviors by restoring glutamatergic transmission. Our results have identified p11 as a key molecule in a specific cell type that regulates stress-induced depression, which provides a framework for the development of new strategies to treat stress-associated mental illnesses.

Mechanical stimulation enhanced estrogen receptor expression and callus formation in diaphyseal long bone fracture healing in ovariectomy-induced osteoporotic rats

Estrogen receptor (ER) in ovariectomy-induced osteoporotic fracture was reported to exhibit delayed expression. Mechanical stimulation enhanced ER-α expression in osteoporotic fracture callus at the tissue level. ER was also found to be required for the effectiveness of vibrational mechanical stimulation treatment in osteoporotic fracture healing.

INTRODUCTION

Estrogen receptor(ER) is involved in mechanical signal transduction in bone metabolism. Its expression was reported to be delayed in osteoporotic fracture healing. The purpose of this study was to investigate the roles played by ER during osteoporotic fracture healing enhanced with mechanical stimulation.

METHODS

Ovariectomy-induced osteoporotic SD rats that received closed femoral fractures were divided into five groups, (i) SHAM, (ii) SHAM-VT, (iii) OVX, (iv) OVX-VT, and (v) OVX-VT-ICI, where VT stands for whole-body vibration treatment and ICI for ER antagonization by ICI 182,780. Callus formation and gene expression were assessed at 2, 4, and 8 weeks postfracture. In vitro osteoblastic differentiation, mineralization, and ER-α expression were assessed.

RESULTS

The delayed ER expression was found to be enhanced by vibration treatment. Callus formation enhancement was shown by callus morphometry and micro-CT analysis. Enhancement effects by vibration were partially abolished when ER was modulated by ICI 182,780, in terms of callus formation capacity at 2-4 weeks and ER gene and protein expression at all time points. In vitro, ER expression in osteoblasts was not enhanced by VT treatment, but osteoblastic differentiation and mineralization were enhanced under estrogen-deprived condition. When osteoblastic cells were modulated by ICI 182,780, enhancement effects of VT were eliminated.

CONCLUSIONS

Vibration was able to enhance ER expression in ovariectomy-induced osteoporotic fracture healing. ER was essential in mechanical signal transduction and enhancement in callus formation effects during osteoporotic fracture healing enhanced by vibration. The enhancement of ER-α expression by mechanical stimulation was not likely to be related to the increased expression in osteoblastic cells but rather to the systemic enhancement in recruitment of ER-expressing progenitor cells through increased blood flow and neo-angiogenesis. This finding might explain the observed difference in mechanical sensitivity of osteoporotic fracture to mechanical stimulation.

[Characterization of mutational pattern in patients with Ph negative myeloproliferative neoplasms]

OBJECTIVE

To characterize the molecular profile in patients with Ph negative myeloproliferative neoplasms (MPN) by exploring 49 gene mutations.

METHODS

Targeted gene sequencing were performed to analyze 49 MPN-associated genes in 51 patients with Ph negative MPN, of which CARL (exon 9), NPM1 (exon 12) and CEBPA (TAD, BZIP domains) were investigated by using Sanger sequencing simultaneously, while FLT3-ITD was assessed by PCR method.

RESULTS

Mutations were detected in 73.5% (36/49) of genes, and the mutational rates of JAK2-V617F, CALR (exon 9) and MPL were 60.8%(31/51), 7.8%(4/51) and 7.8%(4/51) respectively, whereas the mutational rates of ASXL1, SETBP1, and SF3B1 were around 10%. In addition, 96.1% (49/51) of patients harbored at least one mutation, and more than half of the patients (52.9%, 27/51) possessed 3 or 4 gene mutations. The amount of gene mutations was significantly higher in patients with JAK2-V617F mutation than those without JAK2-V617F or CALR (exon 9) mutation (P<0.05). The last finding was that there was no statistically significant difference in the amount of mutations among four MPN subtypes (PV, ET, PMF, and MPN-U).

CONCLUSION

Most patients with Ph negative MPN possesses three or more gene mutations, with various mutational profiles.

Twist1 promotes breast cancer invasion and metastasis by silencing Foxa1 expression

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

Porous tantalum seeded with bone marrow mesenchymal stem cells attenuates steroid-associated osteonecrosis

OBJECTIVE

Bone marrow mesenchymal stem cells (BMMSCs) have been widely applied in osteonecrosis. However, lack of biomechanical support limited application of BMMSCs. And porous tantalum (PTA) has been identified as a cell-friendly scaffold for bone regeneration. Herein, we aimed to investigate the efficacy of PTA seeded with BMMSCs in the treatment of osteonecrosis.

MATERIALS AND METHODS

After the production of PTA seeded with BMMSCs, MTT and GFP were performed to identify the proliferation and adhesion of BMMSCs respectively, which was further examined by scanning electron microscopy (SEM). And real-time PCR was also used to determine mRNA level of osteogenic markers, including Alp, OCN, OPN, Col I and Runx-2 in BMMSCs. Nineteen adult rabbits were applied for building steroid-associated osteonecrosis (SAON) models. Bone formation rate (BFR) and mineral apposition rate (MAR) were determined. And Goldner Trichrome Staining was used in these SAON models, which further confirmed the efficacy of PTA seeded with BMMSCs in SAON.

RESULTS

PTA seeded with BMMSCs showed excellent biocompatibility. Additionally, SEM assay showed that BMMSCs adhered tightly and spread fully in the pores of PTA. Next, the expression of ALP and OPN mRNA in BMMSCs were significantly (p < 0.05) higher in the PTA-treated group compared to those in the PTA-untreated group. Furthermore, compared to those treated by only PTA, the dynamic bone formation in rabbits treated by PTA seeded with BMMSCs was significantly increased (p < 0.001) at both week 3rd and week 6th.

CONCLUSIONS

The product, PTA seeded with BMMSCs, was successfully produced, and was determined as high efficacy for treatment of steroid-associated osteonecrosis. PTA seeded with BMMSCs may afford a promising option for treating osteonecrosis.

Prevalence of vitamin D insufficiency among adolescents and its correlation with bone parameters using high-resolution peripheral quantitative computed tomography

Vitamin D deficiency and insufficiency are highly prevalent among adolescents in Hong Kong, which is a sub-tropical city with ample sunshine. Vitamin D level is significantly correlated with key bone density and bone quality parameters. Further interventional studies are warranted to define the role of vitamin D supplementation for improvement of bone health among adolescents.

INTRODUCTION

The relationship between bone quality parameters and vitamin D (Vit-D) status remains undefined among adolescents. The aims of this study were to evaluate Vit-D status and its association with both bone density and bone quality parameters among adolescents.

METHODS

Three hundred thirty-three girls and 230 boys (12-16 years old) with normal health were recruited in summer and winter separately from local schools. Serum 25(OH) Vit-D level, bone density and quality parameters by Dual Energy X-ray Absorptiometry (DXA) and High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT), dietary calcium intake, and physical activity level were assessed.

RESULTS

Sixty-four point seven percent and 11.4 % of subjects were insufficient [25 ≤ 25(OH)Vit-D ≤ 50 nmol/L] and deficient [25(OH)Vit-D < 25 nmol/L] in Vit-D, respectively. The mean level of serum 25(OH)Vit-D in summer was significantly higher than that in winter (44.7 ± 13.6 and 35.9 ± 12.6 nmol/L, respectively) without obvious gender difference. In girls, areal bone mineral density (aBMD) and bone mineral content (BMC) of bilateral femoral necks, cortical area, cortical thickness, total volumetric bone mineral density (vBMD), and trabecular thickness were significantly correlated with 25(OH)Vit-D levels. In boys, aBMD of bilateral femoral necks, BMC of the dominant femoral neck, cortical area, cortical thickness, total vBMD, trabecular vBMD, BV/TV, and trabecular separation were significantly correlated with 25(OH)Vit-D levels.

CONCLUSION

Vit-D insufficiency was highly prevalent among adolescents in Hong Kong with significant correlation between Vit-D levels and key bone density and bone quality parameters being detected in this study. Given that this is a cross-sectional study and causality relationship cannot be inferred, further interventional studies investigating the role of Vit-D supplementation on improving bone health among adolescents are warranted.

Knockdown of eIF3a ameliorates cardiac fibrosis by inhibiting the TGF-β1/Smad3 signaling pathway

Cardiac fibroblasts are key effector cells in the pathogenesis of cardiac fibrosis. The eukaryotic translation initiation factor (eIF) 3a is the largest subunit of the eIF3 complex and has been involved in renal fibrosis. However, the precise role of eIF3a in myofibroblast differentiation and cardiac fibrosis remains unknown. Accordingly, in our present study, we tested the expression of eIF3a in transforming growth factor β1 (TGF-β1)-induced rat CFs and found that eIF3a was upregulated in TGF-β1-induced rat CFs. Then the role and mechanism of eIF3a in cardiac fibrosis were explored. Our results found that the eIF3a expression was significantly up-regulated in TGF-β1-induced CFs. Knockdown of eIF3a significantly inhibited TGF-β1-induced CF proliferation, as well as suppressed the expression levels of α-smooth muscle actin (α-SMA) and SM22α. Mechanistically, knockdown of eIF3a attenuated TGF-β1-induced Smad3 activation in CFs. In summary, our present study firstly demonstrated that silencing eIF3a might alleviate TGF-β1-induced cardiac fibrogenesis in CFs by inhibiting Smad3 activation, and suggest that eIF3a may be positioned as a new and promising target for the prevention and treatment of cardiac fibrosis.

[The expression of transcription factors Snail and Slug in epithelial-mesenchymal transition of human lens epithelial cells induced by transforming growth factor-β2]

OBJECTIVE

To investigate the expression of transcription factors snail and slug in epithelial mesenchymal transition (EMT) of human lens epithelial cells (HLEC) induced by transforming growth factor-β2 (TGF-β2).

METHODS

Experimental research. HLEC were treated with different concentrations of TGF-β2 (1.0 and 10.0 μg/L) for different time. The morphological changes were observed under inverted microscope. The expression and cellular localization of snail and slug were evaluated by immunofluorescence. Expressions of snail, slug, E-Cadherin and α-SMA were further determined by Western blot analysis. Single factor analysis of variance, rank sum test and Pearson correlation were used for statistical analysis.

RESULTS

Cultured HLEC were polygonal monolayer cells with tight intercellular adhesion closely and patchy distribution. After treatment of different doses of TGF-β2 for 24 h, HLEC became isolated, exhibited long spindle-like shape as fibroblastic phenotype. The immunofluorescence staining indicated that snail and slug were localized in the nuclei. The expressions of snail and slug appeared to be positive correlative to TGF-β2 dose (snail protein expression: 0.74±0.16, 1.13±0.03, 1.54±0.18 and slug protein expression: 1.96±0.02, 3.12±0.09, 4.07±0.12 in HLEC treated with 0.1, 1.0 and 10 μg/L TGF-β2 respectively) (χ(2)=9.62,P=0.022;F=241.10,P<0.01). In addition, the expression of α-SMA and E-Cadherin showed the similar form (α-SMA protein expression: 0.87±0.04, 1.42±0.11, 2.17±0.36 and E-Cadherin protein expression: 2.50±0.36, 1.65±0.32, 0.41±0.14 in HLEC treated with 0.1, 1.0 and 10.0 μg/L TGF-β2 respectively) (χ(2)=9.97,P=0.019;F=19.99,P<0.01). All Pearson correlation coefficient were close to 1. The expression of snail and slug in HLEC were also increased with extending duration of TGF-β2 (1.0 μg/L). The expression levels of both proteins were modestly up-regulated at 8 hours, robustly increased at 24 h, reached peak at 48h and began to decline at 72 h (snail protein expression: 0.90±0.13, 1.43±0.14, 1.96±0.27, 1.57±0.16 and slug protein expression: 0.91±0.36, 1.24±0.16, 2.44±0.26, 1.43±0.16 in HLEC treated with 1.0 μg/L TGF-β2 for 8 h, 24 h, 48 h and 72 h respectively) (F=12.49,P=0.001;F=14.03,P<0.01).

CONCLUSION

Transcription factors snail and slug might be time and dose-dependently involved in in-vitro TGF-β2-induced EMT of HLEC. (Chin J Ophthalmol, 2016, 52: 285-290).

Promoting inflammatory lymphangiogenesis by vascular endothelial growth factor-C (VEGF-C) aggravated intestinal inflammation in mice with experimental acute colitis

Angiogenesis and lymphangiogenesis are thought to play a role in the pathogenesis of inflammatory bowel diseases (IBD). However, it is not understood if inflammatory lymphangiogenesis is a pathological consequence or a productive attempt to resolve the inflammation. This study investigated the effect of lymphangiogenesis on intestinal inflammation by overexpressing a lymphangiogenesis factor, vascular endothelial growth factor-C (VEGF-C), in a mouse model of acute colitis. Forty eight-week-old female C57BL/6 mice were treated with recombinant adenovirus overexpressing VEGF-C or with recombinant VEGF-C156S protein. Acute colitis was then established by exposing the mice to 5% dextran sodium sulfate (DSS) for 7 days. Mice were evaluated for disease activity index (DAI), colonic inflammatory changes, colon edema, microvessel density, lymphatic vessel density (LVD), and VEGFR-3mRNA expression in colon tissue. When acute colitis was induced in mice overexpressing VEGF-C, there was a significant increase in colonic epithelial damage, inflammatory edema, microvessel density, and neutrophil infiltration compared to control mice. These mice also exhibited increased lymphatic vessel density (73.0±3.9 vs 38.2±1.9, P<0.001) and lymphatic vessel size (1974.6±104.3 vs 1639.0±91.5, P<0.001) compared to control mice. Additionally, the expression of VEGFR-3 mRNA was significantly upregulated in VEGF-C156S mice compared to DSS-treated mice after induction of colitis (42.0±1.4 vs 3.5±0.4, P<0.001). Stimulation of lymphangiogenesis by VEGF-C during acute colitis promoted inflammatory lymphangiogenesis in the colon and aggravated intestinal inflammation. Inflammatory lymphangiogenesis may have pleiotropic effects at different stages of IBD.

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

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

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

Abstract P2-04-01: The role of Jmjd1a in mammary gland development and breast tumor growth

Histone modification alters chromatin architecture and thereby influences gene transcription. Histone methylation status is reversible and counter-regulated by methyltransferases and demethylases. Jmjd1a (also known as KDM3A, TSGA, JMJD1, JHDM2A and JHMD2A) is a histone demethylase. It belongs to JmjC domain-containing protein family and could specifically remove di- and mono- methyl residues from di or mono-methylated histone H3K9 (H3K9me2/me1). Recent studies showed that Jmjd1a plays an important role in embryonic stem cell self-renewal, spermatogenesis, regulation of metabolic gene expression and body weight, sex determination, tumor angiogenesis, and macrophage infiltration. However, its role in mammary gland (MG) development, breast carcinogenesis and breast cancer progression hasn't been systemically investigated. In this study, we found that Jmjd1a is expressed in mouse luminal epithelial cells. Genetic disruption of the Jmjd1a gene significantly slowed down MG development as indicated by retarded MG elongation and decreased ductal density in virgin mice observed at the ages of 4, 6 and 8 weeks. In agreement with the retarded MG development, the expression of Ki67 and cyclinD1 in epithelial cells of MGs from Jmjd1a knockout (KO) mice dramatically reduced compared with that from wild type (WT) mice. H3K9me1 and H3K9me2 levels in the epithelial cells of KO MGs are much higher than that in WT MGs. To assess the role of Jmjd1a in breast cancer progression, we crossbred Tg(Jmjd1a-/-) mice with MMTV-TVA(RCAS-PyMT) mice and obtained Tg(Jmjd1a-/-)×MMTV-TVA(RCAS-PyMT) mice. Infection of the TVA-expressing MG epithelial cells with the RCAS-PyMT virus induced mammary tumors in these mice and MMTV-TVA(RCAS-PyMT) control mice. We found that KO of Jmjd1a slightly accelerated mammary tumor initiation but significantly decreased tumor growth. Ki67 and cyclinD1 expression statistically reduced in KO tumors versus WT tumors. At the molecular level, Jmjd1a expression positively correlated with cyclin D1 expression in mammary epithelial cells and mammary tumors. Knockdown of Jmjd1a in MCF-7 cells significantly reduced cyclin D1 expression, while ectopic expression of Jmjd1a in MCF-7 cells increased cyclin D1 expression. ChIP assay revealed that Jmjd1a is associated with a promoter region of cyclin D1. Co-expression of c-Myc and Jmjd1a boosted the activity of the cyclin D1 reporter. In conclusion, our study indicated that Jmjd1a plays an important role in promoting mammary gland development and breast tumor growth by up-regulating cyclin D1 expression. Targeting Jmjd1a may inhibit breast cancer progression.

Citation Format: Qin L, Xu Y, Wu Y, Yu X, Toneff MJ, Liao L, Li Y, Xu J. The role of Jmjd1a in mammary gland development and breast tumor growth. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-04-01.

CAMK4 gene variation is associated with hypertension in a Uygur population

Considering that calcium/calmodulin-dependent kinase 4 (CAMK4) plays a pivotal role in blood pressure regulation, we investigated the association between a CAMK4 polymorphism (rs10491334) and hypertension in the Han, Kazak, and Uygur ethnic groups. We studied 1224 patients with hypertension and 967 normotensive controls classified into three ethnic groups (Han, Kazak, and Uygur). The rs10491334 polymorphism was genotyped using a TaqMan® 5'-nuclease assay. In the Uygur group, the T-allele frequency in patients with hypertension was twice that of the controls (12.5 vs 6.38%), and T-allele carriers had a significantly increased risk of hypertension compared with non-carriers (odds ratio = 2.200; 95% confidence interval = 1.473-3.285, P < 0.001). However, no significant correlation was found in the Han and Kazak groups. The T-allele of rs10491334 in CAMK4 was associated with hypertension in the Uygur group.

Successful infection control for a vancomycin-intermediate Staphylococcus aureus outbreak in an advanced emergency medical service centre

BACKGROUND

A vancomycin-intermediate Staphylococcus aureus (VISA) (vancomycin minimum inhibitory concentration: 4mg/L) outbreak occurred in an advanced emergency medical service centre [hereafter referred to as the intensive care unit (ICU)] between 2013 and 2014.

AIM

Our objective was to evaluate the infection control measures that were successful.

METHODS

Seventeen VISA strains were isolated from the sputum of 15 inpatients and the skin of two inpatients. Fourteen VISA strains were recognized as colonization. However, three VISA strains were isolated from the sputum of three inpatients with pneumonia. Environmental cultures were performed and VISA strains were detected in five of 65 sites. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) was performed on 21 VISA strains.

FINDINGS

Molecular typing including PFGE and MLST showed that the patterns of 19 VISA strains were identical and those of the other two VISA strains were possibly related. This meant that a horizontal transmission of VISA strains had occurred in the ICU. In August 2013, the infection control team began interventions. However, new inpatients with VISA strains continued to appear. Therefore, in October 2013, the ICU was partially closed in order to try to prevent further horizontal transmission, and existing inpatients with the VISA strain were isolated. Although new cases quickly dissipated after the partial closure, it took approximately five months to eradicate the VISA outbreak.

CONCLUSION

Our data suggest that despite the employment of various other infection control measures, partial closure of the ICU was essential in terminating this VISA outbreak.