Deleting the first disulphide bond in an arenicin derivative enhances its expression in Pichia pastoris

The marine antimicrobial peptide NZ17074, a variant of arenicin-3 from Arenicola marina that has broad antimicrobial activity and high bioavailability, can be designed to treat bacterial and fungal diseases. To reduce the toxicity of NZ17074, N6 was designed by replacing a cysteine in positions 3 and 20 with alanine, fused to the C-terminus of the small ubiquitin-like modifier tag (SUMO), and expressed in yeast. SUMO-N6 yielded as much as 921 mg l^-1 at 72 h after induction in a fermentor and increased 1·8-fold over SUMO-NZ17074. After cleavage with 30% formic acid and purification by a Sephadex G-25 column, 9·7 mg of the recombinant peptide N6 (rN6) was obtained from one-litre fermentation broth, increasing 1·4-fold over NZ17074. Compared to NZ17074, rN6 displayed almost identical antimicrobial activity with a minimal inhibitory concentration of 0·5, 0·25-0·5, 4, 0·25-16 and 16 μg ml^-1 against Escherichia, Salmonella, Pseudomonas, Staphylococcus and Streptococcus strains. Our results indicate that the first disulphide bond, Cys3-Cys20, in NZ17074 is not necessary for antimicrobial activity and that its deletion might reduce toxicity to host cells. These findings may help design new antimicrobial peptides harbouring fewer disulphide bridges and may have more potent activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

Disulphide bond formation is an important step in the protein expression and can also influence protein secretion. A deletion of the first disulphide bond in NZ17074 increased the secreted level of target protein, and its antimicrobial activity was almost unaffected by the deletion of the first disulphide bond. The first disulphide bond in NZ17074 is favourable for correctly forming another disulphide bond during expression but not necessary for its activity. This may help design and produce a novel class of antimicrobial peptides harbouring fewer disulphide bridges to save the cost.

Effect of Retrievable Stent Size on Endovascular Treatment of Acute Ischemic Stroke: A Multicenter Study

BACKGROUND AND PURPOSE

In clinical practice, stent diameter is one of the variable properties important for endovascular treatment. A consensus guideline for stent retriever size selection has yet to be established. The aim of this study was to investigate the effects of different diameters of Solitaire retrievers on outcomes.

MATERIALS AND METHODS

Of 628 patients enrolled from the Endovascular Treatment for Acute Anterior Circulation Ischemic Stroke Registry, 256 were treated with the Solitaire 4-mm device and 372, with the 6-mm device. We matched patients treated with the 2 stent sizes using propensity score analysis. The successful outcome was reperfusion as measured by the modified Thrombolysis in Cerebral Infarction score immediately postprocedure and the dichotomized modified Rankin Scale score at 90 days. Symptomatic intracerebral hemorrhage and in-hospital mortality were also recorded.

RESULTS

After propensity score analysis, group outcomes did not differ. In addition, in patients with atherosclerosis-related occlusion, a higher reperfusion rate (P = .021) was observed in the Solitaire 4 group, as well as a shorter time interval (P = .002) and fewer passes (P = .025). Independent predictors of successful reperfusion in patients with atherosclerotic disease on logistic analysis were the small stent (OR, 3.217; 95% CI, 1.129-9.162; P = .029) and the propensity score acting as a covariate (OR, 52.84; 95% CI, 3.468-805.018; P = .004).

CONCLUSIONS

We found no evidence of a differential effect of intra-arterial therapy based on the size of Solitaire retrievers. In patients with atherosclerotic disease, favorable reperfusion was associated with deployment of a small stent.

Dysfunction of the WT1-MEG3 signaling promotes AML leukemogenesis via p53-dependent and -independent pathways

Long non-coding RNAs (lncRNAs) play a pivotal role in tumorigenesis, exemplified by the recent finding that lncRNA maternally expressed gene 3 (MEG3) inhibits tumor growth in a p53-dependent manner. Acute myeloid leukemia (AML) is the most common malignant myeloid disorder in adults, and TP53 mutations or loss are frequently detected in patients with therapy-related AML or AML with complex karyotype. Here, we reveal that MEG3 is significantly downregulated in AML and suppresses leukemogenesis not only in a p53-dependent, but also a p53-independent manner. In addition, MEG3 is proven to be transcriptionally activated by Wilms’ tumor 1 (WT1), dysregulation of which by epigenetic silencing or mutations is causally involved in AML. Therefore MEG3 is identified as a novel target of the WT1 molecule. Ten–eleven translocation-2 (TET2) mutations frequently occur in AML and significantly promote leukemogenesis of this disorder. In our study, TET2, acting as a cofactor of WT1, increases MEG3 expression. Taken together, our work demonstrates that TET2 dysregulated WT1-MEG3 axis significantly promotes AML leukemogenesis, paving a new avenue for diagnosis and treatment of AML patients.

Abstract P6-08-02: Disruption of the estradiol-regulated NTN1-UNC5A dependence receptor signaling axis causes a hybrid basal/luminal molecular phenotype in estrogen receptor-positive breast cancer cells

Luminal subtype of breast cancers that express the estrogen receptor alpha (ERα) represents approximately two-thirds of all breast cancer cases. ER+ tumors tend to have the most favorable prognoses when treated with endocrine therapy. However, a relapse or endocrine therapy resistance is often seen in ER+ breast tumors. UNC5A belongs to the dependence receptor family which can mediate two different intracellular signals: cell survival, differentiation or migration when engaged with its ligand (such as Netrin-1; NTN1) or cell death/apoptosis in the absence of the ligand. Here we demonstrate that, depending upon the cell type, UNC5A and NTN1 are estradiol (E2)-inducible genes. Using shRNA or CRISPR knockdown strategies, we show that the disruption of the NTN1-UNC5A signaling axis in ER+ (MCF7 and T-47D) cells generates a mixed basal-like/luminal phenotype with stem cell-like characteristics. RNA-seq of UNC5A knockdown cells showed deregulated expression of several E2-target genes in both cell lines. Moreover, knockdown of UNC5A resulted in increased cell proliferation, and elevated expression of the E2-inducible anti-apoptotic, BCL2. Furthermore, the expression of ΔNp63 was enhanced in UNC5A knockdown cells. ΔNp63 is a TP53 family transcription factor that promotes breast epithelial stem cell maintenance and basal-like breast cancer. Accordingly, UNC5A knockdown cells displayed cancer stem cell phenotype as evident from ~3-fold increase in the number of CD44+/CD24+, CD44+/EPCAM+ and ITGA6+/EPCAM+ subpopulation compared with control cells. In addition, the expression of NTN4, a pro-angiogenic and lymphangiogenic factor, was increased upon UNC5A knockdown. In vivo, UNC5A knockdown cells implanted in nude mice were able to form tumors in the mammary fat pad independent of E2 supplementation and were able to colonize and develop into overt metastasis in multiple organs such as lungs, ovaries and adrenal glands. Consequently, analysis of mammary fat pad tumors from animals that received UNC5A knockdown cells revealed an increased expression of PECAM1 (CD31), a marker for endothelial cells used to evaluate tumor angiogenesis. In contrast to UNC5A, knocking down NTN1, decreased the expression of BCL2 and TP63 in both cell lines. Thus, knockdown of UNC5A resulted in deregulated expression of E2-regulated genes, E2-independent and anti-estrogen-resistant growth in vitro, and E2-independent tumor formation in xenograft models. Consistent with results of in vitro studies, analysis of tissue samples from breast cancer patients (n=196) revealed that lower expression of UNC5A is associated with lower overall survival (P < 0.05). Thus, loss or mutational inactivation of UNC5A could lead to unrestricted E2:ERα signaling and anti-estrogen resistant growth while simultaneously enabling ERα-positive luminal breast cancer cells to acquire basal-like and cancer stem cell-like features.

Citation Format: Padua MB, Bhat-Nakshatri P, Anjanappa M, Hao Y, Liu Y, McElyea K, Sandusky G, Althouse S, Perkins S, Nakshatri H. Disruption of the estradiol-regulated NTN1-UNC5A dependence receptor signaling axis causes a hybrid basal/luminal molecular phenotype in estrogen receptor-positive breast cancer cells [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 P6-08-02.

Abstract P4-22-19: Time on treatment of everolimus versus endocrine monotherapy or chemotherapy for early-line treatment of HR+/HER2- metastatic breast cancer: A retrospective chart review study in the US

Background:

Among postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer (mBC) whose disease progressed on a non-steroidal aromatase inhibitor (NSAI), everolimus-based therapy (EVE), different endocrine monotherapies (ET mono), and chemotherapies (CT) are commonly used. Time on treatment is an outcome primarily determined by a therapy's combined efficacy and safety profile. This study assessed the real-world time on treatment (TOT) among patients receiving these treatments in early-line (i.e., 1st and 2nd) settings.

Methods:

A nationwide sample of postmenopausal HR+/HER2- mBC patients treated by community oncologists in the US was included in this retrospective chart review. Eligible patients for this study were required to fail NSAI and then receive EVE, ET mono or CT (index therapy) as an early-line therapy for mBC between July 1, 2012 and April 15, 2013. TOT was measured from index therapy initiation to physician-reported treatment discontinuation and compared among treatment groups using Kaplan-Meier analyses with log-rank tests and Cox proportional hazards models adjusting for the line of therapy and baseline characteristics including recurrent or de novo disease status, age, race, insurance type, Charlson comorbidity index, sites of metastases (e.g., bone, any other visceral site), ECOG performance status, previous CT treatment in the mBC setting, and duration from the initiation of the last adjuvant ET to mBC diagnosis.

Results:

A total of 145 patients treated with EVE, 217 patients treated with ET mono, and 102 patients treated with CT were included in the analysis. Baseline characteristics among the three treatment groups were similar, although EVE-treated patients had higher burden of metastases relative to ET mono-treated patients, but lower burden relative to CT-treated patients. TOT was longer among EVE-treated patients than ET mono- and CT- treated patients (log-rank tests: p=0.01 and p<0.01). For patients who completed their index treatment, the median TOT among EVE, ET mono, and CT treatment groups were 8.9, 5.7, and 6.1 months, respectively. After adjusting for baseline characteristics, EVE was associated with significantly longer TOT compared with ET mono [hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.45 – 0.85] and with CT (HR = 0.32, 95% CI: 0.22 – 0.46).

Conclusions:

This real-world US chart review study of postmenopausal women with HR+/HER2- mBC showed that patients receiving EVE in line 1 or 2 experienced significantly longer TOT than those receiving ET mono or CT.

Citation Format: Li N, Ohashi E, Koo V, Xie J, Hao Y, Tang DH. Time on treatment of everolimus versus endocrine monotherapy or chemotherapy for early-line treatment of HR+/HER2- metastatic breast cancer: A retrospective chart review study in the US [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 P4-22-19.

Novel iodine-doped reduced graphene oxide anode for sodium ion batteries

It is reported for the first time that iodine-doped reduced graphene oxide (I-rGO) has been designed as an anode material for sodium ion batteries (SIBs).

Measurements of nanoresonator-qubit interactions in a hybrid quantum electromechanical system

Experiments to probe the basic quantum properties of motional degrees of freedom of mechanical systems have developed rapidly over the last decade. One promising approach is to use hybrid electromechanical systems incorporating superconducting qubits and microwave circuitry. However, a critical challenge facing the development of these systems is to achieve strong coupling between mechanics and qubits while simultaneously reducing coupling of both the qubit and mechanical mode to the environment. Here we report measurements of a qubit-coupled mechanical resonator system consisting of an ultra-high-frequency nanoresonator and a long coherence-time superconducting transmon qubit, embedded in a superconducting coplanar waveguide cavity. It is demonstrated that the nanoresonator and transmon have commensurate energies and transmon coherence times are one order of magnitude larger than for all previously reported qubit-coupled nanoresonators. Moreover, we show that numerical simulations of this new hybrid quantum system are in good agreement with spectroscopic measurements and suggest that the nanoresonator in our device resides at low thermal occupation number, near its ground state, acting as a dissipative bath seen by the qubit. We also outline how this system could soon be developed as a platform for implementing more advanced experiments with direct relevance to quantum information processing and quantum thermodynamics, including the study of nanoresonator quantum noise properties, reservoir engineering, and nanomechanical quantum state generation and detection.

Preoperative ropivacaine with or without tramadol for femoral nerve block in total knee arthroplasty

PURPOSE

To compare the analgesic effect of preoperative ropivacaine with or without tramadol for femoral nerve block in total knee arthroplasty (TKA).

METHODS

14 men and 46 women aged 59 to 80 years who were American Society of Anesthesiologists (ASA) grade I or II and were scheduled for TKA were randomised to receive preoperative femoral nerve block with 20 ml of 0.375% ropivacaine plus tramadol 0 mg (n=15), 50 mg (n=15), or 100 mg (n=15), or no preoperative femoral nerve block (control) [n=15]. Femoral nerve block was performed by a single anaesthesiologist before the standardised combined spinal epidural anaesthesia. Postoperatively, patientcontrolled analgesia was given. The visual analogue score (VAS) for pain at rest and on movement was recorded at 8, 12, 24, 48, and 72 hours. Passive knee range of motion (ROM) was measured at 24, 48, and 72 hours.

RESULTS

The 4 groups were comparable in terms of age, gender, weight, ASA grade, and operating time. Compared with patients who received no femoral nerve block or ropivacaine alone, those who received femoral nerve block with 20 ml of 0.375% ropivacaine plus tramadol 50 mg or 100 mg recorded a lower VAS for pain at rest and on movement at 8 to 72 hours, longer sensory and motor block time, and lower demand, delivery, and total amount of patientcontrolled analgesia. The passive knee ROM at 24 to 72 hours was greater in patients with femoral nerve block than in those without.

CONCLUSION

Preoperative femoral nerve block with 20 ml of 0.375% ropivacaine and 100 mg tramadol resulted in the best analgesic effect.

Abstract P4-13-14: Time on treatment of everolimus, fulvestrant, and capecitabine for the treatment of HR+/HER2- metastatic breast cancer: A retrospective claims study in the US

Background:

Treatment guidelines for hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer (mBC) recommend extending the time on treatment (TOT) of endocrine therapy (ET) prior to the initiation of chemotherapy (CT) to avoid its serious side effects and preserve patients' quality of life. Everolimus-based therapy (EVE), fulvestrant monotherapy (FUL mono), and capecitabine monotherapy (CAP mono) are among the latest ET and CT agents approved for the treatment of HR+/HER2- mBC in the US. This retrospective claims analysis compared TOT among HR+/HER2- mBC patients who received EVE versus those who received FUL mono or CAP mono respectively.

Methods:

Postmenopausal women with HR+/HER2- mBC who initiated ≥ 1 new line of therapy for mBC between 7/20/2012 (the approval date of EVE, the latest of all three therapies) and 3/31/2014 (which allowed for ≥ 3 months of potential follow-up) after a non-steroidal aromatase inhibitor were identified from the MarketScan and PharMetrics databases (2002Q1-2014Q2) using an algorithm adapted from the literature. Treatment discontinuation was defined as a treatment gap of ≥ 60 days. Patients' lines of therapies were classified into mutually-exclusive regimen groups (i.e., EVE, FUL mono, and CAP mono) and followed until discontinuation of the line of therapy, end of insurance eligibility, or data cut-off (06/30/2014). Patients who did not discontinue their treatment were censored at the end of follow-up. TOT was compared between EVE versus FUL mono and versus CAP mono using Kaplan-Meier (K-M) analyses with log-rank tests and multivariable Cox models adjusting for the line of therapy and differences in patient characteristics, including age, insurance type, de novo vs non-de-novo mBC, prior use of CT for mBC, sites of metastases (e.g., bone, brain, and visceral), and Charlson comorbidity index.

Results:

Across the first four lines of therapies for mBC, a total of 940 EVE, 953 FUL mono, and 721 CAP mono regimens were included. Based on the different lines of therapies, the K-M estimators of median TOT ranged from 5.5 to 7.2 months for EVE, 4.9 to 8.4 months for FUL mono, and 3.5 to 6.0 months for CAP mono.

Table 1. Comparison of TOT between EVE, FUL mono, and CAP mono by line of therapy Median TOT (months) EVEFUL monoCAP monoLine 16.28.43.5*Line 26.25.64.6*Line 37.25.3*6.0*Line 45.54.95.1**indicates p-value <0.05 for pairwise log-rank tests in comparison with EVE.

Pooling all lines of therapies, EVE was associated with significantly longer TOT compared to FUL mono (multivariable-adjusted hazard ratio [HR] = 0.87, 95% confidence interval [CI]: 0.76-0.99) or CAP mono (multivariable-adjusted HR = 0.73, 95% CI: 0.64-0.83). Similar results were observed in each line of therapy.

Conclusions:

This real-world US claims study of postmenopausal women with HR+/HER2- mBC showed that patients receiving EVE experienced significantly longer TOT than those receiving FUL mono or CAP mono, suggesting a comparative advantage of EVE in extending the duration of ET.

Citation Format: Li N, Hao Y, Kageleiry A, Peeples M, Fang A, Koo V, Guérin A. Time on treatment of everolimus, fulvestrant, and capecitabine for the treatment of HR+/HER2- metastatic breast cancer: A retrospective claims study in the US. [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 P4-13-14.

Abstract P2-08-20: Clinical outcomes among HR+/HER2- metastatic breast cancer patients with multiple metastatic sites

Background:

Hormone receptor-positive, human epidermal growth factor receptor-2-negative (HR+/HER2-) is the most common type of metastatic breast cancer (mBC). While overall the prognosis among these patients is poor with short progression-free survival (PFS) and overall survival (OS), those with multiple metastatic sites (multiple mets) may have even worse clinical outcomes due to multiple organ involvement. This real-world study examined clinical outcomes among HR+/HER2- mBC patients with multiple mets.

Methods:

In this retrospective chart review, a sample of postmenopausal women with HR+/HER2- mBC was collected from community-based oncology practices in the US. Patients were required to have failed a non-steroidal aromatase inhibitor and later initiated a new treatment (defined as the index therapy) for mBC between July 1, 2012 and April 15, 2013. Patients were classified into two mutually exclusive groups: multiple mets or single metastatic site (single met), based on the number of non-lymph-node metastatic sites at index therapy initiation. PFS, time on treatment (TOT), and OS were compared between the two study groups using Kaplan-Meier analyses with log-rank tests and multivariable Cox proportional hazards models adjusting for baseline characteristics, including age, race, insurance, mBC type, and months from initiation of last adjuvant endocrine therapy to mBC diagnosis, index therapy type, index therapy line, adjusted Charlson comorbidity index (CCI), Eastern Cooperative Oncology Group (ECOG) performance status, and prior chemotherapy for mBC. Patients without an event were censored at the last follow-up. In addition, separate Cox proportional hazard models were conducted including an interaction term between line of therapy and study group to assess the impact of multiple mets on clinical outcomes across different lines of therapy.

Results:

A total of 408 patients in the single met group and 291 patients in the multiple mets group were included. Patients with multiple mets had worse ECOG performance status and a higher rate of prior chemotherapy use for mBC compared with patients in the single met group. Relative to patients with single met, patients with multiple mets were associated with significantly shorter PFS (log-rank test p<0.001, hazard ratio (HR)=1.68, 95% confidence interval (CI): 1.32-2.14), TOT (log-rank test p<0.001, HR=1.37, 95% CI: 1.09-1.72) and OS (log-rank test p<0.001, HR=1.71, 95% CI: 1.12-2.63). Similar outcomes were observed in each line of therapy.

Table 1. Multivariable -adjusted comparisons of PFS, TOT, and OS between patients with multiple mets and single met by line of therapy PFSTOTOSMultiple mets vs. single metHR (95% CI)p-valueHR (95% CI)p-valueHR (95% CI)p-valueLine of therapy 11.51 (1.04,2.19)0.030*1.22 (0.86,1.73)0.2561.94 (1.06,3.56)0.032*Line of therapy 21.79 (1.17,2.74)0.008*1.50 (1.02,2.21)0.042*2.35 (1.03,5.38)0.043*Line of therapy 3+1.82 (1.18,2.83)0.007*1.46 (0.97,2.21)0.0721.03 (0.48,2.20)0.936*P < 0.05

Conclusion:

Among HR+/HER2- mBC patients, those with multiple mets had significantly worse clinical outcomes, highlighting substantial disease burden and unmet need for more efficacious treatment for these patients.

Citation Format: Xie J, Hao Y, Li N, Lin PL, Ohashi E, Koo V, Wu EQ. Clinical outcomes among HR+/HER2- metastatic breast cancer patients with multiple metastatic sites. [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 P2-08-20.

Abstract P4-13-13: Real-world effectiveness of everolimus versus endocrine monotherapy or chemotherapy in HR+/HER2- metastatic breast cancer patients with liver metastasis or multiple metastatic sites

Background:

Liver metastasis and multiple metastatic sites are associated with higher risk of progression or death among women with hormone receptor-positive, human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer (mBC). Traditional treatments, like endocrine monotherapy (ET mono) or chemotherapy (CT), have limited effectiveness in these high-risk patients. Everolimus-based therapy (EVE) is a new treatment option with different mechanism of action. This study examined the real-world comparative effectiveness of EVE vs. ET mono or CT in patients with liver metastasis or multiple metastatic sites.

Methods:

A sample of postmenopausal women with HR+/HER2- mBC was obtained through a retrospective chart review of community-based oncology practices in the US. All patients initiated EVE, ET mono, or CT (defined as the index therapy) for mBC between July 2012 and April 2013 after the failure of a non-steroidal aromatase inhibitor. Patients with liver metastasis and those with multiple metastatic sites (i.e., ≥2 non-lymph-node metastases) at the index therapy initiation were analyzed separately. In each group, progression-free survival (PFS) and time on treatment (TOT) were compared between EVE vs. ET mono or CT, respectively, using Kaplan-Meier analyses with log-rank tests and Cox proportional hazards models adjusting for patient and disease characteristics, such as age, mBC type, performance status, tumor burden, and prior treatment. Patients without an event were censored at the last follow-up.

Results:

A total of 202 patients had liver metastasis, including 82 treated with EVE, 49 with ET mono, and 71 with CT. EVE patients had more severe mBC than ET mono patients and less severe mBC than CT patients, as indicated by proportion of patients receiving prior CT for mBC and tumor burden. Compared with ET mono, EVE was associated with significantly longer PFS (log-rank test p=0.049; hazard ratio (HR)=0.48, 95% confidence interval (CI): 0.27-0.87) and TOT (log-rank test p=0.054, HR=0.49, 95% CI: 0.28-0.86). Similarly, compared with CT, EVE was associated with significantly longer PFS (log-rank test p=0.024, HR=0.76, 95% CI: 0.44-1.32) and TOT (log-rank test p<0.001, HR=0.35, 95% CI: 0.22-0.55).

A total of 265 patients had multiple metastatic sites, including 100 treated with EVE, 79 with ET mono, and 86 with CT. Similarly, EVE patients had more severe mBC than ET mono patients and less severe mBC than CT patients, as indicated by tumor burden. Compared with ET mono, EVE was associated with significantly longer PFS (log-rank test p=0.043, HR=0.62, 95% CI: 0.41-0.95) and TOT (log-rank test p=0.054, HR=0.64, 95% CI: 0.42-0.97). Compared with CT, EVE was also associated with longer PFS (log-rank test p=0.004, HR=0.60, 95% CI: 0.39-0.92) and TOT (log-rank test p<0.001, HR=0.36, 95% CI: 0.24-0.53).

Conclusion:

In this retrospective chart review of HR+/HER2- mBC patients, EVE was associated with significantly longer PFS and TOT compared with ET mono or CT in high-risk patients with liver metastasis or multiple metastatic sites.

Citation Format: Li N, Hao Y, Lin PL, Koo V, Ohashi E, Wu EQ, Xie J. Real-world effectiveness of everolimus versus endocrine monotherapy or chemotherapy in HR+/HER2- metastatic breast cancer patients with liver metastasis or multiple metastatic sites. [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 P4-13-13.

Zoledronic acid suppresses callus remodeling but enhances callus strength in an osteoporotic rat model of fracture healing

MINI-ABSTRACT

In this study, we demonstrated that the use of zoledronic acid does not impair fracture healing, but results in superior callus size and resistance at the fracture site, which could be the consequence of a lower rate of bone turnover due to its anti-catabolic effect.

OBJECTIVE

To investigate the effect of inhibition of bone remodeling by the bisphosphonate, zoledronic acid, on callus properties in an osteoporotic rat model of fracture healing.

METHODS

Ovariectomized (OVX) rats were randomly divided into four treatment groups (n=24 per group): saline control (CNT); and three systemic zoledronic acid-injected groups (0.1mg/kg), administered 1 day (ZOLD1), 1 week (ZOLW1), and 2 weeks (ZOLW2) after fracture. Rats were killed at either 6 or 12 weeks postoperatively. Postmortem analyses included radiography, microcomputed tomography, histology, histomorphometry, biomechanical tests, and nanoindentation tests.

RESULTS

Treatment with zoledronic acid led to a significant increase in trabecular bone volume within the callus, as well as in callus resistance, compared to those in the saline control rats; delayed administration (ZOLW2) reduced intrinsic material properties, including ultimate stress and elastic modulus, and microarchitecture parameters, including bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), and connectivity density (Conn.D), compared with ZOLD1 at 12 weeks after surgery. OVX had a negative effect on the progression of endochondral ossification at 6 weeks. Zoledronic acid administration at an early stage following fracture may bind to early callus, and thus not affect subsequent callus formation and endochondral ossification, while delayed administration (ZOLW2) mildly suppresses bony callus remodeling.

CONCLUSION

The superior results obtained with zoledronic acid (ZOLD1, ZOLW1, and ZOLW2) compared to CNT in terms of callus size and resistance could be the consequence of a lower rate of bone turnover at the fracture site due to the anti-catabolic effect of zoledronic acid. Mild suppression of callus remodeling by delayed administration did not impair the initial phase of the fracture healing process.

Well plate-based perfusion culture device for tissue and tumor microenvironment replication

There are significant challenges in developing in vitro human tissue and tumor models that can be used to support new drug development and evaluate personalized therapeutics. The challenges include: (1) working with primary cells which are often difficult to maintain ex vivo, (2) mimicking native microenvironments from which primary cells are harvested, and (3) the lack of culture devices that can support these microenvironments to evaluate drug responses in a high-throughput manner. Here we report a versatile well plate-based perfusion culture device that was designed, fabricated and used to: (1) ascertain the role of perfusion in facilitating the expansion of human multiple myeloma cells and evaluate drug response of the cells, (2) preserve the physiological phenotype of primary murine osteocytes by reconstructing the 3D cellular network of osteocytes, and (3) circulate primary murine T cells through a layer of primary murine intestine epithelial cells to recapitulate the interaction of the immune cells with the epithelial cells. Through these diverse case studies, we demonstrate the device's design features to support: (1) the convenient and spatiotemporal placement of cells and biomaterials into the culture wells of the device; (2) the replication of tissues and tumor microenvironments using perfusion, stromal cells, and/or biomaterials; (3) the circulation of non-adherent cells through the culture chambers; and (4) conventional tissue and cell characterization by plate reading, histology, and flow cytometry. Future challenges are identified and discussed from the perspective of manufacturing the device and making its operation for routine and wide use.

Psychrophilic fungi from the world's roof

During a survey of cold-adapted fungi in alpine glaciers on the Qinghai-Tibet Plateau, 1 428 fungal isolates were obtained of which 150 species were preliminary identified. Phoma sclerotioides and Pseudogymnoascus pannorum were the most dominant species. Psychrotolerant species in Helotiales (Leotiomycetes, Ascomycota) were studied in more detail as they represented the most commonly encountered group during this investigation. Two phylogenetic trees were constructed based on the partial large subunit nrDNA (LSU) to infer the taxonomic placements of these strains. Our strains nested in two well-supported major clades, which represented Tetracladium and a previously unknown lineage. The unknown lineage is distant to any other currently known genera in Helotiales. Psychrophila gen. nov. was therefore established to accommodate these strains which are characterised by globose or subglobose conidia formed from phialides on short or reduced conidiophores. Our analysis also showed that an LSU-based phylogeny is insufficient in differentiating strains at species level. Additional analyses using combined sequences of ITS+TEF1+TUB regions were employed to further investigate the phylogenetic relationships of these strains. Together with the recognisable morphological distinctions, six new species (i.e. P. antarctica, P. lutea, P. olivacea, T. ellipsoideum, T. globosum and T. psychrophilum) were described. Our preliminary investigation indicates a high diversity of cold-adapted species in nature, and many of them may represent unknown species.