Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles

AIM

Sphingosine-1-phosphate (S1P) influences resistance vessel function and is implicated in renal pathological processes. Previous studies revealed that S1P evoked potent vasoconstriction of the pre-glomerular microvasculature, but the underlying mechanisms remain incompletely defined. We postulated that S1P-mediated pre-glomerular microvascular vasoconstriction involves activation of voltage-dependent L-type calcium channels (L-VDCC) and the rho/rho kinase pathway.

METHODS

Afferent arteriolar reactivity was assessed in vitro using the blood-perfused rat juxtamedullary nephron preparation, and diameter was measured during exposure to physiological and pharmacological agents.

RESULTS

Exogenous S1P (10^-9 -10^-5 mol L^-1 ) evoked concentration-dependent vasoconstriction of afferent arterioles. Superfusion with nifedipine, a L-VDCC blocker, increased arteriolar diameter by 39 ± 18% of baseline and significantly attenuated the S1P-induced vasoconstriction. Superfusion with the rho kinase inhibitor, Y-27632, increased diameter by 60 ± 12% of baseline and also significantly blunted vasoconstriction by S1P. Combined nifedipine and Y-27632 treatment significantly inhibited S1P-induced vasoconstriction over the entire concentration range tested. In contrast, depletion of intracellular Ca²⁺ stores with the Ca²⁺ -ATPase inhibitors, thapsigargin or cyclopiazonic acid, did not alter the S1P-mediated vasoconstrictor profile. Scavenging reactive oxygen species (ROS) or inhibition of nicotinamide adenine dinucleotide phosphate oxidase activity significantly attenuated S1P-mediated vasoconstriction.

CONCLUSION

Exogenous S1P elicits potent vasoconstriction of rat afferent arterioles. These data also demonstrate that S1P-mediated pre-glomerular vasoconstriction involves activation of L-VDCC, the rho/rho kinase pathway and ROS. Mobilization of Ca²⁺ from intracellular stores is not required for S1P-mediated vasoconstriction. These studies reveal a potential role for S1P in the modulation of renal microvascular tone.

Effects of caponization and ovariectomy on objective indices related to meat quality in chickens

Capons and ovariectomized chickens are birds that have been gonadectomized to improve the meat quality. This study investigated the effects of caponization and ovariectomy on physical, chemical, and fatty acid and amino acid profiles of meat from Beijing-You chickens (a Chinese local breed) at market age (17 wk). All birds (20 capons, 20 ovariectomized, and 40 controls) were reared under the same conditions. Breast muscle fiber diameter and area were significantly smaller and the fiber density was higher in capons and ovariectomized chickens than in controls (P < 0.05). Compared with controls, caponization and ovariectomy significantly decreased breast muscle shear values and redness (a*), as well as increased yellowness (b*), hue (H*), and chroma (C*) (P < 0.05). There was significantly more intramuscular fat (IMF) in capons than in controls (P < 0.05), and there was a tendency for more inosine-5΄-monophosphate (IMP) in capons than in controls (P = 0.10). The levels of IMF and IMP in ovariectomized chickens were significantly higher than those in controls (P < 0.05). Capons and ovariectomized chickens exhibited a significantly higher content of palmitic acid (C16:0), palmitoleic acid (C16:1) and oleic acid (C18:1), together with a lower content of stearic acid (C18:0), arachidonic acid (C20:4), and lignoceric acid (C24:0) compared to controls (P < 0.05). The total saturated, monounsaturated, and polyunsaturated fatty acids as well as amino acid composition were not affected by gonadectomy (P > 0.05). Overall, this study indicates that both caponization and ovariectomy likely improve the meat quality of the breast muscle based on the objective indices of IMF, appearance (color), texture, and minor change of the fatty acid profile; ovariectomy improves flavor-related indices.

Analysis of the safety and efficacy of combined extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy for the treatment of complex renal calculus

OBJECTIVE

To investigate the safety and efficacy of extracorporeal shock wave lithotripsy (ESWL) combined with percutaneous nephrolithotomy (PCNL) for treatment of complex renal calculus.

PATIENTS AND METHODS

Seventy-eight patients diagnosed with complex renal calculus and who accepted treatment in our hospital were consecutively selected. Patients were divided randomly into the observation group (n=40) treated by combined ESWL and PCNL and the control group (n=38) treated by PCNL. The effect of treatment between the two groups was compared.

RESULTS

The stone-free rate at 3 months after surgery was higher in the observation group than in the control group. There were no differences in the rates of complications (including infection, hemorrhage, collection system perforation and laceration, peripheral organ impairment, and urination extravasation). There were gradual decreases of serum creatinine in the observation group at 4 weeks after extubation of the double J catheter and at 3 months after surgery, while there were no apparent decreases in the control group. The levels of cysteine protease inhibitor and neutrophil gelatinase-associated lipocalin in both groups increased at 4 weeks after extubation of the double J catheter, and decreased at 3 months after surgery. The decreases were more apparent in the observation group compared with the control group, and the differences were statistically significant (p<0.05).

CONCLUSIONS

Combined use of ESWL and PCNL to treat complex renal calculus can improve the stone-free rate and renal function, and does not increase the complication rate. It is, therefore, safe and effective.

FOXC1: an emerging marker and therapeutic target for cancer

The Forkhead box C1 (FOXC1) transcription factor is involved in normal embryonic development and regulates the development and function of many organs. Most recently, a large body of literature has shown that FOXC1 plays a critical role in tumor development and metastasis. Clinical studies have demonstrated that elevated FOXC1 expression is associated with poor prognosis in many cancer subtypes, such as basal-like breast cancer (BLBC). FOXC1 is highly and specifically expressed in BLBC as opposed to other breast cancer subtypes. Its functions in breast cancer have been extensively explored. This review will summarize current knowledge on the function and regulation of FOXC1 in tumor development and progression with a focus on BLBC as well as the implications of these new findings in cancer diagnosis and treatment.

Abstract P6-09-55: “Quality, not quantity”: 10X hot-spot (HS) analysis of lymphocyte markers (CD3, CD8, CD4, CD20) in tumor-infiltrating lymphocytes (TILs) is superior to whole tumor (WT) analysis in triple-negative breast cancer (TNBC)

This abstract was withdrawn by the authors.

Abstract P4-12-14: Folate receptor alpha (FOLR1) expression in triple-negative breast cancer (TNBC)

Background Folate receptor alpha (FOLR1) has been identified as a potential prognostic and therapeutic target in breast cancer. The limited studies evaluating the role of FOLR1 in breast cancer have shown that FOLR1 protein expression is enriched in triple-negative breast cancer (TNBC). Newly developed anti-FOLR1 therapy could potentially be used for patients with TNBC for whom few therapeutic options exist. We sought to evaluate FOLR1 protein expression in a cohort of patients with TNBC to determine its prevalence and prognostic value. Design Immunohistochemistry was performed for FOLR1 (26B3.F2, Biocare, RTU) on tissue microarray (TMA) slides consisting of 62 primary TNBC. Membranous staining in ≥5% of cells was deemed positive in a given case. Statistical analyses correlating FOLR1 protein expression with clinicopathologic parameters and clinical outcome [disease-free survival (DSF) and overall survival (OS) (range: 16 to 196 months, mean: 111 months)] were performed. Results 62 cases of primary TNBC from 61 patients were studied. All patients were female and the mean age was 55 years (range 30 to 91 years). Histologically, almost all tumors were invasive ductal carcinoma (94%; 58/62) and grade 3 (89%; 55/62). Most were pT1 tumors (71%; 44/62) or pT2 (27%; 17/62). For the majority of patients, the nodal status was N0 (61%; 38/62) or N1 (24%; 15/62) and the stage was 1 (53%; 33/62) or 2 (32%; 20/62). Most cases were negative for FOLR1 (84%; 52/62). FOLR1 expression did not correlate with any clinicopathologic parameters, DFS or OS (P&gt;0.05). Conclusion Similar to other studies, we found no correlation with FOLR1 expression and common clinicopathologic parameters and clinical outcome in TNBC. While FOLR1 expression has been previously reported to confer poor prognosis in breast cancer (all types), our findings suggest that in TNBC specifically, FOLR1 expression is not prognostically significant.

Citation Format: Cui X, McIntire PJ, Ginter PS, Irshaid L, Chen Z, Shin SJ. Folate receptor alpha (FOLR1) expression in triple-negative breast cancer (TNBC) [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 P4-12-14.

Abstract P4-12-15: Triple-negative breast cancers (TNBCs) rich in infiltrating stromal plasma cells have improved disease-free survival and overall survival

Background Tumor-infiltrating lymphocytes (TILs) have emerged as a prognostic indicator in patients with TNBC. Furthermore, lymphocyte-predominant breast cancer (LPBC), defined as those containing ≥50% stromal TILs has been shown to be associated with better prognosis. While cell-mediated immunity has received much of the credit for anti-tumor responses, the International TILs Working Group recommends that the assessment of stromal density of TILs should incorporate all mononuclear cells including plasma cells. Very little is known about the role of humoral immunity, particularly the role of plasma cells in the anti-tumoral response in breast cancer. We sought to evaluate the prognostic value of plasma cells in the setting of stromal TIL assessment of TNBC. Design Morphologic assessment of TILs was performed on a representative H&E slide of 76 cases of primary TNBC. For each case, the stromal density of TILs was estimated and then classified as LPBC or non-LPBC using a cutoff of ≥50% for the former. Also, the plasma cell intensity defined as the mean percentage of stromal plasma cells of five 40x high power microscopic fields of TILs was recorded at 5% increments. Statistical analyses were performed using disease-free survival (DFS) and overall survival (OS) (range: 16 to 196 months, mean: 110 months) as primary endpoints. Results Plasma cell intensity was dichotomized at 12.5% and predictive of OS [.21, 95% confidence interval (CI) .05-.93, P = 0.0401)]. A positive dose related response trended toward significance for each 5% increase in plasma cell intensity (.97, 95% CI .93-1.01, P = 0.1168). Disease-free survival also trended positively towards significance (.39, 95% CI .13-1.20, P = 0.0991). When comparing LPBC, tumors rich in plasma cells (&gt;12.5% of TILs) trended towards longer DFS (.17, 95% CI .02-1.62, P = 0.1226) when compared to plasma cell poor LPBC. Conclusion In addition to the cell-mediated immune response in TNBC, our findings suggest that humoral immunity may also play a role in predicting recurrence and survival in these patients. Our findings suggest that inclusion of an additional parameter of plasma cell intensity may be prognostically valuable in TIL assessment of TNBC.

Citation Format: McIntire PJ, Cui X, Ginter PS, Irshaid L, Chen Z, Shin SJ. Triple-negative breast cancers (TNBCs) rich in infiltrating stromal plasma cells have improved disease-free survival and overall survival [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 P4-12-15.

Abstract P6-09-56: Tissue microarray (TMA) based immunohistochemical studies of lymphocyte-specific markers yield inaccurate results

This abstract was withdrawn by the authors.

Advances in multicellular spheroids formation

Three-dimensional multicellular spheroids (MCSs) have a complex architectural structure, dynamic cell-cell/cell-matrix interactions and bio-mimicking in vivo microenvironment. As a fundamental building block for tissue reconstruction, MCSs have emerged as a powerful tool to narrow down the gap between the in vitro and in vivo model. In this review paper, we discussed the structure and biology of MCSs and detailed fabricating methods. Among these methods, the approach in microfluidics with hydrogel support for MCS formation is promising because it allows essential cell-cell/cell-matrix interactions in a confined space.

Stretchable and compressible strain sensors based on carbon nanotube meshes

Flexible strain sensors have promising applications in healthcare and human movement detection. Herein, we report stretchable and compressible strain sensors based on carbon nanotube meshes (CNTMs) with unique structures consisting of macroscopic grids and microscopic spider-web networks. The stretchable strain sensor shows good reliability for long cyclic tests and can be used for weak stimuli and large motion detection. The compressible strain sensor also shows good reliability after long cyclic tests and can be used to detect large strains induced by walking or running motion. Both the stretchable and compressible CNTM strain sensors are reliable and stable at detecting large stretching and compressing deformation.

Hepatic fibrosis and supersonic shear imaging in patients with different etiological chronic hepatic diseases

The objective of the present study was to investigate whether hepatic fibrosis difference of supersonic shear imaging (SSI) value existed in patients with different etiological chronic hepatic diseases. Retrospective analysis was used to study chronic hepatitis. All the subjects were diagnosed by shear wave elastography and percutaneous liver biopsy. The shear moduli were analyzed to check whether any difference existed between groups. For the chronic hepatitis B, autoimmune hepatitis and fatty hepatitis, the shear moduli in S0 stage were (8.50±3.1)kPa, (9.41±2.5)kPa, (8.97±3.8)kPa; the shear moduli in S1 stage were (9.54±3.0)kPa, (10.42±5.1)kPa, (9.51±4.6)kPa; the shear moduli in S2 stage were (11.77±4.8) kPa, (13.25±5.6)kPa, (11.03±6.0)kPa; the shear moduli in S3 stage were (14.96±6.1)kPa, (19.03±7.8) kPa, (15.38±7.8)kPa; the shear moduli in S4 stage were (20.36±7.5)kPa, (24.99±9.5)kPa, (19.53±5.6)kPa. Shear wave elastography could measure the different etiological chronic hepatic diseases.

Training in metabolomics research. I. Designing the experiment, collecting and extracting samples and generating metabolomics data

Metabolomics is perhaps the most challenging of the -omics fields, given the complexity of an organism's metabolome and the rapid rate at which it changes. When one sets out to study metabolism there are numerous dynamic variables that can influence metabolism that must be considered. Recognizing the experimental challenges confronting researchers who undertake metabolism studies, workshops like the one at University of Alabama at Birmingham have been established to offer instructional guidance. A summary of the UAB course training materials is being published as a two-part Special Feature Tutorial. In this month's Part I the authors discuss details of good experimental design and sample collection and handling. In an upcoming Part II, the authors discuss in detail the various aspects of data analysis.

Positive feedback regulation between microRNA-132 and CREB in spinal cord contributes to bone cancer pain in mice

BACKGROUND

cAMP response element-binding protein (CREB)-dependent gene expression plays an important role in central sensitization. CREB-regulated transcription coactivator 1 (CRTC1) dramatically increase CREB-mediated transcriptional activity. microRNA-132 (miR-132), which is highly CREB-responsive, functions downstream from CREB/CRTC1 to mediate activity-dependent synaptic plasticity and in turn loops back to amplify CREB/CRTC1 signalling. This study aimed to investigate the positive feedback regulation between miR-132 and CREB in spinal cord in the maintenance of bone cancer pain.

METHODS

Osteosarcoma cells were implanted into the intramedullary space of the right femurs of C3H/HeNCrlVr mice to induce bone cancer pain. We further investigated effects of repeated intrathecal administration with Adenoviruses expressing CREB-siRNA or miR-132 antisense locked nucleic acid (LNA), respectively, on nociceptive behaviours and on the activity of CREB/CRTC1 signalling.

RESULTS

Intramedullary inoculation of osteosarcoma cells resulted in up-regulation of spinal p-CREB, CRTC1 and CREB-target genes (NR2B and miR-132). Repeated intrathecal administration with Adenoviruses expressing CREB-siRNA or miR-132 LNA-AS, respectively, attenuated bone cancer-evoked pain behaviours, reduced the activity of CREB/CRTC1 signalling and down-regulated CREB-target gene NR2B expression in spinal cord.

CONCLUSIONS

These findings suggest that activation of spinal CREB/CRTC1 signalling may play an important role in bone cancer pain. Interruption to the positive feedback regulation between CREB/CRTC1 and its target gene miR-132 can effectively relieved the bone cancer-induced mechanical allodynia and spontaneous pain. WHAT DOES THIS STUDY ADD?: The positive feedback regulation between CREB/CRTC1 and its target gene miR-132 in spinal cord plays an important role in bone cancer pain.

Abstract P5-01-03: Stratifying triple-negative breast cancer prognosis using 18F-FDG-PET/CT imaging

Introduction: Triple-negative breast cancer (TNBC) is a highly diverse group of cancers, and may benefit from molecular-targeted therapies. This study aims to stratify prognosis of TNBC patients using pre-treatment 18F-FDG PET/CT, alone and with correlation to immunohistochemistry biomarkers.

Method: 200 consecutive TNBC breast cancer patients treated between 2008 and 2012 who received lumpectomy or mastectomy as primary treatment were retrieved. Among the full cohort, 79 patients had pre-treatment 18F FDG PET/CT scans. Immunostaining status (percentage and intensity) of basal biomarkers (EGFR, CK5/6), Ki-67, P53, and other clinicopathological variables (age, tumor size, pathological T/N stage, nuclear grade, and lymph node metastasis) were obtained. Three PET image features were evaluated: maximum uptake values (SUVmax), mean uptake (SUVmean) and target volume (SUVvol) defined by SUV&gt;2.5. The relationships among tumor metabolic activities and clinicopathological factors were evaluated. All variables were analyzed versus disease-free survival (DFS) using univariate and multivariate Cox analysis, Kaplan-Meier curves and log-rank tests. The optimal cutoff points of variables were estimated using time-dependent survival receiver operating characteristic (ROC) analysis.

Results: All PET features significantly correlated with proliferation marker Ki-67 (all p&lt;0.010). SUVmax stratified the prognosis of TNBC patients with optimal cutoff derived by ROC analysis (≤3.5 vs &gt;3.5, AUC=0.654, p=0.006). Basal biomarkers EGFR and CK5/6 and image features SUVmax, SUVmean, SUVvol were significant associated with DFS in univariate Cox analysis, whereas SUVmax (p=0.001) and EGFR (p=0.001) were also significant in multivariate Cox analysis. To integrate prognosis of biological and imaging markers, patients were first stratified by EGFR into low (≤15%) and high (&gt;15%) risk groups. Further, SUVmax was used as a variable to stratify the two EGFR groups. In the high EGFR group, patients with high FDG uptake (SUVmax&gt;3.5) had worse survival outcome (median DFS=7.6 months) than those patients with low FDG uptake (SUVmax≤3.5, median DFS=11.6 months). In the low EGFR group, high SUVmax also indicated worse survival outcome (17.2 months) than low SUVmax (22.8 months). The risk stratification with integrative EGFR and PET was statistically significant with log-rank p&lt;&lt;0.001.

Multivariate Cox analysis for disease-free survivalVariablesHR (95% CI)p-valuePathology, T stage, ≤ 3 vs &gt;32.337(0.428-7.384)0.148EGFR, ≤15% vs &gt; 15%9.109(1.997-41.55)0.004CK5/6, ≤ 50% vs &gt; 50%1.471(0.598-3.614)0.401SUVmax, ≤3.5 vs &gt; 3.53.883(1.13-13.32)0.031

TNBC patient risk groups stratified by EGFR and SUVmax (with the median values of variables)Risk groups (EGFR&gt;15, SUVmax&gt;3.5)patient#DFS monthsEGFR %SUVmaxSUVmeanSUVvolKi-67%1 (-, -)1222.852.00.60.2342 (-, +)1517.258.94.37.2673 (+, -)1311.6502.72.60.9354 (+, +)377.66011.35.210.960

Conclusions: Pre-treatment 18F-FDG PET/CT imaging has significant prognostic value for predicting survival outcome of TNBC patients. Integrated with basal-biomarker EGFR, PET imaging can further stratify patient risks in the pre-treatment stage, and help select appropriate treatment strategies for individual patients.

Citation Format: Yue Y, Cui X, Bose S, Audeh W, Zhang X, Fraass B. Stratifying triple-negative breast cancer prognosis using 18F-FDG-PET/CT imaging. [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 P5-01-03.

Abstract P3-12-13: Radiation enhancement with cysteine coated platinum nanoparticles

Background: Radiation is the current choice treatment for non-operable metastatic breast-brain cancer. When cancer lesions are located in sensitive areas like the brain or have excessive amounts of metastatic sites, radiation usually proves to be a more viable option than excision. Ionizing (X-ray and gamma) radiation is non-selective and affects all the tissue it penetrates. In order to concentrate the dose on tumors, high energy radiation from multiple directions is typically used, reaching the highest dose where the radiation crosses. This type of multiple angle treatment minimizes the dose to normal tissue by increasing overall normal tissue irradiation. The objective is to achieve sufficient radiation in the tumor tissue to cause the DNA strands to break and to disrupt the reproduction and maintenance of cancer cells while keeping the damage to normal tissue in a reasonable range for tissue preservation.

Metal nanoparticles have shown promising results for reinforcing the radiation dose effect. High atomic number (Z) elements absorb a greater amount of radiation because the higher density raises the probability of interaction. The metal nanoparticles interact with the energy of the ionizing radiation by either scattering or absorbing, or accumulating the energy, thus increasing the number of DNA strand breaks in the nucleus of cells.

Methods: Four breast cancer cell lines (BT-474, MDA-231, BT-549 and MCF-7) were incubated with 1-2 nm platinum nanoparticles (0-1000 μg/mL) produced with a cysteine coating. 24 hours later cells were exposed to 2 Gy radiation with a C-arm (Toshiba Infinix VF-i/SP) using 125 KVP to deliver a spectrum of KeV low energy X-rays. After 24 hours the cells were washed and analyzed using a bioluminescence assay to assess cell proliferation based on ATP production.

Results: Of the four cell lines tested the BT-474 and BT-549 demonstrated limited reduction in cell proliferation at up to the highest treatment concentration 1000 μg/mL with no radiation exposure. As a result of the limited toxicity of the platinum nanoparticles the effect from increased radiation can be more readily observe when 2 Gy radiation is added resulting a in platinum nanoparticle dose dependent decrease in proliferation in the BT-474 cell line.

Nanoparticle Toxicity Concentration of Platinum Nanoparticles (μ/mL) 02505007501000MDA-2311.000±0.0050.995±0.0120.974±0.0130.979±0.0140.777±0.014BT-5491.000±0.0131.003±0.0091.003±0.0170.969±0.0170.894±0.009MCF-71.000±0.0140.960±0.0150.927±0.0220.851±0.0220.769±0.032BT-4741.000±0.0240.961±0.0290.957±0.0330.965±0.0630.985±0.065Table 1: Indexed values for cell proliferation for the BT-474 cell

Radiation Toxicity Concentration of Platinum Nanoparticles (μ/mL) 02505007501000*0 Gy1.000±0.0240.961±0.0290.957±0.0330.965±0.0630.985±0.0652 Gy1.027±0.0380.966±0.0230.908±0.0340.870±0.0310.799±0.037Table 2: Indexed values for cell proliferation for the BT-474 cell line 0 and 2 Gy radiation doses, 6 averages. * Student T-TEST P&lt;0.05

Conclusions: At moderate doses of low energy radiation, a reduction in cell proliferation can be detected. This data supports follow-up experiments to add a targeting protein to facilitate uptake by cancer cells based on cell receptor expression. Experiments are current being done to utilize the HER2+ cell receptor upregulation to increase internalization of the particles to achieve a greater effect.

Citation Format: Wagner S, Yue Y, Cui X, Zhang G, Bingchen H, Li D, Medina-Kauwe L. Radiation enhancement with cysteine coated platinum nanoparticles. [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 P3-12-13.

Abstract P6-17-05: A corrole nanobiologic crosses the blood-brain-barrier and recognizes triple negative breast cancer: Implications for targeting brain metastases

Patients with breast cancer metastases to the brain on average survive less than one year. These tumors tend to be resistant to current therapies, and the majority of targeted therapeutics are unable to breach the blood brain barrier (BBB) to reach these tumors, thus improved alternatives are urgently needed.

Elevated cell surface levels of the human epidermal growth factor receptor subunit 3 (HER3) is associated with metastatic breast tumors, including those that spread to the brain. Elevated HER3 is also associated with resistance to a number of targeted therapies currently used in the clinic, including inhibitors of EGFR (lapatinib), HER2 (lapatinib, trastuzumab, T-DM1), HER2-3 (pertuzumab), and combination therapy.

Whereas a number of targeted therapies are currently used to combat peripheral breast tumors, the delivery of these molecules to brain metastases is limited by the blood brain barrier (BBB). This is exemplified by HER2+ breast tumors that metastasize to the brain: these tumors, while targetable outside of the central nervous system (CNS) by HER2 antibodies such as trastuzumab, are unreachable by these same antibodies because the HER2 subunit, though present on the brain endothelium, does not mediate antibody transcytosis across the blood vessel wall.

HER3, on the other hand, undergoes rapid transcytosis across the brain endothelium upon ligand binding, which normally occurs to mediate the delivery of neuregulin growth factors for neural growth and maintenance. We have developed a self-assembling nanobiological particle, HerMn, which uses HER3 as a portal for targeted entry of toxic molecules into tumor cells.

HerMn is a 10-20 nm diameter serum-stable particle comprised of a HER3-targeted cell penetration protein non-covalently assembled with a sulfonated manganese(III) corrole (S2Mn or Mn-corrole). Tumor-targeted toxicity by HerMn occurs by mitochondria membrane disruption and superoxide-mediated damage to the cytoskeleton. HerMn can also elicit tumor-selective detection by magnetic resonance imaging (MRI) due to the paramagnetic property of the corrole. HerMn distributes to the brain after systemic injection in mice, in addition to showing preferential homing and toxicity to subcutaneous tumors expressing the HER2-3 dimer. Interestingly, the Mn corrole is known to exhibit neuroprotective effects due to its antioxidant activity on normal tissue. Consistent with this, we have found that HerMn supports human cardiac cell survival ex vivo. Our studies interrogating the therapeutic potential of HerMn suggest that this nanobiologic bears the capacity for targeting toxicity to brain-metastatic breast tumors while sparing off-target tissue due to both its targeting capacity and ability to provide beneficial protective effects to normal tissue such as the brain and heart.

Citation Format: Medina-Kauwe L, Sims J, Taguiam M, Hanson C, Alonso-Valenteen F, Cui X, Wagner S, Sorasaenee K, Moats R, Marban E, Chung A, Gray H, Gross Z, Giuliano A. A corrole nanobiologic crosses the blood-brain-barrier and recognizes triple negative breast cancer: Implications for targeting brain metastases. [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 P6-17-05.

Abstract P6-13-10: Therapeutic efficacy of HER3-targeted nanobiologics on resistant tumors

Elevated cell surface levels of the human epidermal growth factor receptor subunit 3 (HER3) are associated with resistance to a number of signal-blocking breast cancer treatments, including inhibitors of EGF-R (lapatinib), HER2 (lapatinib, trastuzumab, T-DM1), HER2-3 (pertuzumab), and combination therapy. Additionally, HER3 elevation has been identified on "untarget-able" tumors such as triple-negative breast cancer (TNBC), including TNBC with acquired resistance to EGF-R inhibition. Patients with such refractory tumors currently have limited treatment options and a poor prognosis. Moreover, as up to 70% of cases resist or acquire resistance to signal-blocking therapies, an alternative approach addressing this important clinical problem has the potential for significant clinical impact.

We have developed a protein construct, HerPBK10, which self-assembles with a variety of payloads (including nucleic acids, chemotherapy agents, and imaging agents) and uses HER3 as a portal for targeted entry into cells. In contrast to receptor-targeted antibodies and tyrosine kinase inhibitors currently used in the clinic, HerPBK10 circumvents the need to modulate signaling by inducing rapid entry of toxic molecules into tumor cells through receptor-mediated endocytosis and membrane penetration.

We have previously shown that nanobiological particles formed between HerPBK10 and therapeutic payloads can elicit targeted toxicity to HER2+ tumors due to the prevalence of HER2-3 heterodimers on the tumor cell surface, while sparing heart and liver tissue. The particles that form (20-40 nm dia.) exhibit stability in serum and no detectable immunogenicity. Here we show that such particles resolve breast tumor cells with acquired resistance to HER2 and/or EGFR inhibitors in contrast to trastuzumab, pertuzumab, and combination treatment. Additionally, therapeutic efficacy is augmented on resistant over parental tumor cells, due in part to the elevated HER3 expression associated with resistance to these inhibitors. Our studies in preclinical models show that these nanoparticles ablate the growth of tumors with both acquired and pre-existing resistance to trastuzumab. Moreover, we have found that signal-inhibitors currently used in the clinic, such as trastuzumab, effectively augment the efficacy of our nanobiologic on both naïve and inherently-resistant breast tumor cells, in part through induced elevation of HER3. Thus, current targeted molecules such as trastuzumab or lapatinib may act as adjuvants to enhance tumor cell-sensitivity to HerPBK10-particles. Such an approach may address the tumor-heterogeneity associated with resistance, and corner tumors for attack by our particles.

Citation Format: Medina-Kauwe L, Sims J, Taguiam M, Hanson C, Alonso-Valenteen F, Cui X, Chung A, Gray H, Gross Z, Giuliano A. Therapeutic efficacy of HER3-targeted nanobiologics on resistant tumors. [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 P6-13-10.

Percutaneous sclerotherapy of liver and renal cysts, comments on the EFSUMB guidelines

Cystic lesions in the liver and kidneys are common incidental findings. They are generally benign and require no treatment. They can appear sporadically or as part of a syndrome, and are characterised by their anechoic structure and posterior enhancement in ultrasound imaging. Increased size, haemorrhage or infection of a cyst can lead to development of symptoms. Along with surgical options and laparoscopic cyst fenestration, ultrasound-guided sclerotherapy of symptomatic cysts represents an effective and safe minimally invasive treatment option.