Subcutaneous Xenotransplantation of Hybrid Artificial Pancreas Encapsulating Pancreatic B Cell Line (MIN6): Functional and Histological Study

The biohybrid artificial pancreas is designed to enclose pancreatic endocrine tissues with a selectively permeable membrane that immunoisolates the graft from the host immune system, allowing those endocrine tissues to survive and control glucose metabolism for an extended period of time. The pancreatic B cell line MIN6 is established from a pancreas B cell tumor occurring in transgenic mice harboring the human insulin promoter gene connected to the SV40 T-antigen hybrid gene. It has been proven that glucose-stimulated insulin secretion in MIN6 cells retains a concentration-dependent response similar to that of normal islets. In this study, we performed the histological and functional examination of three-layer microbeads employing MIN6 cells after subcutaneous xenotransplantation to evaluate this device as bioartificial pancreas. MIN6 cells were microencapsulated in three-layer microbeads formulated with agarose, polystyrene sulfonic acid, polybrene, and carboxymethyl cellulose. Microbeads were xenogenically implanted in the subcutaneous tissue of the back of Lewis rats with streptozotocin-induced diabetes. One week after implantation, microbeads were retrieved and cultured for 24 h before the static incubation. There was no evidence of adhesion to the graft and the fibrosis in the transplantation site as determined by gross visual inspection. Microscopic examination demonstrated that retrieved microbeads maintained normal shape, containing intact MIN6 cells. Histological study showed that these MIN6 cells in the microbeads appeared to be viable without cellular infiltration within or around the microbeads. Immunohistochemical analysis of the microbeads clearly revealed the intense staining of insulin in the cytoplasm of encapsulated MIN6 cells. Insulin productivity of MIN6 cells in the microbeads is strongly suggested to be preserved. In response to 16.7 mM glucose stimulation, static incubation of microbeads 1 wk after implantation caused the 2.3 times increase in insulin secretion seen after 3.3 mM glucose stimulation (84.3 ± 10.0 vs. 37.4 ± 10.7 μU/3 × 106 cells/hr, n = 5 each, p < 0.01). This study demonstrates that three-layer microbeads encapsulating MIN6 cells retain excellent biocompatibility and maintain good insulin secretion even after subcutaneous xenotransplantation, suggesting the possible future clinical application of this unique bioartificial pancreas to subcutaneous xenotransplantation.

Improved Large-Scale Isolation of Breeder Porcine Islets: Possibility of Harvesting from Nonheart-Beating Donor

To establish a large-scale isolation procedure for adult porcine islets usable as a donor source for xenotransplantation and as a model of human islet isolation, we improved several characteristics of the conventional isolation procedure. At a slaughterhouse we first selected a breeder pig over 1.5 years old (and over 200 kg in weight) with warm ischemic time (WIT) of 15 ± 2 minutes as nonheart-beating donors. Then, we made a special enzymic mixture that consisted of collagenase S-1 (260 U/mg, NittaZelatin, Japan), collagenase P (1.86 U/ml Lyo Boehringer-Mannheim, USA), DNase (Sigma, St. Louis, Mo), Disparse (NittaZelatin, Japan), and protease inhibitor (Sigma). Third, this mixture was injected very gently into the pancreatic duct at the time of pancreatic harvesting. To prevent overdigestion of the pancreas, the mixture was first cooled to less than 10°C. Fourth, during the warm digestion of pancreas, the pancreas with the enzymic mixture was quietly put in a water bath at 37°C without mechanical shaking. Fifth, we purified the islets with a COBE 2991 cell processor by the Dextran 70 gradient method, because Dextran 70 is very cheap and has the same purification effect as the Ficoll gradient. The results of 10 consecutive breeder porcine islet isolations are reported. The total yield of isolations of islets over 50 μm in the longest diameter after staining with Dithizone (DTZ) was 85,900 ± 19,954 islets, 291,667 ± 240,452 IEQ (2,900 ± 2,324 IEQ/g). The purity of the isolated islets was very high: 90.2 ± 3.8%. Glucose stimulation during in vitro incubation induced significant insulin release from isolated breeder porcine islets. In two of the diabetic rats receiving encapsulated islets grafts using a mesh-reinforced polyvinyl alcohol hydrogel bag (MRPB), a prominent reduction in serum glucose levels (less than 200 mg/dL) persisted for 13 and 19 days, respectively, after intraperitoneal xenotransplantation islets without immunosuppression. In conclusion, we succeeded in a more efficient and less-expensive isolation of a large amount of adult porcine islets from a nonheart-beating donor.

Transplantation of Xenogeneic Cells Secreting β-Endorphin for Pain Treatment: Analysis of the Ability of Components of Complement to Penetrate through Polymer Capsules

The permeation of components of complement and secreted peptides through polymer capsules (PM30, K6305, and K5708) were examined. To analyze permeability by complement, the degree of hemolysis of sensitized sheep erythrocytes (EA) (1 × 109/ml) enclosed in each type of capsule was examined after 24-h incubation in culture medium containing 10% human serum. PM30 and K6305 prevented the permeation of complement well, while K5708 did not. EA suspended in alginate prevented hemolysis even in K5708. Peptide permeation through the capsules was assessed by measuring the concentration of ACTH secreted by proopiomelanocortin (POMC)-gene-transfected-Neuro2A in the culture medium on days 4, 7, 14, 21, and 28 after encapsulation. The ACTH levels in the culture medium remained high until day 28. Alginate appeared to prevent the secretion, because ACTH levels decreased in alginate-suspended cells after day 14. The PM30-K6305 double capsules containing cell lines, Neuro2A, BHK21 (hamster fibroblasts), L929 (mouse fibroblasts), and HF-SKFII (human fibroblasts) were transplanted into the cerebrospinal fluid (CSF) space of the monkeys in the lumber region. The morphological examination showed the partial survival of Neuro2A, and BHK21 and HF-SKFII, which were cells concordant with the monkeys. On the other hand, L929 cells, which were discordant with the monkeys, could not survive at all. Because these results suggest that the complement components penetrate the polymer capsules, concordant cells are preferable for xenografting with polymer capsules into the CSF space.

Gelatin Density Gradient for Isolation of Islets of Langerhans

Isolation of islets of Langerhans (islets) has been performed by means of collagenase digestion of the pancreatic tissue combined with density gradient separation of islets from unwanted exocrine tissues. An enormous number of islets are necessary for clinical islet transplantation. The density gradient used for isolation of a large number of islets should satisfy several requirements in addition to those for the conventional density gradients, such as high viscosity for creating fine interfaces with a large area, easy sterilization, and low cost. This study is concerned with the development of a new density gradient made of low-molecular-weight gelatin. We isolated islets from the hamster pancreatic tissue using the gelatin density gradients. The yield and purity of islet and its insulin release function were compared with those of islets isolated using Ficoll and Ficoll-Conray density gradients that have been conventionally used. The new gelatin density gradient can separate islets from the unwanted exocrine tissue as effectively as the Ficoll density gradient and more effectively than the Ficoll-Conray density gradients. The islets collected using the gelatin gradient retain ability of insulin release increase in response to glucose stimulation, similar to those isolated by the Ficoll-Conray gradient and more than those collected by the Ficoll gradient. In addition, the gelatin effectively inhibited enzyme activities, that is, collagenase and proteolytic enzymes released from the exocrine tissue, and thus it can inhibit overdigestion of islets during their density gradient isolation. The gelatin gradient satisfies most of the additional requirements for islet isolation from the pancreatic tissue of large animals mentioned above. Although several factors, such as molecular weight of gelatin, osmolality of the gradient, and centrifugal conditions, still remain to be optimized, our results suggest that the gelatin gradient has potentiality to isolate islets from the pancreatic tissue of a large animal.

Prolonged Effect of Troglitazone (CS-045) on Xenograft Survival of Hybrid Artificial Pancreas

Troglitazone (CS-045), a thiazolidinedione derivative, is a new oral antidiabetic agent that enhances insulin sensitivity and improves insulin responsiveness. In this study we examined the effects of CS-045 on the survival of xenografted bioartificial pancreas. Isolated rat islets were microencapsulated with three-layer agarose microcapsules (polybrene, carboxymethyl cellulose, and an agarose-polystyrene sulfonic acid mixture). Diabetes was induced by intraperitoneal injection of streptozotocin 220 mg/kg. Recipient diabetic mice were separated into two groups. In the CS-045 treated group, the recipient mice were given feed mixed with CS-045 (0.2% w/w) starting from 1 wk before transplantation up to graft failure. The mice in the control group had feed without CS-045. Three hundred microencapsulated rat islets were xenotransplanted into the intraperitoneal cavity of each recipient mouse in both groups. One month after xenotransplantation, IVGTT was performed for all recipients. Xenotransplantation of 300 rat islets in microcapsules decreased the nonfasting blood glucose levels of both groups within 2 days. In the CS-045-treated group (n = 3), the normoglycemic period lasted for more than 1 mo without administration of immunosuppressive drugs (45 ± 4.3 days). However, in the control group (n = 4), the blood glucose levels of all recipients were already elevated on day 4. In the IVGTT study, the glucose assimilation was markedly and significantly better in the CS-045-treated group than in the control group (K = 1.7 ± 0.1 vs. 0.7 ± 0.28 respectively, p <0.01). This study demonstrates that a newly developed oral antidiabetic agent, CS-045 could favorably ameliorate the diabetic state of the recipients xenotransplanted with the bioartificial pancreas, leading to an improved glucose tolerance and longer xenograft survival.

MET Tyrosine Kinase Inhibition Enhances the Antitumor Efficacy of an HGF Antibody

Receptor tyrosine kinase therapies have proven to be efficacious in specific cancer patient populations; however, a significant limitation of tyrosine kinase inhibitor (TKI) treatment is the emergence of resistance mechanisms leading to a transient, partial, or complete lack of response. Combination therapies using agents with synergistic activity have potential to improve response and reduce acquired resistance. Chemoreagent or TKI treatment can lead to increased expression of hepatocyte growth factor (HGF) and/or MET, and this effect correlates with increased metastasis and poor prognosis. Despite MET's role in resistance and cancer biology, MET TKI monotherapy has yielded disappointing clinical responses. In this study, we describe the biological activity of a selective, oral MET TKI with slow off-rate and its synergistic antitumor effects when combined with an anti-HGF antibody. We evaluated the combined action of simultaneously neutralizing HGF ligand and inhibiting MET kinase activity in two cancer xenograft models that exhibit autocrine HGF/MET activation. The combination therapy results in additive antitumor activity in KP4 pancreatic tumors and synergistic activity in U-87MG glioblastoma tumors. Pharmacodynamic characterization of biomarkers that correlate with combination synergy reveal that monotherapies induce an increase in the total MET protein, whereas combination therapy significantly reduces total MET protein levels and phosphorylation of 4E-BP1. These results hold promise that dual targeting of HGF and MET by combining extracellular ligand inhibitors with intracellular MET TKIs could be an effective intervention strategy for cancer patients who have acquired resistance that is dependent on total MET protein. Mol Cancer Ther; 16(7); 1269-78. ©2017 AACR.

Abstract P5-09-07: Impact of germinalcenter-associated nuclear protein polymorphisms on breast cancer risk and prognosis in a Japanese population

Background: Germinal center-associated nuclear protein (GANP) is a phosphoprotein which is involved in mRNA export and the regulation of DNA recombination. We have previously demonstrated that deficiency of GANP led to spontaneous development of mammary gland tumors in a mouse model. In addition, we found that decreased GANP expression in human breast cancer tissue was an independent prognostic factor. Here, we conducted a case-control study and a retrospective cohort study to investigate whether single nucleotide polymorphisms (SNPs) of GANP are associated with sporadic breast cancer risk and prognosis in a Japanese population.

Subjects and Methods: Six hundred-ninety-four breast cancer cases and 1,376 age- and menopausal status-matched controls were selected within the framework of the Hospital-based Epidemiologic Research Program at Aichi Cancer Center. Cases and controls were genotyped using an Infinium iSelect custom array (iCOGS, Illumina Inc., San Diego, CA, USA). We assessed 13 SNPs at the GANP locus, 2 SNPs (rs2839178 and rs11702450) were selected for further analysis by considering linkage disequilibrium. Conditional logistic regression methods were used to estimate odds ratios (ORs) and 95% confidence intervals. In addition, the survival impact of the two SNPs was retrospectively analyzed using the 694 breast cancer cases. To evaluate the effect of SNPs on overall survival (OS) and disease-free survival (DFS), multivariate Cox proportional hazards modeling was applied.

Results: Compared to the AA genotype of rs2839178, the GG genotype showed statistically significant associations with breast cancer risk (OR: 0.48, 95%CI:0.30–0.76, P = 0.002). In prognostic analysis, compared to those with the genotype AA at rs2839178, patients with AG or GG showed longer DFS (HR: 0.71, 95%CI: 0.49–1.04 and 0.42, 0.13–1.42, respectively, P for trend = 0.04). The GG genotype of rs2839178 also showed a positive tendency for longer OS although it was not statistically significant (HR: 0.69, 95%CI: 0.44–1.08, P = 0.11). We did not find that rs11702450 was associated with either breast cancer risk or prognosis.

Conclusion: This is the first study to investigate the association between GANP SNPs and breast cancer risk and prognosis. The direction of association with DFS was consistent with that of susceptibility. These results demonstrate that GANP SNPs presumably prevent the occurrence and malignant advancement of sporadic breast cancers.

Citation Format: Kotani H, Ito H, Kuwahara K, Kuzushima K, Iwata H, Tsunoda N, Nagino M, Tanaka H, Matsuo K. Impact of germinalcenter-associated nuclear protein polymorphisms on breast cancer risk and prognosis in a Japanese population [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 P5-09-07.

Abstract P4-21-24: Development of mathematical prediction models to identify disease-free survival events for HER2-positive primary breast cancer patients treated by neoadjuvant chemotherapy and trastuzumab

Background)

The addition of trastuzumab to standard neoadjuvant chemotherapy (NAC) doubles the pathological complete response (pCR) rate in patients with HER2-positive primary breast cancer. Patients who achieved pCR after NAC with trastuzumab showed a better prognosis compared to those without pCR. However, it is still difficult to predict the likelihood of recurrence after surgery at an individual patient-level. The aim of this study was to develop a mathematical model to predict disease-free survival (DFS) events such as recurrence for patients treated with NAC and trastuzumab. Because brain metastasis (BM) often occurs in HER2-positive cancer patients and it is a particular event for those, we planned to develop a specific model for BM as well.

Patients and Methods)

Data of 776 HER2-positive primary breast cancer patients from the multicenter cohort study (JBCRG-C03) were used in the analysis. All patients had received NAC plus trastuzumab between 2001 and 2010. Two prediction models using a machine learning method (alternating decision tree algorithm) were developed using age, body-mass index, menopausal status, clinical stage, histological type, ER/PgR status, histological/nuclear grade, type of surgery, pathological response, adjuvant radiation therapy, and adjuvant hormonal therapy. The model A (DFS) predicted the probability of any disease recurrence, death by any cause, or secondary malignancy within 5 years after starting treatment. The model B (BM) predicted the probability of occurrence of BM within the 5 years. First, bias-controlled virtual datasets were generated for the training of the models using a resampling method. Second, the models were optimized by cross-validation (CV). Finally, the developed models were validated using the original dataset. The area under the receiver operating characteristics curve (AUC) was calculated to assess the discrimination ability of the models.

Results)

The DFS and BM event was observed in 118 and 30 patients, respectively. The AUC values for the model A and model B were 0.833 (95% CI, 0.798–0.868, P &lt; 0.001) and 0.927 (95% CI, 0.905–0.949, P &lt; 0.001), respectively. The sensitivity and specificity at the cut-off value of 50% were 72.0% and 78.4% for the model A, and 100% and 83.7% for the model B, respectively. Patients predicted as “low-risk” by the model A showed a significantly better 5-year DFS rate than “high-risk” patients (91.2% vs 53.8%, P &lt; 0.001). Patients predicted as “low-risk” by the model B showed a significantly better 5-year BM-free survival rate than “high-risk” patients (100% vs 76.1%, P &lt; 0.001). The discrimination ability of these models were maintained for both ER/PgR-positive and ER/PgR-negative subgroups, and also for both pCR and non-pCR subgroups.

Conclusions)

Our models showed high accuracy for predicting DFS events and BM in HER2-positive primary breast cancer patients treated with NAC and trastuzumab. These two models would help to realize accurate prediction of DFS events and to optimize the postoperative surveillance plan. The identification of high-risk patients for recurrence including BM may be useful for selecting a patient-subpopulation who requires new therapeutic approach.

Citation Format: Takada M, Sugimoto M, Masuda N, Iwata H, Kuroi K, Yamashiro H, Ohno S, Ishiguro H, Inamoto T, Toi M. Development of mathematical prediction models to identify disease-free survival events for HER2-positive primary breast cancer patients treated by neoadjuvant chemotherapy and trastuzumab [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 P4-21-24.

Abstract OT2-01-04: SOLAR-1: A phase III study of alpelisib and fulvestrant in men and postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (BC) progressing on or after aromatase inhibitor (AI) therapy

Background: The phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway is often dysregulated in HR+ BC and is associated with resistance to endocrine therapy (ET). Alpelisib (BYL719; PI3Kα-specific inhibitor) and fulvestrant showed signs of antitumor activity in patients (pts) with estrogen receptor-positive (ER+), HER2– advanced BC (phase I), especially in PIK3CA-altered tumors (Janku et al. SABCS 2014, PD5-5).

Methods: SOLAR-1 (NCT02437318) is a phase III, randomized, double-blind study in men and postmenopausal women with HR+, HER2– advanced BC. Pts are assigned to 1 of 2 cohorts based on PIK3CA tumor status (mutant vs non-mutant), and randomized 1:1 to oral alpelisib/placebo (300 mg once daily) and intramuscular fulvestrant (500 mg on Day 1 and 15 of Cycle 1; Day 1 of Cycles ≥2 [28-day cycles]) until disease progression or discontinuation. Randomization is stratified by presence of liver and/or lung metastases and prior CDK4/6 inhibitor therapy. Key inclusion criteria: recurrence or progression on or after AI therapy, ≥1 measurable lesion (RECIST v1.1) or predominantly lytic bone lesion, and ECOG performance status ≤1. Key exclusion criteria: symptomatic visceral disease or disease burden precluding ET, acute pancreatitis ≤1 year prior to screening or history of chronic pancreatitis, and prior therapy with fulvestrant, chemotherapy (except [neo]adjuvant), or PI3K/AKT/mTOR inhibitors.

The primary and key secondary endpoints are progression-free survival (PFS; RECIST v1.1; local assessment) and overall survival (OS), respectively, in the PIK3CA-mutant cohort. Other secondary endpoints include PFS and OS in the PIK3CA non-mutant cohort, PFS (Blinded Independent Central Review; RECIST v1.1), the association between PFS and baseline PIK3CA status in circulating tumor DNA, overall response rate, clinical benefit rate, safety, and pharmacokinetics. The primary endpoint will be analyzed by a stratified log-rank test at one-sided 2% level of significance.

Recruitment of the planned 560 pts is ongoing.

Citation Format: Andre F, Kaufman B, Juric D, Ciruelos EM, Iwata H, Mayer IA, Rugo HS, Conte P, Liobl S, Rubovszky G, Inoue K, Tesch H, Lu Y-S, Ryvo L, Longin A-S, Mills D, Wilke C, Germa C, Campone M. SOLAR-1: A phase III study of alpelisib and fulvestrant in men and postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (BC) progressing on or after aromatase inhibitor (AI) therapy [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 OT2-01-04.

Using a biologically annotated library to analyze the anticancer mechanism of serine palmitoyl transferase (SPT) inhibitors

Mechanistic understanding is crucial to anticancer drug discovery. Here, we reveal that inhibition of serine palmitoyl transferase (SPT), the rate-limiting enzyme in sphingolipid synthesis, induced death in a lung cancer cell line via a necrosis-dependent pathway. To elucidate the mechanism of cell death induced by SPT inhibition, a biologically annotated library of diverse compounds was screened with an SPT inhibitor. This analysis identified suppressors of SPT inhibitor-mediated cell death. Further analysis using hit compounds from this screening revealed that SPT inhibitors induce COX-2 expression, leading to necrosis-dependent cell death. SPT inhibitors might therefore represent novel candidates for cancer therapy via necrosis pathway regulation. Our data illustrate that compound combination screening of biologically annotated libraries could be used for mechanistic elucidation.

Efficiency of genomic selection for breeding population design and phenotype prediction in tomato

Genomic selection (GS), which uses estimated genetic potential based on genome-wide genotype data for a breeding selection, is now widely accepted as an efficient method to improve genetically complex traits. We assessed the potential of GS for increasing soluble solids content and total fruit weight of tomato. A collection of big-fruited F1 varieties was used to construct the GS models, and the progeny from crosses was used to validate the models. The present study includes two experiments: a prediction of a parental combination that generates superior progeny and the prediction of progeny phenotypes. The GS models successfully predicted a better parent even if the phenotypic value did not vary substantially between candidates. The GS models also predicted phenotypes of progeny, although their efficiency varied depending on the parental cross combinations and the selected traits. Although further analyses are required to apply GS in an actual breeding situation, our results indicated that GS is a promising strategy for future tomato breeding design.

A comparison of physical methods for prophylaxis of deep vein thrombosis on augmentation of venous flow velocity and reduction of calf volume

Objective: This study was designed to determine the optimal physical methods for promoting venous return of the leg.

Methods: Ten healthy volunteers were investigated in the supine position on a couch, and their peak femoral venous velocity and calf muscle volume were determined using duplex ultrasound and strain gauge plethysmography,respectively,before and during deep respiration, limb elevation, calf squeezing and various types of leg exercises.

Results: Deep respiration showed the smallest effect on both percentage increase of peak flow velocity and expelled volume. Elevation of the leg showed the same effect on the expelled volume as calf muscle squeezing and ankle movement, while the former showed significantly less effect than the latter on the percentage increase of peak flow velocity. In both dorsal flexion of the ankle and squeezing at the calf, the stronger of each procedure caused more effective changes in haemodynamics. Ankle exercise was more effective in promoting venous return in the calf muscle than wiggling the toes, making circling movements with the feet or alternately flexing and spreading the toes.

Conclusions: Ankle exercise or calf muscle squeezing, performed maximally,may be the first recommendation for reducing venous stasis at the calf muscle and prophylaxis of deep vein thrombosis..

Modification of Immediately Electrically Detachable Coil

An immediately electrically detachable coil (IEDC) that we previously developed was modified to enhance the reliability in its detachment system. IEDC is detached by applying a monopolar high-frequency electrical current that heat and disrupt a junction between a platinum coil and a delivery wire. The original IEDC immediately detaches only when the junction is just outside the catheter tip and precise positioning of the junction is required. In the modified IEDC Its delivery wire was insulated with polytetra fluoroethylene (PTFE) to concentrate electrical current to the junction. The modified IEDC was tested in vitro and in animal experiments.

Modified IEDC always detached instantaneously even when the junction was far beyond the catheter tip. Insulated delivery wire enabled the electrical current to be concentrated at the PVA junction and produce appropriate heat to disrupt the junction.

Tubulin is a molecular target of the Wnt-activating chemical probe

Background

In drug discovery research, cell-based phenotypic screening is an essential method for obtaining potential drug candidates. Revealing the mechanism of action is a key step on the path to drug discovery. However, elucidating the target molecules of hit compounds from phenotypic screening campaigns remains a difficult and troublesome process. Simple and efficient methods for identifying the target molecules are essential.

Results

2-Amino-4-(3,4-(methylenedioxy)benzylamino)-6-(3-methoxyphenyl)pyrimidine (AMBMP) was identified as a senescence inducer from a phenotypic screening campaign. The compound is widely used as a Wnt agonist, although its target molecules remain to be clarified. To identify its target proteins, we compared a series of cellular assay results for the compound with our pathway profiling database. The database comprises the activities of compounds from simple assays of cellular reporter genes and cellular proliferations. In this database, compounds were classified on the basis of statistical analysis of their activities, which corresponded to a mechanism of action by the representative compounds. In addition, the mechanisms of action of the compounds of interest could be predicted using the database. Based on our database analysis, the compound was anticipated to be a tubulin disruptor, which was subsequently confirmed by its inhibitory activity of tubulin polymerization.

Conclusion

These results demonstrate that tubulin is identified for the first time as a target molecule of the Wnt-activating small molecule and that this might have misled the conclusions of some previous studies. Moreover, the present study also emphasizes that our pathway profiling database is a simple and potent tool for revealing the mechanisms of action of hit compounds obtained from phenotypic screenings and off targets of chemical probes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12858-016-0066-9) contains supplementary material, which is available to authorized users.

Quality of life with palbociclib plus fulvestrant in previously treated hormone receptor-positive, HER2-negative metastatic breast cancer: patient-reported outcomes from the PALOMA-3 trial

In treating HR+, HER2− metastatic breast cancer, novel agents that enhance endocrine therapy activity but do not worsen quality of life (QoL) are clinically desired. Patient-reported outcomes data from the PALOMA-3 study suggest palbociclib plus fulvestrant allow patients to maintain good QoL in the endocrine resistance setting while experiencing a substantially delayed disease progression.

Background

In the PALOMA-3 study, palbociclib plus fulvestrant demonstrated improved progression-free survival compared with fulvestrant plus placebo in hormone receptor-positive, HER2− endocrine-resistant metastatic breast cancer (MBC). This analysis compared patient-reported outcomes (PROs) between the two treatment groups.

Patients and methods

Patients were randomized 2 : 1 to receive palbociclib 125 mg/day orally for 3 weeks followed by 1 week off (n = 347) plus fulvestrant (500 mg i.m. per standard of care) or placebo plus fulvestrant (n = 174). PROs were assessed on day 1 of cycles 1–4 and of every other subsequent cycle starting with cycle 6 using the EORTC QLQ-C30 and its breast cancer module, QLQ-BR23. High scores (range 0–100) could indicate better functioning/quality of life (QoL) or worse symptom severity. Repeated-measures mixed-effect analyses were carried out to compare on-treatment overall scores and changes from baseline between treatment groups while controlling for baseline. Between-group comparisons of time to deterioration in global QoL and pain were made using an unstratified log-rank test and Cox proportional hazards model.

Results

Questionnaire completion rates were high at baseline and during treatment (from baseline to cycle 14, ≥95.8% in each group completed ≥1 question on the EORTC QLQ-C30). On treatment, estimated overall global QoL scores significantly favored the palbociclib plus fulvestrant group [66.1, 95% confidence interval (CI) 64.5–67.7 versus 63.0, 95% CI 60.6–65.3; P = 0.0313]. Significantly greater improvement from baseline in pain was also observed in this group (−3.3, 95% CI −5.1 to −1.5 versus 2.0, 95% CI −0.6 to 4.6; P = 0.0011). No significant differences were observed for other QLQ-BR23 functioning domains, breast or arm symptoms. Treatment with palbociclib plus fulvestrant significantly delayed deterioration in global QoL (P < 0.025) and pain (P < 0.001) compared with fulvestrant alone.

Conclusion

Palbociclib plus fulvestrant allowed patients to maintain good QoL in the endocrine resistance setting while experiencing substantially delayed disease progression.

Clinical Trial Registration

NCT01942135.

Abstract P3-06-14: DSS1 depletion is a promising strategy increasing chemosensitivity possibly independent of BRCA2 expression

Background

DSS1 (deleted in split-hand/split-foot malformation 1) was originally identified as a BRCA2-associated protein, and its downregulation results in the degradation of BRCA2. Some reports demonstrated that BRCA2 overexpression was correlated with histopathological grade III in sporadic breast cancers, implicating the involvement of BRCA2 overexpression in the proliferation rate of breast cancer cells. Because DSS1 is a stabilizer of BRCA2, we investigated whether altered expression of DSS1 was associated with malignant advancement of sporadic breast cancers. By comparison of DSS1 mRNA level, we reported that the high DSS1 expression groups in breast cancer patients showed worse prognosis in relapse-free survival; however, DSS1 expression per se was not correlated with other clinical parameters including cellular proliferation or tumor grade. Therefore, we hypothesized that breast cancer cells highly expressing DSS1 might be resistant to anti-cancer drugs, and compared chemosensitivity in overexpression or underexpression of DSS1 in breast cancer cells.

Methods

We established MCF7 overexpressing DSS1 (MCF7/DSS1) by retroviral transfection. DSS1 or BRCA2 knockdown in MCF7 was performed using siRNA transfection. The susceptibility to the cytotoxic chemotherapy such as doxorubicin and paclitaxel in breast cancer cells was analyzed by flow cytometry to detect apoptosis.

Results

MCF7/DSS1 showed more resistant to cytotoxic drugs compared with GFP-control MCF7 transfectants (MCF7/GFP). The percentages of apoptotic cells in MCF7/DSS1 and MCF7/GFP treated by doxorubicin were 40.2% and 12.0%, respectively. Conversely, depletion of DSS1 in breast cancer cells resulted in enhanced chemosensitivity compared to control cells. Although DSS1 knockdown induced the downregulation of BRCA2, BRCA2 depletion itself did not show such enhancement of chemosensitivity.

Conclusion

Consistent with the cohort study of sporadic breast cancers, we demonstrated that high expression of DSS1 increased resistance of breast cancer cells to cytotoxic chemotherapy in vitro. Conversely, DSS1 knockdown increased the susceptibility to these drugs in spite that BRCA2 depletion did not affect chemosensitivity. These results indicate that DSS1 could be a molecular target to increase chemosensitivity, which is independent of BRCA2 expression.

Citation Format: Gondo N, Rezano A, Kuzushima K, Iwata H, Kuwahara K. DSS1 depletion is a promising strategy increasing chemosensitivity possibly independent of BRCA2 expression. [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 P3-06-14.

Abstract P5-18-01: A randomized clinical trial of postoperative adjuvant therapy for elderly breast cancer patients: Conditions of obtaining informed consent and reasons for declining participation

Background: There are few randomized clinical trials examining adjuvant treatment in elderly breast cancer patients. While obtaining informed consent is essential for participation in clinical studies, there is little information on the frequency of agreement to participate among elderly patients. Furthermore, elderly patients might have specific reasons to decline participation.

Patients and Method: The National Surgical Adjuvant Study of Breast Cancer 07 (N-SAS BC 07) is a randomized clinical trial in women over 70 years with HER2-positive primary breast cancer. The primary aim was to investigate the benefit of trastuzumab monotherapy compared with the combination of trastuzumab and chemotherapy. Key inclusion criteria were as follows: women between 70 and 80 years old with HER2-positive breast cancer; underwent curative operation; stage I to IIIA; with sufficient organ function. Patients were randomized to receive either trastuzumab plus chemotherapy or trastuzumab monotherapy. The primary endpoint was disease-free survival, and the secondary endpoints were overall survival, relapse-free survival, safety, health-related quality of life, and cost effectiveness (NCT01104935). It was not possible to predict the number of patients who would agree to participate. In order to comprehensively assess the effect of postoperative adjuvant therapy, we evaluated the reasons why eligible patients declined to participate. The patients were registered in a cohort study to prospectively evaluate the subsequent treatment options and prognosis (07-Cohort). This study examined the obtaining of informed consent for N-SAS BC 07 and the reasons for declining participation, and compared the clinicopathological backgrounds between the N-SAS BC 07 and 07-Cohort groups.

Results: 398 eligible patients have been recruited. Informed consent to participate in N-SAS BC 07 has been obtained from 275 patients (69%) and 123 patients (31%) who declined to participate in the RCT have been registered in the 07-Cohort. The common reasons to decline participation in the RCT were "cannot choose the treatment option (55%)", "refused chemotherapy (16%)", "wanted chemotherapy (9%)", "anxious about clinical studies (9%)" and "family opposition (8%)". The mean ages of the patients in N-SAS BC 07 and 07-Cohort were 73.9 and 74.6 years old, respectively. There were no differences in stage, surgical procedure, lymph node metastasis, or co-morbidities between the groups. ER-positive rate was higher in 07-Cohort group compared with N-SAS BC 07 group (53% vs. 37%, p=0.017, χ2 test).

Conclusion: While we expected the number of registrants to be small, since N-SAS BC 07 investigated whether elderly patients with HER2-positive breast cancer should undergo chemotherapy, almost 70% of the patients accepted informed consent. The most common reason to decline participation in N-SAS BC 07 was "cannot choose the treatment option" and the majority refused chemotherapy. Furthermore, ER-positivity was higher in the 07-Cohort group, which suggested that ER expression in the patients with HER2-positive breast cancer might influence their decision to participate in the study or to choose the treatment option.

Citation Format: Sagara Y, Sawaki M, Taira N, Saito T, Kashiwaba M, Iwata H, Kobayashi K, Nakayama T, Bando H, Mizuno T, Yamamoto Y, Tsuneizumi M, Takahashi M, Yamaguchi M, Kawashima H, Takashima T, Uemura Y, Hozumi Y, Sagawa N, Mukai H, Ohashi Y. A randomized clinical trial of postoperative adjuvant therapy for elderly breast cancer patients: Conditions of obtaining informed consent and reasons for declining participation. [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 P5-18-01.

Abstract P4-13-03: Updated safety from a double-blind phase 3 trial (PALOMA-3) of fulvestrant with placebo or with palbociclib in pre- and postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer that progressed on prior endocrine therapy

Background: Endocrine therapy (ET) resistance remains a major clinical problem for patients (pts) with hormone receptor (HR+) breast cancer (BC). In PALOMA-3, palbociclib (P) combined with fulvestrant (F) demonstrated significant prolongation of progression-free survival (PFS) vs F plus placebo (PLB) in pre/peri and postmenopausal women with HR+/HER2– metastatic BC (MBC) whose disease progressed on prior ET (median PFS 9.2 vs 3.8 m; HR=0.422, P=0.0001).

Methods: In this double-blind phase 3 study, 521 pts with HR+/HER2– MBC were randomized 2:1 to receive P (125 mg/d orally for 3 weeks followed by 1 week off) and F (500 mg given per standard of care) or PLB plus F. Pre- and perimenopausal women also received goserelin. One previous line of chemotherapy (CT) for MBC was allowed. Safety assessments occurred at baseline and D1 of each cycle; blood counts occurred every 2 wks for the first 2 cycles and on D1 of subsequent cycles. As pts may have experienced multiple episodes of neutropenia during treatment, we analyzed all episodes in aggregate based on laboratory data per CTCAE4.0.

Results: The results reported here are from the data cutoff of Dec 2014, with a median follow-up of 5.6 m. Overall rate of any grade (G) and G3/4 AEs was 98/70% of pts in P+F vs 89/18% in PLB+F. The most commonly reported AEs in P+F (≥20%) were hematologic toxicities, fatigue, nausea, and headache. Per lab data, G3/G4 neutropenia occurred in 52.2/8.2%, G3/G4 leukopenia in 39.5/1.2%, G3/G4 anemia in 20.8/2.9% and G3/G4 thrombocytopenia in 2.1/1.2% of pts on P+F. Neutropenia occurred early, with a median onset time for first episode of ≥G3 neutropenia of 15 d (13–197) and median time from first dose to the lowest absolute neutrophil count (ANC) of 29 d (13–334). The median duration of ≥G3 episode was 7 d (1–35), suggesting that most pts can resume treatment after a 1-week cycle delay. A comparable proportion of any grade neutropenia was observed in pts with or without prior CT (prior CT 88.4% vs no prior CT 85.4%). There was no difference in the rate of G3/G4 neutropenia in the older pts (&gt;65 yrs, 51% vs ≤65 yrs, 57%) in P+F arm. Concurrent G≥3 infections occurred in 1% of pts with G≥3 neutropenia (2/192 pts). Febrile neutropenia occurred in 0.6% of pts in both arms. 21% of pts had dose reductions and 45% had dose interruption due to neutropenia. Dose intensity was maintained at 89.7% for P. Serious adverse events (SAEs) were reported in 9.6% of pts on P+F and in 14% of pts on PLB+F. The most common SAEs on P+F were pulmonary embolism (0.9%) and pyrexia (0.9%). Safety analyses with longer follow-up (data cut off, March 2015) are ongoing and will be presented.

Conclusions: Findings suggest P+F has a favorable safety profile characterized mainly by asymptomatic hematologic toxicity. Overall SAE rates were low and comparable between the 2 arms. Palbociclib-related neutropenia differs from that seen with CT, consistent with proposed mechanism of action, in that it is not commonly associated with fever, and can be effectively managed by a dose interruption or cycle delay.

Funding: Pfizer, Inc.

Citation Format: Verma S, DeMichele AM, Loi S, Ro J, Colleoni M, Iwata H, Harbeck N, Stearns V, Cristofanilli M, Huang Bartlett C, Schnell P, Zhang K, Thiele A, Turner NC, Rugo HS. Updated safety from a double-blind phase 3 trial (PALOMA-3) of fulvestrant with placebo or with palbociclib in pre- and postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer that progressed on prior endocrine therapy. [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 P4-13-03.

Abstract P4-11-02: Endocrine-related symptoms during neoadjuvant endocrine therapy for breast cancer: Agreement between patient and physician reporting in a prospective clinical trial

Background: There is a high risk of under-reporting subjective toxicities by physicians, even when collected prospectively in clinical trials. It has been recommended to include patient reported measures regarding symptoms in prospective clinical comparative effectiveness trials. However, there have been few reports of agreement in endocrine related symptoms between patient and physician reporting.

Patients and Method: The National Surgical Adjuvant Study of Breast Cancer 06 (N-SAS BC 06) is a multicenter, randomized clinical trial of postmenopausal, hormone receptor-positive breast cancer patients, with a two-stage (preoperative and postoperative) enrollment, and intervention. The primary aim was to evaluate the need for adjuvant chemotherapy in the treatment of postmenopausal breast cancer patients who responded to neoadjuvant treatment with Letrozole (LET) for 24-28 weeks. After surgery, responders were randomized into two arms receiving either chemotherapy plus LET, or LET alone. The primary endpoint was disease-free survival, and the secondary endpoints included adverse events, quality of life and health economic evaluation. This study enrolled 497 subjects from the N-SAS BC 06 who were evaluated by Patient Reported Outcomes (PROs). The concordance rate between Clinician Reported Outcomes (CROs) and PROs in their endocrine symptoms during neoadjuvant endocrine therapy was examined. Symptoms were collected prospectively by physicians using the Common Toxicity Criteria for Adverse Events at enrollment, i.e., baseline, and 4 and 16 weeks after starting neoadjuvant LET. Patients also completed the FACT-G (General), B (Breast), ES (Endocrine Symptoms), and HADS. The endocrine symptoms according to the PROs, included nausea, hot flushes, cold sweats, headaches, and HADS-Depression score. In FACT, "Not at all" was used to express the absence of the symptoms, and "A little bit", "Some-what", "Quite a bit", and "Very much" were used to express the presence of symptoms. The HADS-Depression score threshold was 10/11. According to the CROs, grade 0 was defined as the absence of symptoms and grade 1 or more was defined as the presence of symptoms. Cohen's kappa was used to determine the concordance between CROs and PROs. The sensitivity of CROs was also calculated.

Results: The calculated point estimates of Cohen's kappa at Weeks 4 and 16 after starting neoadjuvant LET were 0.12 and 0.01 for nausea, 0.16 and 0.18 for hot flushes, 0.12 and 0.09 for cold sweats, 0.03 and 0.02 for headaches, and 0.11 and 0.11 for dysthymia/depression, respectively; the concordance was quite low. The sensitivity of CROs at Weeks 4 and 16 after starting neoadjuvant LET was 0.07 and 0.03 for nausea, 0.16 and 0.17 for hot flushes, 0.1 and 0.08 for cold sweats, 0.03 and 0.03 for headaches, and 0.11 and 0.1 for dysthymia/depression, respectively; the sensitivity was quite low.

Conclusion: This study showed that there were big differences between CROs and PROs in endocrine symptoms associated with endocrine therapy for breast cancer and that physicians could not obtain sufficient information on the endocrine symptoms. It is recommended that PROs be used to evaluate adverse events caused by endocrine therapy.

Citation Format: Fujisawa T, Iwata H, Sakai T, Nakamura R, Hasegawa Y, Ohtani S, Kashiwaba M, Taira N, Toyama T, Masuda N, Yamamoto Y, Kihara K, Shimozuma K, Ohashi Y, Mukai H. Endocrine-related symptoms during neoadjuvant endocrine therapy for breast cancer: Agreement between patient and physician reporting in a prospective clinical trial. [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 P4-11-02.

Abstract P4-11-09: A randomized controlled trial of postoperative adjuvant therapy for elderly breast cancer patients: Comparison of health-related quality of life between clinical trial participants and decliners

Background: Health-related quality of life (HRQoL) is one of the important outcomes in cancer control trials and has increasingly become the one of the primary foci. Obtaining informed consent from participants is essential for participation in randomized controlled trials (RCTs), but the participation in these RCTs may directly influence HRQoL, because treatment options are determined according to the allocation schedule. To date, only a few studies have compared HRQoL between clinical trial participants and decliners.

Patients and Method: The National Surgical Adjuvant Study of Breast Cancer 07 (N-SAS BC 07) is a randomized controlled trial in women with HER2-positive primary breast cancer who are over 70 years of age. The primary aim was to investigate the benefit of trastuzumab monotherapy compared with combination therapy using trastuzumab and chemotherapy. The study concept and design were published in concept paper (Sawaki M. et al., Jpn J Clin Oncol. 2011). In this study, patients were randomized to receive either trastuzumab plus chemotherapy or trastuzumab monotherapy. The primary endpoint was disease-free survival, and the secondary endpoints were overall survival, relapse-free survival, safety, HRQoL, comprehensive geriatric assessment (CGA) and cost effectiveness (protocol ID; NCT01104935).

HRQoL and CGA were assessed at registration (baseline), 2 month, 1 year, and 3 years after the start of protocol treatments using the Functional Assessment of Cancer Therapy-General (FACT-G), Hospital Anxiety and Depression Scale (HADS), EuroQol 5 Dimension (EQ-5D), Tokyo Metropolitan Institute of Gerontology (TMIG) index of competence, and the Philadelphia Geriatric Center (PGC) Morale Scale.

The patients who declined to participate in N-SAS BC 07 were registered in a cohort study to prospectively evaluate the subsequent treatment options and prognosis (07-Cohort). The same questionnaire that was used in N-SAS BC 07 was used in 07-Cohort to evaluate HRQoL and CGA at entry.

Results: Patients were enrolled from October 2012 to October 2016. During this period, 275 and 123 patients were registered in N-SAS BC 07 and 07-Cohort, respectively. The mean age at entry of the patients in the N-SAS BC 07 and 07-Cohort groups was 73.9 and 74.6 years, respectively. The questionnaire response rates at baseline in the patients in N-SAS BC 07 and 07-Cohort groups were 89% and 82%, respectively. There were no significant differences in FACT-G, HADS, EQ-5D, or TMIG index of competence at baseline between the groups, but the mean (standard deviation) scores of PGC Morale Scale in N-SAS BC 07 and 07-Cohort groups were 10.8 (3.3) and 9.9 (3.7), respectively, with the scores being significantly greater in the N-SAS BC 07 group (p=0.020, t-test).

Conclusion: The PGC Morale Scale provides a multidimensional approach to assess the psychological state of older people. This study indicated that participation in the RCT did not affect the baseline QoL of elderly patients but suggested that the baseline QoL of the RCT participants was better than decliners.

Citation Format: Saito T, Sawaki M, Hozumi Y, Sagawa N, Iwata H, Kashiwaba M, Kawashima H, Kobayashi K, Taira N, Takashima T, Takahashi M, Tsuneizumi M, Nakayama T, Baba S, Bando H, Mizuno T, Yamaguchi M, Yamamoto Y, Uemura Y, Ohashi Y, Mukai H. A randomized controlled trial of postoperative adjuvant therapy for elderly breast cancer patients: Comparison of health-related quality of life between clinical trial participants and decliners. [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 P4-11-09.