Pretreatment of Crude Pancreatic Islets with Mitomycin C (Mmc) Prolongs Islet Graft Survival in a Xenogeneic Rat-To-Mouse Model

In this study, we examined the effect of mitomycin C (MMC) treatment on graft survival and evaluated its efficacy in immunomodulation of islet graft for transplantation. Male WS rats were used as islet donors and streptozotocin-induced diabetic C57BL/6 mice as recipients. The isolated islets were treated with MMC at concentrations of 0, 0.1, 1, 3.2, 10, 32, 100, 320, and 1000 μg/mL for 30 min, and were cultured for 20 h. Then, 300–400 islets were transplanted into the renal subcapsular space of diabetic mice. Significant prolongation of graft survival was obtained when the islets were treated with MMC at a concentration of 10, 32, or 100 μg/mL (MST 23 ± 7.4, 17.5 ± 5.4, 29.6 ± 9.7 days: p < 0.003, p < 0.012, p < 0.001, respectively, vs. 12.3 ± 2.7 days for culturing alone). Islets treated with MMC at a concentration of 320 μg/mL or more failed to restore normoglycemia in the diabetic recipient mice after transplantation. Viability of islets incubated with doses up to 100 μg/mL, assessed under the confocal microscope after propidium iodide and Hoechst 33342 staining, was maintained well comparable to that of freshly isolated islets, while those treated at 320 μg/mL was significantly decreased. Thus, a therapeutic window for MMC efficacy was found at concentrations from 10 μg/mL to 100 μg/mL. This modality is simple and effective and underlying molecular mechanisms need to be determined in the future.

Structure-Dependent Binding of hnRNPA1 to Telomere RNA

Telomeric repeat-containing RNA is a new noncoding RNA molecule that performs various biofunctions. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an RNA-binding protein involved in the telomere maintenance machinery. To date, little is known about how hnRNPA1 binds to telomeric RNA. In this study, we investigated the binding affinity and recognition mechanism of telomere RNA with the RNA recognition motif of hnRNPA1. Using the photochemical cross-linking method, we showed that the telomere RNA G-quadruplex with loops is important in the interaction of telomere RNA with hnRNPA1. Using small-molecule probes, we directly visualized the complex formed by the telomere RNA G-quadruplex and hnRNPA1 in vitro and in live cells. The results suggested that the structure-dependent binding of hnRNPA1 to telomere RNA regulates the telomere function. Therefore, our study provides new insights into the interactions between the RNA G-quadruplex and proteins at the telomere.

Abstract P4-21-08: A phase I/II of S-222611, a reversible EGFR and HER2 inhibitor, combined with trastuzumab +/- chemotherapy in patients with HER2-positive metastatic breast cancer

Background: S-222611, an oral, reversible EGFR and HER2 inhibitor, has been shown to be well-tolerated as monotherapy at a dose of 800mg daily with good anti-tumor activity in patients previously treated with other anti-HER2-based regimens. This study evaluated the tolerability and safety of daily oral administration of S-222611 (S) in combination with trastuzumab (T), trastuzumab + vinorelbine (T+V) and trastzumab + capecitabine (T+C) in HER2-positive (HER2+) metastatic breast cancer (MBC) with or without brain metastases.

Methods: This study was performed as a 3+3 dose escalation followed by expansion to examine the tolerability and safety of S in combination with T, T+V and T+C in Arms A, B and C, respectively. S was administered orally once daily, starting at a dose of 400mg in Arm A, and 200mg in Arms B and C. The dosing of T was 8mg/kg loading followed by 6mg/kg or fixed dose of 600mg subcutaneously every 21 days as recommended. V was administered at 60mg/m2 orally on Day 1 and 8 of a 21-day cycle, and C 1000mg/m2 orally daily for 14 days followed by a 7-day rest period. All patients had HER2+ MBC and were required to have progressed following at least one prior line of anti-HER2 therapy. Prior treatments with V and C were permitted. Anti-diarrhea prophylaxis with loperamide was not required.

Results: A total of 45 patients were enrolled. All patients had received prior anti-tumor regimens including T (n=45), T-DM1 (n=26), pertuzumab (n=9) and lapatinib (n=12). The clinically recommended doses of S at which most adverse events were manageable,were determined as:600mg in Arm A, 200mg in Arm B and 400mg in Arm C. Dose limiting toxicities included Grade 3 diarrhea for Arm A; and Grade 4 neutropenia, Grade 3 Hypokalemia and Hypophosphatemia for Arm B. As of 13 May 2016, treatment is ongoing in 2 patients. No other Grade 4 AEs related to S-222611 have been observed. Grade 3 bilirubin elevation was observed in 5/45 patients, probably due to transporter (UGT1A1) inhibition, while no G3/4 liver dysfunction was reported. RECIST partial responses (PR) were observed in 6 of 9 patients in Arm A and 5 of 9 patients in Arm C, at respective clinically recommended doses. Nine of 45 patients had brain metastases; 4 of these patients showed RECIST PR including an intracranial tumor response in one patient (400mg in Arm C) who had prior treatments with paclitaxel, T+C, T-DM1 and V after diagnosis of BM.

Conclusions: The clinically recommended doses of S-222611 combined with T, T +V and T+C were determined for further clinical studies. Clinical benefit (PR and SD &gt;6 month) was seen with each combination even in heavily pre-treated HER2+ MBC patients.

Summary of the safety and efficacy of S-222611 (S) combination. Dose (mg)nDLT (1st cycle)G3 Diarrhea during study (N of patients)RECIST tumor response, PR n/ SD ≥6M nORR n (%)CBR n (%)Arm A: S + T4005010/10/5 (0%)1/5 (20%)Arm A: S + T6009036/06/9 (67%)6/9 (67%)Arm A: S + T8007141/11/7 (14%)2/7 (29%)Arm B: S + T + V2005020/40/5 (0%)4/5 (80%)Arm B: S + T + V4002211/01/2 (50%)1/2 (50%)Arm C: S + T + C2004010/10/4 (0%)1/4 (25%)Arm C: S + T + C4009025/05/9 (56%)5/9 (56%)Arm C: S + T + C6004022/12/4 (50%)3/4 (75%)

Citation Format: Rafii S, Macpherson I, Baird R, Saggese M, Spiliopoulou P, Kumar S, Italiano A, Bonneterre J, Campone M, Cresti N, Posner J, Takeda Y, Arimura A, Spicer J. A phase I/II of S-222611, a reversible EGFR and HER2 inhibitor, combined with trastuzumab +/- chemotherapy in patients with HER2-positive metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-08.

The pattern of GPI-80 expression is a useful marker for unusual myeloid maturation in peripheral blood

Myeloid-derived suppressor cells (MDSCs) have a wide spectrum of immunosuppressive activity; control of these cells is a new target for improving clinical outcomes in cancer patients. MDSCs originate from unusual differentiation of neutrophils or monocytes induced by inflammatory cytokines, including granulocyte-colony stimulating factor (G-CSF) and granulocyte-macrophage (GM)-CSF. However, MDSCs are difficult to detect in neutrophil or monocyte populations because they are not uniform cells, resembling both neutrophils and monocytes; thus, they exist in a heterogeneous population. In this study, we investigated GPI-80, a known regulator of Mac-1 (CD11b/CD18) and associated closely with neutrophil maturation, to clarify this unusual differentiation. First, we demonstrated that the mean fluorescence intensity (MFI) of GPI-80 and coefficient of variation (CV) of GPI-80 were increased by treatment with G-CSF and GM-CSF, respectively, using a human promyelocytic leukaemia (HL60) cell differentiation model. To confirm the value of GPI-80 as a marker of unusual differentiation, we measured GPI-80 expression and MDSC functions using peripheral blood cells from metastatic renal cell carcinoma patients. The GPI-80 CV was augmented significantly in the CD16^hi neutrophil cell population, and GPI-80 MFI was increased significantly in the CD33^hi monocyte cell population. Furthermore, the GPI-80 CV in the CD16^hi population was correlated inversely with the proliferative ability of T cells and the GPI-80 MFI of the CD33^hi population was correlated with reactive oxygen species production. These results led us to propose that the pattern of GPI-80 expression in these populations is a simple and useful marker for unusual differentiation, which is related to MDSC functions.

Successful treatment of cytomegalovirus enteritis after unrelated allogeneic stem cell transplantation by the infusion of ex vivo-expanded CD4+ lymphocytes derived from the recipient's peripheral blood donor cells

Adoptive immunotherapies have been developed for antiviral agent-refractory cytomegalovirus (CMV) disease after stem cell transplantation (SCT). However, the application of such strategies is limited, particularly in terms of need for donor cooperation regarding blood sampling and inaccessibility in the setting of cord blood transplantation. Herein, we describe the first successful treatment of antiviral agent-refractory CMV enteritis after allogeneic SCT by the infusion of ex vivo-expanded donor-derived CD4(+) lymphocytes obtained from the recipient's peripheral blood.

Electronic excitations of a magnetic impurity state in the diluted magnetic semiconductor (Ga,Mn)As

The electronic structure of doped Mn in (Ga,Mn)As is studied by resonant inelastic x-ray scattering. From configuration-interaction cluster-model calculations, the line shapes of the Mn L3 resonant inelastic x-ray scattering spectra can be explained by d-d excitations from the Mn ground state dominated by charge-transferred states, in which hole carriers are bound to the Mn impurities, rather than a pure acceptor Mn2+ ground state. Unlike archetypical d-d excitation, the peak widths are broader than the experimental energy resolution. We attribute the broadening to a finite lifetime of the d-d excitations, which decay rapidly to electron-hole pairs in the host valence and conduction bands through the hybridization of the Mn 3d orbital with the ligand band.

Myositis in primary Sjögren's syndrome: clinical and pathological report

Abstract To clarify the clinical features of myositis complicated with primary Sjögren's syndrome (SS), we studied 89 patients with Sjögren's syndrome (one male and 88 females; mean age 56.0 ± 15.31 years). Myositis was diagnosed from clinical findings, muscle enzymes, electromyographic findings, and muscle biopsy findings. Myositis was diagnosed in 5 of 89 SS patients (5.6%). One patient developed myositis 7 months after the onset of SS. The other four patients were diagnosed with myositis and SS simultaneously. Muscular weakness was mild and slowly progressive over 4-14 months (mean 8.4 months). All patients were able to walk without any assistance at the start of prednisolone therapy. Muscular enzymes were slightly elevated (from 1.5- to 12-fold). All patients tested negative for anti-Jo1 antibody and tested positive for antinuclear antibody. Anti-Ro(SSA) antibody was positive in 4/5 (90%); anti-La(SSB) was positive in 2/5 (40%). Although the clinical features of all patients met the criteria for polymyositis of Bohan, they responded well to small or moderate doses of prednisolone, which could be decreased without a recurrence of muscular weakness in all patients. Myositis with Sjögren's syndrome showed relatively moderate symptoms and responded well to prednisolone. A prospective follow-up of patients may provide further information.