Hepatitis B surface antigen reduction by switching from long-term nucleoside/nucleotide analogue administration to pegylated interferon

Hepatitis B surface antigen (HBsAg) reduction during nucleoside/nucleotide analogue (NA) therapy is slow and an alternative strategy for patients receiving ongoing NA to facilitate HBsAg reduction is required. We investigated whether switching to pegylated interferon (PEG-IFN) after long-term NA administration enhances HBsAg reduction. Forty-nine patients who switched from long-term NA to 48 weeks of PEG-IFN alfa-2a were studied. The mean duration of previous NA was 48 months (sequential group). A total of 147 patients who continued NA and matched for baseline characteristics were analysed for comparison (NA continuation group). The treatment response was defined as HBsAg reduction ≥1.0 logIU/mL at the end of PEG-IFN. HBsAg reduction at week 48 was 0.81±1.1 logIU/mL in the sequential group, which was significantly higher than that in the NA continuation group (0.11±0.3 logIU/mL, P < .001). The treatment response was achieved in 29% and 2% of the sequential group and NA continuation group (P < .001), and the odds ratio of sequential therapy for the treatment response was 19 compared with the NA continuation (P < .001). In patients tested positive for hepatitis B e antigen (HBeAg), HBeAg seroconversion was higher in the sequential group (44% vs 8%, P < .001). In HBeAg-negative patients, only patients in the sequential group achieved HBsAg loss. No patient needed to resume NA administration because of HBV DNA increase accompanied by alanine aminotransferase flares. In summary, sequential therapy with PEG-IFN after long-term NA enhances the reduction of HBsAg and may represent a treatment option to promote HBsAg loss.

Graft-Versus-Host Disease Following Liver Transplantation: Development of a High-Incidence Rat Model and a Selective Prevention Method

Graft-versus-host disease (GvHD) following liver transplantation (LT) is a rare but serious complication with no presently available animal model and no preventive measures. To develop a rat model of GvHD after LT (LT-GvHD), we preconditioned hosts with sublethal irradiation plus reduction of natural killer (NK) cells with anti-CD8α mAb treatment, which invariably resulted in acute LT-GvHD. Compared with those in the peripheral counterpart, graft CD4⁺ CD25^- passenger T cells showed lower alloreactivities in mixed leukocyte culture. Immunohistology revealed that donor CD4⁺ T cells migrated and formed clusters with host dendritic cells in secondary lymphoid organs, with early expansion and subsequent accumulation in target organs. For selectively preventing GvHD, donor livers were perfused ex vivo with organ preservation media containing anti-TCRαβ mAb. T cell-depleted livers almost completely suppressed clinical GvHD such that host rats survived for >100 days. Our results showed that passenger T cells could develop typical LT-GvHD if resistant cells such as host radiosensitive cells and host radioresistant NK cells were suppressed. Selective ex vivo T cell depletion prevented LT-GvHD without affecting host immunity or graft function. This method might be applicable to clinical LT in prediagnosed high-risk donor-recipient combinations and for analyzing immunoregulatory mechanisms of the liver.

High-resolution copy number variation analysis of schizophrenia in Japan

Recent schizophrenia (SCZ) studies have reported an increased burden of de novo copy number variants (CNVs) and identified specific high-risk CNVs, although with variable phenotype expressivity. However, the pathogenesis of SCZ has not been fully elucidated. Using array comparative genomic hybridization, we performed a high-resolution genome-wide CNV analysis on a mainly (92%) Japanese population (1699 SCZ cases and 824 controls) and identified 7066 rare CNVs, 70.0% of which were small (<100 kb). Clinically significant CNVs were significantly more frequent in cases than in controls (odds ratio=3.04, P=9.3 × 10^-9, 9.0% of cases). We confirmed a significant association of X-chromosome aneuploidies with SCZ and identified 11 de novo CNVs (e.g., MBD5 deletion) in cases. In patients with clinically significant CNVs, 41.7% had a history of congenital/developmental phenotypes, and the rate of treatment resistance was significantly higher (odds ratio=2.79, P=0.0036). We found more severe clinical manifestations in patients with two clinically significant CNVs. Gene set analysis replicated previous findings (e.g., synapse, calcium signaling) and identified novel biological pathways including oxidative stress response, genomic integrity, kinase and small GTPase signaling. Furthermore, involvement of multiple SCZ candidate genes and biological pathways in the pathogenesis of SCZ was suggested in established SCZ-associated CNV loci. Our study shows the high genetic heterogeneity of SCZ and its clinical features and raises the possibility that genomic instability is involved in its pathogenesis, which may be related to the increased burden of de novo CNVs and variable expressivity of CNVs.

Abstract P4-21-14: A randomized phase II trial of trastuzumab + capecitabine versus lapatinib + capecitabine in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and taxanes: WJOG6110B/ELTOP

Background: In patients with HER2-positive metastatic breast cancer (MBC) who progressed on trastuzumab (H)-based therapy, both continuing H beyond progression and switching to lapatinib (L) in combination with chemotherapy are valid options. However, it is unclear which strategy is more effective and how we can select a proper strategy in each patient.

Methods: We conducted an open label, multicenter, randomized phase II trial to comparatively evaluate efficacy and safety of H + capecitabine (X) (HX) or L + X (LX) in women with HER2-positive MBC who were previously treated with taxanes and progressed on H-containing regimens. Patients treated with more than two chemotherapy regimens for MBC were excluded. Those treated with pertuzumab and/or T-DM1 were allowed to enroll in this study. Patients with brain metastases were also included if they are asymptomatic. Patients received H (4mg/kg loading then 2mg/kg weekly or 8mg/kg loading then 6mg/kg every 3 weeks) and X (2500 mg/m2/day on days 1-14 every 3weeks) in HX arm and L (1250 mg/day) and X (2000 mg/m2/day on days 1-14 every 3weeks) in LX arm until progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS) and secondary endpoints included overall survival (OS), objective response rate (ORR), proportion of subjects progressing with brain metastases as site of first progression, and safety.We also assessed biomarkers in tumor tissues and circulating cell-free DNA.

Results: Between May 2011 and December 2014, 86 patients (43 in HX arm and 43 in LX arm) were enrolled in this study. Median age was 58 years (range 34-81), ECOG performance status was 0 (63%), 1 (35%), or 2 (2%), 63% had hormone receptor-positive disease, 15% had brain metastases, 56% had relapsed after primary surgery, and 23% had received adjuvant or neo-adjuvant trastuzumab. Median follow-up time was 44.6 months. Median PFS was 6.1 months in HX arm and 7.1 months in LX arm (hazard ratio 0.81 90% CI 0.55-1.21; p=0.39), median OS was 31.0 months in HX arm and not reached in LX arm (hazard ratio 0.58 95% CI 0.26-1.31; p=0.18), ORR was 40% in HX arm and 41% in LX arm (p=1.00), disease control rate was 73% in HX arm and 92% in LX arm (p=0.038), and proportion of subjects progressing with brain metastases as site of first progression was 5% in HX arm and 5% in LX arm. Grade 3-4 toxicities included hand-foot syndrome (21% in HX arm and 21% in LX arm) and diarrhea (9% in HX arm and 16% in LX arm). In subgroup analyses, PFS benefit in LX arm compared to HX arm was significantly larger among patients who had received previous systemic treatment for metastatic disease for less than 1 year (interaction p=0.007). Subgroup analyses by biomarkers will be presented at the meeting.

Conclusions: In women with HER2-positive MBC previously treated with trastuzumab and taxanes, lapatinib + capecitabine tended to yield better PFS and OS than trastuzumab beyond progression + capecitabine, although they were not statistically significant.Background: In patients with HER2-positive metastatic breast cancer (MBC) who progressed on trastuzumab (H)-based therapy, both continuing H beyond progression and switching to lapatinib (L) in combination with chemotherapy are valid options. However, it is unclear which strategy is more effective and how we can select a proper strategy in each patient.

Methods: We conducted an open label, multicenter, randomized phase II trial to comparatively evaluate efficacy and safety of H + capecitabine (X) (HX) or L + X (LX) in women with HER2-positive MBC who were previously treated with taxanes and progressed on H-containing regimens. Patients treated with more than two chemotherapy regimens for MBC were excluded. Those treated with pertuzumab and/or T-DM1 were allowed to enroll in this study. Patients with brain metastases were also included if they are asymptomatic. Patients received H (4mg/kg loading then 2mg/kg weekly or 8mg/kg loading then 6mg/kg every 3 weeks) and X (2500 mg/m2/day on days 1-14 every 3weeks) in HX arm and L (1250 mg/day) and X (2000 mg/m2/day on days 1-14 every 3weeks) in LX arm until progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS) and secondary endpoints included overall survival (OS), objective response rate (ORR), proportion of subjects progressing with brain metastases as site of first progression, and safety.We also assessed biomarkers in tumor tissues and circulating cell-free DNA.

Results: Between May 2011 and December 2014, 86 patients (43 in HX arm and 43 in LX arm) were enrolled in this study. Median age was 58 years (range 34-81), ECOG performance status was 0 (63%), 1 (35%), or 2 (2%), 63% had hormone receptor-positive disease, 15% had brain metastases, 56% had relapsed after primary surgery, and 23% had received adjuvant or neo-adjuvant trastuzumab. Median follow-up time was 44.6 months. Median PFS was 6.1 months in HX arm and 7.1 months in LX arm (hazard ratio 0.81 90% CI 0.55-1.21; p=0.39), median OS was 31.0 months in HX arm and not reached in LX arm (hazard ratio 0.58 95% CI 0.26-1.31; p=0.18), ORR was 40% in HX arm and 41% in LX arm (p=1.00), disease control rate was 73% in HX arm and 92% in LX arm (p=0.038), and proportion of subjects progressing with brain metastases as site of first progression was 5% in HX arm and 5% in LX arm. Grade 3-4 toxicities included hand-foot syndrome (21% in HX arm and 21% in LX arm) and diarrhea (9% in HX arm and 16% in LX arm). In subgroup analyses, PFS benefit in LX arm compared to HX arm was significantly larger among patients who had received previous systemic treatment for metastatic disease for less than 1 year (interaction p=0.007). Subgroup analyses by biomarkers will be presented at the meeting.

Conclusions: In women with HER2-positive MBC previously treated with trastuzumab and taxanes, lapatinib + capecitabine tended to yield better PFS and OS than trastuzumab beyond progression + capecitabine, although they were not statistically significant.

Citation Format: Takano T, Tsurutani J, Takahashi M, Yamanaka T, Sakai K, Ito Y, Fukuoka J, Kimura H, Kawabata H, Tamura K, Matsumoto K, Aogi K, Sato K, Nishio K, Nakagawa K, Saeki T. A randomized phase II trial of trastuzumab + capecitabine versus lapatinib + capecitabine in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and taxanes: WJOG6110B/ELTOP [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 P4-21-14.

Abstract P2-05-24: Prognostic value of circulating PIK3CA mutations revealed with digital PCR in patients with HER2-positive advanced breast cancer: Results of West Japan Oncology Group study 6110BTR

This abstract was withdrawn by the authors.

Mechanisms of Impaired Neutrophil Migration by MicroRNAs in Myelodysplastic Syndromes

In myelodysplastic syndromes (MDS), functional defects of neutrophils result in high mortality because of infections; however, the molecular basis remains unclear. We recently found that miR-34a and miR-155 were significantly increased in MDS neutrophils. To clarify the effects of the aberrant microRNA expression on neutrophil functions, we introduced miR-34a, miR-155, or control microRNA into neutrophil-like differentiated HL60 cells. Ectopically introduced miR-34a and miR-155 significantly attenuated migration toward chemoattractants fMLF and IL-8, but enhanced degranulation. To clarify the mechanisms for inhibition of migration, we studied the effects of miR-34a and miR-155 on the migration-regulating Rho family members, Cdc42 and Rac1. The introduced miR-34a and miR-155 decreased the fMLF-induced active form of Cdc42 to 29.0 ± 15.9 and 39.7 ± 4.8% of that in the control cells, respectively, although Cdc42 protein levels were not altered. miR-34a decreased a Cdc42-specific guanine nucleotide exchange factor (GEF), dedicator of cytokinesis (DOCK) 8, whereas miR-155 reduced another Cdc42-specific GEF, FYVE, RhoGEF, and PH domain-containing (FGD) 4. The knockdown of DOCK8 and FGD4 by small interfering RNA suppressed Cdc42 activation and fMLF/IL-8-induced migration. miR-155, but not miR-34a, decreased Rac1 protein, and introduction of Rac1 small interfering RNA attenuated Rac1 activation and migration. Neutrophils from patients showed significant attenuation in migration compared with healthy cells, and protein levels of DOCK8, FGD4, and Rac1 were well correlated with migration toward fMLF (r = 0.642, 0.686, and 0.436, respectively) and IL-8 (r = 0.778, 0.659, and 0.606, respectively). Our results indicated that reduction of DOCK8, FGD4, and Rac1 contributes to impaired neutrophil migration in MDS.

Discovery and Mechanistic Characterization of Selective Inhibitors of H2S-producing Enzyme: 3-Mercaptopyruvate Sulfurtransferase (3MST) Targeting Active-site Cysteine Persulfide

Very recent studies indicate that sulfur atoms with oxidation state 0 or −1, called sulfane sulfurs, are the actual mediators of some physiological processes previously considered to be regulated by hydrogen sulfide (H₂S). 3-Mercaptopyruvate sulfurtransferase (3MST), one of three H₂S-producing enzymes, was also recently shown to produce sulfane sulfur (H₂S_n). Here, we report the discovery of several potent 3MST inhibitors by means of high-throughput screening (HTS) of a large chemical library (174,118 compounds) with our H₂S-selective fluorescent probe, HSip-1. Most of the identified inhibitors had similar aromatic ring-carbonyl-S-pyrimidone structures. Among them, compound 3 showed very high selectivity for 3MST over other H₂S/sulfane sulfur-producing enzymes and rhodanese. The X-ray crystal structures of 3MST complexes with two of the inhibitors revealed that their target is a persulfurated cysteine residue located in the active site of 3MST. Precise theoretical calculations indicated the presence of a strong long-range electrostatic interaction between the persulfur anion of the persulfurated cysteine residue and the positively charged carbonyl carbon of the pyrimidone moiety of the inhibitor. Our results also provide the experimental support for the idea that the 3MST-catalyzed reaction with 3-mercaptopyruvate proceeds via a ping-pong mechanism.

Development of a reversible fluorescent probe for reactive sulfur species, sulfane sulfur, and its biological application

We developed a reversible fluorescent probe for sulfane sulfur. This probe enabled us to monitor concentration changes of sulfane sulfur.

Distribution of Serotonergic Neurons in the Central Nervous System: A Peroxidase-Antiperoxidase Study with Anti-Serotonin Antibodies

Distribution of serotonin (5-HT) neurons in the central nervous system (CNS) of various vertebrates was investigated with a highly sensitive immunohistochemical technique. Antibodies were raised in rabbits against an antigen prepared by coupling 5-HT to bovine thyroglobulin. 5-HT neurons were found to be distributed more widely and densely than has been heretofore described. Serotonergic neuronal somata are organized according to certain basic patterns, but there are interspecific differences with regard to the distribution of 5-HT fibers. The processes of 5-HT neurons form a dense plexus by ramification and anastomosis in almost all areas of the CNS, including the ventricular surfaces. In the light of our observations, Golgi's reticular theory may have to be revised.

Tiny adiabatic-demagnetization refrigerator for a commercial superconducting quantum interference device magnetometer

A tiny adiabatic-demagnetization refrigerator (T-ADR) has been developed for a commercial superconducting quantum interference device magnetometer [Magnetic Property Measurement System (MPMS) from Quantum Design]. The whole T-ADR system is fit in a cylindrical space of diameter 8.5 mm and length 250 mm, and can be inserted into the narrow sample tube of MPMS. A sorption pump is self-contained in T-ADR, and hence no complex gas handling system is necessary. With the single crystalline Gd₃Ga₅O₁₂ garnet (∼2 g) used as a magnetic refrigerant, the routinely achievable lowest temperature is ∼0.56 K. The lower detection limit for a magnetization anomaly is ∼1 × 10^-7 emu, estimated from fluctuation of the measured magnetization. The background level is ∼5 × 10^-5 emu below 2 K at H = 100 Oe, which is largely attributable to a contaminating paramagnetic signal from the magnetic refrigerant.

MR Imaging of Monostotic Fibrous Dysplasia of the Clivus

We describe the MR appearance of a case of monostotic fibrous dysplasia confined to the clivus. The lesion showed intermediate signal intensity on T2-weighted images which is uncommon among clival diseases.