Dynamics of depressive states among university students in Japan during the COVID-19 pandemic: an interrupted time series analysis

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic was reported to have increased depression among university students which was associated with impairments in their campus lives. This study examined changes in depressive states among Japanese university students during the COVID-19 pandemic.

METHODS

A secondary data analysis from a factorial randomized controlled trial involving smartphone-based cognitive-behavioral therapy was performed. Six cohorts (N = 1626) underwent an 8-week intervention during the spring or autumn of 2019-2021, with a 9-month follow-up. We evaluated participants' depressive states weekly using the Patient Health Questionnaire-9 (PHQ-9) during the intervention, with monthly evaluations thereafter. The follow-up periods included Japan's four states of emergency (SOEs) to control COVID-19. Hypothesizing that SOEs caused a sudden worsening of depressive states, Study 1 compared the cohorts' PHQ-9 scores, and Study 2 employed time series analysis with a mixed-effects model to estimate identified changes in PHQ-9 scores.

RESULTS

Although no changes in depressive states were observed in relation to the SOEs, Study 1 identified sudden increases in PHQ-9 scores at the 28-week evaluation point, which corresponded to the beginning of the new academic year for the three autumn cohorts. In contrast, the three spring cohorts did not exhibit similar changes. Study 2 showed that, for all three autumn cohorts (n = 522), the 0.60-point change was significant (95% CI 0.42-0.78; p < .001) at 28 weeks; that is, when their timeline was interrupted.

CONCLUSIONS

While the results do not indicate any notable impact of the SOEs, they highlight the influence of the new academic year on university students' mental health during COVID-19. Trial registration UMIN, CTR-000031307. Registered on February 14, 2018.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100  TeV. As a result, we observed 24 photonlike events with E>100  TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100  TeV from an astrophysical source.

The cosmic ray energy spectrum measured with the new Tibet hybrid experiment

We have upgraded the new Tibet ASgamma experiment in China since 2014 to measure the chemical composition of cosmic rays around the knee. This hybrid experiment consist of an air-shower-core detector array (YAC-II) to detect high energy electromagnetic component, the Tibet air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD). We have carried out a detailed air-shower Monte Carlo (MC) simulation to study the performance of the hybrid detectors by using CORSIKA (version 7.5000), which includes EPOS-LHC, QGSJETII-04, SIBYLL2.1 and SIBYLL2.3 hadronic interaction models. The preliminary results of the interaction model checking above 50 TeV energy region are reported in this paper, and the primary proton and helium spectra in the energy range 50 TeV to 1015 eV was derived from YAC-I data and is smoothly connected with direct observation data at lower energies and also with our previously reported works at higher energies within statistical errors. The knee of the (P+He) spectra is located around 400 TeV. The interaction model dependence in deriving the primary (P+He) spectra is found to be small (less than 25% in absolute intensity, 10% in position of the knee), and the composition model dependence is less than 10% in absolute intensity.

Test of the hadronic interaction models SIBYLL2.3, EPOS-LHC and QGSJETII- 04 with Tibet EAS core data

A hybrid experiment has been started by the ASγ experiment at Yangbajing (4300m a.s.l.) in Tibet since May 2009, that consists of a high-energy air-shower-core array (YAC-I) and a high-density air-shower array (Tibet-III). In this paper, we report our results to check the hadronic interaction models SIBYLL2.3, SIBYLL2.1, EPOS-LHC and QGSJETII-04 in the multi-tens TeV energy region using YAC-I+Tibet-III experimental data from May 2009 through January 2010. The effective live time is calculated as 106.05 days. The results show that the description of transverse momentum, inelastic cross-section and inelasticity for the 4 hadronic interaction models is consistent with YAC-I experimental data within 15% systematic errors range in the forward region below 100 TeV. Among them, the EPOS-LHC model is the best hadronic interaction model. Furthermore, we find that the H4a composition model is the best one below the 100 TeV energy region.

On the Solar Cycle Variation of the Solar Diurnal Anisotropy of Multi-TeV Cosmic-ray Intensity Observed with the Tibet Air Shower Array

We analyze the temporal variation of the solar diurnal anisotropy of the multi-TeV cosmic-ray intensity observed with the Tibet air shower array from 2000 to 2009, covering the maximum and minimum of the 23rd solar cycle. We comfirm that a remarkable additional anisotropy component is superposed on the Compton-Getting anisotropy at 4.0 TeV, while its amplitude decreases at higher energy regions. In constrast to the additional anisotropy reported by the Matsushiro experiment at 0.6 TeV, we find the residual component measured by Tibet at multi-TeV energies is consistent with being stable, with a fairly constant amplitude of 0.041% ± 0.003% and a phase at around 07.17 ± 00.16 local solar time at 4.0 TeV. This suggests the additional anisotropy observed by the Tibet experiment could result from mechanisms unrelated to solar activities.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

Cellularity of Thymic Epithelial Cells in the Postnatal Mouse

The molecular and cellular biology of thymic epithelial cells (TECs) often relies on the analysis of TECs isolated in enzymatically digested single-cell suspensions derived from mouse thymus. Many independent studies have reported that the estimated cellularity of total TECs isolated from one adult mouse is on the order of up to 10⁵ However, these numbers appear extremely small given that the cellularity of total thymocytes exceeds 10⁸ and that TECs play multiple roles in thymocyte development and repertoire formation. In the present study, we aimed to measure the numbers of β5t-expressing cortical TECs and Aire-expressing medullary TECs in postnatal mouse thymus in situ without enzymatic digestion. The numbers of these TECs were manually counted in individual thymic sections and were three-dimensionally summed throughout the entire thymic lobes. The results show that the cellularity of total TECs in one 5-wk-old female mouse exceeds 10⁶, containing ∼9 × 10⁵ β5t⁺ cortical TECs and ∼1.1 × 10⁶ Aire⁺ medullary TECs. These results suggest that the use of conventional enzymatic digestion methods for the isolation of TECs may have resulted in the underestimation of the cellularity, and possibly the biology, of TECs.

Foxn1-β5t transcriptional axis controls CD8+ T-cell production in the thymus

The thymus is an organ that produces functionally competent T cells that protect us from pathogens and malignancies. Foxn1 is a transcription factor that is essential for thymus organogenesis; however, the direct target for Foxn1 to actuate thymic T-cell production is unknown. Here we show that a Foxn1-binding cis-regulatory element promotes the transcription of β5t, which has an essential role in cortical thymic epithelial cells to induce positive selection of functionally competent CD8⁺ T cells. A point mutation in this genome element results in a defect in β5t expression and CD8⁺ T-cell production in mice. The results reveal a Foxn1-β5t transcriptional axis that governs CD8⁺ T-cell production in the thymus.

Foxn1 is involved in thymic epithelial cell (TEC) and CD8⁺ T cell development. Here the authors show this development requires Foxn1 binding proximal to, and inducing transcription of, the gene encoding β5t in cortical TECs.

Development of an improved RT-LAMP assay for detection of currently circulating rubella viruses

Rubella virus is the causative agent of rubella. The symptoms are usually mild, and characterized by a maculopapular rash and fever. However, rubella infection in pregnant women sometimes can result in the birth of infants with congenital rubella syndrome (CRS). Global efforts have been made to reduce and eliminate CRS. Although a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for detection of rubella virus has been reported, the primers contained several mismatched nucleotides with the genomes of currently circulating rubella virus strains. In the present study, a new RT-LAMP assay was established. The detection limit of this assay was 100-1000PFU/reaction of viruses for all rubella genotypes, except for genotype 2C, which is not commonly found in the current era. Therefore, the new RT-LAMP assay can successfully detect all current rubella virus genotypes, and does not require sophisticated devices like TaqMan real-time PCR systems. This assay should be a useful assay for laboratory diagnosis of rubella and CRS.

Gender differences in the incidence and progression of diabetic retinopathy among Japanese patients with type 2 diabetes mellitus: a clinic-based retrospective longitudinal study

A clinic-based retrospective longitudinal study conducted for 5.8 ± 2.5 years, including 383 (M/F 245/138) Japanese patients with type 2 diabetes mellitus showed that females exhibit a significantly higher prevalence of proliferative diabetic retinopathy (DR) at baseline and that female gender is an independent risk factor for the development of DR.

Increased number of Hassall's corpuscles in myasthenia gravis patients with thymic hyperplasia

The thymus is implicated as an organ that contributes to autoimmunity in myasthenia gravis (MG) patients. Hassall's corpuscles (HCs) are assumed to represent the terminally differentiated stage of medullary thymic epithelial cells (mTECs). By using multicolor immunohistofluorescence analysis, we examined HCs in thymuses that were therapeutically excised from MG (+) and MG (-) patients. We found that the number of HCs per unit area of the thymic medulla was significantly elevated in the thymuses of MG (+) patients with thymic hyperplasia. CCL21 expression increased in the hyperplastic MG thymuses. We speculate that the altered differentiation of mTECs is associated with the thymic hyperplasia and the onset of MG.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun

We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.

Aire-expressing thymic medullary epithelial cells originate from β5t-expressing progenitor cells

The thymus provides multiple microenvironments that are essential for the development and repertoire selection of T lymphocytes. The thymic cortex induces the generation and positive selection of T lymphocytes, whereas the thymic medulla establishes self-tolerance among the positively selected T lymphocytes. Cortical thymic epithelial cells (cTECs) and medullary TECs (mTECs) constitute the major stromal cells that structurally form and functionally characterize the cortex and the medulla, respectively. cTECs and mTECs are both derived from the endodermal epithelium of the third pharyngeal pouch. However, the molecular and cellular characteristics of the progenitor cells for the distinct TEC lineages are unclear. Here we report the preparation and characterization of mice that express the recombinase Cre instead of β5t, a proteasome subunit that is abundant in cTECs and not detected in other cell types, including mTECs. By crossing β5t-Cre knock-in mice with loxP-dependent GFP reporter mice, we found that β5t-Cre-mediated recombination occurs specifically in TECs but not in any other cell types in the mouse. Surprisingly, in addition to cTECs, β5t-Cre-loxP-mediated GFP expression was detected in almost all mTECs. These results indicate that the majority of mTECs, including autoimmune regulator-expressing mTECs, are derived from β5t-expressing progenitor cells.

Role of macrophage-derived hypoxia-inducible factor (HIF)-1α as a mediator of vascular remodelling

AIMS

Excessive vascular remodelling leads to progression of a wide range of vasculopathies, and the immune response to intimal injuries is crucial in this process. This vascular remodelling occurs in the hypoxic microenvironment and is closely related to the immune system. Macrophages play a key role in immunological-cell-mediated arterial remodelling. In this study, we clarified the role of macrophage-derived hypoxia-inducible factor (HIF-1α) in vascular remodelling.

METHODS AND RESULTS

Wire-induced femoral arterial injury was inflicted in mice lacking the macrophage-specific HIF-1α gene and in their wild-type counterparts. The mutant mice showed both suppressed wire-induced neointimal thickening and decreased infiltration of inflammatory cells in the adventitia, compared with wild-type mice. Studies to clarify the mechanism of restrained vascular remodelling in the mutant mice revealed decreased production of pro-inflammatory cytokines by the activated macrophages and suppressed macrophage migration activity in the mutant mice. Gene expressions of the HIF-1α-deficient macrophages positively correlated with the phenotypic profile of M2 macrophages and negatively correlated with that of M1 macrophages.

CONCLUSION

Our results show that HIF-1α in macrophages plays a crucial role in promoting vascular inflammation and remodelling. As decreasing HIF-1α activity in macrophages may prevent the progression of vascular remodelling, HIF-1α may be a possible therapeutic target in vascular diseases.

Lymphotoxin β receptor regulates the development of CCL21-expressing subset of postnatal medullary thymic epithelial cells

Medullary thymic epithelial cells (mTECs) play a pivotal role in the establishment of self-tolerance in T cells by ectopically expressing various tissue-restricted self-Ags and by chemoattracting developing thymocytes. The nuclear protein Aire expressed by mTECs contributes to the promiscuous expression of self-Ags, whereas CCR7-ligand (CCR7L) chemokines expressed by mTECs are responsible for the attraction of positively selected thymocytes. It is known that lymphotoxin signals from the positively selected thymocytes preferentially promote the expression of CCR7L rather than Aire in postnatal mTECs. However, it is unknown how lymphotoxin signals differentially regulate the expression of CCR7L and Aire in mTECs and whether CCR7L-expressing mTECs and Aire-expressing mTECs are distinct populations. In this study, we show that the majority of postnatal mTECs that express CCL21, a CCR7L chemokine, represent an mTEC subpopulation distinct from the Aire-expressing mTEC subpopulation. Interestingly, the development of CCL21-expressing mTECs, but not Aire-expressing mTECs, is impaired in mice deficient in the lymphotoxin β receptor. These results indicate that postnatal mTECs consist of heterogeneous subsets that differ in the expression of CCL21 and Aire, and that lymphotoxin β receptor regulates the development of the CCL21-expressing subset rather than the Aire-expressing subset of postnatal mTECs.

Mechanistic correlations between two itch biomarkers, cytokine interleukin-31 and neuropeptide β-endorphin, via STAT3/calcium axis in atopic dermatitis

BACKGROUND

Itch is the cardinal symptom of atopic dermatitis (AD). β-Endorphin, a neuropeptide, is increased in both AD skin and sera. Interleukin (IL)-31, an itch-relevant cytokine, activates IL-31 receptors in keratinocytes. However, how IL-31 and β-endorphin interact in AD skin remains elusive.

OBJECTIVES

To investigate the mechanistic interaction of IL-31 and β-endorphin in AD.

METHODS

This was a prospective cross-sectional study. We recruited adult patients with AD and controls according to Hanifin's AD criteria. Serum levels of IL-31 and β-endorphin were measured by enzyme-linked immunosorbent assay. Expressions of IL-31 receptor A (IL-31RA) and β-endorphin in the skin were assessed by immunohistochemistry. Their expression in the skin and blood was compared and correlated in patients with AD and in controls. We also treated primary keratinocytes with IL-31 and measured calcium influx, β-endorphin production and signalling pathways to define their mechanistic interactions.

RESULTS

β-Endorphin was increased in the supernatant from IL-31-treated keratinocytes. IL-31 receptor activation resulted in calcium influx and STAT3 activation; pretreatment with STAT3 inhibitor stopped the increase of β-endorphin. Notably, either replacement of extracellular calcium or treatment with 2-aminoethoxydiphenyl borate, an inhibitor for the store-operated channel, blocked STAT3 activation. We found higher levels of blood β-endorphin and IL-31, which were significantly correlated, in patients with AD. Moreover, IL-31RA and β-endorphin were increased and colocalized both in AD human skin and TPA-painted mouse skin.

CONCLUSIONS

IL-31 receptor activation in keratinocytes induces calcium influx and STAT3-dependent production of β-endorphin. These results might contribute to an understanding of the regulatory mechanisms underlying peripheral itch.

Estradiol and raloxifene induce the proliferation of osteoblasts through G-protein-coupled receptor GPR30

BACKGROUND

Although G-protein-coupled receptor, GPR30, has been considered as a G-protein-coupled estrogen receptor, conflicting results have been reported and the function of GPR30 in bone remains unresolved. The aim of this study was to clarify the functional role of GPR30 in osteoblasts using its derived cell line.

METHODS AND RESULTS

Immunohistochemical study revealed that GPR30 is expressed in human osteoblasts. Human fetal osteoblast cell lines, hFOB cells, which express GPR30 but lack estrogen receptor, were used for the in vitro experiments. Estradiol or raloxifene induced the proliferation of hFOB cells, which was accompanied by the activation of mitogen-activated protein (MAP) kinase. Those proliferative effects were completely abrogated by the transfection of GPR30 small interfering RNA, while the transfection alone did not affect the cell viability.

CONCLUSION

GPR30 is required for the proliferation of hFOB cells induced by estradiol or raloxifene. This proliferative effect was at least partly mediated via MAP kinase activation. These findings revealed a novel function of GPR30 in osteoblasts and might lead to a better understanding of how estrogen and selective estrogen receptor modulators show their osteoprotective effects.

Adsorption of cellulase from Trichoderma viride on cellulose

The adsorption of cellulase from Trichoderma viride (Meicelase CEP) on the surface of pure cellulose was studied. The adsorption was found to obey apparently the Langmuir isotherm. From the data concering the effects of temperature and the crystallinity of cellulose on the Langmuir adsorption parameters, the characteristics of the adsorption of the individual cellulase components, namely CMCase (endoglucanase) and Avicelase (exoglucanase), were discussed. While beta-glucosidase also adsorbed on the surface of cellulose at 5 degrees C, it did not at 50 degrees C.

Enhancement of enzymatic hydrolysis of cellulose by surfactant

Effects of surfactants on enzymatic saccharification of cellulose have been studied. Nonionic, amphoteric, and cationic surfactants enhanced the saccharification, while anionic surfactant did not. Cationic and anionic surfactants denatured cellulase in their relatively low concentrations, namely, more than 0.008 and 0.001%, respectively. Using nonionic surfactant Tween 20, which is most effective to the enhancement (e.g., the fractional conversion attained by 72 h saccharification of 5 wt % Avicel in the presence of 0.05 wt % Tween 20 is increased by 35%), actions of surfactant have been examined. As the results, it was suggested that Tween 20 plays an important role in the hydrolysis of crystalline cellulose and that Tween 20 disturbs the adsorption of endoglucanase on cellulose, i.e., varies the adsorption balance of endo- and exoglucanase, resulting in enhancing the reaction. The influence of Tween 20 to the saccharification was found to remain in simultaneous saccharification and fermentation of Avicel.

Ischaemic colitis during interferon treatment for chronic hepatitis C: report of two cases and literature review

Ischaemic colitis is known to be a severe emergency complication of interferon (IFN) therapy. However, as ischaemic colitis is an infrequent complication of IFN therapy, limited information is available regarding the safety of resuming IFN therapy after resolution of ischaemic colitis and subsequent recurrence. Here, we report two cases of ischaemic colitis during IFN therapy for chronic hepatitis C. Ischaemic colitis was fully healed within 1 week after its onset and IFN withdrawal, and IFN therapy was resumed following patients' wishes to do so. Ischaemic colitis did not recur after the resumption of IFN therapy, and sustained virological response was achieved in both patients. In this report, we also summarize the findings of 11 cases of IFN-associated ischaemic colitis (nine previously published cases plus our two cases) and review the clinical characteristics of ischaemic colitis during IFN therapy in patients with chronic hepatitis C.

Note: high-pressure generation using nano-polycrystalline diamonds as anvil materials

Nano-polycrystalline diamonds (NPDs) consist of nanosized diamond grains oriented in random directions. They have high toughness and isotropic mechanical properties. A NPD has neither the cleavage feature nor the anisotropy of hardness peculiar to single-crystal diamonds. Therefore, it is thought to be useful as a diamond anvil. We previously reported the usefulness of a NPD as an anvil for high-pressure development. In this study, some additional high-pressure generating tests using diamond anvils of various shapes prepared from NPDs were conducted to investigate the advantage of using NPDs for anvil applications. The results revealed that the achievable pressure value of a NPD anvil with a culet size of more than 300 μm is about 1.5 to 2 times higher than that of single-crystal diamond anvils, indicating that NPD anvils have considerable potential for large-volume diamond anvils with large culet sizes.

Striatal Distribution of Dopamine Transporters and Dopamine D2 Receptors at Different Stages of Parkinson's Disease

We investigated the alteration of dopaminergic system in striata of Parkinson's disease (PD) at different stages using positron emission tomography (PET), [11C]2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT) for dopamine transporter (DAT), and [11C]raclopride (RAC) for dopamine D2 receptor (D2R). We studied eight elderly healthy volunteers (Group A), 13 drug naïve patients with PD (Group B), and seven advanced PD patients with mild dyskinesia (Group D). Six patients in Group B were re-examined after antiparkinsonian therapy (Group C). Regions of interest were drawn on the cerebellar hemisphere, head of the caudate nucleus (CN), and anterior (AP) and posterior putamen (PP) in the PET images. We calculated uptake ratio index (URI), asymmetry index (AI) and presynapse-to-postsynapse ratio (PPR) to evaluate dopaminergic function. DAT was smaller in the three PD groups than the Group A. URI of RAC in the PP was significantly larger in Group B than in Groups A and C. AI of CFT in the putamen was larger in the PD groups than in normal subjects, and AI of RAC in the PP was the largest in the Group B. PPRs in the AP and PP were smaller in the three PD groups than in Group A. DAT decreased with disease progression in patients with PD. Binding of RAC was largest in the putamen of drug-naïve PD patients, but the enhanced binding could not be detected in the therapeutic patients with PD because of weak D2R affinity of RAC.

Abstract P5-10-13: Phase I Dose Escalation Study of Pirarubicin in Combination with Cyclophosphamide in Breast Cancer

Background: Doxorubicin containing combination chemotherapy regimens are widely used for treatment of breast and other cancers. However, these regimens are associated with significant toxicities including myocardialdysfunction and alopecia. Analogues of doxorubicin are being developed to reduce these side effects. Pirarubicin is a more lipophilic derivative of doxorubicin, with a higher uptake rate of cells, lower cardiotoxicity and better antitumor efficacy in preclinical models.

Purpose: We conducted a single-institution phase I clinical trial to determine the maximum-tolerated dose (MTD) and define the toxic effects and recommended dose (RD) of pirarubicin in combination with cyclophosphamide in patients with breast cancer. Patients and Methods: Patients who had received prior anthracycline therapy were excluded. Cohorts of three patients with breast cancer were treated with escalating doses of pirarubicin (40 to 70 mg/m2) intravenously administered every three weeks in combination with cyclophosphamide (60 mg/m2) for 4 or more cycles.

Results: Eleven patients of stage I/II operable breast cancer received a total of 46 cycles of pirarubicin and cyclophosphamide as post-operative adjuvant chemotherapy. The most frequently reported treatment-related grade 2 adverse events were constipation (36%) and nausea (27%). There were no grade 3/4 events. Grade 2 leukocytopenia and grade 2 fatigue were dose-limiting at 70 mg/m2, the maximum-tolerated dose was 60 mg/m2. Grade 2 alopecia was reported in 60 and 70 mg/m2 pirarubicin group. Conclusion: At the MTD of 60 mg/m2 every 3 weeks, pirarubicin in combination with cyclophosphamide was associated with mild, reversible toxicity. The recommended phase II dose is pirarubicin 50 mg/m2 and cyclophosphamide 60 mg/m2 on day 1 every 21 days.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-10-13.

Abstract P2-09-35: Differential Pathologic Response from Primary Systemic Chemotherapy across Breast Cancer Intrinsic Subtypes

Purpose: This study's purpose was to evaluate the clinical utility of breast cancer intrinsic subtypes in the prediction of pathological complete response (pCR) in a cohort of breast cancer patients receiving primary systemic chemotherapy.

Patients and Methods: Patients with stage II/III breast cancer received 4 cycles of XT (capecitabine 1650 mg/m2 on days 1-14 and docetaxel 60 mg/m2 on day 8 every 3 weeks), followed by 4 cycles of FEC (fluorouracil 500 mg/m2, epirubicin 90 mg/m2, cyclophosphamide 500 mg/m2 on day 1 every 3 weeks). Immunohistochemical analysis of estrogen receptor (ER), progesterone receptor (PgR), HER2, epidermal growth factor receptor (EGFR), cytokeratin (ck) 5/6, and Ki67 was performed in core needle biopsy samples at baseline. Tumors were classified as luminal A (ER+ and/or PgR+, and Ki67&lt;20%), luminal B(ER+ and PgR+, and Ki67≥20%), luminal-HER2 (ER+ and/or PgR+, and HER2+), HER2-enriched (ER-PgR-, and HER2+), or triple-negative (ER-, PgR-, and HER2-). Triple-negative tumors with and without EGFR+ and/or ck 5/6+ were further classified as basal-like and non-basal-like TN (NBTN), respectively. pCR was defined as no microscopic evidence of residual viable tumor cells, invasive or noninvasive, in all resected specimens of the breast. Results: Twenty-six (31.3%) patients were classified as luminal A, 12 (14.5%) were luminal B, 15 (18.1%) were luminal-HER2, 9 (10.8%) were HER2, 10 (12.0%) were basal-like, and 11 (13.3%) were NBTN. The overall response rate was 90.4%, including a complete response in 30 patients and a partial response in 45 patients. The overall pCR rate was 15.5% (12/83). The highest pCR rate (40.0%) was observed in patients with basal-like tumors. In triple-negative patients, basal-like patients showed significantly higher pCR rate than NBTN patients (40.0% vs. 9.1%, p=0.01). There were no cases with pCR in a cohort of luminal-HER2 subtype patients. A higher proportion of luminal B patients had pCR than luminal A patients (25.0% vs. 3.8%, p=0.01). With 33 months median follow-up, estimated 2-year disease-free survival for luminal A, luminal B, luminal-HER2, HER2, basal-like, and NBTN was 80.8%, 83.3%, 66.7%, 88.9%, 80.0%, and 81.8%, respectively.

Conclusions: Our data indicate that breast cancer subtypes are useful predictive biomarkers of pCR in breast cancer patients treated with primary systemic chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-35.

Abstract P4-07-07: HOXB9 Expression as a New Independent Prognostic Factor in Human Breast Cancer

Background: There are several reports showing a HOX gene family, which plays the critical roles for the differentiation during the embryonic stage, is associated with the tumorigenicity. It was demonstrated that HOXB9 is overexpressed in 42% of breast cancers, specifically those with high histological grade, and we defined the functional consequences of elevated HOXB9 expression in breast cancer. Moreover, HOXB9 expression promotes increased neovascularization and tumor metastasis to the lung in mouse xenograft models (Hayashida et al., PNAS, 2010). The puropose of this report is to evaluate the correlation between HOXB9 and clinicopathological variables in breast cancer patients. Patients and methods: A consecutive series of 141 patients with invasive ductal carcinoma who underwent surgical treatment at Keio University Hospital from January 2004 to January 2005 was involved. HOXB9 expression was analyzed immunohistochemically on formalin-fixed, paraffin-embedded tumor sections using rabbit anti-human HOXB9polyclonal antibody. Moreover, immunohistochemical stainings for Ki-67, CD31, and CD34 were also performed to evaluate the association with HOXB9 expression.

Results: The age at the diagnosis ranged from 30 to 93 years (median age, 58 years), and median observation period was 62.2 months. Of 141 tumor specimens immunostained for HOXB9, 69 specimens (48.9%) were positive staining. Univariate logistic regression revealed ER negativity (P&lt;0.001), PR negativity (P&lt;0.001), HER2 positivity (p=0.031), high nuclear grade (P&lt;0.001) and large pathological tumor size (p=0.002) as significant variables associated with HOXB9 expression. Notably, 12 (92. 3%) out of 13 triple negative breast cancer showed HOXB9 expression. The disease-free survival (DFS) at 5 year and the overall survival at 5 year were significantly different between the HOXB9 positive group and HOXB9 negative group; HR=8.5, 95%CI 3.3-21.9, p=0.001, HR 3.8, 95%CI 1.5-9.6, p=0.003, respectively. A Multivariate analysis indicated that HOXB9 expression was the independent prognostic factor for DFS (HR=14.1, 95% CI 1.851 to 107.4, p=0.011). Since HOXB9 expression accelerates the tumor angiogenesis in vitro and in vivo, we also evaluated the expression of vascular endothelial marker, CD31 and CD34 and cellular proliferation marker, Ki-67 in 45 patients with clinical T2 (tumor size, 2 to 5cm) tumor. In this subgroup analysis, HOXB9 positive patients (n=22) showed increased number of vasculature and Ki-67 ratio in comparison with HOXB9 negative patients (n=23) with statistical significance.

Correlations between HOXB 9 expression and Ki-67, CD31 and CD 34

Conclusion: The data identify HOXB9 expression as a new independent prognostic factor in breast cancer, which might help to improve the selection for appropriate therapy. Possibly, it might be useful to determine the application of anti-angiogenic therapy.

Abstract P1-11-04: A Phase II Preoperative Trial of Concurrent Trastuzumab and Paclitaxel without Anthracycline in HER2-Positive Operable Breast Cancer

Background

Concurrent trastuzumab with paclitaxel/fluorouracil, epirubicin, and cyclophosphamide (P/FEC) chemotherapy as neoadjuvant treatment revealed the high pathologic complete response (pCR) rate of 54.5% (Buzdar, 2007). Deregulation of the phosphatidylinositol 3-kinase (PI3K) pathway either through loss of PTEN or mutation of the catalytic subunit alpha of PI3K (PIK3CA) might confer resistance to trastuzumab. The objective of this study was to determine the efficacy of concurrent administration of trastuzumab and paclitaxel wtihout anthracycline as preoperative chemotherapy. The correlation between deregulation of PI3K and resistance to trastuzumab was also investigated. Patients & methods

Patients with HER2-positive, operable breast cancer received 12 cycles of weekly paclitaxel (80 mg/m2) and trastuzumab (4mg/kg loading dose then 2 mg/kg) for 12 weeks before surgery. PTEN status was evaluated by immunohistochemistry. PTEN staining intensity scores was recorded on an integer scale from 0 to 2+ (0; no staining, 1+; reduced staining, and 2+; equal staining as compared to the internal control). Sequencing of PIK3CA exons 9 and 20 was done by PCR amplification and direct sequencing. pCR was defined as no residual invasive carcinoma in the breast. Results

Twenty-eight patients were enrolled and assessable for clinical and pathologic responses. The overall response rate was 92.9%, including a complete response in 13 patients and a partial response in 13 patients. The pCR rate was 53.6% (15/28). Twenty-three patients (82.1%) underwent breast concerving surgery. Progesteron receptor (PgR) status was significantly correlated with pCR (p=0.025). Eight of 24 patients (33.3%) were scored PTEN negative. PIK3CA mutations were identified in 4 of 13 patients (30.8%). There was no significant difference in pCR rate and PTEN loss/PIK3CA mutation.

Correlation of PgR status and pCR

Conclusions

These data indicate that the combination of trastuzumab and paclitaxel without anthracycline is effective preoperative chemotherapy with high pCR rate. PTEN loss and/or PIK3CA mutation were not useful predictors of resistance to trastuzumab.