An optimal method of hydrogel spacer insertion for stereotactic body radiation therapy of prostate cancer

PURPOSE

This study aimed to explore an ideal method for hydrogel spacer insertion by analyzing the efficacy and safety of our originally developed apex expansion method.

MATERIALS AND METHODS

Overall, 100 patients with low- and intermediate-risk localized prostate cancer treated with stereotactic body radiation therapy were included. A hydrogel spacer was inserted in 64 and 36 patients using the conventional and apex expansion methods, respectively. For dosimetry, we trisected the rectum into the upper rectum, middle rectum, and lower rectum on the sagittal section of magnetic resonance imaging. We compared the dose to each part of the rectum between the two methods using dose-volume histograms. Genitourinary and gastrointestinal toxicity assessments were conducted until 3 months of follow-up.

RESULTS

The whole rectal dose in the apex expansion method group was lower than that in the conventional method group, which was significant in all dose regions (V5-V35). Similarly, in the apex expansion method group, the dose to the middle rectum was lower in the low- to high-dose region (V10-V35), and the dose to the lower rectum was lower in the middle- to high-dose region (V15-35). No Grade ≥ 3 toxicity or procedure-related complications were observed. Additionally, Grade 2 genitourinary and gastrointestinal toxicities during the treatment showed no significant differences between the two methods.

CONCLUSION

The apex expansion method may be safe and effective in achieving a more efficient rectal dose reduction by expanding the anterior perirectal space in the prostatic apex area.

Cell death signalling is competitively but coordinately regulated by repressor-type and activator-type ethylene response factors in tobacco (Nicotiana tabacum) plants

Ethylene response factors (ERFs) comprise one of the largest transcription factor families in many plant species. Tobacco (Nicotiana tabacum) ERF3 (NtERF3) and other ERF-associated amphiphilic repression (EAR) motif-containing ERFs are known to function as transcriptional repressors. NtERF3 and several repressor-type ERFs induce cell death in tobacco leaves and are also associated with a defence response against tobacco mosaic virus (TMV). We investigated whether transcriptional activator-type NtERFs function together with NtERF3 in the defence response against TMV infection by performing transient ectopic expression, together with gene expression, chromatin immunoprecipitation (ChIP) and promoter analyses. Transient overexpression of NtERF2 and NtERF4 induced cell death in tobacco leaves, albeit later than that induced by NtERF3. Fusion of the EAR motif to the C-terminal end of NtERF2 and NtERF4 abolished their cell death-inducing ability. The expression of NtERF2 and NtERF4 was upregulated at the early phase of N gene-triggered hypersensitive response (HR) against TMV infection. The cell death phenotype induced by overexpression of wild-type NtERF2 and NtERF4 was suppressed by co-expression of an EAR motif-deficient form of NtERF3. Furthermore, ChIP and promoter analyses suggested that NtERF2, NtERF3 and NtERF4 positively or negatively regulate the expression of NtERF3 by binding to its promoter region. Overall, our results revealed the cell death-inducing abilities of genes encoding activator-type NtERFs, including NtERF2 and NtERF4, suggesting that the HR-cell death signalling via the repressor-type NtERF3 is competitively but coordinately regulated by these NtERFs.

Suitability of Metastatic Lung Tumors for Stereotactic Body Radiotherapy

We investigated factors influencing local control of lung metastases treated with stereotactic body radiotherapy (SBRT) and determined the type of lesions for which SBRT is more suitable. Ninety-six patients and 196 tumors were included. Median follow-up duration was 32.0 months (range 4.7-95.8). The two-year local recurrence rate was 15.2% (95% confidence interval: 10.2-21.3). Multivariate analysis revealed biological effective dose, ultracentral tumor location, reirradiation, and prior chemotherapy as significant factors. SBRT is suitable for lung metastases, especially for peripheral tumors and those located in the inner lung parenchyma. For ultracentral lesions and recurrent lesions after SBRT, metastasectomy is recommended.

Cavin-1 modulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

Background

Pulmonary hypertension (PH) is a progressive disease associated with poor outcomes. Caveolin-1 (Cav1) and Cavin-1 are components of caveolae, and Cav1 is identified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is the most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known.

Purpose

Our study aims to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway in pulmonary artery endothelial cells (PAECs). [Methods] Cav1 knockout mice were used to assess PH, and caveolae in PAECs were observed by electron microscope. After knocking down Cav1 and/or Cavin-1 in human PAECs (hPAECs) using siRNA, we evaluated the phosphorylation of Smad by Western blotting. Apoptosis was explored by flow cytometry. To assess the interaction between Cav1 and BMPRII, and the effect of Cavin-1 for this interaction and BMP/Smad signaling, we performed immunoprecipitation, Co-immunostaining, Proximal Ligation Assay (PLA), GST pulldown assay, and Western blotting.

Results

As in previous reports, Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy and PAECs isolated from Cav1 knockout mice showed caveolae disappearance. Cav1 knockdown in hPAECs reduced BMPRII at the plasma membrane and Smad 1/5/9 phosphorylation. Cav1 knockdown also significantly increased hypoxia-induced apoptosis in hPAECs. Co-immunostaining revealed that Cav1 was associated with BMPRII at the membrane of hPAECs. Cavin-1 inhibited the interaction of BMPRII with Cav1 and reduced BMPRII localization on the membrane of hPAECs. GST pulldown assay revealed that Cavin-1 and BMPRII were associated with Cav1 through the scaffolding domain in Cav1. These findings suggest that Cavin-1 and BMPRII are competitively associated with Cav1. Cavin-1 knockdown improved the interaction between Cav1 and BMPRII and inhibited both BMPRII reduction at the plasma membrane and Smad 1/5/9 dephosphorylation.

Conclusions

Cavin-1 affects the interaction of Cav1 with BMPRII at the plasma membrane and modulates BMP/Smad signaling in PAECs. The binding of Cavin-1 to Cav1 enhances the interaction between BMPR2 and Cav1, resulting in stabilization of BMPRII localization at the plasma membrane in PAECs and prevention of BMP/Smad signaling attenuation, which is important for PAH development.

Funding Acknowledgement

Type of funding sources: None.

The use of ultrasound in central vascular ligation during laparoscopic right-sided colon cancer surgery: technical notes

BACKGROUND

Complete mesocolic excision (CME) with central vascular ligation (CVL) requires the surgeon to sharply dissect the mesocolon and approach the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) for ligation of the supplying vessels relating to right-sided colon cancer at their origin. Even with preoperative images, it can still be challenging to identify these structures during laparoscopic surgery because of various intraoperative conditions. The aim of this study was to assess the efficacy of intraoperative ultrasound (IOUS) for identification of blood vessels during right-sided colon cancer surgery.

METHODS

We performed IOUS on 19 patients diagnosed with right-sided colon cancer at our institution, in January-October 2020. Preoperatively, a three-dimensional computed tomography (3D-CT) angiogram was obtained for the majority of patients to visualize the SMA, SMV, and their respective branches. The running position of the ileocolic artery (ICA) and right colic artery (RCA) related to the SMV and the presence of the middle colic artery were identified and compared using preoperative 3D-CT, IOUS, and intraoperative findings.

RESULTS

Nineteen patients [seven men and 12 women with a mean age of 73.9 ± 8.4 years (range 58-82 years)] were studied, including some with a body mass index of > 30 kg/m², locally advanced cancer, and severe adhesion. There were IOUSs that detected the SMA, SMV, and their tributaries in all patients. The positional relationships between the SMV and the ICA and RCA revealed by IOUS were consistent with the preoperative and intraoperative findings.

CONCLUSION

IOUS is a safe, feasible, and reproducible technique that can assist in detecting the branching of the SMA and SMV during CME with CVL in laparoscopic right-sided colon cancer surgery, regardless of individual conditions.

Distribution analysis of hydrogel spacer and evaluation of rectal dose reduction in Japanese prostate cancer patients undergoing stereotactic body radiation therapy

BACKGROUND

To report on our primary experience with the placement of a hydrogel spacer following stereotactic body radiation therapy (SBRT) in low- and intermediate-risk prostate cancer patients and assess its impact on dosimetry as well as acute toxicity.

METHODS

A total of 70 patients treated with SBRT (total dose of 36.25 Gy) in 5 fractions were included. Hydrogel spacers were inserted in 53 patients along with gold fiducial markers. For dosimetry, we trisected the rectum on the sagittal image of magnetic resonance imaging and defined it as the upper rectum (UR), middle rectum (MR), and lower rectum (LR). We compared the dose to each part of the rectum with and without hydrogel spacer using dose volume histograms. Genitourinary (GU) and gastrointestinal (GI) toxicity assessments were conducted until 6 months of follow-up visits.

RESULTS

The median volume of the hydrogel spacer was 12.3 mL. Overall, the hydrogel spacer could significantly reduce the rectal dose in the middle-to-high-dose region (V20-V35). The rectum doses at the UR and MR were significantly lower in the spacer group in the middle to high dose region (V20-V35); the dose at the LR was significantly lower in the spacer group in the high-dose region (V30-V35). There was no grade ≥ 3 toxicity observed, but grade 2 toxicity of GU and GI occurred in 17.1% and 1.4% of the patients, respectively.

CONCLUSION

Hydrogel spacers could contribute to rectal dose reduction, especially in high dose regions, by creating a prostate-rectum distance.

Low prevalence of maternal microchimerism in peripheral blood of Japanese children with type 1 diabetes

AIM

To clarify the prevalence and degree of maternal microchimerism in Japanese children with type 1 diabetes, as well as its effect on phenotypic variation.

METHODS

We studied 153 Japanese children with type 1 diabetes, including 124 children positive for β-cell autoantibodies, and their 71 unaffected siblings. The number of circulating microchimeric cells per 10⁵ host cells was estimated by the use of quantitative-polymerase chain reaction targeting non-transmitted maternal human leukocyte antigen alleles. The results were compared to previous data from white European people. Phenotypic comparison was performed between maternal microchimerism carriers and non-carriers with diabetes.

RESULTS

Maternal microchimerism was detected in 15% of children with autoantibody-positive type 1 diabetes, 28% of children with autoantibody-negative type 1 diabetes, and 16% of unaffected siblings. There were no differences in the prevalence or levels of maternal microchimerism among the three groups or between the children with type 1 diabetes and their unaffected siblings. Furthermore, maternal microchimerism carriers and non-carriers exhibited similar phenotypes.

CONCLUSIONS

Maternal microchimerism appears to be less common in Japanese children with type 1 diabetes than in white European people. Our data indicate that maternal microchimerism is unlikely to be a major trigger or a phenotypic determinant of type 1 diabetes in Japanese children and that the biological significance of maternal microchimerism in type 1 diabetes may differ among ethnic groups.

Cavin-1 regulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

Background

Pulmonary hypertension (PH) is a progressive disease associated with poor outcome. Caveolin-1 (Cav1) is a component of caveolae and classified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is a most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known.

Purpose

The aim of our study is to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway and explore the mechanism of downstream signal transduction of BMP signaling by the interaction between Caveolin and BMPRII.

Methods

Cav1 knockout mice were used to assess PH and caveolae in pulmonary artery endothelial cells were observed by electron microscope. Cav1 and Cavin-1, which is a component of caveolae and form a complex with Cav1, were knocked-down in human pulmonary artery endothelial cell (hPAEC) using siRNA and phosphorylation of Smad signal was evaluated. Apoptosis of these cells was explored by flow cytometry. We investigated the interaction between Cav1 and BMPRII, and evaluated whether Cavin-1 affects this interaction and signal transduction of BMP signaling.

Results

As previously described, deletion of Cav1 revealed disappearance of caveolae in pulmonary artery endothelial cells (PAECs), and Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy. We then examined roles of Cav1 in human PAECs (hPAECs). Cav1 knockdown in hPAECs reduced phosphorylation of Smad 1/5/9. In addition, Cav1 knockdown significantly increased hypoxia-induced apoptosis in hPAEC. Knockdown of Cavin-1 reversed phosphorylation of Smad 1/5/9 decreased by Cav1 knockdown in BMP9 stimulation. Cavin-1 reversed the expression of BMPRII decreased by overexpression of Cav1. Cav1 was associated with Cavin-1 at the plasma membrane in PAECs. Cav1 also associated with BMPRII at the membrane of hPAECs that was inhibited by Cavin-1, and Cavin-1 reduced the localization of BMPRII to the membrane of hPAECs. These results suggest that BMPRII interacts with Cav1 via Cavin-1-associated localization at the plasma membrane in hPAECs, resulting in regulating BMP/Smad signaling pathway and involving in the development of PAH.

Conclusions

Cavin-1 affects the interaction of Cav1 with BMPRII at the membrane of PAECs, and regulates BMP/Smad signaling. These results reveal a previously undescribed function of Cavin-Caveolin system in the development of PAH through regulation of BMP/Smad signaling.

Funding Acknowledgement

Type of funding source: None

SDPR/Cavin-2 loss inhibits monocyte adhesion to endothelial cells in abdominal aortic aneurysm via suppressing the expression of adhesion molecules

Background

Abdominal aortic aneurysm (AAA) is a common and life-threatening vascular disease. The initial phase of AAA progression is vascular inflammation. Inflammation sites present adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1). These molecules play a crucial role in recruiting inflammatory cells to endothelial cells through NF-κB signaling. Endothelial cells express serum deprivation response (SDPR)/Cavin-2 localized in caveolae on the cell membrane. Although Cavin-2 is involved in such as cell proliferation, migration, and signal transduction, the role of Cavin-2 in vascular inflammation in the development of AAA is still unclear.

Purpose

To assess the influence of Cavin-2 deficiency in AAA development and clarify the role of Cavin-2 in the regulation of inflammatory cell adhesion in endothelial cells.

Methods

CaCl2-induced AAAs were induced by the periaortic application of 0.5 M CaCl2 in male SDPR-knockout (KO) and wild-type (WT) mice at 8–10 weeks of age. Angiotensin II (Ang II)-induced AAAs were created by 4-week-subcutaneous drug infusion in male ApoE-KO and ApoE/Cavin-2-double KO (DKO) mice at 24 weeks of age. Inflammatory response and cell adhesion were evaluated using human aortic endothelial cells (HAECs) and human monocytes (THP-1 cells).

Results

Six weeks after CaCl2 treatment, Cavin-2 deficiency significantly attenuated the development of AAAs. Elastin degradation was markedly suppressed and F4/80-positive macrophages infiltration in aortic walls were decreased in Cavin-2-KO mice. Although Ang II infusion for 4 weeks formed AAAs in ApoE KO mice and ApoE/Cavin-2-DKO mice, ApoE/Cavin-2-DKO mice exhibited the suppression of AAA formation independently of blood pressure. Immunohistochemical staining showed VCAM-1 expression on endothelial cells was suppressed in ApoE/Cavin-2-DKO mice. Further, in vitro co-culture experiment, the number of THP-1 cells adhered to TNF-treated SDPR-knockdown HAECs was decreased compared with that to control HAECs. Moreover, mRNA expression of VCAM-1 and ICAM-1 was decreased in TNFα-treated SDPR-knockdown HAECSs. Protein expression of VCAM-1 was also suppressed in TNFα-treated SDPR-knockdown HAECSs. The activity of NF-κB p65, an upstream regulator of VCAM-1 and ICAM-1,tended to be suppressed in TNFα-treated SDPR-knockdown HAECs.

Conclusion

In this study, we revealed that SDPR/Cavin-2 loss attenuated AAA development with the suppression of elastin degradation and macrophage infiltration. Our findings suggest that SDPR/Cavin-2 in the endothelial cells regulates the expression of adhesion molecules via NF-κB signaling and promotes the adhesion and infiltration of inflammatory cells to the aortic wall.

Funding Acknowledgement

Type of funding source: None

Aneuploid rescue precedes X-chromosome inactivation and increases the incidence of its skewness by reducing the size of the embryonic progenitor cell pool

STUDY QUESTION

Do monosomy rescue (MR) and trisomy rescue (TR) in preimplantation human embryos affect other developmental processes, such as X-chromosome inactivation (XCI)?

SUMMARY ANSWER

Aneuploid rescue precedes XCI and increases the incidence of XCI skewness by reducing the size of the embryonic progenitor cell pools.

WHAT IS KNOWN ALREADY

More than half of preimplantation human embryos harbor aneuploid cells, some of which can be spontaneously corrected through MR or TR. XCI in females is an indispensable process, which is predicted to start at the early-blastocyst phase.

STUDY DESIGN, SIZE, DURATION

We examined the frequency of XCI skewness in young females who carried full uniparental disomy (UPD) resulting from MR or TR/gamete complementation (GC). The results were statistically analyzed using a theoretical model in which XCI involves various numbers of embryonic progenitor cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We studied 39 children and young adults ascertained by imprinting disorders. XCI ratios were determined by DNA methylation analysis of a polymorphic locus in the androgen receptor gene. We used Bayesian approach to assess the probability of the occurrence of extreme XCI skewness in the MR and TR/GC groups using a theoretical model of 1-12 cell pools.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 12 of 39 individuals (31%) showed skewed XCI. Extreme skewness was observed in 3 of 15 MR cases (20%) and 1 of 24 TR/GC cases (4.2%). Statistical analysis indicated that XCI in the MR group was likely to have occurred when the blastocyst contained three or four euploid embryonic progenitor cells. The estimated size of the embryonic progenitor cell pools was approximately one-third or one-fourth of the predicted size of normal embryos. The TR/GC group likely had a larger pool size at the onset of XCI, although the results remained inconclusive.

LIMITATIONS, REASONS FOR CAUTION

This is an observational study and needs to be validated by experimental analyses.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides evidence that the onset of XCI is determined by an intrinsic clock, irrespectively of the number of embryonic progenitor cells. Our findings can also be applied to individuals without UPD or imprinting disorders. This study provides a clue to understand chromosomal and cellular dynamics in the first few days of human development, their effects on XCI skewing and the possible implications for the expression of X-linked diseases in females.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Grants-in-aid for Scientific Research on Innovative Areas (17H06428) and for Scientific Research (B) (17H03616) from Japan Society for the Promotion of Science (JSPS), and grants from Japan Agency for Medical Research and Development (AMED) (18ek0109266h0002 and 18ek0109278h0002), National Center for Child Health and Development and Takeda Science Foundation. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Repeated Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma

PURPOSE

In clinical practice, whether cirrhotic livers in patients with hepatocellular carcinoma (HCC) can withstand repeated stereotactic body radiation therapy (SBRT) remains unclear. This study aimed to evaluate the outcomes and toxicities in these patients.

METHODS AND MATERIALS

This retrospective study included patients with HCC who were treated with SBRT at least twice between January 2012 and June 2019. Local control and overall survival rates were calculated. Liver function before and after irradiation was evaluated using the Child-Pugh score and modified albumin-bilirubin grade. All toxicities were assessed using the Common Terminology Criteria for Adverse Events (version 4.0).

RESULTS

Fifty-two patients underwent 136 courses (148 lesions) of SBRT, which was mostly performed for out-of-field tumors but 3 in-field recurrences. The median follow-up duration from the first SBRT was 52.6 months (range, 15.7-89.3 months). The median gross tumor volume was 4.6 cm³ (range, 0.8-55.2 cm³) at the second SBRT. The 3-year local control rate was 94.5% (95% confidence interval, 88.0%-97.5%). The 3-year overall survival rate after the second course was 62.8% (95% confidence interval, 45.1%-76.2%). Although the Child-Pugh score did not deteriorate after the second course, deterioration of the modified albumin-bilirubin grade at 6, 12, and 24 months was statistically significant compared with that before the second course. One patient (1.9%) experienced grade 3 hypoalbuminemia and 2 patients (3.8%) had grade 3 thrombocytopenia 6 months after the second course. Mild fatigue and nausea were reported in 9 (17.3%) and 6 (11.5%) patients, respectively. One instance of grade 5 toxicity was observed. Two patients (1.5%) had grade 2 gastric ulcers. No other grade ≥3 gastrointestinal toxicities occurred.

CONCLUSIONS

Repeated SBRT is feasible and produces minimal toxicity in patients with HCC and Child-Pugh scores of ≤7 and a low normal liver dose.

Mechanical regulation of bone homeostasis through p130Cas-mediated alleviation of NF-κB activity

Mechanical loading plays an important role in bone homeostasis. However, molecular mechanisms behind the mechanical regulation of bone homeostasis are poorly understood. We previously reported p130Cas (Cas) as a key molecule in cellular mechanosensing at focal adhesions. Here, we demonstrate that Cas is distributed in the nucleus and supports mechanical loading-mediated bone homeostasis by alleviating NF-κB activity, which would otherwise prompt inflammatory processes. Mechanical unloading modulates Cas distribution and NF-κB activity in osteocytes, the mechanosensory cells in bones. Cas deficiency in osteocytes increases osteoclastic bone resorption associated with NF-κB-mediated RANKL expression, leading to osteopenia. Upon shear stress application on cultured osteocytes, Cas translocates into the nucleus and down-regulates NF-κB activity. Collectively, fluid shear stress-dependent Cas-mediated alleviation of NF-κB activity supports bone homeostasis. Given the ubiquitous expression of Cas and NF-κB together with systemic distribution of interstitial fluid, the Cas-NF-κB interplay may also underpin regulatory mechanisms in other tissues and organs.

Abstract P1-12-03: Prevalence, predictive factors, and clinical outcomes of anthracycline induced cardiac dysfunction among patients with breast cancer in Japan, where the normal body weight (BMI < 25) is dominant

Objective: Cardiac dysfunction (CD) is a major clinical problem for survivors of breast cancer. ASCO released a guideline for prevention and monitoring CD in survivors of adult cancer in 2017. Exposure to anthracycline (A) and trastuzumab are both risk factor for CD, as well as obesity is a part of multiple risk factors in the guideline. Meta-analysis shown obesity itself increases risk of A induced CD (A-CD). Prevalence of obesity and CD among non-oncology patients vary in countries, as many Western countries have obesity dominant population. Then little is known about clinical characteristics of A-CD in survivors of adult cancer among normal weight dominant countries, especially in Asia. This study was conducted to understand characteristics of A-CD among patients with breast cancer in Japan.

Method: This study used electrical charts, breast oncology database, and cardiology database to find prevalence, predictive factors, and clinical outcomes of A-CD in Hyogo Cancer Center. The definition of CD is based on diagnosis by the cardiologist. Major Cardiac Events (MACE) is defined as cardiac death or emergency admission due to CD. Obesity is defined as BMI > 30, normal body weight is defined as BMI < 25, and elderly is defined as age > 60 years old, same as in ASCO guideline. Patients gave written informed consent. IRB approved this study.

Result: From Apr. 2006, to Mar. 2017, 855 patients received A for the treatment of breast cancer. Median body weight was 55 Kg, median BMI was 23, and 93.4 % of patients are non-obese. Half of patients (46.9 %) are elderly. Almost a quarter (24 %) of patients received trastuzumab. At the median follow up 60 months, 20 patients (2.3 %) experienced CD, one patient (0.11 %) passed away due to CD, and four patients were admitted as emergency, then five patients (0.58 %) experienced MACE. Median time to onset of CD after the last dose of A is seven months. Among patients with CD, 18 patients (90 %) recovered their ejection fraction (EF), and the median time to recover of EF was two months. Predictive factors for CD include usage of trastuzumab (15 patients), elderly (eight patients), high dose anthracycline (four patients), and multiple cardiac risk factors at base line (four patients). Among patients treated without trastuzumab, only five (0.76 %) patients experienced CD, but four of them experienced MACE.

Conclusion: Prevalence of A-CD in the normal weight dominant population was lower than reported in obesity dominant population, especially in patients treated without trastuzumab. In this population, clinical outcome such as prevalence of MACE may vary depending on the usage of trastuzumab. Further study is warranted to set an optimal strategy for the prevention and monitoring of A-CD in non-obese dominant population.

Citation Format: Matsumoto K, Nonaka A, Ogata T, Ogata M, Sakai H, Nishimura M, Onoe T, Soyama M, Hashimoto K, Tane K, Hirokaga K, Takao S. Prevalence, predictive factors, and clinical outcomes of anthracycline induced cardiac dysfunction among patients with breast cancer in Japan, where the normal body weight (BMI < 25) is dominant [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-12-03.

Protein-altering variants of PTPN2 in childhood-onset Type 1A diabetes

AIM

To examine the contribution of PTPN2 coding variants to the risk of childhood-onset Type 1A diabetes.

METHODS

PTPN2 mutation analysis was carried out for 169 unrelated Japanese people with childhood-onset Type 1A diabetes. We searched for coding variants that were absent or extremely rare in the general population and were scored as damaging by multiple in silico programs. We performed mRNA analysis and three-dimensional structural prediction of the detected variants, when possible. We also examined possible physical links between these variants and previously reported risk SNPs as well as clinical information from variant-positive children.

RESULTS

One frameshift variant (p.Q286Yfs*24) and two probably damaging missense substitutions (p.C232W and p.R350Q) were identified in one child each. Of these, p.Q286Yfs*24 and p.C232W were hitherto unreported, while p.R350Q accounted for 2/121,122 alleles of the exome datasets. The p.Q286Yfs*24 variant did not encode stable mRNA, and p.C232W appeared to affect the structure of the tyrosine-protein phosphatase domain. The three variants were physically unrelated to known risk SNPs. The variant-positive children manifested Type 1A diabetes without additional clinical features and invariably carried risk human leukocyte antigen alleles.

CONCLUSIONS

The results provide the first indication that PTPN2 variants contribute to the risk of Type 1A diabetes, independently of known risk SNPs. PTPN2 coding variants possibly induce non-specific Type 1A diabetes phenotypes in individuals with human leukocyte antigen-mediated disease susceptibility. Our findings warrant further validation.

Abstract P6-12-26: The axonal damage marker, serum phosphorylated neurofilament heavy subunit, as a potential marker of chemotherapy-induced neuropathy

Background: Chemotherapy-induced neurologic disorders such as peripheral neuropathy and cognitive disturbance are clinically significant problems for cancer survivors, but their objective assessment methods have not been established. We previously reported in a cross-sectional study that the serum phosphorylated neurofilament heavy subunit (pNF-H), a biomarker of axonal damage, was increased in breast cancer patients treated with chemotherapy. The aim of this study is to temporally assess the neurological adverse events and evaluate the association of serum pNF-H level with cognitive functions and neuropathy following sequential chemotherapy.

Methods: Thirty-five breast cancer patients who received neoadjuvant or adjuvant chemotherapy were enrolled prospectively. They underwent brain MRI and cognitive function tests including Controlled Oral Word Association (COWA), Trail Making Test (TMT), and Hopkins Verbal Learning Test-Revised (HVLT-R) before chemotherapy (baseline), one month after completing sequential chemotherapy (post-phase) and more than six months after completing chemotherapy (late-phase). Serum pNF-H levels and questionnaires reporting peripheral neuropathy were measured at the three phases, and every 3 weeks during chemotherapy. Brain MRI volumetry was calculated by the automatic analysis software, BAAD® (Brain Anatomical Analysis using Dartel). The correlations among cognitive functions, brain volume, peripheral neuropathy and serum pNF-H levels were statistically analyzed.

Results: Patients' median age was 48 years (range 24-71). A decrease of more than 10% in cognitive function test (COWA) scores was seen in 10 cases (31%) at post-phase. A brain volume loss of more than 10% was seen in 5 cases (15%) at post-phase. The correlation between brain volume change and cognitive disturbance was not significant (p=0.45) and both changes were improved at late-phase. A peripheral neuropathy grade above CTCAE grade 2 was seen in 19 cases (54%). The neuropathy was significantly more severe in anthracycline followed by taxane regimen than taxane followed by anthracycline during chemotherapy (p=0.016), although this difference was not seen at the late-phase (p=0.08). An elevated serum pNF-H level at baseline was seen in only one case, and this case demonstrated the cognitive disturbance, brain volume loss, and peripheral neuropathy following chemotherapy. During chemotherapy, pNF-H was elevated in 24 patients (69%), with especially higher levels noted during the taxane regimen compared to the anthracycline regimen (p=0.019). In the cases treated with anthracycline followed by taxane, the taxane-phase elevation was especially significant (p=0.014). The maximum pNF-H level during taxane therapy was significantly correlated with peripheral neuropathy grade (p=0.002). At late-phase, the significant reduction of pNF-H level was seen in all cases.

Conclusions: Change of cognitive function, brain volume and peripheral neuropathy was observed following chemotherapy in breast cancer patients. This study suggests that the serum axonal damage marker, pNF-H, may reflect chemotherapy-induced neuropathy.

Citation Format: Kida K, Sumitani M, Ogata T, Kotake R, Natori A, Hashimoto J, Shimokawa T, Yamauchi H, Yamauchi T. The axonal damage marker, serum phosphorylated neurofilament heavy subunit, as a potential marker of chemotherapy-induced neuropathy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-26.

Next-generation sequencing for patients with non-obstructive azoospermia: implications for significant roles of monogenic/oligogenic mutations

Azoospermia affects up to 1% of adult men. Non-obstructive azoospermia is a multifactorial disorder whose molecular basis remains largely unknown. To date, mutations in several genes and multiple submicroscopic copy-number variations (CNVs) have been identified in patients with non-obstructive azoospermia. The aim of this study was to clarify the contribution of nucleotide substitutions in known causative genes and submicroscopic CNVs in the genome to the development of non-obstructive azoospermia. To this end, we conducted sequence analysis of 25 known disease-associated genes using next-generation sequencing and genome-wide copy-number analysis using array-based comparative genomic hybridization. We studied 40 Japanese patients with idiopathic non-obstructive azoospermia. Functional significance of molecular alterations was assessed by in silico analyses. As a result, we identified four putative pathogenic mutations, four rare polymorphisms possibly associated with disease risk, and four probable neutral variants in 10 patients. These sequence alterations included a heterozygous splice site mutation in SOHLH1 and a hemizygous missense substitution in TEX11, which have been reported as causes of non-obstructive azoospermia. Copy-number analysis detected five X chromosomal or autosomal CNVs of unknown clinical significance, in addition to one known pathogenic Y chromosomal microduplication. Five patients carried multiple molecular alterations. The results indicate that monogenic and oligogenic mutations, including those in SOHLH1 and TEX11, account for more than 10% of cases of idiopathic non-obstructive azoospermia. Furthermore, this study suggests possible contributions of substitutions in various genes as well as submicroscopic CNVs on the X chromosome and autosomes to non-obstructive azoospermia, which require further validation.

Incidence and prevalence of childhood-onset Type 1 diabetes in Japan: the T1D study

AIMS

A majority of children with Type 1 diabetes in Japan are registered with the government-subsidized Specified Pediatric Chronic Disease Treatment Research Projects (SPCDTRP). In this study, the incidence and prevalence of childhood-onset (< 15 years) Type 1 diabetes in Japan were estimated by drawing on SPCDTRP data.

METHODS

Data available for 2005-2012 from the SPCDTRP and Statistics Bureau, Ministry of Internal Affairs and Communications were used to estimate the incidence of Type 1 diabetes for 2005-2010, adjusted to cover those registered within 3 years of disease onset and stratified by sex, age at onset and period of onset.

RESULTS

The incidence of Type 1 diabetes for 2005-2010 was 2.25/100,000 persons [95% confidence intervals (95% CI), 2.14-2.36] (boys: 1.91, 95% CI, 1.83-1.98; girls: 2.52, 95% CI, 2.34-2.69), with that for the age brackets 0-4, 5-9 and 10-14 years being 1.48 (95% CI, 1.29-1.66), 2.27 (95% CI, 2.08-2.47) and 3.00 (95% CI, 2.74-3.25), respectively. The onset of disease was shown to peak at age 13 among boys (3.28, 95% CI, 3.02-3.55) and at age 10 among girls (3.28, 95% CI, 3.02-3.55). The peak periods of disease onset were April/May and December. The number of children aged < 15 years with Type 1 diabetes for 2005-2012 was estimated to be 2326 (95% CI, 2202-2450) with the prevalence estimated as 13.53/100,000 persons (95% CI, 12.63-14.43).

CONCLUSIONS

Study findings demonstrated no increase in the incidence of Type 1 diabetes, although suggesting, in agreement with earlier reports, that the onset of disease peaks in adolescence with a female predominance. In addition, the incidence of childhood-onset diabetes exhibited an annual bimodal pattern in this study.