Abstract P2-08-52: A predictive model for distant metastasis in breast cancer patients using machine learning

Introduction

Tumor metastasis is a major clinical challenge accounting for the vast majority of cancer related deaths.In previous studies, prediction of distant metastasis was based on subtypes,clinical status and sometimes gene expression were used however clinical application was difficult.

In this study, we develop the easy to use prediction tool for distant metastasis using clinical characteristics and gene profiles which came from CancerSCANTM, Next Generation Sequencing based targeted-sequencing platform designed at Samsung Medical Center(SMC).

Methods

We performed a retrospective chart review of 326 breast cancer patients who underwent surgery and CancerSCAN TM between Jan 2001 and Dec 2014 at SMC. Median follow up period was 83 months (Range 1˜190). Cancer scanTM cover 381 genes but 27 genes and 34 occasions (loss of function, mutation or copy number variation) were selected for analysis through gradient boosting and Wilcoxon Signed rank test. Azure Machine Learning is a cloud service that enables the execution of machine learning processes.This was accomplished using the steps of (1) edit the data, (2) split the data, (3) train the model, (4) score the model, and (5) evaluate the model. We split the modeling data into training and testing sets using a randomized 50–50 split. Two-class Decision Forest method was used. After deploying the Azure ML predictive model as a web service, we used a Representational State Transfer application programming interface to send data and obtained predictions in real-time.

Results

No distant metastasis group and distant metastasis group consisted of 267 and 59 patients, respectively. HR-/HER2+ and 50 years old and over patients were higher in metastasis group (p-value = 0.003 and p-value = 0.000). Nuclear grade 3 and N2,3 were higher in metastasis group (p-value = 0.010 and p-value = 0.000, p-value = 0.001 respectively). Stage III was also higher in metastasis group (p-value = 0.000). Among 59 patients with distantmetastasis, multiple sites metastasis was 21 cases (35.6%) and then lung metastasis was 19 cases (32.2%). In the 21 cases of multiple sites metastasis, triple sites was 6 cases (28.6%) and double sites was 15 cases (71.4%). PIK3CA mutation was the most frequent gene variation in all patients (34.5% of no metastasis group and 27.1% of metastasis group) but there was no difference between two groups(p-value = 0.278). BRCA 1 loss of function and BRCA2 loss of function were more frequent in metastasis group than no metastasis group(p-value = 0.033 and p-value = 0.024, respectively) but total counts was too small. We assessed the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for predictive value. The AUC of ROC curve was 1.000 and also accuracy, precision, recall were 1.000. In addition, we conducted internal validation using 83 patients during 2015. When we applied a 0.5 threshold value with our predictive model, true negative was 81 and true positive was 2 among 83 patients. Finally, the accuracy of validation was 1.000.

Conclusion

Our predicted model could represent a useful and easy-to-access tool for the selection of patients with distant metastasis. After additional evaluation with large data and external validation, worldwide use of our model could be expected.

Citation Format: Kim I, Choi HJ, Ryu JM, Lee SK, Yu JH, Kim SW, Nam SJ, Seo SW, Lee JE. A predictive model for distant metastasis in breast cancer patients using machine learning [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 P2-08-52.

Abstract P1-15-18: Not presented

This abstract was not presented at the conference.

Citation Format: Choi HJ, Kim SW, Ryu JM, Kim I, Nam SJ, Yu J, Lee SK, Lee JE. Not presented [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 P1-15-18.

Abstract P2-08-29: The impact of time interval between diagnosis and surgery in each type and stage of breast cancer

Background: There are many factors that might contribute to the delay of surgery in patients with breast cancer. Previous studies investigate the influence of delay of surgery, but they reported inconsistent results. The purpose of this study was to evaluate the impact of time of surgery on prognosis of breast cancer.

Methods: We performed a retrospective review of the patients with breast cancer, who received surgery between 1992 and 2009, by using data from Korea Breast Cancer Society Registry. Kaplan-Meier survival analysis and Cox regression model were used to evaluate the impact of time to surgery in breast cancer and subgroup analyses were performed for each disease stage and molecular subtype.

Result: A total 14727 patients were included for analysis. Delay of surgery more than 31 days was associated with worse survival for breast cancer [hazard ratio (HR) = 2.16; 95% confidence interval (CI), 1.936-2.408, p<0.001]. Subgroup analyses revealed that over 31 days of surgical delay were significantly associated with worse survival in hormone receptor positive and HER-2 negative (p<0.001), hormone receptor positive and HER-2 positive (p<0.001), hormone receptor negative and HER-2 positive (p<0.001), triple negative (p<0.001) and stage II, III breast cancer patients (p<0.001).

Conclusion: Surgical delay of more than 31 days were independent risk factors for worse outcome of breast cancer in each molecular subtype and breast cancer group except stage 0 and I. Although preoperative evaluation is required, surgical delay should be shortened to enhance survival of breast cancer, especially in patients with tumor size more than 2cm or presence of lymph node metastasis.

Citation Format: Kim J-M, Choi HJ, Kim I, Ryu JM, Yu J, Lee JE, Kim SW, Nam SJ, Lee SK. The impact of time interval between diagnosis and surgery in each type and stage of breast cancer [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 P2-08-29.

Abstract P1-07-25: Differences among young breast cancer patients based on subtype: A study from the Korean Breast Cancer Society – Running head: Do breast cancers in 20s have worse prognosis than 30s?

Purpose Numerous studies demonstrated that breast cancer in young women (BCY) has unfavorable prognostic features and unfavorable subtype. However, there were few studies to evaluate the effect on the prognosis of breast cancer according to the subtype disparities by age especially BCY. We analyzed breast cancer mortality stratified tumor subtype according to age among the patients with less than 50 year-old. Patients and Methods Data obtained from the Korean Breast Cancer Society Registry (KBCSR), patients diagnosed with invasive breast cancer were retrospectively between 2003 and 2010. We excluded patients with male breast cancer, underwent neoadjuvant chemotherapy, distant metastasis or inflammatory breast cancer at presentation, and other histopathology except invasive ductal or invasive lobular carcinoma. We also excluded patients with lack of immunohistochemistry data and short-term follow-up duration (<12 months). Results We identified 37,865 patients, and excluded by study protocol. Among those, 30,793 patients with breast cancer for eligible for analysis, 793 (2.6%) were 20-29 years and 8,926 (28.8%) were 30-39 years of age. Median follow-up duration was 84 months. Mean age was 42.4 years old. Younger patients with breast cancer were more likely to have advanced stage, higher nuclear grade, present lymphovascular invasion, and more likely to be unfavorable subtype such as triple negative breast cancer (TNBC)

Table 1. Baseline Characteristics Age at Presentation 20-29, N(%)30-39, N(%)40-49, N(%)P-valueOverall793 (2.6)8,133 (26.4)21,867 (71.0) Pathologic stage   <.0001I295 (37.2)2,928 (36.0)9,288 (42.5) II373 (47.0)3,644 (44.8)9,078 (41.5) III119 (15.0)1,442 (17.7)3,211 (14.7) Family history   <.0001Yes81 (10.2)674 (8.3)1,391 (6.4) No712 (89.8)7,459 (91.7)20,476 (93.6) Nuclear grade   <.0001Low85 (10.2)941 (11.6)3,824 (17.5) Intermediate288 (36.3)3,340 (41.1)9,688 (44.3) High331 (41.7)3,165 (38.9)6,650 (30.4) LVI   <.0001Yes249 (31.4)2,840 (34.9)6,711 (30.7) No433 (54.6)4,367 (53.7)13,005 (59.5) Subtype   <.0001Luminal A314 (39.6)3,529 (43.4)11,716 (53.6) Luminal B190 (24.0)1,895 (23.3)4,775 (21.8) Her-252 (6.6)724 (8.9)1,723 (7.9) TNBC237 (29.8)1,895 (24.4)3,653 (16.7) HER-2, human epidermal growth factor-2; TNBC, triple negative breast cancer

. Patients with younger age group showed worse prognosis than patients with older age patients. In multivariate analysis for overall survival, as patients were younger group, hazard ratio was increased, and the patients with TNBC showed higher HR than HER-2, Luminal B, and Luminal A subtype (P< .0001, P< .0001, P< .0001, and P< .0001, respectively). Stratified by subtype, luminal subtype showed significant worse prognosis as the age group was younger, while as, Her-2 and TNBC subtype showed no significantly difference by the age group. Conclusion Patients with 20s breast cancer showed unfavorable characteristics and worse prognosis than 30s and older aged group. Stratified by tumor subtype, breast cancer in 20s with luminal subtype showed worse prognosis, while as HER-2 and TNBC showed no significantly different compare to breast cancer in 30s.

Citation Format: Ryu JM, Yu J, Nam SJ, Kim I, Lee JE, Lee SK, Kim JM, Choi HJ, Kim SW. Differences among young breast cancer patients based on subtype: A study from the Korean Breast Cancer Society – Running head: Do breast cancers in 20s have worse prognosis than 30s? [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 P1-07-25.

Silibinin inhibits the fibrotic responses induced by cigarette smoke via suppression of TGF-β1/Smad 2/3 signaling

Cigarette smoke (CS) is generally accepted as a major contributor to chronic obstructive pulmonary disease (COPD) which is characterized by chronic inflammation, fibrotic response, and airway obstruction. In this study, we investigated the preventive effects of silibinin, an active constitute of silymarin on CS and lipopolysaccharide (LPS) exposure-induced fibrotic response. Mice were exposed to CS for 1 h per day (8 cigarettes per day) for 4 weeks. On day 12 and 26, mice were treated with LPS intranasally. Silibinin (10 or 20 mg/kg) was administered orally 1 h before CS exposure. Silibinin markedly decreased the inflammatory cell count in the bronchoalveolar lavage fluid, and reduced levels of proinflammatory mediators. Silibinin suppressed CS + LPS-induced collagen deposition in lung tissue, as evidenced via immunohistochemistry and Masson's trichrome stain. Additionally, silibinin effectively inhibited CS + LPS-mediated expression of transforming growth factor-β1 (TGF-β1) and Smad 2/3 phosphorylation. Taken together, our data indicate that silibinin effectively inhibits the fibrotic response induced by CS + LPS exposure, possibly via suppression of TGF-β1/Smad 2/3 signaling, which results in reduced collagen deposition. These findings suggest that silibinin has therapeutic potential for the treatment of COPD.

Protective effect of HwangRyunHaeDok-Tang water extract against chronic obstructive pulmonary disease induced by cigarette smoke and lipopolysaccharide in a mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Hwangryunhaedok-tang is an oriental herbal formula treated to cure inflammation and gastric disorders in China, Japan, and Korea. We explored the protective effects of Hwangryunhaedok-tang water extract (HRWE) against airway pathophysiological changes caused by cigarette smoke (CS) and lipopolysaccharide (LPS) in a mouse.

MATERIALS AND METHODS

We performed quantitative analyses of five marker components, namely geniposide, baicalin, coptisine, plamatine, and berberine, using high-performance liquid chromatography. Animals were received CS exposure (1h per day) for 7 days. LPS was administered intranasally on day 4. Mice were received HRWE at dose of 100 or 200mg/kg for 1h before CS exposure.

RESULTS

Treatment with HRWE significantly suppressed the increased inflammatory cell count induced by CS and LPS exposure. In addition, reduction in IL-6, TNF-α and IL-1β in broncho-alveolar lavage fluid (BALF) was observed after HRWE treatment. HRWE not only decreased inflammatory cell infiltration in lung, but also decreased the expression of iNOS, NF-κB and matrix metallopeptidase (MMP)-9 in lung tissues.

CONCLUSION

This study showed that HRWE can attenuate respiratory inflammation caused by CS and LPS exposure. Therefore, HRWE has potential for treating airway inflammatory disease.

Abstract P3-14-12: Oncologic outcomes of immediate breast reconstruction after neoadjuvant chemotherapy in breast cancer patients: A matched case control study

Introduction: Although the indication for total mastectomy (TM) with immediate breast reconstruction (IBR) has been expanded, IBR after neoadjuvant chemotherapy (NACT) is still controversy. We assumed that TM with IBR after NACT is feasible surgical treatment in breast cancer patients. Methods: A retrospective review of breast cancer patients who underwent TM with IBR after NACT between 2008 and 2015 at a single center was conducted. These cases were matched by 1:5 to patients who underwent mastectomy alone after NACT. Matching variables included age, clinical T and N staging before NACT, response to NACT, and pathologic staging after NACT. Pathological stage was followed by seventh American Joint Committee on Cancer (AJCC) classification. Results: Overall, 31 patients were identified in the TM with IBR group (Study group) and 85 patients (Control group) were matched. In the study group, 13 (41.9%) patients underwent nipple-sparing mastectomy (NSM) and 18 (58.1%) underwent skin-sparing mastectomy (SSM). Median follow-up duration was 29.2 (7-31) and 38.8 (11-85) months for the study and control group, respectively. Median age was 37.0 (26-57) and 40.0 (24-56) years for the study and control group, respectively. The clinicopathologic characteristics of both groups are summarized in Table1. Disease-free survival (p=0.520), local recurrence-free survival (p=0.610), distant metastasis-free survival (p=0.795), and over survival (p=0.971) did not differ significantly between two groups. Conclusion: TM with IBR after NACT is feasible surgical treatment option in breast cancer patients.

Clinicopathologic characteristicsVariablesControl group (n=85)Study group (n=31)p-valueAge, years (matching variables)  0.890≤3515 (17.7)9 (29.0) 36-5061 (71.8)21 (67.7) 51≥9 (10.6)1 (3.2) BMI, m2/kg  0.13025≤62 (72.9)28 (90.3) 26-3018 (21.2)2 (6.5) 30>5 (5.9)1 (3.2) Histology  0.326Ductal carcinoma in situ2 (2.4)3 (9.7) Invasive ductal carcinoma74 (87.1)28 (90.3) Invasive lobular carcinoma2 (2.4)0 (0) Others7 (8.2)0 (0) Multiplicity  0.063yes19 (22.6)12 (40.0) no65 (77.4)18 (60.0) Lymphovascular invasion  0.161yes33 (39.3)17 (54.8) no51 (60.7)14 (45.2) Nuclear grade  0.317Low10 (11.9)1 (3.3) Intermediate27 (32.1)14 (46.7) High47 (56.0)15 (24.2) Pathologic T stage (matching variable)  0.154T17 (8.2)6 (19.4) T229 (34.1)15 (48.4) T331 (36.5)4 (12.9) T418 (21.2)6 (19.4) Pathologic N stage (matching variable)  0.494N036 (42.4)13 (41.9) N123 (27.1)13 (41.9) N216 (18.8)4 (12.9) N310 (11.8)1 (3.2) Estrogen receptor  0.608positive49 (57.7)15 (48.4) negative36 (42.4)16 (51.6) Progesterone receptor  0.291positive40 (47.1)10 (32.3) negative45 (52.9)21 (67.7) HER2 status  0.345amplification29 (34.1)10 (32.3) not amplification56 (65.9)21 (67.7) Clinical T-stage (matching variable)  0.897cT12 (2.4)1 (3.2) cT231 (36.5)12 (38.7) cT346 (54.1)16 (51.6) cT46 (7.1)2 (6.5) Clinical N stage (matching variable)  0.947cN03 (3.5)1 (3.2) cN120 (23.5)10 (32.3) cN236 (42.4)10 (32.3) cN326 (30.6)10 (32.3) Response (matching variable)  1.000Partial response64 (75.3)27 (29.7) Stable disease21 (24.7)4 (12.9) 

Citation Format: Ryu JM, Lee JE, Kim SW, Yu J, Rayzah M, Lee SK, Mansoor A, Bae SY, Park S, Paik H-J, Kim I, Bang SI, Jeon BJ, Mun G-H, Pyon J-K. Oncologic outcomes of immediate breast reconstruction after neoadjuvant chemotherapy in breast cancer patients: A matched case control study [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 P3-14-12.

Glycerol-3-phosphate acyltransferase-1 upregulation by O-GlcNAcylation of Sp1 protects against hypoxia-induced mouse embryonic stem cell apoptosis via mTOR activation

Oxygen signaling is critical for stem cell regulation, and oxidative stress-induced stem cell apoptosis decreases the efficiency of stem cell therapy. Hypoxia activates O-linked β-N-acetyl glucosaminylation (O-GlcNAcylation) of stem cells, which contributes to regulation of cellular metabolism, as well as cell fate. Our study investigated the role of O-GlcNAcylation via glucosamine in the protection of hypoxia-induced apoptosis of mouse embryonic stem cells (mESCs). Hypoxia increased mESCs apoptosis in a time-dependent manner. Moreover, hypoxia also slightly increased the O-GlcNAc level. Glucosamine treatment further enhanced the O-GlcNAc level and prevented hypoxia-induced mESC apoptosis, which was suppressed by O-GlcNAc transferase inhibitors. In addition, hypoxia regulated several lipid metabolic enzymes, whereas glucosamine increased expression of glycerol-3-phosphate acyltransferase-1 (GPAT1), a lipid metabolic enzyme producing lysophosphatidic acid (LPA). In addition, glucosamine-increased O-GlcNAcylation of Sp1, which subsequently leads to Sp1 nuclear translocation and GPAT1 expression. Silencing of GPAT1 by gpat1 siRNA transfection reduced glucosamine-mediated anti-apoptosis in mESCs and reduced mammalian target of rapamycin (mTOR) phosphorylation. Indeed, LPA prevented mESCs from undergoing hypoxia-induced apoptosis and increased phosphorylation of mTOR and its substrates (S6K1 and 4EBP1). Moreover, mTOR inactivation by rapamycin (mTOR inhibitor) increased pro-apoptotic proteins expressions and mESC apoptosis. Furthermore, transplantation of non-targeting siRNA and glucosamine-treated mESCs increased cell survival and inhibited flap necrosis in mouse skin flap model. Conversely, silencing of GPAT1 expression reversed those glucosamine effects. In conclusion, enhancing O-GlcNAcylation of Sp1 by glucosamine stimulates GPAT1 expression, which leads to inhibition of hypoxia-induced mESC apoptosis via mTOR activation.

Abstract P3-01-08: Sentinel lymph node biopsy alone after neoadjuvant chemotherapy in patients with cytologically proven node-positive breast cancer

Background

The purpose of this study was to identify the feasibility and accuracy of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) in patients with axillary lymph node (ALN) metastasis at diagnosis.

Methods

This is a retrospective study of 332 patients who were diagnosed with invasive breast cancer and ALN metastasis and treated with NAC followed by curative surgery at Samsung Medical Center between January 2007 and December 2013. Patients were classified into five groups according to surgical procedure for the ALNs and pathologic results; group 1, patients with negative SLN status and no further dissection was performed; group 2, patients with negative SLN status undergoing further axillary lymph node dissection (ALND); group 3, patients with positive or undetected SLNs undergoing further ALND; group 4, patients without residual axillary metastasis undergoing complete ALND; and group 5, patients with pathologic nodal positive disease undergoing ALND.

Results

Sentinel lymph nodes identification rate after NAC was 99.1% and false negative rate was 24.1%. The median number of retrieved SLNs was 4 (range, 1–10). There was no difference in the overall survival among the groups (p=0.06). There was no significant difference in the disease-free survival rate between the SLNB only and complete ALN dissection groups who revealed a pathologic complete node response (79.6% versus 80.5%) and the rate of axillary recurrence demonstrated no significant differences among the groups. (p=0.225) There was a statistical difference of recurrence between group 1 versus 2, and group 1 versus 4 in hormone receptor-negative patients. (p=0.027)

Conclusion

SLNB after NAC in breast cancer patients with initial ALN metastasis may help identify downstaging to negative nodal status and thereby reduce the surgical morbidity by avoiding standard ALN dissection.

Citation Format: Park S, Ryu JM, Paik H-J, Yi HW, Bae SY, Lee SK, Kil WH, Kim SW, Lee JE, Nam SJ. Sentinel lymph node biopsy alone after neoadjuvant chemotherapy in patients with cytologically proven node-positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-08.

Abstract P1-11-01: Depression and anxiety after adjuvant ovarian function suppression in premenopausal breast cancer patients

Purpose

The results of the Suppression of Ovarian Function Trial (SOFT) and the Tamoxifen and Exemestane Trial (TEXT) showed that ovarian function suppression (OFS) in premenopausal early breast cancer patients improves disease control. However, mood swings after OFS is one of the chief complaints to make patients stop undergoing endocrine therapy. Studies about complications of OFS in breast cancer patients are not established well. We designed this randomized controlled trial to evaluate psychological functioning of patients after undergoing adjuvant OFS by goserelin.

Patients and Methods

We randomly assigned 64 premenopausal women with hormone receptor positive early breast cancer to the tamoxifen or tamoxifen plus goserelin group for a period of 1 year. Participants were screened for depression and generalized anxiety disorder using Hamilton Rating Scale for Depression (HAMD), Hamilton Rating Scale for Anxiety (HAM-A), Anxiety Sensitivity Index (ASI) and Albany panic and phobia questionnaire (APPQ) at baseline, 6 months and 12 months. Brain-derived Neurotrophic Factor (BDNF) levels were measured, as well. The results were analyzed by using a linear mixed model and a generalized linear mixed model.

Results

Thirty two patients were distributed in each group, equally. Linear mixed-mixed model analyses revealed that, compared with HAM-A scores of each group at baseline, HAM-A scores at 12 months showed increments (p=0.0078). Among HAM-A questions, Questions for intellectual, sensory and autonomic status were scored significantly high at 12 months (p=0.0018, p=0.0132, p=0.0006). Platelet BDNF levels reported a statistically significant rise at 12 months (p=0.0006). There was no significant time-by-study group effect in all scales.

Conclusion

Compared with the patients without OFS, patients with Goserelin showed no difference in anxiety or depression scales. Thought the levels of anxiety of each group at 12 months were increased, they do not indicate medical interventions. Patients with increased levels of BDNF at 12 months are expected to have good recovery from anxious and depressive symptoms.

Citation Format: Yi HW, Nam SJ, Kim SW, Lee JE, Lee SK, Bae SY, Park S, Paik H-J, Ryu JM. Depression and anxiety after adjuvant ovarian function suppression in premenopausal breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-11-01.

Blood levels of cadmium and lead in residents near abandoned metal mine areas in Korea

We analyzed national data on blood lead levels (BLL) and blood cadmium levels (BCL) in residents living near 38 abandoned metal mining areas (n = 5,682, 18-96 years old) in Korea that were collected by the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM) from 2008 to 2011. The geometric mean BCL and BLL were 1.60 μg/L (95 % CI = 1.57-1.62 μg/L) and 2.87 μg/dL (95 % CI = 2.84-2.90 μg/dL), respectively, notably higher than levels in the general population in Korea and other countries. We found significantly higher BLL and BCL levels in people living within 2 km of an abandoned metal mine (n = 3,165, BCL = 1.87 μg/L, BLL = 2.91 μg/dL) compared to people living more than 2 km away (n = 2,517, BCL = 1.31 μg/L, BLL = 2.82 μg/dL; P < 0.0001) and to the general population values reported in the literature.

Prenatal exposure to PM₁₀ and NO₂ and children's neurodevelopment from birth to 24 months of age: mothers and Children's Environmental Health (MOCEH) study

INTRODUCTION

Previous studies have suggested adverse effects of maternal exposure to air pollution on neurodevelopment in early childhood.

OBJECTIVES

We aimed to investigate the association between prenatal exposure to particulates of less than 10 μm in diameter (PM10) and nitrogen dioxide (NO2) and neurodevelopment in children during the first 24 months of their lives.

METHODS

The MOCEH study is a prospective birth cohort study in South Korea. Average exposure levels to PM10 and NO2 during the entire pregnancy were estimated using the inverse distance weighting (IDW) method. A total of 520 mother-child pairs who completed neurodevelopmental assessments using the Korean Bayley Scale of Infant Development II (K-BSID-II) more than once at ages of 6, 12 and 24 months were included. Mental developmental index (MDI) and psychomotor developmental index (PDI) from the K-BSID-II were used as outcome variables.

RESULTS

There were negative associations between maternal exposure to PM10 and MDI (β=-2.83; p=0.003) and PDI (β=-3.00; p=0.002) throughout the first 24 months of life as determined by the generalized estimating equation (GEE) model. Maternal NO2 exposure was related with impairment of psychomotor development (β=-1.30; p=0.05) but not with cognitive function (β=-0.84; p=0.20). In a multiple linear regression model, there were significant effects of prenatal air pollution exposure on MDI (PM10: β=-4.60; p<0.001, NO2: β=-3.12; p<0.001) and PDI (PM10: β=-7.24; p<0.001, NO2: β=-3.01; p<0.001) at 6 months, but no significant association was found at 12 and 24 months of age.

CONCLUSIONS

The findings suggest that exposure to air pollution may result in delayed neurodevelopment in early childhood.

Netrin-1 protects hypoxia-induced mitochondrial apoptosis through HSP27 expression via DCC- and integrin α6β4-dependent Akt, GSK-3β, and HSF-1 in mesenchymal stem cells

Netrin (Ntn) has the potential to be successfully applied as an anti-apoptotic agent with a high affinity for tissue, for therapeutic strategies of umbilical cord blood-derived mesenchymal stem cells (UCB-MSC), although the mechanism by which Ntn-1 protects hypoxic injury has yet to be identified. Therefore, the present study examined the effect of Ntn-1 on hypoxia-induced UCB-MSC apoptosis, as well as the potential underlying mechanisms of its protective effect. Hypoxia (72 h) reduced cell viability (MTT reduction, and [³H]-thymidine incorporation) and cell number, and induced apoptosis (annexin and/or PI positive), which were reversed by Ntn-1 (10 ng/ml). Moreover, Ntn-1 decreased the increase of hypoxia-induced Bax, cleaved caspase-9, and -3, but blocked the decrease of hypoxia-reduced Bcl-2. Next, in order to examine the Ntn-1-related signaling cascade in the protection of hypoxic injury, we analyzed six Ntn receptors in UCB-MSC. We identified deleted in colorectal cancer (DCC) and integrin (IN) α6β4, except uncoordinated family member (UNC) 5A–C, and neogenin. Among them, IN α6β4 only was detected in lipid raft fractions. In addition, Ntn-1 induced the dissociation of DCC and APPL-1 complex, thereby stimulating the formation of APPL-1 and Akt2 complex. Ntn-1 also reversed the hypoxia-induced decrease of Akt and glycogen synthase kinase 3β (GSK-3β) phosphorylation, which is involved in heat shock factor-1 (HSF-1) expression. Ntn-1-induced phospho-Akt and -GSK-3β were inhibited by DCC function-blocking antibody, IN a6b4 function-blocking antibody, and the Akt inhibitor. Hypoxia and/or Ntn-1 stimulated heat shock protein (HSP)27 expression, which was blocked by HSF-1-specific small interfering RNA (siRNA). Furthermore, HSP27-specific siRNA reversed the Ntn-1-induced increase of phospho-Akt. Additionally, HSP27-specific siRNA attenuated the Ntn-1-reduced loss of mitochondrial membrane injury via the inhibition of cytochrome c (cyt c) release and formation of cyt c and HSP27 complex. Moreover, the inhibition of each signaling protein attenuated Ntn-1-induced blockage of apoptosis. In conclusion, Ntn-1-induced HSP27 protected hypoxic injury-related UCB-MSC apoptosis through DCC- and IN α6β4-dependent Akt, GSK-3β, and HSF-1 signaling pathways.

Interaction between PGE2 and EGF receptor through MAPKs in mouse embryonic stem cell proliferation

Identifying the small molecules that permit precise regulation of embryonic stem (ES) cell proliferation should further support our understanding of the underlying molecular mechanisms of self renewal. In the present study, we showed that PGE(2) increased [(3)H]-thymidine incorporation in a time and dose dependent manner. In addition, PGE(2) increased the expression of cell cycle regulatory proteins, the percentage of cells in S phase and the total number of cells. PGE(2) obviously increased E-type prostaglandin (EP) receptor 1 mRNA expression level compare to 2, 3, 4 subtypes. EP1 antagonist also blocked PGE(2)-induced cell cycle regulatory protein expression and thymidine incorporation. PGE(2) caused phosphorylation of protein kinase C, Src, epidermal growth factor (EGF) receptor, phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation, and p44/42 mitogen-activated protein kinase (MAPK), which were blocked by each inhibitors. In conclusion, PGE(2)-stimulated proliferation is mediated by MAPK via EP1 receptor-dependent PKC and EGF receptor-dependent PI3K/Akt signaling pathways in mouse ES cells.

Effects of peripheral benzodiazepine receptor ligands on proliferation and differentiation of human mesenchymal stem cells

The peripheral benzodiazepine receptor (PBR) has been known to have many functions such as a role in cell proliferation, cell differentiation, steroidogenesis, calcium flow, cellular respiration, cellular immunity, malignancy, and apoptosis. However, the presence of PBR has not been examined in mesenchymal stem cells. In this study, we demonstrated the expression of PBR in human bone marrow stromal cells (hBMSCs) and human adipose stromal cells (hATSCs) by RT-PCR and immunocytochemistry. To determine the roles of PBR in cellular functions of human mesenchymal stem cells (hMSCs), effects of diazepam, PK11195, and Ro5-4864 were examined. Adipose differentiation of hMSCs was decreased by high concentration of PBR ligands (50 microM), whereas it was increased by low concentrations of PBR ligands (<10 microM). PBR ligands showed a biphasic effect on glycerol-3-phosphate dehydrogenase (GPDH) activity. High concentration of PBR ligands (from 25 to 75 microM) inhibited proliferation of hMSCs. However, clonazepam, which does not have an affinity to PBR, did not affect adipose differentiation and proliferation of hMSCs. The PBR ligands did not induce cell death in hMSCs. PK11195 (50 microM) and Ro5-5864 (50 microM) induced cell cycle arrest in the G(2)/M phase. These results indicate that PBR ligands play roles in adipose differentiation and proliferation of hMSCs.

Insulin sensitivity is inversely correlated with plasma intact parathyroid hormone level

Abnormal glucose metabolism and a high prevalence of diabetes have been reported in patients with primary and secondary hyperparathyroidism. We hypothesize that plasma intact parathyroid hormone (iPTH) level is a determinant of either insulin sensitivity or beta-cell function. The study included 52 normotensive, healthy subjects with glucose tolerance. Insulin sensitivity and beta-cell function were assessed using a hyperglycemic clamp. Fasting plasma iPTH was determined. The relationships between its level and insulin sensitivity index and beta-cell function were examined. Insulin sensitivity index was inversely correlated with plasma iPTH level (r2 = .104, P = .020). The first phase insulin response was positively correlated with plasma iPTH level (r2 = .098, P = .023), but no correlation existed with the second phase insulin response. After adjusting for age, gender, ethnicity, and waist-to-hip ratio, plasma iPTH level was an independent determinant of insulin sensitivity index (P = .019). However, no independent relationship between plasma iPTH level and beta-cell function (the first phase and second phase insulin response) was found. In normotensive, glucose-tolerant, and healthy subjects, plasma iPTH level accounts for 10.4% of the variation in insulin sensitivity index. For each pg/mL increment in plasma iPTH level, there is a decrease of 0.247 micromol/L/m2/min/pmol/L in insulin sensitivity index. Although the molecular basis of this relationship is not clear, our results indicate that plasma iPTH level is inversely correlated with insulin sensitivity index.

The I27L amino acid polymorphism of hepatic nuclear factor-1alpha is associated with insulin resistance

Mutations of the hepatic nuclear factor-1alpha (HNF-1alpha) gene have been found in patients with maturity-onset diabetes of the young. We examined the relation between the I27L polymorphism of HNF-1alpha and insulin sensitivity and beta-cell function assessed by a hyperglycemic clamp. This study included 52 healthy glucose-tolerant and normotensive subjects (age, 19-40 yr; body mass index, 17.58-35.61 kg/m2; waist/hip ratio, 0.65-1.03). We identified 19 LL subjects, 24 IL, and 9 II subjects. No difference was noted in the demographic features among the three genotypes. The LL group had the highest postchallenge insulin levels at 30 and 90 min (P = 0.038 and P = 0.015, respectively) and also the highest insulin area under curve (P = 0.009) among the three genotypes. The LL group was more insulin resistant than the IL and II groups (P = 0.042 for insulin sensitivity index). After adjusting for age, gender, obesity, and ethnicity, the I27L polymorphism was an independent determinant of the insulin sensitivity index (P = 0.001). However, it had no impact on either the first or second phase insulin response. Therefore, we conclude that the I27L polymorphism is associated with insulin resistance, but not beta-cell function. The mechanism of this association is unclear, but HNF-1alpha may play a role in regulating hepatic glucose metabolism.

Increased bioavailability of propranolol in rats by retaining thermally gelling liquid suppositories in the rectum

Mucoadhesive liquid suppositories were prepared by adding mucoadhesive polymers (0.6%) to a formulation of thermally gelling suppositories that contained poloxamer 407 (15%), poloxamer 188 (15%) and propranolol HCl (2%). Hydroxypropylcellulose (HPC), polyvinylpyrrolidone (PVP), carbopol, polycarbophil and sodium alginate were examined as mucoadhesive polymers. The characteristics of the suppositories differed depending on the choice of mucoadhesive polymer. For example, the gelation temperature was between 30 and 36 degrees C, the mucoadhesive force was between 430 and 5800 dyne/cm2, the apparent first-order release rate constant in phosphate buffer, pH 6.8, was between 0.399 and 0.271 h-1, the migration distance of the suppository in the rectum 4 h after administration was between 1 and 5 cm, and the bioavailability of propranolol was between 60.9 and 84.7%. Rectal bioavailability increased as the mucoadhesive force increased (r=0.984, p<0.0005), and the migration distance decreased (r=-0.951, p<0.005). No relationship was found between the bioavailability and the gelation temperature, drug release or irritation of the rectal mucosal membrane by the suppository. Therefore, retaining propranolol at the dosed site in the rectum by the addition of appropriate mucoadhesives to the formulation of liquid suppositories appears to be a very important factor in avoiding first-pass hepatic elimination and thereby increasing the bioavailability of the drug. Among the mucoadhesive polymers examined, sodium alginate and polycarbophil exhibited the largest mucoadhesive force and the smallest intrarectal migration resulting in the largest bioavailability of propranolol (84.7 and 82.3%, respectively). In contrast to other polymers, sodium alginate alone caused no irritation of the rectal mucosal membrane. Thus, poloxamer liquid suppositories containing sodium alginate appears to be a preferred formulation for drugs that are sensitive to extensive first-pass metabolism.

Biodistribution and kinetics of holmium-166-chitosan complex (DW-166HC) in rats and mice

The fate of 166Ho-chitosan complex, a radiopharmaceutical drug for cancer therapy, was determined by studying its absorption, distribution and excretion in rats and mice.

METHODS

Holmium-166-chitosan complex [0.75 mg of Ho(NO3)3 x 5H2O and 1 mg chitosan/ head] was administered intrahepatically to male rats. Radioactive concentrations in blood, urinary and fecal excretion and radioactive distribution in tissues were examined. To determine the effects of chitosan in 166Ho-chitosan complex, 166Ho alone [0.75 mg of Ho(NO3)3 x 5H2O/head] was intrahepatically administered to male rats, and radioactive concentrations in blood, urinary and fecal excretion and radioactive distribution were examined. In B16 melanoma-transplanted nude mice, radioactive distribution after intratumoral administration of 166Ho-chitosan complex [0.075 mg of Ho(NO3)3 x 5H2O and 0.10 mg chitosan/head] was investigated also.

RESULTS

After administration of 166Ho-chitosan complex, the radioactive concentrations in blood were low, and cumulative urinary and fecal excretions over a period of 0-72 hr were 0.53% and 0.54%, respectively. The radioactive concentrations in tissues and the whole-body autoradiography images showed that most of the administered radioactivity was localized at the administration site, and only slight radioactivity was detected from the liver, spleen, lungs and bones. On the other hand, results of intrahepatic administration of 166Ho alone showed high radioactive concentrations in the blood, and the whole-body autoradiographs showed that the administered radioactivity was distributed in many organs and tissues. These results strongly suggest that 166Ho is retained at the administration site only when it forms a chelate complex with chitosan. Autoradiographs after intratumoral administration of 166Ho-chitosan complex showed that radioactivity was localized at the site of administration without distribution to the other organs and tissues.

CONCLUSION

Administered 166Ho-chitosan complex is retained at the administration site after either intrahepatic or intratumoral administration to rats or tumor-transplanted nude mice.

Safety, tolerability and pharmacokinetics of the new long-acting quinolone DW-116 after single and multiple dosing in healthy subjects

The safety, tolerability and pharmacokinetics of DW-116, a new fluoroquinolone with a broad antibacterial spectrum, were evaluated in healthy male subjects after administration of single oral doses of 100, 200, 300 and 800 mg and after administration of multiple oral doses of 300 or 400 mg, respectively, for 7 days. DW-116 was well tolerated. Gastrointestinal symptoms and skin reactions were noted and considered to be possibly related to DW-116. The geometric means of the maximum plasma concentrations (Cmax) linearly increased with the dose administered from 1.19 mg/L to 8.73 mg/L after single dose administration. At steady state, the geometric mean minimum and maximum plasma concentrations were 2.14 and 5.65 mg/L, respectively, after the multiple 300 mg dose and 2.73 and 8.00 mg/L, respectively, for the multiple 400 mg dose. Tmax varied between 1 and 5 h. The terminal half-life ranged from 11.37 to 24.89 h. The geometric mean renal clearance was approximately 30 mL/min. Approximately 45% of the dose was excreted unchanged in urine within 60 h. There was no clinically relevant deviation from dose proportionality. The changes in steady-state pharmacokinetic parameters when DW-116 was taken before a high-fat breakfast were not clinically relevant. In conclusion, DW-116 was safe in this study, the first administration to human subjects. Its pharmacokinetics indicate that once-daily dosing may be possible.

Toxicities of 166Holmium-chitosan in mice

166Holmium (166Ho) is a radionuclide of rare earth chemical and is known to have antitumor activity. Several chemicals were complexed with 166Ho to facilitate the transport of this radionuclide to the site of action. In this study, 166Ho was complexed to chitosan (Chit) which decreases the distribution of Ho into other tissues when applied intrahepatically. To investigate the single dose toxicity, mice were administered intravenously with 1 mCi/kg body weight of 166Ho-Chit (DW-166HC), Chit or nothing. Organ weights, hematological and histopathological studies were performed in 6 animals per group at 1, 3 and 14 days after administration. In 166Ho-Chit treated animals, a slight decrease of erythrocyte number was observed at day 14 and increases of relative liver and lung weights were found at day 3. Although marked multiple necrotic foci in the white pulp and depletion of marginal zone in the spleen were noted at day 1, these findings were decreased in severity and fully recovered at day 3 and day 14, respectively. Slightly decreased kidney weights were observed both in Chit and in 166Ho-Chit treated groups without histological alterations. Thus it is suggested that most effects of 166Ho-Chit observed at an early stage after administration are limited to rapidly dividing cells and reversible within 14 days.