Acquired hydrocephalus following hypoxic ischemic encephalopathy without intraventricular hemorrhage: A case report

The most common cause of acquired hydrocephalus in infants is hemorrhage, most often as a consequence of prematurity. Other important causes include neoplasm and infection, usually bacterial meningitis. Hypoxic ischemic encephalopathy (HIE) in term infants usually results in secondary microcephaly. We report an infant with severe HIE at birth treated by therapeutic hypothermia who developed progressive acquired hydrocephalus over 2 months, although no cause of the hydrocephalus was identified. Although hydrocephalus, even intraventricular hemorrhage, is uncommon in term infants with HIE, careful follow-up of the head circumference is important, even if no findings indicating possible causes of hydrocephalus, such as hemorrhage, are detected on ultrasound or magnetic resonance imaging.

Dual-Task Training Combining Cognitive Tasks and Occupations among Japanese Community-Dwelling Older Adults: A Pilot Study

This study investigated whether dual tasks comprising cognitive tasks and occupations related to daily living can improve the mental and cognitive function of Japanese community-dwelling older adults. Participants included 30 older adults, equally divided into intervention and control groups. The outcome measures were memory, attention, depression, and health-related quality of life. No adverse effects of the intervention were observed in any participant in the intervention group. Logical memory I, logical memory II, and Center for Epidemiologic Studies Depression Scale scores showed a significant interaction. Dual tasks combining cognitive tasks and occupations may help improve delayed recall and alleviate depression. A novel attempt to integrate cognitive stimulation and activities valued by individuals may help mediate age-related cognitive function decline and reduce depressive symptoms in community-dwelling older adults.

Serial evaluation of cardiac allograft vasculopathy after heart transplantation by dual-modality intravascular ultrasound and optical coherence tomography

Background

Cardiac allograft vasculopathy is a combination of the development of de novo plaque and the progression of donor-transmitted plaque.

Purpose

This study aimed to evaluate the development of de novo plaque and the progression of donor-transmitted plaque within 12-month after heart transplantation (HTx) using serial intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The association between inflammatory cytokines and plaque progression was also examined.

Methods

We prospectively enrolled 40 recipients to conduct serial three-vessel IVUS and OCT analysis at 8-week and 12-month after HTx. De novo plaque was defined as having maximum intimal thickness (MIT) ≥0.5 mm at 12-month in the absence of donor-transmitted plaques (MIT ≥0.5 mm at 8-week). Serum cytokines were screened with a bead-based multiplex assay.

Results

A total of 13 de novo plaques (fibrous, n=10; fibroatheroma, n=3) were detected in eight recipients. Serum interleukin (IL)-31 at 8-week was associated with the development of de novo plaques (p=0.009). A total of 31 donor-transmitted plaques (fibrous, n=12; fibroatheroma, n=11; fibrocalcific, n=8) were detected in 17 recipients. Multiple regression analysis revealed that fibrous (p=0.026) and fibroatheroma (p=0.012) observed at 8-week were significantly associated with subsequent plaque progression within 12-month after HTx. ΔPlaque burden was significant higher in de novo plaque than donor-transmitted plaque (38.8% [29.6–41.2] versus 8.7% [1.3–13.6], p<0.001). The prevalence of macrophage accumulation was lower in de novo plaque than in donor-transmitted plaque (8% versus 52%, p=0.006). Serum IL-31 at 8-week was correlated with the progression of donor-transmitted plaque as well as de novo plaque (r=0.663, p=0.029) although other cytokines like IL-1β, IL-6, IL-17, and tissue necrotic factor alpha were not.

Conclusions

In de novo plaques, fibrous plaque was the most common and macrophage accumulation was rarely observed. In donor-transmitted plaque, fibrous and fibroatheroma were independent predictor for the subsequent plaque progression. Serum interleukin-31 surge at subacute phase may play pathogenic role in cardiac allograft vasculopathy.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grants-in-Aid for Scientific Research (KAKENHI)

Progression-dependent transport heterogeneity of breast cancer liver metastases as a factor in therapeutic resistance

Metastatic disease is a major cause of mortality in cancer patients. While many drug delivery strategies for anticancer therapeutics have been developed in preclinical studies of primary tumors, the drug delivery properties of metastatic tumors have not been sufficiently investigated. Therapeutic efficacy hinges on efficient drug permeation into the tumor microenvironment, which is known to be heterogeneous thus potentially making drug permeation heterogeneous, also. In this study, we have identified that 4 T1 liver metastases, treated with pegylated liposomal doxorubicin, have unfavorable and heterogeneous transport of doxorubicin. Our drug extravasation results differ greatly from analogous studies with 4 T1 tumors growing in the primary site. A probabilistic tumor population model was developed to estimate drug permeation efficiency and drug kinetics of liver metastases by integrating the transport and structural properties of tumors and delivered drugs. The results demonstrate significant heterogeneity in metastases with regard to transport properties of doxorubicin within the same animal model, and even within the same organ. These results also suggest that the degree of heterogeneity depends on the stage of tumor progression and that differences in transport properties can define transport-based tumor phenotypes. These findings may have valuable clinical implications by illustrating that therapeutic agents can permeate and eliminate metastases of "less resistant" transport phenotypes, while sparing tumors with more "resistant" transport properties. We anticipate that these results could challenge the current paradigm of drug delivery into metastases, highlight potential caveats for therapies that may alter tumor perfusion, and deepen our understanding of the emergence of drug transport-based therapeutic resistance.

Comprehensive molecular exploration identified promoter DNA methylation of the CRBP1 gene as a determinant of radiation sensitivity in rectal cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (NCRT) for advanced rectal cancer (RC) is a well-evidenced therapy; however, some RC patients have no therapeutic response. Patient selection for NCRT so that non-responsive patients are excluded has been subjective. To date, no molecular markers indicating radiation sensitivity have been reported.

METHODS

We irradiated six colorectal cancer (CRC) cell lines and identified HCT116 cells as radiation-sensitive and HCT15 and DLD-1 cells as radiation resistant. Using a microarray, we selected candidate radiation sensitivity marker genes by choosing genes whose expression was consistent with a radiation-resistant or sensitive cell phenotype.

RESULTS

Among candidate genes, cellular retinol binding protein 1 (CRBP1) was of particular interest because it was not only induced in HCT116 cells by tentative 10 Gy radiation treatments, but also its expression was increased in HCT116-derived radiation-resistant cells vs parental cells. Forced expression of CRBP1 decreased the viability of both HCT15 and DLD-1 cells in response to radiation therapy. We also confirmed that CRBP1 was epigenetically silenced by hypermethylation of its promoter DNA, and that the quantitative methylation value of CRBP1 significantly correlated with histological response in RC patients with NCRT (P=0.031).

CONCLUSIONS

Our study identified CRBP1 as a radiation-sensitive predictor in RC.

The clinical significance of cysteine dioxygenase type 1 methylation in Barrett esophagus adenocarcinoma

Methylation of cysteine dioxygenase type 1 (CDO1) gene, a tumor suppressor gene, has been studied in various cancers; however, there is no information regarding Barrett esophagus cancer. In this study, the clinical significance of CDO1 methylation in Barrett esophagus adenocarcinoma (BEA) was clarified. CDO1 gene promoter methylation was analyzed for DNA from the patient's specimens using quantitative methylation-specific polymerase chain reaction. Thirty-eight BEA patients who underwent resection were identified between 2000 and 2014. Hypermethylation of CDO1 gene was demonstrated to be frequently recognized even at early stage in BEA by quantitative methylation-specific polymerase chain reaction. In BEA, there is a robust prognostic difference between stage I and stage II/III/IV with regard to 5-year relapse-free survival (P = 0.0016) and 5-year overall survival (P = 0.0024), and the tumor size separated by 7 cm was also a prognostic factor. There was significant difference in CDO1 gene methylation according to the tumor size (P = 0.036). BEA patients with CDO1 gene methylation were shown marginally significantly poorer prognosis (P = 0.054) than otherwise patients. In conclusion, higher CDO1 gene methylation was seen in BEA at earlier stage than in squamous cell carcinoma, and it may account for aggressive phenotype of BEA.

The question of whether or not to perform therapeutic hypothermia: A case of neonatal spinal cord injury

Neonatal spinal cord injury is an extremely rare perinatal complication that often occurs concurrently with hypoxic ischemic encephalopathy (HIE), further complicating diagnosis of spinal cord injury. Although therapeutic hypothermia for moderate to severe HIE is widely recommended in Japan, it is difficult to determine whether it satisfies the neurological findings-related entry criteria in some patients.We describe a female infant with neonatal spinal cord injury after forceps delivery, who underwent therapeutic hypothermia upon diagnosis of HIE. The Apgar scores were 5 at 1 min, 6 at 5 min, and not recorded at 10 min. Blood gas analysis of her umbilical artery was not performed. Since respiratory failure, hypotonia and the absence of primitive reflexes were found at 2 hours after birth, she was initially diagnosed with moderate HIE and underwent a therapeutic hypothermia. Magnetic resonance imaging after therapeutic hypothermia revealed the spinal cord was narrowed from the lower medulla oblongata to the upper cervical cord. Thus she was diagnosed with an upper spinal cord injury at that time.Some patients with neonatal spinal cord injuries satisfy the criteria for therapeutic hypothermia. When neonates with asphyxia present with prolonged respiratory failure and hypotonia, spinal cord injury should be considered in the differential diagnosis. Thus, an early MRI is vital for the diagnosis of spinal cord injury.

Robots in Human Environments: Basic Autonomous Capabilities

This article discusses the basic capabilities needed to enable robots to operate in human-populated environments for accomplishing both autonomous tasks and human-guided tasks. These capabilities are key to many new emerging robotic applications in service, construction, field, underwater, and space. An important characteristic of these robots is the “assistance” ability they can bring to humans in performing various physical tasks. To interact with humans and operate in their environments, these robots must be provided with the functionality of mobility and manipulation. The article presents developments of models, strategies, and algorithms concerned with a number of autonomous capabilities that are essential for robot operations in human environments. These capabilities include: integrated mobility and manipulation, cooperative skills between multiple robots, interaction ability with humans, and efficient techniques for real-time modification of collision-free path. These capabilities are demonstrated on two holonomic mobile platforms designed and built at Stanford University in collaboration with Oak Ridge National Laboratories and Nomadic Technologies.

Abstract P3-06-07: Changes in the tumor microenvironment develop acquired resistance to pegylated liposomal doxorubicin in breast cancer mouse model

Pegylated liposomal doxorubicin (PLD) is one of the most widely used nanotherapeutics for the treatment of advanced/metastatic breast cancer. PLD accumulates in tumors utilizing so-called the enhanced permeation and retention (EPR) effect. Nevertheless, therapeutic efficacy and long term survival remain variable due to the development of acquired resistance. Elucidating the mechanisms of acquired resistance to PLD shall help developing new strategies to improve therapeutic outcome. It has been largely overlooked that the transport of therapeutics across biological barriers can significantly affect the efficacy of cancer therapies. Previously, we showed that the transport of PLD to tumors depends both on the tumor type and organ site. This effect is controlled by the extent to which endothelial cells (ECs) are covered by the collagen type IV (Col4) in the basement membrane, which in turn is influenced by the levels of MMP-9. Here, we have developed 4T1 tumor model which develops acquired resistance to PLD and spontaneous lung metastases. Our objective is to elucidate the resistant mechanism by evaluating the changes in the transport of PLD to the sensitive and resistant/metastatic tumors.

BALB/c mice bearing 4T1 cancers were treated with PLD intravenously when tumor volumes reached a size of approximately 100-200 mm3 . Tumor volumes in all mice decreased after initial PLD injections (sensitive). However, tumors started to grow again after 20 days and didn't respond to the second/third injections (resistant). Furthermore, 13 out of 14 mice developed spontaneous lung metastases. To elucidate the mechanisms of the resistance, mice bearing sensitive or resistant tumors were sacrificed after 24 hours of PLD injection, respectively. PLD accumulation in tumors was evaluated by imaging fluorescence of doxorubicin. Immunofluorescence staining was performed to evaluate the expression of ECs, Col4, MMP-9, and efflux pump associated p-glycoprotein (P-gp) in the primary tumors, and the expression of ECs and Col4 were also evaluated in lung metastases.

PLD accumulation was significantly decreased in the resistant tumors compared to the sensitive tumors, although P-gp expression was not increased in the resistant tumors. The amount of ECs and Col4 increased in the resistant tumors. Interestingly, ECs were covered more tightly by Col4 in the resistant tumors as compared with the sensitive tumors, which could decrease the EPR effect in the tumors. MMP-9 expression decreased in the resistant tumors, suggesting less degradation of Col4 in the basement membrane. Coverage of ECs by Col4 was similar between the metastatic lung tumors and uninvolved lung tissue as well as the resistant primary tumors, indicating the EPR effect is not increased in the metastatic tumors.

In summary, ratio of ECs covered by Col4 is higher in the resistant/metastatic tumors as compared to that in the sensitive primary tumors. This structural change in the tumor microenvironment, impeding the sufficient PLD transport to the tumors after the initial PLD therapy, can be a cause of acquired resistance/development of lung metastasis. These changes should be taken into account to develop strategies for overcoming the acquired resistance and metastasis.

Citation Format: Kai M, Liu YT, Saito Y, Ferrari M, Yokoi K. Changes in the tumor microenvironment develop acquired resistance to pegylated liposomal doxorubicin in breast cancer mouse model. [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 P3-06-07.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for the Revision of the Clinical and Pathologic Staging of Small Cell Lung Cancer in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Small cell lung cancer (SCLC) is commonly classified as either limited or extensive, but the Union for International Cancer Control TNM Classification of Malignant Tumours seventh edition (2009) recommended tumor, node, and metastasis (TNM) staging based on analysis of the International Association for the Study of Lung Cancer (IASLC) database.

METHODS

Survival analyses were performed for clinically and pathologically staged patients presenting with SCLC from 1999 through 2010. Prognosis was compared in relation to the TNM seventh edition staging to serve as validation and analyzed in relation to proposed changes to the T descriptors found in the eighth edition.

RESULTS

There were 5002 patients: 4848 patients with clinical and 582 with pathological stages. Among these, 428 had both. Survival differences were confirmed for T and N categories and maintained in relation to proposed revisions to T descriptors for seventh edition TNM categories and proposed changes in the eighth edition. There were also survival differences, notably at 12 months, in patients with brain-only single-site metastasis (SSM) compared to SSM at other sites, and SSM without a pleural effusion showed a better prognosis than other patients in the M1b category.

CONCLUSION

We confirm the prognostic value of clinical and pathological TNM staging in patients with SCLC, and recommend continued usage for SCLC in relation to proposed changes to T, N, and M descriptors for NSCLC in the eighth edition. However, for M descriptors, it remains uncertain whether survival differences in patients with SSM in the brain simply reflect better treatment options rather than better survival based on anatomic extent of disease.

Abstract P6-04-21: Novel therapy of liver metastases of cancer using abraxane loaded into multi-stage nanovector

Purpose; To investigate whether the Abraxane loaded within Multi-Stage Nanovector (MSV) system (MSV-ABX) is more effective in therapy of liver metastases of breast and lung cancer as compared to Abraxane (ABX).

Experimental Design; MTT assay was performed to evaluate sensitivity of 4T1, murine breast cancer cells and 3LL, murine lung cancer cells to ABX or MSV-ABX in vitro. Experimental liver metastases were produced by intra-splenic injection of 4T1 or 3LL cells in Balb/C mice. The mice bearing liver metastases were treated with intravenous injection of (1) control (PBS), (2) ABX or (3) MSV-ABX. Then the mice were sacrificed and liver weight was measured to evaluate the therapeutic efficacy. To evaluate the biological the effects of therapeutics, we performed histological and immunohistochemical analysis of the tumor specimens. Apoptosis of 4T1 and 3LL tumor cells were evaluated by TUNEL staining, and proliferation of the tumor cells were stained using antibody to Ki67. Tumor diameter was measured in H&E stained sections.

Results; There was no significant difference in the sensitivity of 4T1 and 3LL cancer cells to ABX and MSV-ABX, in vitro. All the mice injected with 4T1 or C3LL cells developed multiple liver metastases. The liver weight was significantly lower in the mice treated with MSV-ABX as compared to those in the other groups. The tumor diameters in the liver were significantly smaller in the mice treated with MSV-ABX as compared to those in the other two groups. Immunofluorescent analysis revealed that MSV-ABX inhibited proliferation and increased apoptosis of 4T1 and 3LL tumor cells in the liver significantly more than ABX.Conclusions; These studies demonstrate that MSV-ABX is more effective than ABX in therapy of the liver metastasis of breast and colorectal cancer in our mouse models. These data can be translated into the clinic for planning novel clinical trials using MSV-ABX.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-04-21.

Abstract P4-06-13: Discovering serum biomarkers for predicting accumulation of nanotherapeutics to different tumor and organ microenvironments

Surrogate biomarkers in the circulation for the enhanced permeation and retention (EPR) effect in different tumor and organ microenvironment shall aid in selecting patients who are likely to accumulate higher amount of nanotherapeutics to tumors and thus show better response to the therapeutics. In this study, 4T1 and 3LL murine cancer cell lines, known to have similar sensitivity to pegylated liposomal doxorubicin (PLD) in vitro, were shown to accumulate significantly different quantities of PLD in vivo. PLD accumulation correlated with tumor-specific differences in therapeutic efficacy and vascular permeability, which was modulated by the extent of coverage of tumor-associated endothelial cells by basement membrane. Matrix metalloproteinase (MMP)-9 and its endogenous inhibitor, tissue inhibitor of metalloproteinase (TIMP)-1, played a pivotal role in these phenomena. Differences in vascular permeability and PLD accumulation were also organ-specific and significantly correlated with the relative ratio of MMP-9 and TIMP-1 in the systemic circulation of the tumor-bearing mice. Our findings support the further development of MMP-9 and TIMP-1 as paired serum biomarkers for predicting accumulation of PLD to tumor and the application of these biomarkers could be expanded to other types of nanotherapeutics utilizing the EPR effect for the personalization of cancer therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-06-13.

Time to first cigarette and lung cancer risk in Japan

BACKGROUND

Cigarette smoking is the major cause of lung cancer (LC). Although the time to first cigarette (TTFC) of the day is a distinct indicator of nicotine dependence, little information is available on its possible relation to LC.

PATIENTS AND METHODS

This case-control study includes a total of 1572 incident LC cases and 1572 non-cancer controls visiting for the first time the Aichi Cancer Center Hospital between 2001 and 2005. We estimated the odds ratio (OR) and 95% confidence interval (CI) for TTFC using a logistic regression model after adjustment for several potential confounders.

RESULTS

TTFC was inversely associated with the risk of LC. This association was consistent across histological subtypes of LC. For all LCs considered among ever smokers and after accurate allowance for smoking quantity and duration, besides other relevant covariates, compared with TTFC >60 min, the adjusted ORs were 1.08 (95% CI, 0.73-1.61) for TTFC of 31-60 min, 1.40 (0.98-2.01) for 6-30 min and 1.86 (1.28-2.71) for within 5 min (Ptrend, < 0.001). Statistically marginally significant heterogeneity by histological subtype was observed (Pheterogeneity, 0.002).

CONCLUSIONS

Nicotine dependence, as indicated by the TTFC, is associated with increased risk of LC and is therefore an independent marker of exposure to tobacco smoking.

YAP induces malignant mesothelioma cell proliferation by upregulating transcription of cell cycle-promoting genes

Malignant mesothelioma (MM) shows frequent inactivation of the neurofibromatosis type 2 (NF2) -tumor-suppressor gene. Recent studies have documented that the Hippo signaling pathway, a downstream cascade of Merlin (a product of NF2), has a key role in organ size control and carcinogenesis by regulating cell proliferation and apoptosis. We previously reported that MMs show overexpression of Yes-associated protein (YAP) transcriptional coactivator, the main downstream effector of the Hippo signaling pathway, which results from the inactivation of NF2, LATS2 and/or SAV1 genes (the latter two encoding core components of the mammalian Hippo pathway) or amplification of YAP itself. However, the detailed roles of YAP remain unclear, especially the target genes of YAP that enhance MM cell growth and survival. Here, we demonstrated that YAP-knockdown inhibited cell motility, invasion and anchorage-independent growth as well as cell proliferation of MM cells in vitro. We analyzed genes commonly regulated by YAP in three MM cell lines with constitutive YAP-activation, and found that the major subsets of YAP-upregulating genes encode cell cycle regulators. Among them, YAP directly induced the transcription of CCND1 and FOXM1, in cooperation with TEAD transcription factor. We also found that knockdown of CCND1 and FOXM1 suppressed MM cell proliferation, although the inhibitory effects were less evident than those of YAP knockdown. These results indicate that constitutive YAP activation in MM cells promotes cell cycle progression giving more aggressive phenotypes to MM cells.

P4-17-10: Insights into Mechanisms Involved in the Accumulation of Nanovectors within the Breast Cancer Brain Metastasis

Systemic chemotherapy for brain metastasis of breast cancer (BMBC) is considered to be inefficient. It is widely accepted in the literature that blood-brain-barrier (BBB) is responsible for clinical failures with the conventional chemotherapy. We hypothesized that nanovectors, therapeutic carriers with submicron dimensions, can be delivered to the brain tissue through a different pathway than molecular therapeutics. The objective of this study was to examine the accumulation of various intravenously injected nanovectors into the brain metastasis of breast and other cancers loci and to explore possible mechanisms involved.

Both human (MDAMB231) and mouse (4T1) breast cancer brain metastasis were evaluated. We also tested lung (3LL) and colon (CT26) originated cancers. Orthotopic brain tumors were produced either by intracarotid injection or stereotactic brain injection of cancer cells. When the animals became moribund, they were injected intravenously with one of the following nanovectors including fluorescently labeled PEGylated (100nm) and non-PEGylated (100nm, 250nm, 500nm) liposomes, disc-shape silicon particles (600, 1000nm in diameter). The accumulation of the nanovectors was compared to an unencapsulated fluorescent molecule. The accumulation of the nanovectors in the brain tumor tissue was evaluated through live animal imaging (IVIS) and immunohistochemical analysis. Immunohistochemical staining of endothelial cells and basal membrane markers was performed to determine the integrity of the tumor associated vasculature and the co-localization of the fluorescent nanovectors/molecules with tumor associated vasculature.

Interestingly, we have found that brain metastasis of different tumors (originated form breast, lung and colon cancers) possess dissimilar accumulation profiles for intravenously administered nanovectors. For example when comparing various tumor origins, 4T1 breast cancer originated brain tumors enabled the highest accumulation of the nanovectors as compared to CT26 and 3LL. On the other hand, free molecule accumulated into the 4T1 brain metastasis model to a much lower extend than in nanovector. Finally, the observed brain distribution of nanovectors corresponded well with impairment in vascular endothelium and basal membrane integrity shown in immunohistochemical analysis.

The results of our study point toward a possibility to treat specific patients with impaired BBB function with nanovector encapsulated chemotherapeutics based on the fact that their transport, accumulation and retention in the brain tissue are governed by different biological mechanisms, such as Enhanced Permeation and Retention (EPR) effect. These studies indicate that it is possible to cross the blood brain barrier, thus giving hope to patients with brain metastasis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-17-10.

Association of a polymorphism of BTN2A1 with type 2 diabetes mellitus in Japanese individuals

AIMS

We previously showed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with myocardial infarction in Japanese individuals by a genome-wide association study. Given that diabetes mellitus is an important risk factor for myocardial infarction, the association of rs6929846 of BTN2A1 with myocardial infarction might be attributable, at least in part, to its effect on susceptibility to diabetes. The purpose of this study was to examine the relation of rs6929846 of BTN2A1 to Type 2 diabetes mellitus.

METHODS

A total of 8650 Japanese individuals from two independent subject panels were examined: Panel A comprised 1141 individuals with Type 2 diabetes and 3161 control subjects and panel B comprised 1664 individuals with Type 2 diabetes and 2684 control subjects.

RESULTS

The chi-square test revealed that rs6929846 of BTN2A1 was significantly related to the prevalence of Type 2 diabetes in subject panel A (P = 0.0002) and subject panel B (P=0.006). Multivariable logistic regression analysis with adjustment for age, sex, body mass index and smoking status revealed that rs6929846 was significantly associated with Type 2 diabetes (P = 0.0006; odds ratio 1.25) in all individuals, with the T allele representing a risk factor for this condition. Multiple regression analysis with adjustment for age, sex and body mass index revealed that rs6929846 was significantly (P=0.04) related to blood glycosylated haemoglobin content in control subjects.

CONCLUSIONS

BTN2A1 may be a susceptibility gene for Type 2 diabetes in Japanese individuals.

Association of a polymorphism of BTN2A1 with hypertension in Japanese individuals

BACKGROUND

We previously showed that the C→T polymorphism (rs6929846) in butyrophilin, subfamily 2, member A1 gene (BTN2A1) was associated with myocardial infarction in Japanese individuals. Given that hypertension is a major risk factor for myocardial infarction, the association of rs6929846 of BTN2A1 with myocardial infarction might be attributable, at least in part, to its effect on susceptibility to hypertension. We have thus examined the relation of rs6929846 of BTN2A1 to hypertension in Japanese individuals.

METHODS

A total of 8,567 Japanese individuals from two independent subject panels were examined: Subject panels A and B comprised 2,317 hypertensive individuals and 1,933 controls, and 2,911 hypertensive individuals and 1,406 controls, respectively. The genotype of rs6929846 was determined by a method that combines the PCR and sequence-specific oligonucleotide probes with suspension array technology.

RESULTS

Multivariable logistic regression analysis with adjustment for covariates revealed that rs6929846 of BTN2A1 was significantly associated with hypertension in subject panel A (P = 2.6 × 10(-6); odds ratio, 1.69) and in subject panel B (P = 0.0284; odds ratio, 1.24), with the T allele representing a risk factor for hypertension. The rs6929846 was associated with systolic blood pressure (BP) in subject panels A (P = 0.0063) and B (P = 0.0115) and with diastolic BP in subject panel B (P = 0.0323), with the T allele being related to high BP.

CONCLUSIONS

BTN2A1 may be a susceptibility gene for hypertension in Japanese individuals. Determination of genotype for this polymorphism may prove informative for assessment of the genetic risk for hypertension.