Abstract P1-01-06: Targeting the SphK1/S1P/S1PR1 axis that connects obesity, chronic inflammation, and breast cancer metastasis

Introduction: Obesity with associated inflammation is now recognized as a risk factor for breast cancer and increased incidence of distant metastases. However, the link between obesity and breast cancer progression remains poorly understood. There is growing evidence that sphingosine-1-phosphate (S1P), a pleiotropic bioactive sphingolipid metabolite enriched both in blood and lymphatic fluid is involved in inflammation, obesity, and breast cancer progression. Our hypothesis is that obesity increases levels of S1P in both tumor and its microenvironment, which play a role in obesity-induced inflammation and breast cancer metastasis. The aim of this study is to test this hypothesis in in vitro and in vivo as well as patient settings.

Methods: Levels of sphingolipids including S1P in serum from breast cancer patients were quantified. Orthotopically-implanted E0771 syngeneic breast cancer and MMTV-PyMT transgenic breast cancer mouse models were used. Mice were fed with normal or high-fat diet (HFD). FTY720 was administered orally (1 mg/kg/day). To examine pre-metastatic niche formation, a mouse model utilizing tail vein injection of E0771 cells was used. In this model, mice were treated with conditioned media from E0771 breast cancer cells overexpressing SphK1 (K1-CM) or that from E0771 cells cultured with the vector control (CT-CM), prior to tail vein injections of naive E0771 cells. S1P levels were determined by electrospray ionization-tandem mass spectrometry.

Results: We found that obesity significantly increased S1P levels in serum from breast cancer patients. In animal breast cancer models, HFD upregulated expression of sphingosine kinase 1 (SphK1), the enzyme that produces S1P, and its receptor S1PR1 in syngeneic and spontaneous breast tumors. HFD also significantly increased S1P in breast tumors and in the tumor interstitial fluid, which is a component of the tumor microenvironment and bathes cancer cells in the tumor. Targeting the SphK1/S1P/S1PR1 axis with FTY720/fingolimod attenuated obesity-induced key pro-inflammatory cytokines, macrophage infiltration, and tumor progression. In addition, S1P produced by tumor SphK1 primed lung pre-metastatic niches, increased macrophage recruitment into the lung, and induced IL-6 and signaling pathways important for lung metastatic colonization. FTY720 suppressed HFD-induced lung IL-6 and macrophage infiltration as well as S1P-mediated signaling pathways and dramatically reduced formation of metastatic foci. In tumor bearing mice, FTY720 also suppressed obesity-related inflammation, S1P signaling, pulmonary metastasis, and prolonged survival.

Conclusion: Our results highlight a critical role for circulating S1P produced by tumor and the SphK1/S1P/S1PR1 axis in obesity-related inflammation, metastatic niche formation and breast cancer metastasis and suggest that targeting the SphK1/S1P/S1PR1 axis would be a useful therapeutic for obesity promoted metastatic breast cancer.

Citation Format: Nagahashi M, Yamada A, Aoyagi T, Huang W-C, Terracina KP, Hait N, Allegood JC, Tsuchida J, Nakajima M, Katsuta E, Milstien S, Wakai T, Spiegel S, Takabe K. Targeting the SphK1/S1P/S1PR1 axis that connects obesity, chronic inflammation, and breast cancer metastasis [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 P1-01-06.

Abstract P1-01-21: The levels of sphingosine-1-phosphate and its related gene expressions in breast cancer patients

Background: The bioactive lipid mediator sphingosine-1-phosphate (S1P) has emerged as a key regulatory molecule in cancer progression. We previously demonstrated that S1P is a crucial mediator of breast cancer-induced angiogenesis and lymphangiogenesis, and promote metastasis. Although increasing number of in vitro and in vivo experiments have revealed the importance of S1P in cancer progression, the data on the roles of S1P in human patients are very limited. The aim of this study is to reveal the clinical relevance of S1P in the interaction between cancer and the tumor microenvironment by examining the levels of the sphingolipids in patient breast cancer tissue samples.

Material and Method: Breast cancer tissue, peri-tumor tissue, and normal breast tissue were collected from 20 breast cancer patients immediately after surgery that were conducted from November 2015 to February 2016 at Niigata University Medical and Dental Hospital. Sphingolipids were quantified by liquid chromatography–electrospray ionization tandem mass spectrometry. The expression level of each enzyme-encoding gene involved in S1P production was evaluated by retrieving RNA sequencing and gene expression quantification data from breast cancer tissues (n = 112) and paired normal breast tissues (n = 112) using the Genomics Data Commons (GDC) data portal of the The Cancer Genome Atlas (TCGA) cohort. Gene expression levels were derived using normalization methods provided in the DESeq2 package.

Result: The levels of the sphingolipids sphingosine (Sph), dihydro-sphingosine (DHSph), S1P, and dihydro-S1P (DHS1P) were successfully determined in breast cancer, peri-tumor, and normal breast tissues from all of the 20 patients. As expected, a one-way ANOVA revealed that S1P levels were significantly different depending on the location (F(2,57) = 7.029, P = 0.002). The Tukey post hoc test revealed that S1P levels in tumors were significantly higher than those in normal breast tissue and peri-tumor tissue (P < 0.05). Similarly, Sph and DHSph levels in tumors were significantly higher than in normal breast tissue and peri-tumor tissue. Both SPHK1 and SPHK2 gene expression levels in breast cancer tissue were higher than those in normal breast tissue. Interestingly, expression of some of the S1P-related genes; S1PR3, ABCC1, SGPL1, and ORMDL2, were significantly increased in the breast cancer tissue compared to normal breast tissue. On the other hand, there was significantly decreased expression of the S1P-related genes S1PR1, S1PR2, ABCG2, SPNS2, SGPP1 and ORMDL3, in breast cancer tissue compared to normal breast tissue.

Conclusion: We demonstrated that the major source of S1P is the tumor tissue, and not the peri-tumor tissue despite the fact that angiogenesis and lymphangiogenesis are occurring more in the peri-tumor area, which implicate that S1P may have further role inside the tumor. Our results indicated the complexity of S1P signaling in human cancer than expected based on the results in vivo experiments.

Citation Format: Tsuchida J, Nagahashi M, Nakajima M, Takabe K, Wakai T. The levels of sphingosine-1-phosphate and its related gene expressions in breast cancer patients [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 P1-01-21.

Orbital-anisotropic electronic structure in the nonmagnetic state of BaFe2(As1-xP x )2 superconductors

High-temperature superconductivity in iron-pnictides/chalcogenides arises in balance with several electronic and lattice instabilities. Beside the antiferromagnetic order, the orbital anisotropy between Fe 3d xz and 3d yz occurs near the orthorhombic structural transition in several parent compounds. However, the extent of the survival of orbital anisotropy against the ion-substitution remains to be established. Here we report the composition (x) and temperature (T) dependences of the orbital anisotropy in the electronic structure of a BaFe2(As1-xP x )2 system by using angle-resolved photoemission spectroscopy. In the low-x regime, the orbital anisotropy starts to evolve on cooling from high temperatures above both antiferromagnetic and orthorhombic transitions. By increasing x, it is gradually suppressed and survives in the optimally doped regime. We find that the in-plane orbital anisotropy persists in a large area of the nonmagnetic phase, including the superconducting dome. These results suggest that the rotational symmetry-broken electronic state acts as the stage for superconductivity in BaFe2(As1-xP x )2.

Ipsilateral hemiparesis in ischemic stroke patients

OBJECTIVES

To investigate clinical characteristics of ipsilateral hemiparesis in ischemic stroke patients.

MATERIALS AND METHODS

Patients with acute ischemic stroke were prospectively examined. Ipsilateral hemiparesis was defined as hemiparesis ipsilateral to recent stroke lesions. Patients with ipsilateral hemiparesis were examined with functional neuroimaging studies including transcranial magnetic stimulation (TMS) and functional MRI.

RESULTS

Of 8360 patients, ipsilateral hemiparesis was detected in 14 patients (0.17%, mean age 71±6 years, eight men). Lesions responsible for the recent strokes were located in the frontal cortex in three patients, corona radiata in seven, internal capsule in one, and pons in three. These lesions were located along the typical route of the corticospinal tract in all but one patient. Thirteen patients also had a past history of stroke contralateral to the recent lesions; 12 of these had motor deficits contralateral to past stroke lesions. During TMS, ipsilateral magnetic evoked potentials were evoked in two of seven patients and contralateral potentials were evoked in all seven. Functional MRI activated cerebral hemispheres ipsilaterally in eight of nine patients and contralaterally in all nine.

CONCLUSIONS

Most patients with ipsilateral hemiparesis had a past history of stroke contralateral to the recent one, resulting in motor deficits contralateral to the earlier lesions. Moreover, functional neuroimaging findings indicated an active crossed corticospinal tract in all of the examined patients. Both findings suggest the contribution of the uncrossed corticospinal tract contralateral to stroke lesions as a post-stroke compensatory motor system.

Enhanced superconductivity in surface-electron-doped iron pnictide Ba(Fe1.94Co0.06)2As2

The superconducting transition temperature (T_C) in a FeSe monolayer on SrTiO₃ is enhanced up to 100 K (refs ,,,). High T_C is also found in bulk iron chalcogenides with similar electronic structure to that of monolayer FeSe, which suggests that higher T_C may be achieved through electron doping, pushing the Fermi surface (FS) topology towards leaving only electron pockets. Such an observation, however, has been limited to chalcogenides, and is in contrast to the iron pnictides, for which the maximum T_C is achieved with both hole and electron pockets forming considerable FS nesting instability. Here, we report angle-resolved photoemission characterization revealing a monotonic increase of T_C from 24 to 41.5 K upon surface doping on optimally doped Ba(Fe_1-xCo_x)₂As₂. The doping changes the overall FS topology towards that of chalcogenides through a rigid downward band shift. Our findings suggest that higher electron doping and concomitant changes in FS topology are favourable conditions for the superconductivity, not only for iron chalcogenides, but also for iron pnictides.

Molecular genetic analysis of 30 families with Joubert syndrome

Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.

Can multilocus heterozygosity reveal inbreeding depression?

Inbred lines of fish have been widely exploited as model organisms to determine the effect of inbreeding, which is often closely related to fitness such as endurance and productivity compared to morphological traits. Until now, much is unknown about the effects of inbreeding to fish. In the present study, inbred lines of guppies were used to examine the inbreeding effect on morphological traits corresponding to genotype variation. Two strains, called AY and NA1, were selected from the closed culture system. Both strains showed different levels of inbreeding coefficients when compared to microsatellite markers. The AY strain was less inbred as compared to NA1 strain. However, correlation between the standard lengths with multilocus heterozygosity (MLH) at the individual level was observed in the AY, but not in the NA1 strain. This indicated that highly inbred animals have higher similarity in morphological traits as compared to less inbred ones. The inbreeding process showed the importance of heterozygosity, even in laboratory-reared animals. This experiment illustrated the effects of inbreeding towards morphological and genetic changes. ?

CMAP decrement as a potential diagnostic marker for ALS

OBJECTIVE

We previously reported that decrement of compound muscle action potential (CMAP) by repetitive nerve stimulation (RNS) was greater in the median nerves than in the ulnar nerves of patients with amyotrophic lateral sclerosis (ALS). The aim of this study was to evaluate whether CMAP decrement by RNS is a feasible marker for the differentiation of ALS from other diseases.

MATERIALS & METHODS

We performed RNS in the median and ulnar nerves of 51 patients with ALS and 40 patients with other diseases.

RESULTS

The CMAP decrement was significantly greater in the median nerves of patients with ALS, compared to the disease control patients. In the median nerves of patients with ALS, CMAP decrement was significantly greater in the cervical region-onset group than in the other region-onset group.

CONCLUSIONS

The finding of CMAP decrement in the median nerves can be useful for differentiating ALS patients with cervical region onset from other controls with active neuropathic diseases.

Effects of introducing isotropic artificial defects on the superconducting properties of differently doped Ba-122 based single crystals

The effects of isotropic artifical defects, introduced via fast neutron (E > 0.1 MeV) irradiation, on the physical properties of differently (Co, P and K) doped BaFe2As2 superconducting single crystals were studied. The Co- and P-doped single crystals showed a second peak in the magnetization curve (fishtail effect) in the pristine state. Significant variations in the radiation-induced changes in the critical current density Jc were observed in the different types of crystal, while the irreversibility fields did not change remarkably. The highest Jcs were obtained for the K-doped crystal, exceeding 3 × 10(10) Am(-2) (T = 5 K, B = 4 T) and remaining above 8.5 × 10(9) Am(-2) at 30 K and 1 T. The pinning force was analyzed to compare the pinning mechanisms of the individual samples. While distinct differences were found before the irradiation, the same pinning behavior prevails afterwards. The pinning efficiency η = Jc/Jd was estimated from the depairing current density Jd. η was similar in all irradiated crystals and comparable to the value in neutron irradiated cuprates, suggesting that the huge critical current densities measured in the irradiated K-doped crystal are due to its large depairing current density, making this compound the most promising for applications.