[The role of expression of monocarboxylates of the first and fourth types (MCT1, MCT4) by tumor and stromal cells of prostate cancer in determining the prognosis and the efficiency of definitive treatment].

AIM: A search for new methods for diagnosing clinically significant prostate cancer is of importance due to the insufficient accuracy of modern methods in detecting aggressive tumors. One of the promising opportunities for the early diagnosis of clinically significant prostate cancer is the assessment of the glycolytic profile of the tumor by determining the expression of monocarboxylates (MCT) types 1 and 4 in tumor cells, as well as in adjacent stromal cells. MATERIALS AND METHODS: An analysis of patients of who underwent radical prostatectomy at the Institute of Urology and Reproductive Health of Sechenov University from 2015 to 2017 was carried out. The patients with histologically confirmed prostate adenocarcinoma were included in the study. Among them, the presence or absence of biochemical recurrence during the first year was studied. An immunohistochemical (IHC) study of postoperative specimen was performed to determine the expression of MCT1 and MCT4 by tumor and stromal cells. The correlation between the intensity of their expression and the risk of biochemical recurrence and the tumor characteristics was evaluated. RESULTS: High membrane expression of MCT1 directly correlated with high stromal expression of MCT4 (r=0.314, p<0.003). A significant direct correlation was found between the predominance of stromal expression of MCT4 over membrane expression and biochemical recurrence (r=0.403, p<0.001), as well as a high ISUP group (4 and 5) (r=0.294, p=0.005). CONCLUSIONS: Determination of the level of expression of type 1 and 4 monocarboxylate transporters in adenocarcinoma cells and tumor stromal cells can become an effective tool for risk stratification, and may also predict the biological behaviors of the prostate cancer and the efficiency of definitive treatment.

Coexpression of MCT1 and MCT4 in ALK-positive Anaplastic Large Cell Lymphoma: Diagnostic and Therapeutic Implications.

In solid tumors, glycolytic cancer or stromal cells export lactates through monocarboxylate transporter (MCT) 4, while oxidative cancer or stromal cells take up lactates as metabolic fuels or signaling molecules through MCT1. CD147 acts as a chaperone of MCT1 or MCT4. Unlike solid tumors, malignant lymphomas have a peculiar tumor microenvironment. To investigate the metabolic phenotype of malignant lymphoma associated with lactate transport, we analyzed immunohistochemical expressions of MCT1, MCT4, and CD147 in 247 cases of various malignant lymphomas. Surprisingly, both MCT1 and MCT4 were diffusely expressed on tumor cell membranes in all cases (11/11, 100%) of anaplastic lymphoma kinase (ALK) (+) anaplastic large cell lymphoma (ALCL). In contrast, only MCT1 was diffusely expressed in tumor cells of ALK(-) ALCL, as well as in B-cell, natural killer/T-cell, T-cell, and classic Hodgkin lymphomas. In these lymphomas, MCT4 expression was mostly localized to adjacent stromal cells. The pattern of diffuse membranous MCT1 and partial MCT4 expressions in tumor cells was observed in 1 case each of peripheral T-cell lymphoma (1/15, 6.7%) and multiple myeloma (1/34, 2.9%). CD147 was diffusely expressed in all types of lymphoma tumor and/or stromal cells. In conclusion, ALK(+) ALCL has a unique metabolism showing high coexpression of MCT1 and MCT4 in tumor cells. Because only ALK(+) ALCL overexpresses MCT4, immunostaining for MCT4 together with ALK is very useful for differential diagnosis from ALK(-) ALCL or peripheral T-cell lymphoma. Moreover, dual targeting against MCT1 and MCT4 would be an appropriate therapeutic approach for ALK(+) ALCL.

Development of a Clinically Relevant Reporter for Chimeric Antigen Receptor T-cell Expansion, Trafficking, and Toxicity.

Although chimeric antigen receptor T (CART)-cell therapy has been successful in treating certain hematologic malignancies, wider adoption of CART-cell therapy is limited because of minimal activity in solid tumors and development of life-threatening toxicities, including cytokine release syndrome (CRS). There is a lack of a robust, clinically relevant imaging platform to monitor in vivo expansion and trafficking to tumor sites. To address this, we utilized the sodium iodide symporter (NIS) as a platform to image and track CART cells. We engineered CD19-directed and B-cell maturation antigen (BCMA)-directed CART cells to express NIS (NIS+CART19 and NIS+BCMA-CART, respectively) and tested the sensitivity of 18F-TFB-PET to detect trafficking and expansion in systemic and localized tumor models and in a CART-cell toxicity model. NIS+CART19 and NIS+BCMA-CART cells were generated through dual transduction with two vectors and demonstrated exclusive 125I uptake in vitro. 18F-TFB-PET detected NIS+CART cells in vivo to a sensitivity level of 40,000 cells. 18F-TFB-PET confirmed NIS+BCMA-CART-cell trafficking to the tumor sites in localized and systemic tumor models. In a xenograft model for CART-cell toxicity, 18F-TFB-PET revealed significant systemic uptake, correlating with CART-cell in vivo expansion, cytokine production, and development of CRS-associated clinical symptoms. NIS provides a sensitive, clinically applicable platform for CART-cell imaging with PET scan. 18F-TFB-PET detected CART-cell trafficking to tumor sites and in vivo expansion, correlating with the development of clinical and laboratory markers of CRS. These studies demonstrate a noninvasive, clinically relevant method to assess CART-cell functions in vivo.

Identification of the HT-29 cell line as a model for investigating MCT1 transporters in sigmoid colon adenocarcinoma.

MCT1 transporters play a crucial role in the symbiotic relationship between humans and their colonic microbiome by facilitating the transport of bacteria-derived short chain fatty acids. Expression of colonic MCT1 transporters, localized in surface epithelial cells, is regulated by luminal butyrate levels. However, MCT1 also transports lactate and can be used by cancer cells to facilitate anaerobic glycolysis. Using immunolocalization techniques, this study investigated whether changes in MCT1 during cancer varied between different colonic regions. Whilst MCT1 abundance did not significantly change in transverse colon adenocarcinoma (P = 0.363, N = 6, paired T-Test), there was an increase in MCT1 in sigmoid colon adenocarcinoma (P = 0.010, N = 21, paired T-test). Using RT-PCR and western blotting, three human intestinal cell lines were tested for their suitability as a MCT1 cancer cell model. Experiments with Caco-2 cells confirmed that they modelled normal cells, with MCT1 only expressed after exposure to butyrate. In contrast, MCT1 was expressed in the absence of butyrate in both HCT-8 and HT-29 cell lines, with consistently high levels of MCT1 protein being present in HT-29 cells. Furthermore, butyrate treatment of HT-29 cells significantly decreased both MCT1 protein abundance (P < 0.001, N = 4, unpaired T-test) and glycosylation of its' chaperone protein, CD147 (P < 0.001, N = 4, unpaired T-test). These data suggest that (i) MCT1 transporter abundance increases in sigmoid colon adenocarcinoma, and (ii) HT-29 cells are an appropriate cell model with which to investigate MCT1 function in this disease.

Child Head Circumference and Placental MFSD2a Expression Are Associated to the Level of MFSD2a in Maternal Blood During Pregnancy.

Gestational diabetes mellitus (GDM) is a world-wide health challenge, which prevalence is expected to increase in parallel to the epidemic of obesity. Children born from GDM mothers have lower levels of docosahexaenoic acid (DHA) in cord blood, which might influence their neurodevelopment. Recently, the membrane transporter Major Family Super Domain 2a (MFSD2a) was associated with the selective transportation of DHA as lysophospholipids. The expression of the DHA membrane transporter MFSD2a is lower in GDM placentas, which could affect materno-fetal DHA transport. Humans with homozygous inactivating mutations in the MFSD2a gene present severe microcephaly and intellectual impairments. Herein, we intended to identify early blood biomarkers that may be of use during pregnancy to monitor the offspring development and the adequate nutritional interventions, such as nutritional supplementation, that may be selected to improve it. We evaluated MFSD2a expression in maternal blood at the third trimester of pregnancy, and its potential relationship with the expression of placental MFSD2a at delivery and child outcomes. Three groups of pregnant women were recruited: 25 controls, 23 GDM with dietary treatment, and 20 GDM with insulin treatment. Maternal and neonatal anthropometric and biochemical parameters were evaluated. MFSD2a was analyzed in placenta, blood and serum. MFSD2a protein expression in maternal blood was significantly lower in GDM groups and correlated with placental MFSD2a and Z-score neonatal head circumference during the first 6 months of life. The cord/maternal serum ratio of DHA, a solid indicator of materno-fetal DHA transport, was reduced in GDM groups and correlated with MFSD2a in maternal blood at the third trimester and in placenta at delivery. This indicates that altered MFSD2a levels in maternal blood during pregnancy might influence placental nutrient transport and fetal neurodevelopment. Furthermore, MFSD2a levels in maternal blood on the third trimester were inversely correlated to DHA in maternal serum lyso-PL. Thus, the level of MFSD2a in maternal blood could be used as a potential biomarker for the early detection of disturbances of MFSD2a expression during pregnancy and the subsequent consequences for the neurodevelopment of the child, as well as it may help to choose the optimal treatment approach for the affected subjects.

Uptake of [¹8F]tetrafluoroborate in MCF-7 Breast Cancer Cells is Induced after Stimulation of the Sodium Iodide Symporter.

BACKGROUND: The human sodium iodide symporter (hNIS) has been the most important target in nuclear medicine regarding thyroid-related diseases. Although hNIS-expression can also be determined in extra-thyroidal tumors, imaging hNIS with positron emission tomography has not been exploited clinically. OBJECTIVE: Here, we evaluated the accumulation of the novel hNIS-substrate [18F]tetrafluoroborate ([18F]TFB) in the endogenously hNIS-expressing breast cancer cell line MCF-7 after an improved radiosynthesis and pharmacological stimulation. METHODS: [18F]TFB was prepared under mild reaction conditions (40°C, 25 min) and its uptake properties were investigated in MCF-7 cells pretreated with a combination of all-trans retinoic acid plus methasone-derivatives and compared to the clinically established tracers [131I]iodide and [99mTc]pertechnetate. Specificity of the tracer accumulation was assessed by inhibition experiments using NaBF4, KSO3F, KI and KIO3. RESULTS: [18F]TFB was obtained with a radiochemical yield of 24.0 ± 6.6 % (n = 17) within 40 min after high pressure liquid chromatography-separation and with 26.8 ± 6.2 % (n = 13) within 45 min after adapting the procedure on a synthesis module using higher starting activities (> 10 GBq). After pharmacological treatment, a 4-fold increase in hNIS-expression on the MCF-7 cell surface was achieved, resulting in a significantly higher [18F]TFB uptake into the cells (up to 58-fold) as compared to control experiments. Inhibition studies using various NIS-substrates confirmed the specificity of [18F]TFB for hNIS. CONCLUSION: [18F]TFB was shown to be a promising hNIS-substrate in our model using the human MCF-7 breast cancer cell line mandating in vivo evaluations in xenografted studies and in patients.

Integrated profiling identifies SLC5A6 and MFAP2 as novel diagnostic and prognostic biomarkers in gastric cancer patients.

Gastric cancer (GC) is one of the leading causes of malignancy­associated mortality worldwide. However, the underlying molecular mechanisms of GC are unclear and the prognosis of GC is poor. Therefore, it is important and urgent to explore the underlying mechanisms and screen for novel diagnostic and prognostic biomarkers, as well as therapeutic targets. In the current study, scale­free gene co­expression networks were constructed using weighted gene co­expression network analysis, the potential associations between gene sets and clinical features were investigated, and the hub genes were identified. The gene expression profiles of GSE38749 were downloaded from the Gene Expression Omnibus database. RNA­seq and clinical data for GC from The Cancer Genome Atlas were utilized for verification. Furthermore, the expression of candidate biomarkers in gastric tissues was investigated. Survival analysis was performed using Kaplan­Meier and log­rank test. The predictive role of candidate biomarkers in GC was evaluated using a receiver operator characteristic (ROC) curve. Gene Ontology, gene set enrichment analysis and gene set variation analysis methods were used to interpret the function of candidate biomarkers in GC. A total of 29 modules were identified via the average linkage hierarchical clustering. A significant module consisting of 48 genes associated with clinical traits was found; three genes with high connectivity in the clinical significant module were identified as hub genes. Among them, SLC5A6 and microfibril­associated protein 2 (MFAP2) were negatively associated with the overall survival, and their expression was elevated in GC compared with non­tumor tissues. Additionally, ROC curves indicated that SLC5A6 and MFAP2 showed a good diagnostic power in discriminating cancerous from normal tissues. SLC5A6 and MFAP2 were identified as novel diagnostic and prognostic biomarkers in GC patients; both of these genes were first reported here in connection with GC and deserved further research.

KCC2 membrane diffusion tunes neuronal chloride homeostasis.

Neuronal Cl- homeostasis is regulated by the activity of two cation chloride co-transporters (CCCs), the K+-Cl- cotransporter KCC2 and the Na+-K+-Cl- cotransporter NKCC1, which are primarily extruding and importing chloride in neurons, respectively. Several neurological and psychiatric disorders including epilepsy, neuropathic pain, schizophrenia and autism are associated with altered neuronal chloride (Cl-) homeostasis. A current view is that the accumulation of intracellular Cl- in neurons as a result of KCC2 down-regulation and/or NKCC1 up-regulation may weaken inhibitory GABA signaling and thereby promote the development of pathological activities. CCC activity is determined mainly by their level of expression in the plasma membrane. Furthermore, CCCs undergo "diffusion-trapping" in the membrane, a mechanism that is rapidly adjusted by activity-dependent post-translational modifications i.e. phosphorylation/dephosphorylation of key serine and threonine residues. This represents probably the most rapid cellular mechanism for adapting CCC function to changes in neuronal activity. Therefore, interfering with these mechanisms may help restoring Cl- homeostasis and inhibition under pathological conditions. This article is part of the special issue entitled 'Mobility and trafficking of neuronal membrane proteins'.

lncRNA SLC16A1-AS1 as a novel prognostic biomarker in non-small cell lung cancer.

Long non-coding RNAs (lncRNAs) have proved to act as crucial biomarkers in tumors. Novel biomarkers in non-small cell lung cancer (NSCLC) need to be investigated badly. To identify the differentially expressed lncRNAs between NSCLC tissue and adjacent tissue, microarray analysis was performed. lncRNA SLC16A1-AS1 was significantly less expressed in NSCLC tissue than that in adjacent tissue. Gain-of-function experiments was performed to determine the biological functions of SLC16A1-AS. In situhybridization and survival analysis were applied in lung cancer tissue samples to determine the prognostic role of SLC16A1-AS1. It was showed that SLC16A1-AS1 was remarkably downregulated in NSCLC tissues and cell lines. Functionally, SLC16A1-AS1 overexpression could inhibit the viability and proliferation of lung cancer cell, block the cell cycle and promote cell apoptosis in vitro which may result from reduced phosphorylation of rat sarcoma (RAS)/ proto-oncogene serine/threonine-protein kinase (RAF)/ mitogen-activated protein kinase kinase (MEK)/ extracellular regulated protein kinases (ERK) pathway caused by elevated expression of SLC16A1-AS1. Clinical sample analysis showed that SLC16A1-AS1 had a favorable impact on the overall survival and progression-free survival of patients with NSCLC. Our results suggested that SLC16A1-AS1 may act as a potential biomarker for patients with NSCLC.

Identification of Susceptibility Genes to Allergic Rhinitis by Gene Expression Data Sets.

As an extremely prevalent disease worldwide, allergic rhinitis (AR) is a condition characterized by chronic inflammation of the nasal mucosa. To identify the finer molecular mechanisms associated with the AR susceptibility genes, differentially expressed genes (DEGs) in AR were investigated. The DEG expression and clinical data of the GSE19187 data set were used for weighted gene co-expression network analysis (WGCNA). After the modules related to AR had been screened, the genes in the module were extracted for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, whereby the genes enriched in the KEGG pathway were regarded as the pathway-genes. The DEGs in patients with AR were subsequently screened out from GSE19187, and the sensitive genes were identified in GSE18574 in connection with the allergen challenge. Two kinds of genes were compared with the pathway-genes in order to screen the AR susceptibility genes. Receiver operating characteristic (ROC) curve was plotted to evaluate the capability of the susceptibility genes to distinguish the AR state. Based on the WGCNA in the GSE19187 data set, 10 co-expression network modules were identified. The correlation analyses revealed that the yellow module was positively correlated with the disease state of AR. A total of 89 genes were found to be involved in the enrichment of the yellow module pathway. Four genes (CST1, SH2D1B, DPP4, and SLC5A5) were upregulated in AR and sensitive to allergen challenge, whose potentials were further confirmed by ROC curve. Taken together, CST1, SH2D1B, DPP4, and SLC5A5 are susceptibility genes to AR.

Decreased Blood Level of MFSD2a as a Potential Biomarker of Alzheimer's Disease.

The protein Major Facilitator Superfamily Domain containing 2A (MFSD2a) was recently described as the primary carrier for docosahexaenoic acid (DHA) into the brain. Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by lower DHA levels in blood lipids. The aim of this study was to investigate the expression of MFSD2a in the whole blood and brain as a potential biomarker of AD. Three groups were established: 38 healthy controls, 48 subjects with moderate AD (GDS4), and 47 with severe AD (GDS6). We analyzed postmortem brain samples from the hippocampus of 11 healthy controls and 11 severe AD patients. Fatty acid (FA) was determined in serum and brain by gas chromatography. Blood and brain MFSD2a protein expression was analyzed by Western blotting. We found a significant and progressive decline of MFSD2a levels in blood of AD patients (Control 0.83 ± 0.13, GDS4 0.72 ± 0.09, GDS6 0.48 ± 0.05*, p ˂ 0.01). We also corroborated a significant reduction of DHA and other n-3 long-chain polyunsaturated FA in serum of AD. No differences were found in MFSD2a expression or FA levels in brain of controls and AD subjects. MFSD2A carrier was analyzed in AD patients for the first time and the level of MFSD2a in the whole blood could be a potential biomarker of this disease.

Quantifying secondary transport at single-molecule resolution.

Secondary active transporters, which are vital for a multitude of physiological processes, use the energy of electrochemical ion gradients to power substrate transport across cell membranes1,2. Efforts to investigate their mechanisms of action have been hampered by their slow transport rates and the inherent limitations of ensemble methods. Here we quantify the activity of individual MhsT transporters, which are representative of the neurotransmitter:sodium symporter family of secondary transporters3, by imaging the transport of individual substrate molecules across lipid bilayers at both single- and multi-turnover resolution. We show that MhsT is active only when physiologically oriented and that the rate-limiting step of the transport cycle varies with the nature of the transported substrate. These findings are consistent with an extracellular allosteric substrate-binding site that modulates the rate-limiting aspects of the transport mechanism4,5, including the rate at which the transporter returns to an outward-facing state after the transported substrate is released.

K+-Cl- cotransporter 1 (KCC1): a housekeeping membrane protein that plays key supplemental roles in hematopoietic and cancer cells.

During the 1970s, a Na+-independent, ouabain-insensitive, N-ethylmaleimide-stimulated K+-Cl- cotransport mechanism was identified in red blood cells for the first time and in a variety of cell types afterward. During and just after the mid-1990s, three closely related isoforms were shown to account for this mechanism. They were termed K+-Cl- cotransporter 1 (KCC1), KCC3, and KCC4 according to the nomenclature of Gillen et al. (1996) who had been the first research group to uncover the molecular identity of a KCC, that is, of KCC1 in rabbit kidney. Since then, KCC1 has been found to be the most widely distributed KCC isoform and considered to act as a housekeeping membrane protein. It has perhaps received less attention than the other isoforms for this reason, but as will be discussed in the following review, there is probably more to KCC1 than meets the eye. In particular, the so-called housekeeping gene also appears to play crucial and specific roles in normal as well as pathological hematopoietic and in cancer cells.

[18F]Tetrafluoroborate ([18F]TFB) and its analogs for PET imaging of the sodium/iodide symporter.

Sodium/iodide symporter (NIS)-mediated iodide uptake in thyroid follicular cells is the basis of clinical utilization of radioiodines. The cloning of the NIS gene enabled applications of NIS as a reporter gene in both preclinical and translational research. Non-invasive NIS imaging with radioactive iodides and iodide analogs has gained much interest in recent years for evaluation of thyroid cancer and NIS reporter expression. Although radioiodines and [99mTc]pertechnetate ([99mTc]TcO4-) have been utilized in positron emission tomography (PET) and single photon emission computed tomography (SPECT), they may suffer from limitations of availability, undesirable decay properties or imaging sensitivity (SPECT versus PET). Recently, [18F]tetrafluoroborate ([18F]TFB or [18F]BF4-) and other fluorine-18 labeled iodide analogs have emerged as a promising iodide analog for PET imaging. These fluorine-18 labeled probes have practical radiosyntheses and biochemical properties that allow them to closely mimic iodide transport by NIS in thyroid, as well as in other NIS-expressing tissues. Unlike radioiodides, they do not undergo organification in thyroid cells, which results in an advantage of relatively lower uptake in normal thyroid tissue. Initial clinical trials of [18F]TFB have been completed in healthy human subjects and thyroid cancer patients. The excellent imaging properties of [18F]TFB for evaluation of NIS-expressing tissues indicate its bright future in PET NIS imaging. This review focuses on the recent evolution of [18F]TFB and other iodide analogs and their potential value in research and clinical practice.

KCC2-GABAA pathway correlates with the analgesic effect of electro-acupuncture in CCI rats.

Potassium-chloride cotransporter 2 (KCC2) has been indicated to serve a crucial role during chronic neuropathic pain (NP). Following the emergence of NP, γ­aminobutyric acid (GABA) A receptor­mediated signaling may be further impaired by the changes of KCC2 chloride anion gradient. In the present study, the authors investigate the effect of electro-acupuncture (EA) on the behavior and the expression of KCC2 and GABAA receptor γ2 subunit in the spinal cord of chronic constriction injury (CCI) model rats. A total of 60 adult male Sprague­Dawley rats were divided into four groups: Normal group, sham­CCI group, CCI group and CCI+EA group. The effect of EA was assessed via the values of mechanical withdrawal threshold and thermal withdrawal latency, which were significantly improved upon stimulation of the ST­36 and GB­34 acupoints. In addition, a marked reduction in both the mRNA and protein levels of KCC2 and GABAA receptor γ2 subunit was observed in the spinal cord following loose ligation of the sciatic nerve. The reductions in KCC2 and GABAA receptor γ2 subunit expression were reversed by EA treatment. These results support the notion that KCC2 and GABAA receptor γ2 subunit contribute to NP following peripheral nerve injury and extend the understanding of the analgesic effects of EA on NP.

Synthesis and evaluation of 18F-hexafluorophosphate as a novel PET probe for imaging of sodium/iodide symporter in a murine C6-glioma tumor model.

Noninvasive imaging of iodide uptake via the sodium/iodide symporter (NIS) has received great interest for evaluation of thyroid cancer and reporter imaging of NIS-expressing viral therapies. In this study, we investigate 18F-labeled hexafluorophosphate (HFP or PF6-) as a high-affinity iodide analog for NIS imaging. 18F-HFP was synthesized by radiofluorination of phosphorus pentafluoride·N-methylpyrrolidine complex and evaluated in human NIS (hNIS)-expressing C6 glioma cells and a C6 glioma xenograft mouse model. 18F-HFP was obtained in radiochemical yield of 10 ±â€¯5%, radiochemical purity of >96% and specific radioactivity of 604 ±â€¯18 MBq/µmol. Specific uptake of 18F-HFP and high affinity of 19F-HFP were observed in hNIS+ C6-glioma cells. PET imaging showed robust uptake of 18F-HFP in NIS-expressing tissues (thyroid, stomach, and hNIS+ C6 glioma xenografts), and the uptake of 18F-HFP was blocked by NaClO4 pretreatment. Specific accumulation in hNIS-expressing xenograft (hNIS+) was observed relative to isogenic control tumor (hNIS-). Clearance of 18F-HFP was predominantly through renal excretion. The biodistribution showed consistent results with PET imaging. Minimal bone uptake was observed over 2 h period post-injection, indicating excellent in vivo stability of 18F-HFP. Although improvement in specific radioactivity is desirable, the results indicate that 18F-HFP is a promising candidate radiotracer for further evaluation for NIS imaging.

SLC14A1: a novel target for human urothelial cancer

Urinary bladder cancer is the second commonly diagnosed genitourinary malignancy. Previously, bio-molecular alterations have been observed within certain locations such as chromosome 9, retinoblastoma gene and fibroblast growth factor receptor-3. Solute carrier family 14 member 1 (SLC14A1) gene encodes the type-B urea transporter (UT-B) which facilitates the passive movement of urea across cell membrane, and has recently been related with human malignancies, especially for bladder cancer. Herein, we discussed the SLC14A1 gene and UT-B protein properties, aiming to elucidate the expression behavior of SLC14A1 in human bladder cancer. Furthermore, by reviewing some well-established theories regarding the carcinogenesis of bladder cancer, including several genome wide association researches, we have bridged the mechanisms of cancer development with the aberrant expression of SLC14A1. In conclusion, the altered expression of SLC14A1 gene in human urothelial cancer may implicate its significance as a novel target for research (AU)

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Oligopeptide Transport in Rat Lung Alveolar Epithelial Cells is Mediated by Pept2.

PURPOSE: Studies were conducted in primary cultured rat alveolar epithelial cell monolayers to characterize peptide transporter expression and function. METHODS: Freshly isolated rat lung alveolar epithelial cells were purified and cultured on permeable support with and without keratinocyte growth factor (KGF). Messenger RNA and protein expression of Pept1 and Pept2 in alveolar epithelial type I- and type II-like cell monolayers (±KGF, resp.) were examined by RT-PCR and Western blotting. 3H-Glycyl-sarcosine (3H-gly-sar) transmonolayer flux and intracellular accumulation were evaluated in both cell types. RESULTS: RT-PCR showed expression of Pept2, but not Pept1, mRNA in both cell types. Western blot analysis revealed presence of Pept2 protein in type II-like cells, and less in type I-like cells. Bi-directional transmonolayer 3H-gly-sar flux lacked asymmetry in transport in both types of cells. Uptake of 3H-gly-sar from apical fluid of type II-like cells was 7-fold greater than that from basolateral fluid, while no significant differences were observed from apical vs. basolateral fluid of type I-like cells. CONCLUSIONS: This study confirms the absence of Pept1 from rat lung alveolar epithelium in vitro. Functional Pept2 expression in type II-like cell monolayers suggests its involvement in oligopeptide lung disposition, and offers rationale for therapeutic development of di/tripeptides, peptidomimetics employing pulmonary drug delivery.

Low-frequency stimulation of the primary focus retards positive transfer of secondary focus.

Positive transfer of secondary focus (PTS) refers to new epileptogenesis outside the primary focus and is minimally controlled by existing treatments. Low-frequency stimulation (LFS) has benefits on the onset of epilepsy and epileptogenesis. However, it's unclear whether LFS can retard the PTS in epilepsy. Here we found that PTS at both contralateral amygdala and ipsilateral hippocampus were promoted after the primary focus was fully kindled in rat kindling model. The promotion of PTS at the mirror focus started when the primary kindling acquisition reached focal seizures. LFS retarded the promotion of PTS when it was applied at the primary focus during its kindling acquisition, while it only slightly retarded the promotion of PTS when applied after generalized seizures. Meanwhile, we found the expression of potassium chloride cotransporter 2 (KCC2) decreased during PTS, and LFS reversed this. Further, the decreased expression of KCC2 was verified in patients with PTS. These findings suggest that LFS may be a potential therapeutic approach for PTS in epilepsy.

Berberine-induced Inactivation of Signal Transducer and Activator of Transcription 5 Signaling Promotes Male-specific Expression of a Bile Acid Uptake Transporter.

Sodium-taurocholate co-transporting polypeptide (Ntcp/NTCP) is the major uptake transporter of bile salts in mouse and human livers. In certain diseases, including endotoxemia, cholestasis, diabetes, and hepatocarcinoma, Ntcp/NTCP expression is markedly reduced, which interferes with enterohepatic circulation of bile salts, impairing the absorption of lipophilic compounds. Therefore, normal Ntcp/NTCP expression in the liver is physiologically important. Berberine is an herbal medicine used historically to improve liver function and has recently been shown to repress STAT signaling. However, berberine effects on Ntcp/NTCP expression are unknown, prompting use to investigate this possible connection. Our results showed that berberine dose-dependently increased Ntcp expression in male mouse liver and decreased taurocholic acid levels in serum but increased them in the liver. In mouse and human hepatoma cells, berberine induced Ntcp/NTCP mRNA and protein expression and increased cellular uptake of [3H] taurocholate. Mechanistically, berberine decreased nuclear protein levels of phospho-JAK2 and phospho-STAT5, thus disrupting the JAK2-STAT5 signaling. Moreover, berberine stimulated luciferase reporter expression from the mouse Ntcp promoter when one putative STAT5 response element (RE) (-1137 bp) was deleted and from the human NTCP promoter when three putative STAT5REs (-2898, -2164, and -691 bp) were deleted. Chromatin immunoprecipitation demonstrated that berberine decreased binding of phospho-STAT5 protein to the-2164 and -691 bp STAT5REs in the human NTCP promoter. In summary, berberine-disrupted STAT5 signaling promoted mouse and human Ntcp/NTCP expression, resulting in enhanced bile acid uptake. Therefore, berberine may be a therapeutic candidate compound for maintaining bile acid homeostasis.