Association of serum homocysteine levels with the severity and calcification of coronary atherosclerotic plaques detected by coronary CT angiography

AIM

In this study, we aim to evaluate the association of risk factors including homocysteine (Hcy) with the severity and burden of coronary atherosclerotic plaques detected by computed tomography angiography (CTA).

METHODS

Six hundred fifty-nine subjects who underwent CTA for the assessment of coronary artery disease (CAD) were studied. All the subjects enrolled had no clinical cardiovascular disease symptoms. Logistic regression showed apart from age, hypertension, smoking, triglyceride, low-density lipoprotein (LDL) cholesterol, and total bilirubin, Hcy was an independently risk factor of the severity of coronary disease. And Hcy was also found an independent predictor for the presence of calcified plaque. When the participants were divided into 4 groups according to serum Hcy quartiles (Q1-Q4 groups), both the percentage of patients with >50% stenosis and the percentage of patients with calcified plaque were higher in Q4 compared to other groups. The OR of Hcy (>15 µmol/L) for >50% stenosis was 2.212 (95% CI=1.119 to 4.375, P=0.022) and the OR for Hcy (>15 µmol/L) for calcification was 1.668 (95% CI=1.030 to 2.699, P=0.037) respectively.

CONCLUSION

Our study shows Hcy is independently associated with both the severity and calcified plaque detected by CTA. Hcy may provide additional information about CAD in the subjects without clinical symptoms.

KPT-330 has antitumour activity against non-small cell lung cancer

BACKGROUND

We investigated the biologic and pharmacologic activities of a chromosome region maintenance 1 (CRM1) inhibitor against human non-small cell lung cancer (NSCLC) cells both in vitro and in vivo.

METHODS

The in vitro and in vivo effects of a novel CRM1 inhibitor (KPT-330) for a large number of anticancer parameters were evaluated using a large panel of 11 NSCLC cell lines containing different key driver mutations. Mice bearing human NSCLC xenografts were treated with KPT-330, and tumour growth was assessed.

RESULTS

KPT-330 inhibited proliferation and induced cell cycle arrest and apoptosis-related proteins in 11 NSCLC cells lines. Moreover, the combination of KPT-330 with cisplatin synergistically enhanced the cell kill of the NSCLC cells in vitro. Human NSCLC tumours growing in immunodeficient mice were markedly inhibited by KPT-330. Also, KPT-330 was effective even against NSCLC cells with a transforming mutation of either exon 20 of EGFR, TP53, phosphatase and tensin homologue, RAS or PIK3CA, suggesting the drug might be effective against a variety of lung cancers irrespective of their driver mutation.

CONCLUSIONS

Our results support clinical testing of KPT-330 as a novel therapeutic strategy for NSCLC.

Effects of conservatively treated diseased cementum with or without EMD on in vitro cementoblast differentiation and in vivo cementum-like tissue formation of human periodontal ligament cells

OBJECTIVES

The present study aimed to evaluate the effects of conservatively treated diseased cementum on in vitro cementoblast differentiation and in vivo cementum-like tissue formation of human periodontal ligament cells (hPDLCs), and observe differential effects of enamel matrix derivative (EMD) on in vivo cementum formation by hPDLCs.

MATERIALS AND METHODS

Forty-eight cementum slices and 48 dentin slices were prepared from periodontitis compromised teeth, and hPDLCs were inoculated on to all root slices. Twenty-four co-cultured root slices of each group were used for mRNA expression of cementum attachment protein and CEMP1. With application of EMD, 24 co-cultured root slices (divided into groups C, D, C+E, D+E) were transplanted subcutaneously into nude mice. All root fragments were reviewed by histological analysis and immunohistochemical staining for bone sialoprotein.

RESULTS

mRNA expressions of cementum attachment protein and cementum protein - 1 from hPDLCs on cementum slices were statistically higher than those of dentin slices. Seven specimens of group C and 10 specimens of group C+E revealed a layer of cementum-like tissue (NFC) on surfaces of pre-existing cementum. NFC was thicker in group C+E than in group C. All NFCs were positively stained for bone sialoprotein, however, there was no NFC formation on dentin slices.

CONCLUSION

Conservatively treated diseased cementum promoted in vitro cementoblast differentiation and in vivo cementum-like tissue formation by hPDLCs, and the in vivo effect was enhanced by the presence of EMD.

The association of new inflammatory markers with type 2 diabetes mellitus and macrovascular complications: a preliminary study

AIM

Type 2 diabetes mellitus (T2DM) is not simply a disease of hyperglycemia, but also is an inflammatory disorder. This study aimed to observe the expression of inflammation-related factors in elderly T2DM patients with or without macrovascular disease (MVD).

PATIENTS AND METHODS

A total of 64 T2DM patients participated in this study, including 31 patients with MVD (group A) and 33 patients without MVD (group B); and 30 healthy volunteers were recruited as normal control (group C). The levels of serum irisin, retinol-binding protein 4 (RBP4) and adiponectin expression were all detected and compared between groups.

RESULTS

The demographic and clinical characteristics were comparable between T2DM patients and healthy volunteers. For patients in group A, the serum levels of irisin, RBP4 and adiponectin were 12.05 ± 2.12 pg/mL, 2.13 ± 0.83 µg/mL and 45.65±20.13 ng/mL, respectively. While the corresponding parameters were 26.11 ± 4.09 pg/ml, 1.54 ± 0.54 µg/ml and 57.93 ± 23.47 ng/mL for patients in group B; and were 40.25 ± 2.73 pg/mL, 0.98 ± 0.36 µg/mL and 60.03 ± 20.26 ng/mL for healthy volunteers in group C, respectively. As compared to healthy volunteers, the levels of irisin, RBP4 and adiponectin were all significantly changed in T2DM patients; and the difference in irisin, RBP4 and adiponectin between T2DM patients with and without MVD were all significant (p = 0.000, p = 0.001, and p = 0.029, respectively). Multivariate regression analysis showed that irisin and RBP4 are both independent predictors for MVD in T2DM patients.

CONCLUSIONS

Inflammatory disorder is significantly in T2DM patients with MVD, and serum irisin and RBP4 would be reasonable new markers of MVD.

Urinary concentrations of bisphenol A and phthalate metabolites and weight change: a prospective investigation in US women

OBJECTIVE

Both bisphenol A (BPA) and phthalates are known endocrine-disrupting chemicals for which there is widespread general population exposure. Human exposure occurs through dietary and non-dietary routes. Although animal studies have suggested a potential role of these chemicals in obesity, evidence from human studies is sparse and inconsistent, and prospective evidence is lacking. This study evaluated urinary concentrations of BPA and major phthalate metabolites in relation to prospective weight change.

METHODS

The study population was from the controls in a prospective case-control study of type 2 diabetes in the Nurses' Health Study (NHS) and NHSII. A total of 977 participants provided first-morning-void urine samples in 1996-2002. Urinary concentrations of BPA and nine phthalate metabolites were measured using liquid chromatography-mass spectrometry. Body weights were self-reported at baseline and updated biennially thereafter for 10 years.

RESULTS

On average, the women gained 2.09 kg (95% confidence interval (CI), -2.27 to 6.80 kg) during the 10-year follow-up. In multivariate analysis with adjustment of lifestyle and dietary factors, in comparison with women in the lowest quartile of BPA concentration, those in the highest quartile had 0.23 kg per year (95% CI, 0.07-0.38 kg per year) greater weight gain during the 10-year follow-up (P-trend=0.02). Several phthalate metabolites, including phthalic acid, MBzP and monobutyl phthalate, were also associated with faster prospective weight gain in a dose-response fashion (P-trend<0.01), whereas other phthalates metabolites, including MEP and monoethylhexyl phthalate, were not monotonically associated with body weight change.

CONCLUSIONS

These data suggest urinary concentrations of BPA and certain individual phthalate metabolites that were associated with modestly greater weight gain in a dose-response fashion. These data are consistent with a potential role of BPA and phthalates in obesity, although more prospective data are needed to corroborate these observations.

SCAR marker for sex identification of Pistacia chinensis Bunge (Anacardiaceae)

Pistacia chinensis Bunge is a dioecious plant that originated in China, and its sex cannot be identified at the early stage of cultivation by only its appearance. Recent studies show that the seed of P. chinensis is an ideal feedstock for biofuel production. To guide the cultivation of this energy plant scientifically, a new method is urgently needed to identify the sex of P. chinensis seedlings. In this paper, from 21 random-amplified polymorphic DNA primers and 20 inter-simple sequence repeat primers, 2 sex-specific primers (S1 and S281) were identified that can amplify female-specific fragments of 473 and 1242 bp, respectively. However, only 1 fragment (FS281) was converted successfully into a sequence-characterized amplified region marker using S281-1 and S281-2 primers. When the annealing temperature was 64°C, a 636-bp specific sequence appeared in all female specimens but was absent in all the male samples tested. This study will offer some clues to sex selection in P. chinensis plantations.

Effects of tetra-arsenic tetra-sulfide on BXSB lupus-prone mice: a pilot study

Systemic lupus erythematosus (SLE) is an autoimmune disease of uncertain etiology that affects multiple tissues and organs. Arsenic trioxide (ATO) has been used in lupus-prone mice with a regulatory effect on immune abnormality. Tetra-arsenic tetra-sulfide (As4S4), a traditional Chinese medicine, is effective on acute promyelocytic leukemia with mild side effects than ATO. In this study, a pilot study was performed to investigate the effects and the mechanism of As4S4 on the lupus-prone BXSB mice. Improvement of monocytosis (p<0.05) in spleen and decreased serum interleukin-6 (IL-6) (p=0.0277) were observed with As4S4 treatment. As4S4-treated mice exhibited amelioration of skin, liver and renal disease with mild side effects. Histological analysis revealed that As4S4 suppressed immune complex deposition, mesangial proliferation and inflammatory cell infiltration in kidney and liver. Our study support that As4S4 selectively suppresses cutaneous lupus and nephritis in BXSB mice and might be a potential treatment for SLE.

The cyclic hexapeptide AcF attenuates sepsis-induced acute lung injury and mortality in rats

OBJECTIVE

The purpose of this study was to elucidate the possible beneficial effects of AcF on acute lung injury (ALI) in a rat model of sepsis.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomly divided into the following four experimental groups (n = 10 per group): animals undergoing a sham cecal ligature puncture (CLP) (Sham group); animals undergoing CLP (control group); or animals undergoing CLP and treated with saline (Saline group) and animals undergoing CLP and treated with AcF (AcF group). At 24 h after CLP, blood, bronchoalveolar lavage fluid (BALF) and lung tissue were collected. The lung wet/dry weight ratio, Protein concentration and the count of inflammatory cells or neutrophils in the BALF were determined. The pathologic changes in lungs were examined with the optical microscopy. Myeloperoxidase (MPO) activity, the expression of inflammatory cytokines were measured in lung tissue and BALF respectively. Survival rates were recorded at 120h in the four groups in another experiment.

RESULTS

Histology findings revealed acute lung injury in rats in the CLP group, whereas those in the AcF-treated group had mild lung injury. Treatment with AcF significantly attenuated the CLP-induced pulmonary edema and inflammation, as it significantly decreased lung wet/dry ration, protein concentration and the infiltration of inflammatory cells and neutrophils in the lung tissues. In addition, the secretion of inflammatory cytokines, such as TNF-α, IL-6, IL-1b and macrophage inflammatory protein-2 (MIP-2) was decreased in AcF treated group compared with the control saline treated group.

CONCLUSIONS

AcF administration ameliorates acute lung injury in a rat model of sepsis induced by CLP. AcF can be developed as a novel treatment for severe sepsis-induced ALI.

CCAAT/enhancer-binding protein β is involved in the breed-dependent transcriptional regulation of 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase in adrenal gland of preweaning piglets

The enzyme 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase (3β-HSD) catalyzes the biosynthesis of all steroid hormones. The molecular mechanisms regulating porcine adrenal 3β-HSD expression in different breeds are still poorly understood. In this study, we aimed to compare the expression of 3β-HSD between preweaning purebred Large White (LW) and Erhualian (EHL) piglets and to explore the potential factors regulating 3β-HSD transcription. EHL had significantly higher serum levels of cortisol (P<0.01) and testosterone (P<0.01), which were associated with significantly higher expression of 3β-HSD mRNA (P<0.01) and protein (P<0.05) in the adrenal gland, compared with LW piglets. The 5' flanking region of the porcine 3β-HSD gene showed significant sequence variations between breeds, and the sequence of EHL demonstrated an elevated promoter activity (P<0.05) in luciferase reporter gene assay. Higher adrenal expression of 3β-HSD in EHL was accompanied with higher CCAAT/enhancer binding protein β (C/EBPβ) expression (P<0.05), enriched histone H3 acetylation (P<0.05) and C/EBPβ binding to 3β-HSD promoter (P<0.05). In addition, higher androgen receptor (AR) (P=0.06) and lower glucocorticoid receptor (GR) (P<0.05) were detected in EHL. Co-immunoprecipitation analysis revealed interactions of C/EBPβ with both AR and GR. These results indicate that the C/EBPβ binding to 3β-HSD promoter is responsible, at least in part, for the breed-dependent 3β-HSD expression in adrenal gland of piglets. The sequence variations of 3β-HSD promoter and the interactions of AR and/or GR with C/EBPβ may also participate in the regulation.

The Intrinsic Ferromagnetism in a MnO2 Monolayer

The Mn atom, because of its special electronic configuration of 3d(5)4s(2), has been widely used as a dopant in various two-dimensional (2D) monolayers such as graphene, BN, silicene and transition metal dichalcogenides (TMDs). The distributions of doped Mn atoms in these systems are highly sensitive to the synthesis process and conditions, thus suffering from problems of low solubility and surface clustering. Here we show for the first time that the MnO2 monolayer, synthetized 10 years ago, where Mn ions are individually held at specific sites, exhibits intrinsic ferromagnetism with a Curie temperature of 140 K, comparable to the highest TC value achieved experimentally for Mn-doped GaAs. The well-defined atomic configuration and the intrinsic ferromagnetism of the MnO2 monolayer suggest that it is superior to other magnetic monolayer materials.

Liver-directed adeno-associated virus serotype 8 gene transfer rescues a lethal murine model of citrullinemia type 1

Citrullinemia type 1 (CTLN1) is an autosomal recessive disorder of metabolism caused by a deficiency of argininosuccinate synthetase. Despite optimal management, CTLN1 patients still suffer from lethal metabolic instability and experience life threatening episodes of acute hyperammonemia. A murine model of CTLN1 (fold/fold) that displays lethality within the first 21 days of life was used to determine the efficacy of adeno-associated viral (AAV) gene transfer as a potential therapy. An AAV serotype 8 (AAV8) vector was engineered to express the human ASS1 cDNA under the control of a liver-specific promoter (thyroxine binding globulin, TBG), AAV8-TBG-hASS1, and delivered to 7–10 day old mice via intraperitoneal injection. Greater than 95% of the mice were rescued from lethality and survival was extended beyond 100 days after receiving a single dose of vector. AAV8-TBG-hASS1 treatment resulted in liver specific expression of hASS1, increased ASS1 enzyme activity, reduction in plasma ammonia and citrulline concentrations, and significant phenotypic improvement of the fold/fold growth and skin phenotypes. These experiments highlight a gene transfer approach using AAV8 vector for liver targeted gene therapy that could serve as a treatment for CTLN1.

A retrospective analysis of short and long term efficacy of RBL for hemorrhoids

AIMS

Rubber band ligation is an effective treatment for hemorrhoids. A retrospective analysis was performed to evaluate its short and long-term efficacy.

PATIENTS AND METHODS

From 2000 to 2008, 254 outpatients with II- degree and 114 with III-degree hemorrhoids underwent rubber band ligation. Two or three hemorrhoids were ligated per session. Each haemorrhoid was ligated with two rubber bands through a ligator. All patients were visited after two months and followed up through a telephone after two and eleven years.

RESULTS

Twenty-four or forty-eight hours post treatment, 41% of patients had mild-moderate pain. Four patients showed severe pain and required for haemorrhoidectomy within a few days. Only 2% of patients experienced self-limiting rectal bleeding after one week and 6% of patients had an additional ligation within two months. Two months later, 92% of II-degree patients and 76% of III-degree patients showed no residual symptoms. After two and eleven years, the history of 314 patients (85%) were obtained, of them, 70% was asymptomatic, 27% had some residual symptoms of occasional bleeding and prolapse, and 3% needed further surgery.

CONCLUSIONS

Rubber band ligation is an efficient, cost-effective and simple outpatient procedure for the second and third degree hemorrhoids with minimal complications.

Curcumin acts via transient receptor potential vanilloid-1 receptors to inhibit gut nociception and reverses visceral hyperalgesia

BACKGROUND

An antinociceptive effect has been reported for curcumin in animal models and in humans, but the molecular mechanisms of curcumin's effect remain undefined. In this study, we explored the possibility that curcumin inhibit visceral nociception via antagonizing the transient receptor potential vanilloid-1 (TRPV1) receptor.

METHODS

The effects of curcumin were explored using two experimental models: viscero-motor response (VMR) to colorectal distension (CRD) in rats and jejunal afferent firing in the ex vivo mouse jejunum preparations [TRPV1 knockout (KO) and wild-type mice, naive and trinitrobenzene sulfonic acid (TNBS)-treated Kunming mice]. In addition, capsaicin-induced calcium transients and whole-cell currents were examined in acutely dissociated dorsal root ganglia (DRG) neurons.

KEY RESULTS

In the anesthetized rat, curcumin (4 mg kg(-1)  min(-1) for 3 min) caused a marked and rapidly reversible inhibition of CRD-induced VMRs. In the mouse jejunum, the mesenteric afferent nerve response to ramp distension was attenuated by curcumin (3, 10 μmol L(-1) ), an effect that was significantly reduced in TRPV1 KO mice compared with wild-type (WT) controls. Moreover, in WT mice, curcumin (1-30 μmol L(-1) ) was found to inhibit the afferent responses to capsaicin in a concentration-dependent manner. Trinitrobenzene sulfonic acid-induced hypersensitivity of jejunal afferents was also attenuated by curcumin. Curcumin potently inhibited capsaicin-induced rise in intracellular calcium and inward currents in mouse or rat DRG neurons.

CONCLUSIONS & INFERENCES

Our results provide strong evidence that curcumin inhibit visceral nociception via antagonizing TRPV1 and may be a promising lead for the treatment of functional gastrointestinal diseases.

Maternal low-protein diet affects epigenetic regulation of hepatic mitochondrial DNA transcription in a sex-specific manner in newborn piglets associated with GR binding to its promoter

Mitochondrial oxidative phosphorylation (OXPHOS) plays an important role in energy homeostasis by controlling electron transfer and ATP generation. Maternal malnutrition during pregnancy affects mitochondrial (mt) DNA-encoded OXPHOS activity in offspring, yet it is unknown whether epigenetic mechanism is involved in the transcriptional regulation of mtDNA-encoded OXPHOS genes. In this study, 14 primiparous purebred Meishan sows were fed either standard- (SP, 12% crude protein) or low-protein (LP; 6% crude protein) diets throughout gestation, and the hepatic expression and transcriptional regulation of mtDNA-encoded OXPHOS genes were analyzed in newborn piglets. Maternal low protein diet decreased hepatic mtDNA copy number in males, but not in females. LP male piglets had significantly higher hepatic AMP concentration and low energy charge, which was accompanied by enhanced mRNA expression of NADH dehydrogenase subunits 6, cytochrome c oxidase subunit 1, 2, 3 and cytochrome b, as well as increased cytochrome c oxidase enzyme activity. In contrast, LP female piglets showed significantly lower hepatic AMP concentrations and higher energy charge with no alterations in OXPHOS gene expression. Moreover, LP males demonstrated higher glucocorticoid receptor (GR) binding to the mtDNA promoter compared with SP males, which was accompanied by lower cytosine methylation and hydroxymethylation on mtDNA promoter. Interestingly, opposite changes were seen in females, which showed diminished GR binding and enriched cytosine methylation and hydroxymethylation on mtDNA promoter. These results suggest that maternal low protein diet during pregnancy causes sex-dependent epigenetic alterations in mtDNA-encoded OXPHOS gene expression, possibly GR is involved in mtDNA transcription regulation.

Inhibition of transforming growth factor beta-activated kinase 1 confers neuroprotection after traumatic brain injury in rats

The transforming growth factor beta-activated kinase 1 (TAK1), a member of the Mitogen-activated protein kinase kinase kinase family, is characterized as a key regulator in inflammatory and apoptosis signaling pathways. The aim of the present study was to evaluate the role of the TAK1 pathway in experimental traumatic brain injury (TBI) in rats. Adult male Sprague-Dawley rats were subjected to TBI using a modified Feeney's weight-drop model. The time course showed that a significant increase of TAK1 and p-TAK1 expression in the cortex after TBI. Moreover, TBI induced TAK1 redistribution both in neurons and astrocytes of the lesion boundary zone. The effects of specific inhibition of the TAK1 pathway by 5Z-7-oxozeaenol (OZ, intracerebroventricular injection at 10min post-trauma) on histopathological and behavioral outcomes in rats were assessed at 24h post injury. The number of TUNEL-positive stained cells was diminished and neuronal survival and neurological function were improved with OZ treatment. Biochemically, the high dose of OZ significantly reduced the levels of TAK1 and p-TAK1, further decreased nuclear factor-κB and activator protein 1 activities and the release of inflammatory cytokines. In addition, we found that both 10min and 3h post-trauma OZ therapies could markedly improve neurological function and neuronal survival after long-term survival. These results revealed that the TAK1 pathway is activated after experimental TBI and the inhibitor OZ affords significant neuro- protection and amelioration of neurobehavioral deficits after experimental TBI, suggesting a potential rationale for manipulating this pathway in clinical practice.

The pathogenesis of acute allograft dysfunction in desensitized renal transplant recipients

BACKGROUND

Acute allograft rejection after HLA desensitization is common early post-transplant but the sequence of histopathologic changes leading to graft dysfunction has not been well defined.

METHODS

We evaluated the early pathogenesis and sequence of antibody-mediated graft damage of 35 desensitized living donor kidney recipients by studying the course of biopsies taken in the very early post-transplant period (<1 month).

RESULTS

A total of 14 of the 35 patients met criteria for acute antibody-mediated rejection (AMR). In these patients, the chronologic sequence of pathologic changes was C4d peritubular capillary deposition, acute tubular injury, and peritubular capillaritis, followed by glomerulitis and interstitial inflammation. Classic AMR lesions occurred early, followed by mononuclear cellular infiltration, which comprised CD4 and CD8 T cells and monocytes. Development of graft dysfunction in most patients occurred concurrently with the emergence of graft cellular infiltration, rather than at the earlier time of antibody deposition as detected via C4d deposition.

CONCLUSION

These data provide novel insight into the sequence of pathologic changes in patients with AMR post-transplant after HLA desensitization.

BOLDMirror: a global mirror system of DNA barcode data

DNA barcoding is a novel concept for taxonomic identification using short, specific genetic markers and has been applied to study a large number of eukaryotes. The huge amount of data output generated by DNA barcoding requires well-organized information systems. Besides the Barcode of Life Data system (BOLD) established in Canada, the mirror system is also important for the international barcode of life project (iBOL). For this purpose, we developed the BOLDMirror, a global mirror system of DNA barcode data. It is open-sourced and can run on the LAMP (Linux + Apache + MySQL + PHP) environment. BOLDMirror has data synchronization, data representation and statistics modules, and also provides spaces to store user operation history. BOLDMirror can be accessed at http://www.boldmirror.net and several countries have used it to setup their site of DNA barcoding.

[The value of detecting telomerase activity on early diagnosis of lung cancer]

BACKGROUND

To explore the possibility of telomerase as tumor marker of lung cancer and to evaluate its value on early diagnosis of lung cancer.

METHODS

Telomerase activity was measured in 40 resected specimens of lung cancer and 40 preoperative fibro-optic bronchoscope biopsied specimens of suspected lung cancer by PCR based silver staining telomeric repeat amplification protocal (TRAP) respectively.

RESULTS

The positive rate of telomerase was 100% in SCLC, but 84.8% in resected samples and 95.7% in biopsied samples in NSCLC. The positive rate of telomerase was 87.5%(35/40) in resected lung cancer tissues, 7.5%(3/40) in paracancerous tissues and 0%(0/40) in normal lung tissues (P<0.01). 82.5% (34/40) biopsied specimens of suspected lung cancer were detected with telomerase activity. Its sensitivity, specificity, and accurate rate was 96.4%, 71.4%, and 91.4% respectively for detection of lung cancer, Youden's Index (J)=0.678,and SE(J)=0.174.

CONCLUSIONS

Telomerase may be a sensitive tumor marker of lung cancer. Detecting telomerase activity in preoperative fibro-optic bronchoscope biopsied specimens may contribute to early diagnosis of lung cancer.

Antileukemic activity of nuclear export inhibitors that spare normal hematopoietic cells

Drugs that target the chief mediator of nuclear export, chromosome region maintenance 1 protein (CRM1) have potential as therapeutics for leukemia, but existing CRM1 inhibitors show variable potencies and a broad range of cytotoxic effects. Here, we report the structural analysis and antileukemic activity of a new generation of small-molecule inhibitors of CRM1. Designated selective inhibitors of nuclear export (SINE), these compounds were developed using molecular modeling to screen a small virtual library of compounds against the nuclear export signal (NES) groove of CRM1. The 2.2-Å crystal structure of the CRM1-Ran-RanBP1 complex bound to KPT-251, a representative molecule of this class of inhibitors, shows that the drug occupies part of the groove in CRM1 that is usually occupied by the NES, but penetrates much deeper into the groove and blocks CRM1-directed protein export. SINE inhibitors exhibit potent antileukemic activity, inducing apoptosis at nanomolar concentrations in a panel of 14 human acute myeloid leukemia (AML) cell lines representing different molecular subtypes of the disease. When administered orally to immunodeficient mice engrafted with human AML cells, KPT-251 had potent antileukemic activity with negligible toxicity to normal hematopoietic cells. Thus, KPT-SINE CRM1 antagonists represent a novel class of drugs that warrant further testing in AML patients.