CD58, a novel surface marker, promotes self-renewal of tumor-initiating cells in colorectal cancer

Colorectal tumor-initiating cells (CT-ICs) have self-renewal capabilities and have an important role in tumorigenesis, metastasis, recurrence and treatment resistance in colorectal cancer. Multiple cell-surface molecules targeting CT-ICs, possibly representing different CT-IC subpopulations, have been reported. However, whether new surface markers exist, as well as the mechanisms by which the markers regulate self-renewal, remain unclear. In this study, we enriched a CT-IC population through a serum-free low-adhesion system in vitro. Within this population, we found that CD58 and CD44 were upregulated using a cDNA GeneChip, and CD44(high)CD58(high) cancer cells, the common existence of which was demonstrated by flow cytometry in multiple colon cancer cell lines and primary specimens, exhibited enhanced self-renewal ability, epithelial-mesenchymal transition ability and tumorigenicity, both in vitro and in vivo. Furthermore, activated CD58 upregulated the Wnt/β-catenin pathway and thus promoted self-renewal of CT-ICs; conversely, knockdown of CD58 significantly impaired sphere formation and tumor growth. With immunoprecipitation and western blotting approaches, CD58 was found to upregulate the Wnt pathway by degradation of Dickkopf 3. These results indicate that CD58 is a novel cell-surface marker that functionally regulates self-renewal of CT-ICs, which may provide an intriguing therapeutic target for the efficient killing and elimination of CT-ICs.

Advanced spatio-temporal modelling in long-term radiological assessment models--radionuclides in the soil column

Recent developments in the modelling of key radionuclides in long-timescale assessments of the safety of geological disposal of spent fuel and other radioactive wastes emphasise the influence of the redox conditions of the soil column. Models with higher spatial resolution than typically employed in standard modelling approaches have been shown to capture important features of experimental observations that are not otherwise manifested. Furthermore, models with monthly, rather than annually, averaged parameters and with dynamic transfers between soil and plant have been shown to lead to key differences compared with standard models employing soil-plant concentration ratios. This paper looks at the potential for the inclusion of a higher spatio-temporal resolution in models for long-timescale dose assessments and includes representations of measured plant-root distributions as well as the effects of bioturbation. Focusing here on the distribution and dynamics of radionuclides in the soil column, the effects of different spatial and temporal resolution are compared, together with an investigation of the way in which the hydrology of the soil column is represented. The approach has been successfully incorporated into a practical assessment-level model. Results indicate the potential importance of higher spatio-temporal resolution in modelling soil column dynamics, particularly of weakly sorbing radionuclides in long-timescale assessments featuring sudden transitions between ecosystem types.

Eribulin mesilate suppresses experimental metastasis of breast cancer cells by reversing phenotype from epithelial-mesenchymal transition (EMT) to mesenchymal-epithelial transition (MET) states

Background:

Eribulin mesilate (eribulin), a non-taxane microtubule dynamics inhibitor, has shown trends towards greater overall survival (OS) compared with progression-free survival in late-stage metastatic breast cancer patients in the clinic. This finding suggests that eribulin may have additional, previously unrecognised antitumour mechanisms beyond its established antimitotic activity. To investigate this possibility, eribulin's effects on the balance between epithelial–mesenchymal transition (EMT) and mesenchymal–epithelial transition (MET) in human breast cancer cells were investigated.

Methods:

Triple negative breast cancer (TNBC) cells, which are oestrogen receptor (ER−)/progesterone receptor (PR−)/human epithelial growth receptor 2 (HER2−) and have a mesenchymal phenotype, were treated with eribulin for 7 days, followed by measurement of EMT-related gene and protein expression changes in the surviving cells by quantitative real-time PCR (qPCR) and immunoblot, respectively. In addition, proliferation, migration, and invasion assays were also conducted in eribulin-treated cells. To investigate the effects of eribulin on TGF-β/Smad signalling, the phosphorylation status of Smad proteins was analysed. In vivo, the EMT/MET status of TNBC xenografts in mice treated with eribulin was examined by qPCR, immunoblot, and immunohistochemical analysis. Finally, an experimental lung metastasis model was utilised to gauge the metastatic activity of eribulin-treated TNBC in the in vivo setting.

Results:

Treatment of TNBC cells with eribulin in vitro led to morphological changes consistent with transition from a mesenchymal to an epithelial phenotype. Expression analyses of EMT markers showed that eribulin treatment led to decreased expression of several mesenchymal marker genes, together with increased expression of several epithelial markers. In the TGF-β induced EMT model, eribulin treatment reversed EMT, coincident with inhibition of Smad2 and Smad3 phosphorylation. Consistent with these changes, TNBC cells treated with eribulin for 7 days showed decreased capacity for in vitro migration and invasiveness. In in vivo xenograft models, eribulin treatment reversed EMT and induced MET as assessed by qPCR, immunoblot, and immunohistochemical analyses of epithelial and mesenchymal marker proteins. Finally, surviving TNBC cells pretreated in vitro with eribulin for 7 days led to decreased numbers of lung metastasis when assessed in an in vivo experimental metastasis model.

Conclusions:

Eribulin exerted significant effects on EMT/MET-related pathway components in human breast cancer cells in vitro and in vivo, consistent with a phenotypic switch from mesenchymal to epithelial states, and corresponding to observed decreases in migration and invasiveness in vitro as well as experimental metastasis in vivo. These preclinical findings may provide a plausible scientific basis for clinical observations of prolonged OS by suppression of further spread of metastasis in breast cancer patients treated with eribulin.

Association of XRCC5 polymorphisms with COPD and COPD-related phenotypes in the Han Chinese population: a case-control cohort study

Genome-wide association studies (GWAS) and integrative genomic approaches have demonstrated significant associations between chronic obstructive pulmonary disease (COPD) and polymorphisms of the X-ray repair cross-complementing protein 5 gene (XRCC5) in non-Asian populations. We investigated whether XRCC5 polymorphisms might be associated with COPD susceptibility and COPD-related phenotypes in the Chinese Han population. Nine single nucleotide polymorphisms (SNPs) (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, rs7573191, and rs207906) in the XRCC5 gene were genotyped in a case-control study including 680 COPD patients and 687 controls. To estimate the strength of association, odds ratios (ORs) were calculated and the effects of potentially confounding variables were tested by logistic regression analysis. The association between haplotypes and COPD outcome was also assessed. Our data identified that the SNP rs207936 was associated with COPD with an adjusted P value of 0.038, which was also found when analyzing only data of current smokers (P=0.046). No significant associations were found between any of the SNPs and pulmonary function. Eight SNPs (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, and rs7573191) showed strong linkage disequilibrium (R2≥0.9). Two major haplotypes were observed and showed a significant difference between case and control groups (P=0.0054 and 0.0081, respectively). The present study showed that the XRCC5 locus might be a contributor to COPD susceptibility in the Chinese Han population.

Mouse models of pancreatic cancer induced by chronic pancreatitis and smoking

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Background: Chronic pancreatitis (CP) and smoking are two major risk factors for pancreatic cancer (PaCa). Here we developed mouse models of PaCa by exposing mice to CP and/or smoking. Methods: Wild type (WT) and Pdx1-Cre;LSL-Kras transgenic mice were subjected to 7-hourly cerulein injections (50µg/kg) twice a week for 3 weeks to induce CP. Another group of mice was exposed to tobacco smoke (80mg/m3) in chambers for 5days/week during 6 weeks. A third group was exposed to both treatments. Mice were then sacrificed and pancreatic tissue analyzed. Pancreatic lesions, proliferation, fibrosis, inflammation, EMT and stem cell markers were analyzed by immunohistochemistry and Western. Results: CP significantly increased the number and stage of pancreatic neoplastic (PanIN) lesions with fibrosis, stellate cell activation and inflammation in transgenic mice. These changes were significantly less in WT mice. EMT markers (decrease in E-Cadherin and increase in vimentin protein levels) were stimulated by CP in both WT and transgenic mice. Similarly, smoking stimulated PanIN lesion formation, fibrosis and inflammation in transgenic mice, but to a lesser extent than CP model. Expression of EMT and stem cell markers was greater in the smoking model compared to CP. Combination of CP and smoking induced greater stimulation of PanIN lesion formation, fibrosis and inflammation compared to either treatment alone in transgenic mice. Conclusions: The results indicate that both CP and tobacco smoke promote PaCa progression in transgenic mice. The combination of CP and smoking has greater effects than either treatment alone. EMT and stem cell markers developed in WT as well as in transgenic mice with smoking suggesting that smoking has effects independent of Kras on cell transformation.

p63 is a prosurvival factor in the adult mammary gland during post-lactational involution, affecting PI-MECs and ErbB2 tumorigenesis

In embryogenesis, p63 is essential to develop mammary glands. In the adult mammary gland, p63 is highly expressed in the basal cell layer that comprises myoepithelial and interspersed stem/progenitor cells, and has limited expression in luminal epithelial cells. In adult skin, p63 has a crucial role in the maintenance of epithelial stem cells. However, it is unclear whether p63 also has an equivalent role as a stem/progenitor cell factor in adult mammary epithelium. We show that p63 is essential in vivo for the survival and maintenance of parity-identified mammary epithelial cells (PI-MECs), a pregnancy-induced heterogeneous population that survives post-lactational involution and contain multipotent progenitors that give rise to alveoli and ducts in subsequent pregnancies. p63+/- glands are normal in virgin, pregnant and lactating states. Importantly, however, during the apoptotic phase of post-lactational involution p63+/- glands show a threefold increase in epithelial cell death, concomitant with increased activation of the oncostatin M/Stat3 and p53 pro-apoptotic pathways, which are responsible for this phase. Thus, p63 is a physiologic antagonist of these pathways specifically in this regressive stage. After the restructuring phase when involution is complete, mammary glands of p63+/- mice again exhibit normal epithelial architecture by conventional histology. However, using Rosa(LSL-LacZ);WAP-Cre transgenics (LSL-LacZ, lox-stop-lox β-galactosidase), a genetic in vivo labeling system for PI-MECs, we find that p63+/- glands have a 30% reduction in the number of PI-MEC progenitors and their derivatives. Importantly, PI-MECs are also cellular targets of pregnancy-promoted ErbB2 tumorigenesis. Consistent with their PI-MEC pool reduction, one-time pregnant p63+/- ErbB2 mice are partially protected from breast tumorigenesis, exhibiting extended tumor-free and overall survival, and reduced tumor multiplicity compared with their p63+/+ ErbB2 littermates. Conversely, in virgin ErbB2 mice p63 heterozygosity provides no survival advantage. In sum, our data establish that p63 is an important survival factor for pregnancy-identified PI-MEC progenitors in breast tissue in vivo.

The -33C/T polymorphism in the interleukin 4 gene is associated with asthma risk: a meta-analysis

OBJECTIVE

The association between the interleukin 4 (IL-4) gene -33C/T polymorphism and asthma risk is a subject of debate.We conducted a meta-analysis to evaluate the association between this polymorphism and asthma susceptibility.

MATERIALS AND METHODS

A systematic search of electronic databases (Pubmed, EMBASE, Wanfang, China National Knowledge Infrastructure, and Weipu) was performed, and 18 studies involving 5523 cases and 5618 controls were identified. ORs with 95% CIs were used to assess the strength of association.

RESULTS

A significant association between the -33C/T polymorphism and asthma susceptibility was observed for TT vs CT + CC (OR, 1.16; 95% CI, 1.05-1.28; P=.005). In the subgroup analysis by race, a significant association was found among whites (OR, 1.71; 95% CI, 1.14-2.57; P=.01) and Asians (OR, 1.14; 95% CI, 1.01-1.28; P=.04) but not among African Americans. In the subgroup analysis by atopic status, no significant association was found among atopic asthma patients (OR, 1.05; 95% CI, 0.89-1.24; P=.54) or nonatopic asthma patients (OR, 1.16; 95% CI, 0.81-1.67; P=.42). In the age-stratified analysis, an increased asthma risk was found in children (OR, 1.28; 95% CI, 1.01-1.63; P=.04) but not in adults.

CONCLUSIONS

The results of this meta-analysis suggest that the IL-4 -33C/T polymorphism is a risk factor for asthma.

Ultrasound contrast agents and ultrasound molecular imaging

Ultrasound imaging in combination with microbubble contrast agents has demonstrated its potential for molecular imaging of vascular targets. In this article, we systematically review the technologies related to ultrasound molecular imaging. First, we introduce the basic principles of ultrasound molecular imaging. Then, we discuss ultrasound microbubble contrast agents. This includes selection requirements for targeted contrast agent ligands and receptors, targeted ultrasound contrast agent preparation, targeted ultrasound contrast agent ligands connection methods, and microbubble ultrasound contrast agent safety issues. The use of ultrasound molecular imaging in diagnosis and treatment, as well as some issues relating to high intensity focused ultrasound and ultrasound molecular imaging applications in disease diagnosis are also discussed. Applications include detection of inflammation, thrombus, tumors, and neovascularization. Consideration is also given to the acoustic characteristics of microbubbles and the acoustic principles underlying microbubble ultrasound imaging. Several microbubble scattering models are highlighted (including the Rayleigh-Plesset model, the Rayleigh-Plesset-Noltingk-Neppiras-Poritsky model, the Herring model, the Marmottant model, and the non-spherical bubble dynamics model). The interaction between two microbubbles and the effect of radiation on the microbubbles is also discussed. Finally, from an engineering perspective, we summarize the techniques used to improve the quality of ultrasound molecular images (harmonic imaging, perfusion imaging, and deconvolution technology). It is inevitable that ultrasound molecular imaging will continue to mature and can be expected to play an increasingly larger role in diagnosis and treatment of human diseases in the near future.

Increased expression of α5β1-integrin is a prognostic marker for patients with gastric cancer

OBJECTIVE

The study was to evaluate the association of expression level of α5β1-integrin with clinicopathologic features and prognosis in gastric cancer (GC).

METHODS

The expression of α5β1-integrin in normal gastric mucosa and GC tissue was detected with immunohistochemistry. The level of α5 and β1 mRNA in GC tissues and non-neoplastic tissues was evaluated in 48 paired cases by quantitative real-time polymerase chain reaction (qRT-PCR). Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance.

RESULTS

The α5β1-integrin expression was detected in 68.3 % (127/186) GC samples, and there was a significant difference on their positive expression rate between GC tissue and normal gastric mucosa (P < 0.001). The positive expression rate of α5β1-integrin in patients with poor histologic differentiation (P = 0.001), lymph node metastasis (P < 0.001), and recurrence (P < 0.001) group was heightened. Using Kaplan-Meier analysis, a comparison of survival curves of low versus high expresser of α5β1-integrin revealed a highly significant difference in human GC tissue (P = 0.002), which suggested that overexpression of α5β1-integrin is associated with a worse prognosis. Multivariate analyses showed that α5β1-integrin expression was independent risk factor predicting overall survival [Hazard ratio (HR) 1.594, 95 % confidence interval (CI) 1.236-2.408, P = 0.006] and disease-free survival [HR 3.952, 95 % CI 1.676-9.861, P = 0.003] in GC.

CONCLUSIONS

The α5β1-integrin promotes angiogenesis and associates with lymph node metastasis, vascular invasion and poor prognosis of GC. The current study shows that α5β1-integrin may be an independent prognostic factor for GC patients.

[Effect of postaurical subcutaneously injection of triamcinolone acetonide for subjective tinnitus]

OBJECTIVE

To determine whether postaurical subcutaneous injection of triamcinolone acetonide is effective for subjective tinnitus refractory to medical treatment.

METHODS

A total of 100 adult patients with subjective tinnitus of cochlear origin were randomly assigned to receive postaurical subcutaneous.Injection of either triamcinolone acetonide (n = 50) or saline solution (n = 50). The treatment protocol comprised 5 injections, one per week for 5 weeks.Improvement was measured by tinnitus severity evaluation index evaluation scale, at baseline and one week after the last injection. The follow-up period was 6 months.

RESULTS

No significant difference existed between two groups regarding age, gender, pure tone average, pretreatment tinnitus intensity, tinnitus duration or hearing loss level tinnitus duration (P = 0.316,0.685,0.839,0.682 and 0.881 respectively).No significant post-treatment changes in the tinnitus severity index (experimental group = 52%, control group = 44%) were observed in either group (P = 0.724). The most frequently encountered side effect was pain during injection.

CONCLUSION

The postaurical subcutaneous injection of triamcinolone acetonide has no obvious benefit compared with placebo for subjective tinnitus of cochlear origin refractory to medical treatment.

Calumenin-15 facilitates filopodia formation by promoting TGF-β superfamily cytokine GDF-15 transcription

Filopodia, which are actin-rich finger-like membrane protrusions, have an important role in cell migration and tumor metastasis. Here we identify 13 novel calumenin (Calu) isoforms (Calu 3-15) produced by alternative splicing, and find that Calu-15 promotes filopodia formation and cell migration. Calu-15 shuttles between the nucleus and cytoplasm through interacting with importin α, Ran GTPase, and Crm1. The phosphorylation of the threonine at position 73 (Thr-73) by casein kinase 2 (CK2) is essential for the nuclear import of Calu-15, and either Thr-73 mutation or inhibition of CK2 interrupts its nuclear localization. In the nucleus, Calu-15 increases the transcription of growth differentiation factor-15 (GDF-15), a member of the transforming growth factor-β (TGF-β) superfamily, via binding to its promoter region. Furthermore, Calu-15 induces filopodia formation mediated by GDF-15. Together, we identify that Calu-15, a novel isoform of Calu with phosphorylation-dependent nuclear localization, has a critical role in promoting filopodia formation and cell migration by upregulating the GDF-15 transcription.