Epithelial membrane protein 1 negatively regulates cell growth and metastasis in colorectal carcinoma

AIM:To determine the expression and function of epithelial membrane protein 1(EMP1)in colorectal carcinoma.METHODS:Colorectal samples were taken from cancer lesions and adjacent normal tissue in colorectal cancer patients immediately after endoscopic biopsy.A portion of the sample was either fixed in 4%paraformaldehyde and embedded in paraffin for immunohistochemistry or stored in liquid nitrogen for Western blot.In order to determine protein expression of EMP1in colorectal cancer(n=63)and normal tissue(n=31),semi-quantitative immunohistochemistry and Western blot were utilized.For in vitro studies,the human colorectal cancer cell line SW-480 was maintained in RPMI-1640 medium supplemented with 10%fetal bovine serum.Recombinant lentivirus mediated overexpression of EMP1 in SW-480 cells was quantified by real-time reverse transcription-polymerase chain reaction and Western blot.Control SW-480 cells were transfected with an empty vector.To further study the effect of EMP1 overexpression in SW-480 cells,cell proliferation,apoptosis,migration and invasion assays were conducted.RESULTS:Expression of EMP1 was significantly lower in colorectal cancer tissue than in normal tissue using both immunohistochemistry(39.7%vs 90.3%of tissues,P<0.05)and Western blot(0.126±0.022 vs0.632±0.053,P<0.05).The level of EMP1 protein expression was not correlated with gender,age,or tumor location.Decreased expression of EMP1 was significantly correlated with T stage,lymph node metastasis,clinic stage,and histological grade in patients with colorectal cancer(P<0.05).According to Kaplan-Meier analysis,low EMP1 expression correlated significantly with poor overall five-year survival(34.2%vs 64.0%survival,P<0.05).SW-480 cells transfected with EMP1 had a lower survival fraction,higher cell apoptosis(12.1%±1.3%vs 3.1%±0.6%,P<0.05),a significant decrease in migration and invasion(124.0±17.0 and 87.0±12.0,respectively vs 213.0±29.0 and 178.0±21.0,respectively,P<0.05),higher caspase-9(0.635±0.063 vs0.315±0.032,P<0.05),and lower VEGFC protein expression(0.229±0.021 vs 0.519±0.055,P<0.05)relative to cells not transfected with EMP1.CONCLUSION:Low EMP1 expression in colorectal cancer is associated with increased disease severity,suggesting that EMP1 may be a negative regulator of colorectal cancer.

Discrimination of foodborne pathogenic bacteria using synchrotron FTIR microspectroscopy

Traditional Fourier transform infrared(FTIR)spectroscopy has been recognized as a valuable method to characterize and classify kinds of microorganisms.In this study,combined with multivariate statistical analysis,synchrotron radiation-based FTIR(SR-FTIR) microspectroscopy was applied to identify and discriminate ten foodborne bacterial strains.Our results show that the whole spectra(3000-900 cm^(-1)) and three subdivided spectral regions(3000-2800,1800-1500 and 1200-900 cm^(-1),representing lipids,proteins and polysaccharides,respectively) can be used to type bacteria.Either the whole spectra or the three subdivided spectra are good for discriminating the bacteria at levels of species and subspecies,but the whole spectra should be given preference at the genus level.The findings demonstrate that SR-FTIR microspectroscopy is a powerful tool to identify and classify foodborne pathogenic bacteria at the genus,species and subspecies level.

Synchrotron infrared spectral regions as signatures for foodborne bacterial typing

Fourier-transform infrared(FTIR) spectroscopy has emerged as a viable alternative to biochemical and molecular biology techniques for bacterial typing with advantages such as short analysis time, low cost and laboratorial simplicity. In this study, synchrotron radiationbased FTIR(SR-FTIR) spectroscopy with higher spectral quality was successfully applied to type 16 foodborne pathogenic bacterial strains. Combined with principal component analysis(PCA) and hierarchical cluster analysis(HCA), we found that the specific spectral region1300-1000 cm^(-1), which reflects the information of phosphate compounds and polysaccharides, can be used as the signature region to cluster the strains into groups similar with genetic taxonomic method. These findings demonstrated that FTIR spectra combined with HCA have a great potential in quickly typing bacteria depending on their biochemical signatures.

Synchrotron FTIR spectroscopy reveals molecular changes in Escherichia coli upon Cu^2＋ exposure

Copper ions(e.g.,Cu^(2+)) have outstanding antibacterial properties,but the exact mechanism is rather complex and not fully understood.In this work,synchrotron Fourier transform infrared(FTIR) spectroscopy was used as an analytical tool to investigate the CuCl_2-induced biochemical changes in Escherichia coli.Our spectral measurements indicated that this technique is sensitive enough to detect changes in membrane lipids,nucleic acids,peptidoglycans and proteins of Cu^(2+)-treated bacteria.Interestingly,for short-time treated cells,the effects on phospholipid composition were clearly shown,while no significant alterations of proteins,nucleic acids and peptidoglycans were found.PeakForce quantitative nano-mechanics mode atomic force microscopy(AFM)confirmed the changes in the topography and mechanical properties of bacteria upon the Cu^(2+) exposure.This study demonstrated that FTIR spectroscopy combined with AFM can provide more comprehensive evaluation on the biochemical and mechanical responses of bacteria to copper.

New insight of obesity-associated NAFLD: Dysregulated “crosstalk” between multi-organ and the liver?

Obesity plays a crucial role in the development of non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanism for the pathogenesis of obesity-associated NAFLD remains largely obscure. Although the “multiple hit” theory provides a more accurate explanation of NAFLD pathogenesis, it still cannot fully explain precisely how obesity causes NAFLD. The liver is the key integrator of the body's energy needs, receiving input from multiple metabolically active organs. Thus, recent studies have advocated the “multiple crosstalk” hypothesis, highlighting that obesity-related hepatic steatosis may be the result of dysregulated “crosstalk” among multiple extra-hepatic organs and the liver in obesity. A wide variety of circulating endocrine hormones work together to orchestrate this “crosstalk”. Of note, with deepening understanding of the endocrine system, the perception of hormones has gradually risen from the narrow sense (i.e. traditional hormones) to the broad sense of hormones as organokines and exosomes. In this review, we focus on the perspective of organic endocrine hormones (organokines) and molecular endocrine hormones (exosomes), summarizing systematically how the two types of new hormones mediate the dialogue between extra-hepatic organs and liver in the pathogenesis of obesity-related NAFLD.

Association of serum zinc-α2-glycoprotein with non-alcoholic fatty liver disease

To the Editor:Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease worldwide.It is associated with visceral obesity and is considered to be the hepatic component of metabolic syndrome,as insulin resistance plays a major role in this process.