Tumor cell-derived exosomes mediating hsa_circ_0001739/lncRNA AC159540.1 facilitate liver metastasis in colorectal cancer.

BACKGROUND: The current study probed into how tumor cell-derived exosomes (Exos) mediated hsa_circ_0001739/lncRNA AC159540.1 to manipulate microRNA (miR)-218-5p/FTO-N6-methyladenosine (m6A)/MYC signal axis in liver metastasis in colorectal cancer (CRC). METHODS: hsa_circ_0001739 and lncRNA AC159540.1 were identified as the upstream regulator of miR-218-5p using ENCORI and LncBase databases. Expression patterns of miR-218-5p, hsa_circ_0001739, lncRNA AC159540.1, FTO, and MYC were detected, accompanied by loss-and-gain-of function assays to examine their effects on CRC cell biological functions. SW480 cells-derived Exos were purified, followed by in vitro studies to uncover the effect of hsa_circ_0001739/lncRNA AC159540. RESULTS: miR-218-5p was downregulated while hsa_circ_0001739/lncRNA AC159540.1 was upregulated in CRC tissues and cells. Silencing of hsa_circ_0001739/lncRNA AC159540.1 restrained the malignant phenotypes of CRC cells. Exos-mediated hsa_circ_0001739/lncRNA AC159540.1 competitively inhibited miR-218-5p to elevate FTO and MYC. The inducing role of Exos-mediated hsa_circ_0001739/lncRNA AC159540.1 in CRC was also validated in vivo. CONCLUSION: Conclusively, Exos-mediated circ_0001739/lncRNA AC159540.1 regulatory network is critical for CRC, offering a theoretical basis for CRC treatment.

sMicroRNA-28-5p acts as a metastasis suppressor in gastric cancer by targeting Nrf2.

The transcription factor nuclear factor (erythroid-2)-related factor 2 (Nrf2) can principally serve a mode of protection for both the normal cells and cancer cells from cellular stress, and elevates cancer cell survival. microRNA-28 (miR-28) has been involved in the regulation of Nrf2 expression in breast epithelial cells. However, no comprehensive analysis has been conducted regarding the function of miR-28-5p regulating Nrf2 in gastric cancer (GC). In this study, we aimed to evaluate their interaction and biological roles in the migration and invasion of GC cells. The expression of Nrf2 in the cancer tissues harvested from 42 patients with GC was examined by an array of molecular techniques comprising of Immunohistochemical staining, RT-qPCR and Western blot analysis. Kaplan-Meier method was adopted for analysis of the correlation of Nrf2 with the prognosis of GC patients. Interaction between miR-28-5p and Nrf2 was determined using the bioinformatics analysis and dual luciferase reporter gene assay. Gain- and loss-of-function studies of miR-28-5p and Nrf2 were conducted to elucidate their effects on GC cell migration, invasion and metastasis, as well as expression pattern of several epithelial-mesenchymal transition (EMT)-related proteins. Results indicated that the expression pattern of Nrf2 was significantly upregulated in GC tissues and indicative of poor prognosis of GC patients. miR-28-5p was verified to target Nrf2 and downregulate its expression. GC cells with overexpression of miR-28-5p or Nrf2 knockdown exhibited a marked reduction in the migrated and invasive abilities, along with the N-cadherin expression yet an increase of E-cadherin expression. Furthermore, miR-28-5p exerted an inhibitory function on the metastatic and tumorigenicity of GC cells. In conclusion, miR-28-5p is a comprehensive tumor suppressor that inhibits GC cell migration and invasion through repressing the Nrf2 expression. Therefore, miR-28-5p may serve as a potential biomarker for the prognosis of GC and a novel therapeutic target in advanced GC.

Heavy metal influence on BDE-47 uptake in the human KERTr keratinocyte cell line.

Significant correlations between concentrations of PBDEs and heavy metals were observed in the human body. However, there is a lack of evidence on the linkage between the uptake of heavy metals and PBDEs. This study is the first report on the BDE-47 uptake profile in a human cell line. Hg and As exposures to KERTr (human skin derived keratinocyte) did not significantly (p > 0.05) affect the uptake of BDE47, whereas Pb and Cd significantly (p < 0.05) affected the uptake of BDE-47 in KERTr. The change in Km was minor after exposure to all heavy metals. The maximum transport rate (Vmax) after exposure to Pb (Vmax: 5.23 ± 0.49) and As (Vmax: 4.95 ± 0.60) was significantly increased when compared with the background of the KERTr cell line (Vmax: 4.07 ± 0.35). Real-time RT-PCR indicated that OATP-B, OATP-D, and OATP-E were expressed in the KERTr cell line. The upregulation or downregulation of OATP B and D genes were minor after exposure to heavy metals, but the OATP E gene was upregulated by three to fourfold in KERTr cell line after exposure to Pb an Cd, which may explain the significant increase of uptake of BDE-47 in KERTr after exposures to Pb and Cd. This study indicated that the uptake effects should be considered when performing risk assessment of human exposure to PBDEs and heavy metal.

Germline mutations of the E-cadherin gene in families with inherited invasive lobular breast carcinoma but no diffuse gastric cancer.

BACKGROUND: Present data are highly suggestive but do not unequivocally prove the cosegregation of germ-line CDH1 mutations with inherited invasive lobular breast cancer (ILBC). METHODS: Two Caucasian families with 6 pathologically confirmed ILBC cases but no diffuse gastric cancer (DGC) were identified in our oncogenetics consultations. Screening for mutations of CDH1, BRCA1, and BRCA2 genes was performed on blood samples. When available, loss of heterozygosity (LOH) and immunohistochemistry (IHC) analyses were performed on tumor samples. RESULTS: No BRCA1 or BRCA2 mutation was found. Deleterious CDH1 germ-line mutations c.283C>T and c.1582del were found in all the 4 living women with ILBC in family 1 and family 2, respectively. The mutation c.283C>T was also present in a healthy 71-year-old male and 2 obligate carriers in family 1. No DGC was observed in the 2 families. Loss of the wild-type CDH1 allele in 1 of the breast tumors was confirmed by LOH and IHC studies, in accordance with the "2-hit" model of tumor suppressor genes. CONCLUSIONS: Germline CDH1 mutation can be cosegregated with ILBC in the absence of DGC. Present data do not support recommendation of prophylactic gastrectomy in CDH1 germline mutation carriers with ILBC. Cancer 2011. © 2011 American Cancer Society.

Monodispersed submicron porous silica particles functionalized with CD derivatives for chiral CEC.

Rapid and efficient enantioseparation of halogen aryl alcohols and beta-blockers propranolol and pindolol in packed bed CEC (p-CEC) using as-prepared submicron porous silica chiral stationary phases (CSPs) has been achieved. Monodispersed 0.66 and 0.81 microm chiral submicron porous silica spheres were prepared using tetramethoxysilane and hexadecyltrimethylammonium bromide, followed by a hydrothermal treatment method with ammonia-ethanol to expand the pore of silica spheres without changing their spherical morphology. A proper specific surface of ca. 230 m(2)/g and pore sizes average of 6-8 nm were obtained by this method. The submicron porous silica spheres were modified with mono-6-phenylcarbamoylated beta-CD via thiol-en radical addition. They were packed into 9 cm 50 microm id capillary columns with photopolymerized monolithic frits. These submicron CSPs showed greater column efficiency (about 476 000 plates/m for 4-iodophenyl-1-ethanol) and higher resolution than the corresponding 3 microm CSP.

[Study on the molecular recognition of perhydroxycucurbit[6] uril with methyl orange by spectroscopic methods].

The inclusion interaction of perhydroxycucurbit[6] uril (HOCB6) with methyl orange (MO) was studied by UV spectroscopic and fluorimetric methods. Several effect factors, such as pH values, common organic solvents and surfactants on the fluorescence intensity and the stability of the complex were investigated. The results indicate that the fluorescence intensity of MO was enhanced with a blue shift as host molecules were added, showing that MO was accommodated into the hydrophobic cavities of HOCB6 and an endo-inclusion complex was formed. The hydrophobic interaction between HOCB6 and MO mainly contributed to the formation of 1 : 1 type HOCB6-MO. Its complex constant was determined to be 1.41 x 10(2) L x mol(-1). The comparative study of HOCB6 with other supramolecules, such as cucurbit[6] uril (CB6), p-(N,N-dimethyl-aminomethyl) calix [8]arene and beta-cyclodextrin, was also carried out by using MO as a guest probe. The spectra changes showed that cucurbit[6] uril (CB6) can also form 1 : 1 type endo-inclusion complex with MO, which is similar to HOCB6, but its complex constant (34.65 L x mol(-1)) is small. The spectra changes also showed that the endo-inclusion complex with 2 : 1 type was formed between beta-cyclodextrin and MO, While the exo-inclusion complex was formed between p-(N,N-dimethyl-aminomethyl) calix[8] are-ne and MO, leading to fluorescence quenching, and their complex constants were determined to be 6.14 x 10(6) L2 mol(-2) and 1.35 x 10(4) L x mol(-1), respectively.

[Study on the interaction between p-octacarboxyphenylazocalix[8]arene and norfloxacin by fluorescence spectrometry].

In the present paper, p-octacarboxyphenylazocalix[8]arene (CPAC) was used as supramolecular probe according to a reported method. The interaction of CPAC with drug norfloxacin (NFLX) was studied by fluorescence spectrometry. The results show that CPAC can strongly quench the fluorescence of NFLX because of the complex interaction between host and guest molecules in exo-inclusion complex. The spectral changes indicated that the quenching can be considered as static quenching mode. The hydrophobic interaction between the cavity of CPAC and the quinoline ring was the main force to consolidate the exo-inclusive complex CPAC-NFLX stability. The complex constant (K) and binding ratio (n) were determined to be 6. 38 X 10(5) L x mol(-1) and 1, respectively. Further experiment found that the calf thymus DNA and CPAC can combine, leading to the release of NFLX and the enhancement of fluorescence of the reaction system. It is expected that CPAC will be used as drug carrier and releaser.

High serum uric acid concentration predicts poor survival in patients with breast cancer.

BACKGROUND: Uric acid is a product of purine metabolism. Recently, uric acid has gained much attraction in cancer. In this study, we aim to investigate the clinicopathological and prognostic significance of serum uric acid concentration in breast cancer patients. METHODS: A total of 443 female patients with histopathologically diagnosed breast cancer were included. After a mean follow-up time of 56months, survival was analysed using the Kaplan-Meier method. To further evaluate the prognostic significance of uric acid concentrations, univariate and multivariate Cox regression analyses were applied. RESULTS: Of the clinicopathological parameters, uric acid concentration was associated with age, body mass index, ER status and PR status. Univariate analysis identified that patients with increased uric acid concentration had a significantly inferior overall survival (HR 2.13, 95% CI 1.15-3.94, p=0.016). In multivariate analysis, we found that high uric acid concentration is an independent prognostic factor predicting death, but insufficient to predict local relapse or distant metastasis. Kaplan-Meier analysis indicated that high uric acid concentration is related to the poor overall survival (p=0.013). CONCLUSIONS: High uric acid concentration predicts poor survival in patients with breast cancer, and might serve as a potential marker for appropriate management of breast cancer patients.

[Study on the inclusion interaction of water-soluble p-(N,N-dimethylamino)-calix[8]arene with diphenylamine-4-sulfonic sodium salt].

The inclusion interaction of water-soluble p-(N,N-dimethylaminomethyl)-calix[8]arene with diphenylamine-4-sulfonic acid sodium salt was investigated by fluorimetric method. When diphenylamine-4-sulfonic acid sodium salt was added into the p-(N,N-dimethylaminomethyl)-calix[8]arene solution, the emission spectrum of diphenylamine-4-sulfonic acid sodium salt occurred to a blue shift with the enhancement of the fluorescent intensity. The results show that the formation of the inclusion complex of the p-(N,N-dimethylaminomethyl)-calix[8]arene with diphenylamine-4-sulfonic acid sodium salt. The influence factors such as the pH value of solutions, solvents on the emission and excitation spectra of the inclusion complex were studied. It indicates that diphenylamine-4-sulfonic acid sodium salt penetrated the cavity of the calix[8]arene via the static action between the sulphonyl group of diphenylamine-4-sulfonic acid sodium salt and nitrogen atom of p-(N,N-dimethylaminomethyl)-calix[8]arene and the hydrophobic interaction of the aromatic rings.

[Study on the interaction of water-soluble p-(N,N-dimethylaminomethyl) calix[8] arene with DNA by fluorescent spectrometry].

The interaction of water-soluble p-(N, N-dimethylaminomethyl) calix [8] arene (CX8) with DNA was studied using adriamycin(ADM) as a probe by fluorescent spectrometry. The effect factors such as, pH of solution, salt effect and unlinking DNA on the spectra were also investigated. The interaction mechanism was proposed. The authors observed that the fluorescence of ADM was quenched by calf thymus DNA, and the fluorescence intensity of DNA-ADM enhanced with the increasing of the CX8 gradually. The result indicates that the strong electrostatic interaction between the oxyphosphate anion of DNA and the CX8 existed. According to the plot of scatchard, the results imply that the influence of CX8 on interaction of DNA-ADM belongs to mixed model, on the one hand, in the condition of neutral and acidity, the oxyphosphate anion of DNA can be neutralized by CX8 partially, which induced the contraction of DNA and the conformational change of DNA, which led to release ADM from DNA partially, on the other hand, the CX8 can also compete the electrostatic sites with ADM directly.

Preparation and characterization of a p-tert-butyl-calix[6]-1,4-benzocrown-4-bonded silica gel stationary phase for liquid chromatography.

A p-tert-butyl-calix[6]-1,4-benzocrown-4-bonded silica gel stationary phase (CR6BS) was first prepared via 3-glycidoxypropyltrimethoxysilane as coupling reagent for high performance liquid chromatography. The structure of the new stationary phase was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFT), elemental analysis and thermal analysis. The chromatographic performance of the bonded-stationary phase was evaluated by using neutral, acidic and basic solutes as probes. Meanwhile, comparative study of the new stationary phase with a p-tert-butyl-calix[6]arene-bonded silica gel stationary phase (C6BS, the parent) and ODS was done under the same chromatographic conditions. The results show that the new stationary phase has an excellent reversed-phase property, which is similar to C6BS and ODS. However, the selectivities for some aromatic compounds are different from the parent phase (C6BS) and ODS, especially the latter. In one hand, as hybrid of calixarene and crown ether, CR6BS with the oxygen atoms of ether-bridge can provide the complexation sites for the solutes, lacking of C6BS. On the other hand, the rigid conformation of CR6BS may be responsible to the different performance partially. CR6BS exhibits high selectivity in the separation of alkylated aromatics from their parents as compared with C6BS.

Preparation and characterization of a new p-tert-butyl-calix[8]arene-bonded stationary phase for high-performance liquid chromatography.

A new p-tert-butyl-calix[8]arene-bonded silica gel stationary phase (CABS) was prepared via 3-glycidoxypropyltrimethoxysilane as a coupling reagent for HPLC. Its structure was characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), elemental analysis and thermal analysis. The chromatographic performance of new packing was evaluated by using basic, acidic and neutral aromatic compounds as probes compared with conventional ODS. The results show that the new stationary phase has an excellent reversed-phase property and high selectivities for substituted aromatics compared with ODS, because CABS can provide various sites for the analytes, such as hydrogen-bonding interactions, pi-pi interactions, and inclusion complex, besides hydrophobic interactions.

Metastatic axillary lymph node ratio (LNR) is prognostically superior to pN staging in patients with breast cancer--results for 804 Chinese patients from a single institution.

The number of axillary lymph nodes involved and retrieved are important prognostic factors in breast cancer. The purpose of our study was to investigate whether the lymph node ratio (LNR) is a better prognostic factor in predicting disease-free survival (DFS) for breast cancer patients as compared with pN staging. The analysis was based on 804 breast cancer patients who had underwent axillary lymph node dissection between 1999 and 2008 in Sun Yat-Sen University Cancer Center. Optimal cutoff points of LNR were calculated using X-tile software and validated by bootstrapping. Patients were then divided into three groups (low-, intermediate-, and high-risk) according to the cutoff points. Predicting risk factors for relapse were performed according to Cox proportional hazards analysis. DFS was estimated using the Kaplan-Meier method and compared by the log-rank test. The 5-year DFS rate decreased significantly with increasing LNRs and pN. Univariate analysis found that the pT , pN, LNR, molecule type, HER2, pTNM stage and radiotherapy well classified patients with significantly different prognosis. By multivariate analysis, only LNR classification was retained as an independent prognostic factor. Furthermore, there was a significant prognostic difference among different LNR categories for pN2 category, but no apparent prognostic difference was seen between different pN categories in any LNR category. Therefore, LNR rather than pN staging is preferable in predicting DFS in node positive breast cancer patients, and routine clinical decision-making should take the LNR into consideration.

Enantioseparation of a novel "click" chemistry derived native beta-cyclodextrin chiral stationary phase for high-performance liquid chromatography.

A novel native beta-cyclodextrin chiral stationary phase was prepared via "click" chemistry with cuprous iodide-triphenylphosphine complex as the catalyst and applied for enantioseparation of Dns-amino acids, substituted phenyl and phenoxy group modified propionic acids, flavonoids, and some pharmaceutical compounds such as nimodipine, propranolol, brompheniramine and bendroflumethiazide in reversed-phase high-performance liquid chromatography. The studied analytes could be resolved under different separation conditions. The resolution of Dns-DL-Leu could reach 5.08 using a mobile phase consisting of 1% (w/w) triethylammonium acetate buffer (pH 4.11) and methanol (50:50 v/v). The effects of buffer pH and the content of organic modifier on enantioseparation of Dns-amino acids by this novel chiral phase were being investigated. The separation results demonstrate that click chemistry, a versatile reaction, affords a facile approach towards the preparation of stable chiral stationary phases.

High performance liquid chromatography with cyclodextrin and calixarene macrocycle bonded silica stationary phases for separation of steroids.

Beta-cyclodextrin, p-tert-butyl-calix[8]arene and chloropropyl bonded silica stationary phases have been prepared and were applied at the same time to develop a chromatographic procedure to separate steroids. In order to select the best type of stationary phase for the analysis, similar preparation processes of the two kinds of macrocycle stationary phases with the same spacer were adopted respectively. The chromatographic behaviors and retention mechanisms of the two kinds of macrocycle stationary phases for steroids were systematically studied and compared with those of chloropropyl bonded silica and ODS. The effect of mobile phase variables, such as methanol content, pH value of buffer, ionic strength and buffer composition on chromatographic behaviors was investigated. The results showed that the retention mechanisms of the four stationary phases for steroids were obviously different, and excellent separation was achieved on beta-cyclodextrin bonded silica stationary phase (beta-CD-BS), as a consequence of the structure and the properties of the stationary phase. The retention process on beta-CD-BS exhibited inclusion complexation, hydrogen-bonding and weak hydrophobic interaction, while for p-tert-butyl-calix[8]arene bonded silica stationary phase (CBS), pi-pi and hydrogen-bonding besides hydrophobic interaction played an important role.

High performance liquid chromatography of aromatic carboxylic acids on p-tert-butyl-calix[8]arene-bonded silica gel stationary phase.

A new p-tert-butyl-calix[8]arene-bonded silica gel stationary phase (CABS) was used for the separation of some aromatic carboxylic acids by HPLC. The chromatographic behaviour of the solutes on CABS was studied in comparison with conventional ODS. The results show that the calix[8]arene-bonded phase exhibits a stronger retention and better selectivity than ODS for the aromatic carboxylic acids. The different elution order of the analytes was also observed on both packings, which show the existence of distinct retention mechanisms. According to chromatographic data, it can be concluded that the high selectivity of CABS for aromatic carboxylic acids ascribes to various interactions between CABS and the analytes, such as hydrophobic interaction, hydrogen bonding interaction, pi-pi interaction and inclusion interaction.

Studies on the chromatographic behavior of nucleosides and bases on p-tert-butyl-calix[8]arene-bonded silica gel stationary phase by HPLC.

The chromatographic behavior of some nucleosides, pyrimidines and purines on a new p-tert-butyl-calix[8]arene-bonded silica gel stationary phase (CABS) were studied by high performance liquid chromatography. Their retention behavior on CABS were compared with those on ODS. The influence of mobile phase variables, such as methanol content, pH and ionic strength on the retention behavior were studied. Some nucleosides, pyrimidines and purines on CABS were successfully separated. The results show that the calix[8]arene-bonded phase exhibits high selectivities for the above analytes in high aqueous mobile phases. According to the chromatographic data, it is indicated that hydrophobic interaction, hydrogen-bonding interaction, and dipole-dipole interaction are mainly responsible for the retention behavior. In addition, in some extent, the vertical stacking action of the analytes on CABS can also change the retention behavior. CABS was superior to ODS in the routine fast separation of nucleosides and bases.

Study on the chromatographic behavior of water-soluble vitamins on p-tert-butyl-calix[8]arene-bonded silica gel stationary phase by HPLC.

In this paper, the chromatographic behavior of some water-soluble vitamins was studied on a new p-tert-butyl-calix[8]arene-bonded silica gel stationary phase (CABS, 5mum particle size, the bonded amount 0.071mmolg(-1)) by using vitamin standards as probes for HPLC. The comparative study of the separation of these compounds was done by using CABS and ODS as stationary phases under the same chromatographic conditions. The better separation of six vitamins including: B(1), B(2), B(6), B(12), C, and nicotinic acid (B(5)), on CABS can be achieved by using isocratic mode with methanol-phosphate buffer (25:75, (v/v)) as mobile phase within 20min. The results show that the calix[8]arene-bonded phase exhibits high selectivity for water-soluble vitamins. We found that the elution order of B(2) (12.08min) and B(12) (16.42min) on CABS was very different from that of B(12) (7.76min) and B(2) (18.47min) on ODS, which indicate that different retention mechanisms exist in the chromatographic processes of the two stationary phases. According to the chromatographic data, it can be concluded that various chromatographic retention mechanisms are responsible for the separation of above compounds on CABS, such as hydrophobic interaction, hydrogen bonding interaction, and pi-pi interaction. The new packing has two advantages over ODS. On one hand, the polar and ionized analytes, such as C and B(5), exhibited stronger affinities to CABS because of hydrogen bonding interaction. On the other hand, the retention of B(2) and B(12) became shorter on CABS with weaker hydrophobicity in comparison with ODS. The new material exhibits the promising application in the separation of water-soluble vitamins.