MUC-1 aptamer targeted superparamagnetic iron oxide nanoparticles for magnetic resonance imaging of pancreatic cancer in vivo and in vitro experiment.

This study aims to explore the ability of magnetic resonance imaging (MRI) in mucin 1 (MUC1) modified superparamagnetic iron oxide nanoparticle (SPION) targeting human pancreatic cancer (PC). The MUC1 target-directed probe was prepared through MUC1 conjugated to SPION using the chemical method to assess its physiochemical characteristics, including hydration diameter, surface charge, and magnetic resonance signal. The cytotoxicity of MUC1-USPION was verified by MTS assay. BxPC-3 was cultured with MUC1-USPION and SPION in different concentrations. The combined condition of the targeted probes and cells were observed through Prussian blue staining. The nude mice model of pancreatic cancer was established to investigate the application of the probe. MRI was performed to determine the intensity of the signal of the transplanted tumor, while immunohistochemistry and Western blot analysis were performed to detect the expression of MUC1 after taking the transplanted tumor specimen. The particle size of the prepared molecular probe was 63.5 ± 3.2 nm, and the surface charge was 10.2 mV. Furthermore, the probe solution could significantly reduce the MRI at T2 , and the magnetic resonance transverse relaxation rate (ΔR2 ) has a linear relationship with the concentration of iron in the solution. The cell viability of MUC1-USPION in different concentrations revealed no statistical difference, according to the MTS assay. In vitro, the MRI demonstrated decreased T2WI signal intensity in both groups, especially the targeting group. In vivo, MUC1 could selectively accumulate in the nude mice model, and significantly reduce the T2 signal strength. In subsequent experiments, the expression of MUC1 was high in pancreatic cancer tissues, but low in normal pancreatic tissues, as determined by immunohistochemistry and Western blot analysis. The prepared samples can be combined with pancreatic cancer tissue specificity by in vivo imaging, providing reliable early in vivo imaging data for disease diagnosis.

Osteopontin Promotes Cell Migration and Invasion, and Inhibits Apoptosis and Autophagy in Colorectal Cancer by activating the p38 MAPK Signaling Pathway.

BACKGROUND: Osteopontin (OPN) is highly expressed in colorectal cancer (CRC) and is associated with disease progression in vivo. High levels of OPN have been demonstrated to predict low survival rates in CRC. Autophagy is a process of self-digestion, which is thought to play a significant role in carcinogenesis. However, the mechanisms of OPN's effects on CRC cell autophagy have not been elucidated. Therefore, we aimed to investigate possible mechanisms of OPN's effects on CRC autophagy. METHODS: HCT116 cell proliferation, apoptosis, and migration and invasion ability were identified by cell counting k¡t-8 assay, flow cytometry, wound healing assay, and transwell chamber invasion assay, respectively. The ratios of proteins LC3-II/LC3-I, P62, and Atg7 were analyzed by Western-blot. Expressions of Beclin-1, Atg4b, Bnip3, and Vps34, both in transcriptional and translational levels, were analyzed and compared by RT-PCR and Western blot. Immunofluorescence and co-focusing experiments were used to investigate the formation of autophagosomes. RESULTS: The results showed that OPN can promote cell proliferation, migration, and invasion, as well as inhibit cell apoptosis. It was also demonstrated that OPN could inhibit cell autophagy. Further experiments revealed that the inhibitory effect of OPN on autophagy could be reversed by blocking the p38 MAPK pathway in HCT116 cells. CONCLUSION: OPN is involved in HCT116 cell progression and is capable of inhibiting cell autophagy possibly by activating the p38 MAPK signaling pathway, implying that OPN could be a potential novel molecular therapeutic biomarker in patients with CRC.

A novel water-soluble benzothiazole derivative BD926 triggers ROS-mediated B lymphoma cell apoptosis via mitochondrial and endoplasmic reticulum signaling pathways.

Benzothiazole derivatives are known for various biological activities, and their potency in cancer therapy have received considerable attention in recent years. However, the poor water solubility of most benzothiazole derivatives has limited their clinical application. We developed BD926, a novel water-soluble benzothiazole derivative and showed here that it could inhibit the proliferation and induce apoptosis of human Ramos B-lymphoma cells. We further showed that BD926 triggered apoptosis through both mitochondria and endoplasmic reticulum pathways. Moreover, BD926 caused cell cycle arrest at G0/G1 stage. Furthermore, accumulation of reactive oxygen species (ROS) were observed after BD926 treatment and ROS inhibitor was able to attenuate BD926-induced apoptosis, which suggested that BD926-induced apoptosis may be due to over-producing ROS. These results demonstrate the anticancer effects of BD926 in cell models and raise the possibility for the application of BD926 in cancer therapy.

PEGylation alleviates the non-specific toxicities of Alpha-Momorcharin and preserves its antitumor efficacy in vivo.

Alpha-Momorcharin (α-MMC) is a ribosome inactivating protein from Momordica charantia with anti-tumor activity. Previously, we had observed that modification of α-MMC with polyethylene glycol (PEG) could reduce toxicity, but it also reduces its anti-tumor activity in vitro. This study aims to investigate whether the metabolism-extended properties of α-MMC resulting from PEGylation could preserve its anti-tumor efficacy in vivo through pharmacokinetics and antitumor experiments. The pharmacokinetics experiments were conducted in rats using the TCA (Trichloroacetic Acid) method. Antitumor activity in vivo was investigated in murine mammary carcinoma (EMT-6) and human mammary carcinoma (MDA-MB-231) transplanted tumor mouse models. The results showed that PEGylation increased the plasma half-life of α-MMC in rats from 6.2-7.5 h to 52-87 h. When administered at 1 mg/kg, α-MMC-PEG and α-MMC showed similar anti-tumor activities in vivo, with a T/C% of 38.56% for α-MMC versus 35.43% for α-MMC-PEG in the EMT-6 tumor model and 36.30% for α-MMC versus 39.88% for α-MMC-PEG in the MDA-MB-231 tumor model (p > 0.05). Importantly, at the dose of 3 mg/kg, all the animals treated with α-MMC died while the animals treated with α-MMC-PEG exhibited only moderate toxic reactions, and α-MMC-PEG exhibited improved anti-tumor efficacy with a T/C% (relative tumor growth rate) of 25.18% and 21.07% in the EMT-6 and MDA-MB-231 tumor models, respectively. The present study demonstrates that PEGylation extends the half-life of α-MMC and alleviates non-specific toxicity, thereby preserving its antitumor efficacy in vivo, and a higher lever of dosage can be used to achieve better therapeutic efficacy.

PEGylation is effective in reducing immunogenicity, immunotoxicity, and hepatotoxicity of α-momorcharin in vivo.

BACKGROUND AND AIM: α-momorcharin (α-MMC), a type I ribosome-inactivating protein (RIP) from Momordica charantia, is well known for its antitumor and antivirus activities. However, the immunotoxicity and hepatotoxicity hampers its potential therapeutic usage. In order to reduce its toxicity, we had modified the α-MMC with polyethylene glycol (PEG), and detected the toxicity of the PEGylated α-MMC conjugates (α-MMC-PEG) in vivo. MATERIALS AND METHODS: After α-MMC purified from bitter melon seeds, α-MMC-PEG was constructed with a branched 20 kDa (mPEG) 2-Lys-NHS, the tests of immunogenicity, immunotoxicity, and general toxicity of α-MMC-PEG were conducted in guinea pig and rat. RESULTS: The titer of specific IgG in rats, immunized by α-MMC-PEG, were approximately one-third of those that by α-MMC, all the guinea pigs treated with α-MMC died of anaphylaxis shock within 5 min, while no animals treated with α-MMC-PEG died in the active systemic anaphylaxis (ASA) test. The passive cutaneous anaphylaxis (PCA) reaction of α-MMC-PEG challenge in rats was significantly smaller than that of the α-MMC. The liver damage was greatly released, such as the change of globulin (GLB), aspartate aminotransferase (AST), total bilirubin (TBIL) cholesterol (CHOL), albumin (ALB), and the degree of hepatocyte necrosis in repeated toxicity study. CONCLUSIONS: PEGylation is effective in reducing the immunogenicity, immunotoxicity, and hepatotoxicity of α-MMC in vivo.

[Comparision of intracellular localization and recycling route of mouse nepmucin and CD31 in endothelial cells].

AIM: To compare the localization and recycling between nepmucin and CD31 molecules on transfected endothelial cells, and attempted to clarify the recycling mechanisms of nepmucin in endothelial cells. METHODS: Recycling assay and internalization assay were employed to compare the localization and recycling pathway of nepmucin and CD31. The internalized and recycling nepmucin and CD31 molecules on transfected endothelial cells were double or single stained with specific fluorchrome-labeled monoclonal antibodies against nepmucin (Alexa Fluor 488-ZAQ5) and/or CD31 (Alexa Fluor 488-anti-CD31 or Alexa Fluor 594-anti-CD31), then observed under confocal microscopy. RESULTS: Mouse nepmucin underwent intracellular recycling like CD31, but which recycling rate was significantly lower. The CD31 and nepmucin molecules showed largely distinct localization in endothelial cells. CD31 was found mainly on the cell surface, while nepmucin was found predominantly in the deep area of cytoplasm and partly on the cell membrane. CONCLUSION: The distribution of mouse nepmucin in endothelial cells are different from CD31. Nepmucin underwent intracellular recycling like CD31 but employed different mechanisms.

[Preparation and identification of monoclonal antibody against hMOF].

OBJECTIVE: To prepare and identify the monoclonal antibody (mAb) against hMOF. METHODS: BALB/C mice were immunized with protein from the spleen cells isolated and fused with SP2/0 cells. After several rounds of screening and cloning, the hybridoma cell strain secreting anti-hMOF mAb was obtained. Its specificity was evaluated with ELISA and Western blot, and the titer, immunoglobulin subtype and affinity of the mAb were measured. RESULTS: One cell strains of hybridoma were obtained and named as 4C1C8. The anti-hMOF mAb secreted by the hybridoma cell strain was identified as IgG1 subtype. The mAb titers in ascitic fluid were 1 409600, as determined with ELISA with an affinity reaching to 7.65 x 10(6) L/mol. Western blot demonstrated that the antibodies could specifically recognize the immunogen. The cell immunohistochemistry proved that the antibody could recognize the hMOF antigens expressed on the normal cells HL7702. CONCLUSION: The success in anti-hMOF mAb preparation provides the basis for further study of hMOF.

[Preparation and identification of a monoclonal antibody against recombinant human L-type pyruvate kinase N].

OBJECTIVE: To prepare and identify the monoclonal antibody (mAb) against pyruvate kinase N terminal (PK-N). METHODS: BALB/C mice were immunized with immunogen PK-N-GST-tag. Then the spleen cells were isolated and fused with SP2/0 cells. After several rounds of detecting and cloning, the hybridoma cell strains secreting anti-PK-N mAb were obtained. Its specificity was evaluated with ELISA and Western blot, and the titer, immunoglobulin subtype and affinity of the mAb were measured. RESULTS: Two cell strains of hybridoma, 2B2E4G and 2C6F5, were obtained. The hybridoma cell strains secreting anti-PK-N mAb belonged to IgG2b subtype, with a mAb titer in ascetic fluid of 1 : 409600 and 1 : 102400, respectively. Their affinity reached 3.54 x 10(8) L/mol and 2.72 x 10(8) L/mol, respectively, as determined by ELISA. Western blot demonstrated that the mAb could specifically recognize the immunogen and the natural cell lysis protein. The cell immunohistochemistry proved that the antibody could recognize human L type pyruvate kinase expressed in the plasma of HL-7702 cell strain and paraffin slice of hepatoma. CONCLUSION: The success in anti-PK-N mAb preparation provides a foundation for further studies into glycolysis in normal condition and metabolic diseases.

[Association study on single nucleotide polymorphisms in HTRA1 gene and rheumatoid arthritis].

OBJECTIVE: To study the association between the single nucleotide polymorphisms (SNPs) in the high-temperature requirement A-1 (HTRA1) gene and rheumatoid arthritis (RA) in Chinese Han population. METHODS: Five SNPs in the HTRA1 gene (rs2014307, rs2248799, rs2300433, rs714816 and rs2268356) were genotyped by ABI Snapshot method in Han Chinese cohort composed of 344 patients with RA and 288 healthy controls. The serum rheumatoid factor (RF) and C-reactive protein (CRP) of the patients were determined by endpoint nephelometry method. RESULTS: Genotypes of all the five SNPs in the HTRA1 gene were not significantly different between the RA patients and controls (P> 0.05). Haplotypes generated by these five SNPs did not show significantly difference between the two groups either (P> 0.05). Serum RF levels in the RA patients had no significant difference among the genotypes for four SNPs (rs2014307, rs2248799, rs714816, and rs2268356) in the HTRA1 gene, while RF levels in the RA patients with genotypes AA+AG of the rs2300433 locus were significantly higher than that in genotype GG carriers (P< 0.05). Serum CRP levels in the RA patients had no significant difference among the genotypes for all the five SNPs. CONCLUSION: Author's results suggested that although the five SNPs in the HTRA1 gene were not associated with RA in Chinese Han population, RF levels in the RA patients with genotypes AA and AG in the rs2300433 locus were significantly higher than the GG carriers. The HTRA1 role in RF regulation needs to be further investigated.

[Linkage analysis of one family with autosomal dominant high myopia].

OBJECTIVE: To map the high myopia gene in a Chinese family with autosomal dominant high myopia. METHODS: A family with autosomal dominant high myopia in three generations was collected. Eighteen short-tandem-repeat markers on previously reported loci linked to high myopia were chosen for genotyping and two-point linkage analysis was carried out. RESULTS: The spherical equivalent of affected individuals ranges from -6.00D to -20.00D and the genetic pattern is autosomal dominant. The LOD score was less than -1 in all 18 microsatellite markers, indicating that there was no linkage between these markers and the high myopia related genes in this family. CONCLUSION: A novel myopia locus for high-grade myopia may exist in the kindred. Genome-wide scan will be needed to determine this novel locus.

[Inhibition of proliferation in MCF-7 breast cancer cells by plasmid-based siRNA targeting to oncogene c-myc].

OBJECTIVE: To investigate the effects of plasmid-based siRNA targeting to oncogene c-myc on c-myc/ c-Myc expressions and cells proliferation in MCF-7 breast cancer cells. METHODS: siRNA eukaryotic expression plasmid p-Mat01-1 targeting to the sequence 589-609 of oncogene c-myc and its mismatch plasmid p-Mis09-1 were constructed, and transiently transfected MCF-7 cells using Lipo2000. Semi-quantitative RT-PCR and Western blot were used to analyze the expressions of c-myc/c-Myc in MCF-7 cells, and cells proliferation was detected by MTT assay. RESULTS: p-Mat01-1 inhibited the expressions of c-myc mRNA (24 h: P < 0.01) and c-Myc protein (5 d. P < 0.01) in MCF-7 cells as compared with pEGFP-C1 and p-Mis09-1 controls, and suppressed the proliferation of MCF-7 cells significantly (3 d: P < 0.05, 5, 7 d: P < 0. 01). CONCLUSION: Plasmid-based siRNA targeting to oncogene c-myc could inhibit the expressions of c-myc/c-Myc in MCF-7 breast cancer cells efficiently, suggesting that the downregulation of c-myc/c-Myc could suppress the proliferation of MCF-7 cells in vitro.

[Preparation and characterization of a monoclonal antibody against human SOCS3].

OBJECTIVE: To prepare and characterize the monoclonal antibody (mAb) against human SOCS3. METHODS: BALB/c mice were immunized with recombinant GST-SOCS3 protein, from which the spleen cells were isolated and fused with Sp2/0 cells. After several rounds of screening and cloning, the hybridoma cell strain secreting anti-SOCS3 mAb was obtained, whose specificity was evaluated using ELISA and Western blotting, and the titer, immunoglobulin subtype and affinity of the mAb were also measured. RESULTS: The hybridoma cell strain secreting anti-SOCS3 mAb was identified to belong to IgG2a subtype. The mAb titers in cultural supernatant and acetic fluid were 1:640 and 1:25600, respectively, as determined by ELISA with affinity reaching 4.84x10(6) L/mol. CONCLUSION: The success in anti-SOCS3 mAb preparation provides the basis for further study of the negative regulation of cytokine signal transduction and the immunoregulation in microorganism infections.

[The preparation and identification on monoclonal antibody to platelet-derived growth factor receptor].

OBJECTIVE: Through genetic engineering to produce the fusion protein of glutathione S-transferase (GST) linked to amino-terminal end of platelet-derived growth factor receptor (PDGFR), and to prepare the bioactive monoclonal antibody. METHODS: With taking GST-PDGFR-N fusion protein as immunogen, the anti-PDGFR monoclonal antibody was produced by using the hybridoma technique, of which then the antigen binding characteristic was identified by indirect enzyme-linked immunosorbent assay (ELISA), Western blot and immunohistochemistry methods. RESULTS: Two cell strains of hybridoma were obtained and named as 3B12F5 and 3C6H7C11 which secreted the anti-PDGFR monoclonal antibody, of which the class and subtype identification demonstrated both strains to produce all type of IgG1. The indirect ELISA result showed that the titers of ascites fluid which two hybridoma induced were 1 : 102400 and 1 : 25600. Western blot demonstrated that the two antibodies could recognize specifically the immunogen on PDGFR and U251 cell line. The cell immunohistochemistry proved that the antibody could recognize the expressed PDGFR antigens of neurogliocytoma U251 and bladder carcinoma BIU87 cell lines. CONCLUSION: We prepare successfully the PDGFR monoclonal antibody and provide a useful tool for researching on the PDGFR expression and clinical detection.