Fabrication of doxorubicin conjugated methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) nanoparticles and study on their in vitro antitumor activities.

The purpose of this study was to develop a novel drug-polymer conjugation (mPEG-b-PCL-DOX) and study on its toxicity, bio-safety, and in vitro antitumor activity of mPEG-b-PCL-DOX. The polymer methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) (mPEG-b-PCL) was prepared by ring-opening polymerization. Then, succinic anhydride was reacted with mPEG-b-PCL via esterification reaction to produce mPEG-b-PCL-COOH. Finally, the polymer mPEG-b-PCL-DOX was obtained by conjugating DOX to mPEG-b-PCL-COOH by amidation. The Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectra were used to study the structures of obtained polymers. Transmission electron microscope (TEM) and Dynamic laser scattering (DLS) were employed to monitor the morphology and size distribution of mPEG-b-PCL-DOX nanoparticles (NPs). The mPEG-b-PCL-DOX NPs were administrated to KM rats by intraperitoneal injection to study the bio-safety of final NPs. The cell uptake and in vitro anti-tumor activity of final NPs were carried out with HCT116 cells as models. FTIR and 1H NMR spectra confirmed the obtaining of mPEG-b-PCL-DOX. The fabricated NPs were in round shapes with an average diameter of 300 nm. These NPs did not induce hemolysis and physiological or pathological changes in rats's organs. Finally, cell teats showed that these NPs could be endocytosed by HCT 116 cells, and they had better anti-tumor effects than free DOX did. Therefore, the mPEG-b-PCL-DOX NPs had a potential application in anti-cancer therapy.

A qualitative study on the attitudes of patients with gastrointestinal cancer toward being informed of the truth.

OBJECTIVE: The aim of this study is to investigate the attitudes of hospitalized patients with gastrointestinal cancer toward being informed of the truth and to provide references for informing patients of their gastrointestinal cancer diagnosis. METHODS: Nine patients with gastrointestinal cancer were selected for this study by using a purposive sampling technique from a general surgery ward in a tertiary-level general hospital in Zhejiang Province from June 2016 to October 2016. Semi-structured, in-depth interviews were conducted, and the descriptive phenomenological method (developed by Amedeo Giorgi) was used to analyze the interview data. RESULTS: Five themes were developed through reading, analysis, reflection, and classification of the data: Theme 1, guessing the diagnosis of gastrointestinal cancer before being informed of the truth; Theme 2, eagerness to know the diagnosis results; Theme 3, expectations related to beginning treatment for cancer; Theme 4, stress and anxiety during treatment; and Theme 5, providing patients with hope and optimism at the early diagnosis stage. CONCLUSION: Patients have a strong desire to survive and can confidently confront their gastrointestinal cancer diagnosis. Medical staff should carefully select the appropriate time to inform patients of their diagnosis by evaluating their attitudes toward being informed, thereby actively meeting patients' needs for information and treatment.

Molecular cloning and expression characterization of translationally controlled tumor protein in silkworm pupae.

A Bombyx mori (B. mori) cDNA was isolated from silkworm pupae cDNA library encoding a homologue of translationally controlled tumor protein (BmTCTPk). BmTCTPk was expressed in E. coli; SDS-PAGE and Western blot showed the molecular weight of recombinant and native BmTCTPk is approximately 28 and 25 kDa, respectively; they are larger than the theoretical molecular weight. Immunohistochemical studies showed that BmTCTPk is uniformly distributed throughout the cytoplasm of BmN cells. In silkworm pupae, BmTCTPk is expressed in the midgut wall, the midgut cavity, and some fat body tissues lying between the midgut wall and body wall. Western blot and ELISAs performed on total protein extracts isolated from silkworm pupae at different development stages showed that, although BmTCTPk is expressed during all pupae stages, its expression level increases dramatically during late pupae stages, suggesting that BmTCTPk may play an important role during the developmental transition from pupa to imago.

Subcellular localization and RNA interference of an RNA methyltransferase gene from silkworm, Bombyx mori.

RNA methylation, which is a form of posttranscriptional modification, is catalyzed by S-adenosyl-L-methionone-dependent RNA methyltransterases (RNA MTases). We have identified a novel silkworm gene, BmRNAMTase, containing a 369-bp open reading frame that encodes a putative protein containing 122 amino acid residues and having a molecular weight of 13.88 kd. We expressed a recombinant His-tagged BmRNAMTase in E. coli BL21 (DE3), purified the fusion protein by metal-chelation affinity chromatography, and injected a New Zealand rabbit with the purified protein to generate anti-BmRNAMTase polyclonal antibodies. Immunohistochemistry revealed that BmRNAMTase is abundant in the cytoplasm of Bm5 cells. In addition, using RNA interference to reduce the intracellular activity and content of BmRNAMTase, we determined that this cytoplasmic RNA methyltransferase may be involved in preventing cell death in the silkworm.

Expression analysis and tissue distribution of two 14-3-3 proteins in silkworm (Bombyx mori).

14-3-3 proteins, which have been identified in a wide variety of eukaryotes, are highly conserved acidic proteins. In this study, we identified two genes in silkworm that encode 14-3-3 proteins (Bm14-3-3zeta and Bm14-3-3epsilon). Category of two 14-3-3 proteins was identified according to phylogenetic analysis. Bm14-3-3zeta shared 90% identity with that in Drosophila, while Bm14-3-3epsilon shared 86% identity with that in Drosophila. According to Western blot and real time PCR analysis, the Bm14-3-3zeta expression levels are higher than Bm14-3-3epsilon in seven tissues and in four silkworm developmental stages examined. Bm14-3-3zeta was expressed during every stage of silkworm and in every tissue of the fifth instar larvae that was examined, but Bm14-3-3epsilon expression was not detected in eggs or heads of the fifth instar larvae. Both 14-3-3 proteins were highly expressed in silk glands. These results suggest that Bm14-3-3zeta expression is universal and continuous, while Bm14-3-3epsilon expression is tissue and stage-specific. Based on tissue expression patterns and the known functions of 14-3-3 proteins, it may be that both 14-3-3 proteins are involved in the regulation of gene expression in silkworm silk glands.

Expression and functional analysis of the cellular retinoic acid binding protein from silkworm pupae (Bombyx mori).

Cellular retinoic acid binding protein (CRABP) is a member of intracellular lipid-binding protein (iLBP), and closely associated with retinoic acid (RA) activity. We have cloned the CRABP gene from silkworm pupae and studied the interaction between Bombyx mori CRABP (BmCRABP) and all-trans retinoic acid (atRA). The MTT assay data indicated that when BmCRABP is overexpressed in Bm5 cells, the cells dramatically resisted to atRA-induced growth inhibition. Conversely, the cells were sensitive to atRA treatment upon knocking down the BmCRABP expression. Subcellular localization revealed that BmCRABP is a cytoplasm protein, even when treated with atRA, the CRABP still remained in the cytoplasm. These data demonstrated that the function of BmCRABP have an effect on the physiological function of atRA.