Theoretical Studies for Molecular Modeling of New Camptothecin Analogues

Irinotecan (7-ethyl-10-[4-(1-piperidino)-1-piperidino carbonyloxycamptothecin: CPT-11) is a widely used potent antitumor drug that is developed based on camptothecin. However, overexpression of ABCG2 (BCRP/MXR/ABCP) confers cancer cells resistance to SN-38, that is, the active metabolite of irinotecan. In the present study to develop a platform for the molecular modeling to circumvent cancer drug resistance associated with ABCG2, we have characterized a total of fourteen new SN-38 analogues by some typical properties, which were evaluated by molecular orbital (MO) calculations and neural network (NN) QSAR technique

Endosomal escape and the knockdown efficiency of liposomal-siRNA by the fusogenic peptide shGALA

An siRNA that specifically silences the expression of mRNA is a potential therapeutic agent for dealing with many diseases including cancer. However, the poor cellular uptake and bioavailability of siRNA remains a major obstacle to clinical development. For efficient delivery to tumor tissue, the pharmacokinetics and intracellular trafficking of siRNA must be rigorously controlled. To address this issue, we developed a liposomal siRNA carrier, a multi-functional nano device (MEND). We describe herein an approach for systemic siRNA delivery to tumors by combining the MEND system with shGALA, a fusogenic peptide. In cultured cell experiments, shGALA-modification enhanced the endosomal escape of siRNA encapsulated in a polyethylene glycol modified MEND (PEG-MEND), resulting in an 82% knockdown of the target gene. In vivo systemic administration clarified that the shGALA-modified MEND (shGALA-MEND) showed 58% gene silencing in tumor tissues at a dose of 4 mg of siRNA/kg body weight. In addition, a significant inhibition of tumor growth was observed only for the shGALA-MEND and no somatic or hepatic toxicity was observed. Given the above data, this peptide-modified delivery system, a shGALA-MEND has great potential for the systemic delivery of therapeutic siRNA aimed at cancer therapy

Establishment and characterization of immortalized bovine endometrial epithelial cells

Abstract:Bovine primary uterine endometrial epithelial cells (EECs) are not ideal for long-term studies, because primary EECs lose hormone responsiveness quickly, and/or they tend to have a short life span. The aims of this study were to establish immortalized bovine EECs and to characterize these cells following long-term cultures. Immortalized bovine EECs were established by transfecting retroviral vectors encoding human papillomavirus (HPV) E6 and E7, and human telomerase reverse transcriptase (hTERT) genes. Established bovine immortalized EECs (imEECs) showed the same morphology as primary EECs, and could be grown without any apparent changes for over 60 passages. In addition, imEECs have maintained the features as EECs, exhibiting oxytocin (OT) and interferon tau (IFNT) responsiveness. Therefore, these imEECs, even after numbers of passages, could be used as an in vitro model to investigate cellular and molecular mechanisms, by which the uterine epithelium responds to IFNT stimulation, the event required for the maternal recognition of pregnancy in the bovine species

Physical Activity Attenuates the Obesity-Induced Dysregulated Expression of Brown Adipokines in Murine Interscapular Brown Adipose Tissue

In recent years, brown adipose tissue (BAT), which has a high heat-producing capacity, has been confirmed to exist even in adults, and it has become a focal point for the prevention and the improvement of obesity and lifestyle-related diseases. However, the influences of obesity and physical activity (PA) on the fluid factors secreted from BAT (brown adipokines) are not well understood. In this study, therefore, we focused on brown adipokines and investigated the effects of obesity and PA. The abnormal expressions of gene fluid factors such as galectin-3 (Lgals3) and Lgals3 binding protein (Lgals3bp), whose proteins are secreted from HB2 brown adipocytes, were observed in the interscapular BAT of obese mice fed a high-fat diet for 4 months. PA attenuated the abnormalities in the expressions of these genes. Furthermore, although the gene expressions of factors related to brown adipocyte differentiation such as peroxisome proliferator-activated receptor gamma coactivator 1-α were also down-regulated in the BAT of the obese mice, PA suppressed the down-regulation of these factors. On the other hand, lipogenesis was increased more in HB2 cells overexpressing Lgals3 compared with that in control cells, and the overexpression of Lgals3bp decreased the mitochondrial mass. These results indicate that PA attenuates the obesity-induced dysregulated expression of brown adipokines and suggests that Lgals3 and Lgals3bp are involved in brown adipocyte differentiation