Grafting of anti-nucleolin aptamer into preformed and remotely loaded liposomes through aptamer-cholesterol post-insertion.

A new combination strategy of an active loading and active targeting approach was applied in this work. The liposomes actively loaded with Curcumin (CRM) (LipCRM) were decorated with cholesterol tagged-anti-nucleolin AS1411 aptamer (NCL) via a new post-insertion approach, utilizing the cholesterol as a wedge to incorporate aptamer into the surface of the liposome bilayer. A successful NCL post-insertion was verified by agarose gel electrophoresis and dynamic light scattering (DLS). The cellular uptake of AptNCL-Lip was investigated using flow cytometry and Confocal Laser Scanning Microscopy (CLSM) on two different human breast cancer cell lines (MCF-7 and MDA-MB-231). The uptake and cytotoxicity of loaded CRM were investigated using flow cytometry and MTT assay. Our results showed successful post insertion of NCL aptamer to the surface of Lip. Also, higher cellular uptake was noted for AptNCL-Alexa-LipRhod compared to blank LipRhod in both cell lines. Moreover, CLSM showed prominent endocytosis and uptake of AptNCL-Alexa-LipRhod into the cytoplasm of breast cancer cells. Furthermore, the results showed a significant increase in the uptake and cytotoxicity of AptNCL-LipCRM compared to LipCRM in both cell lines. Overall, our results demonstrate a successful post-insertion of cholesterol-tagged aptamer into liposomes and the possible combination between active loading and active targeting.

Co-encapsulation of thymoquinone with docetaxel enhances the encapsulation efficiency into PEGylated liposomes and the chemosensitivity of MCF7 breast cancer cells to docetaxel.

Combinatorial therapeutic strategies to eradicate tumors can be superior to a single therapeutic modality. Docetaxel (DT) has been approved for the treatment of local or metastasized breast cancer alone or in combination with other chemotherapeutic agents. Thymoquinone (TQ) originated from the seeds of Nigella Sativa plant has been reported to possess in vitro and in vivo antitumor activity against variety of tumors. In the current study, we have investigated the synergistic anticancer efficacy of a novel combination of DT and TQ on MCF7 breast cancer cell line using MTT cell viability assay. Moreover, this study describes for the first time the co-encapsulation of DT and TQ into PEGylated liposomes. The results showed that the combination of DT and TQ resulted in significant synergistic cytotoxicity compared to DT and TQ alone. Moreover, DT and TQ have been successfully co-encapsulated into PEGylated liposomes with higher encapsulation efficiency compared to DT and TQ alone. In conclusion, DT and TQ combination poses a synergistic effect and may aid in decreasing the required doses of DT. Also, the co-encapsulation of DT and TQ into PEGylated liposomes can provide a promising DT and TQ delivery system into cancer cells.

FcRn mediates fast recycling of endocytosed albumin and IgG from early macropinosomes in primary macrophages.

The neonatal Fc receptor (FcRn) rescues albumin and IgG from degradation following endocytosis and thereby extends the half-life of these plasma proteins. However, the pathways for the uptake of these soluble FcRn ligands, and the recycling itinerary of the FcRn-ligand complexes, have not been identified in primary cells. Here, we have defined the recycling of human albumin and IgG in primary mouse macrophages selectively expressing the human FcRn. Albumin is internalised by macropinocytosis; in the absence of FcRn, internalised albumin is rapidly degraded, while in the presence of FcRn albumin colocalises to SNX5-positive membrane domains and is partitioned into tubules emanating from early macropinosomes for delivery in transport carriers to the plasma membrane. Soluble monomeric IgG was also internalised by macropinocytosis and rapidly recycled by the same pathway. In contrast, the fate of IgG bound to surface Fcγ receptors differed from monomeric IgG endocytosed by macropinocytosis. Overall, our findings identify a rapid recycling pathway for FcRn ligands from early macropinosomes to the cell surface of primary cells.

Thymoquinone efficiently inhibits the survival of EBV-infected B cells and alters EBV gene expression.

Epstein--Barr virus (EBV) is a human virus with oncogenic potentials that is implicated in various human diseases and malignancies. In this study, the modulator activity of the potent herbal extract drug thymoquinone on EBV was assessed in vitro. Thymoquinone was tested for cytotoxicity on human cells of lymphoblastoid cells, Raji Burkitt's lymphoma, DG-75 Burkitt's lymphoma, peripheral blood mononuclear cells, and periodontal ligament fibroblast. Apoptosis induction was analyzed via TUNEL assay and activity studies of caspase-3. The effect of thymoquinone on EBV gene expression was determined using real-time polymerase chain reaction. We report here, for the first time, a promising selective inhibitory affect of thymoquinone on EBV-infected B cell lines in vitro, compared with lower activity on EBV negative B cell line and very low toxicity on human peripheral blood mononuclear cells and periodontal ligament fibroblasts. Moreover, the drug was found to efficiently suppress the RNA expression of EBNA2, LMP1, and EBNA1 genes. Specifically, EBNA2 expression levels were the most affected indicating that this gene might have a major contribution to thymoquinone potency against EBV infected cells. Overall, our results suggest that thymoquinone has the potential to suppress the growth of EBV-infected B cells efficiently.

Thymoquinone in liposomes: a study of loading efficiency and biological activity towards breast cancer.

Thymoquinone (2-isopropyl-5-methyl-1,4-benzoquinone) is a herbal-derived drug with potential chemopreventive and chemotherapeutic activity. However, thymoquinone suffers from high hydrophobicity causing poor solubility which limits its bioavailability and high lipophilicity causing poor formulation characteristics. Liposomes are versatile drug carriers that can be used to solve problems of drug solubility, instability, and bio-distribution. In this study, we were able to prepare thymoquinone-loaded liposomes (TQ-LP) and thymoquinone loaded in liposomes modified with Triton X-100 (XLP) with diameters of about 100 nm, and entrapment efficiency of more than 90% for TQ-LP and of 49.6% for XLP. The TQ-LP liposomes were effective in suppressing the proliferation of breast cancer cell lines MCF-7 and T47D, and at the same time exerting very low toxicity on normal periodontal ligament fibroblast. Altogether, this report describes the first successful encapsulation of thymoquinone into liposome; which maintains stability, improves bioavailability and maintains its anticancer activity.

Frequent detection of Human Herpes Virus-8 in bone marrow of Jordanian patients of multiple myeloma.

The association between Human Herpes Virus-8 (HHV-8), also called Kaposi's sarcoma associated herpesvirus (KSHV), and the pathogenesis of multiple myeloma remains controversial. Many past studies conducting on different populations have come to contradicting conclusions. In this study, we attempted to investigate the presence of HHV-8 in Jordanian multiple myeloma patients. We carried out nucleic acid amplification reactions targeting specific viral DNA sequences on 35 fresh bone marrow aspirate samples from 17 patients with multiple myeloma, 9 patients with various hematological malignancies and 9 normal subjects. HHV-8 specific sequences were detected in 7 out of 17 multiple myeloma patients (41%) using primers specific for the open reading frame region 26 (ORF26). All patients with other hematological malignancies as well as the normal subjects did not harbour the virus. These findings support the previous reports of frequent detection of HHV-8 in bone marrow of multiple myeloma patients.

Hotspot mutations of PIK3CA and AKT1 genes are absent in multiple myeloma.

The phosphatidylinositol-3-kinases PI3K/AKT pathway regulates many growth and survival mechanisms in the cell, and it has been implicated in development and progression of many human cancers, including multiple myeloma. Recently, many reports have revealed that the PIK3CA gene which encodes the p110 catalytic subunit of PI3K kinase is mutated in many human malignancies. To investigate the oncogenic role of PI3K/AKT pathway in multiple myeloma we sequenced three hot exons: exons 9 and 20 of PIK3CA gene and exon 3 of AKT1 gene in 27 multiple myeloma patients. Our results indicate the absence of the four hot spot mutations E542K, E545K, H1047R and E17K in all studied cases. These findings suggest that PI3K/AKT mutations may not play a major role in multiple myeloma.