GFP Stable Transfection Facilitated the Characterization of Lung Cancer Stem Cells

Activation of MYO1G by lncRNA MNX1-AS1 Drives the Progression in Lung Cancer

Lung cancer represents the most prevalent cancer worldwide and causes the death of many patients. Cancer stem cells (CSCs), a subpopulation of cancer cells, have the capacities of self-renewal, unlimited proliferation, and multiple differentiation potential. The purpose of this study was to explore the potential role of long noncoding RNA (lncRNA) MNX1-AS1 on maintaining the stemness of CSC in lung cancer. CSCs were firstly sorted by flow cytometry. After the determination of the target of the present study using Gene Expression Omnibus dataset, MNX1-AS1was found to be highly expressed in lung cancer tissues and cells. Deletion of MNX1-AS1 inhibited proliferation, migration, invasion and sphere-forming abilities of CSC. Furthermore, subcellular fractionation, fluorescence in situ hybridization, RNA immunoprecipitation, and dual-luciferase experiments demonstrated that MNX1-AS1 recruited the transcription factor POU domain class 2 transcription factor 2 (POU2F2) to the nucleus and activated the myosin IG (MYO1G) expression. MYO1G overexpression partially reversed the si-MNX1-AS1-decreased stemness of CSCs. Finally, MNX1-AS1 suppression significantly repressed the growth of xenografts in vivo. Our study highlights the importance of the MNX1-AS1/POU2F2/MYO1G axis in stem cell-like properties of lung cancer cells.

Pregnancy promotes pituitary tumors by increasing the rate of the cell cycle

Pituitary tumors may secrete hormones that affect pregnancy. Pregnancy also induces pituitary tumor growth; however, how pregnancy increases the growth of pituitary tumors remains unclear. The present study investigated pregnant female mice with subcutaneous pituitary tumors. The time of tumor occurrence and tumor weight were detected in pregnant and control mice. Tumor weights were measured at the end of the experiment. Blood was collected from pregnant and control mice. Brain-derived neurotrophic factor (BDNF) levels in the blood were detected using an ELISA kit. The in vitro effects of BDNF on pituitary tumor AtT-20 cell proliferation and cell cycle were investigated. It was revealed that pregnancy promoted the growth of pituitary tumors. In comparison to non-pregnant mice, the pregnant mice exhibited increased BDNF levels in the blood. In vitro BDNF treatment was able to increase the rate of proliferation of pituitary tumor cells. Additional cell cycle analysis revealed that BDNF was able to alter the cell cycle distribution of pituitary tumor cells. These results indicated that pregnancy was able to increase the BDNF level and promote the growth of pituitary tumor cells by increasing the rate of the cell cycle, leading to increased tumor growth rate in vivo. The present study provides insights into how pregnancy affects the growth of pituitary tumors. Therefore, it may be beneficial to perform pituitary tumor diagnosis or therapy on pregnant patients.

Covalently bound DNA on naked iron oxide nanoparticles: Intelligent colloidal nano-vector for cell transfection

BACKGROUND

Conversely to common coated iron oxide nanoparticles, novel naked surface active maghemite nanoparticles (SAMNs) can covalently bind DNA. Plasmid (pDNA) harboring the coding gene for GFP was directly chemisorbed onto SAMNs, leading to a novel DNA nanovector (SAMN@pDNA). The spontaneous internalization of SAMN@pDNA into cells was compared with an extensively studied fluorescent SAMN derivative (SAMN@RITC). Moreover, the transfection efficiency of SAMN@pDNA was evaluated and explained by computational model.

METHODS

SAMN@pDNA was prepared and characterized by spectroscopic and computational methods, and molecular dynamic simulation. The size and hydrodynamic properties of SAMN@pDNA and SAMN@RITC were studied by electron transmission microscopy, light scattering and zeta-potential. The two nanomaterials were tested by confocal scanning microscopy on equine peripheral blood-derived mesenchymal stem cells (ePB-MSCs) and GFP expression by SAMN@pDNA was determined.

RESULTS

Nanomaterials characterized by similar hydrodynamic properties were successfully internalized and stored into mesenchymal stem cells. Transfection by SAMN@pDNA occurred and GFP expression was higher than lipofectamine procedure, even in the absence of an external magnetic field. A computational model clarified that transfection efficiency can be ascribed to DNA availability inside cells.

CONCLUSIONS

Direct covalent binding of DNA on naked magnetic nanoparticles led to an extremely robust gene delivery tool. Hydrodynamic and chemical-physical properties of SAMN@pDNA were responsible of the successful uptake by cells and of the efficiency of GFP gene transfection.

GENERAL SIGNIFICANCE

SAMNs are characterized by colloidal stability, excellent cell uptake, persistence in the host cells, low toxicity and are proposed as novel intelligent DNA nanovectors for efficient cell transfection.