Targeted killing of CD133+ lung cancer stem cells using paclitaxel-loaded PLGA-PEG nanoparticles with CD133 aptamers / 南方医科大学学报

OBJECTIVE@#To construct a polylactic acid-glycolic acid-polyethylene glycol (PLGA-PEG) nanocarrier (N-Pac-CD133) coupled with a CD133 nucleic acid aptamer carrying paclitaxel for eliminating lung cancer stem cells (CSCs).@*METHODS@#Paclitaxel-loaded N-Pac-CD133 was prepared using the emulsion/solvent evaporation method and characterized. CD133+ lung CSCs were separated by magnetic bead separation and identified for their biological behaviors and gene expression profile. The efficiency of paclitaxel-loaded N-Pac-CD133 for targeted killing of lung cancer cells was assessed in vitro. SCID mice were inoculated with A549 cells and received injections of normal saline, empty nanocarrier linked with CD133 aptamer (N-CD133), paclitaxel, paclitaxel-loaded nanocarrier (N-Pac) or paclitaxel-loaded N-Pac-CD133 (n=8, 5 mg/kg paclitaxel) on days 10, 15 and 20, and the tumor weight and body weight of the mice were measured on day 40.@*RESULTS@#Paclitaxel-loaded N-Pac-CD133 showed a particle size of about 100 nm with a high encapsulation efficiency (>80%) and drug loading rate (>8%), and was capable of sustained drug release within 48 h. The CD133+ cell population in lung cancer cells showed the characteristic features of lung CSCs, including faster growth rate (30 days, P=0.001) and high expressions of tumor stem cell markers OV6(P < 0.001), CD133 (P=0.001), OCT3/4 (P=0.002), EpCAM (P=0.04), NANOG (P=0.005) and CD44 (P=0.02). Compared with N-Pac and free paclitaxel, paclitaxel-loaded N-Pac-CD133 showed significantly enhanced targeting ability and cytotoxicity against lung CSCs in vitro (P < 0.001) and significantly reduced the formation of tumor spheres (P < 0.001). In the tumor-bearing mice, paclitaxel-loaded N-Pac-CD133 showed the strongest effects in reducing the tumor mass among all the treatments (P < 0.001).@*CONCLUSION@#CD133 aptamer can promote targeted delivery of paclitaxel to allow targeted killing of CD133+ lung CSCs. N-Pac-CD133 loaded with paclitaxel may provide an effective treatment for lung cancer by targeting the lung cancer stem cells.

Effects of Maxing-Shigan decoction on airway remodeling and expression of MMP-9 and TIMP-1 in lung tissues of asthmatic mice / 中国病理生理杂志

AIM:To investigate the effects of Maxing-Shigan decoction on airway remodeling and expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the lung tissues of asthmatic mice, and to explore its possible mechanism in treatment of asthma.METHODS:The BALB/c mice were divided into blank control group, model group, low-dose Maxing-Shigan decoction group, middle-dose Maxing-Shigan decoction group, high-dose Maxing-Shigan decoction group and positive control group.The mice were sensitized and challenged with ovalbumin to establish asthma model.The mice in blank control group and model group were given saline by oral administration before 30 min of suscitation.The mice in low-dose, middle-dose and high-dose Maxing-Shigan decoction groups were given Maxing-Shigan decoction at 5.0 g/kg, 10.0 g/kg and 20.0 g/kg, respectively, by oral administration before 30 min of suscitation.The mice in positive control group was given dexamethasone at 0.005 g/kg by oral administration before 30 min of suscitation.After consecutive administration for 7 d, the variations of airway responsiveness, the percentage of the goblet cells, the collagen deposition, and the eosinophil (EOS) counts in bronchoalveolar lavage fluid (BALF) of each group were observed.The protein levels of MMP-9 and TIMP-1 in the lung tissues were determined by ELISA and Western blot.The mRNA expression of MMP-9 and TIMP-1 was detected by RT-qPCR.RESULTS:Compared with blank control group, the airway responsiveness, the goblet cell percentage, the collagen deposition, the EOS counts in BALF, the protein levels of MMP-9 and TIMP-1, and the mRNA expression of MMP-9 and TIMP-1 were significantly increased in model group (P<0.01).Compared with model group, all of the indexes were reversed in low-dose, middle-dose and high-dose Maxing-Shigan decoction groups and positive control group (P<0.05 or P<0.01).CONCLUSION:Maxing-Shigan decoction improves airway remodeling in asthma model mice by down-regulating the expression of MMP-9 and TIMP-1.

Angiotensin Ⅱ receptor antagonist EMA401 used for sciatic nerve constriction-induced neuropathic pain in rats: behavior assessment and anaIgesic mechanisms / 中国组织工程研究

BACKGROUND: Chronic pain is characterized as high morbidity, long course and poor curative efficacy, and the underlying mechanism still remains unclear. The research on analgesics and analgesic mechanisms is an issue of concern. OBJECTIVE: To explore the effect of angiotensin Ⅱ receptor antagonists EMA401 on the mechanical withdrawal threshold in a rat model of sciatic nerve constriction-induced neuropathic pain and the underlying mechanisms. METHODS: Sprague-Dawley rats were randomized into five groups: the rat sciatic nerve was exposed without ligation (sham group), and NaCl solution was given via gastric lavage;the model of sciatic nerve constriction was established in the remaining rats,followed by treatment with 2,5 and 10 mg/kg EMA401,and NaCl solutions(model group)via gastric lavage,respectively.As a behavioral indicator,mechanical withdrawal threshold was detected at 1 preoperative day, 3, 7 and 14 postoperative days. Subsequently, the spinal dorsal root ganglion was removed, and the expression levels of glial fibrillary acidic protein, brain-derived neurotrophic factor and activating transcription factor 3 were detected by western blot assay. RESULTS AND CONCLUSION: Compared with the model group, EMA401 significantly improved the mechanical withdrawal threshold of the rats with sciatic nerve constriction (P < 0.05). Moreover, EMA401 significantly upregulated the expression levels of glial fibrillary acidic protein, brain-derived neurotrophic factor and activating transcription factor 3 in the dorsal root ganglion (P < 0.05); the expression levels in the 5 and 10 mg/kg EMA401 groups were significantly lower than those in the 2 mg/kg EMA401 group at 3, 7 and 14 days postoperatively (P < 0.05). These findings implicate that EMA401 exerts obvious analgesic effect on the rat model of sciatic nerve constriction,which may be via inhibiting astrocyte activation in the spinal dorsal root ganglion, downregulating the expression level of brain-derived neurotrophic factor, and further inhibiting the dorsal root ganglion neuron activation that appears with an increase in activated transcription factor 3 expression.