Application of cell membrane-functionalized biomimetic nanoparticles in the treatment of glioma.

Glioma is one of the most common malignant tumors with characteristics of strong invasion and high postoperative recurrence rate, which seriously threatens human health. Nanoparticles as an emerging drug delivery system have promoted the development of glioma therapy. However, blocking of nanoparticles by the blood-brain barrier is still serious problem for the use of nanoparticles in glioma therapy. In this context, traditional nanoparticles are dressed with natural cell membranes to prepare biomimetic nanoparticles. Biomimetic nanoparticles show longer blood circulation time, excellent homologous targeting and outstanding immune escape capacity, which significantly improve the accumulation of nanoparticles at the tumor site. The therapeutic effect for glioma has been raised to an advanced level. This review focuses on the preparations and applications of cell membrane-functionalized biomimetic nanoparticles, as while as the advantages and problems of biomimetic nanoparticles in the treatment of glioma. In particular, the approach of using biomimetic nanoparticles to cross the blood-brain barrier is analyzed, in the hope of providing new ideas for further developments in crossing the blood-brain barrier and in glioma therapy.

hMOF induces cisplatin resistance of ovarian cancer by regulating the stability and expression of MDM2.

Histone acetyltransferase human males absent on the first (hMOF) is a member of MYST family which participates in posttranslational chromatin modification by controlling the acetylation level of histone H4K16. Abnormal activity of hMOF occurs in multiple cancers and biological alteration of hMOF expression can affect diverse cellular functions including cell proliferation, cell cycle progression and embryonic stem cells (ESCs) self-renewal. The relationship between hMOF and cisplatin resistance was investigated in The Cancer Genome Atlas (TCGA) and Genomics of Drug Sensitivity in Cancer (GDSC) database. Lentiviral-mediated hMOF-overexpressed cells or hMOF-knockdown cells were established to investigate its role on cisplatin-based chemotherapy resistance in vitro ovarian cancer cells and animal models. Furthermore, a whole transcriptome analysis with RNA sequencing was used to explore the underlying molecular mechanism of hMOF affecting cisplatin-resistance in ovarian cancer. The data from TCGA analysis and IHC identification demonstrated that hMOF expression was closely associated with cisplatin-resistance in ovarian cancer. The expression of hMOF and cell stemness characteristics increased significantly in cisplatin-resistant OVCAR3/DDP cells. In the low hMOF expressing ovarian cancer OVCAR3 cells, overexpression of hMOF improved the stemness characteristics, inhibited cisplatin-induced apoptosis and mitochondrial membrane potential impairment, as well as reduced the sensitivity of OVCAR3 cells to cisplatin treatment. Moreover, overexpression of hMOF diminished tumor sensitivity to cisplatin in a mouse xenograft tumor model, accompanied by decrease in the proportion of cisplatin-induced apoptosis and alteration of mitochondrial apoptosis proteins. In addition, opposite phenotype and protein alterations were observed when knockdown of hMOF in the high hMOF expressing ovarian cancer A2780 cells. Transcriptomic profiling analysis and biological experimental verification orientated that MDM2-p53 apoptosis pathway was related to hMOF-modulated cisplatin resistance of OVCAR3 cells. Furthermore, hMOF reduced cisplatin-induced p53 accumulation by stabilizing MDM2 expression. Mechanistically, the increased stability of MDM2 was due to the inhibition of ubiquitinated degradation, which resulted by increased of MDM2 acetylation levels by its direct interaction with hMOF. Finally, genetic inhibition MDM2 could reverse hMOF-mediated cisplatin resistance in OVCAR3 cells with up-regulated hMOF expression. Meanwhile, treatment with adenovirus expressing shRNA of hMOF improved OVCAR3/DDP cell xenograft sensitivity to cisplatin in mouse. Collectively, the results of the study confirm that MDM2 as a novel non-histone substrate of hMOF, participates in promoting hMOF-modulated cisplatin chemoresistance in ovarian cancer cells. hMOF/MDM2 axis might be a potential target for the treatment of chemotherapy-resistant ovarian cancer.

Identification of four novel XPC mutations in two xeroderma pigmentosum complementation group C patients and functional study of XPC Q320X mutant.

Xeroderma pigmentosum (XP) is a rare, recessive hereditary disease characterized by sunlight hypersensitivity and high incidence of skin cancer with clinical and genetic heterogeneity. We collected two unrelated Chinese patients showing typical symptoms of XPC without neurologic symptoms. Direct sequencing of XPC gene revealed that patient 1 carried IVS1+1G>A and c.958 C>T mutations, and patient 2 carried c.545_546delTA and c.2257_2258insC mutations. All these four mutations introduced premature terminal codons (PTCs) in XPC gene. The nonsense mutation c.958 C>T yielded truncated mutant Q320X, and we studied its function for global genome repair kinetics. Overexpressed Q320X mutant can localize to site of DNA damage, but it is defective in CPD and 6-4PP repair. Readthrough of PTCs is a new approach to treatment of genetic diseases. We found that aminoglycosides could significantly increase the full length protein expression of Q320X mutant, but NER defects were not rescued in vitro.

Combined transjugular intrahepatic portosystemic shunt and other interventions for hepatocellular carcinoma with portal hypertension.

AIM: To evaluate combination transjugular intrahepatic portosystemic shunt (TIPS) and other interventions for hepatocellular carcinoma (HCC) and portal hypertension. METHODS: Two hundred and sixty-one patients with HCC and portal hypertension underwent TIPS combined with other interventional treatments (transarterial chemoembolization/transarterial embolization, radiofrequency ablation, hepatic arterio-portal fistulas embolization, and splenic artery embolization) from January 1997 to January 2010 at Beijing Shijitan Hospital. Two hundred and nine patients (121 male and 88 female, aged 25-69 years, mean 48.3 ± 12.5 years) with complete clinical data were recruited. We evaluated the safety of the procedure (procedure-related death and serious complications), change of portal vein pressure before and after TIPS, symptom relief [e.g., ascites, hydrothorax, esophageal gastric-fundus variceal bleeding (EGVB)], cumulative rates of survival, and distributary channel restenosis. The characteristics of the patients surviving ≥ 5 and < 5 years were also analyzed. RESULTS: The portosystemic pressure was decreased from 29.0 ± 4.1 mmHg before TIPS to 18.1 ± 2.9 mmHg after TIPS (t = 69.32, P < 0.05). Portosystemic pressure was decreased and portal hypertension symptoms were ameliorated. During the 5 year follow-up, the total recurrence rate of resistant ascites or hydrothorax was 7.2% (15/209); 36.8% (77/209) for EGVB; and 39.2% (82/209) for hepatic encephalopathy. The cumulative rates of distributary channel restenosis at 1, 2, 3, 4, and 5 years were 17.2% (36/209), 29.7% (62/209), 36.8% (77/209), 45.5% (95/209) and 58.4% (122/209), respectively. No procedure-related deaths and serious complications (e.g., abdominal bleeding, hepatic failure, and distant metastasis) occurred. Moreover, Child-Pugh score, portal vein tumor thrombosis, lesion diameter, hepatic arterio-portal fistulas, HCC diagnosed before or after TIPS, stent type, hepatic encephalopathy, and type of other interventional treatments were related to 5 year survival after comparing patient characteristics. CONCLUSION: TIPS combined with other interventional treatments seems to be safe and efficacious in patients with HCC and portal hypertension.

Transjugular intrahepatic portosystemic shunt for severe jaundice in patients with acute Budd-Chiari syndrome.

AIM: To evaluate the feasibility of transjugular intrahepatic portosystemic shunt (TIPS) for severe jaundice secondary to acute Budd-Chiari syndrome (BCS). METHODS: From February 2009 to March 2013, 37 patients with severe jaundice secondary to acute BCS were treated. Sixteen patients without hepatic venule, hepatic veins (HV) obstruction underwent percutaneous angioplasty of the inferior vena cava (IVC) and/or HVs. Twenty-one patients with HV occlusion underwent TIPS. Serum bilirubin, liver function, demographic data and operative data of the two groups of patients were analyzed. RESULTS: Twenty-one patients underwent TIPS and the technical success rate was 100%, with no technical complications. Sixteen patients underwent recanalization of the IVC and/or HVs and the technical success rate was 100%. The mean procedure time for TIPS was 84.0±12.11 min and angioplasty was 44.11±5.12 min (P<0.01). The mean portosystemic pressure in the TIPS group decreased significantly from 40.50±4.32 to 16.05±3.50 mmHg (P<0.01). The mean portosystemic pressure gradient decreased significantly from 33.60±2.62 to 7.30±2.21 mmHg (P<0.01). At 8 wk after the procedures, in the TIPS group, total bilirubin (TBIL) decreased significantly from 266.24±122.03 before surgery to 40.11±3.52 µmol/L (P<0.01) and direct bilirubin (DBIL) decreased significantly from 194.22±69.82 µmol/L to 29.82±3.10 µmol/L (P<0.01). In the angioplasty group, bilirubin returned to the normal range, with TBIL decreased significantly from 258.22±72.71 µmol/L to 13.33±3.54 µmol/L (P<0.01) and DBIL from 175.08±39.27 to 4.03±1.74 µmol/L (P<0.01). Liver function improved faster than TBIL. After 2 wk, in the TIPS group, alanine aminotransferase (ALT) decreased significantly from 50.33±40.61 U/L to 28.67±7.02 U/L (P<0.01) and aspartate aminotransferase (AST) from 49.46±34.33 U/L to 26.89±8.68 U/L (P<0.01). In the angioplasty group, ALT decreased significantly from 51.56±27.90 to 14.22±2.59 µmol/L (P<0.01) and AST from 60.66±39.89 µmol/L to 8.18±1.89 µmol/L (P<0.01). After mean follow-up of 12.6 mo, there was no recurrence of jaundice in either group. CONCLUSION: Severe jaundice is not a contraindication for TIPS in patients with acute BCS and TIPS is appropriate for severe jaundice due to BCS.