Real time quantitative methylation detection of PAX1 gene in cervical cancer screening

IntroductionDNA methylation is currently found to be associated with the progression of cervical intraepithelial neoplasia and the development of cervical cancer. The aim of this study was to analyze the role of real time quantitative methylation detection of the PAX1 gene in cervical cancer screening.MethodsAll eligible patients who underwent multiple detections for cervical cancer were assigned to the normal cervical group (n=21), cervical intraepithelial neoplasia I group (n=7), cervical intraepithelial neoplasia II+III group (n=12), or invasive cervical cancer group (n=14) based on pathological gradings. The methylation level of the PAX1 gene was detected using the real time quantitative methylation specific polymerase chain reaction assay and assessed by △Cp value. The diagnostic performance of PAX1 methylation detection was compared with folic acid receptor mediated diagnosis, the Thinprep cytology test, and human papilloma virus (HPV) testing.ResultsThe △Cp value in the invasive cervical cancer group was (6.15±4.07), significantly lower than that in the other groups (F=26.45, p<0.001). The area under the curve (AUC) of PAX1 methylation detection was 0.902 (95% confidence interval (CI) 0.817–0.986; p<0.001), and sensitivity and specificity were 92.30% and 78.60% when the cut-off value of △Cp was 13.28. The AUC of PAX1 methylation detection was notably larger compared with 0.709 for folic acid receptor mediated diagnosis (95% CI 0.568–0.849, p=0.009), 0.702 for the Thinprep cytology test (95% CI 0.559–0.844, p=0.015), and 0.655 for HPV testing (95% CI 0.508–0.802, p=0.014).ConclusionThrough quantitative methylation specific polymerase chain reaction assay characterized by rapid screening and simple operation, the methylation detection of the PAX1 gene exhibited a higher diagnostic performance and may be a promising method for cervical cancer screening.

Characterization and Evaluation of a Folic Acid Receptor-Targeted Norcantharidin/Tetrandrine Dual-Drug Loaded Delivery System

The objective of this study was to construct norcantharidin (NCTD)/tetrandrine (Tet) dual-drug loaded lipid nanoparticles (FA-LP@Tet/(MSNs@NCTD)) based on mesoporous silica nanoparticles (MSNs) for controlling drug release and lowering their systemic toxicity. In this study, MSNs were prepared and used for encapsulating anticancer drug NCTD; then MSNs@NCTD and Tet were loaded into liposomes to construct dual-drug loaded lipid nanoparticles with folic acid (FA) as the targeting moiety. The prepared dual-drug loaded lipid nanoparticles with a uniform particle size distribution of 153.17±4.17 nm (PDI 0.191±0.017, zeta potential -20.93±1.75 mV), had a visible core-shell structure under transmission electron microscopy; the encapsulation efficiency of NCTD and Tet was 86.62% and 79.19%, respectively, with obvious in vitro sustained release characteristics. The cellular uptake results suggested that FA modification could enhance intracellular distribution of FA-LP@Tet/(MSNs@NCTD). Furthermore, cell apoptosis assays showed FA-LP@Tet/(MSNs@NCTD) had better antitumor ability via reversing multidrug resistance. Therefore, FA-LP@Tet/(MSNs@NCTD) was a promising drug delivery system for combination cancer therapy.

Receptor-mediated Uptake of Folic Acid-functionalized Dextran Nanoparticles for Applications in Photodynamic Therapy

In photodynamic therapy (PDT), photosensitizers and light are used to cause photochemically induced cell death. The selectivity and the effectiveness of the phototoxicity in cancer can be increased by a specific uptake of the photosensitizer into tumor cells. A promising target for this goal is the folic acid receptor α (FRα), which is overexpressed on the surface of many tumor cells and mediates an endocytotic uptake. Here, we describe a polysaccharide-based nanoparticle system suitable for targeted uptake and its photochemical and photobiological characterization. The photosensitizer 5, 10, 15, 20-tetraphenyl-21H, 23H-porphyrine (TPP) was encapsulated in spermine- and acetal-modified dextran (SpAcDex) nanoparticles and conjugated with folic acid (FA) on the surface [SpAcDex(TPP)-FA]. The particles are successfully taken up by human HeLa-KB cells, and a light-induced cytotoxicity is observable. An excess of free folate as the competitor for the FRα-mediated uptake inhibits the phototoxicity. In conclusion, folate-modified SpAcDex particles are a promising drug delivery system for a tumor cell targeted photodynamic therapy.

Gemcitabine-loaded Folic Acid Tagged Liposomes: Improved Pharmacokinetic and Biodistribution Profile

Background: Gemcitabine (GEM) is found effective in the treatment of many solid tumors. However, its use is restricted due to its small circulation half-life, fast metabolism and low capacity for selective tumor uptake. Folate receptors (FRs) have been recognized as cellular surface markers, which can be used for cancer targeting. PEGylated liposomes decorated with folic acid have been investigated for several anticancer agents not only to extend plasma half-life but also for tumor targeting via folic acid receptors which overexpressed on tumor cell surface. Objective: Therefore, the objective of the present study was to prepare GEM-loaded folic acid tagged liposomes to improve the pharmacokinetics and tumor distribution of GEM. Methods: The blank folate-targeted liposomes composed of HSPC/DSPE-mPEG2000/DSPE-mPEG-Folic acid were prepared first by thin film hydration technique. GEM was then loaded into liposomes by remote loading technique. The optimized liposomal formulations were evaluated in vitro for GEM release using dialysis technique, HeLa cell uptake using FACS technique, and cytotoxicity using MTT dye reduction assay. The comparative in vivo pharmacokinetic and biodistribution characteristics of radiolabeled (99mTc-labeled) plain GEM solution, and all liposomal formulations (conventional:CLs; stealth: SLs; folate targeted: FTLs) were evaluated in mice model. Results: GEM-loaded FTLs showed sustained release profile, efficient uptake by HeLa cells and greater cytotoxicity. Further, FTLs displayed significantly improved pharmacokinetics, and biodistribution profile of loaded GEM. In conclusion, the developed GEM-loaded folic acid receptor-targeted liposomal formulation could be a promising and potential alternative formulation for further development.