BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

In clinical application, a microneedle system that continuously delivers drugs is of great value for the delivery of some vaccines and hormone drugs. In this study, a controlled-release chitosan-based microneedle array (PVA/CS-MN) was designed, combining microneedle patches with drugs for controlled-release of drugs. Here we report the optimization of the preparation process of PVA/CS-MN. The appearance, morphology, mechanical properties, dissolution and swelling properties, and in vitro penetration properties of the MN arrays were characterized. The PVA/CS-MN prepared by the optimal process showed good morphology and mechanical properties. PVA/CS-MN can smoothly open microchannels on the skin and achieve controllable dissolution and swelling functions. Ascorbic acid (l-ascorbic acid) was used as a model drug to prepare a Vc-PVA/CS-MN. In vitro transdermal diffusion experiments showed that the Vc-PVA/CS-MN released about 57% of the drug within 1 h. About 66.7% of the drug was slowly released within 12 h, and a total of 92% of the drug was released after 7 days. The controllable sustained-release properties and excellent drug delivery efficiency of PVA/CS-MN provide a new option for sustained transdermal drug delivery.
Ascorbic Acid ; Chitosan ; Delayed-Action Preparations ; Drug Delivery Systems ; Hormones ; Vaccines

Objective: To explore the characteristics of acute otitis media(AOM) in children in Beijing and its correlation with meteorological factors. Methods: Data were collected in 2011-2013 in the Otolaryngology Department of Capital Institute of Pediatrics. AOM in children with relevant information, such as age, sex and season, with the same period of the Beijing municipal meteorological data (the average temperature, average pressure, average wind speed, humidity and PM2.5) were compared to analysis the relationship of meteorological environmental parameters and the onset of AOM in children. Results: Annual morbidity of AOM was 7 589, 8 245, 7 242 respectively, no obvious difference(P=0.761). It was noted that one peak could be seen in December, and a valley in February, followed by August. Summer was less than the other three seasons (P<0.05). The morbidity of AOM had a small peak within one year after birth, then reached peak at the age of about 4, and then reduced gradually. In different age groups, male patients were higher than those of female. The incidence of AOM was positively correlation tendency with air pressure and PM2.5 (r=0.333, 0.093, P=0.000, 0.002), which was negatively correlation tendency with daily temperature or humidity (r=-0.327, -0.195, P=0.000, 0.000). Conclusions The incidence of AOM of children in Beijing changes with age, and has obvious seasonal variation. There may be some correlation between the meteorological factors and the incidence of AOM in children.