HOPS/TMUB1 Enhances Apoptosis in TP53 Mutation-Independent Setting in Human Cancers.

TP53 mutations are prevalent in various cancers, yet the complexity of apoptotic pathway deregulation suggests the involvement of additional factors. HOPS/TMUB1 is known to extend the half-life of p53 under normal and stress conditions, implying a regulatory function. This study investigates, for the first time, the potential modulatory role of the ubiquitin-like-protein HOPS/TMUB1 in p53-mutants. A comprehensive analysis of apoptosis in the most frequent p53-mutants, R175, R248, and R273, in SKBR3, MIA PaCa2, and H1975 cells indicates that the overexpression of HOPS induces apoptosis at least equivalent to that caused by DNA damage. Immunoprecipitation assays confirm HOPS binding to p53-mutant forms. The interaction of HOPS/TMUB1 with p53-mutants strengthens its effect on the apoptotic cascade, showing a context-dependent gain or loss of function. Gene expression analysis of the MYC and TP63 genes shows that H1975 exhibit a gain-of-function profile, while SKBR3 promote apoptosis in a TP63-dependent manner. The TCGA data further corroborate HOPS/TMUB1's positive correlation with apoptotic genes BAX, BBC3, and NOXA1, underscoring its relevance in patient samples. Notably, singular TP53 mutations inadequately explain pathway dysregulation, emphasizing the need to explore additional contributing factors. These findings illuminate the intricate interplay among TP53 mutations, HOPS/TMUB1, and apoptotic pathways, providing valuable insights for targeted cancer interventions.

Brushlike Cationic Polymers with Low Charge Density for Gene Delivery.

Using a combined synthesis approach comprising reversible addition-fragmentation transfer polymerization and ring opening reaction, a series of poly glycidyl methacrylate (polyGMA) polymers were designed and synthesized for gene delivery. These polymers characterized by low cationic charge respective to established gene delivery vectors such as PEI were studied to further elucidate the key structure-activity parameters that mediate efficient and biocompatible gene delivery. Compared to PEI, these brushlike polymers facilitated markedly improved safety and gene delivery efficiency.

Thermo- and pH-Responsive, Coacervate-Forming Hyperbranched Poly(ß-amino ester)s for Selective Cell Binding.

We report a new type of thermo- and pH-responsive, coacervate-forming highly degradable polymer-hyperbranched poly(ß-amino esters) (HPAEs) and its selective cell binding behaviors. The HPAEs were synthesized from 5-amino-1-pentanol (S5) and trimethylolpropane ethoxylate triacrylate (TMPETA) via an A2+B3 type Michael addition. The existence of multiple hydrogen bond pairs as well as tertiary amines makes the S5-TMPETA polymers manifest temperature- and pH-dependent phase transition. By varying the length of the ethylene glycol (EG) spacers in the TMPETA, polymer molecular weight, concentration, and pH value, the phase transition of the S5-TMPETA can be easily tuned in aqueous and buffer solutions, as evidenced by UV-vis spectroscopy and DLS measurements. Especially, the S5-TMPETA prepared from S5 and trimethylolpropane ethoxylate triacrylate 692 (S5-TMPETA692) shows a lower critical solution temperature (LCST) around 33 °C, above which the S5-TMPTEA can form coacervate particles able to encapsulate functional molecules effectively. Importantly, when incubation with HeLa cells, the S5-TMPTETA692 exhibits a temperature- and pH-responsive selective cell binding behaviors. In addition, the S5-TMPETA are highly hydrolyzable and elicit negligible cytotoxicity. This new type of "smart" polymer should find use in a variety of biomedical applications.

A new developing class of gene delivery: messenger RNA-based therapeutics.

Gene therapy has long been held as having the potential to become a front line treatment for various genetic disorders. However, the direct delivery of nucleic acids to correct a genetic disorder has numerous limitations owing to the inability of naked nucleic acids (DNA and RNA) to traverse the cell membrane. Recently, messenger RNA (mRNA) based delivery has become a more attractive alternative to DNA due to the relatively easier transfection process, higher efficiency and safety profile. As with all gene therapies, the central challenge that remains is the efficient delivery of nucleic acids intracellularly. This review presents the recent progress in mRNA delivery, focusing on comparing the advantages and limitations of non-viral based delivery vectors.

Highly Branched poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) for High Performance Gene Transfection.

The top-performing linear poly(ß-amino ester) (LPAE), poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (C32), has demonstrated gene transfection efficiency comparable to viral-mediated gene delivery. Herein, we report the synthesis of a series of highly branched poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (HC32) and explore how the branching structure influences the performance of C32 in gene transfection. HC32 were synthesized by an "A2 + B3 + C2" Michal addition strategy. Gaussia luciferase (Gluciferase) and green fluorescent protein (GFP) coding plasmid DNA were used as reporter genes and the gene transfection efficiency was evaluated in human cervical cancer cell line (HeLa) and human recessive dystrophic epidermolysis bullosa keratinocyte (RDEBK) cells. We found that the optimal branching structure led to a much higher gene transfection efficiency in comparison to its linear counterpart and commercial reagents, while preserving high cell viability in both cell types. The branching strategy affected DNA binding, proton buffering capacity and degradation of polymers as well as size, zeta potential, stability, and DNA release rate of polyplexes significantly. Polymer degradation and DNA release rate played pivotal parts in achieving the high gene transfection efficiency of HC32-103 polymers, providing new insights for the development of poly(ß-amino ester)s-based gene delivery vectors.

Star Poly(ß-amino esters) Obtained from the Combination of Linear Poly(ß-amino esters) and Polyethylenimine.

Composed of a three-dimensional structure with a central core and multiple radiating linear "arms", star polymers represent a significant type of branched macromolecular architectures. Due to the spatially defined core-shell-periphery architecture, star polymers have demonstrated their superiority in a variety of biomedical applications such as drug/gene delivery, molecular imaging, antibacterial agents, and so on. In this paper, we report the successful synthesis of a new type of star-shape poly(ß-amino esters) with low molecular weight PEI as core and linear PAE (LPAE) as arms. This new star-PAE exhibits low cytotoxicity and high gene transfection efficacy. Star-PAE achieved between 264-fold and 14781-fold higher gene transfection efficiency of primary rat adipose derived mesenchymal stem cells in comparison with studies performed with the individual PEI and LPAE, respectively. The results suggest that star-PAE is a promising nonviral gene delivery vector.