Ligand-installed polymeric nanocarriers for combination chemotherapy of EGFR-positive ovarian cancer.

Combination chemotherapeutic drugs administered via a single nanocarrier for cancer treatment provides benefits in reducing dose-limiting toxicities, improving the pharmacokinetic properties of the cargo and achieving spatial-temporal synchronization of drug exposure for maximized synergistic therapeutic effects. In an attempt to develop such a multi-drug carrier, our work focuses on functional multimodal polypeptide-based polymeric nanogels (NGs). Diblock copolymers poly (ethylene glycol)-b-poly (glutamic acid) (PEG-b-PGlu) modified with phenylalanine (Phe) were successfully synthesized and characterized. Self-assembly behavior of the resulting polymers was utilized for the synthesis of NGs with hydrophobic domains in cross-linked polyion cores coated with inert PEG chains. The resulting NGs were small (ca. 70 nm in diameter) and were able to encapsulate the combination of drugs with different physicochemical properties such as cisplatin and neratinib. Drug combination-loaded NGs exerted a selective synergistic cytotoxicity towards EGFR overexpressing ovarian cancer cells. Moreover, we developed ligand-installed EGFR-targeted NGs and tested them as an EGFR-overexpressing tumor-specific delivery system. Both in vitro and in vivo, ligand-installed NGs displayed preferential associations with EGFR (+) tumor cells. Ligand-installed NGs carrying cisplatin and neratinib significantly improved the treatment response of ovarian cancer xenografts. We also confirmed the importance of simultaneous administration of the dual drug combination via a single NG system which provides more therapeutic benefit than individual drug-loaded NGs administered at equivalent doses. This work illustrates the potential of our carrier system to mediate efficient delivery of a drug combination to treat EGFR overexpressing cancers.

Nanoscale platform for delivery of active IRINOX to combat pancreatic cancer.

Due to its late diagnosis and dismal prognosis, pancreatic ductal adenocarcinoma (PDAC) is one of the most devastating solid malignancies, with only 9% of patients surviving after being diagnosed. A multidrug chemotherapeutic regimen FOL-F-IRIN-OX (combination of 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) offers survival benefits superior to that of gemcitabine single agent, but the treatment-related side effects are also severe. To overcome this therapeutic barrier, we developed polymeric micelles bearing active formats of irinotecan and oxaliplatin, SN38 and 1,2-diaminocyclohexane­platinum (II), DACHPt. Crosslinked micelles were prepared using amphiphilic PEG-b-poly(L-glutamic acid)/SN38 conjugates and subsequently loaded with DACHPt. The dual drug-loaded micelles exhibited improved colloidal stability, prolonged drug release and remarkable cytotoxicity in human pancreatic cancer cell lines and KrasG12D; Trp52R172H/+; Pdx-1 Cre murine tumor organoids models. In vivo, (SN38 + DACHPt)-loaded micelles displayed superior antitumor and antimetastatic activities without impairing safety. Our results suggest that nanomedicine mimicking irinotecan and oxaliplatin as parts of FOLFIRINOX regimen may further improve the feasibility of this multidrug treatment for patients with advanced pancreatic cancer.

Monocyte metabolic reprogramming promotes pro-inflammatory activity and Staphylococcus aureus biofilm clearance.

Biofilm-associated prosthetic joint infections (PJIs) cause significant morbidity due to their recalcitrance to immune-mediated clearance and antibiotics, with Staphylococcus aureus (S. aureus) among the most prevalent pathogens. We previously demonstrated that S. aureus biofilm-associated monocytes are polarized to an anti-inflammatory phenotype and the adoptive transfer of pro-inflammatory macrophages attenuated biofilm burden, highlighting the critical role of monocyte/macrophage inflammatory status in dictating biofilm persistence. The inflammatory properties of leukocytes are linked to their metabolic state, and here we demonstrate that biofilm-associated monocytes exhibit a metabolic bias favoring oxidative phosphorylation (OxPhos) and less aerobic glycolysis to facilitate their anti-inflammatory activity and biofilm persistence. To shift monocyte metabolism in vivo and reprogram cells to a pro-inflammatory state, a nanoparticle approach was utilized to deliver the OxPhos inhibitor oligomycin to monocytes. Using a mouse model of S. aureus PJI, oligomycin nanoparticles were preferentially internalized by monocytes, which significantly reduced S. aureus biofilm burden by altering metabolism and promoting the pro-inflammatory properties of infiltrating monocytes as revealed by metabolomics and RT-qPCR, respectively. Injection of oligomycin alone had no effect on monocyte metabolism or biofilm burden, establishing that intracellular delivery of oligomycin is required to reprogram monocyte metabolic activity and that oligomycin lacks antibacterial activity against S. aureus biofilms. Remarkably, monocyte metabolic reprogramming with oligomycin nanoparticles was effective at clearing established biofilms in combination with systemic antibiotics. These findings suggest that metabolic reprogramming of biofilm-associated monocytes may represent a novel therapeutic approach for PJI.

Comprehensive Influences of Overexpression of a MYB Transcriptor Regulating Anthocyanin Biosynthesis on Transcriptome and Metabolome of Tobacco Leaves.

Overexpression of R2R3-MYB transcriptor can induce up-expression of anthocyanin biosynthesis structural genes, and improve the anthocyanin content in plant tissues, but it is not clear whether the MYB transcription factor overexpression does effect on other genes transcript and chemical compounds accumulation. In this manuscript, RNA-sequencing and the stepwise multiple ion monitoring-enhanced product ions (stepwise MIM-EPI) strategy were employed to evaluate the comprehensive effect of the MYB transcription factor LrAN2 in tobacco. Overexpression of LrAN2 could promote anthocyanin accumulation in a lot of tissues of tobacco cultivar Samsun. Only 185 unigenes express differently in a total of 160,965 unigenes in leaves, and 224 chemical compounds were differently accumulated. Three anthocyanins, apigeninidin chloride, pelargonidin 3-O-beta-D-glucoside and cyanidin 3,5-O-diglucoside, were detected only in transgenic lines, which could explain the phenotype of purple leaves. Except for anthocyanins, the phenylpropanoid, polyphenol (catechin), flavonoid, flavone and flavonol, belong to the same subgroups of flavonoids biosynthesis pathway with anthocyanin and were also up-accumulated. Overexpression of LrAN2 activated the bHLH (basic helix-loop-helix protein) transcription factor AN1b, relative to anthocyanin biosynthesis and the MYB transcription factor MYB3, relative to proanthocyanin biosynthesis. Then, the structural genes, relative to the phenylpropanoid pathway, were activated, which led to the up-accumulation of phenylpropanoid, polyphenol (catechin), flavonoid, flavone, flavonol and anthocyanin. The MYB transcription factor CPC, negative to anthocyanin biosynthesis, also induced up-expression in transgenic lines, which implied that a negative regulation mechanism existed in the anthocyanin biosynthesis pathway. The relative contents of all 19 differently accumulated amino and derivers were decreased in transgenic lines, which meant the phenylalanine biosynthesis pathway completed the same substrates with other amino acids. Interestingly, the acetylalkylglycerol acetylhydrolase was down-expressed in transgenic lines, which caused 19 lyso-phosphatidylcholine and derivatives of lipids to be up-accumulated, and 8 octodecane and derivatives were down-accumulated. This research will give more information about the function of MYB transcription factors on the anthocyanin biosynthesis and other chemical compounds and be of benefit to obtaining new plant cultivars with high anthocyanin content by biotechnology.

Functional MYB transcription factor encoding gene AN2 is associated with anthocyanin biosynthesis in Lycium ruthenicum Murray.

BACKGROUND: Lycium ruthenicum Murray is an important economic plant in China and contains higher levels of anthocyanins in its fruits than other Lyciums. However, the genetic mechanism of anthocyanin production in this plant is unknown. RESULTS: Based on previous transcriptome analysis, LrAN2 and LbAN2, encoding MYB transcription factors, were isolated from L. ruthenicum and L. barbarum, respectively. Both genes contained two introns, encoded 257 amino acids with two-Aa difference, and carried the unabridged HTH-MYB, MYB-like DNA-binding, and SANT domains. In the phylogenetic trees, LrAN2 and LbAN2 were found to be closely related to NtAN2, which regulates anthocyanin biosynthesis in tobacco. Overexpression of LrAN2 and LbAN2 induced anthocyanin biosynthesis in all tissues of tobacco. The anthocyanin content in the leaves of transgenic lines with LbAN2 was lower than LrAN2. It indicated that the function of LbAN2 was weaker than LrAN2. The AN2 transcript could be detected only in the fruits of L. ruthenicum and increased during fruit development, accompanied by anthocyanin accumulation. In natural population, the alleles LrAN2 and LrAN2 were associated strictly with L. ruthenicum and L. barbarum, respectively. Moreover, an AN2 genetic diversity study suggested that Lyciums with yellow, white, purple, and jujube red fruits were derived from L. ruthenicum. CONCLUSIONS: Two AN2 alleles, from L. ruthenicum and L. barbarum, were functional MYB transcriptor regulating anthocyanin biosynthesis. The functional diversity and high expression level of LrAN2 could be the reason for high anthocyanin content in the fruit of L. ruthenicum. Lyciums with yellow, white, purple, and jujube red fruits were derived from L. ruthenicum based on AN2 sequence diversity. The results may be advantageous in identifying new varieties and breeding new cultivars.

Combination Therapies and Drug Delivery Platforms in Combating Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of cancer-related death in the United States, is highly aggressive and resistant to both chemo- and radiotherapy. It remains one of the most difficult-to-treat cancers, not only due to its unique pathobiological features such as stroma-rich desmoplastic tumors surrounded by hypovascular and hypoperfused vessels limiting the transport of therapeutic agents, but also due to problematic early detection, which renders most treatment options largely ineffective, resulting in extensive metastasis. To elevate therapeutic effectiveness of treatments and overt their toxicity, significant enthusiasm was generated to exploit new strategies for combating PDAC. Combination therapy targeting different barriers to mitigate delivery issues and reduce tumor recurrence and metastasis has demonstrated optimal outcomes in patients' survival and quality of life, providing possible approaches to overcome therapeutic challenges. This paper aims to provide an overview of currently explored multimodal therapies using either conventional therapy or nanomedicines along with rationale, up-to-date progress, as well as the key challenges that must be overcome. Understanding the future directions of the field may assist in the successful development of novel treatment strategies for enhancing therapeutic efficacy in PDAC.

Allelic Variation and Transcriptional Isoforms of Wheat TaMYC1 Gene Regulating Anthocyanin Synthesis in Pericarp.

Recently the TaMYC1 gene encoding bHLH transcription factor has been isolated from the bread wheat (Triticum aestivum L.) genome and shown to co-locate with the Pp3 gene conferring purple pericarp color. As a functional evidence of TaMYC1 and Pp3 being the same, higher transcriptional activity of the TaMYC1 gene in colored pericarp compared to uncolored one has been demonstrated. In the current study, we present additional strong evidences of TaMYC1 to be a synonym of Pp3. Furthermore, we have found differences between dominant and recessive Pp3(TaMyc1) alleles. Light enhancement of TaMYC1 transcription was paralleled with increased AP accumulation only in purple-grain wheat. Coexpression of TaMYC1 and the maize MYB TF gene ZmC1 induced AP accumulation in the coleoptile of white-grain wheat. Suppression of TaMYC1 significantly reduced AP content in purple grains. Two distinct TaMYC1 alleles (TaMYC1p and TaMYC1w) were isolated from purple- and white-grained wheat, respectively. A unique, compound cis-acting regulatory element had six copies in the promoter of TaMYC1p, but was present only once in TaMYC1w. Analysis of recombinant inbred lines showed that TaMYC1p was necessary but not sufficient for AP accumulation in the pericarp tissues. Examination of larger sets of germplasm lines indicated that the evolution of purple pericarp in tetraploid wheat was accompanied by the presence of TaMYC1p. Our findings may promote more systematic basic and applied studies of anthocyanins in common wheat and related Triticeae crops.

The characteristics and functions of a miniature inverted-repeat transposable element TaMITE81 in the 5' UTR of TaCHS7BL from Triticum aestivum.

Miniature inverted-repeat transposable elements (MITEs) are truncated derivatives of autonomous DNA transposons, and are dispersed abundantly in eukaryotic and prokaryotic genomes. In this article, a MITE, TaMITE81, was isolated from the 5' untranslated region (UTR) of TaCHS7BL, chalcone synthase (CHS) catalyzing the first committed step of anthocyanin biosynthesis, in the wheat cultivar 'Opata' with white grain. TaMITE81 was only 81 nucleotides, including a terminal inverted repeat with 39 nucleotides and was flanked by two nucleotides, "TA", target site duplications that were typical features of stowaway-like MITEs. Compared with the wheat cultivar 'Gy115' with purple grain, which is without the insertion, the expression of TaCHS7BL was lower in several organs of 'Opata'. The insertion of TaMITE81 into the 5' UTR of the GUS gene also reduced the transient expression of GUS on the coleoptiles of 'Opata', which means the insertion of TaMITE81 was the reason for the low expression of TaCHS7BL in 'Opata'. But the genotype of TaCHS7BL was not linked to phenotype of grain color in the RILs derived from a cross 'Gy115' and 'Opata'. The TaMITE81 density of the hexaploid variety of T. aestivum was more than 10 times that of diploid relatives, which implies that polyploidization caused the amplification of TaMITE81 homologous sequences. Further research should be conducted on decoding the relationship between TaCHS7BL and other traits relative to anthocyanin biosynthesis in wheat, and discovering the mechanism of TaMITE81 transposon action.

Development and evaluation of a dry powder formulation of liposome-encapsulated oseltamivir phosphate for inhalation.

This study aims to develop oseltamivir phosphate (OP) liposomes as inhalation powders by spray-drying based on the single factor investigation, which was mainly composed of lactose, L-leucine and mannitol. It was found that the ratio of OP and liposomes (1:10), inlet temperature (110 °C) and airflow rate (2.3 mL/min) showed optimized physical properties of OP liposomes. Deposition was evaluated after the aerosolization of powders at 600 L/h via the Aerolizer® into a twin-stage impinger. The concentrations of OP and oseltamivir carboxylate (OSCA) in rats plasma using LC-MS have been determined and performed via pharmacokinetic software DAS 2.0 package. The liposomal OP dry powders displayed an average particle size around 3.5 µm with fine particle fraction (FPF = 35.40%). In vitro evaluation demonstrated a sustained release pattern accounting for 20% drug release compared to that of OP solution up to 90% drug release in 2 h. And the cumulative release percentage was up to 50% in 20 h. Atrioventricular fitting results indicated that all preparations were best fitted with a two-compartment model. There was a significant difference in MRT, Cmax and Tmax (p < 0.01) between the two groups of liposomal OP dry powders and OP solution with t-test, which indicated that the drug released slowly from liposomal OP dry powders in the lung. To sum up, dry powders formulation of liposome-encapsulated OP for inhalation was suitable for pulmonary administration, which offering the opportunity to reduce dosing frequency.