No abstract

Chromosome 7 open reading frame 24 (C7orf24), which was identified by proteome analysis, is upregulated in various types of cancer and is associated with cellular proliferation. However, in vivo antitumor effect by knockdown of C7orf24 has not been clarified. In this study, we investigated that the antitumor effect of anti-C7orf24 small interfering RNA (siRNA) administered by needle-free jet injection (JI) on lung cancer-bearing mice. Transfection of anti-C7orf24 siRNA induced cytotoxicity in cultured human lung cancer cells through specific knockdown of C7orf24. Furthermore, JI could effectively deliver anti-C7orf24 siRNA to tumor tissues, and as a result tumor growth was significantly inhibited. Immunohistochemical analysis revealed that C7orf24 levels were significantly reduced within tumor tissues collected from anti-C7orf24 siRNA-administered mice, indicating that the knockdown of C7orf24 induced cytotoxicity in tumor tissue. In conclusion, these data show for the first time that knockdown of C7orf24 prevents tumor growth in vivo following JI-mediated the siRNA delivery.

The ban on the use of animals in testing cosmetic products has led to the development of animal-free in vitro methods. Strat-M® is an artificial membrane engineered to mimic human skin and is recommended as a replacement for skin. However, its usefulness in the assessment of the permeation of cosmetics in in-use conditions remains unverified. No data have been published on its comparative performance with the membrane of choice, porcine skin. The comparative permeability characteristics of Strat-M® and porcine skin were investigated using Franz diffusion cells. Caffeine (CF) and rhododendrol (RD) in complex vehicles with varying concentrations of polyols were applied as finite and infinite doses. Good rank orders of permeation from finite dose experiments were observed for RD. High correlations were observed in RD permeation between Strat-M® and porcine skin under finite and infinite dose conditions, whereas only finite dose conditions for CF were associated with good correlations. Permeation from formulations with high polyol content and residual formulations was enhanced due to the disruption of the integrity of the Strat-M® barrier. The usefulness of Strat-M® in the assessment of dermal permeation may be limited to finite dose conditions and not applicable to infinite dose conditions or formulations applied in layers.

Recent studies showed that plant-derived nanoparticles (NPs) can be easily produced in high yields and have potential applications as therapeutic agents or delivery carriers for bioactive molecules. In this study, we selected corn as it is inexpensive to grow and mass-produced globally. Super sweet corn was homogenized in water to obtain corn juice, which was then centrifuged, filtered through a 0.45-μm-pore size syringe filter, and ultracentrifuged to obtain NPs derived from corn, or corn-derived NPs (cNPs). cNPs obtained were approximately 80 nm in diameter and negatively charged (− 17 mV). cNPs were taken up by various types of cells, including colon26 tumor cells and RAW264.7 macrophage-like cells, with selective reduction of the proliferation of colon26 cells. Moreover, cNPs induced tumor necrosis factor-α release from RAW264.7 cells. cNPs and RAW264.7 in combination significantly suppressed the proliferation of colon26/fluc cells. Daily intratumoral injections of cNPs significantly suppressed the growth of subcutaneous colon26 tumors in mice, with no significant body weight loss. These results indicate excellent anti-tumor activity of cNPs.

Finite dose experiments represent clinical use wherein depletion of dose, evaporation of excipients, and gradual change in vehicle composition may occur. In the present study, we attempted a mathematical approach for predicting skin permeation and concentration of a cosmetic active, rhododendrol (RD), from complex vehicle-based formulations applied in finite dose. In vitro skin permeation and concentration studies of RD were conducted from formulations containing water and polyols with concentrations ranging from 10 -100% under infinite and finite dose conditions using vertical Franz diffusion cells. Observed data for skin permeation and the viable epidermis and dermis (VED) concentration of RD were estimated by the differential equations under Fick's second law of diffusion together with water evaporation kinetics and changes in the partition coefficient from vehicles to the stratum corneum. As a result, a goodness-of-fit was observed allowing accurate estimation of skin permeation and VED concentration of RD. This mathematical approach could become a useful tool to estimate the skin permeation and concentration of actives from topical formulation applied in finite dose conditions likened in actual use.

Delivery of anticancer drugs into tumor cores comprised of malignant cancer cells can result in potent therapeutic effects. However, conventional nanoparticle-based drug delivery systems used for cancer therapy often exhibit inefficient tumor-penetrating properties, thus, suggesting the need to improve the functional design of such systems. Herein, we focus on the interactions between cancer cells and the extracellular matrix (ECM) and demonstrate that liposomes modified with slightly acidic pH-sensitive peptide (SAPSp-lipo) can penetrate in vivo tumor tissue and in vitro spheroids comprised of cancer cells and ECM. We previously reported SAPSp-lipo, tumor microenvironment-sensitive liposomes, are effectively delivered to tumor tissue (Hama et al. J Control Release 2015, 206, 67-74). Compared with conventional liposomes, SAPSp-lipo could be delivered to deeper regions within both spheroids and tumor tissues. Furthermore, tumor penetration was found to be promoted at regions where actin depolymerization was induced by SAPSp-lipo and inhibited by the polymerization of actin. In addition, SAPSp-lipo attenuated the interaction between cancer cells and ECM, contributing to the penetration of SAPSp-lipo. These results suggest that SAPSp-lipo penetrates tumors via the interspace route and is accompanied by actin depolymerization. Taken together, SAPSp-lipo demonstrates potential as a novel tumor-penetrable drug carrier for induction of therapeutic effects against malignant cells that comprise tumor cores.

Hypoxic tumors have been identified as appropriate indicators of tumor malignancy. However, no convenient plasma marker for hypoxic tumors has been described. Therefore, to identify a novel, convenient plasma marker for hypoxic tumors, we used microarray analysis to compare gene expression profiles of normoxic and hypoxic tumor tissues of mice bearing melanomas. Among the upregulated genes detected in hypoxic tumors, we chose to study the secretory protein lipocalin2 (LCN2) as a marker for hypoxic tumors. LCN2 protein levels in the plasma of mice bearing hypoxic tumors were significantly increased compared with those in mice bearing normoxic tumors. Interestingly, LCN2 mRNA levels were 17-fold higher in HIF-1α-positive hypoxic tumors than in HIF-1α-negative normoxic tumors. Furthermore, LCN2 mRNA levels were significantly higher in the B16-F1 cells and various human tumor cells cultured under hypoxic conditions than in cells cultured under normoxic conditions, while no changes in mRNA expression were observed in nontumor NIH-3T3 cells, even under hypoxic conditions. In cultured cells, the expression pattern of LCN2 was mostly consistent with that of HIF-1α, whereas that of a conventional hypoxic marker, carbonic anhydrase IX, was not. Collectively, our data suggested that LCN2 was a useful plasma marker for hypoxic tumors.

Purpose Penetration enhancers are necessary to overcome a formidable barrier function of the stratum corneum in the development of topical formulations. Recently, non-lamella liquid crystal (NLLC)-forming lipids such as glycerol monooleate and phytantriol (PHY) are gaining increasing attention as a novel skin permeation enhancer. In the present study, fluorescein sodium (FL-Na) was used as a model hydrophilic drug, and acryl-base pressure-sensitive adhesive (PSA) tape containing NLLC forming lipids, mono-O-(5,9,13-trimethyl-4-tetradecenyl) glycerol ester (MGE) or PHY, was prepared to enhance drug permeation through the skin. Methods A PSA patch containing FL-Na was prepared by mixing FL-Na entrapped in NLLC and acrylic polymer. FL permeation through excised hairless rat skin, and also human skin, was investigated. Changes in lipid structure, folding/unfolding state of keratin in the stratum corneum, and penetration of MGE into the stratum corneum were investigated using confocal Raman microscopy. Results Enhanced FL permeation was observed by the application of a PSA patch containing MGE and PHY. Especially, dramatically enhancement effect was confirmed by 15% of MGE contained formulation. Penetration of MGE provided diminished orthorhombic crystal structure and a peak shift of the aliphatic CH3 vibration of keratin chains toward lower wavenumbers. ConclusionThe present results suggested that the formulation development by adding MGE may be useful for improving the skin permeation of mal-permeable drugs such as hydrophilic drugs.