Surface Crystal and Degradability of Shape Memory Scaffold Essentialize Osteochondral Regeneration.

The minimally invasive deployment of scaffolds is a key safety factor for the regeneration of cartilage and bone defects. Osteogenesis relies primarily on cell-matrix interactions, whereas chondrogenesis relies on cell-cell aggregation. Bone matrix expansion requires osteoconductive scaffold degradation. However, chondrogenic cell aggregation is promoted on the repellent scaffold surface, and minimal scaffold degradation supports the avascular nature of cartilage regeneration. Here, a material satisfying these requirements for osteochondral regeneration is developed by integrating osteoconductive hydroxyapatite (HAp) with a chondroconductive shape memory polymer (SMP). The shape memory function-derived fixity and recovery of the scaffold enabled minimally invasive deployment and expansion to fill irregular defects. The crystalline phases on the SMP surface inhibited cell aggregation by suppressing water penetration and subsequent protein adsorption. However, HAp conjugation SMP (H-SMP) enhanced surface roughness and consequent cell-matrix interactions by limiting cell aggregation using crystal peaks. After mouse subcutaneous implantation, hydrolytic H-SMP accelerated scaffold degradation compared to that by the minimal degradation observed for SMP alone for two months. H-SMP and SMP are found to promote osteogenesis and chondrogenesis, respectively, in vitro and in vivo, including the regeneration of rat osteochondral defects using the binary scaffold form, suggesting that this material is promising for osteochondral regeneration.

SET domain-containing protein 5 is required for expression of primordial germ cell specification-associated genes in murine embryonic stem cells.

Primordial germ cell (PGC) specification is one of the most fundamental processes in developmental biology. Because PGCs are a common source of both gametes, generation of PGCs from embryonic stem cells (ESCs) is a useful model for analysing the germ line lineage. Although several studies focused on the role of epigenetic regulation on PGC differentiation from ESCs in vitro have been published, germ line commitment remains poorly understood. Here, we show that SET domain-containing protein (Setd5), which has a previously unknown function, is essential for regulating germ cell-associated genes in murine ESCs (mESCs). Even though Setd5 knockdown with 3 distinct shRNAs did not affect expression of pluripotency genes or levels of global histone methylation, all 3 shRNAs significantly diminished the expression of early and late-stage PGC-associated genes. Furthermore, our immunoprecipitation assay showed that Setd5 can interact with Tbl1xr1 and Ctr9, which are components of 2 different transcriptional regulatory complexes, namely, NcoR1 corepressor complex and Paf1 complex, respectively, in mESCs. Taken together, our data suggest that Setd5 is required for maintaining PGC-associated genes and Setd5-associated protein complexes containing Tbl1xr1 and Ctr9, which in turn are likely involved in regulating germ cell-related genes in mESCs.

Landmark-Based Homing Navigation Using Omnidirectional Depth Information.

A number of landmark-based navigation algorithms have been studied using feature extraction over the visual information. In this paper, we apply the distance information of the surrounding environment in a landmark navigation model. We mount a depth sensor on a mobile robot, in order to obtain omnidirectional distance information. The surrounding environment is represented as a circular form of landmark vectors, which forms a snapshot. The depth snapshots at the current position and the target position are compared to determine the homing direction, inspired by the snapshot model. Here, we suggest a holistic view of panoramic depth information for homing navigation where each sample point is taken as a landmark. The results are shown in a vector map of homing vectors. The performance of the suggested method is evaluated based on the angular errors and the homing success rate. Omnidirectional depth information about the surrounding environment can be a promising source of landmark homing navigation. We demonstrate the results that a holistic approach with omnidirectional depth information shows effective homing navigation.

CDK2-dependent phosphorylation of Suv39H1 is involved in control of heterochromatin replication during cell cycle progression.

Although several studies have suggested that the functions of heterochromatin regulators may be regulated by post-translational modifications during cell cycle progression, regulation of the histone methyltransferase Suv39H1 is not fully understood. Here, we demonstrate a direct link between Suv39H1 phosphorylation and cell cycle progression. We show that CDK2 phosphorylates Suv39H1 at Ser391 and these phosphorylation levels oscillate during the cell cycle, peaking at S phase and maintained during S-G2-M phase. The CDK2-mediated phosphorylation of Suv39H1 at Ser391 results in preferential dissociation from chromatin. Furthermore, phosphorylation-mediated dissociation of Suv39H1 from chromatin causes an enhanced occupancy of JMJD2A histone demethylase on heterochromatin and alterations in inactive histone marks. Overexpression of phospho-mimic Suv39H1 induces early replication of heterochromatin, suggesting the importance of Suv39H1 phosphorylation in the replication of heterochromatin. Moreover, overexpression of phospho-defective Suv39H1 caused altered replication timing of heterochromatin and increases sensitivity to replication stress. Collectively, our data suggest that phosphorylation-mediated modulation of Suv39H1-chromatin association may be an initial step in heterochromatin replication.

Chip collection of hepatocellular carcinoma based on O2 heterogeneity from patient tissue.

Hepatocellular carcinoma frequently recurs after surgery, necessitating personalized clinical approaches based on tumor avatar models. However, location-dependent oxygen concentrations resulting from the dual hepatic vascular supply drive the inherent heterogeneity of the tumor microenvironment, which presents challenges in developing an avatar model. In this study, tissue samples from 12 patients with hepatocellular carcinoma are cultured directly on a chip and separated based on preference of oxygen concentration. Establishing a dual gradient system with drug perfusion perpendicular to the oxygen gradient enables the simultaneous separation of cells and evaluation of drug responsiveness. The results are further cross-validated by implanting the chips into mice at various oxygen levels using a patient-derived xenograft model. Hepatocellular carcinoma cells exposed to hypoxia exhibit invasive and recurrent characteristics that mirror clinical outcomes. This chip provides valuable insights into treatment prognosis by identifying the dominant hepatocellular carcinoma type in each patient, potentially guiding personalized therapeutic interventions.

O2 variant chip to simulate site-specific skeletogenesis from hypoxic bone marrow.

The stemness of bone marrow mesenchymal stem cells (BMSCs) is maintained by hypoxia. The oxygen level increases from vessel-free cartilage to hypoxic bone marrow and, furthermore, to vascularized bone, which might direct the chondrogenesis to osteogenesis and regenerate the skeletal system. Hence, oxygen was diffused from relatively low to high levels throughout a three-dimensional chip. When we cultured BMSCs in the chip and implanted them into the rabbit defect models of low-oxygen cartilage and high-oxygen calvaria bone, (i) the low oxygen level (base) promoted stemness and chondrogenesis of BMSCs with robust antioxidative potential; (ii) the middle level (two times ≥ low) pushed BMSCs to quiescence; and (iii) the high level (four times ≥ low) promoted osteogenesis by disturbing the redox balance and stemness. Last, endochondral or intramembranous osteogenesis upon transition from low to high oxygen in vivo suggests a developmental mechanism-driven solution to promote chondrogenesis to osteogenesis in the skeletal system by regulating the oxygen environment.

The histone demethylase LSD1 is required for estrogen-dependent S100A7 gene expression in human breast cancer cells.

S100A7, a member of S100 calcium binding protein family, is highly associated with breast cancer. However, the molecular mechanism of S100A7 regulation remains unclear. Here we show that long-term treatment with estradiol stimulated S100A7 expression in MCF7 breast cancer cells at both the transcriptional and translational levels. Both treatment with a histone demethylase LSD1 inhibitor and shRNA-based knockdown of LSD1 expression significantly decreased 17ß-estradiol (E2)-induced S100A7 expression. These reduced E2-mediated S100A7 expression are rescued by the overexpressed wild-type LSD1 but not by its catalytically inactive mutant. Our data showed in vivo association of LSD1 with S100A7 promoters, confirming the potential role of LSD1 in regulating S100A7 expression. S100A7 knockdown increased both normal cell growth and estrogen-induced cell proliferation, suggesting a negative influence by S100A7 on the growth of cancer cells. Together, our data suggest that estrogen-induced S100A7 expression mediated by the histone demethylase LSD1 may downregulate breast cancer cell proliferation, implying a potential tumor suppressor-like function for S100A7.

Quenching Epigenetic Drug Resistance Using Antihypoxic Microparticles in Glioblastoma Patient-Derived Chips.

Glioblastoma (GBM) is one of the most intractable tumor types due to the progressive drug resistance upon tumor mass expansion. Incremental hypoxia inside the growing tumor mass drives epigenetic drug resistance by activating nongenetic repair of antiapoptotic DNA, which could be impaired by drug treatment. Hence, rescuing intertumor hypoxia by oxygen-generating microparticles may promote susceptibility to antitumor drugs. Moreover, a tumor-on-a-chip model enables user-specified alternation of clinic-derived samples. This study utilizes patient-derived glioblastoma tissue to generate cell spheroids with size variations in a 3D microchannel network chip (GBM chip). As the spheroid size increases, epigenetic drug resistance is promoted with inward hypoxia severance, as supported by the spheroid size-proportional expression of hypoxia-inducible factor-1a in the chip. Loading antihypoxia microparticles onto the spheroid surface significantly reduces drug resistance by silencing the expression of critical epigenetic factor, resulting in significantly decreased cell invasiveness. The results are confirmed in vitro using cell line and patient samples in the chip as well as chip implantation into a hypoxic hindlimb ischemia model in mice, which is an unprecedented approach in the field.

Tissue Niche Miniature of Glioblastoma Patient Treated with Nano-Awakeners to Induce Suicide of Cancer Stem Cells.

Patient-specific cancer therapies can evolve by vitalizing the mother tissue-like cancer niche, cellular profile, genetic signature, and drug responsiveness. This evolution has enabled the elucidation of a key mechanism along with development of the mechanism-driven therapy. After surgical treatment, glioblastoma (GBM) patients require prompt therapy within 14 days in a patient-specific manner. Hence, this study approaches direct culture of GBM patient tissue (1 mm diameter) in a microchannel network chip. Cancer vasculature-mimetic perfusion can support the preservation of the mother tissue-like characteristic signatures and microenvironment. When temozolomide and radiation are administered within 1 day, the responsiveness of the tissue in the chip reflected the clinical outcomes, thereby overcoming the time-consuming process of cell and organoid culture. When the tissue chip culture is continued, the intact GBM signature gets lost, and the outward migration of stem cells from the tissue origin increases, indicating a leaving-home effect on the family dismantle. Nanovesicle production using GBM stem cells enables self-chasing of the cells that escape the temozolomide effect owing to quiescence. The anti-PTPRZ1 peptide display and temozolomide loading to nanovesicles awakes cancer stem cells from the quiescent stage to death. This study suggests a GBM clinic-driven avatar platform and mechanism-learned nanotherapy for translation.

Sprayable nanomicelle hydrogels and inflammatory bowel disease patient cell chips for development of intestinal lesion-specific therapy.

All-in-one treatments represent a paradigm shift in future medicine. For example, inflammatory bowel disease (IBD) is mainly diagnosed by endoscopy, which could be applied for not only on-site monitoring but also the intestinal lesion-targeted spray of injectable hydrogels. Furthermore, molecular conjugation to the hydrogels would program both lesion-specific adhesion and drug-free therapy. This study validated this concept of all-in-one treatment by first utilizing a well-known injectable hydrogel that underwent efficient solution-to-gel transition and nanomicelle formation as a translatable component. These properties enabled spraying of the hydrogel onto the intestinal walls during endoscopy. Next, peptide conjugation to the hydrogel guided endoscopic monitoring of IBD progress upon adhesive gelation with subsequent moisturization of inflammatory lesions, specifically by nanomicelles. The peptide was designed to mimic the major component that mediates intestinal interaction with Bacillus subtilis flagellin during IBD initiation. Hence, the peptide-guided efficient adhesion of the hydrogel nanomicelles onto Toll-like receptor 5 (TLR5) as the main target of flagellin binding and Notch-1. The peptide binding potently suppressed inflammatory signaling without drug loading, where TLR5 and Notch-1 operated collaboratively through downstream actions of tumor necrosis factor-alpha. The results were produced using a human colorectal cell line, clinical IBD patient cells, gut-on-a-chip, a mouse IBD model, and pig experiments to validate the translational utility.

Cancer Patient Tissueoid with Self-Homing Nano-Targeting of Metabolic Inhibitor.

The current paradigm of cancer medicine focuses on patient- and/or cancer-specific treatments, which has led to continuous progress in the development of patient representatives (e.g., organoids) and cancer-targeting carriers for drug screening. As breakthrough concepts, i) living cancer tissues convey intact profiles of patient-specific microenvironmental signatures. ii) The growth mechanisms of cancer mass with intense cell-cell interactions can be harnessed to develop self-homing nano-targeting by using cancer cell-derived nanovesicles (CaNVs). Hence, a tissueoid model of ovarian cancer (OC) is developed by culturing OC patient tissues in a 3D gel chip, whose microchannel networks enable perfusion to maintain tissue viability. A novel model of systemic cancer responses is approached by xenografting OC tissueoids into ischaemic hindlimbs in nude mice. CaNVs are produced to carry general chemotherapeutics or new drugs under pre/clinical studies that target the BRCA mutation or energy metabolism, thereby increasing the test scope. This pioneer study cross-validates drug responses from the OC clinic, tissueoid, and animal model by demonstrating the alignment of results in drug type-specific efficiency, BRCA mutation-dependent drug efficiency, and metabolism inhibition-based anti-cancer effects. Hence, this study provides a directional foundation to accelerate the discovery of patient-specific drugs with CaNV application towards future precision medicine.

Ginsenosides: the need to move forward from bench to clinical trials.

Panax ginseng, known as Koran ginseng, one of the most commonly used traditional plants, has been demonstrated to show a wide range of pharmacological applications. Ginsenosides are the major active ingredients found in ginseng and are responsible for the biological and pharmacological activities, such as antioxidation, antiinflammation, vasorelaxation, and anticancer actions. Existing studies have mostly focused on identifying and purifying single ginsenosides and investigating pharmacological activities and molecular mechanisms in cells and animal models. However, ginsenoside studies based on clinical trials have been very limited. Therefore, this review aimed to discuss the currently available clinical trials on ginsenosides and provide insights and future directions for developing ginsenosides as efficacious and safe drugs for human disease.

Individualized metabolic profiling stratifies pancreatic and biliary tract cancer: a useful tool for innovative screening programs and predictive strategies in healthcare.

BACKGROUND: Pancreatic cancer (PC) and biliary tract cancer (BTC) are highly aggressive cancers, characterized by their rarity, difficulty in diagnosis, and overall poor prognosis. Diagnosis of PC and BTC is complex and is made using a combination of appropriate clinical suspicion, imaging and endoscopic techniques, and cytopathological examination. However, the late-stage detection and poor prognosis of this tumor have led to an urgent need for biomarkers for early and/or predictive diagnosis and improved personalized treatments. WORKING HYPOTHESIS: There are two hypotheses for focusing on low-mass metabolites in the blood. First, valuable information can be obtained from the masses and relative amounts of such metabolites, which present as low-mass ions (LMIs) in mass spectra. Second, metabolic profiling of individuals may provide important information regarding biological changes in disease states that is useful for the early diagnosis of PC and BTC. MATERIALS AND METHODS: To assess whether profiling metabolites in serum can serve as a non-invasive screening tool for PC and BTC, 320 serum samples were obtained from patients with PC (n = 51), BTC (n = 39), colorectal cancer (CRC) (n = 100), and ovarian cancer (OVC) (n = 30), and from healthy control subjects (control) (n = 100). We obtained information on the relative amounts of metabolites, as LMIs, via triple time-of-flight mass spectrometry. All data were analyzed according to the peak area ratios of discriminative LMIs. RESULTS AND CONCLUSIONS: The levels of the 14 discriminative LMIs were higher in the PC and BTC groups than in the control, CRC and OVC groups, but only two LMIs discriminated between PC and BTC: lysophosphatidylcholine (LysoPC) (16:0) and LysoPC(20:4). The levels of these two LysoPCs were also slightly lower in the PC/BTC/CRC/OVC groups compared with the control group. Taken together, the data showed that metabolic profiling can precisely denote the status of cancer, and, thus, could be useful for screening. This study not only details efficient methods to identify discriminative LMIs for cancer screening but also provides an example of metabolic profiling for distinguishing PC from BTC. Furthermore, the two metabolites [LysoPC(16:0), LysoPC(20:4)] shown to discriminate these diseases are potentially useful when combined with other, previously identified protein or metabolic biomarkers for predictive, preventive and personalized medical approach.

Epigenetic silencing of TNFSF7 (CD70) by DNA methylation during progression to breast cancer.

To escape the immune system, tumor cells may remove surface molecules such as the major histocompatibility complex (MHC) and co-stimulatory molecules, which are essential for recognition by lymphocytes. Down-regulation of the co-stimulatory molecules CD70 (TNFSF7) and CD80 may contribute to tumor cell survival; however, the mechanism of down-regulation of the TNFSF7 gene during tumorigenesis is poorly understood. Here we present evidence indicating that TNFSF7 gene expression is epigenetically down-regulated via DNA hypermethylation within its promoter region during progression in breast cancer cells in the isogenic MCF10 model. Bisulfite sequencing revealed that the CpG pairs at the proximal region of the TNFSF7 promoter are heavily methylated during progression of breast cancer cells but that methylation of the more distal sequences was not changed considerably. Thus, this epigenetic silencing of the TNFSF7 gene via hypermethylation of its proximal region may allow the benign and invasive MCF10 variants to escape immune surveillance.