Myocardial ischaemia (MI) results in extensive cardiomyocyte death and reactive oxygen species (ROS)‐induced damage in an organ with little or no regenerative capacity. Although the use of adult bone ...marrow mesenchymal stem cells (BMMSCs) has been proposed as a treatment option, the high cell numbers required for clinical use are difficult to achieve with this source of MSCs, and animal studies have produced inconsistent data. We recently demonstrated in small and large animal models of acute MI that the application of human term placenta‐derived multipotent cells (PDMCs), a foetal‐stage MSC, resulted in reversal of cardiac injury with therapeutic efficacy. However, the mechanisms involved are unclear, making it difficult to strategize for therapeutic improvements. We found that PDMCs significantly reduced cardiomyocyte apoptosis and ROS production through the paracrine factors GRO‐α, HGF and IL‐8. Moreover, culturing PDMCs on plates coated with laminin, an extracellular matrix (ECM) protein, resulted in significantly enhanced secretion of all three paracrine factors, which further reduced cardiomyocyte apoptosis. The enhancement of PDMC paracrine function by laminin was mediated through αvβ3 integrin, with involvement of the signalling pathways of JNK, for GRO‐α and IL‐8 secretion, and PI3K/AKT, for HGF secretion. Our results demonstrated the utility of PDMC therapy to reduce cardiomyocyte apoptosis through modulation of ECM proteins in in vitro culture systems as a strategy to enhance the therapeutic functions of stem cells.
Triple-negative breast cancer (TNBC) represents up to 20% of all breast cancers. This cancer lacks the expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor ...receptor 2. The current therapeutic strategy for patients with this subtype is the use of cytotoxic chemotherapy and surgery. Luteolin is a natural herbal flavonoid and a potential therapeutic candidate for multiple diseases. The use of a treatment that combines Chinese herbal medicine and western medicine is rising in Asia.
The present study evaluates the effects and molecular mechanisms involved with luteolin treatment and evaluates whether this herb affects androgen receptor-positive breast cancer cell proliferation or metastasis.
In vitro evaluation of the effect of luteolin on androgen receptor-positive TNBC cell proliferation and metastasis
Cell viability analysis was used for the cytotoxicity test. Colony formation and Bromodeoxyuridine (BrdU) staining-based proliferation experiments were used for cell proliferation. Wound healing and transwell assays were used for in vitro migration/invasion. The RT-qPCR analysis was used for gene expression. Furthermore, ChIP-qPCR analysis was used for epigenetic modification of gene promoters.
Luteolin significantly inhibited the proliferation and metastasis of androgen receptor-positive TNBC. Furthermore, luteolin inactivated the AKT/mTOR signaling pathway and reversed the epithelial-mesenchymal transition (EMT). The combination of luteolin and inhibitors of AKT/mTOR synergistically repressed an androgen receptor-positive TNBC cell proliferation and metastasis. Luteolin also downregulated MMP9 expression by decreasing the levels of the AKT/mTOR promoting H3K27Ac and H3K56A on the MMP9 promoter region.
Our findings indicate that luteolin inhibited the proliferation and metastasis of androgen receptor-positive TNBC by regulating MMP9 expression through a reduction in the levels of AKT/mTOR-inducing H3K27Ac and H3K56Ac.
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Over 90% of colorectal cancer (CRC) patients have mutations in the Wnt/β-catenin pathway, making the development of biomarkers difficult based on this critical oncogenic pathway. Recent studies ...demonstrate that CRC tumor niche-stromal cells can activate β-catenin in cancer-initiating cells (CICs), leading to disease progression. We therefore sought to elucidate the molecular interactions between stromal and CRC cells for the development of prognostically relevant biomarkers. Assessment of CIC induction and β-catenin activation in CRC cells with two human fibroblast cell-conditioned medium (CM) was performed with subsequent mass spectrometry (MS) analysis to identify the potential paracrine factors.
In vitro
assessment with the identified factor and
in vivo
validation using two mouse models of disease dissemination and metastasis was performed. Prediction of additional molecular players with Ingenuity pathway analysis was performed, with subsequent
in vitro
and translational validation using human CRC tissue microarray and multiple transcriptome databases for analysis. We found that fibroblast-CM significantly enhanced multiple CIC properties including sphere formation, β-catenin activation, and drug resistance in CRC cells. MS identified galectin-1 (Gal-1) to be the secreted factor and Gal-1 alone was sufficient to induce multiple CIC properties
in vitro
and disease progression in both mouse models. IPA predicted SOX9 to be involved in the Gal-1/β-catenin interactions, which was validated
in vitro
, with Gal-1 and/or SOX9—particularly Gal-1
high
/SOX9
high
samples—significantly correlating with multiple aspects of clinical disease progression. Stromal-secreted Gal-1 promotes CIC-features and disease dissemination in CRC through SOX9 and β-catenin, with Gal-1 and SOX9 having a strong clinical prognostic value.
New potential sources of stem cells for clinical application include bone marrow mesenchymal stem cells (BMMSCs), human embryonic stem cells (hESCs), and induced pluripotent stem cells (iPS). ...However, each source is not without its own concerns. While research continues in an effort to overcome these problems, the generation of mesenchymal progenitors from existing hESC lines may circumvent many of these issues. We report here a simple and efficient method of generating hESC-derived mesenchymal progenitors (EMPs) and transcriptome profiling using a concise, custom-designed, oligomnucleotide gene expression microarray. Characterization of EMPs shows that these cells are similar to BMMSCs in terms of differentiation capacity as well as cell surface marker expression. In addition, EMPs express several ESC markers and HLA-G, a nonclassical MHC class I molecule with immunomodulatory properties. Morevoer, EMPs possess significantly enhanced proliferative ability over BMMSCs during which karyotypic stability was maintained. Although derived from hESCs, EMPs do not form any tumors in immunocompromised mice. To efficiently profile gene expression in multiple samples, we designed an oligoarray to probe just over 11,000 genes highly expressed in stem cells. We found that the transcriptome of EMPs is more similar to BMMSCs than hESCs. Both cell types highly express genes involved in processes related to the cytoskeleton, extracellular matrix, and cell adhesion, but EMPs show higher expression of genes involved in cell proliferation whereas BMMSCs showed higher expression of immune-related genes. Based on our data, EMPs may be an accessible source of mesenchymal progenitor for therapeutic use.
The overexpression of Aurora kinases in multiple tumors makes these kinases appealing targets for the development of anticancer therapies. This study identified two small molecules with a ...furanopyrimidine core, IBPR001 and IBPR002, that target Aurora kinases and induce a DFG conformation change at the ATP site of Aurora A. Our results demonstrate the high potency of the IBPR compounds in reducing tumorigenesis in a colorectal cancer xenograft model in athymic nude mice. Human hepatoma up-regulated protein (HURP) is a substrate of Aurora kinase A, which plays a crucial role in the stabilization of kinetochore fibers. This study used the IBPR compounds as well as MLN8237, a proven Aurora A inhibitor, as chemical probes to investigate the molecular role of HURP in mitotic spindle formation. These compounds effectively eliminated HURP phosphorylation, thereby revealing the coexistence and continuous cycling of HURP between unphosphorylated and phosphorylated forms that are associated, respectively, with microtubules emanating from centrosomes and kinetochores. Furthermore, these compounds demonstrate a spatial hierarchical preference for HURP in the attachment of microtubules extending from the mother to the daughter centrosome. The finding of inequality in the centrosomal microtubules revealed by these small molecules provides a versatile tool for the discovery of new cell-division molecules for the development of antitumor drugs.
Mesenchymal stem cells (MSCs) are paraxial mesodermal progenitors with potent immunomodulatory properties. Reports also indicate that MSCs can undergo neural-like differentiation, offering hope for ...use in neurodegenerative diseases. However, ex vivo expansion of these rare somatic stem cells for clinical use leads to cellular senescence. A newer source of MSCs derived from human pluripotent stem cells (PSC) can offer the 'best-of-both-worlds' scenario, abrogating the concern of teratoma formation while preserving PSC proliferative capacity. PSC-derived MSCs (PSC-MSCs) also represent MSCs at the earliest developmental stage, and we found that these MSCs harbor stronger neuro-differentiation capacity than post-natal MSCs. PSC-MSCs express higher levels of neural stem cell (NSC)-related genes and transcription factors than adult bone marrow MSCs at baseline, and rapidly differentiate into neural-like cells when cultured in either standard neurogenic differentiation medium (NDM) or when the cytoskeletal modulator RhoA kinase (ROCK) is inhibited. Interestingly, when NDM is combined with ROCK inhibition, PSC-MSCs undergo further commitment, acquiring characteristics of post-mitotic neurons including nuclear condensation, extensive dendritic growth, and neuron-restricted marker expression including NeuN, β-III-tubulin and Doublecortin. Our data demonstrates that PSC-MSCs have potent capacity to undergo neural differentiation and also implicate the important role of the cytoskeleton in neural lineage commitment.
This paper is a study of the effects of quadrupole electric fields on the velocities of ions generated by laser desorption ionization (LDI). We used a charge detector to measure ion flight time in ...the absence of electric and magnetic fields to obtain the initial velocity distribution of ions generated in the LDI process. It was found that the measured ion velocity of fullerene and matrix ions was proportional to the energy of the laser pulse. Then we measured velocity distributions of fullerene ions in rf-only quadrupoles. It was observed that the electric field in the fringing field region was proportional to pseudo-potential well depth (Dz) and that ions gained velocity in the fringing field region and speeded up as the Dz was increased due to transfer of rotational energy into translational energy in the high-order field region. Initial velocity of ions passing through different stages of quadruple was increased at every stage. In addition, the mass spectrometric analysis showed when the rf amplitude was low, the quadrupole field allowed stable motion of low mass ions; when the rf amplitude was increased, effective potential well depth was reduced. This is evident that the gradient of ion velocity drops as the difference in Dz increases for C60 and high mass Cn cluster ions.
γS-Crystallin from catfish eye lenses, formerly designated βs-crystallin in mammalian lenses, is structurally characterized in this study by cDNA cloning and sequencing. To facilitate sequence ...characterization of γS-crystallin with structural properties lying between β- and γ-crystallins, a cDNA mixture was constructed from the poly(A)+mRNA isolated from catfish eye lenses, and amplification by polymerase chain reaction (PCR) was carried out to obtain nucleotide segments encoding multiple γS-crystallin isoforms. Sequencing several positive clones revealed that at least two distinct isoforms exist in the γS-crystallin class of this teleostean fish, similar to the authentic γ-crystallin family characterized previously in species of the piscine class. Comparison of protein sequences encoded by two representative catfish γS1 and γS2 cDNAs with the published sequences of β-, γ-, and γS-crystallins from shark, carp, bullfrog, bovine, and human lenses indicates that there is about 20–50% sequence homology between catfish γS-crystallins and various members of the related β/γ-crystallin superfamily from different evolutionary classes, with a higher sequence similarity being found between catfish γS- and mammalian γ-crystallins than between catfish γS- and bovine or carp γS-crystallins. Phylogenetic trees constructed on the basis of the nucleotide and protein sequence divergence among various β-, γ-, and γS-crystallins corroborate the closer relatedness of catfish γS- to authentic γ-crystallin than to bovine and carp γS-crystallins. The results suggest that evolution of catfish γS-crystallins follows a different path from that of bovine and carp γS-crystallins and may represent a more ancient offshoot from the ancestral γ/γS coding gene than carp and bovine γS-crystallins.
Ozone sensitivity was investigated using CAMx simulations and photochemical indicator ratios at three sites （Pingtung City, Chao-Chou Town, and Kenting Town） in Pingtung County in southern Taiwan ...during 2003 and 2004. The CAMx simulations compared fairly well with the hourly concentrations of ozone. Simulation results also showed that Pingtung City was mainly a volatile organic compounds （VOC）-sensitive regime, while Chao-Chou Town was either a VOC-sensitive or a NOx-sensitive regime, depending on the seasons. Measurements of three photochemical indicators （H202, HNO3, and NOy） were conducted, and simulated three transition ranges of H202/HNO3 （0.5-0.8）, O3/HNO3 （10.3-16.2） and O3/NOy （5.7-10.8） were adopted to assess the ozone sensitive regime at the three sites. The results indicated that the three transition ranges yield consistent results with CAMx simulations at most times at Pingtung City. However, both VOC-sensitive and NOx-sensitive regimes were important at the rural site Chao-Chou Town. Kenting Town, a touring site at the southern end of Taiwan, was predominated by a NOx-sensitive regime in four seasons.
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