TIGAR coordinates senescence-associated secretory phenotype via lysosome repositioning and α-tubulin deacetylation.

TP53-induced glycolysis and apoptosis regulator (TIGAR) regulates redox homeostasis and provides the intermediates necessary for cell growth by reducing the glycolytic rate. During cellular senescence, cells undergo metabolic rewiring towards the glycolytic pathway, along with the development of the senescence-associated secretory phenotype (SASP), also known as the secretome. We observed that TIGAR expression increased during replicative senescence following the in vitro expansion of human mesenchymal stromal cells (MSCs) and that TIGAR knockout (KO) decreased SASP factors and triggered premature senescence with decelerated progression.

ZBTB7A suppresses glioblastoma tumorigenesis through the transcriptional repression of EPB41L5.

Glioblastoma multiforme (GBM), the most aggressive and malignant glioma, has a poor prognosis. Although patients with GBM are treated with surgery, chemotherapy, and radiation therapy, GBM is highly resistant to treatment, making it difficult and expensive to treat. In this study, we analyzed the Gene Expression Profiling Interactive Analysis dataset, the Cancer Genome Atlas dataset, and Gene Expression Omnibus array data.

Epigenetic regulation of p62/SQSTM1 overcomes the radioresistance of head and neck cancer cells via autophagy-dependent senescence induction.

Tumors are composed of subpopulations of cancer cells with functionally distinct features. Intratumoral heterogeneity limits the therapeutic effectiveness of cancer drugs. To address this issue, it is important to understand the regulatory mechanisms driving a subclonal variety within a therapy-resistant tumor.

Branched-chain amino acids sustain pancreatic cancer growth by regulating lipid metabolism.

Branched-chain amino acid (BCAA) catabolism and high levels of enzymes in the BCAA metabolic pathway have recently been shown to be associated with cancer growth and survival. However, the precise roles of BCAA metabolism in cancer growth and survival remain largely unclear. Here, we found that BCAA metabolism has an important role in human pancreatic ductal adenocarcinoma (PDAC) growth by regulating lipogenesis.

p53/BNIP3-dependent mitophagy limits glycolytic shift in radioresistant cancer.

The role of p53 in genotoxic therapy-induced metabolic shift in cancers is not yet known. In this study, we investigated the role of p53 in the glycolytic shift in head and neck squamous cell carcinoma cell lines following irradiation. Isogenic p53-null radioresistant cancer cells established through cumulative irradiation showed decreased oxygen consumption and increased glycolysis with compromised mitochondria, corresponding with their enhanced sensitivity to drugs that target glycolysis.

Effect of β-catenin silencing in overcoming radioresistance of head and neck cancer cells by antagonizing the effects of AMPK on Ku70/Ku80.

Background: We attempted to elucidate the mechanism of cell death after radiation by studying how β-catenin silencing controls the radiation sensitivity of radioresistant head and neck cancer cells.

Methods: The most radioresistant cancer cell line (AMC-HN-9) was selected for study. Targeted silencing of β-catenin was used on siRNAs.

Senescence-Associated MCP-1 Secretion Is Dependent on a Decline in BMI1 in Human Mesenchymal Stromal Cells.

Aims: Cellular senescence and its secretory phenotype (senescence-associated secretory phenotype [SASP]) develop after long-term expansion of mesenchymal stromal cells (MSCs). Further investigation of this phenotype is required to improve the therapeutic efficacy of MSC-based cell therapies. In this study, we show that positive feedback between SASP and inherent senescence processes plays a crucial role in the senescence of umbilical cord blood-derived MSCs (UCB-MSCs).

Design of a platform technology for systemic delivery of siRNA to tumours using rolling circle transcription.

For therapeutic applications of siRNA, there are technical challenges with respect to targeted and systemic delivery. We here report a new siRNA carrier, RNAtr NPs, in a way that multiple tandem copies of RNA hairpins as a result of rolling circle transcription (RCT) can be readily adapted in tumour-targeted and systemic siRNA delivery. RNAtr NPs provide a means of condensing large amounts of multimeric RNA transcripts into the compact nanoparticles, especially without the aid of polycationic agents, and thus reduce the risk of immunogenicity and cytotoxicity by avoiding the use of synthetic polycationic reagents.

Prolonged autophagy by MTOR inhibitor leads radioresistant cancer cells into senescence.

Radiotherapy is one of the well-established therapeutic modalities for cancer treatment. However, the emergence of cells refractory to radiation is a major obstacle to successful treatment with radiotherapy. Many reports suggest that inhibitors targeting the mechanistic target of rapamycin (MTOR) can sensitize cancer cells to the effect of radiation, although by which mechanism MTOR inhibitors enhance the efficacy of radiation toward cancer cells remains to be elucidated.

Radioresistant cancer cells can be conditioned to enter senescence by mTOR inhibition.

Autophagy is frequently activated in radioresistant cancer cells where it provides a cell survival strategy. The mTOR inhibitor rapamycin activates autophagy but paradoxically it also enhances radiosensitivity. In this study, we investigated the mechanisms of these opposing actions in radiation-resistant glioma or parotid carcinoma cells.

Promoter methylation of WNT inhibitory factor-1 and expression pattern of WNT/β-catenin pathway in human astrocytoma: pathologic and prognostic correlations.

WNT inhibitory factor-1 (WIF1) is an antagonist of the WNT signaling pathway. We investigated the relationship between WIF1 promoter methylation and regulation of the WNT/β-catenin signaling pathway, tumor grade, and survival in patients with astrocytoma. This study included 86 cases of astrocytoma, comprising 20 diffuse astrocytomas and 66 glioblastomas.

Knockdown of β-catenin controls both apoptotic and autophagic cell death through LKB1/AMPK signaling in head and neck squamous cell carcinoma cell lines.

The Wnt/β-catenin pathway regulates the viability and radiosensitivity of head and neck squamous cancer cells (HNSCC). Increased β-catenin predisposes HNSCC patients to poor prognosis and survival. This study was conducted to determine the mechanism by which β-catenin regulates the viability of HNSCC.

Activation of p53-p21 is closely associated with the acquisition of resistance to apoptosis caused by β1-integrin silencing in head and neck cancer cells.

The issue of whether aberrant expression of β1-integrin is associated with cancer progression and development of resistance to cytotoxic therapy is of considerable interest. Studies to date have shown that the anchorage-independent survival of cancer is attributed, in part, to epithelial-to-mesenchymal transition (EMT). Here, we have reported a novel alternative mechanism of anchorage-independent survival of cancer cells.

A monitoring method for Atg4 activation in living cells using peptide-conjugated polymeric nanoparticles.

To date, several principal methods are presently used to monitor the autophagic process, but they have some potential experimental pitfalls or limitations that make them not applicable to living cells. In order to improve on the currently developed detection methods for autophagy, we report here fluorescent peptide-conjugated polymeric nanoparticles loaded with a lysosome staining dye in their core. The fluorescent peptide is designed to be specifically cleaved by the Atg4 cysteine protease, which plays a crucial role in autophagy activation.

GD2 expression is closely associated with neuronal differentiation of human umbilical cord blood-derived mesenchymal stem cells.

GD2 ganglioside has been identified as a key determinant of bone marrow-derived mesenchymal stem cells (BM-MSCs). Here, we characterized GD2 ganglioside expression and its implications in umbilical cord blood-derived MSCs (UCB-MSCs). Using immune-selection analysis, we showed that both GD2-positive and GD2-negative UCB-MSCs expressed general stem cell markers and possessed mesodermal lineage differentiation potential.

Lipid-based emulsion system as non-viral gene carriers.

The genetic materials for systemic administration meet a number of hurdles before they reach the nucleus of the target cells, such as enzymatic degradation in the bloodstream, extravascularization around the target tissue, endocytosis by the target cells, and endosomal escape of the genes. Therefore, there have been tremendous needs of effective gene carriers that can deliver the genetic materials to the target site. Of numerous approaches, recent studies have demonstrated that the lipid-based emulsion systems have the high potential as non-viral gene carriers: 1 lipid emulsions are biocompatible because their major constituents are composed of the non-toxic oils and amphiphilic lipids; 2 the cationic lipid emulsions can form nano-sized complexes with negatively charged DNAs, through which the genetic materials can be protected from the enzymatic degradation in the body fluids; 3 The emulsion/DNA complexes are shown to be stable in the bloodstream since their surfaces are rarely recognized by the immune-related cells and serum proteins; and 4 the surfaces of the emulsion complexes are readily modified by varying the lipid composition.

Cellular uptake mechanism and intracellular fate of hydrophobically modified glycol chitosan nanoparticles.

Polymeric nanoparticle-based carriers are promising agents for the targeted delivery of therapeutics to the intracellular site of action. To optimize the efficacy in delivery, often the tuning of physicochemical properties (i.e.

In vivo time-dependent gene expression of cationic lipid-based emulsion as a stable and biocompatible non-viral gene carrier.

To make stable and biocompatible non-viral gene carriers for therapeutic gene therapy, we developed a cationic lipid-based emulsion (CLE) prepared by an oil-in-water (O/W) emulsion method, wherein squalene oil was used as an oil core and the cationic lipid, 1,2-dioleoyl-sn-glycero-3-trimethylammonium-propane (DOTAP), was employed as an emulsifier. To evaluate in vivo characteristics such as toxicity and time-dependent gene expression, a bioluminescence reporter gene in pCMV-luc plasmid DNA was simply mixed with CLE in aqueous condition, resulting in a CLE/DNA complex. The CLE/DNA complex was optimized to form a compact and stable nano-sized particle by adding different amounts of plasmid DNA, and an optimal cationic lipid-to-DNA (C/D) weight ratio of 4 was identified.