Loss of TP53I11 Enhances the Extracellular Matrix-independent Survival by Promoting Activation of AMPK.

Extracellular matrix (ECM)-independent survival is an essential prerequisite for tumor metastasis, and a hallmark of epithelial cancer stem cells and epithelial-mesenchymal transition (EMT). Here, we found that loss of TP53I11 enhanced, and overexpression of TP53I11 suppressed the ECM-independent survival, EMT, and migration in MCF10A cells. TP53I11 has long been considered as a transcriptional target of TP53. However, we found that TP53I11 regulated the ECM-independent survival by a TP53-independent way. As a metabolic sensor, AMPK promoted anoikis resistance by inhibiting AKT/m-TOR/p70S6K signaling pathway. It was recently revealed that the reciprocal inhibitory relationship between AKT and AMPK regulated adaptation of cells to ECM-detachment. Our results demonstrated that loss of TP53I11 promoted the activation of AKT/m-TOR pathway, increased PGC-1α expression and thereby enhanced OXPHOS in attach-cultured MCF10A cells, but promoted AMPK activation to inhibit AKT/m-TOR/p70S6K signaling pathway in detach-cultured MCF10A cells. This indicates that TP53I11 functions as a mediator to balance activation of AKT and AMPK to adapt cells to different cellular contexts such as ECM-attachment and -detachment. © 2018 IUBMB Life, 71(1):183-191, 2019.

Single cell derived spheres of umbilical cord mesenchymal stem cells enhance cell stemness properties, survival ability and therapeutic potential on liver failure.

Umbilical cord mesenchymal stem cells (UCMSCs) have shown great potentials in regenerative medicine for their extensive sources, multilineage differentiation potential, low immunogenicity and self-renewal ability. However, the clinical application of UCMSCs still confronts many challenges including the requirement of large quantity of cells, low survival ability in vivo and the loss of main original characteristics due to two-dimensional (2D) culture. The traditional three-dimensional (3D)-spheroid culture can mimic in vivo conditions, but still has limitations in clinical application due to large size of spheroid against direct injection and inner cell death. Based on self-renewal tenet, we produced single cell derived sphere (SCDS) of UCMSCs through combining single cell pattern on chip with 3D culture. Compared with the 2D and traditional 3D culture, SCDS culture has many advantages to meet clinical requirements, including small size, higher abilities of survival and migration, and stronger hypoxia resistance and stemness maintenance. Furthermore, SCDS culture promotes angiogenesis in UCMSCs-xenografts and displays greater therapeutic potential on acute liver failure (ALF) in vivo. Our results suggest that SCDS culture may serve as a simple and effective strategy for UCMSCs optimization to meet clinical demand.

TP53I11 suppresses epithelial-mesenchymal transition and metastasis of breast cancer cells.

Epithelial-mesenchymal transition (EMT) is widely-considered to be a modulating factor of anoikis and cancer metastasis. We found that, in MDA-MB-231 cells, TP53I11 (tumor protein P53 inducible protein 11) suppressed EMT and migration in vitro, and inhibited metastasis in vivo. Our findings showed that hypoxic treatment upregulated the expression of HIF1α, but reduced TP53I11 protein levels and TP53I11 overexpression reduced HIF1α expression under normal culture and hypoxicconditions, and in xenografts of MDA-MB-231 cells. Considering HIF1α is a master regulator of the hypoxic response and that hypoxia is a crucial trigger of cancer metastasis, our study suggests that TP53I11 may suppress EMT and metastasis by reducing HIF1α protein levels in breast cancer cells. [BMB Reports 2019; 52(6): 379-384].

Quantitative assessment of human uterine fibroid xenograft using sequential in vivo bioluminescence imaging.

Uterine fibroid is one of the most common solid tumors occurring in reproductive age women. Lack of accurate methods for In vivo quantitative assessment of uterine fibroid progression severely impedes the basic research and drug screen of this disease. To solve this problem, the correlation between bioluminescence imaging (BLI) and initial cell number used to form xenograft was investigated in this study. The results showed that both subcutaneous (SC) and intraperitoneal (IP) D-luciferin administration led to fast increase of bioluminescence signal (BLS) intensity and caused large variation of peak signal intensity of xenografts through the analysis of BLI kinetic curves. We found that a distinct linear stage appeared in xenograft BLI curve for each mouse subjected to IP-injection of D-luciferin. Moreover, a high positive correlation was found between linear slope and the initial number of human uterine fibroid smooth muscle cells (fSMCs) used for xenograft formation. Our research indicates that the slope of linear stage in BLI curve is more appropriate for in vivo quantitative assessment of human uterine fibroid xenograft.

The extracellular matrix enriched with membrane metalloendopeptidase and insulin-degrading enzyme suppresses the deposition of amyloid-beta peptide in Alzheimer's disease cell models.

Amyloid plaque is a typical feature of Alzheimer's disease (AD) and is one of the targets for AD therapy. Membrane metalloendopeptidase (MME) and insulin-degrading enzyme (IDE) are two types of proteases that could cleave beta-amyloid (Aß) peptides generated by neuron cells of AD patients. Extracellular matrix (ECM) plays a crucial role in regulating tissue-specific functions and is an ideal biomaterial for tissue repair. In this study, we extracted the liquid ECM enriched with collagen-binding-domain-fused IDE or MME from human foreskin fibroblast cells. We found that these ECM biomaterials reduced the aggregation of Aß peptides, prevented the formation of amyloid plaques, and also suppressed phosphorylation of Tau protein in AD cell models. Overall, our research provides a novel ECM biomaterial that can be potentially used for AD therapy.

The effect of surface charge on the cytotoxicity and uptake of carbon quantum dots in human umbilical cord derived mesenchymal stem cells.

Carbon quantum dots (CQDs) are emerging as an ideal agent for efficient stem cell labeling. In current study, we synthesized a series of CQDs carrying different surface charges by changing the mass ratio of diammonium citrate (DC) and spermidine (Spd), and evaluated the effects of different surface charges on the cytotoxicity, cellular uptake, stability in human umbilical cord derived mesenchymal stem cells (hUCMSCs). We ascertained the optimal labeling time (24 h) and subtoxic concentration (50 µg/mL) of all different charged CQDs. Our results demonstrated that, although positively charged CQDs are more cytotoxic and have lower photoluminescence (PL) compared to negative CQDs, they still have higher labeling efficiency for their higher uptake capacity. We found that relatively weak positive surface charges enabled CQDs to possess good biocompatibility and labeling efficiency in hUCMSCs. This work will helpfully contribute to the design and optimization of CQDs for tracking stem cells and further benefit to clinical research and application.

Nuclear respiratory factor 1 promotes spheroid survival and mesenchymal transition in mammary epithelial cells.

Epithelial cells aggregate into spheroids when deprived of matrix, and the proclivity for spheroid formation and survival is a hallmark of normal and tumorigenic mammary stem cells. We show here that Nuclear Respiratory Factor 1 (NRF1) is a spheroid promoter by in silico identification of this transcription factor as highly connected to top shRNA-hits deduced from re-iterative selections for shRNAs enriched in MCF10A spheroids. NRF1-promoted spheroid survival is linked to its stimulation of mitochondrial OXPHOS, cell migration, invasion, and mesenchymal transition. Conversely, NRF1 knockdown in breast cancer MDA-MB-231 cells reduced spheroids, migration, invasion, and mesenchymal marker expression. NRF1 knockdown also reduced tumor burden in mammary fat pads and lungs of orthotopic- or tail vein-transplanted mice. With the Luminal A subtype of breast cancer, higher NRF1 expression is associated with lower survival. These results show that NRF1, an activator of mitochondrial metabolism, supports mammary spheroid survival and tumor development.

Evaluating Single-Cell DNA Damage Induced by Enhanced Radiation on a Gold Nanofilm Patch.

Although radiotherapy is a general oncology treatment and is often synergistically applied with surgery and chemotherapy, it can cause side effects during and after treatment. Gold nanoparticles were studied as a potential material to enhance radiation to induce damage in cancer cells. However, few studies have been conducted to examine the effects of gold nanofilm on cell impairment under X-ray treatment. This paper describes a microfabrication-based single-cell array platform to evaluate DNA damage induced by enhanced X-ray radiation on gold nanofilm patches (GNFPs). Cancer cells were patterned on GNFPs of different diameters and thicknesses, where each cell was attached on one GNFP. The end-point DNA damage induced by X-ray was examined in situ at the single-cell level using a halo assay. The preliminary data demonstrated that the enhancement of DNA damage was significantly related to the area and thickness of the GNFP. This platform may be hopefully used to establish the mathematical relationships among DNA damage, X-ray dosage, and thickness and area of the GNFP, and further contribute to radiation dosage screening for personalized radiotherapy.

Screening of SSR markers associated with scale cover pattern and mapped to a genetic linkage map of common carp (Cyprinus carpio L.).

Fish scale is an attractive model in bone physiology research and is also a crucial character for breeding new varieties. Thus, it is important to identify loci in the genome associated with scale formation. In this study, 290 microsatellite markers in common carp (Cyprinus carpio L.) were selected and tested for their segregation in a full-sib mapping panel containing 96 individuals (population 1). Association analysis identified seven simple sequence repeats (SSRs) (HLJ2509, HLJ3227, HLJ3675, HLJ3766, HLJ3863, FGFR1, FGFR7) that showed significant correlation with scale cover pattern in population 1. When the seven SSRs were investigated in two other populations, seven and five SSRs were significantly correlated with scale cover pattern in population 2 (116 individuals) and population 3 (57 individuals), respectively. The exceptions were FGFR1 and HLJ3227. A genetic linkage map was constructed using the 290 SSRs and 241 SSRs were mapped into 47 linkage groups (LGs), with 2-15 markers per LG. The map spanned 2,241.7 cM, with LG sizes that varied from 1.1 to 124.9 cM. All seven markers associated with scale cover mapped into LG3. We considered that a gene cluster that affected the scale cover pattern possibly existed in LG3. By aligning the seven markers with the zebrafish (Danio rerio) genome, we identified six candidate genes (atoh1a, ptch1, bmp1a, fgfr1a, fgf17, wnt5a) that may be associated with scale formation. We propose that the seven markers could be used with marker-assisted selection to breed a new variety of common carp, and the six candidate genes could help in understanding the scale cover mechanism.