Biology subjects

Wei, D.

Publications and source records attributed to Wei, D..

7 recordsLinked to original sources

bioRxiv2018

KPNA2 promotes cellular proliferation and inhibits apoptosis in the Saos-2 osteosarcoma cell line

Karyopherin 2 plays a critical role in tumorigenesis and tumor progression. However, nothing is currently known about the effects of KPNA2 on osteosarcomas. This study aimed to investigate differential KPNA2 protein and mRNA expression in human osteosarcoma tumor cells and normal bone tissue. We also sought to determine whether KPNA2 can influence the proliferation and apoptosis of the Saos-2 osteosarcoma cell line. Immunohistochemistry (IHC) was used to investigate KPNA2 protein expression. Real-time quantitative PCR (qPCR) was used to detect levels of KPNA2 mRNA expression, and lentivirus-mediated short-hairpin RNAs (shRNAs) were used to knock down KPNA2 expression in Saos-2 cells. The MTT assay and multiparametric high-content screening (HCS) were used to measure cell proliferation and growth, respectively. Flow cytometry was conducted to detect cell cycle distribution and apoptosis. The results revealed significantly higher KPNA2 expression levels in osteosarcoma tissues than in normal bone tissues; furthermore, KPNA2 mRNA was also highly expressed in three osteosarcoma cell lines. After transducing Saos-2 cells with KPNA2-shRNA lentivirus, the proliferative rate was notably decreased compared to that of the negative control (NC) lentivirus group (P<0.05). Flow cytometry results indicated that KPNA2 may arrest cell cycle progression and regulate the growth of these cells. The results for apoptosis indicated an apoptotic rate of 13.38{+/-}0.48% in KPNA2-shRNA cells, which was significantly higher than the rate for cells in the control group (5.13 {+/-}0.33%). Therefore, this study showed that KPNA2 is highly expressed in osteosarcoma tissues and that reduced KPNA2mRNA levels inhibited proliferation and promoted apoptosis in an osteosarcoma cell line.

cancer biology↗

bioRxiv2018

Pleotropic effects of PPARD accelerate colorectal tumor progression and invasion

Colorectal carcinogenesis (CRC) progression requires additional molecular mechanisms to APC mutations/aberrant {beta}-catenin signaling. PPARD is a druggable ligand-activated nuclear receptor that regulates essential genes involved in cell fate. PPARD is upregulated in intestinal epithelial cells (IECs) of human colorectal adenomas and adenocarcinomas. The mechanistic significance of PPARD upregulation in CRC remains unknown. Here we show that targeted PPARD overexpression in IECs of mice strongly augmented {beta}-catenin activation via BMP7/TAK1 signaling, promoted intestinal tumorigenesis in Apcmin mice, and accelerated CRC progression and invasiveness in mice with IEC-targeted Apc{Delta}580 mutation. Human CRC invasive fronts had higher PPARD expression than their paired adenomas. A PPARD agonist (GW501516) enhanced APC{Delta}580 mutation-driven CRC, while a PPARD antagonist (GSK3787) suppressed it. Functional proteomics analyses and subsequent validation studies uncovered PPARD upregulation of multiple pro-invasive pathways that drive CRC progression (e.g. PDGFR{beta}, AKT1, CDK1 and EIF4G1). Our results identify novel mechanisms by which PPARD promotes CRC invasiveness and provide the rational for the development of PPARD antagonists to suppress CRC.

cancer biology↗

bioRxiv2018

Enterovirus 71 structural viral protein 1 promotes mouse Schwann cell autophagy via endoplasmic reticulum stress-mediated peripheral myelin protein 22 upregulation

Enterovirus 71 (EV71) accounts for the majority of hand, foot and mouth disease-related deaths due to fatal neurological complications. The clinical observations and animal models found the early invasion of nervous system, and the demyelinating phenomenon was observed. As one of the receptors of EV71 structural viral protein 1 (VP1), SCARB2 mainly exists on the myelin sheath. EV71 VP1 can promote viral replication through inducing autophagy in neuron cells. This study aims to investigate the role and mechanism of VP1 in autophagy of mouse Schwann cells (MSCs). An EV71 VP1-expressing vector (pEGFP-C3-VP1) was generated and transfected into MSCs. Transmission electron microscopy (TEM) and Western blot analysis of the autophagy marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) were used to assess autophagy in the cells. Real-time PCR and immunofluorescent staining were performed to determine the expression of PMP22. Small interfering RNA against PMP22 was employed to investigate the role of PMP22 in MSCs autophagy. Selective endoplasmic reticulum (ER) stress inhibitor salubrinal (SAL) was employed to determine whether PMP22 is mediated by ER stress. Our results demonstrated that VP1 played a promotive role in MSC autophagy. Overexpression of VP1 upregulated PMP22. PMP22 deficiency downregulated LC3B and thus inhibited autophagy. Furthermore, PMP22 expression was significantly suppressed by SAL. VP1 promotes MSC autophagy through upregulating ER stress-mediated PMP22 expression. VP1/ER stress/ PMP22 axis in autophagy may be a potential therapeutic target for EV71 infection-induced fatal neuronal damage.

cell biology↗

bioRxiv2018

A chemoproteomic portrait of the oncometabolite fumarate

Hereditary cancer disorders often provide an important window into novel mechanisms supporting tumor growth and survival. Understanding these mechanisms and developing biomarkers to identify their presence thus represents a vital goal. Towards this goal, here we report a chemoproteomic map of the covalent targets of fumarate, an oncometabolite whose accumulation marks the genetic cancer predisposition syndrome hereditary leiomyomatosis and renal cell carcinoma (HLRCC). First, we validate the ability of known and novel chemoproteomic probes to report on fumarate reactivity in vitro. Next, we apply these probes in concert with LC-MS/MS to identify cysteine residues sensitive to either fumarate treatment or fumarate hydratase (FH) mutation in untransformed and human HLRCC cell models, respectively. Mining this data to understand the structural determinants of fumarate reactivity reveals an unexpected anti-correlation with nucleophilicity, and the discovery of a novel influence of pH on fumarate-cysteine interactions. Finally, we show that many fumarate-sensitive and FH-regulated cysteines are found in functional protein domains, and perform mechanistic studies of a fumarate-sensitive cysteine in SMARCC1 that lies at a key protein-protein interface in the SWI-SNF tumor suppressor complex. Our studies provide a powerful resource for understanding the influence of fumarate on reactive cysteine residues, and lay the foundation for future efforts to exploit this distinct aspect of oncometabolism for cancer diagnosis and therapy.

cancer biology↗

bioRxiv2017

PPARD regulation in gastric progenitor cells drives gastric tumorigenesis in mice

Little is known about the cell origin of gastric cancer. Peroxisome proliferator-activated receptor-delta (PPARD) is a druggable ligand-activated nuclear receptor that impacts protumorigenic cellular events. However, PPARDs role in tumorigenesis, especially gastric tumorigenesis, remains to be defined. We found that targeting PPARD overexpression in murine gastric progenitor cells (GPC), via a villin promoter, spontaneously induced gastric tumorigenesis that progressed to invasive adenocarcinoma. PPARD overexpression in GPC upregulated tumorigenic proinflammatory cytokine and CD44 expression, expanded GPC population in vivo, enhanced GPC self-renewal and proliferation in organoid cultures, and endowed these cells with tumorigenic properties. Our findings identify PPARD as a driver of gastric tumorigenesis via GPC transformation.

cancer biology↗

bioRxiv2017

Structural and functional MRI from a cross-sectional Southwest University Adult lifespan Dataset (SALD)

Recently, the field of developmental neuroscience has aimed to uncover the developmental trajectory of the human brain and understand the changes that occur as a function of aging. Here we present an adult lifespan dataset of functional magnetic resonance imaging (fMRI) data including structural MRI and resting-state functional MRI. 494 healthy adults (age range: 19-80 years; Males=187) were recruited and completed two multi-modal MRI scan sessions in the Brain Imaging Central of Southwest University, Chongqing, China. The goals of the dataset are to give researchers the opportunity to map the developmental trajectory of structural and functional changes of human brain and to replicate previous findings.

neuroscience↗

bioRxiv2017

Deubiquitylation and stabilization of p21 by USP11 is critical for cell cycle progression and DNA damage responses

p21WAF1/CIP1 is a broad-acting cyclin-dependent kinase inhibitor. Its stability is essential for proper cell cycle progression and cell fate decision. Ubiquitylation by the multiple E3 ubiquitin ligases complex is the major regulatory mechanism of p21, which induces p21 degradation. However, it is unclear whether ubiquitylated p21 can be recycled. In this study, we report USP11 as a deubiquitylase of p21. In the nucleus, USP11 binds to p21, catalyzes the removal of polyubiquitin chains conjugated onto p21 and stabilizes p21 protein. As a result, USP11 reverses p21 polyubiquitylation and degradation mediated by SCFSKP2, CRL4CDT2 and APC/CCDT20 in a cell cycle-independent manner. Loss of USP11 causes the destabilization of p21 and induces the G1/S transition in unperturbed cells. Furthermore, p21 accumulation mediated by DNA damage is completely abolished in cells depleted of USP11, which results in abrogation of the G2 checkpoint and induction of apoptosis. Functionally, USP11-mediated stabilization of p21 inhibits cell proliferation and tumorigenesis in vivo. These findings reveal an important mechanism by which p21 can be stabilized by direct deubiquitylation and pinpoint a crucial role of the USP11-p21 axis in regulating cell cycle progression and DNA damage responses.

cell biology↗