Direct regulation of FNIP1 and FNIP2 by MEF2 sustains MTORC1 activation and tumor progression in pancreatic cancer.

MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) orchestrates diverse environmental signals to facilitate cell growth and is frequently activated in cancer. Translocation of MTORC1 from the cytosol to the lysosomal surface by the RRAG GTPases is the key step in MTORC1 activation. Here, we demonstrated that transcription factors MEF2A and MEF2D synergistically regulated MTORC1 activation via modulating its cyto-lysosome shutting. Mechanically, MEF2A and MEF2D controlled the transcription of FNIP1 and FNIP2, the components of the FLCN-FNIP1 or FNIP2 complex that acts as a RRAGC-RRAGD GTPase-activating element to promote the recruitment of MTORC1 to lysosome and its activation. Furthermore, we determined that the pro-oncogenic protein kinase SRC/c-Src directly phosphorylated MEF2D at three conserved tyrosine residues. The tyrosine phosphorylation enhanced MEF2D transcriptional activity and was indispensable for MTORC1 activation. Finally, both the protein and tyrosine phosphorylation levels of MEF2D are elevated in human pancreatic cancers, positively correlating with MTORC1 activity. Depletion of both MEF2A and MEF2D or expressing the unphosphorylatable MEF2D mutant suppressed tumor cell growth. Thus, our study revealed a transcriptional regulatory mechanism of MTORC1 that promoted cell anabolism and proliferation and uncovered its critical role in pancreatic cancer progression.Abbreviation: ACTB: actin beta; ChIP: chromatin immunoprecipitation; EGF: epidermal growth factor; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; FLCN: folliculin; FNIP1: folliculin interacting protein 1; FNIP2: folliculin interacting protein 2; GAP: GTPase activator protein; GEF: guanine nucleotide exchange factors; GTPase: guanosine triphosphatase; LAMP2: lysosomal associated membrane protein 2; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MEF2: myocyte enhancer factor 2; MEF2A: myocyte enhancer factor 2A; MEF2D: myocyte enhancer factor 2D; MEF2D-3YF: Y131F, Y333F, Y337F mutant; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; NR4A1: nuclear receptor subfamily 4 group A member 1; RPTOR: regulatory associated protein of MTOR complex 1; RHEB: Ras homolog, mTORC1 binding; RPS6KB1: ribosomal protein S6 kinase B1; RRAG: Ras related GTP binding; RT-qPCR: real time-quantitative PCR; SRC: SRC proto-oncogene, non-receptor tyrosine kinase; TMEM192: transmembrane protein 192; WT: wild-type.

Transverse facial cleft (macrostomia) repair: Modification of a traditional technique.

OBJECTIVE: Outcomes from surgical repair of transverse facial cleft (macrostomia) may not be very satisfactory when conventional methods are used to position the oral commissure to be repaired. To improve patient outcomes, we developed a modified oral commissure positioning and reconstruction method for transverse facial cleft repair. METHOD: In the modified positioning method, the oral commissure at the abnormal side was positioned precisely and reconstructed by a combination of two conventional methods, namely, the distance measurement method and the anatomical charateristics method. The function of the orbicularis oris muscle was preserved. Postoperative surgical scar score and oral commissure symmetry score were determined and compared between patients and healthy controls. The scores ranged from one to five, with one representing the best and five indicating the worst results. RESULTS: Nine patients aged 4-31 months (7 girls) underwent the modified transverse facial cleft repair surgery. All the patients had unilateral transverse facial cleft with or without microsomia and/or complete cleft lip. The patients were followed up for one to five years. Although average surgical scar scores of patients (close-mouth: 1.8 ± 0.8, range: 1.0-2.8; open-mouth: 1.8 ± 0.9, range 1.0-3.6) remained significantly higher (P < 0.05) than those of the healthy controls (N = 8, close-mouth 1.1 ± 0.4, range: 1.0-1.4, open-mouth: 1.1 ± 0.3, range: 1.0-1.2) 6 months after the surgery, their average close-mouth oral commissure symmetry score (1.9 ± 0.7, range: 1.6-2.8) was similar (P = 0.381) to those of the healthy controls (1.8 ± 0.8, range: 1.0-2.6). CONCLUSIONS: The modified procedure appears to lead to promising long-term benefit on restoring oral commissure symmetry.

Integrated transcriptomic and proteomic analyses of a molecular mechanism of radular teeth biomineralization in Cryptochiton stelleri.

Many species of chiton are known to deposit magnetite (Fe3O4) within the cusps of their heavily mineralized and ultrahard radular teeth. Recently, much attention has been paid to the ultrastructural design and superior mechanical properties of these radular teeth, providing a promising model for the development of novel abrasion resistant materials. Here, we constructed de novo assembled transcripts from the radular tissue of C. stelleri that were used for transcriptome and proteome analysis. Transcriptomic analysis revealed that the top 20 most highly expressed transcripts in the non-mineralized teeth region include the transcripts encoding ferritin, while those in the mineralized teeth region contain a high proportion of mitochondrial respiratory chain proteins. Proteomic analysis identified 22 proteins that were specifically expressed in the mineralized cusp. These specific proteins include a novel protein that we term radular teeth matrix protein1 (RTMP1), globins, peroxidasins, antioxidant enzymes and a ferroxidase protein. This study reports the first de novo transcriptome assembly from C. stelleri, providing a broad overview of radular teeth mineralization. This new transcriptomic resource and the proteomic profiles of mineralized cusp are valuable for further investigation of the molecular mechanisms of radular teeth mineralization in chitons.

Gene expression profile analysis of U251 glioma cells with shRNA-mediated SOX9 knockdown.

PURPOSE: In glioma, the sex-determining region Y-box 9 gene (SOX9) is overexpressed and its downregulation leads to inhibition of cell proliferation, invasion and increased cell apoptosis. To further evaluate the molecular and signal pathways associated with the function of SOX9 and SOX9 target genes, a global gene expression profile of the established SOX9-knockdown U251 cells was investigated. METHODS: The molecular function and biological pathways of differentially expressed genes (DEGs) were identified by gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The interactome networks of DEGs were constructed using the STRING online tool. The genes were further validated by RT-qPCR. RESULTS: GO analysis revealed that a set of 194 DEGs was shared in both the SOX9 KD-1 and SOX9 KD-2 U251 cells. GO analysis and KEGG pathway analysis showed that the DEGs were associated with biological processes involving cellular responses to hypoxia, osteoblast differentiation and angiogenesis, and special biological pathways, such as a TGF-beta signaling pathway and a HIF-1 signaling pathway. In addition, computational network of novel identified potential target genes linked to SOX9, including TGFB2, VEGFA, EGLN3 (PHD3), CA9 and HIF-1a. All of these genes were downregulated in the SOX9 knockdown U251 cells. CONCLUSIONS: SOX9 may be a key regulator impacting the glioma cellular processes by influencing the cellular response to hypoxia and HIF-1 signaling pathway. TGFB2, VEGFA, EGLN3 (PHD3), CA9, and HIF-1a may be the target genes of SOX9.

Genetic variants of SOX9 contribute to susceptibility of gliomas among Chinese population.

Gliomas make up about 80% of all malignant brain tumors, and cause serious public health problem. Genetic factors and environmental factors jointly caused the development of gliomas, and understanding of the genetic basis is a key component of preventive oncology. However, most genetic factors underlying carcinogenesis of gliomas remain largely unclear. In current study, we systematically evaluated whether genetic variants of SOX9 gene, a transcription factor that plays a central role in the development and differentiation of tumors, contribute to susceptibility of gliomas among Chinese population using a two-stage, case-control study. Results showed that SOX9 rs1042667 was significant associated with increased gliomas risk after adjusted by age, gender, family history of cancer, smoking status and alcohol status (Allele C vs A: OR=1.25; 95% CI=1.11-1.40; P=1.2×10-4). Compared with the carriers of genotype AA, both those of genotype AC (OR=1.37; 95% CI=1.13-1.66) and CC (OR=1.53; 95% CI=1.22-1.91) had significantly increased gliomas risk. This should be the first genetic association study which aims to evaluated the association between genetic variants of SOX9 and susceptibility of gliomas. Additional functional and association studies with different ethnic groups included are needed to further confirm our results.

[Preparation and characterization of monoclonal antibodies against F domain of human progranulin].

OBJECTIVE: To prepare and characterize the monoclonal antibody (mAb) against F domain of human progranulin (GrnF). METHODS: Yeast expression vector containing GrnF gene was constructed using molecular biological technology. Then eukaryotic fusion protein human serum albumin (HSA)-GrnF from yeast vector was expressed and purified. BALB/c mice were immunized by the purified HSA-GrnF fusion protein. The splenocytes of the BALB/c mice were isolated from spleen and fused with Sp2/0 myeloma cells. Indirect ELISA and limiting dilution assay were used for screening hybridoma cell lines. The specificity of monoclonal antibodies against GrnF was evaluated with indirect ELISA, Western blotting and immunohistochemistry. The immunoglobulin subclass was identified with mouse monoclonal antibody isotyping reagents. RESULTS: Two hybridoma cell lines, 1G6 and 4E8, were obtained and heavy chain subclasses of the two hybridoma cell lines were IgG1. CONCLUSION: The mAbs that can specifically recognize GrnF have been successfully prepared.