Epithelial-mesenchymal transition (EMT) is a developmental program, which is associated with breast cancer progression and metastasis. Here, we report that ectopic overexpression of SOX4 in immortalized human mammary epithelial cells is sufficient for acquisition of mesenchymal traits, enhanced cell migration, and invasion, along with epithelial stem cell properties defined by the presence of a CD44 high /CD24 low cell subpopulation. SOX4 positively regulated expression of known EMT inducers, also activating the TGF-b pathway to contribute to EMT. SOX4 itself was induced by TGF-b in mammary epithelial cells and was required for TGF-b-induced EMT. Murine xenograft experiments showed that SOX4 cooperated with oncogenic Ras to promote tumorigenesis in vivo. Finally, in clinical specimens of human breast cancer, we found that SOX4 was abnormally overexpressed and correlated with the triple-negative breast cancer subtype (ER À

Protein self-assembly, through specific, high affinity, and geometrically constraining protein-protein interactions, can control and lead to complex cellular nano-structures. Establishing an understanding of the underlying principles that govern protein self-assembly is not only essential to appreciate the fundamental biological functions of these structures, but could also provide a basis for their enhancement for nano-material applications. The ferritins are a superfamily of well studied proteins that self-assemble into hollow cage-like structures which are ubiquitously found in both prokaryotes and eukaryotes. Structural studies have revealed that many members of the ferritin family can self-assemble into nano-cages of two types. Maxi-ferritins form hollow spheres with octahedral symmetry composed of twenty-four monomers. Mini-ferritins, on the other hand, are tetrahedrally symmetric, hollow assemblies composed of twelve monomers. This review will focus on the structure of members of the ferritin superfamily, the mechanism of ferritin self-assembly and the structure-function relations of these proteins.

Amplification of 3q26 is one of the most frequent chromosomal alterations in many solid tumors, including ovarian, lung, esophageal, prostate, breast, and nasopharyngeal cancers. A candidate oncogene to eukaryotic initiation factor 5A2 (eIF-5A2), a member of eukaryotic initiation factor 5A subfamily, has been isolated from a frequently amplified region at 3q26.2. In this work, the tumorigenic ability of eIF-5A2 was demonstrated by anchorage-independent growth in soft agar and tumor formation in nude mice. Furthermore, antisense DNA against eIF-5A2 could inhibit cell growth in ovarian cancer cell line UACC-1598 with amplification of eIF-5A2 in form of double minutes. Cell growth rate in UACC-1598 was also inhibited when the expression level of EIF-5A2 was decreased by the reduction of the copy number of double minutes. The correlation of EIF-5A2 overexpression and clinical features of ovarian cancer was investigated using tissue microarray, and the result showed that eIF-5A2 overexpression was significantly associated with the advanced stage of ovarian cancer. These findings suggest that eIF-5A2 plays important roles in ovarian pathogenesis.

BackgroundMicroRNAs (miRNAs) have been suggested to play a vital role in tumor initiation and progression by negatively regulating oncogenes and tumor suppressors. Quite recently, studies have identified some miRNAs operating to promote or suppress tumor invasion or metastasis via regulating metastasis-related genes, providing potential therapeutic targets on anti-metastasis strategy. Metastasis-associated in colon cancer-1 (MACC1) has been newly identified to express highly in colorectal cancer (CRC) and promote tumor metastasis through transactivating metastasis-inducing HGF/MET signaling pathway. In this study, we investigated whether miRNA 143 is involved in the regulation of MACC1 and thus plays a functional role in CRC.ResultsUsing both in silico prediction and western blot assay, we found the previously reported tumor suppressive miR-143 targeted MACC1 in CRC. The direct interaction between them was confirmed by 3' UTR luciferase reporter gene. In concordance with the inhibitory effects induced by siRNA mediated knockdown of MACC1, restoration of miR-143 by mimics in SW620 cells significantly attenuated cell growth, migration and invasion. It is notable that combined treatment of miR-143 mimics and MACC1 siRNA induced synergistic inhibitory effects compared to either miR-143 mimics or MACC1 siRNA treatment alone. Conversely, reduction of miR-143 by inhibitors in SW480 cells apparently stimulated these phenotypes. Furthermore, we observed that miR-143 level was inversely correlated with MACC1 mRNA expression in CRC tissues.ConclusionsOur findings newly described miR-143/MACC1 link and provided a potential mechanism for MACC1 dysregulation and contribution to CRC cell invasion. It may help to estimate the therapeutic utility of miR-143 in CRC.

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The fundamental process of protein self-assembly is governed by protein-protein interactions between subunits, which combine to form structures that are often on the nano-scale. The nano-cage protein, bacterioferritin from Escherichia coli, a maxi-ferritin made up of 24 subunits, was chosen as the basis for an alanine-shaving mutagenesis study to discover key amino acid residues at symmetry-related protein-protein interfaces that control protein stability and self-assembly. By inspection of these interfaces and "virtual alanine scanning," nine mutants were designed, expressed, purified, and characterized using transmission electron microscopy, size exclusion chromatography, dynamic light scattering, native PAGE, and temperaturedependent CD. Many of the selected amino acids act as hot spot residues. Four of these (Arg-30, which is located at the two-fold axis, and Arg-61, Tyr-114, and Glu-128, which are located at the three-fold axis), when individually mutated to alanine, completely shut down detectable solution formation of 24-mer, favoring a cooperatively folded dimer, suggesting that they may be oligomerization "switch residues." Furthermore, two residues, Arg-30 and Arg-61, when changed to alanine form mutants that are more thermodynamically stable than the native protein. This investigation into the structure and energetics of this self-assembling nano-cage protein not only can act as a jumping off point for the eventual design of novel protein nanostructures but can also help to understand the role that structure plays on the function of this important class of proteins.

The study aimed to estimate dietary flavonol and flavone intakes and investigate major dietary sources by FFQ in Harbin of China. A total of 5,046 volunteers completed a semiquantitative food frequency questionnaire (FFQ). A random subsample of 167 healthy subjects completed the 7 consecutive 24-h dietary recalls and 2 FFQ for assessing the reproducibility and validity of FFQ. The correlation coefficients between 2 FFQ were 0.72 for flavonols and 0.65 for flavones; and between FFQ 2 and the 24-h dietary recall, they were 0.62 for flavonols and 0.58 for flavones. When flavonol and flavone intakes were categorized by quartile, complete and partial agreement ranged from 76% to 84%. The total intake of flavonols and flavones was 19.13 mg/day, and the mean flavonol and flavone intakes were 14.30 mg/day and 4.82 mg/day, respectively. Quercetin was the major contributor (31%) to total intake of flavonols and flavones, followed by kaempferol (22%). The main food sources of flavonols and flavones were apple (12%), potato (8%), celery (7%), eggplant (7%), and actinidia (5%). This work could facilitate the investigation on the proposed relation between these flavonoids and the prevention of chronic diseases.

MicroRNAs (miRNAs) decrease the expression of specific target oncogenes or tumor suppressor genes and thereby play crucial roles in tumorigenesis and tumor growth. To date, the potential miRNAs regulating osteosarcoma growth and progression are not fully identified yet. In this study, the miRNA microarray assay and hierarchical clustering analysis were performed in human osteosarcoma samples. In comparison with normal human skeletal muscle, 43 miRNAs were significantly differentially expressed in human osteosarcomas (fold change ≥2 and p≤0.05). Among these miRNAs, miR-133a and miR-133b expression was decreased by 135 folds and 47 folds respectively and the decreased expression was confirmed in both frozen and paraffin-embedded osteosarcoma samples. The miR-133b precursor expression vector was then transfected into osteosarcoma cell lines U2-OS and MG-63, and the stable transfectants were selected by puromycin. We found that stable over-expression of miR-133b in osteosarcoma cell lines U2-OS and MG-63 inhibited cell proliferation, invasion and migration, and induced apoptosis. Further, over-expression of miR-133b decreased the expression of predicted target genes BCL2L2, MCL-1, IGF1R and MET, as well as the expression of phospho-Akt and FAK. This study provides a new insight into miRNAs dysregulation in osteosarcoma, and indicates that miR-133b may play as a tumor suppressor gene in osteosarcoma.