Osteosarcoma cells differentiate into phenotypes from all three dermal layers

Antisense mediated blockade of Dickkopf 1 attenuates tumor survival, metastases and bone damage in experimental osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy. The canonical Wnt inhibitor Dickkopf-1 (Dkk-1) has been implicated in bone destruction, tumor survival and metastases during OS. We examined the role of Dkk-1 in OS disease progression and explored strategies for targeting its activity. Dkk-1 enhances OS survival by amplifying a non-canonical Wnt pathway that upregulates aldehyde dehydrogenase 1A1. Targeting of Dkk-1 transcription with a vivo morpholino (DkkMo) reduced OS survival and enhanced osteogenic activity of OS in vitro. DkkMo as a single agent slowed tumor expansion, increased tumor necrosis, inhibited metastases and preserved bone in a PDX model of OS. DkkMo also reduced the frequency of dividing tumor cells and reinitiated a regenerative osteogenic phenotype in tumors and stroma while reducing infiltration of inflammatory cells. These findings indicate that DkkMo has the potential to safely target osteosarcoma growth, survival, metastases and bone destruction.

Sprayed cultured autologous keratinocytes in the treatment of severe burns: a retrospective matched cohort study

The standard treatment of burns is early excision followed by autologous skin grafting. The closure of extensive deep burns poses a considerable challenge. Cultured autologous keratinocytes have been used since 1981 in an effort to improve healing. However, the time required to culture the cells and the lack of a dermal component limit the expectations of outcome. Our aim was to compare the duration of hospital stay between patients who were treated with autologous skin grafts and cultured autologous keratinocytes and those who were treated with autologous skin grafting without cultured autologous keratinocytes. In this retrospective study all patients treated with cultured autologous keratinocytes between 2012 and 2015 were matched by size and depth of burn with patients not treated with cultured autologous keratinocytes. Multivariable regression was used to analyse associations between duration of hospital stay and treatment adjusted for age, mortality, size and depth of the burn. Then, we investigated the possibility of differentiation of human bone marrow stem cell line to keratinocyte- like cells as a future direction. The regression analysis showed a coefficient of 17.36 (95% CI -17.69 to 52.40), p= 0.32, for hospital stay in the treatment group, compared with the matched group. Our results showed no difference in the duration of hospital stay between the two treatments. Autologous stem cells should be considered as a future modality of burn management, although further studies are needed.

Possible role of H1 histone in replication timing

AT-rich repetitive DNA sequences become late replicating during cell differentiation. Replication timing is not correlated with LINE density in human cells (Ryba et al. 2010). However, short and properly spaced runs of oligo dA or dT present in nuclear matrix attachment regions (MARs) of the genome are good candidates for elements of AT-rich repetitive late replicating DNA. MAR attachment to the nuclear matrix is negatively regulated by chromatin binding of H1 histone, but this is counteracted by H1 phosphorylation, high mobility group proteins or, indirectly, core histone acetylation. Fewer MAR attachments correlates positively with longer average DNA loop size, longer replicons and an increase of late replicating DNA.

Gallic acid induces apoptosis and inhibits cell migration by upregulating miR-518b in SW1353 human chondrosarcoma cells

Gallic acid (GA), a natural agent, is widely distri-buted in plants with a range of biological effects and has been of potential interest as anticancer agent. However, its effects on chondrosarcoma cell apoptosis are still undefined. In the present study, the possible mechanisms of GA-induced apoptosis were explored in SW1353 cells, a human chondrosarcoma cell line. Our results showed that GA inhibited cell viability dose- and time-dependently. Morphological examination of GA-treated cells exhibited the typical features of cell death, such as rounding up of the cells and cell shrinkage. Wound-healing assay indicated that GA inhibited the migratory abilities of SW1353 cells. Hoechst 33258 staining assay and Annexin V/PI staining assay exhibited apoptosis induction by GA. To determine the molecular mechanism of GA-induced apoptosis, the expression levels Bcl-2, Bax, caspase-3 and caspase-9 were determined in SW1353 cells treated with GA. We found that GA downregulated the expression of the anti-apoptotic protein Bcl-2, and upregulated the expression of the pro-apoptotic protein Bax, and the activation of caspase-3 and caspase-9. To identify the possible mechanisms, the changes of microRNA expression were tested using the miRCURY™ LNA expression array. It was observed that the miR-518b gene was upregulated in treated cells. Taken together, these data show that GA induces apoptosis and inhibits cell migration by upregulating miR-518b in SW1353 cells.