Australien levererar ny forskningsrapport

Åtta forskare från universiteten QIMR Berghofer , Queensland University of Technology och
The University of Queensland har studerat förekomsten av syrebrist (hypoxia) i solida cancertumörer och därmed den ökande risken för metastasering (spridning av cancer i kroppen). Tidigare kliniska studier har visat att hypoxia vid en tumör associerar direkt med en aggresiv phenotype (uttryck för en gens karakteristiska) vilket visat sig leda till metastasering med riktigt dålig prognos.
"Hypoxic tumour microenvironment often occurs in solid tumors and clinical studies have shown that it directly associates with a more aggressive phenotype by increasing the risk of metastasis,
hence correlating with poor prognosis."
De 8 forskarna har studerat hur enzymet G9a påverkas vid en syrefattig miljö kopplad till en cancertumör.
"Hypoxia is an important factor known to initiate the metastatic cascade in cancer, activating cell motility and invasion by silencing cell adhesion genes.
G9a is a histone methyltransferase previously shown to accumulate in hypoxic conditions.
While its oncogenic activity has been previously reported, not much is known about the role G9a plays in the hypoxia-mediated metastatic cascade."

 G9a-mediated repression of CDH10 in hypoxia enhances breast tumour cell motility and associates with poor survival outcome

Francesco Casciello a,b, Fares Al-Ejeh a, Mariska Miranda a, Greg Kelly a, Eva Baxter a, Karolina Windloch a, Frank Gannon a and Jason S Lee a,b,c*. 

a QIMR Berghofer Medical Research Institute, Herston Rd, Herston, QLD 4006, Australia.
b School of Biomedical Sciences, Queensland University of Technology, Kelvin Grove, QLD
4059, Australia.
c School of Medicine, University of Queensland, Herston, QLD 4006, Australia

Abstract
Rationale: Epigenetic mechanisms are fundamental processes that can modulate gene expression, allowing cellular adaptation to environmental conditions.
Hypoxia is an important factor known to initiate the metastatic cascade in cancer, activating cell motility and invasion by silencing cell adhesion genes.
G9a is a histone methyltransferase previously shown to accumulate in hypoxic conditions.
While its oncogenic activity has been previously reported, not much is known about the role G9a plays in the hypoxia-mediated metastatic cascade.
Methods: The role of G9a in cell motility in hypoxic condition was determined by inhibiting
G9a either by short-hairpin mediated knock down or pharmacologically using a small molecule
inhibitor. Through gene expression profiling, we identified CDH10 to be an important G9a
target that regulates breast cancer cell motility.
Lung metastasis assay in mice was used to determine the physiological significance of G9a and CDH10.
Results: We demonstrate that, while hypoxia enhances breast cancer migratory capacity, blocking G9a severely reduces cellular motility under both normoxic and hypoxic conditions and prevents the hypoxia mediated induction of cellular movement.
Moreover, inhibition of G9a histone methyltransferase activity in mice using a specific small molecule inhibitor significantly reduced growth and colonisation of breast cancer cells in the lung. We identify the type-II cadherin CDH10 as being a novel hypoxia-dependent gene, directly repressed by G9a through histone methylation.
CDH10 overexpression significantly reduces cellular movements in breast cancer cell lines and prevents the hypoxia-mediated increase in cell motility.
In addition, we show that CDH10 expression is prognostic in breast cancer and that it is inversely correlated to EHMT2 (G9a) transcript levels in many tumor-types, including breast cancer.
Conclusion: We propose that G9a promotes cellular motility during hypoxic stress through the silencing of the cell adhesion molecule CDH10 and we describe CDH10 as a novel prognostic biomarker for breast cancer.

Jag klipper som vanligt in det PHI-relevanta.

Material and Methods
Holographic imaging and cell motility.
Cell motility was analysed by the holographic microscope HoloMonitor M4 (Phase Holographic Imaging, Lund, Sweden).
Cells (5×103/well) were seeded in a six well plate and allowed to attach for 24 h prior to treatment with either G9a inhibitor (UNC0642) or vehicle (DMSO).
Digital images were captured every 10 minutes for 96 and 48 hours and cell motility was analysed using Hstudio M4 2.6.3 (Phase Holographic Imaging, Lund, Sweden).
The distance covered over the 48 hours has been determined for a total of 20 individual cells per treatment, merged from three independent experiments.
For the displacement graphs, boxed position (X and Y) were used to plot cellular movements in 2D.

Cells were treated with a small molecule inhibitor of G9a, UNC0642 (2 and 5 μM), and motility was analysed by performing holographic timelapse imaging for up to 96 hours (HoloMonitor M4, Phase).
Holographic microscopy allowed precise single cell-tracking and quantification of the total distance travelled. Results demonstrated that UNC0642 treatment was able to significantly reduce cellular motility, with the highest effects observed at 5 μM in both cell lines.
At this concentration, effects on cellular movements were clear as early as 48 hours of treatment.
The effects of inhibiting G9a on cell motility were then investigated under hypoxic (1% O2) conditions in the two cell lines. Analysis revealed that the hypoxic environment was able to enhance cell motility in both cell lines, increasing the average distance travelled.
In contrast, G9a inhibition in MDA-MB-231 and MCF7 cells led to a significant reduction in cell motility compared to the vehicle treated cells in both normoxic and hypoxic conditions.

Figure 1. G9a inhibition reduces cell motility in breast cancer cell lines 
G9a inhibition represses breast cancer cell motility in vitro.
(A) Microarray analysis of differentially expressed genes comparing hypoxia-responsive genes from MCF7 cells expressing shNS and shG9a identifies a subset of 212 genes downregulated in hypoxia in a G9a-dependent manner. (B) Ingenuity Pathway Analysis results of the 212 G9a-dependent genes. (C) Evaluation of the migratory distance covered by MDA-MB-231 treated with UNC0642 (5 μM) or (D) transfected with either vector or shG9a. Results were evaluated through real-time imaging using the HoloMonitor M4, taking pictures every 10 minutes for 48 hours, in three independent experiments. An average of 20 cells per condition is shown for the representative circular displacement images. (E) Western blot analysis of G9a, H3K9me1 and H3K9me2 in MDA-MB-231 transfected with vector or shG9a and incubated in hypoxia for 24 hours. HIF1α was included as positive control for hypoxic conditions. H3 and Lamin A/C were used as loading control (F) Scratch wound assay for MDA-MB-231 breast cancer cells treated with 5 μM UNC0642, under both normoxic (21% O2) and hypoxic (1% O2) conditions. Results were evaluated by real-time imaging performed by the IncuCyte Zoom every 24 hours and wound closure was quantified using ImageJ. Scale bar represents 500 μm. (G) Scratch wound assay of MCF7 breast cancer cells following G9a KD and G9a reconstitution. Scale bar represents 500 μm. (H) Western blot analysis of MCF7 cells transfected with shG9a and reconstituted with WT G9a. Data are represented as mean ± SEM of three independent xperiments (unpaired, non-parametric Student’s t-test, **p<0.005, ****p<0.0001).

Resultaten (med bistånd av HoloMonitor) man presenterar sammanfattas enligt följande:
- In the present study, we demonstrate that G9a accumulation in hypoxia leads to the transcriptional repression of CDH10. We show that CDH10 expression is directly regulated by G9a under reduced oxygen pressure and that its loss enhances breast cancer cell motility, even in metastatic cell lines that have already lost expression of E-cadherin and Ep-CAM. In addition, we demonstrate that CDH10 expression is associated with improved relapse-free survival in breast cancer, indicating that CDH10 acts as a metastasis suppressor and its downregulation is an integral part of hypoxia-mediated EMT in breast cancer.

Glasklart eller hur?

En intressant detalj i dessa Coronatider är att sistnämnda universitet, The University of Queensland, är involverade i att få fram ett vaccin mot detta skräckinjagande virus.

Race to develop coronavirus vaccine

 The University of Queensland has been asked to develop a vaccine for the recent coronavirus outbreak at unprecedented speed, using new technology.

Coronavirus breakthrough as Australian researchers claim they have developed a vaccine for the deadly illness

Australian scientists have made a key breakthrough in a desperate bid to develop a vaccine for the killer coronavirus. 

Researchers at the University of Queensland are making a fast-tracked attempt to make a cure for the disease, which has killed more than 2,200 people worldwide.

There are now dozens of Australians suffering from the respiratory disease, with 47 contracting it on the Diamond Princess cruise ship in Japan.

Working with the global Coalition for Epidemic Preparedness Innovations rapid response program, Australian researchers have now met a key milestone in their vaccine effort.

Nån koppling mellan Coronavaccinets framtagande och HoloMonitor vet jag inte.

Men intressant att universitetet har kompetens att bedriva hög forskning som spänner över Corona till Cancer.

Hög kompetens kräver avancerad utrustning/instrument vilket definierar HoloMonitor.

                                       Mvh the99