Researchers at UT Southwestern Medical Center and the Gill Center for Cancer and Blood Disorders at Children’s Medical Center, Dallas, have made significant progress in defining new genetic causes of Wilms tumor, a type of kidney cancer found only in children.

Wilms tumour is the most common childhood genitourinary tract cancer and the third most common solid tumour of childhood.

“While most children with Wilms tumour are thankfully cured, those with more aggressive tumours do poorly, and we are increasingly concerned about the long-term adverse side effects of chemotherapy in Wilms tumour patients. We wanted to know – what are the genetic causes of Wilms tumour in children and what are the opportunities for targeted therapies? To answer these questions, you have to identify genes that are mutated in the cancer,” said Dr. James Amatruda, Associate Professor of Pediatrics, Molecular Biology, and Internal Medicine at UT Southwestern and senior author for the study.

Collaborating with Dr. Amatruda on the study were UT Southwestern faculty members Dr. Dinesh Rakheja, Associate Professor of Pathology and Pediatrics; Dr. Kenneth S. Chen, Assistant Instructor in Pediatrics; and Dr. Joshua T. Mendell, Professor of Molecular Biology. Dr. Jonathan Wickiser, Associate Professor in Pediatrics, and Dr. James Malter, Chair of Pathology, are also co-authors.

Previous research has identified one or two mutant genes in Wilms tumours, but only about one-third of Wilms tumors had these mutations.

“We wanted to know what genes were mutated in the other two-thirds. To accomplish this goal, we sequenced the DNA of 44 tumours and identified several new mutated genes,” said Dr. Amatruda, who holds the Nearburg Family Professorship in Pediatric Oncology Research and is an Attending Physician in the Pauline Allen Gill Center for Cancer and Blood Disorders at Children’s Medical Center. “The new genes had not been identified before. The most common, and in some ways the most biologically interesting, mutations were found in genes called DROSHA and DICER1. We found that these mutations affected the cell’s production of microRNAs, which are tiny RNA molecules that play big roles in controlling the growth of cells, and the primary effect was on a family of microRNAs called let-7.”

“Let-7 is an important microRNA that slows cell growth and in Wilms tumours in which DROSHA or DICER1 were mutated, let-7 RNA is missing, which causes the cells to grow abnormally fast,” Dr. Amatruda said.

These findings have implications for future treatment of Wilms tumour and several other childhood cancers, including neuroblastoma, germ cell tumour, and rhabdomyosarcoma.

“What’s exciting about these results is that we can begin to understand what drives the growth of different types of Wilms tumours. This is a critical first step in trying to treat the cancer based on its true molecular defect, rather than just what a tumour looks like under a microscope,” Dr. Amatruda said. “Most importantly, we begin to think in concrete terms about a therapy, which is an exciting translational goal of our work in the next few years. UT Southwestern Medical Center

Scientists have identified four biomarkers that may help resolve the difficult differential diagnosis between malignant pleural mesothelioma (MPM) and non-cancerous pleural tissue with reactive mesothelial proliferations (RMPs). This is a frequent differential diagnostic problem in pleural biopsy samples taken from patients with clinical suspicion of MPM. The ability to make more accurate diagnoses earlier may facilitate improved patient outcomes.
‘Our goal was to identify microRNAs (miRNAs) that can aid in the differential diagnosis of MPM from RMPs,’ says lead investigator Eric Santoni-Rugiu, MD, PhD, of the Laboratory of Molecular Pathology at the Department of Pathology of Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. miRNAs, which are small, non-coding RNA strands composed of approximately 22 nucleotides, have been shown to be potential diagnostic, prognostic, and predictive markers in other cancers.
After screening 742 miRNAs, the investigators identified miR-126, miR-143, miR-145, and miR-652 as the best candidates to diagnose MPM. Using results from these four miRNAs, tissue samples from patients with known outcomes could be classified as MPM or non-cancerous with an accuracy of 0.94, sensitivity of 0.95, and specificity of 0.93. Further, an association between miRNA levels and patient survival could be made.
‘The International Mesothelioma Interest Group (IMIG) recommends that a diagnostic marker of MPM have sensitivity/specificity of >0.80, and these criteria are fulfilled by our miRNA classifier,’ comments Dr. Santoni-Rugiu. The authors suggest that diagnostic accuracy can be further improved by adding immunohistochemical testing of miRNA targets in biopsy tissue to their miRNA assay. This combined assay could enable analysis of samples with low tumour cell count.
MPM, which is linked to long-term asbestos exposure, is an aggressive cancer originating from the mesothelial cells that line the membrane surrounding each lung, known as the pleura. Distinguishing MPM from non-cancerous abnormalities, such as reactive mesothelial hyperplasia or fibrous pleurisy (organising pleuritis), can be challenging as there are no generally accepted diagnostic biomarkers for differentiating these two conditions. As a result, patients often present with the disease when they are already at an advanced stage, and less than 20% of patients can be successfully treated surgically.
The current study, however, suggests that miRNAs may provide new opportunities for improving the accuracy of the differential diagnosis between MPM and noncancerous pleural conditions. If further validated, the combination of ISH for miRNAs with immunohistocemical testing of miRNA targets may therefore have the potential to aid in the diagnosis, and thus outcome, of MPM. EurekAlert

High blood pressure is a leading cause of death around the world, and its prevalence continues to rise. A study shows that a protein in the spleen called placental growth factor (PlGF) plays a critical role in activating a harmful immune response that leads to the onset of high blood pressure in mice. The findings pave the way for the development of more effective treatments for this common and deadly condition.

High blood pressure, also known as hypertension, affects more than 1 billion people worldwide and is a major risk factor for stroke, heart failure, and kidney diseases. Mounting evidence suggests that immune cells such as T cells contribute to the development of hypertension, but the underlying mechanisms have not been clear. Senior study author Giuseppe Lembo of IRCCS Neuromed and his team suspected that PlGF could be the missing link because it plays important roles in both the cardiovascular system and the immune system.

The researchers found support for this idea in the new study. Mice that were genetically engineered to lack PlGF did not develop hypertension after they were infused with angiotensin II–a hormone that normally increases blood pressure. These mice were also protected from hypertension-related heart and kidney damage, unlike genetically normal mice. Moreover, PlGF deficiency prevented T cells from leaving the spleen, entering the blood stream, and infiltrating the vessels and kidneys where hypertension was manifested. Additional experiments revealed that the nervous system controls levels of PlGF in the spleen, and PlGF in the spleen in turn is essential for the activation of T cells and the onset of hypertension.

‘In recent years, anti-PlGF monoclonal antibodies have been developed as a strategy to slow tumor growth and for age-related macular degeneration,’ says lead study author Daniela Carnevale. ‘The ongoing clinical trials testing humanized monoclonal antibodies directed to PlGF opens up the possibility of targeting it in hypertension too.’

‘There is a pressing need for new treatments to control and better target resistant hypertension,’ says Lembo. ‘PlGF is an appealing molecular therapeutic target because clinical tools to target this pathway already exist.’ EurekAlert

GNA Biosolutions GmbH (‘GNA’), a company developing ultra-fast diagnostic instruments for human pathogens, announced recently the start of the FILODIAG (Filovirus Diagnostics) project for developing an ultra-fast Ebola detection system based on GNA’s novel Laser PCR technology. GNA is leading a consortium of the Mendel University in Brno (Czech Republic), the Istituto Nazionale per le Malattie Infettive “Lazzaro Spallanzani” (Italy) and the Italian NGO EMERGENCY. The Project Number 115844 of this Ebola+ programme will be funded with EUR 2.3 million by the Innovative Medicines Initiative (IMI2).
There is an urgent need for fast and accurate diagnostic tests in the current and any future Ebola crisis. The rapid diagnosis of Ebola Virus Disease (EVD) during early and late stage of infection is a decisive step for risk assessment and for guidance to physicians to take the necessary decisions to limit the spread of the infection, and to safely nurse the infected patients. While fast and easy-to-use tests usually rely on immuno-diagnostic approaches, they typically lack high sensitivity and specificity. The gold standard for accurate diagnostics is Real-Time PCR but this procedure requires special laboratory facilities and a long processing time of up to several hours.  The aim of the FILODIAG project is to deliver a potentially multiplexed diagnostic system fast enough for point-of-need testing of incoming patients as well as at critical infrastructure checkpoints like airports by withdrawal of blood, or less invasive fluids, such as saliva or urine.
The core technology being used is based on GNA’s laser-heated nanoparticles (Laser PCR) that helps to overcome the time-limiting step of heating and cooling the reaction sample in conventional PCR reactions. GNA have revolutionized this standard procedure by inducing the necessary temperature cycles with laser-heated nanoparticles that can be heated and cooled more than a million times faster than in conventional PCR. GNA has already performed Ebola Laser PCR assays that detect 10 target copies of synthetic nucleotides, corresponding to the Ebola genome sequence, in less than 12 minutes.
Members of the Department of Chemistry and Biochemistry at Mendel University, Brno, will work on integrating the sample preparation with virus-binding magnetic particles. Leading scientist Dr. Vojtech Adam explains: “We will synthesize, characterize and modify the surfaces of nanomaterials to achieve a highly specific binding of viral proteins that will allow for a faster preparation step from patient samples.”
Project coordinator Dr. Lars Ullerich, a Managing Director of GNA, said: “We are working with our international partners to develop a highly sensitive and specific Laser PCR assay based on saliva, urine or blood for Ebola detection. Our proprietary Laser PCR with ten times faster cycles allows us to utilize the gold standard of PCR also in Ebola diagnostics. Together with a label-free detection, the test results will be available in less than 15 minutes. Our Pharos400 system can already detect other highly dangerous pathogens within three minutes and a rapid, simple testing workflow will be crucial to deliver effective support in the management of Ebola outbreaks.”
Dr. Antonino Di Caro, director of microbiology, National Institute for Infectious Diseases “Lazzaro Spallanzani”, will test the device and the assay in a biosafety level 4 laboratory in advance of EMERGENCY conducting field testing in their recently established Ebola treatment centre in Sierra Leone.
The IMI2 Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA. IMI2 has recently launched the programme Ebola+, in which eight funded projects have been announced, including FILODIAG, and two further projects with a diagnostic focus. The FILODIAG project will present future progress on www.filodiag.eu.