A report describes a new simple molecular test to detect chromosomal abnormalities — biomarkers known as telomere fusions–in pancreatic tumour specimens and pancreatic cyst fluids. This assay may help predict the presence of high-grade or invasive pancreatic cancers requiring surgical intervention.
More sophisticated imaging of the pancreas has led to increased detection of presymptomatic lesions. The detection of telomere fusions has the potential to help physicians determine whether these lesions have a high likelihood of developing into pancreatic cancer requiring surgical resection or are more likely to be benign and can be followed by “watchful waiting.”
“Clinicians rely on international consensus guidelines to help manage patients with pancreatic cancer precursor lesions such as intraductal papillary mucinous neoplasms (IPMNs). These guidelines are useful but pancreatic imaging does not provide sufficient information about the neoplastic nature of a pancreatic cyst. Better characterization of pancreatic cysts could allow more patients with worrisome cysts to continue with surveillance, avoiding the morbidity and risks related to pancreatic surgery,” explained Michael Goggins, MD, Sol Goldman Professor of Pancreatic Cancer Research, Departments of Pathology, Surgery, and Oncology, Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins University School of Medicine (Baltimore).
Telomeres are regions of repetitive nucleotide sequences found at the ends of chromosomes that, under normal circumstances, keep the chromosome intact. When telomeres lose most or all of their telomere repeat sequences, the ends can fuse, leading to cell death or chromosomal instability. “This is a major mechanism that contributes to the progression of many precancerous neoplasms to invasive cancers,” said Dr. Goggins. “Telomere fusions can serve as a marker for predicting the presence of high-grade dysplasia and/or invasive cancer.”
In this report, investigators describe a PCR-based assay to detect telomere fusions in samples of pancreatic tumour or cyst fluid. The assay incorporates two rounds of PCR with the second round using a telomere repeat probe to detect the fusions.
The researchers analysed tissues from IPMN tumour samples taken from patients undergoing resection, surgical cyst fluid samples, and normal pancreas. IPMNs are the most common type of pancreatic neoplastic cysts. They are characterized by the papillary proliferation of mucin-producing epithelial cells and cystic dilatation of the main or branch pancreatic duct.
This telomere fusion assay was able to identify telomere fusions in more than half of the pancreatic cell lines. Telomere fusions were often detected in tumours with high-grade dysplasia (containing more abnormal cells). Telomere fusions were not found in normal pancreas or samples with low-grade dysplasia.
Similar findings were seen in analyses of cyst fluid, in which the presence of telomere fusions raised the likelihood of high-grade dysplasia or invasive cancer six fold. The telomere fusion events were found to be associated with high telomerase activity (an enzyme that lengthens telomeres) and shortened telomere length.
“We have developed a simple molecular test to detect telomere fusions. This telomere fusion detection assay is a cheaper method for evaluating pancreatic cyst fluid than many next-generation sequencing approaches that are being evaluated for this purpose,” noted Dr. Goggins.
“The authors succeed in showing the presence of shortened telomeres, sporadic telomeric fusions, and increased telomerase activity in a modest proportion of pancreatic lesions,” commented Loren Joseph, MD, of the Department of Pathology at Beth Israel Deaconess Medical Center, Harvard Medical School (Boston), in an accompanying editorial. He added that the techniques used to detect fusions from cyst DNA and to measure telomere length and telomerase activity are within the scope of many molecular diagnostic laboratories.
Science Articleshttps://tinyurl.com/y9mse347

Being on the cutting edge of science and technology excites Hollings Cancer Center (HCC) researcher Carsten Krieg, Ph.D. Each day, he walks into his lab that houses a mass cytometry machine aptly labelled Helios. Krieg explains how it can heat plasma up to 6,000 degrees Celsius, levels comparable to temperatures found on the sun.
This allows the German native, who recently joined the faculty of the Medical University of South Carolina’s departments of immunology and dermatology, to accomplish an interesting feat. He creates a sort of ‘Instagram’ of a person’s immune system. For cancer patients on experimental immunotherapy treatments, the practical application is obvious and exciting, he said.
“What I use here is a very new and nerdy technology, which is called mass cytometry, that allows you with a very high sensitivity to make pictures of your immune system. And this is possible because there’s artificial intelligence, machine learning combined with algorithms that can make a very complex system easy to visualize.”
Basically, how it works is that researchers stain cells using rare metal-conjugated antibodies that target surface and intracellular proteins. “Normally in biological tissues, there are no rare metals, so this technique offers greater sensitivity in detecting targets.”
Inside the Helios, the cells are ionized using an inductively-coupled plasma. The ions derived from each stained cell are maintained in discrete clouds that can be detected in a mass spectrometer. The technique can potentially detect up to 100 markers per cell, although, due to practical restrictions, about 40 are more realistic, he said. Then researchers use artificial intelligence and bioinformatics to create a two-dimensional mapping that can read the results, creating an Instagram of millions of blood cells.
This is critical as Krieg and other cancer researchers hope to advance the field of immunotherapy. Though immunotherapy has shown great promise, the vast majority of patients either don’t respond, have adverse side effects or relapse. Krieg, who comes to HCC from the University Research Priority Program (URPP) in Zurich, Switzerland, wanted to know if the technology could be used to predict which patients might respond to certain treatments.
While in Zurich, he and his colleagues decided to use the technique to study melanoma. The research identified biomarkers in the blood that can predict whether metastatic melanoma cancer patients will respond positively to immunotherapy. The goal was to see if a blood test for these biomarkers could identity those who are likelier to benefit, while allowing “non-responders” to begin other treatments without losing time, he said. “It’s a decision instrument for physicians and for the health care system.”
It’s also a powerful research tool as it gets to the mechanisms behind what makes immunotherapy work. The recent study found an immune cell type known as classical monocytes in the peripheral blood may be a potential biomarker for patients who will respond to anti-PD-1 immune checkpoint therapy in metastatic melanoma. “Surprisingly, what we clearly found is that it’s the frequency of monocytes that is enhanced in responders over non-responders before immunotherapy.”
Hollings Cancer Centeracademicdepartments.musc.edu/newscenter/2018/hcc-krieg-instagram/index.html

A discovery sheds light on how cancerous cells differ from healthy ones, and could lead to the development of new strategies for therapeutic intervention for difficult-to-treat cancers in the future.
An international team of investigators found a “stop sign”—a modified protein researchers named a PIP-stop—inside cells that are overused by cancerous cells that effectively prevents healthy ones from sorting material in the way they were designed to.
“We have discovered that breast cancer, leukaemia, lymphoma and neuroblastoma cells have too many PIP-stops. This would upset protein function, and opens up a new avenue for developing drugs that block PIP-stop formation by kinase enzymes,” said Michael Overduin, a University of Alberta cancer researcher and professor of biochemistry, who led the research project.
The team named the modification a PIP-stop because it stops proteins from interacting with lipid molecules called PIP.
Before making their discovery, the researchers first solved the 3-D structure of a sorting nexin protein, which is key to sorting proteins to their proper locations within the cell. Powerful magnets in the U.K. and in the National High Field Nuclear Magnetic Resonance Centre (NANUC), Canada’s national magnet lab based in Edmonton, were then used to detect signals from within individual atoms within the protein structure.
By focusing on the protein structure, the team was able to discover the PIP-stop and see how it blocked the protein’s function. The PIP-stop is a phosphate which is added to the protein surface that binds the PIP lipid, and normally controls how proteins attach to membranes.
Samples from cancer patients have too many PIP-stops, which could lead to the unregulated growth seen in tumour cells. Similar PIP-stops were found to be overused in a large number of other proteins involved in other cancer types, where they could also influence tumour growth.
“Our goal now is to design inhibitors for the overactive kinases that create PIP-stops, and to use this information to design drug molecules that block the progression of cancers, particularly those which lack effective treatments,” said Overduin.
University of Alberta Faculty of Medicine & Dentistrywww.folio.ca/medical-researchers-find-protein-that-marks-difference-between-cancer-and-non-cancer-cells/

Research from the University of Liverpool identifies a genetic variant that could improve the safety and effectiveness of corticosteroids, drugs that are used to treat a range of common and rare conditions including asthma, and chronic obstructive pulmonary disease (COPD).
Corticosteroids are very effective in the treatment of asthma and COPD, with more than 20 million prescriptions issued in the UK annually. Unfortunately, corticosteroids can also cause side effects, one of which is adrenal suppression, seen in up to 1/3 of people tested. People with this condition do not make enough cortisol. Cortisol helps the body respond to stress, recover from infections and regulate blood pressure and metabolism.
Adrenal suppression can be very difficult to diagnose, as it can present with a spectrum of symptoms from non-specific symptoms such as tiredness, to serious illness and death. The majority of patients do not develop adrenal suppression, and the reasons why some do, and while other don’t, despite using similar doses of corticosteroids were not previously understood.
In researchers from the University’s Institute of Translational Medicine, led by Professor Sir Munir Pirmohamed, conducted a genome-wide association study (GWAS) to pinpoint the genes responsible for increasing the risk of a person developing adrenal suppression. This method searches for single nucleotide polymorphisms (SNPs). Each person carries about three million SNPs, but if a particular SNP occurs more frequently in people with a particular condition than in people without the condition, it can pinpoint the underlying reason for the difference.
The researchers identified two groups of children with asthma, and one group of adults with chronic obstructive pulmonary disease (COPD), all of whom used inhaled corticosteroid medications. Each patient’s adrenal function was tested. This is the largest published cohort of children ever tested for adrenal suppression (580 children in total).
Individuals who had a particular variation in a specific gene (platelet derived growth factor D; PDGFD) had a markedly increased risk of adrenal suppression, both in the children with asthma and adults with COPD. This risk increased if the patient had two copies of the variation (one from their mother, one from their father). Children with two copies of the high risk variation in PDGFD were nearly six times more likely to develop adrenal suppression than children with no copies.
University of Liverpoolnews.liverpool.ac.uk/2018/03/16/genetic-variant-discovery-to-help-asthma-sufferers/

Tumour cells circulating throughout the body in blood vessels have long been feared as harbingers of metastasizing cancer — even though most free-floating cancer cells will not go on to establish a new tumour.
But if these cast-offs could be accurately counted, they could provide an additional way to track treatment or screen for the disease.
New research by University of Wisconsin–Madison School of Pharmacy Professor Seungpyo Hong and his collaborators builds on several years of work in isolating these circulating tumour cells, or CTCs, by demonstrating improved methods for their capture on clinical samples for the first time. By forcing cancer cells to slow down and developing stronger molecular traps specific to CTCs, researchers were able to identify large numbers of the cells in cancer patients undergoing radiation therapy.
The number of CTCs dropped during therapy and subsequently rebounded in those patients that ended up requiring additional treatment — suggesting that this technology could supplement other techniques for tracking the progress of treatment.
Scientists have recognized CTCs as potentially useful metrics for tracking a patient’s disease for some time. But the cells are the proverbial needle-in-a-haystack, drowned out by billions of ordinary red blood cells and other cells found in the blood. Developing ways to specifically concentrate and trap CTCs has been technically challenging, with existing technologies only identifying a handful of cells from certain patients.
Hong’s team was inspired by the behaviour of CTCs in the blood, which attach themselves to blood vessel walls and begin tumbling along looking for suitable places to invade. This behaviour separates them from the oxygen-carrying cells floating by and is mimicked in the CapioCyte technology using an array of sticky proteins that force the CTCs to begin rolling, which slows them down.
The cells are then trapped using a series of three cancer-specific antibodies, proteins that tightly bind and hold onto the CTCs. To make the connection even stronger, the researchers developed a nanoscale structure shaped a little like a tree, with each branch tipped with an antibody. As a cancer cell passes nearby, many individual branches can latch on, increasing the strength of the attachment.
The cell rolling and multi-tipped branches helped the researchers capture an average of 200 CTCs from each millilitre of a patient’s blood, many times the number of cells captured with previous technology. They identified cancer cells in each of 24 patients undergoing treatment for head-and-neck, prostate, rectal or cervical cancer that enrolled in the study.
“The absolute numbers of CTCs don’t represent too much because there’s too much variation individually, but the more important thing we found was the trend — how the CTC numbers change over time upon treatment. So, for example, we’ve shown that the CTCs go down when the patients are responding really well to the radiotherapy,” says Hong.
Although the number of cells did not correlate with the stage, and thus severity, of the cancer, the reduction in cells was correlated with successful radiation therapy. In two of the three patients that had recurring or persistent disease, CTC numbers came back up.
“Our data suggest that we have a good chance of making CTCs a predictive biomarker or biomarker for surveillance for at least a few cancers, and that’s always exciting,” says Wang.
University of Wisconsin – Madisonnews.wisc.edu/improved-capture-of-cancer-cells-in-blood-could-help-track-disease/