The World Health Organisation (WHO) has urged countries with possible cases of novel coronavirus to share information. The move comes after Saudi Arabia said the development of diagnostic tests had been delayed by patent rights on the NCoV virus by commercial laboratories.
Twenty-two deaths and 44 cases have been reported worldwide since 2012, the WHO says. NCoV is from the same family of viruses as the one that caused Severe Acute Respiratory Syndrome (Sars). An outbreak of Sars in 2003 killed about 770 people. However, NCoV and Sars are distinct from each other, the WHO says.
The virus first emerged in Saudi Arabia, which is where most cases have since arisen. Saudi Deputy Health Minister Ziad Memish raised his concerns at the World Health Assembly in Geneva.
‘We are still struggling with diagnostics and the reason is that the virus was patented by scientists and is not allowed to be used for investigations by other scientists,’ he said. ‘I think strongly that the delay in the development of … diagnostic procedures is related to the patenting of the virus.’
WHO chief Margaret Chan expressed dismay at the information.
‘Why would your scientists send specimens out to other laboratories on [sic] a bilateral manner and allow other people to take intellectual property rights on a new disease?’ she asked.
‘Any new disease is full of uncertainty.’
She is urging the WHO’s 194 member states to only share ‘viruses and specimens with WHO collaborating centres… not in a bilateral manner.’
She added: ‘I will follow it up. I will look at the legal implications together with the Kingdom of Saudi Arabia. No IP (intellectual property) should stand in the way of you, the countries of the world, to protect your people.’
BBC
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Autophagy, the process by which cells that are starved for food resort to chewing up their own damaged proteins and membranes and recycling them into fuel, has emerged as a key pathway that cancer cells use to survive in the face of assault by chemotherapy and radiation. Using drugs to shut down that survival mechanism shows great promise, especially when combined with targeted agents and standard chemotherapies, but until recently, it has been unclear which patients’ cancers would respond to that combination therapy.
A team led by researchers from the Perelman School of Medicine at the University of Pennsylvania will present findings showing that colon cancer and lung cancer cell lines which expressed a gene known as helicase-like transcription factor (HLTF) tended to be impervious to the effects of the autophagy inhibition drug hydroxycholoroquine (HCQ). Cells where HLTF is silent, however, appeared to be sensitive to HCQ, which led the team to test HLTF expression in a group of colon cancer patients treated with two chemotherapies (the FOLFOX regimen plus bevacizumab) and HCQ. They found that low expression of HLTF predicted those who would respond to the combination therapy.
Since previous studies have shown that HLTF gene silencing is common in 20 to 40 percent of many epithelial cancers, the Penn team is hopeful their findings could lead to the development of a predictive biomarker to identify patients with other cancers who are most likely to respond to drug therapies involving autophagy inhibitors.
Penn Medicine
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A JDRF-funded study out of Switzerland has shown that a single gene called SIRT1 may be involved in the development of type 1 diabetes (T1D) and other autoimmune diseases. The study represents the first demonstration of a mono-genetic defect leading to the onset of T1D.
The research began when Marc Donath, M.D., endocrinologist and researcher at the University Hospital Basel in Switzerland, discovered an interesting pattern of autoimmune disease within the family of one of his patients, a 26-year-old male who had recently been diagnosed with T1D. The patient showed an uncommonly strong family history of T1D; his sister, father, and paternal cousin had also been diagnosed earlier in their lives. Additionally, another family member had developed ulcerative colitis, also an autoimmune disease.
‘This pattern of inheritance was indicative of dominant genetic mutation, and we therefore decided to attempt to identify it,’ Dr. Donath said.
Four years of analysis using three different genotyping and sequencing techniques pointed to a mutation on the SIRT1 gene as the common indicator of autoimmune disease within the family. The SIRT1 gene plays a role in regulating metabolism and protecting against age-related disease. To gain more understanding of how this genetic change in SIRT1 leads to T1D, Dr. Donath and his team performed additional studies with animal models of T1D. When the mutant SIRT1 gene found in the families was expressed in beta cells, those beta cells generated more mediators that were destructive to them. Furthermore, knocking out the normal SIRT1 gene in mice resulted in their becoming more susceptible to diabetes with greatly increased islet destruction. Dr. Donath speculates that the beta cell impairment and death due to the SIRT1 mutation subsequently activates the immune system toward T1D.
‘The identification of a gene leading to type 1 diabetes could allow us to understand the mechanism responsible for the disease and may open up new treatment options,’ Dr. Donath explained.
Patricia Kilian, Ph.D., director of the Beta Cell Regeneration Program at JDRF, concurred, and said that the development is exciting for many reasons: ‘While the change in the genetic makeup within this family with type 1 diabetes is rare, the discovery of the role of the SIRT1 pathway in affecting beta cells could help scientists find ways to enhance beta cell survival and function in more common forms of the disease. This study also reinforces increasing evidence that abnormal beta cell function has a role in the development of type 1 diabetes, and that blocking or reversing early stages of beta cell dysfunction may help prevent or significantly delay the disease’s onset. Drug companies are already in the process of developing SIRT1 activators, which could eventually speed our ability to translate these new research findings into meaningful therapies for patients.’
JDRF
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A new genomic test for prostate cancer can help predict whether men are more likely to harbour an aggressive form of the disease, according to a new UC San Francisco study.
The test, which improves risk assessment when patients are first diagnosed, can also aid in determining which men are suitable for active surveillance – a way of managing the disease without direct treatment.
Prostate cancer often grows slowly, and many of the quarter-million patients diagnosed annually in the United States never need treatment, which typically involves surgery, radiation or both. Still, most patients with low-risk prostate cancer in this country immediately undergo treatment.
The researchers found the new test provides ‘statistically significant and clinically meaningful’ prognostic information, and can help identify many more low-risk men who could safely choose surveillance, sparing them from unnecessary treatment and avoidable adverse side effects. At the same time, the test can pinpoint men at apparent low-risk who in fact may have potentially aggressive tumours, the authors said.
The independent UCSF clinical study of 395 men validated the Oncotype DX Genomic Prostate Score (GPS), a biopsy-based pre-treatment tool of Genomic Health, Inc. as a predictor of high grade or extracapsular prostate cancer.
‘With the new test, we can more confidently recommend active surveillance when it is appropriate,’’ said the study’s lead author Matthew R. Cooperberg, MD, MPH, a UCSF assistant professor of urology and epidemiology & biostatistics. ‘And patients through active surveillance can avoid or delay surgery or radiation for their condition.
‘Active surveillance is increasingly acknowledged as a preferred strategy for most men with low-risk disease, but in practice it is used relatively infrequently,’ he noted. ‘There are many reasons why – financial, legal and cultural among others. Many men don’t want to live with anxiety over the chances of their disease progressing. So we need to predict with better accuracy which tumors harbor metastatic potential. If we are able to risk-stratify men more consistently and identify a greater proportion for active surveillance, we should be able to ameliorate over-treatment rates, and by extension help resolve the ongoing debate about PSA screening.’
The second most common cancer in men, prostate cancer affects about one man in six, according to the American Cancer Society. Typically the disease occurs in older men – the average age at diagnosis is about 67 – and an aggressive form kills as many as 30,000 men annually in the U.S. Most men, however, do not die from the disease because they have relatively indolent, low-risk tumours that do not progress even without treatment.
Active surveillance involves closely monitoring a patient’s condition through serial PSA screening and prostate biopsies, but otherwise the disease is not treated unless tests show the condition is getting worse. Active surveillance is not entirely benign – biopsies are uncomfortable and carry a risk of bleeding and infection. Moreover, some patients experience a higher level of anxiety over the potential of their cancers to advance.
While active surveillance can help patients avoid or delay surgery or radiation, scientists have faced a major challenge: how to identify – consistently and reliably – which patients can safely embark on it and which patients face clinically meaningful risk of disease progression.
In the new UCSF study, investigators evaluated the ability of the 17-gene assay through prostate needle biopsy specimens to predict pathologic stage and grade at prostatectomy. The researchers focused on whether the test’s biomarkers added independent predictive information beyond what could already be determined about a patient through standard PSA, Gleason grade and biopsy detail variables.
The men in the study, identified from the UCSF Helen Diller Family Comprehensive Cancer Center Urologic Oncology Database, ranged from 38 to 77 years old at the time they were diagnosed – the median age was 58. The patients represented a range of low- and intermediate-risk tumours in terms of clinical risk characteristics.
The researchers found that the test ‘contributed statistically significant, and clinically meaningful, additional prognostic information above and beyond existing, previously well-validated clinical risk stratification instruments.’
The authors noted a number of study limitations including an explicit intention to include men whose tumours were expected to show a wider range of risk. Further, they said with additional study, the test might be used to identify men with particularly low risk tumours who might be candidates for less-intense surveillance requiring – for example – fewer biopsies.
University of California San Francisco
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Two studies led by investigators at Weill Cornell Medical College shed light on the molecular biology of three blood disorders, leading to novel strategies to treat these diseases.
The two new studies propose two new treatments for beta-thalassaemia, a blood disorder which affects thousands of people globally every year. In addition, they suggest a new strategy to treat thousands of Caucasians of Northern European ancestry diagnosed with HFE-related hemochromatosis and a novel approach to the treatment of the rare blood disorder polycythaemia vera.
These research insights were only possible because two teams that included 24 investigators at six American and European institutions decoded the body’s exquisite regulation of iron, as well as its factory-like production of red blood cells.
‘When you tease apart the mechanisms leading to these serious disorders, you find elegant ways to manipulate the system,’ says Dr. Stefano Rivella, associate professor of genetic medicine in pediatrics at Weill Cornell Medical College.
For example, Dr. Rivella says, two different gene mutations lead to different outcomes. In beta-thalassemia, patients suffer from anaemia — the lack of healthy red blood cells — and, as a consequence, iron overload. In HFE-related haemochromatosis, patients suffer of iron overload. However, he adds, one treatment strategy that regulates the body’s use of iron may work for both disorders.
Additionally, investigators found another strategy, based on manipulating red blood cell production, could also potentially treat beta-thalassaemia as well as a very different disorder, polycythaemia vera.
Dr. Rivella and his colleagues tackled erythropoiesis — the process by which red blood cells (erythrocytes) are produced — as a way to decipher and decode the two blood disorders beta-thalassaemia and polycythaemia vera.
Beta-thalassaemia, a group of inherited blood disorders, is caused by a defect in the beta globin gene. This results in production of red blood cells that have too much iron, which can be toxic, resulting in the death of many of the blood cells. What are left are too few blood cells, which leads to anaemia. At the same time, the excess iron from destroyed blood cells builds up in the body, leading to organ damage. In polycythaemia vera, a patient’s bone marrow makes too many red blood cells due to a genetic mutation that doesn’t shut down erythropoiesis — the production of the cells.
The researchers studied both normal erythropoiesis, in which a person makes enough red blood cells to replace those that are old, and a mechanism called stress erythropoiesis, which flips on when a person requires extra blood cells — such as loss of blood from an accident. The hormone erythropoietin (EPO) controls red blood cell production, and can also induce stress erythropoiesis. Iron is also essential, says Dr. Rivella. ‘The two well-known elements needed to switch between normal and stress erythropoiesis are EPO and iron,’ he says.
But Dr. Rivella and his team found that a third player is essential: macrophages, the immune cells that engulf cellular garbage and pathogens. Macrophages had been known to digest the iron left when old blood cells are targeted for destruction, but Dr. Rivella discovered that they also are necessary for stress erythropoiesis. He found macrophages need to physically touch erythroblasts, the factories that make red blood cells, in order for more factories to be created so that they can churn out red blood cells.
‘No one knew macrophages were a part of emergency red blood cell production. We now know they provide fuel to push red blood cell factories to work faster,’ says the study’s lead author Dr. Pedro Ramos, a former postdoctoral researcher at Weill Cornell.
The research team then looked at diseases in which there are too many red blood cell factories. Polycythemia vera was one of the conditions examined. The researchers disabled macrophage functioning in mice with polycythemia vera and found that red blood cell production returned to normal.
In beta-thalassemia, the body increases the number of red blood cell factories to make up for the lack of viable blood cells — a strategy that doesn’t work. As a result, patients develop enlarged spleens and livers due to the overload of erythroblasts in those organs.
The researchers found in mouse models that if they suppress the function of macrophages, the number of blood cell factories revert back to normal levels. However, there was also an additional benefit discovered. One of the functions of macrophages is to put excess recycled iron into erythroblasts. Researchers report if you suppress that function, less iron goes into the red blood cells. ‘So you then make red blood cells that have less iron, and they are now closer in structure to what they should be,’ says Dr. Rivella.
In animal studies, the researchers saw that decoupling macrophages from the erythroblasts not only reduced the number of blood cell factories, but also improved anaemia.
The discovery could be translated into an experimental therapy by finding the molecule that physically binds a macrophage to an erythroblast, and then targeting and inhibiting it. ‘We need macrophages for good health, but it may be possible to decouple the macrophages that contribute to blood disorders,’ Dr. Rivella says. ‘I estimate that up 30 to 40 percent of the beta-thalassaemia population could benefit from this treatment strategy.’
Dr. Rivella also made another connection. He says polycythaemia vera ‘is sort of a tumour of the red cells, because you make too many of them.’ And he notes that previous research on macrophages found that they are very important in cancer metastasis. ‘I see a parallel between the activity of macrophages in supporting the proliferation of cells that are under stress conditions — growing tumors and red blood cells that need to grow,’ he says. ‘It seems to us that macrophages are important in supporting a switch between normal growth and increased growth.’
Weill Cornell Medical College
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A new test may help to streamline genetic testing for Huntington Disease (HD) by generating accurate results, avoiding unnecessary additional testing, and improving turnaround time. The test, which uses chimeric or triplet repeat primed PCR (TP PCR) methodology, yielded results that were 100% concordant with standard genotyping methods in an analysis of 246 samples. The high sensitivity and specificity of the test could reduce the number of false negative results and facilitate both diagnosis and prognosis by correctly sizing the genetic abnormality characteristic of HD.
Huntington disease (also known as Huntington’s disease or Huntington’s chorea) is an inherited and progressive neuro-degenerative disorder that typically becomes apparent during a person’s thirties or forties. With time, HD patients develop diminished muscle co-ordination that is evident in walking, speaking, and swallowing and undergo changes in personality and thinking ability. A mutation in the Huntingtin gene leads to an abnormal number of repeats of a sequence of three nucleotides known as CAG. Based on the number of CAG repeats, a person may be deemed to be normal (10-35 repeats), at low risk (36-39 repeats), or at high risk (greater than 40 repeats) of having or developing HD symptoms. That is why accurately determining the number of CAG repeats is so important.
In this study, 246 samples that had been previously analysed by other methods were tested with the new method (TP PCR). The samples included 14 DNA reference samples from the Coriell Cell Repositories, three samples from the College of American Pathologists 2002 Survey, and 229 samples from individuals tested at ARUP Laboratories for clinical purposes by standard technologies, explained lead investigator Elaine Lyon, PhD, Medical Director of Molecular Genetics, ARUP Laboratories and its Institute for Clinical and Experimental Pathology, and Department of Pathology, University of Utah, Salt Lake City, UT. Normal samples were included as well as those with a wide range of CAG repeats. The samples were blinded and analysed.
The results showed that TP PCR correctly sized 240 of the 246 samples. All of the 100 samples in the normal and low risk groups were correctly sized. In the 146 samples of those known to be affected by HD (those with > 39 CAG repeats), the results for 140 correctly matched that found with other methods whereas the number of CAG repeats differed by ±1 in 6 samples, a difference said by the authors to be within the precision of the method at higher repeat numbers. Up to 101 CAG repeats could be accurately sized with this test. Even samples that were found to be challenging to analyse with other methods could be assessed solely and accurately by TP PCR.
Another advantage of this new method is its ability to identify true homozygous normal samples, thus avoiding further testing. With other methodologies, if a sample appears homozygous for the normal allele, additional testing, often with Southern blot analysis, is still recommended because of the risk of false negatives. ‘Southern blotting is expensive, labour intensive, requires high concentrations of DNA, and can delay turnaround time,’ says Dr. Lyon. However, when HD is suspected in children, Dr. Lyon and colleagues recommend that even with TP PCR, apparently homozygous samples should undergo further testing.
TP PCR uses a forward and reverse chimeric primer to amplify from multiple priming sites within the trinucleotide repeat. TP PCR produces a characteristic ladder on a fluorescence electropherogram that allows the rapid and inexpensive identification and quantification of expanded repeats. Major peaks and minor peaks (stutters) representing CAG repeats can be analysed and sized automatically using commercially available software.
EurekAlert
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For the first time, scientists from the German Cancer Research Center (DKFZ) and the National Center for Tumor Diseases (NCT) Heidelberg have characterised cancer cells that can initiate metastasis in the blood of breast cancer patients. These cells have properties of cancer stem cells and are characterised by three surface proteins. Patients with large numbers of these cells found in their blood show a rather unfavourable disease progression. The pattern of the three molecules may therefore be used as a biomarker for disease progression. The scientists plan to investigate whether the characteristic surface molecules may be used as targets for specific therapies for patients with advanced breast cancer.
Individual cancer cells that break away from the original tumour and circulate through the blood stream are considered responsible for the development of metastases. These dreaded secondary tumours are the main cause of cancer-related deaths. Circulating tumour cells (CTCs) detectable in a patient’s blood are associated with a poorer prognosis. However, up until now, experimental evidence was lacking as to whether ‘stem cells’ that lead to metastases can be found among CTCs.
‘We were convinced that only a very few of the various circulating tumour cells are capable of forming a secondary tumour in a different organ,’ says Prof. Andreas Trumpp, a stem cell expert. ‘Many patients do not develop metastases even though they have cancer cells circulating through their blood.’ Trumpp is head of DKFZ’s Division of Stem Cells and Cancer and director of the Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM) at DKFZ. ‘Metastasis is a complex process and cancer cells need to have very specific properties for it,’ he says. ‘Our hypothesis was that the characteristics of cancer stem cells, which are resistant to therapy and very mobile, are best suited.’
Irène Baccelli from Trumpp’s team developed a transplantation test for the experimental detection of metastasis-initiating cells. In collaboration with Prof. Andreas Schneeweiss from the National Center for Tumor Diseases (NCT) Heidelberg, along with colleagues from the Institute of Tumor Biology in Hamburg and the Institute of Pathology of Heidelberg University Hospitals, the researchers analysed the blood of more than 350 breast cancer patients. Using specific surface molecules, Baccelli isolated circulating tumour cells from the blood and directly transplanted them into the bone marrow of mice with defective immune systems. ‘Bone marrow is a perfect niche for tumour sells to colonise,’ Trumpp explains. After more than one hundred transplantations, metastases started forming in the bones, lungs and livers of some of the animals.
This proved that CTCs do contain metastasis stem cells – even though their frequency is apparently low. What characterises these cells? To define their molecular properties, the researchers analysed the surface molecules of the CTCs that had led to metastases after transplantation.
Three molecules characterise the metastasis stem cell
In a systematic screening process, Baccelli first isolated cells carrying a typical breast cancer stem cell protein (CD44) on their surface from the CTCs. This protein helps the cell to settle in bone marrow. Next, the researchers screened this cell population for specific surface markers which help the cells to survive in foreign tissue. These include, for example, a signalling molecule (CD47) that protects them from attacks by the immune system, and a surface receptor that enhances the cells’ migratory and invasive capabilities (MET).
Using a cell sorter, the researchers were then able to isolate CTCs which simultaneously exhibit all three characteristic molecules (CD44, CD47, MET). Another round of transplantation tests showed that these were in fact the cells from which the metastases originated.
Depending on the patient, cells exhibiting all three surface molecules (‘triple-positive’ cells) made up between 0.6 and 33 percent of all CTCs. ‘It is interesting that only cells with the stem cell marker CD44 carry the combination of the other two surface molecules,’ said Irène Baccelli. ‘It looks like the triple-positive cells are a specialized subtype of breast cancer stem cells circulating in the blood.’
Triple-positive cells as prognostic biomarkers
Are the triple-positive cells a more precise biomarker of breast cancer progression than the number of CTCs alone? In a small patient group, the researchers observed that as the disease advances, the number of triple-positive cells increases, but the total number of CTCs does not. In addition, patients with very high numbers of triple-positive cells had particularly high numbers of metastases and a much poorer prognosis than women in whom only a few metastasis-inducing cells were detected. ‘On the whole, triple-positive cells seem to have a substantially higher biological relevance for disease progression than previously studied CTCs,’ Andreas Schneeweiss explains. The researchers plan to confirm these new results in a large study.
Andreas Trumpp considers it good news that metastasis-initiating cells are characterised by the two proteins CD47 and MET. Therapeutic antibodies that target CD47 and inhibit its functions are already being developed. A substance inhibiting the activity of the MET receptor has already been approved and shows good effectiveness in treating a type of lung cancer. The substance may also help breast cancer patients with detectable metastasis-inducing cells. ‘The triple-positive cells we have found turn out to be not only a promising biomarker of disease progression in breast cancer but also a prospect for potential new therapeutic approaches for treating advanced breast cancer,’ says Andreas Trumpp.
German Cancer Research Center
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Some diseases are caused by single gene mutations. Current techniques for identifying the disease-causing gene in a patient produce hundreds of potential gene candidates, making it difficult for scientists to pinpoint the single causative gene. Now, a team of researchers led by Rockefeller University scientists have created a map of gene ‘shortcuts’ to simplify the hunt for disease-causing genes.
The investigation, spearheaded by Yuval Itan, a postdoctoral fellow in the St. Giles Laboratory of Human Genetics of Infectious Diseases, has led to the creation of what he calls the human gene connectome, the full set of distances, routes (the genes on the way) and degrees of separation between any two human genes. Itan, a computational biologist, says the computer program he developed to generate the connectome uses the same principles that GPS navigation devices use to plan a trip between two locations. The research is reported in the online early edition of the journal Proceedings of the National Academy of Sciences.
‘High throughput genome sequencing technologies generate a plethora of data, which can take months to search through,’ says Itan. ‘We believe the human gene connectome will provide a shortcut in the search for disease-causing mutations in monogenic diseases.’
Itan and his colleagues, including researchers from the Necker Hospital for Sick Children and the Pasteur Institute in Paris and Ben-Gurion University in Israel, designed applications for the use of the human gene connectome. They began with a gene called TLR3, which is important for resistance to herpes simplex encephalitis, a life-threatening infection from the herpes virus that can cause significant brain damage in genetically susceptible children. Researchers in the St. Giles lab, headed by Jean-Laurent Casanova, previously showed that children with HSE have mutations in TLR3 or in genes that are closely functionally related to TLR3. In other words, these genes are located at a short biological distance from TLR3. As a result, novel herpes simplex encephalitis-causing genes are also expected to have a short biological distance from TLR3.
To test how well the human gene connectome could predict a disease-causing gene, the researchers sequenced exomes – all DNA of the genome that is coding for proteins – of two patients recently shown to carry mutations of a separate gene, TBK1.
‘Each patient’s exome contained hundreds of genes with potentially morbid mutations,’ says Itan. ‘The challenge was to detect the single disease-causing gene.’ After sorting the genes by their predicted biological proximity to TLR3, Itan and his colleagues found TBK1 at the top of the list of genes in both patients. The researchers also used the TLR3 connectome – the set of all human genes sorted by their predicted distance from TLR3 – to successfully predict two other genes, EFGR and SRC, as part of the TLR3 pathway before they were experimentally validated, and applied other gene connectomes to detect Ehlers-Danlos syndrome and sensorineural hearing loss disease causing genes.
‘The human gene connectome is, to the best of our knowledge, the only currently available prediction of the specific route and distance between any two human genes of interest, making it ideal to solve the needle in the haystack problem of detecting the single disease causing gene in a large set of potentially fatal genes,’ says Itan. ‘This can now be performed by prioritising any number of genes by their biological distance from genes that are already known to cause the disease.
Rockefeller University
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Scientists from the University of Iowa and Brigham Young University (BYU) have identified a gene that may be a target for overcoming drug resistance in cancer. The finding could not only improve prognostic and diagnostic tools for evaluating cancer and monitoring patients’ response to treatment but also could lead to new therapies directed at eradicating drug-resistant cancer cells.
Drug resistance is a common problem in many metastatic cancers. It leads to failure of chemotherapy treatments and is associated with poor patient outcomes, including rapid relapse and death.
Fenghuang Zhan, Ph.D.The research team, including Fenghuang (Frank) Zhan, M.D., Ph.D., and Guido Tricot, M.D., Ph.D., from the UI, and David Bearss, Ph.D., from BYU, initially focused on identifying genes linked to the development of drug resistance in multiple myeloma, a bone marrow cancer that affects more than 20,000 Americans and causes almost 11,000 deaths annually.
Working with serial biopsied cells from 19 myeloma patients, the researchers analysed genetic changes in the cells that occurred over the course of treatment with very intensive chemotherapy drugs. This approach identified a gene called NEK2 that is strongly associated with increased drug-resistance, faster cancer growth, and poorer survival for patients.
Guido Tricot, M.D., Ph.D.Having established the relationship between high expression of the NEK2 gene and poor patient outcome in myeloma, the team then examined the relationship in other common cancers—including breast, lung, and bladder cancer—by analysing gene expression profiles from 2,500 patients’ cells with eight different cancers in Zhan’s lab.
Taking the findings back to the lab, the team then examined the effect on cancer cells of either enhancing or blocking the expression of the NEK2 gene. "In all cases, an increase in the NEK2 gene was associated with rapid death of the patient," says Tricot, who is director of Holden Comprehensive Cancer Center’s Bone Marrow Transplant and Myeloma Program at UI Hospitals and Clinics. "So this finding was not unique to myeloma; this is basically seen in every single cancer we looked at."
The research team is now developing compounds to inhibit NEK2 by collaborating with David Bearss, Ph.D., associate professor of physiology and developmental biology at BYU, in the hope that these compounds may overcome drug resistance in cancer cells. "Our studies show that over-expression of NEK2 in cancer cells significantly enhances the activity of drug efflux proteins to pump chemotherapy drugs out of cells, resulting in drug resistance. Furthermore, silencing NEK2 in cancer cells potently decreased drug resistance, induced cell-cycle arrest, cell death, and inhibited cancer cell growth in vitro and in vivo," says Zhan, UI professor of internal medicine.
“We were able to show that if we inhibit NEK2, then we can actually restore sensitivity to drugs that we use right now,” Bearss says.
Although development and clinical testing of such drugs for use in patients is not imminent, Tricot notes that the findings may have clinical use within the next several years.
"NEK2 expression may be a diagnostic or prognostic marker for drug-resistant cancer," he says. "If NEK2 is high, that would suggest that the prognosis is poorer and the patient might benefit from more aggressive treatment. The other potential use is for monitoring the cancer’s response to therapy. If NEK2 levels increase, that would suggest development of increased drug resistance and might indicate that a change of treatment would be helpful."University of Iowa Health Care
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A new diagnostic test for a worm infection that can lead to severe enlargement and deformities of the legs and genitals is far more sensitive than the currently used test, according to results of a field study in Liberia, in West Africa, where the infection is endemic.
The new test found evidence of the infection – lymphatic filariasis – in many more people that the standard test had missed.
The study, the first to independently evaluate the new test, was led by researchers at Washington University School of Medicine in St. Louis and funded by the Bill & Melinda Gates Foundation.
The infection affects 120 million people living in 73 countries, leaving some 40 million profoundly disfigured and incapacitated. Both tests detect the presence of worms that cause lymphatic filariasis, a devastating mosquito-borne illness also known as elephantiasis.
But the new test has significant advantages over the test that has been used for more than a decade not only to diagnose the disease, but to map, monitor and evaluate the success of a massive global public health program aimed at completely eliminating the disease by 2020.
‘The older test has had a major impact, but the new one is even better,’ says lead author Gary J. Weil, MD, an infectious diseases specialist at Washington University School of Medine. ‘Annually, medication to treat and prevent the infection is distributed to more than 500 million people worldwide. The improved sensitivity of the new test will help determine whether the mass treatment program has been effective and also identify regions that need additional attention.’
An accompanying editorial by Maria Rebollo, MD, and Moses Bockarie, PhD, at the Centre for Neglected Tropical Diseases in the United Kingdom says the new diagnostic test ‘represents a major breakthrough for rapid diagnosis of lymphatic filariasis in the blood.’
The new test also has a longer shelf life, estimated at two years without refrigeration, compared with three months for the older version, and is expected to cost less.
Weil’s research team worked with colleagues at the Liberian Institute for Medical Research to conduct a side-by-side comparison of the new test strip and the currently used test. They evaluated the tests in 503 people ranging in age from 6 to 89.
Both versions of the test are manufactured by Alere Scarborough Inc. of Maine and detect the presence in the blood of a protein produced by the worm parasite Wuchereria bancrofti that causes lymphatic filariasis. The new test is performed by pricking the finger and placing a person’s blood onto the test strip, which looks similar to an over-the-counter pregnancy test. Like many pregnancy tests, the lymphatic filariasis test is positive if two lines appear in the test window and negative if only one line shows.
The study’s results show that the new test is highly sensitive, detecting nearly 26 percent more infections of lymphatic filariasis than the standard test (124/503 infections vs. 98/503 infections). The new test also was easier to perform and results were easier to read.
‘This gives us some indication of the numbers of infections we were missing with the older test,’ Weil says. ‘On a global scale, it’s a huge number of cases. We need to have an accurate test to be sure we are reaching all the people who have the disease or are at risk of developing it.’
Worldwide, some 1.4 billion people are at risk of lymphatic filariasis, which is endemic in many countries in Africa, Southeast Asia and other tropical regions. Worm larvae deposited by the bite of an infected mosquito enter the body and migrate to the lymphatic system, where they mature into adult worms.
The thread-like parasitic worms can live and reproduce in the body for years. Ultimately, this damages the lymphatic vessels that drain fluid from the tissues and causes the enormous swelling and disabling deformity of the legs and in males, the scrotum.
Weil has been active for years in efforts to eliminate lymphatic filariasis via mass drug administration, an approach that involves giving antifilarial drugs to everyone in areas with high infection rates. Organizers of the Global Programme to Eliminate Lymphatic Filariasis, launched in 2000, co-ordinate periodic, repeated mass drug administration of antifilarial medications to more than 500 million people annually, making it the world’s largest public health intervention program based on mass drug administration.
Washington University School of Medicine
https://clinlabint.com/wp-content/uploads/sites/2/2020/06/clinlab-logo.png003wmediahttps://clinlabint.com/wp-content/uploads/sites/2/2020/06/clinlab-logo.png3wmedia2020-08-26 09:35:432021-01-08 11:12:55New test better detects elephantiasis worm infection
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