Saltar para: Posts [1], Pesquisa e Arquivos [2]

http://cyto.blogs.sapo.pt

Espaço de publicação e discussão sobre oncologia. GBM IMMUNOTHERAPY ONCO-VIRUS ONCOLOGY CANCER CHEMOTHERAPY RADIOTHERAPY


Quarta-feira, 19.08.15

Unituxin (dinutuximab) granted EC Marketing Authorisation for treatment of childhood neuroblastoma

Unituxin (dinutuximab) granted EC Marketing Authorisation for treatment of childhood neuroblastoma

Published on August 17, 2015 at 7:21 AM ·

United Therapeutics Corporation (NASDAQ: UTHR) announced today that the European Commission (EC) has granted Marketing Authorisation for Unituxin™ (dinutuximab) for the treatment of high-risk neuroblastoma in patients aged 12 months to 17 years, who have previously received induction chemotherapy and achieved at least a partial response, followed by myeloablative therapy and autologous stem cell transplantation (ASCT). Unituxin is administered in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2 (IL-2), and isotretinoin.

Neuroblastoma is the most common extracranial solid cancer in childhood and the most common cancer in infancy, with an annual incidence in the European Union of approximately 1500 patients, of whom 50% are diagnosed as having high-risk disease.

The European approval was based on demonstration of improved event-free survival (EFS) and overall survival (OS) in a multicenter, open-label, randomized trial (ANBL0032) sponsored by the US National Cancer Institute under a Cooperative Research and Development Agreement with United Therapeutics and conducted by the Children's Oncology Group (COG).

Trial design and results

The trial randomized (1:1) 226 patients to either the Unituxin/13-cis-retinoic acid (RA) arm or the RA alone arm. Patients in each arm received six cycles of treatment. The Unituxin/RA arm consisted of Unituxin in combination with granulocyte macrophage-colony stimulating factor and RA (cycles 1, 3, and 5), Unituxin in combination with interleukin-2 and RA (cycles 2 and 4), and RA (cycle 6). Patients were 11 months to 15 years of age (median age 3.8 years).

The major efficacy outcome measure was investigator-assessed EFS, defined as the time from randomization to the first occurrence of relapse, progressive disease, secondary malignancy or death. The primary intent-to-treat analysis found an improvement in EFS associated with dinutuximab immunotherapy plus isotretinoin as compared to isotretinoin alone. The two-year estimates of EFS were 66% among subjects receiving dinutuximab immunotherapy plus isotretinoin as compared with 48% in subjects receiving isotretinoin alone (log-rank test p = 0.033) although this difference did not reach formal statistical significance according to the pre-specified plan for interim analyses. In addition, OS was evaluated with 3 years of follow-up after the EFS analysis as a secondary endpoint with a significant improvement observed among ITT subjects randomly allocated to receive dinutuximab immunotherapy plus isotretinoin as compared with isotretinoin alone. The three-year estimates of OS were 80% compared with 67% among subjects receiving dinutuximab immunotherapy plus isotretinoin and isotretinoin alone, respectively (log-rank test p = 0.0165). Long-term overall survival was evaluated with five years of follow up after the EFS analysis and continued to demonstrate a survival advantage for patients who received dinutuximab immunotherapy compared to those who received isotretinoin alone. The five-year estimates of OS were 74% for dinutuximab immunotherapy compared to 57% for isotretinoin alone (log-rank test p = 0.030).

Frequently occurring adverse reactions

The most frequently occurring (more than 30% of patients) adverse reactions reported during the neuroblastoma studies were hypotension (67%), pain (66%), hypersensitivity (56%), pyrexia (53%), urticaria (49%), capillary leak syndrome (45%), anaemia (45%), hypokalaemia (41%), platelet count decreased (40%), hyponatraemia (37%), alanine aminotransferase increased (35%), decreased lymphocyte count (34%) and decreased neutrophil count (31%). Additional adverse reactions characteristic of an allergic response were also reported – including anaphylactic reaction (18%) and bronchospasm (4%).

Posology and method of administration

Unituxin is to be administered by intravenous infusion over five courses at a daily dose of 17.5 mg/m2. It is administered on days 4-7 during courses 1, 3 and 5 (each course lasting approximately 24 days) and on days 8-11 during courses 2 and 4 (each course lasting approximately 28 days).

The treatment regimen consists of Unituxin, GM-CSF, IL-2, and isotretinoin, administered over six consecutive courses.

Source:

United Therapeutics Corporation

Autoria e outros dados (tags, etc)

por cyto às 12:08

Quarta-feira, 19.08.15

Inflammation from diets deficient in nutrients contribute to weight despite intake of macronutrients

 

Inflammation from diets deficient in nutrients contribute to weight despite intake of macronutrients

Published on August 6, 2015 at 8:41 AM ·

If you are watching what you eat, working out, and still not seeing improvements in your cholesterol, blood pressure, blood sugar, etc., here's some hope. A new report appearing in the August 2015 issue of The FASEB Journal suggests that inflammation induced by deficiencies in vitamins and minerals might be the culprit. In this report, researchers show that - in some people - improvement results in many of the major markers of health when nutritional deficiencies are corrected. Some even lost weight without a change in their diet or levels of activity.

"It is well known that habitual consumption of poor diets means increased risk of future disease, but clearly this is not a compelling enough reason for many to improve their eating habits," said Bruce Ames, Ph.D., a senior scientist at Children's Hospital Oakland Research Institute, director of their Nutrition and Metabolism Center, and a professor emeritus of Biochemistry and Molecular Biology at the University of California, Berkeley. "However, a relatively easy intervention with something like the nutrient bar used in this study may help people to realize the positive impact that a diet with adequate nutrition can have in their daily lives, which may be a stronger incentive for change."

To make their Ames and colleagues undertook three clinical trials in which adults ate two nutrient bars each day for two months. Participants acted as their own controls, meaning that changes in a wide variety of biochemical (e.g., HDL-c, LDL-c, insulin) and physical (e.g., blood pressure, weight) measurements were recorded in each individual over the two-month period. People who were overweight/obese moved in a healthier metabolic direction (e.g., improved HDL, LDL, insulin, glucose, etc.), and some lost weight by just eating small, low-calorie, nutrient bars each day for two months, without any additional requirements.

"If being healthy was as simple as 'losing weight' or 'keeping thin,' our ancient ancestors who lived in times of extreme food scarcity might still be with us today," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "This report shows that what you eat is as important, if not more, than how much you eat and how many calories you burn in the gym."

Source:

Federation of American Societies for Experimental Biology

Autoria e outros dados (tags, etc)

por cyto às 11:56

Quinta-feira, 23.07.15

Magnetic nanoparticles may hold key to bringing immunotherapy into successful clinical use

 

Magnetic nanoparticles may hold key to bringing immunotherapy into successful clinical use

Published on July 16, 2015 at 1:54 AM

In recent years, researchers have hotly pursued immunotherapy, a promising form of treatment that relies on harnessing and training the body's own immune system to better fight cancer and infection. Now, results of a study led by Johns Hopkins investigators suggests that a device composed of a magnetic column paired with custom-made magnetic nanoparticles may hold a key to bringing immunotherapy into widespread and successful clinical use. A summary of the research, conducted in mouse and human cells, appears online July 14 in the journal ACS Nano.

The Johns Hopkins team focused on training and rapidly multiplying immune system white blood cells known as T cells because of their potential as an effective weapon against cancer, according to Jonathan Schneck, M.D., Ph.D., a professor of pathology, medicine and oncology at the Johns Hopkins University School of Medicine's Institute for Cell Engineering. "The challenge has been to train these cells efficiently enough, and get them to divide fast enough, that we could use them as the basis of a therapy for cancer patients. We've taken a big step toward solving that problem," he says.

In a bid to simplify and streamline immune cellular therapies, Schneck, Karlo Perica, a recent M.D./Ph.D. graduate who worked in Schneck's lab, and others worked with artificial white blood cells. These so-called artificial antigen-presenting cells (aAPCs) were pioneered by Schneck's lab and have shown promise in activating laboratory animals' immune systems to attack cancer cells.

To do that, Perica explains, the aAPCs must interact with naive T cells already present in the body, awaiting instructions about which specific invader to target and battle. The aAPCs bind to specialized receptors on the T cells' surfaces and "present" them with distinctive proteins called antigens. This process activates the T cells to ward off a virus, bacteria or tumor, as well as to make more T cells.

In a previous study in mice, Schneck's team found that naive T-cells activated more effectively when multiple aAPCs bound to different receptors on the cells, and then were exposed to a magnetic field. The magnets brought the aAPCs and their receptors closer together, priming the T cells both to battle the target cancer and divide to form more activated cells.

But naive T cells are as rare in the blood as a "needle in a haystack," Perica says. Because the ultimate goal is to harvest a patient's T cells from a blood sample, then train them and expand their numbers before putting them back into the patient, Schneck's research team looked to magnets as a potential way to separate the naive T cells from others in the blood.

The team mixed blood plasma from mice and, separately, humans with magnetic aAPCs bearing antigens from tumors. They then ran the plasma through a magnetic column. The tumor-fighting T cells bound to aAPCs and stuck to the sides of the column, while other cells washed straight through and were discarded. The magnetic field of the column activated the T cells, which were then washed off into a nourishing broth, or culture, to grow and divide. After one week, their numbers had expanded by an estimated 5,000 to 10,000 times. Because numbers of these cells could be expanded quickly enough to be therapeutically useful, the approach could open the door to individualized immunotherapy treatments that rely on a patient's own cells, says Perica.

Schneck says that the use of naive T cells could make the new technique useful for more patients than another immunotherapy now being tested, which relies on other white blood cells called tumor-infiltrating lymphocytes. Those cells are already "trained" to fight cancer, and researchers have shown some success isolating some of the cells from tumors, inducing them to divide, and then transferring them back into patients. But, Schneck says, not all patients are eligible for this therapy, because not all have tumor-infiltrating lymphocytes. By contrast, all people have naive T cells, so patients with cancer could potentially benefit from the new approach whether or not they have tumor-infiltrating lymphocytes.

"The aAPCs and magnetic column together provide the foundation for simplifying and streamlining the process of generating tumor-specific T cells for use in immunotherapy," says Juan Carlos Varela, M.D., Ph.D., a former member of Schneck's laboratory who is now an assistant professor at the Medical University of South Carolina.

The researchers found that the technique also worked with a mixture of aAPCs bearing multiple antigens, which they say could help combat the problem of tumors mutating to evade the body's defenses. "We get multiple shots on the goal," Schneck says.

While the team initially tested the new method only on cancer antigens, Schneck says it could also potentially work for therapies against chronic infectious diseases, such as HIV. He says that if further testing goes well, clinical trials of the technique could begin within a year and a half.

Source:

Johns Hopkins Medicine

Autoria e outros dados (tags, etc)

por cyto às 22:49

Quinta-feira, 23.07.15

New UW-Madison study links two unrelated cancer treatments

 

New UW-Madison study links two unrelated cancer treatments

Published on July 14, 2015 at 5:10 AM 

A new study at the University of Wisconsin-Madison has linked two seemingly unrelated cancer treatments that are both now being tested in clinical trials.

One treatment is a vaccine that targets a structure on the outside of cancer cells, while the other is an altered enzyme that breaks apart RNA and causes the cell to commit suicide. The study was published July 13 in the new journal of the American Chemical Society: ACS Central Science.

The new understanding could help both approaches, says UW-Madison professor of biochemistry Ronald Raines, who has long studied ribonucleases -- enzymes that break apart RNA, a messenger with multiple roles inside the cell. In 1998, he discovered how to alter one ribonuclease to avoid its deactivation in the body. Soon thereafter, he found that the engineered ribonuclease was more toxic to cancer cells than to others.

Raines patented the advance through the Wisconsin Alumni Research Foundation and with UW-Madison chemist Laura Kiessling cofounded Quintessence Biosciences in Madison. They remain shareholders in the firm, which has licensed the patent from WARF and begun early-phase human trials with the ribonuclease at the UW Carbone Cancer Center and MD Anderson Cancer Center in Houston.

The current study began as an effort to figure out why the ribonuclease was selective for cancer cells. To identify which structure on the cell surface helped it enter the cell, Raines screened 264 structures using a specially designed chip. The winner was a carbohydrate called Globo H.

"We were surprised -- delighted -- to see that because we already knew that Globo H is an antigen that is abundant in many tumors," Raines says. Antigens are complex molecules with structures that are recognizable to proteins called antibodies. "Globo H is under development as the basis for a vaccine that will teach the immune system to recognize and kill cancer cells," he says.

Working with Samuel Danishefsky, who solved the difficult problem of synthesizing Globo H at the Memorial Sloan-Kettering Cancer Center in New York, Raines found that reducing the Globo H display on the surface made breast cancer cells less vulnerable to ribonucleases like those that Quintessence is testing. "This was exciting, as we now have a much clearer idea of how our drug candidate is working."

Biochemistry Professor John Markley aided the research with studies of the structure of the molecules in question.

The picture that emerges from the work is of ribonucleases patrolling our bodies, looking for telltales of cancer cells, Raines says. "We are working to demonstrate this surveillance more clearly in mice, but don't have direct evidence yet."

As other scientists test whether using a vaccine will start an immune attack on Globo H, Raines says, "we are probing a different type of immunity. This innate immunity does not involve the immune system. It's a way for our bodies to fight cancer without using white blood cells or antibodies, just an enzyme and a carbohydrate."

Source:

University of Wisconsin-Madison

Autoria e outros dados (tags, etc)

por cyto às 22:46

Quinta-feira, 23.07.15

Emory University immunologists identify long-lived antibody-producing cells in bone marrow

 

Emory University immunologists identify long-lived antibody-producing cells in bone marrow

Published on July 16, 2015 at 2:40 AM · 

Immunologists from Emory University have identified a distinct set of long-lived antibody-producing cells in the human bone marrow that function as an immune archive.

The cells keep a catalog of how an adult's immune system responded to infections decades ago in childhood encounters with measles or mumps viruses. The results, published Tuesday, July 14 in , could provide vaccine designers with a goalpost when aiming for long-lasting antibody production.

"If you're developing a vaccine, you want to fill up this compartment with cells that respond to your target antigen," says co-senior author F. Eun-Hyung Lee, MD, assistant professor of medicine at Emory University School of Medicine and director of Emory Healthcare's Asthma, Allergy and Immunology program.

The findings could advance investigation of autoimmune diseases such as lupus erythematosus or rheumatoid arthritis, by better defining the cells that produce auto-reactive antibodies.

Co-senior author of the Immunity paper is Iñaki Sanz, MD, professor of medicine and pediatrics, chief of the Division of Rheumatology, Mason I. Lowance Chair of Allergy and Immunology and a Georgia Research Alliance Eminent Scholar. The research was started when Lee, Sanz and colleagues were investigators at the University of Rochester Medical Center, and continued when they arrived at Emory in 2012. The first author of the paper is Jessica Halliley, MS from Rochester.

As described in part of the Immunity paper, the researchers studied 11 older individuals (aged 43 to 70) who had not been immunized against measles or mumps, but who had antibodies in their blood indicating infection by those viruses in childhood. Measles and mumps vaccines first became available in the 1960s.

Antibodies in the blood have a half-life of just a few weeks, so researchers thought these individuals had long-lived plasma cells, or white blood cells secreting antibodies, dating from the childhood infection.

Examining bone marrow samples obtained from these volunteers, researchers divided plasma cells into four different groups based on the proteins found on their surfaces. Only one group ("subset D", CD19-, CD38high, CD138+) contained the cells that produce antibodies that react with measles or mumps virus.

"I like to call this group of cells the 'historical record' of infection or vaccination," Lee says.

In contrast, cells producing anti-influenza antibodies were found spread across three of the subsets. Because study participants were likely to have been exposed to influenza by annual vaccination or infection more recently than measles or mumps, the researchers inferred that cells specific to recent exposures can reside in multiple subsets while subset D represents the long-lived plasma cells.

In separate experiments, volunteers who were vaccinated against tetanus did have some plasma cells producing anti-tetanus antibodies within three weeks in several subsets, but over time tetanus-specific plasma cells were found in subset D.

The team proved that subset D cells were exclusively responsible for producing the measles- and mumps-specific antibodies in the blood of one of the older volunteers, through proteomics and RNA sequencing techniques.

Compared with other subsets, subset D cells are more quiescent: they displayed less signs of proliferation. In addition, subset D cells have a distinct "fried egg" appearance, containing bubble-like vacuoles or lipid droplets, which are rare in bone marrow cell samples, and a tighter, more condensed nucleus than other white blood cells.

Plasma cells differ from many other cells in the body in that they undergo changes in their DNA -- specifically, their antibody genes. In the patients the researchers examined, antibody genes from subset D are much more diverse than those from other plasma cells. Lee says this finding also reflects subset D's role as an archive, which does not devote too much cellular space to any one vaccination or infection.

Source:

Emory Health Sciences

Autoria e outros dados (tags, etc)

por cyto às 22:43

Terça-feira, 21.07.15

Patients' own genetically engineered immune cells show significant success against multiple myeloma

 

Patients' own genetically engineered immune cells show significant success against multiple myeloma

Published on July 21, 2015 at 2:37 AM 

In recent years, immunotherapy has emerged as a promising treatment for certain cancers. Now this strategy, which uses patients' own immune cells, genetically engineered to target tumors, has shown significant success against multiple myeloma, a cancer of the plasma cells that is largely incurable. The results appeared in a study published online today in Nature Medicine.

Patients received an infusion of altered immune cells known as T-cells - roughly 2.4 billion of them - after undergoing a stem cell transplantation of their own stem cells. In 16 of 20 patients with advanced disease, there was a significant clinical response. The scientists found that the T-cell therapy was generally well-tolerated and that modified immune cells traveled to the bone marrow, where myeloma tumors typically are found, and showed a long-term ability to fight the tumors. Relapse was generally associated with a loss of the engineered T-cells.

"This study suggests that treatment with engineered T-cells is not only safe but of potential clinical benefit to patients with certain types of aggressive multiple myeloma," says first author Aaron P. Rapoport, MD, the Gary Jobson Professor in Medical Oncology at the University of Maryland School of Medicine. "Our findings provide a strong foundation for further research in the field of cellular immunotherapy for myeloma to help achieve even better results for our patients."

The trial is the first published use of genetically modified T-cells for treating patients with multiple myeloma. The approach has been used to treat leukemia as well as lymphoma, according to Dr. Rapoport, who is the Director of the Blood and Marrow Transplant Program at the University of Maryland Marlene and Stewart Greenebaum Cancer Center.

More than 77,000 people in the United States have multiple myeloma, with about 24,000 new cases diagnosed each year. Patients are treated with chemotherapy and in many cases an autologous stem cell transplant, but long-term response rates are low, and median survival is three to five years.

"The majority of patients who participated in this trial had a meaningful degree of clinical benefit," Dr. Rapoport notes. "Even patients who later relapsed after achieving a complete response to treatment or didn't have a complete response had periods of disease control that I believe they would not have otherwise experienced. Some patients are still in remission after nearly three years."

The research is a collaboration between the University of Maryland School of Medicine, the Perelman School of Medicine at the University of Pennsylvania and Adaptimmune, a clinical stage biopharmaceutical company which owns the core T-cell receptor technology and funded the study. Dr. Rapoport and co-authors Edward A. Stadtmauer, MD, of the University of Pennsylvania Abramson Cancer Center, and Gwendolyn K. Binder-Scholl, PhD, of Adaptimmune, contributed equally to the research. Dr. Rapoport is the study's principal investigator.

In the clinical study, patients' T-cells were engineered to express an affinity-enhanced T-cell receptor (TCR) specific for a type of tumor antigen, or protein, known as a cancer-testis antigen (CT antigen). The target CT antigens were NY-ESO-1 and LAGE-1. Up to 60 percent of advanced myelomas have been reported to express NY-ESO-1 and/or LAGE-1, which correlates to tumor proliferation and poorer outcomes. According to Adaptimmune, the trial is the first published study of lentiviral vector mediated TCR gene expression in humans.

Of the 20 patients treated, 14 (70 percent) had a near complete or complete response three months after treatment. Median progression-free survival was 19.1 months and overall survival was 32.1 months. Two patients had a very good partial response three months post treatment. Half the patients were treated at the University of Maryland Greenebaum Cancer Center and half at the University of Pennsylvania Abramson Cancer Center. Researchers note that the response rate was better than would be expected for a standard autologous stem cell transplant. In addition, patients did not experience side effects which have been associated with another type of genetically engineered T-cells (chimeric antigen receptors, or CARS) used to treat other cancers.

The study was originally developed by Carl H. June, MD, of the University of Pennsylvania Abramson Cancer Center, and Dr. Rapoport, who have been research collaborators for 18 years.

"Multiple myeloma is a treatable but largely incurable cancer. This study reveals the promise that immunotherapy with genetically engineered T-cells holds for boosting the body's ability to attack the cancer and provide patients with better treatments and control of their disease," says E. Albert Reece, MD., PhD, MBA, vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine. "This trial is also an excellent example of significant scientific advances that result from collaborations between academic medical institutions and private industry."

Source:

University of Maryland Medical Center

Autoria e outros dados (tags, etc)

por cyto às 18:10

Terça-feira, 21.07.15

clinical study data on ImmunTraCkeR assay in the Journal for ImmunoTherapy of Cancer

 

ImmunID announces publication of clinical study data on ImmunTraCkeR assay in the Journal for ImmunoTherapy of Cancer

Published on July 8, 2015 at 10:02 AM 

ImmunID today announced the publication of a short report in the Journal for ImmunoTherapy of Cancer (JITC) showing that the analysis of peripheral T cell receptor diversity using the company's ImmunTraCkeR® assay is associated with clinical outcomes following Ipilimumab treatment in metastatic melanoma. Results from the study, conducted at Memorial Sloan Kettering Cancer Center, were first presented at the SITC 2014 Annual Meeting.

Study results suggest that ImmunTraCkeR® may ultimately be used as a companion diagnostic for immune checkpoint agents, to determine eligibility to the treatment.

"We are delighted to have been selected by the JITC editorial board for publication. ImmunID's mission is to add precision to the immuno-oncology revolution by personalizing immunotherapy. A large multicenter study is currently underway (Predict-ID Melanoma, France) with the aim to validate prediction capabilities of ImmunTraCkeR® for response to immune checkpoint inhibitors. This is an area of high unmet medical need and could be game-changing for patients," said Bernhard Sixt, ImmunID's Chairman and Chief Executive Officer.

Autoria e outros dados (tags, etc)

por cyto às 18:06

Domingo, 19.07.15

Link found in regulation of blood glucose

 

Link found in regulation of blood glucose

Insight into a molecular mechanism for regulating blood sugar could enhance our understanding of diabetes

Published online 27 May 2015

Insulin released into the blood when levels of glucose are high activates mechanisms to reduce glucose levels, including the transport of GLUT4 to the membranes of muscle and fat cells.

© Ugreen/iStock/Thinkstock

A key mechanism in the regulation of blood sugar levels has been identified in work led by A*STAR researchers1. The findings could help us understand the mechanisms of diabetes and might lead to new treatments.

Blood levels of the sugar glucose increase after a meal. In response, the body releases insulin, which activates mechanisms to return these levels to normal. One such mechanism involves transport of the protein GLUT4 to the membranes of muscle and fat cells, enabling the uptake of glucose from the blood into the cells.

“Defects in glucose uptake in response to insulin generally manifest as type 2 diabetes,” explains Han Weiping from the Laboratory of Metabolic Medicine at A*STAR Singapore Bioimaging Consortium who led the study. “Insulin-stimulated GLUT4 translocation is central to the maintenance of blood glucose levels. An understanding of the mechanisms that underlie this process will help us to work out what goes wrong in diabetes.”

Previous studies had identified two important elements involved in the transport of GLUT4: an insulin-activated kinase called Akt2 and rearrangement of the cell’s skeleton, which consists of fibers of the protein actin. Han, his graduate student Lim Chun-Yan and collaborators investigated the molecular pathway that connects these two elements.

They did this by screening proteins in fat cells to identify those involved in the delivery of GLUT4 to cell membranes. They identified one — tropomodulin3 (Tmod3) — that is also involved in the rearrangement of the cell’s actin skeleton. The researchers showed that Tmod3 is modified by insulin-activated Akt2 and that GLUT4 translocation and glucose uptake are impaired in cells with reduced Tmod3 levels.

By making cells with fluorescently labeled actin, the team also found that low expression of Tmod3 reduced the ability of a cell to rearrange its skeleton in response to insulin; the same effect was seen in cells that expressed a form of Tmod3 that cannot be modified by Akt2. The fluorescently labeled actin also revealed that modification of Tmod3 by Akt2 potentiates the insulin-induced actin reorganization.

“Our study highlights a direct link between Akt2 signaling and the actin skeleton that is essential for insulin-stimulated GLUT4 translocation,” says Han. “But the identification of Tmod3 might represent the tip of the iceberg of a vast signaling network involved in glucose uptake. A complete understanding of the mechanism of GLUT4 transport would help to pinpoint the key molecular nodes that underlie this process and to develop a therapeutic intervention to help clear glucose more efficiently from the body.”

 

The A*STAR-affiliated researchers contributing to this research are from the Singapore Bioimaging Consortium, the Bioprocessing Technology Institute and the Institute of Molecular and Cell Biology.

 

Related Links

Molecular biology: Taking full control of diabetes

Metabolism: Striking a balance

Cell biology: Cellular damage control’s link with diabetes

 

 

Reference

  1. Lim, C.-Y., Bi, X., Wu, D., Kim, J. B., Gunning, P. W. et al. Tropomodulin3 is a novel Akt2 effector regulating insulin-stimulated GLUT4 exocytosis through cortical actin remodeling.Nature Communications 6, 5951 (2015). | article

Autoria e outros dados (tags, etc)

por cyto às 13:50

Sábado, 04.07.15

new protein that affects growth of secondary breast tumours in the brain

Scientists identify new protein that affects growth of secondary breast tumours in the brain

Published on July 1, 2015 at 7:19 AM 

Scientists from the University of Leeds and The Institute of Cancer Research, London, have discovered a new protein which triggers the growth of blood vessels in breast cancer tumours which have spread to the brain, a common location which breast cancer can spread to.

Dr Georgia Mavria's team in the School of Medicine at Leeds found that by withholding the DOCK4 protein in mouse models, a particular part of the blood vessel did not form as quickly, meaning tumours grew at a slower rate.

Dr Mavria said: "We want to understand how these tumours form and grow, but we still need to do more research to stop these tumours growing altogether.

"The finding gives an important indicator of how the protein affects the growth of secondary breast tumours in the brain. The discovery could also enable experts to predict which patients might be at risk of their breast cancer spreading, and develop drugs to prevent the growth of secondary tumours."

Working with Professor Chris Marshall, Professor of Cell Biology at The Institute of Cancer Research, London and the late Dr Tony Pawson at the Lunenfeld-Tanenbaum Research Institute in Toronto, researchers found that a complex of two related proteins, DOCK4 and DOCK9, is critical in the formation of the lumen, the interior space of a vessel through which blood flows.

By impeding the speed at which the lumen forms, tumours are not fed as effectively by blood vessels.

Normally, when breast cancer spreads to other parts of the body, it forces new blood vessels to form to supply it with nutrients and oxygen to help it to grow, resulting in tumours that are very difficult to treat.

Professor Marshall said: "Our study reveals new insights into how the complex process of forming blood vessels is controlled. This knowledge could lead to new approaches to preventing the blood supply to tumours and metastases. If we can find new ways to reduce the blood supply to tumours, we might be able to find new ways to slow cancer growth in future."

The research, which has been published in Nature Communications, was funded by Breast Cancer Now, Yorkshire Cancer Research and Cancer Research UK.

Dr Matthew Lam, Senior Research Communications Officer at Breast Cancer Now, said: "These findings could one day help us better identify and treat patients that might be at risk of their breast cancer spreading to the brain, a particularly common site for metastasis.

"12,000 women have their lives cut short by breast cancer in the UK each year. An understanding of what is happening on a molecular level - such as the role played by DOCK proteins - will be essential if we are to find ways to prevent secondary tumours and finally stop women dying from the disease."

Kathryn Scott, Head of Research and Innovation at Yorkshire Cancer Research, said: "Tumours need blood vessels to grow, but these blood vessels could be the cancer's weakest link because it is believed that they are less able to become resistant to drugs than the cancer cells themselves. Targeting drugs to the blood vessels that are serving the tumour rather than the tumour itself is an exciting new area of research and we are supporting a number of projects in Yorkshire which are investigating this approach."

Dr Aine McCarthy, Science Information Officer at Cancer Research UK, said: "This research shows for the first time that a molecule called DOCK4 is a key player in tumour blood vessel development and blocking it could slow tumour growth by starving the cancer cells. But the study was carried out in mice, so more research is needed to see if drugs can be developed that target the molecule and whether this approach would be safe and effective in people with cancer."

Source:

University of Leeds

Autoria e outros dados (tags, etc)

por cyto às 11:34

Sábado, 04.07.15

way to stop growth of cancer cells by targeting the Warburg Effect

SLU researchers find way to stop growth of cancer cells by targeting the Warburg Effect

Published on June 26, 2015 at 10:55 PM 

In research published in Cancer Cell, Thomas Burris, Ph.D., chair of pharmacology and physiology at Saint Louis University, has, for the first time, found a way to stop cancer cell growth by targeting the Warburg Effect, a trait of cancer cell metabolism that scientists have been eager to exploit.

Unlike recent advances in personalized medicine that focus on specific genetic mutations associated with different types of cancer, this research targets a broad principle that applies to almost every kind of cancer: its energy source.

The Saint Louis University study, which was conducted in animal models and in human tumor cells in the lab, showed that a drug developed by Burris and colleagues at Scripps Research Institute can stop cancer cells without causing damage to healthy cells or leading to other severe side effects.

The Warburg Effect

Metabolism -- the ability to use energy -- is a feature of all living things. Cancer cells aggressively ramp up this process, allowing mutated cells to grow unchecked at the expense of surrounding tissue.

"Targeting cancer metabolism has become a hot area over the past few years, though the idea is not new," Burris said.

Since the early 1900s, scientists have known that cancer cells prefer to use glucose as fuel even if they have plenty of other resources available. In fact, this is how doctors use PET (positron emission tomography) scan images to spot tumors. PET scans highlight the glucose that cancer cells have accumulated.

This preference for using glucose as fuel is called the Warburg effect, or glycolysis.

In his paper, Burris reports that the Warburg effect is the metabolic foundation of oncogenic (cancer gene) growth, tumor progression and metastasis as well as tumor resistance to treatment.

Cancer's goal: to grow and divide

Cancer cells have one goal: to grow and divide as quickly as possible. And, while there are a number of possible molecular pathways a cell could use to find food, cancer cells have a set of preferred pathways.

"In fact, they are addicted to certain pathways," Burris said. "They need tools to grow fast and that means they need to have all of the parts for new cells and they need new energy."

"Cancer cells look for metabolic pathways to find the parts to grow and divide. If they don't have the parts, they just die," said Burris. "The Warburg effect ramps up energy use in the form of glucose to make chemicals required for rapid growth and cancer cells also ramp up another process, lipogenesis, that lets them make their own fats that they need to rapidly grow."

If the Warburg effect and lipogenesis are key metabolic pathways that drive cancer progression, growth, survival, immune evasion, resistance to treatment and disease recurrence, then, Burris hypothesizes, targeting glycolysis and lipogenesis could offer a way to stop a broad range of cancers.

Cutting off the energy supply

Burris and his colleagues created a class of compounds that affect a receptor that regulates fat synthesis. The new compound, SR9243, which started as an anti-cholesterol drug candidate, turns down fat synthesis so that cells can't produce their own fat. This also impacts the Warburg pathway, turning cancer cells into more normal cells. SR9243 suppresses abnormal glucose consumption and cuts off cancer cells' energy supply.

When cancer cells don't get the parts they need to reproduce through glucose or fat, they simply die.

Because the Warburg effect is not a feature of normal cells and because most normal cells can acquire fat from outside, SR9243 only kills cancer cells and remains non-toxic to healthy cells.

The drug also has a good safety profile; it is effective without causing weight loss, liver toxicity, or inflammation.

Promising Results So far, SR9243 has been tested in cultured cancer cells and in human tumor cells grown in animal models. Because the Warburg pathway is a feature of almost every kind of cancer, researchers are testing it on a number of different cancer models.

"It works in a wide range of cancers both in culture and in human tumors developing in animal models," Burris said. "Some are more sensitive to it than others. In several of these pathways, cells had been reprogramed by cancer to support cancer cell growth. This returns the metabolism to that of more normal cells."

In human tumors grown in animal models, Burris said, "It worked very well on lung, prostate, and colorectal cancers, and it worked to a lesser degree in ovarian and pancreatic cancers."

It also seems to work on glioblastoma, an extremely difficult to treat form of brain cancer, though it isn't able to cross the brain/blood barrier very effectively. The challenge for researchers in this scenario will be to find a way to allow the drug to cross this barrier, the body's natural protection for the brain, which can make it difficult for drug treatments to reach their target.

And, in even more promising news, it appears that when SR9243 is used in combination with existing chemotherapy drugs, it increases their effectiveness, in a mechanism apart from SR9243's own cancer fighting ability.

Source:

Saint Louis University

Autoria e outros dados (tags, etc)

por cyto às 11:25


Mais sobre mim

foto do autor


Subscrever por e-mail

A subscrição é anónima e gera, no máximo, um e-mail por dia.

Pesquisar

Pesquisar no Blog  

calendário

Fevereiro 2016

D S T Q Q S S
123456
78910111213
14151617181920
21222324252627
2829