Colourised scanning electron micrograph of a breast cancer cell. Credit: NIH
Researchers from Tampere University, Finland, and Izmir Institute of Technology, Turkey, have developed an in vitro cancer model to investigate why breast cancer spreads to bone. Their findings, published in PLOS One, hold promise for advancing the development of preclinical tools to predict breast cancer bone metastasis.
Breast canceris a significant global public health challenge, with 2.3 million new cases and 700 000 deaths every year. Approximately 80% of patients with primary breast cancer can be cured, if they are diagnosed and treated promptly. However, in many cases, the cancer has already metastasised at the time of diagnosis.
Metastatic cancer is incurable and accounts for more than 90% of cancer-related deaths. Currently, there are no reliable in vitro models to study how breast cancer spreads to secondary organs such as bone, lung, liver or brain. Now, researchers from the Precision Nanomaterials Group at Tampere University in Finland, and the Cancer Molecular Biology Lab at Izmir Institute of Technology in Turkey, have used lab-on-a-chip platforms to create a physiologically relevant metastasis model to study the factors controlling breast cancer bone metastasis.
“Breast cancer most frequently spreads to bone, with an estimated rate of 53%, resulting in severe symptoms such as pain, pathological bone fractures, and spinal cord compressions. Our research provides a laboratory model that estimates the likelihood and mechanism of bone metastasis occurring within a living organism. This advances the understanding of molecular mechanisms in breast cancer bone metastasis and provides the groundwork for developing preclinical tools for predicting bone metastasis risk,” says Burcu Firatligil-Yildirir, postdoctoral researcher at Tampere University and the first author of the paper.
According to Nonappa, Associate Professor and leader of the Precision Nanomaterials Group at Tampere University, developing sustainable in vitro models that mimic the complexity of the native breast and bone microenvironment is a multidisciplinary challenge.
“Our work shows that physiologically relevant in vitro models can be generated by combining cancer biology, microfluidics and soft materials. The results open new possibilities for developing predictive disease, diagnostic and treatment models,” he says.
The largest population-based study to date supports the survival benefits of immunotherapy for people with metastatic non–small cell lung cancer.
Squamous cancer cell being attacked by cytotoxic T cells. Image by National Cancer Institute on Unsplash
Since the first immunotherapy drug to boost the body’s immune response against advanced lung cancer was introduced in the United States in 2015, survival rates of patients with the disease have improved significantly. That’s the conclusion of a recent real-world study published by Wiley online in CANCER, a peer-reviewed journal of the American Cancer Society.
For the research, a team led by Dipesh Uprety, MD, FACP, of the Barbara Ann Karmanos Cancer Institute and the Wayne State University School of Medicine, analysed data from the National Cancer Institute Surveillance, Epidemiology, and End Results database, which compiles cancer-related data covering approximately 48% of the US population. The investigators’ analysis focused on non–small cell lung cancer (NSCLC), which accounts for up to 90% of all cases of lung cancer and is the leading cause of cancer-related death among both men and women in the United States.
In a comparison of 100 995 patients with metastatic NSCLC treated in 2015–2020 (after immunotherapy was deemed the standard of care) and 90 807 patients with metastatic NSCLC in the pre-immunotherapy era of 2010–2014, patients in the immunotherapy era were less likely to die from any cause. The overall survival rates at one, three, and five years were 40.1% versus 33.5%, 17.8% versus 11.7%, and 10.7% versus 6.8%. The median overall survival was eight months in patients in the immunotherapy era and seven months in those in the pre-immunotherapy era.
Similarly, patients treated after immunotherapy was available were less likely to die specifically from cancer than those treated before immunotherapy. The one-, three-, and five-year cancer-specific survival rates were 44.0% versus 36.8%, 21.7% versus 14.4%, and 14.3% versus 9.0%, with a median survival of 10 months versus eight months.
Survival rates remained significantly better in the immunotherapy era even after accounting for factors including age, sex, race, income, and geographical area.
“By utilizing a large national database, our study provided real-world evidence of the positive impact of immunotherapy in patients with lung cancer,” said Dr Uprety. The investigators stressed that additional studies are needed, however. “Immunotherapy provides long-term benefits. Since the durable benefits of immunotherapy are limited to a small subset of patients, future research should aim to optimize immunotherapy with new agents that can benefit a broader population,” said lead author Yating Wang, MD, of Ascension Providence Hospital.
There is a surprising dearth of research about how breast cancer cells can go dormant, spread and then resurface years or even decades later, according to a new review of in vitro breast cancer studies conducted by researchers at the University of Massachusetts Amherst.
“[Our review found that] less than 1% of all these studies that combine cells with designer environments look at dormancy,” says Shelly Peyton, Provost Professor of Chemical Engineering. “It’s not enough. We just don’t understand what’s happening – and it’s killing patients.”
Breast cancer dormancy is a phenomenon in which breast cancer cells metastasise (typically to the liver, lungs, brain or bones) but don’t grow. “They’re not detectable or symptomatic tumours,” Peyton explains. “A patient will have their primary tumour removed and appear to be disease-free for months, years, even decades. And for reasons we don’t understand, something changes about the environment that causes those cells to start regrowing, and then you have a deadly metastasis.”
Patients with metastatic breast cancer have a 30% five-year survival rate, compared to a 99% survival rate for localised breast cancer. “Early detection is key, particularly in the Western world,” says Peyton. “You can have lumpectomies, radiation, small surgeries. And women can survive. It’s when that cancer has spread that it becomes much harder to treat.”
This relapse in distant organs impacts 40% of early-stage breast cancer patients, and breast cancer dormancy is a contributing factor. But while metastasis has known biomarkers, dormant cancer cells are very hard to identify.
“When you have a single dormant breast cancer cell that’s hiding in a distant tissue, it’s really hard to detect that,” says Nate Richbourg, lead author on the paper and postdoctoral researcher in the Peyton Lab. “And you don’t want to do an invasive biopsy or prescribe toxic chemotherapy for something that might not be a problem.”
With these challenges in mind, the review, published in Science Advances, aimed to identify gaps in the research, particularly focusing on in vitro studies, or research using benchtop-model environments instead of animal models or humans. In vitro studies allow for the precise control of the environment, which Peyton’s research group says may play a deciding role in whether a cell remains dormant or reactivates into a deadly metastatic tumor.
“What can we control in these artificial environments that will give us insight into how breast cancer dormancy happens, and what we can do to treat it as well?” Richbourg asks, describing the importance of in vitro modelling. “When we create this artificial dormancy, we can see how many of those cells could turn back into proliferating and potentially deadly cells.”
Their review highlights just how complex the role of the environment is. “If you have a [breast cancer] cell somewhere in the bone marrow, you’re going to have other cells there, the physical factors in your environment, and the biochemical factors,” Richbourg gives as an example. “We try to use reductive models to separate the thing that is influencing this behaviour. But what we’re seeing is that everything works together to create this breast cancer dormancy effect. The better we can create models that capture all that nuance, the better we’re going to be able to understand it.”
For Peyton, their work is also a call to action. “The paper is calling out to the field that we need to do more,” she says. This includes being more creative with the materials that already exist and developing new materials; identifying ways to model the decades-long progression of dormancy that is impossible to recreate in a single study; and expanding the diversity of cell lines used for research (Richbourg points out that many of the studies they reviewed used the same cell line, MDA-MB-231, derived from one 40-to-50-year-old white woman).
Finally, the researchers have an eye to the ultimate goal: better treatments to save patients. “We see that that there are some clinical trials that are happening that are derived from some of those in vitro models,” says Ninette Irakoze, graduate student in the Peyton Lab. “The paper gives hope that, with more development of these in vitro models, eventually we could find treatments to eradicate dormant cancer.”
Deaths from breast cancer dropped 58% between 1975 and 2019 due to a combination of screening mammography and improvements in treatment, according to a new study led by Stanford Medicine clinicians and biomedical data scientists.
Nearly one-third of the decrease (29%) is due to advances in treating metastatic breast cancer, also known as stage 4 breast cancer or recurrent cancer. Although these advanced cancers are not considered curable, women with metastatic disease are living longer than ever.
The analysis helps cancer researchers assess where to focus future efforts and resources.
“We’ve known that deaths from breast cancer have been decreasing over the past several decades, but it’s been difficult or impossible to quantify which of our interventions have been most successful, and to what extent,” said Jennifer Caswell-Jin, MD, assistant professor of medicine. “This type of study allows us to see which of our efforts are having the most impact and where we still need to improve.”
Caswell-Jin and Liyang Sun are co-first authors of the study, which was published in the Journal of the American Medical Association. Sylvia Plevritis, PhD, professor and chair of biomedical data science, and Allison Kurian, MD, MSc, professor of medicine and of epidemiology and population health, are co-senior authors.
The study was a collaborative effort by a national consortium of researchers called CISNET, or the Cancer Intervention and Surveillance Modeling Network. CISNET was established in 2000 by the National Cancer Institute to understand the impact of cancer surveillance, screening and treatment on incidence and mortality. Doing so requires sophisticated computer algorithms capable of modelling the natural course of the disease and the typical treatment paths of individual patients, then translating that information to population-level data collected by the national Surveillance, Epidemiology, and End Results Program, or SEER registry, from 1975 to 2019.
The study is the third in a trio of papers from CISNET published since 2005 that assess the relative contributions of regular screening and treatment advances on breast cancer deaths. The previous two papers informed national guidelines and helped cancer researchers focus their efforts on the most intractable problems.
“Twenty years ago, there was a question whether routine screening mammography actually decreased the number of deaths from breast cancer,” Plevritis said. But in 2005, she and other CISNET researchers published a paper in the New England Journal of Medicine that conclusively demonstrated that screening was responsible for anywhere from 28% to 65% (different models came up with varying degrees of impact) of the reduction in mortality by 2000 between 1975 and 2000.
The second paper, published in 2018 in the Journal of the American Medical Association, highlighted the differences in treatment responsiveness and survival outcomes among women with differing breast cancer subtypes from 2000 to 2012, pinpointing subgroups with poorer survival.
“We found that, while screening still had an important impact, most of the decline in annual deaths was due to improvements in treating early-stage breast cancer based on each cancer’s molecular profile,” Plevritis said.
The current study is the first to explicitly include patients with metastatic breast cancer in its models. The finding that 29% of the decrease in mortality is due to advances in treating metastatic breast cancer both surprised and gratified the researchers.
“Initially, we assumed that treatment of advanced disease was unlikely to make a significant contribution to the declines in mortality we documented in the previous two papers,” Caswell-Jin said. “But our treatments have improved, and it’s clear that they are having a significant impact on annual mortality.”
The CISNET researchers used four computer models to assess the SEER data from 1975 to 2019 — one developed at Stanford Medicine in the Plevritis Lab, one by researchers at the Dana-Farber Cancer Institute, one at MD Anderson Cancer Center, and another jointly developed by researchers at the University of Wisconsin and Harvard Medical School. The four models came up with remarkably similar estimates for the impact of each intervention: screening mammography, treatment of early-stage (stages 1, 2 or 3) breast cancer and treatment of metastatic breast cancer.
The models reproduced the decline in mortality in breast cancer known from SEER data, from 48 per 100 000 women dying of breast cancer each year in 1975 to 27 per 100,000 in 2019, a decrease of about 44%. The models arrived at a larger estimated reduction in mortality of about 58% because the incidence of breast cancer has risen during the same period and more women would have died had screening and treatments not improved.
The models concluded that about 47% of this reduction in mortality is the result of improved treatments for early-stage breast cancer, and about 25% is attributed to screening mammography. The remainder, or about 29%, is due to improvements in treating metastatic disease.
“Designing the new model, which had to account for individuals with non-metastatic cancer who underwent treatment but later progressed to metastatic cancer, and who may have been treated with multiple drugs over the course of their disease, was extremely complex,” Plevritis said. “It took about four years. But it was really satisfying when we were able to validate the model’s behaviour and see that all four models from different institutions, which used the new model inputs in different ways, delivered consistent findings. The models not only make sense, but also produce meaningful insights.”
The impact of treating metastatic disease is exemplified by the increases in median survival time after metastasis: Patients diagnosed in 2000 with metastatic disease lived an average of 1.9 years versus an average of 3.2 years for those diagnosed in 2019. Survival time varies by subgroup status, however. Patients with what are known as oestrogen receptor-positive and HER2 positive cancers saw an average increase in survival time of 2.5 years. Those with oestrogen receptor-positive and HER2-negative cancers lived an average of 1.6 years longer, but those with cancers that are oestrogen receptor-negative and HER2-negative lived about 0.5 years longer in 2019 than in 2000.
“It was meaningful as a breast oncologist to spend time with this history and see real progress over the past decades,” Caswell-Jin said. “There is much more work to be done; metastatic breast cancer isn’t yet curable. But it is rewarding to see that advances have made a difference in these numbers,” she added. “Our scientific and clinical work is helping our patients live longer, and I believe deaths from breast cancer will continue to steadily decline as innovation continues to grow.”
The vertebral bones that constitute the spine are derived from a distinct type of stem cell that secretes a protein favouring tumour metastases, according to a study led by researchers at Weill Cornell Medicine. The discovery, published in Nature, opens up a new line of research on spinal disorders and helps explain why solid tumours so often spread to the spine, and could lead to new orthopaedic and cancer treatments.
Vertebral bone was found to be derived from a stem cell that is different from other bone-making stem cells. Using bone-like “organoids” made from vertebral stem cells, they showed that the known tendency of tumours to spread to the spine rather than long bones is due largely to a protein called MFGE8, secreted by these stem cells.
“We suspect that many bone diseases preferentially involving the spine are attributable to the distinct properties of vertebral bone stem cells,” said study senior author Dr Matthew Greenblatt.
In recent years, Dr Greenblatt and other scientists have found that different types of bone are derived from different types of bone stem cells. Since vertebrae develop along a different pathway early in life, and also appear to have had a distinct evolutionary trajectory, Dr Greenblatt and his team hypothesised that a distinct vertebral stem cell probably exists.
The researchers started out by isolating what are broadly known as skeletal stem cells, which give rise to all bone and cartilage, from different bones in lab mice based on known surface protein markers of such cells. They then analysed gene activity in these cells to see if they could find a distinct pattern for the ones associated with vertebral bone.
This effort yielded two key findings. The first was a new and more accurate surface-marker-based definition of skeletal stem cells as a whole. This new definition excluded a set of cells that are not stem cells that had been included in the old stem cell definition, thus clouding some prior research in this area.
The second finding was that skeletal stem cells from different bones do indeed vary systematically in their gene activity. From this analysis, the team identified a distinct set of markers for vertebral stem cells, and confirmed these cells’ functional roles to form spinal bone in further experiments in mice and in lab-dish cell culture systems.
The researchers next investigated the phenomenon of the spine’s relative attraction for tumour metastases, including breast, prostate and lung tumours, compared to other types of bone. The traditional theory, dating to the 1940s, is that this “spinal tropism” relates to patterns of blood flow that preferentially convey metastases to the spine versus long bones. But when the researchers reproduced the spinal tropism phenomenon in animal models, they found evidence that blood flow isn’t the explanation, finding instead a clue pointing to vertebral stem cells as the possible culprits.
“We observed that the site of initial seeding of metastatic tumour cells was predominantly in an area of marrow where vertebral stem cells and their progeny cells would be located,” said study first author Dr Jun Sun, a postdoctoral researcher in the Greenblatt laboratory.
Subsequently, the team found that removing vertebral stem cells eliminated the difference in metastasis rates between spine bones and long bones. Ultimately, they determined that MFGE8, a protein secreted in higher amounts by vertebral compared to long bone stem cells, is a major contributor to spinal tropism. To confirm the relevance of the findings in humans, the team collaborated with investigators at Hospital for Special Surgery to identify the human counterparts of the mouse vertebral stem cells and characterise their properties.
The researchers are now exploring methods for blocking MFGE8 to reduce the risk of spinal metastasis in cancer patients. More generally, said Dr Greenblatt, they are studying how the distinctive properties of vertebral stem cells contribute to spinal disorders.
“There’s a subdiscipline in orthopaedics called spinal orthopaedics, and we think that most of the conditions in that clinical category have to do with this stem cell we’ve just identified,” Dr Greenblatt said.
In a paper published in the journal Biomolecules, UK and Chinese researchers report their creation of a biomedical compound that has the potential to stop breast cancer metastasis.
The scientists from the Chemistry and Biochemistry Departments at the University of Liverpool and Nanjing Medical School in China have discovered a possible way to block proteins produced by cancer cells that promote metastasis – the chief impediment to successful cancer treatment.
Prof Philip Rudland from the University of Liverpool explained: “As a general rule, cancer that has spread is treated with chemotherapy, but this treatment can rarely be given without severely harming or becoming toxic to the patient. The importance of our work was to identify a specific and important target to attack, without toxic side effects.”
The University’s research team have in the past discovered that specific proteins are involved in the metastatic process; these proteins are different from those involved in the production of the primary tumour. One such example is a protein called ‘S100A4’, and is the protein chosen by the research team to target for the identification of chemical inhibitors of metastasis, using model systems of cells from the highly metastatic and incurable hormone receptor-free breast cancer.
Using these model systems, researchers at the University’s Department of Biochemistry discovered a novel compound that can specifically block the interaction of this metastasis-inducing protein S100A4 with its target inside the cell. Researchers in the Department of Chemistry then synthesised a simpler chemical and connected it to a warhead which stimulates cells’ normal protein-degrading machinery. This compound now works at very low doses to inhibit properties associated with metastasis, an improvement of over 20 000-fold on the original unarmed inhibitor, with virtually no toxic side effects. Moreover, in collaboration with Chinese researchers at Nanjing Medical School, they have shown that this compound inhibits metastasis in similar metastatic tumours in mice, suggesting a potential therapeutic role.
Dr Gemma Nixon, Senior Lecturer in Medicinal Chemistry at the University of Liverpool said: “This is an exciting breakthrough in our research. We now hope to take the next steps, and repeat this study in a large group of animals with similar metastatic cancers so that the efficacy and stability of the compounds can be thoroughly investigated and if necessary improved by further design and syntheses, prior to any clinical trials.”
“Significantly, this particular protein we’re investigating occurs in many different cancers, which could mean this approach may be valid for many other commonly occurring human cancers.”
Physicians at Cedars-Sinai Cancer are now using a unique therapy, called hepatic artery infusion (HAI) pump chemotherapy, that offers hope to colorectal cancer patients whose disease has spread and who now have inoperable liver tumours. The system, which was developed over two decades ago, is only now being adopted more widely, also spares the rest of the body from much of the chemotherapy drugs’ toxicity.
“Many of these patients are not candidates for curative surgery and we now have a meaningful option for treating them,” said Cristina Ferrone, MD, chair of the Department of Surgery at Cedars-Sinai and a specialist in the care of patients with complex hepato-pancreato-biliary disorders. “This therapy has been shown to extend both life and quality of life.”
Colorectal cancer is the fourth-leading cause of cancer-related death in the US. In as many as 25% of patients diagnosed with the disease, the cancer spreads to the liver, where it can be difficult to treat. However, more than half of patients receiving hepatic artery infusion pump therapy go on to receive curative surgery, studies have shown.
Cedars-Sinai Cancer and associate professor of Surgery at Cedars-Sinai, sat down with the Cedars-Sinai Newsroom to explain this lifesaving therapy.
How do the pumps work?
We surgically place the pump underneath the skin, outside of the abdominal cavity, and it is attached to tubing that enters the abdominal cavity and goes into the gastroduodenal artery. That artery feeds into the hepatic artery, which supplies blood to the liver. During surgery, we block blood flow from the gastroduodenal artery from going into portions of the small intestine so that the therapy flows only to the liver.
The pump has a soft centre, allowing its internal reservoir to be filled through the skin via a syringe. After surgery, the patient comes in every two weeks and we refill the pump, which then allows the chemotherapy drug to flow directly into the liver via the arterial supply.
Which patients are likely to benefit from hepatic artery infusion pump therapy?
This therapy is designed for patients, based on the distribution of the metastatic disease (where are the tumours and how many), for whom curative surgery is not an option at the time of diagnosis. The best we had been able to offer these patients was lifelong chemotherapy that had potential systemic toxicities, and that never quite reduced their tumour size to the point that we could surgically remove it. This therapy offers an additional option for liver-directed therapy that can potentially make patients candidates for surgery by specifically targeting the liver disease.
What are the advantages of the hepatic artery infusion pump over traditional chemotherapy delivery?
A majority of these tumours derive their blood supply from the hepatic arterial system, and delivering chemotherapy to the tumours through the hepatic arterial system allows us to give higher doses of specific chemotherapeutic agents without exposing the patient to their systemic toxicities. Data shows that up to 60% of appropriately selected patients receiving hepatic artery infusion pump chemotherapy were then able to receive curative surgery. Patients can often continue receiving systemic chemotherapy in combination with hepatic artery infusion pump chemotherapy.
Are hepatic artery infusion pumps used to treat other types of liver cancer?
Some patients with cholangiocarcinoma are currently treated with HAI pumps, but this is not yet standard of care. Colon cancer is the second most common cancer, and colon cancer that has metastasized to the liver affects a significant number of patients. And we have seen good outcomes with those patients. Other types of cancers that metastasise to the liver are significantly more challenging to treat, and thus far, we don’t think this therapy will benefit those patients.
Is this a new therapy?
Hepatic artery infusion pumps have actually been around for about 25 to 30 years, but until quite recently only a few medical centres were using them. But more and more centres are realising that this therapy can truly benefit patients, and it is becoming more widely available.
Breast cancer cells. Image by National Cancer Institute
A new international study has for the first time, identified that beta-blockers could significantly enhance the therapeutic effect of anthracycline chemotherapy in triple negative breast cancer (TNBC) by reducing metastasis. The results are published in Science Translational Medicine.
Anthracyclines are a class of drugs used in chemotherapy to treat many cancers, including TNBC.
Monash University researchers have previously shown in a clinical trial that beta blockers are linked with reduced metastasis. However, until now, it was unclear how beta-blockers would interact with common cancer treatments.
In this new study, the team used mouse models of cancer and analysed large-scale patient clinical data, in collaboration with the Cancer Registry of Norway, to discover that anthracycline chemotherapy on its own, in the absence of a beta-blocker, induces nerve growth in tumours.
However, adding a beta blocker to chemotherapy inhibited nerve fibre activity in tumours and stopped the cancer from coming back after treatment.
Lead author Dr Aeson Chang said the findings reveal an unanticipated insight into why chemotherapy treatment does not always work as it should.
“We set out to build on previous studies that have shown beta-blockers can halt the stress response experienced by cancer patients at the time of diagnosis and stop the cancer from spreading.
In this new study, not only did we discover the biological effect of beta-blockers when used alongside anthracycline chemotherapy, we also discovered why they are effective,” said Dr Chang.
“In mouse models of TNBC, we found that anthracycline chemotherapy was able to increase sympathetic nerve fibre activity in tumours. Activation of these stress neurons can help tumour cells spread and, fortunately, we found that beta blockers could stop this effect. Our hope is that this exciting discovery will pave the way for further research and, ultimately, lead to improved outcomes for patients.”
Senior author, Professor Erica Sloan, who has been exploring the use of beta-blockers as a novel strategy to slow cancer progression for a number of years, said the study provides important clues about why beta-blockers may help improve the clinical management of TNBC.
“While many patients will be cured by treatment, unfortunately, in some patients the cancer may return – this study has helped us understand why. Our findings show that anthracycline chemotherapy supports the growth of nerves, which can support cancer relapse. This is important, as it tells us that targeting nerves using a beta blocker can improve response to treatment,” said Professor Sloan.
“Beta blocker use has been consistently linked to reduced metastatic relapse and cancer-specific survival in TNBC patients. However, the lack of understanding of how beta blockers improve chemotherapy – which is a core component of the standard treatment for TNBC – has limited the translation of these findings into the cancer clinic,” said Professor Sloan.
“We believe this study presents an exciting opportunity to further explore the use of beta-blockers as a novel strategy in the treatment of TNBC.”
Lung cancer cells in the process of metastasising. Source: National Cancer Institute on Unsplash
When cancer cells metastasise, they have to break connections with neighbouring cells and migrate to other tissues. Both processes are promoted by signalling molecules released by the cancer cells, which thereby increase the malignancy of tumours. Researchers found that the release of these ‘prometastatic’ factors is influenced by the cellular skeleton – specifically, actin filaments. The study was published in Advanced Science.
Actin’s multiple role functions in cancer propagation
Actin filaments are part of the cell skeleton and essential for stability and motility. They form a network that dynamically builds up and gets broken down by the addition or detachment of building blocks at the filaments’ ends. These processes are precisely regulated by other molecules, such as formins. The dynamics of the actin network enable the movement of cells, for example during development or wound closure, but also that of spreading cancer cells. Actin also plays a role in the transport of substances within the cell. However, this is less well understood than that of other intracellular transport mechanisms.
The research team led by Prof Dr Robert Grosse and Dr Carsten Schwan from the University of Freiburg, now found that the actin network also enables the release of prometastatic factors, such as ANGPTL4 which is an important prometastatic factor that promotes the formation of metastases in various types of cancer. For their study, they used high-resolution microscopy to track the movement of individual transport vesicles within living cancer cells.
“We observed that ANGPTL4-loaded vesicles are conveyed to the periphery of the cell by means of dynamic and localised polymerisation of actin filaments,” says Grosse, who is a member of the Cluster of Excellence CIBSS – Centre for Integrative Biological Signalling Studies at the University of Freiburg.
Transportation along actin filaments
Based on microscopic observations and genetic analyses, the scientists conclude that the vesicles’ movement is controlled by the formin-like molecule FMNL2 by initiating polymerisation (ie elongation) of actin filaments directly at the vesicle. “We already knew that increased FMNL2 activity has prometastatic effects in many types of tumours,” says Grosse. “In our current work we could now demonstrate an important underlying process and a connection to the TGFbeta signalling pathway.” According to the scientist, this knowledge could be used for tumour diagnostics or therapy. for example, by developing an antibody that indicates the presence of active FMNL2 or pharmacologically targets active, phosphorylated FMNL2.
The evolutionary secrets that enable the traditional Chinese medicinal herb known as barbed skullcap to produce cancer fighting compounds have been unlocked by a collaboration of UK and Chinese researchers, who published their research in the journal Molecular Plant.
The researchers used DNA sequencing technology to assemble the genomic sequence of skullcap (Scutellaria barbata) known in China as banzhilian. This gave researchers the genetic information, a microevolutionary history, required to identify how the plant produces the compound scutebarbatine A, which acts against a range of cancer cells.
Professor Cathie Martin, Group Leader at the John Innes Centre, and one of the authors of the study said, “We have found that the primary metabolite has activity against cancer cells but not non-cancer cells which is especially important for an anti-cancer metabolite. Now we are looking to develop synthetic methods for producing more of the lead compound.”
In Traditional Chinese Medicine (TCM), to isolate medicinal chemistry from the plant, the herb is boiled in water for two hours and extract is dried to produce a powder and taken as a decoction (concentrated liquid). Now, with the knowledge of the genes that make up the biochemical pathway behind the anti-cancer activity of the herb, researchers are close to being able to synthesise larger quantities of compounds more rapidly and sustainably by using a host such as yeast.
The research is led by CEPAMS, a partnership between the John Innes Centre and the Chinese Academy of Science and supported by The Royal Society.
“This is a fantastic collaboration about developing interesting drug leads from natural resources and shows the practical value of focusing on the microevolution of a species” said Professor Martin.
The Skullcap genus has been used for centuries in TCM for treatment of different medical conditions. Clinical work has shown that preparations based on Scutellaria barbata during chemotherapy can reduce the risk of metastatic tumours.
CEPAMS Group Leader based at Shanghai Dr Evangelos Tatsis said, “Natural products have long been the lead compounds for the discovery of new drugs. By following the trail of the traditional Chinese plants, we can develop new anti-cancer medicines and this research marks a crucial step in that direction.”
Plant-based traditional medicines have long been used to provide leads for the new drug discovery, leading to drugs such as vinblastine and taxol which are now used clinically as anticancer drugs.
TCM is one of the best catalogued systems with empirical information about the therapeutic properties of herbal remedies.
Anti-cancer drugs obtained from traditional Chinese medicine have higher efficacy than chemical synthetic drugs and with less toxic side effects. The genomes of medicinal skullcaps reveal the polyphyletic origins of clerodane diterpene biosynthesis in the family Laminiaceae, is published in Molecular Plant
