Tag: cancer treatment

Capsaicin Sustained Release Formations – a Spicy Anti-cancer Treatment?

A study published in Pharmacology & Therapeutics provides the first in-depth description of the anti-cancer activity of capsaicin sustained release formulations. Capsaicin, responsible for the hot and spicy taste of chili peppers, is being, explored in sustained release formulations of capsaicin for extended anti-cancer activity. However, how to get around its fiery taste remains a challenge.

The article chronicles the growth-suppressive activity of sustained release capsaicin drugs, including solid dispersion systems, liposomes, phospholipid complexes and nanoparticles. This marks the first publication to provide an in-depth description of the anti-cancer activity of capsaicin sustained release formulations. The research team was led by Associate Professor of Biomedical Sciences Piyali Dasgupta, PhD., and Professor of Biomedical Sciences Monica Valentovic, PhD.

“This review article is the first to provide a comprehensive overview of capsaicin formulations in human cancer,” said Prof Dasgupta, the study’s corresponding author. “Previous publications in the literature only briefly address sustained release formulations of capsaicin.”

The reviewers found that capsaicin displayed robust growth-inhibitory activity in a diverse array of human cancers. However, the clinical applications of capsaicin as a viable anti-cancer agent were hindered by three factors: poor solubility, low bioavailability and spicy flavour.

“Oral use of capsaicin is associated with unfavourable side effects such as stomach cramps, nausea, a burning sensation in the gut and gastrointestinal irritation,” said Prof Valentovic, a senior author on the publication. “A strategy to overcome these drawbacks is the development of different delivery systems, such as encapsulating capsaicin in long-acting sustained release drug delivery systems could allow for more consistent capsaicin levels that could be more efficient as anti-cancer agents.”

Source: Marshall University

Unlikely Allies: Bacteria can Promote Cancer Metastasis

Scanning Electron Micrograph of a breast cancer cell. Credit: NIH

Researchers have found that bacteria lurking inside tumours promote cancer metastasis. They do so by enhancing the strength of host cells against mechanical stress in the bloodstream, promoting cell survival during tumour progression, researchers report in the journal Cell.

“Our study reveals that the cancer cell’s behaviour is also controlled by the microbes hiding inside tumours, the majority of which were originally thought to be sterile,” said senior author Shang Cai of the Westlake Laboratory of Life Sciences and Biomedicine. “This microbial involvement is distinct from the genetic, epigenetic, and metabolic components that most cancer drugs target.”

“However, our study does not mean that using antibiotics during cancer treatment will benefit patients,” he cautioned. “Therefore, it is still an important scientific question of how to manage the intratumor bacteria to improve cancer treatment in the future.”

It is known that microbes play a critical role in affecting cancer susceptibility and tumour progression, particularly in colorectal cancers. New evidence suggests however that, in a broad range of cancer types, they also form integral components of the tumour tissue itself, such as pancreatic cancer, lung cancer, and breast cancer. Microbial features are linked to cancer risk, prognosis, and treatment responses, yet the biological functions of tumour-resident microbes in tumour progression remain unclear.

Whether these microbes are actually drivers of tumour progression has been an intriguing question. “Tumour cells hijacked by microbes could be more common than previously thought, which underscores the broad clinical value of understanding the exact role of the tumour-resident microbial community in cancer progression,” Cai explained.

To find answers, Cai’s team utilised a mouse model of breast cancer with significant amounts of bacteria inside cells, similar to human breast cancer. The bacteria were found to be capable of travelling through the circulatory system with the cancer cells, playing critical roles in tumour metastasis. These passenger bacteria have the capacity to modulate the cellular actin network, promoting cell survival against mechanical stress in circulation.

“We were surprised initially at the fact that such a low abundance of bacteria could exert such a crucial role in cancer metastasis. What is even more astonishing is that only one shot of bacteria injection into the breast tumour can cause a tumour that originally rarely metastasises to start to metastasise,” Cai said. “Intracellular microbiota could be a potential target for preventing metastasis in broad cancer types at an early stage, which is much better than to have to treat it later on.”

While intratumour bacteria was found to have a clear role in promoting cancer cell metastatic colonisation, the authors did not exclude the possibility that the gut microbiome and immune system may act together with intratumour bacteria to determine cancer progression. Future in-depth analyses of how bacteria invade tumour cells, how intracellular bacteria are integrated into the host cell system, and how bacteria-containing tumor cells interact with the immune system will help inform how to properly deploy antibiotics in cancer treatment.

Source: ScienceDaily

‘A-Maize-ing’ Nanoparticles Target Cancer Cells Directly

Computer=generated depiction of nanoparticles

Researchers have recently developed novel nanoparticles derived from maize that can target cancer cells directly, via an immune mechanism. The results of this study, published in Scientific Reports, are encouraging, and the technique has demonstrated efficacy in treating tumour-bearing laboratory mice with no adverse effects.

Nanoparticles, or particles whose size varies between 1 and 100nm, have shown tremendous potential in many areas of science and technology, including therapeutics. However, conventional, synthetic nanoparticles are complicated and expensive to produce and alternatives such as extracellular vesicles (EVs) have mass production challenges.
Another recently emerging option is that of plant-derived nanoparticles (NPs), which can be easily produced in high levels at relatively lower costs. Like EVs, these nanoparticle-based systems also contain bioactive molecules, including polyphenols (which are known antioxidants) and microRNA, and they can serve as vehicles for targeted drug delivery.

Recently, researchers from the Tokyo University of Science (TUS) developed anti-cancer bionanoparticles, using corn (maize) as the raw material.
Lead researcher Professor Makiya Nishikawa explained: “By controlling the physicochemical properties of nanoparticles, we can control their pharmacokinetics in the body; so, we wanted to explore the nanoparticulation of edible plants. Maize, or corn, is produced in large quantities worldwide in its native form as well as in its genetically modified forms. That is why we selected it for our study.” 

The team centrifuged a super-sweet corn juice and then filtered it through a syringe filter with a 0.45μm pore size, then ultracentrifuged to obtain NPs derived from corn. The corn-derived NPs (cNPs) were approximately 80nm in diameter with a tiny net negative charge of -17mV.

The research team then set up experiments to see whether these cNPs were being taken up by various types of cells. In a series of promising results, the cNPs were taken up by multiple types of cells, including the clinically relevant colon26 tumor cells (cancer cells derived from mice), RAW264.7 macrophage-like cells, and normal NIH3T3 cells. RAW264.7 cells are commonly used as in vitro screens for immunomodulators.

The results were astounding: of the three types of cells, cNPs only significantly inhibited the growth of colon26 cells, indicating their selectivity for carcinogenic cell lines. Moreover, cNPs were able to successfully induce the release of tumour necrosis factor-α (TNF-α) from RAW264.7 cells. TNFα is primarily secreted by macrophages, natural killer cells, and lymphocytes, which help mount an anticancer response. “The strong TNFα response was encouraging and indicated the role of cNPs in treating various types of cancer,” explains Dr. Daisuke Sasaki, first author of the study and an instructor and researcher at TUS.

A luciferase-based assay revealed that the potent combination of cNPs and RAW264.7 cells significantly suppressed the proliferation of colon26 cells. Finally, the research team studied the effect of cNPs on laboratory mice bearing subcutaneous tumours. Once again, the results were astonishing: daily injections of cNPs into colon26 tumours significantly suppressed tumour growth, without causing serious side effects, or weight loss.

“By optimising nanoparticle properties and by combining them with anticancer drugs, we hope to devise safe and efficacious drugs for various cancers,” observed an optimistic Prof Nishikawa.

Source: Tokyo University of Science

The Search for New Cancer Therapies Strikes Gold

Photo by Jingming Pan on Unsplash

The gold complex auranofin has traditionally been used for treating rheumatism but is also being evaluated as a one number of new cancer therapies. According to a study published in Redox Biology, molecules with the same inhibition effect have been discovered that have a more specific effect than auranofin and therefore may have greater potential as cancer therapies.

Auranofin (AF) is classed by the WHO (World Health Organization) as an anti-rheumatic agent and is an active component in the drug Ridaura. AF is also currently being assayed in a string of clinical trials as a possible cancer therapy. One reason for the researchers’ interest in AF is its ability to inhibit thioredoxin reductase (TrxR), a protein central to the thioredoxin system, which protects cells from oxidative stress in all mammals. 

However, TrxR also protects cancer cells, making cancer therapies less effective. Moreover, TrxR, which affects cellular growth and survival, is upregulated in certain forms of cancer.

“There’s a great deal of interest in the ability to inhibit the thioredoxin system in the treatment of cancer, but there’s a risk that healthy cells will also be damaged and killed,” says the study’s co-last author Elias Arnér, professor at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet. “Our aim is for TrxR inhibitors to be as specific as possible.”

The researchers studied the effects of AF in mouse cancer cells (lung adenocarcinoma and melanoma) and compared them with other recently-developed TrxR-inhibiting molecules called TRi-1 and TRi-2 (thioredoxin reductase inhibitors 1 and 2). 

The study, which was based on new proteomic methods of analysing the entire set of proteins in cells, suggests that the TRi compounds are more specific in their effect than AF. The results show that AF causes very high levels of oxidative stress and has other effects that seem unrelated to the inhibition of TrxR. They also demonstrate that TRi-1 seems to be the most specific TrxR inhibitor so far.

“Our results can serve as an important blueprint for further studies of AF’s mechanism of action and side effects,” said the study’s other co-last author Roman Zubarev, professor at the Department of Medical Biochemistry and Biophysics, Karolinska Institutet. “Having now compared AF with the more specific molecules TRi-1 and TRi-2, we hope that our findings will contribute to the further development of TrxR inhibitors as anticancer drugs.”

Source: Karolinska Insitutet

Treating Cancer with the Toxoplasma Gondii Parasite

Source: National Cancer Institute on Unsplash

Scientists have discovered that Toxoplasma gondii, a parasite known to cause illness in pregnant women and immunocompromised patients, could potentially enhance the treatment of various types of tumours.

The parasite Toxoplasma gondii is a single-celled opportunistic protozoan capable of infecting a broad range of warm-blooded animals and has been reported in nearly one-third of the world’s human population. It has a number of health effects, including a strong link to schizophrenia and has even been associated with increased suicide attempts in mothers.

While many treatments have been able to treat tumours and prolong the lives of patients, there is a need to further enhance these. In the study, published in the Journal for ImmunoTherapy Cancer, scientists found that the commonly found parasite  is able to sensitise ‘cold’  tumours, that is, tumours unlikely to trigger a strong immune response, to immune checkpoint blockade therapy.

The researchers believe that this finding could have broader therapeutic implications for many types of cancers.

T. gondii has to live inside the cells of its host and secretes numerous proteins to counter the host’s immune defences and to facilitate their own invasion and colonisation of the host cells. The researchers first built a T. gondii mutant strain with limited growth and disease-causing ability, but which is also able to manipulate the host immune system.

By directly injecting this mutant parasite into solid tumours, it induces inflammatory responses in those tumours and even in tumours located in a distant location in the mouse body. The researchers further demonstrated that this treatment approach has made tumours more responsive to treatment with immune checkpoint inhibitors.

This dual treatment significantly extended the survival of mice and reduced tumour growth in mouse models of melanoma, Lewis lung carcinoma, and colon adenocarcinoma.

Dr Hany Elsheikha, Associate Professor in the School of Veterinary Medicine and Science at the University of Nottingham, and one of the lead authors of the study, said: “The use of a mutant version of Toxoplasma gondii in the treatment of certain tumours in mice models has been previously reported. What makes this study different is the confirmation that intratumoural injection with mutant Toxoplasma gondii strain boosts antitumour immunity and the effectiveness of checkpoint inhibition therapy.

“These are significant findings and are relevant to future tumour therapy. The marked reduction in tumour size and the significant improvement in the survival of mice that received this novel combinational therapy is promising but should be interpreted with caution as further research is needed.”

Source: University of Nottingham

Added Salt Found to Suppress Tumours in Mice

Source: Pixabay CC0

new study has found that adding salt to the diet of lab mice can suppress the growth of cancerous tumours.

Dietary salt reduction has been stressed by clinicians for many years, as research has shown that a high-sodium diet can result in inflammation, high blood pressure and an increased heart attack risk. Researchers from the Translational Health Science and Technology Institute wondered if the inflammation resulting from a high-salt diet could also confer positive health benefits, such as fighting cancerous tumours. 

To find out, the researchers fed two groups of mice with implanted melanoma tumours either a normal diet or a high-sodium diet (4.0% sodium chloride above normal diet) and then measured the differences in tumour suppression abilities between the two groups. They found that the mice on the high-sodium diet had an increase in Bifidobacterium probiotics, leading to an increase in natural killer cells that attack cancerous tumors. They also found an increased ability to inhibit PD-1 proteins which have been found to prevent T cells from attacking tumours.

On close examination, it was found that the high-sodium diet caused the gut barrier to be leakier, enabling the movement of Bifidobacteria from the gut to tumour locations. In addition, they found that once the Bifidobacteria arrived at a tumour, crosstalk between them and the immune cells engaged in attacking the tumour improved the success of the attack.

However, the researchers also found that a low-sodium diet worked in conjunction with several cancer-fighting drugs, showing an increased ability to reduce tumour growth. Since the researchers hypothesised that Bifidobacteria were responsible for the tumour immunity of a high-sodium diet, they performed faecal transplants from mice on a high-sodium diet to those on a normal diet and found that it also improved their ability to fight tumour growth.

The study was published in Science Advances.

Source: MedicalXpress

Cancer Follow-up Care Needs Improvement

With greater long-term cancer survival, previous standards of cancer follow-up care and support may no longer meet current needs.

The side-effects of anticancer medicines and impacts of the illness itself that sometimes persist after the end of treatment can hinder  a return to normal life after beating cancer. A study presented at the ESMO Congress 2021 showed that a significant proportion of survivors continue to suffer from burdensome symptoms for several years and reveal widespread dissatisfaction with the assistance provided.

Prof Dorothy Keefe, CEO of Australia’s national cancer agency, Cancer Australia, chair of the congress’s supportive and palliative care track, not involved in the study, underlined its importance in a context where survivorship research has lagged behind research on cancer treatment. “This is probably due to the increase in survival rates itself lagging behind the introduction of new therapies, but also to a lack of prioritisation compared to the need to develop a cure,” Keefe said, and highlighted the scale of the issue today: “We now have millions of cancer survivors in Australia, hundreds of millions around the world – and an ever-increasing number who could potentially have long-term side-effects.”

One of the most common symptoms experienced by patients and survivors alike is cancer-related fatigue (CRF), a persistent sense of exhaustion, not alleviated by sleep or rest and significantly interferes with the person’s usual functioning. The FiX study initially evaluated the patterns, severity and management of CRF among 2508 patients with 15 different types of cancer two years after the discovery of their illness. In a follow-up survey, 36 potential long-term problems, completed by participants around four years after diagnosis, almost 40% of survivors continued to report fatigue that they rated as a moderate or severe burden. As well as fatigue, over 40% of patients reported loss of physical capacity as a burden and over one third suffered from trouble sleeping, sexual problems, joint pains and anxiety.

Although there are recommendations for managing side-effects like CRF, study author Dr Martina Schmidt from the German Cancer Research Centre (DKFZ) in Heidelberg, Germany, drew attention to their lack of implementation and reported that more than one in three affected individuals in the study evaluated the support they were offered for fatigue as poor. “Despite increasing awareness of the effectiveness of mitigating measures like exercise to reduce fatigue, patients are still too often left alone to seek help for symptoms that cannot be directly addressed with medicines in the same way as something like pain, for which satisfaction with the support received was high in our study.”

Prof Keefe commented on the results, saying: “This research shows that a staggeringly high number of patients still suffer from significant health issues years after being declared disease-free. Their dissatisfaction with the care available is a wake-up call that we should be paying more attention to these individuals, trying to understand the mechanisms at play in order to identify interventions that could help them to better recover.”

According to Dr Schmidt, cancer follow-up care should therefore also incorporate more systematic screening for additional symptoms that can burden patients. “The first step should be to make sure that patients themselves are better informed about these potential issues early on, so they know that conditions like CRF are not only expected, but often manageable and that they should not wait for symptoms to disappear on their own,” she said.

Recognising that possible models of long-term support remain largely untested, Keefe further advocated that all patients should be provided with a survivorship care plan when they reach the end of their treatment. “Going forward, we need to develop these models of care in a way that minimises the burden on healthcare systems, implement them and research their impact so that we can come back in five years’ time and evaluate whether they have made a difference for cancer survivors,” she concluded.

Source: European Society for Medical Oncology

How Cancer Cells Develop Resistance to Chemotherapy

Source: National Cancer Institute on Unsplash

Researchers have found some answers as to why cancer cells can develop resistance to the cytotoxic drugs used in chemotherapy.

“We haven’t understood very much about how this resistance to chemotherapy develops and even less about how the microenvironment in cancer can affect the process,” said Kaisa Lehti, a professor at the Norwegian University of Science and Technology’s (NTNU) Department of Biomedical Laboratory Science.

Lehti has led this study into how cancerous tissues develop resistance to a particular form of chemotherapy, the results of which appear in Nature Communications.

If ovarian cancer is picked up early, almost all patients survive the first five years, while chances of survival are much worse if detected later. Finding effective treatment is therefore very important.

Platinum chemotherapy is one of the standard treatments for ovarian cancer, but cancer cells often develop resistance to this particular treatment. The reason lies in how the platinum-based cytotoxin itself can change the cancer cells and their environment.

Cytotoxin influences cancer cells and their environment
Lehti summed up the process: “The cytotoxin can change the way the cancer cells send and perceive signals and can modify the microenvironment around the cells.”

This change allows the cancer cells to withstand the damage caused by the cytotoxin—and can thus survive the chemotherapeutic attack. The researchers have found this key to the puzzle in a layer of tissue that often surrounds cancer cells.

“A fibrotic network of proteins, known as the extracellular matrix or ECM, surrounds the cancer cells, particularly the most aggressive ones,” said Lehti.

The fibrotic tissue, with the ECM network around the cancer cells, is mainly produced by normal connective tissue cells. But the cancer cells and connective tissue cells in the network can alter this tissue themselves.

“Previously, we haven’t known how the communication between the cancer cells and the extracellular matrix is affected by, or even itself influences, the development of cancer and its response to chemotherapy,” said Prof Lehti.

But it is now known that chemical and mechanical signals in the surrounding ECM tissue help cancer develop its ability to spread and to resist treatment.

“Certain signals from the ECM can critically change the cancer cells’ resistance to platinum-based cytotoxic drugs,” Prof Lehti explained.

In this way, the cytotoxin itself helps change both the microenvironment around the cancer cells and the ability of the cancer cells to sense their environment, and so resist the cytotoxin. By understanding this process, better therapies can be developed.

Source: MedicalXpress

Powering Up NK Cells With Magnetism

NK cells attack a cancer cell (centre). Source: NIH

Powering up natural killer cells with magnetic nanoparticles could enhance cancer immunotherapy, according to a Northwestern Medicine study published in ACS Nano.

This method could allow for the unleashing of natural killer (NK) cells on a variety of solid tumours, according to senior author Dong-Hyun Kim, PhD, associate professor at Northwestern.

“People have had trouble applying NK cells to solid tumours,” said Prof Kim. “If we can provide an easy path to modulate NK cells, perhaps this can become a useful therapy.”

Most cell-based immunotherapies involve T-cells, but these chimeric antigen receptor (CAR) T-cell therapies are costly and have a long incubation period and strong side effects.

On the other hand, NK cells belong to the innate immune system and are quicker to respond to pathogens. NK cell immunotherapy has been explored, according to Prof Kim, but that too has barriers.

“It’s pretty hard for these cells to penetrate inside the tumours which have thick barrier tissues,” Prof Kim said.

Magnetically activated NK cells
Boosting NK cell function with cytokines have proven unsuccessful and, like CAR T-cell therapy, have a high cost and lengthy manufacturing time. However, Prof Kim’s previous work with nanoparticles inspired a different approach.

Prof Kim and colleagues developed a magnetic nanocomplex that binds with NK cells and, when activated with an alternating magnetic field, exerts force on the exterior of the cell, promoting secretion of cytotoxic compounds. Testing this nanocomplex in animal models of hepatocellular carcinoma, the investigators found that magnetic activation increased the cancer-killing ability of NK cells when injected into solid tumours.

As a bonus, these nanoparticles show up with MRI, allowing for precise monitoring of NK cell distribution during and after injection.

“This creates a stronger NK cell, and can hopefully enhance the efficacy of the treatment,” Prof Kim said.

Source: Northwestern University

FLASH Radiation Treatment for Tumours a Step Closer

Heavy ion bombardment in FLASH radiation treatment could be the future of radiotherapy, with encouraging findings from a German lab.

The GSI Helmholtzzentrum für Schwerionenforschung and the future accelerator centre FAIR succeeded in performing a carbon ion FLASH experiment for the first time in their Phase 0 experiment. 

The scientists involved were able to achieve the very high dose rates required to irradiate tumours. The success was a collective effort of the GSI Biophysics Department and the accelerator crew on the GSI/FAIR campus in close collaboration with the German Cancer Research Center DKFZ and the Heidelberg Ion Therapy (HIT) center.

FLASH irradiation involves utra-short and ultra-high radiation, delivering the treatment dose in fractions of a second. Traditional radiation therapy, as well as proton or ion therapy, deliver smaller doses of radiation to a patient over an extended time period, whereas FLASH radiotherapy is thought to require only a few short irradiations, all lasting less than 100 milliseconds.

In the field of electron radiation, recent in vivo investigations have shown that the FLASH method’s ultra-high dose rate is less harmful to healthy tissue, but just as efficient as conventional dose-rate radiation to inhibit tumour growth. Such an effect has not yet been demonstrated for proton and for ion beam irradiation, which is the basis of the tumour therapy with carbon ions developed at GSI. There is still a lot of research to be done here. The results of the current experiment at GSI are now being evaluated and will contribute to new knowledge.

There have also been technical barriers to FLASH radiation. Until now, FLASH technique has only been applicable using electron and proton accelerators. While the required dose rates for electrons and protons can be achieved with a cyclotron (circular accelerator), this is more difficult with the synchrotrons required in heavy ion therapy, such as the SIS18 at GSI.

That is why the current FAIR Phase 0 experiment is a very crucial step: Thanks to the improvements at the existing GSI accelerator facility as part of the preparations for FAIR, the necessary dose rate in millisecond range can now also be achieved for carbon ions. However,  much development work remains to be done before this procedure is mature enough to be routinely used on patients in the field of electron radiation.

Professor Marco Durante, Head of the GSI Biophysics Research Department, was very pleased with this important milestone in  the development of FLASH irradiation:

“It is a forward-looking method that could significantly increase the therapeutic window in radiotherapy. I am very happy that the researchers and the accelerator team were able to demonstrate the possibility to create conditions with carbon beams that are necessary for FLASH therapy of tumors. If we can combine the great effect and precision of heavy ion therapy with FLASH irradiation while maintaining efficacy and causing little damage to healthy tissue, this could pave the way of a future radiation therapy several years from now.”

Professor Paolo Giubellino, The Scientific Managing Director of GSI and FAIR, expressed his delight at the results: “The combination of expertise in biophysics and medicine as well as engineering excellence allows the first world-class experiments FLASH irradiation with ion beams to be performed. This could result in important complements to existing radiation therapies. Applications in tumour therapy are one of the research areas that can benefit from the recent increased intensities of GSI accelerators. However, modern radiobiology will substantially benefit from beams with even higher intensities, such as we will have at the FAIR facility currently under construction. FLASH is a first example of these future directions of work”.

Source: GSI Helmholtzzentrum für Schwerionenforschung GmbH