Tag: melanoma

Categories : CancerTags :

How, When and Where: Sex Matters in Melanoma Development

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Melanoma rates differ consistently between men and women in terms of the ages at which melanomas occur and the locations on the body where they occur. Over time, melanoma rates have increased in both men and women, but the trends differ by body site. A new study in the Journal of Investigative Dermatology, published by Elsevier, presents the findings from a large-scale, long-term melanoma data analysis investigating incidence trends by age, sex, and anatomic site.

Lead investigator David C. Whiteman, MBBS, PhD, Cancer Control Group, QIMR Berghofer Medical Research Institute, and Faculty of Medicine, The University of Queensland, Brisbane, Australia, explains, “There has been a general observation in numerous populations that melanomas appear to arise at different rates in men and women. We decided to investigate this observation rigorously and assess whether these differences have been constant through time or across generations by using large-scale data from population registries to investigate long-term melanoma trends in men and women.”

The research team analysed more than 40 years of melanoma data from Queensland, Australia, the USA, and Scotland. These three populations were chosen because historically they have had high (Queensland), moderate (USA), and low (Scotland) rates of melanoma. Over time, the rates of melanoma increased in all three populations, especially among women. In women in all populations, melanomas arise most commonly on the limbs, whereas in men, melanomas arise most commonly on the trunk and head and neck. In both sexes, there has been a steady increase in melanomas on the head and neck with increasing age.

Researchers found that in virtually all investigated populations, women experience higher rates of melanoma than men in early life (up to age ~45 years), but men develop melanomas at higher rates than women later in life (from ages ≥ 65 years). Furthermore, these sex-specific trends reflect complex patterns of incidence across body sites that vary consistently with age. Thus, in early life, women experience higher rates of lower limb melanomas than men, which persists into older ages. Also, on the upper limbs, women experience substantially higher rates than men from young ages until middle age (45–64 years), after which men experience higher rates. In contrast, on the head and neck and the trunk, melanomas occur at higher incidence in men than in women early in life. On all body sites, the rate at which melanoma incidence rises with age is much more rapid for men than for women.

The study confirms that men and women experience melanoma in different ways. While this is most likely driven by different patterns of sun exposure between men and women, there appear to be inherent differences in the ways in which melanomas develop at different body sites in women compared with men. Understanding the underlying biological differences could provide important clues about the etiology of this enigmatic cancer.

Source: Elsevier

Categories : Cardiovascular Disease Environmental EffectsTags :

Benefits of UV Exposure may Outweigh Risks in Low-sunlight Countries

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Photo by Julian Jagtenberg on Pexels

The health benefits of spending time in the sun could outweigh the risks for those living in areas with limited sunshine, a UK study suggests. In low-sunlight locations such as parts of the UK, exposure to higher levels of ultraviolet (UV) radiation was linked to a drop in deaths due to cardiovascular disease and cancer.

Adapting public health advice to reflect both the risks and benefits of UV exposure may help to reduce disease burden and improve life expectancy in low-sunlight countries, the research team says.

Experts caution that measures should still be taken to protect the skin when UV levels are high, to prevent sunburn and the development of skin cancer.

Volunteer data

University of Edinburgh scientists used genetic and health information from the UK BioBank – an anonymised database of health details from volunteers – to examine the UV exposure of 395 000 people across the UK. Participants were restricted to those of white European descent, due to the role skin pigmentation plays in the body’s response to UV exposure.

The team applied two measures to identify those exposed to higher levels of UV. They used the geographical location of participants to calculate their average annual exposure to solar energy and, separately, whether they used sunbeds.

The findings were adjusted for other factors that might influence health – including smoking, exercise, social deprivation and gender – to reduce the chance that these factors were responsible for any of the changes observed.

Health impact

Living in locations with higher UV levels, for example Cornwall, was associated with a lower risk of death from cardiovascular disease and cancer – 19% and 12%, respectively – than living in areas with lower UV levels, such as Edinburgh or Glasgow.

Sunbed use was linked to a 23% lower risk of death from cardiovascular disease and a 14% lower risk of death from cancer, compared to non-users. It is possible that people who use sunbeds may also seek out greater sun exposure and so this result may reflect broader sun seeking behaviour, the team says.

Those with a higher estimated UV exposure had a slightly increased risk of being diagnosed with melanoma, but their risk of dying from the condition was not raised.

As the study is based on UK data from a white European population, the findings are of most relevance to similar groups in low-sunlight countries. Further research into locations with higher UV exposure is needed to build a clearer picture of the potential benefits to health, experts say.

The study, funded by Health Data Research UK, is published in the journal Health and Place.

Our paper adds to a growing body of evidence suggesting that in lower light environments, relatively higher exposure to UV is good for your health. Though there may be an increased risk of skin cancer incidence with higher UV exposure, this risk appears to be outweighed by a larger reduction in the risk of death from cancer and cardiovascular related disease.

Professor Chris Dibben, University of Edinburgh’s School of GeoSciences

Dermatologists have traditionally only considered possible harm to the skin caused by sunlight, much of which dates from the experience of white-skinned individuals in sunny countries such as Australia. When the UV index is very high, protecting skin is important.

However, this research shows that in the UK, the balance of benefit and risk from sunlight exposure is probably very different from that in sunnier countries.

Professor Richard Weller, University of Edinburgh’s Centre for Inflammation Research

Source: The University of Edinburgh

Categories : CancerTags :

Unique Genetic Pattern can Predict Severe Side Effects of Melanoma Immunotherapy

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Melanoma Cells. Credit: National Cancer Institute

An activity pattern in certain genes responsible for building proteins known as spleen tyrosine kinases can predict which melanoma patients are likely to have severe side effects from immunotherapy designed to treat the most deadly skin cancer, as shown by a new study published in the journal Clinical Cancer Research.

Led by researchers at NYU Langone Health and its Perlmutter Cancer Center, the latest experiments focused on checkpoint inhibitors, drugs that have in the last decade become a mainstay of treating melanoma. This form of skin cancer kills nearly 10 000 Americans annually.

The drugs work by blocking molecules (checkpoints) that sit on the surface of immune T which the immune system uses to recognise and protect healthy cells. Cancer cells are able to hijack and turn off immune cell surveillance, evading detection. Immunotherapy drugs like nivolumab and ipilimumab are designed to block checkpoints, making cancer cells more “visible” again to T cells.

More than a third of melanoma patients given checkpoint inhibitors develop side effects so severe that they compromise their quality of life and ability to continue therapy. Side effects most often involve some form of inflammation, a sign of an overactive immune response. Patients may experience severe skin rashes, diarrhoea, or hyperthyroidism. More-severe side effects can include liver toxicity, colitis, and rheumatoid arthritis.

In the new study researchers found that even before treatment began in their test subjects, the activity of genes controlling the production of spleen tyrosine kinases predicted 83% of melanoma patients who eventually developed severe side effects from combined immunotherapy with nivolumab and ipilimumab.

Moreover, the researchers found that this heightened gene signature, as evidenced by the production of spleen tyrosine kinases, or the SYK pathway, did not interfere with the effectiveness of therapies in preventing recurrence of melanoma. The impact was connected only to side effects.

“Predictive information of this kind is critically important to oncologists and patients to help guide their immunotherapy decisions, to either minimize these side effects by taking additional precautions or to choose alternative immunotherapies,” said study co-senior investigator Tomas Kirchhoff, PhD.

“Our study results show that increased gene activity in the spleen tyrosine kinase pathway could be the basis of a possible blood test that identifies those melanoma patients most susceptible to having severe side effects from immunotherapy, and well before they start treatment,” said study co-lead investigator Kelsey Monson, PhD. 

For the study, researchers analysed immune system cell samples from 212 men and women with melanoma participating in the CheckMate-915 trial. The trial was designed to test whether combined therapy with nivolumab and ipilimumab worked better than single therapy with nivolumab in preventing postsurgical recurrence of melanoma. All immune cell samples were taken prior to the start of immunotherapy. Both drugs are manufactured by the pharmaceutical company Bristol Myers Squibb, which sponsored the CheckMate-915 trial, and provided the patient specimens and data used in the analysis.

When researchers looked at what genes were more active than others in patients who experienced side effects from their immunotherapy, they found a specific pattern among 24 genes tied to the production of spleen tyrosine kinases. Further statistical analyses showed that increased or decreased activity (transcription) of only five of these genes – CD22, PAG1, CD33, HNRNPU, and FCGR2C – along with patients’ age and the stage severity of their melanoma served as the best predictors of who would experience side effects from immunotherapy.

Study co-senior investigator Jeffrey S. Weber, MD, PhD, says that the SYK pathway has previously been linked to other autoimmune diseases, including lupus, rheumatoid arthritis, and colitis. He also points out that immunotherapy side effects were also most common in areas affected by these autoimmune diseases, including the skin, colon, and liver.

Dr Weber says the team next plans to investigate if an activated SYK pathway is predictive of side effects in patients treated with ipilimumab alone or with other combination immunotherapies.

“If our future research can explain how an activated spleen tyrosine kinase pathway leads to increased risk of side effects from immunotherapy, then it could also potentially help us to design better cancer immunotherapies and potentially other treatments for autoimmune diseases,” said Dr Kirchhoff.

Source: NYU Langone Health / NYU Grossman School of Medicine

Categories : CancerTags :

Malignant Melanoma Resists Treatment by Subverting Immune Cells

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

Malignant melanoma is one of the most aggressive types of cancer. Despite recent progress in effective therapies, the tumours of many patients are either resistant from the outset or become so during the course of treatment.

A University of Zurich (UZH) study published in Cell Reports Medicine has now identified a mechanism involving subverted immune cells that impedes the effectiveness of therapies. The result provides new ideas for treatments to suppress the development of resistance.

Comparing resistant and non-resistant tumour cells

For the study, the team utilised an innovative fine-needle biopsy to sample tumour cells before and during therapy. This allowed the researchers to analyse each cell individually. The patients providing the samples were undergoing targeted cancer therapy for malignant melanoma, which inhibits signalling pathways for tumour formation.

“It was important that some of the tumours responded to the therapy, while others showed resistance,” says study leader Lukas Sommer, professor of stem cell biology at the Institute of Anatomy at UZH. This allowed the team to compare the metabolism and environment of resistant and non-resistant tumour cells and look for significant differences.

Interaction between tumour factor and immune cells

One of the most relevant findings concerned the POSTN gene: it codes for a secreted factor that plays an important role in resistant tumours. In fact, the tumours of patients with rapidly progressing disease despite treatment showed increased POSTN levels. In addition, the microenvironment of these tumours contained a larger number of a certain type of macrophage – a subtype of immune cell that promotes the development of cancer.

Through a series of further experiments – both with human cancer cells and with mice – the research team was able to show how the interaction of increased POSTN levels and this type of macrophage triggers resistance: the POSTN factor binds to receptors on the surface of the macrophages and polarises them to protect melanoma cells from cell death. “This is why the targeted therapy no longer works,” says Sommer.

No resistance without cancer-promoting macrophages

The team considers this mechanism a promising starting point. “The study highlights the potential of targeting specific types of macrophages within the tumour microenvironment to overcome resistance,” says Sommer. “In combination with already known therapies, this could significantly improve the success of treatment for patients with malignant melanoma.”

Source: University of Zurich

Categories : Cancer DermatologyTags :

Among Black Men, Study Finds Increased Mortality from Melanoma Diagnoses

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Photo by Nsey Benajah on Unsplash

Melanoma is often detected later in people with darker skin complexions – and the consequences can be devastating, according to the results of a Mayo Clinic study published in the Journal of Surgical Oncology.

While melanoma may be found less frequently in people with darker complexions than fair ones, this aggressive form of skin cancer, accounting for 75% of all skin-cancer-related deaths, can strike anyone. The study, which consisted of 492 597 patients with melanoma, suggests that added vigilance in early screening is particularly needed for Black men, whose cancers are often found at later stages, leading to worse outcomes compared to white patients or Black women.

“We compared non-Hispanic Black patients to white patients and saw striking differences in how patients presented with the disease,” says surgical oncologist Tina Hieken, MD, senior author of the study and a researcher at Mayo Clinic Comprehensive Cancer Center. “We saw more extremity melanoma, and more later-stage disease.”

Extremity melanoma refers to skin cancer that can develop on the arms, legs, hands and feet. Various factors, including social risk factors and biological components, could be at play, but further research is needed to help determine why these differences exist.

Revealing differences in sex-based immune response

The research found that Black female patients with melanoma fared better than Black male patients. Men tended to be older at diagnosis and more likely to have cancer that had spread to their lymph nodes compared to women. This translated to worse survival rates: the five-year survival for Black men with stage 3 melanoma was only 42% chance, compared to 71% for Black women.

Most research on melanoma hasn’t focused on how race and sex affect outcomes and hasn’t looked at the influence of race and ethnicity across all groups. Dr Hieken says the study highlights the need to understand these differences better, noting that this is the first large study to confirm that sex-based differences in melanoma outcomes exist within the non-Hispanic Black population.

“When we talk about later-stage melanoma patients who are female versus male in that non-Hispanic Black patient cohort who ended up doing worse, some biological things may be going on here that are interesting,” says Dr Hieken.

One theory centres on variations in immune response.

“Several immune signals suggest that women may respond better to some immunotherapies than males,” says Dr Hieken.

Researchers note that more studies focused on melanoma in a broader range of people, including more Black participants in clinical trials, is key to bridging this knowledge gap and potentially identifying more effective treatments.

Healthcare professionals should screen carefully

Dr Hieken notes that this study is a wake-up call for everyone battling to diagnose and cure melanoma, regardless of the patient’s sex or skin tone.

She emphasises that healthcare professionals should carefully examine areas like palms, soles and under fingernails, where melanoma might be more challenging to spot on darker skin.

“We can incorporate screening for skin lesions or lesions under the nails into the visit for patients as part of their regular checkups,” says Dr Hieken. “What we want to do is elevate care for our patients.”

Source: Mayo Clinic

Categories : Cancer IT in HealthcareTags :

AI-based App can Help Physicians Diagnose Melanomas

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

A mobile app that uses artificial intelligence, AI, to analyse images of suspected skin lesions can diagnose melanoma with very high precision. This is shown in a study led from Linköping University in Sweden where the app has been tested in primary care. The results have been published in the British Journal of Dermatology.

“Our study is the first in the world to test an AI-based mobile app for melanoma in primary care in this way. A great many studies have been done on previously collected images of skin lesions and those studies relatively agree that AI is good at distinguishing dangerous from harmless ones. We were quite surprised by the fact that no one had done a study on primary care patients,” says Magnus Falk, senior associate professor at the Department of Health, Medicine and Caring Sciences at Linköping University, specialist in general practice at Region Östergötland, who led the current study.

Melanoma can be difficult to differentiate from other skin changes, even for experienced physicians. However, it is important to detect melanoma as early as possible, as it is a serious type of skin cancer.

There is currently no established AI-based support for assessing skin lesions in Swedish healthcare.

“Primary care physicians encounter many skin lesions every day and with limited resources need to make decisions about treatment in cases of suspected skin melanoma. This often results in an abundance of referrals to specialists or the removal of skin lesions, which in the majority of cases turn out to be harmless. We wanted to see if the AI support tool in the app could perform better than primary care physicians when it comes to identifying pigmented skin lesions as dangerous or not, in comparison with the final diagnosis,” says Panos Papachristou, researcher affiliated with Karolinska Institutet and specialist in general practice, main author of the study and co-founder of the company that developed the app.

And the results are promising.

“First of all, the app missed no melanoma. This disease is so dangerous that it’s essential not to miss it. But it’s almost equally important that the AI decision support tool could acquit many suspected skin lesions and determine that they were harmless,” says Magnus Falk.

In the study, primary care physicians followed the usual procedure for diagnosing suspected skin tumours. If the physicians suspected melanoma, they either referred the patient to a dermatologist for diagnosis, or the skin lesion was cut away for tissue analysis and diagnosis.

Only after the physician decided how to handle the suspected melanoma did they use the AI-based app. This involves the physician taking a picture of the skin lesion with a mobile phone equipped with an enlargement lens called a dermatoscope. The app analyses the image and provides guidance on whether or not the skin lesion appears to be melanoma.

To find out how well the AI-based app worked as a decision support tool, the researchers compared the app’s response to the diagnoses made by the regular diagnostic procedure.

Of the more than 250 skin lesions examined, physicians found 11 melanomas and 10 precursors of cancer, known as in situ melanoma. The app found all the melanomas, and missed only one precursor. In cases where the app responded that a suspected lesion was not a melanoma, including in situ melanoma, there was a 99.5% probability that this was correct.

“It seems that this method could be useful. But in this study, physicians weren’t allowed to let their decision be influenced by the app’s response, so we don’t know what happens in practice if you use an AI-based decision support tool. So even if this is a very positive result, there is uncertainty and we need to continue to evaluate the usefulness of this tool with scientific studies,” says Magnus Falk.

The researchers now plan to proceed with a large follow-up primary care study in several countries, where use of the app as an active decision support tool will be compared to not using it at all.

Source: Linköping University

Categories : Cancer Lab Tests and ImagingTags :

Terahertz Biosensor can Accurately Detect Skin Cancer

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

Researchers have developed a revolutionary biosensor using terahertz (THz) waves that can detect skin cancer with exceptional sensitivity, potentially paving the way for earlier and easier diagnoses. Published in the journal IEEE Transactions on Biomedical Engineering, the study presents a significant advancement in early cancer detection, thanks to a multidisciplinary collaboration of teams from Queen Mary University of London and the University of Glasgow.

“Traditional methods for detecting skin cancer often involve expensive, time-consuming, CT, PET scans and invasive higher frequencies technologies,” explains Dr Shohreh Nourinovin, Postdoctoral Research Associate at Queen Mary’s School of Electronic Engineering and Computer Science, and the study’s first author.

“Our biosensor offers a non-invasive and highly efficient solution, leveraging the unique properties of THz waves – a type of radiation with lower energy than X-rays, thus safe for humans – to detect subtle changes in cell characteristics.”

The key innovation lies in the biosensor’s design. Featuring tiny, asymmetric resonators on a flexible substrate, it can detect subtle changes in the properties of cells.

Unlike traditional methods that rely solely on refractive index, this device analyses a combination of parameters, including resonance frequency, transmission magnitude, and a value called “Full Width at Half Maximum” (FWHM). This comprehensive approach provides a richer picture of the tissue, allowing for more accurate differentiation between healthy and cancerous cells and to measure malignancy degree of the tissue.

In tests, the biosensor successfully differentiated between normal skin cells and basal cell carcinoma (BCC) cells, even at different concentrations. This ability to detect early-stage cancer holds immense potential for improving patient outcomes.

“The implications of this study extend far beyond skin cancer detection,” says Dr Nourinovin.

“This technology could be used for early detection of various cancers and other diseases, like Alzheimer’s, with potential applications in resource-limited settings due to its portability and affordability.”

Dr Nourinovin’s research journey wasn’t without its challenges.

Initially focusing on THz spectroscopy for cancer analysis, her project was temporarily halted due to the COVID pandemic. However, this setback led her to explore the potential of THz metasurfaces, a novel approach that sparked a new chapter in her research.

Source: Queen Mary University of London

Categories : CancerTags :

Scientists Find a Protein That Keeps Melanoma Hidden from the Immune System

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

New research has helped explain how melanoma evades the immune system and may guide the discovery of future therapies for the disease. The study found that a protein known to be active in immune cells is also active inside melanoma cells, helping promote tumour growth. The findings, published in the journal Science Advances, suggest that targeting this protein with new drugs may deliver a powerful double hit to melanoma tumours.

“The immune system’s control of a tumour is influenced by both internal factors within tumour cells, as well as factors from the tumour’s surroundings,” says first author Hyungsoo Kim, PhD, a research assistant professor at Sanford Burnham Prebys in the lab of senior author Ze’ev Ronai, PhD. “We found that the protein we’re studying is involved in both, which makes it an ideal target for new cancer therapies.”

“Immunotherapy is the first-line therapy for several cancers now, but the success of immunotherapy is limited because many cancers either don’t respond to it or become resistant over time,” says Kim. “An important goal remains to improve the effectiveness of immunotherapy.”

To find ways to boost immunotherapy in melanoma, the research team analysed data from patient tumours to identify genes that may coincide with patients’ responsiveness to immunotherapy. This led to the identification of a protein that helps tumours evade the immune system – called NR2F6 – which was found not only in tumour cells, but also in the surrounding noncancerous cells.

“Often we find that a protein has the opposite effect outside of tumours compared to what it does within a tumour, which is less effective for therapy,” says Kim. “In the case of NR2F6, we found that it elicits the same change in the tumour and in its surrounding tissues, pointing to a synergistic effect. This means that treatments that block this protein’s activity could be twice as effective.”

In a mouse model, the researchers then deleted the NR2F6 protein in both melanoma tumours and in the tumours’ environment. This inhibited melanoma growth more strongly, compared to when this effect occurs in either the tumour or its microenvironment alone. The cancer’s response to immunotherapy was also enhanced upon loss of NR2F6 in both tumours and their microenvironment.

“This tells us that NR2F6 helps melanoma evade the immune system, and without it, the immune system can more readily suppress tumour growth,” adds Kim.

To help advance their discovery further, the team is working with the Institute’s Conrad Prebys Center for Chemical Genomics to identify new drugs that can target NR2F6.

“Discovering drugs that can target this protein are expected to offer a new way to treat melanomas, and possibly other tumours, that would otherwise resist immunotherapy,” says Kim.

Source: Sanford Burnham Prebys

Categories : CancerTags :

Faecal Microbiota Transplants Could Boost Melanoma Immunotherapy

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

In a world-first clinical trial published in the journal Nature Medicine, a multi-centre study has found faecal microbiota transplants (FMT) from healthy donors are safe and show promise in improving response to immunotherapy in patients with advanced melanoma.

While immunotherapy drugs can significantly improve survival outcomes in those with melanoma, they are only effective in 40–50% of patients. Preliminary research has suggested that the human microbiome may play a role in whether or not a patient responds.

“In this study, we aimed to improve melanoma patients’ response to immunotherapy by improving the health of their microbiome through faecal transplants,” says Dr John Lenehan, Medical Oncologist at London Health Sciences Centre’s (LHSC).

A faecal transplant involves collecting stool from a healthy donor, screening and preparing it in a lab, and transplanting it to the patient. The goal is to transplant the donor’s microbiome so that healthy bacteria will prosper in the patient’s gut.

“The connection between the microbiome, the immune system and cancer treatment is a growing field in science,” explains Dr Saman Maleki, senior investigator on the study. “This study aimed to harness microbes to improve outcomes for patients with melanoma.”

The phase I trial included 20 melanoma patients recruited from LHSC, CHUM and Jewish General Hospital. Patients were administered approximately 40 faecal transplant capsules orally during a single session, one week before they started immunotherapy treatment.

The trial found that combining faecal transplants with immunotherapy is safe for patients. The study also found 65% of patients who retained the donors’ microbiome had a clinical response to the combination treatment. Five patients experienced adverse events sometimes associated with immunotherapy and had their treatment discontinued.

“We have reached a plateau in treating melanoma with immunotherapy, but the microbiome has the potential to be a paradigm shift,” says oncologist Dr Bertrand Routy.

The study is unique due to its administration of faecal transplants (from healthy donors) in capsule form to cancer patients – a technique pioneered in London by Dr Michael Silverman.

“Our group has been doing faecal transplants for 20 years, initially finding success treating C. difficile infections. This has enabled us to refine our methods and provide an exceptionally high rate of the donor microbes surviving in the recipient’s gut with just a single dose,” says Dr Silverman. “Our data suggests at least some of the success we are seeing in melanoma patients is related to the efficacy of the capsules.”

The team has already started a larger phase II trial involving centres in Ontario and Quebec.

Source: Lawson Health Research Institute

Categories : Cancer Immune SystemTags :

Researchers Discover an Anti-tumour Regulator on B Cells

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Melanoma Cells. Credit: National Cancer Institute

B cells are thought to play a critical role in innate and adaptive immunity, but their exact role in anti-tumour immunity remains unknown. Looking at B cells with a technique called single-cell profiling, which looks at all the genes in the cell, researchers found a protein that – when deleted – reduced tumour growth. The researchers write in Nature that this regulator could be a target for new cancer treatments.

The team, consisting of immunologists at Brigham and Women’s Hospital and dermatologists from Massachusetts General Hospital, identified a subset of B cells that expands specifically in the draining lymph node over time in mice with melanoma tumours.

They found a cell surface receptor called TIM-1 expressed on these B cells during melanoma growth. They also characterised multiple accompanying cell surface proteins that were involved in the B cell’s immune function. Interestingly, they found that deleting a molecule TIM-1, but not any of the other accompanying proteins, dramatically decreased tumour growth. The researchers concluded that TIM-1 controls B cell activation and immune response that combats cancer, including activating another type of the killer tumour-specific T cells for inhibiting tumour growth.

“The collaboration across institutions was extremely fruitful as we combined our immunology expertise at the Brigham with work at David Fisher’s MGH laboratory where seminal discoveries in skin malignancies have been made,” said lead author Lloyd Bod, PhD, of the Department of Neurology at the Brigham, who conducted this work while completing his postdoctoral fellowship at the Brigham. “The collaboration allowed us to test and demonstrate the therapeutic potential of targeting TIM-1 in melanoma models.”

Source: Mass General Brigham