Tag: moles

Categories : Cancer DermatologyTags :

Huge Genetic Study of ‘Moliness’ Helps Unravel Mysteries of Melanoma

On By ModernMedia
Photo by Bermix Studio on Unsplash

QIMR Berghofer scientists have uncovered hundreds of genes that play a role in the growth of both moles and melanoma, in a discovery that could lead to new ways of preventing and treating the deadliest form of skin cancer.

The world’s largest genetics study of ‘moliness’, published in Nature Communications, is unravelling the complex causes of both moles and melanomas that are not related to well-known risks caused by sun exposure, skin colour, and pigmentation.

The team found risk genes linked to biological pathways that could lead to the development of a mole or melanoma. These include an immune response pathway that may be failing to control cell growth, and genes implicated in harmful cell proliferation in other types of cancer, such as breast cancer, prostate, and brain cancers.

Working out how to stop these risk pathways could lead to new melanoma drug targets and prevention strategies that go beyond sun protection.

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Associate Professor Matthew Law, Team Head of QIMR Berghofer’s Genetics and Skin Cancer Lab, said research has made massive inroads but Australia still has the world’s highest incidence of melanoma. Around 1400 Australians lose their lives to the complex disease each year.

“We know how to reduce sun exposure and risk through SunSmart behaviours, and new immunotherapies have greatly improved survival rates. But people still get melanoma and people still die from melanoma,” A/Prof Law said.

“Existing immunotherapies fail to work for half of all patients with late-stage melanoma, so we need to find other ways to target the disease. By studying moles, we’re learning more about the biology of melanoma so we can find new ways of controlling it.”

Moles and melanomas share the same cellular origin, forming from a pigment-producing cell called a melanocyte that gives skin its colour. In moles, the cell multiplies to form a cluster then stops growing, leaving a harmless spot. In melanoma, the cell growth continues aggressively.

Moliness is strongly influenced by your genes and having a high mole count is a major risk factor for melanoma. Around a third of melanomas develop from a mole. 

The QIMR Berghofer research analysed data from more than 85000 participants of European ancestry discovering 24 new genetic regions that determine the number of moles someone has. This is a five-fold increase on the five areas found in an earlier 2018 study also led by QIMR Berghofer researchers.

All but one of the genetic regions for mole count also play a role in melanoma. The team pinpointed more than 250 key genes in these regions to prioritise for further research.

One of the new genes, SIKE1, regulates immune responses to viral infections. The researchers think it could enable the development of melanomas by malfunctioning and affecting the immune system’s ability to detect and destroy melanocytes that are multiplying abnormally. This could be a promising target for a potential immunotherapy that could possibly prevent early stage melanoma growth.

Lead author Shanika Jayasinghe from QIMR Berghofer said the study builds on decades of world-leading skin cancer research at the Institute which has been involved in every major study of the genetics of moles and melanomas from twin studies to large-scale genome-wide research.

“I’m really proud to be continuing this long legacy of research. Our study increases understanding of why some people have a lot of moles and why some people develop melanoma so we can better treat and prevent this skin cancer,” Ms Jayasinghe said.

The researchers used the study insights to create a Polygenic Risk Score (PRS) for moliness to predict those who are genetically more likely to have a large number of moles, which could be integrated into melanoma screening tools in future to improve their accuracy in finding those at high risk so they can receive extra monitoring.

The next step is to analyse even larger data sets to find more genetic regions involved in moliness and melanoma. The researchers are also searching for existing drugs that could potentially target the newly identified biological pathways.

The scientists are grateful for the contribution of the many patients who participated in the 13 studies that were analysed for this project, including QIMR Berghofer’s QSkin Sun and Health Study and the Australian Genetics of Depression Study.

The study is available in Nature Communications with DOI 10.1038/s41467-026-70368-5.

Source: QIMR Berghofer

Categories : CancerTags : 1 Comment

A New Understanding of How Moles Turn into Melanoma

On By ModernMedia
Melanoma cells. Source: National Cancer Institute.

Moles and melanomas are both skin tumours that come from melanocytes. Moles are usually harmless, while melanomas are cancerous and often deadly without treatment. A study published in eLife Magazine explains how common moles and melanomas form and why sometimes moles turn into melanoma.

Melanocytes produce melanin that protects the skin against UV radiation. Specific changes to the DNA sequence of melanocytes, called BRAF gene mutations, are found in over 75% of moles. The same change is also found in 50% of melanomas and is common in lung, colon and other cancers. It was thought that when melanocytes only have the BRAFV600E mutation the cell stops dividing, resulting in a mole. When melanocytes have other mutations with BRAFV600E, they divide uncontrollably, turning into melanoma. This model is called ‘oncogene-induced senescence’.

“A number of studies have challenged this model in recent years,” said Robert Judson-Torres, PhD, Huntsman Cancer Institute (HCI) researcher and University of Utah (U of U) assistant professor. “These studies have provided excellent data to suggest that the oncogene-induced senescence model does not explain mole formation but what they have all lacked is an alternative explanation – which has remained elusive.”

The study team took moles and melanomas donated by patients and used transcriptomic profiling and digital holographic cytometry. Transcriptomic profiling lets researchers determine molecular differences between moles and melanomas. Digital holographic cytometry helps researchers track changes in human cells.

“We discovered a new molecular mechanism that explains how moles form, how melanomas form, and why moles sometimes become melanomas,” said Prof Judson-Torres.

The study shows that additional mutations for melanocytes to turn into melanoma are not needed, but environmental signalling can be a trigger for the cells. Melanocytes express genes in different environments, instructing them to either divide uncontrollably or stop dividing altogether.

“Origins of melanoma being dependent on environmental signals gives a new outlook in prevention and treatment,” said Prof Judson-Torres. “It also plays a role in trying to combat melanoma by preventing and targeting genetic mutations. We might also be able to combat melanoma by changing the environment.”

These findings create a foundation for researching potential melanoma biomarkers, allowing doctors to spot cancerous changes in the blood sooner. The researchers are also keen to use these data to better understand potential topical agents to reduce risk melanoma risk, delay development, or stop recurrence, and to detect melanoma early.

Source: Huntsman Cancer Institute