ADELAIDE, Australia / RankWire.AI / – Researchers from Adelaide University and the Olivia Newton-John Cancer Research Institute have uncovered a new molecular mechanism that influences the progression of highly invasive tumors. Their findings, published in EMBO Molecular Medicine, reveal a novel method to combat triple-negative breast cancer by reinstating a vital regulatory molecule called miR-342. This breakthrough paves the way for new strategies to prevent life-threatening secondary malignancies in organs like the lungs and bones.
While triple-negative breast cancer makes up 10% to 15% of the approximately 21,000 breast cancer cases diagnosed annually in Australia, it is responsible for a disproportionate share of mortality. This subtype does not express estrogen, progesterone, or HER2 receptors, which makes targeted hormone therapies ineffective. The principal investigators demonstrated that a decline in miR-342 leads to the overactivation of the E2F pathway, a driver of cancer progression. This overactivity enables dormant cancer cells to disseminate and establish dangerous secondary tumors throughout the body.
Potential for Diagnostic Biomarker Testing to Guide Treatment Decisions
In pre-clinical experiments, scientists found that increasing miR-342 levels significantly curtailed metastasis to distant organs. Additionally, they observed that palbociclib, an already approved CDK4/6 inhibitor used for hormone receptor-positive breast cancers, effectively suppressed the growth of metastatic tumors in models with low miR-342 expression. These results suggest that testing miR-342 levels could enable clinicians to repurpose existing drugs to treat patients at high risk of metastasis.
Associate Professor Philip Gregory from Adelaide University’s Centre for Cancer Biology, who is a co-senior author, reaffirmed that the biggest challenge in treating aggressive breast cancers is preventing metastasis. Gregory highlighted that because palbociclib targets the hyperactive E2F pathway, giving the drug after cancer cells have spread can prevent microscopic deposits from enlarging. Instead of focusing solely on reducing primary tumor size, this treatment approach aims to stop early secondary cancers from progressing into deadly conditions.
miR-342, a Molecular Switch, Regulates Key Genes in Cancer Development
The research team emphasized that the biological heterogeneity of triple-negative breast cancer has historically impeded the development of broad-spectrum targeted therapies. By identifying a shared biological vulnerability within a specific patient subgroup, their study opens new possibilities for personalized treatment plans. As Australian scientists develop this promising new strategy, efforts are underway to validate the findings using patient-derived models before progressing to clinical trials.
The results have been well-received by medical oncologists and cancer research organizations across Australia, who recognize the critical need for alternative options when primary treatments fall short. The research team intends to partner with international clinical networks to speed up biomarker screening processes. Confirming the effectiveness of miR-342 testing could soon enable doctors to identify suitable candidates for targeted CDK4/6 inhibitor therapies early, improving intervention outcomes.