<p>Hard, oxygen-poor tumours trigger a biological switch that causes cancer stem cells to invade other tissues, and could offer a promising treatment target to stop the disease from spreading, scientists have found.<br /><br /></p>.<p>Scientists from Princeton University and the Mayo Clinic Cancer Centre in the US suggests that the biological switch is critical to a tumour's ability to invade other tissue, a process called metastasis.<br /><br />"Our study suggests that to combat cancer, we should be developing treatments that target the stiff, hypoxic regions of tumours," said lead author Celeste Nelson, professor at Princeton.<br />"We were surprised to see just how important these two properties in the tumour microenvironment - stiffness and hypoxia - were for regulating cancer stem cells," Nelson said.<br /><br />The specific cells triggered by stiffness and hypoxia are called cancer stem cells. These cells represent only a small proportion of the total cells in a tumour, but researchers believe they play a key role in spreading the disease.<br /><br />As normal stem cells help form an embryo, or aid in repairing muscles, cancer stem cells specialise in generating new malignant cells.<br /><br />In addition to spreading cancer, just 10 to 100 leftover cancer stem cells are needed to regenerate a tumour after it has been removed.<br /><br />Using cultures of human breast-cancer cells and mouse mammary-cancer cells, researchers discovered an association between a protein called integrin-linked kinase and the creation of cancer stem cells.<br /><br />Normally, integrin-linked kinase assists cells with a variety of important cellular tasks. But in dense, oxygen-poor tumours, the protein's function goes awry.<br /><br />Researchers created a range of human and mouse breast-cancer cultures reflecting different tissue conditions.<br /><br />They showed that stiff hypoxic cultures did indeed promote cancer stem cells.<br />However, when they eliminated the integrin-linked kinase from those samples, they found that the cancer stem cells stopped forming.<br /><br />Conversely, when they forced abnormal levels of integrin-linked kinase in samples containing softer or less hypoxic tissue, cancer stem cells formed.<br /><br />They also confirmed a significant association between tumour stiffness, integrin-linked kinase and cancer stem cell presence in samples from human breast-cancer patients.<br /><br />The findings suggest that stiffness and hypoxia cause integrin-linked kinase to behave abnormally, which in turn triggers cancer stem-cell formation.<br /><br />There are likely other features in tumours that cause cancer stem cells to form, but the findings indicate that stiff, hypoxic conditions and their effects on integrin-linked kinase are two of the most prominent ones.The study appears in the journal Cancer Research</p>
<p>Hard, oxygen-poor tumours trigger a biological switch that causes cancer stem cells to invade other tissues, and could offer a promising treatment target to stop the disease from spreading, scientists have found.<br /><br /></p>.<p>Scientists from Princeton University and the Mayo Clinic Cancer Centre in the US suggests that the biological switch is critical to a tumour's ability to invade other tissue, a process called metastasis.<br /><br />"Our study suggests that to combat cancer, we should be developing treatments that target the stiff, hypoxic regions of tumours," said lead author Celeste Nelson, professor at Princeton.<br />"We were surprised to see just how important these two properties in the tumour microenvironment - stiffness and hypoxia - were for regulating cancer stem cells," Nelson said.<br /><br />The specific cells triggered by stiffness and hypoxia are called cancer stem cells. These cells represent only a small proportion of the total cells in a tumour, but researchers believe they play a key role in spreading the disease.<br /><br />As normal stem cells help form an embryo, or aid in repairing muscles, cancer stem cells specialise in generating new malignant cells.<br /><br />In addition to spreading cancer, just 10 to 100 leftover cancer stem cells are needed to regenerate a tumour after it has been removed.<br /><br />Using cultures of human breast-cancer cells and mouse mammary-cancer cells, researchers discovered an association between a protein called integrin-linked kinase and the creation of cancer stem cells.<br /><br />Normally, integrin-linked kinase assists cells with a variety of important cellular tasks. But in dense, oxygen-poor tumours, the protein's function goes awry.<br /><br />Researchers created a range of human and mouse breast-cancer cultures reflecting different tissue conditions.<br /><br />They showed that stiff hypoxic cultures did indeed promote cancer stem cells.<br />However, when they eliminated the integrin-linked kinase from those samples, they found that the cancer stem cells stopped forming.<br /><br />Conversely, when they forced abnormal levels of integrin-linked kinase in samples containing softer or less hypoxic tissue, cancer stem cells formed.<br /><br />They also confirmed a significant association between tumour stiffness, integrin-linked kinase and cancer stem cell presence in samples from human breast-cancer patients.<br /><br />The findings suggest that stiffness and hypoxia cause integrin-linked kinase to behave abnormally, which in turn triggers cancer stem-cell formation.<br /><br />There are likely other features in tumours that cause cancer stem cells to form, but the findings indicate that stiff, hypoxic conditions and their effects on integrin-linked kinase are two of the most prominent ones.The study appears in the journal Cancer Research</p>