In Cancer Research this week, an international team of researchers says there is a paradoxical relationship between chromosomal instability and survival outcomes in cancer. Chromosomal instability is associated with poor prognosis in patients with cancer, but in certain animal models, the instability negatively impacts on the fitness of the organism, and therefore is "poorly tolerated" by cancer cells, the authors write. Tumors with extreme chromosomal instability — predominantly estrogen receptor-negative tumors — were associated with improved prognosis as compared to tumors with intermediate instability, the team found. "The data are consistent with the intolerance of excessive chromosomal instability in carcinomas and provide a plausible strategy to define distinct prognostic patient cohorts with ER-negative breast cancer. Inclusion of a surrogate measurement of CIN may improve cancer risk stratification and future therapeutic approaches," the researchers add.
Also in Cancer Research this week, researchers in the US and Europe say growth in human gliomas is controlled by microRNA-10b. Inhibition of miR-10b — which is not expressed in the human brain, and has been found to be strongly upregulated in both low- and high-grade brain cancers — reduces glioma cell growth by arresting the cell cycle and inducing apoptosis, the authors write. By analyzing expression data from The Cancer Genome Atlas, the team found a strong positive correlation between several genes that sustain cellular growth and levels of miR-10b in human glioblastomas. "Furthermore, survival of glioblastoma patients expressing high levels of miR-10 family members is significantly reduced in comparison to patients with low miR-10 levels, indicating that miR-10 may contribute to glioma growth in vivo," the team adds, suggesting a possible use for the miRNA as a therapeutic target in gliomas.
And finally in Cancer Research this week, researchers in Japan explore the effects of a carbon ion beam on putative colon cancer stem cells. Although carbon ion therapy is expensive, the effects may be better against cancer than a photon beam, the authors say. They compared the effects of a carbon ion beam versus X-rays on human colon cancer cells in vivo and in vitro, and found that cancer stem cells were "more highly enriched" after irradiation with X-rays than with carbon ion. "Taken together, carbon ion beam therapy may have an advantage over photon beam therapy by improved targeting of putative colon cancer stem–like cells," the team adds.