A recent study published in the scientific journal Nature has found a link between the loss of Y chromosomes in aging men and the body’s ability to fight bladder cancer. Researchers from Cedars-Sinai Medical Center discovered that the loss of the Y chromosome allows bladder cancer cells to evade the immune system and grow aggressively.
In normal human cells, each cell typically has a pair of sex chromosomes, with men having one X and one Y chromosome, while women have two X chromosomes. The loss of the Y chromosome has been observed in various cancer types, including 10 to 40 percent of bladder cancers. It has also been associated with heart disease and Alzheimer’s disease.
The Y chromosome contains specific genes that play a role in normal cell functioning. Based on the expression of these genes in the bladder lining, the researchers developed a scoring system to measure the loss of the Y chromosome in cancer cells.
The study involved analyzing data from two groups of men: one group had muscle invasive bladder cancer and underwent bladder removal without immune checkpoint inhibitor treatment, while the other group participated in a clinical trial and received immune checkpoint inhibitor treatment. The results showed that patients with loss of the Y chromosome had a poorer prognosis in the first group but had better overall survival rates in the latter group.
To investigate further, the researchers conducted experiments using cancer cells grown in a dish and in mice lacking T-cells, a type of immune cell. In both cases, tumors with and without the Y chromosome grew at the same rate. However, in mice with intact immune systems, tumors lacking the Y chromosome grew much faster than those with the intact Y chromosome.
The findings suggest that the loss of the Y chromosome leads to the depletion of T-cells, which are crucial for fighting cancer. Without T-cells, the tumor is able to grow aggressively. This study provides a new understanding of the connection between the loss of the Y chromosome and the immune system’s response to bladder cancer.