Cell Cycle Length Identified as Key Factor in Cancer Development

Researchers at Lunenfeld-Tanenbaum Research Institute, part of Sinai Health in Toronto, have found that the likelihood of a mutation causing cancer is strongly influenced by how quickly the affected cells divide. The study, led by Rod Bremner and published in Nature, highlights cell cycle length, the time it takes for one cell to divide into two, as a critical determinant in whether a mutation will drive cancer or remain harmless.

Cancer arises when cells acquire genetic mutations that trigger uncontrolled growth and tumor formation. However, not all mutated cells become cancerous, as the body has evolved mechanisms such as apoptosis and clearance by the immune system to neutralize or eliminate potentially dangerous cells. “An average adult has millions and millions of cells which have mutations in them, yet thankfully, we don’t develop cancer all the time,” Dr. Bremner explained.

The research team, including Danian Chen, discovered that the speed of cell division is another important cancer resistance mechanism. Their findings show that mutated cells with shorter, faster cell cycles are more likely to become cancerous, while those with longer cycles are more resistant. This pattern was observed across several tissue types and cancers, including retinoblastoma, pituitary cancer, and lung cancer.

Further experiments revealed that most mutation-carrying cells eventually stop dividing and revert to a normal state. Dr. Bremner noted, “The most common way that mutated cells escape cancer is just by becoming normal cells. They divide abnormally a little bit and then they stop and look like any other normal cell.”

The team also demonstrated that slowing cell division suppresses cancer independently of other resistance mechanisms. In various tissues, cancer consistently developed in the mutated cell type that divided the fastest. These results suggest that targeting cell cycle length could offer a new strategy for cancer prevention. Dr. Bremner stated, “Our work suggests that we might be able to intervene in cancer-prone cells to slow them down a little bit with the right therapeutic agents. But first, we need to understand the mechanisms governing cell cycle rate in different cell types.”