The testicular stem cells are more sensitive to chemotherapy than other cells in a tumour, which explains why there is the complete recovery of testicular cancer with conventional therapy even after it has spread to lungs and brain. A new study published in the recent issue of the journal Cell Reports shows that testicular cancer cells are more responsive to chemotherapy. The similar effectiveness observed with testicular cancer even after it metastasizes.

The group's study, published in the journal Cell Reports, also helped confirm that risk for testicular cancer is determined in utero. The research offers some evidence to support a hypothesis that, in humans, testicular cancers are initiated during embryonic development and lay dormant for 18 to 35 years.

Robert Weiss, professor of biomedical sciences at Cornell's College of Veterinary Medicine, said, "The study provides new insights into the basis for the responsiveness of testicular cancer to chemotherapy, which has always been an intriguing observation, but the basis for it was not clear."

Majority of the cancer types carry distinct populations of cells. Among, stem cells are in small fractions, and those cells could develop new tumors from a single cell, and sometimes they are highly resistant to therapy.

The research team led by Weiss used an engineered mouse model that could accurately mimic the properties of human testicular cancers. The mice could develop cancers with the strong expression of stem cell markers. The engineered mouse model could demonstrate realistic cancer traits, such as the rate of tumor growth and the ability to give rise to several different tumor cell types.

Testicular cancer mainly affects young men between the ages of 18 and 40 years old. The researcher found that germ cells become vulnerable to developing into testicular cancer only during a restricted period of embryonic development. As they age, they become resistant to transformation.

The study also reported that genetic risk factors could transform embryonic germ cells to the tumor, but when adult germ cells are exposed to the same conditions; those cells die instead of giving rise to cancer cells. The study findings align well with human epidemiological data and raise some intriguing questions about what makes embryonic germ cells susceptible to developing into cancer and how adult germ cells could tackle those challenges, Weiss noted.

If the researchers succeed to find the testicular cancer stem cells characteristic that makes the cells more sensitive to chemotherapy and compare those features in other cancer types, could lead to the development of advanced treatment, Weiss concluded.