Hydra Study Unveils Secrets of Transmissible Cancers: Environmental Factors Key

Hydra Study Reveals New Insights into Transmissible Cancers

A groundbreaking study on jellyfish-like creatures called hydras has shed new light on the development and transmission of tumors, potentially improving our understanding of transmissible forms of cancer. The research, published in Proceedings of the Royal Society B, presents the first experimental observation of the evolution of a transmissible tumor.

Sophie Tissot and her team from the French National Centre for Scientific Research (CNRS) conducted the study using Hydra oligactis, a species related to jellyfish and sea anemones. These creatures, which reproduce asexually by cloning, can form tumors under laboratory conditions, making them valuable subjects for cancer research.

The experiment involved collecting 50 hydras from Montaud Lake in France and setting them up in a laboratory environment. To ensure a high tumor development rate, some hydras were overfed with brine shrimp larvae. Nineteen overfed hydras that developed tumors were selected, and their buds were collected and grown through five generations of clonal offspring.

The researchers found that hydras from parents with tumors were more likely to develop tumors themselves compared to those from tumor-free parents. This discovery suggests that tumors can be induced in H. oligactis and that transmission rates can increase over time.

Interestingly, the fifth generation of hydras with transmissible tumors showed changes in life history traits. The study observed increased investment in asexual reproduction before tumor development and higher bud mortality after tumor appearance, indicating an adjustment in life-history traits.

While tumors are a risk associated with being multicellular, few examples of cancer can be passed between individuals. Known examples include two affecting the Tasmanian devil, one in dogs, and eleven in bivalves. Understanding contagious cancers is crucial to avoid their occurrence in humans and protect other species.

The study’s findings suggest that the scarcity of transmissible cancers may be due to the lack of suitable environmental conditions. Human activities could potentially modify conditions that favor the spread of transmissible cancers, emphasizing the importance of considering environmental factors in cancer research.

This research provides valuable insights into the origins and transmission of contagious cancers, offering a new perspective on a complex and potentially dangerous phenomenon in multicellular organisms.