The HPV16 Oncogenes Cause Aberrant Stem Cell Mobilization

In the 2013 study, researchers used transgenic mice to investigate the impact of HPV16 E6 and E7 oncogenes on epithelial stem cells in the hair follicle bulge. They discovered that while the total number of stem cells remained unchanged, their quiescence was disrupted, as shown by a decrease in label-retaining cells (LRCs) during the resting phase of the hair cycle. Upon induction of the growth phase, there was an increased mobilization and proliferation of these stem cells in the presence of the oncogenes. The study also revealed that the expression of stem cell markers like K15 was not reduced, suggesting that the decrease in LRCs was due to an aberrant expansion of the stem cell compartment rather than a loss of stem cells. The Nfatc1 pathway, which is linked to stem cell quiescence, was found to be disturbed by the expression of the oncogenes. These findings indicate that HPV16 oncogenes can alter the behavior of tissue stem cells, which may influence infection outcomes and contribute to the development of cancer. The study involved at least 3 mice per genotype and analyzed approximately 50 hair follicles from each mouse.