Two pathways can activate IL-2 receptor signaling in HPV-associated cancer.

2004 DEC 2 - (NewsRx.com & NewsRx.net) -- According to a study from Mexico, "Activation of the interleukin-2 receptor (IL-2R) induces signaling cascades promoting T-cell proliferation. However, signal transduction pathways triggered in IL-2R-expressing solid tumors are unknown.

"This report shows that human papillomavirus (HPV)-associated cervical cancer cells express an IL-2R composed of beta and gamma chains (IL-2Rbetagamma), and that IL-2-mediated activation increases the phosphorylation of JAK3 and STAT5, stimulating cell proliferation," wrote L. Rocha-Zavaleta and colleagues.

The researchers noted, "Interestingly, endogenous IL-2 is not produced by these cells, suggesting the activation of IL-2R by an alternative mechanism.

"Accordingly, we found that stem cell factor (SCF)-activated c-Kit induces phosphorylation of the IL-2Rbeta chain in the absence of IL-2.

"Moreover," they continued, "inhibition of IL-2R phosphorylation by blocking c-Kit tyrosine kinase activity abolishes both IL-2 and SCF-mediated proliferation."

Rocha-Zavaleta and colleagues wrote, "Thus, these results demonstrate that IL-2 triggers a JAK3/STAT5 cascade ...