Ammonium trichloro(dioxoethylene-o,o')tellurate (AS101) sensitizes tumors to chemotherapy by inhibiting the tumor interleukin 10 autocrine loop.

Cancer cells of different solid and hematopoietic tumors express growth factors in respective stages of tumor progression, which by autocrine and paracrine effects enable them to grow autonomously. Here we show that the murine B16 melanoma cell line and two human primary cultures of stomach adenocarcinoma and glioblastoma multiforme (GBM) constitutively secrete interleukin (IL)-10 in an autocrine/paracrine manner. This cytokine is essential for tumor cell proliferation because its neutralization decreases clonogenicity of malignant cells, whereas addition of recombinant IL-10 increases cell proliferation.