Evidence that cervical cancer cells secrete IL-2, which becomes an autocrine growth factor.
We present evidence that cervical cancer cells express a functional IL-2 receptor (IL-2R). In fact, by RT-PCR we obtained that the IL-2R is present in CALO, and INBL cells, and that it consisted of the alphaIL-2R, betaIL-2R, and gammaIL-2R chains. We also found that IL-2 is a growth factor for these cell lines, and unexpectedly that CALO and INBL themselves being cancer cells produce, and secrete IL-2. Antibodies against the alpha and beta subunits of the IL-2R inhibited cell proliferation thus hinting to a cell growth dependency on this factor. Our results thus provide evidence that the IL-2R on cervical cancer cells is part of an autocrine mechanism for its growth to the extent that, like lymphocytes, they produce and become partially dependent on this growth factor. We think that in view of our results caution should be taken when IL-2 is being considered for cancer therapy; in particular when the patient's cancer cells present the IL-2R, because as indicated by our results, the use of this factor could promote tumor growth. Finally, the possible implications of the expression of both IL-2, and IL-2R on cervical cancer cells on the immune escape mechanism of tumor cells are discussed.
Laboratory of Cellular Oncology, Research Unit Cell Differentiation and Cancer, L-4 P.B. UMIE-Z, Facultad de Estudios Superiores Zaragoza, UNAM, Iztapalapa México City. Av., Guelatao No. 66 Col. Ejército de Oriente, Iztapalapa, C.P. 09230 México D.F., Mexico. rancor@servidor.unam.mx
R
R
Rangel-Corona
T
T
Corona-Ortega
I
I
Soto-Cruz
A
A
López-Labra
T
T
Pablo-Arcos
C F
CF
Torres-Guarneros
B
B
Weiss-Steider
D000912:Antibodies, Neoplasm / Q000276:immunology; D019898:Autocrine Communication / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
D000912:Antibodies, Neoplasm; C508594:IL2 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D007376:Interleukin-2; D015375:Receptors, Interleukin-2