Opioid-like immunoreactants in human cervical cancer

Abstract

Cervical carcinoma cell lines produce several polypeptide hormones. While screening human cervical cancers for such factors we have found many tumors to be immunoreactive for opioid peptides. The tumors were collected at surgery or prior to actinotherapy, fixed in buffered formalin, paraffin-embedded, and immunocytochemically stained using the PAP method. The localization of opioid-like immunoreactivity was investigated using a primary antiserum recognizing the Tyr-Gly-Gly-Phe sequence common to all known opioid peptides. The presence of neuropeptide Y (NPY) and peptide histidine methionine (PHM), both known to be present in normal human cervical tissue, was also investigated using specific antisera. Controls included staining controls and absorption controls, using Sepharose-coupled antigen and were all negative. Out of 40 cervical carcinomas, 27 displayed varying numbers of opioid-immunoreactive cells. In 12 normal cervical specimens no specific staining was observed. None of the tumors displayed any NPY-like or PHM-like immunoreactivity. The growth of cervical carcinoma seems therefore to be accompanied by a destruction of the local peptidergic innervation of blood vessels and smooth muscle cells. The demonstration of opioid-like immunoreactants and the known immunoregulatory properties of these peptides, indicate that opioid peptides may be important in the regulation of growth of human cervical carcinoma.