Expression of E-cadherin in drug resistant human breast cancer cells and their sensitivity to lymphokine-activated lymphocytes action.

AIM To analyze the correlation between the elevated sensitivity of drug resistant breast cancer cells to the action of lymphokine-activated lymphocytes (LAK) and expression of E-cadherin and other marker proteins by cancer cells and lymphocytes. METHODS Breast tumor explants were cultured with autologous lymphocytes in double diffusion chambers. The results were evaluated by morphological criteria of explants growth. Expression level of proteins on tumor cells was analyzed using immunohistochemical method on paraffin embedded sections, and by indirect immunofluorescence - on lymphocytes. RESULTS Significant decrease of E-cadherin expression and significant increase of nuclear antigen of proliferating cells expression have been detected on drug resistant malignant human breast tumor (DRHBT) cells compared with drug sensitive breast tumor (DSHBT) cells. Autologous LAK possessed the highest antitumor activity against DRHBT cells that was associated with high expression level of soybean lectin receptor. CONCLUSION Malignant drug resistant tumors are characterized by reverse relation between E-cadherin expression level and their proliferative activity. Marked antitumor action of LAK against these tumors is associated with high expression level of soybean lectin receptor on the lymphocytes.