TY - JOUR
T1 - Chapter 18 Stability and shedding of small cell carcinoma membrane antigens
T2 - Applications to detection of antigens in marrow and serum
AU - Bernal, Samuel D.
AU - Cualing, Hernani M.
AU - Elias, Anthony D.
AU - Siegel, Robert D.
PY - 1988/5
Y1 - 1988/5
N2 - Flow cytometry and radioimmunoassays were used to evaluate the stability, shedding, and internalisation of SCLC antigens by varying the time and sequence of primary and secondary antibodies. The antigens recognised by the different anti-SCLC antibodies used in this study showed three types of expression. The antigen recognised by SM1 antibody typified stable expression on the surface membrane of SCLC cells in spite of prolonged incubation with antibody. LAM6 was an example of an extensively shed antigen, whereas LAM7 appeared to be internalised. Small amounts of SM1 antigen appeared to be shed from SCLC cells but the regeneration of antigenic sites on the surface membrane is rapid so that high amounts of SM1 antigen remains on the surface membrane in spite of repeated or continuous exposure to SM1 antibody. A shed SCLC antigen, recognised by SM1 antibody, was also detected in serum of patients with SCLC tumours. Prior to treatment, all sera from patients with extensive disease and 50% of those with limited disease were found to have high SM1 antigen. In contrast, sera from normal volunteers, patients with benign disease, and patients with nonpulmonary primary tumours had low SM1 antigen. The serum SM1 antigen levels of SCLC patients treated with chemotherapy were influenced by tumour response. The serum SM1 antigen level was also observed to rise many months prior to any radiologic evidence of recurrent disease and antedated the elevation in CEA level. The detection of shed SCLC antigen may therefore by useful in monitoring tumour response and relapse after therapy of patients with lung cancer. SCLC monoclonal antibodies were found to be more sensitive than conventional histology in screening bone marrows for SCLC metastasis. However, the handling of specimens is critical in obtaining useful data. These antibodies can also be used to eradicate SCLC in marrows without affecting normal marrow precursors.
AB - Flow cytometry and radioimmunoassays were used to evaluate the stability, shedding, and internalisation of SCLC antigens by varying the time and sequence of primary and secondary antibodies. The antigens recognised by the different anti-SCLC antibodies used in this study showed three types of expression. The antigen recognised by SM1 antibody typified stable expression on the surface membrane of SCLC cells in spite of prolonged incubation with antibody. LAM6 was an example of an extensively shed antigen, whereas LAM7 appeared to be internalised. Small amounts of SM1 antigen appeared to be shed from SCLC cells but the regeneration of antigenic sites on the surface membrane is rapid so that high amounts of SM1 antigen remains on the surface membrane in spite of repeated or continuous exposure to SM1 antibody. A shed SCLC antigen, recognised by SM1 antibody, was also detected in serum of patients with SCLC tumours. Prior to treatment, all sera from patients with extensive disease and 50% of those with limited disease were found to have high SM1 antigen. In contrast, sera from normal volunteers, patients with benign disease, and patients with nonpulmonary primary tumours had low SM1 antigen. The serum SM1 antigen levels of SCLC patients treated with chemotherapy were influenced by tumour response. The serum SM1 antigen level was also observed to rise many months prior to any radiologic evidence of recurrent disease and antedated the elevation in CEA level. The detection of shed SCLC antigen may therefore by useful in monitoring tumour response and relapse after therapy of patients with lung cancer. SCLC monoclonal antibodies were found to be more sensitive than conventional histology in screening bone marrows for SCLC metastasis. However, the handling of specimens is critical in obtaining useful data. These antibodies can also be used to eradicate SCLC in marrows without affecting normal marrow precursors.
UR - http://www.scopus.com/inward/record.url?scp=58149370652&partnerID=8YFLogxK
U2 - 10.1016/S0169-5002(88)80020-5
DO - 10.1016/S0169-5002(88)80020-5
M3 - Article
AN - SCOPUS:58149370652
SN - 0169-5002
VL - 4
SP - 79
EP - 80
JO - Lung Cancer
JF - Lung Cancer
IS - 1-2
ER -