Comparative characterization of pulmonary surfactant aggregates and alkaline phosphatase isozymes in human lung carcinoma tissue.
Alkaline phosphatase (AP) isozymes are surfactant-associated proteins (SPs). Since several different AP isozymes have been detected in the pneumocytes of lung cancer patients, we attempted to identify the relationship between pulmonary surfactant aggregate subtypes and AP isozymes. Pulmonary surfactant aggregates were isolated from carcinoma and non-carcinoma tissues of patients with non-small cell carcinoma of the lung. Upon analysis, ultraheavy, heavy, and light surfactant aggregates were detected in the non-carcinoma tissues, but no ultraheavy surfactant aggregates were found in the carcinoma tissues. Surfactant-associated protein A (SP-A) was detected as two bands (a 27-kDa band and a 54-kDa band) in the ultraheavy, heavy, and light surfactant aggregates found in the non-carcinoma tissues. Although both SP-A bands were detected in the heavy and light surfactant aggregates from adenocarcinoma tissues, the 54-kDa band was not detected in squamous cell carcinoma tissues. Liver AP (LAP) was detected in the heavy and light surfactant aggregates from both non-carcinoma and squamous carcinoma tissues, but not in heavy surfactant aggregates from adenocarcinoma tissues. A larger amount of bone type AP (BAP) was found in light surfactant aggregate fractions from squamous cell carcinomas than those from adenocarcinoma tissues or non-carcinoma tissues from patients with either type of cancer. LAP, BAP, and SP-A were identified immunohistochemically in type II pneumocytes from non-carcinoma tissues and adenocarcinoma cells, but no distinct SP-A staining was observed in squamous cell carcinoma tissues. The present study has thus revealed several differences in pulmonary surfactant aggregates and AP isozymes between adenocarcinoma tissue and squamous cell carcinoma tissue.
Iino
Nozomi
N
Department of Biochemistry, Saitama Medical University, Saitama, Japan. niino@tcc.pref.tochigi.jp
Matsunaga
Toshiyuki
T
Harada
Tsuyoshi
T
Igarashi
Seiji
S
Koyama
Iwao
I
Komoda
Tsugikazu
T
D000469:Alkaline Phosphatase / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology; D010743:Phospholipids / Q000378:metabolism; D021381:Protein Transport; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000378:metabolism*; D013501:Surface-Active Agents / Q000302:isolation & purification; D014020:Tissue Extracts
D007527:Isoenzymes; D010743:Phospholipids; D037662:Pulmonary Surfactant-Associated Protein A; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents; D014020:Tissue Extracts; D000469:Alkaline Phosphatase