Platelet-derived endothelial cell growth factor/thymidine phosphorylase concentrations differ in small cell and non-small cell lung cancer.
OBJECTIVE
Platelet-derived endothelial cell growth factor (PD-ECGF)/thymidine phosphorylase (TP) has been implicated in cancer angiogenesis, which is critical for tumor growth and metastasis. We investigated the relationship between the tissue concentration of PD-ECGF/TP and the clinicopathologic status in human lung cancer.


METHODS
The concentrations of PD-ECGF/TP in the tumor extracts of 139 primary human lung carcinomas were measured by using a highly specific and sensitive enzyme-linked immunosorbent assay.


RESULTS
PD-ECGF/TP was detected in the extracts from 137 of 139 specimens at concentrations that ranged from 2.0 to 169.5 U/mg protein. PD-ECGF/TP concentrations in patients with adenocarcinoma (n = 73) and squamous cell carcinoma (n = 49) were (mean +/- SD) 30.7+/-22.9 U/mg protein (range, 7.6 to 169.5 U/mg protein) and 32.0+/-19.8 U/mg protein (range, 8.0 to 84.4 U/mg protein), respectively. No significant difference was found in the PD-ECGF/TP concentration between these two types of non-small cell lung cancer (NSCLC). However, a > 8-fold lower mean concentration of PD-ECGF/TP was found in tissue extracts from small cell lung cancer (SCLC) (n = 17; 3.65+/-2.01 U/mg protein, ranging from undetectable to 6.1 U/mg protein) than in those from adenocarcinomas (p = 0.00005) or squamous cell carcinomas (p < 0.00001).


CONCLUSIONS
The striking difference in PD-ECGF/TP concentrations between SCLC and NSCLC suggests that these two types of lung cancer use alternative pathways for angiogenesis. The present study suggests that inhibitors of PD-ECGF/TP, which have been recently developed and are under laboratory investigation to test their effectiveness as treatments for various types of cancer, may not be effective against SCLC.
Yamashita
J
J
Department of Surgery II, Kumamoto University School of Medicine, Honjo, Japan.
Ogawa
M
M
Abe
M
M
Nishida
M
M
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000098:blood supply / Q000378:metabolism*; D018288:Carcinoma, Small Cell / Q000098:blood supply / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008168:Lung / Q000098:blood supply; D008175:Lung Neoplasms / Q000098:blood supply / Q000378:metabolism*; D008297:Male; D009389:Neovascularization, Pathologic; D013939:Thymidine Phosphorylase / Q000378:metabolism*
D013939:Thymidine Phosphorylase