Yozo Kawano

PURPOSE: Angiogenesis is an essential process in the progression of malignant tumors. Whereas pan-endothelial markers, such as CD34, are generally used in evaluation of angiogenesis, pan-endothelial antibodies react with not only "newly forming" vessels but also normal vessels just trapped within tumor tissues. It has been recently reported that anti-CD105 antibody preferentially reacts with "activated" endothelial cells in angiogenic tissues. Thus, the superiority of anti-CD105 monoclonal antibody (mAb) in evaluation of angiogenesis of non-small cell lung cancer (NSCLC) was assessed. EXPERIMENTAL DESIGN: A total of 236 patients with resected NSCLC were retrospectively reviewed. Intratumoral microvessel density (IMVD) was determined with an anti-CD34 mAb (CD34-IMVD) and with an anti-CD105 mAb (CD105-IMVD). RESULTS: The mean CD34-IMVD and CD105-IMVD were 179.9 and 41.6, respectively. Whereas CD34-IMVD was significantly correlated with the expression of vascular endothelial growth factor (P = 0.003), CD105-IMVD was more closely correlated with vascular endothelial growth factor expression (P < 0.001). The 5-year survival rate of the lower CD105-IMVD patients was 74.9%, significantly higher than that of the higher CD105-IMD patients (60.4%, P = 0.018). Whereas the 5-year survival rate of the lower CD34-IMVD patients seemed higher than that of the higher CD34-IMVD patients (63.7%), the difference did not reach a statistical significance (P = 0.137). Multivariate analysis confirmed that higher CD105-IMVD was a significant factor to predict poor prognosis (P = 0.029), whereas CD34-IMVD was not (P = 0.070). CONCLUSIONS: Anti-CD105 mAb proved to be superior to anti-CD34 mAb in evaluation of angiogenesis in NSCLC.

Angiopoietin (Ang)-1 and -2 have been recently identified as potent angiogenic factors which function in concert with vascular endothelial growth factor (VEGF), but no detailed clinical study on Ang expression has been reported. To assess the clinical significance of Ang expression in non-small cell lung cancer (NSCLC), a total of 236 patients with pathological stage-I-IIIA disease were retrospectively reviewed. Expression of Ang-1, Ang-2, or VEGF was examined immunohistochemically; intratumoral microvessel density (IMVD) was examined with immunohistochemical staining against CD34, a marker of pan-endothelial cells (CD34-IMVD), and that against CD105, a marker of proliferative endothelial cells (CD105-IMVD). Positive expression of Ang-1 and that of Ang-2 were seen in 101 (42.8%) and 40 patients (16.9%), respectively. There was no significant correlation between Ang-1 expression and CD34-IMVD or CD105-IMVD. In contrast, the average CD105-IMVD for Ang-2-positive tumor was significantly higher than that for Ang-2-negative tumor (56.7 versus 38.5; P = 0.032). More interestingly, such an angiogenic effect of Ang-2 was seen only when VEGF expression was high; when VEGF expression was high, the average CD105-IMVD for Ang-2-positive tumor was significantly higher than that for Ang-2-negative tumor (89.1 versus 63.6; P = 0.045); when VEGF expression was low, the average CD105-IMVD for Ang-2-positive tumor and that for Ang-2-negative tumor were almost the same (27.4 and 27.1, respectively). Moreover, positive expression of Ang-2, not Ang-1, was a significant factor to predict a poor postoperative survival (5-year survival rates for Ang-2-positive patients and -negative patients were 53.5 and 70.3%, respectively; P = 0.027), which was confirmed by a multivariate analysis. The influence of Ang-2 status on postoperative survival was enhanced when VEGF expression was high. That said, the 5-year survival of Ang-2-positive and VEGF-high patients was extremely low (41.4%) as compared with that for Ang-2-negative and VEGF-low patients (66.6%), as compared with that for Ang-2-positive and VEGF-low patients (63.6%), and as compared with that for Ang-2-negative and VEGF-low patients (71.8%). In conclusion, positive Ang-2 expression was significantly correlated with a poor prognosis, as well as with aggressive angiogenesis in resected NSCLC that was enhanced in the presence of high VEGF expression.

Polysialic acid (PSA) is a carbohydrate composed of a linear homopolymer of alpha-2-8-linked sialic acid residues and is mainly attached to the neural cell adhesion molecule (NCAM). Because of the large negative charge of PSA, presence of PSA attenuates the adhesive property of NCAM and increases the cellular motility. PSA expression on NCAM is developmentally regulated, and PSA plays important roles in formation and remodeling of the neural system through regulation of the adhesive property of NCAM. Expression of the polysialated form of NCAM has been also demonstrated in some malignant tumors, such as Wilms' tumor and small cell lung cancer. Despite the possible importance as an onco-developmental antigen, however, significance of PSA expression in most malignant tumors has not been revealed. Therefore, PSA expression in non-small cell lung cancer was assessed in the present study. PSA was expressed only in 5 (20.8%) of 24 pathological stage I cases, whereas it was expressed in most stage IV cases (76.8%, 11 of 14 cases). PSA expression was correlated with nodal metastasis and distant metastasis, but not with local extent of the primary tumor. Next, expression of polysialyltransferase genes (PST and STX genes) which controlled formation of PSA, was examined. The PST gene was constantly expressed in both normal lung tissue and tumor tissue of all cases. In contrast, the STX gene was not expressed in normal lung tissue of any case, and STX gene expression in tumor tissue was closely correlated with tumor progression. The STX gene was expressed only in 1 (4.2%) of 24 stage I cases, whereas it was expressed in most stage IV cases (85.7%, 12 of 14 cases). These results suggested that the PSA and STX genes could be new targets of cancer therapy as well as important clinical markers.

PURPOSE: The clinical significance of p21 expression remains unclear, whereas many experimental studies have demonstrated that p21, the product of the WAF1/CIP1/SDI1 gene, plays an important role in regulation of the cell cycle as an inhibitor of cyclin-dependent kinases. The purpose of this study was to clarify the clinical significance in resected non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 233 consecutive patients with completely resected pathologic stage I to IIIA NSCLC were retrospectively reviewed. Expression of p21 and the status of p53 were examined immunohistochemically. Proliferative activity was also evaluated immunohistochemically. The incidence of apoptotic cell death was evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling staining. RESULTS: Expression of p21 was positive in 120 patients (51.5%). The 5-year survival rate of p21-positive patients was 73.8%, significantly higher than that of p21-negative patients (60.7%; P =.006). Aberrant expression of p53 was positive in 98 patients (42.1%). When combined with p53 status, the prognostic value of p21 status was enhanced: the 5-year survival rate of p21-positive and p53-negative patients was 80.7%, markedly higher than that of p21-negative and p53-positive patients (50.0% for both; P =.001). Multivariate analysis confirmed that positive expression of p21 was a significant factor for predicting a favorable prognosis. There was no significant correlation between p21 expression and p53 status, proliferative activity, or incidence of apoptosis. CONCLUSION: p21 expression was shown to be an independent prognostic factor in NSCLC.