Silvana Chinè

Neoangiogenesis and p53 protein in lung cancer: their prognostic role and their relation with vascular endothelial growth factor (VEGF) expression.

Following up-regulation of an angiogenesis inhibitor by the wild-type p53 protein proven recently, we have analysed on the one hand the prognostic impact of microvessel count (MC) and p53 protein overexpression in non-small-cell lung carcinoma (NSCLC) progression and, on the other hand, the inter-relation between the microvascular pattern and the p53 protein expression. Moreover, we assessed the expression of vascular endothelial growth factor (VEGF), one of the pivotal mediators of tumour angiogenesis, in order to investigate its relation to p53 protein expression and MC. Tumours from 73 patients resected for NSCLC between March 1991 and April 1992 (median follow-up 47 months, range 32-51 months) were analysed using an immunohistochemical method. In univariate analysis, MC and p53 accumulation were shown to affect metastatic nodal involvement, recurrence and death significantly. Multiple logistic regression analysis showed an important prognostic influence of MC and nodal status on overall (P = 0.0009; P = 0.01) and disease-free survival (P = 0.0001; P = 0.03). Interestingly, a strong statistical association was observed between p53 nuclear accumulation and MC (P = 0.0003). The same inter-relationship was found in non-squamous histotype (P = 0.002). When we analysed the concomitant influence of MC and p53 expression on overall survival, we were able to confirm a real predominant role of MC in comparison with p53. With regard to VEGF expression, p53-negative and lowly vascularized tumours showed a mean VEGF expression significantly lower than p53-positive and highly vascularized cancers (P = 0.02). These results underline the prognostic impact of MC and p53 protein accumulation in NSCLC and their reciprocal inter-relationship, supporting the hypothesis of a wild-type p53 regulation on the angiogenetic process through a VEGF up-regulation.

Expression of vascular endothelial growth factor mRNA in non-small-cell lung carcinomas

SummaryThe vascular endothelial growth factor (VEGF) has been shown to be strictly related to vascular permeability and endothelial cell growth under physiological and pathological conditions. In tumour development and progression, VEGF plays a pivotal role in the development of the tumoral vascular network, and useful information in the progression of human cancer can be obtained by analysing the vascular endothelial growth factor expression of the tumours. In this study, we investigated the vascular endothelial growth factor transcript expression in non-small-cell lung carcinomas to evaluate the significance of this factor in a group of cancers in which the vascular pattern has been shown to significantly affect progression. Surgical samples of 42 patients with NSCLC were studied using reverse transcription polymerase chain reaction (PCR) analysis and in situ hybridization. Thirty-three out of 42 cases (78.6%) showed VEGF transcript expression predominantly as transcripts for the secretory forms of VEGF (isoforms 121 and 165). In situ hybridization, performed on 24 out of 42 samples, showed that the VEGF transcript expression was in several cases present in the cytoplasm both of neoplastic and normal cells, even if the VEGF mRNA was less expressed in the corresponding non-tumoral part. The VEGF 121 expression was associated with hilar and/or mediastinal nodal involvement (P = 0.02), and, taken together, the VEGF isoforms were shown to significantly influence overall (P = 0.02) and disease-free survival (P = 0.03). As a regulator of tumour angiogenesis, VEGF may represent a useful indicator of progression and poor prognosis in non-small-cell lung carcinomas.

Bcl2 and p53 regulate vascular endothelial growth factor (VEGF)-mediated angiogenesis in non-small cell lung carcinoma.

The aim of this study was to investigate the expression of p53 and bcl2 proteins in a series of 107 non-small cell lung cancers (NSCLC), and to relate such protein expression to neovascularisation and the expression of vascular endothelial growth factor (VEGF). Moreover, we analysed the prognostic impact of these biological parameters on overall survival, both in univariate and multivariate analyses. An inverse association was found between bcl2 expression and microvessel count (MVC; P = 0.0004) and bcl2 and VEGF (P = 0.007). In contrast, a significant association was found between p53 expression and MVC (P = 0.03) and p53 and VEGF expression (P = 0.04). In univariate analysis, nodal status (P < 0.000001), MVC (P < 0.000001), bcl2 (P = 0.002), p53 (P = 0.03) and VEGF expression (P < 0.000001) significantly affected overall survival, but in multivariate analysis only MVC and VEGF expression retained their prognostic influence. Our results suggest that bcl2 and p53 possibly control the development of tumour angiogenesis in NSCLC, with putative mediation by VEGF. Moreover, the important influence of angiogenesis in the progression of NSCLC is further highlighted.