p53AIP1 expression can be a prognostic marker in non-small cell lung cancer

AIMS

p53AIP1 is a potential mediator of p53-dependent apoptosis that is mutated in many kinds of carcinoma. To investigate the role of this gene for non-small cell lung cancer, we compared the relationship between p53AIP1 gene expression and clinicopathological status of lung cancer.

MATERIALS AND METHODS

Seventy samples from non-small cell lung cancer patients were obtained between 1997 and 2003. For quantitative evaluation of RNA expression by polymerase chain reaction (PCR) we used the Taqman PCR methods. Exons 5-8 of the p53 gene were analysed using PCR-single-stranded conformation polymorphism and sequenced for mutation analysis.

RESULTS

p53AIP1 gene expression levels in the lymph node metastasis-positive group were significantly lower than in the negative group (positive 35.1+/-83.9; negative 64.2+/-113.4; P=0.0486). The overall survival of the p53AIP1 low expression group was significantly worse than that of the p53AIP1 high expression group (P=0.0206). In the multivariate Cox proportional hazard model, p53AIP1 (P=0.0489) was the independent predictor for overall survival. When we investigated mutation analyses of the p53 gene, we could find several point mutations in 15.7% of all samples. However, there was no relationship between p53AIP1 expression and p53 status.

CONCLUSIONS

These data suggest that the p53AIP1 gene is important for non-small cell lung cancer progression and may be a possible prognostic marker.

Production of immunoreactive polymorphonuclear leucocyte elastase in human breast cancer cells: possible role of polymorphonuclear leucocyte elastase in the progression of human breast cancer

Breast cancer cells are known to express various proteolytic enzymes, which make them invasive and favour their dissemination to distant sites. However, it is unclear whether breast cancer cells have the ability to produce polymorphonuclear leucocyte elastase (PMN-E). We measured immunoreactive (ir) PMN-E content in the conditioned medium of two breast cancer cell lines, MCF-7 and ZR-75-1, and two normal breast epithelial cell lines, HBL-100 and Hs 578Bst, using a highly specific and sensitive enzyme immunoassay. Furthermore, ir-PMN-E content was determined in tissue extracts from 62 human breast cancers. ir-PMN-E content in the culture medium of MCF-7 cells and ZR-75-1 cells increased as a function of time, regardless of the presence or absence of oestradiol. On the other hand, no detectable ir-PMN-E was secreted into the culture medium of HBL-100 and Hs 578Bst cells. ir-PMN-E was detectable in 59 of 62 tissue extracts prepared from human breast cancers, the concentration ranging from 0.12 to 19.17 micrograms per 100 mg of protein. When 62 breast cancer specimens were categorised into four groups in terms of clinical stage, ir-PMN-E content in breast cancer tissue was significantly higher in stage III (8.90 +/- 5.13 micrograms 100 mg-1 protein) and stage IV (12.19 +/- 5.44 micrograms 100 mg-1 protein) patients than in stage I (1.64 +/- 1.54 micrograms 100 mg-1 protein) and stage II (4.23 +/- 3.74 micrograms 100 mg-1 protein) patients. Breast cancer patients with high levels of ir-PMN-E showed significantly shorter disease-free survival and overall survival than those with low levels of ir-PMN-E at the cut-off point of 8.99 micrograms 100 mg-1 protein. In the multivariate analysis, ir-PMN-E content was found to be a significant prognostic factor for disease recurrence and death in human breast cancer.