Overexpression of TMPRSS4 in non-small cell lung cancer is associated with poor prognosis in patients with squamous histology.

BACKGROUND: Mortality rates in lung cancer patients have not decreased significantly in recent years, even with the implementation of new therapeutic regimens. One of the main problems is that a large proportion of patients present local or distant metastasis at the time of diagnosis. The need for identification of novel biomarkers and therapeutic targets for a more effective management of lung cancer led us to investigate TMPRSS4, a protease reported to promote tumour growth and metastasis. MATERIAL AND METHODS: In all, 34 lung cancer cell lines were used to evaluate the TMPRSS4 expression. Cell migration and clonogenic assays, and an in-vivo lung metastasis model were used for functional analysis of the TMPRSS4 downregulation in H358, H441 and H2170 cell lines. The TMPRSS4 expression analysis in normal and malignant lung tissue samples was performed by qPCR. Five different microarray-based publicly available expression databases were used to validate our results and to study prognosis. RESULTS: The TMPRSS4 knock down in H358, H441 and H2170 cells resulted in a significant reduction in proliferation, clonogenic capacity and invasion. A significant (P<0.05) decrease in the lung colonisation and growth was found when mice were injected with TMPRSS4-depleated H358-derived clones, as compared with controls. Expression of TMPRSS4 showed a >30-fold increase (P<0.001) in tumours in comparison with non-malignant samples. Levels in tumours with squamous cell carcinoma (SCC) histology were found to be significantly higher (P<0.001) than those with adenocarcinoma (AC) histology, which was confirmed in data retrieved from the microarrays. Kaplan-Meier curves demonstrated that high levels of TMPRSS4 were significantly associated (P=0.017) with reduced overall survival in the patients with SCC histology, whereas no correlation was found for the AC histology. CONCLUSION: Our results demonstrate that TMPRSS4 has a role in the lung cancer development. The potential use of TMPRSS4 as a biomarker for lung cancer detection or as a predictor of patient's outcome warrants further investigation.

Use of transgenic mice as models for prostate cancer chemoprevention.

Prostate cancer is a long latency type of tumor that usually develops in men older than 50 years of age. Prostate epithelial neoplasia (PIN), the initial malignant lesion, progresses to invasive carcinoma over the course of years. Because of the particular features of prostate carcinogenesis, this type of tumor may represent a paradigm for cancer prevention. Several clinical trials have evaluated the effect of different compounds on prostate tumor development, including finasteride, selenium, vitamin E, and carotenes. Although some results are promising, no conclusive data have been achieved as to recommend any of these compounds as preventive agents. Results from some trials, such as SELECT, where supplementation of selenium and/or vitamin-E was used, have been rather disappointing. However, many novel chemopreventive agents that target different cancer-related pathways are being developed lately. Appropriate animal models (in particular, genetically modified mice) are being used to assess the efficacy of these novel compounds. The transgenic adenocarcinoma of the mouse prostate (TRAMP) model has been validated as an accurate model to test a variety of preventive agents. Genistein, alpha-difluoromethylornithine, toremifene, R-flurbiprofen, celecoxib, and green tea polyphenols have been shown to prevent prostate cancer development in TRAMP mice. In conclusion, new chemopreventive compounds which are effective in animal models are likely to be tested soon in clinical trials, with the final goal of reducing prostate cancer incidence in men.

The novel Akt inhibitor Palomid 529 (P529) enhances the effect of radiotherapy in prostate cancer.

Radiotherapy (RT) is a common treatment for localised prostate cancer, but can cause important side effects. The therapeutic efficacy of RT can be enhanced by pharmacological compounds that target specific pathways involved in cell survival. This would elicit a similar therapeutic response using lower doses of RT and, in turn, reducing side effects. This study describes the antitumour activity of the novel Akt inhibitor 8-(1-Hydroxy-ethyl)-2-methoxy-3-(4-methoxy-benzyloxy)-benzo[c]chromen-6-one (Palomid 529 or P529) as well as its ability to decrease radiation-activated phospho-Akt (p-Akt) signalling in a prostate cancer model. P529 showed a potent antiproliferative activity in the NCI-60 cell lines panel, with growth inhibitory 50 (GI50) <35 microM. In addition, P529 significantly enhanced the antiproliferative effect of radiation in prostate cancer cells (PC-3). Analysis of signalling pathways targeted by P529 exhibited a decrease in p-Akt, VEGF, MMP-2, MMP-9, and Id-1 levels after radiation treatment. Moreover, the Bcl-2/Bax ratio was also reduced. Treatment of PC-3 tumour-bearing mice with 20 mg kg(-1) P529 or 6 Gy radiation dose decreased tumour size by 42.9 and 53%, respectively. Combination of both treatments resulted in 77.4% tumour shrinkage. Decreased tumour growth was due to reduced proliferation and increased apoptosis (as assessed by PCNA and caspase-3 immunostaining). Our results show the antitumour efficacy of P529 alone, and as a radiosensitiser, and suggest that this compound could be used in the future to treat human prostate cancer.