Previous studies have detected high levels of matrix metalloproteinases (MMPs) in metastatic prostate cancer. In this study, we recruited 40 patients with prostate cancer (PCa): 20 presented organ-confined carcinoma and 20 had metastatic cancer. We also recruited 40 subjects for control groups, 20 with benign prostate hyperplasia (BPH) and 20 healthy males with similar characteristics. All of the patients were monitored at the beginning (time 0) and after 90 days. We analyzed the plasma concentrations of MMP-2, MMP-9, MMP-13, TIMP-1 and the enzyme activity of MMP-2 and MMP-9,using specific ELISA tests. The plasma concentrations of MMP-2, MMP-9 and MMP-13 were higher in PCa patients with metastasis than in the other groups, and in these patients decreased markedly after therapy began. For MMP-2 and MMP-9, greater differences were observed in enzyme activity than in plasma concentrations. TIMP-1 was reduced in PCa patients with metastasis, even if the intergroup differences were not statistically significant. Our results suggest that the plasma concentration and activity of MMPs, in association with PSA determination, could play a role in diagnosis, monitoring therapy and evaluating malignant progression in PCa.

Overexpression of wild-type p53 protein has been shown to induce arrest in the G, stage of the cell cycle and to transactivate expression of the gene that encodes the 21-kDa Wafl/Cipl protein, a potent inhibitor of cyclin-dependent kinase activity. p53-dependent G, arrest is accompanied by decreased expression of the B-myb gene, a relative of the c-myb cellular oncogene. In this study we show that B-myb expression is required for cells to progress from G, into S phase and that high levels of ectopic B-myb expression uncoupled from cell cycle regulation rescues cells from p53-induced G, arest even in the presence of Wafl/Cipl transactivation and inhibition of cyclin E/Cdk2 kinas activity. Cotransfection experiments with p53 expression plaids and expression plasmids encoding in-frame deletion mutations in B-myb coding sequences indicate that the DNA-binding domain of the B-Myb protein is required for this activity. These results provide evidence of a bypass of p53-induced Wafl/Cipl-mediated cell cycle regulatory pathways by a member of the myb oncogene family.

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Mutation of BRAF has been proposed to contribute to melanoma development. However, it remains unclear whether or not BRAF mutation is associated with any particular stage of melanoma progression. Tumor biopsy specimens from patients with melanoma were analyzed to determine whether the frequency of BRAF mutation in metastatic melanoma differed from primary melanoma. BRAF mutation was present in 15 of 23 (61%) patients with primary melanoma and in 7 of 12 (58%) patients with metastatic melanoma. These results suggest that BRAF mutation in melanoma is most likely to occur prior to the development of metastatic disease.

Purpose: Prostate cancer remains the second most frequent cause of tumor-related deaths in the Western world. Additional markers for the identification of prostate cancer development and progression are needed. Osteopontin (OPN), which activates matrix metalloproteinases (MMP), is considered a prognostic biomarker in several cancers. ''In silico'' and experimental approaches were used to determine whether OPN-mediated MMP activation may be a signal of prostate cancer progression. Experimental Design: Pearson correlation coefficients were computed for each OPN/MMP pair across seven publicly available prostate cancer gene expression data sets. Using Gene Set Enrichment Analysis, 101 cancer-related gene sets were analyzed for association with OPN and MMP-9 expression. OPN, MMP-9, MMP-2 tissue inhibitor of metalloproteinase-1 plasma levels, and MMP gelatinase activity were measured by ELISA and zymography in 96 and 92 patients with prostate cancer and benign prostatic hyperplasia, respectively, and 125 age-matched healthy men. Results: Computational analyses identified a significant correlation only between MMP-9 and OPN, and showed significant enrichment scores in ''cell proliferation'', ''genes constituting the phosphoinositide-3-kinase predictor'', ''proliferation signature'', and ''tumor metastasis'' gene sets in association with both OPN and MMP-9. Plasma analyses revealed a significant increase in OPN and MMP-9 levels and activity in patients with prostate cancer in association with clinical variables (prostate-specific antigen >4 ng/mL and Gleason score >7). Significant correlation between OPN and MMP-9 levels were also observed. Mean plasma levels of OPN and MMP-9 decreased in patients with prostate cancer within 6 months after prostatectomy. Conclusions: The concordant computational and experimental data indicate that the extent of OPN pathway activation correlates with prostate cancer progression.