ADAM9 Expression is a Significant and Independent Prognostic Marker of PSA Relapse in Prostate Cancer

Increased expression of a disintegrin and metalloprotease-9 in hepatocellular carcinoma: implications for tumor progression and prognosis

OBJECTIVE

A disintegrin and metalloprotease-9 has been involved in the carcinogenesis of various solid tumors. However, its role in hepatocellular carcinoma remains unknown. The aim of this study was to investigate the clinicopathological and prognostic relevance of a disintegrin and metalloprotease-9 by immunohistochemistry.

METHODS

The expression profile of a disintegrin and metalloprotease-9 in association with the clinicopathological factors was determined by immunohistochemical analysis in hepatocellular carcinoma patients, and its potential prognostic value was investigated by comparing the survival rate between a disintegrin and metalloprotease-9-positive and a disintegrin and metalloprotease-9-negative patients.

RESULTS

Hepatocellular carcinoma tissues with positive a disintegrin and metalloprotease-9 expression were larger and less differentiated than those with negative expression (P = 0.02 and 0.008, respectively). Portal venous invasion, hepatic venous invasion, bile duct invasion and intrahepatic metastasis were detected significantly more frequently in a disintegrin and metalloprotease-9-positive group (P = 0.009, 0.01, 0.03 and 0.02, respectively). In addition, high alpha-fetoprotein levels were significantly associated with the expression of a disintegrin and metalloprotease-9 in hepatocellular carcinoma (P = 0.01). Moreover, a disintegrin and metalloprotease-9-positive group had significantly poorer outcomes than a disintegrin and metalloprotease-9-negative group (P = 0.01) and was an independent prognostic factor for overall survival.

CONCLUSIONS

A disintegrin and metalloprotease-9 is over-expressed in hepatocellular carcinoma tissues, consistent with findings in other tumor entities, and is an independent prognostic marker of overall survival following hepatectomy. Further studies are needed to investigate the precise function of a disintegrin and metalloprotease-9 in the progression of hepatocellular carcinoma.

Involvement of ADAMs in tumorigenesis and progression of hepatocellular carcinoma: Is it merely fortuitous or a real pathogenic link?

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and one of the most frequent types of cancer worldwide. It normally develops in patients with chronic liver disease, especially cirrhosis, although some cases without an apparent underlying liver disease have been reported. The pathogenesis of HCC is multi-factorial and complex. Hepatitis viruses are the main factors favoring the development of HCC. In fact, chronic inflammation associated with hepatitis C or B virus infection can lead to progressive liver fibrosis, cirrhosis and ultimately HCC. Chronic inflammation and liver fibrosis cause a continuous remodeling of the extracellular matrix (ECM), a dynamic process that involves several molecules including integrins and matrix processing enzymes. An increasing body of evidence indicates that ADAMs are involved in promoting tumor formation and progression of HCC. A Disintegrin And Metalloproteases (ADAMs) are a group of proteins belonging to the zinc protease superfamily. ADAMs are usually transmembrane proteins that contain disintegrin and metalloprotease domains and are, therefore, able to carry out both cell adhesion and protease activities. Soluble isoforms of ADAMs have also been discovered and characterized. In this review, we focus on the contribution of ADAM proteins to HCC tumorigenesis and cancer progression. The potential role of ADAMs as key modulators of tumor-stroma interactions during tumor progression, by means of the activities of their constituent domains, is also discussed.

Matrix metalloproteinases as novel biomarkers and potential therapeutic targets in human cancer

The matrix metalloproteinase (MMP) family of enzymes is comprised of critically important extracellular matrix remodeling proteases whose activity has been implicated in a number of key normal and pathologic processes. The latter include tumor growth, progression, and metastasis as well as the dysregulated angiogenesis that is associated with these events. As a result, these proteases have come to represent important therapeutic and diagnostic targets for the treatment and detection of human cancers. In this review, we summarize the literature that establishes these enzymes as important clinical targets, discuss the complexity surrounding their choice as such, and chronicle the development strategies and outcomes of their clinical testing to date. The status of the MMP inhibitors currently in US Food and Drug Administration approved clinical trials is presented and reviewed. We also discuss the more recent and successful targeting of this enzyme family as diagnostic and prognostic predictors of human cancer, its status, and its stage. This analysis includes a wide variety of human cancers and a number of human sample types including tissue, plasma, serum, and urine.

Matrix metalloproteinases as novel biomarkers and potential therapeutic targets in human cancer

The matrix metalloproteinase (MMP) family of enzymes is comprised of critically important extracellular matrix remodeling proteases whose activity has been implicated in a number of key normal and pathologic processes. The latter include tumor growth, progression, and metastasis as well as the dysregulated angiogenesis that is associated with these events. As a result, these proteases have come to represent important therapeutic and diagnostic targets for the treatment and detection of human cancers. In this review, we summarize the literature that establishes these enzymes as important clinical targets, discuss the complexity surrounding their choice as such, and chronicle the development strategies and outcomes of their clinical testing to date. The status of the MMP inhibitors currently in US Food and Drug Administration approved clinical trials is presented and reviewed. We also discuss the more recent and successful targeting of this enzyme family as diagnostic and prognostic predictors of human cancer, its status, and its stage. This analysis includes a wide variety of human cancers and a number of human sample types including tissue, plasma, serum, and urine.

Brain-type and liver-type fatty acid-binding proteins: new tumor markers for renal cancer?

BACKGROUND

Renal cell carcinoma (RCC) is the most common renal neoplasm. Cancer tissue is often characterized by altered energy regulation. Fatty acid-binding proteins (FABP) are involved in the intracellular transport of fatty acids (FA). We examined the level of brain-type (B) and liver-type (L) FABP mRNA and the protein expression profiles of both FABPs in renal cell carcinoma.

METHODS

Paired tissue samples of cancerous and noncancerous kidney parts were investigated. Quantitative RT-PCR, immunohistochemistry and western blotting were used to determine B- and L-FABP in tumor and normal tissues. The tissue microarray (TMA) contained 272 clinico-pathologically characterized renal cell carcinomas of the clear cell, papillary and chromophobe subtype. SPSS 17.0 was used to apply crosstables (chi2-test), correlations and survival analyses.

RESULTS

B-FABP mRNA was significantly up-regulated in renal cell carcinoma. In normal tissue B-FABP mRNA was very low or often not detectable. RCC with a high tumor grading (G3 + G4) showed significantly lower B-FABP mRNA compared with those with a low grading (G1 + G2). Western blotting analysis detected B-FABP in 78% of the cases with a very strong band but in the corresponding normal tissue it was weak or not detectable. L-FABP showed an inverse relationship for mRNA quantification and western blotting. A strong B-FABP staining was present in 52% of the tumor tissues contained in the TMA. In normal renal tissue, L-FABP showed a moderate to strong immunoreactivity in proximal tubuli. L-FABP was expressed at lower rates compared with the normal tissues in 30.5% of all tumors. There was no correlation between patient survival times and the staining intensity of both FABPs.

CONCLUSION

While B-FABP is over expressed in renal cell carcinoma in comparison to normal renal tissues L-FABP appears to be reduced in tumor tissue. Although the expression behavior was not related to the survival outcome of the RCC patients, it can be assumed that these changes indicate fundamental alterations in the fatty metabolism in the RCC carcinogenesis. Further studies should identify the role of both FABPs in carcinogenesis, progression and with regard to a potential target in RCC.

Early prostate-specific antigen changes and the diagnosis and prognosis of prostate cancer

PURPOSE OF REVIEW

To delineate how recent findings on prostate-specific antigen (PSA) can improve prediction of risk, detection, and prediction of clinical endpoints of prostate cancer (PCa).

RECENT FINDINGS

The widely used PSA cut-point of 4.0 ng/ml increasingly appears arbitrary, but no cut-point achieves both high sensitivity and high specificity. The accuracy of detecting PCa can be increased by additional predictive factors and a combinations of markers. Evidence implies that a panel of kallikrein markers improves the specificity and reduces costs by eliminating unnecessary biopsies. Large, population-based studies have provided evidence that PSA can be used to predict PCa risk many years in advance, improve treatment selection and patient care, and predict the risk of complications and disease recurrence. However, definitive evidence is currently lacking as to whether PSA screening lowers PCa -specific mortality.

SUMMARY

PSA is still the main tool for early detection, risk stratification, and monitoring of PCa. However, PSA values are affected by many technical and biological factors. Instead of using a fixed PSA cut-point, using statistical prediction models and considering the integration additional markers may be able to improve and individualize PCa diagnostics. A single PSA measurement at early middle age can predict risk of advanced PCa decades in advance and stratify patients for intensity of subsequent screening.

Role of ADAMs in cancer formation and progression

The ADAMs (a disintegrin and metalloproteinase) comprise a family of multidomain transmembrane and secreted proteins. One of their best-established roles is the release of biologically important ligands, such as tumor necrosis factor-alpha, epidermal growth factor, transforming growth factor-alpha, and amphiregulin. Because these ligands have been implicated in the formation and progression of tumors, it might be expected that the specific ADAMs involved in their release would also be involved in malignancy. Consistent with this hypothesis, emerging data from model systems suggest that ADAMs, such as ADAM-9, ADAM-12, ADAM-15, and ADAM-17, are causally involved in tumor formation/progression. In human cancer, specific ADAMs are up-regulated, with levels generally correlating with parameters of tumor progression and poor outcome. In preclinical models, selective ADAM inhibitors against ADAM-10 and ADAM-17 have been shown to synergize with existing therapies in decreasing tumor growth. The ADAMs are thus a new family of potential targets for the treatment of cancer, especially malignancies that are dependent on human epidermal growth factor receptor ligands or tumor necrosis factor-alpha.