Malignancy prostate-specific antigen

Prostate-specific antigen (PSA) is one of the most reliable cancer-specific molecular markers. PSA expression is, for the most part, restricted to the prostate and elevated serum PSA indicates the possibility of malignant prostate cancer. Use of serum PSA as a diagnostic tool is still controversial since PSA levels are also elevated in benign prostatic hyperplasia (BPH),... 

Baffa R, Moreno JG, Monne M, Veronese ML, Gomella LG. A comparative analysis of prostate-specific antigen gene sequence in benign and malignant prostate tissue. Urology 1996 47 795-800. 

Magklara A, Scorilas A, Stephan C, et al. Decreased concentrations of prostate-specific antigen and human glandular kallikrein 2 in malignant versus nonmalignant prostatic tissue. Urology 2000 56 527-532. 

Although efforts are underway to identify markers in serum and prostate tissue, the question arose as to whether metastatic prostate cancer cell lines accurately represent in vivo disease. It was found that in vitro cell cultures (LnCaP and PC3) shared less than 20% of proteins when compared to in vivo LCM procured malignant prostate cancer. 2D-PAGE protein profiles were used to compare normal and malignant cells to immortalized cells from the same patient. Protein expression patterns were dramatically altered when cells were grown in culture and immortalized most notably, a loss of prostate specific antigen expression was observed [18]. Thus, caution must be used when working with immortalized cell lines to discover potential disease markers. 

Wang and co-workers purified a protein from prostatic tissue and called it prostate-specific antigen. PSA is found in normal, benign, hyperplastic, and malignant prostatic tissues, y-seminoprotein, p30, and PSA are biochemically very similar. 

As stated earlier in this discussion, most non-hema-topoietic malignancies of the mediastinum should be presumed metastatic until proven otherwise. Immunohistologic analysis is only variably productive in establishing a site of origin for secondary carcinomas in this location. If determinants are found that are unassociated with PTCs, such as TTF-1, thyroglobulin, prostate-specific antigen, S-100 protein, FLAP, CA 19-9 (an enteric carcinoma marker), or CA 125 (a serosal and Mullerian tract marker),it is likely that the lesion is a metastasis. Conversely, the presence of coexpression of keratin 5/6, p63, and CD5 would, at least tentatively, appear to support a thymic origin for such a neoplasm. 

Prostate cancer is the most common cancer form in males in the USA and Western Europe. One of the methods to diagnose prostate cancer is to measure the prostate-specific antigen (PSA) which leaks into the bloodstream from the prostate. In cancer patients the cells in the prostate are growing unrestrained and become more unstructured which leads to an increased leakage of PSA into the blood. But only 25 % of men with elevated PSA levels have prostate cancer, while the remaining patients have, for example, benign prostatic hyperplasia (BPH) or a temporary infection. This makes it important to develop improved and more differentiated PSA assays to enable discrimination of patients with malignant disease. 

Despite improvements in screening and therapy of prostate cancer, it still is the most common malignancy in men. The use of prostate-specific antigen (PSA) has led to an early detection of the carcinomas, with a lower tumor stage and a better survival. Today, only 5% of the patients with carcinoma of the prostate demonstrate with distant metastases and only 2% with lymph nodes metastases at initial diagnosis (SoH et al. 1997). De-... 

Silver DA, Pellicer I, Fair WR, et al. Prostate-specific membrane antigen expression in normal and malignant human tissues. Clin Cancer Res. 1997 3 81-85. 

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