Prostate Cancer and Screening
Prostate cancer is the second most common cancer type and second most common cause of cancer-related death in American men. Most prostate cancers are of epithelial origin, which means that the cells that become transformed to initiate a tumor are the normal prostate epithelial cells. As men age, the risk for prostate cancer increases; therefore, the development of a reliable screening and diagnostic method is critical. Currently, the most common prostate cancer screening is the prostate-specific antigen, or PSA, test, which measures the levels of PSA in the blood. High levels of this enzyme may be indicative of prostate cancer. There is a lot of debate over the reliability of the PSA test, however, as there are multiple causes of false positives. Raised PSA levels may merit a digital rectal exam, a physical exam in which a doctor examines the prostate. If abnormalities are still suspected, a biopsy may be performed, which ultimately determines the presence of cancer.
Recent Research Using Lifeline® Prostate Epithelial Cells
Given the complications related to PSA test false positives, it is critical to identify new biomarkers that will improve diagnosis and help predict which patients will progress. The first step in this process is to identify unique molecules expressed by cancer cells. To begin to address this, in his master’s thesis, Su-Shin Hao set out to examine the differences between prostate cancer and normal prostate using prostate cancer cells isolated from patients and grown in culture for a few passages.
With RNA-Seq, the author first compared early prostate cancer cells (those isolated from patient biopsies and passaged once) and the same prostate cancer cells passaged three or more times. The transcriptome of both early and passaged prostate cancer cells were compared to Lifeline® Normal Human Prostate Epithelial cells. The expression of approximately 20 genes was significantly different between early and passaged prostate cancer cells. Interestingly, genes that were upregulated in early prostate cancer cells were downregulated in passaged prostate cancer cells. The opposite was also true: downregulated genes from early prostate cancer cells were upregulated in passaged prostate cancer cells. This observation suggests that even two or three passages of these primary cells changes their identity.
Many of the genes that were upregulated in the early prostate cancer cells are implicated in metastasis/invasion, proliferation, anti-apoptosis, and hypoxia, including SERPINB2, RRAD, S100P, SLPI, LCN2, EDN1, CLDN4, LAMP3, ANGPL4, and COL1A2. While the author suggests there is still more analysis to be done, the results of this study demonstrate that primary human prostate cancer cells change dramatically when passaged multiple times in culture. This may obstruct the study of cancer pathogenesis and highlight the importance of understanding one’s chosen culture model.
Check out our catalog to purchase Normal Human Prostate Epithelial cells, which are optimized for growth in ProstaLife™ Medium. Our medium is always phenol red-free and our Prostate Epithelial cells are optimized for growth for up to 15 population doublings. They offer an ideal control for studying prostate cancer pathogenesis.
Keep up with us on the blog for more. We are here every other week with a new look at our different cell systems, brought to you by researchers around the world. If you use Lifeline® cells or media in your research, let us know and your work could be featured here on the blog!
Prostate cancer statistics from www.cancer.org