Prostate cancer is a scary word for men, no matter how macho or healthy they are. These days however, prostate cancer is no longer a death sentence for them. In fact, many men survive this disease if diagnosed early. However, for those unlucky ones who have more advanced stages of prostate cancer (where the tumor has metastasized and spread to other organs), the typical treatments used to fight the tumors don’t work effectively because advanced tumors become resistant to these therapies.
To help those afflicted with late stage prostate cancer, scientists are trying to understand the nature of prostate cancer cells and what makes them so “deadly”. By understanding the biology behind these tumor cells, they hope to develop better therapies to treat the late-stage forms of this disease.
But don’t worry, help is already on its way. Two groups from the University of California, Los Angeles and the University of California, Santa Cruz published a breakthrough discovery yesterday on the similarity between prostate cancer cells and prostate stem cells. The study was published in the journal PNAS and was led by senior author and director of the UCLA Broad Stem Cell Research Center, Dr. Owen Witte.
Using bioinformatics, Witte and his team compared the gene expression profiles of late-stage, metastatic prostate cancer cells sourced from tumor biopsies of living patients to healthy cell types in the male prostate. Epithelial cells are one of the main cell types in the prostate (they form the prostate glands) and they come in two forms: basal and luminal. When they compared the gene expression profiles of the prostate cancer cells to healthy prostate epithelial cells, they found that the cancer cells had a similar profile to normal prostate epithelial basal stem cells.
In fact, they discovered a 91-gene signature specific to the basal stem cells in the prostate. This profile included genes important for stem cell signaling and invasiveness. That meant that the metastatic prostate cancer cells also expressed “stem-like” genes.
First author Bryan Smith explained how their results support similar findings for other types of cancers. “Evidence from cancer research suggests that aggressive cancers have stem–cell-like traits. We now know this to be true for the most aggressive form of prostate cancer.”
So what does this study mean for prostate cancer patients? I’ll let Dr. Witte answer this one…
Treatments for early stage prostate cancer are often successful, but therapies that target the more aggressive and late-stage forms of the disease are urgently needed. I believe this research gives us important insight into the cellular nature of aggressive prostate cancer. Pinpointing the cellular traits of cancer — what makes those cells grow and spread — is crucial because then we can possibly target those traits to reverse or stop cancer’s progression. Our findings will inform our work as we strive to find treatments for aggressive prostate cancer.