BUFFALO, N.Y. (Roswell Park Cancer Institute) — Metastatic prostate cancer, or prostate cancer that has spread to other organs, is incurable. In new research published in the journal Science, Roswell Park Cancer Institute scientists have identified two gatekeeper genes that allow prostate cancer to progress and resist treatment. Their work illuminates the mechanisms behind lineage plasticity, the ability of prostate cancer to adapt to therapy, and highlights opportunities to disrupt and even reverse this deadly process.


Interview with PCF Young Investigator Dr. Leigh Ellis (video credit: Roswell Park Cancer Institute)

Androgen-deprivation therapy is commonly used to treat patients whose prostate cancer has spread beyond the prostate. While most men initially respond to this therapy, the cancer nearly always returns and is often aggressive and lethal. We have discovered a mechanism that causes progression to this aggressive form of prostate cancer, providing a new opportunity to prevent or treat lethal forms of prostate cancer,” says co-senior author David Goodrich, PhD, Professor of Oncology in the Department of Pharmacology and Therapeutics at Roswell Park.

“Importantly, these findings offer a new understanding of prostate cancer lineage plasticity, which involves the conversion of cancer cells that are dependent on a specific therapeutic target to cancer cells that are now indifferent to that target’s function,” adds co-senior author Leigh Ellis, PhD, Assistant Professor of Oncology in the Department of Pharmacology and Therapeutics. “This discovery offers the possibility to reverse or delay lineage plasticity, thereby prolonging the effectiveness of the currently used therapies, like androgen deprivation. And this new understanding has the potential to be applicable in other types of cancers.”

Using preclinical models, the scientists demonstrated that loss of the tumor-suppressor gene known as Rb1 induces lineage plasticity and metastatic progression of prostate cancer. They also show that increased expression of another gene, Ezh2, is associated with lineage plasticity and may be therapeutically exploited. Treatment of resistant tumors with drugs that inhibit the Ezh2 gene may resensitize prostate cancer to androgen-deprivation therapy. The team expects to pursue these findings further in clinical studies at Roswell Park.

This research was supported, in part, by grants from the National Cancer Institute (project nos. R21CA179907, R01CA70292, R01CA155169, P50CA092629, P30CA016056 and P30CA008748) and the Prostate Cancer Foundation (a Young Investigator Award to Dr. Ellis). The study, “Rb and p53 cooperate to suppress prostate cancer lineage plasticity, metastasis and antiandrogen resistance,” will be available beginning Jan. 6 at sciencemag.org/journals.

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See video interview with  David Goodrich, co-senior author, at https://youtu.be/4zrUWVi5Fn0.

The mission of Roswell Park Cancer Institute (RPCI) is to understand, prevent and cure cancer. Founded in 1898, RPCI is one of the first cancer centers in the country to be named a National Cancer Institute-designated comprehensive cancer center and remains the only facility with this designation in Upstate New York. The Institute is a member of the prestigious National Comprehensive Cancer Network, an alliance of the nation’s leading cancer centers; maintains affiliate sites; and is a partner in national and international collaborative programs. For more information, visit www.roswellpark.org, call 1-877-ASK-RPCI (1-877-275-7724) or email askrpci@roswellpark.org. Follow Roswell Park on Facebook and Twitter.

Terms to know from this article:

androgen

A type of hormone that promotes the development and maintenance of male sex characteristics.

Progression

Increase in the size of a tumor or spread of cancer in the body.

Metastasis

The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a "metastatic tumor" or a "metastasis." The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-ta-seez).

Tumor

A mass of excess tissue that results from abnormal cell division. Tumors perform no useful body function. They may be benign (not cancerous) or malignant (cancerous).

Gene

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.