Overexpression of PEA-15, which binds and drags an oncoprotein out of the cell nucleus where it fuels cancer growth, steeply reduced breast cancer tumors in a preclinical experiment, researchers at The University of Texas M. D. Anderson Cancer Center reported at the 100th annual meeting of the American Association for Cancer Research.
Human breast cancer grafts in mice dropped to nearly undetectable levels after 35 days when treated with an adenoviral PEA-15 vector that overexpressed the protein in tumors.
"Treated mice had a dramatic response, while tumors continued to grow in control mice," said first author and presenter Chandra Bartholomeusz, M.D., Ph.D., a post-doctoral fellow in M. D. Anderson's Department of Breast Medical Oncology. Bartholomeusz presented the findings at a minisymposium titled "Up and Coming Targeted Biologic Strategies."
"This first animal model experiment demonstrates the therapeutic potential of PEA-15," said senior author Naoto Ueno, M.D., Ph.D., associate professor of breast medical oncology. "PEA-15 is a different way of modulating growth because it's based on location of the protein in the cell rather than, for example, protein regulation by phosphorylation."
Ueno and colleagues previously showed that PEA-15 stymied ovarian cancer in lab experiments, and that high expression of the protein in tumors is tied to improved overall survival. They had also examined PEA-15 expression in 26 breast cancer specimens and found the protein was more heavily expressed in the 13 low-grade tumors analyzed.
In the breast cancer experiments, the team first tested overexpression in three breast cancer cell line cultures. Lines treated with PEA-15 developed 30 to 60 percent fewer colonies of cancer cells than did control cultures. Further analysis of one cell line showed that adenovirally delivered PEA-15 overexpression inhibited cell growth and reduced DNA synthesis.
They also found that activated ERK - a protein active in growth, differentiation and mobility of cells that can fuel cancer growth when in the nucleus - was sequestered in the cell's cytoplasm. This is consistent with previous research by Ueno's team that showed PEA-15 works by binding and dragging ERK and phosphorylated ERK from the nucleus, inducing cell death.
Cell cycle analysis indicated the onset of apoptosis - programmed cell death - in breast cancer cells treated with PEA-15. In the case of ovarian cancer, the team found evidence of death by autophagy - cellular self-consumption - rather than apoptosis. The varied forms of cellular death may indicate that the protein's mechanisms differ from one form of cancer to another, Ueno said.
PEA-15 is a versatile protein, serving multiple cellular functions, including glucose metabolism and regulating the tumor necrosis factor (TNF) pathway in addition to its role regulating ERK, Ueno said.
"We are committed to further developing PEA-15 and making it a druggable target," Ueno said. The team is developing a non-gene therapy treatment because adenovirally delivered gene therapies such as those used to overexpress PEA-15 in the mouse experiments have had less success in humans.
Funding for this research was provided by a Susan G. Komen Postdoctoral Fellowship to Bartholomeusz and a National Cancer Institute grant to Ueno.
Co-authors with Bartholomeusz and Ueno are Linda Yuan, Fumiyuki Yamasaki, M.D., Ph.D., Anna Kazansky, Dongwei Zhang, M.D., PhD, Francisco Esteva, M.D., Ph.D., and Gabriel Hortobagyi, M.D., all of M. D. Anderson's Breast Cancer Translational Research Laboratory and the Department of Breast Medical Oncology; and Savithri Krishnamurthy, M.D., of M. D. Anderson's Department of Pathology.
About M. D. Anderson
The University of Texas M. D. Anderson Cancer Center in Houston ranks as one of the world's most respected centers focused on cancer patient care, research, education and prevention. M. D. Anderson is one of only 40 comprehensive cancer centers designated by the National Cancer Institute. For four of the past six years, including 2008, M. D. Anderson has ranked No. 1 in cancer care in "America's Best Hospitals," a survey published annually in U.S. News & World Report.
Scott Merville | EurekAlert!
Further reports about: > Cancer > DNA synthesis > ERK > Medical Wellness > Oncology > PEA-15 > apoptosis > breast cancer > breast cancer tumors > cancer cells > cell death > cellular self-consumption > death by autophagy > metabolism > ovarian cancer > protein in tumors > protein regulation by phosphorylation > tumor necrosis factor
Historical rainfall levels are significant in carbon emissions from soil
30.05.2017 | University of Texas at Austin
3D printer inks from the woods
30.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Scientists have developed a new method of characterizing graphene’s properties without applying disruptive electrical contacts, allowing them to investigate both the resistance and quantum capacitance of graphene and other two-dimensional materials. Researchers from the Swiss Nanoscience Institute and the University of Basel’s Department of Physics reported their findings in the journal Physical Review Applied.
Graphene consists of a single layer of carbon atoms. It is transparent, harder than diamond and stronger than steel, yet flexible, and a significantly better...
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
30.05.2017 | Life Sciences
30.05.2017 | Life Sciences
30.05.2017 | Physics and Astronomy