Progress Report: David Heber, MD, Ph.D

Investigator: David Heber, MD, PhD–Professor, Medicine and Public Health, Director, Center for Human Health, Chief, Division of Clinical Nutrition in the Department of Medicine, University of California, Los Angeles

Development of an Ex Vivo Bioassay to Examine Modulation of PSA-Positive Macrophage Invasiveness and Inflammatory Activities in Prostate Cancer Patients with Abdominal Obesity—The Identification of New Biomarkers May Be Able to Assess the Effectiveness of Diet and Lifestyle Changes

Epidemiological studies have revealed that obese men with prostate cancer have poor prognosis and an elevated risk of prostate cancer specific death. Increased inflammation caused by activated macrophages (specialized white blood cells) in obese men may be a significant contributing factor, as these cells have been shown to be involved in prostate cancer progression and metastasis. Dr. Heber is studying the molecular differences between activated macrophages isolated from the blood of lean men and obese men. His research team has designed an ex vivo (outside of the body) assay using prostate cancer cells grown in suspension as spheroids (balls of cells). These prostate cancer spheroids are then exposed to activated macrophages from either lean or obese men. Early data shows that activated macrophages from obese men readily invade the prostate cancer spheroids unlike macrophages from lean men. Future investigations will determine how the interaction between the activated macrophages from obese men and prostate cancer cells stimulates cancer cell growth and survival. Ultimately, the hope is to use this assay as a rapid test for potentially useful nutritional and pharmacological interventions in advanced prostate cancer, whereby active agents would result in a reduction in activated macrophage invasion of the prostate cancer spheroids.

Terms to know from this article:


The likely outcome or course of a disease; the chance of recovery or recurrence.


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


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).