Pepper component hot enough to trigger suicide in prostate cancer cells

March 15, 2006

Capsaicin, the stuff that turns up the heat in jalapeños, not only causes the tongue to burn, it also drives prostate cancer cells to kill themselves, according to studies published in the March 15 issue of Cancer Research.

According to a team of researchers from the Samuel Oschin Comprehensive Cancer Institute at Cedars-Sinai Medical Center, in collaboration with colleagues from UCLA, the pepper component caused human prostate cancer cells to undergo programmed cell death or apoptosis.

Capsaicin induced approximately 80 percent of prostate cancer cells growing in mice to follow the molecular pathways leading to apoptosis. Prostate cancer tumors treated with capsaicin were about one-fifth the size of tumors in non-treated mice.

"Capsaicin had a profound anti-proliferative effect on human prostate cancer cells in culture," said Sören Lehmann, M.D., Ph.D., visiting scientist at the Cedars-Sinai Medical Center and the UCLA School of Medicine. "It also dramatically slowed the development of prostate tumors formed by those human cell lines grown in mouse models."

Lehmann estimated that the dose of pepper extract fed orally to the mice was equivalent to giving 400 milligrams of capsaicin three times a week to a 200 pound man, roughly equivalent to between three and eight fresh habañera peppers - depending on the pepper's capsaicin content. Habañeras are the highest rated pepper for capsaicin content according to the Scoville heat index. Habañero peppers, which are native to the Yucatan, typically contain up to 300,000 Scoville units. The more popular Jalapeño variety from Oaxaca, Mexico, and the southwest United States, contains 2,500 to 5,000 Scoville units.

As described in their study, the scientists observed that capsaicin inhibited the activity of NF-kappa Beta, a molecular mechanism that participates in the pathways leading to apoptosis in many cell types.

Apoptosis is a normal cellular event in many tissues that maintains a balance between newer replacement cells and aged or worn cells. In contrast, cancer cells seek to be immortal and often dodge apoptosis by mutating or deregulating the genes that participate in programmed cell death.

"When we noticed that capsaicin affected NF-kappa Beta, that was an indication that we might expect some of the apoptotic proteins to be affected," said the study's senior author, Phillip Koeffler, M.D., director of Hematology and Oncology, Cedars-Sinai Medical Center, and professor at UCLA.

The pepper extract also curbed the growth of prostate cancer cells through regulation of androgen receptors, the steroid activated proteins that control expression of specific growth relating genes.

In prostate cancer cells whose growth is dependent on testosterone, the predominant male sex steroid, capsaicin reduced cell proliferation in a dose-dependent manner. Increased concentrations of capsaicin caused more prostate cancer cells to freeze in a non-proliferative state, called G0/G1.

Prostate cancer cells that are androgen independent reacted to capsaicin in a similar manner. Capsaicin reduced the amount of androgen receptor that the tumor cells produced, but did not interfere with normal movement of androgen receptor into the nucleus of the cancer cells where the steroid receptor acts to regulate androgen target genes such as prostate specific antigen (PSA). Capsaicin also interfered with the action of androgen receptors even in cells that were modified to produce excess numbers of androgen receptors.

The hot pepper component also reduced cancer cell production of PSA, a protein that often is produced in high quantities by prostate tumors and can signal the presence of prostate cancer in men. PSA content in the blood of men is used as a diagnostic prostate cancer screening measure. PSA is regulated by androgens, and capsaicin limited androgen-induced increases of PSA in the cancer cell lines.

More men in the United States develop prostate cancer than any other type of malignancy. Every year, more than 232,000 new cases of prostate cancer are diagnosed in the U.S., and more than 680,000 develop the disease worldwide. Approximately 30,000 men die from prostate cancer in the U.S. each year, which is about 13 percent of all new cases. Worldwide, there are 221,000 deaths - approximately 31 per cent - among men with prostate cancer.

Lehman conducted the studies in Koeffler's laboratory in collaboration with UCLA cancer researchers Akio Mori, James O'Kelly, Takishi Kumagai, Julian Desmond, Milena Pervan, and William McBride. Mosahiro Kizaki, a former post-doctoral fellow in Koeffler's laboratory who initiated the capsaicin studies, is currently at the Keio University School of Medicine, Tokyo, Japan.
-end-
The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. Our members include more than 24,000 basic, translational, and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 60 other countries. AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs, and funding meritorious research projects. The AACR Annual Meeting attracts some 16,000 participants who share the latest discoveries and developments. Special Conferences throughout the year present novel information across a wide variety of cancer research and patient care topics. AACR publishes five major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention, as well as CR, a magazine about people and progress in cancer.

American Association for Cancer Research

Related Prostate Cancer Articles from Brightsurf:

Low risk of cancer spread on active surveillance for early prostate cancer
Men undergoing active surveillance for prostate cancer have very low rates - one percent or less - of cancer spread (metastases) or death from prostate cancer, according to a recent study published in the Journal of Urology®, an Official Journal of the American Urological Association (AUA).

ESMO 2020: Breast cancer drug set to transform prostate cancer treatment
A drug used to treat breast and ovarian cancer can extend the lives of some men with prostate cancer and should become a new standard treatment for the disease, concludes a major trial which is set to change clinical practice.

Major trial shows breast cancer drug can hit prostate cancer Achilles heel
A drug already licensed for the treatment of breast and ovarian cancers is more effective than targeted hormone therapy at keeping cancer in check in some men with advanced prostate cancer, a major clinical trial reports.

The Lancet: Prostate cancer study finds molecular imaging could transform management of patients with aggressive cancer
Results from a randomised controlled trial involving 300 prostate cancer patients find that a molecular imaging technique is more accurate than conventional medical imaging and recommends the scans be introduced into routine clinical practice.

Common genetic defect in prostate cancer inspires path to new anti-cancer drugs
Researchers found that, in prostate cancer, a mutation leading to the loss of one allele of a tumor suppressor gene known as PPP2R2A is enough to worsen a tumor caused by other mutations.

First prostate cancer therapy to target genes delays cancer progression
For the first time, prostate cancer has been treated based on the genetic makeup of the cancer, resulting in delayed disease progression, delayed time to pain progression, and potentially extending lives in patients with advanced, metastatic prostate cancer, reports a large phase 3 trial.

Men taking medications for enlarged prostate face delays in prostate cancer diagnosis
University of California San Diego School of Medicine researchers report that men treated with medications for benign prostatic hyperplasia (enlarged prostate) experienced a two-year delay in diagnosis of their prostate cancer and were twice as likely to have advanced disease upon diagnosis.

CNIO researchers confirm links between aggressive prostate cancer and hereditary breast cancer
The study has potential implications for families with members suffering from these types of tumours who are at an increased risk of developing cancer.

Distinguishing fatal prostate cancer from 'manageable' cancer now possible
Scientists at the University of York have found a way of distinguishing between fatal prostate cancer and manageable cancer, which could reduce unnecessary surgeries and radiotherapy.

Researchers find prostate cancer drug byproduct can fuel cancer cells
A genetic anomaly in certain men with prostate cancer may impact their response to common drugs used to treat the disease, according to new research at Cleveland Clinic.

Read More: Prostate Cancer News and Prostate Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.