ScienceDaily (Oct. 24, 2008) — The leading cause of death in all cancer patients continues to be the resistance of tumor cells to chemotherapy, a form of treatment in which chemicals are used to kill cells.

Now a study by UC Riverside biochemists that focuses on cancer cells reports that ingesting apigenin – a naturally occurring dietary agent found in vegetables and fruit – improves cancer cells’ response to chemotherapy.

Xuan Liu, a professor of biochemistry, and Xin Cai, a postdoctoral researcher working in her lab, found that apigenin localizes tumor suppressor p53, a protein, in the cell nucleus – a necessary step for killing the cell that results in some tumor cells responding to chemotherapy.

The study, published in the online early edition of the Proceedings of the National Academy of Sciences, provides a novel approach to conquer tumor resistance to chemotherapy, and suggests an avenue for developing safe chemotherapy via naturally occurring agents.

Normally, cells have low levels of p53 diffused in their cytoplasm and nucleus. When DNA in the nucleus is damaged, p53 moves to the nucleus where it activates genes that stop cell growth and cause cell death. In this way, p53 ensures that cells with damaged DNA are killed.

In many cancers, p53 is rendered inactive by a process called cytoplasmic sequestration. Apigenin is able to activate p53 and transport it into the nucleus, resulting in a stop to cell growth and cell death.

“In therapy you want to kill cancer cells,” explained Cai, the first author of the research paper. “But to stop cell growth and to kill the cell, p53 first needs to be moved to the cell’s nucleus to function. Apigenin is very effective in localizing p53 this way.”

Apigenin is mainly found in fruit (including apples, cherries, grapes), vegetables (including parsley, artichoke, basil, celery), nuts and plant-derived beverages (including tea and wine). It has been shown by researchers to have growth inhibitory properties in several cancer lines, including breast, colon, skin, thyroid and leukemia cells. It has also been shown to inhibit pancreatic cancer cell proliferation.

“Our study advocates the inclusion of vegetables and fruit in our daily diet to help prevent cancer,” said Liu, the research paper’s coauthor.

The National Institutes of Health supported the five-year study.

Next in their research Liu and Cai plan to design therapies for cancer by finding compounds that are like, but perform better than, apigenin.

Adapted from materials provided by University of California - Riverside

ScienceDaily (Nov. 12, 2006) — Cancer patients can get the vital nutritional benefits from taking antioxidants without the risk of interfering with radiation treatment, according to research findings being presented this weekend at the Society of Integrative Oncology’s Third International Conference in Boston. The Society for Integrative Oncology is a non-profit organization of oncologists and other health professionals studying and integrating effective complementary therapies in cancer care.

The study, Effect of Concomitant Naturopathic Therapies on Clinical Tumor Response to External Beam Radiation Therapy for Prostate Cancer, was conducted by researchers at Cancer Treatment Centers of America and reviewed PSA levels of prostate cancer patients after receiving radiation therapy. Researchers found no difference between patients taking antioxidants and those who did not. Antioxidants used in the study included green tea extract, melatonin, high-potency multivitamins, vitamin C and vitamin E.

Cancer Treatment Centers of America chose this study to address clinical concerns about the use of dietary supplements in conjunction with conventional cancer therapies. The study addressed the concern that antioxidants might interfere with cancer cell oxidation levels that contribute to tumor killing by chemotherapy and radiation therapy.

“This study provides evidence that antioxidants as a complementary therapy in cancer treatment do not interfere with external beam radiation therapy,” said Timothy Birdsall, ND, vice president of integrative medicine for Cancer Treatment Centers of America and lead author of the paper. “Antioxidants are one of many complementary and alternative medicine (CAM) therapies that are crucial in today’s fight against cancer.”

Treating cancer with advanced radiation, chemotherapy and surgery remains the best option for patients medically. But the side effects of these treatments can devastate a patient physically and emotionally. Through a fully integrated whole person care model, combining the best of traditional medicine with scientifically supported complementary and alternative therapies, cancer patients appear to be living a better quality of life.

“In cancer treatment today, we have to look beyond the traditional focus of treating only the tumor,” Birdsall said.

“Cancer patients will be the first to tell you that’s not enough. The integrated, whole person approach to cancer is highly valued, so much so that cancer patients and their caregivers are seeking out complementary or alternative therapies on their own.”

More than 80 percent of cancer patients report using some sort of CAM treatmenti, many of them without medical supervisionii. Taking supplements without supervision, however, creates a huge patient safety risk. St. John’s Wort, for example, is taken by some cancer patients to help lessen feelings of depression. But St. John’s Wort can interfere with the effectiveness of some forms of chemotherapy, ultimately doing patients more harm than good.

John C. Williams, Jr., a prostate cancer survivor from Reidsville, GA, credits having fully integrated cancer care with helping him get through his cancer treatment. “I didn’t know which was scarier, being diagnosed with cancer or when the doctor told me about the treatments,” Williams said. “The whole person approach at Cancer Treatment Centers of America was my choice because they used nutrition, supplements, physical therapy and other therapies to help me keep my body, mind and spirit strong.”

Adapted from materials provided by Cancer Treatment Centers of America, via EurekAlert!, a service of AAAS.