Expression profiling by RNA-Seq of breast cancer samples from patients in walnut-consuming and control groups

Consumption of walnuts has slowed breast cancer growth and/or reduced the risk of breast cancer in mice. The significantly reduced mean tumor size or numbers of tumors was associated with changing the expressions of many genes that are associated with cancer growth, survival and metastasis. Many women treated for breast cancer are interested in reducing the risk for recurrence. The study was a non-placebo, two-arm, clinical trial. Women with lumps large enough for research and pathology biopsies were recruited to the trial. One or two additional biopsies were taken for gene expression analyses using next generation RNA Sequencing methods. The subjects randomized to the walnut group immediately began to consume 2 ounces of walnuts per day until follow-up surgery, if surgery were needed. At follow up surgery, additional biopsies were taken from the surgically removed, cancerous tissue for additional gene expression analyses. Changes in gene expression compared to baseline were determined in tumors of each individual woman in walnut-consuming and control groups. Overall design: Gene expression profiles of two samples from each of ten breast cancer patients were obtained via RNA-Seq in a 2x50bp paired-end design. The first sample was obtained from biopsy; the second sample was taken at the time of surgery 2-3 weeks later. Five patients consumed two one-ounce packets of walnuts daily between the biopsy and surgery, while the other five remained on their regular diet.