Suppression of the Tumorigenic Phenotype in Human Oral Squamous Cell Carcinoma Cells by an Ethanol Extract Derived From Freeze-Dried Black Raspberries

Abstract

Despite focused efforts to improve therapy, 5-yr survival rates for persons with advanced-stage oral squamous cell carcinoma (SCC) remain discouragingly low. Clearly, early detection combined with strategies for local intervention, such as chemoprevention prior to SCC development, could dramatically improve clinical outcomes. Previously conducted oral cavity human chemoprevention trials, however, have provided mixed results. Although some therapies showed efficacy, they were often accompanied by either significant toxicities or circulating antiadenoviral antibodies. It is clearly apparent that identification of nontoxic, effective treatments is essential to prevent malignant transformation of oral epithelial dysplasias. This study employed cell lines isolated from human oral SCC tumors to investigate the effects of a freeze-dried black raspberry ethanol extract (RO-ET) on cellular growth characteristics often associated with a transformed phenotype such as sustained proliferation, induction of angiogenesis, and production of high levels of reactive species. Our results demonstrate that RO-ET suppresses cell proliferation without perturbing viability, inhibits translation of the complete angiogenic cytokine vascular endothelial growth factor, suppresses nitric oxide synthase activity, and induces both apoptosis and terminal differentiation. These data imply that RO-ET is a promising candidate for use as a chemopreventive agent in persons with oral epithelial dysplasia.

Formulation and In-Vitro and In-Vivo Evaluation of a Mucoadhesive Gel Containing Freeze Dried Black Raspberries: Implications for Oral Cancer Chemoprevention

“…The berries were harvested mechanically (with a picker) in a total period of 4 hr, washed, and frozen at −20°C within an hour of the time of harvest. The berries remain frozen until they are transported frozen to Van Drunen Farms in Momence, IL, where they are then freeze-dried and ground into a powder as described previously (9)(10)(11)(12)(13)(14).…”

“…One gram of berry gel (containing either 5% or 10% w/w FBR) was placed on the epithelial surface of the explant, followed by gently rubbing of the site for 30 s to facilitate uptake. Explants were then placed into artificial saliva, incubated for 30 min (37°C, 5% CO 2 ), and treated tissues then frozen at −80°C until HPLC-mass spectroscopy analyses, as reported in our recent publication (13). Tissue preparation for HPLC analyses consisted of homogenization of the entire oral mucosal specimen, removal of an aliquot for sample protein level determination, followed by the addition of collagenase type II (0.1 mg/mL, GIBCO, Grand Island, NY) and 1% formic acid.…”

“…Consequently, identification of nontoxic, effective chemo-preventive compounds is of paramount importance. Recent studies from our laboratories have demonstrated that black raspberries possess cancer preventing properties at both in-vitro and in-vivo levels (9)(10)(11)(12)(13). Dietary administration of freeze-dried black raspberries (FBR) successfully inhibited nitrosamine-induced esophageal tumorigenesis in rats (9) and also prevented dimethylbenz(a)anthracene (DMBA)-initiated oral carcinogenesis in the hamster cheek pouch (10).…”

Cancer prevention with freeze-dried berries and berry components

“…ß-sitosterol treatment led to accumulation of both premalignant and malignant cell lines in the G 2 /M and G 0 /G 1 phases of the cell cycle, increased levels of p21 waf1/cip1 and decreased levels of cyclin B1 and cdc2 genes in both cell lines. Rodrigo, et al [44] also evaluated the preventative effects of the alcohol fraction on human oral cancer cell lines and found inhibition of cell proliferation, VEGF production, nitric oxide synthase activity, apoptosis, and terminal cell differentiation. Lastly, preliminary data from our laboratory indicates that treatment of tumorigenic and non-tumorigenic rat esophageal epithelial cells with the alcohol fraction, or individual anthocyanins (cyanidin-3-O-glucoside or cyanidin-3-O-rutinoside) inhibits proliferation, induces apoptosis and modulates the expression of COX-2 and iNOS in tumorigenic cells as compared to non-tumorigenic cells [45].…”

Current and Novel Treatments for Ulcerative Colitis

“…As well as exhibiting ability to limit the inflammatory response in cell culture (135)(136)(137), black raspberries (BRB) have the highest concentration of antioxidant polyphenols compared to other dark berries (138)(139). These antioxidants (anthocyanins and ellagic acid) have been shown to scavenge free radicals, increase expression of detoxification enzymes and increase the capacity of the cell to absorb radicals (140)(141)(142)(143).…”