Folic acid supplementation increases survival and modulates high risk HPV-induced phenotypes in oral squamous cell carcinoma cells and correlates with p53 mRNA transcriptional down-regulation

Abstract

BackgroundAlthough the primary risk factors for developing oral cancers are well understood, less is known about the relationship among the secondary factors that may modulate the progression of oral cancers, such as high-risk human papillomavirus (HPV) infection and folic acid (FA) supplementation. This study examined high-risk HPV and FA supplementation effects, both singly and in combination, to modulate the proliferative phenotypes of the oral cancer cell lines CAL27, SCC25 and SCC15.ResultsUsing a comprehensive series of integrated in vitro assays, distinct effects of HPV infection and FA supplementation were observed. Both high-risk HPV strains 16 and 18 induced robust growth-stimulating effects in CAL27 and normal HGF-1 cells, although strain-specific responses were observed in SCC25 and SCC15 cells. Differential effects were also observed with FA administration, which significantly altered the growth rate of the oral cancer cell lines CAL27, SCC15, and SCC25, but not HGF-1 cells. Unlike HPV, FA administration induced broad, general increases in cell viability among all cell lines that were associated with p53 mRNA transcriptional down-regulation. None of these cell lines were found to harbor the common C677T mutation in methylenetetrahydrofolate reductase (MTHFR), which can reduce FA availability and may increase oral cancer risk.ConclusionIncreased FA utilization and DNA hypermethylation are common features of oral cancers, and in these cell lines, specifically. The results of this study provide further evidence that FA antimetabolites, such as Fluorouracil (f5U or 5-FU) and Raltitrexed, may be alternative therapies for tumors resistant to other therapies. Moreover, since the incidence of oral HPV infection has been increasing, and can influence oral cancer growth, the relationship between FA bioavailability and concomitant HPV infection must be elucidated. This study is among the first pre-clinical studies to evaluate FA- and HPV-induced effects in oral cancers, both separately and in combination, which provides additional rationale for clinical screening of HPV infection prior to treatment.

Dental pulp-derived stem cells (DPSC) differentiation in vitro into odontoblast and neuronal progenitors during cell passaging is associated with alterations in cell survival and viability

“…To determine if any cells derived from dental pulp were dental pulp stem cells (DPSC), RNA was isolated from 1.5 x 10 7 cells of each of the experimental cell lines, using ABgene Total RNA Isolation Reagent (Epsom, Surrey, UK) in accordance with the procedure recommended by the manufacturer for RT-PCR analysis, as previously described. [19,20] The concentration and purity of were determined using UV spectroscopy. The absorbance of diluted RNA samples (10 µL of RNA sample in 490 µL nuclease-free water, pH 7.0) was measured at 260 and 280 nm.…”

“…The absorbance of diluted RNA samples (10 µL of RNA sample in 490 µL nuclease-free water, pH 7.0) was measured at 260 and 280 nm. [19,20] RNA purity was determined by calculating the ratio of A260:A280, which should be > 1.80. [19,20] Concentration for RNA samples was determined by the A260 reading of 1 = 40 µg/mL RNA, based on an extinction coefficient calculated for RNA in nucleasefree water.…”

“…[19,20] RNA purity was determined by calculating the ratio of A260:A280, which should be > 1.80. [19,20] Concentration for RNA samples was determined by the A260 reading of 1 = 40 µg/mL RNA, based on an extinction coefficient calculated for RNA in nucleasefree water. [19,20] Concentration was calculated as 40 x A260 absorbance measure x dilution factor (50).…”

Using frogs faces to dissect the mechanisms underlying human orofacial defects

“…Thus, we propose that folate supplementation might prevent median clefts by enhancing cell survival. Precedent for such a protective role of folate supplementation exists in the immune system and in cancer cells [91, 92]. Together, our results point toward an interaction where folate and retinoic acid converge on the regulation of facial prominence growth by altering apoptosis and cell division.…”

Carcinoma verrucoso periimplantario: A propósito de un caso

“…Respecto a las lesiones precancerosas orales se deben recordar: la leucoplasia, eritroplasia, liquen plano oral (LPO), fibrosis oral submucosa, el lupus eritematoso y la queratosis actínica 4,6,7 . Además el aumento de la frecuencia del cáncer oral en las últimas décadas de la vida parece indicar que con el paso del tiempo se acumulan mutaciones en el material genético de las células del epitelio oral, responsables de la transformación cancerosa.…”