Laura A. Kresty

Effects of lyophilized black raspberries on azoxymethane-induced colon cancer and 8-hydroxy-2'-deoxyguanosine levels in the Fischer 344 rat

This study examined the effects of lyophilized black raspberries (BRB) on azoxymethane (AOM)-induced aberrant crypt foci (ACF), colon tumors, and urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels in male Fischer 344 rats. AOM was injected (15 mg/kg body wt ip) once per week for 2 wk. At 24 h after the final injection, AOM-treated rats began consuming diets containing 0%, 2.5%, 5%, or 10% (wt/wt) BRB. Vehicle controls received 5% BRB or diet only. Rats were sacrificed after 9 and 33 wk of BRB feeding for ACF enumeration and tumor analysis. ACF multiplicity decreased 36%, 24%, and 21% (P < 0.01 for all groups) in the 2.5%, 5%, and 10% BRB groups, respectively, relative to the AOM-only group. Total tumor multiplicity declined 42%, 45%, and 71% (P < 0.05 for all groups). Although not significant, a decrease in tumor burden (28%, 42%, and 75%) was observed in all BRB groups. Adenocarcinoma multiplicity decreased 28%, 35%, and 80% (P < 0.01) in the same treatment groups. Urinary 8-OHdG levels were reduced by 73%, 81%, and 83% (P < 0.01 for all groups). These results indicate that BRB inhibit several measures of AOM-induced colon carcinogenesis and modulate an important marker of oxidative stress in the Fischer 344 rat.

Effects of a Topically Applied Bioadhesive Berry Gel on Loss of Heterozygosity Indices in Premalignant Oral Lesions

Purpose: The aim of this study was to assess the effects of topical application of a 10% (w/w) freeze-dried black raspberry (FBR) gel on oral intraepithelial neoplasia (IEN) variables that included histologic diagnoses and loss of heterozygosity (LOH) indices. Microsatellite instability and/or LOH at tumor suppressor gene–associated chromosomal loci have been associated with a higher risk for oral IEN progression to oral squamous cell carcinoma. Previously, our laboratories have shown that FBRs are well tolerated and possess potent antioxidant, apoptotic, and differentiation-inducing properties. Experimental Design: Each participant with IEN served as their own internal control. Before treatment, all lesions were photographed, and lesional tissue was hemisected to obtain a pretreatment diagnosis and baseline biochemical and molecular variables. Gel dosing (0.5 g applied four times daily for 6 weeks) was initiated 1 week after the initial biopsy. Genomic DNA was isolated from laser-captured basilar and suprabasilar surface epithelial cells followed by PCR amplification using primer sets that targeted known and presumed tumor suppressor gene loci associated with INK4a/ARF, p53, and FHIT. Allelic imbalance was determined by sequence analysis using normal participant tissues to establish microsatellite marker peak patterns and allele sizes. Results: Confirming earlier phase I data, none of the 27 participants developed FBR gel–associated toxicities. Furthermore, our results show histologic regression in a subset of patients as well as statistically significant reduction in LOH at tumor suppressor gene–associated loci. Conclusions: These preliminary data suggest that further evaluation of berry gels for oral IEN chemoprevention is warranted.

Measurement and treatment of agitation following traumatic brain injury: II. a survey of the brain injury special interest group of the american academy of physical medicine and rehabilitation☆☆☆

OBJECTIVE Determine national patterns of measuring and treating agitation after traumatic brain injury (TBI) by physiatrists with expressed interest in treating TBI survivors. DESIGN A 70% random sample of members of the Brain Injury Special Interest Group of the American Academy of Physical Medicine and Rehabilitation was surveyed by telephone. MAIN OUTCOME MEASURE The survey instrument was designed to determine the most common pharmacologic interventions for agitation and, where possible, match each drug with the target behavioral and cognitive characteristics for which it is prescribed. Data were also collected on the manner in which participants measured agitation and judged treatment efficacy. RESULTS One hundred twenty-nine of 157 responded, yielding an 82% response rate. The majority of respondents were not measuring agitation in a standard fashion. The five most frequently prescribed drugs by the expert stratum were carbamazepine, tricyclic antidepressants (TCAs), trazodone, amantadine, and beta-blockers. In comparison, the nonexperts most often reported prescribing carbamazepine, beta-blockers, haloperidol, TCAs, and benzodiazepines. Desyrel (p = .06) and amantadine (p = .001) were significantly more likely to be chosen by experts than by nonexperts. Experts chose haloperidol significantly less often than nonexperts (p = .01). Prescription of sedating drugs such as haloperidol or benzodiazepines was not found to be associated with the acuity of injury of TBI patients in the respondents practice, practice setting, or years of practice since completing residency. Choice of haloperidol to treat agitation was not significantly associated with the degree to which explosive anger, verbal aggression, or physical aggression were considered important to the respondents definition of agitation. CONCLUSIONS The majority of physiatrists surveyed did not formally measure agitation. Treatment strategies differ significantly between general physiatrists and those who specialize in the treatment of patients with TBI. The breadth of pharmacologic agents and strategies identified in this survey probably reflects the lack of research specific to the pathophysiology of the disorder of posttraumatic agitation.

Intake of Plant Foods and Associated Nutrients in Prostate Cancer Risk

Plant foods and associated nutrients may impact prostate cancer (PC) risk and survival. Therefore, we compared dietary intake, mainly plant food groups among 382 controls and 478 PC cases (373 incident and 105 prevalent cases). Caucasian controls had significantly higher daily servings of vegetables (3.4 vs. 2.5, P= 0.002) and fruits and/or fruit juices (1.6 vs. 1.3, P = 0.02) compared to African American controls. In Caucasians, incident cases reported lower intake of fiber, vitamin C, vitamin A, α -carotene, β -carotene, cryptoxanthin, folate, genistein, daidzein, and fruits and/or fruit juice than controls and/or prevalent cases. In African Americans, incident cases had lower intake of α -carotene compared to controls and prevalent cases. Reduced PC risk was associated with the highest tertile of cryptoxanthin (OR = 0.51; 95% CI = 0.35–0.75), fiber (OR = 0.56; 95% CI = 0.35–0.89), vitamin C (OR = 0.60; 95% CI = 0.41–0.88), and fruits and/or fruit juices (OR = 0.46; 95% CI = 0.31–0.68), with significant linear trends. Increased risk of PC was associated with the highest tertile of protein (OR = 1.99; 95% CI = 1.05–3.79) and daily servings of grains (OR = 1.99; 95% CI = 1.23–3.22) with significant linear trends. In summary, we demonstrate racial/ethnic differences in dietary intake of plant foods. The significantly higher consumption of protective dietary constituents among prevalent cases compared to incident cases suggests that PC survivors may be amenable to dietary change.

Chemopreventive Effects of a Selective Nitric Oxide Synthase Inhibitor on Carcinogen-Induced Rat Esophageal Tumorigenesis

The inducible nitric oxide synthase (iNOS) generates a high concentration of nitric oxide (NO) in tissues. Increased NO production is associated with many disorders including esophageal cancer. Previous studies in our laboratory demonstrated an association between increased iNOS expression and the development of N-nitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus. On the basis of these observations, we initiated a bioassay to evaluate the ability of S,S′-1,4-phenylene-bis(1,2-ethanediyl)bis-isothiourea (PBIT), a selective iNOS inhibitor, to prevent the progression of esophageal tumors in rats preinitiated with NMBA. Rats were given s.c. injections of NMBA (0.25 mg/kg body weight) three times per week for 5 weeks. One week later, they were fed a synthetic diet containing either 50 or 100 ppm PBIT until the end of the bioassay (25 weeks). PBIT reduced the incidence of esophageal cancer from 96% in NMBA-treated rats to 83% and 77% (P < 0.05) in rats treated with 50 and 100 ppm PBIT, respectively. Tumor multiplicity was reduced from 3.64 ± 0.42 tumors per esophagus in NMBA-treated rats to 1.79 ± 0.25 (P < 0.001) and 1.50 ± 0.24 (P < 0.0001) in rats treated with 50 and 100 ppm PBIT, respectively. PBIT reduced the production of NO in NMBA-induced preneoplastic and papillomatous esophageal lesions when compared with comparable lesions in rats treated with NMBA only. iNOS mRNA expression was not modulated by PBIT. These observations suggest that iNOS plays a role in tumor development and that its selective inhibitor, PBIT, significantly inhibits esophageal tumor progression presumably through reducing the production of NO.

Effects of theaflavins on N-nitrosomethylbenzylamine-induced esophageal tumorigenesis

The purpose of this experiment was to compare the inhibitory effects of the polyphenol fraction of black tea, theaflavins (TF), the polyphenol fraction of green tea, and (-)-epigallocatechin-3-gallate (EGCG) in the rat esophageal tumor model. The tea fractions were administered in the drinking water at concentrations of 360 and 1,200 ppm for two weeks before administration of the esophageal carcinogen N-nitrosomethylbenzylamine (NMBA). NMBA was administered subcutaneously in 10% dimethyl sulfoxide three times weekly for five weeks. Additional groups of rats received only vehicle and plain drinking water or vehicle and drinking water containing 1,200 ppm of each tea fraction. Twenty-five weeks after NMBA administration began, the experiment was terminated and esophagi were excised and scored for tumors. Rats that were not dosed with NMBA had no tumors. Rats treated with NMBA only had an esophageal tumor incidence of 100% and a multiplicity of 3.3 +/- 0.4 tumors/rat. The proportion of rats developing tumors was not significantly reduced by any of the four tea fractions at the concentrations tested. However, the 1,200 ppm concentrations of each tea fraction in the drinking water produced some reduction in esophageal tumor multiplicity, although only TF significantly reduced tumor multiplicity compared with rats treated with NMBA only. The rates of esophageal tumor formation were significantly reduced at 360 and 1,200 ppm by TF and EGCG.

Cranberry Proanthocyanidins Induce Apoptosis and Inhibit Acid-Induced Proliferation of Human Esophageal Adenocarcinoma Cells

The occurrence of esophageal adenocarcinoma and its only recognized precursor lesion, Barretts esophagus, has rapidly increased during the past three decades. The precise reason for the rise remains to be elucidated, but increasing rates have been linked to multiple nutritional factors. Plant-based diets have generally been associated with a reduction of risk for esophageal adenocarcinoma and those of animal origin with risk escalation. Moreover, a number of recent in vitro and limited in vivo investigations have reported that cranberry extracts affect multiple cancer-associated processes in breast, colon, prostate, and other cancer cell lines of epithelial origin. Thus, this study sought to investigate the chemopreventive potential of a cranberry proanthocyanidin rich extract (PAC) in SEG-1 human esophageal adenocarcinoma (EAC) cells. PAC pretreatment significantly inhibited the viability and proliferation of EAC cells in a time- and dose-dependent manner. Moreover, PAC (50 microg/mL) significantly inhibited acid-induced cell proliferation of SEG-1 cells. PAC treatment induced cell cycle arrest at the G1 checkpoint and significantly reduced the percentage of SEG-1 cells in S-phase following 24 and 48 h of exposure. PAC treatment also resulted in significant induction of apoptosis. Thus, PAC modulates cell cycle regulation, aberrant proliferation, and apoptosis, all key biological processes altered during progression to esophageal adenocarcinoma. These findings support that further mechanistic studies are warranted to more fully elucidate the inhibitory potential of PAC against esophageal cancer.

Frequent Alterations of p16INK4a and p14ARF in Oral Proliferative Verrucous Leukoplakia

Proliferative verrucous leukoplakia (PVL) represents a rare but highly aggressive form of oral leukoplakia with >70% progressing to malignancy. Yet, PVL remains biologically and genetically poorly understood. This study evaluated the cell cycle regulatory genes, p16INK4a and p14ARF, for homozygous deletion, loss of heterozygosity, and mutation events in 20 PVL cases. Deletion of exon 1β, 1α, or 2 was detected in 40%, 35%, and 0% of patients, respectively. Deletions of exons 1α and 1β markedly exceed levels reported in non-PVL dysplasias and approximate or exceed levels reported in oral squamous cell carcinomas. Allelic imbalance was assessed for markers reported to be highly polymorphic in squamous cell carcinomas and in oral dysplasias. Loss of heterozygosity was detected in 35.3%, 26.3%, and 45.5% of PVLs for the markers IFNα, D9S1748, and D9S171, respectively. INK4a and ARF sequence alterations were detected in 20% and 10% of PVL lesions, accordingly. These data show, for the first time, that both p16INK4a and p14ARF aberrations are common in oral verrucous leukoplakia; however, the mode and incidence of inactivation events differ considerably from those reported in non-PVL oral premalignancy. Specifically, concomitant loss of p16INK4a and p14ARF occurred in 45% of PVL patients greatly exceeding loss reported in non-PVL dysplastic oral epithelium (15%). In addition, p14ARF exon 1β deletions were highly elevated in PVLs compared with non-PVL dysplasias. These data illustrate that molecular alterations, even within a specific genetic region, are associated with distinct histologic types of oral premalignancy, which may affect disease progression, treatment strategies, and ultimately patient prognosis. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3179–87)

Cranberry Proanthocyanidins Mediate Growth Arrest of Lung Cancer Cells through Modulation of Gene Expression and Rapid Induction of Apoptosis

Cranberries are rich in bioactive constituents purported to enhance immune function, improve urinary tract health, reduce cardiovascular disease and more recently, inhibit cancer in preclinical models. However, identification of the cranberry constituents with the strongest cancer inhibitory potential and the mechanism associated with cancer inhibition by cranberries remains to be elucidated. This study investigated the ability of a proanthocyanidin rich cranberry fraction (PAC) to alter gene expression, induce apoptosis and impact the cell cycle machinery of human NCI-H460 lung cancer cells. Lung cancer is the leading cause of cancer-related deaths in the United States and five year survival rates remain poor at 16%. Thus, assessing potential inhibitors of lung cancer-linked signaling pathways is an active area of investigation.

Incidence and effects of Ha‐ras codon 12 G→A transition mutations in preneoplastic lesions induced by N‐nitrosomethylbenzylamine in the rat esophagus

N‐nitrosomethylbenzylamine (NMBA)–induced rat esophageal tumorigenesis is an important model for squamous cell carcinoma of the human esophagus. In this model, previous studies have shown that the GGA→GAA Ha‐ras codon 12 mutation is present in the majority of papillomas. No other Ha‐ras mutation has been identified. Studies using other models of chemical carcinogenesis suggest that Ha‐ras activation has a critical role during tumor initiation. We have used laser‐capture microdissection and polymerase chain reaction–restriction fragment length polymorphism analysis to study the role of codon 12 Ha‐ras mutation at various stages of tumor development in the rat esophagus. Our results indicate that Ha‐ras mutation was present infrequently (4.3%) in premalignant lesions. The incidence of Ha‐ras mutation was high in papillomas (57.1%), however, and 50% of papillomas expressed mutant Ha‐ras RNA message. Additionally, there was a linear trend correlating increased incidence of Ha‐ras mutation with later papilloma stage. These data suggest the role of ras activation later in neoplastic development. To evaluate the potential mechanism of action by which Ha‐ras contributes to promotion and progression in this model, we compared mRNA expression of cyclin D1 and p27 in Ha‐ras mutant and Ha‐ras normal papillomas. We found no differences in mRNA expression of either cyclin D1 or p27 between these two papilloma populations. Our data suggest an important paradigm shift for the role of ras mutations in this model of chemical carcinogenesis, indicating a functional role of Ha‐ras activation in promotion/progression and not in the initiation phase of NMBA‐induced papillomagenesis.