A clinical study to assess the gingivitis reduction efficacy of a novel stannous-containing fluoride dentifrice.

PURPOSE: To assess the gingivitis reduction efficacy of a novel stannous-containing fluoride dentifrice relative to a negative control. METHODS: 100 generally healthy adults with 10 or more gingival bleeding sites based on the Mazza Modification of the Papillary Bleeding Index (Mazza GI) were enrolled into a 2-week randomized, controlled, double-blind, single-center, two-treatment, parallel group clinical study. The subjects were randomly assigned to the stannous-containing dentifrice group (experimental group) or the sodium fluoride dentifrice group (negative control group). An oral examination and Mazza GI examination were conducted at Baseline, Day 3 and Week 2 post-baseline by a qualified dental examiner. RESULTS: 98 subjects completed the study. The experimental group provided a significant reduction in Mazza GI scores and number of bleeding sites relative to baseline at Day 3 and Week 2 (P< 0.0001). The negative control did not provide significant reductions versus baseline for either measure at either timepoint (P> 0.3). At Day 3, the experimental group provided a statistically significant reduction of Mazza GI scores and number of bleeding sites compared with the negative control group (P< 0.0001). At Week 2, the experimental group showed 24.11% lower Mazza GI scores and 54.81% fewer bleeding sites than the negative control group (P< 0.0001). CLINICAL SIGNIFICANCE: The results demonstrated that the novel stannous-containing fluoride dentifrice had a superior anti-gingivitis effect compared to the sodium fluoride negative control dentifrice, which was evident as quickly as 3 days after use and further improved after 2 weeks of usage.

Is the Internet Different from Traditional Mass Media in Promoting Patient Compliance with Mature Treatments?

Background: Through mass media, some patients tend to seek mature treatment-related health information whereas some prefer information related to emerging treatments, which may influence patient compliance, specifically, following the medical diagnoses and treatment regimens. Given that traditional mass media (TMM) and the internet (INT) may promote the publication of different treatment-related information, this study aims to identify the difference between TMM and the INT in influencing patient compliance with mature treatments (PCMTs). Materials and Methods: Our subjects were Chinese who had received therapies within a month and had experience of seeking health information through mass media. An online survey involving 384 valid responses was conducted to collect data. The confirmatory factor analysis and structural equation modeling were adopted to test hypotheses. Results: Both TMM and the INT significantly affect PCMTs, through the mediation of mature treatment-related health information. Conclusions: A provision of mature treatment-related information via TMM can effectively help patients gain awareness and knowledge about treatments. In addition, physicians can update patients' knowledge by making cutting-edge treatments continuously available to patients through the mass media and analyzing patient's access patterns for different treatment-related information.

Enhancing direct cytotoxicity and response to immune checkpoint blockade following ionizing radiation with Wee1 kinase inhibition.

Tumor cells activate the G2/M cell cycle checkpoint in response to ionizing radiation (IR) and effector immune cell-derived granzyme B to facilitate repair and survival. Wee1 kinase inhibition reverses the ability of tumor cells to pause at G2/M. Here, we hypothesized that AZD1775, a small molecule inhibitor of Wee1 kinase, could sensitize tumor cells to IR and T-lymphocyte killing and improve responses to combination IR and programmed death (PD)-axis immune checkpoint blockade (ICB). Multiple models of head and neck carcinoma, lung carcinoma and melanoma were used in vitro and in vivo to explore this hypothesis. AZD1775 reversed G2/M cell cycle checkpoint activation following IR, inducing cell death. Combination IR and AZD1775 induced accumulation of DNA damage in M-phase cells and was rescued with nucleoside supplementation, indicating mitotic catastrophe. Combination treatment enhanced control of syngeneic MOC1 tumors in vivo, and on-target effects of systemic AZD1775 could be localized with targeted IR. Combination treatment enhanced granzyme B-dependent T-lymphocyte killing through reversal of additive G2/M cell cycle block induced by IR and granzyme B. Combination IR and AZ1775-enhanced CD8+ cell-dependent MOC1 tumor growth control and rate of complete rejection of established tumors in the setting of PD-axis ICB. Functional assays demonstrated increased tumor antigen-specific immune responses in sorted T-lymphocytes. The combination of IR and AZD1775 not only lead to enhanced tumor-specific cytotoxicity, it also enhanced susceptibility to T-lymphocyte killing and responses to PD-axis ICB. These data provide the pre-clinical rationale for the combination of these therapies in the clinical trial setting.

Medical service unity: an effective approach for medical care in rural areas in China.

CONTEXT: Medical care in rural China has long suffered because of a concentration of medical resources in major hospitals in cities. The patients in rural areas thus do not have affordable access to quality medical services. To tackle such issues, a tiered medical scheme (TMS) was promoted by the Chinese State Council in 2015. It divides hospitals into three tiers and encourages collaborations among different tiers within a region in order to provide better accessibility to medical care for patients in rural areas. ISSUES: The implementation of the TMS policy has not been successful, because the previous funding model, which allocated funding to each hospital according to the number of patients treated, did not facilitate close collaborations between different hospitals. In this report, the medical service unity (MSU) approach, which has been piloted in Funan county, is reported. The MSU organises the tiered hospitals as a unity in terms of medical capabilities and financial abilities. With the radical reform of financial decentralisation, three flows are thereby enabled: the funding flow binds together the hospitals into a unity, the patient flow shares the load across the providers and eases barriers to access, and the resource flow ensures accessibility and affordability for patients. LESSONS LEARNED: The MSU approach has been shown by the pilot project in Funan to be effective for the realisation of the TMS policy, benefiting hospitals, doctors and patients. The successful experience of the Funan MSU could be introduced to other regions across China and other countries. In particular, future finance reform policies for the health system would largely benefit the health reforms and especially the decentralisation of medical resources to rural areas.

A randomized 3-month clinical comparison of a power toothbrush to a manual toothbrush in the reduction of gingivitis.

PURPOSE: To compare the anti-gingivitis effect of a power toothbrush relative to a manual toothbrush control. METHODS: This was a 3-month, randomized and controlled, single-center, parallel group, examiner-blinded clinical study. 123 Chinese adults in good general health and with at least 15 gingival bleeding sites, as measured by the Gingival Bleeding Index, were enrolled into the study. At baseline, pre-treatment gingivitis levels were assessed using the Mazza Bleeding Index. Subjects were then randomly assigned to receive either an oscillating-rotating power toothbrush [Oral-B Professional Care 7000 (D17u/EB17)] or a flat-trim manual toothbrush with tapered filaments (Lion Dentor Systema). Subjects brushed at home twice-daily with their assigned toothbrush and a marketed sodium fluoride dentifrice (Crest Cavity Protection dentifrice), and were reevaluated at Months 1, 2, and 3. RESULTS: 113 evaluable subjects completed the study. Both groups showed significant reductions in gingivitis from baseline for all time points measured (P< 0.001). At Months 1, 2 and 3, the power toothbrush demonstrated significantly greater gingivitis reductions of 7.11%, 9.20% and 8.47%, respectively, than the manual toothbrush (P< 0.01), and significantly fewer bleeding sites (17.3%, 23.9% and 24.3%, respectively, P< 0.05). No adverse events were reported or observed for either brush during the study. CLINICAL SIGNIFICANCE: The power brush provided statistically significantly greater reductions in gingivitis compared with a manual toothbrush at Months 1, 2 and 3.

Usability of the Novel Liraglutide 3.0 mg Pen Injector Among Overweight or Obese Adult Patients With or Without Prior Injection Experience.

BACKGROUND: Obesity is associated with multiple comorbidities and increased mortality, making it an important target for treatment. However, achieving and maintaining weight loss by diet and physical activity remains challenging, and may often require pharmacotherapy. Liraglutide 3.0 mg has recently been approved for weight management in the United States, Canada, and EU. The current analysis used a summative usability test to assess safety and effectiveness, ease of use, and training requirements for the novel liraglutide 3.0 mg pen injector. METHODS: Of the 234 participants, half received instructions for use and video-based training and/or opportunity to handle the device. All participants (excluding pharmacists) performed 6 tasks followed by post- task interviews on task difficulty, device ease of use, and any use errors, close calls, and operational difficulties. Tasks included differentiation of correct box and pen injector, medication clarity assessment, normal, dose reversal, and end-of-content injection. Number/type of use errors, close calls, and operational difficulties were evaluated. RESULTS: All assessed participants interpreted the instructions for use correctly. No potentially serious use errors, and low numbers of nonserious errors, were reported. Overall, participants committed 105 use errors related to handling, with no potential for harm. A total of 25 close calls and 44 operational difficulties were reported without any pattern indicative of a design flaw. Marked differences in the incidence of events were observed for trained versus untrained participants regardless of prior injection experience. Participants rated ease of use as 6.4/7. CONCLUSIONS: The liraglutide 3.0 mg pen injector is safe and easy to use for liraglutide administration. New device features allow for safe use after brief training.

Information analytics for healthcare service discovery.

The concept of being 'patient-centric' is a challenge to many existing healthcare service provision practices. This paper focuses on the issue of referrals, where multiple stakeholders, such as General Practitioners (GPs) and patients, are encouraged to make a consensual decision based on patients' needs. In this paper, we present an ontology-enabled healthcare service provision, which facilitates both patients and GPs in jointly deciding upon the referral decision. In the healthcare service provision model, we define three types of profiles which represent different stakeholders' requirements. This model also comprises a set of healthcare service discovery processes: articulating a service need, matching the need with the healthcare service offerings, and deciding on a best-fit service for acceptance. As a result, the healthcare service provision can carry out coherent analysis using personalised information and iterative processes that deal with requirements which change over time.

Two-week extrinsic stain removal efficacy of a sodium fluoride dentifrice with high cleaning silica: results from two randomized, controlled clinical trials.

PURPOSE: To evaluate a stannous-containing sodium fluoride dentifrice with high cleaning silica and polychelation technology (test dentifrice) compared to a currently marketed whitening dentifrice, which carries the ADA Seal of Acceptance for whitening, for its efficacy in removing existing natural stain over a 2-week period. METHODS: Two independent, randomized, positive-controlled, 2-treatment, parallel group, double-blind, 2-week studies with identical protocols were conducted in China. At baseline, subjects received an oral soft tissue (OST) examination followed by a Lobene stain examination. In each study, approximately 60 subjects having a Lobene stain composite score above 1 were randomized to one of two dentifrice products: the test dentifrice or the positive control. Subjects were instructed to brush twice daily for at least 1 minute with their assigned product. Lobene stain and OST examinations were conducted again after 2 weeks of use. RESULTS: In both studies, the test dentifrice and the positive control dentifrice demonstrated statistically significant reductions in Lobene composite (P<0.0001), area (P<0.0001) and intensity (P<0.0001) stain scores after 2 weeks of use versus baseline. At Week 2, there were no statistically significant differences in stain scores between treatment groups in either study (P>0.12).

Rapid desensitizing efficacy of a stannous-containing sodium fluoride dentifrice.

OBJECTIVE: To evaluate the efficacy of an experimental stannous-containing sodium fluoride dentifrice (1450 ppm fluoride) in the reduction of dentinal hypersensitivity over a three-day period as compared to a positive control dentifrice containing 8% arginine, calcium carbonate, and 1450 ppm fluoride as sodium monofluorophosphate. METHODS: This study, conducted in China, had a controlled, randomized, examiner-blind, two-treatment, parallel-group design. Eighy-one healthy adult subjects with moderate dentinal hypersensitivity were enrolled, two bicuspid or cuspid teeth in different quadrants demonstrating reproducible thermal (cold air) sensitivity with a score of > 1 on the SchiffAir Sensitivity Scale were chosen for each subject. Subjects also assessed their own level of pain on a Visual Analog Scale (VAS). Subjects were randomized to treatment with either the experimental or positive control dentifrice. At the baseline visit, sensitivity to thermal stimuli was assessed by both the examiner (Schiff Air Sensitivity) and the subject (pain VAS), and subjects were instructed to brush with their assigned study dentifrice according to the manufacturer's instructions provided. Immediately after brushing, thermal sensitivity for each enrolled tooth was reassessed by both examiner and subject. Subjects used their assigned dentifrices at home for three days, after which thermal sensitivity was reassessed by both examiner and subject. Subjects received an oral soft tissue examination at baseline and on Day 3. RESULTS: Forty subjects in the experimental group and 41 subjects in the positive control group completed all study procedures. On the Schiff Air Sensitivity Scale, the experimental dentifrice provided statistically significant (p < 0.001) reductions of 14.8% and 54.1% in sensitivity relative to the positive control dentifrice immediately after first use and at Day 3, respectively. On the pain VAS, the experimental dentifrice provided statistically significant (p < 0.001) reductions of 22.3% and 74.1% in sensitivity relative to the positive control dentifrice immediately after first use and at Day 3, respectively. No adverse events were reported for any subject. CONCLUSION: An experimental stannous-containing sodium fluoride dentifrice provided significantly better dentin hypersensitivity relief relative to a positive control dentifrice both immediately and after three days of product use.

Clinical evaluation of the fast onset and sustained sensitivity relief of a 0.454% stannous fluoride dentifrice compared to an 8.0% arginine-calcium carbonate-sodium monofluorophosphate dentifrice.

PURPOSE: To evaluate the efficacy of a dentifrice containing 0.454% stannous fluoride (SnF2) in the reduction of dentin hypersensitivity immediately after use, after 3 days and after a 2-week use period as compared to a positive control dentifrice containing 8.0% arginine, calcium carbonate and 1450 ppm fluoride as sodium monofluorophosphate. METHODS: 80 healthy adult subjects with moderate dentin hypersensitivity were enrolled in this clinical study, which had a controlled, randomized, examiner-blind, two-treatment (40 subjects per treatment group), parallel group design. For each subject, two sensitive bicuspid or cuspid teeth in different quadrants demonstrating reproducible sensitivity to thermal stimuli (Schiff air sensitivity score of > 1) were chosen for evaluation. Subjects were randomized to treatment with either the SnF2 dentifrice or the positive control dentifrice. At the baseline visit, subjects were assessed for sensitivity to thermal stimuli, received an oral soft tissue examination, and were instructed to brush with their assigned dentifrice according to manufacturers' usage instructions. Immediately after brushing, sensitivity to thermal stimuli for each enrolled tooth was assessed by an experienced dental examiner using the Schiff air sensitivity index and by study subjects based on air visual analog scale (VAS). After using their assigned dentifrice for 3 days and for 2 weeks, thermal sensitivity was re-assessed by both examiner and subject, and each subject received an oral soft tissue examination. RESULTS: 40 subjects in the SnF2 dentifrice group and 38 subjects in the control group completed all study procedures. Both dentifrice groups showed significant sensitivity relief relative to baseline (P < 0.01). The SnF2 dentifrice provided a statistically significant (P = 0.005) 7.4% reduction in sensitivity relative to the positive control dentifrice immediately after first use and an even more significant (P = 0.001) 20% reduction at Week 2 based on the Schiff air sensitivity scale. Based on the VAS, the SnF2 dentifrice provided statistically significant (P < 0.0001) reduction in sensitivity relative to the positive control dentifrice immediately after first use, at Day 3, and Week 2, with percent reductions of 7.2%, 15.8% and 28.2%, respectively. No adverse events were reported with either dentifrice.

A randomized cross-over clinical trial to evaluate the effect of a 0.454% stannous fluoride dentifrice on the reduction of oral malodor.

PURPOSES: To compare the oral malodor protection efficacy of a 0.454% stannous fluoride dentifrice versus a negative control (0.243% sodium fluoride) using a sulfide monitor (halimeter) as the measurement. A secondary objective was to assess the effects of tongue brushing. METHODS: This was a four-treatment, five-period, examiner-blinded, crossover, randomized study. Healthy subjects who met the entrance criteria were enrolled into the study. A 5-day acclimation period, in which subjects brushed twice daily in their customary manner with a standard sodium fluoride dentifrice, occurred prior to baseline. After baseline halimeter measurements, subjects were randomly assigned to one of four treatments (SnF2 dentifrice groups, with or without tongue brushing; negative control dentifrice groups, with or without tongue brushing) based on baseline halimeter scores, age, and gender. Test products were used three times a day. Breath measurements were taken 24 hours after baseline (after three product uses). Subjects then brushed again with the product treatment. Final breath measurements were taken 4 hours later, 28 hours after baseline. A 5-day washout separated each treatment period. RESULTS: 33 subjects were enrolled and completed the study. The adjusted mean volatile sulfur compound (VSC) levels were significantly lower in the SnF2 groups than the NaF groups, at both 24 (P < 0.01) and 28 (P < 0.001) hours post baseline time points. Tongue brushing did not provide additional statistically significant breath benefits when compared to toothbrushing alone. Both dentifrices were well tolerated.

The desensitizing efficacy of a novel stannous-containing sodium fluoride dentifrice: an 8-week randomized and controlled clinical trial.

PURPOSE: To assess the efficacy of a novel stannous-containing dentifrice in the reduction of dentin hypersensitivity when compared to a marketed positive control dentifrice. METHODS: An 8-week, single-center, randomized, parallel group, two-treatment, double-blind clinical study was conducted in a generally healthy adult population with moderate thermal and tactile dentin hypersensitivity. A total of 60 adults were enrolled into the study. Participants were stratified at baseline by age, gender, and cold air sensitivity scores, and randomly assigned to either an experimental stannous-containing sodium fluoride dentifrice or a marketed potassium nitrate positive control. Brushing was supervised on site after baseline and Week 4 examinations. All other product usage was unsupervised. Subjects brushed 2 minutes twice daily. At baseline, Week 4 and Week 8, efficacy outcomes were assessed for tactile sensitivity via the Yeaple Probe, and for thermal sensitivity with air-blast/SchiffAir Index. RESULTS: Fifty-eight subjects completed all evaluations. Both the experimental stannous-containing and positive control dentifrices provided significant (P< 0.05) reductions in both tactile and thermal dentin hypersensitivity compared to baseline at both Weeks 4 and 8. There were no significant differences in Yeaple Probe or Schiff Air Index results between the dentifrices with either efficacy measurement at Week 4 and Week 8 (P > or = 0.5375).

The anti-plaque efficacy of a novel stannous-containing sodium fluoride dentifrice: a randomized and controlled clinical trial.

PURPOSE: To evaluate the anti-plaque efficacy of a novel stannous-containing sodium fluoride dentifrice compared to a negative control regular anti-caries dentifrice and a positive control marketed triclosan-containing dentifrice. METHODS: This was a randomized and controlled, single-center, double-blind, three-treatment, three-period, crossover clinical trial in generally healthy adults. A prophylaxis was followed by three 4-day treatment periods of limited brushing, each separated by an approximate 7-day washout phase. Subjects used the test dentifrice on Days 0-3 of each period according to their randomly assigned sequence; either Crest Cavity Protection (negative control); an experimental stannous-containing sodium fluoride dentifrice; or a marketed triclosan positive control (Colgate Total). A dental polishing was given at Day 0 of each treatment period, and subjects brushed the lingual surfaces only and then swished the entire dentition with a dentifrice slurry twice daily under supervision through Day 3. At baseline and Day 4 of each treatment period, plaque levels were assessed via the Turesky Modification of the Quigley-Hein Plaque Index (TMQHPI). RESULTS: Twenty-eight fully evaluable subjects completed the trial. Both the experimental and positive control dentifrices provided significantly lower mean whole mouth TMQHPI plaque scores after treatment compared to the negative control: 11.4% lower for the experimental stannous-containing dentifrice and 8.4% for Colgate Total (P< 0.0001). The experimental stannous-containing dentifrice group resulted in directionally lower whole mouth plaque scores when compared to Colgate Total (P= 0.07). The experimental stannous-containing dentifrice had significantly lower mean plaque scores post-treatment at lingual sites compared with Total (P= 0.0355). All dentifrices were well-tolerated.

Breath malodor reduction with use of a stannous-containing sodium fluoride dentifrice: a meta-analysis of four randomized and controlled clinical trials.

PURPOSE: To determine the effectiveness of a novel stannous-containing sodium fluoride dentifrice in reducing malodor-causing volatile sulfur compound (VSC) levels versus a standard marketed fluoride (negative control) anti-caries dentifrice using pooled data from independent clinical trials. METHODS: Four randomized and controlled, evaluator-blinded, 3- or 4-period, 2-treatment crossover clinical studies were conducted at four separate centers in Asia and the United States in subjects with a baseline VSC score of > 100 ppb. Following a week-long acclimation period, subjects were randomly assigned to a treatment sequence specifying the order of use of a stannous-containing sodium fluoride dentifrice and a negative control dentifrice (Crest Cavity Protection). VSC levels were assessed at four time points using a Halimeter during each treatment period: (1) baseline prior to treatment; (2) 3-4 hours after baseline and a single brushing; (3) 24 hours post-baseline and after two total brushings ("overnight"/"morning breath"); and (4) 27-28 hours post-baseline following three total product uses. Brushing instructions were standardized and required two minutes of timed toothbrushing with the assigned dentifrice. Washout periods of at least 2 days separated the treatment periods. RESULTS: A total of 100 subjects were included in the meta-analysis. The stannous-containing dentifrice showed statistically significantly greater breath benefits via VSC reduction compared to the negative control dentifrice (P < 0.047) at all three time points. The stannous-containing dentifrice provided increasingly greater superior relative breath protection benefits of 7.7% at Hour 3-4 post-baseline, 10.6% after 24 hours ("overnight"/"morning breath"), and 24.5% at Hour 27-28. Similar malodor reduction benefits in favor of the stannous-containing dentifrice relative to the negative control were observed for each individual study.

Clinical comparison of the plaque removal efficacy of a manual toothbrush with criss-cross bristle design.

PURPOSE: To compare the plaque removal efficacy of two manual toothbrushes: Oral-B Exceed and Asian Colgate 36 degrees manual toothbrush. METHODS: The study used an examiner-blind, two-treatment, randomized, four-period (visits) crossover design. Subjects used each brush twice during the study. At the first visit, 41 subjects who met inclusion criteria and provided informed consent received a baseline plaque examination using the Turesky Modified Quigley-Hein Plaque Index. Subjects then used their assigned toothbrush for 1 minute with a marketed toothpaste without access to a mirror. Brushing was monitored. A post-brushing plaque exam was then performed. Subjects were rescheduled for their next visit in approximately 3 days. At visits 2, 3 and 4 the same disclosing, brushing and plaque grading procedures were followed. Subjects used their own products at home between visits. RESULTS: 39 subjects presented data for all four study periods; two subjects missed one period each. Baseline plaque scores were balanced between the two groups. Adjusted mean plaque removal (baseline minus post-brushing) scores were 0.479 for the Exceed toothbrush and 0.425 for the Asian Colgate 360 degrees toothbrush (P < 0.002). This translates to 12.7% greater plaque removal for the Exceed toothbrush versus the Asian Colgate 360 degrees toothbrush. No adverse events were reported during the study.

Autophagy induced by farnesyltransferase inhibitors in cancer cells.

The mechanisms of action of farnesyltransferase inhibitors (FTIs) involve Rheb and the phosphatidylinositide 3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway. mTOR in particular plays a key role in the regulation of autophagy. Collectively, the literature suggests that FTIs very likely induce autophagy, but thus far there have been no reports that FTIs affect this process relevant to cancer cell biology. We hypothesized that FTIs can induce autophagy. In this study, we found that the FTIs manumycin A, FTI-276, and lonafarnib induced autophagy in two human cancer cell lines. We also found that neither inhibition of apoptosis with a pan-caspase inhibitor nor inhibition of autophagy increased the number of clones of lonafarnib-treated U2OS osteosarcoma cells that formed in soft agar. Although whether autophagy is a cell death or cell survival mechanism after FTI treatment remains unresolved, our data show that cancer cells apparently can shift between apoptosis and autophagy once they are committed to die after FTI treatment.

Combination chemotherapy including combretastatin A4 phosphate and paclitaxel is effective against anaplastic thyroid cancer in a nude mouse xenograft model.

CONTEXT: Anaplastic thyroid cancer (ATC) is extremely aggressive, and no effective treatment is available. Combretastatin A4 phosphate (CA4P), a vascular disrupting agent, has limited activity against ATC in a clinical trial, and so does paclitaxel. OBJECTIVE: We hypothesized that a triple-drug combination including CA4P and paclitaxel would improve efficacy against ATC. Therefore, we evaluated two such combinations in vivo. SETTING: We used a nude mouse xenograft model with ARO and KAT-4 cells. INTERVENTIONS: The first combination consisted of CA4P, paclitaxel, and manumycin A (a farnesyltransferase inhibitor), and the second, CA4P, paclitaxel, and carboplatin. MAIN OUTCOME MEASURES: Main outcome measures included tumor growth curves and tumor weights. RESULTS: Tumor growth curve analysis (linear mixed models, P < 0.05) and xenograft weight analysis (Kruskal-Wallis one-way ANOVA on ranks, post hoc pairwise comparison, Dunn's test, P < 0.05) demonstrated that both triple-drug combinations were significantly better than placebo for both cell lines. Anti-bromodeoxyuridine immunostaining of xenograft sections from animals injected with bromodeoxyuridine before being killed showed that CA4P alone did not inhibit DNA synthesis, but manumycin A and paclitaxel did. CA4P decreased the depth of the viable outer rim of tumor cells on xenograft sections. Using electron microscopy, we found blebbing/budding of endothelial cells into capillary lumens and autophagy of tumor cells in CA4P-treated xenografts. CONCLUSIONS: Both triple-drug combinations demonstrated excellent antineoplastic activity against ATC. The correlative findings in xenografts were consistent with vascular disruption but not direct inhibition of cell proliferation as the primary antineoplastic mechanism contributed by CA4P. These regimens warrant further investigation in clinical trials for ATC.

Redox control of manumycin A-induced apoptosis in anaplastic thyroid cancer cells: involvement of the xenobiotic apoptotic pathway.

Our previous studies demonstrated that manumycin A, a farnesyltransferase inhibitor, induced apoptosis of anaplastic thyroid cancer cells via the intrinsic apoptosis pathway and induced reactive oxygen species (ROS), which mediated DNA damage. In this study, we investigated the hypothesis that the mechanism of apoptosis induced by manumycin in anaplastic thyroid cancer cells fits the general pattern of the "xenobiotic apoptosis pathway," the hallmarks of which are induction of oxidative stress, mitogen-activated protein kinase (MAPK) signaling, and cytochrome c release, which activates the intrinsic apoptosis pathway. We found that manumycin reduced intracellular glutathione and generated ROS: nitric oxide and superoxide anions. Manumycin-induced apoptosis correlated with increase in ROS. Quenching of ROS with N-acetyl-L-cysteine prevented cytochrome c release by manumycin. Manumycin induced phosphorylation of p38 MAPK, which was blocked by N-acetyl-L-cysteine. p38 MAPK may be an important signaling mediator in the activation of the intrinsic apoptotic pathway by manumycin because the p38 MAPK inhibitor SB203580 inhibited cytochrome c release and activation of caspase-3 by manumycin. In conclusion, manumycin activated the intrinsic apoptosis pathway via activation of p38 MAPK by oxidative stress. The mechanism of apoptosis induced by manumycin fits the emerging general pattern for apoptosis induced by xenobiotics.

Farnesyltransferase inhibitors induce DNA damage via reactive oxygen species in human cancer cells.

Farnesyltransferase inhibitors (FTIs) possess antitumor activity. Based on recent findings, we hypothesized that FTIs induce reactive oxygen species (ROS) that damage DNA, leading to DNA damage responses. To test this hypothesis, we investigated the effects of FTIs on the generation of ROS, DNA double-strand breaks (DSB), DNA damage responses, and RhoB, and the effects of quenching ROS on these FTI effects. We evaluated four FTIs in human cancer cell lines of different tissue origins. We found that FTIs induced ROS and DSBs. Suppressing expression of the beta-subunit of farnesyltransferase with siRNA did not induce ROS, but slightly attenuated the ROS induced by FTIs. N-acetyl-L-cysteine (NAC), but not caspase inhibitors, blocked FTI-induced DSBs, suggesting that the DSBs were caused by ROS and did not result from apoptosis. The DSBs led to DNA damage responses. H2AX became phosphorylated and formed nuclear foci. The DNA-damage-sensing molecules involved were probably ataxia-telangiectasia mutated protein (ATM) and DNA-dependent protein kinase (DNA-PK) but not ATM- and Rad3-related protein (ATR). Key components of the homologous recombination and nonhomologous end joining repair pathways (DNA-PK, BRCA1, and NBS1) underwent phosphorylation and formed nuclear foci. RhoB, a mediator of the antineoplastic effect of FTIs and a protein inducible by DNA damage, was increased by FTIs. This increase was blocked by NAC. We concluded that FTIs induced oxidative DNA damage by inducing ROS and initiated DNA damage responses, including RhoB induction, and there was a complex relationship among FTIs, farnesyltransferase, ROS, and RhoB. Our data also imply that inhibitors of DNA repair may accentuate the clinical efficacy of FTIs.