Biomedical subjects

David R Jones

Publications and source records attributed to David R Jones.

At least 55 records · Page 3Linked to original sources

PubMed2005

Suberoylanilide hydroxamic acid combined with gemcitabine enhances apoptosis in non-small cell lung cancer.

BACKGROUND: We have shown that non-small cell lung cancer (NSCLC) is resistant to the histone deacetylase inhibitor (HDI) suberoylanilide hydroxamic acid (SAHA) through upregulation of the antiapoptotic transcription factor nuclear factor-kappaB (NF-kappaB). HDIs also promote chromatin remodeling, potentially making the DNA more accessible to chemotherapy. We hypothesize that combined SAHA and gemcitabine sensitizes NSCLC to apoptosis. METHODS: Three NSCLC cell lines (A549, H358, H460) were untreated, or treated with SAHA, gemcitabine, or both agents. NF-kappaB-dependent transcription was determined by reporter gene assays, reverse transcriptase-polymerase chain reaction RT-PCR, and Western blot analysis for the NF-kappaB-regulated antiapoptotic gene MnSOD. Survival of NSCLC cells overexpressing Bfl/A1, Bcl-X(L), or MnSOD and treated with SAHA and gemcitabine was determined in the presence or absence of NF-kappaB. Survival of treated cells overexpressing HDAC-1, 2, 3 or p/CAF was determined. Apoptosis was determined by fluorescence-activated cell sorter analysis, DNA fragmentation, and caspase-3 activity. Colony formation assays were performed on cells treated concurrently and sequentially with SAHA and gemcitabine. Assays were performed in triplicate, and the Student t test was applied as appropriate. RESULTS: SAHA-activated NF-kappaB (P <or= .05) and gemcitabine inhibited these effects (P <or= .01). Increased cell survival was observed after overexpression of antiapoptotic genes, as well as in cells overexpressing HDAC-1, -2, and -3. Fluorescence-activated cell sorter analysis, DNA fragmentation, and caspase-3 assays all showed enhanced apoptosis with combined therapy, compared with single-agent therapy (P <or= .01). Sequential treatment offered no improvement over concurrent treatment. CONCLUSIONS: Combined SAHA and gemcitabine sensitized NSCLC cells to apoptosis. Potential "proapoptotic" mechanisms for this finding include gemcitabine inhibition of SAHA-induced NF-kappaB activation and chromatin remodeling mediated by the inhibition of histone deacetylases.

Acetylation↗

PubMed2005

Biotransformation of nitric oxide in the cerebrospinal fluid of amyotrophic lateral sclerosis patients.

Recent findings indicate that nitric oxide (NO*) over-production might be an important factor in the pathogenesis of sporadic amyotrophic lateral sclerosis (SALS). We measured significantly higher concentrations of uric acid and thiol group-containing molecules (R-SH groups) in the cerebrospinal fluid (CSF) from SALS patients compared to controls. The above factors, together with a slightly increased free iron concentration found in the CSF, favour conditions necessary for the formation of the dinitrosyl iron complex, capable of NO* bio-transformation. Thus, we performed ex vivo saturation of CSF (from both SALS patients and controls) with NO*. A decrease in the level of R-SH was found. This was more pronounced in the CSF from SALS patients. In the CSF from SALS patients the production of nitrite and hydroxylamine was greater than that observed in the CSF from controls. Moreover, we also found increased Cu,Zn-SOD activity in the CSF from SALS patients (when compared to control subjects) but no activity corresponding to Mn-SOD in any CSF samples. As Cu,Zn-SOD can react with nitroxyl forming NO*, the conditions for a closed, but continuous, loop of NO* biotransformation are present in the CSF of ALS patients.

Adult↗

PubMed2005

The use of systematic reviews when designing studies.

BACKGROUND: The importance of systematic reviews in identifying gaps in the evidence base and providing a quantitative basis for informing new research initiatives is widely acknowledged, but little is known about what actually happens in practice. Our objective was to assess the use made of results of reviews in the designing of new studies. METHODS: Of all Cochrane reviews published in 1996, those updated in 2002 or 2003 were identified. Authors of trials added in the updates were contacted and asked if use had been made of the 1996 Cochrane or other reviews in designing their study. RESULTS: Of 32 authors of studies newly included in 33 Cochrane reviews which met our inclusion criteria, 24 (75%) responded. Eleven (46%) respondents were aware of the relevant Cochrane review at the time they designed their study. In eight (33%) cases the design of the new study had been influenced by a review; in two (8%) this was the relevant Cochrane review. CONCLUSIONS: Cautious interpretation of these results is necessary, but it is apparent that the proportion of study investigators using Cochrane or other systematic reviews in designing their new studies was very limited. Inclusion of encouragement in publication or application guidelines to consider and cite review results is desirable.

Clinical Trials as Topic↗

PubMed2004

The effect of O2 and CO2 on the dive behavior and heart rate of lesser scaup ducks (Aythya affinis): quantification of the critical PaO2 that initiates a diving bradycardia.

Lesser scaup ducks were trained to dive for short and long durations following exposure to various gas concentrations to determine the influence of oxygen (O2) and carbon dioxide (CO2) on diving behavior and heart rate. Compared with normoxia, hyperoxia (50% O2) significantly increased the duration of long dives, whereas severe hypoxia (9% O2) significantly decreased the duration of both short and long dives. Hypercapnia (5% CO2) had no effect on dive duration. Surface intervals were not significantly altered by the oxygen treatments, but significantly increased following CO2 exposure. Heart rate during diving was unaffected by hyperoxia and hypercapnia, but gradually declined in long dives after severe hypoxia. Thus, our results suggest that during the majority of dives, O2 and CO2 levels in lesser scaup ducks are managed through changes in diving behavior without any major cardiovascular adjustments, but below a threshold PaO2, a bradycardia is evoked to conserve the remaining oxygen for hypoxia sensitive tissues. A model of oxygen store utilization during voluntary diving was developed to estimate the critical PaO2 below which bradycardia is initiated (approximately 26 mmHg) and predicted that this critical PaO2 would be reached 19s into a dive after exposure to severe hypoxia, which corresponded exactly with the time of initiation of bradycardia in the severe hypoxia trials.

Analysis of Variance↗

PubMed2004

Mechanism-based inactivation of CYP3A by HIV protease inhibitors.

Human immunodeficiency virus (HIV) protease inhibitors (PIs) are inhibitors of CYP3A enzymes, but the mechanism is poorly defined. In this study, time- and concentration-dependent decreases in activity as defined by maximum rate of inactivation (k(inact)) and inhibitor concentration that gives 50% maximal inactivation (K(I)) of CYP3A by amprenavir, indinavir, lopinavir, nelfinavir, ritonavir, and saquinavir were quantified using testosterone 6beta-hydroxylation as a marker for CYP3A activity with recombinant CYP3A4(+b(5)), recombinant CYP3A5, and pooled human liver microsomes (HLMs). All the PIs, except indinavir, displayed inactivation with CYP3A4(+b(5)) and HLMs. Ritonavir was the most potent (K(I) = 0.10 and 0.17 microM) and demonstrated high k(inact) values (0.32 and 0.40 min(-1)) with both CYP3A4(+b(5)) and HLMs. Ritonavir was not significantly depleted by high-affinity binding with CYP3A4(+b(5)) and confirmed that estimation of reversible inhibition was confounded with irreversible inhibition. For CYP3A5, nelfinavir exhibited the highest k(inact) (0.47 min(-1)), but ritonavir was the most potent (K(I) = 0.12 microM). Saquinavir and indinavir did not show time- and concentration-dependent decreases in activity with CYP3A5. Spectrophototmetrically determined metabolic intermediate complex formation was observed for all of the PIs with CYP3A4(+b(5)), except for lopinavir and saquinavir. The addition of nucleophilic and free aldehyde trapping agents and free iron and reactive oxygen species scavengers did not prevent inactivation of CYP3A4(+b(5)) by ritonavir, amprenavir, or nelfinavir, but glutathione decreased the inactivation by saquinavir (17%) and catalase decreased the inactivation by lopinavir (39%). In conclusion, all the PIs exhibited mechanism-based inactivation, and predictions of the extent and time course of drug interactions with PIs could be underestimated if based solely on reversible inhibition.

Aldehydes↗

PubMed2004

Modulation of NF-kappaB-dependent transcription and cell survival by the SIRT1 deacetylase.

NF-kappaB is responsible for upregulating gene products that control cell survival. In this study, we demonstrate that SIRT1, a nicotinamide adenosine dinucleotide-dependent histone deacetylase, regulates the transcriptional activity of NF-kappaB. SIRT1, the mammalian ortholog of the yeast SIR2 (Silencing Information Regulator) and a member of the Sirtuin family, has been implicated in modulating transcriptional silencing and cell survival. SIRT1 physically interacts with the RelA/p65 subunit of NF-kappaB and inhibits transcription by deacetylating RelA/p65 at lysine 310. Treatment of cells with resveratrol, a small-molecule agonist of Sirtuin activity, potentiates chromatin-associated SIRT1 protein on the cIAP-2 promoter region, an effect that correlates with a loss of NF-kappaB-regulated gene expression and sensitization of cells to TNFalpha-induced apoptosis. While SIRT1 is capable of protecting cells from p53-induced apoptosis, our work provides evidence that SIRT1 activity augments apoptosis in response to TNFalpha by the ability of the deacetylase to inhibit the transactivation potential of the RelA/p65 protein.

Base Sequence↗

PubMed2004

Finding qualitative research: an evaluation of search strategies.

BACKGROUND: Qualitative research makes an important contribution to our understanding of health and healthcare. However, qualitative evidence can be difficult to search for and identify, and the effectiveness of different types of search strategies is unknown. METHODS: Three search strategies for qualitative research in the example area of support for breast-feeding were evaluated using six electronic bibliographic databases. The strategies were based on using thesaurus terms, free-text terms and broad-based terms. These strategies were combined with recognised search terms for support for breast-feeding previously used in a Cochrane review. For each strategy, we evaluated the recall (potentially relevant records found) and precision (actually relevant records found). RESULTS: A total yield of 7420 potentially relevant records was retrieved by the three strategies combined. Of these, 262 were judged relevant. Using one strategy alone would miss relevant records. The broad-based strategy had the highest recall and the thesaurus strategy the highest precision. Precision was generally poor: 96% of records initially identified as potentially relevant were deemed irrelevant. Searching for qualitative research involves trade-offs between recall and precision. CONCLUSIONS: These findings confirm that strategies that attempt to maximise the number of potentially relevant records found are likely to result in a large number of false positives. The findings also suggest that a range of search terms is required to optimise searching for qualitative evidence. This underlines the problems of current methods for indexing qualitative research in bibliographic databases and indicates where improvements need to be made.

Breast Feeding↗

PubMed2004

Role of diacylglycerol induced by hypoxia in the regulation of HIF-1alpha activity.

Hypoxia-inducible factor 1 (HIF-1) is a critical transcription factor for the adaptation to lowered oxygen environments. We have previously reported that hypoxia induced phosphatidic acid (PA) accumulation through diacylglycerol kinase (DGK) activity and provided evidence that this PA production regulated HIF-1 expression. Here we report that hypoxia also produces a marked intracellular accumulation of diacylglycerol (DAG) in different cell types. The previously proposed inhibitor of phosphatidylcholine phospholipase C (PC-PLC)/sphingomyelin synthase (SMS) activities, D609, specifically abrogates both hypoxia-dependent DAG accumulation and hypoxia-induced HIF-1 expression. We show that DAG-dependent protein kinase C (PKC) isoforms do not play an essential role in the regulation of HIF-1 expression. D609 inhibits PA accumulation triggered by hypoxia, suggesting that DAG could act as substrate for its conversion into PA by DGK upon these conditions. Therefore, this work provides novel evidence for the existence of DAG/PA-dependent intracellular mechanisms involved in the regulation of HIF-1 expression.

Bridged-Ring Compounds↗

PubMed2004

A systematic review of molecular and biological tumor markers in neuroblastoma.

PURPOSE: The aim of this study was to conduct a systematic review, and where possible meta-analyses, of molecular and biological tumor markers described in neuroblastoma, and to establish an evidence-based perspective on their clinical value for the screening, diagnosis, prognosis, and monitoring of patients. EXPERIMENTAL DESIGN: A well-defined, reproducible search strategy was used to identify the relevant literature from 1966 to February 2000. RESULTS: A total of 428 papers studying the use of 195 different tumor markers in neuroblastoma were identified. Small sample sizes, poor statistical reporting, large heterogeneity across studies (e.g., in cutoff levels), and publication bias limited meta-analysis to the area of prognosis only; MYCN, chromosome 1p, DNA index, vanillylmandelic acid:homovanillic acid ratio, CD44, Trk-A, neuron-specific enolase, lactate dehydrogenase, ferritin, and multidrug resistance were all identified as potentially important prognostic tools. CONCLUSIONS: This systematic review forms a knowledge base of the tumor markers studied thus far in neuroblastoma, and has identified some of the most important prognostic markers, which should be considered in future research and treatment strategies. Importantly, the review has also highlighted some general problems across primary tumor marker studies, in particular poor and heterogeneous reporting. These need to be addressed to allow better clinical interpretation and enable more appropriate evidence-based reviews in the future. In particular, collaboration of cancer research groups is needed to enable bigger sample sizes, standardize methods of analysis and reporting, and facilitate the pooling of individual patient data.

Biomarkers, Tumor↗

PubMed2004

The role of sleep-disordered breathing, daytime sleepiness, and impaired performance in motor vehicle crashes-a case control study.

STUDY OBJECTIVE: To examine levels of sleep-disordered breathing, daytime sleepiness, and impaired performance in 60 motor vehicle crash drivers and 60 controls matched for age, gender, and body mass index. MEASUREMENTS AND RESULTS: All participants underwent polysomnography and daytime function assessments. Cases reported significantly higher levels of driver sleepiness (% sleepiness: mean +/- SD; cases: 26 +/- 17%; controls: 16 +/- 12%; p = 0.003) and demonstrated slower reaction times on a sustained attention task ( p = 0.02). There was a trend for more objective sleepiness in cases (maintenance of wakefulness test: cases: 17 +/- 4 minutes; controls: 18 +/- 3 minutes, p = 0.06) despite no differences in general subjective sleepiness (Epworth score: cases: 8 +/- 4; controls: 8 +/- 4; p = 0.93). There were no significant differences in polysomnography measures between groups (apneas + hypopneas per hour slept: cases: 8 +/- 9; controls: 9 +/- 16; p = 0.89; arousals per hour slept: cases: 18 +/- 8; controls: 21 +/- 12; p = 0.11). CONCLUSION: Crash drivers demonstrated significantly more driver sleepiness, slower reaction times and a trend for greater objective sleepiness compared with well-matched controls. However, the findings in crash drivers were independent of medical causes of sleep fragmentation, with both cases and controls showing moderate levels of unrecognized mild sleep-disordered breathing. Crash prevention strategies should focus on increasing personal awareness of the risks of sleepiness behind the wheel in all individuals.

Accidents, Traffic↗

PubMed2004

Elevated posture for the management of obstructive sleep apnea.

This study aimed to evaluate the effectiveness of elevated posture in the management of obstructive sleep apnea (OSA). Fourteen subjects presenting with mild-moderate OSA, (apnea-hypopnea index [AHI] 10 to 60/h), were included in a randomized crossover investigation. A shoulder-head elevation pillow (SHEP) was compared with nasal continuous positive airway pressure (nCPAP) therapy. Treatment success was defined as AHI 10<16/h. Four subjects achieved treatment success with the SHEP and three achieved partial success. The remaining seven subjects were treatment failures. In contrast, success was achieved with nCPAP in 12 subjects. One subject achieved partial success and one was a treatment failure. With the SHEP, the mean AHI decreased from 27+/-12/h to 21+/-17/h. With nCPAP, the mean AHI was 5+/-3/h; (p=0.008 for the difference between treatments). Although somewhat variable, these data provide evidence that elevated posture during sleep is helpful in the management of OSA in some individuals. Results support the use of elevated posture as second-line therapy in the management of OSA. However, no relationships could be identified between baseline data, including the identification of positional OSA, and objective outcomes that might predict patients who are likely to benefit from treatment in an elevated position.

Body Mass Index↗

PubMed2004

A novel technique for localization and excisional biopsy of small or ill-defined pulmonary lesions.

BACKGROUND: The purpose of this study was to develop and evaluate radiotracer-guided localization of small or ill-defined pulmonary nodules for thoracoscopic excisional biopsy. METHODS: This study consisted of two parts: a laboratory study in rats to determine the most suitable radiotracer, and a pilot study in humans to determine the feasibility of radiotracer lung nodule localization. The right lung of 12 rats was injected with a technetium 99m (Tc 99m) based radiotracer solution: 4 each with macroaggregated albumin (MAA), unfiltered sulfur colloid (SC), and pertechnetate (TcO(4)). Serial imaging was performed using a small animal gamma camera for 4 hours following injection. In 13 patients, computed tomographic (CT) guided injection of Tc 99m MAA solution was made into or adjacent to a pulmonary nodule suspicious for primary lung cancer. Gamma probe localization of the nodule was performed during subsequent thoracoscopic surgery. RESULTS: In the animal model, MAA provided more precise localization than SC or TcO(4) and was selected for the human study. In the human series, all 13 patients had successful gamma probe localization of their lesion. There were no radiologic or surgical complications. Seven of 13 nodules were malignant, and five of these nodules were stage IA primary lung carcinomas. CONCLUSIONS: Computed tomographic-guided radiotracer localization of small or ill-defined pulmonary nodules using Tc 99 m MAA before thoracoscopic excisional biopsy is feasible and may make excisional biopsy the preferred management strategy for the management of small pulmonary nodules in patients at high risk for malignancy.

Aged↗

PubMed2004

Proteasome inhibition sensitizes non-small-cell lung cancer to gemcitabine-induced apoptosis.

BACKGROUND: My colleagues and I have previously shown that chemotherapy activates the antiapoptotic transcription factor nuclear factor (NF)-kappaB in non-small-cell lung cancer (NSCLC). We hypothesized that inhibition of NF-kappaB by using the proteasome inhibitor bortezomib (Velcade) would sensitize NSCLC to gemcitabine-induced apoptosis. METHODS: Tumorigenic NSCLC cell lines (H157 and A549) were treated with nothing, gemcitabine, bortezomib, or both compounds. NF-kappaB activity was determined by nuclear p65 protein levels, electrophoretic mobility shift assays, and reverse transcription-polymerase chain reaction of the NF-kappaB-regulated genes interleukin-8, c-IAP2, and Bcl-xL. The p21 and p53 protein levels were determined in similarly treated cells. Cell-cycle dysregulation was assessed by fluorescence-activated cell sorting analysis. Cell death and apoptosis were quantified by clonogenic assays, caspase-3 activation, and DNA fragmentation. NSCLC A549 xenografts were generated and treated as noted previously. Tumor growth was assessed over a 4-week treatment period. Statistical analysis was performed with analysis of variance. RESULTS: Gemcitabine enhanced nuclear p65 levels, NF-kappaB binding to DNA, and transcription of all NF-kappaB-regulated genes. Bortezomib inhibited each of these effects. Combined gemcitabine and bortezomib enhanced p21 and p53 expression and induced S-phase and G2/M cell-cycle arrests, respectively. Combined treatment killed 80% of the NSCLC cells and induced apoptosis, as determined by caspase-3 activation (p = 0.05) and DNA fragmentation (p = 0.02). NSCLC xenografts treated with combination therapy grew significantly slower than xenografts treated with gemcitabine alone (p = 0.02). CONCLUSIONS: Bortezomib inhibits gemcitabine-induced activation of NF-kappaB and sensitizes NSCLC to death in vitro and in vivo. This combined treatment strategy warrants further investigation and may represent a reasonable treatment strategy for select patients with NSCLC given the current clinical availability of both drugs.

Adenocarcinoma↗

PubMed2004

Linking lipids to chromatin.

Dynamic regulation of chromatin structure is thought to be a prerequisite for nuclear functions that require accessibility to DNA such as replication, transcription and DNA repair. The phosphoinositide (PI) pathway is a second messenger signalling system regulated in response to a variety of extracellular (growth factors, differentiation signals) and intracellular (cell cycle progression, DNA damage) stimuli. The presence of a PI pathway in the nucleus together with the recent findings that specific nuclear proteins can interact with and are regulated by phosphoinositides suggest that changes in the nuclear phosphoinositide profile may have a direct role in modulating chromatin structure.

Chromatin↗

PubMed2004

Proteasome inhibition sensitizes non-small cell lung cancer to histone deacetylase inhibitor-induced apoptosis through the generation of reactive oxygen species.

OBJECTIVES: The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces apoptosis in some malignancies through mitochondrial injury and generation of reactive oxygen species. Histone deacetylase inhibitors also activate the antiapoptotic transcription factor nuclear factor kappaB. We hypothesize that proteasome inhibition with bortezomib (Velcade; Millennium Pharmaceuticals, Inc, Cambridge, Mass)will inhibit nuclear factor kappaB activation, enhance suberoylanilide hydroxamic acid-induced mitochondrial injury, and sensitize non-small cell lung cancer cells to apoptosis. METHODS: Four tumorigenic non-small cell lung cancer cell lines were treated with nothing, suberoylanilide hydroxamic acid, bortezomib, or both drugs. Nuclear factor kappaB-dependent transcription was determined by reporter gene assays and endogenous interleukin 8 transcription. Reactive oxygen species were quantified by using the fluorophore H 2 DCFDA. Cell viability was determined on the basis of clonogenic survival, and apoptosis was measured by quantifying caspase-3 activity and DNA fragmentation. Apoptosis and cell-survival assays were repeated in similarly treated cells incubated in the presence or absence of N-acetyl cysteine. Statistical significance was determined by means of analysis of variance. RESULTS: Suberoylanilide hydroxamic acid significantly enhanced interleukin 8 and nuclear factor kappaB-dependent reporter gene transcription, and these effects were inhibited by bortezomib ( P < or = .01). Combined treatment with suberoylanilide hydroxamic acid and bortezomib induced greater reactive oxygen species generation, more apoptosis ( P < or = .02), and more cell death ( P < or = .001) than either drug alone. N-acetyl cysteine diminished the induction of apoptosis and enhanced cell survival ( P < or = .04). CONCLUSIONS: Suberoylanilide hydroxamic acid and bortezomib synergistically induce reactive oxygen species generation in non-small cell lung cancer, and this plays a critical role in the induction of apoptosis after treatment. Combined treatment with suberoylanilide hydroxamic acid and bortezomib might be an effective treatment strategy for non-small cell lung cancer.

Apoptosis↗

PubMed2004

Combined histone deacetylase and NF-kappaB inhibition sensitizes non-small cell lung cancer to cell death.

BACKGROUND: Non-small cell lung cancer (NSCLC) remains resistant to traditional and novel chemotherapeutic agents, relating, in part, to the activation of the antiapoptotic transcription factor NF-kappaB. We hypothesize that inhibition of NF-kappaB using BAY-11-7085 will sensitize NSCLC cells to death, induced by the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA). METHODS: Five tumorigenic NSCLC cell lines (A549, H157, H358, H460, H1299) were treated with nothing, SAHA, BAY-11-7085, or both compounds. Cell death was determined by crystal violet staining. p65 nuclear translocation was determined by Western blot analysis. NF-kappaB activity was determined by reporter-gene assays and by reverse transcriptase-polymerase chain reaction of the endogenous NF-kappaB-dependent gene interleukin 8. Apoptosis was determined by DNA fragmentation. Clonogenic cell survival assays were also performed. Data was analyzed with the Student t test when appropriate. RESULTS: SAHA alone resulted in no meaningful NSCLC cell death. SAHA induced nuclear translocation of p65, which was inhibited by BAY-11-7085. SAHA significantly induced NF-kappaB-dependent transcription which was ameliorated after treatment with BAY-11-7085 (P = .01). Combined SAHA and BAY-11-7085 induced significantly more apoptosis and cell death than either drug alone (P = .002). CONCLUSIONS: Combined HDI and NF-kappaB inhibition using BAY-11-7085 sensitizes NSCLC cells to cell death and appears promising as a novel treatment strategy for this disease.

Active Transport, Cell Nucleus↗

PubMed2004

Combined proteasome and histone deacetylase inhibition in non-small cell lung cancer.

OBJECTIVE: Inhibitors of histone deacetylases are potent inducers of cell-cycle arrest and apoptosis in certain malignancies. We have previously demonstrated that chemotherapy activates the antiapoptotic transcription factor nuclear factor kappa B in non-small cell lung cancer and fails to induce significant levels of apoptosis. We hypothesize that nuclear factor kappa B inhibition with the proteasome inhibitor bortezomib (formerly known as PS-341) will sensitize non-small cell lung cancer cells to histone deacetylase inhibitor-mediated apoptosis. METHODS: Tumorigenic non-small cell lung cancer cells (A549, H358, and H460) were treated with bortezomib, followed by the histone deactylase inhibitor sodium butyrate. After treatment, nuclear factor kappa B transcriptional activity was measured by using a luciferase reporter assay and transcription of the nuclear factor kappa B-dependent gene IL8. Apoptosis was determined on the basis of caspase-3 activation and DNA fragmentation. Western blot analyses for the cell-cycle regulatory proteins p21 and p53 were performed, and cell-cycle alterations were determined by means of FACS analysis. Experiments were performed in triplicate, and statistical significance was determined by using unpaired t tests. RESULTS: Butyrate increased nuclear factor kappa B transcriptional activity 4-fold relative to that seen in control cells (P =.05) in all non-small cell lung cancer cell lines. Treatment with bortezomib reduced butyrate-induced activation of nuclear factor kappa B to baseline levels. The proteins p21 and p53 were stabilized after treatment with bortezomib, correlating with a G(2)/M cell-cycle arrest. Treatment with butyrate alone resulted in minimal apoptosis, but combined histone deacetylase and proteasome inhibition increased apoptosis 3- to 4-fold (P =.02). CONCLUSIONS: Combined molecular targeting of histone deacteylases and proteasomes synergistically induced apoptosis in non-small cell lung cancer. Pharmacologic nuclear factor kappa B suppression through proteasome inhibition, followed by treatment with histone deacetylase inhibitors, might represent a novel treatment strategy for patients with non-small cell lung cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2004

Providing more up-to-date estimates of patient survival: a comparison of standard survival analysis with period analysis using life-table methods and proportional hazards models.

OBJECTIVE: Standard survival methods can yield out-of-date estimates of long-term survival. Period analysis, based on life-table methodology, provides more up-to-date survival estimates by exploring survival during a restricted recent period of interest. It excludes the short-term survival of patients recruited at the start of the study. We use statistical models to further develop the method of period analysis, providing more up-to-date estimates of survival and the ability to explore differences in survival by covariates and adjust for case mix. METHODS: We use cancer registry data for colorectal cancer in Leicestershire, UK, to illustrate the use of Cox proportional hazards (CPH) models to estimate period and standard survival. We compare these estimates with those obtained using life-table methodology. RESULTS: Period estimates were slightly higher than the standard estimates as they reflect recent improvements in short-term survival. The results for period analysis using the life-table approach and using CPH models were similar. However, CPH models allowed further investigation of other risk factors and the ability to control for potential confounding variables. CONCLUSION: Using period survival estimates, more up-to-date information is available to clinicians and others with an interest in monitoring survival. Period CHP models offer all the advantages of statistical modeling, and are straightforward to fit in standard statistical packages.

Colorectal Neoplasms↗