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1.
JAMA Oncol ; 3(11): 1538-1545, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-28715540

ABSTRACT

IMPORTANCE: Hand-foot syndrome (HFS) is a common adverse effect of capecitabine treatment. OBJECTIVE: To compare the incidence and time to onset of grade 2 or greater HFS in patients receiving pyridoxine vs placebo and to identify biomarkers predictive of HFS. DESIGN, SETTING, AND PARTICIPANTS: This single-center, randomized double-blind, placebo-controlled phase 3 trial conducted at National Cancer Centre Singapore assessed whether oral pyridoxine could prevent the onset of grade 2 or higher HFS in 210 patients scheduled to receive single-agent capecitabine chemotherapy for breast, colorectal, and other cancers. INTERVENTIONS: Patients were randomized to receive concurrent pyridoxine (200 mg) or placebo daily for a maximum of 8 cycles of capecitabine, with stratification by sex and use in adjuvant or neoadjuvant vs palliative setting. Patients were withdrawn from the study on development of grade 2 or higher HFS or cessation of capecitabine. MAIN OUTCOMES AND MEASURES: Primary end point was the incidence of grade 2 or higher HFS in patients receiving pyridoxine. Secondary end points included the time to onset (days) of grade 2 or higher HFS and identification of biomarkers predictive of HFS, including baseline folate and vitamin B12 levels, as well as genetic polymorphisms with genome-wide arrays. RESULTS: In this cohort of 210 patients (median [range] age, 58 [26-82] years; 162 women) grade 2 or higher HFS occurred in 33 patients (31.4%) in the pyridoxine arm vs 39 patients (37.1%) in the placebo arm (P = .38). The median time to onset of grade 2 or higher HFS was not reached in both arms. In univariate analysis, the starting dose of capecitabine (odds ratio [OR], 1.99; 95% CI, 1.32-3.00; P = .001), serum folate levels (OR, 1.27; 95% CI, 1.10-1.47; P = .001), and red blood cell folate levels (OR, 1.25; 95% CI, 1.08-1.44; P = .003) were associated with increased risk of grade 2 or higher HFS. In multivariate analyses, serum folate (OR, 1.30; 95% CI, 1.12-1.52; P < .001) and red blood cell folate (OR, 1.28; 95% CI, 1.10-1.49; P = .001) were the only significant predictors of grade 2 or higher HFS. Grade 2 or higher HFS was associated with 300 DNA variants at genome-wide significance (P < 5 × 10-8), including a novel DPYD variant (rs75267292; P = 1.57 × 10-10), and variants in the MACF1 (rs183324967, P = 4.80 × 10-11; rs148221738, P = 5.73 × 10-10) and SPRY2 (rs117876855, P < 1.01 × 10-8; rs139544515, P = 1.30 × 10-8) genes involved in wound healing. CONCLUSIONS AND RELEVANCE: Pyridoxine did not significantly prevent or delay the onset of grade 2 or higher HFS. Serum and red blood cell folate levels are independent predictors of HFS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00486213.


Subject(s)
Antimetabolites, Antineoplastic/adverse effects , Capecitabine/adverse effects , Hand-Foot Syndrome/prevention & control , Neoplasms/drug therapy , Pyridoxine/administration & dosage , Adult , Aged , Aged, 80 and over , Asian People/genetics , Chi-Square Distribution , Dihydrouracil Dehydrogenase (NADP)/genetics , Double-Blind Method , Drug Administration Schedule , Female , Folic Acid/blood , Genetic Predisposition to Disease , Genome-Wide Association Study , Hand-Foot Syndrome/blood , Hand-Foot Syndrome/ethnology , Hand-Foot Syndrome/genetics , Humans , Incidence , Intracellular Signaling Peptides and Proteins/genetics , Kaplan-Meier Estimate , Logistic Models , Male , Membrane Proteins/genetics , Microfilament Proteins/genetics , Middle Aged , Multivariate Analysis , Neoplasms/blood , Neoplasms/ethnology , Odds Ratio , Pharmacogenomic Variants , Polymorphism, Single Nucleotide , Predictive Value of Tests , Risk Assessment , Risk Factors , Severity of Illness Index , Singapore/epidemiology , Time Factors , Treatment Outcome
2.
J Clin Epidemiol ; 67(7): 811-20, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24656406

ABSTRACT

OBJECTIVES: This is the first reported study to determine the minimal clinically important difference (MCID) of Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog), a validated subjective neuropsychological instrument designed to evaluate cancer patients' perceived cognitive deterioration. STUDY DESIGN AND SETTING: Breast cancer patients (n = 220) completed FACT-Cog and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30) at baseline and at least 3 months later. Anchor-based approach used the validated EORTC-QLQ-C30-Cognitive Functioning scale (EORTC-CF) as the anchor for patients who showed minimal deterioration and a receiver operating characteristic (ROC) curve to identify the optimal MCID cutoff for deterioration. Distribution-based approach used one-third standard deviation (SD), half SD, and one standard error of measurement (SEM) of the total FACT-Cog score (148 points). RESULTS: There was a moderate correlation between changes in FACT-Cog and EORTC-CF scores (r = 0.43; P < 0.001). The EORTC-CF-anchored MCID was 9.6 points (95% confidence interval: 4.4, 14.8). The MCID from the ROC method was 7.5 points (area under the curve: 0.75; sensitivity: 75.6%; specificity: 68.8%). For the distribution-based approach, the MCIDs corresponding to one-third SD, half SD, and one SEM were 6.9, 10.3, and 10.6 points, respectively. Combining the approaches, the MCID identified for FACT-Cog ranged from 6.9 to 10.6 points (4.7-7.2% of the total score). CONCLUSION: The estimates of 6.9-10.6 points as MCID can facilitate the interpretation of patient-reported cognitive deterioration and sample size estimates in future studies.


Subject(s)
Breast Neoplasms/psychology , Breast Neoplasms/therapy , Cognition Disorders/diagnosis , Cognition/physiology , Adult , Female , Humans , Longitudinal Studies , Middle Aged , Prospective Studies , Quality of Life , ROC Curve , Self Report/standards , Surveys and Questionnaires
3.
J Pain Symptom Manage ; 45(4): 782-91, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22926085

ABSTRACT

CONTEXT: The Functional Assessment of Cancer Therapy--Breast Symptom Index (FBSI) is an eight-item instrument extracted from the Functional Assessment of Cancer Therapy--Breast (FACT-B). There has been no formal assessment of this eight-item version. OBJECTIVES: This study aimed to examine the measurement properties of and comparability between the English and the Chinese versions of the FBSI and to compare it with its parent instrument, the FACT-B, in breast cancer patients in Singapore. METHODS: This was an observational study of 271 breast cancer patients. Known-group validity of FBSI scores was assessed using four health indicators. Convergent and divergent validity was examined by correlation coefficients between the FBSI and the FACT-B. Responsiveness was assessed in relation to longitudinal changes in performance status. Test-retest reliability was evaluated by the intraclass correlation coefficient. Multiple regression analyses were performed to compare the scores on the two language versions. Receiver operating characteristic curve analyses were used for comparison between the FBSI and the FACT-B. RESULTS: For both language versions, the FBSI demonstrated known-group validity, convergent and divergent validity, and sufficient test-retest reliability (intraclass correlation coefficient = 0.75-0.77). The English version was responsive to changes in performance status. The Chinese version was responsive to decline in performance status, but there was no conclusive evidence about its responsiveness to improvement in performance status. No practical significant difference was found in the outcomes between the two language versions despite minor difference in one item. The FBSI performed comparably with the FACT-B. CONCLUSION: The English and Chinese versions of the FBSI are valid and reliable and provide comparable FBSI scores. The English version is responsive to change, whereas the responsiveness of the Chinese version warrants further study.


Subject(s)
Attitude to Health , Breast Neoplasms/epidemiology , Breast Neoplasms/therapy , Outcome Assessment, Health Care/methods , Patient Satisfaction/statistics & numerical data , Quality of Life , Surveys and Questionnaires , Aged, 80 and over , Female , Humans , Prevalence , Singapore/epidemiology , Treatment Outcome
4.
Support Care Cancer ; 21(1): 201-9, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22669608

ABSTRACT

OBJECTIVE: To examine the measurement properties of and comparability between the English and Chinese versions of the five-level EuroQoL Group's five-dimension questionnaire (EQ-5D) in breast cancer patients in Singapore. METHODS: This is an observational study of 269 patients. Known-group validity and responsiveness of the EQ-5D utility index and visual analog scale (VAS) were assessed in relation to various clinical characteristics and longitudinal change in performance status, respectively. Convergent and divergent validity was examined by correlation coefficients between the EQ-5D and a breast cancer-specific instrument. Test-retest reliability was evaluated. The two language versions were compared by multiple regression analyses. RESULTS: For both English and Chinese versions, the EQ-5D utility index and VAS demonstrated known-group validity and convergent and divergent validity, and presented sufficient test-retest reliability (intraclass correlation = 0.72 to 0.83). The English version was responsive to changes in performance status. The Chinese version was responsive to decline in performance status, but there was no conclusive evidence about its responsiveness to improvement in performance status. In the comparison analyses of the utility index and VAS between the two language versions, borderline results were obtained, and equivalence cannot be definitely confirmed. CONCLUSION: The five-level EQ-5D is valid, responsive, and reliable in assessing health outcome of breast cancer patients. The English and Chinese versions provide comparable measurement results.


Subject(s)
Asian People , Breast Neoplasms , Health Status , Quality of Life , Surveys and Questionnaires , Asian People/psychology , Breast Neoplasms/ethnology , Female , Humans , Language , Middle Aged , Multivariate Analysis , Psychometrics , Regression Analysis , Reproducibility of Results , Singapore
5.
Qual Life Res ; 22(7): 1745-51, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23054499

ABSTRACT

PURPOSE: To compare the measurement precision and related properties between the 5-level EuroQoL Group's 5-dimension (EQ-5D-5L) questionnaire and the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire in assessing breast cancer patients. METHODS: An observational study of 269 Singaporean breast cancer patients. To compare discriminative ability and responsiveness, the effect sizes (in standard deviation) of the EQ-5D-5L and the FACT-B in relation to health indicators and the change in performance status or quality of life were estimated. Test-retest reliability was examined using the intraclass correlation (ICC). RESULTS: Using performance status, evidence of disease, and treatment status as the criteria, the differences (FACT-B minus EQ-5D-5L) in the effect size for discriminative ability were negative or closed to zero, and the 90% confidence intervals totally fell within the zone that indicated the non-inferiority of the EQ-5D-5L. For responsiveness and test-retest reliability, the confidence intervals of the differences in effect size and ICC overlapped the non-inferiority margin; thus, non-inferiority in these two aspects could neither be confirmed nor rejected. CONCLUSIONS: The EQ-5D-5L was non-inferior to the FACT-B in discriminating breast cancer patients with different health conditions cross-sectionally. The EQ-5D-5L serves as a reasonable alternative or supplementary instrument to the FACT-B in assessing breast cancer patients' health outcomes.


Subject(s)
Asian People/psychology , Breast Neoplasms/psychology , Health Status Indicators , Psychometrics/instrumentation , Quality of Life , Surveys and Questionnaires , Confidence Intervals , Cross-Sectional Studies , Female , Humans , Language , Male , Middle Aged , Patient Outcome Assessment , Reproducibility of Results , Sensitivity and Specificity , Singapore
6.
Ann Pharmacother ; 46(12): 1645-55, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23249868

ABSTRACT

BACKGROUND: There is conflicting evidence on the effect of chemotherapy and psychosocial distress on perceived cognitive changes in cancer patients. OBJECTIVE: To compare the severity of perceived cognitive disturbance in Asian breast cancer patients receiving chemotherapy and those not receiving chemotherapy, and identify clinical characteristics associated with perceived cognitive disturbances. METHODS: A cross-sectional, observational study was conducted at the largest cancer center in Singapore. Breast cancer patients receiving chemotherapy and not receiving chemotherapy completed the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30), and Beck Anxiety Inventory to assess their perceived cognitive functioning, health-related quality of life, and anxiety, respectively. Multiple regression was conducted to delineate the factors associated with perceived cognitive disturbances. RESULTS: A total of 85 breast cancer patients receiving chemotherapy and 81 not receiving chemotherapy were recruited. Chemotherapy patients experienced more fatigue (QLQ-C30 fatigue scores: 33.3 vs 22.2 points; p = 0.005) and moderate-to-severe anxiety (21.9% vs 8.6%; p = 0.002) compared to non-chemotherapy patients. Non-chemotherapy patients reported better perceived cognitive functioning than those who received chemotherapy (FACT-Cog scores: 124 vs 110 points, respectively; p < 0.001). Chemotherapy and endocrine therapy were strongly associated with perceived cognitive disturbances (p < 0.001 and 0.021, respectively). The interacting effect between anxiety and fatigue was moderately associated with perceived cognitive disturbances (ß = -0.29; p = 0.037). CONCLUSIONS: Chemotherapy and endocrine treatment were associated with significant cognitive disturbances among Asian breast cancer patients. Psychosocial factors could be used to identify cancer patients who are more susceptible to cognitive disturbances in the clinical setting.


Subject(s)
Antineoplastic Agents/therapeutic use , Breast Neoplasms/psychology , Quality of Life , Stress, Psychological/etiology , Adult , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacology , Anxiety/epidemiology , Anxiety/etiology , Breast Neoplasms/drug therapy , Cancer Care Facilities , Cognition Disorders/epidemiology , Cognition Disorders/etiology , Cross-Sectional Studies , Fatigue/epidemiology , Fatigue/etiology , Female , Humans , Middle Aged , Psychometrics , Regression Analysis , Singapore , Stress, Psychological/epidemiology , Surveys and Questionnaires
7.
Breast Cancer Res Treat ; 131(2): 619-25, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21922244

ABSTRACT

The objective of the study was to examine the measurement properties of and comparability between the English and Chinese versions of the Functional Assessment of Cancer Therapy-Breast (FACT-B) in breast cancer patients in Singapore. This is an observational study of 271 Singaporean breast cancer patients. The known-group validity of FACT-B total score and Trial Outcome Index (TOI) were assessed in relation to performance status, evidence of disease, and treatment status cross-sectionally; responsiveness to change was assessed in relation to change in performance status longitudinally. Internal consistency and test-retest reliability were evaluated by the Cronbach's alpha and intraclass correlation coefficient (ICC), respectively. Multiple regression analyses were performed to compare the scores on the two language versions, adjusting for covariates. The FACT-B total score and TOI demonstrated known-group validity in differentiating patients with different clinical status. They showed high internal consistency and test-retest reliability, with Cronbach's alpha ranging from 0.87 to 0.91 and ICC ranging from 0.82 to 0.89. The English version was responsive to the change in performance status. The Chinese version was shown to be responsive to decline in performance status but the sample size of Chinese-speaking patients who improved in performance status was too small (N = 6) for conclusive analysis about responsiveness to improvement. Two items concerning sexuality had a high item non-response rate (50.2 and 14.4%). No practically significant difference was found in the total score and TOI between the two language versions despite minor differences in two of the 37 items. The English and Chinese versions of the FACT-B are valid, responsive, and reliable instruments in assessing health-related quality of life in breast cancer patients in Singapore. Data collected from the English and Chinese versions can be pooled and either version could be used for bilingual patients.


Subject(s)
Breast Neoplasms/epidemiology , Adult , Asian People/psychology , Asian People/statistics & numerical data , Breast Neoplasms/psychology , Breast Neoplasms/therapy , Female , Humans , Language , Middle Aged , Quality of Life , Reproducibility of Results , Singapore/epidemiology , Singapore/ethnology , Surveys and Questionnaires
8.
Biomaterials ; 32(23): 5515-23, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21543115

ABSTRACT

Gold nanoparticles (AuNPs) are one of the most versatile and widely researched materials for novel biomedical applications. However, the current knowledge in their toxicological profile is still incomplete and many on-going investigations aim to understand the potential adverse effects in human body. Here, we employed two dimensional gel electrophoresis to perform a comparative proteomic analysis of AuNP treated MRC-5 lung fibroblast cells. In our findings, we identified 16 proteins that were differentially expressed in MRC-5 lung fibroblasts following exposure to AuNPs. Their expression levels were also verified by western blotting and real time RT-PCR analysis. Of interest was the difference in the oxidative stress related proteins (NADH ubiquinone oxidoreductase (NDUFS1), protein disulfide isomerase associate 3 (PDIA3), heterogeneous nuclear ribonucleus protein C1/C2 (hnRNP C1/C2) and thioredoxin-like protein 1 (TXNL1)) as well as proteins associated with cell cycle regulation, cytoskeleton and DNA repair (heterogeneous nuclear ribonucleus protein C1/C2 (hnRNP C1/C2) and Secernin-1 (SCN1)). This finding is consistent with the genotoxicity observed in the AuNP treated lung fibroblasts. These results suggest that AuNP treatment can induce oxidative stress-mediated genomic instability.


Subject(s)
Fibroblasts/drug effects , Genomic Instability/drug effects , Gold/pharmacology , Lung/cytology , Metal Nanoparticles/adverse effects , Cell Line , Chromosome Breakage/drug effects , Comet Assay , Down-Regulation/drug effects , Electrophoresis, Gel, Two-Dimensional , Fibroblasts/metabolism , Gene Expression/drug effects , Humans , In Situ Hybridization, Fluorescence , Proteins/genetics , Proteins/metabolism , Proteomics/methods , Reverse Transcriptase Polymerase Chain Reaction , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Up-Regulation/drug effects
9.
J Clin Pathol ; 64(2): 153-8, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21169639

ABSTRACT

AIM: To determine the expression pattern and prognostic value of heparan sulfate in gastric cancer. METHOD: The 10E4 antiheparan sulfate monoclonal antibody was used to examine the expression pattern of heparan sulfate in tissue microarrays consisting of 162 cases of gastric carcinoma by immunohistochemistry. The immunoreactivities of both epithelial and stromal components of the specimens were examined and analysed statistically for significant associations with clinicopathological parameters, including histological grade of the tumour, extent of cancer infiltration and presence of lymph-node metastases, lymphovascular invasion, perineural invasion, perforation of gastric wall and stromal reaction. The potential use of heparan sulfate as a predictive factor for patient survival was also evaluated. RESULTS: Reduced expression of heparan sulfate in the epithelial component was associated with higher histological grades of gastric cancer as well as the presence of more extensive tumour infiltration. Furthermore, this decrease in heparan sulfate expression was found to be predictive of reduced patient survival after tumour recurrence. CONCLUSION: The data suggest that heparan sulfate may play an important role in regulating the biology of gastric cancer, and that it may be a useful prognostic marker of this tumour.


Subject(s)
Adenocarcinoma/metabolism , Biomarkers, Tumor/metabolism , Heparitin Sulfate/metabolism , Stomach Neoplasms/metabolism , Adenocarcinoma/pathology , Adenocarcinoma/secondary , Adult , Aged , Aged, 80 and over , Cell Differentiation , Epidemiologic Methods , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Invasiveness , Prognosis , Stomach Neoplasms/pathology , Tumor Cells, Cultured
10.
Exp Dermatol ; 19(11): 987-93, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20812968

ABSTRACT

The keloid fibroblast (KF) is known to have higher proliferative capacity than normal dermal fibroblast (NF). Metallothionein (MT), a metal-binding protein, has been reported to promote cell proliferation. In this study, we evaluated the expression of MT isoforms at the mRNA level in fetal bovine serum (FBS)-stimulated proliferating KF. Although the morphological appearance of NF and KF was similar when viewed under light, confocal and transmission electron microscopy, there was surprisingly a generally lower expression of MT isoforms in KF when compared with NF and also reduced MT staining in dermal fibroblasts of keloids as opposed to normal skin. Primary cultures of KF grown in 5% FBS or 10% FBS compared to without FBS demonstrated significantly higher proliferative activity and more abundant deposition of collagen. Contrary to expectation, MT-1A, -1F, -1G, -1X and -2A isoforms were significantly down-regulated in proliferating KF. Moreover, stimulating KF with TGF ß1, which is known to promote collagen synthesis and keloid formation, increased expression of Collagen 1A and 3A genes accompanied by reduction in MT-2A gene expression. Furthermore, down-regulation of the MT-2A gene in proliferating KF by siRNA-mediated silencing enhanced cell proliferation with concomitant up-regulation of the NF-κB gene and 10 of 13 other NF-κB pathway-related genes analysed but no alteration of the Collagen 1 and Collagen 3 gene expression. It would appear that down-regulation of MT isoforms in proliferating KF, in particular MT-2A, enhances keloidogenesis with the possible involvement of the NF-κB signalling pathway.


Subject(s)
Cell Proliferation , Collagen/metabolism , Fibroblasts/metabolism , Keloid/pathology , Metallothionein/metabolism , Protein Isoforms/metabolism , Cells, Cultured , Collagen/genetics , Culture Media, Serum-Free/pharmacology , Down-Regulation/genetics , Fibroblasts/drug effects , Fibroblasts/pathology , Gene Expression/drug effects , Gene Expression/genetics , Humans , In Vitro Techniques , Keratinocytes/metabolism , Keratinocytes/pathology , Metallothionein/genetics , NF-kappa B/genetics , Protein Isoforms/genetics , RNA, Small Interfering/genetics , Serum/physiology , Signal Transduction/genetics , Skin/metabolism , Skin/pathology , Transforming Growth Factor beta1/pharmacology , Up-Regulation/genetics
11.
Anat Rec (Hoboken) ; 292(4): 536-43, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19301279

ABSTRACT

Sirtuins are protein deacetylases, which are dependent on nicotine adenine dinucleotide. They are phylogenetically conserved from bacteria to humans. Seven sirtuin proteins localized in a wide variety of subcellular locations have been identified in the human genome. The most important known function of sirtuins is their regulation of transcriptional repression, mediated through binding of a complex containing sirtuins and other proteins. Studies have shown that sirtuins have pathophysiological relevance to neurodegeneration, muscle differentiation, inflammation, obesity, and cancer. In addition, sirtuin activity extends the lifespan of several organisms. In this review, we discuss the mode(s) of action of sirtuins, and their biological role(s) in health and disease.


Subject(s)
Cell Nucleus/metabolism , Histone Deacetylases/metabolism , Mitochondria/metabolism , Nuclear Proteins/metabolism , Sirtuins/metabolism , Acetylation , Animals , Cell Nucleus/genetics , Cell Nucleus/ultrastructure , Histone Deacetylases/genetics , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Mitochondria/genetics , Mitochondria/ultrastructure , NAD/metabolism , Nuclear Proteins/genetics , Protein Transport/physiology , Sirtuins/genetics
12.
Int J Oncol ; 27(2): 337-44, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16010413

ABSTRACT

The pathways which are activated following damage to nuclear DNA in cancer cells are well understood. There is evidence that treatment with several chemotherapeutic agents may result in damage to mitochondrial DNA. This study investigated the contribution of mitochondrial DNA to cytotoxicity of DNA-interactive agents. To understand the significance of drug interactions with mitochondrial DNA, we investigated A549 non-small cell lung cancer cell lines and their rho0 derivatives in which mitochondrial DNA has been eradicated. The parental cell line showed increased sensitivity to the anthracycline daunorubicin when compared with the A549 rho0 line. In addition, the A549 rho0 line was resistant to the rhodacyanine derivative, MKT-077, which has been shown to interact with mitochondrial DNA. Southern blotting demonstrated that MKT-077 mediated damage to mitochondrial but not nuclear DNA. Restoration of mitochondrial DNA by formation of cybrids restored sensitivity to these agents. The mitochondrial DNA damage, following treatment of A549 rho0 cells with MKT-077, resulted in G2 arrest which was not mediated by expression of p53. Mitochondrial DNA is a critical target for MKT-077 and daunorubicin, and is a potential target for novel chemotherapeutic agents.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Proliferation/drug effects , DNA Damage , DNA, Mitochondrial/drug effects , Daunorubicin/pharmacology , ATP Binding Cassette Transporter, Subfamily B/metabolism , Antigens, Neoplasm/metabolism , Apoptosis/drug effects , Blotting, Southern , Cell Cycle/drug effects , Cell Line, Tumor , Cytochromes c/metabolism , DNA Topoisomerases, Type II/metabolism , DNA, Mitochondrial/genetics , DNA, Mitochondrial/metabolism , DNA-Binding Proteins/metabolism , Dose-Response Relationship, Drug , Flow Cytometry , Humans , Immunoblotting , Inhibitory Concentration 50 , Intracellular Membranes/drug effects , Intracellular Membranes/physiology , Membrane Potentials/drug effects , Pyridines/pharmacology , Thiazoles/pharmacology , Tumor Suppressor Protein p53/metabolism
13.
Surg Oncol ; 12(4): 277-87, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14998568

ABSTRACT

The rapid expansion in our knowledge of the molecular pathogenesis of cancer has created several opportunities for novel strategies in anti-cancer drug design and development. Recent developments have included a series of new endocrine therapies such as pure anti-oestrogens and selective oestrogen receptor modulators, and trials are in progress to determine their role in the sequence of therapies given the first-line role now occupied by the aromatase inhibitors. Novel cytotoxic drugs have been developed with an improved toxicity profile, including oral prodrugs that are activated within tumour cells, and liposomal delivery mechanisms for conventional drugs that reduce some of the systemic toxicities. There has been much success with monoclonal antibodies targeted against growth factor receptors, both as monotherapy and in enhancing the efficacy of cytotoxic drugs. A number of small molecule signal transduction inhibitors are in early stages of clinical development for breast cancer, including tyrosine-kinase inhibitors and farnesyl transferase inhibitors. Emerging pre-clinical evidence suggests that these drugs may best be used in combination with endocrine therapy. Other novel strategies that are being tested include vaccines and anti-angiogenesis drugs. As these new therapies evolve towards the clinic, the challenge to oncologists is whether their potential seen in the laboratory can be matched by further substantial improvements in clinical outcome.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antineoplastic Agents, Hormonal/administration & dosage , Breast Neoplasms/drug therapy , Cancer Vaccines/administration & dosage , Immunologic Factors/administration & dosage , Selective Estrogen Receptor Modulators/administration & dosage , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Biopsy, Needle , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Follow-Up Studies , Humans , Middle Aged , Neoplasm Staging , Randomized Controlled Trials as Topic , Risk Assessment , Survival Analysis , Treatment Outcome
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