ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of PARP1 inhibitor PJ34 on multi-drug resistance in a human multiple myeloma cell line and its connection with FA/BRCA pathway in DNA damage repair.</p><p><b>METHODS</b>A CCK8 assay was used to measure the inhibition rate. Real-time quantitative PCR was used to detect expression changes of DNA repair genes involved in the FA/BRCA pathway. Western blotting assay was used to detect expression of key protein FANCD2 in the FA/BRCA pathway. Annexin VFITC/PI double staining flow cytometry was used to measure cell apoptosis induced by PJ34. A COMET assay was used to detect the effect of PJ34 on DNA damage repair.</p><p><b>RESULTS</b>PJ34 could significantly enhance the sensitivity of RPMI8226/R cells to melphalan. The IC50 value of melphalan was dropped from 20.43 mol/L to 7.8 mol/L. PJ34 could inhibit the DNA damage repair, and the effect was related with the inhibition of FA/BRCA pathway. PJ34 and melphalan showed a synergistic effect in promoting the apoptosis of RPMI8226/R cells.</p><p><b>CONCLUSION</b>PJ34 can reverse the resistance of RPMI8226/R cells to melphalan by inhibiting the FA/BRCA pathway, which in turn can induce suppression of DNA damage repair. Therefore, PJ34 may have clinical value in overcoming the multi-drug resistance of multiple myeloma.</p>
Subject(s)
Humans , Antineoplastic Agents , Pharmacology , BRCA2 Protein , Genetics , Metabolism , Cell Line, Tumor , Drug Resistance, Neoplasm , Fanconi Anemia Complementation Group D2 Protein , Genetics , Metabolism , Multiple Myeloma , Drug Therapy , Genetics , Metabolism , Phenanthrenes , Pharmacology , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerase Inhibitors , Poly(ADP-ribose) Polymerases , Genetics , MetabolismABSTRACT
<p><b>BACKGROUND</b>Fanconi anemia is a severe congenital disorder associated with mutations in a cluster of genes responsible for DNA repair. Arriving at an accurate and timely diagnosis can be difficult in cases of Fanconi anemia with atypical clinical features. It is very important to increase the rate of accurate diagnosis for such cases in a clinical setting. The purpose of this study is to explore the clinical diagnosis of Fanconi anemia in children with atypical clinical features.</p><p><b>METHODS</b>Six cases of Fanconi anemia with atypical clinical features were enrolled in the study, and their clinical features were recorded, their FANCA gene transcription was assessed by RT-PCR, and FANCA mutations and the ubiquitination of FANCD2 protein were analyzed using DNA sequencing and western blotting respectively.</p><p><b>RESULTS</b>All six cases showed atypical clinical features including no apparent deformities, lack of response to immune therapy, and progressively increasing bone marrow failure. They also have significantly increased fetal hemoglobin, negative mitomycin-induced fracture test results, and carry a FANCA gene missense mutation. Single protein ubiquitination of FANCD2 was not observed in those patients.</p><p><b>CONCLUSION</b>The combination of clinical features, FANCA pathogenic gene mutation genotype and the absence of FANCD2 protein ubiquitination are helpful in the accurate and timely diagnosis of Fanconi anemia in children.</p>
Subject(s)
Child , Child, Preschool , Female , Humans , Male , Fanconi Anemia , Diagnosis , Genetics , Metabolism , Fanconi Anemia Complementation Group D2 Protein , Genetics , Metabolism , Mutation , UbiquitinationABSTRACT
<p><b>OBJECTIVE</b>To investigate the reverse effect of mutidrug resistance of curcumin combined with melphalan on the mutidrug-resistant human multiple myeloma cell line MOLP-2/R and the relation with FA/BRCA pathway.</p><p><b>METHODS</b>The inhibitory effects of the drugs on the growth of MOLP-2/R cells were determined by MTT assay. Cell cycle analysis, intracellular drug concentration and apoptosis were assayed by flow cytometry. The expression of FANCD2 monoubiquitination was determined by Western blot analysis.</p><p><b>RESULTS</b>Co-administration of curcumin and melphalan had an synergistic inhibitory effects on the proliferation, IC50 of melphalan with 10 micromol/L curcumin reduced from 45.5 micromol/L to 19 micromol/L in MOLP-2/R cells. The apoptosis percentage of MOLP-2/R cells was significantly increased from (23.3 +/- 0.6)% to (52.6% +/- 0.8)% by the treatment of melphalan 20 micromol/L plus curcumin 10 micromol/L with the increased percentage of cells in the G2/M phase (from 9.1% to 18.5%) and enhanced intracellular drug concentration of MOLP-2/ R cells (from 15.2 +/- 0.3 to 21.4 +/- 0.8 ). The effects were accompanied with inhibition of FA/BRCA pathway by down regulation of FANCD2 protein monoubiquitination.</p><p><b>CONCLUSION</b>Curcumin combined with melphalan results in synergistic effects and reverses multiple drug resistance of MOLP-2/R cells effectively. The inhibition of FA/BRCA pathway may be the mechanism.</p>
Subject(s)
Humans , Apoptosis , Cell Cycle , Cell Line, Tumor , Cell Proliferation , Curcumin , Pharmacology , Drug Resistance, Multiple , Drug Resistance, Neoplasm , Fanconi Anemia Complementation Group D2 Protein , Metabolism , Multiple Myeloma , Drug Therapy , Metabolism , PathologyABSTRACT
<p><b>OBJECTIVE</b>To investigate the possible relationship between defects in the FA/BRCA pathway of genomic stability and potential pathogenesis of T and B cell lymphoma.</p><p><b>METHODS</b>Nineteen cell lines derived from diverse subtypes of lymphoma for possible FA pathway defects were screened.</p><p><b>RESULTS</b>No defect in FANCD2 ubiquitination was observed. However, the FANCN protein was absent in cell lines HT and Sudhl4. This absence was correlated with enhanced MMC-induced G2 arrest, growth inhibition and high chromosomal breakage rate in both cell lines. In addition, in exon-5a of FANCN gene, a mutation of c.1769 C>T, p. A590V was found in cell line HT, but not in cell line Sudhl4.</p><p><b>CONCLUSION</b>This mutation may be the reason causing the absence of the FANCN protein expression or making the protein unstable and losing its function.</p>
Subject(s)
Animals , Humans , Antibiotics, Antineoplastic , Pharmacology , BRCA2 Protein , Metabolism , Base Sequence , Cell Cycle , Cell Line, Tumor , Cell Proliferation , Chromosome Breakage , Fanconi Anemia , Metabolism , Fanconi Anemia Complementation Group D2 Protein , Metabolism , Fanconi Anemia Complementation Group N Protein , Gene Expression Regulation, Neoplastic , Genomic Instability , Lymphoma , Genetics , Pathology , Mitomycin , Pharmacology , Molecular Sequence Data , Mutation , Nuclear Proteins , Chemistry , Genetics , Metabolism , Protein Stability , Sequence Analysis, DNA , Signal Transduction , Tumor Suppressor Proteins , Chemistry , Genetics , MetabolismABSTRACT
The aim of this study was to investigate the antiproliferative effect of curcumin combined with cyclophosmide on the growth of human lymphoma cell line HT/CTX with drug resistance and its relation with FA/BRCA pathway. The inhibitory effects of the drugs on the growth of HT/CTX cells were determined by MTT assay. Cell cycle phase and apoptosis were analyzed by flow cytometry. The expression of FANCD2 protein in FA/BRCA pathway was determined by Western blot. The results indicated that the combination of curcumin with CTX had an additional synergistic inhibitory effects on the proliferation and cell cycle distribution of HT/CTX cells. The curcumin could enhance toxicity of CTX on HT/CTX cells through inhibition of FA/BRCA pathway which was realized by suppression of FANCD2 monoubiquitination. The curcumin combined with CTX could increase apoptosis inducing effect on HT/CTX cells, while the curcumin or CTX alone did not showed this effect, and without inhibition of FA/BRCA pahtway. It is concluded that combination of curcumin and CTX produces synergistic effects and reverses multiple drug resistance of HT/CTX cells effectively. The prevention of cells from entering the next cell cycle and down regulation of FANCD2 protein monoubiquitination may be involved in the mechanism.
Subject(s)
Humans , BRCA1 Protein , Genetics , Metabolism , Cell Proliferation , Curcumin , Pharmacology , Cyclophosphamide , Pharmacology , Drug Resistance, Multiple , Drug Resistance, Neoplasm , Drug Synergism , Fanconi Anemia Complementation Group D2 Protein , Genetics , Lymphoma, B-Cell , Genetics , Pathology , Signal Transduction , Tumor Cells, CulturedABSTRACT
Fanconi anaemia (FA) is an autosomal recessive inherited disorder caused by defects in hematopoietic stem cells. The clinical manifestations of FA are diverse and complicated. FA cells display high hypersensitivity to agents which produce interstrand DNA cross-links such as mitomycin C (MMC) or diepoxybutane (DEB). At least eight complementation groups with defects in eight genes (FANCA, FANCB, FANCC, FANCD(1), FANCD(2), FANCE, FANCF and FANCG) have been identified by gene analysis. Six genes (corresponding to subtypes A, C, D(2), E, F and G) have been coloned, and the encoded FA proteins interact in a common cellular pathway - "FA Pathway", through which modulate DNA repair. The progress of research on FA molecular mechanism provides gene therapy of FA with theory basis. FA cells transduced with the use of retrovirus carring the normal FA gene cDNA manifestate phenotypic correction of hypersensitivity to DNA cross-linking agents, such as MMC. In this review the clinical manifestations and gene composition of FA, and the functions of encoded FA proteins were summarized. The hematopoietic stem cell transplantation and gene therapy for FA patients were discussed.