The study was aimed to investigate the possible effects of 8-chloroadenosine 3', 5'-monophosphate (8-Cl-cAMP) on the multiple myeloma cells. The multiple myeloma cell line RPMI8226 was used as in vitro models. The effect on growth inhibition of RPMI8226 cells was evaluated by cell growth and viability curve. DNA fragment was visualized by agarose gel electrophoresis. The amount of apoptosis cells was measured by flow cytometry. Meanwhile Western blot assay were used to detect the change of several key cell cycle regulatory proteins CDK2 and cyclin E in these cells before and after the treatment. The results showed that low dose 8-Cl-cAMP (1-30 micromol/L) inhibited the proliferation and viability of RPMI8226 cells significantly. Agarose gel electrophoresis of DNA revealed the apoptosis characteristic "ladder" pattern. Apoptosis was also confirmed by flow cytometry. In addition, 8-Cl-cAMP was able to inhibit the cell growth through modulating expression of cell cycle regulators CDK2 and cyclin E. It is concluded that 8-cl-cAMP inhibits the proliferation and induce apoptosis of multiple myeloma cells effectively.
8-Bromo Cyclic Adenosine Monophosphate ; analogs & derivatives ; pharmacology ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; Humans ; Multiple Myeloma ; pathology

Previous reports raised question as to whether 8-chloro-cyclic adenosine 3,5-monophosphate (8-Cl-cAMP) is a prodrug for its metabolite, 8-Cl-adenosine which exerts growth inhibition in a broad spectrum of cancer cells. The present study was carried out to clarify overall cellular affects of 8-Cl-cAMP and 8-Cl-adenosine on SK-N-DZ human neuroblastoma cells by ystematically characterizing gene expression using radioactive human cDNA microarray. Microarray was prepared with PCR-amplified cDNA of 2,304 known genes spotted on nylon membranes, employing (1)P-labeled cDNAs of SK-N-DZ cells as a probe. the expression levels of approximately 100 cDNAs, representing about 8% of the total DNA elements on the array, were altered in 8-Cl-adenosine- or 8-Cl-cAMP-treated cells, respectively. The genome-wide expression of the two samples exhibited partial overlaps; different sets of up-regulated genes but the same set of down-regulated genes. 8-Cl-adenosine treatment up- egulated genes involved in differentiation and development (LIM protein, connexin 26, neogenin, neurofilament triplet L protein and p21( WAF1/CIP1)) and immune response such as natural killer cells protein 4, and down-regulated ones involved in proliferation and transformation (transforming growth factor-beta, DYRK2, urokinase-type plasminogen activator and proteins involved in transcription and translation) which were in close parallel with those by 8-Cl-cAMP. Our results indicated that the two drugs shared common genomic pathways for the down-regulation of certain genes, but used distinct pathways for the up-regulation of different gene clusters. Based on the findings, we suggest that the anti-cancer activity of 8-Cl-cAMP results at least in part through 8-Cl-adenosine. Thus, the systematic use of DNA arrays can provide insight into the dynamic cellular pathways involved in anticancer activities of chemotherapeutics.
2-Chloroadenosine/*analogs & derivatives/chemistry/*pharmacology ; 8-Bromo Cyclic Adenosine Monophosphate/*analogs & derivatives/chemistry/*pharmacology ; Antineoplastic Agents/chemistry/*pharmacology ; Blotting, Western ; *Gene Expression Profiling ; Gene Expression Regulation, Neoplastic/*drug effects ; Genome, Human ; Human ; Neuroblastoma/*genetics ; Oligonucleotide Array Sequence Analysis ; Reproducibility of Results ; Tumor Cells, Cultured ; Up-Regulation/drug effects