Recombinant adenoviral microRNA-206 induces myogenesis in C2C12 cells.

BACKGROUND: The expression of microRNA-206 (miR-206) is high in skeletal muscle but low in most other tissues. The expression of miR-206 is increased in muscular dystrophy, suggesting its involvement in the pathogenesis of muscle diseases. To determine the role of miR-206 in muscle cell differentiation and explore a possible gene therapy vector, we constructed a miR-206 adenoviral expression vector (AdvmiR-206) and tested for transfection into C2C12 stem cells. MATERIAL/METHODS: A 355-bp PCR amplicon from C57B6 mouse skeletal muscle genomic DNA was inserted into the adenoviral shuttle vector pAdTrack-CMV, which was then co-transformed with the adenoviral backbone plasmid pAdEasy-1 into competent E. coli BJ5183 bacteria. The specificity and function of this recombinant adenoviral MiR-206 were studied in C2C12 cells by Northern blot, immunofluorescence, Western blot, and flow cytometry. RESULTS: Increased expression of miR-206 in AdvmiR-206 transfected C2C12 cells (P < 0.001) and resulted in morphological and biochemical changes over time that were similar to serum deprivation, including elongated cells and increased myosin heavy chain proteins. Even in the absence of serum deprivation, miR-206 overexpression accounted for a 50% reduction of S-phase cells (P < 0.01). Moreover, in untransfected C2C12 cells, the introduction of miR-206-specific antisense oligoribonucleotides inhibited the normal response to serum deprivation. Twenty-four hours after lipofection of antisense oligoribonucleotides, the number of elongated cells was reduced by half (P < 0.01). CONCLUSIONS: Collectively, these data support a role for miR-206 in myoblast differentiation. We foresee potential applications for the AdvmiR-206 vector in research and therapy.

The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure.

We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p = 0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+-) genotypes were associated with a decrease in urine naphthalene level (p < 0.0001). The NKA show great promise as biomarkers for dermal exposure to naphthalene. Further studies are warranted to characterize the relationship between NKA, other exposure biomarkers, and/or biomarkers of biological effects due to naphthalene and/or PAH exposure.

Genistein inhibited proliferation and induced apoptosis in acute lymphoblastic leukemia, lymphoma and multiple myeloma cells in vitro.

Genistein is one of the major isoflavones in soy products. It has been reported that genistein has apoptotic effects on certain hematological malignancies. However, so far there have been no completely comparative studies of the effect of genistein on malignant hematological diseases, especially multiple myeloma. We investigated genistein's inhibitory effect on the growth of acute lymphoblastic leukemia (RS4;11 and CEM), lymphoma (Toledo and GA10) and multiple myeloma (OPM-2 and U266) cell lines in vitro. We observed that genistein dose- and time-dependently inhibited proliferation of these cells. The cell line sensitivity to genistein treatment based on the 50% inhibitory concentration (IC(50)) values in decreasing order of toxicity was found to be as follows: RS4;11 (4.89 ± 4.28 µM) > GA10 (13.08 ± 3.49 µM) > Toledo (16.94 ± 3.89 µM) > CEM (17.31 ± 0.72 µM) > OPM-2 (46.76 ± 2.26 µM) > U266 (128.82 ± 1.90 µM). The mechanism of growth inhibition was through induction of apoptosis and cell cycle arrest. The concomitant altered expression of apoptosis pathway proteins and cell cycle modulators (caspases 9, 3, 7, PARP [poly(ADP-ribose) polymerase], cIAP1 [inhibitor of apoptosis protein 1], Bcl-2 and cyclin B1) were observed by Western blot and real-time polymerase chain reaction (PCR) analyses. In addition, some malignancy-related embryologic pathway proteins, e.g. Notch1 and Gli1, were modulated by genistein treatment in sensitive cell lines.

Genistein and hematological malignancies.

Genistein is an isoflavanoid from soybeans and promising cancer chemotherapeutic agent. Genistein exposure varies widely because of cultural differences in diet. Hypothetically, this could account for differential cancer risk across ethnic populations. Genistein inhibits the growth of many different cancer cell lines by increasing apoptosis, inducing cell cycle delays, and modulating intracellular signaling pathways. Data from recent studies suggest that the therapeutic potential of genistein extends to cancers that affect blood, bone marrow, and lymph nodes. The objective of this paper is to provide background information on genistein, and discuss its potential as a therapeutic agent for treating hematological malignancies.