In vitro apoptotic mechanism of a novel synthetic Quinazolinyl derivative: Induces caspase-dependent intrinsic pathway on THP-1, leukemia cell line.

Several quinazoline derivatives have been found to possess a broad spectrum of biological activities. Previously our research group has synthesized and studied the anti-proliferative effects of N-Decyl-N-(2-Methyl-4-Quinazolinyl) Amine (DMQA). The current study evaluated the cytotoxic and apoptotic properties of DMQA in THP-1 cells. The cytotoxic potential of DMQA was assessed using MTT assay on a panel of cancer cell lines which include HeLa, Mia PaCa-2, A 375, B16-F10, A 549,A 431, U937, THP-1, HL-60 and peripheral blood mononuclear cells (PBMC's). Preliminary data revealed that the highest cytotoxic activity was against THP-1 leukemia cell line (IC50=0.66 µg/ml). The apoptotic properties of DMQA on THP-1 cells were characterized by change in nuclear morphology, DNA fragmentation, reduction of pro-caspases-3, 9, Bax/Bcl-2 levels, cleavage of poly (ADP-ribose) polymerase and cytosolic release of cytochrome c. Further investigation revealed a sub-G1 peak, phosphatidyl serine exposure and loss of mitochondrial membrane potential (MMP) in THP-1 cells. The role of caspases was crucial and was demonstrated by the inhibitors Z-VAD-FMK and Z-DEVD-FMK. Moreover DMQA was markedly less effective in inhibiting the growth of normal cells (PBMC's, IC50 =62.17 µg/ml). Based on the results we suggest that DMQA induced apoptosis via intrinsic pathway and could be a promising anticancer agent.

Exome sequencing: an efficient diagnostic tool for complex neurodegenerative disorders.

BACKGROUND AND PURPOSE: Autosomal recessive cerebellar ataxia (ARCA) comprises a large and heterogeneous group of neurodegenerative disorders. We studied three families diagnosed with ARCA. METHODS: To determine the gene lesions responsible for their disorders, we performed high-density single-nucleotide polymorphism genotyping and exome sequencing. RESULTS: We identified a new mutation in the SACS gene and a known mutation in SPG11. Notably, we also identified a homozygous variant in APOB, a gene previously associated with ataxia. CONCLUSIONS: These findings demonstrate that exome sequencing is an efficient and direct diagnostic tool for identifying the causes of complex and genetically heterogeneous neurodegenerative diseases, early-stage disease or cases with limited clinical data.

Evaluation of antineoplastic activity of extracellular asparaginase produced by isolated Bacillus circulans.

L-Asparaginase is an important component in the treatment of acute lymphoblastic leukemia in children. Its antineoplastic activity toward malignant cells is due to their characteristic nature in slow synthesis of L-asparagine (Asn), which causes starvation for this amino acid, while normal cells are protected from Asn starvation due to their ability to produce this amino acid. The relative selectivity with regard to the metabolism of malignant cells forces to look for novel asparaginase with little glutaminase-producing systems compared to existing enzyme. In this investigation, the role of the extracellular asparaginase enzyme produced by an isolated bacterial strain was studied. Biochemical characterization denoted that this isolated bacterial strain belongs to the Bacillus circulans species. The strain was tested for L-asparaginase production, and it was observed that, under an optimized environment, this isolate produces a maximum of 85 IU ml(-1) within 24-h incubation. This enzyme showed less (60%) glutaminase activity compared to commercial Erwinia sp. L-asparaginase. The partially purified enzyme showed an approximate molecular weight of 140 kDa. This enzyme potency in terms of antineoplastic activity was analyzed against the cancer cells, CCRF-CEM. Flow cytometry experiments indicated an increase of sub-G1 cell population when the cells were treated with L-asparaginase.

Furano-sesquiterpene from soft coral, Sinularia kavarittiensis: induces apoptosis via the mitochondrial-mediated caspase-dependent pathway in THP-1, leukemia cell line.

Bioassay directed fractionation and purification led to the successful isolation of a furano sesquiterpene, Methyl 5-[(1E,5E)-2,6-Dimethyl octa-1,5,7-trienyl] furan-3-carboxylate (MDTFC), a bioactive component from a soft coral, Sinularia kavarittiensis. Its structure was determined by analyzing (1)H, (13)C NMR and FAB-MS. The results show that MDTFC could efficiently and selectively inhibit the proliferation of several human cancer cell lines. Among all the cell lines, THP-1 was found to be most sensitive (IC(50) 29.59 microM), whereas the peripheral blood mononuclear cells were least effected (IC(50) 464.16 microM). The molecular mechanism of MDTFC mediated apoptosis was investigated for the first time. Induction of apoptosis in THP-1 cells was characterized by cell membrane blebbing, chromatin condensation, DNA fragmentation, and decrease in level of pro-caspases 3, 9 and increase in Bax/Bcl-2 ratio. Our results were further strengthened through cleavage of poly (ADP-ribose) polymerase, reduction of mitochondrial membrane potential (Psim) and cytosolic release of cytochrome c, which are key events during apoptosis. Moreover, phosphatidyl serine exposure and appearance of sub-G1 peak also demonstrated cell death, when analyzed by flow cytometry. DNA fragmentation was prevented moderately when pretreated with caspase-9 inhibitor (Z-LEHD-FMK) and largely with caspase-3 inhibitor (Z-DEVD-FMK). In summary, MDTFC mediated apoptosis involves mitochondria-dependent pathway and the present compound of marine origin might have a therapeutic value against human cancer cell lines and especially on leukemia cells.