Effect of CDA-II, urinary preparation, on lipofuscin, lipid peroxidation and antioxidant systems in young and middle-aged rat brain

Human Urine Extract Cell Differentiation Agent 2 Protects PC12 Cells from Serum Deprivation-Induced Apoptosis Accompanied with Priming of Extracellular Signal-Regulated Kinase Activation and Differentiation Induction

OBJECTIVE

To investigate the potential neuroprotective effect of human urine extract cell differentiation agent 2 (CDA-2) by the model of serum deprivation-induced apoptosis of PC12 cells and study the underlying molecular mechanisms.

METHODS

Apoptosis of PC12 cells was induced by serum deprivation. CDA-2 at doses of 0.5-4 mg/mL was used to treat the serum-deprived PC12 cells. The cellular viability was measured by sulforhodamine B binding assay and the cell apoptosis was determined by flow cytometer. Western blot was used to analyze the expression of differentiation markers and activity of extracellular signal-regulated kinase (ERK). The cellular morphology was examined under an inverted microscope.

RESULTS

CDA-2 inhibited apoptotic cell death of serum-deprived PC12 cells in a dose-dependent manner. Expression of low- and mid-sized neurofilaments was observed in serum-deprived PC12 cells treated with CDA-2 or nerve growth factor (NGF). However, CDA-2 did not induce proliferation of these cells like NGF. The morphology of CDA-2 treated cells was changed from rounded to neuron-like flat polygonal shape in contrast to the extensive neurite outgrowth induced by NGF. CDA-2 transiently induced the phosphorylation of ERK in serum deprived-PC12 cells and the expression of neurofilaments induced by CDA-2 was attenuated by mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor PD98059.

CONCLUSIONS

Human urine extract CDA-2 showed a potential neuroprotective activity which may correlate with ERK activation and differentiation induction.

Antitumor activity of CDA-Ⅱ, a urinary preparation, on human multiple myeloma cell lines via the mitochondrial pathway

Cell differentiation agent II (CDA‑II) is a DNA methyltransferase inhibitor isolated from healthy human urine. In the present study, the antitumor activity of CDA‑II on human multiple myeloma (MM) cell lines via the mitochondrial pathway was first revealed. The human MM cell lines were exposed to CDA‑II. Cytotoxicity, caspase activation, apoptosis and the effects on the mitochondrial pathway were assessed. CDA‑Ⅱ was capable of decreasing the depolarized mitochondrial membranes and activating caspase‑3 and ‑9 and poly (ADP‑ribose) polymerase in MM cells treated with CDA‑II. CDA‑II induced caspase‑dependent cell death accompanied by a significant decrease in X-linked inhibitor of apoptosis protein (XIAP), survivin and Mcl‑1 levels. The caspase‑3 inhibitor, Z‑DEVD‑FMK, inhibited CDA‑II‑induced apoptosis. CDA‑II potently increased the Bax levels, decreased the Bcl‑2/Bax ratio and decreased the expression of the downstream targets of NF‑κB. In conclusion, the results of the present study demonstrated that CDA‑II treatment leads to the inhibition of p65 nuclear localization and potently induces caspase‑dependent apoptosis in MM cells mediated through the mitochondrial pathway at low nanomolar concentrations. These results indicate that CDA‑II is a novel inhibitor of NF‑κB activity, with notable antimyeloma efficacy. This study provides a rationale for the clinical investigation of CDA‑Ⅱ in human MM.

CDA-II, a urinary preparation, induces growth arrest and apoptosis of human leukemia cells through inactivation of nuclear factor-kappaB in a caspase-dependent manner

CDA-II (cell differentiation agent II) was a urinary preparation, isolated from healthy human urine. We determined the anticancer activity of CDA-II using human acute myeloid leukemia (AML) cell lines, K562, Kasumi-1 and KG-1. An in vitro cytotoxicity assay showed that CDA-II exhibited growth arrest in leukemic cells, while it did not induce cytotoxicity in normal peripheral blood mononuclear cells (PBMCs). In vivo studies using the Kasumi-1 xenografted SCID mouse model showed tumor inhibition rate were increased and the survival time were prolonged in a dose-dependent manner, without any significant toxicity on mice body. Depolarized mitochondrial membranes and the activation of caspase-3, 9 as well as PARP were found in leukemic cells treated with CDA-II for 6-24h. We further found NF-kappaB nuclear translocation were prevented by CDA-II treatment, which therefore inactivated NF-kappaB and down-regulated its target genes expression, including Bcl-2/Bax ratio, Mcl-1 and XIAP. The caspase-3 inhibitor Z-DEVD-FMK inhibited CDA-II-induced apoptosis and CDA-II combined with NF-kappaB inhibitor PDTC significantly increased the apoptotic rate of leukemic cells. We concluded that CDA-II potently induced caspase-dependent leukemia-specific apoptosis in leukemic cells mediated through inactivation of NF-kappaB, involving in Bcl-2 family and XIAP, which has no cytotoxicity on normal cells.

Human urine extract CDA-2 induces apoptosis of myelodysplastic syndrome-derived MUTZ-1 cells through the PI3K/Akt signaling pathway in a caspase-3-dependent manner

AIM

The aim of this study was to investigate the antitumoral activity of human urine extract against myelodysplastic syndrome (MDS)-derived MUTZ-1 cells in vitro and in vivo.

METHODS

The MDS-refractory anemia with excess of blasts (RAEB)-derived MUTZ-1 cell line was used to examine the effects of a human urine preparation, CDA-2, on the induction of growth arrest and apoptosis. Apoptotic proteins, including caspase family, Bcl-2 family, the inhibitor of apoptosis protein (IAP) family, and the FLICE-like inhibitory protein (FLIP), as well as cell cycle-associated proteins were studied. The phosphoinositide 3 kinase (PI3K)/Akt survival signaling pathway and the NF-kappaB pathway were also examined. The caspase-3 inhibitor Z-DEVD-fmk was used to examine the involvement of caspase-3 and poly (ADP-ribose) polymerase (PARP). PI3K inhibitor LY294002 was used to examine the involvement of the PI3K/Akt signaling pathway in this apoptosis-inducing effect. MUTZ-1 cell xenografted serious combined immunodeficiency disease mice were used for the in vivo study.

RESULTS

We found that CDA-2 could induce growth arrest and apoptosis of MUTZ-1 cells in vitro and in vivo. The main mechanisms were related to the inhibition of PI3Kp110alpha expression at the transcriptional level, which inactivated the phosphorylation of Akt involving the prevention NF-kappaB phosphorylation and nuclear translocation, the downregulation of the IAP family and FLIPL protein, and the dephosphorylation of the Bad protein, which then triggered the activation of the caspase cascades. This phenomenon could be inhibited by the PI3K inhibitor LY294002 and caspase-3 inhibitor Z-DEVD-fmk.

CONCLUSION

Our results demonstrate the presence of active components in the human urine extract that can induce the growth arrest and apoptosis of MDS-RAEB-derived MUTZ-1 cells and may involve the PI3K/Akt signaling pathway in a caspase-3-dependent manner. This may provide new insights for the treatment of high-risk MDS.

Differentiation of pheochromocytoma PC12 cells induced by human urine extract and the involvement of the extracellular signal-regulated kinase signaling pathway

OBJECTIVE

The aim of this study was to investigate the effects of a human urine preparation on the differentiation of tumor cells.

DESIGN

The pheochromocytoma PC12 cells were used to examine the effects of a human urine preparation, CDA-2 on the induction of differentiation markers, neurofilaments, and compared with that induced by nerve growth factor (NGF). The MAPK/ERK kinase (MEK) inhibitor U0126 was used to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathway in this differentiation inducing effect.

RESULTS

We find that CDA-2 could induce differentiation of pheochromocytoma PC12 cells, as evidenced by the markedly increased expression of neurofilaments to a level comparable to those induced by NGF. This phenomenon was accompanied by the phosphorylation of extracellular-signal-regulated kinase (ERK) and could be inhibited by the MEK inhibitor, U0126.

CONCLUSIONS

Our results demonstrate the presence of active components in the human urine extract that can induce differentiation of PC12 cells and may involve the ERK signaling pathway. This may provide new insights for seeking novel differentiation agents and offer hope for cancer patients.

Effect of CDA-II on cell viability, lipid peroxidation, glutathione concentration and its related enzyme activities in primary rat hepatocytes

This study investigated the effects of various concentrations and incubation time intervals of CDA-II (cell differentiation agent: a preparation of human urine) on cell viability, lipid peroxidation and glutathione and its related enzyme activities in rat hepatocytes. Based on the results of lactate dehydrogenase leakage and microscopic examination, treatment with CDA-II significantly elevated the viability of hepatocytes. The level of lipid peroxidation of cells treated with 2.5 or 5 mg/ml CDA-II was lower than the control after 4, 8 and 24 hours of incubation. Intracellular glutathione (GSH) content of cells treated with 0.25-5 mg/ml CDA-II was significantly higher than controls after 8 and 24 hours of incubation. These phenomena are beneficial to the antioxidant capabilities of hepatocytes. Furthermore, treatment of hepatocytes with CDA-II has no effect on the activities of GSH peroxidase, GSH reductase and GSH S-transferase. In conclusion, adequate concentration of CDA-II could enhance the viability and antioxidative capability of hepatocytes.

Synergistic effect of cell differential agent-II and arsenic trioxide on induction of cell cycle arrest and apoptosis in hepatoma cells

AIM: To illustrate the possible role of cell differential agent-II (CDA-II) in the apoptosis of hepatoma cells induced by arsenic trioxide (As₂O₃).

METHODS: Hepatoma cell lines BEL-7402 and HepG2 were treated with As₂O₃ together with CDA-II. Cell surviving fraction was determined by MTT assay; morphological changes were observed by immunofluorescence staining of Hoechst 33258; and cell cycle and the apoptosis index were determined by flow cytometry (FCM).

RESULTS: Cytotoxity of CDA-II was low. Nevertheless, CDA-II could strongly potentiate arsenic trioxide-induced apoptosis. At 1.0 g/L CDA-II, IC₅₀ of As₂O₃ in hepatoma cell lines was reduced from 5.0 µmol/L to 1.0 µmol/L (P < 0.01). The potentiation of apoptosis was dependent on the dosage of CDA-II. FCM indicated that in hepatoma, cell growth was inhibited by CDA-II at lower concentrations (< 2.0 g/L) primarily by arresting at S and G₂ phase, and at higher concentrations (> 2.0 g/L) apoptotic cell and cell cycle arresting at G₁ phase increased proportionally. The combination of two drugs led to much higher apoptotic rates, as compared with the either drug used alone.

CONCLUSION: CDA-II can strongly potentiate As₂O₃-induced apoptosis in hepatoma cells, and two drugs can produce a significant synergic effect.