Activation of caspase-3 in molt4 cells by apoptosis-inducing nucleosides from CD57(+)HLA-DR(bright) natural suppressor cell line

Caspase-3 inhibitor prevents apoptosis of human islets immediately after isolation and improves islet graft function

OBJECTIVES

Apoptosis appears in islets after isolation, and it has a detrimental effect on the islet function. To improve the outcome of clinical islet transplantation, it is crucial to protect islets from apoptosis. The aim of this study was to determine whether a caspase-3 inhibitor (Z-DEVD-FMK) added to culture media protects islets from apoptosis and to compare the effects of fetal bovine serum (FBS) with human serum albumin (HSA) as a protein supplement in culture.

METHODS

Isolated human islets were cultured under 4 different conditions: 0.5% HSA (control), 0.5% HSA + 25 micromol/L Z-DEVD-FMK, 0.5% HSA + 100 micromol/L Z-DEVD-FMK and 10% FBS for 2 days. Next, 1000 IEQ islets precultured with 0.5% HSA and with or without 100 micromol/L Z-DEVD-FMK were transplanted to diabetic nude mice.

RESULTS

The islet yields were higher in Z-DEVD-FMK-treated groups, and the inhibitor prevented apoptosis dose dependently. The yield and insulin release were higher in FBS-treated group than in the control group, but FBS did not affect apoptosis. All 6 mice transplanted with islets pretreated with Z-DEVD-FMK, and 3 of 8 mice with control islets became normoglycemic posttransplantation.

CONCLUSION

Z-DEVD-FMK prevented apoptosis of isolated human islets and improved its function. FBS (10%) improved the islet yield and insulin secretion more than 0.5% HSA.

Human prostate cancer cell death by novel anticancer compounds, apoptosis-inducing nucleosides from CD57+ HLA-DR(bright) natural suppressor cell line

BACKGROUND

We validated the induction of apoptosis in human prostate cancer PC3 cells by apoptosis-inducing nucleosides (AINs) released from the CD57(+)HLA-DR(bright)-natural suppressor (57.DR-NS) cell line. We analyzed the molecular signaling pathway during AINs-induced apoptosis in PC3 cells.

METHODS

Direct and indirect co-cultures between 57.DR-NS and PC3 cells were performed. AINs were isolated by high-performance liquid chromatography (HPLC) from 57.DR-NS cell cultures. Apoptosis in PC3 cells was analyzed by DNA fragmentation, sub-G(1) DNA content with flow cytometry, and terminal deoxynucleotide transferase-mediated dUTP nick end-labeling (TUNEL) method. The DNA strand breaks and activation of caspase-3 in PC3 cells were measured by DNA unwinding and flow cytometry assay.

RESULTS

The 57.DR-NS cell line generated apoptosis in PC3 cells via AINs. AINs isolated from 57.DR-NS cell cultures induced apoptosis in PC3 cells. Furthermore, we found DNA strand breaks followed by activation of caspase-3 during AINs-induced apoptosis in PC3 cells.

CONCLUSIONS

The data obtained here indicated that AINs could induce apoptosis in PC3 cells through DNA strand breaks and activation of caspase-3.

Human malignant cell death by apoptosis-inducing nucleosides from the decidua derived CD57(+)HLA-DR(bright) natural suppressor cell line

The CD57(+)HLA-DR(bright) natural suppressor (57.DR-NS) cell line derived from human decidual tissue mediated apoptosis of human leukemia Molt4 and carcinoma BeWo/GCIY cells but not human fibroblast WI-38 cells, and apoptosis-inducing nucleosides (AINs) appeared to be involved. Six AINs were released into 57.DR-NS cell culture media and were isolated by the combination of physicochemical procedures of C18 preparative column, thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC). Subsequently, we demonstrated that AINs could induce apoptosis in the human malignant Molt4/BeWo/GCIY cell line but not human normal WI-38 fibroblasts. Apoptosis was characterized by DNA strand breaks and activation of the caspase cascade, especially caspase-3. The administration of AINs into GCIY tumor bearing SCID mice culminated in suppression of tumor growth due to apoptosis of tumor cells.

Human T cell leukemia cell death by apoptosis-inducing nucleosides from CD57(+) HLA-DR(bright) natural suppressor cell line

Apoptosis-inducing nucleosides (AINs) released from CD57( +) HLA-DR(bright) natural suppressor (57.DR-NS) cell line, derived from human decidual tissue, were isolated from 57.DR-NS cell culture supernatant by the combination of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Apoptotic cell death was strongly induced in human T cell leukemia Molt4 cells treated with AINs, absolutely depending on DNA strand breaks, with activation of the caspase cascade, especially caspase-3. The administration of AINs to Molt4 tumor-bearing severe combined immunodeficiency (SCID) mice resulted in drastic suppression of tumor growth, with a decrease of tumor size and the appearance of apoptotic signals in tumor tissue. Thus, AINs are candidates for development as anticancer agents.