Hypoxia- and radiation-induced overexpression of Smac by an adenoviral vector and its effects on cell cycle and apoptosis in MDA-MB-231 human breast cancer cells.

A conditionally replicative adenoviral (CRAd) vector, designated as CRAd.pEgr-1-Smac, that promotes the overexpression of second mitochondria-derived activator of caspase (Smac) when stimulated by hypoxia and radiation was constructed. MDA-MB-231 cells were transfected with CRAd.

Mitochondrial modulation of apoptosis induced by low-dose radiation in mouse testicular cells.

Objective: To investigate whether apoptosis induced by low-dose radiation (LDR) is regulated by mitochondrial pathways in testicular cells.

Methods: Male mice were exposed to whole-body LDR, and changes in mitochondrial function and in expression of apoptotic factors were analyzed in the testicular cells as follows. Total nitric-oxide synthase (T-NOS) and Na+/K+ ATPase activities were biochemically assayed.

Involvement of endoplasmic reticulum stress in apoptosis of testicular cells induced by low-dose radiation.

The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor-6 (ATF6) in apoptosis of mouse testicular cells treated with low-dose radiation (LDR). In the dose-dependent experiment, the mice were treated with whole-body X-ray irradiation at different doses (25, 50, 75, 100 or 200 mGy) and sacrificed 12 h later. In the time-dependent experiment, the mice were exposed to 75 mGy X-ray irradiation and killed at different time points (3, 6, 12, 18 or 24 h).

Conditionally replicating adenovirus combined with gene-targeted radiotherapy induces apoptosis via TRAIL death receptors in MDA-MB-231 cells.

Malignant tumors are usually treated using monotherapies, which are not always effective. Therefore, combination therapies have gained increasing attention. The aims of this study were to investigate the effects of conditionally replicating adenovirus (CRAd) in combination with X-ray irradiation on the proliferation and apoptosis of MDA-MB-231 cells, as well as to determine the molecular mechanisms involved.

[Low-dose radiation induces endoplasmic reticulum stress and activates PERK-CHOP signaling pathway in mouse testicular cells].

Objective: To explore the correlation of low-dose radiation with endoplasmic reticulum stress and the activation of the PERK-CHOP signaling pathway in mouse testicular cells.

Methods: Healthy Kunming mice were randomly assigned to time-effect (0, 3, 6, 12 and 24 h of irradiation at 75 mGy) and dose-effect (12 h of irradiation at 0, 50, 75, 100 and 200 mGy) groups. The contents of H202 and MDA were measured by colorimetry with the agent kits, the expressions of GRP78, PERK and CHOP mRNA detected by quantitative RT-PCR, and the levels of GRP7B, PERK, phosphorylated PERK (pho-PERK) and CHOP proteins determined by Western blotting and image analysis.

Increased levels of p53 and PARP-1 in EL-4 cells probably related with the immune adaptive response induced by low dose ionizing radiation in vitro.

Objective: This paper is to explore the DNA repair mechanism of immune adaptive response (AR) induced by low dose radiation (LDR), the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic subunit (DNA-PKcs) and PARP-1 genes in the LDR-induced AR in EL-4 cells.

Methods: The apoptosis and cell cycle progression of EL-4 cells were detected by flow cytometry in 12 h after the cells received the pre-exposure of 0.075 Gy X-rays (inductive dose, D1) and the succeeding high dose irradiation (challenge dose, D2; 1.

Anti-tumor effect of 125I-UdR in combination with Egr-1 promoter-based IFNγ gene therapy in vivo.

Although (125)I-UdR treatment of malignant tumors in animal models and patients has achieved a certain effect, the short half-life of (125)I-UdR in vivo and its cellular uptake only in S phase of the cell cycle are limiting factors with regard to tumor eradication, and therefore its combination with other applications is a promising strategy in cancer therapy. In this study, we show that (125)I-UdR radionuclide therapy in combination with Egr-1 promoter-based IFNγ gene therapy is more effective than (125)I-UdR therapy alone in suppressing tumor growth and extending survival duration in mice bearing H22 hepatomas. Combined therapy could significantly inhibit cell proliferation and tumor angiogenesis, induce apoptosis and enhance cytotoxic activities of splenic CTL of the mice.

Effects of corticosterone, cAMP, cGMP, Ca2+, and protein kinase C on apoptosis of mouse thymocytes induced by X-ray irradiation.

Objective: To observe the effects of signal factors of corticosterone (CS), cAMP, cGMP, Ca2+ andprotein kinase C (PKC) on lymphocyte apoptosis in mouse thymus induced by X-rays of 4 Gy in vitro.

Methods: The DNA lytic rate for thymocytes was measured by fluorospectrophotometry.

Results: The DNA lyric rate for thymocytes 4-8 hours after irradiation with 2-8 Gy was significantly higher than that in the control (P<0.

Taurolidine induces apoptosis of murine melanoma cells in vitro and in vivo by modulation of the Bcl-2 family proteins.

Background: This study evaluates whether taurolidine, a novel antibiotic agent, induces murine melanoma cell apoptosis in vitro and in vivo.

Methods: Murine melanoma cells (B16 4A5 and B16 F10) were treated with taurolidine (0-100 microM) for 12 and 24 hr. Cell viability and apoptosis were assessed by MTT assay and FACScan analysis.

The macrophage heterogeneity: difference between mouse peritoneal exudate and splenic F4/80+ macrophages.

Macrophages isolated from various tissues manifest differences in cell shape, the expression of surface markers, as well as metabolic and functional activities. However, the heterogeneity of macrophages expressing the same marker in different tissues has not been fully addressed. In the present study, mouse F4/80+ peritoneal exudate macrophages (PEMs) and splenic macrophages (SPMs) appeared similar in most respects.

[Changes of cycle and apoptosis of spermatogenic cells and antioxidant capacity in male rats with diabetes mellitus].

Objective: To explore the changes of cycle and apoptosis of spermatogenic cells and antioxidant capacity of the serum and testis in male rats with diabetes mellitus.

Methods: Thirty male rats were divided into two groups, 10 for normal control and 20 for the diabetes group. The rats were injected intraperitoneally with streptozocin (TZ) to develop diabetes, and 12 weeks later, their survival rate and testis weight were recorded.

Ability of luteinizing hormone releasing hormone-Pseudomonas aeruginosa exotoxin 40 binding to LHRH receptor on human liver cancer cells.

Aim: To explore the ability of recombinant toxin luteinizing hormone releasing hormone-Pseudomonas aeruginosa exotoxin 40 (LHRH-PE40) and LHRH binding to LHRH receptor (LHRHR) on the membrane surface of human liver cancer HEPG cells.

Methods: LHRH was labeled by using (125)I with enzymatic reaction. The affinity and receptor volume of LHRH-PE40 and LHRH binding to LHRHR on the membrane surface of human liver cancer cells were measured with radioligand receptor assay.