Changes In Bcl-2 Gene Expression Research Articles

Comparing the Effects of Free and Liposomal Indole Compounds on Bax and Bcl2 Gene Expression Changes in the KG-1 Cell Line

Background: For patients with acute myeloid leukemia (AML), the long-term survival rate is still very low. This study examines the effects on AML cell lines of an indole chemical in its free and liposomal forms.
 Material and Method: In this experimental case control study, an AML-originated KG-1 cell line was cultured in RPMI 1640 medium. The cells were treated with the free and liposomal forms of an indole compound (C18H10N2F6O) at different concentrations of 20, 40, 100, 200, and 400 µg/mL after they attained the proper confluence. The cellular metabolic activity was examined by an MTT assay. The expression of BAX and BCL-2 genes was investigated by q-PCR to assess the apoptotic effect of that compound. The analysis was also done between each experimental group and the control group using t-test. P<0.05 was assumed significant.
 Results: Based on the MTT assay, the lethal effective dose of free indole was found to be 245.1 µg/ml and 164.8 µg/ml in 24 and 48 hours, respectively. The corresponding values for liposomal indole were 47.2 µg/ml and 40.6 µg/ml. Furthermore, treatment with free and liposomal forms of indole resulted in a decline in the expression level of the BCL-2 gene. However, in the case of the liposomal compound, this decrease was only statistically significant after 48 hours of treatment (P < 0.05). Furthermore, the expression of BAX gene increased after treatment with both free and liposomal forms of indole, but it significantly increased only after treatment with the liposomal compound (p < 0.05).
 Conclusion: These results suggest that an indole derivative, especially when liposomal, causes apoptosis in AML cells, hence exhibiting cytotoxic effects. To confirm the potential usefulness of this indole derivative as a therapeutic agent for inhibiting tumor progression in the setting of human malignancies, more studies on physiologically relevant models are necessary.

Effect of photodynamic therapy based on indocyanine green on expression of apoptosis-related genes in human gingival fibroblast cells

BackgroundPeriodontal diseases refer to inflammation of the gingiva, induction of apoptosis in human gingival fibroblast cells, destruction of the surrounding tissues, and early bone loss resulting in infections due to the pathogenic activity of the microorganisms and the host immune inflammatory responses. Recent investigations have suggested that antimicrobial photodynamic therapy (aPDT) can be an adjunct treatment therapy for periodontal infections. AimTo prove the lack of side effects of PDT on periodontal tissues, we investigated the expression of BAX and BCL-2 genes that are involved in apoptosis after the PDT on human gingival fibroblast (HGF) cells. Materials and methodsIn this study the effect of PDT based on indocyanine green (ICG) as a photosensitizer with the diode laser were tested on the expression of BAX and BCL-2 genes in monolayers of HGF cells. The effects of PDT on the expression of BAX and BCL-2 genes were evaluated by real-time quantitative reverse transcription PCR. ResultsThe results of the genes expression analysis revealed that ICG-PDT at concentrations 1000μg/mL, induced the significant expression of BAX in HGF cells; however, the laser irradiation as well as ICG showed no significant effects on the expression of these genes. Treatment with ICG alone, laser irradiation and ICG-PDT caused no observable BCL-2 gene expression changes between the tested and control groups. ConclusionOur findings indicate that ICG-PDT at 1000μg/mL of ICG with the exposure time of 60s for the diode laser would appear to be an inducer of apoptosis in HGF at transcriptome level.

The Effects of ATO on Mitochondria Apoptosis Pathway Genes Expression in APL Cell Line

Purpose and Background: Acute promyelocystic leukemia is the most malignant acute leukemia that leads to death in few weeks. It constitutes 10-15% of acute myelocystic leukemia. Arsenic trioxide, as a single agent factor, is known as the best treatment for acute promyelocystic leukemia, which mainly functions by inducing apoptosis. However, there is no clear image of the mechanism through which apoptosis is induced and how the genes expression is deeply affected. Thus, the present study is an attempt to examine the effect of the agent on expression of the genes dealing with the cancer. Methodology: The study was carried out as an analytical work. To find out about the mechanisms effective on inducing apoptosis, cell line NB4 were cultured with 0.5µM, 1 µM, and 2 µM arsenic trioxide and their RNA was extracted after 12hrs, 24hrs, 28hrs, and 72hrs. Following cDNA synthesis, apoptosis genes expression at mitochondria pathway including caspase 3, Mcl-1, and Bcl-2 were examined using Real-Time PCR. The data was analyzed using t-test and variance analysis in Excel.Findings: It was found that arsenic caused apoptosis was featured with decrease of mRNA expression of Bcl-2 anti-apoptotic. However, expression of caspase 3 and Mcl-1 genes remained unchanged after culturing by arsenic. Conclusion: The results showed that changes in Bcl-2 gene expression can be considered as a mechanism of apoptosis caused by arsenic, while caspase 3 and Mcl-1 genes had no effect on the mechanism.

The Study of Pentoxifylline Drug Effects on Renal Apoptosis and BCL-2 Gene Expression Changes Following Ischemic Reperfusion Injury in Rat.

Ischemia Reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. In this study, the effect of pentoxyfylline on BCL-2 gene expression changes and cell injury in kidney of rat following Ischemia Reperfusion were evaluated. In this experimental study, 20 male wistar rats with average weight of 250-300 g were selected and then were accidently divided them on two tenth group of control and treatment groups. In the control group, celiotomy was performed by ventral midline incision. The left kidney was isolated, and then both the renal artery and vein were obstructed. After 60 minutes of warm ischemia, vessel obstruction resolved and the right kidney was removed. 72 hours after reperfusion, tissue samples were taken from left kidney for Tunel assay. We used quantitative real time PCR for detection of BCL-2 gene expression in treated groups and then compared them to control samples. In the treatment group, the cell death changes, showed lower level than the control group. The results also showed the BCL-2 gene expression was declined in ischemia group as campared to PNT drug group. The pentoxyfylline might have a role in control of apoptosis result from Ischemia- reperfusion and quantitative real-time PCR can be used as a direct method for detection BCL-2 gene expression in tested samples and normal samples.

The Effect of Pentoxifylline on bcl-2 Gene Expression Changes in Hippocampus after Long-term use of Ecstasy in Wistar Rats.

3,4- Methylenedioxymethamphetamine (MDMA or "Ecstasy") is a psychoactive and hallucinogenic drug of abuse. MDMA has been shown to produce neurotoxicity both in animals and humans. Recently, the vasodilator drugs such as pentoxifylline is one of the new strategies which have been considered as neuroprotector. In this study effect of pentoxifylline on bcl- 2 gene expression changes in hippocampus of rat following long- term use of ecstasy was investigated. 30 male Wistar rats weighing 250-300 g were randomly divided into 5 groups: control (normal), sham (MDMA injection), experimental 1 (MDMA and then PTX injections), experimental 2 (PTX injection and after 1 week, MDMA injection) and vehicle (saline injection) groups. All drugs were injected intraperitoneally.Two weeks later, the hippocampi were removed for studying the changes in bcl-2 gene expression. We used quantitative real time PCR for detection of bcl-2 gene expression in treated groups and then compared them to control samples. The results showed the gene dosage ratio of 0.49, 0.78 and 1.17 for sham, experimental 1 and experimental 2 groups, respectively. The results also showed the bcl-2 gene expression declined in sham group as compared to the experimentalgroups. Furthermore, we observed a significant difference in the bcl-2 gene expression between sham and experimental 2 groups. We conclude that quantitative real time PCR could be used as a direct method for the detection of bcl-2 gene expression in tested and normal samples.

The Effect of Pentoxifylline on bcl-2 Gene Expression Changes in Hippocampus after Ischemia-Reperfusion in Wistar Rats by a Quatitative RT-PCR Method.

Ischemia-reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. Ischemia-reperfusion brain injury initiates an inflammatory response involving the expression of adhesion molecules and cytokines. Twenty-four male Wistar rats (250-300 g body wt) were used in this study. The animals were divided into four groups of 6 rats each: I: Control group that was subjected to ischemia-reperfusion, II: Ischemia-reperfusion group that was subjected to all surgical procedures, III: Drug group that received pentoxifylline (200, 400 and 600 mg/kg) 60 min before and after ischemia and IV: Vehicle group that received saline. Seventy two h after ischemia-reperfusion, the hippocampus was taken for studying the changes in bcl-2 gene expression. We used quantitative real-time PCR for the detection of bcl-2 gene expression in ischemia and drug groups and then compared them to normal samples. The results showed the gene dosage ratio of 0.66 and 1.5 for ischemia group and the drug groups, respectively. The results also showed the bcl-2 gene expression declined in ischemia group as compared to the drug group. Furthermore, we observed a significant difference in the bcl-2 gene expression between ischemia and drug groups. These findings are consistent with anti-apoptotic properties of bcl-2 gene. Furthermore this method provides a powerful tool for the investigators to study brain ischemia and respond to the treatment drugs with anti-apoptotic agents.

Phase II Trial of Oblimersen Sodium (G3139), Dexamethasone (Dex) and Thalidomide (Thal) in Relapsed Multiple Myeloma Patients (Pts).

Bcl-2 acts as an important regulator of the mitochondrial pathway of apoptosis and promotes resistance of MM cells to chemotherapy. The Bcl-2 antisense oligonucleotide G3139 specifically targets Bcl-2 and may enhance the anti-tumor efficacy of Dex and Thal. In this trial G3139 was administered at 5 mg to the first 3 Pts and then 7 mg/kg/d by IVCI for 7d of 21d cycle. On day 4, Pts started Dex 40 mg daily for 4 d and Thal 100-400 mg as tolerated. After 3 cycles, responding Pts continued G3139 on a 5-week cycle with Dex 20 mg x 4d and Thal at the tolerated daily dose for up to 1 yr with an optional second yr for responding Pts. Thirty-three Pts treated to date had the following characteristics: median age 60 yrs (range: 28- 76), 22 males; 16 Pts had complex karyotypes; 14 Pts had B2M > 2.5 g/dl; LDH >1.5 normal in 7 Pts; Cr >1.5 mg/dl in 6 Pts; platelets <100,000/ul in 4 Pts. Pts had received a median of 3 prior regimens (range 2-4) including auto-SCT. Seventeen Pts had received prior Thal for a median duration of 6.5 mos. (range 2–8); 11 had no response or progressed on Thal. G3139/Thal/Dex regimen was well tolerated. The median number of cycles per Pt was 8 (range: 1–16). Toxicities included reversible increase in Cr from a median of 1.2 (0.6–2.5) at baseline to 1.5 (range: 0.9–2) at cycle 6. G3139 dose was decreased (3–5 mg/kg/d) for Cr elevations in teh majority of Pts. Thrombocytopenia <100K occurred between cycle 1 and 2 (P= 0.008), and was reversible. Other toxicities (>grade 2) included fatigue, neutropenia, fever, electrolyte disturbance, muscle cramps, rash, hypotension, constipation and infections. Only 3 Pts maintained 400 mg/d of Thal, most Pts required dose reduction to 50–200 mg/d due neuropathy. Thirty Pts were evaluable for response; 24 Pts (80%) had documented responses, including 2 CR, 4 near-CR (+ immunofixation) and 12 PR; 6 had minimal response and 6 Pts had PD. The median duration of response is 13 mos. The estimated PFS is 12 mos and the median OS is 17.4 mo. The upper limits of the 95% confidence interval for PFS and OS have not been reached. At a median follow up of 1 yr (range 1.5–16.6 mo), 7 Pts had died and 26 are alive, of them 16 Pts continue on the study. Responding Pts had an early and significant increase in polyclonal IgM from a median baseline of 35.5 mg/dl (range: 8–75) to 94 (45–211) after cycle 3 (P=0.005), suggesting activation of the innate immune system. CD138+ cells were isolated from BM aspirates pre-treatment, and on d 4 or 7, and 28. Western blot analysis of Bcl-2 protein demonstrated demonstrated a decrease in Bcl-2 levels after normalization for protein loading by densitometry in 3 of 7 Pts with sufficient cells for analysis. The change of Bcl-2 protein levels did not correlate with response. Real time quantitative RT-PCR analysis was subsequently used to evaluate changes in Bcl-2 gene expression. Of 9 Pts evaluated, 6 demonstrated a significant decrease in Bcl-2 mRNA expression when normalized against GAPDH; 5 of them had a clinical response. In conclusion, G3139, Dex and Thal regimen is well tolerated in relapsed MM Pts. G3139 was associated with significant decrease in Bcl-2 gene expression in some Pts. G3139 appears to over-come resistance to Dex/Thal with impressive clinical responses in relapsed/refractory MM patients.