Bcl-2 Messenger RNA Research Articles

Epithelial cell protein milk fat globule–epidermal growth factor 8 and human chorionic gonadotropin regulate stromal cell apoptosis in the human endometrium

To study the regulation of apoptosis in human endometrial cells. The specific aims were to determine whether milk fat globule-epidermal growth factor 8 (MFG-E8), a novel endometrial epithelial protein, modulates caspase activation and DNA fragmentation; and to examine whether hCG, an early embryonic product, regulates Bax and Bcl-2 equilibrium, as well as MFG-E8 expression. Primary cultures of human endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs). Academic center. Ovulatory women aged 21-30 years. Treatment with MFG-E8 and hCG. Apoptotic activity was quantified using a luciferase assay. Deoxyribonucleic acid fragmentation was detected by TUNEL assay. Bax, Bcl-2, and MFG-E8 messenger RNA expression levels were determined by quantitative reverse transcription-polymerase chain reaction. Immunocytochemistry was used to establish cell purity and presence of MFG-E8 and hCG-R (receptor) proteins. Endometrial epithelial cells were cytokeratin(+), vimentin(-), MFG-E8(+), and hCG-R(+), whereas ESC were vimentin(+), cytokeratin(-), MFG-E8(-), and hCG-R(+). Treatment of ESC with MFG-E8 resulted in a 13-fold increase in caspase activity and a 30-fold increase in TUNEL. On the other hand, hCG decreased messenger RNA expression of Bax in ESC. Milk fat globule-epidermal growth factor 8 has proapoptotic activity, suggesting participation in endometrial remodeling via an epithelial-stromal cell paracrine effect. Conversely, pregnancy levels of hCG has opposite effects on stromal cells.

Expression of Angiogenic Factors in Rat Periapical Lesions

IntroductionAngiogenic factors such as VEGFR2 (vascular endothelial cell growth factor receptor 2), Bcl-2 (a prosurvival and proangiogenic signaling molecule), and chemokine (C-X-C motif) ligand 1 (CXCL1) (a proangiogenic chemokine) may have critical roles in enhancing the establishment of apical periodontitis. To understand the role of these factors in the pathogenesis of apical periodontitis, we conducted immunohistochemical and molecular biological analysis. MethodsApical periodontitis was induced in the lower first molars of Wistar rats by making unsealed pulp exposures. After, 14, 21, and 28 days, the molars were retrieved, embedded as frozen sample blocks, and cut in a cryostat. Normal lower first molars served as controls. Immunostaining for CD31 (a marker for endothelial cells), Bcl-2, and real-time polymerase chain reaction analysis of VEGFR2, Bcl-2, CXCL1, and CXCR2 messenger RNA were performed. In the real-time polymerase chain reaction analysis, messenger RNA was extracted from CD31-stained endothelial cells that were retrieved with laser capture microdissection. For statistical analysis of immunohistochemistry, the immunostained area was plotted, and pixel counts were determined. Then, the percentage of the immunostained area in the total area was calculated. ResultsThe density of the CD31-stained area increased until 21 days after pulp exposure. On the other hand, Bcl-2–stained area showed the highest density at 14 days (active lesion expanding phase) and then decreased until 28 days (lesion stability phase). VEGFR2, Bcl-2, CXCL1, and CXCR2 messenger RNA expression in endothelial cells showed the highest levels at 14 days and then decreased until 28 days. ConclusionsThe increase in microvascular density and the up-regulation of VEGFR2, Bcl-2, CXCL1, and CXCR2 messenger RNA expression in endothelial cells took place coincidently with the expanding phase of experimentally induced periapical lesions. These data suggest that these angiogenic factors play a role in the lesion development.

Protective Effect of Bax Ablation Against Cell Loss in the Retinal Ganglion Layer Induced by Optic Nerve Crush in Transgenic Mice

Bax expression is a prerequisite for retinal ganglion cell (RGC) apoptosis. Experimental studies have reported Bax protein upregulation following optic nerve transection. The stimuli that trigger apoptosis share a common executioner proteolysis cascade, including caspase-3 and poly-(adenosine diphosphate ribose) polymerase cleavage. This study sought to elucidate the role of the mitochondrial apoptotic pathway in RGCs using a Bax transgenic knockout mouse model. The right optic nerves of 26 C57BL mice, 7 Bax, 7 Bax, and 12 Bax, were subjected to crush injury and analyzed for apoptosis and neuronal cell loss on days 1, 3, and 21. Levels of Bax, Bcl-2, and caspase-3 messenger RNA expression were determined with real-time polymerase chain reaction. Multiple apoptotic cells were detected in the retinas of the Bax and Bax mice at days 1 and 3, but not in the Bax mice. The Bax/Bcl-2 ratio was higher in the Bax than in the Bax mice on day 1 (1.33 and 0.83, respectively), with a trend toward an increase on day 3 (1.47 and 1.66, respectively); Bax/Bcl-X showed the same elevation on day 1 in the wild-type mice (1.34) but decreased on day 3 (0.8). Bax gene expression was undetectable in the Bax mice. Caspase-3 gene expression was higher in the Bax than in the Bax mice on day 1 and dropped toward baseline on day 3. The opposite trend was noted in the Bax mice. The lack of apoptosis combined with the reduction in proapoptotic genes in the Bax mice after injury compared to the Bax and Bax mice suggests that Bax plays a crucial role in the induction of apoptosis. Suppression of Bax expression may reduce retinal cell loss.

Parenteral omega-3 fatty acids (Omegaven) modulate intestinal recovery after intestinal ischemia-reperfusion in a rat model

Background/purpose Fatty acids from fish oil (omega-3 polyunsaturated fatty acids, 3PUFAs) are emerging as powerful yet safe disease-modifying nutrients and are protective in severe critical care conditions including ischemia-reperfusion (IR) injury. The purpose of the present study was to examine the effects of 3PUFAs on intestinal structural changes, enterocyte proliferation, and apoptosis after intestinal IR in a rat. Methods Male rats were divided into three experimental groups: sham rats underwent laparotomy, IR rats underwent occlusion of both superior mesenteric artery and portal vein for 30 minutes followed by 48 hours of reperfusion, and 3PUFA-treated IR (IR-3PUFA) rats underwent IR and were treated with Omegaven (Fresenius Kabi, Bad Homburg, Germany) given intraperitoneally at a dose of 1 mL twice a day. Intestinal structural changes (Park injury score, overall bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depth, cell proliferation, and apoptosis) were determined 48 hours after IR. Real-time polymerase chain reaction (PCR) was used to determine the level of bax and bcl-2 messenger RNA. Results A significant decrease in bowel and mucosal weight was observed in the ileum of untreated IR rats compared with sham animals. Forty-eight hours after IR, cell apoptosis remained increased in the jejunum and ileum, which coincided with increased bax/bcl-2 ratio. Cell proliferation was increased 48 hours after IR, suggesting tissue repair. Treatment with Omegaven resulted in a significant increase in bowel and mucosal weight in the jejunum and ileum, villus height in the jejunum and ileum, and crypt depth in the jejunum compared with untreated IR animals. IR-3PUFA rats also demonstrated a significantly lower Park injury score in the jejunum and ileum as well as a lower apoptotic index in the ileum compared with untreated IR animals. Conclusions Parenteral Omegaven administration decreases the intestinal mucosal injury and inhibits enterocyte apoptosis after intestinal IR in a rat.

The Bcl-2 Gene Polymorphism rs956572AA Increases Inositol 1,4,5-Trisphosphate Receptor–Mediated Endoplasmic Reticulum Calcium Release in Subjects with Bipolar Disorder

Bipolar disorder (BPD) is characterized by altered intracellular calcium (Ca(2+)) homeostasis. Underlying mechanisms involve dysfunctions in endoplasmic reticulum (ER) and mitochondrial Ca(2+) handling, potentially mediated by B-cell lymphoma 2 (Bcl-2), a key protein that regulates Ca(2+) signaling by interacting directly with these organelles, and which has been implicated in the pathophysiology of BPD. Here, we examined the effects of the Bcl-2 gene single nucleotide polymorphism (SNP) rs956572 on intracellular Ca(2+) dynamics in patients with BPD. Live cell fluorescence imaging and electron probe microanalysis were used to measure intracellular and intra-organelle free and total calcium in lymphoblasts from 18 subjects with BPD carrying the AA, AG, or GG variants of the rs956572 SNP. Analyses were carried out under basal conditions and in the presence of agents that affect Ca(2+) dynamics. Compared with GG homozygotes, variant AA-which expresses significantly reduced Bcl-2 messenger RNA and protein-exhibited elevated basal cytosolic Ca(2+) and larger increases in inositol 1,4,5-trisphosphate receptor-mediated cytosolic Ca(2+) elevations, the latter in parallel with enhanced depletion of the ER Ca(2+) pool. The aberrant behavior of AA cells was reversed by chronic lithium treatment and mimicked in variant GG by a Bcl-2 inhibitor. In contrast, no differences between SNP variants were found in ER or mitochondrial total Ca(2+) content or in basal store-operated Ca(2+) entry. These results demonstrate that, in patients with BPD, abnormal Bcl-2 gene expression in the AA variant contributes to dysfunctional Ca(2+) homeostasis through a specific ER inositol 1,4,5-trisphosphate receptor-dependent mechanism.

Parenteral but Not Enteral Omega‐3 Fatty Acids (Omegaven) Modulate Intestinal Regrowth After Massive Small Bowel Resection in Rats

The purpose of the present study was to evaluate the effects of ω-3 fatty acids (Omegaven) on early intestinal adaptation in rats with short bowel syndrome (SBS). Male Sprague-Dawley rats were randomly assigned to 1 of 4 groups: sham rats underwent bowel transection; SBS rats underwent 75% bowel resection; SBS-O ω-3 rats underwent bowel resection and were treated with oral Omegaven given by gavage; and SBS-I ω-3 rats underwent bowel resection and were treated with Omegaven given intraperitoneally. Rats were killed on day 14. Parameters of intestinal adaptation (bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depths, cell proliferation and apoptosis) were determined at time of death. Real-time polymerase chain reaction was used to determine the level of Bax and Bcl-2 messenger RNA (mRNA). Statistical analysis was performed using Kruskal-Wallis test followed by post hoc test, with P < .05 considered statistically significant. Oral ω-3 supplementation did not significantly change intestinal regrowth. In contrast, parenteral ω-3 in rats that underwent resection resulted in higher bowel and mucosal weights, mucosal DNA and protein in ileum, villus height in ileum, crypt depth in jejunum and ileum, and greater rates of cell proliferation in jejunum and ileum compared with SBS animals. The initial decreased levels of apoptosis corresponded with the early decrease in Bax and increase in Bcl-2 mRNA levels. Parenteral but not enteral Omegaven augments and accelerates structural bowel adaptation in a rat model of SBS. Increased cell proliferation and decreased apoptosis reflect increased cell turnover in Omegaven-treated animals.

Yin-Chen-Hao-Tang ameliorates obstruction-induced hepatic apoptosis in rats

The accumulation of hydrophobic bile acids in the liver is considered to play a pivotal role in the induction of apoptosis of hepatocytes during cholestasis. Thus, factors that affect apoptosis may be used to modulate liver fibrosis. Yin-Chen-Hao-Tang (YCHT) decoctions have been recognised as a hepatoprotective agent for jaundice and various types of liver diseases. We used an experimental rat model of bile-duct ligation (BDL) to test whether YCHT plays a regulatory role in the pathogenesis of hepatic apoptosis. BDL-plus-YCHT groups received 250 or 500 mg kg (-1) YCHT by gavage once daily for 27 days. YCHT significantly ameliorated the portal hypertensive state and serum TNF-alpha compared with the vehicle-treated control group. In BDL-plus-YCHT-treated rats, hepatic glutathione contents were significantly higher than than in BDL-only rats. BDL caused a prominent liver apoptosis that was supported by an increase in Bax and cytochrome c protein and increased expression of Bax and Bcl-2 messenger RNA. The normalising effect of YCHT on expression of Bax and Bcl-2 mRNA was dependent on the dose of YCHT, 500 mg kg (-1) having the greater effect on both Bax and Bcl-2 of mRNA levels. Additionally, YCHT treatment down-regulated both hepatic caspase-3 and -8 activities of BDL rats. This study demonstrates the anti-apoptotic properties of YCHT and suggests a potential application of YCHT in the clinical management of hepatic disease resulting from biliary obstruction.

Phase I study of apoptosis gene modulation with oblimersen within preoperative chemotherapy in patients with primary breast cancer

Expression of the Bcl-2 protein confers resistance to chemotherapy-mediated apoptotic signals in patients with breast cancer. We investigated effects of Bcl-2 down-regulation by the Bcl-2 antisense oligodeoxynucleotide oblimersen in breast tumor biopsies. Oblimersen targets Bcl-2 messenger RNA (mRNA), down-regulates Bcl-2 protein translation and enhances antitumor effects of subtherapeutic chemotherapy doses. Within a phase I trial, we administered escalating doses of oblimersen (3, 5 or 7 mg/kg/day) as continuous infusion on days 1–7 in combination with standard-dose docetaxel (Taxotere), Adriamycin and cyclophosphamide (TAC) on day 5 as preoperative chemotherapy in 28 patients with T2–4 tumors. Effects of oblimersen were evaluated in tumor biopsies and peripheral blood mononuclear cells (PBMCs) 4 days after start of oblimersen and before TAC treatment by quantitative microfluidic real-time PCR. Read-outs consisted in measurement of Bcl-2 mRNA modulations and of 18 putative predictive markers. Two of 13 patients showed a diminution of Bcl-2 transcripts after 4 days of treatment with oblimersen 5 mg/kg/day. PBMCs could not be evaluated as a surrogate tissue because no qualified RNA could be isolated. Nevertheless, we demonstrated feasibility to process clinical samples and to obtain good quality RNA from tumor biopsies and indicated the potential of oblimersen to lower Bcl-2 mRNA in breast cancer.

Involvement of the bax and bcl-2 system in the induction of germ cell apoptosis is correlated with the time of reperfusion after testicular ischemia in a rat model

The objective of this study was to examine the relationship between time of reperfusion and bax/bcl-2-dependent germ cell apoptosis after testicular ischemia-reperfusion injury in the rat. In ischemic testis, bax/bcl-2 ratio did not change significantly, and the elevation of germ cell apoptosis was not marked; in the contralateral testis, germ cell apoptosis increased after 6 hours of reperfusion, achieved statistical significance after 24 hours, and decreased after 72 hours of reperfusion and was initiated by decreased bcl-2 messenger RNA levels and elevated bax/bcl-2 ratio within the first 6 hours of reperfusion.

Gli1 maintains cell survival by up-regulating IGFBP6 and Bcl-2 through promoter regions in parallel manner in pancreatic cancer cells

Background:Aberrant activation of Hedgehog (Hh) signaling pathway has been reported to be related to malignant biological behavior of pancreatic cancer but its mechanism is unclear yet. Since IGF pathway and Bcl-2 family are involved in proliferation and apoptosis of pancreatic cancer cells, we hypothesize that they are possibly associated with Hh pathway.Materials and Methods:We studied the relationship of Shh-Gli1 signaling pathway with proliferation and apoptosis of pancreatic cancer cells and the regulation of transcription factor Gli1 to insulin-like growth factor binding protein 6 (IGFBP6) and Bcl-2 genes at the level of transcription.Results:Sonic hedgehog (Shh), Smoothened (Smo), patched and Gli1 were expressed in pancreatic cancer cells. Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration. Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis. The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01). Finally PCNA, IGFBP6 and Bcl-2 mRNA were upregulated as well as Shh or Gli1 in pancreatic cancer tissues (p < 0.01).Conclusions:Our study reveals that Gli1 maintained cell survival by binding the promoter regions and facilitating transcription of IGFBP6 and Bcl-2 genes in a parallel manner in pancreatic cancer cells and suggests it may be one of the mechanisms of Shh-Gli1 signaling pathway in pancreatic cancer.

5′-triphosphate-siRNA: turning gene silencing and Rig-I activation against melanoma

Genetic and epigenetic plasticity allows tumors to evade single-targeted treatments. Here we direct Bcl2-specific short interfering RNA (siRNA) with 5'-triphosphate ends (3p-siRNA) against melanoma. Recognition of 5'-triphosphate by the cytosolic antiviral helicase retinoic acid-induced protein I (Rig-I, encoded by Ddx58) activated innate immune cells such as dendritic cells and directly induced expression of interferons (IFNs) and apoptosis in tumor cells. These Rig-I-mediated activities synergized with siRNA-mediated Bcl2 silencing to provoke massive apoptosis of tumor cells in lung metastases in vivo. The therapeutic activity required natural killer cells and IFN, as well as silencing of Bcl2, as evidenced by rescue with a mutated Bcl2 target, by site-specific cleavage of Bcl2 messenger RNA in lung metastases and downregulation of Bcl-2 protein in tumor cells in vivo. Together, 3p-siRNA represents a single molecule-based approach in which Rig-I activation on both the immune- and tumor cell level corrects immune ignorance and in which gene silencing corrects key molecular events that govern tumor cell survival.

Evidence for Involvement of ERK, PI3K, and RSK in Induction of Bcl-2 by Valproate

Valproate, an anticonvulsant and mood stabilizer, up-regulates Bcl-2, a neurotrophic/neuroprotective protein. In this study, we investigated the molecular mechanism through which Bcl-2 is up-regulated by valproate using cultured human neuron-like cells. Valproate, within therapeutically relevant ranges, induced time- and concentration-dependent up-regulations of both Bcl-2 messenger RNA and protein implicating an underlying gene transcriptional-mediated mechanism. Bcl-2 up-regulations were associated with ERK1/2 and PI3K pathway activations and elevated levels of activated phospho-RSK and phospho-CREB, convergent targets of the ERK1/2 and PI3K pathways. Valproate increased transcriptional activity of a human bcl-2 promoter-reporter gene construct. This effect was attenuated, but not blocked, by mutation of a CREB DNA binding site, a CRE site in the human bcl-2 promoter sequence. ERK and/or PI3K pathway inhibitors and RSK1 small hairpin RNA knockdown reduced, but did not abolish, baseline and valproate-induced promoter activities and lowered Bcl-2 protein levels. These data collectively suggest that valproate induces Bcl-2 regulation partially through activations of the ERK and PI3K cascades and their convergent kinase, RSK, although other unknown mechanism(s) are likely involved. Given the known roles of Bcl-2 in the central nervous system, the current findings offer a partial yet complex molecular mechanistic explanation for the known neurobiological effects of valproate including neurite growth, neuronal survival, and neurogenesis.

Molecular Imaging of bcl-2 Expression in Small Lymphocytic Lymphoma Using 111In-Labeled PNA–Peptide Conjugates

The bcl-2 gene is overexpressed in non-Hodgkin's lymphoma (NHL), such as small lymphocytic lymphoma (SLL), and many other cancers. Noninvasive imaging of bcl-2 expression has the potential to identify patients at risk for relapse or treatment failure. The purpose of this study was to synthesize and evaluate radiolabeled peptide nucleic acid (PNA)-peptide conjugates targeting bcl-2 gene expression. An (111)In-labeled PNA complementary to the translational start site of bcl-2 messenger RNA was attached to Tyr(3)-octreotate for somatostatin receptor-mediated intracellular delivery. DOTA-anti-bcl-2-PNA-Tyr(3)-octreotate (1) and 3 control conjugates (DOTA-nonsense-PNA-Tyr(3)-octreotate (2), DOTA-anti-bcl-2-PNA-Ala[3,4,5,6]-substituted congener (3), and DOTA-Tyr(3)-octreotate (4) [DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid]) were synthesized by standard solid-phase 9-fluorenylmethoxycarbonyl (Fmoc) chemistry. In vitro studies were performed in Mec-1 SLL cells, which express both bcl-2 messenger RNA and somatostatin receptors. Biodistributions and microSPECT/CT studies were performed in Mec-1-bearing SCID (severe combined immunodeficiency) mice, a new animal model of human SLL. (111)In-Labeled conjugate 1 was taken up by Mec-1 cells through a somatostatin receptor-mediated mechanism. Biodistribution studies showed specific tumor uptake of conjugate 1, the somatostatin analog 4, and the PNA nonsense conjugate 2, but not of the mutant peptide conjugate 3. Mec-1 tumors could be detected by microSPECT/CT using (111)In-labeled DOTA-Tyr(3)-octreotate (4) and the targeted anti-bcl-2 conjugate (1), but not using the 2 negative control conjugates 2 and 3. A new (111)In-labeled antisense PNA-peptide conjugate demonstrated proof of principle for molecular imaging of bcl-2 expression in a new mouse model of human SLL. This imaging agent may be useful for identifying NHL patients at risk for relapse and conventional treatment failure.

Bcl-2 and Bax messenger RNA Gene expression detected by reverse transcriptase polymerase chain reaction after partial hepatectomy and licorice in rats

Bcl-2 and Bax messenger RNA Gene expression detected by reverse transcriptase polymerase chain reaction after partial hepatectomy and licorice in rats

Apoptotic Effect of Biophytum sensitivum on B16F-10 Cells and Its Regulatory Effects on Nitric Oxide and Cytokine Production on Tumor-Associated Macrophages

The present study is part of a large-scale investigation of the antitumor effects of Biophytum sensitivum on B16F-10 melanoma cells. The investigation involved the regulatory effect of B sensitivum on nitric oxide and cytokine production in B16F-10 cells, tumor-associated macrophages, and peritoneal macrophages as well as on the apoptotic process in B16F-10 melanoma cells. B sensitivum at a concentration of 10 microg/mL could significantly (P< .001) inhibit production of nitric oxide and proinflammatory cytokines such as interleukin-1beta, interleukin-6, granulocyte monocyte-colony stimulating factor, and tumor necrosis factor-alpha in B16F-10 cells, tumor-associated macrophages, and peritoneal macrophages. Incubation of B16F-10 cells with B sensitivum showed the presence of apoptotic bodies and induced DNA fragmentation. Furthermore, B sensitivum showed an inhibitory effect on inducible nitric oxide synthase as well as bcl-2 expression, and up-regulated p53 and caspase-3 messenger RNA expression in B16F-10 melanoma cells. The observed results suggest that regulation of proinflammatory cytokine production by tumor cells, tumor-associated macrophages, and resident macrophages accompanied by altered inducible nitric oxide synthase, bcl-2, caspase-3, and p53 messenger RNA expression by B sensitivum methanol extract induces apoptosis in B16F-10 melanoma cells.

Spatiotemporal patterns of smooth muscle cell changes in ascending aortic dilatation with bicuspid and tricuspid aortic valve stenosis: Focus on cell–matrix signaling

The present study examined temporal and spatial patterns of extracellular matrix and smooth muscle cell changes in the ascending aorta with bicuspid and tricuspid aortic valve stenosis. Wall specimens were retrieved from both the greater and the lesser curvature ("convexity" and "concavity") of 14 nonaneurysmal and 12 aneurysmal aortas (aortic ratios 1.2 and 1.5, respectively) and from 3 heart donors (normal). Immunochemistry was performed for detection of apoptotic (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling [TUNEL]-positive) and proliferating (Ki-67-positive) smooth muscle cells and for semiquantification of matrix proteins (collagens, fibronectin, tenascin, laminin). Co-immunoprecipitation assessed the extent of Bcl-2-modifying factor binding to Bcl-2, indicating a matrix-derived cytoskeleton-mediated proapoptotic signaling. Polymerase chain reaction allowed for quantification of messenger RNA expression for Bcl-2. In both bicuspid and tricuspid aneurysms, fibrillar collagens were reduced, whereas fibronectin and tenascin were increased compared with those in normal conditions. These matrix alterations were already evident in bicuspid nonaneurysmal aortas at the convexity, with significant elevation of apoptotic indexes (P = .02 bicuspid vs normal; P = .48 tricuspid vs normal). Apoptotic indexes correlated with aortic dimensions only in tricuspid aortas (P = .01). No significant increase in Ki-67 was found. Higher levels of Bcl-2-modifying factor-Bcl-2 binding were found in bicuspid nonaneurysmal aorta versus tricuspid (P = .03) and normal aortas (P = .01). Bcl-2 messenger RNA expression was reduced in the bicuspid aorta versus normal (P = .08). Smooth muscle cell apoptosis with bicuspid aortic valve stenosis occurred before overt aortic dilation, mainly at the convexity, where wall stress is expectedly higher. In this setting, a matrix-dependent proapoptotic signaling was evidenced by increased Bcl-2-modifying factor-Bcl-2 binding. Stress-dependent bicuspid aortic valve matrix changes may trigger early apoptosis by inducing cytoskeletal rearrangement.

Prognostic relevance of a novel semiquantitative classification of Bcl2 immunohistochemical expression in human infiltrating ductal carcinomas of the breast

Bcl2 is an important prognostic parameter in human breast cancer. However, the evaluation of Bcl2 expression by immunohistochemistry is carried out using arbitrary scoring criteria. In the present study, we evaluated the clinical relevance of a novel, semiquantitative classification of the Bcl2 immunostaining based on both the distribution and the intensity of the staining reaction. The proposed classification was first validated in 69 breast cancer specimens by comparing the Bcl2 immunostaining with the Bcl2 messenger RNA (mRNA) levels evaluated by real-time RT-PCR. Since a highly significant association was found between protein and mRNA for Bcl2, the immunohistochemical scoring system was applied to 442 patients with infiltrating ductal carcinomas of the breast with long-term follow-up (median observation time 106 months). In the entire series, the Bcl2 variable was an independent predictor of clinical outcome, and its prognostic independence was maintained when lymph node-negative and -positive patients were considered separately. In this regard, of particular interest was the observation of a subgroup of node-negative breast cancer patients with a negative Bcl2 immunostaining, who had a very high probability of relapse or death (respectively about five and seven times greater than patients with a positive Bcl2 immunostaining). Moreover, the Bcl2 variable retained prognostic significance also in subgroups of patients treated with either adjuvant endocrine therapy or chemotherapy. Our results demonstrated that in breast cancer, Bcl2 protein expression parallels its mRNA level, and it has a highly significant and independent prognostic relevance.

Comparison of D-G3139 and Its Enantiomer L-G3139 in Melanoma Cells Demonstrates Minimal In Vitro but Dramatic In Vivo Chiral Dependency

G3139 (Genasense), an 18mer phosphorothioate antisense oligonucleotide targeted to the initiation codon region of the Bcl-2 messenger RNA (mRNA), downregulates Bcl-2 protein and mRNA expression in many cell lines. However, both the in vitro and in vivo mechanisms of action of G3139 are still uncertain. The isosequential L-deoxyribose enantiomer L-G3139, which does not downregulate Bcl-2 expression, was synthesized to study the role of the Bcl-2 protein in melanoma cells. Both D-G3139 and L-G3139 bind nonspecifically to basic fibroblast growth factor with approximately the same K(c), and cause highly effective inhibition of net formation in 518A2 melanoma cells on Matrigel. The uptakes of D-G3139 and L-G3139 in melanoma cells were also similar. However, unlike D-G3139, L-G3139 does not produce poly ADP-ribose polymerase-1 and procaspase-3 cleavage at 9.5 h after the initiation of the transfection, but can activate the intrinsic pathway of apoptosis at approximately 48 h. Furthermore, treatment of A375 melanoma human xenografts in severe combined immunodeficiency (SCID) mice demonstrates that tumor growth is not inhibited by L-G3139, whereas D-G3139 significantly inhibits the rate of tumor growth. Furthermore, the immunostimulatory properties of L-G3139 appear to be nil, which differs dramatically from those of D-G3139. In conclusion, profound differences exist between D-G3139 and L-G3139 in vivo despite their similarities in vitro.

Bcl-2 and Bax Messenger RNA Gene Expression Detected by Reverse Transcriptase Polymerase Chain Reaction after Partial Hepatectomy and Licorice in Rats

Liver regeneration is a complex physiological response that takes place after the loss of hepatocytes caused by toxic or viral injury or secondary to liver resection. This work purposed to investigate the implication of bcl-2 and bax expression as an important contribute in liver transplant donors and also the possible modulatory effect of licorice on their expression. Forty eight male albino rats weighing 250–320 g were divided into 6 groups (8 animals for each). The rats underwent partial hepatectomy (PH) represents 3 groups (sacrificed after 24, 48 and 72 h after PH) and other 3 groups after oral receiving of licorice extract for 4 weeks (2.4 g/kg b.w.). The resected liver was considered as control (zero time). The expression of bcl-2 and bax mRNA of normal liver and liver of PH were measured by reversed transcriptase polymerase chain reaction (RT-PCR). The distinct changes in the expression of the mRNA encoding these 2 genes were confirmed by an immunohistochemical staining of the liver tissues (streptavidin-biotin method). The analysis of mRNA level revealed a significant increase of anti-apoptotic bcl-2 mRNA expression after 24 h (p<0.05), while, it was declined in the following 2 d. In contrast, bax mRNA expression showed delayed increase reaching a peak at 48 h after PH. The pretreatment with licorice caused a statistically significant increase in bax mRNA expression; meanwhile, the change in bcl-2 expression was not significant when compared to the control. Furthermore, immunohistochemical staining of regenerating liver with bcl-2 and bax antibodies showed that the changes in the bcl-2 and bax protein levels were similar and consistent to that found for mRNA. It was suggested that licorice may provide a mechanism in the induction of apoptosis through modulation of bcl-2 and bax expression in regenerating liver as a model for chemopreventive drug of cancers.

The Antibiotic Erythromycin Induces Tolerance against Transient Global Cerebral Ischemia in Rats (Pharmacologic Preconditioning)

Cerebral ischemic tolerance can be induced by a variety of noxious stimuli, but no clinically applicable regimen for preconditioning has been described. Therefore, the authors tested the ability of a pharmacologic preconditioning strategy using the well-known macrolide antibiotic erythromycin to induce tolerance against transient global cerebral ischemia in vivo. They also investigated whether tolerance induction by erythromycin involves transcriptional and translational changes of cerebral B-cell leukemia/lymphoma-2 (bcl-2) expression. Male Wistar rats were treated with erythromycin (25 mg/kg intramuscularly) or vehicle and subjected to 15 min of transient global cerebral ischemia 6, 12, or 24 h after pretreatment. Neurologic deficit was evaluated once daily, and neuronal cell survival was assessed after 7 days of reperfusion. Additional animals were similarly pretreated, and cerebral bcl-2 messenger RNA (mRNA) and protein expression was analyzed 6 and 24 h later. Erythromycin improved postischemic neuronal survival in hippocampal CA1 and CA3 sectors and reduced functional deficit, with 12 h being the most efficient pretreatment interval. Bcl-2 mRNA in hippocampus was transiently up-regulated 6 h after erythromycin, but neuronal Bcl-2 protein remained unchanged. Erythromycin can induce cerebral ischemic tolerance in vivo (pharmacologic preconditioning), suggesting a potential clinical strategy of preemptive neuroprotection. Changes in bcl-2 expression after erythromycin were small and transient. The induction of bcl-2-related pathways, although important for other preconditioning regimens, may therefore be less relevant for the neuroprotective effects of pharmacologic preconditioning using erythromycin.