Microplastics and di (2-ethylhexyl) phthalate synergistically induce apoptosis in mouse pancreas through the GRP78/CHOP/Bcl-2 pathway activated by oxidative stress

With the widespread use of plastics, microplastics (MPs) and di(2-ethylhexyl) phthalate (DEHP) have become emerging environmental pollutants. The combined toxicity of MPs and DEHP on the mouse pancreas and the specific mechanism of toxicity remain unclear. To establish in vitro and in vivo models to address these questions, mice were continuously exposed to 200 mg/kg/d DEHP and 10 mg/L MPs for 4 weeks. In vitro, MIN-6 cells were treated with 200 μg/mL MPs and 200 μM DEHP for 24 h. Based on toxicity assessed using CCK8 of the equivalent TU binary mixture, the IC50 of the TU-mix of DEHP and MPs 0.692 < 0.8, indicating a synergistic effect of the two toxicants. Meanwhile, our data revealed that compared to the control group, MPs and DEHP combined treatment increased ROS levels, inhibited the activity, and enhanced the expression of GRP78, and CHOP. Simultaneously, activated CHOP decreased the expression of Bcl-2, and increased the expression of Bax. In conclusion, DEHP and MPs synergistically induce oxidative stress, and activate the GRP78/CHOP/Bcl-2 pathway to induce pancreatic apoptosis in mice. Our finding provides a new direction for the research on the specific mechanism of MPs and DEHP combined toxicity.

Multimeric Anti-DR5 IgM Agonist Antibody IGM-8444 Is a Potent Inducer of Cancer Cell Apoptosis and Synergizes with Chemotherapy and BCL-2 Inhibitor ABT-199

Death receptor 5 (DR5) is an attractive target for cancer therapy due to its broad upregulated expression in multiple cancers and ability to directly induce apoptosis. Though anti-DR5 IgG antibodies have been evaluated in clinical trials, limited efficacy has been attributed to insufficient receptor crosslinking. IGM-8444 is an engineered, multivalent agonistic IgM antibody with 10 binding sites to DR5 that induces cancer cell apoptosis through efficient DR5 multimerization. IGM-8444 bound to DR5 with high avidity and was substantially more potent than an IgG with the same binding domains. IGM-8444 induced cytotoxicity in a broad panel of solid and hematologic cancer cell lines but did not kill primary human hepatocytes in vitro, a potential toxicity of DR5 agonists. In multiple xenograft tumor models, IGM-8444 monotherapy inhibited tumor growth, with strong and sustained tumor regression observed in a gastric PDX model. When combined with chemotherapy or the BCL-2 inhibitor ABT-199, IGM-8444 exhibited synergistic in vitro tumor cytotoxicity and enhanced in vivo efficacy, without augmenting in vitro hepatotoxicity. These results support the clinical development of IGM-8444 in solid and hematologic malignancies as a monotherapy and in combination with chemotherapy or BCL-2 inhibition.

Assessment of gentamicin and cisplatin-induced kidney damage mediated via necrotic and apoptosis genes in albino rats

BACKGROUND

Gentamicin (GM) is a low-cost, low-resistance antibiotic commonly used to treat gram-negative bacterial diseases. Cisplatin (Csp) is a platinum-derived anti-neoplastic agent. This experiment aimed to identify the early signs of gentamicin and cisplatin-induced nephrotoxicity in rats. Thirty Wistar rats were divided into three groups of 10: a control group, which received no treatment; a gentamicin group administered by a dose of (100 mg/kg, IP) for 7 consecutive days, and a cisplatin group was administered intraperitoneal in a dose of (1.5 mg/kg body weight) repeated twice a week for 3 weeks.

RESULTS

Both experimental groups exhibited increased levels of creatinine, urea, and uric acid, with the cisplatin-treated group showing higher levels than the gentamicin group. Experimental groups also exhibited significantly increased Malondialdehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GSH-Px) with more pronounced effects in the cisplatin-treated group. Further, both experimental groups exhibited significant up-regulation of Tumor Necrosis Factor α (TNF-α), caspase-3, and Bax and down regulation of Bcl-2.

CONCLUSION

These findings confirm the use of necrotic, apoptotic genes as early biomarkers in the detection of tubular kidney damage. Further, cisplatin was shown to have a greater nephrotoxic effect than gentamicin; therefore, its use should be constrained accordingly when co-administered with gentamicin.

CD34 and Bcl-2 as predictors for the efficacy of neoadjuvant chemotherapy in cervical cancer

BACKGROUND

Successful neoadjuvant chemotherapy (NACT) could improve the surgical resection rate and radical curability of patients with cervical cancer, but only a subset of patients benefits. Therefore, identifying predictive biomarkers are urgently needed. The aim of this study was to evaluate the predictive value of CD34 and Bcl-2 in the NACT effectiveness of cervical cancer.

METHODS

Sixty-seven patients with locally advanced cervical cancer (FIGO stages IB3, IIA2 or IIB) were classified into two groups based on effective (n = 48) and ineffective (n = 19) response to NACT. Immunohistochemistry was employed to identify CD34 and Bcl-2 expression before and after NACT. We analyzed the associations between the pre-NACT expression of these two biomarkers and the response of NACT. The expression of these two biomarkers before and after NACT was also assessed and compared.

RESULTS

More patients were CD34 positive expression before NACT in effective group compared to ineffective group (p = 0.005). However, no statistically significant difference in Bcl-2 expression before NACT were found between two groups (p = 0.084). In NACT effective group, the expression of both CD34 and Bcl-2 after NACT are down-regulated (p < 0.001 and p < 0.001, respectively), while there are no statistical differences between the pre- and post-NACT expression of CD34 and Bcl-2 in NACT ineffective group (p = 0.453 and p = 0.317, respectively).

CONCLUSION

The positive CD34 expression before NACT may serve as a predictive biomarker for NACT of cervical cancer, but the pre-NACT expression of Bcl-2 is not an independent predictor. The down-regulated expression of these two indicators after NACT may indicate effective NACT.

Neuroprotective effects of aucubin on hydrogen peroxide-induced toxicity in human neuroblastoma SH-SY5Y cells via the Nrf2/HO-1 pathway

BACKGROUND

When redox balance is lost in the brain, oxidative stress can cause serious damage that leads to neuronal loss, in congruence with neurodegenerative diseases. Aucubin (AU) is an iridoid glycoside and that is one of the active constituents of Eucommia ulmoides, has many pharmacological effects such as anti-inflammation, anti-liver fibrosis, and anti-atherosclerosis.

PURPOSE

The present study aimed to evaluate the inhibitory effects of AU on cell oxidative stress against hydrogen peroxide (H₂O₂)-induced injury in SH-SY5Y cells in vitro.

METHODS

SH-SY5Y cells were simultaneously treated with AU and H₂O₂ for 24 h. Cell viability was measured by CCK-8. Additionally, mitochondrial membrane depolarization, reactive oxygen species (ROS) generation, and cell apoptosis were measured by flow cytometry.

RESULTS

The results showed that AU can significantly increase the H₂O₂-induced cell viability and the mitochondrial membrane potential, decrease the ROS generation, malondialdehyde (MDA), and increase glutathione (GSH) contents and the superoxide dismutase (SOD) activity. We also found that H₂O₂ stimulated the production of nitric oxide (NO), which could be reduced by treatment with AU through inhibiting the inducible nitric oxide synthase (iNOS) protein expression. In H₂O₂-induced SH-SY5Y cells, the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) content and cell apoptosis were significantly reduced by AU treatment through nuclear factor E2-related factor 2/hemo oxygenase-1 (Nrf2/HO-1) activation, inhibiting the expression of p-NF-κB/NF-κB and down-regulating MAPK and Bcl-2/Bax pathways.

CONCLUSION

These results indicate that AU can reduce inflammation and oxidative stress through the NF-κB, Nrf2/HO-1, and MAPK pathways.

Robust detection of translocations in lymphoma FFPE samples using targeted locus capture-based sequencing

In routine diagnostic pathology, cancer biopsies are preserved by formalin-fixed, paraffin-embedding (FFPE) procedures for examination of (intra-) cellular morphology. Such procedures inadvertently induce DNA fragmentation, which compromises sequencing-based analyses of chromosomal rearrangements. Yet, rearrangements drive many types of hematolymphoid malignancies and solid tumors, and their manifestation is instructive for diagnosis, prognosis, and treatment. Here, we present FFPE-targeted locus capture (FFPE-TLC) for targeted sequencing of proximity-ligation products formed in FFPE tissue blocks, and PLIER, a computational framework that allows automated identification and characterization of rearrangements involving selected, clinically relevant, loci. FFPE-TLC, blindly applied to 149 lymphoma and control FFPE samples, identifies the known and previously uncharacterized rearrangement partners. It outperforms fluorescence in situ hybridization (FISH) in sensitivity and specificity, and shows clear advantages over standard capture-NGS methods, finding rearrangements involving repetitive sequences which they typically miss. FFPE-TLC is therefore a powerful clinical diagnostics tool for accurate targeted rearrangement detection in FFPE specimens.

The protective effects of Ziziphora tenuior L. against chlorpyrifos induced toxicity: Involvement of inflammatory and cell death signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphora tenuior L. is used as a medicinal plant in treatment of various diseases such as gastric disorders, stomach ache, dysentery, uterus infection, gut inflammation and menstruation.

AIM OF THE STUDY

In the present study, the protective effects of Ziziphora tenuior extract against chlorpyrifos (CPF), the most commonly or popularly used insecticide in Asia and Africa were investigated in liver and lung tissues with emphasis in apoptotic and inflammatory pathways in rat model.

MATERIALS AND METHODS

The experiments were performed by gavage of male rats for 8 weeks. The extract of Z. tenuior was administrated at three different doses (40, 80, 160 mg/kg). 6.75 mg/kg CPF was administrated as the maximum tolerable dose based on our previous study.

RESULTS

Our data indicated that CPF can increase the expression of some inflammatory genes (IL-6, TLR-2, IL-1β, TNF-α, and NLPR3) and apoptosis genes (Caspase 3, Caspase 9, Caspase 8 and Bax). On the other hand, it can down regulate Bcl-2 gene expression. Post-treatment of Z. tenuior extract in CPF- treated rats showed significant decrease in apoptotic and inflammatory gene expression in the liver and lung due to its anti-apoptotic effects which confirmed by Bcl-2 gene overexpression.

CONCLUSION

The present study suggested that Z. tenuior extract, as a traditional treatment can be able to moderate CPF toxicity via significant effect on inflammatory and apoptotic cell death signaling pathway. Also, based on our preliminary data, it is suggested that Z. tenuior extract can prevent the adverse effects of CPF in liver and lung tissues.

BH3 Mimetic ABT-199 Enhances the Sensitivity of Gemcitabine in Pancreatic Cancer in vitro and in vivo

BACKGROUND AND AIMS

Pancreatic cancer is an aggressive malignancy with poor prognosis. Gemcitabine is the standard chemotherapeutic drug used to treat the disease; however, it has a low response rate. Therefore, there is an urgent need to develop new and safe therapies to enhance sensitivity to gemcitabine in treating pancreatic cancer.

METHODS

The synergistic effect of gemcitabine combined with specific B cell CLL/lymphoma 2 (Bcl-2) inhibitor ABT-199 against pancreatic cancer was tested using cell viability, cell cycle, and apoptosis assays in vitro and in an MIA Paca-2 xenograft model in vivo. Its underlying mechanism was explored using western blotting analysis of Bcl-2 family proteins.

RESULTS

ABT-199 not only enhanced the effect of gemcitabine on cell growth inhibition but also promoted gemcitabine-induced apoptosis in pancreatic cancer cell lines. Gemcitabine decreased the expression of anti-apoptotic protein Mcl-1 but increased the expression of anti-apoptotic protein Bcl-2. ABT-199 downregulated the gemcitabine-induced production of Bcl-2 and increased the expression of pro-apoptotic protein Bcl-2 interacting protein (BIM). Mouse xenograft experiments also confirmed the synergistic effect of gemcitabine and ABT-199 on tumor growth inhibition and the induction of tumor cell apoptosis.

CONCLUSION

Our results indicated that ABT-199 improved the anti-tumor effect of gemcitabine on pancreatic cancer by downregulating gemcitabine-induced overexpression of Bcl-2. ABT-199 has already been investigated in phase 3 clinical trials for chronic lymphocytic leukemia; therefore, it may serve as a potential drug to improve the sensitivity of pancreatic cancer to gemcitabine.

Nutritionally Available Selenocysteine Derivative Antagonizes Cisplatin-Induced Toxicity in Renal Epithelial Cells through Inhibition of Reactive Oxygen Species-Mediated Signaling Pathways

Discovery of nutritionally available agents that could antagonize cisplatin-induced nephrotoxicity is of great significance and clinical application potential. 3,3'-Diselenodipropionic acid (DSePA) is a seleno-amino acid derivative that exhibits strong antioxidant activity. Therefore, this study aimed to examine the protective effects of DSePA on cisplatin-induced renal epithelial cells damage as well as the molecular mechanisms. The results revealed that DSePA effectively inhibited cell apoptosis induced by cisplatin through suppressing the caspase activation and poly(ADP-ribose) polymerase cleavage. In addition, DSePA blocked the cisplatin-induced mitochondrial dysfunction, as evidenced by the loss of mitochondrial membrane potential and reduction of mitochondrial mass. The results of western blot analysis showed that DSePA reversed the expression level of Bcl-2 family proteins altered by cisplatin. The cisplatin-activated AKT pathway was also modulated by DSePA. Moreover, these results indicate that DSePA could protect HK-2 cells from cisplatin-induced toxicity in renal epithelial cells by inhibiting intracellular reactive oxygen species-mediated apoptosis while showing an unobvious effect on its anticancer efficacy. Taken together, this study demonstrates that selenocysteine could be further developed as novel nutritionally available agents to antagonize cisplatin-induced nephrotoxicity during cancer therapy.

Ameliorative effects of nano-elemental selenium against hexavalent chromium-induced apoptosis in broiler liver

The current study examined the ameliorative effects of nano-elemental selenium (Nano-Se) against chromium-VI (K₂Cr₂O₇)-induced apoptosis in chickens. The expression of apoptosis-related genes was evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. A total of 60, one-day-old broiler chickens allotted to six equal groups, i.e., control group (standard diet), Cr(VI)-exposed group (K₂Cr₂O₇ via drinking water), Nano-Se group (Nano-Se at 0.5 mg/kg via diet), protection group (K₂Cr₂O₇ + Nano-Se), cure group (K₂Cr₂O₇ for initial 2 weeks and then Nano-Se), and prevention group (opposite to the cure group) and were detected by the activities of pro-apoptosis (Bax, Caspase-3) and anti-apoptosis (Bcl-2) genes expression at day 35 of the experiment. Intense apoptosis was observed in liver tissues of chickens exposed to K₂Cr₂O₇. The Nano-Se supplementation caused a significant decrease (P < 0.01) in the mRNA expression levels of Bax and Caspase-3 genes, while significantly elevated (P < 0.05) mRNA expression level of Bcl-2 gene was observed in Nano-Se experimental groups as compare to control and Cr(VI)-exposed group. The results quantified by the RT-qPCR were further confirmed by the western blot analysis. Altogether, these results suggest anti-apoptotic effects of Nano-Se in the chicken liver, which is interesting for further study. The present findings suggested that Nano-Se has protective effects against K₂Cr₂O₇-induced apoptosis in broilers liver and can serve a key role as a protective agent against apoptosis.

Mutational Analysis of the BH3 Domains of Proapoptotic Bcl-2 Family Genes Bad, Bmf and Bcl-G in Laryngeal Squamous Cell Carcinomas

Aims

There is mounting evidence that deregulation of apoptosis is involved in the mechanisms of cancer development. Somatic mutations of apoptosis-related genes have been reported in many human cancers. The aim of this study was to explore the possibility that mutation of the BH3 domains of the proapoptotic Bcl-2 genes Bad, Bmf and Bcl-G might be involved in the development of laryngeal cancer.

Methods

We analyzed the BH3 domains of Bad, Bmf and Bcl-G for the detection of somatic mutations in 33 squamous cell carcinomas of the larynx by a polymerase chain reaction-based single-strand conformation polymorphism assay.

Results

There were no somatic mutations of the BH3 domains of Bad, Bmf and Bcl-G in the laryngeal squamous cell carcinoma samples.

Conclusions

The data presented here indicate that BH3 domain mutation of the proapoptotic genes Bad, Bmf and Bcl-G is rare in laryngeal squamous cell carcinoma and may not contribute to the apoptosis-resistance mechanisms of laryngeal squamous cell carcinoma.

The roles of microRNA-34b-5p in angiogenesis of thyroid carcinoma

PURPOSE

This study aims to determine the expression of miR-34b-5p in thyroid carcinomas and to investigate the role of miR34b-5p in the modulation of proteins involved in angiogenesis of thyroid carcinoma cells.

METHODS

The expressions of miR-34b-5p levels in five cell lines and 65 tissue samples from thyroid carcinomas were examined by real-time polymerase chain reaction. An exogenous miR-34b-5p (mimic) transiently overexpress miR-34b-5p in theses thyroid carcinoma cells. The effects of miR-34b-5p overexpression on the proteins involved in angiogenesis and cell cycle regulations (VEGF-A, Bcl-2 and Notch1) were investigated by Western blot, immunofluorescence, enzyme-linked immunosorbent assay followed by cell cycle analysis and apoptosis assays.

RESULTS

miR-34b-5p is markedly downregulated in all thyroid carcinoma cell lines and tissues samples when compared with non-neoplastic immortalised thyroid cell line and non-neoplastic thyroid tissues, respectively. The expression levels of miR-34b were significantly associated with T-stages of thyroid carcinomas (p = 0.042). Downregulation of VEGF-A, Bcl-2 and Notch1 proteins in thyroid carcinoma cells were noted in cells that transiently transfected with miR-34b-5p mimic. In addition, enzyme-linked immunosorbent assay confirmed the decreased expression of VEGF in thyroid carcinoma cells after transfection with miR-34b-5p mimic. Furthermore, miR-34b-5p mimic transfection induces significant accumulation of cells in G0-G1 of the cell cycle by blocking of their entry into the S transitional phase as well as increasing the total apoptosis.

CONCLUSIONS

miR-34b-5p functions as a potent regulator of angiogenesis, apoptosis and cell proliferation via modulation of VEGF-A, Bcl-2 and Notch1 proteins. It could be a target for developing treatment strategies of thyroid carcinoma with aggressive clinical behaviour.

miR-34a/Bcl-2 signaling pathway contributes to age-related hearing loss by modulating hair cell apoptosis

MicroRNAs, such as miR-34, have been reported to influence age-related diseases. In this study, we explored the role of the miR-34a/Bcl-2 signaling pathway in age-related hearing loss (AHL). Using an AHL mouse model (C57BL/6), we found that the expression of miR-34a in the cochlea increased with age, whereas expression of Bcl-2 decreased. Increasing the amount of a miR-34a mimetic in a mouse auditory cell line (HEI-OC1) inhibited Bcl-2, leading to enhanced apoptosis; in contrast, miR-34a inhibition produced the opposite effect. Our results support a link between age-related cochlear hair cell apoptosis and miR-34a/Bcl-2 signaling. The latter may thus serve as a potential target for AHL therapy.

microRNA-181a is upregulated in human atherosclerosis plaques and involves in the oxidative stress-induced endothelial cell dysfunction through direct targeting Bcl-2

OBJECTIVE

Atherosclerosis is featured as artery wall thickness as a result of invasion and accumulation of white blood cells and proliferation of intimal smooth muscle cells. Endothelial dysfunction has been linked to a variety of vascular diseases, including atherosclerosis. MicroRNAs play essential roles during the atherosclerotic plaques formation. In this study, we investigate the roles of miR-181a in the oxidative stress-induced endothelial cells dysfunction.

MATERIALS AND METHODS

The expressions of miR-181a were compared between human atherosclerotic plaques and normal blood vessels. The Bcl-2 protein expression was measured by Western blot and mRNA expression was measured by qRT-PCR. HUVECs were transiently transfected with pre-miR-181a or control microRNAs by Lipofectamine 2000. The viability of HUVECs in response to H2O2 was measured by MTT assay.

RESULTS

We report miR-181a is upregulated in human atherosclerotic plaques compared with the normal blood vessel. The miR-181a is induced by H2O2 treatments. The exogenous overexpression of miR-181a accelerates the apoptosis rates of HUVECs in response to H2O2. We identify Bcl-2 as a direct target of miR-181a. Also, we observed H2O2 treatments inhibited Bcl-2 expressions at both protein and mRNA levels. Inhibition of miR-181a restores Bcl-2 expressions, leading to increased resistance to H2O2. Moreover, restoration of Bcl-2 in miR-181a-overexpressing HUVECs renders cells tolerate higher concentrations of H2O2. Finally, a reverse correlation between miR-181a and Bcl-2 expression in human atherosclerosis plaques is illustrated.

CONCLUSIONS

Our results revealed an essential role of miR-181a in the development of atherosclerosis through the regulation of the endothelial dysfunction, providing mechanisms for the development of new antioxidant drugs for the treatment of atherosclerosis.

C-Myc And Bcl-2 Expression In Supraglottic Squamous Cell Carcinoma of the Larynx

OBJECTIVES: To evaluate the expression and prognostic significance of c-myc and bcl-2 oncogenes in squamous cell carcinoma (SCC) of the supraglottic larynx.

STUDY DESIGN: A retrospective cohort study of 61 patients who underwent surgery for SCC of the supraglottic larynx. Gender, age, TNM status, operative procedure, recurrences, and disease-free survival periods were recorded.

METHODS: Hematoxylin and eosin-stained sections were reexamined for grade, invasion of tumor margins, lymphovascular invasion, lymphocyte infiltration, and perineural invasion. Immunohistochemical detection of c-myc and bcl-2 oncogenes was performed using monoclonal antibodies.

RESULTS: No correlation was observed between either c-myc or bcl-2 and the clinical and histopathologic parameters. Survival analysis revealed no correlation of either c-myc ( P = 0.88) or bcl-2 ( P = 0.85) with the disease-free survival. c-myc expression was found to be significantly higher in bcl-2-positive patients ( P = 0.001).

CONCLUSION: Neither c-myc nor bcl-2 had shown to be prognostic factor for laryngeal carcinoma in this present study. Correlation between c-myc and bcl-2 supports the experimental observations of cooperative action between these two genes in tumorigenesis.

miR-7 expression in serous ovarian carcinomas

BACKGROUND/AIM

miR-7 has recently been linked to cancer. Some miR-7 targets, including B-cell lymphoma 2 (BCL2) and epidermal growth factor receptor (EGFR), are involved in ovarian cancer (OC) pathogenesis. The majority of OCs display TP53 mutations, which are critically important for OC development. We aimed to study the expression level of miR-7 and of two of its postulated target genes, BCL2 and EGFR, in serous ovarian carcinomas of different TP53 status and tumour grade.

MATERIALS AND METHODS

Gene and miR expression was assessed by real-time reverse transcription polymerase chain reaction in 45 clinical samples of low- (G1+G2) and high- (G3) grade primary serous OC with wild-type (wt) or mutated TP53, as well as in three OC cell lines, each representing a different TP53 status. The results obtained in patients with OC were analysed against their disease-free survival (DFS).

RESULTS

In high-grade OC with TP53 mutations, the level of miR-7 expression significantly exceeded (by several fold) that in wtTP53 cancer (p<0.01). Within the wtTP53 tumour series, the level of miR-7 expression was significantly higher (by over 10-fold) in high-grade than in low-grade OC (p<0.01). miR-7 expression was not found to influence DFS. The differences in miR-7 expression depending on TP53 status found in clinical OC samples were not observed in OC cell lines. miR-7 overexpression correlated with diminished BCL2 expression, but there was no relationship between miR-7 and EGFR expression, neither in tumour samples nor in the cell lines.

CONCLUSION

There is a link between miR-7 expression and TP53 status and tumour grade in serous OC. Molecular mechanisms of these relationships need to be elucidated. Of the two postulated miR-7 target genes we examined, BCL2, but not EGFR, seems to be a possible miR-7 target in OC.

Intraclonal diversity in follicular lymphoma analyzed by quantitative ultradeep sequencing of noncoding regions

Cancers are characterized by genomic instability, and the resulting intraclonal diversity is a prerequisite for tumor evolution. Therefore, metrics of tumor heterogeneity may prove to be clinically meaningful. Intraclonal heterogeneity in follicular lymphoma (FL) is apparent from studies of somatic hypermutation (SHM) caused by activation-induced deaminase (AID) in IGH. Aberrant SHM (aSHM), defined as AID activity outside of the IG loci, predominantly targets noncoding regions causing numerous "passenger" mutations, but it has the potential to generate rare significant "driver" mutations. The quantitative relationship between SHM and aSHM has not been defined. To measure SHM and aSHM, ultradeep sequencing (>20,000-fold coverage) was performed on IGH (~1650 nt) and nine other noncoding regions potentially targeted by AID (combined 9411 nt), including the 5' untranslated region of BCL2. Single-nucleotide variants (SNVs) were found in 12/12 FL specimens (median 136 SHMs and 53 aSHMs). The aSHM SNVs were associated with AID motifs (p < 0.0001). The number of SNVs at BCL2 varied widely among specimens and correlated with the number of SNVs at eight other potential aSHM sites. In contrast, SHM at IGH was not predictive of aSHM. Tumor heterogeneity is apparent from SNVs at low variant allele frequencies; the relative number of SNVs with variable allele frequency < 5% varied with clinical grade, indicating that tumor heterogeneity based on aSHM reflects a clinically meaningful parameter. These data suggest that genome-wide aSHM may be estimated from aSHM of BCL2 but not SHM of IGH. The results demonstrate a practical approach to the quantification of intratumoral genetic heterogeneity for clinical specimens.

Chronic hypoxemia in late gestation decreases cardiomyocyte number but does not change expression of hypoxia-responsive genes

Background

Placental insufficiency is the leading cause of intrauterine growth restriction in the developed world and results in chronic hypoxemia in the fetus. Oxygen is essential for fetal heart development, but a hypoxemic environment in utero can permanently alter development of cardiomyocytes. The present study aimed to investigate the effect of placental restriction and chronic hypoxemia on total number of cardiomyocytes, cardiomyocyte apoptosis, total length of coronary capillaries, and expression of genes regulated by hypoxia.

Methods and Results

We induced experimental placental restriction from conception, which resulted in fetal growth restriction and chronic hypoxemia. Fetal hearts in the placental restriction group had fewer cardiomyocytes, but interestingly, there was no difference in the percentage of apoptotic cardiomyocytes; the abundance of the transcription factor that mediates hypoxia‐induced apoptosis, p53; or expression of apoptotic genes Bax and Bcl2. Likewise, there was no difference in the abundance of autophagy regulator beclin 1 or expression of autophagic genes BECN1, BNIP3, LAMP1, and MAP1LC3B. Furthermore, fetuses exposed to normoxemia (control) or chronic hypoxemia (placental restriction) had similar mRNA expression of a suite of hypoxia‐inducible factor target genes, which are essential for angiogenesis (VEGF, Flt1, Ang1, Ang2, and Tie2), vasodilation (iNOS and Adm), and glycolysis (GLUT1 and GLUT3). In addition, there was no change in the expression of PKC‐ε, a cardioprotective gene with transcription regulated by hypoxia in a manner independent of hypoxia‐inducible factors. There was an increased capillary length density but no difference in the total length of capillaries in the hearts of the chronically hypoxemic fetuses.

Conclusion

The lack of upregulation of hypoxia target genes in response to chronic hypoxemia in the fetal heart in late gestation may be due to a decrease in the number of cardiomyocytes (decreased oxygen demand) and the maintenance of the total length of capillaries. Consequently, these adaptive responses in the fetal heart may maintain a normal oxygen tension within the cardiomyocyte of the chronically hypoxemic fetus in late gestation.

Localization of apoptotic and proliferating cells and mRNA expression of caspases and Bcl-2 in gonads of chicken embryos

The aim of the present study was to analyze participation of apoptosis and proliferation in gonadal development in the chicken embryo by: (1) localization of apoptotic (TUNEL) and proliferating (PCNA immunoassay) cells in male and female gonads and (2) examination of mRNA expression (RT-PCR) of caspase-3, caspase-6 and Bcl-2 in the ovary and testis during the second half of embryogenesis and in newly hatched chickens. Apoptotic cells were found in gonads of both sexes. At E18 the percentage of apoptotic cells (the apoptotic index, AI) in the ovarian medulla and the testis was lower (p<0.05) than in the ovarian cortex. In the ovarian medulla, the AI at E18 was lower (p<0.05) than on E12. In the testis, the AI was significantly lower (p<0.05) at E18 than at E15 and 1D. The percentage of proliferating cells (the proliferation index: PI) within the ovary significantly increased from E15 to 1D in the cortex, while proliferating cells in the medulla were detected only at E15. In the testis, the PI gradually increased from E12 to 1D. The mRNA expression of caspase-3 and -6 as well as Bcl-2 was detected in male and female gonads at days 12 (E12), 15 (E15) and 18 (E18) of embryogenesis and the day after hatching (1D). The expression of all analyzed genes on E12 was significantly higher (p<0.05) in female than in male gonads. This difference was also observed at E15 and E18, but only for the caspase-6. The results obtained showed tissue- and sex-dependent differences in the number of apoptotic and proliferating cells as well as mRNA expression of caspase-3, -6 and Bcl-2 genes in the gonads of chicken embryos. Significant increase in the number of proliferating cells in the ovarian cortex and lack of these cells in the ovarian medulla (stages E12, E18, 1D) simultaneous with decrease in the intensity of apoptosis only in the medulla indicates that proliferation is the dominant process involved in the cortical development, which constitutes the majority of the functional structure of the fully developed ovary. No pronounced changes in the expression of apoptosis-related genes found during embryogenesis suggest that they cannot be considered as important indicators of gonad development. The molecular mechanisms of the regulation of balance between apoptosis and proliferation in developing avian gonads need to be further investigated.

Grafting aptamers onto gold nanostars increases in vitro efficacy in a wide range of cancer cell types

We report the design of a nanoconstruct that can function as a cell-type independent agent by targeting the ubiquitous protein nucleolin. Gold nanostars (AuNS) loaded with high densities of nucleolin-specific DNA aptamer AS1411 (Apt-AuNS) produced anticancer effects in a panel of 12 cancer lines containing four representative subcategories. We found that the nanoconstructs could be internalized by cancer cells and trafficked to perinuclear regions. Apt-AuNS resulted in downregulation of antiapoptotic Bcl-2 mRNA expression by ca. 200% compared to cells without the nanoconstructs. The caspase 3/7 activity (apoptosis) and cell death in cancer cells treated with Apt-AuNS increased by 1.5 times and by ca. 17%, respectively, compared to cells treated with free AS1411 at over 10 times the concentration. Moreover, light-triggered release of aptamer from the AuNS further enhanced the in vitro efficacy of the nanoconstructs in the cancer line panel with a 2-fold increase in caspase activity and a 40% decrease in cell viability compared to treatment with Apt-AuNS only. In contrast, treatments of the nanoconstructs with or without light-triggered release on a panel of normal cell lines had no adverse effects.

[Doublehit lymphomas - review of the literature and case report]

Blymphocytes are cells of the immune system responsible for the antibody  mediated immune response. As estimated, a human body can produce as much as 1011 specific antibodies. There are no specific genes coding for every individual antibody in the human genome. Discrepancy between the huge diversity of antibodies and limited coding capacity of the genome is solved by combination of unique arrangement of genetic information for immunoglobulin and unique genetic and somatic processes providing this wide spectrum of antibodies. On one side, these mechanisms represent a life protecting source of a wide spectrum of antibodies but at the same time, they can be life threatening by raising the risk of a serious tumor disease, the B cell lymphoma. Double hit lymphomas represent a specific group of B cell lymphomas often featuring concurrent rearrangements of BCL2 and MYC genes. Activation of the MYC oncogene, typical for Burkitt lymphoma (BL), causes strong stimulation of cell proliferation. High activity of BCL 2, typical for follicular lymphoma, induces resistance to apoptosis. Concurrent damage of regulation of apoptosis and proliferation is probably responsible for the typical clinical manifestation of double hit lymphomas - aggressive course, resistance to conventional chemotherapy, high-risk of early relapse, short overall survival, frequent extranodal and central nervous system involvement. Recently, these lymphomas have attracted a strong attention of researchers as they provide sharp insights into processes of lymphocytes maturing and lymphomas development and highlight the double edged nature of mechanisms allowing the antibody broad diversity.

CASE REPORT

Fifty  three year  old man was diagnosed with B cell lymphoma unclassifiable with features intermediate between diffuse large B cell lymphoma (DLBCL) and BL, based on morphology and immunophenotype. Fluorescent in situ hybridization analysis revealed double hit lymphoma diagnosis as the tumor cells bear t(14;18) translocation concurrently with the MYC gene rearrangement. The patient died five months after dia-gnosis.

[Fas, FasL, and bcl-2 expression on hepatic intralobar lymphocytes in different variants of the natural course of chronic HBV and HCV infection and in its outcomes]

The investigation revealed the specific features of cell-mediated hepatocyte damage in different variants of the natural course of chronic HBV and HCV infection and in its outcomes (chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma), by determining the expression of proapoptotic (Fas, FasL) and antiapoptotic (bcl-2) factors on the surface of intralobular lymphocytes. Comparative analysis of the magnitude and pattern of cell infiltration in the liver parenchyma, the functional activity of intralobular lymphocytes showed significant differences in the above indicators in relation to the etiology and stage of the pathological process, suggesting that there were different pathogenetic mechanisms of their natural course. There was a varying potential readiness of intralobular lymphocytes for apoptosis, giving rise to different clinical manifestations in the similar morphological picture.

Hinokitiol inhibits cell growth through induction of S-phase arrest and apoptosis in human colon cancer cells and suppresses tumor growth in a mouse xenograft experiment

Hinokitiol (1), a tropolone-related natural compound, induces apoptosis and has anti-inflammatory, antioxidant, and antitumor activities. In this study, the inhibitory effects of 1 were investigated on human colon cancer cell growth and tumor formation of xenograft mice. HCT-116 and SW-620 cells derived from human colon cancers were found to be similarly susceptible to 1, with IC50 values of 4.5 and 4.4 μM, respectively. Compound 1 induced S-phase arrest in the cell cycle progression and decreased the expression levels of cyclin A, cyclin E, and Cdk2. Conversely, 1 increased the expression of p21, a Cdk inhibitor. Compound 1 decreased Bcl-2 expression and increased the expression of Bax, and cleaved caspase-9 and -3. The effect of 1 on tumor formation when administered orally was evaluated in male BALB/c-nude mice implanted intradermally separately with HCT-116 and SW-620 cells. Tumor volumes and tumor weights in the mice treated with 1 (100 mg/kg) were decreased in both cases. These results suggest that the suppression of tumor formation by compound 1 in human colon cancer may occur through cell cycle arrest and apoptosis.

Comparative biodistributions and dosimetry of [¹⁷⁷Lu]DOTA-anti-bcl-2-PNA-Tyr³-octreotate and [¹⁷⁷Lu]DOTA-Tyr³-octreotate in a mouse model of B-cell lymphoma/leukemia

INTRODUCTION

The B-cell lymphoma/leukemia-2 (bcl-2) proto-oncogene in non-Hodgkin's lymphoma (NHL) is a dominant inhibitor of apoptosis. We developed a (177)Lu-labeled bcl-2 antisense peptide nucleic acid (PNA)-peptide conjugate designed for dual modality NHL therapy, consisting of a radiopharmaceutical capable of simultaneously down-regulating apoptotic resistance and delivering cytotoxic internally emitted radiation.

METHODS

DOTA-anti-bcl-2-Tyr(3)-octreotate was synthesized, labeled with (177)Lu, and purified using RP-HPLC. The PNA-peptide conjugate was evaluated in Mec-1 NHL-bearing mice and compared to [(177)Lu]DOTA-Tyr(3)-octreotate in biodistribution and excretion studies. These data were then used to generate in vivo dosimetry models.

RESULTS

The PNA-peptide conjugate was readily prepared and radiolabeled in high yield and radiochemical purity. An in vivo blocking study determined that administration of 50 μg of non-radioactive PNA-peptide was the optimal mass for maximum delivery to the tumor. Based on that result, a dosing regimen of (177)Lu-PNA-peptide, for radiologic effect, followed by the optimal mass of non-radioactive compound, for antisense effect, was designed. Using that dosing regimen, biodistribution of the PNA-peptide showed uptake in the tumor with minimal washout over a 4-day period. Uptakes in receptor-positive normal organs were low and displayed nearly complete washout by 24h. Dosimetry models showed that the tumor absorbed dose of the PNA-peptide conjugate was approximately twice that of the peptide-only conjugate.

CONCLUSIONS

Biodistribution data showed specific tumor targeting of the (177)Lu-labeled PNA-peptide compound with minimal receptor-positive normal tissue uptake when compared to [(177)Lu]DOTA-Tyr(3)-octreotate. In vivo dosimetry models predicted a more favorable tumor absorbed dose from [(177)Lu]DOTA-anti-bcl-2-Tyr(3)-octreotate.

Effect of Bcl-2 rs956572 SNP on regional gray matter volumes and cognitive function in elderly males without dementia

The Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. A single-nucleotide polymorphism (SNP) in the Bcl-2 gene, Bcl-2 rs956572, significantly modulates the expression of Bcl-2 protein and cellular vulnerability to apoptosis. This study investigated the association between the Bcl-2 rs956572 SNP and brain structural abnormalities in non-demented elders, and to test the relationship between neuropsychological performance and regional gray matter (GM) volumes. Our sample comprised 97 non-demented elderly men with a mean age of 80.6 ± 5.6 years (range, 65 to 92 years). Cognitive test results, magnetic resonance imaging, and genotyping of Bcl-2 rs956572 were examined for each subject. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. Subjects with G homozygotes exhibited significantly worse performance in the language domain of the Cognitive Abilities Screening Instrument (CASI; p = 0.009). They also showed significantly smaller GM volumes in the right middle temporal gyrus (MTG) (BA 21), but larger GM volumes in the left precuneus (BA 31), right lingual gyrus (BA 18), and left superior occipital gyrus (BA 19) relative to A-allele carriers (p < 0.001). A trend toward a positive correlation between right MTG GM volumes and the language domain of CASI was also evident (r = 0.181; p = 0.081). The findings suggest that Bcl-2 rs956572 SNP may modulate cognitive function and regional GM volume in non-demented elderly men, and that this polymorphism may affect language performance through its effect on the right MTG.

Flavanols from evening primrose (Oenothera paradoxa) defatted seeds inhibit prostate cells invasiveness and cause changes in Bcl-2/Bax mRNA ratio

In this study, we assessed the influence of an evening primrose flavanol preparation (EPFP) on proliferation and invasiveness of human prostate cancer cells (DU 145) and immortalized prostate epithelial cells (PNT1A). We report for the first time that EPFP reduces DU 145 cell proliferation (IC50 = 97 μM GAE for 72 h incubation) and invasiveness (by 24% versus control at 75 μM GAE). EPFP strongly inhibited PNT1A invasiveness in a concentration-dependent manner (by 67% versus control at 75 μM GAE) and did not cause a reduction in their proliferation. Furthermore, EPFP inhibited the activities of MMP-2 and MMP-9 secreted to culture medium by PNT1A cells by 84% and 34% versus control at 100 μM GAE, respectively. In the case of DU 145, MMP-9 activity at 100 μM GAE was reduced by 37% versus control. Moreover, the evening primrose seed flavanols suppressed the expression of selected genes (MMP-1, MMP-9, MMP-14, c-Fos, c-Jun, and VEGF) and also caused favorable changes in Bcl-2/Bax mRNA ratio which render DU 145 cells more sensitive to apoptosis-triggering agents. An additional confirmation of the proapoptotic activity of EPFP toward DU 145 was visualization of characteristic apoptotic bodies by DAPI staining. In conclusion, this study suggests that EPFP may increase apoptosis and reduce angiogenesis of prostate cancer cells.

Bcl-2/Bcl-xL inhibition increases the efficacy of MEK inhibition alone and in combination with PI3 kinase inhibition in lung and pancreatic tumor models

Although mitogen-activated protein (MAP)-extracellular signal-regulated kinase (ERK) kinase (MEK) inhibition is predicted to cause cell death by stabilization of the proapoptotic BH3-only protein BIM, the induction of apoptosis is often modest. To determine if addition of a Bcl-2 family inhibitor could increase the efficacy of a MEK inhibitor, we evaluated a panel of 53 non-small cell lung cancer and pancreatic cancer cell lines with the combination of navitoclax (ABT-263), a Bcl-2/Bcl-xL (BCL2/BCL2L1) antagonist, and a novel MAP kinase (MEK) inhibitor, G-963. The combination is synergistic in the majority of lines, with an enrichment of cell lines harboring KRAS mutations in the high synergy group. Cells exposed to G-963 arrest in G1 and a small fraction undergo apoptosis. The addition of navitoclax to G-963 does not alter the kinetics of cell-cycle arrest, but greatly increases the percentage of cells that undergo apoptosis. The G-963/navitoclax combination was more effective than either single agent in the KRAS mutant H2122 xenograft model; BIM stabilization and PARP cleavage were observed in tumors, consistent with the mechanism of action observed in cell culture. Addition of the phosphatidylinositol 3-kinase (PI3K, PIK3CA) inhibitor GDC-0941 to this treatment combination increases cell killing compared with double- or single-agent treatment. Taken together, these data suggest the efficacy of agents that target the MAPK and PI3K pathways can be improved by combination with a Bcl-2 family inhibitor.

[The effect of Bcl-2 gene silencing on the sensitivity of cell line A549 to chemotherapeutic drugs]

OBJECTIVE

To investigate the effects of miRNA-mediated down-regulation of the Bcl-2 gene on the chemotherapeutic sensitivities and mRNA transcriptions of sensitivity associated genes in human lung adenocarcinoma cell line A549 cells, and therefore to provide experimental data for improving the chemotherapeutic effects on non-small cell lung cancer (NSCLC).

METHODS

The miRNA recombinant plasmid targeting to human Bcl-2 gene was designed, synthesized and stably transferred into A549 cells by lipofectin technique as the experiment group. The transcription of Bcl-2 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) by agarose gel electrophoresis, real-time PCR, and the protein level of Bcl-2 was measured by Western blot to confirm the function of miRNA plasmid. The cell proliferation was examined by methyl thiazolyl tetrazolium (MTT) assay. Cell cycle was measured by flow cytometry. Drug sensitivities of A549 cells to etoposide, 5-fluorouracil, cisplatin, adriamycin, vincristine, paclitaxel and navelbine were analyzed by MTT assay. The mRNA expressions of excision repair cross-complementing gene 1 (ERCC1), thymidylate synthase (TYMS), Class III β-tubulin, topoisomerase 2 alpha (TOP2α) genes were detected by RT-PCR and real-time PCR.

RESULTS

The recombinant miRNA plasmid was successfully synthesized and stably transferred into A549 cells. The transcription of Bcl-2 mRNA dramatically decreased by 98.1% in the experiment group (RQ = 0.002 ± 0.001) compared to that in the negative control group (RQ = 0.104 ± 0.003) by real-time PCR (t = 98.70, P < 0.05); and the protein level of Bcl-2 in the experiment group decreased by 57.6% by Western blot (t = 7.66, P < 0.05). The cell cycle profile showed that the low expression of Bcl-2 gene led to A549 cell cycle arrest at G1-phase. The results of MTT showed that the growth of A549 cells in the experiment group was markedly inhibited. The sensitivities of A549 cells to etoposide, cisplatin, paclitaxel, and navelbine were significantly enhanced [IC₅₀ values in the experiment group were (107.3 ± 0.1) mg/L, (7.7 ± 0.6) mg/L, (11.5 ± 1.9) mg/L and (10.8 ± 1.6) mg/L; IC₅₀ values in the negative control group were (145.8 ± 0.1) mg/L, (60.7 ± 1.4) mg/L, (80.6 ± 1.7) mg/L and (20.6 ± 1.7) mg/L], the respective t values being 655.33, 108.04, 82.16 and 12.48, all P < 0.05. The mRNA level of ERCC1, TYMS, and TOP2α genes in the experiment group decreased by 99.6%, 92.9% and 96.1% respectively, but Class III β-tubulin mRNA increased by 122% compared to the negative control group (1.154 ± 0.008, 0.520 ± 0.009), the respective t values being 689.79, 689.37, 768.04 and 160.07, all P < 0.05.

CONCLUSION

Targeting to inhibit antiapoptotic mitochondrial gene Bcl-2 expression in A549 cells specifically decreased the mRNA of ERCC1, TYMS, and TOP2α genes, and significantly increased the sensitivities of A549 cells to chemotherapeutic agents such as etoposide, cisplatin, paclitaxel and navelbine.

Embryonic exposure to cis-bifenthrin enantioselectively induces the transcription of genes related to oxidative stress, apoptosis and immunotoxicity in zebrafish (Danio rerio)

Cis-bifenthrin (cis-BF) is used widely for agricultural and non-agricultural purpose. Thus, cis-BF is one of the most frequently detected insecticides in the aquatic ecosystem. As a chiral pesticide, the commercial cis-BF contained two enantiomers including 1R-cis-BF and 1S-cis-BF. However, the difference in inducing oxidative stress, apoptosis and immunotoxicity by the two enantiomers in zebrafish still remains unclear. In the present study, the zebrafish were exposed to environmental concentrations of cis-BF, 1R-cis-BF and 1S-cis-BF during the embryos developmental stage. We observed that the mRNA levels of the most genes related to oxidative stress, apoptosis and immunotoxicity including Cu/Zn-superoxide dismutase (Cu/Zn-Sod), catalase (Cat), P53, murine double minute 2 (Mdm2), B-cell lymphoma/leukaemia-2 gene (Bcl2), Bcl2 associated X protein (Bax), apoptotic protease activating factor-1 (Apaf1), Caspase 9 (Cas9), Caspase 3 (Cas3), interleukin-1 beta (IL-1β) and interleukin-8(Il-8) were much higher in 1S-cis-BF treated group than those in cis-BF or 1R-cis-BF treated ones, suggesting that 1S-cis-BF has higher risk to induced oxidative stress, apoptosis and immunotoxicity than 1R-cis-BF in zebrafish. The information presented in this study will help with elucidating the differences and environmental risk of the two enantiomers of cis-BF-induced toxicity in aquatic organisms.

SIRT3 protects cardiomyocytes from oxidative stress-mediated cell death by activating NF-κB

Oxidative stress-mediated cell death in cardiomyocytes reportedly plays an important role in many cardiac pathologies. Our previous report demonstrated that mitochondrial SIRT3 plays an essential role in mediating cell survival in cardiac myocytes, and that resveratrol protects cardiomyocytes from oxidative stress-induced apoptosis by activating SIRT3. However, the exact mechanism by which SIRT3 prevents oxidative stress remains unknown. Here, we show that exposure of H9c2 cells to 50 μM H(2)O(2) for 6h caused a significant increase in cell death and the down-regulation of SIRT3. Reactive oxygen species (ROS)-mediated NF-κB activation was involved in this SIRT3 down-regulation. The SIRT3 activator, resveratrol, which is considered an important antioxidant, protected against H(2)O(2)-induced cell death, whereas the SIRT inhibitor, nicotinamide, enhanced cell death. Moreover, resveratrol negatively regulated H(2)O(2)-induced NF-κB activation, whereas nicotinamide enhanced H(2)O(2)-induced NF-κB activation. We also found that SOD2, Bcl-2 and Bax, the downstream genes of NF-κB, were involved in this pathological process. These results suggest that SIRT3 protects cardiomyocytes exposed to oxidative stress from apoptosis via a mechanism that may involve the NF-κB pathway.

Induction of beta-cell resistance to hypoxia and technologies for oxygen delivery to transplanted pancreatic islets

Hypoxia is believed to be a crucial factor involved in cell adaptation to environmental stress. Islet transplantation, especially with immunoisolated islets, interrupts vascular connections, resulting in the substantially decreased delivery of oxygen and nutrients to islet cells. Insulin-producing pancreatic beta cells are known to be highly susceptible to oxygen deficiency. Such susceptibility to hypoxia is believed to be one of the main causes of beta-cell death in the post-transplantation period. Different strategies have been developed for the protection of beta cells against hypoxic injury and for oxygen delivery to transplanted islets. The enhancement of beta-cell defense properties against hypoxia has been achieved using various techniques such as gene transfection, drug supplementation, co-culturing with stem cells and cell selection. Technologies for oxygen delivery to transplanted islets include local neovascularization of subcutaneous sites, electrochemical and photosynthetic oxygen generation, oxygen refuelling of bio-artificial pancreas and whole body oxygenation by using hyperbaric therapy. Progress in the field of oxygen technologies for islet transplantation requires a multidisciplinary approach to explore and optimize the interaction between components of the biological system and different technological processes. This review article focuses mainly on the recently developed strategies for oxygenation and protection from hypoxic injury - to achieve stable and long-term normoglycaemia in diabetic patients with transplanted pancreatic islets.

Expression profile of apoptosis-related genes in childhood adrenocortical tumors: low level of expression of BCL2 and TNF genes suggests a poor prognosis

BACKGROUND

Impaired apoptosis has been implicated in the development of childhood adrenocortical tumors (ACT), although the expression of apoptosis-related gene expression in such tumors has not been reported.

METHODS

The mRNA expression levels of the genes CASP3, CASP8, CASP9, FAS, TNF, NFKB, and BCL2 were analyzed by quantitative real-time PCR in consecutive tumor samples obtained at diagnosis from 60 children with a diagnosis of ACT and in 11 non-neoplastic adrenal samples. BCL2 and TNF protein expression was analyzed by immunohistochemistry.

RESULTS

A significant association was observed between tumor size ≥100 g and lower expression levels of the BCL2 (P=0.03) and TNF (P=0.05) genes; between stage IV and lower expression levels of CASP3 (P=0.008), CASP9 (P=0.02), BCL2 (P=0.002), TNF (P=0.05), and NFKB (P=0.03); Weiss score ≥3 and lower expression of TNF (P=0.01); unfavorable event and higher expression values of CASP9 (P=0.01) and lower values of TNF (P=0.02); and death and lower expression of BCL2 (P=0.04). Underexpression of TNF was associated with lower event-free survival in uni- and multivariate analyses (P<0.01). Similar results were observed when patients with Weiss score <3 were excluded.

CONCLUSION

This study supports the participation of apoptosis-related genes in the biology and prognosis of childhood ACT and suggests the complex role of these genes in the pathogenesis of this tumor.

Differential regulation of microRNA expression in irradiated and bystander cells

The ionizing radiation (IR) induces a variety of biological effects in irradiated cells. Additionally, the irradiated cells communicate with unirradiated cells and induce changes in them through a phenomenon termed as the bystander effect. The nature of the bystander effect signal and how it impacts unirradiated cells remains to be discovered. Examination of molecular changes in bystander cells due to signals from irradiated cells could lead to the identification of the pathways underlying the bystander effect. To gain insight into the molecular pathways affected by the transmission of signal from irradiated cells to bystander cells, we monitored the microRNA (miRNA) transcriptional changes. miRNAs control gene expression at the posttranscriptional level. In previous studies from our laboratory the modulation of miRNA in irradiated human cells were identified. In the present work human lymphoblasts TK6 cells in a medium exchanged bystander effect model system were used to analyze miRNA expression alterations by employing the real time RT-PCR technology. The relative expression of several miRNAs involved in RAS, c-MYC and BCL2 gene regulation were examined. The let-7 family of miRNAs was upregulated in irradiated cells but most of these miRNAs remained repressed in bystander cells. The miR-17-3p, miR-19b, and miR-18a were upregulated in irradiated cells but were repressed in the bystander cells. The miR-17-5p, miR-142-3p, miR-142-5p, and miR-19a were induced only for a short time in bystander cells. The miR-15a, miR-16, miR-143, miR-145, miR-155, and miR21 were upregulated in irradiated TK6 cells. While the expression of miR-15a, miR-16, miR-155, and miR-21 was repressed, the miR-143 and miR-145 expression was induced in bystander cells. These results indicate the involvement of miRNA modulation in irradiated and bystander cells.

DAP5 ameliorates cisplatin-induced apoptosis of renal tubular cells

BACKGROUND

Nephrotoxicity of cisplatin limits its clinical application. Cisplatin-induced acute renal tubular epithelial cell apoptosis is one of the major mechanisms of cisplatin nephrotoxicity. Here, the role and regulation of death-associated protein 5 (DAP5) in cisplatin-induced tubular cell apoptosis were investigated.

METHODS

After upregulation of DAP5 expression by plasmid transfection and downregulation of DAP5 expression by small interfering RNA in human kidney tubular epithelial cell line (HKC) cells, the degree of cell apoptosis was assessed by flow cytometric analysis. The expression of Bax and Bcl-2 proteins was detected by Western blot analysis. The relationship between the PI3K/Akt/mTOR signaling pathway and DAP5 was also evaluated.

RESULTS

During cisplatin-induced apoptosis in HKC cells, DAP5 underwent proteolytic fragmentation, yielding an 86-kDa species, DAP5/p86. Overexpression of DAP5/p97 and DAP5/p86 increased the translation of Bcl-2 and reduced the extent of cisplatin-induced apoptosis. Knockdown of DAP5 expression using small interfering RNA decreased the translation of Bcl-2 and increased the degree of apoptosis. Neither manipulation affected the expression of Bax. DAP5 expression was positively regulated by the PI3K/Akt/mTOR signaling pathway.

CONCLUSION

Collectively, the results from the present study revealed a new role for DAP5 in cisplatin-induced apoptosis: DAP5/p97 and DAP5/p86 enhanced the translation of the anti-apoptotic protein Bcl-2 and inhibited cisplatin-induced apoptosis. The PI3K/Akt/mTOR signaling pathway may positively regulate the expression of DAP5.

miR-181a sensitizes a multidrug-resistant leukemia cell line K562/A02 to daunorubicin by targeting BCL-2

The aim of this study was to investigate whether miR-181a could modulate the sensitivity of the leukemia drug-resistant cell line K562/A02 to the chemotherapeutic agent daunorubicin (DNR), and explore the mechanism of miR-181a on the DNR sensitivity of K562/A02 cells. MicroRNA microarray and stem-loop reverse transcription-polymerase chain reaction were used to detect the expression of miR-181a. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to quantify the effect of miR-181a on K562 cells growth and viability. Apoptotic cells were quantitatively detected using Annexin V/FITC and PI apoptosis detection kit. BCL-2 protein expression was measured by western blot. Luciferase reporter vector with the putative BCL-2 3' untranslated region was constructed to explore whether BCL-2 was a direct target gene of miR-181a. BCL-2 siRNA was transfected into the cell to explore the relationship between BCL-2 and DNR resistance. The miR-181a expression level was lower in the K562/A02 cells than in the K562 cells (P< 0.05). K562 cells that were transfected with miR-181a inhibitor had a significantly higher survival than K562 cells, and K562/A02 cells that were transfected with the miR-181a mimic had a significantly lower survival than K562/A02 cells (P< 0.05). miR-181a could enhance DNR-induced apoptosis in K562/A02 cells. BCL-2 siRNA transfected K562/A02 cells had decreased survival compared with the K562/A02 control group. In conclusion, miR-181a could play a role in the development of DNR resistance in K562/A02 cells and the over-expression of miR-181a could sensitize K562/A02 cells to DNR by targeting BCL-2.

[Association of polymorphic markers of CASP8, BCL2 and BAX genes with aging and longevity]

We performed the analysis of genotype frequency dynamics of CASP8, BCL2 and BAX genes polymorphic markers between 21 and 109 years in the group of Ethnic Tatars from Bashkortostan. Genotyping was carried out using PCR and PCR-RFLP. We found associations between age and -652(6N)I/D polymorphism of CASP8 gene (rs3834129), 140016C>T polymorphism of BCL2 gene (rs12454712) and 919A>G polymorphism of BAX gene (rs1805419). An increase of genotype frequency of BCL2*C/*C and decrease of genotype frequency of CASP8*I/*D was observed in male of senile age; and also decrease of genotype frequency of BAX*G/*G among long-livers. In female of longevity age, the number of CASP8*I/*D, BCL2*T/*T and BAX*A/*A genotype carriers was higher and number of CASP8*DI/*D, BCL2*C/*C, BAX*A/*G and BAX *G/*G genotype carriers was reduced.

Apoptosis and expression of the Bcl-2 family of proteins and P53 in human pancreatic ductal adenocarcinoma

OBJECTIVE

The purpose of this study was to clarify the association between P53 and the Bcl-2 family (Bcl-2, Bax, Bcl-xL, Bcl-xS) expression and apoptosis in pancreatic ductal adenocarcinoma (PDAC).

SUBJECTS AND METHODS

A total of 70 patients with PDAC were studied. The expression of P53 protein in PDAC was assessed using the immunohistochemical method, which categorized the PDAC patients into two groups: group 1: 36 cases with immunonegative P53(-), and group 2: 34 cases with immunopositive P53(+). The expression of Bcl-2, Bax, Bcl-xL, and Bcl-xS in the 70 PDAC cases was detected by immunohistochemical and Western blotting methods. The apoptotic index (AI) was also measured in these samples by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. The relation between P53 and the Bcl-2 protein family and apoptosis was then evaluated.

RESULTS

Bcl-2 and Bcl-xS expression was significantly associated with P53 (p < 0.05). No clear associations were found among P53, Bax and Bcl-xL expression (p > 0.05). The AI of groups 1 and 2 was 12.1 ± 2.47 and 8.1 ± 1.48, respectively (p = 0.023). There was no relationship between AI and Bcl-2, Bax, Bcl-xL and Bcl-xS expression (p > 0.05, respectively). Bcl-2/Bax ratio was significantly associated with AI (p < 0.01).

CONCLUSION

Bcl-2 and Bcl-xS represent significant anti- and proapoptotic proteins, respectively, modulated through a P53-dependent pathway in PDAC, and P53 modulated apoptosis mainly through Bcl-2/Bax ratio.

Association of BCL-2 polymorphism with the presence and severity of lumbar disc degeneration in the Chinese Han population

BACKGROUND

Apoptosis is involved in the mechanism of lumbar disc disease (LDD). BCL-2 has been shown to play an anti-apoptosis role. The present study aims to examine the association of -938C > A polymorphism of the BCL-2 gene with the presence and severity of LDD in the Chinese Han population.

METHODS

This study consisted of 325 patients with LDD and 236 normal controls. The grade of disc degeneration was determined according to Schneiderman's classification for MRI. -938C > A polymorphism was determined by "slow-down" polymerase chain reaction (PCR) method.

RESULTS

The genotype frequency of -938C > A polymorphism was consistent with Hardy-Weinberg equilibrium (p = 0.136). Higher frequencies of -938CA and AA genotypes were found in patients with LDD compared with normal controls (p = 0.019). Furthermore, there were higher frequencies of the A allele in LDD patients than in normal controls (p = 0.005). Unconditional logistic regression analysis revealed that -938CA and AA genotypes were significantly associated with the presence of LDD compared with CC genotype (p = 0.041; OR 1.449; 95% CI 1.015 - 2.067 and p = 0.015; OR 2.102; 95% CI 1.158 - 3.813, respectively). The A allele was significantly associated with the susceptibility to LDD compared with the C allele (p = 0.005; OR 1.436; 95% CI 1.113 - 1.851). In addition, -938CA and AA genotypes, as well as the A allele were found to be associated with the risk for higher degenerative grades of LDD compared with the CC genotype and C allele, respectively (p = 0.017 and p = 0.003, respectively).

CONCLUSIONS

The -938C > A polymorphism of BCL-2 may be associated with the presence and severity of LDD in the Chinese Han population.

Effect of Goji (Lycium barbarum) on expression of genes related to cell survival

This study investigated the interrelationship between Lycium barbarum (goji) and gene expression in mouse spleen. Oligomicroarray technology was employed to explore the comprehensive response of gene expression and to screen candidate marker genes in the spleens of mice fed a goji suspension. Goji was micronized by media milling and then used to evaluate the effect of size reduction. The average diameter of nano/submicrometer goji was about 100 nm, which exhibited no cytotoxicity to cell lines IEC-6 (rat normal small intestinal cell line) and Caco-2 (human colon adenocarcinoma cell line). It was found that three genes, TNF, Nfkb1, and Bcl-2, were up-regulated and two genes, APAF-1 and caspase-3, were down-regulated by goji. This phenomenon could be helpful for cytoprotection when cells undergo stress or damage that induces the apoptotic pathway. Size reduction into nano/submicrometer scale enhanced bioactivity.

Cigarette smoke suppresses Bik to cause epithelial cell hyperplasia and mucous cell metaplasia

RATIONALE

Aberrant regulation of airway epithelial cell numbers in airways leads to increased mucous secretions in chronic lung diseases such as chronic bronchitis. Because the Bcl-2 family of proteins is crucial for airway epithelial homeostasis, identifying the players that reduce cigarette smoke (CS)-induced mucous cell metaplasia can help to develop effective therapies.

OBJECTIVES

To identify the Bcl-2 family of proteins that play a role in reducing CS-induced mucous cell metaplasia.

METHODS

We screened for dysregulated expression of the Bcl-2 family members.

MEASUREMENTS AND MAIN RESULTS

We identified Bik to be significantly reduced in bronchial brushings of patients with chronic epithelial cell hyperplasia compared with nondiseased control subjects. Reduced Bik but increased MUC5AC mRNA levels were also detected when normal human airway epithelial cells (HAECs) were exposed to CS or when autopsy tissues from former smokers with and without chronic bronchitis were compared. Similarly, exposure of C57Bl/6 mice to CS resulted in increased numbers of epithelial and mucous cells per millimeter of basal lamina, along with reduced Bik but increased Muc5ac expression, and this change was sustained even when mice were allowed to recover in filtered air for 8 weeks. Restoring Bik expression significantly suppressed CS-induced mucous cell metaplasia in differentiated primary HAEC cultures and in airways of mice in vivo. Bik blocked nuclear translocation of phospho-ERK1/2 to induce apoptosis of HAECs. The conserved Leu61 within Bik and ERK1/2 activation were essential to induce cell death in hyperplastic mucous cells.

CONCLUSIONS

These studies show that CS suppresses Bik expression to block airway epithelia cell death and thereby increases epithelial cell hyperplasia in chronic bronchitis.

A methylene chloride fraction of Saururus chinensis induces apoptosis through the activation of caspase-3 in prostate and breast cancer cells

The aerial parts of Saururus chinensis (SC) have been used for the treatment of edema, fever, jaundice, and inflammatory diseases in Korean folk medicine for centuries. However, the mechanism by which SC exerts these anti-tumorigenic activities in human prostate and breast cancer cells has not yet been fully understood. In this study, we report on the methylene chloride fraction from SC exerting cytotoxicity against prostate and breast cancer cells in a dose-dependent manner. Specifically, SC exerted the most potent cytotoxicity in LNCaP and MCF-7 cells. SC was shown to down-regulate various angiogenetic (VEGF), proliferative (Cyclin D₁, anti-apoptotic (Bcl-2) gene products in these cells. SC also increased the number of annexin V-positive apoptotic bodies and the sub-G1 DNA contents of the cell cycle undergoing apoptosis through caspase-3 activation in both LNCaP and MCF-7 cells. We further confirmed that caspase-3 plays an important role in SC-induced apoptosis in LNCaP and MCF-7 cells through the use of the caspase-3 inhibitor. Moreover, we observed that SC potentiated paclitaxel-induced apoptosis in MCF-7 cells and sauchinone is a major active constituent of SC, which could induce apoptosis in the cells. Taken together, our data provide the evidence that SC induces apoptosis depending on caspase-3 activation and overcomes the natural biological resistance to chemotherapy found in human prostate and breast cancer cells.

[Expression of Ki-67, p53, bcl-2, estrogen receptors alpha in patients with clear cell renal carcinoma and epidermal growth factor receptor mutation]

Three hundred and thirty-six cases of clear-cell renal carcinoma (CCRC) were examined for epidermal growth factor receptor (EGFR) mutation: exon 19 deletion and L858R mutation in exon 21 of the EGFR gene. The expression of Ki-67, bcl-2, p53, and estrogen receptors alpha was studied in CCRC with EGFR mutation. There were 4 cases of CCRC with EGFR exon 19 deletion. The frequency of EGFR gene mutations was 1.2%. L858R missense mutations in exon 21 of the EGFR gene were absent. In CCRC, EGFR gene mutation (exon 19 deletion) was detected in 3 men and 1 woman with an age range of 50 to 60 years and Fuhrman differentiation grade 2 or 3. The Ki-67 index varied from 4 to 23%. The expression of bcl-2 and p53 was negative. A moderate estrogen receptor alpha expression was revealed in 1 of 4 cases.

Single nucleotide polymorphisms in the p21 and bcl2 cancer susceptibility genes and breast cancer risk in Saudi Arabia

Certain single nucleotide polymorphisms (SNPs) in genes like p21 or bcl2 increase susceptibility to breast cancer but it has not, until now, been clear whether common polymorphic variants in the same genes also increase risk in Saudi Arabian population. The aim of this study was therefore to determine whether polymorphisms of p21 or Bcl2 might be associated with an increased risk of breast cancer in Saudi women. p21 (rs733590) C/T SNP was not found to be associated with breast cancer pathogenesis. However, we found that a reverse mutation T/C might be linked with breast cancer occurrence. Bcl2 genotypes were marginally associated overall with breast cancer risk. In addition, the alleles of this gene were significantly associated with risk of breast cancer. The allelic frequency of G was higher (0.68) in patients than in healthy women. AA vs. AG+GG genotype [OR=3.56 (1.24-10.68); P=0.008] was the dominant genotype. It is likely that these genes conferring measurably increased risks of breast cancer in our study population.

Survivin downregulation is associated with vasectomy-induced spermatogenic damage and apoptosis

OBJECTIVE

To evaluate the expression of the apoptotic genes survivin, Bax and Bcl-2 in vasectomized rabbits and to determine their relation with vasectomy-induced spermatogenic impairment and germ cell apoptosis.

MATERIALS AND METHODS

Twelve adult rabbits (6-12 months old) were divided into three groups: sham control, unilateral vasectomy or bilateral vasectomy. Six months after vasectomy, testicular tissue was analyzed for germ cell apoptosis and DNA fragmentation by the TUNEL assay and gel electrophoresis, respectively. Spermatogenesis was assessed using the Johnsen score. The relative gene expression of survivin, Bax and Bcl-2 was measured using reverse transcription followed by real-time PCR.

RESULTS

Compared to sham animals, a significant decrease in testicular survivin mRNA levels was measured in the two vasectomy animal groups (p < 0.05). This was accompanied by a significant increase in the Bax:Bcl-2 ratio in the vasectomized animals (p < 0.05). In addition, these data showed positive correlation with enhanced apoptotic index, damage to spermatogenesis and DNA fragmentation after vasectomy.

CONCLUSION

These findings demonstrate that vasectomy-induced damage to spermatogenesis due to testicular apoptosis may be associated with survivin downregulation and Bax overexpression.

Cryptic IGH/BCL2 rearrangements with variant FISH patterns in follicular lymphoma

Follicular lymphoma (FL) is one of the most common non-Hodgkin lymphomas (NHL). Translocation t(14;18)(q32;q21) involving IGH and BCL2 genes represents its genetic hallmark. We present six cases of a series of 75 well diagnosed FL patients in which variant fluorescence in situ hybridization (FISH) patterns for this rearrangement were found. Moreover, G-banding cytogenetics and polymerase chain reaction (PCR) methods were unable to detect t(14;18)(q32;q21). According to our results, FISH is the best technique to define variant rearrangements of IGH/BCL2 genes and is important to detect it in cases with non-conclusive FL characteristics to avoid misdiagnosis with other NHL.

Study of the immunoexpression of Bcl-2 by a cutaneous granular cell tumor

BACKGROUND

Cutaneous granular cell tumors have only rarely been examined for Bcl-2, a marker that is expressed by granular cell tumors from other parts of the body.

OBJECTIVE

We retrospectively studied three cases of cutaneous granular tumors from our archives.

METHODS

We immunohistochemically tested for neuron-specific enolase (NSE), CD68 (KP1), Bcl-2, and S-100. In Cases 1 and 3, we also tested for CD34, HMB-45, and melan-A. In Case 3, we additionally tested for smooth muscle actin, CD68-PGM1, cytokeratin AE1-AE3, epithelial membrane antigen, desmin, CD1a, and CD117.

RESULTS

None of our cases presented any of the histological markers traditionally considered to be indicators of potential malignancy in granular cell tumors. All cases strongly expressed S-100, CD68, NSE, and Bcl-2. Case 3 also expressed CD68-PGM1. The rest of the markers were not expressed by the tumors.

CONCLUSIONS

Bcl-2 is expressed by cutaneous granular cell tumors.