Role Of Bcl-2 Research Articles

Analysis of Immunohistochemical Expression of Bcl-2 in Cases of Psoriasis and Psoriasiform Dermatitis.

Introduction Psoriasis involves rapid cell growth and abnormal differentiation of skin cells. Dysregulation of apoptosis has been proposed in the pathogenesis of psoriasis. The role of Bcl-2 as an anti-apoptotic proteinin pathogenesis has not been studied in detail in these cases.Our study aims to evaluate the expression of Bcl-2 in different skin compartments in psoriasis and psoriasiform dermatitis cases. Materials and methodology An analytical cross-sectional study was performed using paraffin blocks of psoriasis and psoriasiform dermatitis patients between 2022 and 2023. For light microscopy screening, sections were initially stained with hematoxylin and eosin stains. In further sections, a primary antibody against Bcl-2 was applied. The level of Bcl-2 expression in keratinocytes of supra-basal and basalepidermal layers and dermal lymphocytes was evaluated using a scoring system. Results Sixty patients, 30 with psoriasis and 30 with psoriasiform dermatitis were included. Among the histopathological features, parakeratosis (p - 0.038), Munro's microabscesses (p - 0.001), supra-papillary plate thinning (p - 0.004), and increased dermal vasculature (p - 0.001) were significantly associated with psoriasis when compared with psoriasiform dermatitis. Most psoriatic lesions had hypogranulosis whereas it was alternating hypo and hypergranulosis in psoriasiform dermatitis (p - 0.001). Acanthosis was regular in psoriasis lesions (p - 0.036). Bcl-2 expression was seen in dermal lymphocytes in all psoriasis and psoriasiform lesions with significantly stronger positive expression compared to basal and supra-basal layers. Psoriasis cases demonstrated more significant Bcl-2 positivity in dermal lymphocytes and basal layers than psoriasiform dermatitis cases. Conclusion Bcl-2 has stronger expression in dermal lymphocytes and basal layers than supra-basal layers, which comply with the proposed pathogenesis. Increased Bcl-2 expression in psoriasis cases compared with other psoriasiform dermatitis lesions implies the more chronic and recurrent nature of the disease.

Role of Bcl-2, Apoptotic Index, and Ki-67 Expression in Basal Cell Carcinoma and their Association with Aggressive and Non- Aggressive Histological Phenotypes

Role of Bcl-2, Apoptotic Index, and Ki-67 Expression in Basal Cell Carcinoma and their Association with Aggressive and Non- Aggressive Histological Phenotypes

Impact of BCL-2 Expression on Course of Disease in Neuroblastoma.

The antiapoptotic BCL-2 protein has implications for maturation and differentiation of neural tissue and acts as a strong modulator of carcinogenesis in different tumors. Recent research focuses not only on its benefit as a prognostic factor, but also as a potential therapeutic target. The role of BCL-2 in neuroblastoma, the most common extracranial solid tumor in childhood, remains controversial. The aim of our study was to determine the gene expression level of BCL-2 in a large cohort of neuroblastoma patients and its correlation with clinical parameters. Tumor samples and clinical data were collected from 100 neuroblastoma patients treated according to the NB2004 protocol of the German Society of Pediatric Oncology and Hematology. BCL-2 gene expression levels were measured by quantitative reverse transcription polymerase chain reaction and correlated with clinical parameters. BCL-2 expression was detected in all tumor samples. Relative BCL-2 expression levels were higher in females versus males (1.839 vs. 1.342; p = 0.0143), in patients with low versus high International Neuroblastoma Staging System stage (2.051 vs. 1.463; p = 0.0206), in nonmetastatic versus metastatic disease (1.801 vs. 1.342; p = 0.0242), as well as in patients without presurgical chemotherapy (2.145 vs. 1.402; p = 0.0016), but was not associated with overall survival and MYCN amplification. Our study demonstrates the ubiquitous expression of BCL-2 in neuroblastoma and suggests the possibility for targeted therapy with BCL-2 inhibitors, even in lower-stage neuroblastoma. It also underlines the need for further research on concomitant genetic alterations for a better understanding of the impact of BCL-2 on this pediatric tumor type.

Impaired Autophagy in Krabbe Disease: The Role of BCL2 and Beclin-1 Phosphorylation

Autophagic impairment was identified in many lysosomal storage diseases and adult neurodegenerative diseases. It seems that this defect could be directly related to the appearance of a neurodegenerative phenotype and could contribute to worsen metabolite accumulation and lysosomal distress. Thus, autophagy is becoming a promising target for supportive therapies. Autophagy alterations were recently identified also in Krabbe disease. Krabbe disease is characterized by extensive demyelination and dysmyelination and it is due to the genetic loss of function of the lysosomal enzyme galactocerebrosidase (GALC). This enzyme leads to the accumulation of galactosylceramide, psychosine, and secondary substrates such as lactosylceramide. In this paper, we induced autophagy through starvation and examined the cellular response occurring in fibroblasts isolated from patients. We demonstrated that the inhibitory AKT-mediated phosphorylation of beclin-1 and the BCL2-beclin-1 complex concur to reduce autophagosomes formation in response to starvation. These events were not dependent on the accumulation of psychosine, which was previously identified as a possible player in autophagic impairment in Krabbe disease. We believe that these data could better elucidate the capability of response to autophagic stimuli in Krabbe disease, in order to identify possible molecules able to stimulate the process.

To analyse the mitotic and keratinisation correlation with bcl-2 expression in varying grades of oral epithelial dysplasia and squamous cell carcinoma.

The bcl-2 proto-oncogene was discovered at the chromosomal breakpoint of t (14;18) found in follicular lymphoma. Histological changes in dysplasia are considered the earliest signs preceding the progression into squamous cell carcinoma. Serving as critical regulators of apoptotic pathways, bcl-2 prohibits programmed cell death and subsequently assists in uncontrolled neoplastic growth. This study included 48 cases, eight each of epithelial dysplasia and squamous cell carcinoma. Immunohistochemical staining using bcl-2 antibody was performed and different histological parameters were correlated with bcl-2 positive cells in all the cases. All 3 μm thick sections were stained with bcl-2 antibody. After identifying four representative fields at 40x, their images were obtained for assessment of bcl-2 labelled cells and their intensity along with different histological parameters in all the cases. The differences between different histological parameters were analysed using the Anova test, post hoc test and Bonferroni test. Pearson's Chi-square test was carried out to determine the level of correlation between the bcl-2 positive cells in both epithelial dysplasia and oral squamous cell carcinoma cases. Sequential increase in the bcl-2 expression was observed in increasing grades of epithelial dysplasia, whereas bcl-2 expression was significantly decreased in ascending stages of squamous cell carcinoma thus, suggesting a possible role of bcl-2 in disease progression from premalignancy to malignancy.

Neuroprotective Effect of Bcl-2 on Lipopolysaccharide-Induced Neuroinflammation in Cortical Neural Stem Cells.

Neuroinflammation is involved in the pathogenesis of neurodegenerative diseases due to increased levels of pro-inflammatory cytokines in the central nervous system (CNS). Chronic neuroinflammation induced by neurotoxic molecules accelerates neuronal damage. B-cell lymphoma 2 (Bcl-2) is generally accepted to be an important anti-apoptotic factor. However, the role of Bcl-2 in neuroprotection against neuroinflammation remains to be determined. The purpose of this study was to investigate the neuroprotective effect of Bcl-2 on lipopolysaccharide (LPS)-induced neuroinflammation in cortical neural stem cells (NSCs). LPS decreased mRNA and protein levels of Tuj-1, a neuron marker, and also suppressed neurite outgrowth, indicating that LPS results in inhibition of neuronal differentiation of NSCs. Furthermore, LPS treatment inhibited Bcl-2 expression during neuronal differentiation; inhibition of neuronal differentiation by LPS was rescued by Bcl-2 overexpression. LPS-induced pro-inflammatory cytokines, including interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α), were decreased by Bcl-2 overexpression. Conversely, Bcl-2 siRNA increased the LPS-induced levels of IL-6 and TNF-α, and decreased neuronal differentiation of NSCs, raising the possibility that Bcl-2 mediates neuronal differentiation by inhibiting the LPS-induced inflammatory response in NSC. These results suggest that Bcl-2 has a neuroprotective effect by inhibiting the LPS-induced inflammatory response in NSCs.

Role of Bcl-2, p53, and Ki-67 expression in basal cell carcinoma and their association with aggressive and non-aggressive histological phenotypes.

IntroductionThere is increasing evidence that immunohistochemical expression of p53, Ki-67, and Bcl-2 is associated with aggressive (aBCC) and less aggressive (nBCC) histological subtypes and may have a prognostic role.AimTo investigate the clinicopathological features and immunohistochemical expressions of p53, Ki-67, and Bcl-2 in cutaneous basal cell carcinoma focusing on histological subtypes. Their roles and possible interactions in the development and progression of BCC are discussed.Material and methodsA total of 50 BCC samples from 50 patients from Western Mexico between June 2018 and June 2019 were included. Paraffin-embedded samples were immunostained with p53, Ki-67, and Bcl-2 antibodies. Semi-quantitative analysis was performed to determine the intensity and positivity of immunostained cells. Parametrical and non-parametrical tests were performed according to the sample’s distribution.ResultsSamples included 21 nBCC and 29 aBCC. The statistical analysis showed statistical association when grouped as non-aggressive and aggressive subtypes for p53 (p = 0.04) and Bcl-2 (p < 0.01). An inverse negative correlation was found between age and Bcl-2 expression. No statistical association was found between Ki-67 immunoreactivity and any of the other variables.ConclusionsWe found that a high expression of Bcl-2 and a low expression of p53 was associated with more indolent histopathological features of BCC and therefore better outcomes. These findings suggest that examination of p53 and Bcl-2 expression in BCC patients may provide valuable prognostic information. These biomarkers may play a role in the development and progression of some cases of BCC.

The Role of Bcl-2 in Pediatric Functional Bowel Obstruction Cases with Ganglionated Specimens

Abstract Background Functional disturbances of the gastrointestinal tract is caused by a number of neurodysplastic conditions including other diseases, rarer than the Hirschsprung’s disease dysganglionosis, such as ganglion cells immaturity including Intestinal Neuronal Dysplasia (IND). Bcl-2 shows positive immunoreactivity in the degenerative and immature ganglion cells . Aim This work evaluates the role of immunohistochemical expression of Bcl-2 in pediatric functional bowel obstruction cases with ganglionated specimens. Material and Methods Twenty one cases of functional bowel obstruction were enrolled in our study including the Hirschsprung Allied Disorders (HAD) and operated cases of Hirschsprung’s Disease (HD) with adequate ganglionated resection margins and presented by obstructive symptoms following surgery. All cases underwent histologic examination of ganglion cells and nerve bundles as well as evaluation for Bcl-2 immunohistochemical expression. Results 57.1% of the cases were strongly positive for Bcl-2 protein, 19% were weakly positive and 23.8 % were negative. A highly significant correlation was demonstrated between Bcl-2 expression and ganglion cell number ( P &amp;lt; 0.001 ) where all hyperganglionic specimens showed strong positivity in contrast to the hypoganglionic and adequately ganglionic ones. A positive association was also found between Bcl-2 expression and IND in comparison to other disorders of dysganglionsis (P = 0.04) and recurrent HD cases (P = 0.002). A significant correlation was also detected between ganglion cell number and nerve bundle hypertrophy (P = 0.02). Conclusion Bcl-2 immunohistochemistry can be used as a valuable tool in the diagnosis of Hirschsprung’s disease allied disorders through its expression in the immature ganglion cells which are difficult to be identified by conventional H &amp; E staining.

Inhibition of ROS-Induced Nrf2 Antioxidant Pathway Activation May Explain Synergy between Venetoclax and Hypomethylating Agents Against Acute Myeloid Leukemia

The selective Bcl-2 inhibitor venetoclax (ABT-199) has shown potent anti-leukemic activity in combination with hypomethylating agents (HMA) against Acute Myeloid Leukemia (AML). Induction of Reactive Oxygen Species (ROS) mediates the cytotoxicity of various AML therapies including HMA. Induction of ROS concurrently activates the Nrf2 antioxidant response pathway which in turn results in induction of antioxidant enzymes that in turn neutralize ROS. Nrf2 is critical to hematopoietic stem cell function and high Nrf2 expression has been implicated in chemoresistance of AML stem cells. In this study, we demonstrate that Nrf2 inhibition by venetoclax is an additional mechanism responsible for the marked anti-leukemic activity in AML seen with the combination of HMAs and venetoclax.Venetoclax increased cellular and mitochondrial ROS in AML cells. Venetoclax showed strong synergy with decitabine in inducing apoptosis and further augmented ROS induction by HMA in AML cell lines including MV-4-11, KG1A and Kasumi. For example, the percentage of apoptotic cells increased from 6% or 20.3% after decitabine or ABT-199 treatment alone, respectively, to 37.6 % after treatment with the combination in MV-4-11 cells. Cytotoxicity of HMA was inhibited by the ROS scavenger N-acetyl cysteine. Knock down of Nrf2 augmented the cytotoxicity of HMA against AML cells. Indeed, Nrf2 depletion by siRNA increases apoptotic ratio from 3.8% to 18.5% after treatment with 5-Azacitidine and from 5.4% to 32.8% after treatment with decitabine. Increased nuclear translocation of Nrf2 as well as induction of antioxidant enzyme response was observed after treatment of AML cells with decitabine. Treatment of AML cell lines as well as primary AML cells with venetoclax inhibited the increased nuclear translocation of Nrf2 and induction of downstream antioxidant enzymes including HO-1 and NQO1 seen in response to decitabine treatment alone (Figure 1, top panels). Using immunofluorescence and immunoprecipitation experiments we further show that Bcl-2 associates with Nrf2, and venetoclax treatment leads to dissociation of Bcl-2 from the Nrf2-Keap1 complex thereby targeting Nrf2 for ubiquitination and proteosomal degradation (Figure 1, bottom panels).Our results demonstrate an undiscovered mechanism namely Nrf2 inhibition that may underlie the synergistic effect of HMA and venetoclax in AML cells. Nrf2 inhibition by venetoclax has the potential to target leukemia stem cells and could explain the impressive results seen in early clinical studies of AML using combination therapy with HMA and venetoclax. We also show the novel role of Bcl-2 in regulating Nrf2 by its association with Nrf2 and Keap1 and further show increased ubiquitination of Nrf2 after venetoclax treatment. Dissociation of Bcl-2 binding to Nrf2/Keap1 complex leading to increased proteosomal degradation may explain the inhibition of nuclear Nrf 2 translocation seen with combination of venetoclax and HMA treatment in AML cells. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Obatoclax, the pan-Bcl-2 inhibitor sensitizes hepatocellular carcinoma cells to promote the anti-tumor efficacy in combination with immune checkpoint blockade

Bcl-2 family proteins play critical roles in regulating lymphocyte development and maintain homeostasis, and have also been proved to be involved in various cancer types development. However, the role of Bcl-2 in hepatocellular carcinoma (HCC) development has not been clearly studied. Here, we reported the pan-Bcl-2 inhibitor, obatoclax could directly inhibit HCC growth in vitro. We further demonstrated in murine HCC model that obatoclax also suppressed HCC development in vivo. We also proved that although obatoclax inhibited T cells expansion, it had no influence on T cells activation in vivo. Mechanism study revealed that obatoclax sensitized HCC cells to T cell-mediated killing. Combination therapy of obatoclax with anti-PD-1 antibody synergistically suppressed HCC development and prolonged the survival rate of tumor-bearing mice. The combination therapy promoted T cells activation and effector cytokines expression both in spleen and tumor. In summary, our results proved that obatoclax sensitized HCC cells to T cell -mediated killing. Combination of obatoclax with immune checkpoint blockade served as a promising therapeutic strategy for HCC treatment.

Overexpression of the OCT-1 Gene Is a Biomarker Associated with Poor Outcomes in Diffuse Large B-Cell Lymphoma (DLBCL) - Data from a Retrospective Cohort from Latin America: Defining a Very High-Risk Clinical-Molecular Subgroup

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most frequent lymphoid malignancy, representing 30-40% of all non-Hodgkin's lymphomas (NHLs). They comprise a group of aggressive and heterogeneous neoplasms in terms of clinical presentation, response to therapy and prognosis. The OCT-1 gene is a member of the homodomain-POU family of transcriptional regulators of B-lymphoid differentiation. OCT-1 acts by controlling the expression of specific B-cell genes, such as BCL-2, a potent inhibitor of apoptosis that is essential for the differentiation of B-cells in the germinal center. These genes can be expressed in DLBCL, but the role of BCL-2 in its prognosis has been contradictory and the prognostic impact of the OCT-1 gene has not yet been tested in this lymphoma. Methods: In this observational, retrospective, single-center study, we investigated the prognostic impact of BCL-2 and OCT-1 gene expression in Brazilian patients with DLCBL treated with immunopolychemotherapy R-CHOP in a real-world context. The BCL-2 and OCT-1 genes were assessed in 78.5% (77/98) DLBCL patients, and the RNA for quantitative real-time PCR (qRT-PCR) was isolated from formalin-fixed and paraffin-embedded (FFPE) samples. The values obtained for gene expression were transformed into categorical variables according to their medians (6.27 for BCL-2 and 24.5 for OCT-1). The association between clinical and laboratory variables and results of gene expression was verified by the Fischer test. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Univariate analysis was performed using Cox's bivariate regression method and multivariate analysis using Cox multiple regression methodology. Results: The median age of the cohort was 54.5 years (15-84), 50% (49/98) were male, 49.4% (38/77) and 51.4% (40/77) showed expression of OCT-1 and BCL- 2 ≥ median, respectively. The clinical characteristics of the 98 Brazilian patients with DLBCL that comprised our cohort are summarized in Table 1. The overall response rate (ORR) in all patients was 68.4% (67/98), 65.3% (64/98) showed a complete response (CR), and 3.1% (3/98) showed partial response (PR), while 6.1% (6/98) were primary refractory. With a median follow-up of 3.77 years (95% CI: 3.2-4.1), the median overall survival (OS) was 5.43 years (95% CI: 2.2-NR) and the median progression-free survival (PFS) was 5.15 years (95% CI: 2.9-NR). The 5-year OS and PFS was 54.2% (42.2% -64.8%) and 52.0% (40.1-62.6%), respectively. In the univariate analysis OCT-1 ≥ median was associated with shortened OS (HR: 2.45, 95% CI: 1.21-4.96, p = 0.013) and PFS (HR: 2.27, 95% CI: 1.14-4.51, p = 0.019). Overexpression of BCL-2 was associated with worse PFS (HR: 2.00, 95% CI: 1.02-3.95, p = 0.043). Subgroup analysis showed that OCT-1 overexpression predominated in elderly individuals (≥ 60 years) in a statistically significant mode (29/38 cases - 76.3%, p = 0.029). It was also observed that overexpression of OCT-1 was associated with worse OS in the high-risk adjusted International Prognostic Index (aIPI) subgroup (p = 0.048) - Figure 1, and worse PFS in patients ≥ 60 years old (p = 0.025) - Figure 2. In the multivariate analysis, overexpression of OCT-1 was associated with poor PFS (HR: 2.22, 95% CI: 1.06-4.76, p = 0.035). Conclusion: In this study, we demonstrated that overexpression of the OCT-1 gene was an independent prognostic factor associated with adverse outcomes in Brazilian patients with DLCBL. We also show that in patients with unfavorable risk, such as the elderly and those with intermediate-high and high-risk IPI, overexpression of OCT-1 contributed to the identification of a very high-risk clinical-molecular subgroup, where the results with standard R-CHOP therapy are unsatisfactory, and they may benefit from intensified therapeutic strategies. Our results are preliminary and need to be validated in subsequent studies of prospective nature and with an expanded sample. Disclosures No relevant conflicts of interest to declare.

Overexpression of OCT-1 gene is a biomarker of adverse prognosis for diffuse large B-cell lymphoma (DLBCL): data from a retrospective cohort of 77 Brazilian patients

BackgroundOCT-1 gene is a member of the POU-homeodomain family of transcriptional regulators of B-lymphocyte differentiation by controlling expression of B-cell specific genes. BCL-2 gene is a potent inhibitor of apoptosis and it is essential during B-cell differentiation into germinal center. These genes may be expressed in diffuse large B-cell lymphoma (DLBCL), but the role of BCL-2 in its prognosis has been contradictory, and OCT-1 has yet to be tested.MethodsIn this study, we aimed to investigate the prognostic impact of OCT-1 and BCL-2 expression in DLBCL treated in the real world with immunochemotherapy in a single center. BCL-2 and OCT-1 genes were available in 78.5% (77/98) DLBCL patients, and the RNA for quantitative real-time PCR was isolated from formalin-fixed paraffin-embedded samples. The values obtained for gene expression were transformed in categorical variable according to their median.ResultsCohort median age was 54.5 years (15–84), 49 (50%) were male, 38/77 (49.4%) and 40/77 (51.9%) presented OCT-1 and BCL-2 expression ≥ median, respectively. The overall response rate (ORR) in all patients was 68.4% (67/98), 65,3% (64/98) of patients acquired complete response, and 3.1% (3/98) partial response, while 6.1% (6/98) were primary refractory. The median follow-up was 3.77 years (95% CI: 3.2–4.1), with 5.43 (95% CI: 2.2-NR) of overall survival (OS) and 5.15 years (95% CI: 2.9-NA) of progression free survival (PFS). OCT-1 ≥ median was associated with shorter OS at univariate analysis (p = 0.013; [HR] 2.450, 95% CI: 1.21–4.96) and PFS (p = 0.019; [HR] 2.270, 95%CI: 1.14–4.51) and BCL-2 gene overexpression presented worse PFS (p = 0.043, [HR] 2.008, 95% CI: 1.02–3.95). At multivariate analysis, OCT-1 overexpression was associated with poor PFS (p = 0.035, [HR] 2.22, 95% CI: 1.06–4.67).ConclusionIn this study, we showed that overexpression of OCT1 gene was an independent prognostic factor of adverse outcomes in DLBCL.

A direct comparison of selective BH3-mimetics reveals BCL-XL, BCL-2 and MCL-1 as promising therapeutic targets in neuroblastoma

BackgroundDespite advances in the treatment of neuroblastoma, patients with high-risk disease still have dismal survival prognosis. Neuroblastoma cells display elevated expression of the antiapoptotic BCL-2 proteins, suggesting that BH3-mimetics may be a promising treatment option. Here, we investigated the role of BCL-2, BCL-XL and MCL-1 in neuroblastoma.MethodsA panel of neuroblastoma cell lines and primary patient-derived cells were exposed to BH3-mimetics targeting BCL-2 (ABT-199), BCL-XL (A1331852) or MCL-1 (S63845). In addition, protein expression and interaction patterns were analysed using Western blotting and immunoprecipitation.ResultsAll tested BH3-mimetics were able to induce apoptosis in neuroblastoma cell lines, indicating that not only BCL-2 but also BCL-XL and MCL-1 may be promising therapeutic targets. Primary patient-derived cells displayed highest sensitivity to A1331852, highlighting the important role of BCL-XL in neuroblastoma. Further analysis into the molecular mechanisms of apoptosis revealed that A1331852 and S63845 displaced proapoptotic proteins like BIM and BAK from their antiapoptotic targets, subsequently leading to the activation of BAX and BAK and caspase-dependent apoptosis.ConclusionsBy using selective BH3-mimetics, this study demonstrates that BCL-2, BCL-XL, and MCL-1 are all relevant therapeutic targets in neuroblastoma. A1331852 and S63845 induce rapid apoptosis that is initiated following a displacement of BAK from BCL-XL or MCL-1, respectively.

Role of Bcl-2 on drug resistance in breast cancer polyploidy-induced spindle poisons.

Spindle poisons are chemotherapeutic drugs used in the treatment of malignant tumors; however, numerous patients develop resistance following chemotherapy. The present study aimed to induce polyploidy in breast cancer cells using the spindle poison nocodazole to investigate the mechanism of polyploid-induced tumor resistance. It was revealed that the spindle poison nocodazole induced apoptosis in HCC1806 cells but also induced polyploidy in MDA-MB-231 cells. The drug sensitivities of the polyploid MDA-MB-231 cells to paclitaxel, docetaxel, epirubicin, 5-fluorouracil and oxaliplatin were lower than those of the original tumor cells; however, the polyploid MDA-MB-231 cells were more sensitive to etoposide than the original tumor cells. The expression of F-box and WD repeat domain containing 7 (FBW7) was decreased, while the expression of MCL1 apoptosis regulator BCL2 family member (MCL-1) and Bcl-2 was increased, and caspase-3/9 and Bax were not expressed in MDA-MB-231 cells. The resistance to docetaxel and etoposide was reversed, but the sensitivity of paclitaxel was not changed following Bcl-2 silencing. The formation of polyploidy in tumors may be one of the molecular mechanisms underlying tumor resistance to spindle poisons. Expression of the Bcl-2 family members, for example FBW7 and MCL-1, plays a key role in apoptosis and the cell escape process that forms polyploid cells. However, Bcl-2 silencing has different reversal effects on different anti-tumor drugs, which requires further investigation.

The Induction of Apoptosis by Resveratrol Through Regulatory Effect of miR-21 on the Gene Expression of Bcl2 and Bax in HCT-116 Cells

Background: Resveratrol (RezV) which is found in several plants including grapes and types of berries has a vital role in inducing apoptosis and suppressing cell proliferation. Although the role of Bcl-2 in the apoptosis has been known in several pathways, the role and mechanism of miR-21 in the regulation of apoptosis in colorectal cancer (CRC) cells are unclear. Objectives: The main aim of this study was to evaluate the effects of RezV on the expression level of miR-21, Bax, and Bcl2 in colorectal tumor cells. Methods: In this study, the effect of RezV on the viability of CRC cells was evaluated by MTT assay. Then, the expression level of miR-21 was evaluated by real-time polymerase chain reaction (PCR) method. For evaluating HCT-116 cells apoptosis, the expression level of Bax and Bcl2 that are involved in the apoptosis pathway was investigated by the same method. Results: RezV inhibits the viability of HCT-116 cells. MiR-21 gene expression was decreased after 24 hours of treatment with RezV. The reduction of miR-21 expression leads to the reduction of the Bcl2 gene expression level. Moreover, increasing the Bax/Bcl2 ratio enhances HCT-116 cells apoptosis. Conclusion: In summary, RezV might be used as a co-treatment agent for CRC. On the other hand, conducting the in vivo study to evaluate the effects of RezV was critical.

SpBcl2 promotes WSSV infection by suppressing apoptotic activity of hemocytes in mud crab, Scylla paramamosain

White spot syndrome virus (WSSV) is one of the most virulent and widespread pathogens that infect almost all marine crustaceans and therefore cause huge economic losses in aquaculture. The Bcl2 protein plays a key role in the mitochondrial apoptosis pathway, which is a crucial immune response in invertebrates. However, the role of Bcl2 in apoptosis and immunoregulation in mud crab, Scylla paramamosain, is poorly understood. Here, the Bcl2 homolog (SpBcl2) in S. paramamosain was cloned and its role in WSSV infection explored. The expression of SpBcl2 increased at both the transcriptional level and post-transcriptional level after WSSV infection, while the hemocytes apoptosis decreased significantly. Furthermore, there was increase in the level of cytochrome c coupled with an upregulation in the expression of SpBcl2. These results indicated that SpBcl2 suppressed apoptosis by preventing the release of cytochrome c from mitochondria, thereby promoting WSSV replication in mud crab. The findings here therefore provide novel insight into the immune response of mud crabs to WSSV infection.

Creating a New Cancer Therapeutic Agent by Targeting the Interaction between Bcl-2 and IP3 Receptors.

Bcl-2 is a member of a family of proteins that regulate cell survival. Expression of Bcl-2 is aberrantly elevated in many types of cancer. Within cells of the immune system, Bcl-2 has a physiological role in regulating immune responses. However, in cancers arising from cells of the immune system Bcl-2 promotes cell survival and proliferation. This review summarizes discoveries over the past 30 years that have elucidated Bcl-2's role in the normal immune system, including its actions in regulating calcium (Ca2+) signals necessary for the immune response, and for Ca2+-mediated apoptosis at the end of an immune response. How Bcl-2 modulates the release of Ca2+ from intracellular stores via inositol 1,4,5-trisphosphate receptors (IP3R) is discussed, and in particular, the role of Bcl-2/IP3R interactions in promoting the survival of cancer cells by preventing Ca2+-mediated cell death. The development and usage of a peptide, referred to as TAT-Pep8, or more recently, BIRD-2, that induces death of cancer cells by inhibiting Bcl-2's control over IP3R-mediated Ca2+ elevation is discussed. Studies aimed at discovering a small molecule that mimics BIRD-2's anticancer mechanism of action are summarized, along with the prospect of such a compound becoming a novel therapeutic option for cancer.

Immunohistochemical expression of Bcl-2 in oral squamous cell carcinoma: a clinicopathological correlation

Background Oral malignancy includes a group of neoplasms affecting any district of the oral cavity, salivary glands, and pharyngeal regions. Notwithstanding, this term has a tendency to be utilized conversely with oral squamous cell carcinoma (OSCC), which represents the most incessant of every oral neoplasm. It is evaluated that a greater than of 90% of oral neoplasm are OSCC malignancies. The Bcl-2 protein is the encoding result of Bcl-2 proto-oncogene. The overexpression of Bcl-2 protein assumes an imperative part in apoptosis protection in many tumors, including head and neck squamous cell carcinoma. Aim/objectives This study was conducted to scope and find out the possible role of Bcl-2 in the biological behavior of OSCC. Methods A total of 20 OSCC cases were immunohistochemically examined for expression of Bcl-2. Results and conclusions There was significant difference among grades of OSCC regarding Bcl-2 expression. A significant correlation between Bcl-2 expression and clinical staging, nodal infiltration, as well as distant metastasis was observed. We concluded that Bcl-2 may be used as a prognostic factor for OSCC and may aid in decisions on cancer diagnosis and therapy.

Preclinical Activity of Novel MCL1 Inhibitor AZD5991 in Multiple Myeloma

Preclinical Activity of Novel MCL1 Inhibitor AZD5991 in Multiple Myeloma

Abstract 303: Novel role of nuclear BH3-only protein BNIP3 in regulation of cellular proliferation

Abstract The objective of this study is to investigate the role of Bcl-2 nineteen kilodalton interacting protein 3 (BNIP3) in regulating cellular proliferation and identifying the proliferation pathways mediated by BNIP3. BNIP3 is a BH3-only proapoptotic member of Bcl-2 family of cell death regulating proteins. The function of BNIP3 is dependent on its localization and expression levels. Under normal conditions, low levels of BNIP3 are present in the nucleus of cells. Low oxygen or hypoxic conditions lead to increased expression of BNIP3, and high levels of BNIP3 are found in the cytoplasm. Cytoplasmic BNIP3 is associated with caspase-independent apoptotic cell death through mitochondria. If, however, BNIP3 levels are increased in the nucleus, it promotes survival of cells by transcriptionally inhibiting several apoptosis-inducing factors. High levels of BNIP3 in nucleus are seen in majority of glioblastoma tumors, where hypoxic environment of tumor core causes an increase in expression of BNIP3 but high amounts of BNIP3 localize to the nucleus, possibly aiding in the survival of the tumor cells. In this study, we found that BNIP3 knockout mice brains have increased cellularity compared to wild-type brains. We also found that both mouse primary astrocytes and embryonic fibroblasts (MEFs) lacking BNIP3 expression have an increased capacity for proliferation compared to wild-type MEFs. Overexpressing BNIP3 in the nucleus of HEK 293 cells also resulted in reduced proliferation. In contrast, both astrocytes and MEFs lacking BNIP3 failed to show differences in cell death compared to wild-type cells. This reveals a novel function for BNIP3 in regulating cellular proliferation that may lead to new targets for cancer therapy. In future studies, we will identity genes regulated by nuclear BNIP3 that may lead to suppression of cellular proliferation in cancer cells. Citation Format: Amandeep Singh, Meghan Azad, Spencer Gibson. Novel role of nuclear BH3-only protein BNIP3 in regulation of cellular proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 303.