BMI-1 Gene Expression Research Articles

Senescence ofbone marrow mesenchymal stem cells in Wistar malerats receiving normal chow/high-calorie diets with/without vitamin D.

Bone marrow mesenchymal stem cells (BM-MSCs) have a momentous function in the composition of the bone marrow microenvironment because of their many valuable properties and abilities, such as immunomodulation and hematopoiesis. The features and actions of MSCs are influenced by senescence, which may be affected by various factors such as nutritional/micronutrients status, e.g., vitamin D. This study aimed to examine the effects of a high-calorie diet (HCD) with/without vitamin D on BM-MSCs senescence. In the first phase, 48 middle-aged rats were fed a normal chow diet (NCD, n = 24) and an HCD (n = 24) for 26 weeks. Afterward, the rats in each group were randomly divided into three equal subgroups. Immediately, eight-rat from each diet group were sacrificed to assess the HCD effects on the first phase measurements. In the second phase, the remaining 4 groups of rats were fed either NCD or HCD with (6 IU/g) or without vitamin D (standard intake: 1 IU/g); in other words, in this phase, the animals were fed (a) NCD, (b) NCD plus vitamin D, (c) HCD, and (d) HCD plus vitamin D for 4 months. BM-MSCs were isolated and evaluated for P16INK4a, P38 MAPK, and Bmi-1 gene expression, reactive oxygen species (ROS) levels, SA-β-gal activity, and cell cycle profile at the end of both phases. After 26 weeks (first phase), the ROS level, SA-β-gal-positive cells, and cells in the G1 phase were significantly higher in HCD-fed rats than in NCD-fed ones (P < 0.05). HCD prescription did not significantly affect cells in the S and G2 phases (p > 0.05). Compared with the NCD-fed animals, P16INK4a and P38 MAPK gene expression were up-regulated in the HCD-fed animals; also, Bmi-1 gene expression was down-regulated (P < 0.05).BM-MSCs from vitamin D-treated rats (second phase) exhibited reduced mRNA levels of P16INK4a and P38 MAPK genes and increased Bmi-1 mRNA levels (all P<0.05). Vitamin D prescription also declined the percentage of SA-β-gal-positive cells, ROS levels, and the cells in the G1 phase and increased the cells in the S phase in both NCD and HCD-fed animals (P <0.05). The reduction of the cells in the G2 phase in rats fed with an NCD plus vitamin D was statistically non-significant (P=0.128) and significant in HCD plus vitamin D rats (P=0.002).HCD accelerates BM-MSCs senescence, and vitamin D reduces BM-MSCs senescence biomarkers.

Abstract 2478: The interplay between Apurinic/apyrimidinic Endonuclease 1 (APE1) and DNA G-quadruplex (G4) in regulating triple-negative breast cancer (TNBC) metastasis

Abstract Triple-negative breast cancer (TNBC) is the most aggressive breast cancer (BC) among all the BC subtypes due to its exceptionally high metastasis rate. TNBC patients with metastasis have a short overall survival as the endocrine therapy and chemotherapy are inefficient in TNBC treatment. Hence, efforts are still needed to figure out the molecular mechanism driving TNBC metastasis and find promising therapeutic targets for TNBC treatment. A newly published study revealed that a secondary DNA structure G-quadruplex (G4) is highly enriched in TNBC signature genes’ promoters, and our lab was the first one to uncover that DNA repair protein Apurinic/apyrimidinic endonuclease 1 (APE1) binds to G4 and regulates its stability in cells, so we are aimed to investigate the interaction between APE1 and G4 in TNBC and their roles in regulating TNBC metastasis. We found that knocking out or knocking down APE1 in TNBC cell lines, MDA-MB-231 and BT-549, significantly impaired the cell migration ability. RNA-seq analysis and Gene Ontology analysis revealed that APE1 knockout downregulated expression of genes such as CXCL1, VEGFA, PIK3R3, BMI1, etc. which are mostly involved in promoting cell migration. Further, APE1 ChIP-seq analysis showed that APE1 was highly enriched in CXCL1, VEGFA, PIK3R3 and BMI1 gene promoters, and these regions contained potential G4 folding sequences, suggesting a potential interaction between APE1 and G4 in these gene promoters. Consisted with this, our study with the enzyme linked immunosorbent assays (ELISA) showed that recombinant APE1 bound with high affinity to CXCL1 and VEGFA G4 secondary structures as compared to double-strand DNA oligos in vitro, suggesting that APE1’s enrichment to the metastasis-related gene promoters attributes to the G4 structures in those promoter regions. Promoter-directed ChIP assay further revealed that downregulating APE1 inhibited transcription factor (TF) c-JUN’s occupancy to VEGFA promoters. Interestingly, we discovered that the G4-targeted small molecule TMPyP4 blocked APE1-G4 binding in vitro and reduced APE1’s occupancy at gene promoters in cells. Treatment of cells with TMPyP4 significantly downregulated CXCL1, VEGFA, PIK3R3, and BMI1 gene expression as well as inhibiting cell migration. In orthotopic TNBC metastasis mouse model, mice treating with TMPyP4 significantly reduced the frequency and volume of metastatic tumors in lung tissues. Overall, our study revealed that G4 in gene promoters recruited APE1 which further promoted transcription factors’ binding to promoters and enhanced metastasis-related gene expression. Blocking APE1-G4 interaction by TMPyP4 is a potential therapeutic approach to inhibit TNBC metastasis. Citation Format: Yingling Chen, Suravi Pramanik, Mason Tarpley, Achyuth Kalluchi, Bhopal Mohapatra, Kyle Hewitt, Michael J. Rowley, Vimla Band, Kishor Bhakat. The interplay between Apurinic/apyrimidinic Endonuclease 1 (APE1) and DNA G-quadruplex (G4) in regulating triple-negative breast cancer (TNBC) metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2478.

Acute lymphoblastic leukemia in children and SALL4 and BMI-1 gene expression.

Sal-like protein 4 transcription factor (SALL4) and B cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) gene were reported to cause treatment failure and relapse in several malignancies. We aimed to evaluate the prognostic value of SALL4 and BMI-1 in children with acute lymphoblastic leukemia (ALL). This prospective cohort study was carried out on 60 children with ALL as the patient group and 60 age- and sex-matched children as the control group. We evaluated the expression pattern of both SALL4 and BMI-1 genes in the peripheral blood using real-time reverse transcriptase-polymerase chain reaction in children with ALL at initial diagnosis before chemotherapy. We followed up with the patient group for 2 years for relapse or death. Both SALL4 and BMI-1 were overexpressed in ALL children compared to the control group. Moreover, the expression of SALL4 and BMI-1 in patients with relapse was significantly higher than those with complete remission. The best cut-off of SALL4 and BMI-1 to predict relapse were >2.21 and 0.55 yielding sensitivity of 92.3% and 84.6%, respectively. Patients with overexpression of SALL4 and BMI-1 had significantly shorter overall and disease-free survival. SALL4 and BMI-1 could be useful prognostic markers in children with ALLto predict relapse.

BMI-1 Gene Expression in Patients with Acute and Chronic Myeloid Leukemia in the Northeast of Iran

Background: The B-cell-specific Moloney murine leukemia virus integration site1 (BMI-1) is one of the famous members of the Polycomb ring finger group, which plays a crucial role in the gene transcription regulation through histone changes. Hence, it is believed to be necessary to further clarify the effects of the BMI-1 clinical. Method: This cross-sectional study was conducted on 70 acute myeloid leukemia (AML), 70 chronic myeloid leukemia (CML), and 20 healthy individuals, as the control group. We used Real-Time quantitative polymerase chain reaction (Real-Time PCR) in order to assess the BMI-1 level expression and its effect on prognosis in AML patients in the Molecular Pathology Research Center. Results: The results of the present work indicated that the BMI-1 overexpression was significantly higher in the AML and CML patients compared to that in the healthy controls (P < 0.001). Furthermore, a significant relationship was observed between the BMI-1 overexpression and poor prognosis in the AML patients (Hazard ratio=1.749, P < 0.001, 95% confidence interval = 1.31-2.32). Additionally, BMI-1high was found in chronic and blastic phase in the CML patients (P < 0.001). Conclusion: We concluded that investigation of BMI-1 gene expression pattern will be conducive to the prognosis and treatment of myeloid leukemia.

Effect of Bmi-1 Expression on Chemotherapy Sensitivity in THP-1 Cells

To investigate the effect of Bmi-1 expression on the chemosensitivity of THP-1 cells and its relative mechanism. The pGenesil-2-Bmi-1 1 siRNA, p-MSCV-Bmi-1 plasmid was transfected into THP-1 cells to reduce or increase the expression of Bmi-1. The expression of Bmi-1 mRNA and protein was verified by PCR and Western blot. The effect of camptothecin (CPT) on the proliferation and chemosensitivity of THP-1 cells affected by Bmi-1 gene were detected by MTT assay. The expression of DNA double-strand breaks marker-γ-H2AX was detected by immunofluorescence assay. Mitochondrial membrane potential and apoptosis were observed by flow cytometry. The expression of Cytochrome C, Caspase 3, Bax and BCL-2 was detected by Western blot. Silencing Bmi-1 could inhibit proliferation and enhance the sensitivity of THP-1 cells to CPT, while overexpressed Bmi-1 could promote the cell proliferation and attenucate sensitivity of THP-1 cells to CPT. Silencing Bmi-1 could enhance CPT-induced DNA double-strand breaks, decrease mitochondrial membrane potential and promote CPT-induced apoptosis. While increasing Bmi-1 gene expression could attenuate CPT-induced DNA double-strand breaks, enhamce mitochondrial membrane potential and significantly reduce CPT-induced apoptosis of cells. Bmi-1 expression could influence the sensitivity of THP-1 cells to CPT, and its relative mechanism may relate to DNA double-strand breaks and endogenous apoptotic pathways.

BMI1-Inhibitor PTC596 in Combination with MCL1 Inhibitor S63845 or MEK Inhibitor Trametinib in the Treatment of Acute Leukemia.

Simple SummaryPrognosis for acute myeloid leukemia (AML) patients is poor, particularly in TP53 mutated AML, secondary, relapsed, and refractory AML, and in patients unfit for intensive treatment, thus highlighting an unmet need for novel therapeutic approaches. Targeting the stem cell oncoprotein BMI1 in leukemic cells may represent a promising novel treatment option for poor risk AML patients, especially in combination with other targeted therapies. Here we tested the BMI1 inhibitor PTC596 in combination with a variety of targeted therapies in AML cell lines and patient samples in vitro. In addition, we defined the biomarkers of response to the combination treatments in the leukemic cells. The combination treatment with the BMI1 inhibitor PTC596 and the MCL1 inhibitor S63845 may be an effective treatment in CD34+ adverse risk AML with elevated MN1 gene expression and MCL1 protein levels, while combination treatment with BMI1 inhibitor PTC596 and the MEK inhibitor trametinib may be more effective in CD34+ adverse risk AML with elevated BMI1 gene expression and MEK protein levels. The determination of gene and protein expression levels in leukemic cells as biomarkers of response to targeted combination therapies may be helpful to optimize treatment efficacy.Purpose: Prognosis for acute myeloid leukemia (AML) patients is poor, particularly in TP53 mutated AML, secondary, relapsed, and refractory AML, and in patients unfit for intensive treatment, thus highlighting an unmet need for novel therapeutic approaches. The combined use of compounds targeting the stem cell oncoprotein BMI1 and activating the tumor suppressor protein p53 may represent a promising novel treatment option for poor risk AML patients. Experimental Design: The BMI1 inhibitor PTC596, MCL1 inhibitor S63845, and MEK inhibitor trametinib, as well as the p53 activator APR-246 were assessed as single agents and in combination for their ability to induce apoptosis and cell death in leukemic cells. AML cells represented all major morphologic and molecular subtypes including FLT3-ITD and FLT3 wild type, NPM1 mutant and wild type, as well as TP53 mutant and wild type AML cell lines and a variety of patient derived AML cells. Results: AML cell lines were variably susceptible to PTC596 and to combination treatments with PTC596 and MCL1 inhibitor S63845, MEK inhibitor trametinib, or TP53 activator APR-246, independent of TP53 mutational status. Susceptibility of patient samples for PTC596 in combination with S63845 or trametinib was significant for the majority of adverse risk primary and secondary AML with minimal efficacy in favorable risk AML, and correlated significantly with CD34 positivity of the samples. BMI1 and MN1 gene expression, and MCL1 and MEK1 protein levels were identified as biomarkers for response to PTC596 combination treatments. Conclusions: The combination of PTC596 and S63845 may be an effective treatment in CD34+ adverse risk AML with elevated MN1 gene expression and MCL1 protein levels, while PTC596 and trametinib may be more effective in CD34+ adverse risk AML with elevated BMI1 gene expression and MEK protein levels.

Efficient Enucleation and In Vivo Circulation of Differentiated Human Erythroblasts Derived from Peripheral Blood Mononuclear Cells after Extensive Expansion

Transfusion of red blood cells (RBCs) is a standard and indispensable cellular therapy commonly used globally in elective and emergency surgery and for treating anemic patients who need frequent transfusion. However, the current donor-based supply is often insufficient to meet the increasing need especially in pandemic and natural disasters. Thus that, ex vivo production of functional cultured RBCs in a laboratory setting is highly desirable and has been pursued in the past decades. Significant progress has been made in the differentiation of mature human erythrocytes from CD34+ HSPCs and human pluripotent stem cells (PSCs), however, generating physiological numbers of transfusable cultured RBCs (cRBCs) ex-vivo has been challenging. We and others have also tried an alternative approach to directly and extensively expand or immortalize erythroid progenitors (erythroblasts) from a postnatal source of individual patients or desirable donors. Here we report that ectopic expression of the human BMI1 gene confers extensive expansion of human erythroblasts derived from peripheral blood mononuclear cells (PBMCs) while reserving the high efficiency of enucleation after erythroblast differentiation. Being encouraged by previous studies including those with mouse marrow cells, we examined if the BMI1 gene expression is present and critical to human erythroblast proliferation. We observed that the human BMI1 gene is expressed in proliferating erythroblasts as in CD34+ HSPCs, but decreases in late-stage erythroblasts undergoing differentiation. Using a short hairpin RNA-mediated knockdown approach, we found that BMI1 expression is essential to maintain a proliferative state of human erythroblasts established in culture. We next tested whether the ectopic expression of human BMI1 as a transgene can prolong the expansion of human erythroblasts in culture, which only lasts for 3-4 weeks before spontaneous differentiation and ceasing proliferation. The BMI1-transduced erythroblasts continued to proliferate for at least 60 days, resulting in a 1012-fold expansion of erythroblasts established from PBMCs of several adult donors; we termed them as "extensively expanded erythroblasts" or E3 cells. To investigate the capacity of BMI1-E3 cells to terminally differentiate into reticulocytes, a standard maturation medium was applied to replace the serum-free expansion medium at various time points after expansion. We found that these E3 cells are capable of efficient terminal maturation, yielding ~50% enucleated erythrocytes after ex vivo differentiation induction. Moreover, similar results were seen on erythroblasts derived from PBMCs of two adult patients with sickle cell disease. To broaden and enhance the clinical applications of these culture-expanded erythroblasts, we confirmed the feasibility of genetic manipulation on E3 cells by inserting a transgene or ablating an endogenous gene such as CD55. Finally, we examined whether human erythrocytes differentiated from BMI1-E3 cells have the capacity to circulate (and possibly further mature) in vivo using an improved mouse model. E3-derived cultured RBCs can circulate in a mouse model following transfusion similar to primary human RBCs. Interestingly, percentages of enucleated erythrocytes derived from the BMI1-E3 maturation products increased in the circulation in mice, to reach from ~57% at transfusion to approximately 72-84% after transfusion. Therefore, we provide a facile approach of generating physiological numbers of human functional erythroblasts ex-vivo. Disclosures No relevant conflicts of interest to declare.

Resveratrol inhibits cell growth via targeting the Bmi-1 pathway in YD-10B human oral squamous cell carcinoma cells

Resveratrol has been reported to exert anticancer activity via modulation of multiple pathways and genes. In this study, we examined the effect of resveratrol on YD-10B human oral squamous cell carcinoma cells and its molecular mechanisms of action. We found that resveratrol inhibited the proliferation of YD-10B cells in a dose- and timedependent manner. The suppressive effect of resveratrol was accompanied by a reduction in Bmi-1 gene expression. We observed that silencing the Bmi-1 gene by small interfering RNA effectively downregulated the levels of GLUT1 mRNA and protein, which were also repressed by resveratrol. Bmi-1 silencing increased the number of YD-10B cells in S-phase arrest by approximately 2.3-fold compared with the control. In conclusion, the results of the present study demonstrate, for the first time, that resveratrol suppresses Bmi-1-mediated GLUT1 expression in human oral squamous cell carcinoma cells and suggest that the specific molecular targeting of Bmi-1 and/or GLUT1 expression can be combined with a chemotherapeutic strategy to improve the response of oral cancer cells to resveratrol.

The Therapeutic Effects of an Antimicrobial Peptide Protonectin (IL-12) on A549 Cancer Cell Line

In the study, the impact of protonectin (IL-12) on the bioavailability of human lung carcinoma cell line A549 as well as on HFLF healthy lung fibroblast cells was investigated for 24 h and 48 h. Results demonstrated highest cytotoxicity of protonectin on the A549 cell line at 12 µg/ml and 50 µg/ml, and after 48 h and 24 h cell incubation respectively. No cytotoxicity was observed during the incubation of normal HFLF lung cells with the IL-12 peptide. The peptide did not have any significant impact on the hemolysis of human and cattle red blood cells as well as on the viability of human lymphocytes. The effect of protonectin on gene expression of BMI-1 and CD44 as cancer markers was investigated by the real-time RT-PCR. Results indicated that the effect of the peptide on down-regulation of the BMI-1 gene expression was higher compared to CD44 at 12 µg/ml over 24 h and 48 h. A dose and time-dependent pattern was observed in the production of reactive oxygen species (ROS) in the treated A549 cells. From this study, it can be concluded that protonectin has a significant impact on cancer cells for the down-regulation of gene expression of cancer markers and for the up-regulation of the production of ROS.

The Study of SALL4 Gene and BMI-1 Gene Expression in Acute Myeloid Leukemia Patients.

In acute myeloid leukemia (AML), many genes have been studied as prognostic markers. SALL4 is expressed constitutively in human leukemia cell lines and primary AML cells. BMI-1 is expressed highly in purified hematopoietic stem cells (HSCs), and its expression declines with differentiation. To study the expression levels of SALL4 and BMI-1 and their clinical significance in patients with AML. The study was performed with 60 patients newly diagnosed with AML and 50 control individuals. SALL4 and BMI-1 expression detection were performed using real-time polymerase chain reaction (PCR). The expression of SALL4 and BMI-1 was significantly higher in cases of AML and showed a strong association with failure to achieve complete remission (CR) or with relapse (P = .02, P = .03, respectively). In multivariate analysis, these genes were the most powerful independent predictors of poor prognosis (P = .01 for SALL4, P = .02 for BMI-1). SALL4 and BMI-1 are significant prognostic factors in AML and could be strong targets for novel types of therapy.

Effects of siRNA-mediated silencing of Bmi-1 gene expression on proliferation of gastric cancer cells

This study was designed to investigate the effects of siRNA-mediated silencing of Bmi-1 gene expression on proliferation of AGS gastric cancer cell. siRNA Bmi-1 was transfected into human AGS gastric cancer cells by liposome (as siRNA Bmi-1 group) with negative control (as control group); the expressions of Bmi-1 and apoptosis-related genes like P21, Bax, and Bcl-2 in AGS cells were determined by Western blot method; the apoptosis of AGS cells was detected by flow cytometry double staining and Hoechst staining; and cell cycle was measured by flow cytometry. Compared with the control group, the expression of Bmi-1 in the siRNA Bmi-1 group was significantly decreased ( P &lt; 0.05), the apoptosis rate was increased ( P &lt; 0.05), and cell cycles were arrested at G1 phase (P &lt; 0.05); the expression level of P21 and Bax in cells was significantly up-regulated while that of Bcl-2 down-regulated ( P &lt; 0.05). The down regulation of Bmi-1 can inhibit the proliferation of AGS gastric cancer cell and promote its apoptosis, which takes such effects mainly by up-regulating P21 as well as Bax and down-regulating Bcl-2.

Retracted : Anticancer effects of miR‐200c in colorectal cancer through BMI1

Colorectal cancer (CRC) is one of the most leading cancer deaths throughout the world. MiR-200c has been shown to have a critical role in cancer initiation and progression. In this study, we investigated the miR-200c expression in CRC tissues and its effects on CRC cell lines which were mediated by polycomb complex protein (BMI1). Quantitative reverse transcription polymerase chain reaction (QRT-PCR) and immunohistochemistry were used to detect miR-200c and BMI1 expression in tumor tissues from 38 patients with CRC and 38 normal colon tissues. HCT-116 and SW-48 cells were transfected by locked nucleic acid (LNA)-anti-miR-200c. Western blot analysis and real-time PCR were applied to determine the BMI1 protein and microRNA (miRNA) levels. The apoptosis was analyzed via annexin/propidium iodide staining, and cell invasion was evaluated by transwell assay. MiR-200c was markedly downregulated in CRC tissues, whereas the protein expression of BMI1 in CRC tissues was upregulated compared with normal colon tissues. In the colon cancer cell lines, transfection of LNA-anti-miR-200c increased BMI1 gene and protein expression as well as the cell invasion. Downregulation of miR-200c by LNA decreased the apoptotic cells. The results from this study revealed that miR-200c may have antitumor effects through inhibition of BMI1 expression.

MPEG-CS/Bmi-1RNAi Nanoparticles Synthesis and Its Targeted Inhibition Effect on CD133+ Laryngeal Stem Cells.

Previous studies have confirmed that CD133+ cells in laryngeal tumor tissue have the characteristics of cancer stem cells. Bmi-1 gene expression is central to the tumorigenicity of CD133+ cells. In this study, we tried to develop a new siRNA carrier system using chitosan-methoxypolyethylene nanoparticles (CS-mPEG-NPs) that exhibit higher tumor-targeting ability and enhanced gene silencing efficacy in CD133+ tumor stem cells. It is hoped to block the self-renewal and kill the stem cells of laryngeal carcinoma. The mPEG-CS-Bmi-1RNAi-NPs were synthesized and their characters were checked. The changes in invasion ability and sensitivity to radiotherapy and chemotherapy of CD133+Hep-2 tumor cells were observed after Bmi-1 gene silencing. The mPEG-CS-Bmi-1RNAi-NPs synthesized in this experiment have a regular spherical form, a mean size of 139.70 ±6.40 nm, an encapsulation efficiency of 85.21 ± 1.94%, with drug loading capacity of 18.47 ± 1.83%, as well as low cytotoxicity, providing good protection to the loaded gene, strong resistance to nuclease degradation and high gene transfection efficiency. After Bmi-1 gene silencing, the invasion ability of CD133+ cells was weakened. Co-cultured with paclitaxel, the survival rates of CD133+Bmi-1RNAi cells were lower. After radiotherapy, the mean growth inhibition rate of CD133+/Bmi-1RNAi cells was significantly lower than CD133+ cells. In conclusion, the mPEG-CS nano-carrier is an ideal vector in gene therapy, while silencing the Bmi-1 gene can enhance the sensitivity of CD133+ tumor stem cells to chemoradiotherapy and abate their invasion ability.

Prognostic Value of FBXO39 and ETS-1 but not BMI-1 in Iranian Colorectal Cancer Patients

Background:Colorectal cancer (CRC) is one of the most prevalent cancers worldwide. Despite recent progress in diagnosis and treatment, it remains a major health problem and further studies are needed. We here investigated expression profiles of the FBXO39, ETS-1 and BMI-1 genes in CRCs to validate any possible diagnostic/prognostic significance.Material and Methods:Thirty six patients with locally advanced CRC admitted to Hazrate-Rasoul Hospital-Tehran were enrolled. Initially the expression pattern of FBXO39, ETS-1 and BMI-1 genes were determined using RT-PCR in CRC tumor and adjacent normal tissues then real-time RT-PCR was employed to quantify BMI-1 gene expression.Results:FBXO39 expression was restricted to tumor tissues. Interestingly, expression of this gene was detected in all stage-0 tumor samples. There was a significant relation between FBXO39 gene expression and lymph node involvement. The ETS-1 gene was expressed in 66% of all tumor tissues with p-value=0.03 for increase as compared to the adjacent normal samples. In addition, there was a significant relation between ETS-1 gene expression and tumor size and lymph node involvement. RT-PCR demonstrated BMI-1 gene expression in both tumor and normal tissues and quantification by real-time RT-PCR showed no association between BMI-1 levels and CRC clinicopathological features.Conclusion:Expression of FBXO39 and ETS-1 with lymph node involvement may be considered as an alarm for the occurrence of CRC metastasis, and therfore have prognostic value while BMI-1 appears without importance.

유방암세포 성장과 Bmi-1 발현에 대한 레스베라트롤의 억제 효과

Resveratrol has been actively investigated as an anticancer drug since it induces cell growth inhibition and apoptosis in many cancer cells. Resveratrol acts through modulation of multiple pathways and genes. In this study, we found resveratrol reduced cell growth and mammosphere formation in MDA-MB-231 triple-negative human breast cancer cells. This suppressive effect of resveratrol is accompanied by a reduction in Bmi-1 gene expression. We also observed that knockdown of Bmi-1 gene by small interfering RNA effectively sensitizes breast cancer cells to resveratrol treatment. Our data demonstrate, for the first time, that resveratrol down-regulates Bmi-1 expression in human breast cancer cells and suggest that specific molecular targeting of Bmi-1 can be combined with a chemotherapeutic strategy to improve the response of breast cancer cells to resveratrol.

Lower expression of miR-218 in human breast cancer is associated with lymph node metastases, higher grades, and poorer prognosis.

Breast cancer is considered as the most prevalent malignancy in women worldwide. Despite emergence of several prognosticators for better management of patients, there are still limitations for their clinical application due to the complexity of breast tumors, and therefore, new biomarkers for better prognosis of clinical outcomes would be of the great essence. MicroRNAs are highly conserved small non-coding regulatory RNAs involved in post-transcriptional regulating of gene expression during different cellular mechanisms. Accumulating studies suggest that miR-218 plays a multifunctional role in various cancer types and different stages. Here, to address prognostic significance of miR-218 in breast cancer, we investigate the expression profile of miR-218 and B-cell-specific Moloney murine leukemia virus integration site 1 ( BMI1) gene, as one of the putative targets of miR-218, in 33 paired breast tumors and their adjacent normal tissues with respect to the clinicopathological features of patients using quantitative real-time polymerase chain reaction. The correlation of both miR-218 and BMI1 gene expression with overall survival of breast cancer patients was also examined recruiting OncoLNC data portal. Finally, to better understand biological function of miR-218 in breast cancer, we performed in silico Gene Ontology and signaling pathway enrichment analysis on miR-218 targetome. According to our data, significant elevation of the expression of miR-218 and downregulation of BMI1 were observed in clinical breast cancer specimens compared with normal tissues ( p < 0.0001). The lower expression of miR-218 was associated with lymph node metastases, higher grades, and poorer prognosis (logrank p = 0.00988), whereas no significant difference in overall survival was observed between patients with higher and lower expression of BMI1 (logrank p = 0.254). These findings suggest that miR-218 expression profiling might be clinically applicable as a prognostic biomarker in breast cancer. In addition, our in silico enrichment analyses revealed that the association of miR-218 expression with breast cancer prognosis might be through its involvement in endocytosis and gap junction biological pathways.

BMI‐1 protein expression as a negative independent prognostic factor in DLBCL

Introduction: The BMI-1 gene belongs to the polycomp group family and was originally identified as a proto-oncogene during lymphoma development. In diffuse large B-cell lymphoma (DLBCL), high BMI-1 gene expression can be used in distinguishing cell of origin (COO). Expression of BMI-1 protein in DLBCL is however poorly investigated. We aimed to investigate if BMI-1 protein expression was a prognostic factor in a consecutive cohort of patients with DLBCL. Methods: All patients with DLBCL diagnosed and treated 2009-2011 at Copenhagen University Hospital Herlev were collected consecutively and classified according to morphology and COO by immunohistochemistry (IHC, Hans algorithm). BMI-1 protein expression was investigated retrospectively by IHC. A total of 212 patients (163 primary + 49 transformed DLBCL) were included—176 of the patients had received intensive chemotherapy (R-CHOP/R-CHOEP in 174 patients). Results: Tissue was available for BMI-1 analysis in 162 patients. Median BMI-1 expression was 40% with IQR 10-80%. High BMI-1 expression ≥80% was seen in 32% (52/162) of patients and in 30% (42/139) of the patients whom had been intensively treated. Treatment regimens were comparable between patients with high and low BMI-1 expression. A tendency towards an associations between high BMI-1 expression and nonGCB profile (P = .07) and transformed lymphoma (P = .07) was observed (chi-square). High BMI-1 expression was not associated with bone marrow involvement (P = .5), extra nodal involvement (P = .2), performance status (P = .3), IPI score (P = .9), Ann Arbor stage (P = .14), or proliferation rate (P = .7) (chi-square). High BMI-1 expression had negative prognostic impact on both PFS and OS in univariate survival analysis (log rank); PFS (HR 1.9, P = .003), OS (HR 1.6, P = .04) (figure). In multivariable analysis (Cox proportional hazards models) including IPI, COO, and BMI-1 ≥80, both high BMI expression (PFS [HR 2.3, P = .001] and OS [HR 1.9, P = .009]) and IPI (PFS [HR 1.7, P = .001] and OS [HR 1.8, P = .001]) were independent prognostic factors. This was also seen in the subgroup of intensively treated patients. In univariate analysis, similar trends were seen when only patients with primary DLBCL were included. Keywords: diffuse large B-cell lymphoma (DLBCL); prognostic indices

B-cell specific Moloney leukemia virus insert site 1 and peptidyl arginine deiminase IV positively regulate carcinogenesis and progression of esophageal squamous cell carcinoma.

High expression of B-cell specific Moloney leukemia virus insert site 1 (Bmi-1) and peptidyl arginine deiminase IV (PADI4) is associated with esophageal carcinoma. However, few studies have investigated the association between the Bmi-1 and PADI4 genes. The aim of the present study was to evaluate the expression of Bmi-1 and PADI4 and identify the association between the Bmi-1 and PADI4 genes in esophageal squamous cell carcinoma (ESCC) tissues. Bmi-1 and PADI4 gene expression levels were measured using immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction in ESCC tissues from 86 patients who had not received pre-operative chemoradiation. The results revealed that the Bmi-1 and PADI4 genes had increased expression in carcinoma tissues compared with pericarcinous tissue (P<0.05). Bmi-1 gene expression was revealed to be associated with differentiation degree, clinical stage and lymph node metastasis (P<0.05), but had no association with gender, age or depth of invasion (P>0.05). The expression of PADI4 was associated with clinical stage, depth of invasion and lymph node metastasis (P<0.05), but was not associated with gender, age or differentiation degree (P>0.05). In addition, there was a positive association between Bmi-1 and PADI4 gene expression in ESCC (P<0.05). These results indicated that Bmi-1 and PADI4 positively regulate carcinogenesis and progression of ESCC.

THE EXPRESSION PATTERN OF BMI-1 GENE IN ACUTE MYELOID LEUKEMIA

Objectives: B-cell specific moloney murine leukemia virus integration site-1 (BMI-1) gene is a stem cell gene that modulates stem cell pluripotency and is also implicated in the regulation and accumulation of leukemic stem cells (LSCs). The current study aimed at characterizing BMI-1 gene expression in de novo AML patients before the start of chemotherapy and in those who achieved complete remission (CR). Methods: Real-time polymerase chain reaction was used to assess the gene expression in 54 de novo AML patients: 43 AML and 11 in CR as well as in 21 non malignant bone marrow samples. Results: AML patients showed a higher BMI-1 median fold change in expression (median=0.157) as compared to AML-CR patients (median=0.000) but this difference was not statistically significant. A higher median fold change was observed in patients with intermediate/unfavourable risk groups (2.381) than with favourable risk (0.000). BMI-1 expression levels were not seen to be influenced by clinicopatholoical factors of the disease or to affect response to first induction, overall and disease-free survival. Conclusion: The role of BMI-1 in myeloid leukemogenesis needs further delineation to determine its significance in acute leukemia pathogenesis. Our results point to its possible role in AML risk stratification but further studies are needed.

Expressions and clinicopathological significances of BMI-1 and PADI4 in esophageal squamous cell carcinoma

Objective To evaluate the expression levels of peptidylarginine deiminase 4 (PADI4) and B-cells pecific Moloney leukemia virus insert site-1 (BMI-1) in esophageal squamous cell carcinoma (ESCC) tissues and pericarcinous tissues. To explore the function and clinical significance in the development of ESCC and their association. Methods The expression levels of PADI4 and BMI-1 were measured by immunohistochemistry, Western blotting and quantitative real time PCR in ESCC tissues and pericarcinous tissues from 86 patients. The relationships between the expressions of PADI4 and BMI-1 and the clinicopathologic characte-ristics were analyzed. Results The immunohistochemistry showed that the expressions of PADI4 and BMI-1 in ESCC tissues (68.6% and 73.3%) were significantly higher than those in pericarcinous tissues (37.2% and 30.2%, χ2=17.011, P=0.000; χ2=31.876, P=0.000). Western blotting indicated that the levels of PADI4 and BMI-1 were higher than those in pericarcinous tissues (0.919±0.098 vs. 0.718±0.103, t=2.462, P=0.021; 0.975±0.074 vs. 0.717±0.071, t=2.640, P=0.014). The expressions of BMI-1 and PADI4 mRNA in ESCC tissues were higher than those in pericarcinous tissues, but the differences were not statistically significant (0.091±0.005 vs. 0.038±0.002, t=1.701, P=0.101; 0.114±0.075 vs. 0.048±0.003, t=1.499, P=0.146) by the quantitative real time PCR. The expression of PADI4 was correlated with lymph node metastasis (χ2=5.771, P=0.016), depth of invasion (χ2=6.672, P=0.010) and clinical stage (χ2=5.771, P=0.016). The BMI-1 gene expression had a correlation with lymph node metastasis (χ2=7.176, P=0.007), the differentiation degree (χ2=13.787, P=0.001) and clinical stage (χ2=7.176, P=0.007). In addition, there was a positive correlation between PADI4 and BMI-1 expression in ESCC by immunohistochemistry and quantitative real time PCR (r=0.214, P=0.047; r=0.534, P=0.005). Conclusion The expression levels of PADI4 and BMI-1 are significantly higher in ESCC compared to pericarcinous tissues. PADI4 and BMI-1 are positively correlated and may contribute to the diagnosis and prognosis of the ESCC. Key words: Esophageal neoplasms; Peptidylarginine deiminase 4; B-cells pecific Moloney leukemia virus insert site-1