BCL2L1 mRNA Research Articles

Amsacrine downregulates BCL2L1 expression and triggers apoptosis in human chronic myeloid leukemia cells through the SIDT2/NOX4/ERK/HuR pathway

Accumulating evidence indicates that the anticancer activity of acridine derivatives is mediated through the regulation of anti-apoptotic and pro-apoptotic BCL2 protein expression. Therefore, we investigated whether the cytotoxicity of amsacrine with an acridine structural scaffold in human chronic myeloid leukemia (CML) K562 cells was mediated by BCL2 family proteins. Amsacrine induced apoptosis, mitochondrial depolarization, and BCL2L1 (also known as BCL-XL) downregulation in K562 cells. BCL2L1 overexpression inhibited amsacrine-induced cell death and mitochondrial depolarization. Amsacrine treatment triggered SIDT2-mediated miR-25 downregulation, leading to increased NOX4-mediated ROS production. ROS-mediated inactivation of ERK triggered miR-22 expression, leading to increased HuR mRNA decay. As HuR is involved in stabilizing BCL2L1 mRNA, downregulation of BCL2L1 was noted in K562 cells after amsacrine treatment. In contrast, amsacrine-induced BCL2L1 downregulation was alleviated by restoring ERK phosphorylation and HuR expression. Altogether, the results of this study suggest that amsacrine triggers apoptosis in K562 cells by inhibiting BCL2L1 expression through the SIDT2/NOX4/ERK-mediated downregulation of HuR. Furthermore, a similar pathway also explains the cytotoxicity of amsacrine in CML MEG-01 and KU812 cells.

AL amyloidosis clonal plasma cells are regulated by microRNAs and dependent on anti-apoptotic BCL2 family members.

Noncoding RNAs such as microRNAs (miRNAs) have attracted attention as biological pathway regulators, which differ from chromosomal translocations and gene point mutations. Their involvement in the molecular mechanisms underlying light chain (AL) amyloidosis pathogenesis is yet to be elucidated. To decipher specific miRNA expression profile in AL-amyloidosis and to examine how miRNAs are involved in AL pathogenesis. The expression profile of miRNAs and mRNA from bone marrow (BM)-derived CD138+ cells were determined using the NanoString nCounter assay and RNA-Seq, respectively. The effect of aberrantly expressed miRNAs on potential molecular targets was analyzed by qRT-PCR, Western blot, Mito-potential assay, and Annexin-PI staining. Genes which were significantly differentially expressed between AL-amyloidosis and MM, were found to be involved in cell growth and apoptotic mechanisms. Specifically, BCL2L1, MCL1, and BCL2 were upregulated in AL-amyloidosis compared with MM and controls. The levels of miR-181a-5p and miR-9-5p, which regulate the above-mentioned genes, were lower in BM samples from AL-amyloidosis compared with controls, providing a mechanism for BCL2 family gene upregulation. When miR-9-5p and miR-181a-5p were overexpressed in ALMC1 cells, BCL2L1, MCL1, and BCL2 were downregulated and induced apoptosis. Treatment of ALMC-1 cells with venetoclax, (BCL-2 inhibitor), resulted in the upregulation of those miRNAs, the downregulation of BCL2, MCL1, and BCL2L1 mRNA and protein levels, and subsequent apoptosis. Our findings suggest that miR-9-5p and miR-181a-5p act as tumor-suppressors whose downregulation induces anti-apoptotic mechanisms underlying the pathogenesis of AL-amyloidosis. The study highlights the post-transcriptional regulation in AL-amyloidosis and provides pathogenetic evidence for the potential use of BCL-2 inhibitors in this disease.

P415: TARGETED 3RD-GENERATION (NANOPORE) SEQUENCING REVEALS MANY NOVEL CIRCULAR RNAS OF THE APOPTOSIS-RELATED BCL2L12 GENE, EXPRESSED IN HUMAN CELLS FROM ACUTE MYELOID LEUKEMIA AND MYELODYSPLASTIC SYNDROMES

Background: Circular RNAs (circRNAs) are non-coding RNAs generated via back-splicing. They are indirect – yet pivotal – regulators of gene expression, as many of them bind microRNAs (miRNAs) and render them unavailable to exert their direct regulatory functions. They also interact with chromatin, altering its structure and affecting transcription of several genes. Lastly, though considered as non-coding, few of them have also been shown to encode short, functional polypeptides. Due to their multifaceted role and the deregulation of their expression in cancer, circRNAs are related to the development and progression of malignancies, including myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). BCL2L12 is a prominent member of the apoptosis-related BCL2 family, with an already established role in AML. Moreover, BCL2L12 mRNA expression has been associated with chemoresistance of malignant bone marrow blasts. However, the identity and role of the circRNAs produced by alternative back-splicing of BCL2L12 primary transcripts in MDS and AML has not been investigated, so far. Aims: We sought to determine the identity of BCL2L12 circRNAs expressed in MDS and AML cell lines and to explore their putative interactions with miRNAs having an established role in these disease entities. Methods: MDS-L cells [MDS with del(5q) and complex karyotype], NB-4 and HL-60 cells (acute promyelocytic leukemia with and without PML-RARA, respectively), U-937 and THP-1 cells (acute monocytic leukemia), KASUMI-1 cells (AML with t(8;21)(q22;q22.1); RUNX1-RUNX1T1) and MOLM-13 cells (AML with t(9;11)(p21.3;q23.3); KMT2A-MLLT3) were propagated. Total RNA was extracted from these seven cell lines; 2μg of each RNA extract were reverse-transcribed using random hexamers. Next, nested PCR with divergent primers was performed, starting from each exon of the BCL2L12 gene; thus, only cDNAs from BCL2L12 circRNAs were amplified. After having mixed and purified all nested-PCR products of each cell line cDNA, nanopore sequencing libraries were built. Following nanopore sequencing and basecalling in a MinION Mk1C 3rd-generation sequencer, sequencing reads were aligned and corrected using Minimap2 and TranscriptClean, respectively. circRNA identification was performed using an in-house–built, PERL-based algorithm; miRDB was used for prediction of their interactions with miRNAs. Results: We discovered 83 novel BCL2L12 circRNAs, 9 of which were common between MDS-L cells and at least one AML cell line. The exon structure of these novel circRNAs showed a remarkable diversity, comprising exons also encountered in messenger RNAs (mRNAs) of BCL2L12 as intronic regions. This phenomenon was mostly observed in MDS-L cells. Several BCL2L12 circRNAs in NB-4 and HL-60 cells exhibited complete intron retention; additionally, a novel exon was present at a remarkable frequency in NB-4 cells. Moreover, several BCL2L12 circRNAs are predicted to sponge miRNAs with a key role in AML (miR-7-5p, miR-125b-5p and miR-182-5p) and/or MDS (miR-150-5p). Summary/Conclusion: Numerous circRNAs are produced through alternative back-splicing of the primary BCL2L12 transcripts. The circRNA expression profile of this gene differs among the MDS and AML cell lines, as well as among the six AML cell lines. Intronic regions of this apoptosis-related gene are included in several circRNAs, augmenting the repertoire of miRNAs predicted to be bound by BCL2L12 transcripts. This phenomenon was more common in the MDS cell line, followed by both acute promyelocytic leukemia cell lines. Our data suggest an important regulatory role for this gene in MDS and AML subtypes.

The effect of long-term dehydration and subsequent rehydration on markers of inflammation, oxidative stress and apoptosis in the camel kidney

BackgroundDehydration has deleterious effects in many species, but camels tolerate long periods of water deprivation without serious health compromise. The kidney plays crucial role in water conservation, however, some reports point to elevated kidney function tests in dehydrated camels. In this work, we investigated the effects of dehydration and rehydration on kidney cortex and medulla with respect to pro-inflammatory markers, oxidative stress and apoptosis along with corresponding gene expression.ResultsThe cytokines IL-1β and IL-18 levels were significantly elevated in the kidney cortex of dehydrated camel, possibly expressed by tubular epithelium, podocytes and/or mesangial cells. Elevation of IL-18 persisted after rehydration. Dehydration induced oxidative stress in kidney cortex evident by significant increases in MDA and GSH, but significant decreases in SOD and CAT. In the medulla, CAT decreased significantly, but MDA, GSH and SOD levels were not affected. Rehydration abolished the oxidative stress. In parallel with the increased levels of MDA, we observed increased levels of PTGS1 mRNA, in MDA synthesis pathway. GCLC mRNA expression level, involved in GSH synthesis, was upregulated in kidney cortex by rehydration. However, both SOD1 and SOD3 mRNA levels dropped, in parallel with SOD activity, in the cortex by dehydration. There were significant increases in caspases 3 and 9, p53 and PARP1, indicating apoptosis was triggered by intrinsic pathway. Expression of BCL2l1 mRNA levels, encoding for BCL-xL, was down regulated by dehydration in cortex. CASP3 expression level increased significantly in medulla by dehydration and continued after rehydration whereas TP53 expression increased in cortex by rehydration. Changes in caspase 8 and TNF-α were negligible to instigate extrinsic apoptotic trail. Generally, apoptotic markers were extremely variable after rehydration indicating that animals did not fully recover within three days.ConclusionsDehydration causes oxidative stress in kidney cortex and apoptosis in cortex and medulla. Kidney cortex and medulla were not homogeneous in all parameters investigated indicating different response to dehydration/rehydration. Some changes in tested parameters directly correlate with alteration in steady-state mRNA levels.

Abstract A73: BCL-XL dependency in a subset of ovarian clear-cell carcinoma cell lines

Abstract Clear-cell ovarian carcinoma is a rare histologic subtype of epithelial ovarian cancers. Clear-cell ovarian cancers tend to be less responsive to platinum-based chemotherapy compared to high-grade serous ovarian cancers. In a dataset of large-scale CRISPR knockout and RNAi screens of cancer cell lines (depmap.org), a subset of ovarian clear-cell carcinoma cell lines were sensitive to knockout or knockdown of BCL2L1, encoding antiapoptotic protein BCL-XL. Most clear-cell ovarian cancer cell lines also express BCL2L1 mRNA and protein. We therefore tested a panel of ovarian cancer cell lines for response to BH3 mimetic drugs, which inhibit different members of the BCL-2 family of antiapoptotic proteins. Initial data showed that a subset of ovarian clear-cell carcinoma cell lines was sensitive to single-agent BCL-XL inhibition with A1331852 and dual BCL-2/BCL-XL inhibition with ABT-263. In contrast, these cell lines were relatively insensitive to single-agent BCL-2 inhibition or MCL1 inhibition. We are currently applying BH3 profiling, a functional assay for apoptotic priming, to test the response of ovarian clear-cell carcinoma cell lines to BCL-XL inhibition using a BCL-XL specific peptide, HRK. Collectively, these studies suggest that ovarian clear-cell carcinomas may be sensitive to BCL-XL inhibition, either alone or in combination with chemotherapy. Citation Format: Elizabeth H. Stover, Maya K. Gelbard, Ursula A. Matulonis, Matthew Meyerson. BCL-XL dependency in a subset of ovarian clear-cell carcinoma cell lines [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A73.

IGLL5-BCL2L1 Rearrangement with Loss of BCL2 Dependency As Mechanism of Venetoclax Resistance in Multiple Myeloma (MM)

Background: Targeting the anti-apoptotic BCL2 protein in haematological malignancies has demonstrated significant anti-tumoral activity in a subset of multiple myeloma patients harbouring rearrangements involving the CCND1 and the immunoglobulin heavy chain enhancers (Eμ and α1/2). The mechanisms underlying the dependency of this subgroup of MM patients on BCL2 remains to be elucidated as well as the mechanisms of resistance to BCL2 inhibition with BH3 mimetic venetoclax. Methods and Results: Sorted bone marrow plasma cells from a cohort of t(11;14) myeloma patients treated with venetoclax were profiled through multi-omics single cell mRNA expression (scRNAseq), copy number profiling (scCNVseq) as well as chromatin accessibility with single cell ATAC-seq. Sequenced reads were aligned to hg38 reference genome. Samples were processed with CellRanger suite v3.0 and downstream analyses were realized with Seurat, Monocle, Signac, and Cicero R packages. Single plasma cells exhibited differential chromatin accessibility landscapes within and across individual patients as well as pre- and post-venetoclax with enrichment of MYC:MAX, RELA, IRF family, RUNX1/3 and ETS motifs. Integration of mRNA and ATAC data revealed a dynamic change of regulatory motifs across individual cell clusters with evidence of selective pressures driven by venetoclax treatment. Similarly mRNA profiling of the apoptotic genes pre- and post-venetoclax exposure showed loss of BCL2 and upregulation of MCL1 and/or BCL2L1 as well as loss of the BH3-only pro-apoptotic genes PMAIP1 and BCC3 in single cell clusters. mRNA levels mirrored open chromatin at the gene bodies and their respective promoter loci consistent with a direct transcriptional regulation. In a patient with several fold upregulation of the BCL2L1 transcript in the post-venetoclax sample (Figure A-B), scATACseq identified a gain in the chromatin accessibility mapping to a genomic region centromeric to BCL2L1 locus on chromosome 20 (chr20:31,617,200-31,619,900). Single cell CNV analysis identified a 5q loss (chr5:142,400,001-156,240,000) mapping to NR3C1 locus explaining with the clinical resistance to dexamethasone. Importantly scCNV also revealed a copy number gain mapping to the same locus with the newly acquired chromatin accessibility on chromosome 20. Mate-pair analysis of the sequencing reads identified the potent IGLL5 B-cell enhancer on chromosome 22 (chr22:22,960,001-22,980,000) as the mate partner juxtaposed the BCL2L1 locus (Figure C). This finding explains the robust upregulation of BCL2L1 mRNA observed in this patient and the shift in BCL2 dependency detected by ex vivo BH3 sensitivity profiling. Of note, while scCNV analysis also depicted a gain in 1q21 (chr1:149,940,001-169,980,001) MCL1 locus at the time of venetoclax resistance the acquisition of t(20,22) shifted the plasma cells dependency to BCL-xL rather than MCL1. This finding was corroborated by the plasma cells ex vivo resistance to dual BCL2 and MCL1 inhibition. Conclusion: Dynamic single cell epigenome and transcriptome profiling of pre- and post-venetoclax of primary plasma cells identified a de novo translocation driving BCL-xL transcription with the IGLL5 B-cell enhancer. This demonstrates that in addition to canonical TF-promoter regulation, restructuring of immunoglobulin regulatory sequences (i.e., enhancers) can also drive aberrant malignant circuitry endowing resistance to anti-BCL2 agents. Figure. Disclosures Neri: Celgene, Janssen: Consultancy, Honoraria, Research Funding. Bahlis:Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria.

Molecular Effects of Treatment of Human Colorectal Cancer Cells with Natural and Classical Chemotherapeutic Drugs: Alterations in the Expression of Apoptosis-related BCL2 Family Members, Including BCL2L12.

Current chemotherapy regimens for the treatment of colorectal cancer (CRC) include oxaliplatin, irinotecan, and fluorouracil along with leucovorin. Cytotoxicity involves the induction of programmed cell death. The purpose of this study was to assess the molecular effects of doxorubicin (a 14-OH derivative of the natural product daunorubicin) and common chemotherapeutic drugs (used in the clinical practice to treat CRC) on the expression of the most prominent members of the BCL2 family, namely BCL2, BAX, BCLX, and MCL1. Moreover, we sought to define the role of BCL2L12, another member of the BCL2 family, the apoptotic role of which is ambiguous. The MTT cell proliferation assay was used to determine the IC50 of each chemotherapeutic drug at 72 hours of treatment of Caco-2 and DLD-1 colorectal adenocarcinoma cell lines. Real-time PCR was used to quantify the antiapoptotic BCL2-α, BLCX-L, and MCL1-L transcripts, the proapoptotic BAX, BLCX-S, BLCX-ES, MCL1-S, and MCL1-ES transcripts, and BCL2L12 expression in relation to GAPDH mRNA levels. We constructed growth curves of Caco-2 and DLD-1 cells and determined the IC50 of each drug at 72 hours of treatment. Significant alterations in the expression levels of the studied BCL2 family genes and/or particular transcripts were observed. The intrinsic apoptotic pathway is activated during treatment of CRC cells with common chemotherapeutic drugs. Moreover, BCL2L12 mRNA expression increases progressively during treatment, similarly to the expression of other BCL2 family genes favoring apoptosis and/or particular proapoptotic transcripts, thus suggesting a proapoptotic role for BCL2L12 in chemotherapy-treated CRC cells.

Bcl2L12 mediates effects of protease-activated receptor-2 on the pathogenesis of Th2-dominated responses of patients with ulcerative colitis

The immune dysregulation plays an important role in the pathogenesis of ulcerative colitis (UC). Bcl2 like protein-12 (Bcl2L12) and mast cells are involved in immune dysregulation of UC. This study aims to elucidate the role of Bcl2L12 in the contribution to the pathogenesis of T helper (Th)2-biased inflammation in UC patients. The results showed that Bcl2L12 was expressed by peripheral CD4+ T cells that was associated with Th2 polarization in UC patients. Bcl2L12 mediated the protease-activated receptor-2 (PAR2)-induced IL-4 expression in CD4+ cells. Activation of PAR2 increased expression of Bcl2L12 in CD4+ T cells. Bcl2L12 mRNA decayed spontaneously in CD4+ T cells after separated from UC patients which was prevented by activating PAR2. Bcl2L12 mediated the binding between GATA3 and the Il4 promoter in CD4+ T cells. Mice with Bcl2L12 deficiency failed to induce Th2-biased inflammation in the colon mucosa. We conclude that CD4+ T cells from UC patients expressed high levels of Bcl2L12; the latter plays an important role in the development of Th2-biased inflammation in the intestine. Bcl2L12 may be a novel therapeutic target in the treatment of Th2-biased inflammation.

Repression of GRIM19 expression potentiates cisplatin chemoresistance in advanced bladder cancer cells via disrupting ubiquitination-mediated Bcl-xL degradation.

The mainstay of treatment for advanced bladder cancer (BC) is cisplatin (CDDP)-based systematic chemotherapy. However, acquired chemoresistance induced by as yet unidentified mechanisms is encountered frequently and often results in treatment failure and disease progression. The present study was designed to elucidate the expression and potential role of the gene associated with retinoid-interferon-induced mortality-19 (GRIM19) in the pathogenesis of CDDP resistance in BC. RT-qPCR and immunoblotting were employed to evaluate the expression profile of GRIM19 in clinical BC samples and in different BC cells. Using cell viability assay, apoptotic ELISA, xenografts mouse model, and Transwell assay, the effects of GRIM19 inhibition or GRIM19 overexpression on CDDP resistance were determined in different BC cells. Lastly, using co-immunoprecipitation, we provided the molecular evidence for the interaction between GRIM19 and Bcl-xL. Expression levels of GRIM19 were significantly down-regulated in recurrent BC specimens, and in experimentally induced CDDP-resistant BC cells. Functionally, overexpression of the exogenous GRIM19 potentiated CDDP sensitivity and suppressed the survival and invasion of BC cells in the presence of CDDP challenge. Mechanistically, the compromised CDDP chemosensitization induced by GRIM19 loss was at least partially attributed to the attenuation of Bcl-xL polyubiquitination and subsequent degradation, because (1) GRIM19 colocalized with Bcl-xL in the mitochondria of BC cells and (2) GRIM19 overexpression promoted the ubiquitination of Bcl-xL, and this event could be effectively reversed by pretreatment with inhibitors of p38-MAPK and JNK pathways, indicating that GRIM19 overexpression-induced Bcl-xL ubiquitination may achieve in a p38/JNK-dependent manner. Using the UMUC-3 cells stably depleted of endogenous GRIM19, we further show that inhibition of Bcl-xL rectified GRIM19 deficiency-caused CDDP resistance in BC cells. In addition, BCL2L1 mRNA levels were negatively correlated with GRIM19 mRNA levels in CDDP-associated clinical BC tissues. Disruption of GRIM19/Bcl-xL is a key mechanism of CDDP resistance in advanced BC. Therapeutically, enhancement of GRIM19 expression or employment of p38/JNK inhibitors may serve as resensitizing therapies for subgroups of CDDP-resistant or refractory BC patients.

MiR-1266-5p and miR-185-5p Promote Cell Apoptosis in Human Prostate Cancer Cell Lines

Objective:Small non-coding RNA molecules are dysregulated in prostate cancer (PCa). In our previous study, downregulation of miR-1266 and miR-185 was demonstrated in PCa tissues and cell lines. The aim of the present study was to investigate whether miR-1266 and miR-185 are involved in the regulation of B-cell lymphoma (BCL) 2 and BCL2L1, respectively, and whether transfection of PCa cell lines with miR-1266 and miR-185 mimics can alter tumorigenic phenotypes.Methods:In order to investigate the regulation of BCL2 and BCL2L1 mRNA levels by miR-1266 and miR-185, respectively, a luciferase reporter assay was used. Real-time PCR was also used to analyze changes in the levels of BCL2 and BCL2L1 mRNAs in PCa cell lines following transfection with synthetic miR-1266 and miR-185. Cell apoptosis was determined by Annexin V protein expression analysis via flow cytometry. In addition to the MTT assay, a cell proliferation assay was performed.Result:A luciferase assay confirmed that the BCL2 and BCL2L1 genes may be targeted by miR-1266 and miR-185, respectively, through binding to their 3′UTR regions. Transfection of PC3 and DU145 cells with miR-1266 and miR-185 induced apoptosis and reduced proliferation, which also revealed an inverse correlation with BCL2 and BCL2L1 gene expression in the treated cells.Conclusion:Our data suggests that miR-1266 and miR-185 may be novel candidates for further research in PCa treatment through the anti-apoptotic pathway.

MiR-182-5p regulates BCL2L12 and BCL2 expression in acute myeloid leukemia as a potential therapeutic target

The importance of microRNAs (miRNAs) are shown during various cancers including acute myeloid leukemia (AML). MiR-182-5p functions as an oncogene or a potential suppressive miRNA in cancers, but its expression and function in AML is unknown. The purpose is to investigate the roles of miR-182-5p in AML in this study. MiR-182-5p was examined in the blood samples of AML and it was found that miR-182-5p expression levels were higher in AML tissues than it in their normal controls, so did in the AML cells. BCL2L12 and BCL2 were predicted as target genes of miR-182-5p and verified using luciferase reporter assay. BCL2L12 and BCL2 mRNA and protein levels were up-regulated in the AML cells with miR-182-5p inhibition. Cellular function of miR-182-5p indicated that miR-182-5p suppression in AML cells could decrease cell proliferation and reverse cisplatin (DDP) resistance via targeting BCL2L12 and BCL2 expression. Inhibition of miR-182-5p promoted AML cell apoptosis by targeting BCL2 or BCL2L12. The study demonstrates that high levels of miR-182-5p in AML promotes cell proliferation and suppresses cell apoptosis by targeting BCL2L12 and BCL2.

Retinoic-acid-orphan-receptor-C inhibition suppresses Th17 cells and induces thymic aberrations.

Retinoic-acid-orphan-receptor-C (RORC) is a master regulator of Th17 cells, which are pathogenic in several autoimmune diseases. Genetic Rorc deficiency in mice, while preventing autoimmunity, causes early lethality due to metastatic thymic T cell lymphomas. We sought to determine whether pharmacological RORC inhibition could be an effective and safe therapy for autoimmune diseases by evaluating its effects on Th17 cell functions and intrathymic T cell development. RORC inhibitors effectively inhibited Th17 differentiation and IL-17A production, and delayed-type hypersensitivity reactions. In vitro, RORC inhibitors induced apoptosis, as well as Bcl2l1 and BCL2L1 mRNA downregulation, in mouse and nonhuman primate thymocytes, respectively. Chronic, 13-week RORC inhibitor treatment in rats caused progressive thymic alterations in all analyzed rats similar to those in Rorc-deficient mice prior to T cell lymphoma development. One rat developed thymic cortical hyperplasia with preneoplastic features, including increased mitosis and reduced IKAROS expression, albeit without skewed T cell clonality. In summary, pharmacological inhibition of RORC not only blocks Th17 cell development and related cytokine production, but also recapitulates thymic aberrations seen in Rorc-deficient mice. While RORC inhibition may offer an effective therapeutic principle for Th17-mediated diseases, T cell lymphoma with chronic therapy remains an apparent risk.

Melatonin inhibits apoptosis and improves the developmental potential of vitrified bovine oocytes.

Vitrification of oocytes has been shown to be closely associated with increased levels of reactive oxygen species (ROS) and apoptotic events. However, little information is available the effect of melatonin on the ROS levels and apoptotic events in vitrified oocytes. Therefore, we studied the effect of melatonin on ROS and apoptotic events in vitrified bovine oocytes by supplementing vitrification solution or in vitro maturation (IVM) and vitrification solution with 10(-9) m melatonin. We analyzed the ROS, mitochondrial Ca(2+) (mCa(2+) ) and membrane potential (ΔΨm), externalization of phosphatidylserine (PS), caspase-3 activation, DNA fragmentation, mRNA expression levels of Bax and Bcl2 l1, and developmental potential of vitrified bovine oocytes. Vitrified bovine oocytes exhibited increased levels of ROS, mCa(2+) , Bax mRNA, and caspase-3 protein and higher rates of PS externalization and DNA fragmentation, and decreased ΔΨm and Bcl2 l1 mRNA expression level. However, melatonin supplementation in vitrification solution or IVM and vitrification solution significantly decreased the levels of ROS, mCa(2+) , Bax mRNA expression, and caspase-3 protein, and PS externalization and DNA fragmentation rates, and increased the ΔΨm and Bcl2 l1 mRNA expression level in vitrified oocytes, resulting in an increased developmental ability of vitrified bovine oocytes after parthenogenetic activation. The developmental ability of vitrified oocytes with melatonin supplementation in IVM and vitrification solution was similar to that of fresh ones. This study showed that supplementing the IVM and vitrification medium or vitrification medium with 10(-9) m melatonin significantly decreased the ROS level and inhibited apoptotic events of vitrified bovine oocytes, consequently increasing their developmental potential.

Differential roles of Bcl2L12 and its short variant in breast cancer lymph node metastasis.

Bcl2L12 plays a role in post-mitochondrial apoptosis through multiple mechanisms involving p53, αB-crystallin, caspase-3 and -7 in glioblastoma. Bcl2L12 is reported to be a good prognostic marker in breast cancer and correlated with ER and Bcl2 expression status. However, the mechanisms by which Bcl2L12 regulates apoptosis in breast cancer (BCa) remain unknown. Recent studies have shown that Bcl2L12 expression is a useful biomarker in other types of cancer. Thus, we examined whether Bcl2L12 and Bcl2L12A mRNA were associated with breast cancer progression or a specific subtype. In total, 106 paraffin-embedded, different stage breast cancer specimens were prepared and quantified for Bcl2L12 and Bcl2L12A expression by PCR. The correlation between Bcl2L12 and Bcl2L12A mRNA levels and clinicopathological characteristics was statistically analyzed. The results showed that Bcl2L12 and Bcl2L12A mRNA expression was not significantly different across the different stage, grade and TNM classification groups (P>0.005). Using linear regression, Bcl2L12 mRNA was associated with Bcl2L12A mRNA, grade 3 tumor and the triple-negative breast cancer (TNBC) subtype. In non-TNBC specimens, Bcl2L12 mRNA was only correlated with Bcl2L12A mRNA. Bcl2L12A mRNA was positively associated with Bcl2L12 mRNA and the number of lymph node metastases, but negatively correlated with staging in the non-TNBC group. Specifically, Bcl2L12, but not Bcl2L12A, mRNA was significantly higher in TNBC and grade 3 tumors, respectively. In non-TNBC, Bcl2L12A mRNA was significantly highly expressed in tumors with ≥ 12 metastatic lymph nodes. Bcl2L12 and its variant mRNA were highly expressed in carcinoma in situ (CIS) samples. In addition, they were estimated to be correlated with the total sample and non-TNBC, but not the TNBC group. In summary, a high Bcl2L12 mRNA expression was associated with the high-grade BCa and TNBC subtype. In addition, the interplay between Bcl2L12 and its variant may be associated with high lymph node metastasis in non-TNBC tumors.

BCL2L12: A promising molecular prognostic biomarker in breast cancer

ObjectivesBCL2-like 12 (BCL2L12) is a new member of the BCL2 gene family that was discovered and cloned by members of our group and found to be expressed in the mammary gland. Many genes of the BCL2 family were found to be implicated in breast carcinogenesis and to serve as possible prognostic markers. The aim of the present study was the quantification of BCL2L12 mRNA expression in order to assess its value as a prognostic tissue biomarker in breast cancer (BC). Design and methodsBCL2L12 mRNA levels were determined in a statistically significant sample size of cancerous (N=108) and adjacent non-cancerous (N=71) breast tissues using a highly sensitive quantitative real-time polymerase chain reaction (qRT-PCR) method. Relative quantification analysis was conducted using the comparative CT (2−ΔΔCT) method, whereas the association between BCL2L12 expression and clinopathological data, disease-free survival (DFS) and overall survival (OS) were estimated by statistical analysis. ResultsBCL2L12 mRNA expression was decreased in malignant samples compared to the histologically normal counterparts (p=0.012). Significant relationships between BCL2L12 expression and TNM stages (p=0.009), metastatic potential (p=0.012), tumor size (p=0.04) and age (p=0.024) were observed. Moreover, Kaplan–Meier and Cox univariate analyses indicated that BCL2L12 expression is associated with longer DFS, whereas multivariate analysis pointed out the independent favorable prognostic value of BCL2L12. ConclusionsAccording to our results, BCL2L12 mRNA expression is a favorable prognostic marker of DFS for BC patients, suggesting its possible application as a novel prognostic indicator of this malignancy.

Spherical nucleic acids for precision medicine

Spherical nucleic acids for precision medicine

Spherical Nucleic Acid Nanoparticle Conjugates as an RNAi-Based Therapy for Glioblastoma

Glioblastoma multiforme (GBM) is a neurologically debilitating disease that culminates in death 14 to 16 months after diagnosis. An incomplete understanding of how cataloged genetic aberrations promote therapy resistance, combined with ineffective drug delivery to the central nervous system, has rendered GBM incurable. Functional genomics efforts have implicated several oncogenes in GBM pathogenesis but have rarely led to the implementation of targeted therapies. This is partly because many "undruggable" oncogenes cannot be targeted by small molecules or antibodies. We preclinically evaluate an RNA interference (RNAi)-based nanomedicine platform, based on spherical nucleic acid (SNA) nanoparticle conjugates, to neutralize oncogene expression in GBM. SNAs consist of gold nanoparticles covalently functionalized with densely packed, highly oriented small interfering RNA duplexes. In the absence of auxiliary transfection strategies or chemical modifications, SNAs efficiently entered primary and transformed glial cells in vitro. In vivo, the SNAs penetrated the blood-brain barrier and blood-tumor barrier to disseminate throughout xenogeneic glioma explants. SNAs targeting the oncoprotein Bcl2Like12 (Bcl2L12)--an effector caspase and p53 inhibitor overexpressed in GBM relative to normal brain and low-grade astrocytomas--were effective in knocking down endogenous Bcl2L12 mRNA and protein levels, and sensitized glioma cells toward therapy-induced apoptosis by enhancing effector caspase and p53 activity. Further, systemically delivered SNAs reduced Bcl2L12 expression in intracerebral GBM, increased intratumoral apoptosis, and reduced tumor burden and progression in xenografted mice, without adverse side effects. Thus, silencing antiapoptotic signaling using SNAs represents a new approach for systemic RNAi therapy for GBM and possibly other lethal malignancies.

Abstract B071: Targeting the antiapoptotic protein Mcl-1 in luminal B breast cancers

Abstract In an effort to improve therapeutic tumor cell killing in luminal B breast cancers, we are investigating the combination of endocrine therapies with targeted inhibition of pro-survival proteins of the Bcl2 family, including Bcl2, Bcl-xL, and Mcl-1. Bcl2-family proteins are often overexpressed in breast cancers and are associated with tumor progression, therapeutic resistance, and poor patient survival. These proteins function by sequestering pro-apoptotic BH3-only proteins (BIM, BID, Noxa and Puma), thus inhibiting caspase-dependent apoptosis. We found Mcl1 gene amplification in 15/133 luminal B breast tumors (11%) curated through the Cancer Genome Atlas (TCGA), and Bcl2l1 (encoding Bcl-xL) gene amplification in 1/133 luminal B breast tumors, although Bcl2l1 mRNA was upregulated in 19/133 samples. Bcl2 was not amplified or overexpressed in TCGA-curated luminal B breast tumors. The BH3 mimetic ABT-263, which specifically binds Bcl2 and Bcl-xL, increased tumor cell killing in 3 out of 4 estrogen-deprived luminal B human breast cancer cell lines. However, ZR75-1 cells, which are Mcl1 gene amplified, were resistant to ABT-263. Further, Mcl-1 protein upregulation was induced in HCC-1428 and T47D cells treated with ABT-263, suggesting that cells may use Mcl-1 upregulation to partially mitigate the effects of Bcl-xL targeting with ABT-263. Mcl-1 knockdown using an shRNA approach, decreased cell growth and increased caspase-dependent apoptosis, and increased sensitivity to ABT-263 in 4 of the 4 cell lines tested, including ZR75-1 cells. We used long-term estrogen withdrawal (LTED) to model the sustained response of breast cancer cells to aromatase inhibitors (e.g., exemestane). As compared to parental breast cancer cell lines under estrogen withdraw conditions, LTED populations drastically increased protein levels of Mcl-1. Future experiments will be aimed at assessing the impact of Mcl-1 depletion on ABT-263-treated LTED populations. We predict that combined inhibition of Bcl-2, Bcl-xL and Mcl-1 will improve response of cells to estrogen deprivation. In summary, these preliminary studies suggest that BH3 mimetics targeting Bcl-2 family proteins may be therapeutically efficacious in endocrine-refractory luminal B breast tumors, and support future endeavors to generate BH3-mimetics specifically targeting Mcl-1. Citation Format: Michelle M. Williams, Steve Fesik, Donna Hicks, Rebecca S. Cook. Targeting the antiapoptotic protein Mcl-1 in luminal B breast cancers. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B071.

Expression of Bcl2L12 in chronic lymphocytic leukemia patients: association with clinical and molecular prognostic markers

Dysregulation of apoptosis is a distinctive feature of chronic lymphocytic leukemia (CLL), although a unique mechanism underlying apoptosis resistance of CLL B lymphocytes has not been identified yet. Aberrant expression as well as genetic and epigenetic alterations of numerous genes involved in different pathways of apoptosis regulation has been described in CLL. Here, we report the expression analysis of Bcl2L12 (Bcl2-like 12), a novel apoptotic gene belonging to Bcl2 family, in 58 Serbian CLL patients. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) analysis revealed a significant overexpression of Bcl2L12 mRNA in CLL samples compared to non-leukemic samples, implying its role in the pathogenesis of the disease. Receiver operating characteristic (ROC) analysis showed that Bcl2L12 expression efficiently discriminates CLL cases from healthy controls. However, relatively homogenous Bcl2L12 mRNA expression among patients did not reflect their clinical characteristics (with the exception of lactate dehydrogenase status and time from diagnosis to treatment) and failed to show association with the most informative prognostic markers, namely the mutational status of rearranged immunoglobulin heavy chain variable region genes, CD38 and lipoprotein lipase gene (LPL) expression.

Malign Plevral Mezotelyoma Hücre Hattında Histon Asetil Transferaz İnhibitörü Olan Anakardik Asitin Sisplatin Cevabını Arttırıcı Etkisi

Objective: Various signaling pathways that play important roles in cell proliferation, translation, energy production, cytoskeleton re-organization and angiogenesis are thought to be effective during the de - velopment of malignant pleural mesothelioma (MPM). In recent years, it has been shown that epigenetic changes involving histon modifications play important roles in the development of cancer and may also lead to emergence of MPM. Currently, more effective treatment options have been investigated by combining new molecules with the classic chemotherapy agents. One of these molecules is anacardic acid (AA), which is a histone acetyl transferase (HAT) inhibitor. In our study, we aimed to determine the effects of AA and cisplatin (CDDP) combination on cMYC, NFK B, FOXO3A and BCL2L1 mRNA expression in MPM cell line (MSTO-211H: biphasic). Material and Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bro - mide test was performed to determine the effect of cisplatin and AA on cell viability. RNA isolation was performed after the treatment with selected appropriate doses of the cells. cMYC, NFK B, FOXO3A and BCL2L1 mRNA expression levels were determined by quantitative real-time polymeras4e chain reaction method from isolated RNA. Results: We determined that CDDP doses higher than 10 μM were effective on MSTO-211H cells. Cell viability in the group AA+CDDP was lower than the CDDP alone group. Pretreat - ment with AA caused a significant decline in the mRNA expression levels of investigated genes compared to CDDP alone in MSTO-211H cells. Conclusion: Our data demonstrate that pretreatment with AA lead to an effective cell death response by making cells more susceptible to CDDP, a classical chemotherapeutic agent. This preclinical study emphasizes the importance of epigenetic changes in the development of MPM.