Gene Summary

Gene:BIRC3; baculoviral IAP repeat containing 3
Aliases: AIP1, API2, MIHC, CIAP2, HAIP1, HIAP1, MALT2, RNF49, c-IAP2
Summary:This gene encodes a member of the IAP family of proteins that inhibit apoptosis by binding to tumor necrosis factor receptor-associated factors TRAF1 and TRAF2, probably by interfering with activation of ICE-like proteases. The encoded protein inhibits apoptosis induced by serum deprivation but does not affect apoptosis resulting from exposure to menadione, a potent inducer of free radicals. It contains 3 baculovirus IAP repeats and a ring finger domain. Transcript variants encoding the same isoform have been identified. [provided by RefSeq, Aug 2011]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:baculoviral IAP repeat-containing protein 3
Source:NCBIAccessed: 09 March, 2017


What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 09 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 09 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (8)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: BIRC3 (cancer-related)

Hatem J, Schrank-Hacker AM, Watt CD, et al.
Marginal zone lymphoma-derived interfollicular diffuse large B-cell lymphoma harboring 20q12 chromosomal deletion and missense mutation of BIRC3 gene: a case report.
Diagn Pathol. 2016; 11(1):137 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) typically leads to effacement of the nodal architecture by an infiltrate of malignant cells. Rarely (<1%), DLBCL can present with an interfollicular pattern (DLBCL-IF) preserving the lymphoid follicles. It has been postulated that DLBCL-IF is derived from marginal zone B cells and may represent a large-cell transformation of marginal zone lymphoma (MZL), however no direct evidence has been provided to date. Here we describe a rare case of a diagnostically challenging DLBCL-IF involving a lymph node in a patient with a prior history of lymphadenopathy for several years and MZL involving skin.
CASE PRESENTATION: A 53-year old man presented to our Dermatology Clinic due to a 1-year history of generalized itching, fatigue of 2-3 month's duration, nausea and mid back rash that was biopsied. PET (positron emission tomography)/CT (computed tomography) was performed and revealed inguinal, pelvic, retroperitoneal, axillary, and cervical lymphadenopathy. The patient was referred to surgery for excisional biopsy of a right inguinal lymph node. Diagnostic H&E stained slides and ancillary studies were reviewed for the lymph node and skin specimens. B-cell clonality by PCR and sequencing studies were performed on both specimens. We demonstrate that this patient's MZL and DLBCL-IF are clonally related, strongly suggesting that transformation of MZL to DLBCL had occurred. Furthermore, we identified a novel deletion of the long arm of chromosome 20 (del(20q12)) and a missense mutation in BIRC3 (Baculoviral IAP repeat-containing protein 3) in this patient's DLBCL that are absent from his MZL, suggesting that these genetic alterations contributed to the large cell transformation.
CONCLUSIONS: To our knowledge, this is the first report providing molecular evidence for a previously suspected link between MZL and DLBCL-IF. In addition, we describe for the first time del(20q12) and a missense mutation in BIRC3 in DLBCL. Our findings also raise awareness of DLBCL-IF and discuss the diagnostic pitfalls of this rare entity.

Jagadish N, Gupta N, Agarwal S, et al.
Sperm-associated antigen 9 (SPAG9) promotes the survival and tumor growth of triple-negative breast cancer cells.
Tumour Biol. 2016; 37(10):13101-13110 [PubMed] Related Publications
Recently, we demonstrated the association of sperm-associated antigen 9 (SPAG9) expression with breast cancer. Among breast cancer, 15 % of the cancers are diagnosed as triple-negative breast cancers (TNBC) based on hormone receptor status and represent an important clinical challenge because of lack of effective available targeted therapy. Therefore, in the present investigation, plasmid-based small hairpin (small hairpin RNA (shRNA)) approach was used to ablate SPAG9 in aggressive breast cancer cell line model (MDA-MB-231) in order to understand the role of SPAG9 at molecular level in apoptosis, cell cycle, and epithelial-to-mesenchymal transition (EMT) signaling. Our data in MDA-MB-231 cells showed that ablation of SPAG9 resulted in membrane blebbing, increased mitochondrial membrane potential, DNA fragmentation, phosphatidyl serine surface expression, and caspase activation. SPAG9 depletion also resulted in cell cycle arrest in G0-G1 phase and induced cellular senescence. In addition, in in vitro and in vivo xenograft studies, ablation of SPAG9 resulted in upregulation of p21 along with pro-apoptotic molecules such as BAK, BAX, BIM, BID, NOXA, AIF, Cyto-C, PARP1, APAF1, Caspase 3, and Caspase 9 and epithelial marker, E-cadherin. Also, SPAG9-depleted cells showed downregulation of cyclin B1, cyclin D1, cyclin E, CDK1, CDK4, CDK6, BCL2, Bcl-xL, XIAP, cIAP2, MCL1, GRP78, SLUG, SNAIL, TWIST, vimentin, N-cadherin, MMP2, MMP3, MMP9, SMA, and β-catenin. Collectively, our data suggests that SPAG9 promotes tumor growth by inhibiting apoptosis, altering cell cycle, and enhancing EMT signaling in in vitro cells and in vivo mouse model. Hence, SPAG9 may be a potential novel target for therapeutic use in TNBC treatment.

Yang Y, Kelly P, Shaffer AL, et al.
Targeting Non-proteolytic Protein Ubiquitination for the Treatment of Diffuse Large B Cell Lymphoma.
Cancer Cell. 2016; 29(4):494-507 [PubMed] Related Publications
Chronic active B cell receptor (BCR) signaling, a hallmark of the activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), engages the CARD11-MALT1-BCL10 (CBM) adapter complex to activate IκB kinase (IKK) and the classical NF-κB pathway. Here we show that the CBM complex includes the E3 ubiquitin ligases cIAP1 and cIAP2, which are essential mediators of BCR-dependent NF-κB activity in ABC DLBCL. cIAP1/2 attach K63-linked polyubiquitin chains on themselves and on BCL10, resulting in the recruitment of IKK and the linear ubiquitin chain ligase LUBAC, which is essential for IKK activation. SMAC mimetics target cIAP1/2 for destruction, and consequently suppress NF-κB and selectively kill BCR-dependent ABC DLBCL lines, supporting their clinical evaluation in patients with ABC DLBCL.

Kim SH, Ho JN, Jin H, et al.
Upregulated expression of BCL2, MCM7, and CCNE1 indicate cisplatin-resistance in the set of two human bladder cancer cell lines: T24 cisplatin sensitive and T24R2 cisplatin resistant bladder cancer cell lines.
Investig Clin Urol. 2016; 57(1):63-72 [PubMed] Free Access to Full Article Related Publications
PURPOSE: The mechanism of resistance to cisplatin during treatment of bladder cancer (BC) has been a subject of intense investigation in clinical research. This study aims to identify candidate genes associated with resistance to cisplatin, in order to understand the resistance mechanism of BC cells to the drug, by combining the use of microarray profiling, quantitative reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analyses.
MATERIALS AND METHODS: The cisplatin sensitive human BC cell line (T24) and the cisplatin resistant BC cell line, T24R2, were used for microarray analysis to determine the differential expression of genes that are significant in cisplatin resistance. Candidate upregulated genes belonging to three well-known cancer-related KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways (p53 tumor suppressor, apoptosis, and cell cycle) were selected from the microarray data. These candidate genes, differentially expressed in T24 and T24R2, were then confirmed by quantitative RT-PCR and western blot. A fold change ≥2 with a p-value <0.05 was considered significant.
RESULTS: A total of 18 significantly upregulated genes were detected in the three selected cancer-related pathways in both microarray and RT-PCR analyses. These genes were PRKAR2A, PRKAR2B, CYCS, BCL2, BIRC3, DFFB, CASP6, CDK6, CCNE1, STEAP3, MCM7, ORC2, ORC5, ANAPC1, and ANAPC7, CDC7, CDC27, and SKP1. Western blot analyses also confirmed the upregulation of BCL2, MCM7, and CCNE1 at the protein level, indicating their crucial association with cisplatin resistance.
CONCLUSIONS: The BCL2, MCM7, and CCNE1 genes might play distinctive roles in cisplatin resistance in BC.

Gerges S, Rohde K, Fulda S
Cotreatment with Smac mimetics and demethylating agents induces both apoptotic and necroptotic cell death pathways in acute lymphoblastic leukemia cells.
Cancer Lett. 2016; 375(1):127-32 [PubMed] Related Publications
Treatment resistance in acute lymphoblastic leukemia (ALL) is often caused by defects in programmed cell death, e.g. by overexpression of Inhibitor of Apoptosis (IAP) proteins. Here, we report that small-molecule Smac mimetics (i.e. BV6, LCL161, birinapant) that neutralize x-linked IAP (XIAP), cellular IAP (cIAP)1 and cIAP2 cooperate with demethylating agents (i.e. 5-azacytidine (5AC) or 5-aza-2'-deoxycytidine (DAC)) to induce cell death in ALL cells. Molecular studies reveal that induction of cell death is preceded by BV6-mediated depletion of cIAP1 protein and involves tumor necrosis factor (TNF)α autocrine/paracrine signaling, since the TNFα-blocking antibody Enbrel significantly reduces BV6/5AC-induced cell death. While BV6/5AC cotreatment induces caspase-3 activation, the broad-range caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) only partly rescues ALL cells from BV6/5AC-induced cell death. This indicates that BV6/5AC cotreatment engages non-apoptotic cell death upon caspase inhibition. Indeed, genetic silencing of key components of necroptosis such as Receptor-Interacting Protein (RIP)3 or mixed lineage kinase domain-like (MLKL) in parallel with administration of zVAD.fmk provides a significantly better protection against BV6/5AC-induced cell death compared to the use of zVAD.fmk alone. Similarly, concomitant administration of pharmacological inhibitors of necroptosis (i.e. necrostatin-1s, GSK'872, dabrafenib, NSA) together with zVAD.fmk is superior in rescuing cells from BV6/5AC-induced cell death compared to the use of zVAD.fmk alone. These findings demonstrate that in ALL cells BV6/5AC-induced cell death is mediated via both apoptotic and necroptotic pathways. Importantly, BV6/5AC cotreatment triggers necroptosis in ALL cells that are resistant to apoptosis due to caspase inhibition. This opens new perspectives to overcome apoptosis resistance with important implications for the development of new treatment strategies for ALL.

Cheng X, Shi W, Zhao C, et al.
Triptolide sensitizes human breast cancer cells to tumor necrosis factor‑α‑induced apoptosis by inhibiting activation of the nuclear factor‑κB pathway.
Mol Med Rep. 2016; 13(4):3257-64 [PubMed] Related Publications
Tumor necrosis factor‑α (TNF‑α) can act as either a tumor promoter, linking inflammation with carcinogenesis, or a tumor inhibitor, inducing cancer cell death. However, several types of cancer, including breast cancer, are resistant to TNF‑α therapy. Triptolide, a diterpene triepoxide, has been reported to exert anti‑inflammatory and antiproliferative effects, associated with the inhibition of nuclear factor‑κB (NF‑κB). The present study investigated the effects of triptolide sensitization on human breast cancer cells to TNF‑α‑induced apoptosis by inhibiting activation of the NF‑κB pathway. Human breast cancer MDA‑MB‑231 cells and MCF‑7 cells were treated with different concentrations of triptolide, with or without 10 ng/ml TNF‑α, for different durations, followed by measurement of cell proliferation using a 3‑[4,5‑dimethyltiazol‑2‑yl]‑2.5‑diphenyl‑tetrazolium bromide assay, apoptosis induction, through determination of caspase‑3 activity and poly (ADP‑ribose) polymerase (PARP) cleavage, and NF‑κB pathway activation, through determination of inhibitor of NF‑κB (IκB) and the NF‑κB downstream genes, X‑linked inhibitor of apoptosis protein (XIAP) and cellular inhibitor of apoptosis protein1/2 (cIAP1/2)] using Western blot and reverse transcription‑quantitative polymerase chain reaction analyses. TNF‑α, when combined with triptolide, was observed to inhibit the activation of IκBα, increase the level of cleaved PARP, and further activate caspase‑3 in the breast cancer cells. Triptolide also inhibited the expression levels of the downstream anti‑apoptotic genes of NF‑κB activation, XIAP and cIAP1/2. The results of the present study demonstrated that triptolide sensitized human breast cancer cells to TNF‑α‑induced apoptosis, which may provide a promising combination strategy for human breast cancer therapeutics.

Tausch E, Mertens D, Stilgenbauer S
Genomic Features: Impact on Pathogenesis and Treatment of Chronic Lymphocytic Leukemia.
Oncol Res Treat. 2016; 39(1-2):34-40 [PubMed] Related Publications
Genomic markers are among the strongest prognostic factors in chronic lymphocytic leukemia (CLL). Chromosomal aberrations, IGHV and TP53 mutation status are well-established and essential to discriminate between a more indolent course of disease and a high-risk CLL, which requires an alternative treatment regimen. In addition, a variety of gene mutations with unclear prognostic value have been identified: SF3B1, ATM, and BIRC3 may describe CLL with adverse outcome, whereas NOTCH1 is predictive for resistance against CD20 antibodies. Integration of novel drivers into a small set of key pathways forms the basis for future pathogenetic and therapeutic implications.

Wang D, Berglund A, Kenchappa RS, et al.
BIRC3 is a novel driver of therapeutic resistance in Glioblastoma.
Sci Rep. 2016; 6:21710 [PubMed] Free Access to Full Article Related Publications
Genome-wide analysis of glioblastoma (GBM) reveals pervasive aberrations in apoptotic signaling pathways that collectively contribute to therapeutic resistance. Inhibitors of apoptosis proteins (IAP) exert critical control on the terminal segment of apoptosis leading to apoptosis evasion. In this study, we uncover a unique role for BIRC3, as an IAP that is critical in GBM in response to therapy. Using the TCGA dataset of 524 unique samples, we identify BIRC3 is the only IAP whose differential expression is associated with long-term survival in GBM patients. Using patient tissue samples we further show that BIRC3 expression increases with recurrence. When extrapolated to a preclinical model of a human GBM cell line, we find an increase in BIRC3 expression in response to irradiation (RT) and temozolomide (TMZ) treatment. More importantly, we mechanistically implicate STAT3 and PI3K signaling pathways as drivers of RT-induced up-regulation of BIRC3 expression. Lastly, we demonstrate that both in-vivo and in-vitro BIRC3 up-regulation results in apoptosis evasion and therapeutic resistance in GBM. Collectively, our study identifies a novel translational and targetable role for BIRC3 expression as a predictor of aggressiveness and therapeutic resistance to TMZ and RT mediated by STAT3 and PI3K signaling in GBM.

Lu W, Ning H, Gu L, et al.
MCPIP1 Selectively Destabilizes Transcripts Associated with an Antiapoptotic Gene Expression Program in Breast Cancer Cells That Can Elicit Complete Tumor Regression.
Cancer Res. 2016; 76(6):1429-40 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
The ability of cancer cells to evade apoptosis is dictated by a shift in the balance between proapoptotic and antiapoptotic gene expression programs. Monocyte chemotactic protein-induced protein 1 (MCPIP1) is a zinc-finger RNA binding protein with important roles in mediating inflammatory responses. Overexpression of MCPIP1 in different cancer cell types has been implicated in eliciting an antitumor response, but a direct role of MCPIP1 in apoptosis has not been established. In this study, we demonstrate that MCPIP1 functions as a potent tumor suppressor that induces apoptosis of breast tumor cells by selectively enhancing mRNA decay of antiapoptotic gene transcripts, including Bcl2L1, Bcl2A1, RelB, Birc3, and Bcl3. Mechanistically, MCPIP1 physically interacted with a stem-loop structure in the 3' untranslated region of these transcripts through its PIN domain, causing mRNA destabilization. Furthermore, we found that MCPIP1 expression was repressed in breast tumor cells, and overexpression of MCPIP1 induced apoptosis, whereas its depletion enhanced cancer cell proliferation. Moreover, MCPIP1 induction in vivo resulted in complete regression of established tumors and a significant reduction in metastatic disease. Notably, low MCPIP1 expression in tumor samples from breast cancer patients was strongly associated with poor survival over 13 years of follow-up. Collectively, our results highlight that MCPIP1 is a new tumor suppressor in breast cancer that induces cell death by tipping the balance in favor of proapoptotic gene expression.

Gan H, Liu H, Zhang H, et al.
SHh-Gli1 signaling pathway promotes cell survival by mediating baculoviral IAP repeat-containing 3 (BIRC3) gene in pancreatic cancer cells.
Tumour Biol. 2016; 37(7):9943-50 [PubMed] Related Publications
The abnormally activated hedgehog (Hh) signaling pathway is involved in the regulation of proliferation and apoptosis in pancreatic cancer cells, while its exact molecular mechanism is not clear. The purpose of this study was to investigate the regulatory effect of Hh signaling pathway on the transcription of BIRC3 gene and its underlying mechanism in pancreatic cancer cells, as well as the relationship between the Gli1-dependent BIRC3 transcription and cell survival. Firstly, we examined the effect of knockdown or overexpression of Hh on BIRC3 messenger RNA (mRNA) expression by real-time RT-PCR. Then, the regulatory mechanism of Gli1 to BIRC3 gene transcription was investigated by XChIP-PCR and luciferase assays. Finally, the cell survival mediated by the Gli1-dependent BIRC3 transcription was studied by MTT and annexin V-FITC/propidiumiodide (PI) assays. We found that the expression level of BIRC3 mRNA was positively correlated to SHh/Gli1 signaling activation in three pancreatic cancer cell lines. The XChIP-PCR and luciferase assays data showed that the transcription factor Gli1 bound to some enhancers within the promoter regions of BIRC3 gene and promoted gene transcription. The cell proliferation was increased significantly by SHh/Gli1 expression while the apoptotic rate was reduced under the same condition. Moreover, BIRC3 knockdown inhibited cell proliferation and survival induced by SHh overexpression. Our study reveals that Gli1 promoted transcription of BIRC3 gene via cis-acting elements and the SHh-Gli1 signaling pathway maintained cell survival partially through this Gli1-dependent BIRC3 model in pancreatic cancer cells.

Baliakas P, Mattsson M, Stamatopoulos K, Rosenquist R
Prognostic indices in chronic lymphocytic leukaemia: where do we stand how do we proceed?
J Intern Med. 2016; 279(4):347-57 [PubMed] Related Publications
The remarkable clinical heterogeneity in chronic lymphocytic leukaemia (CLL) has highlighted the need for prognostic and predictive algorithms that can be employed in clinical practice to assist patient management and therapy decisions. Over the last 20 years, this research field has been rewarding and many novel prognostic factors have been identified, especially at the molecular genetic level. Whilst detection of recurrent cytogenetic aberrations and determination of the immunoglobulin heavy variable gene somatic hypermutation status have an established role in outcome prediction, next-generation sequencing has recently revealed novel mutated genes with clinical relevance (e.g. NOTCH1, SF3B1 and BIRC3). Efforts have been made to combine variables into prognostic indices; however, none has been universally adopted. Although a unifying model for all groups of patients and in all situations is appealing, this may prove difficult to attain. Alternatively, focused efforts on patient subgroups in the same clinical context and at certain clinically relevant 'decision points', that is at diagnosis and at initiation of first-line or subsequent treatments, may provide a more accurate approach. In this review, we discuss the advantages and disadvantages as well as the clinical applicability of three recently proposed prognostic models, the MD Anderson nomogram, the integrated cytogenetic and mutational model and the CLL-international prognostic index. We also consider future directions taking into account novel aspects of the disease, such as the tumour microenvironment and the dynamics of (sub)clonal evolution. These aspects are particularly relevant in view of the increasing number of new targeted therapies that have recently emerged.

Ljungström V, Cortese D, Young E, et al.
Whole-exome sequencing in relapsing chronic lymphocytic leukemia: clinical impact of recurrent RPS15 mutations.
Blood. 2016; 127(8):1007-16 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
Fludarabine, cyclophosphamide, and rituximab (FCR) is first-line treatment of medically fit chronic lymphocytic leukemia (CLL) patients; however, despite good response rates, many patients eventually relapse. Although recent high-throughput studies have identified novel recurrent genetic lesions in adverse prognostic CLL, the mechanisms leading to relapse after FCR therapy are not completely understood. To gain insight into this issue, we performed whole-exome sequencing of sequential samples from 41 CLL patients who were uniformly treated with FCR but relapsed after a median of 2 years. In addition to mutations with known adverse-prognostic impact (TP53, NOTCH1, ATM, SF3B1, NFKBIE, and BIRC3), a large proportion of cases (19.5%) harbored mutations in RPS15, a gene encoding a component of the 40S ribosomal subunit. Extended screening, totaling 1119 patients, supported a role for RPS15 mutations in aggressive CLL, with one-third of RPS15-mutant cases also carrying TP53 aberrations. In most cases, selection of dominant, relapse-specific subclones was observed over time. However, RPS15 mutations were clonal before treatment and remained stable at relapse. Notably, all RPS15 mutations represented somatic missense variants and resided within a 7 amino-acid, evolutionarily conserved region. We confirmed the recently postulated direct interaction between RPS15 and MDM2/MDMX and transient expression of mutant RPS15 revealed defective regulation of endogenous p53 compared with wild-type RPS15. In summary, we provide novel insights into the heterogeneous genetic landscape of CLL relapsing after FCR treatment and highlight a novel mechanism underlying clinical aggressiveness involving a mutated ribosomal protein, potentially representing an early genetic lesion in CLL pathobiology.

Liu L, Xu C, Hsieh JT, et al.
DAB2IP in cancer.
Oncotarget. 2016; 7(4):3766-76 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
DOC-2/DAB2 is a member of the disable gene family that features tumor-inhibiting activity. The DOC-2/DAB2 interactive protein, DAB2IP, is a new member of the Ras GTPase-activating protein family. It interacts directly with DAB2 and has distinct cellular functions such as modulating different signal cascades associated with cell proliferation, survival, apoptosis and metastasis. Recently, DAB2IP has been found significantly down regulated in multiple types of cancer. The aberrant alteration of DAB2IP in cancer is caused by a variety of mechanisms, including the aberrant promoter methylation, histone deacetylation, and others. Reduced expression of DAB2IP in neoplasm may indicate a poor prognosis of many malignant cancers. Moreover, DAB2IP stands for a promising direction for developing targeted therapies due to its capacity to inhibit tumor cell growth in vitro and in vivo. Here, we summarize the present understanding of the tumor suppressive role of DAB2IP in cancer progression; the mechanisms underlying the dysregulation of DAB2IP; the gene functional mechanism and the prospects of DAB2IP in the future cancer research.

Kobayashi T, Masaki T, Nozaki E, et al.
Microarray Analysis of Gene Expression at the Tumor Front of Colon Cancer.
Anticancer Res. 2015; 35(12):6577-81 [PubMed] Related Publications
Budding or the presence poorly differentiated clusters at the boundary of cancer tissue is a pathologically important finding and serves as a prognostic factor in colorectal cancer. However, few studies have examined the cancer tissue boundary in clinical samples. The purpose of the present study was to examine gene expression at the tumor front of colon cancer in surgically resected samples. Cancer tissues were obtained by laser microdissection of 20 surgically resected specimens. Genes with significantly different microarray signals between the tumor front and the tumor center were identified. Among genes showing significant up-regulation at the tumor front were six chemokines [chemokine c-c motif ligand (CCL)2 and -18, chemokine (C-X-C motif) ligand (CXCL)9-11, and interleukin 8 (IL8)], and two apoptosis-related molecules [ubiquitin D (UBD) and baculoviral iap repeat-containing 3 (BIRC3)]. Expression of laminin gamma 2 (LAMC2), matrix metallopeptidase 7 (MMP7) and epithelial-mesenchymal transition (EMT)-related molecules were elevated in the tumor front, but their fold changes were smaller than those of the aforementioned genes. These results suggest that chemokines, in addition to EMT-related molecules, may play important roles in invasion of colon cancer.

Hernández JÁ, Hernández-Sánchez M, Rodríguez-Vicente AE, et al.
A Low Frequency of Losses in 11q Chromosome Is Associated with Better Outcome and Lower Rate of Genomic Mutations in Patients with Chronic Lymphocytic Leukemia.
PLoS One. 2015; 10(11):e0143073 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
To analyze the impact of the 11q deleted (11q-) cells in CLL patients on the time to first therapy (TFT) and overall survival (OS), 2,493 patients with CLL were studied. 242 patients (9.7%) had 11q-. Fluorescence in situ hybridization (FISH) studies showed a threshold of 40% of deleted cells to be optimal for showing that clinical differences in terms of TFT and OS within 11q- CLLs. In patients with ≥40% of losses in 11q (11q-H) (74%), the median TFT was 19 months compared with 44 months in CLL patients with <40% del(11q) (11q-L) (P<0.0001). In the multivariate analysis, only the presence of 11q-L, mutated IGHV status, early Binet stage and absence of extended lymphadenopathy were associated with longer TFT. Patients with 11q-H had an OS of 90 months, while in the 11q-L group the OS was not reached (P = 0.008). The absence of splenomegaly (P = 0.02), low LDH (P = 0.018) or β2M (P = 0.006), and the presence of 11q-L (P = 0.003) were associated with a longer OS. In addition, to detect the presence of mutations in the ATM, TP53, NOTCH1, SF3B1, MYD88, FBXW7, XPO1 and BIRC3 genes, a select cohort of CLL patients with losses in 11q was sequenced by next-generation sequencing of amplicons. Eighty % of CLLs with 11q- showed mutations and fewer patients with low frequencies of 11q- had mutations among genes examined (50% vs 94.1%, P = 0.023). In summary, CLL patients with <40% of 11q- had a long TFT and OS that could be associated with the presence of fewer mutated genes.

Song Y, Peng X, Wang M, et al.
Gene expression profiling of taxol-resistant nasopharyngeal carcinoma cells with siRNA-mediated FOLR1 downregulation.
Int J Clin Exp Pathol. 2015; 8(9):11314-22 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
OBJECTIVES: Our previous study has shown that downregulation of FOLR1 by siRNA partially reversed taxol-resistant phenotype in taxol-resistant nasopharyngeal carcinoma cell lines. We aim to gain further insight into the molecular mechanisms of this process and identify the differentially expressed genes after FOLR1 downregulation.
METHOD: The global gene expression profile was identified and analyzed using the Affymetrix HG-U133 Plus 2.0 array.
RESULTS: There was a significant dysregulation in the global gene expression of the FOLR1-suppressed taxol-resistant nasopharyngeal carcinoma cell lines. There were 41 upregulated genes and 109 downregulated genes. QRT-PCR validation of the selected differentially expressed genes demonstrated there was a good correlation with the microarray analysis. There was a significant deregulation of expression in the apoptosis-related genes such as BIRC3, PRKX, TNFRSF10A and involved in Viral carcinogenesis, MAPK signaling pathways after FOLR1 was downregulated.
CONCLUSION: The suppression of FOLR1 by RNA interference altered gene expression profile of taxol-resistant nasopharyngeal carcinoma cell lines. The apoptosis-related genes and the gene alterations in viral carcinogenesis, MAPK signaling pathways might be important in FOLR1 siRNA-induced taxol-resistant reversal.

Jagadish N, Parashar D, Gupta N, et al.
A-kinase anchor protein 4 (AKAP4) a promising therapeutic target of colorectal cancer.
J Exp Clin Cancer Res. 2015; 34:142 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
BACKGROUND: Colorectal cancer (CRC) ranks third among the estimated cancer cases and cancer related mortalities in the Western world. Early detection and efficient therapy of CRC remains a major health challenge. Therefore, there is a need to identify novel tumor markers for early diagnosis and treatment of CRC.
METHODS: A-kinase anchor protein 4 (AKAP4) gene and protein expression was monitored by quantitative polymerase chain reaction (qPCR), reverse transcription (RT)-PCR and Western blotting in normal colon tissue lysate, normal colon epithelial cells and in colon cancer cell lines viz., Caco-2, COLO205, COLO320DM, HCT-15, HCT116, HT-29, SW480, and SW620. The effect of AKAP4 on cellular growth, migration and invasion abilities was studied using gene silencing approach. The role of AKAP4 in various pathways involved in cell cycle, apoptosis, senescence was investigated in in vitro and in human xenograft mouse model.
RESULTS: Our studies showed that AKAP4 gene and protein expression was expressed in all colon cancer cells while no expression was detectable in normal colon cells. Ablation of AKAP4 led to reduced cellular growth, migration, invasion and increased apoptosis and senescence of CRC cells in in vitro assays and tumor growth in human xenograft mouse. Human colon xenograft studies showed a significant decrease in the levels of cyclins B1, D and E and cyclin dependent kinases such as CDK1, CDK2, CDK4 and CDK6. Interestingly, an up-regulation in the levels of p16 and p21 was also observed. Besides, an increase in the levels of pro-apoptotic molecules AIF, APAF1, BAD, BID, BAK, BAX, PARP1, NOXA, PUMA and cyt-C and Caspase 3, 7, 8 and 9 was also found in cancer cells as well as in xenograft tissue sections. However, anti-apoptotic molecules BCL2, Bcl-xL, cIAP2, XIAP, Axin2 and Survivin were down regulated in these samples. Our data also revealed elevated expression of epithelial marker E-cadherin and down regulation of EMT markers N-cadherin, P-cadherin, SLUG, α-SMA, SNAIL, TWIST and Vimentin. Further ablation of AKAP4 resulted in the down regulation of invasion molecules matrix metalloproteinase MMP2, MMP3 and MMP9.
CONCLUSION: AKAP4 appears to be a novel CRC-associated antigen with a potential for developing as a new clinical therapeutic target.

Choung H, Kim YA, Kim N, et al.
Clinicopathologic Study of Chromosomal Aberrations in Ocular Adnexal Lymphomas of Korean Patients.
Korean J Ophthalmol. 2015; 29(5):285-93 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
PURPOSE: The incidence and clinical correlation of MALT1 translocation and chromosomal numerical aberrations in Korean patients with ocular adnexal mucosa associated lymphoid tissue (MALT) lymphoma have not yet been reported. We investigated the incidence and clinicopathologic relationship of these chromosomal aberrations in ocular adnexal MALT lymphomas in a Korean population.
METHODS: Thirty ocular adnexal MALT lymphomas were investigated for the t(11;18) API2-MALT1, t(14;18) IgH-MALT1 translocations and chromosomes 3 and 18 aneuploidies using fluorescence in situ hybridization. Patient medical records were reviewed retrospectively for information on demographics and clinical characteristics, including treatment response.
RESULTS: The MALT1 gene rearrangement was found in one out of 30 cases. The t(14;18) IgH-MALT1 translocation was demonstrated in only one case (3.3%), and the t(11;18) API2-MALT1 translocation was not found in any of the cases. Trisomy 3 was observed in three ocular adnexal MALT lymphomas (10.0%), and five cases showed trisomy 18 (16.7%). Translocation positive cases also showed trisomy 18. One case of tumor relapse showed trisomy 18 only in the recurrent biopsies. There were no statistically significant correlations between chromosomal aberrations and clinical characteristics and treatment responses.
CONCLUSIONS: Translocations involving the MALT1 gene are not common in Korean ocular adnexal MALT lymphomas. The t(14;18) translocation was detected in only one out of 30 cases, and the t(11;18) translocation was not found at all. Furthermore, the chromosomal aberrations found in this study had no prognostic implications.

Hehlgans S, Oppermann J, Reichert S, et al.
The SMAC mimetic BV6 sensitizes colorectal cancer cells to ionizing radiation by interfering with DNA repair processes and enhancing apoptosis.
Radiat Oncol. 2015; 10:198 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
BACKGROUND: In the present study, we aimed to investigate the effect of counteracting inhibitor of apoptosis (IAP) proteins using the small molecule Second Mitochondria-derived Activator of Caspase (SMAC) mimetic BV6 in combination with ionizing radiation on apoptosis, cell cycle regulation, DNA double-strand break (DSB) repair, three-dimensional (3D) clonogenic survival and expression of IAPs in colorectal carcinoma cells.
MATERIAL AND METHODS: Colorectal cancer cell lines (HCT-15, HT-29, SW480) were subjected to BV6 treatment (0-4 μM) with or without irradiation (2-8 Gy, single dose) followed by MTT, Caspase 3/7 activity, γH2AX/53BP1 foci assays, AnnexinV staining, cell cycle analysis, 3D colony forming assays and Western blotting (cellular IAP1 (cIAP1) and cIAP2, Survivin, X-linked IAP (XIAP)).
RESULTS: BV6 treatment decreased cell viability and significantly increased irradiation-induced apoptosis as analyzed by Caspase 3/7 activity, AnnexinV-positive and subG1 phase cells. While basal 3D clonogenic survival was decreased in a cell line-dependent manner, BV6 significantly enhanced cellular radiosensitivity of all cell lines in a concentration-dependent manner and increased the number of radiation-induced γH2AX/53BP1-positive foci. Western blot analysis revealed a markedly reduced cIAP1 expression at 4 h after BV6 treatment in all cell lines, a substantial reduction of XIAP expression in SW480 and HT-29 cells at 24 h and a slightly decreased cIAP2 expression in HCT-15 cells at 48 h after treatment. Moreover, single or double knockdown of cIAP1 and XIAP resulted in significantly increased residual γH2AX/53BP1-positive foci 24 h after 2 Gy and radiosensitization relative to control small interfering RNA (siRNA)-treated cells.
CONCLUSION: The SMAC mimetic BV6 induced apoptosis and hampered DNA damage repair to radiosensitize 3D grown colorectal cancer cells. Our results demonstrate IAP targeting as a promising strategy to counteract radiation resistance of colorectal cancer cells.

Guièze R, Robbe P, Clifford R, et al.
Presence of multiple recurrent mutations confers poor trial outcome of relapsed/refractory CLL.
Blood. 2015; 126(18):2110-7 [PubMed] Related Publications
Although TP53, NOTCH1, and SF3B1 mutations may impair prognosis of patients with chronic lymphocytic leukemia (CLL) receiving frontline therapy, the impact of these mutations or any other, alone or in combination, remains unclear at relapse. The genome of 114 relapsed/refractory patients included in prospective trials was screened using targeted next-generation sequencing of the TP53, SF3B1, ATM, NOTCH1, XPO1, SAMHD1, MED12, BIRC3, and MYD88 genes. We performed clustering according to both number and combinations of recurrent gene mutations. The number of genes affected by mutation was ≥ 2, 1, and 0 in 43 (38%), 49 (43%), and 22 (19%) respectively. Recurrent combinations of ≥ 2 mutations of TP53, SF3B1, and ATM were found in 22 (19%) patients. This multiple-hit profile was associated with a median progression-free survival of 12 months compared with 22.5 months in the remaining patients (P = .003). Concurrent gene mutations are frequent in patients with relapsed/refractory CLL and are associated with worse outcome.

Piro G, Giacopuzzi S, Bencivenga M, et al.
TAK1-regulated expression of BIRC3 predicts resistance to preoperative chemoradiotherapy in oesophageal adenocarcinoma patients.
Br J Cancer. 2015; 113(6):878-85 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
BACKGROUND: About 20% of resectable oesophageal carcinoma is resistant to preoperative chemoradiotherapy. Here we hypothesised that the expression of the antiapoptotic gene Baculoviral inhibitor of apoptosis repeat containing (BIRC)3 induced by the transforming growth factor β activated kinase 1 (TAK1) might be responsible for the resistance to the proapoptotic effect of chemoradiotherapy in oesophageal carcinoma.
METHODS: TAK1 kinase activity was inhibited in FLO-1 and KYAE-1 oesophageal adenocarcinoma cells using (5Z)-7-oxozeaenol. The BIRC3 mRNA expression was measured by qRT-PCR in 65 pretreatment frozen biopsies from patients receiving preoperatively docetaxel, cisplatin, 5-fluorouracil, and concurrent radiotherapy. Receiver operator characteristic (ROC) analyses were performed to determine the performance of BIRC3 expression levels in distinguishing patients with sensitive or resistant carcinoma.
RESULTS: In vitro, (5Z)-7-oxozeaenol significantly reduced BIRC3 expression in FLO-1 and KYAE-1 cells. Exposure to chemotherapeutic agents or radiotherapy plus (5Z)-7-oxozeaenol resulted in a strong synergistic antiapoptotic effect. In patients, median expression of BIRC3 was significantly (P<0.0001) higher in adenocarcinoma than in the more sensitive squamous cell carcinoma subtype. The BIRC3 expression significantly discriminated patients with sensitive or resistant adenocarcinoma (AUC-ROC=0.7773 and 0.8074 by size-based pathological response or Mandard's tumour regression grade classifications, respectively).
CONCLUSIONS: The BIRC3 expression might be a valid biomarker for predicting patients with oesophageal adenocarcinoma that could most likely benefit from preoperative chemoradiotherapy.

Barghout SH, Zepeda N, Vincent K, et al.
RUNX3 contributes to carboplatin resistance in epithelial ovarian cancer cells.
Gynecol Oncol. 2015; 138(3):647-55 [PubMed] Related Publications
OBJECTIVE: Resistance to platinum-based therapeutic agents represents a major hurdle in the treatment of epithelial ovarian cancer (EOC). There is an urgent need to better understand the underlying mechanisms. Here, we investigated the role of RUNX3 in carboplatin resistance in EOC cells.
METHODS: Expression of RUNX3 was determined in human EOC cell line A2780s (cisplatin-sensitive) and A2780cp (cisplatin-resistant), human ovarian surface epithelium (OSE) and primary EOC cells. The effects of RUNX3 expression on sensitivity to carboplatin were determined in A2780s and A2780cp cells using neutral red uptake and clonogenic assays. Carboplatin-induced apoptosis was determined by measuring cleaved PARP using Western blotting. The expression of cellular inhibitor of apoptosis protein-2 (cIAP2) and its regulation by RUNX3 were assessed by quantitative RT-PCR and Western blotting.
RESULTS: The expression of RUNX3 was elevated in A2780cp cells compared to A2780s cells and in EOC tissues from chemoresistant patients compared to those from chemosensitive patients. Overexpression of RUNX3 rendered A2780s cells more resistant to carboplatin, whereas inhibition of RUNX3 increased sensitivity to carboplatin in A2780cp cells. Inhibition of RUNX3 potentiated carboplatin-induced apoptosis in A2780cp cells as demonstrated by more pronounced PARP cleavage. Interestingly, the expression of cIAP2 was elevated in A2780cp cells compared to A2780s cells. Overexpression of RUNX3 increased cIAP2 expression in A2780s cells, whereas inhibition of RUNX3 decreased cIAP2 expression and potentiated carboplatin-induced decrease of cIAP2 in A2780cp cells.
CONCLUSIONS: RUNX3 contributes to carboplatin resistance in EOC cells and may hold promise as a therapeutic target to treat EOC and/or a biomarker to predict chemoresistance.

Xu J, Huang G, Zhang Z, et al.
Up-Regulation of Glioma-Associated Oncogene Homolog 1 Expression by Serum Starvation Promotes Cell Survival in ER-Positive Breast Cancer Cells.
Cell Physiol Biochem. 2015; 36(5):1862-76 [PubMed] Related Publications
BACKGROUND/AIMS: Cancer cells are resistant to ischemia and starvation. Glioma-associated oncogene homolog 1 (Gli1) is a positive transcriptional activator of Hedgehog (Hh) pathway and plays an essential role in the development of cancers, including breast cancer. However, how Gli1 promotes cell survival remains elusive. The main purpose of this study is to investigate the pro-survival effect of Gli1 under serum starvation and its molecular mechanism in ER-positive breast cancer cells.
METHODS: Gene expression was determined by quantitative real-time PCR (QRT-PCR) and Western blot. The survival of Gli1 stably transfected ER-positive breast cancer cell lines (Gli1-MCF-7 and Gli1-T47D cells) and their untransfected control cells was estimated by WST-8 assay. Microarray analysis was performed to screen downstream Hh/Gli1 target genes in Gli1-overexpressed MCF-7 cells. Transcriptional activities of NF-kappaB were measured by luciferase assays. ChIP analysis was performed to explore whether cIAP2 was a direct target gene of Gli1.
RESULTS: Serum starvation significantly up-regulated the expression of Gli1 gene through activating PI3K/AKT pathway. Over-expression of Gli1 markedly promoted cell survival under serum starvation. Microarray analysis revealed that 338 genes were differentially expressed in Gli1-MCF-7 cells compared with those in the control cells. Among these genes, cellular inhibitor of apoptosis 2 (cIAP2), coding an anti-apoptosis and pro-survival protein, was significantly up-regulated not only by Hh/Gli1 pathway, but also by serum starvation. However, ChIP assay revealed no binding of Gli1 to cIAP2 promoter at the region of -1792 to -1568bp. Moreover, over-expression of Gli1 resulted in enhanced trans-activation of transcriptional factor NF-κB. Suppression of NF-κB signaling with NF-κB inhibitor Bay11-7082, significantly reduced the expression of cIAP2 and the cell survival under serum starvation.
CONCLUSION: Serum starvation significantly up-regulated the expression of Gli1, which in turn increased its key target cIAP2 expression and enhanced NF-κB/cIAP2 pathway, resulting in promoting cell survival under serum starvation. These findings may provide new insights into the pro-survival mechanisms of Gli1 in breast cancer.

Nabhan C, Raca G, Wang YL
Predicting Prognosis in Chronic Lymphocytic Leukemia in the Contemporary Era.
JAMA Oncol. 2015; 1(7):965-74 [PubMed] Related Publications
IMPORTANCE: Next-generation sequencing has identified new genetic markers that have altered prognosis for patients with chronic lymphocytic leukemia (CLL) at diagnosis. Understanding the significance of these prognostic indicators and recognizing their potential impact on treatment selection and patients' outcomes is critical for clinicians and investigators.
OBJECTIVE: To review novel prognostic factors at CLL diagnosis that have shown an impact on the prognosis and outcomes of this disease.
EVIDENCE REVIEW: Literature from January 2004 through December 2014 was searched in PubMed, Cochrane Central Register of Controlled Trials, and Scopus to identify English-language, peer-reviewed articles on clinical and prognostic factors for CLL (TP53, ATM, NOTCH1, SF3B1, BIRC3, and MYD88). Reference lists were subsequently reviewed for additional articles. A total of 450 articles was identified, and 48 articles meeting inclusion criteria were reviewed.
FINDINGS: Among prognostic markers reviewed, chromosomal aberrations have been validated and are currently used clinically to predict prognosis. Patients with 17p13.1 deletion have poor response to chemoimmunotherapy and are treated differently, with some undergoing allogeneic transplantation in first remission. CD38 and ZAP-70 status of malignant cells and unmutated immunoglobulin variable heavy chain gene have similarly been validated to predict adverse prognosis, but their implications on treatment selection have not been proven. The presence of TP53 and ATM mutations predicts worse prognosis, which has been corroborated in various studies. Patients with TP53 mutations have lower responses to chemoimmunotherapy. Furthermore, patients with TP53 and ATM mutations have inferior progression-free survival and overall survival, independent of other factors. Patients carrying the NOTCH1 and SF3B1 mutations have worse prognosis; patients with the NOTCH1 mutation have lower response rates to standard chemoimmunotherapy. The impact of BIRC3 on prognosis and survival requires further confirmation.
CONCLUSIONS AND RELEVANCE: The heterogeneous clinical course of CLL is likely explained by underlying molecular prognostic factors. Moving forward, analyzing these factors at diagnosis is recommended for better prognostication.

Ji W, Li Y, He Y, et al.
AIP1 Expression in Tumor Niche Suppresses Tumor Progression and Metastasis.
Cancer Res. 2015; 75(17):3492-504 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
Studies from tumor cells suggest that tumor-suppressor AIP1 inhibits epithelial-mesenchymal transition (EMT). However, the role of AIP1 in the tumor microenvironment has not been examined. We show that a global or vascular endothelial cell (EC)-specific deletion of the AIP1 gene in mice augments tumor growth and metastasis in melanoma and breast cancer models. AIP1-deficient vascular environment not only enhances tumor neovascularization and increases premetastatic niche formation, but also secretes tumor EMT-promoting factors. These effects from AIP1 loss are associated with increased VEGFR2 signaling in the vascular EC and could be abrogated by systemic administration of VEGFR2 kinase inhibitors. Mechanistically, AIP1 blocks VEGFR2-dependent signaling by directly binding to the phosphotyrosine residues within the activation loop of VEGFR2. Our data reveal that AIP1, by inhibiting VEGFR2-dependent signaling in tumor niche, suppresses tumor EMT switch, tumor angiogenesis, and tumor premetastatic niche formation to limit tumor growth and metastasis.

Yang PY, Hu DN, Lin IC, Liu FS
Butein Shows Cytotoxic Effects and Induces Apoptosis in Human Ovarian Cancer Cells.
Am J Chin Med. 2015; 43(4):769-82 [PubMed] Related Publications
Butein is a polyphenol, one of the compounds of chalcones, which are flavonoids that are widely biosynthesized in plants, and exhibits different pharmacological activities. Plants containing butein have been used in Chinese traditional medicine. Recently, it has been reported that butein suppresses proliferation and triggers apoptosis in various human cancer cells in vitro and in vivo. The aim of this study was to investigate its pro-apoptotic effect and mechanisms in two cultured human ovarian cancer cells (ES-2 and TOV-21G). The effects of butein on cell viability were assessed by a MTT assay at 3, 10, 30, and 100 μ/M. The apoptotic pathway related factors, including the mitochondrial transmembrane potential (MTP), cytochrome c, caspase cascade, and Bcl-2 family proteins, were examined. MTT assay revealed that butein was cytotoxic to both ovarian cancer cells in a dose- and time-dependent manner. JC-1 flow cytometry, cytochrome c, and caspase activity assays revealed that butein damaged the MTP, increased the level of cytosol cytochrome c and the activities of caspase-3, -8, and -9 in the two ovarian cancer cells. Western blot analysis revealed that butein down-regulated the anti-apoptotic proteins Bcl-2 and Bcl-xL and increased the pro-apoptotic proteins Bax and Bad. These findings suggest that butein-induced apoptosis in ovarian cancer cells via the activation of both extrinsic and intrinsic pathways. In addition, butein also down-regulated the expressions of the inhibitor of apoptosis (IAP) proteins, XIAP, survivin, CIAP-1, and CIAP-2. This indicates that the inhibition of IAP proteins was also involved in butein-induced apoptosis. The results of our study suggest that butein may be a promising anticancer agent in treating ovarian cancer.

Opel D, Schnaiter A, Dodier D, et al.
Targeting inhibitor of apoptosis proteins by Smac mimetic elicits cell death in poor prognostic subgroups of chronic lymphocytic leukemia.
Int J Cancer. 2015; 137(12):2959-70 [PubMed] Related Publications
Inhibitor of apoptosis (IAP) proteins are highly expressed in chronic lymphocytic leukemia (CLL) cells and contribute to evasion of cell death and poor therapeutic response. Here, we report that Smac mimetic BV6 dose-dependently induces cell death in 28 of 51 (54%) investigated CLL samples, while B-cells from healthy donors are largely unaffected. Importantly, BV6 is significantly more effective in prognostic unfavorable cases with, e.g., non-mutated VH status and TP53 mutation than samples with unknown or favorable prognosis. The majority of cases with 17p deletion (10/12) and Fludarabine refractory cases respond to BV6, indicating that BV6 acts independently of p53. BV6 also triggers cell death under survival conditions mimicking the microenvironment, e.g., by adding CD40 ligand or conditioned medium. Gene expression profiling identifies cell death, NF-κB and redox signaling among the top pathways regulated by BV6 not only in CLL but also in core-binding factor (CBF) acute myeloid leukemia (AML). Consistently, BV6 stimulates production of reactive oxygen species (ROS), which are contributing to BV6-induced cell death, since antioxidants reduce cell death. While BV6 causes degradation of cellular inhibitor of apoptosis (cIAP)1 and cIAP2 and nuclear factor-kappaB (NF-κB) pathway activation in primary CLL samples, BV6 induces cell death independently of caspase activity, receptor-interacting protein (RIP)1 activity or tumor necrosis factor (TNF)α, as zVAD.fmk, necrostatin-1 or TNFα-blocking antibody Enbrel fail to inhibit cell death. Together, these novel insights into BV6-regulated cell death in CLL have important implications for developing new therapeutic strategies to overcome cell death resistance especially in poor prognostic CLL subgroups.

Flanagan L, Kehoe J, Fay J, et al.
High levels of X-linked Inhibitor-of-Apoptosis Protein (XIAP) are indicative of radio chemotherapy resistance in rectal cancer.
Radiat Oncol. 2015; 10:131 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
BACKGROUND: The mainstay of treatment in rectal cancer is neoadjuvant radio chemotherapy prior to surgery, in an attempt to downstage the tumour, allowing for more complete removal during surgery. In 40 % of cases however, this neoadjuvant radio chemotherapy fails to achieve tumour regression, partly due insufficient apoptosis signaling. X-linked Inhibitor of Apoptosis Protein (XIAP) is an anti-apoptotic protein that has been reported to contribute to disease progression and chemotherapy resistance.
METHODS: We obtained rectal biopsy normal and matched tumour tissue from 29 rectal cancer patients with varying degrees of tumour regression, and using Western blot, examined anti-apoptotic XIAP and pro-apoptotic Smac protein levels in these tissues, with the aim to examine whether disturbed XIAP/Smac levels may be an indicator of neoadjuvant radio chemotherapy resistance. Expression of inhibitor of apoptosis proteins cIAP-1 and cIAP-2 was also examined.
RESULTS: We found that levels of XIAP increased in accordance with the degree of radio chemotherapy resistance of the tissue. Levels of this protein were also significantly higher in tumour tissue, compared to matched normal tissue in highly resistant tissue. In contrast, Smac protein levels did not increase with radio chemotherapy resistance, and the protein was similarly expressed in normal and tumour tissue, indicating a shift in the balance of these proteins. Post treatment surgical resection tissue was available for 8 patients. When we compared matched tissue pre- and post- radio chemotherapy we found that XIAP levels increased significantly during treatment in both normal and tumour tissue, while Smac levels did not change. cIAP-1 and cIAP-2 levels were not differentially expressed in varying degrees of radio chemotherapy resistance, and neoadjuvant therapy did not alter expression of these proteins.
CONCLUSION: These data indicate that disturbance of the XIAP/Smac balance may be a driver of radio chemotherapy resistance, and hence high levels of XIAP may be a useful indicator of neoadjuvant radio chemotherapy resistance in rectal cancer. Moreover, as XIAP levels increase with radio chemotherapy it is possible that a subset of more resistant tumour cells survive this treatment and may be resistant to further adjuvant treatment. Patients with resistant tumours highly expressing XIAP may benefit from alternative treatment strategies, such as Smac mimetics post neoadjuvant radio chemotherapy.

Dagenais M, Dupaul-Chicoine J, Champagne C, et al.
A critical role for cellular inhibitor of protein 2 (cIAP2) in colitis-associated colorectal cancer and intestinal homeostasis mediated by the inflammasome and survival pathways.
Mucosal Immunol. 2016; 9(1):146-58 [PubMed] Related Publications
Cellular inhibitors of apoptosis proteins (cIAPs) are critical arbiters of cell death and key mediators of inflammation and innate immunity. cIAP2 is frequently overexpressed in colorectal cancer and in regenerating crypts of ulcerative colitis patients. However, its corresponding functions in intestinal homeostasis and underlying mechanisms in disease pathogenesis are poorly understood. We found that mice deficient in cIAP2 exhibited reduced colitis-associated colorectal cancer tumor burden but, surprisingly, enhanced susceptibility to acute and chronic colitis. The exacerbated colitis phenotype of cIAP2-deficient mice was mediated by increased cell death and impaired activation of the regenerative inflammasome-interleukin-18 (IL-18) pathway required for tissue repair following injury. Accordingly, administration of recombinant IL-18 or pharmacological inhibition of caspases or the kinase RIPK1 protected cIAP2-deficient mice from colitis and restored intestinal epithelial barrier architecture. Thus, cIAP2 orchestrates intestinal homeostasis by exerting a dual function in suppressing cell death and promoting intestinal epithelial cell proliferation and crypt regeneration.

Fristedt Duvefelt C, Lub S, Agarwal P, et al.
Increased resistance to proteasome inhibitors in multiple myeloma mediated by cIAP2--implications for a combinatorial treatment.
Oncotarget. 2015; 6(24):20621-35 [PubMed] Article available free on PMC after 15/03/2017 Related Publications
Despite the introduction of new treatment options for multiple myeloma (MM), a majority of patients relapse due to the development of resistance. Unraveling new mechanisms underlying resistance could lead to identification of possible targets for combinatorial treatment. Using TRAF3 deleted/mutated MM cell lines, we evaluated the role of the cellular inhibitor of apoptosis 2 (cIAP2) in drug resistance and uncovered the plausible mechanisms underlying this resistance and possible strategies to overcome this by combinatorial treatment. In MM, cIAP2 is part of the gene signature of aberrant NF-κB signaling and is heterogeneously expressed amongst MM patients. In cIAP2 overexpressing cells a decreased sensitivity to the proteasome inhibitors bortezomib, MG132 and carfilzomib was observed. Gene expression analysis revealed that 440 genes were differentially expressed due to cIAP2 overexpression. Importantly, the data imply that cIAPs are rational targets for combinatorial treatment in the population of MM with deleted/mutated TRAF3. Indeed, we found that treatment with the IAP inhibitor AT-406 enhanced the anti-MM effect of bortezomib in the investigated cell lines. Taken together, our results show that cIAP2 is an important factor mediating bortezomib resistance in MM cells harboring TRAF3 deletion/mutation and therefore should be considered as a target for combinatorial treatment.

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