Bcl3 selectively promotes metastasis of ERBB2-driven mammary tumors

Variant of BCL3 gene is strongly associated with five-year survival of non-small-cell lung cancer patients

OBJECTIVES

BCL3, a known atypical IκB family member, has been documented to be upregulated in hematological malignancies and in some solid tumors, functioning as a crucial player in tumor development. Recently, rs8100239, a tag-Single Nucleotide Polymorphism (SNP) in BCL3 (T>A) has been identified, but there are no data regarding its involvement in non-small-cell lung cancer (NSCLC) initiation and progression.

MATERIALS AND METHODS

To study the possible association of BCL3 with NSCLC, 268 patients and 279 healthy controls were genotyped for rs8100239. Moreover, BCL3 protein expression was also investigated in 112 NSCLC cases through an immunohistochemical analysis.

RESULTS

NSCLC patients with AA genotype displayed significantly worse prognosis compared to T allele carriers (P<0.001), who had less frequent intermediate nuclear BCL3 expression (P=0.042). In addition, overexpression of BCL3 was detected in tumor specimens, compared to normal tissue (P<0.001). Furthermore, BCL3 protein levels were associated with five-year survival (P=0.039), maximum diameter of lesion (P=0.012), grade (P=0.002) and relapse frequency (P=0.041).

CONCLUSIONS

The present study is the first to show a relationship between the genetic variation rs8100239 of BCL3 and cancer patients' survival. It also represents the first quantitative evaluation of BCL3 expression in NSCLC. Our findings indicate that rs8100239 may be considered as a novel prognostic indicator, demonstrating also the overexpression of BCL3 protein in NSCLC and implicating this pivotal molecule in the pathogenesis of NSCLC.

Mouse models of breast cancer

Breast cancer is the most common cause of cancer death in women worldwide. This malignancy is a complex disease, which is defined by an intrinsic heterogeneity on the histopathological and molecular level as well as response to therapy and outcome. In addition to classical histopathological features, breast cancer can be categorized into at least five major subtypes based on comprehensive gene expression profiling: luminal A, luminal B, basal-like, ERBB2-positive, and normal-like breast cancer. Genetically engineered mouse models can serve as tools to study the molecular underpinnings for this disease. Given the genetic complexity that drives the initiation and progression of individual breast cancer subtypes, it is evident that certain models can reflect only particular aspects of this malignancy. In this book chapter, we will primarily focus on advances in modeling breast cancer at defined stages of carcinogenesis using genetically engineered mice. We will discuss the ability as well as shortcomings of these models to faithfully recapitulate the spectrum of human breast cancer subtypes.

Integrative analysis of micro-RNA, gene expression, and survival of glioblastoma multiforme

Glioblastoma multiforme (GBM), the most common type of malignant brain tumor, is highly fatal. Limited understanding of its rapid progression necessitates additional approaches that integrate what is known about the genomics of this cancer. Using a discovery set (n = 348) and a validation set (n = 174) of GBM patients, we performed genome-wide analyses that integrated mRNA and micro-RNA expression data from GBM as well as associated survival information, assessing coordinated variability in each as this reflects their known mechanistic functions. Cox proportional hazards models were used for the survival analyses, and nonparametric permutation tests were performed for the micro-RNAs to investigate the association between the number of associated genes and its prognostication. We also utilized mediation analyses for micro-RNA-gene pairs to identify their mediation effects. Genome-wide analyses revealed a novel pattern: micro-RNAs related to more gene expressions are more likely to be associated with GBM survival (P = 4.8 × 10(-5)). Genome-wide mediation analyses for the 32,660 micro-RNA-gene pairs with strong association (false discovery rate [FDR] < 0.01%) identified 51 validated pairs with significant mediation effect. Of the 51 pairs, miR-223 had 16 mediation genes. These 16 mediation genes of miR-223 were also highly associated with various other micro-RNAs and mediated their prognostic effects as well. We further constructed a gene signature using the 16 genes, which was highly associated with GBM survival in both the discovery and validation sets (P = 9.8 × 10(-6)). This comprehensive study discovered mediation effects of micro-RNA to gene expression and GBM survival and provided a new analytic framework for integrative genomics.

BIMMER: a novel algorithm for detecting differential DNA methylation regions from MBDCap-seq data

DNA methylation is a common epigenetic marker that regulates gene expression. A robust and cost-effective way for measuring whole genome methylation is Methyl-CpG binding domain-based capture followed by sequencing (MBDCap-seq). In this study, we proposed BIMMER, a Hidden Markov Model (HMM) for differential Methylation Regions (DMRs) identification, where HMMs were proposed to model the methylation status in normal and cancer samples in the first layer and another HMM was introduced to model the relationship between differential methylation and methylation statuses in normal and cancer samples. To carry out the prediction for BIMMER, an Expectation-Maximization algorithm was derived. BIMMER was validated on the simulated data and applied to real MBDCap-seq data of normal and cancer samples. BIMMER revealed that 8.83% of the breast cancer genome are differentially methylated and the majority are hypo-methylated in breast cancer.

α-Mangostin: a dietary antioxidant derived from the pericarp of Garcinia mangostana L. inhibits pancreatic tumor growth in xenograft mouse model

AIMS

Pancreatic cancer (PC) is the most aggressive malignant disease, ranking as the fourth most leading cause of cancer-related death among men and women in the United States. In this study, we provide evidence of chemotherapeutic effects of α-mangostin, a dietary antioxidant isolated from the pericarp of Garcinia mangostana L. against human PC.

RESULTS

The chemotherapeutic effect of α-mangostin was determined using four human PC cells (PL-45, PANC1, BxPC3, and ASPC1). α-Mangostin resulted in a significant inhibition of PC cells viability without having any effects on normal human pancreatic duct epithelial cells. α-Mangostin showed a dose-dependent increase of apoptosis in PC cells. Also, α-mangostin inhibited the expression levels of pNF-κB/p65Ser552, pStat3Ser727, and pStat3Tyr705. α-Mangostin inhibited DNA binding activity of nuclear factor kappa B (NF-κB) and signal transducer and activator 3 (Stat3). α-Mangostin inhibited the expression levels of matrix metallopeptidase 9 (MMP9), cyclin D1, and gp130; however, increased expression of tissue inhibitor of metalloproteinase 1 (TIMP1) was observed in PC cells. In addition, i.p. administration of α-mangostin (6 mg/kg body weight, 5 days a week) resulted in a significant inhibition of both primary (PL-45) and secondary (ASPC1) human PC cell-derived orthotopic and ectopic xenograft tumors in athymic nude mice. No sign of toxicity was observed in any of the mice administered with α-mangostin. α-Mangostin treatment inhibited the biomarkers of cell proliferation (Ki-67 and proliferating cell nuclear antigen [PCNA]) in the xenograft tumor tissues.

INNOVATION

We present, for the first time, that dietary antioxidant α-mangostin inhibits the growth of PC cells in vitro and in vivo.

CONCLUSION

These results suggest the potential therapeutic efficacy of α-mangostin against human PC.

Bcl3 regulates pro-survival and pro-inflammatory gene expression in cutaneous T-cell lymphoma

The advanced stages of cutaneous T cell lymphoma (CTCL) are characterized not only by decreased levels of pro-inflammatory cytokines, resulting in high susceptibility to infections, but also by high constitutive activity of NFκB, which promotes cell survival and resistance to apoptosis. The increased expression of the proto-oncogene Bcl3 belonging to IκB family is associated with the pathogenesis of the different types of human cancer, yet, the function and regulation of Bcl3 in CTCL have not been studied. Here, we show that Bcl3 is highly expressed in CTCL Hut-78 and HH cells. The suppression of Bcl3 levels decreases the expression of the pro-survival genes cIAP1 and cIAP2, reduces cell viability, and increases CTCL apoptosis. Interestingly, Bcl3 suppression concomitantly increases expression and the release of the pro-inflammatory cytokines IL-8 and IL-17 in CTCL cells. Chromatin immunoprecipitation studies show that Bcl3 regulates cIAP1, cIAP2, IL-8 and IL-17 gene expression through direct binding to their promoters. Bcl3 expression is regulated by bortezomib (BZ)-mediated proteasome inhibition, and BZ inhibits Bcl3 recruitment to its target promoters, resulting in decreased expression of cIAP1 and cIAP2, but increased expression of IL-8 and IL-17. The Bcl3 expression is regulated through NFκB subunit exchange on Bcl3 promoter. In untreated cells, the Bcl3 promoter is occupied predominantly by p65/p50 heterodimers, inducing Bcl3 expression; however, in BZ-treated cells, the p65/50 heterodimers are replaced by p52 subunits, resulting in Bcl3 transcriptional repression. These data provide the first insights into the function and regulation of Bcl3 in CTCL, and indicate that Bcl3 has an important pro-survival and immunosuppressive role in these cells.

When Good Turns Bad: Regulation of Invasion and Metastasis by ErbB2 Receptor Tyrosine Kinase

Overexpression and activation of ErbB2 receptor tyrosine kinase in breast cancer is strongly linked to an aggressive disease with high potential for invasion and metastasis. In addition to inducing very aggressive, metastatic cancer, ErbB2 activation mediates processes such as increased cancer cell proliferation and survival and is needed for normal physiological activities, such as heart function and development of the nervous system. How does ErbB2 activation make cancer cells invasive and when? Comprehensive understanding of the cellular mechanisms leading to ErbB2-induced malignant processes is necessary for answering these questions. Here we present current knowledge about the invasion-promoting function of ErbB2 and the mechanisms involved in it. Obtaining detailed information about the "bad" behavior of ErbB2 can facilitate development of novel treatments against ErbB2-positive cancers.

Tamoxifen integromics and personalized medicine: dynamic modular transformations underpinning response to tamoxifen in breast cancer treatment

Recent advances in pharmacogenomics technologies allow bold steps to be taken towards personalized medicine, more accurate health planning, and personalized drug development. In this framework, systems pharmacology network-based approaches offer an appealing way for integrating multi-omics data and set the basis for defining systems-level drug response biomarkers. On the road to individualized tamoxifen treatment in estrogen receptor-positive breast cancer patients, we examine the dynamics of the attendant pharmacological response mechanisms. By means of an "integromics" network approach, we assessed the tamoxifen effect through the way the high-order organization of interactome (i.e., the modules) is perturbed. To accomplish that, first we integrated the time series transcriptome data with the human protein interaction data, and second, an efficient module-detecting algorithm was applied onto the composite graphs. Our findings show that tamoxifen induces severe modular transformations on specific areas of the interactome. Our modular biomarkers in response to tamoxifen attest to the immunomodulatory role of tamoxifen, and further reveal that it deregulates cell cycle and apoptosis pathways, while coordinating the proteasome and basal transcription factors. To the best of our knowledge, this is the first report that informs the fields of personalized medicine and clinical pharmacology about the actual dynamic interactome response to tamoxifen administration.