Role of nuclear factor-ĸB in breast and colorectal cancer

Cancer-promoting effects of microbial dysbiosis

Humans depend on our commensal bacteria for nutritive, immune-modulating, and metabolic contributions to maintenance of health. However, this commensal community exists in careful balance that, if disrupted, enters dysbiosis; this has been shown to contribute to the pathogenesis of colon, gastric, esophageal, pancreatic, laryngeal, breast, and gallbladder carcinomas. This development is closely tied to host inflammation, which causes and is aggravated by microbial dysbiosis and increases vulnerability to pathogens. Advances in sequencing technology have increased our ability to catalog microbial species associated with various cancer types across the body. However, defining microbial biomarkers as cancer predictors presents multiple challenges, and existing studies identifying cancer-associated bacteria have reported inconsistent outcomes. Combining metabolites and microbiome analyses can help elucidate interactions between gut microbiota, metabolism, and the host. Ultimately, understanding how gut dysbiosis impacts host response and inflammation will be critical to creating an accurate picture of the role of the microbiome in cancer.

Involvement of Different networks in mammary gland involution after the pregnancy/lactation cycle: Implications in breast cancer

Early pregnancy is associated with a reduction in a woman's lifetime risk for breast cancer. However, different studies have demonstrated an increase in breast cancer risk in the years immediately following pregnancy. Early and long-term risk is even higher if the mother age is above 35 years at the time of first parity. The proinflammatory microenvironment within the mammary gland after pregnancy renders an "ideal niche" for oncogenic events. Signaling pathways involved in programmed cell death and tissue remodeling during involution are also activated in breast cancer. Herein, the major signaling pathways involved in mammary gland involution, signal transducer and activator of transcription (STAT3), nuclear factor-kappa B (NF-κB), transforming growth factor beta (TGFβ), and retinoid acid receptors (RARs)/retinoid X receptors (RXRs), are reviewed as part of the complex network of signaling pathways that crosstalk in a contextual-dependent manner. These factors, also involved in breast cancer development, are important regulatory nodes for signaling amplification after weaning. Indeed, during involution, p65/p300 target genes such as MMP9, Capn1, and Capn2 are upregulated. Elevated expression and activities of these proteases in breast cancer have been extensively documented. The role of these proteases during mammary gland involution is further discussed. MMPs, calpains, and cathepsins exert their effect by modification of the extracellular matrix and intracellular proteins. Calpains, activated in the mammary gland during involution, cleave several proteins located in cell membrane, lysosomes, mitochondria, and nuclei favoring cell death. Besides, during this period, Capn1 is most probably involved in the modulation of preadipocyte differentiation through chromatin remodeling. Calpains can be implicated in cell anchoring loss, providing a proper microenvironment for tumor growth. A better understanding of the role of any of these proteases in tumorigenesis may yield novel therapeutic targets or prognostic markers for breast cancer.

Inflammation and cancer: till death tears them apart

Advances in biotechnology have enabled the collection of an immeasurable amount of information from genomic, transcriptomic, metabolomic and proteomic studies of tumours within their microenvironments. The dissection of cytokine and chemokine networks has provided new clues to the interactions between cancer cells and their surrounding inflammatory landscape. To bridge the gap between chronic inflammation and cancer, dynamic participants in the tumour microenvironment have been identified, including tumour-associated macrophages (TAMs) and regulatory T cells (Tregs). Both of these cell types are notable for their ability to cause immunosuppressive conditions and support the evasion of tumour immune surveillance. It is clear now that the tumour-promoting inflammatory environment has to be included as one of the major cancer hallmarks. This review explores the recent advances in the understanding of cancer-related inflammation and how this is being applied to comparative oncology studies in humans and domestic species, such as the dog.

Psoralen derivatives as inhibitors of NF-κB interaction: the critical role of the furan ring

Simplified analogues of previously reported NF-κB interaction inhibitors, lacking the furan moiety, were synthesized and evaluated by performing experiments based on electrophoretic mobility shift assay (EMSA). The synthetic modifications led to simpler coumarin derivatives with lower activity allowing to better understand the minimal structural requirement for the binding to NF-κB.

Nuclear factor kappa B role in inflammation associated gastrointestinal malignancies

Nuclear factor kappa B (NF-κB) has an established role in the regulation of innate immunity and inflammation. NF-κB is also involved in critical mechanisms connecting inflammation and cancer development. Recent investigations suggest that the NF-κB signaling cascade may be the central mediator of gastrointestinal malignancies including esophageal, gastric and colorectal cancers. This review will explore NF-κB’s function in inflammation-associated gastrointestinal malignancies, highlighting its oncogenic contribution to each step of carcinogenesis. NF-κB’s role in the inflammation-to-carcinoma sequence in gastrointestinal malignancies warrants stronger emphasis upon targeting this pathway in achieving greater therapeutic efficacy.

Garcinol, an acetyltransferase inhibitor, suppresses proliferation of breast cancer cell line MCF-7 promoted by 17β-estradiol

The acetyltransferase inhibitor garcinol, a polyisoprenylated benzophenone, is extracted from the rind of the fruit of Garcinia indica, a plant found extensively in tropical regions. Anti-cancer activity has been suggested but there is no report on its action via inhibiting acetylation against cell proliferation, cell cycle progression, and apoptosis-inhibtion induced by estradiol (E2) in human breast cancer MCF-7 cells. The main purposes of this study were to investigate the effects of the acetyltransferase inhibitor garcinol on cell proliferation, cell cycle progression and apoptosis inhibition in human breast cancer MCF-7 cells treated with estrogen, and to explore the significance of changes in acetylation levels in this process. We used a variety of techniques such as CCK-8 analysis of cell proliferation, FCM analysis of cell cycling and apoptosis, immunofluorescence analysis of NF-κB/ p65 localization, and RT-PCR and Western blotting analysis of ac-H3, ac-H4, ac-p65, cyclin D1, Bcl-2 and Bcl- xl. We found that on treatment with garcinol in MCF-7 cells, E2-induced proliferation was inhibited, cell cycle progression was arrested at G0/G1 phase, and the cell apoptosis rate was increased. Expression of ac-H3, ac-H4 and NF-κB/ac-p65 proteins in E2-treated MCF-7 cells was increased, this being inhibited by garcinol but not ac- H4.The nuclear translocation of NF-κB/p65 in E2-treated MCF-7 cells was also inhibited, along with cyclin D1, Bcl-2 and Bcl-xl in mRNA and protein expression levels. These results suggest that the effect of E2 on promoting proliferation and inhibiting apoptosis is linked to hyperacetylation levels of histones and nonhistone NF-κB/ p65 in MCF-7 cells. The acetyltransferase inhibitor garcinol plays an inhibitive role in MCF-7 cell proliferation promoted by E2. Mechanisms are probably associated with decreasing ac-p65 protein expression level in the NF-κB pathway, thus down-regulating the expression of cyclin D1, Bcl-2 and Bcl-xl.

Trianthema portulacastrum Linn. displays anti-inflammatory responses during chemically induced rat mammary tumorigenesis through simultaneous and differential regulation of NF-κB and Nrf2 signaling pathways

Trianthema portulacastrum, a medicinal and dietary plant, has gained substantial importance due to its various pharmacological properties, including anti-inflammatory and anticarcinogenic activities. We have recently reported that a characterized T. portulacastrum extract (TPE) affords a considerable chemoprevention of 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumorigenesis though the underlying mechanisms are not completely understood. The objective of this study was to investigate anti-inflammatory mechanisms of TPE during DMBA mammary carcinogenesis in rats by monitoring cyclooxygenase-2 (COX-2), heat shock protein 90 (HSP90), nuclear factor-kappaB (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2). Mammary tumors were harvested from our previous study in which TPE (50-200 mg/kg) was found to inhibit mammary tumorigenesis in a dose-response manner. The expressions of intratumor COX-2, HSP90, NF-κB, inhibitory kappaB-alpha (IκBα) and Nrf2 were determined by immunohistochemistry. TPE downregulated the expression of COX-2 and HSP90, blocked the degradation of IκBα, hampered the translocation of NF-κB from cytosol to nucleus and upregulated the expression and nuclear translocation of Nrf2 during DMBA mammary carcinogenesis. These results in conjunction with our previous findings suggest that TPE prevents DMBA-induced breast neoplasia by anti-inflammatory mechanisms mediated through simultaneous and differential modulation of two interconnected molecular circuits, namely NF-κB and Nrf2 signaling pathways.

Serine-arginine protein kinase 1 is associated with breast cancer progression and poor patient survival

Breast cancer is the most common cancer and the second leading cause of mortality for women worldwide. It is necessary to identify valuable molecular markers to predict breast cancer progression in patients and treatment effect. Serine-arginine protein kinase 1 (SRPK1), a member of SR kinase family, phosphorylates the SR splicing factors which plays essential roles in normal cell development and multiple human diseases. In the current study, we wanted to explore if there are any relationships between SRPK1 expression in breast cancer and its clinical characteristics. The results showed that SRPK1 is upregulated in breast cancer cell lines and tissues at both mRNA and protein levels, measured by quantitative reverse transcriptase PCR and Western blotting. Immunohistochemical analysis showed a high expression of SRPK1 in 132 paraffin samples of patients with breast cancer; statistical analyses demonstrated that high expression of SRPK1 significantly correlated with clinical staging of patients with breast cancer (P < 0.001), TNM classification (P < 0.05). Low expression of SRPK1 leads to longer survival time, while high expression of SRPK1 leads to shorter survival time of patients. Multivariate analysis revealed that upregulation of SRPK1 might be an independent prognostic marker for the outcomes of patients with breast cancer. In conclusion, upregulation of SRPK1 might play an important role in the progression of breast cancer and might be considered as the potential diagnostic and therapeutic target to this malignancy.

Inhibitory effects of fucoxanthinol on the viability of human breast cancer cell lines MCF-7 and MDA-MB-231 are correlated with modulation of the NF-kappaB pathway

Fucoxanthin is a carotenoid present in the chloroplasts of brown seaweeds. When ingested, it is metabolized mainly to fucoxanthinol in the gastrointestinal tract by digestive enzymes. These compounds have been shown to have many beneficial health effects. The present study was designed to evaluate the molecular mechanisms of action of fucoxanthin and/or of its metabolite fucoxanthinol against viability of estrogen-sensitive MCF-7 and estrogen-resistant MDA-MB-231 breast cancer cell lines. Fucoxanthin and fucoxanthinol reduced the viability of MCF-7 and MDA-MB-231 cells in dose- and time-dependent manners as a result of increased apoptosis. Furthermore, fucoxanthinol-induced apoptosis was more potent than that of fucoxanthin and correlated, for MDA-MB-231 cells, with inhibitory actions on members of the NF-κB pathway p65, p50, RelB, and p52. Being overexpressed and regulated by NF-κB in different types of cancers, the transcription factor SOX9 was also decreased at the nuclear level by fucoxanthin and fucoxanthinol in MDA-MB-231. Taken together, the current results suggest that fucoxanthinol and fucoxanthin could be potentially effective for the treatment and/or prevention of different types of cancers, including breast cancer.

Molecular therapy of colorectal cancer: progress and future directions

Colorectal cancer (CRC) remains one of the most common types of cancer and leading causes of cancer death worldwide. Although the introduction of cytotoxic drugs such as oxaliplatin, irinotecan and fluorouracil has improved the treatment of advanced CRC, the individual response to chemoradiotherapy varies tremendously from one patient to another. However, recent progress in CRC molecular therapies may provide new insight into the treatment of this disease. Currently, components of the EGFR, VEGF, Wnt and NF-kB pathways are the most important targets for CRC therapy. This review chronicles the development of molecular CRC therapies over the past few decades. We also provide an update on the current progress of research concerning the molecular pathways leading to CRC and discuss the possible implications for CRC therapy.

Identification of epithelial stromal interaction 1 as a novel effector downstream of Krüppel-like factor 8 in breast cancer invasion and metastasis

Krüppel-like factor 8 (KLF8) is a transcriptional factor critical for metastatic progression of breast cancer. Epithelial stromal interaction 1 (EPSTI1), a recently identified stromal fibroblast-induced gene in non-invasive breast cancer cells is highly overexpressed in invasive breast carcinomas. The function and regulation of EPSTI1, however, remain largely unknown. In this paper, we report a novel KLF8 to EPSTI1 signaling pathway in breast cancer. Using various expression analyses, we revealed a high co-overexpression of KLF8 and EPSTI1 in invasive human breast cancer cells and patient tumors. Ectopic overexpression of KLF8 in the non-invasive, MCF-10A cells induced the EPSTI1 expression, whereas KLF8 knockdown from the invasive, MDA-MB-231 cells decreased the EPSTI1 expression. Promoter activation and binding analyses indicated that KLF8 promoted the EPSTI1 expression by directly acting on the EPSTI1 gene promoter. EPSTI1 knockdown dramatically reduced the KLF8-promoted MCF-10A cell invasion and ectopic expression of EPSTI1 in the non-invasive, MCF-7 cells is sufficient to induce the cell invasion. Experiments using nude mice demonstrated that the ectopic EPSTI1 granted the MCF-7 cells capability of both invasive growth in the breasts and metastasis to the lungs. Using co-immunoprecipitation coupled with mass spectrometry, we discovered that EPSTI1 interacts with the valosin containing protein (VCP), resulting in the degradation of IκBα and subsequent activation of NF-κB in the nucleus. These findings suggest a novel KLF8 to EPSTI1 to VCP to NF-κB signaling mechanism potentially critical for breast cancer invasion and metastasis.

Panduratin A, a possible inhibitor in metastasized A549 cells through inhibition of NF-kappa B translocation and chemoinvasion

In the present study, we investigated the effects of panduratin A (PA), isolated from Boesenbergia rotunda, on apoptosis and chemoinvasion in A549 human non-small cell lung cancer cells. Activation of the executioner procaspase-3 by PA was found to be dose-dependent. Caspase-3 activity was significantly elevated at the 5 µg/mL level of PA treatment and progressed to a maximal level. However, no significant elevated level was detected on procaspase-8. These findings suggest that PA activated caspase-3 but not caspase-8. Numerous nuclei of PA treated A549 cells stained brightly by anti-cleaved PARP antibody through High Content Screening. This result further confirmed that PA induced apoptotic cell death was mediated through activation of caspase-3 and eventually led to PARP cleavage. Treatment of A549 cells with PA resulted in a strong inhibition of NF-κB activation, which was consistent with a decrease in nuclear levels of NF-κB/p65 and NF-κB/p50 and the elevation of p53 and p21. Besides that, we also showed that PA significantly inhibited the invasion of A549 cells in a dose-dependent manner through reducing the secretion of MMP-2 of A549 cells gelatin zymography assay. Our findings not only provide the effects of PA, but may also be important in the design of therapeutic protocols that involve targeting of either p53 or NF-κB.

Suppression of inflammatory cascade is implicated in methyl amooranin-mediated inhibition of experimental mammary carcinogenesis

Breast cancer represents the second leading cause of cancer-related deaths among women worldwide and preventive therapy could reverse or delay the devastating impact of this disease. Methyl-amooranin (methyl-25-hydroxy-3-oxoolean-12-en-28-oate, AMR-Me), a novel synthetic oleanane triterpenoid, reduced the incidence and burden of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in rats through antiproliferative and proapoptotic effects. Since chronic inflammation plays an important role in the pathogenesis of breast cancer and several synthetic oleanane compounds are known potent anti-inflammatory agents, we aim to investigate anti-inflammatory mechanisms of AMR-Me by monitoring various proinflammatory and stress markers, such as cyclooxygenase-2 (COX-2) and heat shock protein 90 (HSP90), and nuclear factor-κB (NF-κB) signaling during DMBA mammary tumorigenesis in rats. Mammary tumors were harvested from a chemopreventive study in which AMR-Me (0.8-1.6 mg/kg) was found to inhibit mammary carcinogenesis in a dose-response manner. The expressions of COX-2, HSP90, NF-κB, and inhibitory κB-α (IκB-α) were determined by immunohistochemistry and reverse transcription-polymerase chain reaction. AMR-Me downregulated the expression of intratumor COX-2 and HSP90, suppressed the degradation of IκB-α, and reduced the translocation of NF-κB from cytosol to nucleus. Our present study provides the first in vivo evidence that NF-κB-evoked inflammatory cascade is a major target of AMR-Me in breast cancer. Our current results together with our previous findings suggest that disruption of NF-κB signaling contributes to anti-inflammatory, antiproliferative, and apoptosis-inducing mechanisms involved in AMR-Me-mediated chemoprevention of rat mammary carcinogenesis. These encouraging mechanistic results coupled with a safety profile should facilitate the clinical development of AMR-Me as breast cancer chemopreventive drug.

Mucosal immunology and probiotics

The cross-talk between the mucosa-associated immune system and microbiota is critical in mucosal tissue homeostasis as well as in protection against infectious and inflammatory diseases occurring at mucosal sites. This recent evidence has paved the way to therapeutic approaches aimed at modulating the mucosa-associated immune system using probiotics. Different strains of probiotics possess the ability to finely regulate dendritic cell (DC) activation, polarizing the subsequent T cell activity toward Th1 (e.g. Lactobacillus (Lb) acidophilus), Th2 (Lb.reuteri and Bifidobacterium bifidum) or, as more recently demonstrated, Th17 responses induced by specific strains such as Lb.rhamnosus GG and Lac23a, the latter isolated in our laboratory. Here, we review some recent advances in our understanding of probiotics effects on mucosal immunology, particularly on cells of the innate immunity such as DCs. We also highlight our own experiences in modulating DC functions by commensal bacteria and discuss the relevance of probiotics administration in the treatment of human immunopathologies.

A review on the role of quinones in renal disorders

Quinones are electron and proton carriers that play a primary role in the aerobic metabolism of virtually every cell in nature. Most physiological quinones are benzoquinones. They undergo highly regulated redox reactions in the mitochondria, Golgi apparatus, plasma membrane and endoplasmic reticulum. Important consequences of these electron transfer reactions are the production of and protection against reactive oxygen species (ROS). Quinones have been extensively studied for both their cytotoxic as well as cellular protective properties and they have been particularly useful in rational drug design. The role of quinones in medicine is explored in this literature review with a particular focus on renal diseases. Due to their high basal metabolism and detoxification role, the kidneys are particularly sensitive to oxidative stress. Regardless of the underlying etiology, ROS plays an important role in both acute kidney injury (AKI) and chronic kidney diseases (CKD). Depending on the oxidative state of the kidney, quinones can be nephrotoxoic or nephro-protective. Many factors play a role in the interaction between quinones and the kidney and the consequences of this are just beginning to be explored.

Antibody-based therapeutics for the treatment of human B cell malignancies

The dynamic expression of various phenotypic markers during B cell development not only defines the particular stage in ontogeny but also provides the necessary growth, differentiation, maturation and survival signals. When a B cell at any given stage becomes cancerous, these cell surface molecules, intracellular signaling molecules, and the over-expressed gene products become favorite targets for potential therapeutic intervention. Various adaptive and adoptive immunotherapeutic approaches induce T cell and antibody responses against cancer cells, and successful remission leading to minimal residual disease has been obtained. Nonetheless, subsequent relapse and development of resistant clones prompted further development and several novel strategies are evolving. Engineered monoclonal antibodies with high affinity and specificity to target antigens have been developed and used either alone or in combination with chemotherapeutic drugs. They are also used as vehicles to deliver cytotoxic drugs, toxins, or radionuclides that are either directly conjugated or encapsulated in liposomal vesicles. Likewise, genetically engineered T cells bearing chimeric antigen receptors are used to redirect cytotoxicity to antigen-positive target cells. This review describes recent advancements in some of these adoptive immunotherapeutic strategies targeting B cell malignancies.