Inflammation and cancer: the long reach of Ras

Regulation of immunological tolerance by the p53-inhibitor iASPP

Maintenance of immunological homeostasis between tolerance and autoimmunity is essential for the prevention of human diseases ranging from autoimmune disease to cancer. Accumulating evidence suggests that p53 can mitigate phagocytosis-induced adjuvanticity thereby promoting immunological tolerance following programmed cell death. Here we identify Inhibitor of Apoptosis Stimulating p53 Protein (iASPP), a negative regulator of p53 transcriptional activity, as a regulator of immunological tolerance. iASPP-deficiency promoted lung adenocarcinoma and pancreatic cancer tumorigenesis, while iASPP-deficient mice were less susceptible to autoimmune disease. Immune responses to iASPP-deficient tumors exhibited hallmarks of immunosuppression, including activated regulatory T cells and exhausted CD8+ T cells. Interestingly, iASPP-deficient tumor cells and tumor-infiltrating myeloid cells, CD4+, and γδ T cells expressed elevated levels of PD-1H, a recently identified transcriptional target of p53 that promotes tolerogenic phagocytosis. Identification of an iASPP/p53 axis of immune homeostasis provides a therapeutic opportunity for both autoimmune disease and cancer.

Integrative analysis of genomic and transcriptomic data of normal, tumour and co-occurring leukoplakia tissue triads drawn from patients with gingivobuccal oral cancer identifies signatures of tumour initiation and progression

A thickened, white patch — leukoplakia — in the oral cavity is usually benign, but sometimes (in ~9% of individuals) it progresses to malignant tumour. Because the genomic basis of this progression is poorly understood, we undertook this study and collected samples of four tissues — leukoplakia, tumour, adjacent normal, and blood — from each of 28 patients suffering from gingivobuccal oral cancer. We performed multiomics analysis of the 112 collected tissues (four tissues per patient from 28 patients) and integrated information on progressive changes in the mutational and transcriptional profiles of each patient to create this genomic narrative. Additionally, we generated and analysed whole‐exome sequence data from leukoplakia tissues collected from 11 individuals not suffering from oral cancer. Nonsynonymous somatic mutations in the CASP8 gene were identified as the likely events to initiate malignant transformation, since these were frequently shared between tumour and co‐occurring leukoplakia. CASP8 alterations were also shown to enhance expressions of genes that favour lateral spread of mutant cells. During malignant transformation, additional pathogenic mutations are acquired in key genes (TP53, NOTCH1, HRAS) (41% of patients); chromosomal‐instability (arm‐level deletions of 19p and q, focal‐deletion of DNA‐repair pathway genes and NOTCH1, amplification of EGFR) (77%), and increased APOBEC‐activity (23%) are also observed. These additional alterations were present singly (18% of patients) or in combination (68%). Some of these alterations likely impact immune‐dynamics of the evolving transformed tissue; progression to malignancy is associated with immune suppression through infiltration of regulatory T‐cells (56%), depletion of cytotoxic T‐cells (68%), and antigen‐presenting dendritic cells (72%), with a concomitant increase in inflammation (92%). Patients can be grouped into three clusters by the estimated time to development of cancer from precancer by acquiring additional mutations (range: 4–10 years). Our findings provide deep molecular insights into the evolutionary processes and trajectories of oral cancer initiation and progression. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

An In Vivo Inflammatory Loop Potentiates KRAS Blockade

KRAS (KRAS proto-oncogene, GTPase) inhibitors perform less well than other targeted drugs in vitro and fail clinical trials. To investigate a possible reason for this, we treated human and murine tumor cells with KRAS inhibitors deltarasin (targeting phosphodiesterase-δ), cysmethynil (targeting isoprenylcysteine carboxylmethyltransferase), and AA12 (targeting KRAS^G12C), and silenced/overexpressed mutant KRAS using custom-designed vectors. We showed that KRAS-mutant tumor cells exclusively respond to KRAS blockade in vivo, because the oncogene co-opts host myeloid cells via a C-C-motif chemokine ligand 2 (CCL2)/interleukin-1 beta (IL-1β)-mediated signaling loop for sustained tumorigenicity. Indeed, KRAS-mutant tumors did not respond to deltarasin in C-C motif chemokine receptor 2 (Ccr2) and Il1b gene-deficient mice, but were deltarasin-sensitive in wild-type and Ccr2-deficient mice adoptively transplanted with wild-type murine bone marrow. A KRAS-dependent pro-inflammatory transcriptome was prominent in human cancers with high KRAS mutation prevalence and poor predicted survival. Our findings support that in vitro cellular systems are suboptimal for anti-KRAS drug screens, as these drugs function to suppress interleukin-1 receptor 1 (IL1R1) expression and myeloid IL-1β-delivered pro-growth effects in vivo. Moreover, the findings support that IL-1β blockade might be suitable for therapy for KRAS-mutant cancers.

Neutrophil and Natural Killer Cell Interactions in Cancers: Dangerous Liaisons Instructing Immunosuppression and Angiogenesis

The tumor immune microenvironment (TIME) has largely been reported to cooperate on tumor onset and progression, as a consequence of the phenotype/functional plasticity and adaptation capabilities of tumor-infiltrating and tumor-associated immune cells. Immune cells within the tumor micro (tissue-local) and macro (peripheral blood) environment closely interact by cell-to-cell contact and/or via soluble factors, also generating a tumor-permissive soil. These dangerous liaisons have been investigated for pillars of tumor immunology, such as tumor associated macrophages and T cell subsets. Here, we reviewed and discussed the contribution of selected innate immunity effector cells, namely neutrophils and natural killer cells, as "soloists" or by their "dangerous liaisons", in favoring tumor progression by dissecting the cellular and molecular mechanisms involved.

USP12 downregulation orchestrates a protumourigenic microenvironment and enhances lung tumour resistance to PD-1 blockade

Oncogenic activation of KRAS and its surrogates is essential for tumour cell proliferation and survival, as well as for the development of protumourigenic microenvironments. Here, we show that the deubiquitinase USP12 is commonly downregulated in the Kras^G12D-driven mouse lung tumour and human non-small cell lung cancer owing to the activation of AKT-mTOR signalling. Downregulation of USP12 promotes lung tumour growth and fosters an immunosuppressive microenvironment with increased macrophage recruitment, hypervascularization, and reduced T cell activation. Mechanistically, USP12 downregulation creates a tumour-promoting secretome resulting from insufficient PPM1B deubiquitination that causes NF-κB hyperactivation in tumour cells. Furthermore, USP12 inhibition desensitizes mouse lung tumour cells to anti-PD-1 immunotherapy. Thus, our findings propose a critical component downstream of the oncogenic signalling pathways in the modulation of tumour-immune cell interactions and tumour response to immune checkpoint blockade therapy.

The cancer cell-extrinsic roles of deubiquitinases are unclear. Here the authors show that deubiquitinase USP12 downregulation contributes to development of an immune-suppressive tumour microenvironment in KRAS-driven lung cancers and mechanistically this is through the insufficient deubiquitination of the NF-κB inhibitor, PPM1B.

Pleiotropic nature of curcumin in targeting multiple apoptotic-mediated factors and related strategies to treat gastric cancer: A review

Gastric cancer (GC) is one of the major reasons for cancer-associated death and exhibits the second-highest mortality rate worldwide. Several advanced approaches have been designed to treat GC; however, these strategies possess many innate complications. In view of this, the upcoming research relying on natural products could result in designing potential anticancer agents with fewer side effects. Curcumin, isolated from the rhizomes of Curcuma longa L. has several medicinal properties like antiinflammatory, antioxidant, antiapoptotic, antitumor, and antimetastatic. Such pleiotropic nature of curcumin impedes the invasion and proliferation of GC by targeting several oncogenic factors like p23, human epidermal factor receptor2 including Helicobacter pylori. The side effect of chemotherapy, that is, chemotherapeutic resistance and radiotherapy could be reduced combination therapy of curcumin. Moreover, the photodynamic therapy of curcumin destroys the cancer cells without affecting normal cells. However, further more potential studies are required to establish the potent efficacy of curcumin in the treatment of GC. The current review details the anticancer activities of curcumin and related strategies which could be employed to treat GC with additional focus on its inhibitory properties against viability, proliferation, and migration of GC cells through cell cycle arrest and stimulation by apoptosis-mediated factors.

Tissues and Tumor Microenvironment (TME) in 3D: Models to Shed Light on Immunosuppression in Cancer

Immunosuppression in cancer has emerged as a major hurdle to immunotherapy efforts. Immunosuppression can arise from oncogene-induced signaling within the tumor as well as from tumor-associated immune cells. Understanding various mechanisms by which the tumor can undermine and evade therapy is critical in improving current cancer immunotherapies. While mouse models have allowed for the characterization of key immune cell types and their role in tumor development, extrapolating these mechanisms to patients has been challenging. There is need for better models to unravel the effects of genetic alterations inherent in tumor cells and immune cells isolated from tumors on tumor growth and to investigate the feasibility of immunotherapy. Three-dimensional (3D) organoid model systems have developed rapidly over the past few years and allow for incorporation of components of the tumor microenvironment such as immune cells and the stroma. This bears great promise for derivation of patient-specific models in a dish for understanding and determining the impact on personalized immunotherapy. In this review, we will highlight the significance of current experimental models employed in the study of tumor immunosuppression and evaluate current tumor organoid-immune cell co-culture systems and their potential impact in shedding light on cancer immunosuppression.

From Inflammation to Cutaneous Repair: Topical Application of Lupeol Improves Skin Wound Healing in Rats by Modulating the Cytokine Levels, NF-κB, Ki-67, Growth Factor Expression, and Distribution of Collagen Fibers

Skin wound healing is a highly complex event that involves different mediators at the cellular and molecular level. Lupeol has been reported to possess different biological activities, such as anti-inflammatory, antioxidant, antidiabetic, and in vitro wound healing properties, which motivated us to proceed with in vivo studies. We aimed to investigate the wound healing effect of lupeol-based cream for 3, 7, and 14 days. Wound excisions were induced on the thoraco-lumbar region of rats and topically treated immediately after injury induction. Macroscopic, histopathological, and immunohistochemical analyses were performed. Cytokine levels were measured by ELISA and gene expression was evaluated by real-time RT-qPCR. Our results showed a strong wound-healing effect of lupeol-based cream after 7 and 14 days. Lupeol treatment caused a reduction in proinflammatory cytokines (TNF-a, IL-1β, and IL-6) and gene and protein NF-κB expression, and positively altered IL-10 levels, showing anti-inflammatory effects in the three treatment periods. Lupeol treatment showed involvement in the proliferative phase by stimulating the formation of new blood vessels, increasing the immunostaining of Ki-67 and gene expression, and immunolabeling of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF), and increasing gene expression of transforming growth factor beta-1 (TGF-β1) after seven days of treatment. Lupeol was also involved in the tissue regeneration phase by increasing the synthesis of collagen fibers noted in the three treatment periods analyzed. Our findings suggest that lupeol may serve as a novel therapeutic option to treat cutaneous wounds by regulating mechanisms involved in the inflammatory, proliferative, and tissue-remodeling phases.

Understanding the Complexity of the Tumor Microenvironment in K-ras Mutant Lung Cancer: Finding an Alternative Path to Prevention and Treatment

Kirsten rat sarcoma viral oncogene (K-ras) is a well-documented, frequently mutated gene in lung cancer. Since K-ras regulates numerous signaling pathways related to cell survival and proliferation, mutations in this gene are powerful drivers of tumorigenesis and confer prodigious survival advantages to developing tumors. These malignant cells dramatically alter their local tissue environment and in the process recruit a powerful ally: inflammation. Inflammation in the context of the tumor microenvironment can be described as either antitumor or protumor (i.e., aiding or restricting tumor progression, respectively). Many current treatments, like immune checkpoint blockade, seek to augment antitumor inflammation by alleviating inhibitory signaling in cytotoxic T cells; however, a burgeoning area of research is now focusing on ways to modulate and mitigate protumor inflammation. Here, we summarize the interplay of tumor-promoting inflammation and K-ras mutant lung cancer pathogenesis by exploring the cytokines, signaling pathways, and immune cells that mediate this process.

A simple screening score to predict diabetes in cancer patients: A Korean nationwide population-based cohort study

Many cancer patients develop diabetes, which may result in reduction of chemotherapy effectiveness and increased infection risk and cardiovascular mortality. Diabetes may also increase the risks of chemotherapy-related toxicity and post-operative mortality, or represent an obstacle to optimal cancer treatment. However, the clinical predictors of diabetes in cancer patients remain largely unknown. Therefore, the aim of our study was to evaluate the risk factors for developing diabetes and construct a nomogram to predict diabetes in cancer patients.We investigated patients from a national sample cohort obtained from the Korea National Health Insurance Service (KNHIS), which included 2% of the Korean population. Patients who had undergone routine medical evaluation by the KNHIS between 2004 and 2008 and been hospitalized due to cancer (ICD-10 codes C00-97) during the past 3 years were included. After excluding patients with type 2 diabetes and missing data, 10,899 patients were enrolled and followed-up until 2013. A total of 7630 (70%) patients were assigned as the training cohort and used to construct the nomogram which was based on a multivariable logistic regression model. The remaining patients (n = 3269) were used as the validation cohort.The incidence rate of diabetes was 12.1 per 1000 person-years over a mean follow-up of 6.6 ± 1.8 years. Significant risk factors for developing diabetes were age, sex, obesity, fasting plasma glucose, hypertension, and hypercholesterolmia. A nomogram was constructed using these variables and internally validated. The area under the curve was 0.70 (95% confidence interval, .666-.730, P < .0001) and the calibration plot showed agreement between the actual and nomogram-predicted diabetes probabilities.The nomogram developed in this study is easy to use and convenient for identifying cancer patients at high-risk for type 2 diabetes, enabling early type 2 diabetes screening and management.

Oncogenic Regulation of Extracellular Vesicle Proteome and Heterogeneity

Mutational and epigenetic driver events profoundly alter intercellular communication pathways in cancer. This effect includes deregulated release, molecular composition, and biological activity of extracellular vesicles (EVs), membranous cellular fragments ranging from a few microns to less than 100 nm in diameter and filled with bioactive molecular cargo (proteins, lipids, and nucleic acids). While EVs are usually classified on the basis of their physical properties and biogenetic mechanisms, recent analyses of their proteome suggest a larger than expected molecular diversity, a notion that is also supported by multicolour nano-flow cytometry and other emerging technology platforms designed to analyze single EVs. Both protein composition and EV diversity are markedly altered by oncogenic transformation, epithelial to mesenchymal transition, and differentiation of cancer stem cells. Interestingly, only a subset of EVs released from mutant cells may carry oncogenic proteins (e.g., EGFRvIII), hence, these EVs are often referred to as "oncosomes". Indeed, oncogenic transformation alters the repertoire of EV-associated proteins, increases the presence of pro-invasive cargo, and alters the composition of distinct EV populations. Molecular profiling of single EVs may reveal a more intricate effect of transforming events on the architecture of EV populations in cancer and shed new light on their biological role and diagnostic utility.

Gastric Cancer Screening in Common Variable Immunodeficiency

Individuals with common variable immunodeficiency (CVID) have an increased risk of gastric cancer, and gastrointestinal lymphoma, yet screening for premalignant gastric lesions is rarely offered routinely to these patients. Proposed screening protocols are not widely accepted and are based on gastric cancer risk factors that are not applicable to all CVID patients. Fifty-two CVID patients were recruited for screening gastroscopy irrespective of symptoms or blood results and were compared to 40 controls presenting for gastroscopy for other clinical indications. Overall, 34% of CVID patients had intestinal metaplasia (IM), atrophic gastritis or moderate to severe non-atrophic gastritis, which can increase the risk of gastric cancer, compared to 7.5% of controls (p < 0.01). Focal nodular lymphoid hyperplasia, a precursor lesion for gastrointestinal lymphoma, was seen in eight CVID patients (16%), one of whom was diagnosed with gastrointestinal lymphoma on the same endoscopy. High-risk gastric pathology was associated with increased time since diagnosis of CVID, smoking, Helicobacter pylori, a low-serum pepsinogen I concentration, and diarrhea, but not pepsinogen I/II ratio, iron studies, vitamin B12 levels or upper gastrointestinal symptoms. There was a lower rate of detection of IM when fewer biopsies were taken, and IM and gastric atrophy were rarely predicted by the endoscopist macroscopically, highlighting the need for standardized biopsy protocols. The prevalence of premalignant gastric lesions in patients with CVID highlights the need for routine gastric screening. We propose a novel gastric screening protocol to detect early premalignant lesions and reduce the risk of gastric cancer and gastric lymphoma in these patients.

Potential therapeutic effects of curcumin in gastric cancer

Despite recent advancements in understanding of the biology of gastric cancer, treatment of patients with advanced gastric cancer remains a major problem. Among different type of phytochemicals, curcumin, a welltable -known phytochemical, has been shown to be a promising cancer chemopreventive agent. Pharmacokinetics, safety, and efficacy of curcumin have been evaluated in several clinical trials against numerous diseases, and for the treatment of human cancer. In the present review, we have collected in vitro and in vivo investigations and studied the chemosensitizing and anticancer effects of curcumin against the gastric cancer cells. In summary, curcumin has been found to have efficient chemosensitizing effect and also inhibits viability, proliferation, and migration of gastric cancer cells mainly via cell cycle arrest and induction of apoptosis by both mitochondrial-dependent and -independent pathways.

RASSF1A Deficiency Enhances RAS-Driven Lung Tumorigenesis

Mutant K-RAS has been shown to have both tumor-promoting and -suppressing functions, and growing evidence suggests that the RASSF family of tumor suppressors can act as RAS apoptosis and senescence effectors. It has been hypothesized that inactivation of the RASSF1A tumor suppressor facilitates K-RAS-mediated transformation by uncoupling it from apoptotic pathways such as the Hippo pathway. In human lung tumors, combined activation of K-RAS and inactivation of RASSF1A is closely associated with the development of the most aggressive and worst prognosis tumors. Here, we describe the first transgenic mouse model for activation of K-RAS in the lung in a RASSF1A-defective background. RASSF1A deficiency profoundly enhanced the development of K-RAS-driven lung tumors in vivo Analysis of these tumors showed loss of RASSF1A-uncoupled RAS from the proapoptotic Hippo pathway as expected. We also observed an upregulation of AKT and RALGEF signaling in the RASSF1A^- tumors. Heterozygosity of RASSF1A alone mimicked many of the effects of RAS activation on mitogenic signaling in lung tissue, yet no tumors developed, indicating that nonstandard Ras signaling pathways may be playing a key role in tumor formation in vivo In addition, we observed a marked increase in inflammation and IL6 production in RASSF1A-deficient tumors. Thus, RASSF1A loss profoundly affects RAS-driven lung tumorigenesis and mitogenic signaling in vivo Deregulation of inflammatory pathways due to loss of RASSF1A may be essential for RAS-mediated tumorigenesis. These results may have considerable ramifications for future targeted therapy against RAS⁺/RASSF1A^- tumors.Significance: A transgenic mouse model shows that suppression of RASSF1A dramatically enhances Ras-driven tumorigenesis and alters Ras signaling pathway activity.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/10/2614/F1.large.jpg Cancer Res; 78(10); 2614-23. ©2018 AACR.

Myc Cooperates with Ras by Programming Inflammation and Immune Suppression

The two oncogenes KRas and Myc cooperate to drive tumorigenesis, but the mechanism underlying this remains unclear. In a mouse lung model of KRasG12D-driven adenomas, we find that co-activation of Myc drives the immediate transition to highly proliferative and invasive adenocarcinomas marked by highly inflammatory, angiogenic, and immune-suppressed stroma. We identify epithelial-derived signaling molecules CCL9 and IL-23 as the principal instructing signals for stromal reprogramming. CCL9 mediates recruitment of macrophages, angiogenesis, and PD-L1-dependent expulsion of T and B cells. IL-23 orchestrates exclusion of adaptive T and B cells and innate immune NK cells. Co-blockade of both CCL9 and IL-23 abrogates Myc-induced tumor progression. Subsequent deactivation of Myc in established adenocarcinomas triggers immediate reversal of all stromal changes and tumor regression, which are independent of CD4+CD8+ T cells but substantially dependent on returning NK cells. We show that Myc extensively programs an immune suppressive stroma that is obligatory for tumor progression.

Inhibition of IL-8 secretion on BxPC-3 and MIA PaCa-2 cells and induction of cytotoxicity in pancreatic cancer cells with marine natural products

Pancreatic cancer presents one of the most negative prognosis of all cancers as it has usually metastasized by the time a patient is diagnosed. The American Cancer Society estimates that 93% of patients will die within 5 years of diagnosis, highlighting the need for new drugs to treat this disease. Interleukin 8 (IL-8) mediates the angiogenesis of tumors arising from Ras mutations, which are present in about 90% of pancreatic adenocarcinomas. Overexpression of IL-8 in pancreatic tumors is believed to promote tumor angiogenesis and to activate survival signaling pathways. A 96-well cell-based enzyme-linked immunosorbent assay was set up to screen the Harbor Branch Oceanographic Institute library of marine natural products to identify those with the ability to inhibit IL-8 production by BxPC-3 pancreatic cancer cells. Over 1000 fractions were screened, resulting in the identification of 10 known marine natural products with this ability. These compounds fall into four classes of compounds including the pyrroloiminoquinone alkaloids secobatzelline A and isobatzelline C; mycalamide A and B, onnamide A, discalamide A, and theopederin K from the mycalamide class of polyketides; the lipopeptide microcolin A; and the cyclic depsipeptides didemnin B and nordidemnin B. In addition, didemnin B, nordidemnin B, and theopederin K induce potent cytotoxicity against four pancreatic cancer cell lines tested. Many of these compounds have been previously reported to inhibit protein synthesis and the decrease in IL-8 production may be nonspecific. Nevertheless, this is a new activity for these compounds and inhibition of IL-8 secretion by pancreatic cancer cells can now be added to the previously reported antiangiogenic activities of the didemnins.

Extracellular vesicle communication pathways as regulatory targets of oncogenic transformation

Pathogenesis of human cancers bridges intracellular oncogenic driver events and their impact on intercellular communication. Among multiple mediators of this 'pathological connectivity' the role of extracellular vesicles (EVs) and their subsets (exosomes, ectosomes, oncosomes) is of particular interest for several reasons. The release of EVs from cancer cells represents a unique mechanism of regulated expulsion of bioactive molecules, a process that also mediates cell-to-cell transfer of lipids, proteins, and nucleic acids. Biological effects of these processes have been implicated in several aspects of cancer-related pathology, including tumour growth, invasion, angiogenesis, metastasis, immunity and thrombosis. Notably, the emerging evidence suggests that oncogenic mutations may impact several aspects of EV-mediated cell-cell communication including: (i) EV release rate and protein content; (ii) molecular composition of cancer EVs; (iii) the inclusion of oncogenic and mutant macromolecules in the EV cargo; (iv) EV-mediated release of genomic DNA; (v) deregulation of mechanisms responsible for EV biogenesis (vesiculome) and (vi) mechanisms of EV uptake by cancer cells. Intriguingly, EV-mediated intercellular transfer of mutant and oncogenic molecules between subpopulations of cancer cells, their indolent counterparts and stroma may exert profound biological effects that often resemble (but are not tantamount to) oncogenic transformation, including changes in cell growth, clonogenicity and angiogenic phenotype, or cause cell stress and death. However, several biological barriers likely curtail a permanent horizontal transformation of normal cells through EV-mediated mechanisms. The ongoing analysis and targeting of EV-mediated intercellular communication pathways can be viewed as a new therapeutic paradigm in cancer, while the analysis of oncogenic cargo contained in EVs released from cancer cells into biofluids is being developed for clinical use as a biomarker and companion diagnostics. Indeed, studies are underway to further explore the multiple links between molecular causality in cancer and various aspects of cellular vesiculation.

Genetics and Molecular Pathogenesis of Gastric Adenocarcinoma

Gastric cancer (GC) is globally the fifth most common cancer and third leading cause of cancer death. A complex disease arising from the interaction of environmental and host-associated factors, key contributors to GC's high mortality include its silent nature, late clinical presentation, and underlying biological and genetic heterogeneity. Achieving a detailed molecular understanding of the various genomic aberrations associated with GC will be critical to improving patient outcomes. The recent years has seen considerable progress in deciphering the genomic landscape of GC, identifying new molecular components such as ARID1A and RHOA, cellular pathways, and tissue populations associated with gastric malignancy and progression. The Cancer Genome Atlas (TCGA) project is a landmark in the molecular characterization of GC. Key challenges for the future will involve the translation of these molecular findings to clinical utility, by enabling novel strategies for early GC detection, and precision therapies for individual GC patients.

The marine natural product microsclerodermin A is a novel inhibitor of the nuclear factor kappa B and induces apoptosis in pancreatic cancer cells

Pancreatic cancer, the 4th leading cause of cancer death in the US, is highly resistant to all current chemotherapies, and its growth is facilitated by chronic inflammation. An important mediator of inflammation is the nuclear factor kappa B (NFκB), a transcription factor that regulates over 500 genes including the regulation of anti-apoptotic proteins, cell cycle progression and cytokine production. NFκB is constitutively activated in pancreatic cancer cells contributing to their resistance to apoptosis and high metastatic potential. Although many small molecules that inhibit NFκB have been identified, none are currently used in the clinic, perhaps due to their lack of specificity. To identify novel inhibitors of NFκB, the HBOI library of enriched fractions from marine organisms was screened using a reporter cell line that produces luciferin under the transcriptional control of NFκB. Fractions from the sponge Amphibleptula were active in this screen and contained the antifungal cyclic peptide microsclerodermin A. Microsclerodermin A is shown here to inhibit NFκB transcriptional activity in a reporter cell line, to reduce levels of phosphorylated (active) NFκB in the AsPC-1 cell line, to have an IC50 for cytotoxicity in the low micromolar range against the AsPC-1, BxPC-3, MIA PaCa-2 and PANC-1 pancreatic cancer cell lines, and to induce significant apoptosis in the AsPC-1, BxPC-3 and the PANC-1 cell lines. Treatment of AsPC-1 cells with microsclerodermin A also resulted in an increase in IL-8 production without apparent induction of angiogenic factors and there is the possibility that inhibition of NFκB by microsclerodermin A is mediated by the glycogen synthase kinase 3β pathway.

Orchestration of angiogenesis by immune cells

It is widely accepted that the tumor microenvironment (TUMIC) plays a major role in cancer and is indispensable for tumor progression. The TUMIC involves many "players" going well beyond the malignant-transformed cells, including stromal, immune, and endothelial cells (ECs). The non-malignant cells can acquire tumor-promoting functions during carcinogenesis. In particular, these cells can "orchestrate" the "symphony" of the angiogenic switch, permitting the creation of new blood vessels that allows rapid expansion and progression toward malignancy. Considerable attention within the context of tumor angiogenesis should focus not only on the ECs, representing a fundamental unit, but also on immune cells and on the inflammatory tumor infiltrate. Immune cells infiltrating tumors typically show a tumor-induced polarization associated with attenuation of anti-tumor functions and generation of pro-tumor activities, among these angiogenesis. Here, we propose a scenario suggesting that the angiogenic switch is an immune switch arising from the pro-angiogenic polarization of immune cells. This view links immunity, inflammation, and angiogenesis to tumor progression. Here, we review the data in the literature and seek to identify the "conductors" of this "orchestra." We also suggest that interrupting the immune → inflammation → angiogenesis → tumor progression process can delay or prevent tumor insurgence and malignant disease.

Calorie restriction decreases murine and human pancreatic tumor cell growth, nuclear factor-κB activation, and inflammation-related gene expression in an insulin-like growth factor-1-dependent manner

Calorie restriction (CR) prevents obesity and has potent anticancer effects that may be mediated through its ability to reduce serum growth and inflammatory factors, particularly insulin-like growth factor (IGF)-1 and protumorigenic cytokines. IGF-1 is a nutrient-responsive growth factor that activates the inflammatory regulator nuclear factor (NF)-κB, which is linked to many types of cancers, including pancreatic cancer. We hypothesized that CR would inhibit pancreatic tumor growth through modulation of IGF-1-stimulated NF-κB activation and protumorigenic gene expression. To test this, 30 male C57BL/6 mice were randomized to either a control diet consumed ad libitum or a 30% CR diet administered in daily aliquots for 21 weeks, then were subcutaneously injected with syngeneic mouse pancreatic cancer cells (Panc02) and tumor growth was monitored for 5 weeks. Relative to controls, CR mice weighed less and had decreased serum IGF-1 levels and smaller tumors. Also, CR tumors demonstrated a 70% decrease in the expression of genes encoding the pro-inflammatory factors S100a9 and F4/80, and a 56% decrease in the macrophage chemoattractant, Ccl2. Similar CR effects on tumor growth and NF-κB-related gene expression were observed in a separate study of transplanted MiaPaCa-2 human pancreatic tumor cell growth in nude mice. In vitro analyses in Panc02 cells showed that IGF-1 treatment promoted NF-κB nuclear localization, increased DNA-binding of p65 and transcriptional activation, and increased expression of NF-κB downstream genes. Finally, the IGF-1-induced increase in expression of genes downstream of NF-κB (Ccdn1, Vegf, Birc5, and Ptgs2) was decreased significantly in the context of silenced p65. These findings suggest that the inhibitory effects of CR on Panc02 pancreatic tumor growth are associated with reduced IGF-1-dependent NF-κB activation.

Mechanisms linking excess adiposity and carcinogenesis promotion

Obesity constitutes one of the most important metabolic diseases being associated to insulin resistance development and increased cardiovascular risk. Association between obesity and cancer has also been well established for several tumor types, such as breast cancer in post-menopausal women, colorectal, and prostate cancer. Cancer is the first death cause in developed countries and the second one in developing countries, with high incidence rates around the world. Furthermore, it has been estimated that 15-20% of all cancer deaths may be attributable to obesity. Tumor growth is regulated by interactions between tumor cells and their tissue microenvironment. In this sense, obesity may lead to cancer development through dysfunctional adipose tissue and altered signaling pathways. In this review, three main pathways relating obesity and cancer development are examined: (i) inflammatory changes leading to macrophage polarization and altered adipokine profile; (ii) insulin resistance development; and (iii) adipose tissue hypoxia. Since obesity and cancer present a high prevalence, the association between these conditions is of great public health significance and studies showing mechanisms by which obesity lead to cancer development and progression are needed to improve prevention and management of these diseases.

Argininosuccinate synthase as a novel biomarker for inflammatory conditions

Argininosuccinate synthase (ASS) plays an important role in regulating metabolic functions in mammals. We previously reported that hepatic ASS is released into circulation at very high concentrations in response to endotoxin and acute liver injury. We propose that ASS may serve as a novel biomarker for various inflammatory conditions. Our data showed that ASS accumulated in serum and urine of septic, obese or tumor mice in a condition-dependent fashion. Moreover, ASS significantly increased in urine within the first week after tumor cell implantation in mice which subsequently develop tumors. These results suggest that ASS is a novel biomarker increased upon diverse inflammatory conditions.

Sarcophine-diol inhibits expression of COX-2, inhibits activity of cPLA2, enhances degradation of PLA2 and PLC(γ)1 and inhibits cell membrane permeability in mouse melanoma B16F10 cells

Sarcophine-diol (SD) is a semi-synthetic derivative of sarcophine with a significant chemopreventive effect against non-melanoma skin cancer both in vitro and in vivo. Recently, we have studied the effect of SD on melanoma development using the mouse melanoma B₁₆F₁₀ cell line. In this study, our findings show that SD suppresses cell multiplication and diminishes membrane permeability for ethidium bromide (EB), a model marker used to measure cell permeability for Ca²⁺ ions. SD also decreases protein levels of COX-2, and increases degradation of phospholipases PLA₂ and PLC(γ)1 and diminishes enzymatic activity of the Ca²⁺-dependent cPLA₂. This lower membrane permeability for Ca²⁺-ions, associated with SD, is most likely due to the diminished content of lysophosphosphatidylcholine (lysoPC) within cell membranes caused by the effect of SD on PLA₂. The decrease in diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP₃) due to inhibition of PLC(γ)1, leads to the downregulation of Ca²⁺-dependent processes within the cell and also inhibits the formation of tumors. These findings support our previous data suggesting that SD may have significant potential in the treatment of melanoma.

Tumor promotion via injury- and death-induced inflammation

Inhibition of programmed cell death is considered to be a major aspect of tumorigenesis. Indeed, several key oncogenic transcription factors, such as NF-κB and STAT3, exert their tumor-promoting activity at least in part through upregulation of survival genes. However, many cancers develop in response to chronic tissue injury, in which the resulting cell death increases the tumorigenic potential of the neighboring cells. In this review, we discuss a resolution to this paradox based on cell death-mediated induction of tumor promoting inflammatory cytokines, which enhance cell survival and trigger compensatory proliferation in response to tissue injury.

Identification of tumorigenic cells in Kras(G12D)-induced lung adenocarcinoma

We established an inducible Kras(G12D)-driven lung adenocarcinoma in CCSP-rtTA/TetO-Cre/LSL-Kras(G12D) mice that enable pursuits of the cellular and molecular processes involved in Kras-induced tumorigenesis. To investigate the cellular origin of this cancer, we first report a strategy using fluorescence-activated cell sorting fractionation that could highly enrich bronchiolar Clara and alveolar type II cells, respectively. The EpCAM(+)MHCII(-) cells (bronchiolar origin) were more enriched with tumorigenic cells in generating secondary tumors than EpCAM(+)MHCII(+) cells (alveolar origin) in primary tumors that had been already initiated with oncogenic Kras activation. In addition, secondary tumors derived from EpCAM(+)MHCII(-) cells showed diversity of tumor locations compared with those derived from EpCAM(+)MHCII(+) cells. In the alveolar region, secondary tumors from EpCAM(+)MHCII(-) cells expressed not only bronchiolar epithelial marker, panCK, but also differentiation marker, proSPC, consistent with the notion that cancer-initiating cells display not only the abilities for self-renewal but also the features of differentiation to generate heterogeneous tumors with phenotypic diversity. Furthermore, high level of ERK1/2 activation and colony-forming ability as well as lack of Sprouty-2 expression were also observed in EpCAM(+)MHCII(-) cells. Therefore, these results suggest that bronchiolar Clara cells are the origin of cells and tumorigenesis for Kras(G12D)-induced neoplasia in the lungs.

Local sparse bump hunting reveals molecular heterogeneity of colon tumors

The question of molecular heterogeneity and of tumoral phenotype in cancer remains unresolved. To understand the underlying molecular basis of this phenomenon, we analyzed genome-wide expression data of colon cancer metastasis samples, as these tumors are the most advanced and hence would be anticipated to be the most likely heterogeneous group of tumors, potentially exhibiting the maximum amount of genetic heterogeneity. Casting a statistical net around such a complex problem proves difficult because of the high dimensionality and multicollinearity of the gene expression space, combined with the fact that genes act in concert with one another and that not all genes surveyed might be involved. We devise a strategy to identify distinct subgroups of samples and determine the genetic/molecular signature that defines them. This involves use of the local sparse bump hunting algorithm, which provides a much more optimal and biologically faithful transformed space within which to search for bumps. In addition, thanks to the variable selection feature of the algorithm, we derived a novel sparse gene expression signature, which appears to divide all colon cancer patients into two populations: a population whose expression pattern can be molecularly encompassed within the bump and an outlier population that cannot be. Although all patients within any given stage of the disease, including the metastatic group, appear clinically homogeneous, our procedure revealed two subgroups in each stage with distinct genetic/molecular profiles. We also discuss implications of such a finding in terms of early detection, diagnosis and prognosis.

The growing challenge of obesity and cancer: an inflammatory issue

The prevalence of obesity, an established risk factor for many cancers, has risen steadily for the past several decades in the United States and in many parts of the world. This review synthesizes the evidence on key biological mechanisms underlying the obesity-cancer link, with particular emphasis on the impact of energy balance modulation, such as diet-induced obesity and calorie restriction, on growth factor signaling pathways and inflammatory processes. Particular attention is placed on the proinflammatory environment associated with the obese state, specifically highlighting the involvement of obesity-associated hormones/growth factors in crosstalk between macrophages, adipocytes, and epithelial cells in many cancers. Understanding the contribution of obesity to growth factor signaling and chronic inflammation provides mechanistic targets for disrupting the obesity-cancer link.

Extracellular NM23 Protein as a Therapeutic Target for Hematologic Malignancies

An elevated serum level of NM23-H1 protein is a poor prognostic factor in patients with various hematologic malignancies. The extracellular NM23-H1 protein promotes the in vitro growth and survival of acute myelogenous leukemia (AML) cells and inversely inhibits the in vitro survival of normal peripheral blood monocytes in primary culture at concentrations equivalent to the levels found in the serum of AML patients. The growth and survival promoting activity to AML cells is associated with cytokine production and activation of mitogen-activated protein kinases (MAPKs) and signal transducers and activators of transcription (STAT) signaling pathways. Inhibitors specific for MAPK signaling pathways inhibit the growth/survival-promoting activity of NM23-H1. These findings indicate a novel biological action of extracellular NM23-H1 and its association with poor prognosis. These results suggest an important role of extracellular NM23-H1 in the malignant progression of leukemia and a potential therapeutic target for these malignancies.

Preventive and therapeutic effects of phosphoinositide 3-kinase inhibitors on acute lung injury

BACKGROUND

Phosphoinositide 3-kinases (PI3Ks) are involved in a number of biologic responses. Recent preclinical studies demonstrated that the PI3K-dominant signal pathway could play an important role in the development of acute lung injury, although the mechanism remains unclear.

METHODS

CD-1 mice were administered different PI3K inhibitors either intranasally or intragastrically once a day for 3 days before intratracheal instillation of lipopolysaccharide at 4 h and 24 h. Effects of SHBM1009 on lipopolysaccharide-induced capillary permeability, leukocyte distribution and activation, and epithelial cell function were measured. Therapeutic effects of SHBM1009 on pancreatic elastase-induced lung injury were evaluated in rats.

RESULTS

The data demonstrated that the local delivery of PI3K inhibitors played more effective roles in the prevention of endotoxin-induced lung injury than the systemic delivery. The preventive effects of PI3K inhibitors varied most likely because of chemical properties, targeting sites, and pharmacokinetics. The local PI3K inhibitors prevented both endotoxin- and elastase-induced lung injury in mice and rats, possibly through directly inhibiting or inactivating the function of airway epithelial cells, which could not produce chemoattractant factors to activate neutrophils and macrophages.

CONCLUSIONS

PI3K may be a therapeutic target for lung injury, and local delivery of PI3K inhibitors may be one of the optimal approaches for the therapy.

Role of TLR2-dependent inflammation in metastatic progression

Inflammation is a part of the host defense system, which provides protection against invading pathogens. However, it has become increasingly clear that inflammation can be evoked by endogenous mediators through Toll-like receptors (TLRs) to enhance tumor progression and metastasis. Here, we discuss the roles of TLR-mediated inflammation in tumor progression and the mechanisms through which it accomplishes this pathogenic function.

Specific effects of bortezomib against experimental malignant pleural effusion: a preclinical study

Background

We have previously shown that nuclear factor (NF)-κB activation of mouse Lewis lung carcinoma (LLC) specifically promotes the induction of malignant pleural effusions (MPE) by these cells. In the present studies we hypothesized that treatment of immunocompetent mice with bortezomib tailored to inhibit cancer cell NF-κB activation and not proliferation specifically inhibits MPE formation by LLC cells.

Results

Treatment of LLC cells with low concentrations of bortezomib (100 ng/ml) inhibited NF-κB activation and NF-κB-dependent transcription, but not cellular proliferation. Bortezomib treatment of immunocompetent C57BL/6 mice bearing LLC-induced subcutaneous tumors and MPEs significantly blocked tumor-specific NF-κB activation. However, bortezomib treatment did not impair subcutaneous LLC tumor growth, but was effective in limiting LLC-induced MPE. This specific effect was evidenced by significant reductions in effusion accumulation and the associated mortality and was observed with both preventive (beginning before MPE formation) and therapeutic (beginning after MPE establishment) bortezomib treatment. The favorable impact of bortezomib on MPE was associated with suppression of cardinal MPE-associated phenomena, such as inflammation, vascular hyperpermeability, and angiogenesis. In this regard, therapeutic bortezomib treatment had identical favorable results on MPE compared with preventive treatment, indicating that the drug specifically counteracts effusion formation.

Conclusions

These studies indicate that proteasome inhibition tailored to block NF-κB activation of lung adenocarcinoma specifically targets the effusion-inducing phenotype of this tumor. Although the drug has limited activity against advanced solid lung cancer, it may prove beneficial for patients with MPE.

Antitumor and anti-inflammatory effects of trabectedin on human myxoid liposarcoma cells

Inflammatory mediators present in the tumor milieu may promote cancer progression and are considered promising targets of novel biological therapies. We previously reported that the marine antitumor agent trabectedin, approved in Europe in 2007 for soft tissue sarcomas and in 2009 for ovarian cancer, was able to downmodulate the production of selected cytokines/chemokines in immune cells. Patients with myxoid liposarcoma (MLS), a subtype characterized by the expression of the oncogenic transcript FUS-CHOP, are highly responsive to trabectedin. The drug had marked antiproliferative effects on MLS cell lines at low nanomolar concentrations. We tested the hypothesis that trabectedin could also affect the inflammatory mediators produced by cancer cells. Here, we show that MLS express several cytokines, chemokines, and growth factors (CCL2, CCL3, CCL5, CXCL8, CXCL12, MIF, VEGF, SPARC) and the inflammatory and matrix-binder protein pentraxin 3 (PTX3), which build up a prominent inflammatory environment. In vitro treatment with noncytotoxic concentrations of trabectedin selectively inhibited the production of CCL2, CXCL8, IL-6, VEGF, and PTX3 by MLS primary tumor cultures and/or cell lines. A xenograft mouse model of human MLS showed marked reduction of CCL2, CXCL8, CD68+ infiltrating macrophages, CD31+ tumor vessels, and partial decrease of PTX3 after trabectedin treatment. Similar findings were observed in a patient tumor sample excised after several cycles of therapy, indicating that the results observed in vitro might have in vivo relevance. In conclusion, trabectedin has dual effects in liposarcoma: in addition to direct growth inhibition, it affects the tumor microenvironment by reducing the production of key inflammatory mediators.

Tobacco smoke promotes lung tumorigenesis by triggering IKKbeta- and JNK1-dependent inflammation

Chronic exposure to tobacco smoke, which contains over 60 tumor-initiating carcinogens, is the major risk factor for development of lung cancer, accounting for a large portion of cancer-related deaths worldwide. It is well established that tobacco smoke is a tumor initiator, but we asked whether it also acts as a tumor promoter once malignant initiation, such as caused by K-ras activation, has taken place. Here we demonstrate that repetitive exposure to tobacco smoke promotes tumor development both in carcinogen-treated mice and in transgenic mice undergoing sporadic K-ras activation in lung epithelial cells. Tumor promotion is due to induction of inflammation that results in enhanced pneumocyte proliferation and is abrogated by IKKbeta ablation in myeloid cells or inactivation of JNK1.

Neutrophil elastase-mediated degradation of IRS-1 accelerates lung tumor growth

Lung cancer is the leading cause of cancer death worldwide1. Recent data suggest that tumor-associated inflammatory cells may modify lung tumor growth and invasiveness2-3. To determine the role of neutrophil elastase (NE or Elane) on tumor progression, we utilized the LSL-K-ras model of murine lung adenocarcinoma4 to generate LSL-K-ras/Elane^−/− mice. Tumor burden was markedly reduced in LSL-K-ras/Elane^−/− mice at all time points following induction of mutant K-ras expression. Kaplan-Meier life survival analysis demonstrated that while 100% of LSL-K-ras/Elane^+/+ mice died, none of the mice lacking NE died. NE directly induced tumor cell proliferation in both human and mouse lung adenocarcinomas by gaining access to an endosomal compartment within tumor cells where it degraded insulin receptor substrate-1 (IRS1). Co-immunoprecipitation studies showed that as NE degraded IRS1, there was increased interaction between PI3K and the potent mitogen platelet derived growth factor receptor (PDGFR) thereby skewing the PI3K axis toward tumor cell proliferation. The inverse relationship identified between NE and IRS1 in LSL-K-ras mice was also identified in human lung adenocarcinomas, thus translating these findings to human disease. This study identifies IRS1 as a key regulator of PI3K within malignant cells. Additionally, this is the first description of a secreted proteinase gaining access to a cell beyond its plasma membrane and altering intracellular signaling.

Sleep loss activates cellular markers of inflammation: sex differences

Sleep disturbance is associated with inflammation and related disorders including cardiovascular disease, arthritis, and diabetes mellitus. Given sex differences in the prevalence of inflammatory disorders with stronger associations in females, this study was undertaken to test the effects of sleep loss on cellular mechanisms that contribute to proinflammatory cytokine activity. In 26 healthy adults (11 females; 15 males), monocyte intracellular proinflammatory cytokine production was repeatedly assessed at 08:00, 12:00, 16:00, 20:00, and 23:00h during a baseline period and after partial sleep deprivation (awake from 23:00 to 3.00h). In the morning after a night of sleep loss, monocyte production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) differentially changed between the two sexes. Whereas both females and males showed a marked increase in the lipopolysaccharide (LPS) - stimulated production of IL-6 and TNF-alpha in the morning immediately after PSD, production of these cytokines during the early- and late evening was increased in the females as compared to decreases in the males. Sleep loss induces a functional alteration of monocyte proinflammatory cytokine responses with females showing greater cellular immune activation as compared to changes in males. These results have implications for understanding the role of sleep disturbance in the differential risk profile for inflammatory disorders between the sexes.

Extracellular NM23 protein promotes the growth and survival of primary cultured human acute myelogenous leukemia cells

An elevated serum level of NM23-H1 protein is found in acute myelogenous leukemia (AML), and predicts a poor treatment outcome in AML patients. To investigate the potential pathological link between the elevated serum level of this protein and poor prognosis, we examined the extracellular effects of recombinant NM23-H1 protein on the in vitro growth and survival of primary cultured AML cells at concentrations equivalent to the levels found in the serum of AML patients. Extracellular NM23-H1 protein promoted the in vitro growth and survival of AML cells and this activity was associated with the cytokine production and activation of the MAPK and signal transducers and activators of transcription signaling pathways. Inhibitors specific to MAPK signaling pathways inhibited the growth- and survival-promoting activity of NM23-H1. These findings indicate the novel biological action of extracellular NM23-H1 and its association with poor prognosis, and suggest an important role for extracellular NM23-H1 in the malignant progression of leukemia and a potential therapeutic target for these malignancies.

Animal models of malignant pleural effusion

PURPOSE OF REVIEW

Malignant pleural effusion (MPE) poses a common and significant clinical problem. Its pathogenesis is poorly understood and therapeutic options are limited. Herein are summarized animal models of MPE and their contributions in unveiling new aspects of the pathobiology of the condition.

RECENT FINDINGS

In recent years, different groups have developed novel models of MPE, including a genetic mouse model of spontaneous mesothelioma development, a model of adenocarcinoma-induced MPE in immunocompetent mice, as well as models of human cancer-induced MPE in immunocompromised animals, all relevant to the human condition to a different extent. Work using these models has yielded novel insights into the pathogenesis of mesothelioma as well as into the mechanisms of intrapleural malignant effusion accumulation and tumor dissemination. The data produced underline the significance of tumor-associated inflammation, angiogenesis, and vascular hyperpermeability in the pathogenesis of MPE.

SUMMARY

In the past few years, novel approaches to induce experimental MPE have yielded new insights into its pathogenesis and have identified possible therapeutic targets to block pleural fluid exudation induced by primary and metastatic cancer cells in the pleural space.

Inflammation and proliferation act together to mediate intestinal cell fusion

Cell fusion between circulating bone marrow-derived cells (BMDCs) and non-hematopoietic cells is well documented in various tissues and has recently been suggested to occur in response to injury. Here we illustrate that inflammation within the intestine enhanced the level of BMDC fusion with intestinal progenitors. To identify important microenvironmental factors mediating intestinal epithelial cell fusion, we performed bone marrow transplantation into mouse models of inflammation and stimulated epithelial proliferation. Interestingly, in a non-injury model or in instances where inflammation was suppressed, an appreciable baseline level of fusion persisted. This suggests that additional mediators of cell fusion exist. A rigorous temporal analysis of early post-transplantation cellular dynamics revealed that GFP-expressing donor cells first trafficked to the intestine coincident with a striking increase in epithelial proliferation, advocating for a required fusogenic state of the host partner. Directly supporting this hypothesis, induction of augmented epithelial proliferation resulted in a significant increase in intestinal cell fusion. Here we report that intestinal inflammation and epithelial proliferation act together to promote cell fusion. While the physiologic impact of cell fusion is not yet known, the increased incidence in an inflammatory and proliferative microenvironment suggests a potential role for cell fusion in mediating the progression of intestinal inflammatory diseases and cancer.

Part of the Series: From dietary antioxidants to regulators in cellular signaling and gene regulation

The association of decreased cancer risk with intake of cruciferous vegetables and selenium is stronger than that reported for fruits and vegetables in general. An active constituent in cruciferae is sulforaphane. Chemopreventive effects of both, sulforaphane and selenium have been attributed to an antioxidant action which certainly is too simplicistic. Sulforaphane induces via activation of the Nrf2/Keap1 system phase 2 enzymes that protect against carcinogens and oxidants. Induced enzymes comprise the selenoproteins thioredoxin reductase-1 (TrxR1) and gastrointestinal glutathione peroxidase (GI-GPx, GPx2), which contain antioxidant response elements (ARE) in their promoter regions. Translational realisation of the enhanced transcripts depends on adequate selenium supply, which explains the synergism of Nrf2 activators and selenium. Regarding tumorigenesis the role of TrxR1 is ambiguous: it is essential for fast tumor cell growth but also diminishes vascularisation of tumors. The anticarcinogenic role of GI-GPx is evident from enhanced gastrointestinal tumor formation in gpx2/gpx1 double KO mice.

Past medical conditions and K-ras mutations in pancreatic ductal adenocarcinoma: a hypothesis-generating study

BACKGROUND

In pancreatic ductal adenocarcinoma (PDA) evidence on the etiopathogenic role of past medical conditions in the occurrence and persistence of K-ras mutations is scant.

METHODS

Incident cases of PDA were interviewed face-to-face about past medical history and other factors. Logistic regression was used to compare PDA cases (n = 120) with wild-type and mutated K-ras tumors (case-case study).

RESULTS

Patients with wild-type K-ras tumors were more likely to have a prior diagnosis of pancreatitis (Odds ratio [OR] = 6.11, p = 0.041). Diabetes mellitus (DM) was non-significantly more common among cases with a K-ras wild-type tumor, and the OR for DM of >6 years of duration was 4.54 (p = 0.39). Patients with wild-type K-ras were significantly more likely to have had a surgically treated peptic ulcer (OR = 9.03, p = 0.027). The probability of having a K-ras wild-type tumor increased with the number of medical conditions (p for trend = 0.012); the corresponding OR for two or more medical conditions was 4.46 (95% CI: 1.37-14.50).

CONCLUSIONS

Results raise the hypothesis that pancreatitis and possibly peptic ulcer might influence pancreatic carcinogenesis through pathways independent of K-ras mutation, perhaps related to growth factors or mediators of the inflammatory response. Large unselected studies should be conducted to refute or replicate our findings.

The relationship of endometriosis and ovarian malignancy: a review

OBJECTIVE

To review the malignant potential of endometriosis based on epidemiologic, histopathologic, and molecular data.

DESIGN

Literature review.

RESULT(S)

The pathogenesis of endometriosis remains unclear. The histopathologic development of endometriosis has undergone long-term investigation. Studies have confirmed histologic transition from benign endometriosis to ovarian malignancy, including malignant transformation of extraovarian endometriosis. The prevalence of endometriosis in patients with epithelial ovarian cancer, especially in endometrioid and clear cell types, has been confirmed to be higher than in the general population. Ovarian cancers and adjacent endometriotic lesions have shown common genetic alterations, such as PTEN, p53, and bcl gene mutations, suggesting a possible malignant genetic transition spectrum. Furthermore, endometriosis has been associated with a chronic inflammatory state leading to cytokine release. These cytokines act in a complex system in which they induce or repress their own synthesis and can cause unregulated mitotic division, growth and differentiation, and migration or apoptosis similar to malignant mechanisms.

CONCLUSION(S)

The malignant potential of endometriosis holds serious implications for management, such as the need for earlier and more meticulous surgical intervention for complete disease treatment.

Distinct regulatory profiles of interleukins and chemokines in response to cigarette smoke condensate in normal human bronchial epithelial (NHBE) cells

Bronchial epithelium is frequently exposed to air pollutants, and it is hypothesized that these cells elicit inflammatory responses as early elements in pulmonary defense. Our purpose was to evaluate changes in messenger RNA levels of 84 genes representing cytokines and receptors over a repetitive-exposure time course to further define the inflammatory responses associated with mainstream cigarette smoke (MSS) exposure in an in vitro lung model. Normal human bronchial epithelial cells were treated with mainstream cigarette smoke condensate (CSC) prepared from Kentucky 2R4F cigarettes (60 microg total particulate matter/mL media, 0.2% dimethylsulfoxide), and examined by quantitative real-time polymerase chain reaction. Applications of CSC were designed in seven groups to test immediate, early, intermediate, and late responses evaluated at the end of alternating exposure/recovery periods. Three predominant gene expression responses were observed: adaptive (return to baseline), sustained (maintained expression during treatment), and chronic (maintained expression posttreatment). Overall, 25 genes exhibited statistically significant changes: 14 genes exclusively elevated, 10 genes exclusively depressed, and 1, interleukin-8 (IL8), exhibiting both up- and downregulation in the seven groups. The most responsive genes were osteopontin (34-fold upregulation) and CXCL14 (23-fold downregulation). Our observations suggest that specific genes involved in inflammatory pathways respond to CSC in chronic, sustained, or adaptive patterns with the chronic pattern as the predominant behavior.

The time course of expression of genes involved in specific pathways in normal human bronchial epithelial cells following exposure to cigarette smoke

This study was conducted to determine the time course of gene expression associated with specific signaling pathways in normal human bronchial epithelial (NHBE) cells after exposure to 2 concentrations of 2R4F tobacco mainstream smoke (MSS). Expression of 84 genes representing 18 signal transduction pathways was quantitated in MSS- and air-exposed cultures using real-time polymerase chain reaction (PCR) arrays at 1, 4, and 24 hours following exposure. A confidence score, calculated based on statistical analysis of the degree and reproducibility of expression changes, was used to identify potential biologically significant changes in gene expression. Stimulation of NIAP, an apoptosis inhibitor, suppression of NFKB1 and MYC, representing pro-apoptotic activity, and down-regulation of TCF7 and up-regulation of KLK2, representing anti-/pro-inflammatory responses, were altered 1 hour after exposure to the high concentration of MSS. At the 4-hour time point, the pattern had changed such that 10 different genes were now up-regulated and an additional gene was now down-regulated. Significant changes included genes involved in inflammatory response (LTA, SELPLG, and IL8), repair and wound-healing activity (MMP10), and growth activity (GREB1, EGR1), suggesting repair in this period. By 24 hours, the only up-regulated genes in common with the 4-hour profile were SELPLG and IL8, suggesting continued inflammatory signaling. These results suggest that identification of specific gene expression-based biomarkers of MSS toxicity is promising for investigating specific mechanisms of cellular damage. As expected, the expressed signals were dependent on the concentration of MSS and the postexposure times.

Histone deacetylase regulation of immune gene expression in tumor cells

Epigenetic modifications of chromatin, such as histone acetylation, are involved in repression of tumor antigens and multiple immune genes that are thought to facilitate tumor escape. The status of acetylation in a cell is determined by the balance of the activities of histone acetyltransferases and histone deacetylases. Inhibitors of histone deacetylase (HDACi) can enhance the expression of immunologically important molecules in tumor cells and HDACi treated tumor cells are able to induce immune responses in vitro and in vivo. Systemic HDACi are in clinical trails in cancer and also being used in several autoimmune disease models. To date, 18 HDACs have been reported in human cells and more than thirty HDACi identified, although only a few immune targets of these inhibitors have been identified. Here, we discuss the molecular pathways employed by HDACi and their potential role in inducing immune responses against tumors. We review data suggesting that selection of target specific HDACi and combinations with other agents and modalities, including those that activate stress pathways, may further enhance the efficacy of epigenetic therapies.