Cancer and the complement cascade

Integrative analysis to select cancer candidate biomarkers to targeted validation

Targeted proteomics has flourished as the method of choice for prospecting for and validating potential candidate biomarkers in many diseases. However, challenges still remain due to the lack of standardized routines that can prioritize a limited number of proteins to be further validated in human samples. To help researchers identify candidate biomarkers that best characterize their samples under study, a well-designed integrative analysis pipeline, comprising MS-based discovery, feature selection methods, clustering techniques, bioinformatic analyses and targeted approaches was performed using discovery-based proteomic data from the secretomes of three classes of human cell lines (carcinoma, melanoma and non-cancerous). Three feature selection algorithms, namely, Beta-binomial, Nearest Shrunken Centroids (NSC), and Support Vector Machine-Recursive Features Elimination (SVM-RFE), indicated a panel of 137 candidate biomarkers for carcinoma and 271 for melanoma, which were differentially abundant between the tumor classes. We further tested the strength of the pipeline in selecting candidate biomarkers by immunoblotting, human tissue microarrays, label-free targeted MS and functional experiments. In conclusion, the proposed integrative analysis was able to pre-qualify and prioritize candidate biomarkers from discovery-based proteomics to targeted MS.

Development of a Protein Biomarker Panel to Detect Non-Small-Cell Lung Cancer in Korea

BACKGROUND

Lung cancer screening using low-dose computed tomography reduces lung cancer mortality. However, the high false-positive rate, cost, and potential harms highlight the need for complementary biomarkers. We compared the diagnostic performance of modified aptamer-based protein biomarkers with Cyfra 21-1.

PATIENTS AND METHODS

Participants included 100 patients diagnosed with lung cancer, and 100 control subjects from Asan Medical Center (Seoul, Korea). We investigated candidate biomarkers with new modified aptamer-based proteomic technology and developed a 7-protein panel that discriminates lung cancer from controls. A naive Bayesian classifier was trained using sera from 75 lung cancers and 75 controls. An independent set of 25 cases and 25 controls was used to verify performance of this classifier. The panel results were compared with Cyfra 21-1 to evaluate the diagnostic accuracy for lung nodules detected by computed tomography.

RESULTS

We derived a 7-protein biomarker classifier from the initial train set comprising: EGFR1, MMP7, CA6, KIT, CRP, C9, and SERPINA3. This classifier distinguished lung cancer cases from controls with an area under the curve (AUC) of 0.82 in the train set and an AUC of 0.77 in the verification set. The 7-marker naive Bayesian classifier resulted in 91.7% specificity with 75.0% sensitivity for the subset of individuals with lung nodules. The AUC of the classifier for lung nodules was 0.88, whereas Cyfra 21-1 had an AUC of 0.72.

CONCLUSION

We have developed a protein biomarker panel to identify lung cancers from controls with a high accuracy. This integrated noninvasive approach to the evaluation of lung nodules deserves further prospective validation among larger cohorts of patients with lung nodules in screening strategy.

The dual role of complement in cancer and its implication in anti-tumor therapy

Chronic inflammation has been linked to the initiation of carcinogenesis, as well as the advancement of established tumors. The polarization of the tumor inflammatory microenvironment can contribute to either the control, or the progression of the disease. The emerging participation of members of the complement cascade in several hallmarks of cancer, renders it a potential target for anti-tumor treatment. Moreover, the presence of complement regulatory proteins (CRPs) in most types of tumor cells is known to impede anti-tumor therapies. This review focuses on our current knowledge of complement's potential involvement in shaping the inflammatory tumor microenvironment and its role on the regulation of angiogenesis and hypoxia. Furthermore, we discuss approaches using complement-based therapies as an adjuvant in tumor immunotherapy.

Intratumoral interferon-gamma increases chemokine production but fails to increase T cell infiltration of human melanoma metastases

INTRODUCTION

Optimal approaches to induce T cell infiltration of tumors are not known. Chemokines CXCL9, CXCL10, and CXCL11 support effector T cell recruitment and may be induced by IFN. This study tests the hypothesis that intratumoral administration of IFNγ will induce CXCL9-11 and will induce T cell recruitment and anti-tumor immune signatures in melanoma metastases.

PATIENTS AND METHODS

Nine eligible patients were immunized with a vaccine comprised of 12 class I MHC-restricted melanoma peptides and received IFNγ intratumorally. Effects on the tumor microenvironment were evaluated in sequential tumor biopsies. Adverse events (AEs) were recorded. T cell responses to vaccination were assessed in PBMC by IFNγ ELISPOT assay. Tumor biopsies were evaluated for immune cell infiltration, chemokine protein expression, and gene expression.

RESULTS

Vaccination and intratumoral administration of IFNγ were well tolerated. Circulating T cell responses to vaccine were detected in six of nine patients. IFNγ increased production of chemokines CXCL10, CXCL11, and CCL5 in patient tumors. Neither vaccination alone, nor the addition of IFNγ promoted immune cell infiltration or induced anti-tumor immune gene signatures.

CONCLUSION

The melanoma vaccine induced circulating T cell responses, but it failed to infiltrate metastases, thus highlighting the need for combination strategies to support T cell infiltration. A single intratumoral injection of IFNγ induced T cell-attracting chemokines; however, it also induced secondary immune regulation that may paradoxically limit immune infiltration and effector functions. Alternate dosing strategies or additional combinatorial treatments may be needed to promote trafficking and retention of tumor-reactive T cells in melanoma metastases.

Does it make sense to target one tumor cell chemotactic factor or its receptor when several chemotactic axes are involved in metastasis of the same cancer?

The major problem with cancer progression and anti-cancer therapy is the inherent ability of cancer cells to migrate and establish distant metastases. This ability to metastasize correlates with the presence in a growing tumor of cells with a more malignant phenotype, which express certain cancer stem cell markers. The propensity of malignant cells to migrate and their resistance to radio-chemotherapy somewhat mimics the properties of normal developmentally early stem cells that migrate during organogenesis in the developing embryo. In the past, several factors, including cell migration-promoting cytokines, chemokines, growth factors, bioactive lipids, extracellular nucleotides, and even H(+) ions, were found to influence the metastasis of cancer cells. This plethora of pro-migratory factors demonstrates the existence of significant redundancy in the chemoattractants for cancer cells. In spite of this obvious fact, significant research effort has been dedicated to demonstrating the crucial involvement of particular pro-metastatic factor-receptor axes and the development of new drugs targeting one receptor or one chemoattractant. Based on our own experience working with a model of metastatic rhabdomyosarcoma as well as the work of others, in this review we conclude that targeting a single receptor-ligand pro-metastatic axis will not effectively prevent metastasis and that we should seek other more effective therapeutic options.

New perspectives on role of tumor microenvironment in progression of cutaneous squamous cell carcinoma

Epidermal keratinocyte-derived cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer, and its incidence is increasing worldwide. Solar UV radiation is an important risk factor for cSCC and leads to genetic and epigenetic changes both in epidermal keratinocytes and dermal cells. Tumor cells in cutaneous cSCCs typically harbor several driver gene mutations, but epidermal keratinocytes in sun-exposed normal skin also contain mutations in these same genes. Therefore, alterations in the microenvironment of premalignant lesions are evidently required for their progression to invasive and metastatic cSCC. For example, alterations in the composition of basement membrane and dermal extracellular matrix are early events in cSCC progression. The presence of microbial structures and the influx of inflammatory cells promote the secretion of proteases, which in turn regulate the availability of growth factors, cytokines, and chemokines and thus influence the growth and invasion of cSCC. Together, these observations emphasize the role of the tumor microenvironment in the progression of cSCC and identify it as a novel therapeutic target in cSCC and other malignant tumors. Graphical abstract Tumor-stroma interactions in the progression of cutaneous squamous cell carcinoma (cSCC). Epidermal layer is separated by a well-organized basement membrane (BM) from the dermal layer. UV radiation, other environmental insults, and aging target both epidermal keratinocytes and dermal fibroblasts and lead to genetic and epigenetic changes in these cells. In addition, epidermal keratinocytes in normal sun-exposed skin harbor several mutations in the cSCC driver genes. During transition to premalignant actinic keratosis (AK), the differentiation of keratinocytes is disturbed resulting in a neoplastic epithelium with hyperplastic cells. Expression of proteinases, such as matrix metalloproteinases (MMP) by neoplastic cells and activated stromal fibroblasts and macrophages is induced in AK, and collagen XV and XVIII are lost from the dermal BM. Furthermore, inflammatory cells accumulate at the site of the hyperplastic epithelium. During a later stage of cSCC progression, the number of inflammatory cells increases, and the expression of complement components and inhibitors by tumor cells is induced (CFI complement factor I, CFH complement factor H, FHL-1 Factor H-like protein 1). In addition to MMPs, activated fibroblasts also produce growth factors and promote inflammation, growth, and invasion of tumor cells.

Mutation Drivers of Immunological Responses to Cancer

In cancer immunology, somatic missense mutations have been mostly studied with regard to their role in the generation of neoantigens. However, growing evidence suggests that mutations in certain genes, such as CASP8 or TP53, influence the immune response against a tumor by other mechanisms. Identifying these genes and mechanisms is important because, just as the identification of cancer driver genes led to the development of personalized cancer therapies, a comprehensive catalog of such cancer immunity drivers will aid in the development of therapies aimed at restoring antitumor immunity. Here, we present an algorithm, domainXplorer, that can be used to identify potential cancer immunity drivers. To demonstrate its potential, we used it to analyze a dataset of 5,164 tumor samples from The Cancer Genome Atlas (TCGA) and to identify protein domains in which mutation status correlates with the presence of immune cells in cancer tissue (immune infiltrate). We identified 122 such protein regions, including several that belong to proteins with known roles in immune response, such as C2, CD163L1, or FCγR2A. In several cases, we show that mutations within the same protein can be associated with more or less immune cell infiltration, depending on the specific domain mutated. These results expand the catalog of potential cancer immunity drivers and highlight the importance of taking into account the structural context of somatic mutations when analyzing their potential association with immune phenotypes. Cancer Immunol Res; 4(9); 789-98. ©2016 AACR.

Concise Review: Pancreatic Cancer and Bone Marrow-Derived Stem Cells

Pancreatic adenocarcinoma remains one of the most challenging diseases of modern gastroenterology, and, even though considerable effort has been put into understanding its pathogenesis, the exact molecular mechanisms underlying the development and/or systemic progression of this malignancy still remain unclear. Recently, much attention has been paid to the potential role of bone marrow-derived stem cells (BMSCs) in this malignancy. Hence, herein, we comprehensively review the most recent discoveries and current achievements and concepts in this field. Specifically, we discuss the significance of identifying pancreatic cancer stem cells and novel therapeutic approaches involving molecular interference of their metabolism. We also describe advances in the current understanding of the biochemical and molecular mechanisms responsible for BMSC mobilization during pancreatic cancer development and systemic spread. Finally, we summarize experimental, translational, and/or clinical evidence regarding the contribution of bone marrow-derived mesenchymal stem cells, endothelial progenitor cells, hematopoietic stem/progenitor cells, and pancreatic stellate cells in pancreatic cancer development/progression. We also present their potential therapeutic value for the treatment of this deadly malignancy in humans.

SIGNIFICANCE

Different bone marrow-derived stem cell populations contribute to the development and/or progression of pancreatic cancer, and they might also be a promising "weapon" that can be used for anticancer treatments in humans. Even though the exact role of these stem cells in pancreatic cancer development and/or progression in humans still remains unclear, this concept continues to drive a completely novel scientific avenue in pancreatic cancer research and gives rise to innovative ideas regarding novel therapeutic modalities that can be safely offered to patients.

Role of the BrafV637E mutation in hepatocarcinogenesis induced by treatment with diethylnitrosamine in neonatal B6C3F1 mice

The BrafV637E mutation is frequently reported in mouse hepatic tumors, depending on the mouse strain, and corresponds to the human BrafV600E mutation. In this study, we detected the BrafV637E mutation by whole‐exome analysis in 4/4 hepatic tumors induced by neonatal treatment with diethylnitrosamine (DEN) in male B6C3F1 mice. We also detected the BrafV637E mutation in 54/63 (85.7%) hepatic lesions, including microscopic foci and grossly visible tumors, by PCR‐direct sequencing. Although the mutation was detected in 5/7 (71.4%) hepatic tumors induced by neonatal DEN treatment followed by repeated CCl₄ administration, it was not detected in 24 tumors induced by CCl₄ treatment without DEN or in eight spontaneous lesions in B6C3F1 mice, suggesting that the mutation is induced by the genotoxic action of DEN. The DEN‐induced tumors exhibited hyperphosphorylation of ERK1 and Akt, suggesting that the BrafV637E mutation might activate the MAPK and Akt pathways. Moreover, the DEN‐induced tumors overexpressed mRNAs for the oncogene‐induced senescence (OIS) markers such as p15^Ink4b and p19^Arf as well as pro‐survival/pro‐proliferative cytokines/chemokines such as complement C5/C5a, ICAM‐1, IL‐1 receptor antagonist and CXCL9, suggesting that the BrafV637E mutation influences the expression of genes involved in either OIS or cellular growth/survival. Liver‐specific expression of mutated Braf under control of the albumin enhancer/promoter resulted in an enlarged liver that consisted entirely of small basophilic hepatocytes resembling DEN‐induced preneoplastic hepatocytes with ERK1/Akt hyperphosphorylation and C5/C5a overexpression. These results indicate that the BrafV637E mutation induces hepatocytic changes in DEN‐induced hepatic tumors. © 2016 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.

Parallel Regulation of von Hippel-Lindau Disease by pVHL-Mediated Degradation of B-Myb and Hypoxia-Inducible Factor α

pVHL, the protein product of the von Hippel-Lindau (VHL) tumor suppressor gene, is a ubiquitin ligase that targets hypoxia-inducible factor α (HIF-α) for proteasomal degradation. Although HIF-α activation is necessary for VHL disease pathogenesis, constitutive activation of HIF-α alone did not induce renal clear cell carcinomas and pheochromocytomas in mice, suggesting the involvement of an HIF-α-independent pathway in VHL pathogenesis. Here, we show that the transcription factor B-Myb is a pVHL substrate that is degraded via the ubiquitin-proteasome pathway and that vascular endothelial growth factor (VEGF)- and/or platelet-derived growth factor (PDGF)-dependent tyrosine 15 phosphorylation of B-Myb prevents its degradation. Mice injected with B-Myb knockdown 786-O cells developed dramatically larger tumors than those bearing control cell tumors. Microarray screening of B-Myb-regulated genes showed that the expression of HIF-α-dependent genes was not affected by B-Myb knockdown, indicating that B-Myb prevents HIF-α-dependent tumorigenesis through an HIF-α-independent pathway. These data indicate that the regulation of B-Myb by pVHL plays a critical role in VHL disease.

Complement Membrane Attack and Tumorigenesis: A SYSTEMS BIOLOGY APPROACH

Tumor development driven by inflammation is now an established phenomenon, but the role that complement plays remains uncertain. Recent evidence has suggested that various components of the complement (C) cascade may influence tumor development in disparate ways; however, little attention has been paid to that of the membrane attack complex (MAC). This is despite abundant evidence documenting the effects of this complex on cell behavior, including cell activation, protection from/induction of apoptosis, release of inflammatory cytokines, growth factors, and ECM components and regulators, and the triggering of the NLRP3 inflammasome. Here we present a novel approach to this issue by using global gene expression studies in conjunction with a systems biology analysis. Using network analysis of MAC-responsive expression changes, we demonstrate a cluster of co-regulated genes known to have impact in the extracellular space and on the supporting stroma and with well characterized tumor-promoting roles. Network analysis highlighted the central role for EGF receptor activation in mediating the observed responses to MAC exposure. Overall, the study sheds light on the mechanisms by which sublytic MAC causes tumor cell responses and exposes a gene expression signature that implicates MAC as a driver of tumor progression. These findings have implications for understanding of the roles of complement and the MAC in tumor development and progression, which in turn will inform future therapeutic strategies in cancer.

Dissecting characteristics and dynamics of differentially expressed proteins during multistage carcinogenesis of human colorectal cancer

AIM: To discover novel biomarkers for early diagnosis, prognosis or treatment of human colorectal cancer.

METHODS: iTRAQ 2D LC-MS/MS analysis was used to identify differentially expressed proteins (DEPs) in the human colonic epithelial carcinogenic process using laser capture microdissection-purified colonic epithelial cells from normal colon, adenoma, carcinoma in situ and invasive carcinoma tissues.

RESULTS: A total of 326 DEPs were identified, and four DEPs (DMBT1, S100A9, Galectin-10, and S100A8) with progressive alteration in the carcinogenic process were further validated by immunohistochemistry. The DEPs were involved in multiple biological processes including cell cycle, cell adhesion, translation, mRNA processing, and protein synthesis. Some of the DEPs involved in cellular process such as “translation” and “mRNA splicing” were progressively up-regulated, while some DEPs involved in other processes such as “metabolism” and “cell response to stress” was progressively down-regulated. Other proteins with up- or down-regulation at certain stages of carcinogenesis may play various roles at different stages of the colorectal carcinogenic process.

CONCLUSION: These findings give insights into our understanding of the mechanisms of colorectal carcinogenesis and provide clues for further investigation of carcinogenesis and identification of biomarkers.

Identification of Serum Peptidome Signatures of Non-Small Cell Lung Cancer

Due to high mortality rates of lung cancer, there is a need for identification of new, clinically useful markers, which improve detection of this tumor in early stage of disease. In the current study, serum peptide profiling was evaluated as a diagnostic tool for non-small cell lung cancer patients. The combination of the ZipTip technology with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for the analysis of peptide pattern of cancer patients (n = 153) and control subjects (n = 63) was presented for the first time. Based on the observed significant differences between cancer patients and control subjects, the classification model was created, which allowed for accurate group discrimination. The model turned out to be robust enough to discriminate a new validation set of samples with satisfactory sensitivity and specificity. Two peptides from the diagnostic pattern for non-small cell lung cancer (NSCLC) were identified as fragments of C3 and fibrinogen α chain. Since ELISA test did not confirm significant differences in the expression of complement component C3, further study will involve a quantitative approach to prove clinical utility of the other proteins from the proposed multi-peptide cancer signature.

Cytotoxic mechanisms of immunotherapy: Harnessing complement in the action of anti-tumor monoclonal antibodies

Several mAbs that have been approved for the treatment of cancer make use of complement-dependent cytotoxicity (CDC) to eliminate tumor cells. Comprehensive investigations, based on in vitro studies, mouse models and analyses of patient blood samples after mAb treatment have provided key insights into the details of individual steps in the CDC reaction. Based on the lessons learned from these studies, new and innovative approaches are now being developed to increase the clinical efficacy of next generation mAbs with respect to CDC. These improvements include engineering changes in the mAbs to enhance their ability to activate complement. In addition, mAb dosing paradigms are being developed that take into account the capacity as well as the limitations of the complement system to eliminate a substantial burden of mAb-opsonized cells. Over the next few years it is likely these approaches will lead to mAbs that are far more effective in the treatment of cancer.

C1q acts in the tumour microenvironment as a cancer-promoting factor independently of complement activation

Complement C1q is the activator of the classical pathway. However, it is now recognized that C1q can exert functions unrelated to complement activation. Here we show that C1q, but not C4, is expressed in the stroma and vascular endothelium of several human malignant tumours. Compared with wild-type (WT) or C3- or C5-deficient mice, C1q-deficient (C1qa^−/−) mice bearing a syngeneic B16 melanoma exhibit a slower tumour growth and prolonged survival. This effect is not attributable to differences in the tumour-infiltrating immune cells. Tumours developing in WT mice display early deposition of C1q, higher vascular density and an increase in the number of lung metastases compared with C1qa^−/− mice. Bone marrow (BM) chimeras between C1qa^−/− and WT mice identify non-BM-derived cells as the main local source of C1q that can promote cancer cell adhesion, migration and proliferation. Together these findings support a role for locally synthesized C1q in promoting tumour growth.

C1q is known to initiate the activation of the complement classical pathway. Here, the authors show the C1q is expressed in the tumour microenvironment and can promote cancer cell migration and adhesion in a complement activation-independent manner.

Tumour exosomes display differential mechanical and complement activation properties dependent on malignant state: implications in endothelial leakiness

Background

Exosomes have been implicated in tumour progression and metastatic spread. Little is known of the effect of mechanical and innate immune interactions of malignant cell-derived exosomes on endothelial integrity, which may relate to increased extravasation of circulating tumour cells and, therefore, increased metastatic spread.

Methods

Exosomes isolated from non-malignant immortalized HCV-29 and isogenic malignant non-metastatic T24 and malignant metastatic FL3 bladder cells were characterized by nanoparticle tracking analysis and quantitative nanomechanical mapping atomic force microscopy (QNM AFM) to determine size and nanomechanical properties. Effect of HCV-29, T24 and FL3 exosomes on human umbilical vein endothelial cell (HUVEC) monolayer integrity was determined by transendothelial electrical resistance (TEER) measurements and transport was determined by flow cytometry. Complement activation studies in human serum of malignant and non-malignant cell-derived exosomes were performed.

Results

FL3, T24 and HCV-29 cells produced exosomes at similar concentration per cell (6.64, 6.61 and 6.46×10⁴ exosomes per cell for FL3, T24 and HCV-29 cells, respectively) and of similar size (120.2 nm for FL3, 127.6 nm for T24 and 117.9 nm for HCV-29, respectively). T24 and FL3 cell-derived exosomes exhibited a markedly reduced stiffness, 95 MPa and 280 MPa, respectively, compared with 1,527 MPa with non-malignant HCV-29 cell-derived exosomes determined by QNM AFM. FL3 and T24 exosomes induced endothelial disruption as measured by a decrease in TEER in HUVEC monolayers, whereas no effect was observed for HCV-29 derived exosomes. FL3 and T24 exosomes traffic more readily (11.6 and 21.4% of applied exosomes, respectively) across HUVEC monolayers than HCV-29 derived exosomes (7.2% of applied exosomes). Malignant cell-derived exosomes activated complement through calcium-sensitive pathways in a concentration-dependent manner.

Conclusions

Malignant (metastatic and non-metastatic) cell line exosomes display a markedly reduced stiffness and adhesion but an increased complement activation compared to non-malignant cell line exosomes, which may explain the observed increased endothelial monolayer disruption and transendothelial transport of these vesicles.

A targeted proteomic strategy for the measurement of oral cancer candidate biomarkers in human saliva

Head and neck cancers, including oral squamous cell carcinoma (OSCC), are the sixth most common malignancy in the world and are characterized by poor prognosis and a low survival rate. Saliva is oral fluid with intimate contact with OSCC. Besides non-invasive, simple, and rapid to collect, saliva is a potential source of biomarkers. In this study, we build an SRM assay that targets fourteen OSCC candidate biomarker proteins, which were evaluated in a set of clinically-derived saliva samples. Using Skyline software package, we demonstrated a statistically significant higher abundance of the C1R, LCN2, SLPI, FAM49B, TAGLN2, CFB, C3, C4B, LRG1, SERPINA1 candidate biomarkers in the saliva of OSCC patients. Furthermore, our study also demonstrated that CFB, C3, C4B, SERPINA1 and LRG1 are associated with the risk of developing OSCC. Overall, this study successfully used targeted proteomics to measure in saliva a panel of biomarker candidates for OSCC.

RACK1 is a candidate gene associated with the prognosis of patients with early stage non-small cell lung cancer

Background

This study was conducted to identify genetic polymorphisms associated with the prognosis of patients with early stage NSCLC.

Materials and Methods

We genotyped 1,969 potentially functional single nucleotide polymorphisms (SNPs) of 1,151 genes involved in carcinogenesis in 166 NSCLC patients who underwent curative surgery, using the Affymetrix custom-made GeneChip. A replication study was performed in an independent cohort of 626 patients.

Results

Fifty six SNPs which were associated with both overall survival (OS) and disease-free survival (DFS) with log-rank P values < 0.05 in discovery set were selected for validation. Among those, five SNPs (RACK1 rs1279736C>A and rs3756585T>G, C3 rs2287845T>C, PCAF rs17006625A>G, and PCM1 rs17691523C>G) were found to be significantly associated with survival in the same direction as the discovery set. In combined analysis, the rs1279736C>A and rs3756585T>G were most significantly associated with OS and DFS in multivariate analysis (P for OS = 4 × 10⁻⁵ and 7 × 10⁻⁵, respectively; and P for DFS = 0.003, both; under codominant model). In vitro promoter assay and electrophoretic mobility shift assay revealed that the rs3756585 T-to-G change increased promoter activity and transcription factor binding of RACK1.

Conclusions

We identified five SNPs, especially RACK1 rs3756585T>G, as markers for prognosis of patients with surgically resected NSCLC.

Complement factor H polymorphism rs1061170 and the effect of cigarette smoking on the risk of lung cancer

Aim of the study

Complement factor H (CFH) has been known to inhibit the complement pathway and to contribute to tumour growth by suppressing the anti-tumour cell mediated response in cell lines from several malignancies. We examined the association of Try402His single nucleotide polymorphism in CFH gene with lung cancer and the interaction with cigarette smoking.

Material and methods

This case-control study included 80 primary lung cancer patients and 106 control subjects who were genotyped for Try402His (rs1061170) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

Results

Variant genotypes (Tyr/His and His/His) were overpresented among patients compared to controls (p = 0.03, OR = 2.510, 95% CI: 1.068–5.899), and the frequency of variant H allele was significantly overexpressed in cases compared to controls (p = 0.021). Tyr/His genotype was identified in 100% of small cell lung cancer (SCLC) patients vs. 34.5% of non-SCLC (NSCLC), while 20.7% of NSCLC patients were homozygous for the variant allele (His/His) (p = 0.001). Binary logistic regression analysis revealed a 2.5 times greater estimated risk for NSCLC than for SCLC among variant allele carriers, and a 7.3-fold increased risk of lung cancer among variant allele smoking carriers vs. 1.3-fold increased risk among wild allele smoking carriers. Moreover, the stage of cancer positively correlated with smoking and pack-years in allele H carriers, and the correlation was stronger among those who were homozygous for it (His/His) than those who were heterozygous (Tyr/His).

Conclusions

CFH 402H variant is a smoking-related risk factor for lung cancer, particularly the NSCLC.

The complement system in cancer: Ambivalence between tumour destruction and promotion

Constituting a part of the innate immune system, the complement system consists of over 50 proteins either acting as part of a 3-branch activation cascade, a well-differentiated regulatory system in fluid phase or on each tissue, or as receptors translating the activation signal to multiple cellular effector functions. Complement serves as first line of defence against infections from bacteria, viruses and parasites by orchestrating the immune response through opsonisation, recruitment of immune cells to the site of infection and direct cell lysis. Complement is generally recognised as a protective mechanism against the formation of tumours in humans, but is often limited by various resistance mechanisms interfering with its cytotoxic action, now considered as a great barrier of successful antibody-based immunotherapy. However, recent studies also indicate a pro-tumourigenic potential of complement in certain cancers and under certain conditions. In this review, we present recent findings on the possible dual role of complement in destroying cancer, especially if resistance mechanisms are blocked, but also under certain inflammatory conditions-promoting tumour development.

Extracellular nucleotides as novel, underappreciated pro-metastatic factors that stimulate purinergic signaling in human lung cancer cells

Background

One of the challenging problems of current radio-chemotherapy is recurrence and metastasis of cancer cells that survive initial treatment. We propose that one of the unwanted effects of radiochemotherapy is the release from damaged (“leaky”) cells of nucleotides such as ATP and UTP that exert pro-metastatic functions and can directly stimulate chemotaxis of cancer cells.

Methods

To address this problem in a model of human lung cancer (LC), we employed several complementary in vitro and in vivo approaches to demonstrate the role of extracellular nucleotides (EXNs) in LC cell line metastasis and tumor progression. We measured concentrations of EXNs in several organs before and after radiochemotherapy. The purinergic receptor agonists and antagonists, inhibiting all or selected subtypes of receptors, were employed in in vitro and in vivo pro-metastatic assays.

Results

We found that EXNs accumulate in several organs in response to radiochemotherapy, and RT-PCR analysis revealed that most of the P1 and P2 receptor subtypes are expressed in human LC cells. EXNs were found to induce chemotaxis and adhesion of LC cells, and an autocrine loop was identified that promotes the proliferation of LC cells. Most importantly, metastasis of these cells could be inhibited in immunodeficient mice in the presence of specific small molecule inhibitors of purinergic receptors.

Conclusions

Based on this result, EXNs are novel pro-metastatic factors released particularly during radiochemotherapy, and inhibition of their pro-metastatic effects via purinergic signaling could become an important part of anti-metastatic treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0469-z) contains supplementary material, which is available to authorized users.

Modulatory Role of Surface Coating of Superparamagnetic Iron Oxide Nanoworms in Complement Opsonization and Leukocyte Uptake

Notwithstanding rapid advances of nanotechnology in diagnostic imaging and drug delivery, the engineered nanocarriers still exhibit substantial lack of hemocompatibility. Thus, when injected systemically, nanoparticles are avidly recognized by blood leukocytes and platelets, but the mechanisms of immune recognition are not well understood and strategies to mitigate these phenomena remain underexplored. Using superparamagnetic dextran iron oxide (SPIO) nanoworms (NWs) we demonstrate an efficient and predominantly complement-dependent uptake by mouse lymphocytes, neutrophils and monocytes from normal and tumor bearing mice in vitro. Following intravenous injection into wild type mice, blood leukocytes as well as platelets became magnetically labeled, while the labeling was decreased by 95% in complement C3-deficient mice. Using blood cells from healthy and cancer patient donors, we demonstrated that neutrophils, monocytes, lymphocytes and eosinophils took up SPIO NWs, and the uptake was prevented by EDTA (a general complement inhibitor) and by antiproperdin antibody (an inhibitor of the alternative pathway of the complement system). Cross-linking and hydrogelation of SPIO NWs surface by epichlorohydrin decreased C3 opsonization in mouse serum, and consequently reduced the uptake by mouse leukocytes by more than 70% in vivo. Remarkably, the cross-linked particles did not show a decrease in C3 opsonization in human serum, but showed a significant decrease (over 60%) of the uptake by human leukocytes. The residual uptake of cross-linked nanoparticles was completely blocked by EDTA. These findings demonstrate species differences in complement-mediated nanoparticle recognition and uptake by leukocytes, and further show that human hemocompatibility could be improved by inhibitors of complement alternative pathway and by nanoparticle surface coating. These results provide important insights into the mechanisms of hemocompatibility of nanomedicines.

Targeted complement inhibition and microvasculature in transplants: a therapeutic perspective

Active complement mediators play a key role in graft-versus-host diseases, but little attention has been given to the angiogenic balance and complement modulation during allograft acceptance. The complement cascade releases the powerful proinflammatory mediators C3a and C5a anaphylatoxins, C3b, C5b opsonins and terminal membrane attack complex into tissues, which are deleterious if unchecked. Blocking complement mediators has been considered to be a promising approach in the modern drug discovery plan, and a significant number of therapeutic alternatives have been developed to dampen complement activation and protect host cells. Numerous immune cells, especially macrophages, develop both anaphylatoxin and opsonin receptors on their cell surface and their binding affects the macrophage phenotype and their angiogenic properties. This review discusses the mechanism that complement contributes to angiogenic injury, and the development of future therapeutic targets by antagonizing activated complement mediators to preserve microvasculature in rejecting the transplanted organ.

Pentraxin-3 Is a TSH-Inducible Protein in Human Fibrocytes and Orbital Fibroblasts

CD34(+) fibrocytes are bone marrow-derived monocyte progenitor cells that traffic to sites of tissue injury and repair. They putatively infiltrate the orbit in thyroid-associated ophthalmopathy where they appear to transition into CD34(+) orbital fibroblasts (OFs) that interact with residential CD34(-) fibroblasts. A unique phenotypic attribute of fibrocytes and CD34(+) OFs is their expression of the functional thyrotropin receptor (TSHR) and other "thyroid-specific" proteins. When activated through TSHR, fibrocytes express a number of cytokines and other inflammatory genes. Here we sought to determine whether pentraxin-3 (PTX-3), an acute-phase protein involved in inflammation and autoimmunity, might be induced by TSH in fibrocytes and OFs. These cells were collected from patients with Graves disease and healthy individuals. PTX-3 mRNA levels were determined by real-time PCR, protein was determined by ELISA and Western blot, and PTX-3 gene promoter activity was assessed with reporter assays. PTX-3 expression was induced by TSH in both cell types, regardless of the health status of the donor and was a consequence of increased steady-state PTX-3 mRNA levels. M22, a TSHR-activating monoclonal antibody, also induced PTX-3. The induction could be attenuated by dexamethasone and by IGF-I receptor-blocking antibodies, teprotumumab and 1H7. TSH effects were mediated through phosphatidylinositol 3-kinase/AKT, mammalian target of rapamycin/p70(s6k), Janus tyrosine kinase 2 pathways, and enhanced PTX-3 mRNA stability. These findings indicate that PTX-3 is a TSH target gene, the expression of which can be induced in fibrocytes and OFs. They suggest that PTX-3 might represent a previously unidentified nexus between the thyroid axis and the mechanisms involved in tissue remodeling.

Small cell lung cancer: Recruitment of macrophages by circulating tumor cells

Tumor-associated macrophages (TAMs) play an important role in tumor progression, suppression of antitumor immunity and dissemination. Blood monocytes infiltrate the tumor region and are primed by local microenvironmental conditions to promote tumor growth and invasion. Although many of the interacting cytokines and factors are known for the tumor-macrophage interactions, the putative contribution of circulating tumor cells (CTCs) is not known so far. These specialized cells are characterized by increased mobility, ability to degrade the extracellular matrix (ECM) and to enter the blood stream and generate secondary lesions which is a leading cause of death for the majority of tumor patients. The first establishment of two permanent CTC lines, namely BHGc7 and 10, from blood samples of advanced stage small cell lung cancer (SCLC) patients allowed us to investigate the CTC-immune cell interaction. Cocultures of peripheral blood mononuclear cells (PBMNCs) with CTCs or addition of CTC-conditioned medium (CTC-CM) in vitro resulted in monocyte-macrophage differentiation and appearance of CD14⁺, CD163^weak and CD68⁺ macrophages expressing markers of TAMs. Furthermore, we screened the supernatants of CTC-primed macrophages for presence of approximately 100 cytokines and compared the expression with those induced by the local metastatic SCLC26A cell line. Macrophages recruited by SCLC26A-CM showed expression of osteopontin (OPN), monocyte chemoattractant protein-1 (MCP-1), IL-8, chitinase3-like 1 (CHI3L1), platelet factor (Pf4), IL-1ra and matrix metalloproteinase-9 (MMP-9) among other minor cytokines/chemokines. In contrast, BHGc7-CM induced marked overexpression of complement factor D (CFD)/adipsin and vitamin D-BP (VDBP), as well as increased secretion of OPN, lipocalin-2 (LCN2), CHI3L1, uPAR, MIP-1 and GDF-15/MIC-1. BHGc10, derived independently from relapsed SCLC, revealed an almost identical pattern with added expression of ENA-78/CXCL5. CMs of the non-tumor HEK293 cell line revealed no induction of macrophages, whereas incubation of PBMNCs with recombinant CHI3L1 gave positive results. Thus, the specific contributions of CTCs in SCLC affect CFD/adipsin, possibly involved in immunity/cachexia, VDBP which gives rise to group-specific component protein-derived macrophage-activating factor (GcMAF), GDF-15/MIC-1 which enhances the malignant phenotype of tumor cells and ENA-78/CXCL5 which attracts angiogenic neutrophils. In conclusion, CTCs are competent to specifically manipulate TAMs to increase invasiveness, angiogenesis, immunosuppression and possibly lipid catabolism.

A Panel of Genetic Polymorphism for the Prediction of Prognosis in Patients with Early Stage Non-Small Cell Lung Cancer after Surgical Resection

Background

This study was conducted to investigate whether a panel of eight genetic polymorphisms can predict the prognosis of patients with early stage non-small cell lung cancer (NSCLC) after surgical resection.

Materials and Methods

We selected eight single nucleotide polymorphisms (SNPs) which have been associated with the prognosis of lung cancer patients after surgery in our previous studies. A total of 814 patients with early stage NSCLC who underwent curative surgical resection were enrolled. The association of the eight SNPs with overall survival (OS) and disease-free survival (DFS) was analyzed.

Results

The eight SNPs (CD3EAP rs967591, TNFRSF10B rs1047266, AKT1 rs3803300, C3 rs2287845, HOMER2 rs1256428, GNB2L1 rs3756585, ADAMTSL3 rs11259927, and CD3D rs3181259) were significantly associated with OS and/or DFS. Combining those eight SNPs, we designed a prognostic index to predict the prognosis of patients. According to relative risk of death, a score value was assigned to each genotype of the SNPs. A worse prognosis corresponded to a higher score value, and the sum of score values of eight SNPs defined the prognostic index of a patient. When we categorized the patients into two groups based on the prognostic index, high risk group was significantly associated with worse OS and DFS compared to low risk group (aHR for OS = 2.21, 95% CI = 1.69–2.88, P = 8.0 x 10⁻⁹, and aHR for DFS = 1.58, 95% CI = 1.29–1.94, P = 1.0 x 10⁻⁵).

Conclusions

Prognostic index using eight genetic polymorphisms may be useful for the prognostication of patients with surgically resected NSCLC.

Complement Inhibition: A Novel Form of Immunotherapy for Colon Cancer

BACKGROUND

Complement is a central part of both the innate and adaptive immune response and its activation has traditionally been considered part of the immunosurveillance response against cancer. Its pro-inflammatory role and its contribution to the development of many illnesses associated with inflammatory states implicate complement in carcinogenesis.

METHODS

We evaluated the role of three protein inhibitors of complement-cobra venom factor, humanized cobra venom factor, and recombinant staphylococcus aureus superantigen-like protein 7-in the setting of a transplantable murine colon cancer model. Outcomes were evaluated by monitoring tumor growth, and flow cytometry, ELISPOT, and quantitative real-time PCR were used to determine the impact of complement inhibition on the host immune response.

RESULTS

Complement inhibitors were effective at depleting complement component C3 in tumor bearing mice and this was temporally correlated with a decreased rate of tumor growth during the establishment of tumors. Treatment with cobra venom factor resulted in increased CD8(+) T cells as a percentage of tumor-infiltrating cells as well as a reduced immunosuppressive environment evidenced by decreased myeloid derived suppressor cells in splenocytes of treated mice. Complement inhibition resulted in increased expression of the chemoattractive cytokines CCL5, CXCL10, and CXCL11.

DISCUSSION

Complement depletion represents a promising mode of immunotherapy in cancer by its ability to impair tumor growth by increasing the host's effective immune response to tumor and diminishing the immunosuppressive effect created by the tumor microenvironment and ultimately could be utilized as a component of combination immunotherapy.

Complement and macrophage crosstalk during process of angiogenesis in tumor progression

The complement system, which contains some of the most potent pro-inflammatory mediators in the tissue including the anaphylatoxins C3a and C5a are the vital parts of innate immunity. Complement activation seems to play a more critical role in tumor development, but little attention has been given to the angiogenic balance of the activated complement mediators and macrophage polarization during tumor progression. The tumor growth mainly supported by the infiltration of M2- tumor-associated macrophages, and high levels of C3a and C5a, whereas M1-macrophages contribute to immune-mediated tumor suppression. Macrophages express a cognate receptors for both C3a and C5a on their cell surface, and specific binding of C3a and C5a affects the functional modulation and angiogenic properties. Activation of complement mediators induce angiogenesis, favors an immunosuppressive microenvironment, and activate cancer-associated signaling pathways to assist chronic inflammation. In this review manuscript, we highlighted the specific roles of complement activation and macrophage polarization during uncontrolled angiogenesis in tumor progression, and therefore blocking of complement mediators would be an alternative therapeutic option for treating cancer.

Clinical predictive circulating peptides in rectal cancer patients treated with neoadjuvant chemoradiotherapy

Preoperative chemoradiotherapy is worldwide accepted as a standard treatment for locally advanced rectal cancer. Current standard of treatment includes administration of ionizing radiation for 45-50.4 Gy in 25-28 fractions associated with 5-fluorouracil administration during radiation therapy. Unfortunately, 40% of patients have a poor or absent response and novel predictive biomarkers are demanding. For the first time, we apply a novel peptidomic methodology and analysis in rectal cancer patients treated with preoperative chemoradiotherapy. Circulating peptides (Molecular Weight <3 kDa) have been harvested from patients' plasma (n = 33) using nanoporous silica chip and analyzed by Matrix-Assisted Laser Desorption/Ionization-Time of Flight mass spectrometer. Peptides fingerprint has been compared between responders and non-responders. Random Forest classification selected three peptides at m/z 1082.552, 1098.537, and 1104.538 that were able to correctly discriminate between responders (n = 16) and non-responders (n = 17) before therapy (T0) providing an overall accuracy of 86% and an area under the receiver operating characteristic (ROC) curve of 0.92. In conclusion, the nanoporous silica chip coupled to mass spectrometry method was found to be a realistic method for plasma-based peptide analysis and we provide the first list of predictive circulating biomarker peptides in rectal cancer patients underwent preoperative chemoradiotherapy.

Inherited variation in immune response genes in follicular lymphoma and diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) both depend on immune-mediated survival and proliferation signals from the tumor microenvironment. Inherited genetic variation influences this complex interaction. A total of 89 studies investigating immune-response genes in DLBCL and FL were critically reviewed. Relatively consistent association exists for variation in the tumor necrosis factor alpha (TNFA) and interleukin-10 loci and DLBCL risk; for DLBCL outcome association with the TNFA locus exists. Variations at chromosome 6p31-32 were associated with FL risk. Importantly, individual risk alleles have been shown to interact with each other. We suggest that the pathogenetic impact of polymorphic genes should include gene-gene interaction analysis and should be validated in preclinical model systems of normal B lymphopoiesis and B-cell malignancies. In the future, large cohort studies of interactions and genome-wide association studies are needed to extend the present findings and explore new risk alleles to be studied in preclinical models.

Toward predicting metastatic progression of melanoma based on gene expression data

Primary and metastatic melanoma tumors share the same cell origin, making it challenging to identify genomic biomarkers that can differentiate them. Primary tumors themselves can be heterogeneous, reflecting ongoing genomic changes as they progress toward metastasizing. We developed a computational method to explore this heterogeneity and to predict metastatic progression of the primary tumors. We applied our method separately to gene expression and to microRNA (miRNA) expression data from ~450 primary and metastatic skin cutaneous melanoma (SKCM) samples from the Cancer Genome Atlas (TCGA). Metastatic progression scores from RNA-seq data were significantly associated with clinical staging of patients' lymph nodes, whereas scores from miRNA-seq data were significantly associated with Clark's level. The loss of expression of many characteristic epithelial lineage genes in primary SKCM tumor samples was highly correlated with predicted progression scores. We suggest that those genes/miRNAs might serve as putative biomarkers for SKCM metastatic progression.

Phagocytes as Corrupted Policemen in Cancer-Related Inflammation

Inflammation is a key component of the tumor microenvironment. Tumor-associated macrophages (TAMs) and tumor-associated neutrophils (TANs) are prototypic inflammatory cells in cancer-related inflammation. Macrophages provide a first line of resistance against infectious agents but in the ecological niche of cancer behave as corrupted policemen. TAMs promote tumor growth and metastasis by direct interactions with cancer cells, including cancer stem cells, as well as by promoting angiogenesis and tissue remodeling and suppressing effective adaptive immunity. In addition, the efficacy of chemotherapy, radiotherapy, and checkpoint blockade inhibitors is profoundly affected by regulation of TAMs. In particular, TAMs can protect and rescue tumor cells from cytotoxic therapy by orchestrating a misguided tissue repair response. Following extensive preclinical studies, there is now proof of concept that targeting tumor-promoting macrophages by diverse strategies (e.g., Trabectedin, anti-colony-stimulating factor-1 receptor antibodies) can result in antitumor activity in human cancer and further studies are ongoing. Neutrophils have long been overlooked as a minor component of the tumor microenvironment, but there is evidence for an important role of TANs in tumor progression. Targeting phagocytes (TAMs and TANs) as corrupted policemen in cancer may pave the way to innovative therapeutic strategies complementing cytoreductive therapies and immunotherapy.

Examination of Epigenetic and other Molecular Factors Associated with mda-9/Syntenin Dysregulation in Cancer Through Integrated Analyses of Public Genomic Datasets

mda-9/Syntenin (melanoma differentiation-associated gene 9) is a PDZ domain containing, cancer invasion-related protein. In this study, we employed multiple integrated bioinformatic approaches to identify the probable epigenetic factors, molecular pathways, and functionalities associated with mda-9 dysregulation during cancer progression. Analyses of publicly available genomic data (e.g., expression, copy number, methylation) from TCGA, GEO, ENCODE, and Human Protein Atlas projects led to the following observations: (a) mda-9 expression correlates with both copy number and methylation level of an intronic CpG site (cg1719774) located downstream of the CpG island, (b) cg1719774 methylation is a likely prognostic marker in glioma, (c) among 22 cancer types, melanoma exhibits the highest mda-9 level, and lowest level of methylation at cg1719774, (d) cg1719774 hypomethylation is also associated with histone modifications (at the mda-9 locus) indicative of more active transcription, (e) using Gene Set Enrichment Analysis (GSEA), and the Virtual Gene Overexpression or Repression (VIGOR) analytical scheme, we were able to predict mda-9's association with extracellular matrix organization (e.g., MMPs, collagen, integrins), IGFBP2 and NF-κB signaling pathways, phospholipid metabolism, cytokines (e.g., interleukins), CTLA-4, and components of complement cascade pathways. Indeed, previous publications have shown that many of the aforementioned genes and pathways are associated with mda-9's functionality.

Complement receptor 1 genetic variants contribute to the susceptibility to gastric cancer in chinese population

As the receptor for C3b/C4b, type 1 complement receptor (CR1/CD35) plays an important role in the regulation of complement activity and is further involved in carcinogenesis. This study aimed to elucidate the association of CR1 genetic variants with the susceptibility to gastric cancer in Chinese population. Based on the NCBI database, totally 13 tag single nucleotide polymorphisms (SNPs) were selected by Haploview program and genotyped using iPlex Gold Genotyping Assay and Sequenom MassArray among 500 gastric cancer cases and 500 healthy controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression to evaluate the association of each SNP with gastric cancer. Of all selected Tag SNPs , CR1 rs9429942 T > C was found to confer to the risk of developing gastric cancer. Compared with the carriers with rs9429942 TT genotype, those with CT genotype had 88% decreased risk of developing gastric cancer with OR (95%CI) of 0.12 (0.03-0.50). Generalized multifactor dimensionality reduction (GMDR) analysis revealed a significant three-way interaction among rs75422544 C > A, rs10494885 C > T and rs7525160 G > C in the development of gastric cancer with a maximum testing balance accuracy of 56.07% and a cross-validation consistency of 7/10 (P = 0.011). In conclusion, our findings demonstrated the genetic role of CR1 gene in the development of gastric cancer in Chinese population.

The tag SNP rs10746463 in decay-accelerating factor is associated with the susceptibility to gastric cancer

BACKGROUND

Complement activation involved in the innate immunity and adaptive immunity and further contributed to the development of tumor growth. This study aimed to investigate the association of genetic variants in complement 3 (C3) and decay-accelerating factor (DAF) genes with the risk of gastric cancer.

METHODS

This case-control study included 500 gastric cancer patients and 500 cancer-free controls. Based on the Chinese population data from HapMap database, we used Haploview 4.2 program to select candidate tag SNPs. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression to evaluate the association of each genetic variant with the risk of gastric cancer.

RESULTS

Among 12 tag SNPs of C3, no correlation was observed between C3 genetic variants and risk of gastric cancer. For tag SNPS of DAF, logistic regression analysis revealed that the carriers with DAF rs10746463 AA genotype had a significantly increased risk for developing gastric cancer (OR = 1.46, 95% CI = 1.01–2.10) when compared with GG genotype, but those carrying with rs10746463 AG genotype didn't (OR = 1.31, 95% CI = 0.98-1.75). When stratified by smoking status, we found that the risk of gastric cancer was associated with rs10746463 GA or AA genotype carriers among smoker with OR (95% CI) of 1.64 (1.06-2.54), but not among non-smoker (OR = 1.37, 95% CI = 0.97-1.94).

CONCLUSION

DAF rs10746463 polymorphism effects on the risk of developing gastric cancer in Chinese population.

Prognostic stromal gene signatures in breast cancer

Introduction

Global gene expression analysis of tumor samples has been a valuable tool to subgroup tumors and has the potential to be of prognostic and predictive value. However, tumors are heterogeneous, and homogenates will consist of several different cell types. This study was designed to obtain more refined expression data representing different compartments of the tumor.

Methods

Formalin-fixed paraffin-embedded stroma-rich triple-negative breast cancer tumors were laser-microdissected, and RNA was extracted and processed to enable microarray hybridization. Genes enriched in stroma were identified and used to generate signatures by identifying correlating genes in publicly available data sets. The prognostic implications of the signature were analyzed.

Results

Comparison of the expression pattern from stromal and cancer cell compartments from three tumors revealed a number of genes that were essentially specifically expressed in the respective compartments. The stroma-specific genes indicated contribution from fibroblasts, endothelial cells, and immune/inflammatory cells. The gene set was expanded by identifying correlating mRNAs using breast cancer mRNA expression data from The Cancer Genome Atlas. By iterative analyses, 16 gene signatures of highly correlating genes were characterized. Based on the gene composition, they seem to represent different cell types. In multivariate Cox proportional hazard models, two immune/inflammatory signatures had opposing hazard ratios for breast cancer recurrence also after adjusting for clinicopathological variables and molecular subgroup. The signature associated with poor prognosis consisted mainly of C1Q genes and the one associated with good prognosis contained HLA genes. This association with prognosis was seen for other cancers as well as in other breast cancer data sets.

Conclusions

Our data indicate that the molecular composition of the immune response in a tumor may be a powerful predictor of cancer prognosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0530-2) contains supplementary material, which is available to authorized users.

Tumor necrosis-initiated complement activation stimulates proliferation of medulloblastoma cells

OBJECTIVE AND DESIGN

We sought to determine the effect of necrosis-induced activation of the complement protein C3 in medulloblastoma.

MATERIALS/METHODS

Twelve medulloblastoma surgical specimens were evaluated for complement activation using immunohistochemistry, with H&E stains performed on adjacent tissue sections to determine the relationship of complement activation to necrotic tissue. Flow cytometry and Western blot were performed on three established medulloblastoma lines and one surgically-procured cell culture to determine expression of C3a receptor (C3aR) in medulloblastoma. In vitro proliferation of siRNA C3aR knockdown cells was compared to that of control siRNA cells with cell line Daoy.

RESULTS

Three surgical specimens were found to have necrosis on H&E sections. In each case, iC3b staining was identified on adjacent sections, limited to the necrotic region. In no case did necrosis occur without iC3b staining on adjacent sections. C3aR protein was demonstrated on both the three established cell lines and on the surgical culture. Proliferation assays of Daoy cells with siRNA knockdown vs. control siRNA revealed significantly reduced proliferation at 72 h (p = 0.001).

CONCLUSIONS

Necrosis is associated with complement activation in medulloblastoma. Medulloblastoma cells express C3aR, and siRNA-mediated knockdown of C3aR inhibits proliferation of these cells in vitro.

Cross-species toxicogenomic analyses and phenotypic anchoring in response to groundwater low-level pollution

Background

Comparison of toxicogenomic data facilitates the identification of deregulated gene patterns and maximizes health risk prediction in human.

Results

Here, we performed phenotypic anchoring on the effects of acute exposure to low-grade polluted groundwater using mouse and zebrafish. Also, we evaluated two windows of chronic exposure in mouse, starting in utero and at the end of lactation. Bioinformatic analysis of livers microarray data showed that the number of deregulated biofunctions and pathways is higher after acute exposure, compared to the chronic one. It also revealed specific profiles of altered gene expression in all treatments, pointing to stress response/mitochondrial pathways as major players of environmental toxicity. Of note, dysfunction of steroid hormones was also predicted by bioinformatic analysis and verified in both models by traditional approaches, serum estrogens measurement and vitellogenin mRNA determination in mice and zebrafish, respectively.

Conclusions

In our report, phenotypic anchoring in two vertebrate model organisms highlights the toxicity of low-grade pollution, with varying susceptibility based on exposure window. The overlay of zebrafish and mice deregulated pathways, more than single genes, is useful in risk identification from chemicals implicated in the observed effects.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1067) contains supplementary material, which is available to authorized users.

Quantitative proteomic analysis of meningiomas for the identification of surrogate protein markers

Meningiomas are the most common non-glial tumors of the brain and spine. Pathophysiology and definite histological grading of meningiomas are frequently found to be deceptive due to their unusual morphological features and locations. Here for the first time we report a comprehensive serum proteomic analysis of different grades of meningiomas by using multiple quantitative proteomic and immunoassay-based approaches to obtain mechanistic insights about disease pathogenesis and identify grade specific protein signatures. In silico functional analysis revealed modulation of different vital physiological pathways including complement and coagulation cascades, metabolism of lipids and lipoproteins, immune signaling, cell growth and apoptosis and integrin signaling in meningiomas. ROC curve analysis demonstrated apolipoprotein E and A-I and hemopexin as efficient predictors for meningiomas. Identified proteins like vimentin, alpha-2-macroglobulin, apolipoprotein B and A-I and antithrombin-III, which exhibited a sequential increase in different malignancy grades of meningiomas, could serve as potential predictive markers.

Complement activation in Glioblastoma multiforme pathophysiology: evidence from serum levels and presence of complement activation products in tumor tissue

Inflammation plays a key role in the pathophysiology of Glioblastoma Multiforme (GBM). Here we focus on the contribution of the so far largely ignored complement system. ELISA and immunohistochemistry were combined to assess levels and localization of critical components of the initiation- and effector pathways of the complement cascade in sera and tumor tissue from GBM patients and matched controls. Serum levels of factor-B were decreased in GBM patients whereas C1q levels were increased. C1q and factor-B deposited in the tumor tissue. Deposition of C3 and C5b-9 suggests local complement activation.MBL deficiency, based on serum levels, was significantly less frequent among GBM patients compared to controls (14% vs. 33%). Therefore low levels of MBL may protect against the initiation/progression of GBM.

Tag SNPs of CFI contributed to the susceptibility for non-small cell lung cancer in Chinese population

Complement factor I (CFI) plays an important role in the development of non-small cell lung cancer (NSCLC). This study aims to examine the association of CFI genetic variants with the risk of developing NSCLC in Chinese population. A hospital-based case-control study was conducted in 470 patients with NSCLC and 470 controls in Chinese population. Totally, 13 tag single nucleotide polymorphisms (tag SNPs) of CFI were selected by Haploview software using the HapMap database. Genotyping was performed using iPLEX Gold Genotyping Assay and Sequenom MassARRAY. The odds ratios (ORs) and 95% confidence interval (95% CI) were calculated by logistic regression model. Our results showed that individuals with rs6822976 GG genotype had a significant decreased risk of NSCLC (OR = 0.64; 95% CI = 0.42-0.98) when compared with rs6822976 AA genotype carriers. We also found that rs7671905 TT genotype exhibited a significant decreased risk of NSCLC compared with CC genotype with OR (95% CI) of 0.55 (0.33-0.91). There was no significant association between other selected SNPs and the risk of NSCLC. When stratified by smoking status, the decreased risk of NSCLC was observed to be associated with the genotype with at least one rs6822976 G allele among non-smokers (OR = 0.66; 95% CI = 0.47-0.93), but not among smokers (OR = 1.01; 95% CI = 0.67-1.53). For CFI rs7671905 polymorphism, the individuals with at least one T allele have a decreased risk of NSCLC with OR (95 % CI) of 0.71 (0.51-0.99), but not among smokers (OR = 0.93; 95% CI = 0.61-1.41). When stratified by age, we found that rs7671905 TT genotype has contributed to the decreased risk of NSCLC among older subjects with OR (95% CI) of 0.46 (0.23-0.95), but not among younger subjects with OR (95% CI) of 0.64 (0.31-1.34) (P(interaction) = 0.03). After stratifying by sex, our study showed that rs7671905 TT genotype was related to the risk of NSCLC among males (OR = 0.53; 95% CI = 0.29-0.98), but not among females (OR = 0.62; 95% CI = 0.25-1.57) (P(interaction) = 0.03). CFI genetic variants played an important role in the development of NSCLC in Chinese population.

Immunological effects and therapeutic role of C5a in cancer

The specific role of C5a in cancer, especially in melanoma, has yet to be determined. Differential effects of C5a could be cancer specific. In the host defense system, C5a functions to protect the body from harmful entities via a plethora of mechanisms. Yet, C5a may also serve to potentiate cancerous process. C5a facilitates cellular proliferation and regeneration by attracting myeloid-derived suppressor cells and supporting tumor promotion. In this article, we critically reviewed the properties, mechanisms of action and functions of C5a, with particular emphasis on cancer inhibition and promotion, and clinical application of such knowledge in better management of patients with cancer. Outstanding questions and future directions in regard to the function of C5a in melanoma and other cancers are discussed.

Complement pathway is frequently altered in endometriosis and endometriosis-associated ovarian cancer

PURPOSE

Mechanisms of immune dysregulation associated with advanced tumors are relatively well understood. Much less is known about the role of immune effectors against cancer precursor lesions. Endometrioid and clear-cell ovarian tumors partly derive from endometriosis, a commonly diagnosed chronic inflammatory disease. We performed here a comprehensive immune gene expression analysis of pelvic inflammation in endometriosis and endometriosis-associated ovarian cancer (EAOC).

EXPERIMENTAL DESIGN

RNA was extracted from 120 paraffin tissue blocks comprising of normal endometrium (n = 32), benign endometriosis (n = 30), atypical endometriosis (n = 15), and EAOC (n = 43). Serous tumors (n = 15) were included as nonendometriosis-associated controls. The immune microenvironment was profiled using Nanostring and the nCounter GX Human Immunology Kit, comprising probes for a total of 511 immune genes.

RESULTS

One third of the patients with endometriosis revealed a tumor-like inflammation profile, suggesting that cancer-like immune signatures may develop earlier, in patients classified as clinically benign. Gene expression analyses revealed the complement pathway as most prominently involved in both endometriosis and EAOC. Complement proteins are abundantly present in epithelial cells in both benign and malignant lesions. Mechanistic studies in ovarian surface epithelial cells from mice with conditional (Cre-loxP) mutations show intrinsic production of complement in epithelia and demonstrate an early link between Kras- and Pten-driven pathways and complement upregulation. Downregulation of complement in these cells interferes with cell proliferation.

CONCLUSIONS

These findings reveal new characteristics of inflammation in precursor lesions and point to previously unknown roles of complement in endometriosis and EAOC.

Exploitation of the complement system by oncogenic Kaposi's sarcoma-associated herpesvirus for cell survival and persistent infection

During evolution, herpesviruses have developed numerous, and often very ingenious, strategies to counteract efficient host immunity. Specifically, Kaposi's sarcoma-associated herpesvirus (KSHV) eludes host immunity by undergoing a dormant stage, called latency wherein it expresses a minimal number of viral proteins to evade host immune activation. Here, we show that during latency, KSHV hijacks the complement pathway to promote cell survival. We detected strong deposition of complement membrane attack complex C5b-9 and the complement component C3 activated product C3b on Kaposi's sarcoma spindle tumor cells, and on human endothelial cells latently infected by KSHV, TIME-KSHV and TIVE-LTC, but not on their respective uninfected control cells, TIME and TIVE. We further showed that complement activation in latently KSHV-infected cells was mediated by the alternative complement pathway through down-regulation of cell surface complement regulatory proteins CD55 and CD59. Interestingly, complement activation caused minimal cell death but promoted the survival of latently KSHV-infected cells grown in medium depleted of growth factors. We found that complement activation increased STAT3 tyrosine phosphorylation (Y705) of KSHV-infected cells, which was required for the enhanced cell survival. Furthermore, overexpression of either CD55 or CD59 in latently KSHV-infected cells was sufficient to inhibit complement activation, prevent STAT3 Y705 phosphorylation and abolish the enhanced survival of cells cultured in growth factor-depleted condition. Together, these results demonstrate a novel mechanism by which an oncogenic virus subverts and exploits the host innate immune system to promote viral persistent infection.

The complement system is an important part of the innate immune system. Pathogens have evolved diverse strategies to evade host immune responses including attack of the complement system. Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with Kaposi's sarcoma (KS), primary effusion lymphoma and a subset of multicentric Castleman's disease. KSHV encodes a number of viral proteins to counter host immune responses during productive lytic replication. On the other hand, KSHV utilizes latency as a default replication program during which it expresses a minimal number of proteins to evade host immune detection. Thus, the complement system is expected to be silent during KSHV latency. In this study, we have found that the complement system is unexpectedly activated in latently KSHV-infected endothelial cells and in KS tumor cells wherein KSHV downregulates the expression of CD55 and CD59 complement regulatory proteins. More interestingly, most of latently KSHV-infected cells not only are resistant to complement-mediated cell killing, but also acquire survival advantage by inducing STAT3 tyrosine phosphorylation. These results demonstrate a novel mechanism by which an oncogenic virus exploits the host innate immune system to promote viral persistent infection.