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

Neoadjuvant chemo- or chemo-radiation-therapy of pancreatic ductal adenocarcinoma differentially shift ECM composition, complement activation, energy metabolism and ribosomal proteins of the residual tumor mass

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer, often diagnosed at stages that dis-qualify for surgical resection. Neoadjuvant therapies offer potential tumor regression and improved resectability. Although features of the tumor biology (e.g., molecular markers) may guide adjuvant therapy, biological alterations after neoadjuvant therapy remain largely unexplored. We performed mass spectrometry to characterize the proteomes of 67 PDAC resection specimens of patients who received either neoadjuvant chemo (NCT) or chemo-radiation (NCRT) therapy. We employed data-independent acquisition (DIA), yielding a proteome coverage in excess of 3500 proteins. Moreover, we successfully integrated two publicly available proteome datasets of treatment-naïve PDAC to unravel proteome alterations in response to neoadjuvant therapy, highlighting the feasibility of this approach. We found highly distinguishable proteome profiles. Treatment-naïve PDAC was characterized by enrichment of immunoglobulins, complement and extracellular matrix (ECM) proteins. Post-NCT and post-NCRT PDAC presented high abundance of ribosomal and metabolic proteins as compared to treatment-naïve PDAC. Further analyses on patient survival and protein expression identified treatment-specific prognostic candidates. We present the first proteomic characterization of the residual PDAC mass after NCT and NCRT, and potential protein candidate markers associated with overall survival. We conclude that residual PDAC exhibits fundamentally different proteome profiles as compared to treatment-naïve PDAC, influenced by the type of neoadjuvant treatment. These findings may impact adjuvant or targeted therapy options.

Reduced decay-accelerating factor expression promotes complement-mediated cystogenesis in murine ADPKD

Patients with autosomal dominant polycystic kidney disease (ADPKD), a genetic disease due to mutations of the PKD1 or PKD2 gene, show signs of complement activation in the urine and cystic fluid, but their pathogenic role in cystogenesis is unclear. We tested the causal relationship between complement activation and cyst growth using a Pkd1KO renal tubular cell line and newly generated conditional Pkd1-/- C3-/- mice. Pkd1-deficient tubular cells have increased expression of complement-related genes (C3, C5, CfB, C3ar, and C5ar1), while the gene and protein expression of complement regulators DAF, CD59, and Crry is decreased. Pkd1-/- C3-/- mice are unable to fully activate the complement cascade and are characterized by a significantly slower kidney cystogenesis, preserved renal function, and reduced intrarenal inflammation compared with Pkd1-/- C3+/+ controls. Transgenic expression of the cytoplasmic C-terminal tail of Pkd1 in Pkd1KO cells lowered C5ar1 expression, restored Daf levels, and reduced cell proliferation. Consistently, both DAF overexpression and pharmacological inhibition of C5aR1 (but not C3aR) reduced Pkd1KO cell proliferation. In conclusion, the loss of Pkd1 promotes unleashed activation of locally produced complement by downregulating DAF expression in renal tubular cells. Increased C5a formation and C5aR1 activation in tubular cells promotes cyst growth, offering a new therapeutic target.

A Practical Method for Synthesizing Iptacopan

Iptacopan, the first orally available small-molecule complement factor B inhibitor, was developed by Novartis AG of Switzerland. Iptacopan for the treatment of PNH was just approved by the FDA in December 2023. Other indications for treatment are still in phase III clinical trials. Iptacopan is a small-molecule inhibitor targeting complement factor B, showing positive therapeutic effects in the treatment of PNH, C3 glomerulonephritis, and other diseases. Although Iptacopan is already on the market, there has been no detailed synthesis process or specific parameter report on the intermediates during the synthesis of its compounds except for the original research patent. In this study, a practical synthesis route for Iptacopan was obtained through incremental improvement while a biosynthesis method for ketoreductase was used for the synthesis of the pivotal intermediate 12. Moreover, by screening the existing enzyme library of our research group on the basis of random as well as site-directed mutagenesis methods, an enzyme (M8) proven to be of high optical purity with a high yield for biocatalectic reduction was obtained. This enzyme was used to prepare the compound benzyl (2S,4S)-4-hydroxy-2-(4-(methoxycarbonyl)-phenyl)-piperidine-1-carboxylate) white powder (36.8 g HPLC purity: 98%, ee value: 99%). In the synthesis of intermediate 15, the reaction was improved from two-step to one-step, which indicated that the risk of chiral allosterism was reduced while the scale was expanded. Finally, Iptacopan was synthesized in a seven-step reaction with a total yield of 29%. Since three chiral intermediate impurities were synthesized directionally, this paper lays a solid foundation for the future of pharmaceutical manufacturing.

Therapy-induced senescent cancer cells exhibit complement activation and increased complement regulatory protein expression

Therapy-induced senescence (TIS) is a primary response to chemotherapy, contributing to untoward treatment outcomes such as evasion of immunosurveillance. Despite the established role of the complement system in the immune response to cancer, the role of complement in mediating the immune response against senescent tumor cells remains poorly understood. To explore this relationship, we exposed lung adenocarcinoma (A549), breast adenocarcinoma (MCF7) and pancreatic carcinoma (Panc-1) cell lines to sublethal doses of either etoposide or doxorubicin to trigger TIS. Identification of TIS was based on morphological changes, upregulation of the senescence-associated β-galactosidase, p21Cip1 induction and lamin B1 downregulation. Using immunofluorescence microscopy, quantitative PCR, ELISA of conditioned media and in silico analysis, we investigated complement activation, complement protein expression, C3 levels in the conditioned media of senescent cells and secreted complement proteins as part of the senescence-associated secretory phenotype (SASP), respectively. In cell lines undergoing TIS, complement-related changes included (i) activation of the terminal pathway, evidenced by the deposition of C5b-9 on senescent cells; (ii) an increase in the expression of CD59 and complement factor H and (iii) in A549 cells, an elevation in the expression of C3 with its secretion into the medium. In addition, increased C3 expression was observed in breast cancer samples expressing TIS hallmarks following exposure to neoadjuvant chemotherapy. In conclusion, TIS led to the activation of complement, upregulation of complement regulatory proteins and increased C3 expression. Complement appears to play a role in shaping the cancer microenvironment upon senescence induction.

Complement System and the Kidney: Its Role in Renal Diseases, Kidney Transplantation and Renal Cell Carcinoma

The crosstalk among the complement system, immune cells, and mediators of inflammation provides an efficient mechanism to protect the organism against infections and support the repair of damaged tissues. Alterations in this complex machinery play a role in the pathogenesis of different diseases. Core complement proteins C3 and C5, their activation fragments, their receptors, and their regulators have been shown to be active intracellularly as the complosome. The kidney is particularly vulnerable to complement-induced damage, and emerging findings have revealed the role of complement system dysregulation in a wide range of kidney disorders, including glomerulopathies and ischemia-reperfusion injury during kidney transplantation. Different studies have shown that activation of the complement system is an important component of tumorigenesis and its elements have been proved to be present in the TME of various human malignancies. The role of the complement system in renal cell carcinoma (RCC) has been recently explored. Clear cell and papillary RCC upregulate most of the complement genes relative to normal kidney tissue. The aim of this narrative review is to provide novel insights into the role of complement in kidney disorders.

Identification of a glycolysis-related miRNA Signature for Predicting Breast cancer Survival

Breast cancer (BC) is a common type of cancer and has a poor prognosis. In this study, we collected the mRNA and miRNA expression profiles of BC patients were obtained from The Cancer Genome Atlas (TCGA) to explore a novel prognostic strategy for BC patients using bioinformatics tools. We found that six glycolysis-related miRNAs (GRmiRs, including hsa-mir-1247, hsa-mir148b, hsa-mir-133a-2, has-mir-1307, hsa-mir-195 and hsa-mir-1258) were correlated with prognosis of BC samples. The risk score model was established based on 6 prognosis-associated GRmiRs. The outcome of high risk group was significantly poorer. Cox regression analysis showed that risk score was an independent prognostic factor. Differentially expressed genes identified between high and low risk groups were mainly enriched in inflammation and immune-related signaling pathways. The proportion of infiltration of 12 kinds of immune cells in high and low risk groups were significantly different. Risk score was closely associated with many immune indexes. Multiple DEGRGs and miRNAs were associated with drugs. In conclusion, glycolysis-related miRNA signature effectively predicts BC prognosis.

A Novel Blood Proteomic Signature for Prostate Cancer

Prostate cancer is the most common malignant tumour in men. Improved testing for diagnosis, risk prediction, and response to treatment would improve care. Here, we identified a proteomic signature of prostate cancer in peripheral blood using data-independent acquisition mass spectrometry combined with machine learning. A highly predictive signature was derived, which was associated with relevant pathways, including the coagulation, complement, and clotting cascades, as well as plasma lipoprotein particle remodeling. We further validated the identified biomarkers against a second cohort, identifying a panel of five key markers (GP5, SERPINA5, ECM1, IGHG1, and THBS1) which retained most of the diagnostic power of the overall dataset, achieving an AUC of 0.91. Taken together, this study provides a proteomic signature complementary to PSA for the diagnosis of patients with localised prostate cancer, with the further potential for assessing risk of future development of prostate cancer. Data are available via ProteomeXchange with identifier PXD025484.

Upregulation of complement proteins in lung cancer cells mediates tumor progression

Introduction

In vivo, cancer cells respond to signals from the tumor microenvironment resulting in changes in expression of proteins that promote tumor progression and suppress anti-tumor immunity. This study employed an orthotopic immunocompetent model of lung cancer to define pathways that are altered in cancer cells recovered from tumors compared to cells grown in culture.

Methods

Studies used four murine cell lines implanted into the lungs of syngeneic mice. Cancer cells were recovered using FACS, and transcriptional changes compared to cells grown in culture were determined by RNA-seq.

Results

Changes in interferon response, antigen presentation and cytokine signaling were observed in all tumors. In addition, we observed induction of the complement pathway. We previously demonstrated that activation of complement is critical for tumor progression in this model. Complement can play both a pro-tumorigenic role through production of anaphylatoxins, and an anti-tumorigenic role by promoting complement-mediated cell killing of cancer cells. While complement proteins are produced by the liver, expression of complement proteins by cancer cells has been described. Silencing cancer cell-specific C3 inhibited tumor growth In vivo. We hypothesized that induction of complement regulatory proteins was critical for blocking the anti-tumor effects of complement activation. Silencing complement regulatory proteins also inhibited tumor growth, with different regulatory proteins acting in a cell-specific manner.

Discussion

Based on these data we propose that localized induction of complement in cancer cells is a common feature of lung tumors that promotes tumor progression, with induction of complement regulatory proteins protecting cells from complement mediated-cell killing.

Effect of Heme Oxygenase-1 Depletion on Complement Regulatory Proteins Expression in the Rat

Heme oxygenase has been implicated in the regulation of various immune responses including complement activation. Using a transgenic rat model of HO-1 depletion, the present study assessed the effect of HO-1 absence on the expression of complement regulatory proteins: decay accelerating factor (DAF), CR1-related gene/protein Y (Crry) and CD59, which act to attenuate complement activation. Protein expression was assessed by immunohistochemistry in kidney, liver, lung and spleen tissues. DAF protein was reduced in all tissues retrieved from rats lacking HO-1 (Hmox1-/-) apart from spleen tissue sections. Crry protein was also reduced, but only in Hmox1-/- kidney and liver tissue. C3b staining was augmented in the kidney and spleen from Hmox1-/- rats, suggesting that the decrease of DAF and Crry was sufficient to increase C3b deposition. The observations support an important role of HO-1 as a regulator of the complement system.

Silencing EGFR-upregulated expression of CD55 and CD59 activates the complement system and sensitizes lung cancer to checkpoint blockade

The complement system is a critical immune component, yet its role in tumor immune evasion and CD8⁺ T cell activation is not clearly defined. Here, we demonstrate that epidermal growth factor receptor (EGFR)/Wnt signaling induces β-catenin-mediated long noncoding RNA (lncRNA) LINC00973 expression to sponge CD55-targeting miR-216b and CD59-targeting miR-150. The consequently upregulated CD55/CD59 expression suppresses the complement system and cytokine secretion required for CD8⁺ T cell activation. CD55/CD59-neutralizing antibody treatment or mutation of the LINC00973 promoter activates the complement and CD8⁺ T cells, inhibiting tumor growth. Importantly, combined anti-CD55/CD59 and anti-programmed death 1 (anti-PD-1) antibody treatments elicit a synergistic tumor-inhibiting effect. In addition, CD55/CD59 levels are inversely correlated with infiltration of M1 macrophages and CD8⁺ T cells in human lung cancer specimens and predict patient outcome. These findings underscore the critical role of EGFR/Wnt/β-catenin-upregulated CD55/CD59 expression in inhibiting the complement and CD8⁺ T cell activation for tumor immune evasion and immune checkpoint blockade resistance and identify a potential combination therapy to overcome these effects.

C3a and C5b-9 Differentially Predict COVID-19 Progression and Outcome

SARS-CoV-2 infection may result in severe pneumonia leading to mechanical ventilation and intensive care (ICU) treatment. Complement activation was verified in COVID-19 and implicated as a contributor to COVID-19 pathogenesis. This study assessed the predictive potential of complement factors C3a and C5b-9 for COVID-19 progression and outcome. We grouped 80 COVID-19 patients into severe COVID-19 patients (n = 38) and critically ill (n = 42) and subdivided into non-intubated (n = 48) and intubated (n = 32), survivors (n = 57) and non-survivors (n = 23). Results: A significant increase for C3a and C5b-9 levels was observed between: severely and critically ill patients (p < 0.001 and p < 0.0001), non-intubated vs intubated (p < 0.001 and p < 0.05), survivors vs non-survivors (p < 0.001 and p < 0.01). ROC analysis for the need for ICU treatment revealed a higher AUC for C5b-9 (0.764, p < 0.001) compared to C3a (AUC = 0.739, p < 0.01). A higher AUC was observed for C3a for the need for intubation (AUC = 0.722, p < 0.001) or mortality (AUC = 0.740, p < 0.0001) compared to C5b-9 (need for intubation AUC = 0.656, p < 0.05 and mortality AUC = 0.631, p = NS). Combining the two markers revealed a powerful prediction tool for ICU admission (AUC = 0.773, p < 0.0001), intubation (AUC = 0.756, p < 0.0001) and mortality (AUC = 0.753, p < 0.001). C3a and C5b-9 may be considered as prognostic tools separately or in combination for the progression and outcome of COVID-19.

Mycobiota and C-Type Lectin Receptors in Cancers: Know thy Neighbors

Numerous studies have demonstrated the importance of gut bacteria in the development of malignancy, while relatively little research has been done on gut mycobiota. As a part of the gut microbiome, the percentage of gut mycobiota is negligible compared to gut bacteria. However, the effect of gut fungi on human health and disease is significant. This review systematically summarizes the research progress on mycobiota, especially gut fungi, in patients with head and neck cancer (HNC), esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), hepatocellular carcinoma (HCC), pancreatic cancer, melanoma, breast cancer, and lung carcinoma-induced cachexia. Moreover, we also describe, for the first time in detail, the role of the fungal recognition receptors, C-type lectin receptors (CLRs) (Dectin-1, Dectin-2, Dectin-3, and Mincle) and their downstream effector caspase recruitment domain-containing protein 9 (CARD9), in tumors to provide a reference for further research on intestinal fungi in the diagnosis and treatment of malignant tumors.

Components of the Lectin Pathway of Complement in Solid Tumour Cancers

The complement system is an important branch of the humoral innate immune response that can be activated via three distinct pathways (classical, alternative, lectin), contributing to keeping/restoring homeostasis. It can also interact with cellular innate immunity and with components of acquired immunity. Cross-talk between the complement system and other enzyme-dependent cascades makes it a more influential defence system, but on the other hand, over- or chronic activation can be harmful. This short review is focused on the dual role of the lectin pathway of complement activation in human solid tumour cancers, including those of the female reproductive system, lung, and alimentary tract, with emphasis on the aforementioned cross-talk.

Role of ADCC, CDC, and CDCC in Vaccine-Mediated Protection against Her2 Mammary Carcinogenesis

Amplification or mutation of the Her2 oncoantigen in human mammary glands leads to the development of an aggressive breast carcinoma. Several features of this breast carcinoma are reproduced in mammary carcinomas that spontaneously arise in female transgenic mice bearing the activated rat Her2 oncogene under transcriptional control of the mouse mammary tumor virus promoter-BALB-neuT (neuT) mice. We previously demonstrated that carcinoma progression in neuT mice can be prevented by DNA vaccination with RHuT, a plasmid coding for a chimeric rat/human Her2 protein. RHuT vaccination exerts an antitumor effect, mostly mediated by the induction of a strong anti-rat Her2 antibody response. IgG induced by RHuT vaccine mainly acts by blocking Her2 signaling, thus impairing cell cycle progression and inducing apoptosis of cancer cells, but other indirect effector mechanisms could be involved in the antibody-mediated protection. The recruitment of cells with perforin-dependent cytotoxic activity, able to perform antibody-dependent cellular cytotoxicity, has already been investigated. Less is known about the role of the complement system in sustaining antitumor response through complement-dependent cytotoxicity and cellular cytotoxicity in vaccinated mice. This work highlights that the weight of such mechanisms in RHuT-induced cancer protection is different in transplantable versus autochthonous Her2⁺ tumor models. These results may shed new light on the effector mechanisms involved in antibody-dependent anti-cancer responses, which might be exploited to ameliorate the therapy of Her2⁺ breast cancer.

Complement Factor D Is a Novel Biomarker and Putative Therapeutic Target in Cutaneous Squamous Cell Carcinoma

Simple Summary

The incidence of the most common metastatic skin malignancy, cutaneous squamous cell carcinoma (cSCC), is growing worldwide, and the prognosis of the metastatic disease is poor. Presently, there are no biomarkers or therapeutic targets for high-risk cSCCs. Recent studies have demonstrated the essential role of autocrine complement synthesis in the progression of cSCC. Here, we have evaluated the role of complement Factor D (FD), the rate-limiting enzyme of the alternative complement pathway, in cSCC development. The results identify FD as a novel biomarker and putative therapeutic target for cSCC and propose the small-molecule FD inhibitor Danicopan as a highly specific drug candidate in the therapy of advanced cSCC. It is expected that the discovery of complement-associated molecular markers for cSCC progression would improve diagnosis, classification, prognostication, and targeted therapy of cSCC and its precursors in the future.

Abstract

Cutaneous squamous cell carcinoma (cSCC) is the most prevalent metastatic skin cancer. Previous studies have demonstrated the autocrine role of complement components in cSCC progression. We have investigated factor D (FD), the key enzyme of the alternative complement pathway, in the development of cSCC. RT-qPCR analysis of cSCC cell lines and normal human epidermal keratinocytes (NHEKs) demonstrated significant up-regulation of FD mRNA in cSCC cells compared to NHEKs. Western blot analysis also showed more abundant FD production by cSCC cell lines. Significantly higher FD mRNA levels were noted in cSCC tumors than in normal skin. Strong tumor cell-associated FD immunolabeling was detected in the invasive margin of human cSCC xenografts. More intense tumor cell-specific immunostaining for FD was seen in the tumor edge in primary and metastatic cSCCs, in metastases, and in recessive dystrophic epidermolysis bullosa-associated cSCCs, compared with cSCC in situ, actinic keratosis and normal skin. FD production by cSCC cells was dependent on p38 mitogen-activated protein kinase activity, and it was induced by interferon-γ and interleukin-1β. Blocking FD activity by Danicopan inhibited activation of extracellular signal-regulated kinase 1/2 and attenuated proliferation of cSCC cells. These results identify FD as a novel putative biomarker and therapeutic target for cSCC progression.

A review on association of fungi with the development and progression of carcinogenesis in the human body

The role and impact of commensal and pathogenic fungi in different parts of the human body are being increasingly appreciated, unveiling the importance of such microorganisms in human health. A key function is the involvement of the mycobiota in cross-kingdom interactions within the microbiome. Any disturbance in the functionality of the microbiota could alter metabolic reactions, have a negative impact on homeostasis or induce diseases. The association of fungi with cancer development is the focus of this review. Several studies have reported direct or indirect involvement of fungal pathogens and mycobiome dysbiosis in induction of carcinogenesis. Most studies focused on cancers of the gastrointestinal tract. However, researchers are now investigating other organs, such as the skin, where the significant results obtained confirm the involvement of fungal pathogens and administration of antifungal drugs in development of cancer. This review gives an overview of the different organs affected and describes the mechanisms used by these eukaryotes or antifungals to induce oncogenesis.

Role of Complement in Regulating Inflammation Processes in Renal and Prostate Cancers

For decades, the complement system, the central pillar of innate immune response, was recognized as a protective mechanism against cancer cells and the manipulation of complement effector functions in cancer setting offered a great opportunity to improve monoclonal antibody-based cancer immunotherapies. Similarly, cellular senescence, the process of cell cycle arrest that allow DNA and tissue repair has been traditionally thought to be able to suppress tumor progression. However, in recent years, extensive research has identified the complement system and cellular senescence as two main inducers of tumour growth in the context of chronic, persistent inflammation named inflammaging. Here, we discuss the data describing the ambivalent role of senescence in cancer with a particular focus on tumors that are strongly dependent on complement activation and can be understood by a new, senescence-related point of view: prostate cancer and renal cell carcinoma.

Immunomodulatory and cytotoxic activities of euphol

AIMS

This study evaluated the effect of euphol isolated from Euphorbia umbellata (Pax) Bruyns latex on the activation of complement pathways (classical (CP), alternative (AP) and lectin (LP)), neutrophil chemotaxis, cytotoxic activity, cell morphology and death in HRT-18 and 3T3 cells lines.

MAIN METHODS

CP and AP were assessed using hemolytic assays and ELISA for LP; neutrophil chemotaxis was performed using Boyden's chamber; cytotoxicity was evaluated by neutral red methodology and characteristics of cell death were assessed by cell morphology with hematological staining.

KEY FINDINGS

Although euphol increased CP activation (38% at a concentration of 976.1 μM), an inhibitory effect on AP, LP (31% and 32% reduction in the concentration of 976.1 μM) and neutrophil chemotaxis (inhibit 84% of neutrophil migration at a concentration 292.9 μM) was observed. In addiction euphol was able to induce significant cell death in a time-dependent manner, presenting an IC₅₀ of 70.8 μM and 39.2 μM for HRT-18 and 3T3 cell lines respectively and it was also observed apoptotic characteristics as cellular rounding, chromatin condensation and blebs formation for both cell lines.

SIGNIFICANCE

Euphol has a potential use for the treatment of complement-related inflammatory diseases due to its ability to downregulate inflammation. On the other hand, the controlled activation of CP can contribute to complement-dependent cytotoxicity in the context of monoclonal antibody-based cancer treatment.

Emerging Role of C5 Complement Pathway in Peripheral Neuropathies: Current Treatments and Future Perspectives

The complement system is a key component of innate immunity since it plays a critical role in inflammation and defense against common pathogens. However, an inappropriate activation of the complement system is involved in numerous disorders, including peripheral neuropathies. Current strategies for neuropathy-related pain fail to achieve adequate pain relief, and although several therapies are used to alleviate symptoms, approved disease-modifying treatments are unavailable. This urgent medical need is driving the development of therapeutic agents for this condition, and special emphasis is given to complement-targeting approaches. Recent evidence has underscored the importance of complement component C5a and its receptor C5aR1 in inflammatory and neuropathic pain, indicating that C5a/C5aR1 axis activation triggers a cascade of events involved in pathophysiology of peripheral neuropathy and painful neuro-inflammatory states. However, the underlying pathophysiological mechanisms of this signaling in peripheral neuropathy are not fully known. Here, we provide an overview of complement pathways and major components associated with dysregulated complement activation in peripheral neuropathy, and of drugs under development targeting the C5 system. C5/C5aR1 axis modulators could represent a new strategy to treat complement-related peripheral neuropathies. Specifically, we describe novel C5aR allosteric modulators, which may potentially become new tools in the therapeutic armory against neuropathic pain.

Complement factor I upregulates expression of matrix metalloproteinase-13 and -2 and promotes invasion of cutaneous squamous carcinoma cells

The incidence of cutaneous squamous cell carcinoma (cSCC) is increasing globally. Here, we have studied the functional role of complement factor I (CFI) in the progression of cSCC. CFI was knocked down in cSCC cells, and RNA-seq analysis was performed. Significant downregulation of genes in IPA biofunction categories Proliferation of cells and Growth of malignant tumor, in Gene Ontology (GO) terms Metallopeptidase activity and Extracellular matrix component, as well as Reactome Degradation of extracellular matrix was detected after CFI knockdown. Further analysis of the latter three networks, revealed downregulation of several genes coding for invasion-associated matrix metalloproteinases (MMPs) after CFI knockdown. The downregulation of MMP-13 and MMP-2 was confirmed at mRNA, protein and tissue levels by qRT-qPCR, Western blot and immunohistochemistry, respectively. Knockdown of CFI decreased the invasion of cSCC cells through type I collagen. Overexpression of CFI in cSCC cells resulted in enhanced production of MMP-13 and MMP-2 and increased invasion through type I collagen and Matrigel, and in increased ERK1/2 activation and cell proliferation. Altogether, these findings identify a novel mechanism of action of CFI in upregulation of MMP-13 and MMP-2 expression and cSCC invasion. These results identify CFI as a prospective molecular marker for invasion and metastasis of cSCC.

High fat diet, gut microbiome and gastrointestinal cancer

Gastrointestinal cancer is currently one of the main causes of cancer death, with a large number of cases and a wide range of lesioned sites. A high fat diet, as a public health problem, has been shown to be correlated with various digestive system diseases and tumors, and can accelerate the occurrence of cancer due to inflammation and altered metabolism. The gut microbiome has been the focus of research in recent years, and associated with cell damage or tumor immune microenvironment changes via direct or extra-intestinal effects; this may facilitate the occurrence and development of gastrointestinal tumors. Based on research showing that both a high fat diet and gut microbes can promote the occurrence of gastrointestinal tumors, and that a high fat diet imbalances intestinal microbes, we propose that a high fat diet drives gastrointestinal tumors by changing the composition of intestinal microbes.

Single-cell RNA-seq reveals dynamic change in tumor microenvironment during pancreatic ductal adenocarcinoma malignant progression

Background

Pancreatic ductal adenocarcinoma (PDAC) is most aggressive among all gastrointestinal tumors. The complex intra-tumor heterogeneity and special tumor microenvironment in PDAC bring great challenges for developing effective treatment strategies. We aimed to delineate dynamic changes of tumor microenvironment components during PDAC malignant progression utilizing single-cell RNA sequencing.

Methods

A total of 11 samples (4 PDAC I, 4 PDAC II, 3 PDAC III) were used to construct expression matrix. After identifying distinct cell clusters, subcluster analysis for each cluster was performed. New cancer associated fibroblasts (CAFs) subset was validated by weighted gene co-expression network analysis, RNA in situ hybridization and immunofluorescence.

Findings

We found that ductal cells were not dominant component while tumor infiltrating immune cells and pancreatic stellate cells gradually accumulated during tumor development. We defined several new Treg and exhausted T cell signature genes, including DUSP4, FANK1 and LAIR2. The analysis of TCGA datasets showed that patients with high expression of DUSP4 had significantly worse prognosis. In addition, we identified a new CAFs subset (complement-secreting CAFs, csCAFs), which specifically expresses complement system components, and constructed csCAFs-related module by weighted gene co-expression network analysis. The csCAFs were located in the tissue stroma adjacent to malignant ductal cells only in early PDAC.

Interpretation

We systematically explored PDAC heterogeneity and identified csCAFs as a new CAFs subset special to PDAC, which may be valuable for understanding the crosstalk inside tumor.

Funding

This study was supported by The Natural Science Foundation of China (NO.81572339, 81672353, 81871954) and the Youth Clinical Research Project of Peking University First Hospital (2018CR28).

"Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.

A study of multinucleated giant cells in esophageal cancer

OBJECTIVES

To evaluate the occurrence, abundance, distribution, nature and clinical significance of multinucleated giant cell (MGC) in esophageal cancer.

MATERIALS AND METHODS

MGCs were examined with conventional pathology, immunohistochemistry and immunofluorescence in 107 esophageal cancer tissues. The findings were correlated to pathological diagnosis and clinical behavior of the cancers.

RESULTS

MGCs were identified in 31.7% (34/107) of the cases. MGCs were positive for CD11c, CD11b, CD32, CD16, HLA-DR and MMP9, and negative for CD163, CD206 and CD64 giving a molecular profile of proinflammatory M1 but not immunosuppressive M2. MGCs were significantly related to decreased lymph node metastasis (p = 0.011), low pTNM stage (p = 0.044), favorable survival (p = 0.04), squamous cell cancer type rather than other histopathological subtypes (p = 0.020) and associated to better differentiation (p = 0.063).

CONCLUSIONS

MGCs belong to M1 macrophage and perform phagocytosis and scavenging of cancer cells that would benefit patients' survival and could serve as a prognostic marker.

Evaluation of Serum and Gene Expression of Galectin-4, Interleukin-27, and Complement-7 in Hepatitis C Virus-Infected Egyptian Patients

Background

Hepatitis C virus (HCV) is considered a major global public health problem. Recently, there are great advances in HCV therapy, but there are some limitations that are creating an urgent need for assessment of some cytokines that have a potent antiviral effect in the immune system and anti-inflammatory effects to provide a potential novel immunotherapeutic target in HCV infection.

Objective

This study was directed to assess the serum levels and gene expression levels of Galectin-4 (LEG4), Interleukin-27 (IL-27), and Complement-7 (C-7) and their correlation with the viral load in HCV infection. Subjects and Methods. This work was conducted on 80 subjects, Group 1 (n = 40) early detected HCV patients and Group 2 (n = 40) healthy controls. LEG4, IL-27, and C-7 were assessed at the protein levels by ELISA, and their gene expression was assessed by RT-qPCR. The viral load was measured by PCR.

Results

There were significant elevations in the mean levels of gene expression and serum levels of all studied parameters LEG4, IL-27, and C-7 in the HCV group compared to the control group. Significant negative correlations between the viral load and each of the serum proteins and gene expressions of both LEG4 and IL-27 in HCV patients were found. The gene expression levels of LEG4, IL-27, and C-7 were positively correlated with their corresponding serum proteins in HCV patients.

Conclusion

LEG4 and IL-27 showed significant negative correlations with the viral load, which could be an immune response to the control of the extent of hepatic inflammation, thus creating a potential novel immunotherapeutic approach in HCV infection for further studies or therapeutic clinical trials.

Soluble Membrane Attack Complex: Biochemistry and Immunobiology

The soluble membrane attack complex (sMAC, a.k.a., sC5b-9 or TCC) is generated on activation of complement and contains the complement proteins C5b, C6, C7, C8, C9 together with the regulatory proteins clusterin and/or vitronectin. sMAC is a member of the MACPF/cholesterol-dependent-cytolysin superfamily of pore-forming molecules that insert into lipid bilayers and disrupt cellular integrity and function. sMAC is a unique complement activation macromolecule as it is comprised of several different subunits. To date no complement-mediated function has been identified for sMAC. sMAC is present in blood and other body fluids under homeostatic conditions and there is abundant evidence documenting changes in sMAC levels during infection, autoimmune disease and trauma. Despite decades of scientific interest in sMAC, the mechanisms regulating its formation in healthy individuals and its biological functions in both health and disease remain poorly understood. Here, we review the structural differences between sMAC and its membrane counterpart, MAC, and examine sMAC immunobiology with respect to its presence in body fluids in health and disease. Finally, we discuss the diagnostic potential of sMAC for diagnostic and prognostic applications and potential utility as a companion diagnostic.

Modulation of complement activation by pentraxin-3 in prostate cancer

Pentraxin 3 (PTX3) is an essential component of the innate immune system and a recognized modulator of Complement cascade. The role of Complement system in the pathogenesis of prostate cancer has been largely underestimated. The aim of our study was to investigate the role of PTX3 as possible modulator of Complement activation in the development of this neoplasia. We performed a single center cohort study; from January 2017 through December 2018, serum and prostate tissue samples were obtained from 620 patients undergoing prostate biopsy. A group of patients with benign prostatic hyperplasia (BPH) underwent a second biopsy within 12–36 months demonstrating the presence of a prostate cancer (Group A, n = 40) or confirming the diagnosis of BPH (Group B, N = 40). We measured tissue PTX3 protein expression together with complement activation by confocal microscopy in the first and second biopsy in group A and B patients. We confirmed that that PTX3 tissue expression in the first biopsy was increased in group A compared to group B patients. C1q deposits were extensively present in group A patients co-localizing and significantly correlating with PTX3 deposits; on the contrary, C1q/PTX3 deposits were negative in group B. Moreover, we found a significantly increased expression of C3a and C5a receptors within resident cells in group A patient. Interestingly, C1q/PTX3 deposits were not associated with activation of the terminal Complement complex C5b-9; moreover, we found a significant increase of Complement inhibitor CD59 in cancer tissue. Our data indicate that PTX3 might play a significant pathogenic role in the development of this neoplasia through recruitment of the early components of Complement cascade with hampered activation of terminal Complement pathway associated with the upregulation of CD59. This alteration might lead to the PTX3-mediated promotion of cellular proliferation, angiogenesis and insensitivity to apoptosis possible leading to cancer cell invasion and migration.

Systems-level differential gene expression analysis reveals new genetic variants of oral cancer

Oral cancer (OC) ranked as eleventh malignancy worldwide, with the increasing incidence among young patients. Limited understanding of complications in cancer progression, its development system, and their interactions are major restrictions towards the progress of optimal and effective treatment strategies. The system-level approach has been designed to explore genetic complexity of the disease and to identify novel oral cancer related genes to detect genomic alterations at molecular level, through cDNA differential analysis. We analyzed 21 oral cancer-related cDNA datasets and listed 30 differentially expressed genes (DEGs). Among 30, we found 6 significant DEGs including CYP1A1, CYP1B1, ADCY2, C7, SERPINB5, and ANAPC13 and studied their functional role in OC. Our genomic and interactive analysis showed significant enrichment of xenobiotics metabolism, p53 signaling pathway and microRNA pathways, towards OC progression and development. We used human proteomic data for post-translational modifications to interpret disease mutations and inter-individual genetic variations. The mutational analysis revealed the sequence predicted disordered region of 14%, 12.5%, 10.5% for ADCY2, CYP1B1, and C7 respectively. The MiRNA target prediction showed functional molecular annotation including specific miRNA-targets hsa-miR-4282, hsa-miR-2052, hsa-miR-216a-3p, for CYP1B1, C7, and ADCY2 respectively associated with oral cancer. We constructed the system level network and found important gene signatures. The drug-gene interaction of OC source genes with seven FDA approved OC drugs help to design or identify new drug target or establishing novel biomedical linkages regarding disease pathophysiology. This investigation demonstrates the importance of system genetics for identifying 6 OC genes (CYP1A1, CYP1B1, ADCY2, C7, SERPINB5, and ANAPC13) as potential drugs targets. Our integrative network-based system-level approach would help to find the genetic variants of OC that can accelerate drug discovery outcomes to develop a better understanding regarding treatment strategies for many cancer types.

How Do mAbs Make Use of Complement to Kill Cancer Cells? The Role of Ca2

We examined the kinetics and mechanisms by which monoclonal antibodies (mAbs) utilize complement to rapidly kill targeted cancer cells. Based on results from flow cytometry, confocal microscopy and high-resolution digital imaging experiments, the general patterns which have emerged reveal cytotoxic activities mediated by substantial and lethal Ca2+ fluxes. The Ca2+ fluxes are common to the reported pathways that have been utilized by other toxins in killing nucleated cells. These reactions terminate in very high levels of cell killing, and based on these considerations, we suggest additional strategies to further enhance mAb-based targeting of cancer with complement.

Components of the Lectin Pathway of Complement in Haematologic Malignancies

The complement system is activated cascadically via three distinct major routes: classical pathway (CP), alternative pathway (AP) or lectin pathway (LP). The unique factors associated with the latter are collectins (mannose-binding lectin, collectin-10, collectin-11), ficolins (ficolin-1, ficolin-2, ficolin-3) and proteins of the mannose-binding lectin-associated serine protease (MASP) family (MASP-1, MASP-2, MASP-3, MAp19, MAp44). Collectins and ficolins are both pattern-recognising molecules (PRM), reactive against pathogen-associated molecular patterns (PAMP) or danger-associated molecular patterns (DAMP). The MASP family proteins were first discovered as complexes with mannose-binding lectin (MBL) and therefore named MBL-associated serine proteases, but later, they were found to interact with ficolins, and later still, collectin-10 and collectin-11. As well as proteolytic enzymes (MASP-1, MASP-2, MASP-3), the group includes non-enzymatic factors (MAp19, MAp44). In this review, the association-specific factors of the lectin pathway with haematologic malignancies and related infections are discussed.

Deciphering the Intricate Roles of Radiation Therapy and Complement Activation in Cancer

The complement system consists of a collection of serum proteins that act as the main frontline effector arm of the innate immune system. Activation of complement can occur through 3 individual induction pathways: the classical, mannose-binding lectin, and alternative pathways. Activation results in opsonization, recruitment of effector cells through potent immune mediators known as anaphylatoxins, and cell lysis via the formation of the membrane attack complex. Stringent regulation of complement is required to protect against inappropriate activation of the complement cascade. Complement activation within the tumor microenvironment does not increase antitumoral action; instead, it enhances tumor growth and disease progression. Radiation therapy (RT) is a staple in the treatment of malignancies and controls tumor growth through direct DNA damage and the influx of immune cells, reshaping the makeup of the tumor microenvironment. The relationship between RT and complement activity in the tumor microenvironment is uncertain at best. The following review will focus on the complex interaction of complement activation and the immune-modulating effects of RT and the overall effect on tumor progression. The clinical implications of complement activation in cancer and the use of therapeutics and potential biomarkers will also be covered.

Bioinformatics analysis of key biomarkers and potential molecular mechanisms in hepatocellular carcinoma induced by hepatitis B virus

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for up to 90% of all primary hepatic malignancies; it is the sixth most common cancer and the second most common cause of cancer mortality worldwide. Numerous studies have shown that hepatitis B virus and its products, HBV integration, and mutation can induce HCC. However, the molecular mechanisms underpinning the regulation of HCC induced by HBV remain unclear.

METHODS

We downloaded 2 gene expression profiling datasets, of HBV and of HCC induced by HBV, from the gene expression omnibus (GEO) database. Differentially expressed genes (DEGs) between HCC and HBV were identified to explore any predisposing changes in gene expression associated with HCC. DEGs between HCC and adjacent healthy tissues were investigated to identify genes that may play a key role in HCC. Any overlapping genes among these DEGs were included in our bioinformatics analysis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of overlapping genes were performed using the Metascape online database; the protein-protein interaction (PPI) network was analyzed using the STRING online database; and we obtained the hub genes of the PPI network using Cytoscape software. An overall survival (OS) analysis of hub genes was performed using km-plotter and the gene expression profiling interactive analysis (GEPIA) online database. The expression levels of hub genes were determined using the TCGA and GEPIA databases. Finally, the relationships between hub genes and tumors were analyzed using the comparative toxicogenomics database (CTD).

RESULTS

We identified 113 overlapping genes from the 2 datasets. Using functional and pathway analyses, we found that the overlapping genes were mainly related to the AMPK signaling pathway and cellular responses to cadmium ions. C8A, SPP2, KLKB1, PROZ, C6, FETUB, MBL2, HGFAC, C8B, and ANGPTL3 were identified as hub genes and C8A, SPP2, PROZ, C6, HGFAC, and C8B were found to be significant for survival.

CONCLUSION

The DEGs re-analyzed between HCC and hepatitis B enable a systematic understanding of the molecular mechanisms of HCC reliant on hepatitis B virus.

PTX3 modulates the immunoflogosis in tumor microenvironment and is a prognostic factor for patients with clear cell renal cell carcinoma

Pentraxin-3 (PTX3) belongs to the pentraxine family, innate immune regulators involved in angiogenesis, proliferation and immune escape in cancer. Here, we evaluated PTX3 tissue expression and serum levels as biomarkers of clear cell renal cell carcinoma (ccRCC) and analyzed the possible role of complement system activation on tumor site. A 10-year retrospective cohort study including patients undergoing nephrectomy for ccRCC was also performed. PTX3 expression was elevated in both neoplastic renal cell lines and tissues, while it was absent in both normal renal proximal tubular cells (HK2) and normal renal tissues. Analysis of complement system activation on tumor tissues showed the co-expression of PTX3 with C1q, C3aR, C5R1 and CD59, but not with C5b-9 terminal complex. RCC patients showed higher serum PTX3 levels as compared to non-neoplastic patients (p<0.0001). Higher PTX3 serum levels were observed in patients with higher Fuhrman grade (p<0.01), lymph node (p<0.0001), and visceral metastases (p<0.001). Patients with higher PTX3 levels also showed significantly lower survival rates (p=0.002). Our results suggest that expression of PTX3 can affect the immunoflogosis in the ccRCC microenvironment, by activating the classical pathway of CS (C1q) and releasing pro-angiogenic factors (C3a, C5a). The up-regulation of CD59 also inhibits the complement-mediated cellular lysis.

Dichotomy of complement system: Tumorigenesis or destruction

Complement system proteins, their regulators and endpoint effector complex significantly promote tumor growth by upregulation of oncogenic growth factors, activation of mitogenic signalling pathways and breakage of normal cell cycle. Contrastingly, complement cascades, initiated by anti-tumor therapeutic antibodies, also play a pivotal role in therapy response. This contradictory role of complement system possibly be a very crucial factor for the outcomes of antibody mediated immunotherapies. Herein, we reviewed the twin role of the complement system in cancer and also the genetic variations in complement system genes. Future studies should be focused on the biomarker discovery for the personalised cancer immunotherapies.

Drivers and regulators of humoral innate immune responses to infection and cancer

The complement cascade consists of cell bound and serum proteins acting together to protect the host from pathogens, remove cancerous cells and effectively links innate and adaptive immune responses. Despite its usefulness in microbial neutralization and clearance of cancerous cells, excessive complement activation causes an immune imbalance and tissue damage in the host. Hence, a series of complement regulatory proteins present at a higher concentration in blood plasma and on cell surfaces tightly regulate the cascade. The complement cascade can be initiated by B-1 B cell production of natural antibodies. Natural antibodies arise spontaneously without any known exogenous antigenic or microbial stimulus and protect against invading pathogens, clear apoptotic cells, provide tissue homeostasis, and modulate adaptive immune functions. Natural IgM antibodies recognize microbial and cancer antigens and serve as an activator of complement mediated lysis. This review will discuss advances in complement activation and regulation in bacterial and viral infections, and cancer. We will also explore the crosstalk of natural antibodies with bacterial populations and cancer.

Associations of Ficolins With Hematological Malignancies in Patients Receiving High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantations

A prospective study of 312 patients [194 with multiple myeloma (MM) and 118 with lymphomas (LYMPH)] receiving high-dose chemotherapy and autologous hematopoietic stem cell transplantation (auto-HSCT) was conducted. Ficolins are innate immune defense factors, able to distinguish between "self" "abnormal self," and "non-self" and contribute to the elimination of the last two by direct opsonization and/or initiation of complement activation via the lectin pathway. Concentrations of ficolin-1, ficolin-2, and ficolin-3 in serially taken serum samples were determined as were the polymorphisms of the corresponding (FCN1, FCN2, and FCN3) genes. Serum samples were collected before conditioning chemotherapy, before HSCT, and once weekly post-HSCT (four to five samples in total); some patients were also sampled at 1 and/or 3 months post-transplantation. The control group (C) consisted of 267 healthy unrelated individuals. Median ficolin-1 and ficolin-2 (but not ficolin-3) levels in MM patients' sera taken before chemotherapy were lower (and correspondingly frequencies of the lowest concentrations were higher) compared with controls. That appeared to be associated with the malignant disease itself rather than with post-HSCT complications (febrile neutropenia, infections accompanied, or not with bacteremia). Higher frequencies of the FCN1 genotype G/A-C/C-G/G (corresponding to polymorphisms at positions -542, -144, and +6658, respectively) and FCN2 gene heterozygosity for the -857 C>A polymorphism were found among patients diagnosed with MM compared with the C group. Furthermore, FCN2 G/G homozygosity (-557 A>G) was found more frequently and heterozygosity G/T at +6424 less frequently among LYMPH patients than among the healthy subjects. Heterozygosity for +1637delC mutation of the FCN3 gene was more common among patients diagnosed with lymphomas who experienced hospital infections. Although no evidence for an association of low ficolin-1 or ficolin-2 with infections during neutropenia following chemotherapy before HSCT was found, we observed a possible protective effect of ficolins during follow-up.

Effect of m6A RNA Methylation Regulators on Malignant Progression and Prognosis in Renal Clear Cell Carcinoma

Objectives: This study aims to explore the roles of 13 m⁶A RNA methylation regulators in clear cell renal cell carcinoma (ccRCC), and identify a risk signature and prognostic values of m⁶A RNA methylation regulators in ccRCC. Materials and Methods: RNA sequence data of ccRCC was obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed of 13 m⁶A RNA methylation regulators in ccRCC stratified by different clinicopathological characteristics were unveiled using "limma" package in R version 3.6.0. Cox regression and LASSO analyses were conducted to identify the powerful independent prognostic factors in ccRCC associated with overall survival (OS). Protein-protein interaction (PPI) network and correlation analyses of the 13 m⁶A RNA methylation regulators were performed using "STRING" and R package, respectively. Principal component analysis (PCA) was also done using R. In addition, gene ontology (GO), GSEA and Kyoto Encyclopedia of Genes and Genomes pathways were used to functionally annotate the differentially expressed genes in different subgroups. Results: Most of the 13 m⁶A RNA methylation regulators are differentially expressed in ccRCC tissue samples stratified by different clinicopathological characteristics in 537 patients. Next, a risk signature for predicting prognosis of ccRCC patients, was established based on two powerful independent prognostic m⁶A RNA methylation regulators (METTL14 and METTL3). Then, two subgroups (cluster1 and 2) were identified by consensus clustering to the two powerful independent factors and the cluster1 had a poorer prognosis than cluster2. Furthermore, the genes in cluster1 were significantly enriched in cancer-related pathways, biological process, and hallmarks, including "cell adhesion molecules (CAMs)," "leukocyte migration," "Wnt/β-catenin signaling," and so on. Conclusion: M⁶A RNA methylation regulators play important roles in the initiation and progression of ccRCC and provide a novel sight to understand m⁶A RNA modification in ccRCC.

Preclinical and Clinical Evidence of Immune Responses Triggered in Oncologic Photodynamic Therapy: Clinical Recommendations

Photodynamic therapy (PDT) is an anticancer strategy utilizing light-mediated activation of a photosensitizer (PS) which has accumulated in tumor and/or surrounding vasculature. Upon activation, the PS mediates tumor destruction through the generation of reactive oxygen species and tumor-associated vasculature damage, generally resulting in high tumor cure rates. In addition, a PDT-induced immune response against the tumor has been documented in several studies. However, some contradictory results have been reported as well. With the aim of improving the understanding and awareness of the immunological events triggered by PDT, this review focuses on the immunological effects post-PDT, described in preclinical and clinical studies. The reviewed preclinical evidence indicates that PDT is able to elicit a local inflammatory response in the treated site, which can develop into systemic antitumor immunity, providing long-term tumor growth control. Nevertheless, this aspect of PDT has barely been explored in clinical studies. It is clear that further understanding of these events can impact the design of more potent PDT treatments. Based on the available preclinical knowledge, recommendations are given to guide future clinical research to gain valuable information on the immune response induced by PDT. Such insights directly obtained from cancer patients can only improve the success of PDT treatment, either alone or in combination with immunomodulatory approaches.

Complement C3 overexpression activates JAK2/STAT3 pathway and correlates with gastric cancer progression

Background

Localized C3 deposition is a well-known factor of inflammation. However, its role in oncoprogression of gastric cancer (GC) remains obscured. This study aims to explore the prognostic value of C3 deposition and to elucidate the mechanism of C3-related oncoprogression for GC.

Methods

From August to December 2013, 106 GC patients were prospectively included. The regional expression of C3 and other effectors in gastric tissues were detected by WB, IHC, qRT-PCR and other tests. The correlation of localized C3 deposition and oncologic outcomes was determined by 5-year survival significance. Human GC and normal epithelial cell lines were employed to detect a relationship between C3 and STAT3 signaling pathway in vitro experiments.

Results

C3 and C3a expression were markedly enhanced in GC tissues at both mRNA and protein levels compared with those in paired nontumorous tissues. According to IHC C3 score, 65 (61.3%) and 41 (38.7%) patients had high and low C3 deposition, respectively. C3 deposition was negatively correlated with plasma levels of C3 and C3a (both P < 0.001) and positively correlated with pathological T and TNM stages (both P < 0.001). High C3 deposition was identified as an independent prognostic factor of poor 5-year overall survival (P = 0.045). In vitro C3 administration remarkably enhanced p-JAK2/p-STAT3 expression in GC cell lines but caused a reduction of such activation when pre-incubated with a C3 blocker. Importantly, C3 failed to activate such signaling in cells pre-treated with a JAK2 inhibitor.

Conclusions

Localized C3 deposition in the tumor microenvironment is a relevant immune signature for predicting prognosis of GC. It may aberrantly activate JAK2/STAT3 pathway allowing oncoprogression.

Trial registration

ClinicalTrials.gov, NCT02425930, Registered 1st August 2013.

circRNA-associated ceRNA network construction reveals the circRNAs involved in the progression and prognosis of breast cancer

Recently, increasing evidences show that circular RNAs (circRNAs) are important regulators of various diseases, especially cancer. However, the regulatory role and the potential mechanism of action of circRNAs in breast cancer remain largely unknown. In this study, weighted gene co-expression network analysis was conducted with the differentially expressed miRNAs and mRNAs in breast cancer from The Cancer Genome Atlas database to identify the key modules associated with the carcinogenesis of breast cancer. In the significant turquoise and brown modules, 22 miRNAs and 1877 mRNAs were identified, respectively. Then, We compared and predicted the target genes and performed survival analysis to identify the miRNAs and mRNAs related to the prognosis of breast cancer. A circRNA-related competitive endogenous RNA network was identified by database co-screening, and deleted in liver cancer 1 (DLC1) was identified as a key gene. Finally, to assess how genes in key modules and key genes contribute to the development of breast cancer, relevant pathway information was obtained through DAVID and Gene Set Enrichment Analysis. These data demonstrated that three circRNAs (hsa-circ-0083373, hsa-circ-0083374, and hsa-circ-0083375) that regulate DLC1 expression via hsa-mir-511 and are involved in the pathogenesis and development of breast cancer.

Identification of Salivary Biomarkers for Oral Cancer Detection with Untargeted and Targeted Quantitative Proteomics Approaches

Oral cavity squamous cell carcinoma (OSCC) is one of the most common cancers worldwide. In Taiwan, OSCC is the fifth leading cause of cancer-related mortality and leads to 2800 deaths per year. The poor outcome of OSCC patients is principally ascribed to the fact that this disease is often advanced at the time of diagnosis, suggesting that early detection of OSCC is urgently needed. Analysis of cancer-related body fluids is one promising approach to identify biomarker candidates of cancers. To identify OSCC biomarkers, salivary proteomes of OSCC patients, individuals with oral potentially malignant disorders (OPMDs), and healthy volunteers were comparatively profiled with isobaric tags for relative and absolute quantitation (iTRAQ)-based mass spectrometry (MS). The salivary levels of 67 and 18 proteins in the OSCC group are elevated and decreased compared with that in the noncancerous group (OPMD and healthy groups), respectively. The candidate biomarkers were further selected using the multiple reaction monitoring (MRM)-MS and validated with the immunoassays. More importantly, the higher salivary level of three proteins, complement factor H (CFH), fibrinogen alpha chain (FGA), and alpha-1-antitrypsin (SERPINA1) was correlated with advanced stages of OSCC. Our results indicate that analysis of salivary proteome is a feasible strategy for biomarker discovery, and the three proteins are potential salivary markers for OSCC diagnosis.

Tumour-cell-derived complement components C1r and C1s promote growth of cutaneous squamous cell carcinoma

Background

The incidence of epidermal keratinocyte‐derived cutaneous squamous cell carcinoma (cSCC) is increasing worldwide.

Objectives

To study the role of the complement classical pathway components C1q, C1r and C1s in the progression of cSCC.

Methods

The mRNA levels of C1Q subunits and C1R and C1S in cSCC cell lines, normal human epidermal keratinocytes, cSCC tumours in vivo and normal skin were analysed with quantitative real‐time polymerase chain reaction. The production of C1r and C1s was determined with Western blotting. The expression of C1r and C1s in tissue samples in vivo was analysed with immunohistochemistry and further investigated in human cSCC xenografts by knocking down C1r and C1s.

Results

Significantly elevated C1R and C1S mRNA levels and production of C1r and C1s were detected in cSCC cells, compared with normal human epidermal keratinocytes. The mRNA levels of C1R and C1S were markedly elevated in cSCC tumours in vivo compared with normal skin. Abundant expression of C1r and C1s by tumour cells was detected in invasive sporadic cSCCs and recessive dystrophic epidermolysis bullosa‐associated cSCCs, whereas the expression of C1r and C1s was lower in cSCC in situ, actinic keratosis and normal skin. Knockdown of C1r and C1s expression in cSCC cells inhibited activation of extracellular signal‐related kinase 1/2 and Akt, promoted apoptosis of cSCC cells and significantly suppressed growth and vascularization of human cSCC xenograft tumours in vivo.

Conclusions

These results provide evidence for the role of tumour‐cell‐derived C1r and C1s in the progression of cSCC and identify them as biomarkers and putative therapeutic targets in cSCC.

What's already known about this topic?

The incidences of actinic keratosis, cutaneous squamous cell carcinoma (cSCC) in situ and invasive cSCC are increasing globally.

Few specific biomarkers for progression of cSCC have been identified, and no biological markers are in clinical use to predict the aggressiveness of actinic keratosis, cSCC in situ and invasive cSCC.

What does this study add?

Our results provide novel evidence for the role of complement classical pathway components C1r and C1s in the progression of cSCC.

What is the translational message?

Our results identify complement classical pathway components C1r and C1s as biomarkers and putative therapeutic targets in cSCC.

Linked Comment: https://doi.org/10.1111/bjd.18419.

https://doi.org/10.1111/bjd.18821 available online

Complement System in Cutaneous Squamous Cell Carcinoma

Epidermal keratinocyte-derived cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer with high mortality rates in the advanced stage. Chronic inflammation is a recognized risk factor for cSCC progression and the complement system, as a part of innate immunity, belongs to the microenvironment of tumors. The complement system is a double-edged sword in cancer, since complement activation is involved in anti-tumor cytotoxicity and immune responses, but it also promotes cancer progression directly and indirectly. Recently, the role of several complement components and inhibitors in the regulation of progression of cSCC has been shown. In this review, we will discuss the role of complement system components and inhibitors as biomarkers and potential new targets for therapeutic intervention in cSCC.

Deciphering Fc-mediated Antiviral Antibody Functions in Animal Models

Longstanding discordances and enigmas persist as to the specificities and other properties of antibodies (Abs) most effective in preventing or limiting many viral infections in mammals; in turn, failure to decipher key complexities has added to headwinds for both Ab-based therapeutic approaches and rational vaccine design. More recently, experimental approaches have emerged-and continue to emerge-for discerning the functional role of Ab structure, especially the Fc portion of antibody, in combating viral infections in vivo. A wide range of in vitro measures of antibody activity, from neutralization to antibody-dependent cell mediated cytotoxicity (ADCC)-each of these terms representing only an operational notion defined by the particulars of a given assay-are poised for assignment of both relevance and reliability in forecasting outcomes of infection. Of the several emergent technical opportunities for clarity, attention here is drawn to three realms: the increasing array of known modifications that can be engineered into Abs to affect their in vivo activities; the improvement of murine models involving knockouts and knock-ins of host genes including Fc receptors; and the development of additional virological design tools to differentiate Abs that act primarily by inhibiting viral entry from antibodies that mainly target viral antigens (Ags) on cell surfaces. To illustrate some of the opportunities with either zoonotic (emerging, spillover) or ancient human-adapted viruses, we draw examples from a wide range of viruses that affect humans.

The Role of Membrane Bound Complement Regulatory Proteins in Tumor Development and Cancer Immunotherapy

It has long been understood that the control and surveillance of tumors within the body involves an intricate dance between the adaptive and innate immune systems. At the center of the interplay between the adaptive and innate immune response sits the complement system—an evolutionarily ancient response that aids in the destruction of microorganisms and damaged cells, including cancer cells. Membrane-bound complement regulatory proteins (mCRPs), such as CD46, CD55, and CD59, are expressed throughout the body in order to prevent over-activation of the complement system. These mCRPs act as a double-edged sword however, as they can also over-regulate the complement system to the extent that it is no longer effective at eliminating cancerous cells. Recent studies are now indicating that mCRPs may function as a biomarker of a malignant transformation in numerous cancer types, and further, are being shown to interfere with anti-tumor treatments. This highlights the critical roles that therapeutic blockade of mCRPs can play in cancer treatment. Furthermore, with the complement system having the ability to both directly and indirectly control adaptive T-cell responses, the use of a combinatorial approach of complement-related therapy along with other T-cell activating therapies becomes a logical approach to treatment. This review will highlight the biomarker-related role that mCRP expression may have in the classification of tumor phenotype and predicted response to different anti-cancer treatments in the context of an emerging understanding that complement activation within the Tumor Microenvironment (TME) is actually harmful for tumor control. We will discuss what is known about complement activation and mCRPs relating to cancer and immunotherapy, and will examine the potential for combinatorial approaches of anti-mCRP therapy with other anti-tumor therapies, especially checkpoint inhibitors such as anti PD-1 and PD-L1 monoclonal antibodies (mAbs). Overall, mCRPs play an essential role in the immune response to tumors, and understanding their role in the immune response, particularly in modulating currently used cancer therapeutics may lead to better clinical outcomes in patients with diverse cancer types.

Targeting the Complement Pathway as a Therapeutic Strategy in Lung Cancer

Lung cancer is the leading cause of cancer death in men and women. Lung adenocarcinoma (LUAD), represents approximately 40% of all lung cancer cases. Advances in recent years, such as the identification of oncogenes and the use of immunotherapies, have changed the treatment of LUAD. Yet survival rates still remain low. Additionally, there is still a gap in understanding the molecular and cellular interactions between cancer cells and the immune tumor microenvironment (TME). Defining how cancer cells with distinct oncogenic drivers interact with the TME and new strategies for enhancing anti-tumor immunity are greatly needed. The complement cascade, a central part of the innate immune system, plays an important role in regulation of adaptive immunity. Initially it was proposed that complement activation on the surface of cancer cells would inhibit cancer progression via membrane attack complex (MAC)-dependent killing. However, data from several groups have shown that complement activation promotes cancer progression, probably through the actions of anaphylatoxins (C3a and C5a) on the TME and engagement of immunoevasive pathways. While originally shown to be produced in the liver, recent studies show localized complement production in numerous cell types including immune cells and tumor cells. These results suggest that complement inhibitory drugs may represent a powerful new approach for treatment of NSCLC, and numerous new anti-complement drugs are in clinical development. However, the mechanisms by which complement is activated and affects tumor progression are not well understood. Furthermore, the role of local complement production vs. systemic activation has not been carefully examined. This review will focus on our current understanding of complement action in LUAD, and describe gaps in our knowledge critical for advancing complement therapy into the clinic.

Complementing the Cancer-Immunity Cycle

Reactivation of cytotoxic CD8+ T-cell responses has set a new direction for cancer immunotherapy. Neutralizing antibodies targeting immune checkpoint programmed cell death protein 1 (PD-1) or its ligand (PD-L1) have been particularly successful for tumor types with limited therapeutic options such as melanoma and lung cancer. However, reactivation of T cells is only one step toward tumor elimination, and a substantial fraction of patients fails to respond to these therapies. In this context, combination therapies targeting more than one of the steps of the cancer-immune cycle may provide significant benefits. To find the best combinations, it is of upmost importance to understand the interplay between cancer cells and all the components of the immune response. This review focuses on the elements of the complement system that come into play in the cancer-immunity cycle. The complement system, an essential part of innate immunity, has emerged as a major regulator of cancer immunity. Complement effectors such as C1q, anaphylatoxins C3a and C5a, and their receptors C3aR and C5aR1, have been associated with tolerogenic cell death and inhibition of antitumor T-cell responses through the recruitment and/or activation of immunosuppressive cell subpopulations such as myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), or M2 tumor-associated macrophages (TAMs). Evidence is provided to support the idea that complement blocks many of the effector routes associated with the cancer-immunity cycle, providing the rationale for new therapeutic combinations aimed to enhance the antitumor efficacy of anti-PD-1/PD-L1 checkpoint inhibitors.