Differential expression of IL-6/IL-6R and MAO-A regulates invasion/angiogenesis in breast cancer

Interleukin-6 serves as a critical factor in various cancer progression and therapy

Interleukin-6 (IL-6), a pro-inflammatory cytokine, plays a crucial role in host immune defense and acute stress responses. Moreover, it modulates various cellular processes, including proliferation, apoptosis, angiogenesis, and differentiation. These effects are facilitated by various signaling pathways, particularly the signal transducer and activator of transcription 3 (STAT3) and Janus kinase 2 (JAK2). However, excessive IL-6 production and dysregulated signaling are associated with various cancers, promoting tumorigenesis by influencing all cancer hallmarks, such as apoptosis, survival, proliferation, angiogenesis, invasiveness, metastasis, and notably, metabolism. Emerging evidence indicates that selective inhibition of the IL-6 signaling pathway yields therapeutic benefits across diverse malignancies, such as multiple myeloma, prostate, colorectal, renal, ovarian, and lung cancers. Targeting key components of IL-6 signaling, such as IL-6Rs, gp130, STAT3, and JAK via monoclonal antibodies (mAbs) or small molecules, is a heavily researched approach in preclinical cancer studies. The purpose of this study is to offer an overview of the role of IL-6 and its signaling pathway in various cancer types. Furthermore, we discussed current preclinical and clinical studies focusing on targeting IL-6 signaling as a therapeutic strategy for various types of cancer.

Cell surface CD55 traffics to the nucleus leading to cisplatin resistance and stemness by inducing PRC2 and H3K27 trimethylation on chromatin in ovarian cancer

BACKGROUND

Platinum resistance is the primary cause of poor survival in ovarian cancer (OC) patients. Targeted therapies and biomarkers of chemoresistance are critical for the treatment of OC patients. Our previous studies identified cell surface CD55, a member of the complement regulatory proteins, drives chemoresistance and maintenance of cancer stem cells (CSCs). CSCs are implicated in tumor recurrence and metastasis in multiple cancers.

METHODS

Protein localization assays including immunofluorescence and subcellular fractionation were used to identify CD55 at the cell surface and nucleus of cancer cells. Protein half-life determinations were used to compare cell surface and nuclear CD55 stability. CD55 deletion mutants were generated and introduced into cancer cells to identify the nuclear trafficking code, cisplatin sensitivity, and stem cell frequency that were assayed using in vitro and in vivo models. Detection of CD55 binding proteins was analyzed by immunoprecipitation followed by mass spectrometry. Target pathways activated by CD55 were identified by RNA sequencing.

RESULTS

CD55 localizes to the nucleus of a subset of OC specimens, ascites from chemoresistant patients, and enriched in chemoresistant OC cells. We determined that nuclear CD55 is glycosylated and derived from the cell surface pool of CD55. Nuclear localization is driven by a trafficking code containing the serine/threonine (S/T) domain of CD55. Nuclear CD55 is necessary for cisplatin resistance, stemness, and cell proliferation in OC cells. CD55 S/T domain is necessary for nuclear entry and inducing chemoresistance to cisplatin in both in vitro and in vivo models. Deletion of the CD55 S/T domain is sufficient to sensitize chemoresistant OC cells to cisplatin. In the nucleus, CD55 binds and attenuates the epigenetic regulator and tumor suppressor ZMYND8 with a parallel increase in H3K27 trimethylation and members of the Polycomb Repressive Complex 2.

CONCLUSIONS

For the first time, we show CD55 localizes to the nucleus in OC and promotes CSC and chemoresistance. Our studies identify a therapeutic mechanism for treating platinum resistant ovarian cancer by blocking CD55 nuclear entry.

Sulfonyl thioureas with a benzo[d]thiazole ring as dual acetylcholinesterase/butyrylcholinesterase and human monoamine oxidase A and B inhibitors: An in vitro and in silico study

A series of sulfonyl thioureas 6a-q containing a benzo[d]thiazole ring with an ester functional group was synthesized from corresponding substituted 2-aminobenzo[d]thiazoles 3a-q and p-toluenesulfonyl isothiocyanate. They had remarkable inhibitory activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO)-A, and MAO-B. Among thioureas, several compounds had notable activity in the order of 6k > 6 h > 6c (AChE), 6j > 6g > 6k (BChE), 6k > 6g > 6f (MAO-A), and 6i > 6k > 6h (MAO-B). Compound 6k was an inhibitor of interest due to its potent or good activity against all studied enzymes, with IC50 values of 0.027 ± 0.008 μM (AChE), 0.043 ± 0.004 μM (BChE), 0.353 ± 0.01 μM (MAO-A), and 0.716 ± 0.02 μM (MAO-B). This inhibitory capacity was comparable to that of the reference drugs for each enzyme. Kinetic studies of two compounds with potential activity, 6k (against AChE) and 6j (against BChE), had shown that both 6k and 6j followed competitive-type enzyme inhibition, with Ki constants of 24.49 and 12.16 nM, respectively. Induced fit docking studies for enzymes 4EY7, 7BO4, 2BXR, and 2BYB showed active interactions between sulfonyl thioureas of benzo[d]thiazoles and the residues in the active pocket with ligands 6k, 6i, and 6j, respectively. The stability of the ligand-protein complexes while each ligand entered the active site of each enzyme (4EY7, 7BO4, 2BXR, or 2BYB) was confirmed by molecular dynamics simulations.

GLUT1 regulates the release of VEGF-A in the alveolar epithelium of lipopolysaccharide-induced acute lung injury

Acute lung injury (ALI) is a severe disease with high mortality and poor prognosis, characterized by excessive and uncontrolled inflammatory response. Vascular endothelial growth factor A (VEGF-A) contributes to the development and progression of ALI. The aim of this study was to evaluate the role of glucose transporter 1 (GLUT1) in alveolar epithelial VEGF-A production in lipopolysaccharide (LPS)-induced ALI. An ALI mouse model was induced by LPS oropharyngeal instillation. Mice were challenged with LPS and then treated with WZB117, a specific antagonist of GLUT1. For the vitro experiments, cultured A549 cells (airway epithelial cell line) were exposed to LPS, with or without the GLUT1 inhibitors WZB117 or BAY876. LPS significantly upregulated of GLUT1 and VEGF-A both in the lung from ALI mice and in cultured A549. In vivo, treatment with WZB117 not only markedly decreased LPS-induced pulmonary edema, injury, neutrophilia, as well as levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF), but also reduced VEGF-A production. Yet, the maximum tolerated concentration of WZB117 failed to suppress LPS-induced VEGF-A overexpression in vitro. While administration of BAY876 inhibited gene and protein expression as well as secretion of VEGF-A in response to LPS in A549. These results illustrated that GLUT1 upregulates VEGF-A production in alveolar epithelia from LPS-induced ALI, and inhibition of GLUT1 alleviates ALI.

Targeting inflammation as cancer therapy

Inflammation has accompanied human beings since the emergence of wounds and infections. In the past decades, numerous efforts have been undertaken to explore the potential role of inflammation in cancer, from tumor development, invasion, and metastasis to the resistance of tumors to treatment. Inflammation-targeted agents not only demonstrate the potential to suppress cancer development, but also to improve the efficacy of other therapeutic modalities. In this review, we describe the highly dynamic and complex inflammatory tumor microenvironment, with discussion on key inflammation mediators in cancer including inflammatory cells, inflammatory cytokines, and their downstream intracellular pathways. In addition, we especially address the role of inflammation in cancer development and highlight the action mechanisms of inflammation-targeted therapies in antitumor response. Finally, we summarize the results from both preclinical and clinical studies up to date to illustrate the translation potential of inflammation-targeted therapies.

Paclitaxel combined with Compound K inducing pyroptosis of non-small cell lung cancer cells by regulating Treg/Th17 balance

BACKGROUND

Immune checkpoint inhibitors, which have attracted much attention in recent years, have achieved good efficacy, but their use is limited by the high incidence of acquired drug resistance. Therefore, there is an urgent need to develop new immunotherapy drugs. Compound taxus chinensis capsule (CTC) is an oral paclitaxel compound drug, clinical results showed it can change the number of regulatory T cells and T helper cell 17 in peripheral blood. Regulating the balance between regulatory T cells and T helper cell 17 is considered to be an effective anticancer strategy. Paclitaxel and ginsenoside metabolite compound K are the main immunomodulatory components, it is not clear that paclitaxel combined with compound K can inhibit tumor development by regulating the balance between regulatory T cell and T helper cell 17.

METHODS

MTT, EdU proliferation and plate colony formation assay were used to determine the concentration of paclitaxel and compound K. AnnexinV-FITC/PI staining, ELISA, Western Blot assay, Flow Cytometry and Immunofluorescence were used to investigate the effect of paclitaxel combined with compound K on Lewis cell cultured alone or co-cultured with splenic lymphocyte. Finally, transplanted tumor C57BL/6 mice model was constructed to investigate the anti-cancer effect in vivo.

RESULTS

According to the results of MTT, EdU proliferation and plate colony formation assay, paclitaxel (10 nM) and compound K (60 μM) was used to explore the mechanism. The results of Flow Cytometry demonstrated that paclitaxel combined with compound K increased the number of T helper cell 17 and decreased the number of regulatory T cells, which induced pyroptosis of cancer cells. The balance was mediated by the JAK-STAT pathway according to the results of Western Blot and Immunofluorescence. Finally, the in vivo results showed that paclitaxel combined with compound K significantly inhibit the progression of lung cancer.

CONCLUSIONS

In this study, we found that paclitaxel combined with compound K can activate CD8+ T cells and induce pyroptosis of tumor cells by regulating the balance between regulatory T cells and T helper cell 17. These results demonstrated that this is a feasible treatment strategy for lung cancer.

IL-6 upregulates the expression of IL-6R through the JAK2/STAT3 signalling pathway to promote progression of hepatocellular carcinoma

The progression of hepatocellular carcinoma (HCC) involves multifactor, multistep interactions. High expression of interleukin-6 receptor (IL-6R) plays an important role in the occurrence and development of tumours, but the regulatory mechanism of IL-6R expression and its function in HCC have not been fully defined. Western blot was used to evaluate the phosphorylation of key kinases in the JAK2/STAT3 pathway and the protein expression levels of related proliferation molecules, migration molecules and apoptotic molecules. The antiapoptosis, migration and proliferation of cells of each group were analysed with JC-1 to judge the cell apoptosis rate, the EdU method to determine the proliferation vitality of the cells, clone formation experiments and Transwell experiments. High expression of IL-6R in cell lines, lower protein levels of the apoptotic molecules c-Caspase7 and c-Caspase3 and higher protein levels of the proliferative molecules p-P70S6K and migration molecules MMP9 and MMP2 were consistent with stronger antiapoptosis, proliferation and migration. Interestingly, IL-6 upregulated the expression of IL-6R by activating the JAK2/STAT3 signalling pathway. Also, the expression of IL-6R protein was downregulated after lentivirus knockdown of STAT3. In nude mice bearing subcutaneous tumours, upregulation of IL-6R expression after activation of the JAK2/STAT3 signalling pathway by IL-6 significantly increased tumour growth. Moreover, the expression of IL-6R protein was downregulated, and the terminal tumour volume was significantly downregulated in the lentiviral STAT3 knockdown group. IL-6 regulated the transcription of IL-6R through the activation of the JAK2/STAT3 signalling pathway.

LCK facilitates DNA damage repair by stabilizing RAD51 and BRCA1 in the nucleus of chemoresistant ovarian cancer

Poly-ADP Ribose Polymerase (PARP) targeted therapy is clinically approved for the treatment of homologous recombination (HR) repair deficient tumors. The remarkable success of this therapy in the treatment of HR repair deficient cancers has not translated to HR-proficient cancers. Our studies identify the novel role of non-receptor lymphocyte-specific protein tyrosine kinase (LCK) in the regulation of HR repair in endometrioid epithelial ovarian cancer (eEOC) model. We show that DNA damage leads to direct interaction of LCK with the HR repair proteins RAD51 and BRCA1 in a kinase dependent manner RAD51 and BRCA1 stabilization. LCK expression is induced and activated in the nucleus in response to DNA damage insult. Disruption of LCK expression attenuates RAD51, BRCA1, and BRCA2 protein expression by hampering there stability and results in inhibition of HR-mediated DNA repair including suppression of RAD51 foci formation, and augmentation of γH2AX foci formation. In contrast LCK overexpression leads to increased RAD51 and BRCA1 expression with a concomitant increase in HR DNA damage repair. Importantly, attenuation of LCK sensitizes HR-proficient eEOC cells to PARP inhibitor in cells and pre-clinical mouse studies. Collectively, our findings identify a novel therapeutic strategy to expand the utility of PARP targeted therapy in HR proficient ovarian cancer.

The application and research progress of anti-angiogenesis therapy in tumor immunotherapy

Tumor immunotherapy, as the focus of scientific research and clinical tumor treatment in recent years, has received extensive attention. Due to its remarkable curative effect and fewer side effects than traditional treatments, it has significant clinical benefits for the treatment of various advanced cancers and can improve cancer patient survival in the long term. Currently, most patients cannot benefit from immunotherapy, and some patients may experience tumor recurrence and drug resistance even if they achieve remission overcome. Numerous studies have shown that the abnormal angiogenesis state of tumors can lead to immunosuppressive tumor microenvironment, which affects the efficacy of immunotherapy. Actually, to improve the efficacy of immunotherapy, the application of anti-angiogenesis drugs to normalize abnormal tumor vessel has been widely confirmed in basic and clinical research. This review not only discusses the risk factors, mechanisms, and effects of abnormal and normalized tumor angiogenesis state on the immune environment, but summarizes the latest progress of immunotherapy combined with anti-angiogenic therapy. We hope this review provides an applied reference for anti-angiogenesis drugs and synergistic immunotherapy therapy.

EZH2 promotes angiogenesis in peritoneal dialysis by epigenetically activating SP4 expression in the IL-6/sIL-6R signalling pathway

Background: Interleukin-6 (IL-6)/soluble IL-6 receptor (sIL-6R) promotes peritoneal angiogenesis by stimulating SP4-mediated vascular endothelial growth factor (VEGF) production in peritoneal dialysis (PD). Moreover, histone methyltransferase enhancer of zeste homologue 2 (EZH2) is involved in IL-6/sIL-6R signalling via the acceleration of vascular endothelial growth factor (VEGF)-induced angiogenesis. However, the molecular mechanism underlying how EZH2 epigenetically activates VFGF expression in IL-6/sIL-6R signalling during PD is still unclear. Methods and Results: In this study, we measured the expression of EZH2, DNMT3B and SP4 in human peritoneal mesothelial cells (HPMCs) treated with IL-6/sIL-6R stimulation and/or EZH2 overexpression, silencing or inhibition. Methylation of the CpG site in the SP4 promoter region and VEGF production were measured under these treatments in HPMCs. Moreover, tube formation in human umbilical vein endothelial cells (HUVECs) was detected following treatment with conditioned media from these stimulated HPMCs. The 5/6 nephrectomy (5/6Nx) rat model was established, and the rats were injected with peritoneal dialysate. EZH2, DNMT3B and SP4 expression and microvessels were analysed in 5/6Nx + PD rats treated with IL-6/sIL-6R and EZH2 overexpression. The results showed that IL-6/sIL-6R and EZH2 overexpression enhanced the expression of EZH2, DNMT3B and SP4, but EZH2 silencing/inhibition reduced these expression levels. The results for VEGF production and tube formation in vitro followed the same trend. IL-6/sIL-6R and EZH2 overexpression increased the methylation percentage of the -170 bp CpG site in the SP4 promoter region in HPMCs. Moreover, IL-6/sIL-6R and EZH2 overexpression stimulated EZH2, DNMT3B and SP4 expression and promoted angiogenesis in 5/6Nx + PD rats. Conclusions: Thus, this study indicated that EZH2 is involved in IL-6/sIL-6R signalling and epigenetically regulates SP4 expression, thereby stimulating VEGF production and angiogenesis in PD. Targeting EZH2 is expected to be a novel therapeutic approach for end-stage renal disease (ESRD) patients with PD treatment.

Predictive Role of Soluble IL-6R, TNF-R1/2, and Cell Adhesion Molecules Serum Levels in the Preoperative and Adjuvant Therapy in Women with Nonmetastatic Breast Cancer: A Preliminary Study

Soluble cell adhesion molecules (sCAMs) are involved in the development of neoplastic diseases. sCAMs can block lymphocytes and promote angiogenesis and migration of breast cancer (BC) cells. Interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) enhance metastatic potential via upregulation of CAMs. We assessed soluble interleukin-6 receptor subunit alpha (IL-6Ra), TNF-R1, TNF-R2, E-selectin, P-selectin, VCAM-1, ICAM-1, and EpCAM in 89 women with stage I-III BC and 28 healthy women. Blood samples were obtained at the beginning of neoadjuvant/induction (N = 49) or adjuvant treatment (N = 40), and after 2 months. Surgery revealed complete response in 29.4% of patients, partial response in 67%, and stable disease in 5.9%. Achieving a pathological response was 4 times greater for baseline levels of sIL-6Ra >5.63 ng/mL [odds ratio (OR) = 4.1, 95% confidence interval (CI): 0.8-20.4, P = 0.08] and more than 6 times for soluble tumor necrosis factor receptor 1 (sTNF-R1) ≥ 0.97 ng/mL (OR = 6.2, 95% CI: 1.2-32.3, P < 0.05). Compared with the control group, serum sP-selectin, soluble epithelial cell adhesion molecule (sEpCAM), and sTNF-R2 concentrations were significantly higher in patients who started adjuvant therapy (P < 0.05) and preoperative therapy (P < 0.01). Baseline serum sIL-6Ra concentrations were significantly higher in patients before surgery than in patients after tumor resection (P < 0.05), independent of the follow-up time. The baseline serum soluble receptors of IL-6 (sIL-6R) and TNF-α (sTNF-R1) concentrations have a predictive value for preoperative therapy in patients with BC.

Tumor-associated macrophage derived IL-6 enriches cancer stem cell population and promotes breast tumor progression via Stat-3 pathway

BACKGROUND

Cancer stem cells (CSCs) play crucial role in tumor progression, drug resistance and relapse in various cancers. CSC niche is comprised of various stromal cell types including Tumor-associated macrophages (TAMs). Extrinsic ques derived from these cells help in maintenance of CSC phenotype. TAMs have versatile roles in tumor progression however their function in enrichment of CSC is poorly explored.

METHODS

Mouse macrophages (RAW264.7) cells were activated by interaction with conditioned media (CM) of murine breast cancer cells (4T1) into TAMs and the effect of activated macrophage (TAM) derived factors was examined on enrichment of cancer stem cells (CSCs) and tumor growth using in vitro and in vivo models.

RESULTS

In this study, we report that macrophages upon interaction with breast cancer cells activate tumor promoting function and exhibit differential expression of various proteins as shown by secretome analysis using proteomics studies. Based on secretome data, we found that Interleukin-6 (IL-6) is one of the up-regulated genes expressed in activated macrophages. Further, we confirm that TAMs produce high levels of IL-6 and breast cancer cell derived factors induce IL-6 production in activated macrophages via p38-MAPK pathway. Furthermore, we demonstrate that tumor activated macrophages induce enrichment of CSCs and expression of CSC specific transcription factors such as Sox-2, Oct-3/4 and Nanog in breast cancer cells. We further prove that TAM derived IL-6 plays a key role in TAM mediated CSC enrichment through activation of Signal transducer and activator of transcription 3 (STAT-3) signaling. TAM derived IL-6 influences breast cancer cell migration and angiogenesis. Moreover, our in vivo findings indicated that TAM derived IL-6 induces CSC population and resulting tumor growth in breast cancer.

CONCLUSION

These finding provide evidence that TAM derived IL-6 plays a major role in CSC enrichment and tumor progression in breast cancer and IL-6 and its regulated signalling network may act as potential therapeutic target for management of breast cancer.

Targeting Angiogenesis in Breast Cancer: Current Evidence and Future Perspectives of Novel Anti-Angiogenic Approaches

Angiogenesis is a vital process for the growth and dissemination of solid cancers. Numerous molecular pathways are known to drive angiogenic switch in cancer cells promoting the growth of new blood vessels and increased incidence of distant metastasis. Several angiogenesis inhibitors are clinically available for the treatment of different types of advanced solid cancers. These inhibitors mostly belong to monoclonal antibodies or small-molecule tyrosine kinase inhibitors targeting the classical vascular endothelial growth factor (VEGF) and its receptors. Nevertheless, breast cancer is one example of solid tumors that had constantly failed to respond to angiogenesis inhibitors in terms of improved survival outcomes of patients. Accordingly, it is of paramount importance to assess the molecular mechanisms driving angiogenic signaling in breast cancer to explore suitable drug targets that can be further investigated in preclinical and clinical settings. This review summarizes the current evidence for the effect of clinically available anti-angiogenic drugs in breast cancer treatment. Further, major mechanisms associated with intrinsic or acquired resistance to anti-VEGF therapy are discussed. The review also describes evidence from preclinical and clinical studies on targeting novel non-VEGF angiogenic pathways in breast cancer and several approaches to the normalization of tumor vasculature by targeting pericytes, utilization of microRNAs and extracellular tumor-associate vesicles, using immunotherapeutic drugs, and nanotechnology.

Paracrine production of IL-6 promotes a hypercoagulable state in pancreatic cancer

Venous thromboembolism is the most common complication and the secondary cause of death in pancreatic cancer. Moreover, the hypercoagulable state induces microcirculation dysfunction, acidosis and hypoxia, and further enhances tumor immune evasion, tumor growth and metastasis. Numerous studies have revealed that patients with malignant tumors have high levels of IL-6, which stimulates hepatocytes to synthesize thrombopoietin, causing an increase in platelets. This study found that the concentration of IL-6 in pancreatic cancer patient sera was higher than that in healthy donors, while pancreatic cancer cells had low expression levels of IL-6, which was different from other types of cancer. This contradictory result prompted us to uncover the underlying mechanism. Our data revealed that pancreatic cancer enhanced IL-6 production in fibroblasts via the Jagged/Notch axis, while IL-6 further elevated Jagged-1/2 expression in a paracrine positive feedback loop in pancreatic cancer. Inhibition experiments and RNAi studies demonstrated that IL-6-induced Jagged-1/2 production in pancreatic cancer depended on STAT3 and that Jagged-1/2 enhanced IL-6 mRNA expression in HSFs through the NF-κB pathway. Finally, the animal study showed that knockdown of Jagged-1/2 or blockade of the Jagged/Notch pathway by Nirogacestat could alleviate pancreatic cancer-induced hypercoagulability. Accordingly, our findings clarified the key role of the Jagged/Notch/IL-6/STAT3 feedback loop in the development of a hypercoagulable state in pancreatic cancer, which also provides new therapeutic strategies for pancreatic cancer patients who suffer from hypercoagulability.

The diagnostic value of interleukin 6 as a biomarker for gastric cancer: A meta-analysis and systematic review

BACKGROUND

Gastric cancer is one of the most common cancers and a main cause of global cancer death. The expression of interleukin 6 is associated with the risk of gastric cancer. But the diagnostic accuracy of interleukin 6 remains unclear. This study was designed to assess the diagnostic performance of interleukin 6 in gastric cancer diagnosis.

METHODS

The related data was obtained from Oncomine and studied using bioinformatics analysis. The PubMed, Embase, Cochrane Library, Web of science databases were searched for related studies published from inception to July 14, 2020. Measuring tools of diagnostic performance including sensitivity, specificity, and diagnostic odds ratio were pooled using bivariate mixed-effects meta-analysis model. The summery receiver operator characteristic curves were plotted.

RESULTS

The result from Oncomine showed that the expression of interleukin 6 in gastric cancer (GC) patients was higher than the normal groups (P < .05). Furthermore, a total of 4 eligible articles were enrolled, containing 390 cases and 404 controls. The diagnostic results were as follows: a sensitivity of 0.80 (95% confidence interval [CI] 0.57-0.92), a specificity of 0.86 (95% CI 0.74-0.93), a positive likelihood ratio of 5.76 (95% CI 3.49-9.49), a negative likelihood ratio of 0.23 (95% CI 0.11-0.51) and a diagnostic odds ratio of 24.58 (95% CI 14.14-42.73). The summary area under the receiver operating characteristic curves was 0.90 (95% CI 0.87-0.93).

CONCLUSION

Higher interleukin 6 expression was detected in GC patients, and interleukin 6 could be a helpful indicator of diagnosis of gastric cancer. Further large-scale prospective studies are required for identifying the diagnostic value of interleukin 6 in gastric cancer.

Monoamine Oxidase (MAO) as a Potential Target for Anticancer Drug Design and Development

Monoamine oxidases (MAOs) are oxidative enzymes that catalyze the conversion of biogenic amines into their corresponding aldehydes and ketones through oxidative deamination. Owing to the crucial role of MAOs in maintaining functional levels of neurotransmitters, the implications of its distorted activity have been associated with numerous neurological diseases. Recently, an unanticipated role of MAOs in tumor progression and metastasis has been reported. The chemical inhibition of MAOs might be a valuable therapeutic approach for cancer treatment. In this review, we reported computational approaches exploited in the design and development of selective MAO inhibitors accompanied by their biological activities. Additionally, we generated a pharmacophore model for MAO-A active inhibitors to identify the structural motifs to invoke an activity.

Genetic and Proteinic Linkage of MAO and COMT with Oral Potentially Malignant Disorders and Cancers of the Oral Cavity and Pharynx

Simple Summary

The prevention and treatment of cancers of the oral cavity and pharynx are currently important issues for national health. Currently, the incidence of oral cavity and pharynx cancers is globally the highest in Taiwanese men. Regarding the occurrence of oral cavity and pharynx cancers and oral potentially malignant disorders (OPMD), no report has ascertained how betel quid (BQ) can induce the expression of monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). We aimed to explore the role and clinical significance of specific markers of BQ exposure and human susceptibility to MAO and COMT. Our findings highlight the association of MAO and COMT biomarkers to risks of oral and pharyngeal cancers and OPMD. These novel findings will provide important strategies for disease prevention, early clinical diagnosis, and treatment effectiveness, and will offer a strong foundation to reduce BQ-related cancers of the oral cavity and pharynx and OPMD.

Abstract

Betel quid (BQ), a group I human carcinogen, strongly contributes to an increased risk of oral potentially malignant disorders (OPMD) and cancers of the oral cavity and pharynx. This study was conducted to discover whether monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) variants play a potential role in the risk assessment of oral cavity and pharynx cancers and OPMD, particularly among BQ users. We applied a case–control study to confirm the polymorphism of MAO and COMT using single-nucleotide polymorphisms. We used qRT-PCR, Western blotting, and immunohistochemistry (IHC) to determine MAO and COMT expression. Carriers of the MAOA rs6323 G-allele, MAOB rs6324 G-allele, and COMT rs4633 C/C-genotype had a prominently increased risk of oral cavity and pharynx cancers (AOR = 56.99; p < 0.001). Compared to adjacent noncancerous tissues, a significant downregulation of MAO and COMT expression was exhibited in cancerous tissues (p < 0.01). Furthermore, in different cell models, MAO and COMT expression was significantly downregulated with an increased dose of arecoline (p < 0.01). In personalized preventive medicine for oral and pharyngeal cancers, our findings are the first to demonstrate the potential role of lower MAO and COMT expression levels, with the risk polymorphisms utilized as clinical biomarkers.

Monoamine oxidases in age-associated diseases: New perspectives for old enzymes

Population aging is one of the most significant social changes of the twenty-first century. This increase in longevity is associated with a higher prevalence of chronic diseases, further rising healthcare costs. At the molecular level, cellular senescence has been identified as a major process in age-associated diseases, as accumulation of senescent cells with aging leads to progressive organ dysfunction. Of particular importance, mitochondrial oxidative stress and consequent organelle alterations have been pointed out as key players in the aging process, by both inducing and maintaining cellular senescence. Monoamine oxidases (MAOs), a class of enzymes that catalyze the degradation of catecholamines and biogenic amines, have been increasingly recognized as major producers of mitochondrial ROS. Although well-known in the brain, evidence showing that MAOs are also expressed in a variety of peripheral organs stimulated a growing interest in the extra-cerebral roles of these enzymes. Besides, the fact that MAO-A and/or MAO-B are frequently upregulated in aged or dysfunctional organs has uncovered new perspectives on their roles in pathological aging. In this review, we will give an overview of the major results on the regulation and function of MAOs in aging and age-related diseases, paying a special attention to the mechanisms linked to the increased degradation of MAO substrates or related to MAO-dependent ROS formation.

Codelivery of BV6 and anti-IL6 siRNA by hyaluronate-conjugated PEG-chitosan-lactate nanoparticles inhibits tumor progression

AIMS

Increased expression of inhibitor of apoptosis (IAP) genes has been associated with progressive cancer and chemoresistance. Accordingly, blockade of IAPs by BV6 has resulted in ameliorative outcomes. Interleukin (IL)-6 is another important mediator involved in the growth and survival of tumor cells. Therefore, we hypothesized that simultaneous inhibition of IAPs and IL-6 could be a new promising anti-tumor treatment strategy.

MATERIALS AND METHODS

In this study, we generated and characterized hyaluronate-PEG-Chitosan-Lactate (H-PCL) nanoparticles (NPs) to simultaneously deliver IL6-specific siRNA and BV6 to 4T1 (breast cancer) and CT26 (colon cancer) cells, and investigate the anti-tumor properties of this combination therapy both in vitro and in vivo.

KEY FINDINGS

H-PCL NPs exhibited good physicochemical properties leading to efficient transfection of cancer cells and suppression of target molecules. Moreover, combination therapy synergistically increased apoptosis, as well as decreased cell migration, proliferation, colony formation, and angiogenesis in both 4T1 and CT26 cell lines and suppressed cancer progression in tumor-bearing mice that was associated with enhanced survival time.

SIGNIFICANCE

These findings imply the effectiveness of cancer combination therapy by using H-PCL NPs loaded with anti-IL-6 siRNA and BV6.

Low glucocorticoids in stress-related disorders: the role of inflammation

There is evidence that plasma cortisol concentration can be either increased or decreased in patients with depression and related anxiety and stress-related disorders; the exact pathophysiological mechanisms of this state are not almost clear. Several distinct theories were proposed and mechanisms, which could lead to decreased glucocorticoid signaling and/or levels, were described. However, there is a possible drawback in almost all the theories proposed: insufficient attention to the inflammatory process, which is undoubtedly present in several stress-related disorders, including post-traumatic stress disorder (PTSD). Previous studies only briefly mentioned the presence of an inflammatory reaction's signs in PTSD, without giving it due importance, although recognizing that it can affect the course of the disease. With that, the state of biochemical changes, characterized by the low glucocorticoids, glucocorticoid receptor's resistance and the signs of the persistent inflammation (with the high levels of circulating cytokines) might be observed not only in PTSD but in coronary heart diseases and systemic chronic inflammatory diseases (rheumatoid arthritis) as well. That is why the present review aims to depict the pathophysiological mechanisms, which lead to a decrease in glucocorticoids in PTSD due to the action of inflammatory stimuli. We described changes in the glucocorticoid system and inflammatory reaction as parts of an integral system, where glucocorticoids and the glucocorticoid receptor reside at the apex of a regulatory network that blocks several inflammatory pathways, while decreased glucocorticoid signaling and/or level leads to unchecked inflammatory reactions to promote pathologies such as PTSD. LAY SUMMARY This review emphasizes the importance of inflammatory reaction in the development of puzzling conditions sometimes observed in severe diseases including post-traumatic stress disorder - the decreased levels of glucocorticoids in the blood. Following the classical concepts, one would expect an increase in glucocorticoid hormones, since they are part of the feedback mechanism in the immune system, which reduces stress and inflammation. However, low levels of glucocorticoid hormones are also observed. Thus, this review describes potential mechanisms, which can lead to the development of such a state.

The clinical value and potential molecular mechanism of the downregulation of MAOA in hepatocellular carcinoma tissues

Background

Hepatocellular carcinoma (HCC) remains one of the most common cancers worldwide and tends to be detected at an advanced stage. More effective biomarkers for HCC screening and prognosis assessment are needed and the mechanisms of HCC require further exploration. The role of MAOA in HCC has not been intensively investigated.

Methods

In‐house tissue microarrays, genechips, and RNAsequencing datasets were integrated to explore the expression status and the clinical value of MAOA in HCC. Immunohistochemical staining was utilized to determine MAOA protein expression. Intersection genes of MAOA related co‐expressed genes and differentially expressed genes were obtained to perform functional enrichment analyses. In vivo experiment was conducted to study the impact of traditional Chinese medicine nitidine chloride (NC) on MAOA in HCC.

Results

MAOA was downregulated and possessed an excellent discriminatory capability in HCC patients. Decreased MAOA correlated with poor prognosis in HCC patients. Downregulated MAOA protein was relevant to an advanced TNM stage in HCC patients. Co‐expressed genes that positively related to MAOA were clustered in chemical carcinogenesis, where CYP2E1 was identified as the hub gene. In vivo experiment showed that nitidine chloride significantly upregulated MAOA in a nude mouse HCC model.

Conclusions

A decreased MAOA level is not only correlated with aggressive behaviors in males but also serves as a promising biomarker for the diagnosis and prognosis of HCC patients. Moreover, MAOA may play a role in AFB1 toxic transformation through its synergistic action with co‐expressed genes, especially CYP3A4. MAOA also serves as a potential therapy target of NC in HCC patients.

The modern views of the clinical, morphological and molecular biological predictors of breast cancer sensitivity to chemotherapy

In the treatment of breast cancer, the neoadjuvant chemotherapy is vitally important and the evaluation of its effectiveness is crucial for determining the further therapy treatment, as well as the prognosis of the disease. This review provides current data of the physical, instrumental, morphological, molecular biology and genetics analysis used for the estimation of the neoadjuvant treatment effectiveness. Thus, review discusses the data concerning association of the disease peculiarities with the efficient therapeutic response to neoadjuvant chemotherapy including characteristics of patients (age, status of regional lymph nodes, presence of the lymphovascular invasion) and tumors (size, histological type, degree of differentiation, severity of the lymphoid tumor infiltration, molecular biological and genetic peculiarities). Particular attention is paid to such a promising predictive marker of the breast cancer response to chemotherapy as the level of tissue hypoxia. This section discusses the currently known mechanisms that might enable the effect of tissue hypoxia on the sensitivity of the tumor to drug treatment. The prospects for the use of a comprehensive analysis of predictive markers of the effectiveness of chemotherapeutic treatment are discussed.

Monoamine Oxidase A is a Major Mediator of Mitochondrial Homeostasis and Glycolysis in Gastric Cancer Progression

Objective

Monoamine oxidase A (MAO-A) is a mitochondrial protein involved in tumourigenesis in different types of cancer. However, the biological function of MAO-A in gastric cancer development remains unknown.

Methods

We examined MAO-A expression in gastric cancer tissues and in gastric cancer cell lines by immunohistochemistry and Western blot analyses. CCK8, FACS and bromodeoxyuridine incorporation assays were performed to assess the effects of MAO-A on gastric cancer cell proliferation. The role of MAO-A in mitochondrial function was determined through MitoSOX Red staining, ATP generation and glycolysis assays.

Results

In the present study, we observed that MAO-A was significantly upregulated in gastric cancer tissues and in AGS and MGC803 cells. The observed MAO-A inhibition indicated decreased cell cycle progression and proliferation. Silencing MAO-A expression was associated with suppressed migration and invasion of gastric cancer cells in vitro. Moreover, alleviated mitochondrial damage in these cells was demonstrated by decreased levels of mitochondrial reactive oxygen species and increased ATP generation. MAO-A knockdown also regulated the expression of the glycolysis rate-limiting enzymes hexokinase 2 and pyruvate dehydrogenase. Finally, we observed that the glycolysis-mediated effect was weakened in AGS and MGC803 cells when MAO-A was blocked.

Conclusion

The findings of the present study indicate that MAO-A is responsible for mitochondrial dysfunction and aerobic glycolysis, which in turn leads to the proliferation and metastasis of human gastric tumour cells.

Interleukin-6-mediated epigenetic control of the VEGFR2 gene induces disorganized angiogenesis in human breast tumors

Disorganized vessels in the tumor vasculature lead to impaired perfusion, resulting in reduced accessibility to immune cells and chemotherapeutic drugs. In the breast tumor-stroma interplay, paracrine factors such as interleukin-6 (IL-6) often facilitate disordered angiogenesis. We show here that epigenetic mechanisms regulate the crosstalk between IL-6 and vascular endothelial growth factor receptor 2 (VEGFR2) signaling pathways in myoepithelial (CD10+) and endothelial (CD31+, CD105+, CD146+, and CD133-) cells isolated from malignant and nonmalignant tissues of clinically characterized human breast tumors. Tumor endothelial (Endo-T) cells in 3D cultures exhibited higher VEGFR2 expression levels, accelerated migration, invasion, and disorganized sprout formation in response to elevated IL-6 levels secreted by tumor myoepithelial (Epi-T) cells. Constitutively, compared with normal endothelial (Endo-N) cells, Endo-T cells differentially expressed DNA methyltransferase isoforms and had increased levels of IL-6 signaling intermediates such as IL-6R and signal transducer and activator of transcription 3 (STAT3). Upon IL-6 treatment, Endo-N and Endo-T cells displayed altered expression of the DNA methyltransferase 1 (DNMT1) isoform. Mechanistic studies revealed that IL-6 induced proteasomal degradation of DNMT1, but not of DNMT3A and DNMT3B and subsequently led to promoter hypomethylation and expression/activation of VEGFR2. IL-6-induced VEGFR2 up-regulation was inhibited by overexpression of DNMT1. Transfection of a dominant-negative STAT3 mutant, but not of STAT1, abrogated VEGFR2 expression. Our results indicate that in the breast tumor microenvironment, IL-6 secreted from myoepithelial cells influences DNMT1 stability, induces the expression of VEGFR2 in endothelial cells via a promoter methylation-dependent mechanism, and leads to disordered angiogenesis.

Monoamine oxidase A is down-regulated in EBV-associated nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a highly metastatic cancer that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we identify for the first time a role for monoamine oxidase A (MAOA) in NPC. MAOA is a mitochondrial enzyme that catalyzes oxidative deamination of neurotransmitters and dietary amines. Depending on the cancer type, MAOA can either have a tumour-promoting or tumour-suppressive role. We show that MAOA is down-regulated in primary NPC tissues and its down-regulation enhances the migration of NPC cells. In addition, we found that EBV infection can down-regulate MAOA expression in both pre-malignant and malignant nasopharyngeal epithelial (NPE) cells. We further demonstrate that MAOA is down-regulated as a result of IL-6/IL-6R/STAT3 signalling and epigenetic mechanisms, effects that might be attributed to EBV infection in NPE cells. Taken together, our data point to a central role for EBV in mediating the tumour suppressive effects of MAOA and that loss of MAOA could be an important step in the pathogenesis of NPC.

Nodal promotes the malignancy of non-small cell lung cancer (NSCLC) cells via activation of NF-κB/IL-6 signals

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer deaths worldwide. Understanding the mechanisms responsible for the malignancy of NSCLC cells is important for therapy and drug development. Nodal, an important embryonic morphogen, has been reported to modulate tumorigenesis. We found that Nodal can trigger the proliferation of NSCLC cells and decrease the sensitivity to doxorubicin (Dox) and cisplatin (CDDP) treatment. Targeted inhibition of Nodal can suppress the proliferation of NSCLC cells. Among the measured cytokines, Nodal can increase the expression of interleukin-6 (IL-6) and vascular endothelial growth factor A (VEGFA) in NSCLC cells. Inhibition of IL-6, while not VEGFA, attenuated Nodal induced cell proliferation, suggesting the essential roles of IL-6 in Nodal induced malignancy of NSCLC cells. Nodal can trigger the phosphorylation, nuclear translocation and transcriptional activities of p65, the key signal transducer of NF-κB. This was due to the fact that Nodal can increase the phosphorylation of IKKβ/IκBα. The inhibitor of IKKβ abolished Nodal induced activation of p65 and expression of IL-6. Collectively, we found that Nodal can increase the proliferation and decrease chemosensitivity of NSCLC cells via regulation of NF-κB/IL-6 signals. It indicated that Nodal might be a potential therapeutic target for NSCLC treatment.

Tanshinone IIA reduces secretion of pro‑angiogenic factors and inhibits angiogenesis in human colorectal cancer

Tumor angiogenesis is an important factor which precipitates recurrence and metastasis of colorectal cancer (CRC). Angiogenesis is also a significant feature which accompanies invasion and metastasis of CRC. Tumor hypoxia activates hypoxia inducible factor (HIF), which promotes angiogenesis in CRC. HIF significantly promotes cell proliferation and angiogenesis in CRC, facilitating invasion and metastasis. Tanshinone IIA (Tan IIA) has been revealed to effectively inhibit angiogenesis in CRC, although the underlying mechanism remains to be determined. The aim of the present study was to determine the effects of HIF-1α on hypoxia induced angiogenesis in CRC cells, the effects of Tan IIA on the expression of pro-angiogenic factors in CRC cells, and on human umbilical vein endothelial cell (HUVEC) tube formation in normal and hypoxic conditions. The results of the present study revealed that Tan IIA not only decreased HIF-1α expression and inhibited the secretion level of vascular endothelial growth factor and basic fibroblast growth factor, but also efficiently decreased proliferation, tube formation and metastasis of HUVECs. The results highlight the potential of Tan IIA-mediated targeting of HIF-1α as a potential therapeutic option for treatment of patients with CRC.

Silencing of IL-6 and STAT3 by siRNA loaded hyaluronate-N,N,N-trimethyl chitosan nanoparticles potently reduces cancer cell progression

The immunosuppressive nature of the tumor microenvironment is a critical problem that should be considered before the design of immunotherapies. Interleukin (IL)-6 and its related downstream molecules such as signal transducer and activator of transcription (STAT)3 play an important role in the cancer progression, which can be considered as potential therapeutic targets. In the present study, we generated the active-targeted hyaluronate (HA) recoated N, N, N-trimethyl chitosan (TMC) nanoparticles (NPs) to deliver IL-6- and STAT3-specific small interfering RNAs (siRNAs) to the CD44-expressing cancer cells. We utilized the interaction between HA and CD44 to increase the specificity and efficacy of cellular uptake in NPs. The results showed that the synthesized NPs had efficient physicochemical characteristics, high transfection efficiency, low toxicity, and controlled siRNA release. siRNA-loaded NPs significantly inhibited the IL-6/STAT3 expression, which was associated with blockade of proliferation, colony formation, migration, and angiogenesis in cancer cells. These findings imply the potential of HA-TMC NPs as potent vectors in gene therapy and their application for the silencing of IL-6 and STAT3, as a novel anti-cancer combination therapeutic strategy, for the first time.

Interleukin-6 (IL-6) triggers the malignancy of hemangioma cells via activation of HIF-1α/VEGFA signals

Hemangioma (HA) is tumor formed by hyper-proliferation of vascular endothelial cells. The roles of interleukins on the progression of HA are not well illustrated. Our present study revealed that the expression of interleukin -6 (IL-6) and IL-8 in HA cells were significantly increased as compared with that in the human umbilical vein endothelial cell (HUVEC) cells. Targeted inhibition of IL-6, while not IL-8, can significantly suppress the proliferation and migration of HA cells. IL-6 treatment can increase the expression of vascular endothelial growth factor A (VEGFA), while had no significant effect on the expression of basic fibroblast growth factor (bFGF), in HA cells. Deletion of VEGFA can abolish IL-6 induced progression of HA, suggesting the essential role of VEGFA in IL-6 induced HA development. The specific inhibitor of hypoxia-inducible factor (HIF)-1α, while not Sp1, NF-κB, or AP1, abolished IL-6 induced VEGFA expression. Over expression of HIF-1α can attenuate anti-IL-6 suppressed expression of VEGFA in HA cells. Furthermore, IL-6 triggered the expression, nuclear translocation, and transcription activities of HIF-1α in HA cells via increasing its binding with the signal transducer and activator of transcription-3 (STAT3). STAT3 inhibitor CPA7 or si-STAT3 can abolish IL-6 induced upregulation of HIF-1α in HDEC cells. Collectively, our study revealed that IL-6 can trigger the malignancy of HA cells via induction of proliferation and migration. The activation of STAT3/HIF-1α/VEGFA signal was essential for this process. It suggested that IL-6/STAT3/HIF-1α/VEGFA signal may represent a novel therapeutic target for human HA treatment.