Nicotine promotes proliferation of human nasopharyngeal carcinoma cells by regulating α7AChR, ERK, HIF-1α and VEGF/PEDF signaling

Angiogenesis in nasopharyngeal carcinoma: insights, imaging, and therapeutic strategies

Nasopharyngeal carcinoma (NPC) is a highly prevalent head and neck malignancy in southern China frequently diagnosed at advanced stages owing to subtle early symptoms and associated metastasis. Angiogenesis emerges as a pivotal factor in NPC progression, with numerous angiogenesis-related factors showing aberrant expression and contributing to increased neovascularization within NPC tumors. These abnormal vessels not only nourish tumor growth but also facilitate metastasis, culminating in unfavorable patient outcomes. Multiple studies have demonstrated the applicability of various imaging techniques for assessing angiogenesis in NPC tumors, thus serving as a foundation for personalized treatment strategies and prognostic assessments. Anti-angiogenic therapies have exhibited significant potential for inhibiting NPC angiogenesis and exerting anti-tumor effects. To enhance efficacy, anti-angiogenic drugs are frequently combined with other treatment modalities to synergistically enhance anti-tumor effects while mitigating the side effects associated with single-agent therapies, consequently improving patient prognosis. Identifying the potential mechanisms and key targets underlying NPC angiogenesis and exploring more effective detection and treatment approaches holds promise for shaping the future of NPC diagnosis, treatment, and prognosis, thereby offering new avenues and perspectives for research and clinical practice.

Nicotine neurotoxicity exacerbation following engineered Ag and Cu (50-60 nm) nanoparticles intoxication. Neuroprotection with nanowired delivery of antioxidant compound H-290/51 together with serotonin 5-HT3 receptor antagonist ondansetron

Nicotine abuse is frequent worldwide leading to about 8 millions people die every year due to tobacco related diseases. Military personnel often use nicotine smoking that is about 12.8% higher than civilian populations. Nicotine smoking triggers oxidative stress and are linked to several neurodegenerative diseases such as Alzheimer's disease. Nicotine neurotoxicity induces significant depression and oxidative stress in the brain leading to neurovascular damages and brain pathology. Thus, details of nicotine neurotoxicity and factors influencing them require additional investigations. In this review, effects of engineered nanoparticles from metals Ag and Cu (50-60 nm) on nicotine neurotoxicity are discussed with regard to nicotine smoking. Military personnel often work in the environment where chances of nanoparticles exposure are quite common. In our earlier studies, we have shown that nanoparticles alone induces breakdown of the blood-brain barrier (BBB) and exacerbates brain pathology in animal models. In present investigation, nicotine exposure in with Ag or Cu nanoparticles intoxicated group exacerbated BBB breakdown, induce oxidative stress and aggravate brain pathology. Treatment with nanowired H-290/51 a potent chain-breaking antioxidant together with nanowired ondansetron, a potent 5-HT3 receptor antagonist significantly reduced oxidative stress, BBB breakdown and brain pathology in nicotine exposure associated with Ag or Cu nanoparticles intoxication. The functional significance of this findings and possible mechanisms of nicotine neurotoxicity are discussed based on current literature.

Non-Antigenic Modulation of Antigen Receptor (TCR) Cβ-FG Loop Modulates Signalling: Implications of External Factors Influencing T-Cell Responses

T-cell recognition of antigens is complex, leading to biochemical and cellular events that impart both specific and targeted immune responses. The end result is an array of cytokines that facilitate the direction and intensity of the immune reaction-such as T-cell proliferation, differentiation, macrophage activation, and B-cell isotype switching-all of which may be necessary and appropriate to eliminate the antigen and induce adaptive immunity. Using in silico docking to identify small molecules that putatively bind to the T-cell Cβ-FG loop, we have shown in vitro using an antigen presentation assay that T-cell signalling is altered. The idea of modulating T-cell signalling independently of antigens by directly targeting the FG loop is novel and warrants further study.

VR-10 polypeptide interacts with CD36 to induce cell apoptosis and autophagy in choroid-retinal endothelial cells: Identification of VR-10 as putative novel therapeutic agent for choroid neovascularization (CNV) treatment

Choroid neovascularization (CNV) is important adverse pathological changes that contributes to the aggravation of hypoxic-ischemic eye diseases, and our preliminary work evidences that the thrombospondin-1 (TSP-1) synthetic polypeptide VR-10 may be the candidate therapeutic agent for the treatment of CNV, but its detailed effects and molecular mechanisms are not fully delineated. In this study, the CNV models in BN rats were established by using the laser photocoagulation method, which were further subjected to VR-10 peptide treatment. The RNA-seq and bioinformatics analysis suggested that VR-10 peptide significantly altered the expression patterns of genes in the rat ocular tissues, and the changed genes were especially enriched in the CD36-associated signal pathways. Next, by performing the Real-Time qPCR and Western Blot analysis, we expectedly found that VR-10 upregulated the anti-angiogenesis biomarker (PEDF) and downregulated pro-angiogenesis biomarkers (VEGF, HIF-1 and IL-17) in rat tissues. In addition, we evidenced that VR-10 downregulated CDK2, CDK4, CDK6, Cyclin D1 and Cyclin D2 to induce cell cycle arrest, upregulated cleaved Caspase-3, Bax and downregulated Bcl-2 to promote cell apoptosis, and increased LC3B-II/I ratio and facilitate p62 degradation to promote cell autophagy in RF/6A cells, which were all reversed by knocking down CD36. Moreover, VR-10 upregulated PEDF, and decreased the expression levels of VEGF, HIF-1 and IL-17 to block angiogenesis of RF/6A cells in a CD36-dependent manner. Taken together, VR-10 peptide interacts with its receptor CD36 to regulate the biological functions of RF/6A cells, and these data suggest that VR-10 peptide may be the putative therapeutic drug for the treatment of CNV in clinic.

Nicotine has no significant cytoprotective activity against SARS-CoV-2 infection

When coronavirus disease 2019 (COVID-19) became a pandemic, one of most important questions was whether people who smoke are at more risk of COVID-19 infection. A number of clinical data have been reported in the literature so far, but controversy exists in the collection and interpretation of the data. Particularly, there is a controversial hypothesis that nicotine might be able to prevent SARS-CoV-2 infection. In the present study, motivated by the reported controversial clinical data and the controversial hypothesis, we carried out cytotoxicity assays in Vero E6 cells to examine the potential cytoprotective activity of nicotine against SARS-CoV-2 infection and demonstrated for the first time that nicotine had no significant cytoprotective activity against SARS-CoV-2 infection in these cells.

SHMT2 promotes tumor growth through VEGF and MAPK signaling pathway in breast cancer

Cancer cells modulate their metabolic activities to adapt to their growth and proliferation. Despite advances in breast cancer biology having led to the widespread use of molecular targeted therapy and hormonal drugs, the molecular mechanisms in metabolism related to the regulation of breast cancer cell proliferation are still poorly understood. Here, we investigate the possible role of SHMT2, a key enzyme in serine metabolism, in breast cancer. Firstly, SHMT2 is found highly expressed in both breast cancer cells and tissues, and patients with high expression of SHMT2 have a worse prognosis. Moreover, the intervention of SHMT2 by either knockdown or over-expression in vitro induces the effect on breast cancer proliferation. Mechanistically, RNA-seq shows that over-expression of SHMT2 affect multiple signaling pathways and biological process in breast cancer cells. Furthermore, we confirm that SHMT2 promotes breast cancer cell growth through MAPK and VEGF signaling pathways. Finally, we verify the role of SHMT2 in promoting breast cancer growth in the xenograft tumor model. Our results indicate that SHMT2 plays a critical role in regulating breast cancer growth through MAPK, and VEGF signaling pathways, and maybe serve as a therapeutic target for breast cancer therapy.

Alkaloids exhibit a meaningful function as anticancer agents by restraining cellular signaling pathways

Alkaloids are nitrogen-containing organic compounds widely found in natural products, which play an essential role in clinical treatment. Cellular signaling pathways in tumors are a series of enzymatic reaction pathways that convert extracellular signals into intracellular signals to produce biological effects. The ordered function of cell signaling pathways is essential for tumor cell proliferation, differentiation, and programmed death. This review describes the antitumor progression mediated by various alkaloids after inhibiting classical signaling pathways; related studies are systematically retrieved and collected through PubMed. We selected the four currently most popular pathways for discussion and introduced the molecular mechanisms mediated by alkaloids in different signaling pathways, including the NF-kB signaling pathway, PI3K/AKT signaling pathway, MAPK signaling pathway, and P53 signaling pathway. The research progress of alkaloids related to tumor signal transduction pathways and the realization of alkaloids as cancer prevention drugs by targeting signal pathways remains.

Impact of solitons on the progression of initial lesion in aortic dissection

Aortic dissection (AD) is the most common catastrophic disease reported at cardiovascular emergency in hospitals. Herein, a tear in the tunica intima results into separation of layers of aortic wall leading to rupture and torrential bleed. Hypoxia and oxidative stress are associated with AD. The release of hypoxia inducible factor (HIF)-1[Formula: see text] from the initial flap lesion in the tunica intima is the basis for aneurysmal prone factors. We framed a boundary value problem (BVP) to evaluate homeostatic saturation for oxygen dynamics using steady-state analysis. We prove uniqueness and existence of the solution of the BVP for gas exchange at capillary–tissue interface as a normal physiological function. Failure of homeostatic mechanism establishes hypoxia, a new quasi-steady-state in AD. We model permeation of two-layer fluid comprised of blood and HIF-1[Formula: see text] through tunica media as a generalized [Formula: see text]-dimensional nonlinear evolution equation and solve it using Lie group of transformations method. We note that the two-layer fluid permeates the tunica media as solitary wave including solitons such as bright soliton, dark soliton, peregrine soliton, topological soliton, kink soliton, breather soliton and multi-soliton complex. Also, we introduce the main result and discuss the implications of soliton solution, using graphic interpretation, to describe the early stage of progression of AD.

Histone demethylase KDM4A plays an oncogenic role in nasopharyngeal carcinoma by promoting cell migration and invasion

Compelling evidence has indicated the vital role of lysine-specific demethylase 4 A (KDM4A), hypoxia-inducible factor-1α (HIF1α) and the mechanistic target of rapamycin (mTOR) signaling pathway in nasopharyngeal carcinoma (NPC). Therefore, we aimed to investigate whether KDM4A affects NPC progression by regulating the HIF1α/DDIT4/mTOR signaling pathway. First, NPC and adjacent tissue samples were collected, and KDM4A protein expression was examined by immunohistochemistry. Then, the interactions among KDM4A, HIF1α and DDIT4 were assessed. Gain- and loss-of-function approaches were used to alter KDM4A, HIF1α and DDIT4 expression in NPC cells. The mechanism of KDM4A in NPC was evaluated both in vivo and in vitro via RT-qPCR, Western blot analysis, MTT assay, Transwell assay, flow cytometry and tumor formation experiments. KDM4A, HIF1α, and DDIT4 were highly expressed in NPC tissues and cells. Mechanistically, KDM4A inhibited the enrichment of histone H3 lysine 9 trimethylation (H3K9me3) in the HIF1α promoter region and thus inhibited the methylation of HIF1α to promote HIF1α expression, thus upregulating DDIT4 and activating the mTOR signaling pathway. Overexpression of KDM4A, HIF1α, or DDIT4 or activation of the mTOR signaling pathway promoted SUNE1 cell proliferation, migration, and invasion but inhibited apoptosis. KDM4A silencing blocked the mTOR signaling pathway by inhibiting the HIF1α/DDIT4 axis to inhibit the growth of SUNE1 cells in vivo. Collectively, KDM4A silencing could inhibit NPC progression by blocking the activation of the HIF1α/DDIT4/mTOR signaling pathway by increasing H3K9me3, highlighting a promising therapeutic target for NPC.

Head and neck cancer: Current challenges and future perspectives

Head and neck cancers are a heterogeneous, aggressive and genetically complex collection of malignancies of the oral cavity, nasopharynx, oropharynx, hypopharynx, larynx, paranasal sinuses and salivary glands, which are difficult to treat. About 90% of all head and neck cancers are squamous cell carcinomas (HNSCC). Larynx and Oral cavity carcinomas are generally related with tobacco consumption, alcohol abuse (or both), but pharynx carcinomas are generally associated with infection of human papillomavirus (HPV), especially HPV-16 subtype. Thus, usually HNSCC can be separated into HPV-negative and HPV-positive categories. Despite substantial efforts invested into therapeutic development of HNSCC, the 5-year survival rate of patients with HNSCC still remains dismal. The primary reason being late diagnosis, recurrent metastasis, relapse and resistance to therapies. Currently surgery and radiotherapy represent the baseline treatment options for most initial stage HNSCC patients, but these treatments are associated with significant morbidity and poor prognosis. Moreover, the issue of resistance to both radiotherapy/chemotherapy and recurrent relapse are common in HNSCC. Elucidation of the genetic landscape, tumor microenvironment and aberrant signaling pathways have generated new insights into the molecular pathogenesis of this disease. Thus, the scientific research has therefore been focused on the understanding of HNSCC biology and immunobiology to identification of predictive/prognostic biomarkers, which will be key to develop more effective targeted therapies with less toxicity and high specificity.

Modified Snake α-Neurotoxin Averts β-Amyloid Binding to α7 Nicotinic Acetylcholine Receptor and Reverses Cognitive Deficits in Alzheimer's Disease Mice

Alzheimer's disease (AD) is the most common cause of senile dementia and one of the greatest medical, social, and economic challenges. According to a dominant theory, amyloid-β (Aβ) peptide is a key AD pathogenic factor. Aβ-soluble species interfere with synaptic functions, aggregate gradually, form plaques, and trigger neurodegeneration. The AD-associated pathology affects numerous systems, though the substantial loss of cholinergic neurons and α7 nicotinic receptors (α7AChR) is critical for the gradual cognitive decline. Aβ binds to α7AChR under various experimental settings; nevertheless, the functional significance of this interaction is ambiguous. Whereas the capability of low Aβ concentrations to activate α7AChR is functionally beneficial, extensive brain exposure to high Aβ concentrations diminishes α7AChR activity, contributes to the cholinergic deficits that characterize AD. Aβ and snake α-neurotoxins competitively bind to α7AChR. Accordingly, we designed a chemically modified α-cobratoxin (mToxin) to inhibit the interaction between Aβ and α7AChR. Subsequently, we examined mToxin in a set of original in silico, in vitro, ex vivo experiments, and in a murine AD model. We report that mToxin reversibly inhibits α7AChR, though it attenuates Aβ-induced synaptic transmission abnormalities, and upregulates pathways supporting long-term potentiation and reducing apoptosis. Remarkably, mToxin demonstrates no toxicity in brain slices and mice. Moreover, its chronic intracerebroventricular administration improves memory in AD-model animals. Our results point to unique mToxin neuroprotective properties, which might be tailored for the treatment of AD. Our methodology bridges the gaps in understanding Aβ-α7AChR interaction and represents a promising direction for further investigations and clinical development.

New Pathways for the Skin's Stress Response: The Cholinergic Neuropeptide SLURP-1 Can Activate Mast Cells and Alter Cytokine Production in Mice

Background: The alpha7 nicotinic acetylcholine receptor (Chrna7) plays an essential anti-inflammatory role in immune homeostasis and was recently found on mast cells (MC). Psychosocial stress can trigger MC hyperactivation and increases pro-inflammatory cytokines in target tissues such as the skin. If the cholinergic system (CS) and Chrna7 ligands play a role in these cascades is largely unknown.

Objective: To elucidate the role of the CS in the response to psychosocial stress using a mouse-model for stress-triggered cutaneous inflammatory circuits.

Methods: Key CS markers (ACh, Ch, SLURP-1, SLURP-2, Lynx1, Chrm3, Chrna7, Chrna9, ChAT, VAChT, Oct3, AChE, and BChE) in skin and its MC (sMC), MC activation, immune parameters (TNFα, IL1β, IL10, TGFβ, HIF1α, and STAT3) and oxidative stress were analyzed in skin from 24 h noise-stressed mice and in cultured MC (cMC) from C57BL/6 or Chrna7-Knockout mice.

Results: First, Chrna7 and SLURP-1 mRNA were exclusively upregulated in stressed skin. Second, histomorphometry located Chrna7 and SLURP-1 in nerves and sMC and demonstrated upregulated contacts and increased Chrna7+ sMC in stressed skin, while 5 ng/mL SLURP-1 degranulated cMC. Third, IL1β+ sMC were high in stressed skin, and while SLURP-1 alone had no significant effect on cMC cytokines, it upregulated IL1β in cMC from Chrna7-KO and in IL1β-treated wildtype cMC. In addition, HIF1α+ sMC were high in stressed skin and Chrna7-agonist AR-R 17779 induced ROS in cMC while SLURP-1 upregulated TNFα and IL1β in cMC when HIF1α was blocked.

Conclusions: These data infer that the CS plays a role in the regulation of stress-sensitive inflammatory responses but may have a surprising pro-inflammatory effect in healthy skin, driving IL1β expression if SLURP-1 is involved.

A nicotine-induced positive feedback loop between HIF1A and YAP1 contributes to epithelial-to-mesenchymal transition in pancreatic ductal adenocarcinoma

BACKGROUND

Nicotine, an active ingredient in tobacco, can promote epithelial-to-mesenchymal transition (EMT) processes that enhance the aggressiveness of a number of human cancers. In the present study, we investigated whether cigarette smoke/nicotine drives EMT in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Quantitative real-time PCR, western blot, immunohistochemistry, and immunofluorescence assays were used to evaluate Yes-associated protein 1 (YAP1) expression associated with cigarette smoking in human PDAC tissue samples and with nicotine exposure in PDAC cell lines. Bioinformatics, loss- and gain- of- function experiments, luciferase reporter assays, chromatin immunoprecipitation (ChIP), and murine tumor xenograft models were performed to examine the function of YAP1 in PDAC and to identify potential mechanisms of action.

RESULTS

Exposure to smoking or nicotine promoted EMT and tumor growth in PDAC cells and in xenograft tumors. Functional studies revealed that YAP1 might drive nicotine-stimulated EMT and oncogenic activity in vitro and in vivo. In human PDAC tissues, upregulation of YAP1 was associated with "ever smoking" status and poor overall survival. In term of mechanism, hypoxia inducible factor (HIF)1A promoted YAP1 nuclear localization and YAP1 transactivation by directly binding to the hypoxia responsive elements of the YAP1 promoter upon nicotine treatment. Nicotine stimulated HIF1A and YAP1 expression by activating cholinergic receptor nicotinic alpha7 (CHRNA7). In addition, YAP1 increased and sustained the protein stability of HIF1A.

CONCLUSIONS

These data demonstrate that YAP1 enhances nicotine-stimulated EMT and tumor progression of PDAC through a HIF1A/YAP1 positive feedback loop. Developing inhibitors that specifically target YAP1 may provide a novel therapeutic approach to suppress PDAC growth, especially in PDAC patients who have a history of smoking.

E-Cigarettes and Cancer Risk

From the time of their introduction, the popularity of e-cigarettes (electronic nicotine-delivery systems) has been rising. This trend may reflect the general belief that e-cigarettes are a less hazardous alternative to combustible cigarettes. However, the potential cancer-related effects of increased activation of the sympathoadrenal system induced by the inhalation of nicotine, the primary component of the e-cigarettes, are completely overlooked. Therefore, the aim of this review is to describe mechanisms that may connect the use of e-cigarettes and an increased risk for cancer development, as well as their stimulatory effect on cancer progression. Available preclinical data indicate that activation of the sympathetic nervous system by nicotine inhaled from e-cigarettes may stimulate cancer development and growth by several mechanisms. This issue might be especially important for oncological patients as they may have the misconception that compared with combustible cigarettes, e-cigarettes represent a risk-free alternative.

Effects and significance of formononetin on expression levels of HIF-1α and VEGF in mouse cervical cancer tissue

Effects and significance of formononetin on the expression levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in mouse cervical cancer tissue were investigated. The animal models of Balb/c nude mice with cervical cancer were established by the inoculation of HeLa cells, and randomly divided into positive control (n=10), cisplatin (n=15) and formononetin group (n=15). Mice were all sacrificed on the 31st day after administration, and their tumors were excised and weighed to calculate tumor inhibition rate. At the same time, their cancer tissues were obtained. RT-qPCR was used for detecting the mRNA expression levels of HIF-1α and VEGF, and western blotting for detecting the protein expression levels. During the medication intervention, mice in the formononetin group had no obvious adverse reactions, and were in good condition, whereas mice in the cisplatin group had poor appetite, drooping spirits and decreased activity. Mice in the cisplatin and the formononetin groups had significantly lower tumor mass and volume than those in the positive control group (P<0.05). The tumor inhibition rate of mice was 56.24% in the cisplatin group, and 50.17% in the formononetin group. Cervical cancer mice in the formononetin and the cisplatin groups had significantly lower mRNA and protein expression levels of HIF-1α and VEGF in tissues than those in the positive control group (P<0.05). Formononetin can inhibit the growth of cervical cancer and reduce the mRNA and protein expression levels of HIF-1α and VEGF in mouse cervical cancer. Formononetin has an inhibitory effect on cervical cancer tumors similar to that of cisplatin, but the former has smaller side effects, providing data for the clinical use in cervical cancer.

VPS33B interacts with NESG1 to modulate EGFR/PI3K/AKT/c-Myc/P53/miR-133a-3p signaling and induce 5-fluorouracil sensitivity in nasopharyngeal carcinoma

The vacuolar protein sorting 33B (VPS33B) was rarely reported in malignant tumors. In this research, we demonstrated that overexpression of VPS33B inhibited proliferation and chemoresistance to fluorouracil (5-FU) in nasopharyngeal carcinoma (NPC) in vivo and in vitro. Mechanistic analysis confirmed that overexpression of VPS33B modulated EGFR/PI3K/AKT/c-Myc/P53 signaling to arrest the cell cycle at G1/S phase. In addition, miR-133a-3p, a tumor-suppressive miRNA, was induced by P53 and directly targeted the EGFR/PI3K/AKT/c-Myc/P53 signaling and thus formed a negative feedback loop. Furthermore, another tumor suppressor, NESG1, interacted with VPS33B by colocalizing in the cytoplasm. The knockdown of NESG1 reversed the inhibitory effects of the overexpression of VPS33B in NPC cells by downregulating the PI3K/AKT/c-Jun-mediated transcription repression. Surprisingly, VPS33B was downregulated in the nicotine-treated and LMP-1-overexpressing NPC cells by targeting PI3K/AKT/c-Jun-mediated signaling. In addition, patients with higher VPS33B expression had a longer overall survival. Our study is the first to demonstrate that VPS33B is negatively regulated by LMP-1 and nicotine and thus suppresses the proliferation of NPC cells by interacting with NESG1 to regulate EGFR/PI3K/AKT/c-Myc/P53/miR-133a-3p signaling in NPC cells.

VPS33B interacts with NESG1 to modulate EGFR/PI3K/AKT/c-Myc/P53/miR-133a-3p signaling and induce 5-Fluorouracil sensitivity in nasopharyngeal carcinoma, and VPS33B was inhibited by LMP-1 and nicotine.

Smoking can increase nasopharyngeal carcinoma risk by repeatedly reactivating Epstein-Barr Virus: An analysis of a prospective study in southern China

Background

The association between smoking and nasopharyngeal carcinoma (NPC) is still uncertain. The aim of this study was to validate smoking effect on NPC and explore if smoking can induce NPC by persistently reactivating EBV in long‐term based on a prospective cohort design.

Methods

A NPC screening cohort with 10 181 eligible residents in Sihui city, southern China was conducted from 2008 to 2015. The smoking habit was investigated through the trained interviewers and EBV antibodies (VCA‐IgA, EBNA1‐IgA) as screening markers were tested periodically. New NPC cases were identified through local cancer registry. Cox's regression model was used to estimate the adjusted hazard ratios (aHRs) of smoking on NPC incidence. In the non‐NPC participants, the associations between smoking and EBV seropositivity in different periods were assessed by logistic regression and generalized estimating equations (GEE).

Results

With a median of 7.54 years, 71 NPCs were diagnosed ≥1 year after recruitment. Compared with never smokers, the aHRs of developing NPC among ever smokers were 3.00 (95%CI: 1.46‐6.16). Stratified by sex, the HRs of ever smoking were 2.59 (95%CI: 1.07‐6.23) for male and 3.75 (95%CI: 1.25‐11.20) for female, respectively. Among the non‐NPC individuals, ever smoking was not only associated with EBV seropositivity at baseline, but also in the 3‐5 years of follow up, with adjusted odds ratios (aORs) of 1.68 (95%CI: 1.29‐2.18) for VCA‐IgA and 1.92 (95%CI: 1.42‐2.59) for EBNA1‐IgA. Among the smokers who were tested EBV antibodies at least twice, the similar results were obtained using GEE.

Conclusion

Smoking could significantly increase the long‐term risk of NPC in southern China, partly by persistently reactivating EBV.

Addition of bevacizumab to systemic therapy for locally advanced and metastatic nasopharyngeal carcinoma

Radiotherapy is a vital treatment option for patients with nasopharyngeal carcinoma (NPC). Concurrent cisplatin-based radiochemotherapy with or without adjuvant chemotherapy had acquired good clinical effects with good local control rates. However, a number of patients present with metastasis following systemic regimens or initial diagnosis of locally advanced NPC, which cause difficulty for subsequent therapy. Therefore, there is an urgent requirement to discover novel targeted therapies. The present report describes one case of a patient with NPC and multiple metastases. The patient was treated with systemic therapy in combination with bevacizumab, palliative radiotherapy and chemotherapy following treatment with cetuximab and concurrent chemoradiotherapy in 2015. Following the addition of bevacizumab, metastases were reduced or disappeared after >2 months, and the duration of progression-free survival was 7 months. Bevacizumab is a monoclonal antibody that targets VEGF, and it is associated with angiogenesis, which causes the growth, invasion and progression of tumors. In previous studies, bevacizumab has been approved for the treatment of several types of malignant cancer and it has been able to effectively improve prognosis. In the present review, the effect of adding bevacizumab to systemic therapy for the treatment of NPC was analyzed, with a particular focus on advanced and metastatic diseases. A growing number of phase I/II clinical trials involving bevacizumab for NPC have been conducted with clinical outcomes showing improved rates of overall survival and progression-free survival as well as improvements in the quality of life of patients. However, severe or deadly toxicities can also result from combination treatment with bevacizumab. In the future, bevacizumab may become a common addition to systemic therapy for the treatment of locally advanced and metastatic NPC.

Endothelial Ca2+ Signaling and the Resistance to Anticancer Treatments: Partners in Crime

Intracellular Ca²⁺ signaling drives angiogenesis and vasculogenesis by stimulating proliferation, migration, and tube formation in both vascular endothelial cells and endothelial colony forming cells (ECFCs), which represent the only endothelial precursor truly belonging to the endothelial phenotype. In addition, local Ca²⁺ signals at the endoplasmic reticulum (ER)-mitochondria interface regulate endothelial cell fate by stimulating survival or apoptosis depending on the extent of the mitochondrial Ca²⁺ increase. The present article aims at describing how remodeling of the endothelial Ca²⁺ toolkit contributes to establish intrinsic or acquired resistance to standard anti-cancer therapies. The endothelial Ca²⁺ toolkit undergoes a major alteration in tumor endothelial cells and tumor-associated ECFCs. These include changes in TRPV4 expression and increase in the expression of P2X7 receptors, Piezo2, Stim1, Orai1, TRPC1, TRPC5, Connexin 40 and dysregulation of the ER Ca²⁺ handling machinery. Additionally, remodeling of the endothelial Ca²⁺ toolkit could involve nicotinic acetylcholine receptors, gasotransmitters-gated channels, two-pore channels and Na⁺/H⁺ exchanger. Targeting the endothelial Ca²⁺ toolkit could represent an alternative adjuvant therapy to circumvent patients' resistance to current anti-cancer treatments.

α7 nicotinic acetylcholine receptor in tumor-associated macrophages inhibits colorectal cancer metastasis through the JAK2/STAT3 signaling pathway

Considerable evidence has implied that α7 nicotinic receptor subtypes play an important role in chronic inflammatory and neuropathic pain signaling. The aim of the present study was to determine the role of endogenous α7nAChR signaling in tumor-associated macrophages (TAMs) in human colorectal cancer (CRC) metastasis and prognosis. α7nAChR expression in primary tumor cells and adjacent stroma cells especially in TAMs in 51 CRC patients was observed. Using a human monocyte THP-derived macrophages (TMs) with α7nAChR-siRNA knockdown (TMα7-/-) and a CRC cell Transwell co-culture model, the migration and invasion of two CRC cells, LoVo and SW620, were determined. Western blotting was carried out to investigate the expression of multiple molecules involved in the NF-κB, STAT3, PI3K signaling pathways in mimic TAMs, i.e., TMs exposed to in-direct LoVo cell stimulation. A nicotinic α7 receptor antagonist [α-bungarotoxin (α-Btx)] and three pharmaceutical inhibitors: AG490 (JAK2/STAT3 inhibitor), LY294002 (PI3K inhibitor) and Bay 11-7082 (NF-κB inhibitor) were applied to evaluate whether these signaling pathways were associated with the enhanced migration of CRC cells when co-cultured with α7nAChR knockdown TMs. The results revealed that the expression of α7nAChR in TAMs differed in patients. However, CRC patients who had a high incidence of hepatic metastasis showed no or low expression of α7nAChR in TAMs. TMs with α7nAChR-siRNA knockdown (TMα7-/-) significantly enhanced the migration and invasion of the two CRC cell lines LoVo and SW620. α7nAChR knockdown in TMs significantly downregulated phosphorylation of STAT3, PI3K p85 and NF-κB p65 after co-culturing with LoVo cells. Inhibition of JAK2/STAT3 prevented the TMα7-/--enhanced migration of LoVo cells. α7nAChR expressed in TAMs in human CRC patients plays an important role in preventing metastasis and could be a prognostic marker in CRCs, which may be regulated by the JAK2/STAT3 signaling pathway.

Nicotine suppresses apoptosis by regulating α7nAChR/Prx1 axis in oral precancerous lesions

Nicotine, a tumor promoter in tobacco, can increase Peroxiredoxin (Prx1) and nicotinic acetylcholine receptors (nAChRs) in oral squamous cell carcinoma (OSCC). In the present study, we investigate the effects of nicotine in oral precancerous lesions focusing on apoptosis and nAChR/Prx1 signaling. We detected expression of Prx1, α3nAChR, α7nAChR, phosphorylation of mitogen-activated protein kinases (MAPK) and apoptosis in dysplastic oral keratinocyte (DOK) cells as well as in 4-nitroquinoline 1-oxide (4NQO) or 4NQO + nicotine – induced oral precancerous lesions in Prx1 wild-type (Prx1^+/+) and Prx1 knockdown (Prx1^+/-) mice. In DOK cells, Prx1 knockdown and blocking α7nAChR activated apoptosis, and nicotine increased the expression of Prx1, α3nAChR and α7nAChR, and inhibited MAPK activation. Moreover, nicotine suppressed apoptosis depending on Prx1 and α7nAChR in DOK cells. In animal bioassay, nicotine and Prx1 promoted growth of 4NQO-induced precancerous lesions in mouse tongue. 4NQO plus nicotine suppressed MAPK activation in Prx1 wild-type mice but not in Prx1 knockdown mice. Our data demonstrate that nicotine inhibits cell apoptosis and promotes the growth of oral precancerous lesions via regulating α7nAChR/Prx1 during carcinogenesis of OSCC.

Imperatorin suppresses proliferation and angiogenesis of human colon cancer cell by targeting HIF-1α via the mTOR/p70S6K/4E-BP1 and MAPK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Angelica dahurica is a commonly used traditional Chinese medicine to treat migraine headache, toothache and cancer. Imperatorin is an active natural furocoumarin component originating from Angelica dahurica and has been shown to exhibit multiple bioeffector functions, including anti-cancer activity. However, the mechanism by which imperatorin inhibits tumor growth is not fully understood.

AIM OF THE STUDY

The aim of this study was to investigate the effectiveness of imperatorin as a treatment of cancer and to identify the underlying mechanisms of its anticancer activity.

MATERIALS AND METHODS

HCT116, HeLa, and Hep3B cells were used in this study. Major assays were promoter-reporter gene assay, MTT, western blot analysis, immunofluorescence assay, reverse transcription-PCR (RT-PCR), flow cytometric analysis, clonogenic assay, EdU labeling and immunofluorescence, xenografted assay, and VEGF ELISA.

RESULTS

We here demonstrated the effect of imperatorin on hypoxia-inducible factor-1 (HIF-1) activation. Imperatorin showed a potent inhibitory activity against HIF-1 activation induced by hypoxia in various human cancer cell lines. This compound markedly decreased the hypoxia-induced accumulation of HIF-1α protein dose-dependently, whereas it did not affect the expressions of HIF-1β and topoisomerase-I (Topo-I). Further analysis revealed that imperatorin inhibited HIF-1α protein synthesis, without affecting the expression level of HIF-1α mRNA or degradation of HIF-1α protein. Moreover, the phosphorylation levels of mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase (p70S6K), eIF4E binding protein-1 (4E-BP1), eukaryotic initiation factor 4E (eIF4E), extracellular signal-regulated kinase-1/2 (ERK1/2), SAPK/JNK and p38 were significantly suppressed by imperatorin. Furthermore, imperatorin prevented hypoxia-induced expression of HIF-1 target genes and flow cytometric analysis indicated that imperatorin induced G1 phase arrest in human colon cancer cell (HCT116). We found that imperatorin administration inhibits tumor growth and blocks tumor angiogenesis in a xenograft tumor model.

CONCLUSIONS

These results show that imperatorin inhibited HIF-1α protein synthesis by downregulating the mTOR/p70S6K/4E-BP1 and MAPK pathways. These conclusions suggest that imperatorin is an effective inhibitor of HIF-1 and provide new perspectives into the mechanism of its anticancer activity.

Gestational Exposure to Sidestream (Secondhand) Cigarette Smoke Promotes Transgenerational Epigenetic Transmission of Exacerbated Allergic Asthma and Bronchopulmonary Dysplasia

Embryonic development is highly sensitive to xenobiotic toxicity and in utero exposure to environmental toxins affects physiological responses of the progeny. In the United States, the prevalence of allergic asthma (AA) is inexplicably rising and in utero exposure to cigarette smoke increases the risk of AA and bronchopulmonary dysplasia (BPD) in children and animal models. We reported that gestational exposure to sidestream cigarette smoke (SS), or secondhand smoke, promoted nicotinic acetylcholine receptor-dependent exacerbation of AA and BPD in mice. Recently, perinatal nicotine injections in rats were reported to induce peroxisome proliferator-activated receptor γ-dependent transgenerational transmission of asthma. Herein, we show that first generation and second generation progeny from gestationally SS-exposed mice exhibit exacerbated AA and BPD that is not dependent on the decrease in peroxisome proliferator-activated receptor γ levels. Lungs from these mice show strong eosinophilic infiltration, excessive Th2 polarization, marked airway hyperresponsiveness, alveolar simplification, decreased lung compliance, and decreased lung angiogenesis. At the molecular level, these changes are associated with increased RUNX3 expression, alveolar cell apoptosis, and the antiangiogenic factor GAX, and decreased expression of HIF-1α and proangiogenic factors NF-κB and VEGFR2 in the 7-d first generation and second generation lungs. Moreover, the lungs from these mice exhibit lower levels of microRNA (miR)-130a and increased levels of miR-16 and miR-221. These miRs regulate HIF-1α-regulated apoptotic, angiogenic, and immune pathways. Thus the intergenerational effects of gestational SS involve epigenetic regulation of HIF-1α through specific miRs contributing to increased incidence of AA and BPD in the progenies.

Evaluation of globins expression in brain, heart, and lung in rats exposed to side stream cigarette smoke

The side stream cigarette smoke (SSCS) is a contributing factor in the pathogenesis of cigarette smoking-induced toxicity. Hemoglobin (Hb), myoglobin (Mb), neuroglobin (Ngb), and cytoglobin (Cygb) are globins with different distributions and functions in the tissues and have similar actions by providing O₂ (oxygen) for respiratory chain, detoxification of ROS and nitric oxide (NO), and protect tissues against irreversible lesions. We aimed to investigate the effects of SSCS exposure on gene and protein expression of Ngb, Cygb, and Mb in different tissue. The Ngb and Cygb gene and protein expression in the cerebral cortex increased after 1 week of rat exposure to SSCS. In hippocampus, the Ngb gene and protein expression increased after 1 week or more of exposure and no change was observed in Cygb gene and protein expression. In myocardium, Mb and Cygb gene expression increased at 1 and 4 weeks of exposure, while protein expression of both increased at 1, 2, 3, and 4 weeks. In lung, observed an increase in Cygb gene and protein expression after 2, 3, and 4 weeks of exposure. The findings suggest that SSCS modulates Ngb, Cygb, and Mb in central and peripheral tissue © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1252-1261, 2017.

Overexpression of Kinesin Family Member 20A Correlates with Disease Progression and Poor Prognosis in Human Nasopharyngeal Cancer: A Retrospective Analysis of 105 Patients

BACKGROUND

Numerous studies have shown Kinesin family member 20A (KIF20A) may play a critical role in the development and progression of cancer. However, the clinical value of KIF20A in nasopharyngeal carcinoma (NPC) is unknown. Here, we investigated the expression pattern of KIF20A in NPC and its correlation with clinicopathological features of patients.

METHODS

Real-time PCR and Western blotting were used to quantify KIF20A expression in NPC cell lines and clinical specimens compared with normal controls. KIF20A protein expression was also examined in archived paraffin embedded tumor samples from 105 patients with pathologically confirmed NPC by immunohistochemistry (IHC). Statistical analyses were applied to assess the associations between KIF20A expression and the clinicopathological features and survival outcomes. Effects on migration and invasion were assessed by wound healing and transwell invasion assays after KIF20A silencing.

RESULTS

KIF20A was significantly overexpressed at both the mRNA and protein levels in NPC cell lines and human tumor tissues. 45/105 (42.9%) of NPC specimens expressed high levels of KIF20A among the KIF20A detectable cases. Statistical analysis revealed that high KIF20A expression was significantly associated with gender (P = 0.046), clinical stage (P<0.001), T category (P = 0.022), N category (P<0.001), distant metastasis (P = 0.001) and vital status (P = 0.001). Moreover, Higher KIF20A expression patients had shorter overall survival (OS) and progression-free survival (PFS) (P = 0.001 and P = 0.001; log-rank test). In multivariate analysis, KIF20A was an independent prognostic factor for OS and PFS in the entire cohort (P = 0.033, P = 0.008). Knock down of KIF20A expression significantly suppressed NPC cell's migration and invasion.

CONCLUSIONS

KIF20A is overexpressed and may serve as an independent prognostic biomarker in NPC. Targeting KIF20A reduces migration and invasion of NPC cells.

Combining antiangiogenic therapy and radiation in nasopharyngeal carcinoma

Radiation therapy is the primary treatment in nasopharyngeal carcinoma (NPC), and the effect of radiation therapy is strongly related to the oxygen content of cancer cells. That means, it is imperative to balance the interactions between radiotherapy and anti-angiogenesis therapy when giving combination therapy to improve clinical outcomes. The complicated mechanisms between antiangiogenic agents and radiation involve many interactions between the cancer cells, vasculature, and cancer stroma. The proliferation and metastasis of cancer depends on angiogenesis, while rapid growth of cancers will cause hypoxia, which contributes to radioresistance. Antiangiogenic agents can modulate the cancer blood flow and oxygenation through target cancer vasculature, leading to increased radiosensitivity. This study discusses the mechanisms of the synergistic effect of the antiangiogenic therapy with radiation therapy in metastatic NPC, and reviews the data supporting this strategy as a promising treatment for metastatic NPC.

Nicotine Induces Podocyte Apoptosis through Increasing Oxidative Stress

Background

Cigarette smoking plays an important role in the progression of chronic kidney disease (CKD). Nicotine, one of the major components of cigarette smoking, has been demonstrated to increase proliferation of renal mesangial cells. In this study, we examined the effect of nicotine on podocyte injury.

Methods

To determine the expression of nicotinic acetylcholine receptors (nAChR subunits) in podocytes, cDNAs and cell lysate of cultured human podocytes were used for the expression of nAChR mRNAs and proteins, respectively; and mouse renal cortical sections were subjected to immunofluorescant staining. We also studied the effect of nicotine on podocyte nephrin expression, reactive oxygen species (ROS) generation (via DCFDA loading followed by fluorometric analysis), proliferation, and apoptosis (morphologic assays). We evaluated the effect of nicotine on podocyte downstream signaling including phosphorylation of ERK1/2, JNK, and p38 and established causal relationships by using respective inhibitors. We used nAChR antagonists to confirm the role of nicotine on podocyte injury.

Results

Human podocytes displayed robust mRNA and protein expression of nAChR in vitro studies. In vivo studies, mice renal cortical sections revealed co-localization of nAChRs along with synaptopodin. In vitro studies, nephrin expression in podocyte was decreased by nicotine. Nicotine stimulated podocyte ROS generation; nonetheless, antioxidants such as N-acetyl cysteine (NAC) and TEMPOL (superoxide dismutase mimetic agent) inhibited this effect of nicotine. Nicotine did not modulate proliferation but promoted apoptosis in podocytes. Nicotine enhanced podocyte phosphorylation of ERK1/2, JNK, and p38, and their specific inhibitors attenuated nicotine-induced apoptosis. nAChR antagonists significantly suppressed the effects of nicotine on podocyte.

Conclusions

Nicotine induces podocyte apoptosis through ROS generation and associated downstream MAPKs signaling. The present study provides insight into molecular mechanisms involved in smoking associated progression of chronic kidney disease.

Current relevance of hypoxia in head and neck cancer

Head and Neck cancer (HNC) is a complex mix of cancers and one of the more common cancers with a relatively poor prognosis. One of the factors that may assist us in predicting survival and allow us to adjust our treatment strategies is the presence of tumor hypoxia. In this overview we aim to evaluate the current evidence and potential clinical relevance of tumor hypoxia in head and neck cancer according to an extensive search of current literature.An abundance of evidence and often contradictory evidence is found in the literature. Even the contradictory evidence and comparisons are difficult to judge as criteria and methodologies differ greatly, furthermore few prospective observational studies exist for verification of the pre-clinical studies. Despite these discrepancies there is clear evidence of associations between prognosis and poor tumor oxygenation biomarkers such as HIF-1α, GLUT-1 and lactate, though these associations are not exclusive. The use of genetic markers is expanding and will probably lead to significantly more and complex evidence. The lack of oxygenation in head and neck tumors is of paramount importance for the prediction of treatment outcomes and prognosis. Despite the wide array of conflicting evidence, the drive towards non-invasive prediction of tumor hypoxia should continue.

Inhibition of hypoxia inducible factor-1α attenuates abdominal aortic aneurysm progression through the down-regulation of matrix metalloproteinases

Hypoxia inducible factor-1α (HIF-1α) pathway is associated with many vascular diseases, including atherosclerosis, arterial aneurysms, pulmonary hypertension and chronic venous diseases. Significant HIF-1α expression could be found at the rupture edge at human abdominal aortic aneurysm (AAA) tissues. While our initial in vitro experiments had shown that deferoxamine (DFO) could attenuate angiotensin II (AngII) induced endothelial activations; we unexpectedly found that DFO augmented the severity of AngII-induced AAA, at least partly through increased accumulation of HIF-1α. The findings promoted us to test whether aneurysmal prone factors could up-regulate the expression of MMP-2 and MMP-9 through aberrantly increased HIF-1α and promote AAA development. AngII induced AAA in hyperlipidemic mice model was used. DFO, as a prolyl hydroxylase inhibitor, stabilized HIF-1α and augmented MMPs activities. Aneurysmal-prone factors induced HIF-1α can cause overexpression of MMP-2 and MMP-9 and promote aneurysmal progression. Pharmacological HIF-1α inhibitors, digoxin and 2-ME could ameliorate AngII induced AAA in vivo. HIF-1α is pivotal for the development of AAA. Our study provides a rationale for using HIF-1α inhibitors as an adjunctive medical therapy in addition to current cardiovascular risk-reducing regimens.

Ku80 cooperates with CBP to promote COX-2 expression and tumor growth

Cyclooxygenase-2 (COX-2) plays an important role in lung cancer development and progression. Using streptavidin-agarose pulldown and proteomics assay, we identified and validated Ku80, a dimer of Ku participating in the repair of broken DNA double strands, as a new binding protein of the COX-2 gene promoter. Overexpression of Ku80 up-regulated COX-2 promoter activation and COX-2 expression in lung cancer cells. Silencing of Ku80 by siRNA down-regulated COX-2 expression and inhibited tumor cell growth in vitro and in a xenograft mouse model. Ku80 knockdown suppressed phosphorylation of ERK, resulting in an inactivation of the MAPK pathway. Moreover, CBP, a transcription co-activator, interacted with and acetylated Ku80 to co-regulate the activation of COX-2 promoter. Overexpression of CBP increased Ku80 acetylation, thereby promoting COX-2 expression and cell growth. Suppression of CBP by a CBP-specific inhibitor or siRNA inhibited COX-2 expression as well as tumor cell growth. Tissue microarray immunohistochemical analysis of lung adenocarcinomas revealed a strong positive correlation between levels of Ku80 and COX-2 and clinicopathologic variables. Overexpression of Ku80 was associated with poor prognosis in patients with lung cancers. We conclude that Ku80 promotes COX-2 expression and tumor growth and is a potential therapeutic target in lung cancer.

Activating enhancer-binding protein-2α induces cyclooxygenase-2 expression and promotes nasopharyngeal carcinoma growth

Activating enhancer-binding protein-2α (AP-2α) regulates the expression of many cancer-related genes. Here, we demonstrated a novel mechanism by which AP-2α up-regulated cyclooxygenase-2 (COX-2) expression to promote the growth of nasopharyngeal carcinomas (NPCs). High expression of AP-2α in NPC cell lines and tumor tissues from NPC patients was detected and significantly correlated with COX-2 expression. Overexpression of AP-2α and COX-2 in tumor tissues was associated with advanced tumor stage, clinical progression, and short survival of patients with NPCs. Knockdown of AP-2α by siRNA markedly inhibited COX-2 expression and PGE2 production in NPC cells. Exogenous expression of AP-2α up-regulated the COX-2 and PGE2. Knockdown of AP-2α also significantly suppressed cell proliferation in NPC cells in vitro and tumor growth in a NPC xenograft mouse model. Moreover, we found that p300 played an important role in the AP-2α/COX-2 pathway. AP-2α could co-localize and interact with p300 in NPC cells. Overexpression of the p300, but not its histone acetyltransferase (HAT) domain deletion mutant, promoted the acetylation of AP-2α and its binding on the COX-2 promoter, thereby up-regulated COX-2 expression. Our results indicate that AP-2α activates COX-2 expression to promote NPC growth and suggest that the AP-2α/COX-2 signaling is a potential therapeutic target for NPC treatment.

miR-372 inhibits p62 in head and neck squamous cell carcinoma in vitro and in vivo

Here we showed that exogenous miR-372 expression and knockdown of p62 (sequestosome1 or SQSTM1), both increased migration of head and neck squamous cell carcinoma (HNSCC) cells. p62 induced phase II detoxification enzyme NADPH quinone oxidoreductase 1 (NQO1), which decreased ROS levels and cell migration. Also, miR-372 decreased p62 during hypoxia, thus increasing cell migration. Levels of miR-372 and p62 inversely correlated in human HNSCC tissues. Plasma levels of miR-372 was associated with advanced tumor stage and patient mortality. Both plasma and salivary miR-372 levels were decreased after tumor resection. We conclude that miR-372 decreases p62, thus increasing ROS and motility in HNSCC cells.

Autocrine control of angiogenesis by endogenous acetylcholine in an in vitro model using human endothelial cells: evidence for an autocrine cholinergic system in endothelial cells

We wanted to elucidate whether acetylcholine as the endogenous ligand at cholinoceptors (ChRs) may have effects on angiogenesis and whether they are transduced through muscarinic or nicotinic ChRs. Human umbilical vein endothelial cells were cultured until confluence and thereafter seeded in Matrigel in vitro angiogenesis assays for 18 hours. During the entire cell culture and angiogenesis period, cells were treated with vehicle, eserine (1 μM), in the absence or presence of additional atropine (1 μM) or mecamylamine (1 μM). Finally, the resulting angiogenetic network was investigated histologically. Eserine significantly enhanced acetylcholine formation. When acetylcholine acted through muscarinic ChRs (eserine + mecamylamine), we observed enhanced complexity of the angiogenic network pattern with increased tube length and cell number. In contrast, when acting through nicotinic ChRs (eserine + atropine), we found reduced complexity of pattern with less branches, shorter tubes, and reduced cell number. If acting on both types of ChRs (eserine alone), there were only very small effects. Using α-bungarotoxin, lobeline, and dihydro-β-erythroidine, we also could show that these effects to various degrees involve α7, α3/β2, and α4/β2 n-ChRs. In conclusion, our results support the hypothesis that human umbilical vein endothelial cells possess an autocrine nonneuronal cholinergic system regulating angiogenesic branch formation through the partially opposing effects of n-ChRs and m-ChRs.

Autophagy, a double-edged sword in anti-angiogenesis therapy

Autophagy is a highly conservative cell behavior to keep the intracellular homeostasis and is frequently activated when cells encounter disgusting conditions, such as nutrition or growth factor deprive, hypoxia and cytotoxic agents. However, the precise role of autophagy under various conditions may be opposite, differ from protect cells survival to promote cells death, and the mechanism of this conditional-dependent role is still unclear. Anti-angiogenesis agents, such as bevacizumab, sorafenib and sunitinib, could reduce tumor microvascular density and increase tumor hypoxia, thus up-regulating autophagy activation of tumor cells, but the function of autophagy induced by anti-angiogenesis agents is still divergent and is considered to play a cytoprotective role in most cases. In this review, we mainly discuss the relationship between anti-angiogenesis therapy-induced hypoxia and autophagy, and pay special attention on the exact role of anti-angiogenesis agents induced autophagy in the process of anti-angiogenesis treatment.

Protein N-arginine methyltransferase 5 promotes the tumor progression and radioresistance of nasopharyngeal carcinoma

Radiotherapy resistance is the main cause of the the poor prognosis of some nasopharyngeal carcinoma (NPC) patients. Yet, the exact mechanism is still elusive. In the present study, we explored the clinical and biological role of protein arginine methyltransferase 5 (PRMT5) in NPC. Our results revealed that PRMT5 was overexpressed in NPC tissues when compared with that in adjacent non-tumor tissues by quantitative RT-PCR and immunoblotting. High expression of PRMT5 was correlated with adverse outcomes of NPC patients as determined by the scoring of a tissue microarray. Silencing of PRMT5 promoted the radiosensitivity of 5-8F and CNE2 cells as determined by cell proliferation and colony formation assays. Furthermore, fibroblast growth factor receptor 3 (FGFR3) was identified as one of the downstream targets of PRMT5, and the silencing of PRMT5 decreased the mRNA and protein levels of FGFR3 in the 5-8F and CNE2 cells. Silencing of FGFR3 induced similar phenotypes as the inhibition of PRMT5, and re-expression of FGFR3 in 5-8F/shPRMT5 and CNE2/shPRMT5 cells restored the proliferation and colony formation ability induced by irradiation exposure. Our results indicate that PRMT5 is a marker of poor prognosis in NPC patients. PRMT5 promoted the radioresistance of NPC cells via targeting FGFR3, at least partly if not totally. PRMT5 and its downstream effector FGFR3 may be potential targets for anticancer strategy.

CHRNA7 inhibits cell invasion and metastasis of LoVo human colorectal cancer cells through PI3K/Akt signaling

The α7 neuronal nicotinic receptor gene (CHRNA7) is widely expressed in both the brain and periphery whereas its encoding protein of α7 neuronal acetylcholine receptor (α7nAChR) belongs to the nicotinic acetylcholine receptor family. Considerable evidence suggests that α7nAChR plays an important role in chronic inflammatory and neuropathic pain signaling and thus has been proposed as a potential target for treating cognitive deficits in patients with schizophrenia, attention deficit hyperactivity disorder (ADHD) and Alzheimer's disease. The aim of the present study was to determine the role of endogenous α7nAChR signaling in human colorectal cancer growth and metastasis. pLVX‑CHRNA7 encoding the full length of CHRNA7 was constructed and transfected into LoVo human colorectal cancer cells. Cell proliferation was measured by Cell Counting Kit‑8 (CCK‑8), and cell migration and invasion were detected by Transwell chamber assays. Expression and activity of metastasis‑related metalloproteinases (MMPs) were analyzed by western blotting and gelatin zymography, respectively. Activation of metastasis-related signaling molecules was detected by western blotting. LY294002 was used to specifically block the phosphatidylinositol 3‑kinase/v‑akt murine thymoma viral oncogene homologue (PI3K/Akt) pathway. We showed that concomitantly with an increase in α7nAChR expression after transfection, LoVo cells presented reduced abilities for migration and invasion, which was accompanied by reduced expression levels of MMP‑1 and MMP‑9 as well as activation of the PI3K/Akt signaling pathway. The application of LY294002 restored the migration and invasion abilities of the LoVo cells bearing CHRNA7. Collectively, we conclude that overexpression of CHRNA7 negatively controls colorectal cancer LoVo cell invasion and metastasis via PI3K/Akt pathway activation and may serve as either a diagnostic marker or a therapeutic target for colorectal cancer metastasis.

Nicotine enhances hepatocyte growth factor-mediated lung cancer cell migration by activating the α7 nicotine acetylcholine receptor and phosphoinositide kinase-3-dependent pathway

Cigarette smoking not only promotes lung carcinogenesis, but it has also been demonstrated to promote the progression of lung cancer. Despite nicotine being a major component of cigarette smoke, it is not carcinogenic when acting alone. Instead, it is believed to function as a tumor promoter. Due to the fatal consequences of lung cancer being primarily associated with the processes of invasion and metastasis, the present study aimed to determine the effect of nicotine on the migratory activity of lung cancer cells. The effect of nicotine on the migration of lung cancer A549 cells was evaluated by a wound healing assay. Hepatocyte growth factor (HGF) was used as a pro-migratory stimulus. During several of the experiments, specific inhibitors of α7-nicotine acetylcholine receptor (α7-nAchR), phosphoinositide kinase-3 (PI3K) and extracellular signal-related kinase (ERK)1/2 were included. The phosphorylation levels of Akt and ERK1/2 were examined using a cell-based protein phosphorylation assay. It was observed that nicotine did not induce cell migration by itself, but that it instead promoted HGF-induced cell migration. The effects of nicotine were inhibited by the pretreatment of the cells with the α7-nAchR inhibitor, methyllycaconitine, and the PI3K inhibitor, LY294002. The mitogen-activated protein kinase/ERK kinase kinase inhibitor exerted modest, but non-significant inhibitory activity on the effect of nicotine. Nicotine did not induce Akt phosphorylation by itself, but instead promoted the HGF-induced phosphorylation of Akt. It was also observed that nicotine had no effect on ERK1/2 phosphorylation. The results from the present study indicate that nicotine, when alone, does not have a pro-migratory function, but instead enhances responsiveness to the pro-migratory stimulus emitted by HGF. The current study provides an insight into the mechanism of tumor promotion by demonstrating that nicotine and α7-nAchRs act in synergy with the HGF-induced PI3K/Akt signaling pathway, increasing the sensitivity of lung cancer cells to HGF, and thereby promoting cell migration, a vital step in invasion and metastasis.

Nicotine enhances invasion and metastasis of human colorectal cancer cells through the nicotinic acetylcholine receptor downstream p38 MAPK signaling pathway

Nicotine as a cigarette component is an established risk factor for colorectal cancer tumorigenesis. The downstream signaling pathways of nicotinic acetylcholine receptors (nAchRs) are believed to be responsible for the cellular effects. In the present study, we evaluated the effects and novel mechanisms for nicotine on the capacity for colorectal cancer cell invasion and metastasis. LOVO and SW620 colorectal cancer cells were stimulated with nicotine in vitro. A Transwell chamber model was applied to detect the capacity for tumor cell invasion. Assays for gelatin zymography and western blotting were applied to detect the activity and expression of metastasis-related matrix metalloproteinases (MMPs), respectively. Signal transduction was assessed by immunoblotting for the phosphorylation of relevant signal molecules and the application of pharmaceutical inhibitors. We showed that nicotine increased LOVO and SW620 colorectal cancer cell invasion along with enhanced activity and expression of MMP-1, -2 and -9. Nicotine increased phosphorylation of p38, ERK, Akt and PI3K p85 but had no effect on phosphorylation of JNK, or NF-κB. Of the pharmaceutical inhibitors of U0126 (ERK1/2 inhibitor), LY294002 (Akt activation inhibitor), SB239063 (p38 MAPK activation inhibitor) and hexamethonium (Hex) (nAchRs inhibitor), the cellular and molecular effects were reduced by the applications of SB239063 and Hex. We concluded that nicotine stimulates the invasion and metastasis of colon cancer cells in vitro via activation of the nAchRs and the p38 MAPK downstream signaling pathway. Therefore, p38 MAPK may have potential as a therapeutic target for smoking-related human colorectal cancer metastasis.

HIF-1α Plays a Critical Role in the Gestational Sidestream Smoke-Induced Bronchopulmonary Dysplasia in Mice

Rationale

Smoking during pregnancy increases the risk of bronchopulmonary dysplasia (BPD) and, in mice, gestational exposure to sidestream cigarette smoke (SS) induces BPD-like condition characterized by alveolar simplification, impaired angiogenesis, and suppressed surfactant protein production. Normal fetal development occurs in a hypoxic environment and nicotinic acetylcholine receptors (nAChRs) regulate the hypoxia-inducible factor (HIF)-1α that controls apoptosis and angiogenesis. To understand SS-induced BPD, we hypothesized that gestational SS affected alveolar development through HIF-1α.

Methods

Pregnant BALB/c mice were exposed to air (control) or SS throughout the gestational period and the 7-day-old lungs of the progeny were examined.

Results

Gestational SS increased apoptosis of alveolar and airway epithelial cells. This response was associated with increased alveolar volumes, higher levels of proapoptotic factors (FOXO3a, HIPK2, p53, BIM, BIK, and BAX) and the antiangiogenic factor (GAX), and lower levels of antiapoptotic factors (Akt-PI3K, NF-κB, HIF-1α, and Bcl-2) in the lung. Although gestational SS increased the cells containing the proangiogenic bombesin-like-peptide, it markedly decreased the expression of its receptor GRPR in the lung. The effects of SS on apoptosis were attenuated by the nAChR antagonist mecamylamine.

Conclusions

Gestational SS-induced BPD is potentially regulated by nAChRs and associated with downregulation of HIF-1α, increased apoptosis of epithelial cells, and increased alveolar volumes. Thus, in mice, exposure to sidestream tobacco smoke during pregnancy promotes BPD-like condition that is potentially mediated through the nAChR/HIF-1α pathway.

α5-nAChR modulates nicotine-induced cell migration and invasion in A549 lung cancer cells

Cigarette smoking is the most important risk factor in the development of human lung cancer. Nicotine, the major component in tobacco, not only contributes to carcinogenesis but also promotes tumor metastasis. By binding to nicotinic acetylcholine receptors (nAChRs), nicotine induces the proliferation and migration of non-small cell lung cancer. Recently studies have indicated that α5-nAChR is highly associated with lung cancer risk and nicotine dependence. Nevertheless, it is unclear whether nicotine promotes the migration and invasion through activation of α5-nAChR in lung cancer. In the present study, A549 cell was exposed to 1μN nicotine for 8, 24 or 48h. Wound-healing assay and transwell assay were used to evaluate the capability of A549 cell migration and cell invasion, respectively. Silencing of α5-nAChR was done by siRNA. Western blotting and PCR were used to detect α5-nAChR expression. Nicotine can induce activation of α5-nAChR in association with increased migration and invasion of human lung cancer A549 cell. Treatment of cells with α5-nAChR specific siRNA blocks nicotine-stimulated activation of α5-nAChR and suppresses A549 cell migration and invasion. Reduction of α5-nAChR resulted in upregulation of E-cadherin, consistent with E-cadherin being inhibitive of cancer cell invasion. These findings suggest that nicotine-induced migration and invasion may occur in a mechanism through activation of α5-nAChR, which can contribute to metastasis or development of human lung cancer.

Mechanisms of tumor-promoting activities of nicotine in lung cancer: synergistic effects of cell membrane and mitochondrial nicotinic acetylcholine receptors

Background

One of the major controversies of contemporary medicine is created by an increased consumption of nicotine and growing evidence of its connection to cancer, which urges elucidation of the molecular mechanisms of oncogenic effects of inhaled nicotine. Current research indicates that nicotinergic regulation of cell survival and death is more complex than originally thought, because it involves signals emanating from both cell membrane (cm)- and mitochondrial (mt)-nicotinic acetylcholine receptors (nAChRs). In this study, we elaborated on the novel concept linking cm-nAChRs to growth promotion of lung cancer cells through cooperation with the growth factor signaling, and mt-nAChRs — to inhibition of intrinsic apoptosis through prevention of opening of mitochondrial permeability transition pore (mPTP).

Methods

Experiments were performed with normal human lobar bronchial epithelial cells, the lung squamous cell carcinoma line SW900, and intact and NNK-transformed immortalized human bronchial cell line BEP2D.

Results

We demonstrated that the growth-promoting effect of nicotine mediated by activation of α7 cm-nAChR synergizes mainly with that of epidermal growth factor (EGF), α3 — vascular endothelial growth factor (VEGF), α4 — insulin-like growth factor I (IGF-I) and VEGF, whereas α9 with EGF, IGF-I and VEGF. We also established the ligand-binding abilities of mt-nAChRs and demonstrated that quantity of the mt-nAChRs coupled to inhibition of mPTP opening increases upon malignant transformation.

Conclusions

These results indicated that the biological sum of simultaneous activation of cm- and mt-nAChRs produces a combination of growth-promoting and anti-apoptotic signals that implement the tumor-promoting action of nicotine on lung cells. Therefore, nAChRs may be a promising molecular target to arrest lung cancer progression and re-open mitochondrial apoptotic pathways.

Andrographolide suppresses proliferation of nasopharyngeal carcinoma cells via attenuating NF-κB pathway

Andrographolide (Andro) has been reported to have anticancer activity in multiple types of cancer due to its capacity to inactivate NF-κB pathway. Previous studies showed the therapeutic potential of targeting NF-κB pathway in nasopharyngeal carcinoma (NPC). However, the anticancer activity of Andro in NPC has not been reported. In this study, we defined the anticancer effects of Andro in NPC and elucidated its potential mechanisms of action. Our results showed that Andro significantly inhibited the proliferation and invasion of NPC cells (P < 0.05, resp.). These anticancer activities were associated with cell apoptosis, cell death and induction of cell cycle arrest, and the downregulation of NF-κB target genes. This work provides evidence that NF-κB pathway is a potential therapeutic target and may also be indispensable in the Andro-mediated anticancer activities in nasopharyngeal carcinoma.

Pro- and antiangiogenic markers in patients with pulmonary complications of systemic scleroderma

Systemic sclerosis (SSc) is an autoimmune disorder characterized by skin and internal organs fibrosis and concomitant vascular abnormalities. Although SSc is considered mainly fibrosing disease, underlying vascular pathology plays a fundamental role in its pathogenesis. We have focused on positive and negative serum markers of angiogenesis and fibrosis (pigment epithelium-derived factor [PEDF], vascular endothelial growth factor [VEGF], and soluble VEGF receptor [sVEGFR]), in progressive SSc patients at baseline and after follow-up in relation to cardiopulmonary complications (systemic hypertension [HT], pulmonary arterial hypertension [PAH] and pulmonary fibrosis [PF]). VEGF and PEDF but not sVEGFR were reciprocally regulated in SSc progression. Moreover, VEGF/PEDF ratio significantly increased during follow up suggesting that it might be used as a biomarker of disease progression. No correlation between the studied markers and cardiopulmonary complications was observed. In conclusion, VEGF and PEDF level, and the VEGF/PEDF ratio are significantly changed in the course of SSc progression and these markers can be used to assess SSc activity.

Development of ferret as a human lung cancer model by injecting 4-(Nmethyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

OBJECTIVE

Development of new animal lung cancer models that are relevant to human lung carcino-genesis is important for lung cancer research. Previously we have shown the induction of lung tumor in ferrets (Mustela putorius furo) exposed to both tobacco smoke and a tobacco carcinogen (4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone, NNK). In the present study, we investigated whether NNK treatment alone induces both preneoplastic and neoplastic lesions in the lungs of ferrets.

METHODS

We exposed ferrets to NNK by i.p. injection of NNK (50 mg/kg BW) once a month for four consecutive months and then followed up for 24, 26 and 32 weeks. The incidences of pulmonary pre-neoplastic and neoplastic lesions were assessed by histopathological examination. The expressions of 7 nicotinic acetylcholine receptor ( 7 nAChR, which has been shown to promote lung carcinogenesis)and its related molecular biomarkers in lungs were examined by immunohistochemistry and/or Western blotting analysis.

RESULTS

Ferrets exposed to NNK alone developed both preneoplastic lesions (squamous metaplasia, dysplasia and atypical adenomatous hyperplasia) and tumors (squamous cell carcinoma, adenocarcinoma and adenosquamous carcinoma), which are commonly seen in humans. The incidence of tumor induced by NNK was time-dependent in the ferrets (16.7%, 40.0% and 66.7% for 24, 26 and 32 weeks, respectively). 7 nAChR is highly expressed in the ferret bronchial/bronchiolar epithelial cells, and alveolar macrophages in ferrets exposed to NNK, and in both squamous cell carcinoma and adenocarcinoma of the ferrets. In addition, we observed the tendency for an increase in phospho-ERK and cyclin D1 protein levels (p = 0.081 and 0.080, respectively) in the lungs of ferrets exposed to NNK.

CONCLUSION

The development of both preneoplastic and neoplastic lesions in ferret lungs by injecting NNK alone provides a simple and highly relevant non-rodent model for studying biomarkers/molecular targets for the prevention, detection and treatment of lung carcinogenesis in humans.

Chronic Rhinosinusitis and the Risk of Nasopharyngeal Cancer in a Taiwanese Health Study

Background

Although epidemiological and laboratory studies report that chronic inflammatory conditions contribute to the pathogenesis of cancer, it remains controversial whether chronic rhinosinusitis (CRS) results in nasopharyngeal cancer (NPC).

Methods

Retrospective cohort study was performed from the National Health Insurance (NHI) Taiwan database. This study prospectively examined whether CRS or nasal polyposis is associated with NPC risk in the NHI, a population-based cohort of 231,490 Taiwan Chinese individuals with a mean age of 32 years, recruited between 2000 and 2006. We collected information from the Longitudinal Health Insurance Database. Each subject completed an interview including questions about medical conditions, and the NPC occurrence and survival statuses were determined by linkage to population-based NHI registries in Taiwan. In addition, each NPC and CRS subject had completed an interview on medical condition to confirm their diagnosis.

Results

After adjustment for age, sex, hypertension, diabetes mellitus, allergic rhinitis, otitis media, coronary artery disease, pharyngitis, and tonsillitis, individuals with rhinosinusitis were found to have a 3.55-fold increased risk of developing NPC compared with individuals without rhinosinusitis (hazard ratio = 3.55; 95% CI = 2.22–5.69). The same results were also observed when the study subjects were analyzed without comorbidities.

Conclusion

Adult patients with rhinosinusitis should be followed up with regard to the nasopharynx for at least 3 years, particularly repeat sinusitis patients.

Connections of nicotine to cancer

This Opinion article discusses emerging evidence of direct contributions of nicotine to cancer onset and growth. The list of cancers reportedly connected to nicotine is expanding and presently includes small-cell and non-small-cell lung carcinomas, as well as head and neck, gastric, pancreatic, gallbladder, liver, colon, breast, cervical, urinary bladder and kidney cancers. The mutagenic and tumour-promoting activities of nicotine may result from its ability to damage the genome, disrupt cellular metabolic processes, and facilitate growth and spreading of transformed cells. The nicotinic acetylcholine receptors (nAChRs), which are activated by nicotine, can activate several signalling pathways that can have tumorigenic effects, and these receptors might be able to be targeted for cancer therapy or prevention. There is also growing evidence that the unique genetic makeup of an individual, such as polymorphisms in genes encoding nAChR subunits, might influence the susceptibility of that individual to the pathobiological effects of nicotine. The emerging knowledge about the carcinogenic mechanisms of nicotine action should be considered during the evaluation of regulations on nicotine product manufacturing, distribution and marketing.

TFAP2B overexpression contributes to tumor growth and a poor prognosis of human lung adenocarcinoma through modulation of ERK and VEGF/PEDF signaling

BACKGROUND

TFAP2B is a member of the AP2 transcription factor family, which orchestrates a variety of cell processes. However, the roles of TFAP2B in regulating carcinogenesis remain largely unknown. Here, we investigated the regulatory effects of TFAP2B on lung adenocarcinomas growth and identified the underlying mechanisms of actions in non-small cell lung cancer (NSCLC) cells.

METHODS

We first examined the expression of TFAP2B in lung cancer cell lines and tumor tissues. We also analyzed the prognostic predicting value of TFAP2B in lung adenocarcinomas. Then we investigated the molecular mechanisms by which TFAP2B knockdown or overexpression regulated lung cancer cell growth, angiogenesis and apoptosis, and further confirmed the role of TFAP2B in tumor growth in a lung cancer xenograft mouse model.

RESULTS

TFAP2B was highly expressed in NSCLC cell lines and tumor tissues. Strong TFAP2B expression showed a positive correlation with the poor prognoses of patients with lung adenocarcinomas (P < 0.001). TFAP2B knockdown by siRNA significantly inhibited cell growth and induced apoptosis in NSCLC cells in vitro and in a lung cancer subcutaneous xenograft model, whereas TFAP2B overexpression promoted cell growth. The observed regulation of cell growth was accompanied by the TFAP2B-mediated modulation of the ERK/p38, caspase/cytochrome-c and VEGF/PEDF-dependent signaling pathways in NSCLC cells.

CONCLUSIONS

These results indicate that TFAP2B plays a critical role in regulating lung adenocarcinomas growth and could serve as a promising therapeutic target for lung cancer treatment.