Inflammatory biomarkers and growth factors in saliva and gingival crevicular fluid of e-cigarette users, cigarette smokers, and dual smokers: A pilot study

BACKGROUND

Cigarette smoking remains one of the leading public health threats worldwide. Electronic cigarettes (e-cigs) provide an alternative to conventional cigarette smoking; however, the evidence base of risks and benefits of e-cig use is new and growing. In this cross-sectional pilot study, the effect of e-cig use on biological profiles in saliva and gingival crevicular fluid (GCF) was assessed and compared with the profiles of cigarette smokers (CS), dual users, and non-users. The systemic inflammatory mediators between e-cig users (EC) and these other groups were also assessed.

METHODS

This pilot cross-sectional study recruited volunteer participants consisting of four groups, non-smokers (NS), CS, EC, and dual EC and cigarette smokers (DS). Saliva and GCF samples were collected and analyzed for biomarkers of inflammation, oxidative stress, anti-inflammatory lipid mediators, tissue injury and repair, and growth factors with immunoassay (enzyme-linked immunosorbent assay and Luminex).

RESULTS

Smoking status was confirmed via salivary cotinine. Prostaglandin E2 level was significantly increased in CS compared with EC and DS, but not significantly different in EC and DS groups compared with non-smokers (NS). Statistically significant differences were observed between groups of EC and NS (myeloperoxidase [MPO], matrix metalloproteinase-9) as well as between DS and EC for biomarkers of inflammatory mediators (receptor for advanced glycation end products [RAGE], MPO, uteroglobin/CC-10); between groups of DS and NS for extracellular newly identified RAGE binding protein and between CS and NS for MPO. No statistically significant differences in biomarkers of immunity (S100A8, S100A9, galectin-3), tissue injury and repair (Serpine1/PAI-1) and growth factors (brain-derived neurotrophic factor, fibroblast growth factors, platelet-derived growth factor-AA, vascular endothelial growth factor, and others) were found between any of groups.

CONCLUSION

Statistically significant differences in measurable health outcomes were found between different smoking status groups, suggesting that smoking/vaping produces differential effects on oral health.

[Recommendations for public health protection against flood disaster]

Flood disaster is one of the most serious natural disasters in the world, and it could pose an inestimable impact on the affected people. Based on existing laws, regulations, and emergency manuals in China, extensive literature review, epidemiological and related protection evidence, and expert consultation, this study analyzed different health risk factors of flood disaster and proposed a multi-stage, multi-population, and multi-phase comprehensive protection measures for the public in the perspective of pre-event prevention, in-event intervention and post-event rescue strategy, which could provide a scientific basis for improving the level of public health protection against the flood disaster and corresponding health outcomes.

Decreased Osteogenic Ability of Periodontal Ligament Stem Cells Leading to Impaired Periodontal Tissue Repair in BRONJ Patients

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a severe adverse reaction, which results in progressive bone destruction in the maxillofacial region of patients. To date, the pathological mechanisms remain largely unclear. Recently, we found that BRONJ patient had significantly deep periodontal pockets and severe periodontal bone defects before the exposed necrotic bone. Human periodontal ligament stem cells (hPDLSCs) play key roles in physiological maintenance and regeneration of periodontal tissues. However, the activities of hPDLSCs derived from BRONJ lesions and the role of hPDLSCs in BRONJ periodontal defect repair remain poorly understood. The aim of the present study was to elucidate the role of hPDLSCs in BRONJ. In this study, we found that the capacities of cell proliferation, adhesion, and migration of hPDLSCs derived from BRONJ lesions (BRONJ-hPDLSCs) were significantly decreased compared with control-hPDLSCs. BRONJ-hPDLSCs underwent early apoptosis compared with control-hPDLSCs. Importantly, we first demonstrated that BRONJ-hPDLSCs exhibited impaired osteogenic differentiation abilities in ectopic osteogenesis of nude mice. The above results suggested that the impaired BRONJ-hPDLSCs may be an important factor in deficient periodontal repair of BRONJ lesions and provide new insight into the underlying mechanism of BRONJ.

Systemic biomarkers in electronic cigarette users: implications for noninvasive assessment of vaping-associated pulmonary injuries

Background

Electronic cigarettes (e-cigs) were introduced as electronic nicotine delivery systems, and have become very popular in the USA and globally. There is a paucity of data on systemic injury biomarkers of vaping in e-cig users that can be used as a noninvasive assessment of vaping-associated lung injuries. We hypothesised that characterisation of systemic biomarkers of inflammation, anti-inflammatory, oxidative stress, vascular and lipid mediators, growth factors, and extracellular matrix breakdown may provide information regarding the toxicity of vaping in e-cig users.

Methods

We collected various biological fluids, i.e. plasma, urine, saliva and exhaled breath condensate (EBC), measured pulmonary function and vaping characteristics, and assessed various biomarkers in e-cig users and nonusers.

Results

The plasma samples of e-cig users showed a significant increase in biomarkers of inflammation (interleukin (IL)-1β, IL-6, IL-8, IL-13, interferon (IFN)-γ, matrix metalloproteinase-9, intercellular cell adhesion molecule-1) and extracellular matrix breakdown (desmosine), and decreased pro-resolving lipid mediators (resolvin D₁ and resolvin D₂). There was a significant increase in growth factor (endothelial growth factor, vascular endothelial growth factor, β-nerve growth factor, platelet-derived growth factor-AA, stem cell factor, hepatocyte growth factor and placental growth factor) levels in plasma of e-cig users versus nonusers. E-cig users showed a significant increase in levels of inflammatory biomarker IFN-γ, oxidative stress biomarker 8-isoprostane and oxidative DNA damage biomarker 8-oxo-dG in urine samples, and of inflammatory biomarker IL-1β in saliva samples. EBC showed a slight increase in levels of triglycerides and 8-isoprostane in e-cig users compared with normal nonusers.

Conclusion

E-cig users have increased levels of biomarkers of inflammation and oxidative stress, reduced pro-resolving anti-inflammatory mediators, and endothelial dysfunction, which may act as risk factors for increasing susceptibility to systemic diseases. The identified noninvasive biomarkers can be used for determining e-cig vaping-associated lung injuries, and for regulatory and diagnostic aspects of vaping in humans.

E-cig use adversely affects oxidative stress and inflammatory responses, and induces tissue remodelling. The identified biomarkers can be used for assessment of vaping-associated lung injuries, and for regulatory and diagnostic aspects of vaping in humans.http://bit.ly/2nxZQ8R

Systemic biomarkers of inflammation, oxidative stress and tissue injury and repair among waterpipe, cigarette and dual tobacco smokers

BACKGROUND

Waterpipe tobacco (WPT) smoking is associated with deleterious effects on cardio-pulmonary systems which may have adverse repercussions in pathophysiology and progression of chronic lung and cardiovascular diseases. We compared the biomarkers of systemic inflammation, lipid mediators, injury/repair and oxidative stress between groups of non-smokers (NS), exclusive WPT smokers (WPS), exclusive cigarette smokers (CS) and dual WPS and CS (DS).

METHODS

Two cohorts were recruited. Cohort I consisted of WPS (n=12), CS (n=26), DS (n=10) and NS (n=25). Cohort II consisted of WPS (n=33) and NS (n=24). Plasma and urine samples were collected and analysed for various systemic biomarkers.

RESULTS

Compared with NS, plasma levels of inflammatory mediators (interleukin (IL)-6, IL-8, IL1β and tumor necrosis factor-α) were significantly higher in WPS and CS, and were further augmented in DS. Endothelial biomarkers (intracellular adhesion molecule-1, prostaglandin E-2 and metalloproteinase-9) were significantly higher in CS. Most notably, pro-resolving lipid mediator (resolvin E1) and biomarkers of immunity, tissue injury, and repair were significantly lower in WPS and CS. Urinary levels of 8-isoprostane were significantly higher in all smoking groups in cohort I, while 8-isoprostane, myeloperoxidase, receptor for advanced glycation end products (RAGE), En-RAGE and matrix metalloproteinase-9 were significantly higher in all smoking groups in cohort II.

CONCLUSIONS

Biomarkers of inflammation, oxidative stress, immunity, tissue injury and repair were elevated in WPS and CS groups. Furthermore, concurrent use of WPT and cigarettes is more harmful than cigarette or WPT smoking alone. These data may help inform the public and policy-makers about the dangers of WPT smoking and dual use of tobacco products.

Camera-aided autocollimation approach for increasing the effective measurement range of a photoelectric collimator

A camera aided autocollimation (CAAC) system is proposed to enhance the working range of a photoelectric collimator (PEC). This system consists of a camera surrounded by point light sources (LSs), a PEC, a rotary table, and a translation stage. As the tilt angle of the target varies, the intensity of the light from the LSs that is reflected by the target and received by the camera exhibits two symmetric peaks. The camera guides the target into the scope of the PEC by scanning these two peaks. This CAAC approach can automatically collimate a prism with an edge length of 10 mm and an initial tilt angle of 5° at a working range of 1.5 m. The error of the coarse collimation at 99.7% confidence is 602″.

The impact of SLE on health-related quality of life assessed with SF-36: a systemic review and meta-analysis

OBJECTIVE

To evaluate the impact of systemic lupus erythematosus (SLE) on health-related quality of life (HRQoL) assessed with SF-36 and explore factors associated with HRQoL in SLE patients.

METHODS

A random-effect meta-analysis was performed to calculate extracted data. Sensitivity and subgroup analyses were performed to distinguish sources of heterogeneity.

RESULTS

A total of 36 articles were finally included in this meta-analysis, including 6510 patients. The pooled mean scores of SF-36 physical component summary and mental component summary were 46.10 (95% confidence interval (CI): 43.09-49.10) and 50.37 (95% CI: 47.78-52.87), respectively. Spearman's correlation analysis found that mean age, proportion of female participants, and publication decades were negatively associated with some of the SF-36 domains. Sample size and SLEDAI were positively associated with some of the SF-36 domains. Patients with SLE have lower HRQoL in comparison to the general population.

CONCLUSIONS

SLE has a significant impact on HRQoL, which proves that the necessity of improving HRQoL in SLE patients cannot be ignored. Measuring HRQoL should be considered as an indispensable part of the overall evaluation of health conditions of SLE patients.

Abstract PD3-05: Co-occurring gain-of-function mutations in HER2 and HER3 cooperate to enhance HER2/HER3 binding, HER-dependent signaling, and breast cancer growth

ERBB2, the gene encoding HER2, is mutated in 2-4% of breast cancers. The HER2 tyrosine kinase inhibitor neratinib has shown clinical activity against breast cancers harboring HER2 activating mutations, suggesting these tumors depend on HER2 signaling. Co-occurring HER2 and HER3 (ERBB3) mutations have been reported in patients who respond to neratinib (Hanker et al., Cancer Discov. 2017) suggesting the possibility of cooperativity of both oncogenes. Co-expression of the mutant intracellular domains of HER2 and HER3 in HEK293 cells enhanced phosphorylation of HER3 and ERK compared to expression of either mutant alone, which was blocked by 100 nM neratinib. Interrogation of TCGA, METABRIC, Project GENIE, and Foundation Medicine datasets revealed that gain-of-function mutations in ERBB2 and ERBB3 co-occur with a statistically significant frequency. For example, in GENIE, ERBB2 mutations co-occur with mutations in ERBB3 (8.3% of ERBB2-mutant vs 2.3% of ERBB2 WT; q=1.37x10-10).

We hypothesized that co-occurring mutations in HER2 and HER3 cooperate to enhance HER2 signaling and dependence and breast cancer progression.

Thirty-four unique breast cancers were found to harbor co-occurring mutations in HER2 and HER3, the most common of which were ERBB2L755S/ERBB3E928G (n=10), ERBB2V777L/ERBB3E928G(n=6), and ERBB2L869R/Q/ERBB3E928G (n=4). Using co-immunoprecipitation assays with HER2 and HER3 antibodies in transfected HEK293 cells, we found that co-expression of HER3E928G with wild type (WT) HER2, or co-expression of HER2L755S or HER2L869R with HER3WT, slightly increased HER2-HER3 dimerization. However, binding was strongest between double mutants. This was accompanied by the highest levels of Y1289 p-HER3 in cells expressing both HER3E928G and each HER2L755S, HER2V777L, or HER2L869R compared to cells expressing each HER2 or HER3 mutant with a respective WT heterodimer partner. Structural modeling of the HER2L869R/HER3E928G double-mutant predicted that the HER3 mutation, located at the dimer interface, may enhance heterodimerization of the kinase domains through decreased bulk and electrostatic repulsion. We also noted that the HER2L755S mutation is predicted to be in close proximity to HER3E928G (<4 Å) and may impact binding affinity. Investigation of the structural basis for the enhanced binding of other double mutants is in progress.

MCF7 “knock-in” cells incorporating HER2L755S, HER2V777L, or HER2L869R (or HER2WT) were stably transduced with HER3E928G or HER3WT. Co-expression of double mutants strongly enhanced estrogen-independent growth in 3D Matrigel over cells expressing either mutant alone. We are currently testing inhibitors of HER2/HER3 signaling, including neratinib ± trastuzumab, trastuzumab + pertuzumab, and the ERBB1-3 antibody mixture Sym013, to determine therapeutic strategies to block the cooperative growth induced by co-occurring HER2 and HER2 mutations.

Conclusions: Co-expression of mutant HER2 and mutant HER3 promotes HER2/HER binding, HER3 phosphorylation, and breast tumor cell proliferation. We aim to identify therapeutic vulnerabilities for patients with co-occurring HER2 and HER3 mutations.

Citation Format: Hanker AB, Koch JP, Ye D, Sliwoski G, Sheehan J, Kinch LN, Red Brewer M, He J, Miller VA, Lalani AS, Cutler, Jr. RE, Croessmann S, Zabransky DJ, Meiler J, Arteaga CL. Co-occurring gain-of-function mutations in HER2 and HER3 cooperate to enhance HER2/HER3 binding, HER-dependent signaling, and breast cancer growth [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-05.

Axitinib versus placebo as an adjuvant treatment of renal cell carcinoma: results from the phase III, randomized ATLAS trial

Background

The ATLAS trial compared axitinib versus placebo in patients with locoregional renal cell carcinoma (RCC) at risk of recurrence after nephrectomy.

Patients and methods

In a phase III, randomized, double-blind trial, patients had >50% clear-cell RCC, had undergone nephrectomy, and had no evidence of macroscopic residual or metastatic disease [independent review committee (IRC) confirmed]. The intent-to-treat population included all randomized patients [≥pT2 and/or N+, any Fuhrman grade (FG), Eastern Cooperative Oncology Group status 0/1]. Patients (stratified by risk group/country) received (1 : 1) oral twice-daily axitinib 5 mg or placebo for ≤3 years, with a 1-year minimum unless recurrence, occurrence of second primary malignancy, significant toxicity, or consent withdrawal. The primary end point was disease-free survival (DFS) per IRC. A prespecified DFS analysis in the highest-risk subpopulation (pT3, FG ≥ 3 or pT4 and/or N+, any T, any FG) was conducted.

Results

A total of 724 patients (363 versus 361, axitinib versus placebo) were randomized from 8 May 2012, to 1 July 2016. The trial was stopped due to futility at a preplanned interim analysis at 203 DFS events. There was no significant difference in DFS per IRC [hazard ratio (HR) = 0.870; 95% confidence interval (CI) : 0.660-1.147; P = 0.3211). In the highest-risk subpopulation, a 36% and 27% reduction in risk of a DFS event (HR; 95% CI) was observed per investigator (0.641; 0.468-0.879; P = 0.0051), and by IRC (0.735; 0.525-1.028; P = 0.0704), respectively. Overall survival data were not mature. Similar adverse events (AEs; 99% versus 92%) and serious AEs (19% versus 14%), but more grade 3/4 AEs (61% versus 30%) were reported for axitinib versus placebo.

Conclusions

ATLAS did not meet its primary end point; however, improvement in DFS per investigator was seen in the highest-risk subpopulation. No new safety signals were reported.

Trial registration number

NCT01599754.

Purinergic Signaling Modulates Survival/Proliferation of Human Dental Pulp Stem Cells

Human dental pulp stem cells (hDPSCs) reside in postnatal dental pulp and exhibit the potential to differentiate into odontoblasts as well as neurons. However, the intercellular signaling niches necessary for hDPSC survival and self-renewal remain largely unknown. The objective of this study is to demonstrate the existence of intercellular purinergic signaling in hDPSCs and to assess the impact of purinergic signaling on hDPSC survival and proliferation. hDPSCs were isolated from extracted third molars and cultured in minimum essential medium. To demonstrate responsiveness to ATP application and inhibitions by purinergic receptor antagonists, whole cell patch-clamp recordings of ATP-induced currents were recorded from cultured hDPSCs. Immunofluorescence and enzymatic histochemistry staining were performed to assess purinergic receptor expression and ectonucleotidase activity in hDPSCs, respectively. To determine the effects of purinergic signaling on hDPSC, purinergic receptor antagonists and an ectonucleotidase inhibitor were applied in culture medium, and hDPSC survival and proliferation were assessed with DAPI staining and Ki67 immunofluorescence staining, respectively. We demonstrated that ATP application induced inward currents in hDPSCs. P2X and P2Y receptors are involved in the generation of ATP-induced inward currents. We also detected expression of NTPDase3 and ectonucleotidase activity in hDPSCs. We further demonstrated that purinergic receptors were tonically activated in hDPSCs and that inhibition of ectonucleotidase activity enhanced ATP-induced inward currents. Furthermore, we found that blocking P2Y and P2X receptors reduced-and inhibition of ecto-ATPase activity enhanced-the survival and proliferation of hDPSCs, while blocking P2X receptors alone affected only hDPSC proliferation. Autocrine/paracrine purinergic signaling is essential for hDPSC survival and proliferation. These results reveal potential targets to manipulate hDPSCs to promote tooth/dental pulp repair and regeneration.

Analysis of the Correlation between Morphology and Kinematics of Anteriorly Displaced TMJ Discs Using Cine-MRI and ARCUSdigma Systems

Background:

Studies of mandibular movement trajectories have provided a good understanding of the motion of the condyle but little information on the geometric relationships of the disc because they have not related the movements to anatomic structures.

Objective:

This study investigated the morphology and kinematic characteristics of the Temporomandibular Joint (TMJ) using Cine-MRI and ARCUSdigma systems.

Methods:

For this study population, preliminary clinical diagnoses were asymptomatic in 15 cases, unilateral anterior disc displacement with reduction (ADDWR) in 17 cases, and unilateral Anterior Disc Displacement Without Reduction (ADDWoR) in 14 cases. Patients were investigated with Cine-MRI and ARCUSdigma systems during physiological opening and closing of the mouth.

Results:

In these groups, there were 13 healthy subjects, 19 patients with unilateral ADDWR and 14 patients with unilateral ADDWoR classified by Cine-MRI. (1) To assess morphology by MRI, disc deformities were evaluated as follows: biplanar, rounded, thickening in the posterior band, lengthened and folded. (2) The opening trajectory for healthy subjects was close to the closing trajectory. Conversely, the incisal and condylar trajectories during opening and closing were obviously bounced, deviated or shortened in the ADDWR and ADDWoR groups. The pathway of the kinematic axis was not parallel, and the condylar trajectory had an inflexion. (3) The mean values of the incisal and condylar paths of the ADDWoR group were significantly different from those in the healthy group (P<0.05), whereas there were no significant differences between the ADDWR and the healthy group (P>0.05).

Conclusion:

This study combined analysis of the condylar pathways and disc-condylar relationship to provide good visualization of morphology and kinematics during jaw movement. This process helps improve our understanding of the complexity of disk-condylar movements in subjects with TMJ internal derangement and may also contribute to our knowledge of the etiology of TMJ internal derangement.

Implementation of National Health Reform on China Genitourinary Multidisciplinary Team Consultation Platform

Background and context:: Comprehensive management of multidisciplinary team (MDT) is the most effective mode in genitourinary(GU) cancers. Due to the uneven level in the management of GU cancers in China, top GU MDT services do not meet the medical needs of people. The blooming of “Internet+” mode promotes remote medical services, and is supported by health administrations. Aim: The country wide accessibility of high level medical services, and national health reform, especially in the field of GU cancers, will be addressed by the project. Strategy/Tactics: We developed an Internet platform of MDT management for GU cancers across China: “China GU MDT Consultation Platform (CUMP)”. Led by senior clinical staffs, and based on advanced internet and mobile technologies, CUMP is to meet the needs of clinical practices. With compatibility, universality and practicality, CUMP has the following advantages: unified data management, flexible models, stable and reliable remote video conference system, efficient cooperation, and convenient participation. Program/Policy process: Recruit top GU MDT and experts in China, and make consensus and guidelines of the implementations of MDT in GU cancers; Help other local institutions develop GU MDT and provide services, which are authenticated by the platform; Build a system that a single patient can receive top level GU MDT service locally and remotely, provided by the platform. Outcomes: Since April 2017, CUMP has successfully carried out remote MDT consultations involved 16 medical centers with GU MDT services or individual GU experts across China. As a start, 18 difficult cases were discussed and managed. More than 600 Chinese GU experts from medical institutions at all levels, have registered on CUMP, ready for submitting or accepting MDT service; another 34 top Chinese GU MDT units are on the waiting list to be technically authorized on CUMP. One Chinese consensus on the implementation of GU MDT was released last December. What was learned: The project was relevant to current obstacles in China's health reform by greatly enhancing the accessibility of GU MDT service. The majority of GU cancer patients can receive domestic top-level MDT service in a local institution; this project also helped to provide a great convenience to the development of local MDT service, so as to improve medical qualities, especially in GU cancers in different regions of China. The project made the technology and medical service transcend the boundary of administrative division and institution.

Isoflurane enhances the malignant potential of glioblastoma stem cells by promoting their viability, mobility in vitro and migratory capacity in vivo

BACKGROUND

Isoflurane is one of the most common general anaesthetics used during surgical procedures, including tumour resection. However, the effects of isoflurane on the viability and migration capacity of cancer cells, specifically in the context of brain cancer cells, remain unclear. Therefore, the aim of this study was to evaluate the influence that isoflurane has on the function of glioblastoma stem cells (GCSs) in regards to cell proliferation, survival and migration.

METHOD

U251-GSCs were exposed to isoflurane at clinically relevant concentrations and incubation times. The effects on proliferation, survival and migration capacities of the cells were evaluated in vitro. The potential risk was assessed in mice by intracranial injection of U251-GSCs pretreated with isoflurane. Furthermore, the average tumour volume and migration distance of U251-GSCs from the tumour centre were calculated.

RESULTS

Exposure of U251-GSCs to 1.2% isoflurane for 6 h resulted in increased proliferation (P<0.05) and decreased apoptosis rate (P<0.05) when compared with the control group. In addition, isoflurane exposure caused increased migration capacity in vitro (P<0.05) and the distance migrated was increased in vivo (P<0.05).

CONCLUSION

Clinically relevant concentrations and incubation times of isoflurane could promote the viability and mobility of U251-GSCs, suggesting this general anaesthetic may have detrimental effects in glioblastoma by facilitating its growth and migration.

EGFR activation induced Snail-dependent EMT and myc-dependent PD-L1 in human salivary adenoid cystic carcinoma cells

Epithelial-to-mesenchymal transition (EMT) confers cancer cells the ability of invasion and metastasis. However, how does EMT contribute to evasion of immune surveillance is unclear, especially in salivary adenoid cystic carcinoma (SACC). In this study, we investigated the molecular link between EGF-induced EMT and the immune checkpoint ligand programmed death-ligand 1 (PD-L1) by immunoprecipitation (IP) and Westernblot analysis. Cell migration and invasion activity was assayed by transwell assay. Immunohistochemical (IHC) staining analysis was performed for measurement of EMT markers and PD-L1 expression levels in tumor tissues. We found that EGF-induced EGFR activation stabilized Snail expression and induced EMT in SACC. Interestingly, EGFR activation induced simultaneously both EMT and PD-L1 in SACC. Importantly, knockdown of Snail greatly suppressed EGF-induced EMT, but not EGF-induced PD-L1 expression; whereas knockdown of c-Myc strongly repressed PD-L1 expression, but not snail expression and EMT. The molecular link is strongly supported by robust correlations between the EMT markers and PD-L1 expression in human cancer samples.These results suggest that EGFR activated EMT and PD-L1 via two distinct mechanisms. EGFR activation induced EMT and PD-L1 expression in SACC. Snail is required for EGF-induced EMT, but not PD-L1 expression; whereas c-Myc is required for EGFR-mediated PD-L1 upregulation but not EMT. Thus, targeting activated EGFR may inhibit both EMT and PD-L1, which may potentiate the therapeutic effect of PD-L1-based immunotherapy, especially in the malignant subgroups of SACC patients with activated EGFR.

Identification and characterization of a highly metastatic epithelial cancer cell line from rat tongue cancer

OBJECTIVES

Tongue squamous cell carcinoma (TSCC) is a clinically devastating disease. However, most established TSCC cell lines currently show undesirable malignant behaviours. The purpose of this study is to establish a highly metastatic TSCC cell line to serve as a useful tool for basic research.

MATERIALS AND METHODS

TSCCs were induced by 4-nitroquinoline-1-oxide (4NQO) in Sprague-Dawley rats. Tumor cells were obtained from the cancer tissues by primary culture and were then purified by an in vitro invasion assay and a limiting dilution assay. The growth rate, cell cycle distribution, apoptotic rate, tumorigenicity and distant metastatic phenotypes of the rat tongue cancer cells were fully investigated and characterized.

RESULTS

To date, the rat tongue cancer cell line, named Rca-T, has been continuously cultured in vitro for over 210 passages and exhibit a long spindle-shaped morphology, adherent growth, and a stable epithelial phenotype. The population doubling time of Rca-T cells is 23.35 h. Approximately 39.8% of these cells are in S phase, and the apoptosis rate of Rca-T cells is 7.46%. Furthermore, in immunodeficient nude mice, both the xenograft rate and the incidence of experimental lung metastasis are 100%. The in vitro assays further reveal the highly malignant and epithelial-mesenchymal transition-like properties of Rca-T cells.

CONCLUSION

In this study, the tumorigenic and highly distant metastatic TSCC cell line Rca-T was established. The malignant features of this cell line, especially its metastatic potential, will enable a wealth of functional studies on the molecular mechanisms of TSCC metastasis in the future.

Stabilization of Slug by NF-κB is Essential for TNF-α -Induced Migration and Epithelial-Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma Cells

Background/Aims: Slug protein, a transcription factor for the induction of epithelial-mesenchymal transition (EMT) and cancer cell invasion and metastasis, is frequently upregulated in human epithelial cancers. However, mutation of this gene in cancer is rare, and the mechanism of its dysregulation remains unknown, especially in head and neck squamous cell carcinoma (HNSCC). Methods: We examined the role of TNF-α in the stabilization of Slug by immunoprecipitation-westernblot analysis. Migration of HNSCC cells with or without knockdown of Slug gene expression was assayed by a wound healing assay. Immunohistochemical staining analysis was used to measurement Slug levels in both normal and HNSCC tumor tissues. Results: The inflammatory cytokine TNF-α stabilized Slug protein by inhibiting its ubiquitination through the NF-κB pathway. Inhibition of NF-κB or knockdown of p65 abrogated the TNF-α-induced stabilization of Slug. Knockdown of Slug expression inhibited cancer cell migration and EMT characteristics induced by TNF-α. Moreover, increased levels of Slug were found to correlate with lymph node metastasis and predict poor prognosis in patients with HNSCC. Conclusions: NF-κB-mediated stabilization of Slug underlies the inflammation-induced EMT and metastasis in HNSCC, which may serve as a therapeutic target for metastatic HNSCC.