Safety and protective effects of an avirulent Salmonella Gallinarum isolate as a vaccine candidate against Salmonella Gallinarum infections in young chickens.

Fowl typhoid is an important disease of chickens and turkeys, which is caused by Salmonella Gallinarum (S. Gallinarum). Vaccines with high levels of protective effects against fowl typhoid need to be developed for the poultry industry. In this study, a S. Gallinarum strain, named SG01, was isolated from a poultry farm in Mashan region of Wuxi City, China, and identified through biochemical tests and specific PCR amplifications. Then, safety evaluations of the SG01 strain were performed in young chickens. No clinical symptom including depression and diarrhea and gross lesion involved in the cardiac nodule, hepatic necrotic lesion and splenic necrotic lesion, was determined on fifteen-day-old chickens after immunization with 1 × 1010 CFU of the SG01 strain through the oral route. However, diarrhea symptoms and hepatic lesions were identified from chickens immunized with the commercial vaccine strain SG9R by the same dose and route. At 14 days post inoculation, SG01 strain was eliminated in the liver and spleen from SG01-immunized chickens, while the SG9R strain still could be identified from SG9R-immunized chickens. After challenge with the virulent S. Gallinarum strain, significant reduction of the morbidity rate was found in the SG01 immunized group (20 %) compared to the challenge group (100 %) according to signs scoring systems for clinical symptoms and gross lesions. Additionally, immunization with the SG01 strain could provide more than 8 weeks of protection periods against fowl typhoid. These results demonstrate the SG01 strain is avirulent to young chickens and might be safer compared to the SG9R strain. In addition, SG01 strain is a potential vaccine candidate against fowl typhoid in young chickens.

Eye Movement Control in Tibetan Reading: The Roles of Word Length and Frequency.

We investigated the effects of word length and frequency on eye movement control during Tibetan reading through two experiments. A preliminary experiment examined the predictive effect of word length and frequency on fixation duration and landing position using multiple linear regression analysis. In the formal experiment, we manipulated the length and frequency of target words simultaneously to investigate the effects of word length and frequency on fixation duration and landing position in Tibetan reading. In this study, we found that: (1) there were significant word-length and word-frequency effects affecting all lexical processing in Tibetan reading; (2) there are preferred viewing locations in Tibetan reading; specifically, for short words, it is the end, whereas for long words, it spans from the center to the beginning of the word; (3) word frequency does not affect preferred viewing location in Tibetan reading; (4) the preferred viewing position and the interaction of word length and viewing position found in this study supported the "strategy-tactics" approach.

Inhibition of DEC2 is necessary for exiting cell dormancy in salivary adenoid cystic carcinoma.

BACKGROUND: Patients were prone to have poor prognosis once dormant tumor cells being reactivated. However, the molecular mechanism of tumor cell dormancy remains poorly understood. This study aimed to investigate the function of DEC2 in the dormancy of salivary adenoid cystic carcinoma (SACC) in vitro and vivo. METHODS: The function of DEC2 in tumor dormancy of SACC was investigated in nude mice by establishing primary and lung metastasis model. Meanwhile, the interaction between hypoxia and SACC dormancy and the role of DEC2 were demonstrated through CoCl2 induced hypoxia-mimicking microenvironments. Furthermore, the expression of DEC2 was detected by immunohistochemical staining in primary SACC samples with and without recurrence. RESULTS: In the primary SACC, DEC2 overexpression inhibited cell proliferation, increased cell population arrested in G0/G1 phase, and participated in dormancy regulation, which limited tumor growth. Intriguingly, in the model of lung metastasis, the level of DEC2 was reduced significantly and resulted in dormancy exit and growth resumption of SACC cells. Then, we found that DEC2 may associate with hypoxia in contributing to tumor dormancy, which might provide a possible cue to explain the different roles of DEC2 in primary and metastasis lesions. And overexpression of DEC2 induced dormancy and promoted migration and invasion through activating EMT program. Finally, DEC2 positive expression was shown to be significantly correlated with recurrence and dormancy of SACC patients. CONCLUSIONS: These findings provide a novel insight into the role of DEC2 gene in tumor dormancy and metastasis.

NR2F1 contributes to cancer cell dormancy, invasion and metastasis of salivary adenoid cystic carcinoma by activating CXCL12/CXCR4 pathway.

BACKGROUND: Salivary adenoid cystic carcinoma (SACC) can recur after removal of the primary tumor and treatment, where they can keep no clinical symptoms and dormant state for 10-15 years. NR2F1 has been demonstrated to regulate the tumor cell dormancy in various malignant tumors and has a potential impact on recurrence and metastasis of carcinoma. However, the role and significance of NR2F1 in SACC dormancy still remain unknown. METHODS: A total number of 59 patients with a diagnosis of SACC were included to detected expression of NR2F1, Ki-67 by immunohistochemical (IHC) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling (TUNEL). Fisher's exact test was used to examine the NR2F1 expression and clinicopathologic parameters of SACC. In vitro, SACC cell lines were transfected NR2F1 and knockdown NR2F1 respectively. CCK-8, flow cytometry, wound healing assay and transwell invasion determined SACC cell proliferation, apoptosis, cell cycle, migration and invasion respectively. Chromatin immunoprecipitation (ChIP) assays were utilized to demonstrate the potential role of NR2F1 in SACC invasion via CXCL12/CXCR4 axis. In vivo, xenografts of nude mice via subcutaneous injection or tail vein injection were used to testify the results in vitro. RESULTS: Among the 59 patients with SACC, 23.73% (14/59) were positive to NR2F1 expression, a lower rate of expression compared with 60% (6/10) in normal salivary gland samples. NR2F1 was correlated with metastasis, relapse and dormancy of SACC. SACC cells with transfected NR2F1 remained dormant, as well as enhanced invasion and metastasis. Knockdown of NR2F1 via siRNA after NR2F1 overexpression restored the proliferation and the cell number in G2/M phases, and reduced the abilities of migration and invasion. In addition, NR2F1 promoted the expression of CXCL12 and CXCR4, and overexpression of CXCL12 at least partly rescued the proliferation, migration, and invasion activities induced by NR2F1 silencing. CONCLUSIONS: NR2F1 may be an underlying mechanism of SACC recurrence and metastasis via regulating tumor cell dormancy through CXCL12/CXCR4 pathway.

Macrophage migration inhibitory factor promotes the invasion and metastasis of oral squamous cell carcinoma through matrix metalloprotein-2/9.

Macrophage migration inhibitory factor (MIF) has been shown to closely associate with the malignant progression of a variety of human carcinomas. However, the role and its underlying molecular mechanisms of MIF in the invasion and metastasis of oral squamous cell carcinoma (OSCC) still remains unclear. Here, we found that MIF silencing reduced the cell proliferation, migration, and invasion, as well as matrix metalloprotein-2 (MMP-2) and MMP-9 in OSCC cells. Overexpression of MMP-2 or MMP-9 restored the migration and invasion of MIF-knockdown cells, indicating that MMP-2 and MMP-9 are downstream targets of MIF. In the xenograft model, MIF silencing inhibited tumor growth and in lymph metastasis model, MIF silencing reduced tumor metastasis. More importantly, immunohistochemistry staining in a tissue microarray (TMA) demonstrated that MIF expression was positively correlated with clinic stage, recurrence, metastasis, and poor prognosis of patients with OSCC as well as with the levels of MMP-2 or MMP-9 in TMA. Therefore, our findings suggest that MIF may promote the invasion and metastasis of OSCC through the activation of MMP-2 and MMP-9 and prompt further investigation into the therapeutic value of MIF for OSCC treatment.

Hypoxia promotes vasculogenic mimicry formation by vascular endothelial growth factor A mediating epithelial-mesenchymal transition in salivary adenoid cystic carcinoma.

OBJECTIVES: To investigate the role of hypoxia in vasculogenic mimicry (VM) of salivary adenoid cystic carcinoma (SACC) and the underlying mechanism involved. MATERIALS AND METHODS: Firstly, wound healing, transwell invasion, immunofluorescence and tube formation assays were performed to measure the effect of hypoxia on migration, invasion, EMT and VM of SACC cells, respectively. Then, immunofluorescence and RT-PCR were used to detect the effect of hypoxia on VE-cadherin and VEGFA expression. And pro-vasculogenic mimicry effect of VEGFA was investigated by confocal laser scanning microscopy and Western blot. Moreover, the levels of E-cadherin, N-cadherin, Vimentin, CD44 and ALDH1 were determined by Western blot and immunofluorescence in SACC cells treated by exogenous VEGFA or bevacizumab. Finally, CD31/ PAS staining was performed to observe VM and immunohistochemistry was used to determine the levels of VEGFA and HIF-1α in 95 SACC patients. The relationships between VM and clinicopathological variables, VEGFA or HIF-1α level were analysed. RESULTS: Hypoxia promoted cell migration, invasion, EMT and VM formation, and enhanced VE-cadherin and VEGFA expression in SACC cells. Further, exogenous VEGFA markedly increased the levels of N-cadherin, Vimentin, CD44 and ALDH1, and inhibited the expression of E-cadherin, while the VEGFA inhibitor reversed these changes. In addition, VM channels existed in 25 of 95 SACC samples, and there was a strong positive correlation between VM and clinic stage, distant metastases, VEGFA and HIF-1α expression. CONCLUSIONS: VEGFA played an important role in hypoxia-induced VM through regulating EMT and stemness, which may eventually fuel the migration and invasion of SACC.

[Invasion and metastasis mechanism of human papillomavirus in head and neck squamous cell carcinomas].

Human papillomavirus (HPV) is a major causative agent of head and neck squamous cell carcinomas (HNSCC). Over the past several decades, an increasing number of studies established the strong association of HPV with the invasion and metastasis of HNSCC. In the present study, we reviewed the gene mutations in HPV-associated HNSCC and the unique mechanism of E6- and E7-mediated carcinogenesis via interactions with an array of cellular elements. We further discussed the progress in the mechanisms of invasion and metastasis; these mechanisms include non-coding RNAs, deregulating cellular energetics, tumor microenvironment, cancer stem cells, angiogenesis, and lymphangiogenesis.

Functions of chemokines in the perineural invasion of tumors (Review).

The perineural invasion (PNI) of malignant tumors is a form of tumor progression in which cancer cells encroach along nerves. PNI hinders curative resection. Residual tumor cells in or around nerves can bring about local recurrence, infiltration and metastasis. This behavior is usually associated with a poor clinical prognosis. Therefore, it is necessary to investigate novel ligand-receptor crosstalk between nerves and tumor cells that promote the process of PNI. Chemokines are regarded as one of pivotal factors involved in the process of PNI. The present review collates information provided by previous studies with regard to the role of chemokines in PNI. The study presents a definition of PNI in cancer, generalizes the biological characteristics and the expression of chemokines and their receptors in cancer types associated with PNI, and discusses the underlying molecular mechanisms of chemokines, the reciprocal interactions between chemokines and other factors in PNI, and the interconnectivity of the microenvironment and chemokines. The aim of the review is to thoroughly illustrate the molecular cues of chemokines in cancer with PNI and to identify novel antitumor targets.

Cancer cell dormancy: mechanisms and implications of cancer recurrence and metastasis.

More recently, disease metastasis and relapse in many cancer patients several years (even some decades) after surgical remission are regarded as tumor dormancy. However, the knowledge of this phenomenon is cripplingly limited. Substantial quantities of reviews have summarized three main potential models that can be put forth to explain such process, including angiogenic dormancy, immunologic dormancy, and cellular dormancy. In this review, newly uncovered mechanisms governing cancer cell dormancy are discussed, with an emphasis on the cross talk between dormant cancer cells and their microenvironments. In addition, potential mechanisms of reactivation of these dormant cells in certain anatomic sites including lymph nodes and bone marrow are discussed. Molecular mechanism of cellular dormancy in head and neck cancer is also involved.

Cytokeratin-14 contributes to collective invasion of salivary adenoid cystic carcinoma.

Collective invasion of cells plays a fundamental role in tissue growth, wound healing, immune response and cancer metastasis. This paper aimed to investigate cytokeratin-14 (CK14) expression and analyze its association with collective invasion in the invasive front of salivary adenoid cystic carcinoma (SACC) to uncover the role of collective invasion in SACC. Here, in the clinical data of 121 patients with SACC, the positive expression of CK14 was observed in 35/121(28.93%) of the invasive front of SACC. CK14 expression in the invasive front, local regional recurrence and distant metastasis were independent and significant prognostic factors in SACC patients. Then, we found that in an ex vivo 3D culture assay, CK14 siRNA receded the collective invasion, and in 2D monolayer culture, CK14 overexpression induced a collective SACC cell migration. These data indicated that the presence of characterized CK14+ cells in the invasive front of SACC promoted collective cell invasion of SACC and may be a biomarker of SACC with a worse prognosis.

The etiologic spectrum of head and neck squamous cell carcinoma in young patients.

Head and neck squamous cell carcinoma (HNSCC), accounting for more than 80% in head and neck malignancies, kills thousands of people a year in the world. Despite most of the patients are more than 45, and the occurrences of head and neck cancer shows a decreasing trend; however, horribly, the incidences of the patients under 45 years old is steadily increasing. Hence, it's of vital importance to get more pathogen information about risk factors of HNSCC in children and young adults. This review outlines the etiologic spectrum of HNSCC, especially oral/oropharyngeal squamous cell carcinoma, in patients under 45 years of age.

CD133+ cancer stem-like cells promote migration and invasion of salivary adenoid cystic carcinoma by inducing vasculogenic mimicry formation.

Cancer stem cells (CSCs) have gained much attention due to their roles in the invasion and metastasis of numerous kinds of human cancers. Here, we showed that the positive expression of CD133, the stemness marker, was positively associated with vasculogenic mimicry (VM) formation, local regional recurrence, distant metastasis and poorer prognosis in salivary adenoid cystic carcinoma (ACC) specimens. Compared with CD133- ACC cells, CD133+ cancer stem-like cells had more migration and invasion capabilities, as well as more VM formation. The levels of endothelial cell marker VE-cadherin, MMP-2 and MMP-9 expression in CD133+ cancer stem-like cells and xenograft tumors of nude mice injected with CD133+ cells were significantly higher than those with CD133- cells. The data indicated that CD133+ cancer stem-like cells might contribute to the migration and invasion of ACC through inducing VM formation.

Effect of chronic social defeat stress on behaviors and dopamine receptor in adult mice.

Victims of bullying often undergo depression, low self-esteem, high anxiety and post-traumatic stress disorder symptoms. The social defeat model has become widely accepted for studying experimental animal behavior changes associated with bullying; however, differences in the effects in susceptible and unsusceptible individuals have not been well studied. The present study investigated the effects of social defeat stress on behavior and the expression of dopamine receptors D1 and D2 in the brains of adult mice. Adult mice were divided into susceptible and unsusceptible groups after 10days of social defeat stress. Behavioral tests were conducted, and protein levels in the brains were assessed by Western blotting. The results indicate that all mice undergo decreased locomotion and increased anxiety behavior. However, decreased social interaction and impaired memory performance were only observed in susceptible mice. A significantly decreased expression of D1 was observed in the prefrontal cortex and amygdala of susceptible mice only. No significant differences in D2 expression were shown between control and defeated mice in any area studied. These data indicate that depression-like behavior and cognition impairment caused by social defeat stress in susceptible mice may be related to changes in the dopamine receptor D1.

[Facilitative effect of glycine on regulation of baroreflex in the hypothalamic paraventricular nucleus of conscious rats.].

The hypothalamic paraventricular nucleus (PVN) is a central site for integration of the endocrine system and the autonomic nervous system. Despite a number of studies have pointed out the importance of the PVN in the central regulation of cardiovascular functions, the chemical mediators in the PVN responsible for mediating baroreflex are not well understood. In the present study, we used the conscious rats to investigate the possible involvement of glycine (Gly) in PVN in the central regulation of baroreflex induced by intravenous injection of phenylephrine (0.8 mug/0.04 mL, in 3 min). Then, the microdialysis sampling was performed in the PVN and the concentration of Gly in the microdialysate was measured by high performance liquid chromatography (HPLC) combined with electrochemical techniques, and mean arterial pressure (MAP) and heart rate (HR) were recorded simultaneously. Injection of phenylephrine elicited a significant increase (P<0.01) in MAP from the baseline of (99.5+/-14.2) mmHg to the maximum of (149.8+/-19.5) mmHg and a decrease (P<0.01) in HR from the baseline of (400.8+/-33.1) beats/min to the minimum of (273.4+/-40.8) beats/min, respectively. Synchronously, the injection of phenylephrine increased the level of Gly in the microdialysate from the PVN to (162.9+/-27.3)% of the basal level (P<0.05). Perfusion of strychnine (100 mumol/L), an antagonist of Gly receptor, into the PVN enhanced the pressor response and attenuated the bradycardic response during the baroreflex, resulting in a decrease in baroreflex sensitivity (P<0.001). Whereas, the perfusion of Gly (1 mmol/L) into the PVN did not affect the pressor response but enhanced the bradycardic response during the baroreflex, resulting in an increase in baroreflex sensitivity (P<0.001). These results suggest that endogenous Gly in the PVN may act via strychnine-sensitive Gly receptor to produce a facilitative effect on baroreflex.

[Cardiovascular change induced by central hypertonic saline are accompanied by GABA release in awake rats].

AIM: To investigate the possible involvement of gamma-aminobutyric acid (GABA) in the paraventricular nucleus (PVN) in cardiovascular responses induced by central salt loading. METHODS: Direct perfusion into PVN region with hypertonic saline (0.6 mol/L) was performed in conscious rats by using an in vivo brain microdialysis technique. Then, the extracellular concentration of GABA in the PVN region was measured by microdialysis and high performance liquid chromatography (HPLC) techniques, and the blood pressure (BP) and heart rate (HR) were with recorded simultaneously. Bicuculline (an antagonist of GABAA receptor) or saclofen (an antagonist of GABAB receptor) were coperfused hypertonic saline into PVN region, then the cardiovascular responses were examined. RESULTS: (1) The local perfusion of 0.6 mol/L saline elicited significant increases on BP and HR (P < 0.01). In addition, perfusion of 0.6 mol/L saline increased the extracellular GABA levels in the PVN region, which reached 561.96% +/- 173.96% (P < 0.05) of the basal level. (2) Bicuculline or salcofen significantly attenuated the in-response of BP (P < 0.01, respectively), whereas the antagonists did not influence the response of HR induced by hypertonic saline. CONCLUSION: Local perfusion of hypertonic saline in the PVN region elicits a local release of GABA, which may act via GABA(A) and GABA(B) receptors to produce pressor response.