Downregulation of VAP-1 in OSCC suppresses tumor growth and metastasis via NF-κB/IL-8 signaling and reduces neutrophil infiltration.

BACKGROUND: Vascular adhesion protein-1 (VAP-1) is believed to play a role in inflammation. Studies have suggested that VAP-1-mediated activation of inflammation is dependent on NF-κB, leading to secretion of the interleukin (IL)-8; however, no reports have addressed the association between VAP-1 and NF-κB/IL-8 signaling in oral squamous cell carcinoma (OSCC). This study aimed to investigate the role of VAP-1 in OSCC and further explore whether VAP-1 is involved in the regulation of neutrophil infiltration in the tumor microenvironment (TME). METHODS: Immunochemistry staining was used to observe VAP-1 expression. CCK-8 and Transwell assays were used to measure cell proliferation, migration, and invasion. OSCC xenograft mouse models were used for in vivo verification of the VAP-1 function. The expression of NF-κB and IL-8 were determined by qRT-PCR and western blot. ELISA for IL-8 was also conducted. The relationship between VAP-1 expression and neutrophil infiltration was analyzed by immunofluorescence. RESULTS: VAP-1 was overexpressed in human OSCC tissues. Downregulation of VAP-1 suppressed OSCC cells proliferation, migration, and invasion in vitro and inhibited tumor proliferation and metastasis in vivo. Additionally, downregulation of VAP-1 inhibited NF-κB/IL-8 signaling in vitro and in vivo. VAP-1 expression was positively correlated with neutrophil infiltration in human OSCC tissues. Moreover, blocking VAP-1 decreased neutrophil infiltration by reducing IL-8 production. CONCLUSIONS: VAP-1 downregulation in OSCC suppresses tumor growth and metastasis by inhibiting NF-κB/IL-8 signaling and reducing neutrophil infiltration in the TME, suggesting that VAP-1 may be a potential therapeutic target for OSCC.

Protein overexpression of toll-like receptor 4 and myeloid differentiation factor 88 in oral squamous cell carcinoma and clinical significance.

Oral squamous cell carcinoma (OSCC) is the most common type of malignancy of the head and neck. In the present study, the expression of Toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) was evaluated in 55 OSCC tissues and their corresponding adjacent tissues using immunohistochemistry and reverse-transcription quantitative PCR. The results indicated that TLR4 and MyD88 were overexpressed in OSCC. Furthermore, high expression of MyD88 was negatively associated with a poor degree of differentiation, recurrence and metastasis of the tumor and was positively associated with underlying disease, including hypertension, heart disease and diabetes mellitus. Furthermore, high expression of TLR4 was positively associated with a long growth time of the tumor. In conclusion, the present study evaluated the expression levels of TLR4 and MyD88 in OSCC, as well as the association between them and clinicopathological factors, to provide markers for the prognosis and treatment of OSCC. These two genes may serve as biomarkers to optimize OSCC treatment, setting a new direction for stratifying patients and developing precise and personalized treatment regimens; the TLR4/MyD88 pathway may serve as a potential therapeutic target in the future.

Association between condylar position changes and functional outcomes after condylar reconstruction by free fibular flap.

OBJECTIVES: Stable and appropriate condyle positioning is necessary for maintaining temporomandibular joint function. It is unclear if this position remains stable in patients after free fibular flap (FFF) condylar reconstruction. We investigated whether condylar position deviated after reconstruction, and whether this affected functional recovery. MATERIALS AND METHODS: We retrospectively reviewed 43 patients who underwent conventional FFF condylar reconstruction, and 5 patients who underwent reconstruction by computer-assisted three-dimensional (3D) printing methods. Three-dimensional models were built from cone-beam computed tomography images obtained immediately postoperatively and 1-year postoperatively. The glenoid fossa and fibular condyle centers were used to measure the fibular condyle position in the models. Clinical examination indices, including maximum mouth opening (MMO), pain during chewing/mouth opening, and patient satisfaction with mastication and 1-year outcomes were assessed. RESULTS: Fibular condyle position changed significantly over 1 year in both groups (P < 0.05). Clinical examination at 1 year after the surgery showed that in the conventional group, the MMO range was ≥ 35 mm in 76.7% of patients and < 35 mm in 23.3% of patients; 4.7% experienced pain during chewing/mouth opening, and 7% were dissatisfied with treatment outcomes. In the 3D printing group, all patients had an MMO range exceeding 35 mm, none had pain, and all were satisfied with functional outcomes. CONCLUSIONS: The position of the fibular condyle deviates after reconstructive surgery, but it is unlikely to affect functional recovery. CLINICAL RELEVANCE: These findings can form the basis for evaluation of functional outcomes of patients who have previously undergone condylar reconstruction by FFF.

TGF-ß1 and IL-17A comediate the protumor phenotype of neutrophils to regulate the epithelial-mesenchymal transition in oral squamous cell carcinoma.

BACKGROUND: The role of neutrophils in cancer has been the subject of intense research in recent years. One major theme that has emerged is that not all neutrophils are equal in the field of cancer. However, it remains unclear what induces the protumorigenic or antitumorigenic phenotype predominate in tumor. Therefore, this study aimed to investigate what factors induce which of these two phenotypes of neutrophil predominate in OSCC and to explore the role of neutrophil polarization on tumor. METHODS: Immunofluorescence and immunohistochemistry staining were used to observe neutrophil infiltration and the expression of TGF-ß1 and IL-17A in OSCC tissues. Recombinant human TGF-ß1 and IL-17A were used to modulate neutrophil polarization. OSCC cell (SCC9 and SAS cell lines) migration, proliferation, invasion, stemness, and EMT were analyzed after treatment with conditioned medium from TGF-ß1/IL-17A-activated neutrophils. The levels of neutrophil-associated markers in OSCC tissues and peripheral blood were examined by immunofluorescence staining and quantitative PCR. RESULTS: Our data showed neutrophil infiltration and elevated expression of TGF-ß1 and IL-17A in OSCC tissues. The cooperative effect of TGF-ß1 and IL-17A promoted neutrophils to take on a protumor phenotype in vitro. TGF-ß1/IL-17A-activated neutrophils remarkably induced cell migration, proliferation, invasion, stemness, and EMT in OSCC cells. Additionally, OSCC patients showed increased expression of MMP9 and decreased expression of CCL3 in circulating neutrophils. CONCLUSION: TGF-ß1 and IL-17A cooperated to augment the protumor functions of neutrophils, thereby promoting the progression of OSCC cells. In addition, the combination of neutrophil-associated markers may serve as a predictive method to screen for patients with OSCC.

The association between the socioeconomic status and systemic comorbidities in patients with oral cancers: a retrospective study in Guangxi Province.

BACKGROUND: It is unclear whether and how the prevalence of systemic comorbidities in oral cancer patients would change with socioeconomic development. MATERIALS AND METHODS: A retrospective study of association between socioeconomy and prevalence of systemic comorbidities in oral cancer patients from 2003 to 2017 was performed in Guangxi Province, a southwestern part of China. According to the Union for International Cancer Control (UICC) classification, 2814 patients with squamous cell carcinoma (SCC) of the lip, oral cavity, and oropharynx and 423 patients with ameloblastoma were collected and assigned to the oral cancer group and control group, respectively. Then, comparisons between the socioeconomy and healthcare expenditure in Guangxi Province, the whole China, and the USA were carried out. RESULTS: The prevalence of systemic comorbidities in oral cancer patients increased from 0.820% in 2003 to 32.302% in 2017, which was significantly higher than that in non-cancer patients(P < 0.001) and was positively correlated with the increase in gross regional product (GRP) (r = 0.911, P < 0.001) and per capita GRP (r = 0.910, P < 0.001) of Guangxi Province. In addition, the prevalence of cardiovascular diseases has the largest correlation coefficient with GRP(r = 0.957, P < 0.001) and per capita GRP(r = 0.959, P < 0.001). And the prevalence of endocrine diseases increased by 13.402% and exhibited the most significant increase in 15 years. The per capita health care expenditure of Guangxi Province and whole China was nearly equal (P = 0.353). Although the health care expenditure of Guangxi Province had been increasing year by year, its proportion in GRP remains far below that of the USA. CONCLUSIONS: With socioeconomic growth, oral cancer patients in Guangxi Province are more common to comorbid with systemic diseases. Cardiovascular and endocrine diseases may be the most susceptible systemic comorbidities in oral cancer patients to the socioeconomic status. In order to control the prevalence of systemic diseases, the government of Guangxi Province may need to expend more budgets in the health care. CLINICAL RELEVANCE: Clinicians need to pay more attention to the detection of systemic comorbidities and the concept of multidisciplinary collaboration. Instructing oral cancer patients to treat and control systemic comorbidities is also an indispensable part in the treatment of oral cancer.

Downregulation of FOXP3 in neutrophils by IL-8 promotes the progression of oral squamous cell carcinoma.

The aim of the present study was to investigate the effects of the transcription factor forkhead box P3 (FOXP3) in neutrophils on the progression of oral squamous cell carcinoma (OSCC). Cancer tissue samples and paracarcinoma tissues were collected from 23 patients with OSCC for the current study. In addition, SCC-9, a human tongue carcinoma cell line, was co-cultured with primary human neutrophils and treated with recombinant interleukin 8 (IL-8). The effect of FOXP3 on the proliferation of SCC-9 cells was analyzed using a Cell Counting Kit 8 assay. FOXP3 expression in neutrophils was analyzed by quantitative PCR following IL-8 treatment. FOXP3 protein expression in neutrophils and the amount of IL-8 protein in the OSCC tumor microenvironment were determined by immunofluorescence analysis. The present study demonstrated that IL-8 downregulated FOXP3 mRNA expression in neutrophils. Neutrophils and peptide P60, a specific inhibitor of FOXP3, increased proliferation of SCC-9 cells. In patients with OSCC, FOXP3 protein expression in neutrophils of the stage IV group was significantly lower compared with that of the stage II and stage III groups, while IL-8 protein expression was higher in cancer tissues compared with that in paracarcinoma tissues. In summary, IL-8 in the tumor microenvironment may recruit neutrophils, and downregulation of FOXP3 in neutrophils by IL-8 may promote the progression of OSCC.