Influence of conditioned medium from squamous cell carcinoma of the tongue on lymphoblasts and peripheral blood mononuclear cells

BACKGROUND

Squamous cell carcinoma (SCC) is the most common malignant neoplasm of the oral cavity and is associated with high morbidity and mortality. Attention has been given to the role of inflammatory cells in carcinogenesis because of the ability of cancer cells to subvert the immune response. However, little is known about how molecules from neoplastic cells interact with lymphoblasts and circulating immune cells. This study aimed to understand the mechanisms by which SCC cells modulate the immune response by analyzing the influence of conditioned medium derived from SCC cell lines on immune cells.

METHODS

Lymphoblastic cells (CEM) and peripheral blood mononuclear cells (PBMC) were cultured in a conditioned medium derived from squamous cell carcinoma cells (SCC9 or SCC4) and analyzed for cell viability, CD4/CD8/FOXP3 profile by flow cytometry, and chemokine levels.

RESULTS

Conditioned medium derived from SCC4 and SCC9 presented higher concentrations of IL-6 and IL-8 than IL-1β, IL-10, and IFN-γ. CEM and PBMCs when cultured with conditioned medium derived from SCC4 and SCC9 reduced IL-1β, IL-8, and IFN-γ concentrations. Conditioned medium from SCC4 increased CD4⁺ population in both CEM and PBMCs, while in conditioned medium from SCC9 it occurred only in PBMCs. PBMCs when cultured with both conditioned mediums increased CD8⁺ /FOXP3⁺ cells. CEM cells when cultured with conditioned medium derived from SCC4 and SCC9 reduced.

CONCLUSION

Collectively, our results suggest that the products derived from squamous cell carcinoma on inflammatory cells can promote an immunosuppressed environment by reducing cell viability, changing cytokine expression, and altering the cell immunoprofile. This article is protected by copyright. All rights reserved.

Solitary fibrous tumor of the tongue

Solitary fibrous tumor (SFT) is a benign mesenchymal neoplasm originally described in pleura with a rare presentation in the oral cavity. Herein, we report a case of a 28-year-old male patient who presented an asymptomatic slow-growing mass in the anterior part of the tongue. Intraoral examination revealed a well-circumscribed mass covered by normal mucosa with a fibrous consistency. Due to non-specific clinical findings, the initial diagnostic hypotheses include benign submucosal neoplasms such as leiomyoma, neurofibroma, SFT, and others. An excisional biopsy was performed. Microscopically, the tumor was surrounded by a thick fibrous capsule; hypo and hypercellular areas were arranged in a storiform pattern with a stroma formed by collagen and abundant vascularization. Tumor cells showed immunopositivity for CD34 and STAT-6 and no expression of CD99, AML, S-100, and Ki-67. According to these findings, the diagnosis of SFT was established. After 24 months, the patient is asymptomatic and has no evidence of recurrence. Although oral involvement is rare, SFT should be included in the differential diagnosis of oral submucosal lesions.

Experimental Acute Sepsis Reduced Number of Osteocalcin Immunolabeled Cells in Periodontal Ligament

The aim of this study was to evaluate the effect of acute sepsis in the periodontal ligament, alveolar and furcation bone in absence of periodontitis induction through histological and immunohistochemical analyses. A septic rat model was established by cecal ligation and puncture (CLP). Twelve rats were randomly divided into CLP (n=6) and Sham (n=6) groups. The animals were euthanized at 24 h and hemimandibles were submitted to histomorfometric (bone matrix, collagenous fibers, fibroblasts, osteocytes, inflammatory cells, and blood vessels) and immunohistochemical (BMP-2/4, RANKL and osteocalcin) evaluation in alveolar bone, furcation bone and periodontal ligament. Our results demonstrated that histomorphometric parameters were similar in alveolar bone, furcation bone and periodontal ligament of Sham and CLP rats. Regarding to immunohistochemical analyses, the number of BMP-2/4 and RANKL immunolabeled cells was also similar in both groups. Furthermore, it was detected a reduction in the osteocalcin immunolabeled cells in periodontal ligaments of CLP compared to Sham rats (p=0.0014). In conclusion, the acute sepsis induction resulted in reduced number of osteocalcin labelled cells in periodontal ligament region. Moreover, no significant histological differences were observed in the periodontium of rats under acute sepsis. Considering the role of osteocalcin in bone remodeling, the study contributes to revealing the importance of careful periodontal evaluation in the presence of sepsis.