The expression of chemokines CCL19, CCL21 and their receptor CCR7 in oral squamous cell carcinoma and its relevance to cervical lymph node metastasis.

The purpose of this study is to determine the expression of CCL19, CCL21, and CCR7 in samples of oral squamous cell carcinoma (OSCC) and their relationship with clinical and microscopic parameters. A comparative analysis was made of the mRNA expression of these chemokines and receptor in OSCC and normal oral mucosa. The immunoexpression of CCR7, CCL19, and CCL21 was also verified in OSCC and lymph nodes. Statistical significance was accepted at P < 0.05. Similar levels of CCR7, CCL19, and CCL21 mRNA in OSCC and normal oral mucosa were seen. A low expression of CCL19 and CCL21 in the intra- and peritumoral regions was observed. Scarce CCL19(+) and CCL21(+) cells were also noted in metastatic and non-metastatic lymph nodes. No association was found between the expression of these chemokines and clinical and microscopic parameters. Our findings would suggest that CCL19 and CCL21 may not be associated with cervical lymph node metastasis or other clinical and microscopic factors in OSCC.

Involvement of CXCL12 and CXCR4 in lymph node metastases and development of oral squamous cell carcinomas.

The chemokine stromal cell-derived factor (SDF-1/CXCL12) and its specific receptor, CXCR4, have been implicated in the regulation of tumor growth and organ-specific spread. The aim of this study was to determine the expression of CXCL12 and CXCR4 in samples obtained from primary squamous cell carcinoma (SCC) of the oral cavity (OCSCC) and of the lip (LSCC) and in metastatic and non-metastatic lymph node tissues. The relationship of CXCL12/CXCR4 with clinical and microscopic parameters was also evaluated. The analysis of mRNA expression revealed a higher expression of CXCR4 in oral SCC compared with healthy oral mucosa (p = 0.006). The density of CXCR4+ cells was higher in parenchyma of OCSCC with lymph node metastases than in LSCC. With regard to the stroma, OCSCC showed a greater CXCR4+ and CXCL12+ cell percentage in relation to LSCC. Furthermore, the density of CXCL12+ and CXCR4+ nodal cells was higher in metastatic than non-metastatic lymph nodes in the same patients. Considering clinical and microscopic parameters, we found a positive association between the percentages of CXCL12+ and CXCR4+ stromal cells and the tumor proliferation index. Our findings suggest that the CXCL12/CXCR4 system may play a role in tumor cell spread to lymph nodes and also in neoplastic development.

Dual role of CCL3/CCR1 in oral squamous cell carcinoma: implications in tumor metastasis and local host defense.

Chemokines are small chemotactic cytokines that can induce the migration of leukocytes, activate inflammatory/immune responses and have recently been implicated in the regulation of tumor growth and organ-specific spread. In this setting, the macrophage inflammatory protein-1alpha (CCL3) chemokine displays a diversity of roles that may contribute to the directional migration of squamous cells into cervical lymph nodes or to the defense against tumor initiation and progression. Thus, the aim of this study was to determine, for the first time, the expression of CCL3 and their receptors, CCR1 and CCR5, by real-time polymerase chain reaction in samples obtained from oral squamous cell carcinoma (OSCC) and healthy gingival tissue (control). In addition, we investigated the immunoexpression of these molecules in neoplastic cells (parenchyma), inflammatory/immune cells (stroma) in primary OSCC and in metastatic and non-metastatic lymph node tissues. The relationship of CCL3/CCR1 with survival data was also evaluated. The analysis of mRNA expression revealed a significantly higher expression of CCL3 and CCR1 in OSCC compared with the controls (P<0.05). The expression of CCR5 was not different in the two groups. The percentages of CCL3+ and CCR1+ cells were observed to be similar in parenchyma and stroma in the OSCC without lymph node metastasis when compared with OSCC with lymph node metastasis (P>0.05). However, we observed the density of CCL3+ nodal cells to be significantly higher in metastatic lymph nodes when compared with non-metastatic lymph nodes in the same patients (P<0.05). Considering CCL3 in stroma, the mean survival rate for patients with high CCL3+ cell percentage was better than for those with low CCL3+ cell percentage. Our findings suggest that the CCL3/CCR1 axis may have a role in the spread of tumoral cells to the lymph nodes and also in the local host defense against the tumor.

Decrease in mast cells in oral squamous cell carcinoma: possible failure in the migration of these cells.

It is becoming accepted that multiple cell types in stromal microenvironment are involved in tumorigenesis. In this setting, mast cells (MC) display a diversity of roles that may contribute to the defense against tumors or tumor progression. Thus, the aim of this study was to evaluate density and migration of MCs in OSCC (oral squamous cell carcinoma) and pre-malignant oral hyperkeratosis (leukoplakia) as well as their relationship with clinical and microscopic parameters. The tryptase and c-kit expression was analyzed in 38 cases of OSCC, 26 cases of leukoplakia, and 12 cases of clinically healthy oral mucosa (control) by means of immunohistochemistry. The tryptase(+) cell numbers were decreased in OSCC (P=0.0003) and leukoplakia (P=0.03) compared with control. Similar numbers of tryptase(+) cells were observed in leukoplakia and OSCC (P=0.31). The density of c-kit(+) MCs was also significantly lower in OSCC and leukoplakia in relation to control resulting in a reduced c-kit(+)/tryptase(+) relationship in OSCC (19%) in comparison with leukoplakia (59%) and control (63%). No correlation was observed between MC populations with clinical and microscopic characteristics of OSCC. Our findings suggest that the decrease in MC numbers in pre-malignant and malignant oral lesions may be related to the migration failure of these cells, possibly reflecting an important modification in the microenvironment during tumor initiation and progression.

Lymphangiogenesis and podoplanin expression in oral squamous cell carcinoma and the associated lymph nodes.

The objective of this study was to evaluate lymphangiogenesis in oral squamous cell carcinoma and in the associated lymph nodes and podoplanin expression in neoplastic cells at the invasive front. In addition, the association of the above parameters with lymph node metastasis was also investigated. We used immunohistochemistry to examine primary tumors and lymph nodes, regardless of metastasis. Lymphatic vessel density (LVD) and microvessel density (MVD) were assessed by antibodies D2-40 and CD105, respectively, in intratumoral and peritumoral areas and in lymph node regions. Vascular endothelial growth factor-C and vascular endothelial growth factor receptor-3 expression was evaluated in tumor cells and D2-40 (podoplanin) expression in parenchymal cells found at the invasive front. The majority of cases with nodal involvement presented a high peritumoral LVD. In addition, a strong association of LVD with size and site of primary tumors could also be identified. MVD was statistically associated with metastasis, and a significant association between the lymphangiogenic factors and the density of vessels in the intratumoral region was also seen. The well-differentiated tumors did not express podoplanin. LVD and MVD were higher in metastatic lymph nodes than in nonmetastatic lymph nodes. The enhanced vascular network in metastatic lymph nodes reinforces the previous reports of lymphangiogenesis occurrence in lymph nodes. Moreover, the expression of podoplanin by more undifferentiated tumor cells suggests that this protein could be an indicator of tumor aggressiveness.

A comparative study of microvessel density in squamous cell carcinoma of the oral cavity and lip.

OBJECTIVES: The objective of this study was to comparatively evaluate the density of lymphatic vessels (LVD) and neoformed microvessels (NMVD) in squamous cell carcinoma of the oral cavity (OCSCC) and lip (LSCC). Association between LVD/NMVD and vascular endothelial growth factor (VEGF)-A/-C was also assessed. STUDY DESIGN: OCSCC and LSCC were compared with regard to immunoexpression of LVD, NMVD, and vascular endothelial growth factor-A (VEGF)-A/-C. Association between VEGF-A/-C with vascularity was also assessed. Statistical analyses were performed using t test, Pearson χ(2), and Mann-Whitney tests. Statistical significance was accepted at P less than .05. RESULTS: The NMVD and VEGF-C expressions were significantly higher in OCSCC compared with LSCC. NMVD was associated with VEGF-C in OCSCC, but not in LSCC. CONCLUSIONS: Differences in NMVD and VEGF-C were found between OCSCC and LSCC. Positive association between VEGF-C and NMVD was observed in OCSCC, but not in LSCC, which may be one of the contributing factors that account for the distinctive clinical-biological behavior of these lesions.