Differing Lymphatic Vessels Density in Salivary Adenoid Cystic Carcinoma and Pleomorphic Adenoma

Lymph Vessels Associate with Cancer Stem Cells from Initiation to Malignant Stages of Squamous Cell Carcinoma

Tumor-associated lymph vessels and lymph node involvement are critical staging criteria in several cancers. In skin squamous cell carcinoma, lymph vessels play a role in cancer development and metastatic spread. However, their relationship with the cancer stem cell niche at early tumor stages remains unclear. To address this gap, we studied the lymph vessel localization at the cancer stem cell niche and observed an association from benign skin lesions to malignant stages of skin squamous cell carcinoma. By co-culturing lymphatic endothelial cells with cancer cell lines representing the initiation and promotion stages, and conducting RNA profiling, we observed a reciprocal induction of cell adhesion, immunity regulation, and vessel remodeling genes, suggesting dynamic interactions between lymphatic and cancer cells. Additionally, imaging analyses of the cultured cells revealed the establishment of heterotypic contacts between cancer cells and lymph endothelial cells, potentially contributing to the observed distribution and maintenance at the cancer stem cell niche, inducing downstream cellular responses. Our data provide evidence for an association of lymph vessels from the early stages of skin squamous cell carcinoma development, opening new avenues for better comprehending their involvement in cancer progression.

Characterization of vascular density and collagenous matrix in oral pleomorphic adenomas

BACKGROUND

Tumor vascular density and collagen matrix organization are critical factors to neoplasia development and progression. This study aimed to analyze the variables associated with the extracellular matrix in oral pleomorphic adenomas.

METHODS

This cross-sectional study comparatively evaluated 21 cases of pleomorphic adenomas and 21 sections of regular oral mucosa from the files of an oral pathology department. The tissue sections were subjected to immunohistochemical study with a monoclonal antibody specific to CD31 protein to assess vascular density and were also stained with Sirius red to evaluate the levels of collagen. The numbers of positively-stained cells were enumerated in specific fields through morphometric study, with subsequent statistical analysis.

RESULTS

Higher numbers of CD31-positive cells were observed in tumor cells than in cells in the regular oral mucosa (P=0.004), which were always located around blood vessels. In tumor lesions, the correlation between the collagen area and vascular density was discrete between these two variables (r=0.046), although the association was not statistically significant.

CONCLUSIONS

The results suggested that the increased expression of CD31+ in cells associated with capillaries may be related to tumor neoangiogenesis. Furthermore, an increase in the concentration of collagen fibers proportional to the number of blood vessels in the neoplastic sections suggested the active role of these lesions in the remodeling process.

Analyses of VEGFC/VEGF-D expressions, density and endothelial lymphatic proliferation in salivary gland neoplasms

OBJECTIVE

The aim of this study was to assess vascular endothelial growth factor C (VEGF-C) and VEGF-D expressions, tumor lymphatic density (D2-40) and endothelial lymphatic proliferation (D2-40/Ki-67 double labeling) in a series of salivary gland neoplasm cases.

MATERIALS AND METHODS

Twenty pleomorphic adenomas (PA), 20 adenoid cystic carcinomas (ACC) and 20 mucoepidermoid carcinomas (MEC) were assessed, as well as 10 normal minor salivary gland (SG) tissues for comparison.

RESULTS

All cases presented positive VEGF-C expression in the peritumoral and intratumoral regions, and no differences in immunoexpression were detected between groups. However, the ACC group presented a significant difference in VEGF-C immunoexpression according to the predominant histological pattern. Most cases presented poor VEGF-D labeling in the peritumoral and intratumoral regions. Concerning peritumoral, intratumoral and total lymphatic endothelial density, the assessed groups revealed an increasing gradient, with lower values for PA, followed by MEC and ACC.

CONCLUSION

No correlation was detected between VEGF-C and VEGF-D immunoexpression in relation to lymphatic tumor density and endothelial lymphatic proliferation. Western blotting (WB) revealed no difference between VEGF-C and VEGF-D expression among the lesions, corroborating the immunohistochemistry findings.