Dados do Trabalho

Título

TUMORIGENIC AND METASTATIC POTENTIAL OF DISTINCT CANCER STEM CELLS PHENOTYPES IN ORAL SQUAMOUS CELL CARCINOMA

Introdução

Oral squamous cell carcinoma (OSCC) is associated with considerable rates of early recurrences and low survival rates. Several studies have consistently shown that the presence of cancer stem cells (CSC) contributes to the lack of success of current therapies against advanced cancer. CSC are strongly associated with local recurrence, metastatic spread, and resistance to radio and/or chemotherapy in several types of cancer, including OSCC.

Objetivo

This work aimed to characterize the in vitro and in vivo behavior of CSC subpopulations with distinct expression patterns for cell surface markers CD44 and CD326 and compare them with the LN-1A parental cell lineage established in our laboratory.

Métodos

Three CSC subpopulations with different expression patterns for CD44 and CD326 were isolated by flow cytometry from LN-1A cells: CSC-M1 (CD44+/CD326-); CSC-E (CD44Low/CD326High) and CSC-M2 (CD44High/CD326-). In vitro assays were performed to investigate proliferation rate, clonogenic and sphere formation potential, cell adhesion, and migration. The expression of proteins associated with the epithelial-mesenchymal transition (EMT), the enzyme fatty acid synthase (FASN), the epidermal growth factor receptor (EGFR), and p-Akt were evaluated by western blotting. Cell viability assays were performed to assess sensitivity to antineoplastic drugs cisplatin and TVB-3166. The ability to form tumors was evaluated in vivo by subcutaneous inoculation of cells in the flank region and orthotopically on the lateral border of the tongue of BALB/c nude mice, as well as the formation of metastases to the cervical lymph nodes (CEUA Protocol: 6020 -1/2022).

Resultados

Our results revealed that E-cadherin levels were higher in CSC-E cells, while vimentin and slug were higher in CSC-M2 cells. N-cadherin, FASN, and EGFR levels were similar among all cell lines. CSC-M1 and CSC-M2 cells showed greater proliferative potential, which was accompanied by high production of p-Akt. All cell lines formed spheres, and CSC-M1 and CSC-M2 cells exhibited a greater capacity for colony formation. Cell migration was similar among all cell lines, and myogel adhesion was higher in CSC-M1 and -M2 cells. Cisplatin sensitivity was similar across all cell lines; however, CSC-E cells were slightly more sensitive to TVB-3166. Finally, all cell lines were able to form tumors when inoculated subcutaneously or orthotopically in mice, and CSC-E and CSC-M2 cells metastasized to cervical lymph nodes.

Conclusões

CSC subpopulations derived from OSCC exhibited distinct and enhanced in vitro cancer phenotypes, tumorigenic and metastatic ability in vivo and should be explored to provide new therapeutic targets for OSCC.

Palavras-chave

Oral squamous cell carcinoma. Cancer stem cells. CD44. CD326. Epithelial-mesenchymal transition. EMT.

Financiador do resumo

CNPq (303064/2018-8)