ABSTRACT
This study investigated the antineoplastic effects of crotoxin isolated from snake venom of the South American Crotalus durissus terrificus in oral cancer cell lines and in an animal model of chemically induced oral cancer. We analyzed cell viability and death, clonogenic formation, DNA fragmentation, migration assay, and gene expression of MMP2, MMP9, COL1A1, and CASP3. In the animal model, after induction of oral cancer by 4-nitroquinoline-1-oxide carcinogen, mice were treated with crotoxin to investigate its effects on tumor development in tongue and oral mucosa. Crotoxin inhibited cell proliferation, viability, colony formation, and migration, favoring cell death. Furthermore, crotoxin increased caspase-3 expression, decreased Ki-67 protein and mRNA expression of MMP2, MMP9, and COL1A1. Mice treated with crotoxin at 10 µg/kg did not alter biochemical parameters total cholesterol, very-low-density lipoprotein, high-density lipoprotein, liver transaminases, glycemia, creatinine, and urea. Crotoxin treatment significantly reduced the frequency of oral squamous cell carcinoma lesions by 50%. Thus, this study highlights crotoxin as a promising chemotherapeutic substance, considering its effects on controlling the neoplastic cell population, reducing cell migration, and inhibiting tumor development. Clinical studies are necessary to understand better the impact of crotoxin as a potential adjuvant therapeutic agent for oral cancer patients.
Subject(s)
Antineoplastic Agents , Crotalid Venoms , Crotoxin , Mouth Neoplasms , Squamous Cell Carcinoma of Head and Neck , Animals , Mice , Antineoplastic Agents/pharmacology , Crotalid Venoms/chemistry , Crotalus , Crotoxin/pharmacology , Matrix Metalloproteinase 2 , Matrix Metalloproteinase 9 , Mouth Neoplasms/chemically induced , Mouth Neoplasms/drug therapy , Squamous Cell Carcinoma of Head and Neck/chemically induced , Squamous Cell Carcinoma of Head and Neck/drug therapyABSTRACT
PURPOSE: Leptin, an important hormone controlling energy homeostasis, has been linked to the pathogenesis of oral squamous cell carcinoma (OSCC). Evidence indicates that head and neck cancer patients undergoing radiotherapy show decreased leptin levels after radiotherapy treatment. Thus, we investigated, through phenotypic and molecular analyses, whether leptin can compromise the therapeutic effect of ionizing radiation and neoplastic behavior of OSCC cells. METHODS: The human OSCC-derived cell lines SCC9 and SCC4 were treated with human recombinant leptin and exposed to 6 Gy of irradiation. We performed the in vitro assays of cell migration, death, proliferation, and colony-forming ability. The reactive oxygen species (ROS) levels and proteome analysis by mass spectrometry were also conducted. RESULTS: Leptin was able to increase cell proliferation, migration, and colony-forming ability, despite the suppressive effect induced by irradiation. Furthermore, the leptin promoted a significant reduction of ROS intracellular accumulation, and increased expression of the cancer-related proteins, as ACTC1, KRT6A, and EEF2 in irradiated OSCC cells. CONCLUSIONS: Our findings suggest that leptin impairs responsivity of OSCC cells to the ionizing radiation, reducing the suppressive effects of irradiation on the neoplastic phenotype, and increasing protein expression critical to carcinogenesis.
Subject(s)
Carcinoma, Squamous Cell/pathology , Carcinoma, Squamous Cell/radiotherapy , Leptin/adverse effects , Mouth Neoplasms/pathology , Mouth Neoplasms/radiotherapy , Radiation, Ionizing , Actins/genetics , Actins/metabolism , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/metabolism , Cell Movement/drug effects , Cell Movement/radiation effects , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Gene Expression/drug effects , Gene Expression/radiation effects , Humans , Keratin-6/genetics , Keratin-6/metabolism , Leptin/metabolism , Mouth Neoplasms/genetics , Mouth Neoplasms/metabolism , Reactive Oxygen Species/metabolism , Tumor Cells, CulturedABSTRACT
Gallic acid is a polyphenolic compost appointed to interfere with neoplastic cells behavior. Evidence suggests an important role of leptin in carcinogenesis pathways, inducing a proliferative phenotype. We investigated the potential of gallic acid to modulate leptin-induced cell proliferation and migration of oral squamous cell carcinoma cell lines. The gallic acid effect on leptin secretion by oral squamous cell carcinoma cells, as well as the underlying molecular mechanisms, was also assessed. For this, we performed proliferation, migration, immunocytochemical and qPCR assays. The expression levels of cell migration-related genes (MMP2, MMP9, Col1A1, and E-cadherin), angiogenesis (HIF-1α, mir210), leptin signaling (LepR, p44/42 MAPK), apoptosis (casp-3), and secreted leptin levels by oral squamous cell carcinoma cells were also measured. Gallic acid decreased proliferation and migration of leptin-treated oral squamous cell carcinoma cells, and reduced mRNA expression of MMP2, MMP9, Col1A1, mir210, but did not change HIF-1α. Gallic acid decreased levels of leptin secreted by oral squamous cell carcinoma cells, accordingly with downregulation of p44/42 MAPK expression. Thus, gallic acid appears to break down neoplastic phenotype of oral squamous cell carcinoma cells by interfering with leptin pathway.
