The prediction of mandibular invasion by squamous cell carcinomas with the expression of osteoclast-related cytokines in biopsy specimens

[Advances in molecular mechanisms of bone invasion by oral cancer]

Bone invasion by oral cancer is a common clinical problem, which affects the choice of treatment and predicts a poor prognosis. Unfortunately, the molecular mechanism of this phenomenon has not been fully elucidated. Current studies have revealed that oral cancer cells modulate the formation and function of osteoclasts through the expression of a series of signal molecules. Many signal pathways are involved in this process, of which receptor activator of nuclear factor-κB ligand/receptor activator of nuclear factor-κB/osteoprotegerin signaling pathway attracted much attention. In this review, we introduce recent progress in molecular mechanisms of bone invasion by oral cancer.

Photomodulation of the osteoclastogenic potential of oral squamous carcinoma cells

The treatment for oral cancer usually involves surgical excision followed by chemotherapy and/or radiotherapy. The combination of these therapies generally promotes a serious inflammation of the mucosa of the digestive tract, denominated mucositis, which compromises continuity of treatment. Photobiomodulation (PBM) therapy has been used successfully to reduce the oral mucositis, however there is still some controversy regarding the effects of this therapy on unintentionally irradiated tumor cells that may remain after cancer treatment. The aim of this study was to analyze the effect of PBM therapy (using parameters for mucositis) on the modulation of osteoclastogenic potential of a cell line derived from human lingual squamous cell carcinoma (SCC9). Previously irradiated SCC9 cells were co-cultured with human osteoclast precursors. Co-cultures performed with non-irradiated SCC9 cells served as control. After 7, 14 and 21 days the co-cultures were evaluated for the tartrate-resistant acid phosphatase (TRAP) activity, an osteoclastogenic marker. Additionally, the monocultures of SCC9 cells (non-irradiated and irradiated) were analyzed for cell viability/proliferation and for the expression of IL-11 and PTHrP. The irradiation of SCC9 cells with PBM with an energy density of 4 J/cm² decreased the pro-osteoclastogenic potential of those cells. This may represent a potential useful side effect of PBM therapy. PBM (using recommended parameters for mucositis treatment) decreases the osteoclastogenic potential of oral squamous carcinoma cells.

Bone-invasive oral squamous cell carcinoma in cats: pathology and expression of parathyroid hormone-related protein

Feline oral squamous cell carcinoma (OSCC) is the most common oral tumor in cats. There is no effective treatment, and the average duration of survival after diagnosis is only 2 months. Feline OSCC is frequently associated with osteolysis; however, the mechanisms responsible are unknown. The objective of this study was to characterize the epidemiology and pathology of bone-invasive OSCC in cats and to determine the expression of select bone resorption agonists. In sum, 451 cases of feline OSCC were evaluated. There was no sex or breed predisposition, although there were more intact cats in the OSCC group compared to the control group. Gingiva was the most common site, followed by the sublingual region and tongue. Cats with lingual OSCC were younger (mean, 11.9 years) compared to cats with gingival OSCC (mean, 13.6 years). In addition to osteolysis, there was periosteal new bone formation, osseous metaplasia of tumor stroma, and direct apposition of OSCC to fragments of bone, suggestive of bone-binding behavior. Eighty-two cases were selected for immunohistochemical detection of parathyroid hormone-related protein (PTHrP). Specimens with osteolysis had increased PTHrP expression and nuclear localization, compared to OSCC without osteolysis. Thirty-eight biopsies of OSCC with osteolysis were evaluated for tumor necrosis factor α expression, and only 4 biopsies had such expression in a small proportion of tumor cells. Increased tumor expression of PTHrP and increased localization of PTHrP to the nucleus were associated with osteolysis and may play an important role in bone resorption and tumor invasion in cats with OSCC.