Chronic stress increases the systemic levels of stress hormones norepinephrine and cortisol. As well as tobacco-specific carcinogen NNK (4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone), they can induce expressive DNA damage contributing to the cancer development. However, it is unknown whether stress hormones have genotoxic effects in oral keratinocytes. This study investigated the effects of stress hormones on DNA damage in a human oral keratinocyte cell line (NOK-SI). NOK-SI cells stimulated with norepinephrine or cortisol showed higher DNA damage compared to untreated cells. Norepinephrine-induced DNA damage was reversed by pre-treatment with beta-adrenergic blocker propranolol. Cells treated with NNK combined to norepinephrine displayed reduced levels of caspases 3 and 7. Cortisol also reduced the activity of pro-apoptotic enzymes. NNK or norepinephrine promoted single-strand breaks and alkali-label side breaks in the DNA of NOK-SI cells. Pre-treatment of cells with propranolol abolished these effects. Carcinogen NNK in the presence or absence of cortisol also induced DNA damage of these cells. The genotoxic effects of cortisol alone and hormone combined with NNK were blocked partially and totally, respectively, by the glucocorticoid receptor antagonist RU486. DNA damage promoted by NNK or cortisol and carcinogen combined to the hormone led to intracellular γH2AX accumulation. The effects caused by NNK and cortisol were reversed by propranolol and glucocorticoid receptor antagonist RU486, respectively. Propranolol inhibited the oxidation of basis induced by NNK in the presence of DNA-formamidopyrimidine glycosylase. DNA breaks induced by norepinephrine in the presence or absence of NNK resulted in higher 8OHdG cellular levels. This effect was also induced through beta-adrenergic receptors. Together, these findings indicate that stress hormones induce DNA damage of oral keratinocytes and could contribute to oral carcinogenesis.
Pain associated with head and neck cancer (HNC) is difficult to manage and reduces quality of life. It has been increasingly recognized that HNC patients exhibit a wide range of pain symptoms. Here we developed an orofacial pain assessment questionnaire and conducted a pilot study to improve pain phenotyping in HNC patients at the diagnosis. The questionnaire captures the following pain characteristics: pain intensity, location, quality, duration, and frequency; the impact of pain on daily activities; changes in smell and food sensitivities. Twenty-five HNC patients completed the questionnaire. 88% patients reported pain at the site of tumor; 36% reported multiple pain sites. All patients with pain reported at least one neuropathic pain (NP) descriptor, 54.5% reported at least two NP descriptors. The most common descriptors were “burning” and “pins and needles”. Most patients reported increased pain to sour or hot/spicy food/drinks, and to food with coarse/hard textures. Patients exhibited impaired oral function, especially chewing, talking, mouth/jaw opening, and eating. Tumor progression has a significant impact on pain. Nodal metastasis is linked to pain at multiple body sites. Patients with advanced tumor staging experience greater pain at the primary tumor site, when exposed to hot or spicy food/drinks or food with hard/coarse texture, or when eating or chewing. We conclude that HNC patients experience a wide range of pain symptoms with altered mechanical, chemical, and temperature sensation. Improved phenotyping and stratification of pain in HNC patients will help address the underlying etiology, which may enable personalized therapeutic approaches in the future.
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