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TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active forms of this receptor is nearly equal in many human populations, and heterozygotes with 1 copy of the active form and 1 copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this receptor too, including the nasal sinuses, where it contributes to pathogen defense. We, therefore, wondered whether heterozygous people had a similar wide range of TAS2R38 mRNA in sinonasal tissue and whether those with higher TAS2R38 mRNA expression in taste tissue were similarly high expressers in nasal tissue. To that end, we measured gene expression by quantitative PCR in taste and sinonasal tissue and found that expression abundance in one tissue was not related to the other. We confirmed the independence of expression in other tissue pairs expressing TAS2R38 mRNA, such as pancreas and small intestine, using autopsy data from the Genotype-Tissue Expression project (although people with high expression of TAS2R38 mRNA in colon also tended to have higher expression in the small intestine). Thus, taste tissue TAS2R38 mRNA expression among heterozygotes is unlikely to predict expression in other tissues, perhaps reflecting tissue-dependent function, and hence regulation, of this protein. [ABSTRACT FROM AUTHOR]

Objective: Risk of nodal involvement in patients with sinonasal small-cell carcinoma and sinonasal undifferentiated carcinoma (SNUC) has not been well defined because of their rarity. We describe a population-based assessment of specific nodal level involvement in this group of rare neuroectodermal tumours. Methods: The Surveillance, Epidemiology and End Results (SEER) database from 2004 to 2011 identified patients with SNUC and sinonasal small-cell carcinoma. Overall neck involvement and individual nodal level involvement at presentation were assessed, and comparison was made with a contemporaneous cohort of patients with a borderline clinically significant risk of nodal involvement and recurrence. Results: Of 141 patients, 31 (22%) had gross nodal involvement at presentation (range 14-33% by site and histology). Non-nasal, non-ethmoid site with SNUC histology has the highest rates of initial nodal involvement, whereas higher stage and size do not predict for higher nodal involvement rates. Bilateral Levels 2-3 for all sinonasal small cell; Levels 2-3 for nasal or ethmoid SNUC; and bilateral Levels 1-3 in non-nasal/non-ethmoid SNUC have the highest rates of involvement compared with a clinical reference standard. Conclusion: We found high rates of initial nodal involvement in all SNUC and sinonasal small-cell carcinoma. We found higher initial involvement of Levels 2 and 3 and in certain cases to the Level 1 nodal levels, hypothesizing benefit for elective treatment to those levels. Advances in knowledge: With small single-institution series reporting conflicting nodal involvement rates, our data support high rates of nodal presentation at diagnosis, hypothesizing benefit for elective nodal treatment in this cohort. [ABSTRACT FROM AUTHOR]