Tolfenamic Acid Induces Apoptosis and Growth Inhibition in Head and Neck Cancer: Involvement of NAG-1 Expression

Nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1) is induced by nonsteroidal anti-inflammatory drugs and possesses proapoptotic and antitumorigenic activities. Although tolfenamic acid (TA) induces apoptosis in head and neck cancer cells, the relationship between NAG-1 and TA has not been determined. This study investigated the induction of apoptosis in head and neck cancer cells treated by TA and the role of NAG-1 expression in this induction. TA reduced head and neck cancer cell viability in a dose-dependent manner and induced apoptosis. The induced apoptosis was coincident with the expression of NAG-1. Overexpression of NAG-1 enhanced the apoptotic effect of TA, whereas suppression of NAG-1 expression by small interfering RNA attenuated TA-induced apoptosis. TA significantly inhibited tumor formation as assessed by xenograft models, and this result accompanied the induction of apoptotic cells and NAG-1 expression in tumor tissue samples. Taken together, these results demonstrate that TA induces apoptosis via NAG-1 expression in head and neck squamous cell carcinoma, providing an additional mechanistic explanation for the apoptotic activity of TA

A case report of prostate cancer metastasis to the stomach resembling undifferentiated-type early gastric cancer

Abstract Background Occurrence of metastatic cancer to the stomach is rare, particularly in patients with prostate cancer. Gastric metastasis generally presents as a solitary and submucosal lesion with a central depression. Case presentation We describe a case of gastric metastasis arising from prostate cancer, which is almost indistinguishable from the undifferentiated-type gastric cancer. A definitive diagnosis was not made until endoscopic resection. On performing both conventional and magnifying endoscopies, the lesion appeared to be slightly depressed and discolored area and it could not be distinguished from undifferentiated early gastric cancer. Biopsy from the lesion was negative for immunohistochemical staining of prostate-specific antigen, a sensitive and specific marker for prostate cancer. Thus, false initial diagnosis of an early primary gastric cancer was made and endoscopic submucosal dissection was performed. Pathological findings from the resected specimen aroused suspicion of a metastatic lesion. Consequently, immunostaining was performed. The lesion was positive for prostate-specific acid phosphatase and negative for prostate-specific antigen, cytokeratin 7, and cytokeratin 20. Accordingly, the final diagnosis was a metastatic gastric lesion originating from prostate cancer. Conclusion In this patient, the definitive diagnosis as a metastatic lesion was difficult due to its unusual endoscopic appearance and the negative stain for prostate-specific antigen. We postulate that both of these are consequences of hormonal therapy against prostate cancer