Inhibitory effects of celecoxib combined with capecitabine on H22 hepatoma mice and its mechanism / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the inhibitory effect and its mechanism of celecoxib combined with capecitabine on the growth of implanted H22 hepatoma in mice.</p><p><b>METHODS</b>Tumor model was established by hypodermical injection of H22 cells in BALB/c nude mice. Forty mice were equally randomly divided into 4 groups: control group, celecoxib group (receiving 100 mg/kg celecoxib), capecitabine group (receiving 755 mg/kg capecitabine), and combined treatment group (receiving 100 mg/kg of celecoxib and 755 mg/kg of capecitabine). From the third post-implantation day, each mouse was given relevant drug (or normal saline) by oral gavage. Fifteen days later, all mice were sacrificed and the tumor tissues were measured. The mRNA and protein levels of nuclear factor kappa-B (NF-ΚB) p65 and cyclooxygenase (COX)-2 in tumor tissues were detected by the quantitative polymerase chain reaction (qPCR)and Western blotting, respectively.</p><p><b>RESULTS</b>The tumor inhibition rate was 30.2% in celecoxib group and 49.9% in capecitabine group, which was significantly lower than that (75.4%) in the combined treatment group (P<0.01,P<0.05, respectively). qPCR showed a significant decrease of the mRNA expression of COX-2 in celecoxib group and combined treatment group when compared with control group (P<0.001), but no significant change in NF-ΚB p65.Capecitabine had no significant effects on the mRNA expression of COX-2 and NF-ΚB p65. Western blotting showed that celecoxib and combined treatment significantly inhibited the protein expression of COX-2 and NF-ΚB p65(P<0.05), but not capecitabine.</p><p><b>CONCLUSION</b>Celecoxib can enhance the antitumor effect of capecitabine by inhibiting the expressions of COX-2 and NF-ΚB p65 in mice bearing H22 implanted tumor.</p>

Expression of tumor suppressor gene PRDM1 in lung cancers / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To determine the expression of tumor suppressor gene PRDM1 in lung cancers.</p><p><b>METHODS</b>Forty-five cases were enrolled in this study, including squamous cell carcinoma (20 cases), adenocarcinoma (15 cases), and small cell cancer (10 cases). PRDM1 protein was detected in paraffin-embedded tissue by immunohistochemistry. Tumor cells in lung cancers were further selected by laser microdissection for RT-PCR analysis. PRDM1 protein in frozen tissue was also detected by Western blot.</p><p><b>RESULTS</b>(1) PRDM1 protein was found in paraffin-embedded tissues in 90.0% (18/20) of squamous cell carcinoma, 13.3% (2/15) of adenocarcinoma, and 0 (0/10) small cell lung cancer. Squamous cell carcinoma predominantly expressed PRDM1 protein ( P < 0.01). (2) Gene product of PRDM1 DNA binding region was not found in microdissected tumor cells, but an abnormal PRDM1 protein about 70 KD was detected simultaneously in whole tumor tissue.</p><p><b>CONCLUSION</b>PRDM1 may be considered as a specific biomarker in pulmonary squamous cell carcinoma. The abnormal PRDM1 expression both at transcriptional and protein levels indicated that this tumor suppressor gene lost its function, which may become a new target in the strategy of treatment for lung cancers.</p>