Caffeine Suppresses Apoptosis of Bladder Cancer RT4 Cells in Response to Ionizing Radiation by Inhibiting Ataxia Telangiectasia Mutated-Chk2-p53 Axis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Caffeine suppresses ataxia telangiectasia and Rad3 related and ataxia telangiectasia mutated (ATM) activities; ATM is the major kinase for DNA damage detection. This study aimed to investigate the effects of caffeine on DNA damage responses in cells from the bladder cancer cell line RT4 those were exposed to ionizing radiation (IR).</p><p><b>METHODS</b>Immunofluorescent staining was performed to investigate changes in the proteins involved in DNA damage responses with or without caffeine. A mouse xenograft model was used to study the effects of caffeine on the DNA damage responses. Western blotting was used to investigate the effects of caffeine pretreatment on the ATM-Chk2-p53-Puma axis, while real-time polymerase chain reaction (RT-PCR) assessed changes in messenger RNA levels of p53 and downstream targets responding to IR. Finally, terminal deoxynucleotidyl transferase-dUTP nick end labeling assay. Western blotting and colony formation assay were used to measure the effects of caffeine on radiation-related apoptosis. All of the data were analyzed with a two-tailed Student's t-test.</p><p><b>RESULTS</b>Immunofluorescent staining showed that caffeine pretreatment profoundly suppressed the formation of γH2AXand p53-binding protein 1 foci in RT4 cells in response to irradiation. Cellular and animal experiments suggested that this suppression was mediated by suppression of the ATM-Chk2-p53-Puma DNA damage-signaling axis. RT-PCR indicated caffeine also attenuated transactivation of p53 and p53-inducible genes. The colony formation assay revealed that caffeine displayed radioprotective effects on RT4 cells in response to low-dose radiation compared to the radiosensitization effects on T24 cells.</p><p><b>CONCLUSION</b>Caffeine may inhibit IR-related apoptosis of bladder cancer RT4 cells by suppressing activation of the ATM-Chk2-p53-Puma axis.</p>

Diagnostic value of lesion-directed prostate biopsy under TRUS in early detection of prostate cancer / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate lesion-directed biopsy in improving the detection rate of early prostate cancer (PCa) and in differentiating PCa from other prostate pathological changes.</p><p><b>METHODS</b>We performed TRUS-guided prostate biopsy for 95 patients suspected of PCa, each subjected to extended random biopsy plus lesion-directed biopsy, and analyzed the sonographic characteristics and pathological findings.</p><p><b>RESULTS</b>PCa was detected in 35 of the patients (36.8%), including 16 hypoechoic (45.7%), 4 hyperechoic (11.4%), 10 isoechoic (28.6%) and 5 mixed hetero-echoic lesions (14.3%). Of the 35 PCa cases, 17 (46.2%) were within T2b, 70.6% (12/17) of which were detected by lesion-directed biopsy and 29.4% (5/17) by sextant biopsy, the former obviously higher than the latter (P < 0.05).</p><p><b>CONCLUSION</b>Lesion-directed prostate biopsy under TRUS can significantly improve the early diagnosis of prostate cancer, increase convenience and reduce patients' pain, but is not sufficient to replace traditional sextant biopsy.</p>