Trithorax-like group complex containing KDM6A acts antagonistically to Polycomb-repressive complex 2 (PRC2) containing EZH2 in maintaining the dynamics of the repression and activation of gene expression through H3K27 methylation. In urothelial bladder carcinoma, KDM6A (a H3K27 demethylase) is frequently mutated, but its functional consequences and therapeutic targetability remain unknown. About 70% of KDM6A mutations resulted in a total loss of expression and a consequent loss of demethylase function in this cancer type. Further transcriptome analysis found multiple deregulated pathways, especially PRC2/EZH2, in KDM6A-mutated urothelial bladder carcinoma. Chromatin immunoprecipitation sequencing analysis revealed enrichment of H3K27me3 at specific loci in KDM6A-null cells, including PRC2/EZH2 and their downstream targets. Consequently, we targeted EZH2 (an H3K27 methylase) and demonstrated that KDM6A-null urothelial bladder carcinoma cell lines were sensitive to EZH2 inhibition. Loss- and gain-of-function assays confirmed that cells with loss of KDM6A are vulnerable to EZH2. IGFBP3, a direct KDM6A/EZH2/H3K27me3 target, was up-regulated by EZH2 inhibition and contributed to the observed EZH2-dependent growth suppression in KDM6A-null cell lines. EZH2 inhibition delayed tumor onset in KDM6A-null cells and caused regression of KDM6A-null bladder tumors in both patient-derived and cell line xenograft models. In summary, our study demonstrates that inactivating mutations of KDM6A, which are common in urothelial bladder carcinoma, are potentially targetable by inhibiting EZH2.
Background: Aristolochic acid (AA) is a natural compound found in many plants of the Aristolochia genus, and these plants are widely used in traditional medicines for numerous conditions and for weight loss. Previous work has connected AA-mutagenesis to upper-tract urothelial cell carcinomas and hepatocellular carcinomas. We hypothesize that AA may also contribute to bladder cancer. Methods: Here, we investigated the involvement of AA-mutagenesis in bladder cancer by sequencing bladder tumor genomes from two patients with known exposure to AA. After detecting strong mutational signatures of AA exposure in these tumors, we exome-sequenced and analyzed an additional 11 bladder tumors and analyzed publicly available somatic mutation data from a further 336 bladder tumors. Results: The somatic mutations in the bladder tumors from the two patients with known AA exposure showed overwhelming AA signatures. We also detected evidence of AA exposure in 1 out of 11 bladder tumors from Singapore and in 3 out of 99 bladder tumors from China. In addition, 1 out of 194 bladder tumors from North America showed a pattern of mutations that might have resulted from exposure to an unknown mutagen with a heretofore undescribed pattern of A > T mutations. Besides the signature of AA exposure, the bladder tumors also showed the CpG > TpG and activated-APOBEC signatures, which have been previously reported in bladder cancer. Conclusions: This study demonstrates the utility of inferring mutagenic exposures from somatic mutation spectra. Moreover, AA exposure in bladder cancer appears to be more pervasive in the East, where traditional herbal medicine is more widely used. More broadly, our results suggest that AA exposure is more extensive than previously thought both in terms of populations at risk and in terms of types of cancers involved. This appears to be an important public health issue that should be addressed by further investigation and by primary prevention through regulation and education. In addition to opportunities for primary prevention, knowledge of AA exposure would provide opportunities for secondary prevention in the form of intensified screening of patients with known or suspected AA exposure.
The prevalence of depression in patients with cancer is high, especially for patients with advanced cancer. In this study, we evaluated the prevalence of depression in prostate cancer patients in Taiwan and the association between depression and mortality in prostate cancer. This study included 1101 newly diagnosed patients with prostate cancer. We tracked the medical information of these patients from diagnosis until the end of 2012. Patients were divided into two groups according to presence or absence of depression diagnosis, and were further divided into three stages by initial treatments: localized or locally advanced, metastatic, and castration-resistant prostate cancer. Of 1101 participants, 267 (24.3%) had depression. By the end of the follow-up period (M = 8.30 ± 3.12 years), 77 (28.8%) patients in the depression group and 194 (23.3%) in the non-depressed group died. Depression was associated with higher mortality risk, (aHR 1.37; 95% CI [ 1.04–1.80]; p value 0.01). Patients in the metastatic prostate cancer group with depression had a significantly higher mortality risk compared to the non-depressed group, (aHR, 1.49; 95% CI [1.05–2.11]; p value 0.02). The impact of depression on mortality risk was not significant in either the localized or locally advanced or the castration-resistant prostate cancer groups. Our study showed that depression is related to an increased mortality risk for patients with prostate cancer, especially for metastatic prostate cancer. These results indicate that urologists should pay attention to the mood and psychiatric disorders of patients with prostate cancer.
13 February 2018 in Journal of Medical Internet Research
Background: To assess the efficacy and outcomes of urgent superselective transcatheter arterial embolization for emergency patients with ruptured renal angiomyolipomas. Methods: During a 49-month period, all emergency patients with ruptured angiomyolipomas that underwent urgent superselective transcatheter arterial embolization within the first 24 hours of admission were enrolled in this study. In each case, clinical presentation, trauma history, success or failure of embolization, presence of postembolization syndrome, and the necessity of subsequent emergency surgery of nephron-sparing surgery, and partial or total nephrectomy were recorded and analyzed. Results: The sample population consisted of seven female patients with ruptured angiomyolipomas; mean age was 48 years. The initial presenting symptoms were flank pain (n = 7), hematuria (n = 5), and lower hematocrit (Hb <10; n = 7). All individuals had received blood transfusion before the embolization. Two were traffic crash victims admitted in shock. Successful embolization was achieved in all cases; however, postembolization syndrome was noted in four. There was no requirement for emergent surgery after embolization. Conclusions: Urgent superselective transcatheter arterial embolization was an effective treatment for our sample of emergency patients with ruptured renal angiomyolipomas where conservative supportive treatments had failed. There was no need of emergency surgery after embolization.
1 November 2017 in Biochemical and Biophysical Research Communications