Changhao Chen

Adjuvant and Salvage Radiotherapy after Prostatectomy: A Systematic Review and Meta-Analysis

Purpose In men with adverse prognostic factors (APFs) after radical prostatectomy (RP), the most appropriate timing to administer radiotherapy remains a subject for debate. We conducted a systemic review and meta-analysis to evaluate the therapeutic strategies: adjuvant radiotherapy (ART) and salvage radiotherapy (SRT). Materials and Methods We comprehensively searched PubMed, EMBASE, Web of Science and the Cochrane Library and performed the meta-analysis of all randomized controlled trials (RCTs) and retrospective comparative studies assessing the prognostic factors of ART and SRT. Results Between May 1998 and July 2012, 2 matched control studies and 16 retrospective studies including a total of 2629 cases were identified (1404 cases for ART and 1185 cases for SRT). 5-year biochemical failure free survival (BFFS) for ART was longer than that for SRT (Hazard Ratio [HR]: 0.37; 95% CI, 0.30–0.46; p<0.00001, I2 = 0%). 3-year BFFS was significantly longer in the ART (HR: 0.38; 95% CI, 0.28–0.52; p<0.00001, I2 = 0%). Overall survival (OS) was also better in the ART (RR: 0.53; 95% CI, 0.41–0.68; p<0.00001, I2 = 0%), as did disease free survival (DFS) (RR: 0.53; 95% CI, 0.43–0.66; p<0.00001, I2 = 0%). Exploratory subgroup analysis and sensitivity analysis revealed the similar results with original analysis. Conclusion ART therapy offers a safe and efficient alternative to SRT with longer 3-year and 5-year BFFS, better OS and DFS. Our recommendation is to suggest ART for patients with APFs and may reduce the need for SRT. Given the inherent limitations of the included studies, future well-designed RCTs are awaited to confirm and update this analysis.

An NKX3.1 binding site polymorphism in the l-plastin promoter leads to differential gene expression in human prostate cancer

The L‐plastin gene is involved in the invasion and metastasis of prostate cancer. However, the molecular mechanisms underlying L‐plastin transcription are unclear. We hypothesize that the occurrence of polymorphic genetic variations in the L‐plastin promoter might affect an individuals susceptibility to prostate cancer. In this study, we identified a single nucleotide polymorphism (SNP) at position −1,687 in the L‐plastin promoter by genotype sequencing. The SNP −1,687 showed different transcriptional activity in the luciferase assay in vitro. The TRANSFAC software was applied to predict the multiple cis‐elements, and luciferase assay was used to further identify the L‐plastin regulatory region. We performed EMSAs, supershift assays and ChIP‐qPCR demonstrated that the transcriptional suppressor NKX3.1 binds to the SNP site of the L‐plastin promoter. SNP −1,687 (T/T) led to an increase in the affinity of NKX3.1 for L‐plastin promoter, resulted in lower levels of L‐plastin RNA and protein expression. Furthermore, we collected and sequenced samples from 640 individuals (372 prostate cancer patients and 268 healthy controls) from 2000 to 2013. The results showed that SNP −1,687 (T/T) occurred more frequently in the healthy individuals than that in the prostate cancer patients compared to SNP −1,687 (C/C). Similarly, SNP −1,687 (T/T) genotype occurred more frequently compared to SNP −1,687 (C/C) genotype in the patients with low and moderately differentiated tumors. In conclusion, SNP −1,687, located in the NKX3.1 binding site within the L‐plastin promoter, might reduce the expression of L‐plastin and potentially decrease the tumorigenesis and progression of prostate cancer. This SNP could be a potential prognostic factor for prostate cancer.

Gene expression profiling of WDR5 regulated genes in bladder cancer

WD repeat domain 5 (WDR5) plays an important role in various biological functions through the epigenetic regulation of gene transcription (Wysocka et al., 2005 [1]; Sandstrom et al., 2014[2]; Ang et al., 2011[3]). Recently, our study found that WDR5 was upregulated in bladder cancer tissues, promoted bladder cancer cell proliferation, self-renewal and chemoresistance to cisplatin in bladder cancer cells in vitro, and tumor growth in vivo (Chen et al., 2015). To gain a molecular understanding of the role of WDR5 in promoting bladder cancer, we performed a genome-wide analysis on WDR5 knockdown by microarray gene expression profiling. Here we provide detailed experimental methods and analysis for the microarray data, which have been deposited into Gene Expression Omnibus (GEO): GSE59132.

Long noncoding RNA BLACAT2 promotes bladder cancer–associated lymphangiogenesis and lymphatic metastasis

The prognosis for bladder cancer patients with lymph node (LN) metastasis is dismal and only minimally improved by current treatment modalities. Elucidation of the molecular mechanisms that underlie LN metastasis may provide clinical therapeutic strategies for LN-metastatic bladder cancer. Here, we report that a long noncoding RNA LINC00958, which we have termed bladder cancer–associated transcript 2 (BLACAT2), was markedly upregulated in LN-metastatic bladder cancer and correlated with LN metastasis. Overexpression of BLACAT2 promoted bladder cancer–associated lymphangiogenesis and lymphatic metastasis in both cultured bladder cancer cell lines and mouse models. Furthermore, we demonstrate that BLACAT2 epigenetically upregulated VEGF-C expression by directly associating with WDR5, a core subunit of human H3K4 methyltransferase complexes. Importantly, administration of an anti–VEGF-C antibody inhibited LN metastasis in BLACAT2-overexpressing bladder cancer. Taken together, these findings uncover a molecular mechanism in the lymphatic metastasis of bladder cancer and indicate that BLACAT2 may represent a target for clinical intervention in LN-metastatic bladder cancer.

Heterogeneous nuclear ribonucleoprotein K is associated with poor prognosis and regulates proliferation and apoptosis in bladder cancer.

Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is an essential RNA‐ and DNA‐binding protein that regulates diverse biological events, especially DNA transcription. hnRNPK overexpression is related to tumorigenesis in several cancers. However, both the expression patterns and biological mechanisms of hnRNPK in bladder cancer are unclear. We investigated hnRNPK expression by immunohistochemistry in 188 patients with bladder cancer, and found that hnRNPK expression levels were significantly increased in bladder cancer tissues and that high‐hnRNPK expression was closely correlated with poor prognosis. Loss‐ and gain‐of‐function assays demonstrated that hnRNPK promoted proliferation, anti‐apoptosis, and chemoresistance in bladder cancer cells in vitro, and hnRNPK knockdown suppressed tumorigenicity in vivo. Mechanistically, hnRNPK regulated various functions in bladder cancer by directly mediating cyclin D1, G0/G1 switch 2 (G0S2), XIAP‐associated factor 1, and ERCC excision repair 4, endonuclease catalytic subunit (ERCC4) transcription. In conclusion, we discovered that hnRNPK plays an important role in bladder cancer, suggesting that it is a potential prognostic marker and a promising target for treating bladder cancer.

The long non-coding RNA FOXD2-AS1 promotes bladder cancer progression and recurrence through a positive feedback loop with Akt and E2F1

Long non-coding RNAs (lncRNAs) have been identified as significant regulators in cancer progression. Positive feedback loops between lncRNAs and transcription factors have attracted increasing attention. Akt pathway plays a crucial role in bladder cancer growth and recurrence. In the present study, we demonstrate a novel regulatory pattern involving FOXD2-AS1, Akt, and E2F1. FOXD2-AS1 is highly expressed in bladder cancer and is associated with tumor stage, recurrence, and poor prognosis. Further experiments showed that FOXD2-AS1 promotes bladder cancer cell proliferation, migration, and invasion in vitro and in vivo. Microarray analysis demonstrated that FOXD2-AS1 negatively regulates the expression of Tribbles pseudokinase 3 (TRIB3), a negative regulator of Akt. Mechanistically, FOXD2-AS1 forms an RNA-DNA complex with the promoter of TRIB3, the transcriptional activity of which is subsequently repressed, and leads to the activation of Akt, which further increases the expression of E2F1, a vital transcription factor involved in the G/S transition. Interestingly, E2F1 could bind to the FOXD2-AS1 promoter region and subsequently enhance its transcriptional activity, indicating that FOXD2-AS1/Akt/E2F1 forms a feedback loop. In summary, this regulatory pattern of positive feedback may be a novel target for the treatment of bladder cancer and FOXD2-AS1 has the potential to be a new recurrence predictor.

Gemcitabine Compared With Gemcitabine and S-1 Combination Therapy in Advanced Pancreatic Cancer: A Systematic Review and Meta-Analysis.

AbstractSeveral reports suggest that gemcitabine (GEM) plus S-1 combination (GS) is associated to prolong the survival in patients with unresectable pancreatic cancer (PC). We conducted a systemic review and meta-analysis of studies comparing the safety and efficacy of GS versus GEM.Summary data from randomized trials and retrospective studies were searched in PubMed, EMBASE, Web of Science, and the Cochrane Library. Statistical analyses were conducted to calculate the hazard ratios (HRs) and relative risk (RR) with 95% confidence intervals (CIs) using random-effects models. Subgroup analyses based on the chemotherapy cycles were performed to explore the efficacy and toxicity for therapy. Sensitivity analyses were conducted by removing specific studies to assess the effects of study quality.Between January 2004 and August 2012, 4 RCTs and 2 retrospective studies including a total of 1025 cases were identified. The overall survival (OS) (HR: 0.82; 95% CI, 0.70–0.96; P = 0.01) and progression-free survival (PFS) (HR: 0.65; 95% CI, 0.55–0.77; P < 0.001) for the GS arm were significantly longer than the GEM arm. The differences in objective response rate (ORR) (RR: 1.24; 95% CI, 1.17–1.33; P < 0.001) and disease control rate (DCR) were also better in the GS arm (RR: 1.37; 95% CI, 1.19–1.59; P < 0.001). Grades 3 to 4 toxicities in both the groups were similar except neutropenia and diarrhea, which were more frequent in the GS arm (P < 0.001). In the subgroup analysis, the cycle for chemotherapy every 4 weeks has equivalent efficacy and less toxicity than regimens every 3 weeks in the GS arm.The current meta-analysis suggested that GEM significantly prolonged OS and PFS when added to S-1 combination in patients with unresectable PC. GS therapy also offers better ORR and DCR than GEM monotherapy and no unexpected toxicity was evident.

MP48-14 LONG NONCODING RNA LNCRNA-BNCA PROMOTES THE PROGRESSION OF BLADDER CANCER VIA REGULATING TRANSLATION OF P53

METHODS: We assessed the effects of FOXO1 inhibition via short hairpin RNA (shRNA) virus infection or inhibitor (AS1842856) treatment on bladder cancer cell proliferation (by MTT assay in the presence or absence of cisplatin), migration (by scratch wound healing assay), and invasion (by transwell invasion assay), apoptosis (by TUNEL assay), and the expression of their related molecules (by RTPCR). We also immunohistochemically stained for phospho-FOXO1 (pFOXO1), an inactive form of FOXO1, in tissue microarrays consisting of muscle-invasive bladder cancer specimens from patients who received at least 3 cycles of cisplatin þ gemcitabine neoadjuvant chemotherapy prior to radical cystectomy. RESULTS: FOXO1 silencing via its shRNA in AR-positive bladder cancer lines, UMUC3 and 647V-AR, resulted in significant increases in cell viability, migration, and invasion, and the expression of MMP-2/VEGF, as well as significant decreases in apoptosis and the expression of cyclin-dependent kinase inhibitors p21/p27. In addition, FOXO1 knockdown cells were significantly more resistant to cisplatin treatment at its pharmacological concentrations, compared with control cells. In these control FOXO1-positive lines, AS1842856 treatment also significantly reduced cisplatin sensitivity. Immunohistochemistry in transurethral resection specimens further showed p-FOXO1 positivity in 25 (58%) of 43 cases, including 7 (41%) of 17 responders to chemotherapy versus 18 (69%) of 26 non-responders (P1⁄40.068). CONCLUSIONS: FOXO1, as a tumor suppressor, appears to play an important role in bladder cancer progression and correlates with cisplatin sensitivity. Accordingly, FOXO1 stimulation, with or without AR inactivation, has the potential of being a therapeutic approach for bladder cancer and may also be useful for overcoming chemoresistance.

MP58-04 LONG NONCODING RNA LNMAT1 PROMOTES BLADDER CANCER LYMPHATIC METASTASIS VIA CCL2-DEPENDENT TUMOR-ASSOCIATED MACROPHAGE RECRUITMENT

genes in irradiated AR-positive cells, and HF antagonized the androgen effects. Finally, in xenograft-bearing mice, low-dose flutamide was found to enhance the cytotoxic effects of irradiation, and its tumor size was similar to that of AR knockdown line with radiation alone. CONCLUSIONS: These findings suggest that AR activity inversely correlates with sensitivity to radiotherapy in bladder cancer. Accordingly, anti-androgenic drugs may function as sensitizers of irradiation, especially in patients with AR-positive urothelial cancer.

MP99-07 AP4 PROMOTES PROLIFERATION AND METASTASIS OF CASTRATION-RESISTANT PROSTATE CANCER THROUGH BINDING AND UP-REGULATION OF L-PLASTIN

retention at DSB sites in prostate cancer cells, and also impaired recruitment of Ku70/Ku80 to DSB sites. The impaired recruitment of Ku70 and Ku80 proteins to DNA damage sites upon ELL2 knockdown was rescued by re-expression of an ELL2 transgene insensitive to siELL2. CONCLUSIONS: This study suggests that ELL2 is an important factor mediating androgen protection of DNA damage via Ku70/Ku80 in prostate cancer cells.