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Castration-resistant prostate cancer (CRPC) almost invariably occurs after androgen-deprivation therapy (ADT) for the advanced metastatic disease. It is generally believed that among multiple mechanisms and signaling pathways, CRPC is significantly driven by the reactivation of androgen receptor (AR) signaling in ADT-treated patients with castrate levels of androgen, partially at least mediated by the androgen biosynthesis within the tumor, also known as intratumoral or intraprostatic androgen biosynthesis. Steroidogenic enzymes, such as CYP11A1, CYP17A1, HSD3B1, AKR1C3 and SRD5A, are essential to catalyze the conversion of the initial substrate cholesterol into potent androgens that confers the CRPC progression. Accumulating evidences indicate that many steroidogenic enzymes are upregulated in the progression setting; however, little is known about the dysregulation of these enzymes in CRPC. Orphan nuclear receptors (ONRs) are members of the nuclear receptor superfamily, of which endogenous physiological ligands are unknown and which are constitutively active independent of any physiological ligands. Studies have validated that besides AR, ONRs could be the potential therapeutic targets for prostate cancer, particularly the lethal CRPC progression. Early studies reveal that ONRs play crucial roles in the transcriptional regulation of steroidogenic enzyme genes. Notably, we and others show that three distinct ONRs, including liver receptor homolog-1 (LRH-1, NR5A2), steroidogenic factor 1 (SF-1, AD4BP, NR5A1) and estrogen-related receptor α (ERRα, NR3B1), can contribute to the CRPC progression by promotion of the intratumoral androgen synthesis via their direct transcriptional regulation on multiple steroidogenic enzymes. This review presents an overview of the current understanding on the intratumoral androgen biosynthesis in CRPC, with a special focus on the emerging roles of ONRs in this process.

Prostate cancer (PCa) is a malignant tumor with an extremely high prevalence. Doxorubicin is the first-line clinical treatment for castration-resistant PCa. Clinically, relapse is almost inevitable due to the cancer cells' increasing resistance to doxorubicin. Our previous studies have revealed that retinoic acid-related orphan nuclear receptor γ (RORγ) is a key protein for cancer progression and a promising target for PCa therapy. Though, RORγ's role and mechanism in doxorubicin-resistant PCa remain unclear. To study the mechanism of doxorubicin resistance, we generated a doxorubicin-resistant PCa cell line C4-2B (C4-2B DoxR) in this study, by culturing cells in an increasing doxorubicin concentration. Here, we show that RORγ expression was upregulated in C4-2B DoxR cells compared with that in normal C4-2B cells. The RORγ-stably-overexpressing PCa cell line constructed by lentiviral transfection showed an obvious improvement in doxorubicin resistance and a trend toward castration resistance. Furthermore, RORγ-specific small molecule inhibitors XY018, GSK805, and SR2211 can significantly inhibit the proliferation of C4-2B DoxR cells and promote their apoptosis. Collectively, these results have demonstrated the correlation between the upregulation of RORγ and the development of PCa's doxorubicin resistance, thus providing new ideas for solving the problem of chemotherapy drug resistance in PCa.

To investigated the association between serum total testosterone and Gleason score upgrading of low-risk prostate cancer after radical prostatectomy (RP).Medline, Web of Science, Embase, and Cochrane Library databases were searched to identify eligible studies published before October 2021. Multivariate adjusted odds ratios (ORs) and associated 95% confidence intervals (CIs) were calculated using random or fixed effects models.Five studies comprising 1,203 low-risk prostate cancer patients were included. The results showed that low serum total testosterone (300 ng/dL) is associated with a high rate of Gleason score upgrading after RP (OR, 2.3; 95% CI, 1.38-3.83; p0.001; I², 92.2%). Notably, sensitivity and meta-regression analyses further strengthen the reliability of our results.Our results support the idea that low serum total testosterone is associated with a high rate of Gleason score upgrading in prostate cancer patients after RP. It is beneficial for urologist to ensure close monitoring of prostate-specific antigen levels and imaging examination when choosing non-RP treatment for low-risk prostate cancer patients.

Background Zoledronic acid (ZA) does not improve the overall survival (OS) of metastatic castration-resistant prostate cancer (mCRPC); however, little is known about the efficacy of ZA in to hormone-sensitive prostate cancer (HSPC), metastatic hormone-sensitive prostate cancer (mHSPC), and non- metastatic castration-resistant prostate cancer (nmCRPC). Therefore, we assessed the efficacy of ZA in patients with prostate cancer (PCa) and different disease statuses. Methods Fifteen eligible randomized-control trials (RCTs) with ZA intervention, including 8280 participants with HSPC, mHSPC, nmCRPC, and mCRPC, were analyzed. The primary and secondary outcome were overall survival(OS), and skeletal-related events (SREs), and bone mineral density (BMD). Results The participants included 8280 men (7856 non-Asian and 424 Asian). Seven trials yielded a pooled hazard ratio (HR) of 0.95 (0.88, 1.03; P = 0.19) for OS. Subgroup analysis revealed no significant improvement in OS in the HSPC, castration-resistant prostate cancer (CRPC), M0 and M1(bone metastasis) groups, with pooled HR (95%CI) of 0.96 (0.88,1.05), 0.78 (0.46,1.33), 0.95 (0.81,1.13), 0.85 (0.69,1.04) respectively. The Asian group exhibited improved in OS with an HR of 0.67 (0.48, 0.95; P = 0.02), whereas the non-Asian group showed no improvement in OS with an HR of 0.97 (0.90, 1.06; P = 0.52). Five trials yielded pooled odds ratio (OR) of 0.65 (0.45, 0.95; P = 0.02) for SREs. In the subgroup, SREs were significantly decreased in the M1 and Asian groups with ORs of 0.65 (0.45, 0.95; P = 0.02) and 0.42 (0.24, 0.71; P = 0.001), respectively. Six trials yielded a pooled mean difference (MD) of 8.08 (5.79, 10.37; P < 0.001) for BMD. In the HSPC we observed a stable improvement in increased BMD percentage with an MD (95%CI) of 6.65 (5.67, 7.62) (P = 0.001). Conclusions ZA intervention does not significantly improve OS in patients with prostate cancer (HSPC, CRPC, M0, M1) but probably improves OS in the Asian populations. M1 and Asian groups had exhibit a significant reduction in SREs regardless of the HSPC or CRPC status after ZA administration. Moreover, ZA treatment increases BMD percentage.

We aimed to determine the cancer detection rate and complications of transrectal prostate biopsy (TRBx) and transperineal prostate biopsy (TPBx) in the hospital. However, given the use of antibiotic prophylaxis in TPBx remains controversial according to the current guidelines, we also investigated the safety and side effects of TPBx with and without antibiotic prophylaxis.A total of 777 patients who underwent prostate biopsy were enrolled in this study in accordance with the criteria. The primary outcome was pooled infectious complications (sepsis, fever, symptomatic urinary tract infection and urinary retention), and the secondary outcome was prostate cancer detection rate.Findings showed that TPBx and TRBx were equivalent in terms of prostate cancer detection rate (TPBx: 50.4% vs. TRBx: 47.3%; P = 0.424) and urinary retention (TPBx: 5% vs. TRBx: 6.3%; P = 0.451). However, TRBx had significantly higher incidences of sepsis (risk ratios, RR: 3.65, 95% confidence interval [CI]: 1.21-11.03; P = 0.014) and symptomatic urinary tract infection (RR: 3.04, 95% CI: 1.07-8.66; P = 0.029) than TPBx. Notably, for TPBx, patients who received a single dose of cephazolin prophylaxis were not associated with the risk of sepsis (RR: 0.78, 95% CI: 0.13-4.63; P = 0.783) and symptomatic urinary tract infection (RR: 1.17, 95% CI: 0.24-5.74; P = 0.848) in contrast to patients who did not receive any antibiotic prophylaxis. Meanwhile, no effects on prostate cancer detection rate and urinary retention were observed in the TPBx group.Our findings indicated that TPBx significantly reduced infectious complications compared with TRBx and should therefore be preferred. Importantly, we need to re-examine whether the antibiotic prophylaxis should be routinely applied before TPBx in consideration of increasing antibiotic resistance. This result complements the current national guidelines. Nevertheless, future studies on this topic with improved quality and increased sample size are still needed to minimise bacterial resistance.

To evaluate predictive factors affecting the stone-free rates (SFR) and complications of minimally invasive percutaneous nephrolithotomy (MPCNL) under local infiltration anesthesia (LIA) METHODS: A retrospective analysis was conducted on 976 consecutive patients who underwent MPCNL under LIA from January 2015 to June 2018. Postoperative complications were classified according to modified Clavien classification system. Univariate and multivariate logistic regression analyses were used to determine factors affecting SFR and complications.The pain was acceptable with postoperative visual analog scale (VAS) scores being 3.58, 2.99, 2.25, and 2.07 after 0, 6, 24, and 48 h, respectively. The SFR after primary MPCNL reached 85.7%. Postoperative complications were recorded in 77 patients (7.9%). In the univariate logistic analysis, larger stone size, staghorn stone, and multiple calyxes were significantly associated with lower SFR. The higher American Society of Anesthesiologists (ASA) score, staghorn stone, positive urine culture, multiple tracts, and longer operation time were associated with occurrence of complications. However, hydronephrosis was associated with lower complication rate. Multivariate analysis indicated that larger stone size (P 0.001) and staghorn stone (P 0.001) were associated with lower SFR, while development of complications was independently influenced by higher ASA score (P = 0.002), multiple tract (P = 0.004), and staghorn stone (P = 0.028).MPCNL can be safely and effectively performed under LIA. Stone size and staghorn stone are factors associated with SFR while ASA score, multiple tracts, and staghorn stone are associated with the development of complications. For the first time, we developed a model to predict the SFR and complications in MPCNL under LIA.

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The impact of marital status on the prognosis amongst patients diagnosed with prostate cancer remains controversial. Thus, a meta-analysis was performed to determine whether marital status can influence the prognosis in patients with prostate cancer.Literature search of the MEDLINE, PsycINFO, Embase and Cochrane Library databases was conducted to identify eligible studies published before April 2020. Multivariate adjusted risk estimates and corresponding 95% confidence intervals (CIs) were extracted and calculated using the random effects model.A total of 11 observational studies comprising 1,457,799 patients diagnosed with prostate cancer were identified. Results indicated that unmarried status (separated, divorced, widowed or never married) was associated with an increased risk of all-cause mortality (hazard ratio, HR = 1.39, 95% CI: 1.30-1.50; P.001; I2 = 92.2%) compared with married status, especially for divorced and never-married patients. Similarly, being unmarried had an elevated risk of cancer-specific mortality (HR = 1.29, 95% CI: 1.17-1.41; P.001; I2 = 82.5%) in patients with prostate cancer. A significant difference was also observed between unmarried status and shorter overall survival (HR = 1.37, 95% CI: 1.20-1.56; P.001; I2 = 94.5%).Results demonstrated that unmarried status is associated with a worse prognosis regarding mortality and survival in patients diagnosed with prostate cancer, particularly in divorced and never-married patients. Hence, further research should explore the potential mechanisms which can benefit the development of novel, more personalised management methods for unmarried patients with prostate cancer.

Background: Periodontal disease is reportedly associated with the risk of various systemic diseases, including pancreatic and lung cancers. However, its association with prostate cancer remains inconclusive. Herein, we explored the association of periodontal disease with the risk of prostate cancer through a meta-analysis. Materials and Methods: MEDLINE, Embase, Web of Sciences and Cochrane Library databases were searched for eligible publications up to April 2020. Multivariate adjusted risk estimates with corresponding 95% confidence intervals (CIs) were extracted and calculated using random- or fixed-effect models. Results: Nine cohort studies involving 3.353 prostate cancer cases with 440.911 participants were identified and included in the meta-analysis. We found that periodontal disease significantly increased the risk of prostate cancer by 1.40-fold (hazard ratio [HR]=1.40, 95% CI: 1.16-1.70; P=0.001; I2=76.1%) compared with normal condition. Interestingly, the risk of developing prostate cancer was not significant in patients treated with periodontal therapy (HR=1.22, 95% CI: 0.86-1.73; P=0.272; I2=65.2%). The results of subgroup analyses were also consistent and significant when stratified by study design and follow-up period, whereas conflicting results were observed in periodontal disease ascertainment stratification. These findings were robust as indicated by sensitivity analyses. Conclusions: Periodontal disease was associated with the increased risk of prostate cancer, whereas no significant association was observed in patients treated with periodontal therapy. Hence, the awareness and importance for maintaining oral health should be improved, and the underlying mechanisms linking periodontal disease and prostate cancer should be fully explored in future research.

Patients with bladder cancer have a high risk of suicide. This study aimed to assess how bladder cancer increases suicide risk and to identify the demographic and clinical factors associated with suicidal death among patients with bladder cancer.Literature search of MEDLINE, PsycINFO, Embase, Web of Sciences and Cochrane Library databases was conducted up to April 2020 to identify eligible studies related to the incidence and risk factors of suicide after bladder cancer diagnosis. Summary multivariate-adjusted risk estimates and their associated 95% confidence intervals (CIs) were calculated using inverse variance method with random or fixed-effect modeling.Five retrospective cohorts comprising 563,680 patients with bladder cancer were included. Higher risk of suicide by 1.90-fold was observed among patients with bladder cancer (hazard ratio, HR = 1.90, 95% CI: 1.29-2.81; P = 0.001; ISuicide risk is increased among patients with bladder cancer, particularly those aged 70 years or older, unmarried and those with regional bladder cancer. Hence, early psychological support must be provided during the follow-up period of these special populations with a high suicide risk.

Prostate cancer stem cells (PCSCs) play a critical role in prostate cancer progression and metastasis, which remains an obstacle for successful prostate cancer treatment. Tumor-associated macrophages (TAMs) are the most abundant immune cell population within the tumor microenvironment (TME). Systematic investigation of the interaction and network signaling between PCSCs and TAMs may help in searching for the critical target to suppress PCSCs and metastasis. Herein, we demonstrated that TAMs-secreted CCL5 could significantly promote the migration, invasion, epithelial–mesenchymal transition (EMT) of prostate cancer cells as well as the self-renewal of PCSCs in vitro. QPCR screening validated STAT3 as the most significant response gene in prostate cancer cells following CCL5 treatment. RNA-sequencing and mechanistic explorations further revealed that CCL5 could promote PCSCs self-renewal and prostate cancer metastasis via activating the β-catenin/STAT3 signaling. Notably, CCL5 knockdown in TAMs not only significantly suppressed prostate cancer xenografts growth and bone metastasis but also inhibited the self-renewal and tumorigenicity of PCSCs in vivo. Finally, clinical investigations and bioinformatic analysis suggested that high CCL5 expression was significantly correlated with high Gleason grade, poor prognosis, metastasis as well as increased PCSCs activity in prostate cancer patients. Taken together, TAMs/CCL5 could promote PCSCs self-renewal and prostate cancer metastasis via activating β-catenin/STAT3 signaling. This study provides a novel rationale for developing TAMs/CCL5 as a potential molecular target for PCSCs elimination and metastatic prostate cancer prevention.

Background/Aims: Polyphyllin I (PPI), one of the steroidal saponins in Paris polyphylla, reportedly exhibits antitumor effects. However, the detailed mechanism underlying PPI, particularly in enhancing the effect of the androgen receptor inhibitor enzalutamide in controlling castration-resistant prostate cancer (CRPC) has not been explored. Methods: Cell viability and cell cycle distribution were measured using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) expression was measured by quantitative real time-PCR (qRT-PCR). Western blot analysis was performed to determine the protein expression levels of MUC1, p65, and p50. Silencing of HOTAIR was evaluated using the siRNA procedure. The promoter activity of the MUC1 gene was determined using Secrete-Pair Dual Luminescence Assay Kit. Exogenous expression of HOTAIR, p65, and MUC1 was conducted by transient transfection assay. A xenograft tumor model in nude mice was used to further evaluate the effect of the combination of PPI and enzalutamide in vivo. Results: We showed that PPI significantly inhibited growth and induced cell cycle arrest in CRPC cells. PPI also decreased p65 and MUC1 protein expression and reduced HOTAIR expression. Exogenously expressed p65 resisted the PPI-inhibited expression of HOTAIR, whereas silenced HOTAIR reduced MUC1 protein but exerted no effect on the expression of p65 and p50 proteins. Conversely, exogenously expressed HOTAIR resisted the PPI-inhibited MUC1 protein expression, and excessive expression of MUC1 antagonized the PPI-inhibited cell growth. Notably, PPI combined with enzalutamide exerted a synergistic effect. Consistent with this finding, PPI inhibited tumor growth, HOTAIR expression, as well as p65 and MUC1 protein expressions in vivo. Conclusions: Our results indicate that PPI inhibits the growth of CRPC cells by inhibiting p65 protein and concomitantly reducing HOTAIR expression, thereby suppressing MUC1 gene expression. The novel regulatory interaction of p65 and HOTAIR converge in the inhibition of MUC1 expression and overall PPI response. The combination of PPI and enzalutamide exhibits synergy. This study reveals a novel mechanism underlying the synergistic inhibitory effect of PPI and enzalutamide on the growth of CRPC cells.

Desmosium styracifolium (D. styracifolium), which is considered as a Chinese herbal medicine, has been reported to treat the kidney stone diseases. However, the potential phytochemically active components and the underlying mechanisms associated with its efficacy in targeting urolithiasis remain to be elucidated. This study aims to investigate the anti-urolithiatic effect of total flavonoids of D. styracifolium (TFDS) on calcium oxalate (CaOx) renal stones in Sprague-Dawley rats. Animal models of CaOx urolithiasis were established in male Sprague-Dawley rats by adding 5% w/w hydroxy-L-proline (HLP) in regular rat chow. The TFDS orally at 100, 400 mg/kg, respectively, were administered along with HLP for 28 days. At the end of 28 days of treatment, urine and serum samples were collected for crystalluria determination and various biochemical analysis. Kidney tissues were isolated and processed for antioxidant parameters measurement and histopathological examinations. HLP-induced hyperoxaluria alone reliably caused CaOx nephrolithiasis in rats. We showed that TFDS significantly reduced crystalluria and CaOx crystal deposits in the kidney sections as compared to untreated HLP group. Also, TFDS was observed to decrease urinary oxalate excretion, alleviate the pro-acidosis condition, improve the impaired renal functions and renal epithelial cell injury. Moreover, TFDS protected against the oxidative stress changes via reducing MDA content, increasing CAT and GSH-Px activities in renal homogenate, as well as attenuating the expression of MCP-1, OPN and TGF-β proteins. These results indicated that TFDS had beneficial effect on inhibition of CaOx formation in the rat kidney probably through a combination of antioxidant, anti-inflammatory, urine alkalinizing activities, and lowering the concentration of urinary stone-forming constituents. Thus, TFDS might have clinical implications in preventing oxidative renal cell injury and, ultimately, kidney stone formation. The data provide a rationale for the medicinal use of TFDS in nephrolithiasis and identify this agent as a potential source of new antiurolithic drugs.

Endocrine therapies (e.g. tamoxifen and aromatase inhibitors) targeting estrogen action are effective in decreasing mortality of breast cancer. However, their efficacy is limited by intrinsic and acquired resistance. Our previous study demonstrated that overexpression of a histone methyltransferase NSD2 drives tamoxifen resistance in breast cancer cells and that NSD2 is a potential biomarker of tamoxifen resistant breast cancer. Here, we found that DZNep, an indirect inhibitor of histone methyltransferases, potently induces the degradation of NSD2 protein and inhibits the expression of NSD2 target genes (HK2, G6PD, GLUT1 and TIGAR) involved in the pentose phosphate pathway (PPP). DZNep treatment of tamoxifen-resistant breast cancer cells and xenograft tumors also strongly inhibits tumor growth and the cancer cell survival through decreasing cell production of NADPH and glutathione (GSH) and invoking elevated ROS to cause apoptosis. These findings suggest that DZNep-like agents can be developed to target NSD2 histone methyltransferase for effective treatment of tamoxifen-resistant breast cancer.

Aim Sarcopenia as a reliable prognostic predictor in urologic oncology surgery remains controversial, and no consensus amongst researchers exists regarding the management of patients with sarcopenia. This meta-analysis was conducted to investigate the association between sarcopenia and postoperative outcomes after urologic oncology surgery. Methods A systematic search in MEDLINE (via PubMed), Embase, Web of Science and Cochrane Library databases was conducted to identify the potential studies published before August 2019. Odds ratios and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated through inverse variance with random or fixed effects models. Results Seventeen retrospective cohorts comprising 3,948 patients were included with sarcopenia prevalence between 25% and 68.9%. Patients with sarcopenia had significantly shorter overall survival (OS; HR = 2.06, 95% CI: 1.44–2.95; P Conclusions Sarcopenia is an independent poor prognostic factor for patients undergoing urologic oncology surgery, particularly postoperative risks of short survival and increased mortality. Thus, preoperative sarcopenia evaluation can provide clinicians with important information to guide and individualise patient management and improve surgical outcomes.

This study aims to design a novel semirigid ureterorenoscope with irrigation and vacuum suction system and a modified ureteral access sheath (UAS) named Sotn ureterorenoscope® (Sotn=ShuoTong Medical Company) to overcome the deficiencies of the current procedure and to improve the efficiency and safety of using Sotn ureterorenoscope® for treatment of upper urinary calculi.Fifty-eight patients, comprising 31 males and 27 females, were evaluated. The medical records of 58 patients with upper urinary calculi treated with Sotn ureterorenoscope® from March 2015 to June 2017 were retrospectively reviewed at the Second Affiliate Hospital of Guangzhou University of Chinese Medicine in China. The primary outcome was stone-free rate (SFR) assessed by computed tomography on the 1st day and one month after treatment. The secondary outcome was postoperative complication rate.The mean and SD of operative duration was 78.5 (30.4) min, and the mean and SD of stone size was 15.6 (5.6) mm. The primary overall SFR was 89.7% (52/58) and 100% at 1 month follow-up. Complication, which was Clavien I (minor fever managed by antipyretic therapy), was detected in 1.7% (1/58) of the patients.Sotn ureterorenoscope® is technically feasible, efficacious and safe for treatment of upper urinary calculi because of its advantages of high SFR and low complication rates.

Whether the diagnosis of prostate cancer is a contributory psychological stress that causes excess risk of suicide among affected men remains controversial. We performed a meta-analysis of previous studies to investigate suicide incidence and associated risk factors among men diagnosed with prostate cancer. The MEDLINE, Embase, Cochrane Library, and PsycINFO databases were searched to identify eligible studies published before April 2018. The inverse variance method with random-effects modeling was used to calculate summary relative risks (RRs) and their associated 95% confidence intervals (CIs). Eight observational studies involving 1,281,393 men diagnosed with prostate cancer and 842,294 matched prostate cancer-free men were included. An overall increased RR of suicide of 2.01 (95% CI: 1.52–2.64; P

Whether androgen deprivation therapy (ADT) causes excess thromboembolic events (TEs) in men with prostate cancer (PCa) remains controversial and is the subject of the US Food and Drug Administration safety warning. This study aims to perform a systematic review and meta-analysis on previous studies to determine whether ADT is associated with TEs in men with PCa. Medline, Embase, and Cochrane Library databases were searched for relevant studies. These studies comprised those that compared ADT versus control to treat PCa, reported TEs as outcome, and were published before January 2018. Multivariate adjusted hazard ratios (HRs) and associated 95% confidence intervals (CIs) were calculated using random- or fixed-effects models. Five retrospective population-based cohort studies involving 170,851 ADT users and 256,704 non-ADT users were identified. Deep venous thrombosis (DVT) was found significantly associated with gonadotropin-releasing hormone (GnRH) agonists alone (HR = 1.47, 95% CI: 1.07–2.03; P = 0.017; I2 = 96.3%), GnRH agonists plus oral antiandrogen (AA) (HR = 2.55, 95% CI: 2.21–2.94; P

Background Polyphyllin I (PPI), one of the steroidal saponins in paris polyphylla, has been reported to exhibit antitumor effects. However, the detailed molecular mechanism underlying this has not been elucidated. Methods Cell viability and cell cycle distribution were measured using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and Flow cytometry assays, respectively. Cell invasion and migration were examined by Transwell invasion and wound healing assays. Western blot analysis was performed to examine the protein expressions of zeste homolog 2 (EZH2), DNA methyltransferase 1 (DNMT1). QRT-PCR was used to examine the levels of long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR). Small interfering RNAs (siRNAs) method was used to knockdown HOTAIR. Exogenously expressions of HOTAIR, DNMT1 and EZH2 were carried out by Transient transfection assays. EZH2 promoter activity was measured by Secrete-Pair Dual Luminescence Assay Kit. A nude mice xenograft model was used to confirm the findings in vitro. Results We showed that PPI significantly inhibited growth, induced cell cycle arrest of castration-resistant prostate cancer (CRPC) cells. In addition, PPI also reduced the migration and invasion in CRPC cells. In mechanism, we found that PPI decreased the protein expressions of EZH2, DNMT1 and levels of HOTAIR. Interestingly, silenced HOTAIR reduced EZH2 and DNMT1 protein expressions. On the contrary, exogenously expressed HOTAIR resisted PPI-inhibited EZH2 and DNMT1 protein expressions, EZH2 promoter activity and cell growth. Moreover, excessive EZH2 antagonized PPI-suppressed DNMT1 protein expression or vice versa. Consistent with this, PPI inhibited tumor growth, HOTAIR, the protein expressions of DNMT1 and EZH2 in vivo. Conclusion Our results show that PPI inhibits growth of CRPC cells through inhibition of HOTAIR expression, subsequently; this results in the repression of DNMT1 and EZH2 expressions. The interactions among HOTAIR, DNMT1 and EZH2, and reciprocal regulation of DNMT1 and EZH2 contribute to the overall responses of PPI. This study reveals a novel mechanism for HOTAIR-mediated regulating DNMT1 and EZH2 in response to PPI in inhibition of the growth of CRPC cells.

Prostate cancer is the second most common cause of cancer-related deaths worldwide. The mucin 1 (MUC1) oncoprotein is highly expressed in human prostate cancers with aggressive features. However, the role for MUC1 in occurrence and progression of castration-resistant prostate cancer (CRPC) remained elusive. In this study, we showed that solamargine, a major steroidal alkaloid glycoside, inhibited the growth of CRPC cells, which was enhanced in the presence of metformin. Furthermore, we found that solamargine increased phosphorylation of AMPKα, whereas reducing the protein expression and promoter activity of MUC1. A greater effect was observed in the presence of metformin. In addition, solamargine reduced NF-κB subunit p65 protein expression. Exogenously expressed p65 resisted solamargine-reduced MUC1 protein and promoter activity. Interestingly, exogenously expressed MUC1 attenuated solamargine-stimulated phosphorylation of AMPKα and, more importantly reversed solamargine-inhibited cell growth. Finally, solamargine increased phosphorylation of AMPKα, while inhibiting MUC1, p65 and tumor growth were observed in vivo. Overall, our results show that solamargine inhibits the growth of CRPC cells through AMPKα-mediated inhibition of p65, followed by reduction of MUC1 expression in vitro and in vivo. More importantly, metformin facilitates the antitumor effect of solamargine on CRPC cells.

Supplemental Digital Content is available in the text, Background: The association between serum C-peptide concentration and prostate cancer remains unexplored. Therefore, we conducted a meta-analysis to assess whether C-peptide serum concentrations are associated with increased prostate cancer risk. Methods: Several databases were searched to identify relevant original research articles published before November 2017. Random-effects models were used to summarize the overall estimate of the multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Results: Nine observational studies involving 11,796 participants were identified. The findings of the meta-analysis indicated that the association between serum C-peptide concentration and prostate cancer was not significant (OR: 1.15, 95% CI: 0.85–1.54; for highest versus lowest category C-peptide concentrations, P = .376). The associations were inconsistent, as indicated by subgroup analyses. Conclusion: Although our findings provided no support for the hypothesis that serum C-peptide concentration is associated with excess risk of prostate cancer, people must pay attention to this aspect and increase physical activity or modify dietary habits to constrain insulin secretion, which possibly lead to decreased incidence of prostate cancer. Hence, well-designed observational studies involving different ethnic populations are still needed.