Glycine Decarboxylase (GLDC) Plays a Crucial Role in Regulating Energy Metabolism, Invasion, Metastasis and Immune Escape for Prostate Cancer.

Glycine decarboxylase (GLDC) is one of the core enzymes for glycine metabolism, and its biological roles in prostate cancer (PCa) are unclear. First, we found that GLDC plays a central role in glycolysis in 540 TCGA PCa patients. Subsequently, a metabolomic microarray showed that GLDC enhanced aerobic glycolysis in PCa cells, and GLDC and its enzyme activity enhanced glucose uptake, lactate production and lactate dehydrogenase (LDH) activity in PCa cells. Next, we found that GLDC was highly expressed in PCa, was directly regulated by hypoxia-inducible factor (HIF1-α) and regulated downstream LDHA expression. In addition, GLDC and its enzyme activity showed a strong ability to promote the migration and invasion of PCa both in vivo and in vitro. Furthermore, we found that the GLDC-high group had a higher TP53 mutation frequency, lower CD8+ T-cell infiltration, higher immune checkpoint expression, and higher immune exclusion scores than the GLDC-low group. Finally, the GLDC-based prognostic risk model by applying LASSO Cox regression also showed good predictive power for the clinical characteristics and survival in PCa patients. This evidence indicates that GLDC plays crucial roles in glycolytic metabolism, invasion and metastasis, and immune escape in PCa, and it is a potential therapeutic target for prostate cancer.

Overexpression of SPHK1 associated with targeted therapy resistance in predicting poor prognosis in renal cell carcinoma.

Background: Sphingosine kinase 1 (SPHK1) is a key enzyme that catalyzes the phosphorylation of sphingosine. Recent studies reported SPHK1 to be associated with renal cell carcinoma (RCC) progression by inducing targeted therapy resistance. However, the expression and the clinical significance of SPHK1 on RCC in those having received targeted therapy have not been elucidated. The present study explored the expression of SPHK1 in RCC tissues from targeted therapy recipients, the correlation of SPHK1 with clinicopathological parameters, and the effect of SPHK1 on RCC patient prognosis. Methods: Differential gene expression analysis of RCC treated with and without targeted therapy was performed. The correlations of SPHK1 expression with clinical parameters of RCC were examined. Gene set enrichment analysis (GSEA) was performed to clarify the potential role of SPHK1 associated with targeted therapy resistance. The value of SPHK1 as a diagnostic marker for RCC was also evaluated. The Kaplan-Meier method was applied to analyze the correlation between SPHK1 expression and patient survival rate by using the clinical data from patients with RCC. Results: Significant overexpression of SPHK1 was detected in RCC treated with targeted therapy. SPHK1 expression was closely correlated with RCC progression-related clinicopathological parameters. Therefore, elevated SPHK1 could effectively diagnose RCC and distinguish RCC with an advanced clinical stage and a high pathological grade. SPHK1 was associated with the stemness of RCC cells via the activation of the Wnt, Hedgehog, or Notch signaling pathways in targeted drug-treated or untreated RCC. Survival analysis of a large cohort of RCC samples indicated overexpression of SPHK1 to be inversely correlated with the overall and disease-free survival of patients with RCC. Conclusions: Our study indicated that SPHK1 associated with targeted therapy resistance could serve as a potential prognostic marker and a valuable biomarker of response to angiogenic agents in RCC.

Exosomes derived from BMSCs ameliorate cyclophosphamide-induced testosterone deficiency by enhancing the autophagy of Leydig cells via the AMPK-mTOR signaling pathway.

Cyclophosphamide-induced testosterone deficiency (CPTD) during the treatment of cancers and autoimmune disorders severely influences the quality of life of patients. Currently, several guidelines recommend patients suffering from CPTD receive testosterone replacement therapy (TRT). However, TRT has many disadvantages underscoring the requirement for alternative, nontoxic treatment strategies. We previously reported bone marrow mesenchymal stem cells-derived exosomes (BMSCs-exos) could alleviate cyclophosphamide (CP)-induced spermatogenesis dysfunction, highlighting their role in the treatment of male reproductive disorders. Therefore, we further investigated whether BMSCs-exos affect autophagy and testosterone synthesis in Leydig cells (LCs). Here, we examined the effects and probed the molecular mechanisms of BMSCs-exos on CPTD in vivo and in vitro by detecting the expression levels of genes and proteins related to autophagy and testosterone synthesis. Furthermore, the testosterone concentration in serum and cell-conditioned medium, and the photophosphorylation protein levels of adenosine monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were measured. Our results suggest that BMSCs-exos could be absorbed by LCs through the blood-testis barrier in mice, promoting autophagy in LCs and improving the CP-induced low serum testosterone levels. BMSCs-exos inhibited cell death in CP-exposed LCs, regulated the AMPK-mTOR signaling pathway to promote autophagy in LCs, and then improved the low testosterone synthesis ability of CP-induced LCs. Moreover, the autophagy inhibitor, 3-methyladenine (3-MA), significantly reversed the therapeutic effects of BMSCs-exos. These findings suggest that BMSCs-exos promote LC autophagy by regulating the AMPK-mTOR signaling pathway, thereby ameliorating CPTD. This study provides novel evidence for the clinical improvement of CPTD using BMSCs-exos.

Plasma cell subtypes analyzed using artificial intelligence algorithm for predicting biochemical recurrence, immune escape potential, and immunotherapy response of prostate cancer.

Background: Plasma cells as an important component of immune microenvironment plays a crucial role in immune escape and are closely related to immune therapy response. However, its role for prostate cancer is rarely understood. In this study, we intend to investigate the value of a new plasma cell molecular subtype for predicting the biochemical recurrence, immune escape and immunotherapy response in prostate cancer. Methods: Gene expression and clinicopathological data were collected from 481 prostate cancer patients in the Cancer Genome Atlas. Then, the immune characteristics of the patients were analyzed based on plasma cell infiltration fractions. The unsupervised clustering based machine learning algorithm was used to identify the molecular subtypes of the plasma cell. And the characteristic genes of plasma cell subtypes were screened out by three types of machine learning models to establish an artificial neural network for predicting plasma cell subtypes. Finally, the prediction artificial neural network of plasma cell infiltration subtypes was validated in an independent cohort of 449 prostate cancer patients from the Gene Expression Omnibus. Results: The plasma cell fraction in prostate cancer was significantly decreased in tumors with high T stage, high Gleason score and lymph node metastasis. In addition, low plasma cell fraction patients had a higher risk of biochemical recurrence. Based on the differential genes of plasma cells, plasma cell infiltration status of PCa patients were divided into two independent molecular subtypes(subtype 1 and subtype 2). Subtype 1 tends to be immunosuppressive plasma cells infiltrating to the PCa region, with a higher likelihood of biochemical recurrence, more active immune microenvironment, and stronger immune escape potential, leading to a poor response to immunotherapy. Subsequently, 10 characteristic genes of plasma cell subtype were screened out by three machine learning algorithms. Finally, an artificial neural network was constructed by those 10 genes to predict the plasma cell subtype of new patients. This artificial neural network was validated in an independent validation set, and the similar results were gained. Conclusions: Plasma cell infiltration subtypes could provide a potent prognostic predictor for prostate cancer and be an option for potential responders to prostate cancer immunotherapy.

Abiraterone, Orteronel, Enzalutamide and Docetaxel: Sequential or Combined Therapy?

Objective: To summarize the current therapeutic status using chemotherapeutic agent docetaxel and endocrine therapeutic agents (ARAT, abiraterone, orteronel or enzalutamide) for the treatment of metastatic castration-resistant prostate cancer (mCRPC), including sequential therapy and combined therapy, to promote the consensus on the optimal regimen for achieving superior treatment efficacy. Methods: Through literature search in PubMed, articles with the following relevant keywords were collected and anlyzed: CRPC, abiraterone, orteronel and enzalutamide, median survival, overall survival, prostate specific antigen (PSA), PSA response rate and median radiologic progression-free survival. Results: Fifty-eight articles were obtained and analyzed in this review. These articles included androgen axis-targeting agents after docetaxel, docetaxel after androgen axis-targeting agents, Triple sequential and combination therapy, covering four current drugs for mCRPC treatment: docetaxel, abiraterone, orteronel, and enzalutamide. It was found that there may be some cross-resistance between androgen axis-targeting agents, which will reduce the efficacy of subsequent drug treatment. Although neither of the studies of using combination therapy showed serious drug toxicity, the efficacy of sequential therapy was not as good as expected. Most adverse reactions after treatment were reported to be level 1-2. Conclusion: Based on the results of the current studies, abiraterone followed by enzalutamide treatment is the best sequential treatment for most docetaxel-naïve patients. This treatment achieves not only good OS, but also PFS and PSA response rates. In addition, for patients who have previously failed docetaxel treatment, enzalutamide is the best choice as the subsequent treatment.

[Bone marrow mesenchymal stem cell-derived exosomes protect TM3 Leydig cells from cyclophosphamide-induced injury].

OBJECTIVE: To investigate the effect of exosomes derived from mouse bone marrow mesenchymal stem cells (BMSC) on the injury of TM3 Leydig cells induced by cyclophosphamide (CP). METHODS: The exosomes from BMSCs were extracted by ultrahigh speed centrifugation, and their particle size and morphology observed under the electron microscope, and their typical marker proteins examined by Western blot. The uptake of exosomes by TM3 Leydig cells was observed by co-culturing the exosomes with the TM3 cells. The viability and apoptosis rate of the TM3 cells in the normal control, CP-induction and CP+exosomes groups were detected using the CCK-8 method and flow cytometry respectively. ELISA was used to measure the testosterone (T) level in the cell supernatant, and Western blot adopted to determine the expression level of the steroidogenic acute regulatory (StAR) protein, a key enzyme related to T synthesis. RESULTS: The viability of the TM3 Leydig cells was markedly decreased and the apoptosis rate of the cells remarkably increased in the CP-induction group compared with that in the normal control, but both significantly restored after co-culture with exosomes (P < 0.01 and P < 0.05). The T level in the supernatant and the expression of the StAR protein in the cells were lower in the CP-induction than in the normal control group, but both dramatically increased in the CP+exosomes group (P < 0.01). CONCLUSION: Exosomes from BMSCs and protect TM3 Leydig cells from cyclophosphamide-induced injury and restore the level of testosterone secreted by the TM3 cells to a certain extent.

BMI1 activates P-glycoprotein via transcription repression of miR-3682-3p and enhances chemoresistance of bladder cancer cell.

Chemoresistance is the most significant reason for the failure of cancer treatment following radical cystectomy. The response rate to the first-line chemotherapy of cisplatin and gemcitabine does not exceed 50%. In our previous research, elevated BMI1 (B-cell specific Moloney murine leukemia virus integration region 1) expression in bladder cancer conferred poor survival and was associated with chemoresistance. Herein, via analysis of The Cancer Genome Atlas database and validation of clinical samples, BMI1 was elevated in patients with bladder cancer resistant to cisplatin and gemcitabine, which conferred tumor relapse and progression. Consistently, BMI1 was markedly increased in the established cisplatin- and gemcitabine-resistant T24 cells (T24/DDP&GEM). Functionally, BMI1 overexpression dramatically promoted drug efflux, enhanced viability and decreased apoptosis of bladder cancer cells upon treatment with cisplatin or gemcitabine, whereas BMI1 downregulation reversed this effect. Mechanically, upon interaction with p53, BMI1 was recruited on the promoter of miR-3682-3p gene concomitant with an increase in the mono-ubiquitination of histone H2A lysine 119, leading to transcription repression of miR-3682-3p gene followed by derepression of ABCB1 (ATP binding cassette subfamily B member 1) gene. Moreover, suppression of P-glycoprotein by miR-3682-3p mimics or its inhibitor XR-9576, could significantly reverse chemoresistance of T24/DDP&GEM cells. These results provided a novel insight into a portion of the mechanism underlying BMI1-mediated chemoresistance in bladder cancer.

Comprehensive signature analysis of drug metabolism differences in the White, Black and Asian prostate cancer patients.

The drug response sensitivity and related prognosis of prostate cancer varied from races, while the original mechanism remains rarely understood. In this study, the comprehensive signature including transcriptomics, epigenome and single nucleotide polymorphisms (SNPs) of 485 PCa cases- including 415 Whites, 58 Blacks and 12 Asians from the TCGA database were analyzed to investigate the drug metabolism differences between races. We found that Blacks and Whites had a more prominent drug metabolism, cytotoxic therapy resistance, and endocrine therapy resistance than Asians, while Whites were more prominent in drug metabolism, cytotoxic therapy resistance and endocrine therapy resistance than Blacks. Subsequently, the targeted regulation analysis indicated that the racial differences in cytotoxic therapy resistance, endocrine therapy resistance, might originate from drug metabolisms, and 19 drug metabolism-related core genes were confirmed in the multi-omics network for subsequent analysis. Furthermore, we verified that CYP1A1, CYP3A4, CYP2B6, UGT2B17, UGT2B7, UGT1A8, UGT2B11, GAS5, SNHG6, XIST significantly affected antineoplastic drugs sensitivities in PCa cell lines, and these genes also showed good predictive efficiency of drug response and treatment outcomes for PCa in this cohort of patients. These findings revealed a comprehensive signature of drug metabolism differences for the Whites, Blacks and Asians, and it may provide some evidence for making individualized treatment strategies.

A novel robust nomogram based on peripheral monocyte counts for predicting lymph node metastasis of prostate cancer.

Accurate methods for identifying pelvic lymph node metastasis (LNM) of prostate cancer (PCa) prior to surgery are still lacking. We aimed to investigate the predictive value of peripheral monocyte count (PMC) for LNM of PCa in this study. Two hundred and ninety-eight patients from three centers were divided into a training set (n = 125) and a validation set (n = 173). In the training set, the independent predictors of LNM were analyzed using univariate and multivariate logistic regression analyses, and the optimal cutoff value was calculated by the receiver operating characteristic (ROC) curve. The sensitivity and specificity of the optimal cutoff were authenticated in the validation cohort. Finally, a nomogram based on the PMC was constructed for predicting LNM. Multivariate analyses of the training cohort demonstrated that clinical T stage, preoperative Gleason score, and PMC were independent risk factors for LNM. The subsequent ROC analysis showed that the optimal cutoff value of PMC for diagnosing LNM was 0.405 × 109 l-1 with a sensitivity of 60.0% and a specificity of 67.8%. In the validation set, the optimal cutoff value showed significantly higher sensitivity than that of conventional magnetic resonance imaging (MRI) (0.619 vs 0.238, P < 0.001). The nomogram involving PMC, free prostate-specific antigen (fPSA), clinical T stage, preoperative Gleason score, and monocyte-to-lymphocyte ratio (MLR) was generated, which showed a robust predictive capacity for predicting LNM before the operation. Our results indicated that PMC as a single agent, or combined with other clinical parameters, showed a robust predictive capacity for LNM in PCa. It can be employed as a complementary factor for the decision of whether to conduct pelvic lymph node dissection.

Protective effect of bone marrow mesenchymal stem cell-derived exosomes against the reproductive toxicity of cyclophosphamide is associated with the p38MAPK/ERK and AKT signaling pathways.

Spermatogenic dysfunction caused by cyclophosphamide (CP) chemotherapy has seriously influenced the life quality of patients. Unfortunately, treatments for CP-induced testicular spermatogenic dysfunction are limited, and the molecular mechanisms are not fully understood. For the first time, here, we explored the effects of bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) on CP-induced testicular spermatogenic dysfunction in vitro and in vivo. BMSC-exos could be taken up by spermatogonia (GC1-spg cells). CP-injured GC1-spg cells and BMSC-exos were cocultured at various doses, and then, cell proliferation was measured using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. In addition, photophosphorylation of extracellular-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38MAPK), and protein kinase B (AKT) proteins was evaluated by western blotting as well as apoptosis in GC1-spg cells measured using flow cytometry. Treatment with BMSC-exos enhanced cell proliferation and reduced apoptosis of CP-injured GCI-spg cells. Phosphorylated levels of ERK, AKT, and p38MAPK proteins were reduced in CP-injured spermatogonia when co-treated with BMSC-exos, indicating that BMSC-exos acted against the reproductive toxicity of CP via the p38MAPK/ERK and AKT signaling pathways. In experiments in vivo, CP-treated rats received BMSC-exos by injection into the tail vein, and testis morphology was compared between treated and control groups. Histology showed that transfusion of BMSC-exos inhibited the pathological changes in CP-injured testes. Thus, BMSC-exos could counteract the reproductive toxicity of CP via the p38MAPK/ERK and AKT signaling pathways. The findings provide a potential treatment for CP-induced male spermatogenic dysfunction using BMSC-exos.

Predictive value of cadherin-11 for subsequent recurrence and progression in non-muscle invasive bladder cancer.

BACKGROUND: Cadherin-11 (CDH11) is a type II cadherin and reported to function as an oncogene in various cancers. Our present study aims to investigate the role of CDH11 in bladder cancer (BCA). METHODS: Bioinformatics analysis was performed in four independent microarray data including 56 non-muscle-invasive bladder cancer (NMIBC) and 132 muscle-invasive bladder cancer (MIBC) tissues from Gene Expression Omnibus to screen out differentially expressed genes. Next, we detected CDH11 expression in BCA specimens and cell lines by qPCR and western blotting assays. Immunohistochemical analyses were performed in 209 paraffin-embedded BCA samples and 30 adjacent normal bladder tissues. RESULTS: Bioinformatics analysis revealed that CDH11 had a higher expression level in MIBC tissues than in NMIBC, which was consistent with our clinical BCA specimens and cell lines at both mRNA and protein levels. Immunohistochemical analysis demonstrated that over-expression of CDH11 was closely related to the histological grade, pT status, tumour size and poor outcomes of BCA patients. What's more, CDH11 (area under curve (AUC) = 0.673 and 0.735) had a better predictive value than E-cadherin (AUC = 0.629 and 0.629) and a similar discrimination with the European Organization for Research and Treatment of Cancer (EORTC) score system (AUC = 0.719 and 0.667) in evaluating potential recurrence and progression of NMIBC. Moreover, combination of CDH11 and EORTC score system was the best predictive model in predicting recurrence of NMIBC (AUC = 0.779) among the three models. CONCLUSIONS: CDH11 was a reliable therapeutic target in BCA and a useful index to predict the possibilities of recurrence and progression in NMIBC patients.

Optimal Starting Age and Baseline Level for Repeat Tests: Economic Concerns of PSA Screening for Chinese Men - 10-Year Experience of a Single Center.

OBJECTIVE: To investigate the optimal age for the baseline serum prostate-specific antigen (PSA) test and for repeat screening and its economic burden in a single center in China. MATERIALS AND METHODS: 35,533 men with PSA screening were retrospectively enrolled in this study. Follow-ups were conducted in 1,586 men with PSA >4 ng/mL, and receiver-operating characteristic (ROC) curves were employed to investigate the optimal cutoffs. RESULTS: ROC analysis indicated that the optimal age for initial PSA screening was 57.5 years (AUC = 0.84), 62.5 years (AUC = 0.902), 60.5 years (AUC = 0.909), and 61.5 years (AUC = 0.890) for individuals with PSA >4 and >10 ng/mL, a diagnosis of prostate cancer (PCa), and clinically significant PCa defined as the focus events, respectively. For Chinese men aged 50-59, 60-69, and >70 years, the initial PSA levels of 1.305 ng/mL (AUC = 0.699), 1.975 ng/mL (AUC = 0.711), and 2.740 ng/mL (AUC = 0.720) might have a PSA velocity >0.75 ng/mL per year during the follow-up. In addition, the total cost amounts to CNY 13,609,260 in these cases, but only 60 of the 35,533 (0.17%) men gained benefit from PSA screening. CONCLUSION: In our opinion, the optimal starting age for initial PSA testing was 57.5 years. The necessity for repeat screening should be based on the first PSA level depending on age. A cost--benefit analysis should be included in population-based screening.

With a new clip technique surgically inducing varicocele in Sprague-Dawley rats.

BACKGROUND: We introduced and recreated a more consistent and effective experimental varicocele rat model by a new clip technique. METHODS: A total of 40 rats were numbered and randomly assigned to 5 groups of 8 each, including sham surgery (Group I), conventional (Group II) and clip groups with 0.7, 0.8, 0.9 mm gap widths, respectively (Group III, IV, V). All of the rats in each group were sacrificed at 8 weeks after initial surgery, and the rats forming out with less than 1 mm diameter of left spermatic vein or no presence of the pampiniform plexus dilation were excluded from the experimental groups. The left spermatic vein (LSV) diameter, testicular weight, left kidney weight to body weight coefficients, kidney and testicular histology were determined. RESULTS: The baseline mean diameter of the LSV in Group I, II and III was 0.22 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.03 mm, respectively (P = 0.7504). At 8 weeks after initial surgery, varicocele was successfully created in 6/8 (75%), 7/8 (87.5%), 3/8 (37.5%), 3/8 (37.5%) in GroupII-V, no varicocele was observed in Group I. In Group I, II and III, no pathological changes were observed and the left kidney weight to body weight coefficients showed no significant differences. The diameter of LSV was remarkably increased both in Group II and III compared to Group I (1.72 ± 0.13, 1.57 ± 0.19 and 0.25 ± 0.02, respectively), and Group II and III had a smaller testicular weight than the rats in Group I (1.67 ± 0.05, 1.62 ± 0.06, and 1.92 ± 0.12, respectively). CONCLUSIONS: With a new clip technique, surgically inducing varicocele rat model becomes convenient and safe. This appears to improve the effectiveness of the model and this innovation may allow us to further understand the pathophysiology of varicocele.

[Application value of real-time contrast-enhanced ultrasound in transrectal prostate biopsy].

OBJECTIVE: To explore the application value of real-time contrast-enhanced ultrasound (RTCEU) in improving the detection rate of transrectal ultrasound-guided prostate biopsy. METHODS: This prospective study included 91 male patients with abnormally high PSA (4－20 µg/L) or abnormalities in DRE or MRI, who underwent 12+X prostate biopsy following conventional transrectal ultrasonography (TRUS) and RTCEU examination. We compared the numbers of suspected prostatic nodules before and after RTCEU as well as the detection rates of prostate cancer between conventional TRUS-guided 12PBx and 12PBx plus lesion-targeted biopsy procedures. RESULTS: Totally, 57 of the 86 suspected lesions on TRUS (66.3%), and 108 of the 118 abnormal nodules on RTCEU (91.5%) were confirmed to be prostate cancer. RTCEU achieved a significantly higher detection rate than TRUS (P<0.01). A total of 39 cases of prostate cancer (42.8%) were detected by RTCEU, while only 28 (30.7%) by TRUS, with statistically significant difference in the detection rate between the two procedures (P=0.033). CONCLUSIONS: Real-time contrast-enhanced ultrasound can significantly improve the detection rate of prostate cancer and provide a valuable guide to targeted prostate biopsy.

[B-ultrasound guided aspiration and sclerotherapy with 2% iodophor for renal cysts].

OBJECTIVE: To evaluate the efficacy of B-ultrasound-guided aspiration and sclerotherapy with 2% iodophor for treatment of renal cysts. METHODS: Twenty-eight cases of sympotomatic renal cysts were treated with B-ultrasound-guided aspiration followed by sclerotherapy with 2% iodopher, which was maintained for 20 min. After extraction of iodopher, another injection of 2% iodopher (5-10 ml) into the cysts was given. The patients were followed up for 6 months to 18 months. RESULTS: Full recovery was achieved in 25 cases and improvement in 2 cases. Recurrence was found in 1 case after the treatment. CONCLUSIONS: B-ultrasound-guided aspiration and sclerotherapy with 2% iodophor is safe, minimally invasive, and highly effective for treatment of symptomatic renal cysts.