Chengqiang Mo

The expression and role of protein kinase C (PKC) epsilon in clear cell renal cell carcinoma

Protein kinase C epsilon (PKCε), an oncogene overexpressed in several human cancers, is involved in cell proliferation, migration, invasion, and survival. However, its roles in clear cell renal cell carcinoma (RCC) are unclear. This study aimed to investigate the functions of PKCε in RCC, especially in clear cell RCC, to determine the possibility of using it as a therapeutic target. By immunohistochemistry, we found that the expression of PKCε was up-regulated in RCCs and was associated with tumor Fuhrman grade and T stage in clear cell RCCs. Clone formation, wound healing, and Borden assays showed that down-regulating PKCε by RNA interference resulted in inhibition of the growth, migration, and invasion of clear cell RCC cell line 769P and, more importantly, sensitized cells to chemotherapeutic drugs as indicated by enhanced activity of caspase-3 in PKCε siRNA-transfected cells. These results indicate that the overexpression of PKCε is associated with an aggressive phenotype of clear cell RCC and may be a potential therapeutic target for this disease.

Association between RASSF1A Promoter Methylation and Prostate Cancer: A Systematic Review and Meta-Analysis

Prostate cancer (PCa) remains as one of the most common cause of cancer related death among men in the US. The widely used prostate specific antigen (PSA) screening is limited by low specificity. The diagnostic value of other biomarkers such as RAS association domain family protein 1 A (RASSF1A) promoter methylation in prostate cancer and the relationship between RASSF1A methylation and pathological features or tumor stage remains to be established. Therefore, a meta-analysis of published studies was performed to understand the association between RASSF1A methylation and prostate cancer. In total, 16 studies involving 1431 cases and 565 controls were pooled with a random effect model in this investigation. The odds ratio (OR) of RASSF1A methylation in PCa case, compared to controls, was 14.73 with 95% CI = 7.58–28.61. Stratified analyses consistently showed a similar risk across different sample types and, methylation detection methods. In addition, RASSF1A methylation was associated with high Gleason score OR=2.35, 95% CI: 1.56–3.53. Furthermore, the pooled specificity for all included studies was 0.87 (95% CI: 0.72–0.94), and the pooled sensitivity was 0.76 (95% CI: 0.55–0.89). The specificity in each subgroup stratified by sample type remained above 0.84 and the sensitivity also remained above 0.60. These results suggested that RASSF1A promoter methylation would be a potential biomarker in PCa diagnosis and therapy.

Vasculogenic Mimicry in Prostate Cancer: The Roles of EphA2 and PI3K.

BACKGROUND. Aggressive tumor cells can form perfusable networks that mimic normal vasculature and enhance tumor growth and metastasis. A number of molecular players have been implicated in such vasculogenic mimicry, among them the receptor tyrosine kinase EphA2, which is aberrantly expressed in aggressive tumors. Here we study the role and regulation of EphA2 in vasculogenic mimicry in prostate cancer where this phenomenon is still poorly understood. METHODS. Vasculogenic mimicry was characterized by tubules whose cellular lining was negative for the endothelial cell marker CD34 but positive for periodic acid-Schiff staining, and/or contained red blood cells. Vasculogenic mimicry was assessed in 92 clinical samples of prostate cancer and analyzed in more detail in three prostate cancer cell lines kept in three-dimensional culture. Tissue samples and cell lines were also assessed for total and phosphorylated levels of EphA2 and its potential regulator, Phosphoinositide 3-Kinase (PI3K). In addition, the role of EphA2 in vasculogenic mimicry and in cell migration and invasion were investigated by manipulating the levels of EphA2 through specific siRNAs. Furthermore, the role of PI3K in vasculogenic mimicry and in regulating EphA2 was tested by application of an inhibitor, LY294002. RESULTS. Immunohistochemistry of prostate cancers showed a significant correlation between vasculogenic mimicry and high expression levels of EphA2, high Gleason scores, advanced TNM stage, and the presence of lymph node and distant metastases. Likewise, two prostate cancer cell lines (PC3 and DU-145) formed vasculogenic networks on Matrigel and expressed high EphA2 levels, while one line (LNCaP) showed no vasculogenic networks and lower EphA2 levels. Specific silencing of EphA2 in PC3 and DU-145 cells decreased vasculogenic mimicry as well as cell migration and invasion. Furthermore, high expression levels of PI3K and EphA2 phosphorylation at Ser897 significantly correlated with the presence of vasculogenic mimicry and in vitro inhibition of PI3K by LY294002 disrupted vasculogenic mimicry, potentially through a reduction of EphA2 phosphorylation at Ser897. CONCLUSIONS. The expression levels of PI3K and EphA2 are positively correlated with vasculogenic mimicry both in vivo and in vitro. Moreover, phosphorylation levels of EphA2 regulated by PI3K are also significantly associated with vasculogenic mimicry in vivo. Based on its functional implication in vasculogenic mimicry in vitro, EphA2 signaling may be a potential therapeutic target in advanced prostate cancer.

Association of DSC3 mRNA down-regulation in prostate cancer with promoter hypermethylation and poor prognosis.

Background Desmocollin 3 (DSC3), a member of the cadherin gene superfamily, is associated with pathogenesis of some cancers, but its role in prostate cancer (PCa) remains largely unknown. Methods DSC3 gene expression level in available PCa microarray dataset was examined using the Oncomine database. DSC3 transcript expression in prostate cell line panel and an independent tissue cohort (n = 52) was estimated by quantitative PCR (Q-PCR). Epigenetic status of DSC3 gene promoter in PCa was investigated by uploading three dataset (ENCODE Infinium 450K array data and two methylation sequencing) in UCSC genome browser. While pyrosequencing analysis measured promoter DNA methylation, Q-PCR estimates were obtained for DSC3 transcript re-expression after 5-Aza-deoxycytidine (5-Aza) treatment. Clinical relevance of DSC3 expression was studied by Kaplan-Meier survival analysis. Finally, functional studies monitoring cell proliferation, migration and invasion were performed in prostate cell lines after siRNA mediated DSC3 knockdown or following 5-Aza induced re-expression. EMT markers Vimentin and E-cadherin expression was measured by Western Blot. Results Microarray data analyses revealed a significant decrease in DSC3 transcript expression in PCa, compared to benign samples. Q-PCR analysis of an independent cohort revealed DSC3 transcript down-regulation, both in PCa cell lines and tumor tissues but not in their benign counterpart. Examination of available NGS and Infinium data identified a role for epigenetic regulation DSC3 mRNA reduction in PCa. Pyrosequencing confirmed the increased DSC3 promoter methylation in cancer cell lines and restoration of transcript expression upon 5-Aza treatment further corroborated this epigenetic silencing mechanism. Importantly Kaplan-Meier analysis of an outcome cohort showed an association between loss of DSC3 expression and significantly increased risk of biochemical recurrence. Functional studies indicate a role for epithelial–mesenchymal transition in DSC3 regulated cell migration/invasion. Conclusion Taken together, our data suggests that DNA methylation contributes to down-regulation of DSC3 in prostate cancer, and loss of DSC3 predicts poor clinical outcome.

Matrix metalloproteinase-9 is required for vasculogenic mimicry by clear cell renal carcinoma cells☆

BACKGROUND Vasculogenic mimicry (VM), a new pattern of tumor microcirculation system, has been proved to be important for tumor growth and progression and may be one of the causes of antiangiogenesis resistance. Matrix metalloproteinase-9 (MMP9) was shown to correlate with VM formation in some other cancers. However, the relationship between VM formation and MMP9 in renal cell carcinoma (RCC) has not been determined. METHODS The VM formation and MMP9 expressions were analyzed by CD34/periodic acid-Schiff dual staining and immunohistochemistry in 119 RCC specimens. We used a well-established 3-dimention culture model to compare VM formation in 786-O, 769-P, and HK-2 cell lines in vitro. MMP9 expressions on either messenger RNA or protein levels were compared among the cell lines by quantitative polymerase chain reaction or Western blot. To determine further the relationship between MMP9 and VM in RCC, 786-O and 769-P were treated with specific MMP9 inhibitor or small interfering RNA. VM formation, cell migration, and invasion were subsequently assessed by 3-dimention culture, wound-healing, and transwell assays. RESULTS Immunohistochemistry demonstrated both VM formation and MMP9 overexpression were positively associated with clinical staging, pathological grade, and metastasis (P<0.01). VM formation was closely correlated with MMP9 overexpression in RCC (r = 0.602, P<0.01). Lower MMP9 expression level was observed in normal kidney cell line HK-2, which was unable to form VM on Matrigel, whereas higher expression of MMP9 was found in VM-forming cancer cell lines 786-O and 769-P. Inhibition of MMP9 not only disrupted VM formation in 786-O and 769-P but also reduced cell migration and invasion. CONCLUSIONS These results indicate an intimate relationship between MMP9 overexpression and VM formation in RCC. Treatments targeting VM formation by inhibiting the activity of MMP9 could be beneficial in RCC therapy.

Comparison between laparoscopic partial nephrectomy and laparoscopic ablation therapy: A meta-analysis

Abstract Objective: To conduct a meta-analysis of the literature evaluating comparisons on the peri-operative and oncological outcomes between laparoscopic partial nephrectomy (LPN) and laparoscopic ablation therapy (LAT) in the treatment of small renal masses (SRMs). Material and methods: MEDLINE, EMBASE, Google Scholar, Cochrane Library, and CNKI were searched for clinical trials comparing LPN with LAT. Data of peri-operative and follow-up outcomes were extracted and compared. Publication bias was identified and sensitivity analysis was also performed. Results: Data from 11 studies including 928 patients (525 patients in the LPN group and 403 in the LAT group) were collected. Baseline characteristics were compared and differences were found in age, preoperative renal function and proportion of solitary kidney (p < 0.05 respectively). For peri-operative outcomes, the LPN group had greater estimated blood loss, longer operative duration and length of hospital stay, and more peri-operative complications (p < 0.05, respectively). The LAT group had a significantly higher local recurrence (p < 0.05). There was no significant difference in postoperative change of renal function (p = 0.21). Conclusion: In comparison with LPN, LAT provides better peri-operative outcomes, but a higher local recurrence rate. LAT does not seem to provide an obvious advantage in protecting renal function. Further clinical trials with randomized design and long-term follow-up are needed.

Vasculogenic mimicry in bladder cancer and its association with the aberrant expression of ZEB1

The aim of the present study was to investigate the associations between vasculogenic mimicry (VM) and zinc finger E-box binding homeobox 1 (ZEB1) in bladder cancer. VM structure and ZEB1 expression were analyzed by cluster of differentiation 34/periodic acid Schiff (PAS) double staining and immunohistochemical staining in 135 specimens from patients with bladder cancer, and a further 12 specimens from normal bladder tissues. Three-dimensional (3-D) culture was used to detect VM formation in the bladder transitional cancer cell lines UM-UC-3 and J82, and the immortalized human bladder epithelium cell line SV-HUC-1 in vitro. ZEB1 expression in these cell lines was compared by reverse transcription-quantitative polymerase chain reaction and western blot assays. In addition, small interfering RNA was used to inhibit ZEB1 in UM-UC-3 and J82 cells, followed by 3-D culturing of treated cell lines. As a result, VM was observed in 31.1% of specimens from bladder cancer tissues, and cases with high ZEB1 expression accounted for 60.0% of patients with bladder cancer. In addition, ZEB1 expression was closely associated with VM (r=0.189; P<0.05), and also increased as the grade and stage of the tumor developed. In an in vitro assay, UM-UC-3 and J82 cells exhibited VM formation, however, SV-HUC-1 did not. Furthermore, VM-forming cancer cell lines UM-UC-3 and J82 exhibited higher ZEB1 expression. Notably, VM formation was inhibited following knockdown of ZEB1. In conclusion, ZEB1 may be associated with VM in bladder cancer and serve an important role in the process of VM formation. However, its detailed mechanism requires further study.

Unsupervised clustering reveals new prostate cancer subtypes

Background: Prostate cancer is the second most common cancer in men. It is urgent to develop a genetic classification for prostate cancer. We aimed to establish the basis of genetic typing. Methods: We used four series of prostate cancer data. The Cancer Genome Atlas (TCGA) RNA-Seq data were used to train the classifier. Three subgroups based on the classifier were tested whether to have significant differences in the clinical data. The other three sets were classified by the classifier and validated with respective clinical data. Results: The classifier had 183 genes. Prostate cancer subtype 1 (PCS1) was characterized by high expression of GSTP1, with lower Gleason scores (P Conclusions: We established a PCS classifier (183 genes) based on RNA-Seq data, and identified three PCSs. The classification was robustly relating to clinical data which may have potential for clinical use.

Primary Paraganglioma of Seminal Vesicle

To the Editor: Extra-adrenal paragangliomas are tumors that arise from neural crest-derived endocrine cells. They are most frequently found in the organ of Zuckerkandl but can be found anywhere along the sympathetic chain.[1] Seminal vesicle paragangliomas have been reported to involve bladder and prostate. However, only two cases of primary seminal vesicle paragangliomas were reported in medical literature to the best of our knowledge.[1,2] Here, we reported on one case. A 44-year-old male patient with the family history of hypertension was admitted to the local hospital with a chief complaint of the lower abdominal discomfort and chest distress for more than 2 years. Subsequent examination revealed hypertension and coronary artery computed tomography (CT) did not show any abnormality. As a result, the patient received antihypertensive therapy. Symptoms happened more frequently, about one to two times per day since 6 months ago. Blood pressure was 200–260/120–150 mmHg at onset and partially responded to therapy as 120–130/90–100 mmHg. Therefore, the patient came to our hospital and was admitted in the endocrinology department. The elevated urine vanillylmandelic acid (VMA) and blood catecholamine were confirmed, and abdominal CT was taken. An occupying lesion in the left seminal vesicle was found, considering ectopic pheochromocytoma [Figure 1], while the adrenal glands and other organs are normal. After oral intake of phenoxybenzamine for 14 days, the patient was admitted to the urology department and underwent laparoscopic resection of the mass. The surgery went well and the mass was found to be paraganglioma of seminal vesicle on pathology. Postoperatively, the symptoms disappeared and the blood pressure returned to normal. Antihypertensive therapy was discontinued and no symptoms occurred during the short-term follow-up of 3 months. Written informed consent was obtained from the patient for publication of this case report and accompanying images. Figure 1 Abdominal computed tomography showing an occupying lesion in the left seminal vesicle. Extra-adrenal paraganglioma (pheochromocytoma) is a rare tumor which can be found anywhere along the sympathetic chain from the base of the skull and neck to the bladder and prostate gland. About 90% of sympathetic paragangliomas are intra-adrenal (pheochromocytomas). Furthermore, approximately 10% of all extra-adrenal paraganglioma are malignant.[3] In the genitourinary tract, the urinary bladder is the most common site for paraganglioma (79.2%), followed by the urethra (12.7%), pelvis (4.9%), and ureter (3.2%).[3,4] The histogenesis of seminal vesicle paraganglioma is unknown. Histologically, all paragangliomas show similar morphologic characteristics. Immunohistochemistry shows positive staining for the synaptophysin, chromogranin A, and CD56 neuroendocrine markers. Protein S100 highlights the sustentacular and tumor cells, which is in accordance with our case. Mitotic activity and necrosis have been regarded as some of the unfavorable prognostic factors in histopathology. The only consistent criterion for malignancy in paraganglioma at any site is metastasis. The clinical manifestation of seminal vesicle paraganglioma may largely depends on the size and the functional status of the tumor.[1] The symptoms and signs of catecholamine overproduction such as hypertension, headaches, palpitations, sweating, and tachycardia may be seen. In general, an elevation of the 24 h urinary catecholamine metabolites and VMA levels can be detected as in our case. The standard treatment for localized or locally advanced seminal vesicle paraganglioma is surgery. Laparoscopic resection has been an effective management because it can magnify the anatomic structure for easier removal and decrease the trauma. Primary paraganglioma of the seminal vesicle is rare but important to diagnosis in the differential diagnosis of extra-adrenal paragangliomas. Laparoscopic resection appears to be a safe and effective management for localized seminal vesicle paraganglioma. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

AB121. Laparoendoscopic single-site surgery versus conventional laparoscopic varicocele ligation for varicocele: a meta-analysis.

Objective To compare perioperative and postoperative outcomes of laparoendoscopic single-site (LESS) surgery and conventional transperitoneal laparoscopic varicocele ligation (CTL-VL) for varicocele. Material and methods PubMed, Medline, EMBASE, ISI Web of Knowledge, Cochrane Library, Chinese biomedicine and China Knowledge Resource Integrated (CNKI) databases were searched for studies released prior to February 2014. References of included studies were also searched to identify additional, potentially relevant studies. We analyzed the data using RevMan 5.1. Results Ten randomized controlled trials (RCTs) and seven non-randomized controlled trials (NRCTs) were included, involving 1,183 patients. LESS group showed longer operative time but shorter hospital stay, shorter time to return to normal activity and lower total postoperative complications incidence. No significant difference was found in terms of blood loss, VAS pain score, pregnancy and improvement of semen parameters. Patients’ satisfaction was significantly better in LESS group. Sensitivity analysis showed similar results to the original analysis, and no evidence of publication bias was showed. Conclusions LESS showed comparable outcomes to that of CTL-VL, but it takes shorter to recover, has fewer postoperative complications and shows advantages in patients’ satisfaction potentially for cosmesis and less pain. More high-quality, multicenter and long-term RCTs are required to verify the findings.