Correction to: Targeting TR4 nuclear receptor suppresses prostate cancer invasion via reduction of infiltrating acrophages with alteration of the TIMP-1/MMP2/MMP9 signals.

An amendment to this paper has been published and can be accessed via the original article.

Targeting TR4 nuclear receptor suppresses prostate cancer invasion via reduction of infiltrating macrophages with alteration of the TIMP-1/MMP2/MMP9 signals.

BACKGROUND: TR4 nuclear receptor 4 (TR4) plays an important role in macrophages-associated foam cell formation of cardiovascular diseases and infiltrating macrophages are critical for prostate cancer (PCa) progression. However, the linkage of macrophages and TR4 and their impacts on PCa metastasis remains unclear. RESULTS: Knocking-down TR4 in human PCa cells (C4-2, CWR22Rv1), but not in human macrophages cells (THP-1), led to suppress the macrophages infiltration to PCa cells. The consequences of such suppression of the recruitment of macrophages toward PCa then resulted in suppressing the PCa cell invasion. Mechanism dissection found that knocking-down TR4 in PCa cells suppressed metastasis-related genes including MMP2, with induction of TIMP-1. Interruption assays using TIMP-1 neutralizing antibody could then reverse TR4-macrophage-mediated PCa invasion. IHC staining showed higher TR4 level, more macrophage infiltration, lower TIMP-1 and stronger MMP2/MMP9 in tumor tissues of the Gleason score 5 + 4 patients compared with the Gleason score 3 + 3 patients. CONCLUSION: Targeting TR4 in prostate tumor microenvironment might represent a potential new therapeutic approach to better battle PCa metastasis.

TR4 nuclear receptor promotes prostate cancer metastasis via upregulation of CCL2/CCR2 signaling.

Testicular nuclear receptor 4 (TR4) plays protective roles against oxidative stress and DNA damage and might contribute to aging. Our recent clinical tumor tissue staining results showed higher expression of TR4 in prostate cancer (PCa) patients with high Gleason scores compared to the tissues with the low Gleason scores. In vitro migration/invasion assays after manipulation of the TR4 expression in PCa cells showed that TR4 promoted PCa cells migration/invasion. Mechanism dissection found that the CCL2/CCR2 signal plays the key role in the mediation of TR4-promoted PCa cells migration/invasion. Chromatin immunoprecipitation and Luciferase assays further confirmed TR4 modulation of CCL2 at the transcriptional level and addition of the CCR2 antagonist led to interruption of the TR4-enhanced PCa cells migration/invasion. Finally, the orthotopic xenografted mice studies using the luciferase expressing CWR22Rv1 cells found that TR4 enhanced PCa metastasis and this increased metastasis was reversed when the CCR2 antagonist was injected into the mice. Together, these in vitro and in vivo results revealed a positive role of TR4 in PCa metastasis and demonstrated CCL2/CCR2 signaling as an important mediator in exerting TR4 action. This finding suggests that TR4 may represent a biomarker related to PCa metastasis and targeting the TR4-CCL2/CCR2 axis may become a new therapeutic approach to battle PCa metastasis.

Testicular orphan nuclear receptor 4 is associated with the radio-sensitivity of prostate cancer.

BACKGROUND: It is well known that a significant number of prostate cancers (PCa) showed different extents of radio-resistance and the tumor may recur after treatment. Recent studies demonstrated that Testicular orphan nuclear receptor 4 (TR4) could play a critical role in anti-oxidative stress responses and might modulate the DNA damage repair. The objective of this study is to investigate the role of TR4 in the radiotherapy for PCa. METHODS: The TR4 expression in tissue samples from PCa patients treated with brachytherapy was measured by immunohistochemistry (IHC). Cell survival test and colony formation assay were applied to test the radio-sensitivity of PCa cells with modulated TR4 gene expression upon irradiation. RESULTS: PCa patients with biochemical recurrence (BCR) after brachytherapy tend to have higher TR4 expression (80%, n = 30) as compared to those without BCR (36.67%, n = 30). Survival analysis demonstrated a significant higher BCR occurrence in patients with high level of TR4 expression (HR = 3.474, 95%CI 1.678-7.192, P = 0.0008). Multivariate analysis showed that the TR4 staining score on IHC was the only significant variable for predicting the PCa patients' clinical outcomes after radiotherapy (OR = 9.919, 95% CI 2.516-39.101, P = 0.001). Using cell survival test and colony forming assay, we found that the addition of functional TR4 in PC3 cells lead to elevated radio-resistance. In contrast, knocking-down TR4 in LNCaP cells resulted in increased radio-sensitivity. The γH2AX foci kinetic analysis suggested that knocking down TR4 might delay the PCa cell's DNA damage repair which would enhance the radio-sensitivity. CONCLUSION: TR4 could mediate the PCa cells' radio-sensitivity and might become a prognostic indicator for PCa patients received radiotherapy. This study provides a novel approach to manipulate radio-sensitivity of PCa cells, and may bring a promoted therapeutic outcome of radiotherapy to battle PCa in future.

Increased chemosensitivity via targeting testicular nuclear receptor 4 (TR4)-Oct4-interleukin 1 receptor antagonist (IL1Ra) axis in prostate cancer CD133+ stem/progenitor cells to battle prostate cancer.

Prostate cancer (PCa) stem/progenitor cells are known to have higher chemoresistance than non-stem/progenitor cells, but the underlying molecular mechanism remains unclear. We found the expression of testicular nuclear receptor 4 (TR4) is significantly higher in PCa CD133(+) stem/progenitor cells compared with CD133(-) non-stem/progenitor cells. Knockdown of TR4 levels in the established PCa stem/progenitor cells and the CD133(+) population of the C4-2 PCa cell line with lentiviral TR4 siRNA led to increased drug sensitivity to the two commonly used chemotherapeutic drugs, docetaxel and etoposide, judging from significantly reduced IC50 values and increased apoptosis in the TR4 knockdown cells. Mechanism dissection studies found that suppression of TR4 in these stem/progenitor cells led to down-regulation of Oct4 expression, which, in turn, down-regulated the IL-1 receptor antagonist (IL1Ra) expression. Neutralization experiments via adding these molecules into the TR4 knockdown PCa stem/progenitor cells reversed the chemoresistance, suggesting that the TR4-Oct4-IL1Ra axis may play a critical role in the development of chemoresistance in the PCa stem/progenitor cells. Together, these studies suggest that targeting TR4 may alter chemoresistance of PCa stem/progenitor cells, and this finding provides the possibility of targeting TR4 as a new and better approach to overcome the chemoresistance problem in PCa therapeutics.

Higher expression of peroxisome proliferator-activated receptor γ or its activation by agonist thiazolidinedione-rosiglitazone promotes bladder cancer cell migration and invasion.

OBJECTIVE: To investigate the role of peroxisome proliferator-activated receptor γ (PPARγ) in bladder cancer (BCa) progression. MATERIALS AND METHODS: The gene copy number of PPARγ in human BCa tissue samples was analyzed by fluorescence in situ hybridization. The migration and invasive ability of human BCa cell lines with different PPARγ expression levels or treated with thiazolidinedione-rosiglitazone, a PPARγ agonist and an antidiabetic drug, were investigated. RESULTS: PPARγ amplification was increased dramatically in BCa tissue compared with normal urothelium (38.1% vs 4.3%, P = .0082) and in tumors with lymph node metastasis compared with those without metastasis (75.0% vs 15.4%, P = .0176). The human BCa cell line 5637 with strong PPARγ expression demonstrated a greater ability for cell migration and invasion than the UMUC-3 cell line with weak PPARγ expression. Knocking down PPARγ in BCa 5637 cells led to decreased cell migration, and activation of PPARγ with thiazolidinedione-rosiglitazone promoted their migration and invasive ability. CONCLUSION: PPARγ amplification in BCa could play an important role in BCa cell migration and invasion. Alteration of PPARγ expression by PPARγ-small interfering ribonucleic acid or activation by its agonist rosiglitazone, a diabetic thiazolidinedione drug, could lead to alternation of BCa cell migration and invasion.

Recent advances in the study of testicular nuclear receptor 4.

Testicular nuclear receptor 4 (TR4), also known as NR2C2 (nuclear receptor subfamily 2, group C, member 2), is a transcriptional factor and a member of the nuclear receptor family. TR4 was initially cloned from human and rat hypothalamus, prostate, and testes libraries. For almost two decades, its specific tissue distribution, genomic organization, and chromosomal assignment have been well investigated in humans and animals. However, it has been very difficult to study TR4's physiological functions due to a lack of specific ligands. Gene knock-out animal techniques provide an alternative approach for defining the biological functions of TR4. In vivo studies of TR4 gene knockout mice (TR4(-/-)) found that they display severe spinal curvature, subfertility, premature aging, and prostate prostatic intraepithelial neoplasia (PIN) development. Upstream modulators, downstream target gene regulation, feedback mechanisms, and differential modulation mediated by the recruitment of other nuclear receptors and coregulators have been identified in studies using the TR4(-/-) phenotype. With the establishment of a tissue-specific TR4(-/-) mouse model, research on TR4 will be more convenient in the future.

A new plastic surgical technique for adult congenital webbed penis.

OBJECTIVE: To introduce a novel surgical technique for correction of adult congenital webbed penis. METHODS: From March 2010 to December 2011, 12 patients (age range: 14-23 years old) were diagnosed as having a webbed penis and underwent a new surgical procedure designed by us. RESULTS: All cases were treated successfully without severe complication. The operation time ranged from 20 min to 1 h. The average bleeding volume was less than 50 ml. All patients achieved satisfactory cosmetic results after surgery. The penile curvature disappeared in all cases and all patients remained well after 1 to 3 months of follow-up. CONCLUSIONS: Adult webbed penis with complaints of discomfort or psychological pressure due to a poor profile should be indicators for surgery. Good corrective surgery should expose the glans and coronal sulcus, match the penile skin length to the penile shaft length dorsally and ventrally, and provide a normal penoscrotal junction. Our new technique is a safe and effective method for the correction of adult webbed penis, which produces satisfactory results.

The influence of immunosuppressants on the fertility of males who undergo renal transplantation and on the immune function of their offspring.

AIM: To investigate the influence of immunosuppressants on the fertility of males who undergo renal transplantation as well as on the immune function of their offspring. METHODS: A survey was performed on the fertility of 164 male renal transplant recipients who underwent a long-term treatment with cyclosporine A (CsA), azathioprine (Aza) and prednisone (Pred). The immune function of the recipients' children was also surveyed. RESULTS: The 164 renal transplant recipients produced successful impregnation 15-204 (54.48+/-27.48)months after transplantation, resulting in the births of 167 children (three recipients fathered two children each), including 85 boys and 82 girls. Seven infants (4.2%) were premature. The weight of newborn infants was 2000-4600 (3274+/-395)g. Among the 167 children, 18 children were prone to respiratory tract infection. Examination of serum immunoglobulin from the children aged 1-3 years revealed that the IgA level was slightly lower than the normal reference range, but the difference was not significant (P>0.05). The IgM level of the children aged 7-12 years was higher than the normal reference range (P<0.01). Other immune indexes did not exhibit significant changes (P>0.05). CONCLUSION: A long-term treatment with small-dose immunosuppressants has no obvious effect on the fertility of males who undergo renal transplantation. However, whether immunosuppressants influence the immune function of the offspring of such transplant recipients remains to be clarified by long-term follow up and prospective studies.

Marital status and fertility of 185 male renal transplant recipients in China.

A questionnaire was designed to assess the effects of renal transplantation in men of reproductive age on marital status and fertility. The study sought to correlate recipients' marital status and fertility with the health of the recipients after the transplantation, the health of children they fathered after the procedure, and the functioning of the transplanted kidney. Male recipients (n = 243) who were single and of reproductive age before renal transplantation were selected from 2007 recipients of a renal transplant recorded in the authors' hospitals in China. Of the 243 surveyed, 185 completed the questionnaire and participated in follow-up in the clinic or by telephone. Their marital status and fertility were investigated. Of the 185 recipients, 69 got married 12-88 months (mean, 32.19 +/- 14.30 months) after renal transplantation, and 62 of 69 couples were actively attempting to become pregnant. Fifty-three patients fathered 54 children, including 1 pair of twins, 9-72 months (mean, 25.81 +/- 15.33 months) after marriage. The birth weights of the newborns ranged from 2500 to 4600 g (mean, 3395 +/- 456.80 g). These children developed well. Nine patients did not father any children, and 3 of these 9 cases were attributable to infertility in the wife. Seven patients were using contraceptives. Three recipients suffered from chronic graft rejection and resumed hemodialysis 2-11 years after they fathered children. In addition, 2 patients died after fathering 1 child: 1 from dysfunction of the transplanted kidney 9 years after birth of his child, and another in an accident 1 year after his child's birth. Our findings suggest that, like men without renal transplants, male recipients of renal transplants can get married and father children, and the transplantation procedure appears to have no significant effect on the children fathered afterwards, on the recipients' health, or on the functioning of the transplanted kidney. It is very important to indicate that, in addition to needing contraception if they do not conceive, male renal transplant recipients should expect fertility rates that are similar to those of the general population.