Expression of Peroxisome Proliferator Activated Receptor gamma in Prostatic Adenocarcinoma

Evaluation of the expression pattern and diagnostic value of PPARγ in malignant and benign primary bone tumors

PURPOSE

The quantifiable description of PPARγ expression pattern beside mechanistic in-vitro evidence will provide insights into the involvement of this mediator in tumor pathogenesis. This study is focused on illuminating the PPARγ gene and protein expression pattern, its association with tumor deterioration and its diagnostic value in different types of primary bone tumors.

METHODS

The expression pattern of PPARγ was investigated in the 180 bone tissues including 90 bone tumor tissues and 90 non-cancerous bone tissues. The local PPARγ expression level was assessed using real-time qRT-PCR and the PPARγ protein expression pattern was measured using immunohistochemistry. The correlation of PPARγ expression level with patients' clinic-pathological features, also the value of the variables in predicting PPARγ expression level in tumors and the value of PPARγ to discriminate tumor subtypes were assessed.

RESULTS

The mean PPARγ mRNA expression was significantly higher in bone tumors compared to healthy bone tissues, also the malignant tumors including osteosarcoma and Ewing sarcoma had the elevated level of PPARγ mRNA compared to GCT tumors. Consistently, the protein expression of PPARγ in the tumor site was significantly higher in the bone tumors and malignant tumors compared to non-cancerous and benign tumors, respectively. The PPARγ protein could predict malignant tumor features including tumor grade, metastasis and recurrence significantly. Moreover, PPARγ could potentially discriminate the patients from the controls also malignant tumors from benign tumors with significant sensitivity and specificity.

CONCLUSIONS

PPARγ might be involved in primary bone tumor pathogenesis and determining its molecular mechanism regarding bone cancer pathogenesis is of grave importance.

Regulation of Epigenetic Modifications in the Placenta during Preeclampsia: PPARγ Influences H3K4me3 and H3K9ac in Extravillous Trophoblast Cells

The aim of this study was to analyze the expression of peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RxRα), a binding heterodimer playing a pivotal role in the successful trophoblast invasion, in the placental tissue of preeclamptic patients. Furthermore, we aimed to characterize a possible interaction between PPARγ and H3K4me3 (trimethylated lysine 4 of the histone H3), respectively H3K9ac (acetylated lysine 9 of the histone H3), to illuminate the role of histone modifications in a defective trophoblast invasion in preeclampsia (PE). Therefore, the expression of PPARγ and RxRα was analyzed in 26 PE and 25 control placentas by immunohistochemical peroxidase staining, as well as the co-expression with H3K4me3 and H3K9ac by double immunofluorescence staining. Further, the effect of a specific PPARγ-agonist (Ciglitazone) and PPARγ-antagonist (T0070907) on the histone modifications H3K9ac and H3K4me3 was analyzed in vitro. In PE placentas, we found a reduced expression of PPARγ and RxRα and a reduced co-expression with H3K4me3 and H3K9ac in the extravillous trophoblast (EVT). Furthermore, with the PPARγ-antagonist treated human villous trophoblast (HVT) cells and primary isolated EVT cells showed higher levels of the histone modification proteins whereas treatment with the PPARγ-agonist reduced respective histone modifications. Our results show that the stimulation of PPARγ-activity leads to a reduction of H3K4me3 and H3K9ac in trophoblast cells, but paradoxically decreases the nuclear PPARγ expression. As the importance of PPARγ, being involved in a successful trophoblast invasion has already been investigated, our results reveal a pathophysiologic connection between PPARγ and the epigenetic modulation via H3K4me3 and H3K9ac in PE.

Molecules targeting the androgen receptor (AR) signaling axis beyond the AR-Ligand binding domain

Prostate cancer (PCa) is the second most common cause of cancer-related mortality in men in the United States. The androgen receptor (AR) and the physiological pathways it regulates are central to the initiation and progression of PCa. As a member of the nuclear steroid receptor family, it is a transcription factor with three distinct functional domains (ligand-binding domain [LBD], DNA-binding domain [DBD], and transactivation domain [TAD]) in its structure. All clinically approved drugs for PCa ultimately target the AR-LBD. Clinically active drugs that target the DBD and TAD have not yet been developed due to multiple factors. Despite these limitations, the last several years have seen a rise in the discovery of molecules that could successfully target these domains. This review aims to present and comprehensively discuss such molecules that affect AR signaling through direct or indirect interactions with the AR-TAD or the DBD. The compounds discussed here include hairpin polyamides, niclosamide, marine sponge-derived small molecules (eg, EPI compounds), mahanine, VPC compounds, JN compounds, and bromodomain and extraterminal domain inhibitors. We highlight the significant in vitro and in vivo data found for each compound and the apparent limitations and/or potential for further development of these agents as PCa therapies.

Peroxisome Proliferator-Activated Receptor Modulation during Metabolic Diseases and Cancers: Master and Minions

The prevalence of obesity and metabolic diseases (such as type 2 diabetes mellitus, dyslipidaemia, and cardiovascular diseases) has increased in the last decade, in both industrialized and developing countries. This also coincided with our observation of a similar increase in the prevalence of cancers. The aetiology of these diseases is very complex and involves genetic, nutritional, and environmental factors. Much evidence indicates the central role undertaken by peroxisome proliferator-activated receptors (PPARs) in the development of these disorders. Due to the fact that their ligands could become crucial in future target-therapies, PPARs have therefore become the focal point of much research. Based on this evidence, this narrative review was written with the purpose of outlining the effects of PPARs, their actions, and their prospective uses in metabolic diseases and cancers.

Relationships between FTO rs9939609, MC4R rs17782313, and PPARγ rs1801282 polymorphisms and the occurrence of selected metabolic and hormonal disorders in middle-aged and elderly men - a preliminary study

PURPOSE

Metabolic disorders, including MetS, obesity, and lipid disorders, may be related to genetic factors. Metabolic disorders are associated with decreased TS levels in aging men. The aim of this study was to evaluate the relationship between FTO rs9939609, MC4R rs17782313, and PPARγ rs1801282 polymorphisms and the presence of MetS and its components, the concurrent lipid disorders, as well as sex hormone concentrations.

SUBJECTS AND METHODS

This study involved 272 men of Caucasian descent aged 50-75 years. Lipid profile, including TCh, LDL, HDL, and TG, was evaluated by spectrophotometric method. Anthropometric measurements concerned WC and blood pressure. MetS was diagnosed according to the criteria of the IDF. Sex hormone profile, including TST, FTS, E2, DHEAS, and SHBG, was examined using enzyme-linked immunosorbent assay. Polymorphisms within FTO, MC4R, and PPARγ genes were identified using polymerase chain reaction-restriction fragments length polymorphism.

RESULTS

This study did not show links between the analyzed genetic polymorphisms and the presence of MetS, T2DM, HT, and obesity. However, higher concentrations of TCh and LDL were found in men with the FTO rs9939609 polymorphism in the recessive mode of inheritance (P=0.03 and P=0.05, respectively). Lower WC was found to be associated with MC4R rs17782313 gene inherited in the same model (P=0.005).

CONCLUSION

FTO rs9939609, MC4R rs17782313, and PPARγ rs1801282 polymorphisms seem to have little effect on the incidence of metabolic malfunctions and no effect on androgen-related disorders in the examined middle-aged and elderly men.

Protective potential of epigallocatechin-3-gallate against benign prostatic hyperplasia in metabolic syndrome rats

Epigallocatechin-3-gallate (EGCG) is a major catechin in green tea with functions of antioxidant, anti-proliferative, anti-inflammatory and attenuating metabolic syndrome. In this study, rat model of benign prostatic hyperplasia (BPH) accompanied with metabolic syndrome was induced by fed on high-fat diet for 12 weeks combined with testosterone injection (10mg/kg/d) from 9th to 12th weeks. EGCG was orally given from 9th to 12th weeks. Finally, the levels of glucose, total cholesterol, triglyceride, prostate weight, insulin-like growth factors (IGFs), inflammatory cytokines, antioxidant enzymes, and prostatic expression of IGF binding protein-3 (IGFBP-3) and peroxisome proliferator activated receptors (PPARs) were evaluated. It was found that EGCG significantly decreased the levels of glucose, total cholesterol, triglyceride, IGFs, and inflammatory cytokines, normalized the activities of antioxidant enzymes, as well as increased the prostatic expression of IGFBP-3 and PPARs. These results indicated that EGCG was able to exert anti-BPH activities in metabolic syndrome rats.

Prognostic role of PPAR-γ and PTEN in the renal cell carcinoma

OBJECTIVE

To explore association of peroxisome proliferator-activated receptor gamma (PPAR-γ) and phosphatase and tensin homolog (PTEN) expressions with prognosis of renal cell carcinoma (RCC).

METHODS

Our study subjects included 87 RCC tissues, 28 paracarcinoma tissues and 21 normal renal tissues. PPAR-γ and PTEN detection was conducted using immunohistochemistry staining. The association of PPAR-γ and PTEN with the clinical parameters and prognosis of RCC was analyzed. Kaplan-Meier method and Cox's proportional hazards regression model were used for exploring the relation between variables and prognosis.

RESULTS

Among normal renal tissues, para-carcinoma tissues and renal cell carcinomas, positive PPAR-γ expression presented with a progressive tendency (P < 0.001), while positive PTEN expression a degressive tendency (P < 0.001). PPAR-γ expressions were closely related to tumor size, clinical stage and lymph node metastases (all P < 0.05). PTEN expressions were in close association with tumor size, Fuhrman grading, lymph node metastases (all P < 0.05). PPAR-γ expressions were in a negative relation with PTEN expressions (r = -0.417, P < 0.001). Negative PPAR-γ expressions confer a significantly higher overall survival rate than positive PPAR-γ expressions (P = 0.015), while negative PTEN expressions confer a significantly lower overall survival rate than positive PTEN expressions (P = 0.003). Clinical staging, Fuhrman grading, lymph node metastases, PPAR-γ and PTEN were independent prognostic factors for prognosis (all P < 0.05).

CONCLUSION

PPAR-γ and PTEN expressions are related to the clinical parameters and prognosis of RCC and may be a biomarker for prognosis of RCC.

New nanocomposite-graphene pastes based stochastic microsensors

Stochastic sensors based on metal nanocomposites-graphene pastes modified with protoporphyrin-IX were used for the assay of PPAR-γ in cerebrospinal liquid.