Molecular Mechanism of Activation of Transforming Growth Factor Beta/Smads Signaling Pathway in Ets Related Gene-Positive Prostate Cancers

In vivo study of anticancer activity of ginsenoside Rh2-containing arginine-reduced graphene in a mouse model of breast cancer

Objectives

This study aims to evaluate the in vivo anticancer activity of arginine-reduced graphene (Gr-Arg) and ginsenoside Rh2-containing arginine-reduced graphene (Gr-Arg-Rh2).

Materials and Methods

Thirty-two mice with breast cancer were divided into four groups and treated every three days for 32 days: Group 1, PBS, Group 2, Rh2, Group 3, Gr-Arg, and Group 4, Gr-Arg-Rh2. The tumor size and weight, gene expression (IL10, INF-γ, TGFβ, and FOXP3), and pathological properties of the tumor and normal tissues were assessed.

Results

Results showed a significant decrease in TGFβ expression for all drug treatment groups compared with the controls (P=0.04). There was no significant difference among the groups regarding IL10 and FOXP3 gene expression profiles (P>0.05). Gr-Arg-Rh2 significantly inhibited tumor growth (size and weight) compared with Rh2 and control groups. The highest survival rate and the highest percentage of tumor necrosis (87.5%) belonged to the Gr-Arg-Rh2 group. Lungs showed metastasis in the control group. No metastasis was observed in the Gr-Arg-Rh2 group. Gr-Arg-Rh2 showed partial degeneration of hepatocytes and acute cell infiltration in the portal spaces and around the central vein. The Gr-Arg group experienced a moderate infiltration of acute cells into the port spaces and around the central vein. The Rh2 group also showed a mild infiltration of acute and chronic cells in portal spaces.

Conclusion

Based on the results, Gr-Arg-Rh2 can reduce tumor size, weight, and growth, TGF-β gene expression, and increase tumor necrosis and survival time in mice with cancer.

Effects of butyl benzyl phthalate exposure on Daphnia magna growth, reproduction, embryonic development and transcriptomic responses

Butyl benzyl phthalate (BBP) is widely used as a plasticizer to increase the plasticity and flexibility of plastic products. Although the potential health hazards of BBP have recently received extensive attention, its toxicological properties and mechanisms remain largely undefined. In the present work, growth, reproductive and developmental toxicity of BBP to Daphnia magna were evaluated, and the transcriptomic alteration of early embryos upon BBP exposure was analyzed. In a 21-day chronic toxicity test, reduced survival ratio, decreased body length, increased abnormal ratio, advanced time to first brood, and reduced offspring of D. magna were observed. BBP exposure inhibited expression of the vitellogenin gene. In addition, embryotoxicity of BBP was observed, which showed not only in the induction of abnormal neonates, but also in the shortened embryonic development cycle. RNA-Seq of early embryo treated with 0.1 mg/L BBP indicated that the pathways involved in signal transduction, cell communication, and embryonic development were significantly down-regulated, while those of biosynthesis, metabolism, cell homeostasis, redox homeostasis were remarkably up-regulated upon BBP exposure, which was consistent with the above phenotypic results. Taken together, our results highlight the toxic effects of BBP on the embryonic development and larval growth of D. magna.

Nuclear ELAC2 overexpression is associated with increased hazard for relapse after radical prostatectomy

ELAC2 is a ubiquitously expressed enzyme potentially involved in tRNA processing and cell signaling pathways. Mutations of the ELAC2 gene have been found to confer increased prostate cancer susceptibility in families. ELAC2 protein expression was analyzed by immunohistochemistry in 9,262 patients and Kaplan-Meier curves of PSA recurrence-free survival were calculated in 8,513 patients treated with radical prostatectomy. Nuclear ELAC2 staining was observed in 60.8% of prostate cancers. It was weak in 26.3%, moderate in 26.6% and strong in 7.9%. Strong nuclear ELAC2 expression was associated with advanced tumor stage, nodal metastasis, higher Gleason grade, presence of TMPRSS2:ERG fusion, higher Ki67-labeling index and PTEN deletion. The difference in 1-, 5- and 10-year recurrence-free survival between strong and weak nuclear ELAC2 intensity is 7.2/13.8/17.6% in all cancers, 7.4/16.1/26.5% in the ERG negative subset, and 3.1/5.7/9.8% in the ERG positive subset. Regarding the univariate hazard ratio, PSA recurrence-free survival after prostatectomy for strong nuclear ELAC2 expression is 1.89 (1.64–2.10, p < 0.0001). It is independent of preoperative PSA-level, Gleason grade, pathological stage, surgical margin stage, and lymph node stage (multivariate hazard ratio 1.29 (1.11–1.49, p = 0.001). We conclude that nuclear ELAC2 expression is an independent prognostic marker for PSA recurrence-free survival after radical prostatectomy with a weak to moderate increase of the hazard ratio for biochemical relapse.

The Role of Long Non-coding RNA Prostate Cancer-Associated Transcript 1 in Prostate Cancer

This study aimed to investigate the role of prostate cancer associated transcript 1 (PCAT1) underlying the molecular mechanisms of prostate cancer. Using GSE29886 data set downloaded from Gene Expression Omnibus database, we screened the differentially expressed genes (DEGs) in PCAT1-siRNA interfering (PCAT1-siRNA) LNCaP cells compared with control-siRNA cells. Transcription factor (TF) and tumor-associated genes database were used to obtain oncogenes and tumor suppressor genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were used to investigate the function and pathways of DEGs. Subnetwork was further analyzed using BioNet. A total of 93 DEGs were identified. KEGG analysis showed downregulated TF genes (ID1 and ID3) were enriched in transforming growth factor-β pathway, whereas upregulated genes were involved in pathways associated with immune system, environmental sensing, and metabolism. GO analysis showed that downregulated genes were primarily enriched in cell cycle-related biological functions and upregulated DEGs were related to immune response, exogenous genetic material response, and viral response. Centromere protein F (CENPF) was identified as the central node of the regulatory subnetwork. In the PCAT1 knockdown LNCaP cells, the CENPF, ID1, and ID3 were obviously decreased based on the RT-PCR (quantitative real-time reverse transcription PCR) analysis. PCAT1 may be involved in cell cycle and proliferation of prostate cancers by mediating the expression of CENPF, ID1, and ID3.

Up-regulation of Biglycan is Associated with Poor Prognosis and PTEN Deletion in Patients with Prostate Cancer

Biglycan (BGN), a proteoglycan of the extracellular matrix, is included in mRNA signatures for prostate cancer aggressiveness. To understand the impact of BGN on prognosis and its relationship to molecularly defined subsets, we analyzed BGN expression by immunohistochemistry on a tissue microarray containing 12,427 prostate cancers. Seventy-eight percent of 11,050 interpretable cancers showed BGN expression, which was considered as low intensity in 47.7% and as high intensity in 31.1% of cancers. BGN protein expression rose with increasing pathological tumor stage, Gleason grade, lymph node metastasis and early PSA recurrence (P<.0001 each). Comparison with our molecular database attached to the TMA revealed that BGN expression was linked to presence of TMPRRS2:ERG fusion and PTEN deletion (P<.0001 each). In addition, BGN was strongly linked to androgen-receptor (AR) levels (P<.0001), suggesting a hormone-depending regulation of BGN. BGN up-regulation is a frequent feature of prostate cancer that parallels tumor progression and may be useful to estimate tumor aggressiveness particularly if combined with other molecular markers.

MicroRNA-93 inhibits apoptosis and promotes proliferation, invasion and migration of renal cell carcinoma ACHN cells via the TGF-β/Smad signaling pathway by targeting RUNX3

We investigated the ability of microRNA-93 (miR-93) to influence proliferation, invasion, migration, and apoptosisofrenal cell carcinoma (RCC) cells via transforming growth factor-β/solvated metal atom dispersed (TGF-β/Smad) signaling by targeting runt-related transcription factor 3 (RUNX3). RCC tissues with corresponding adjacent normal tissues were collected from 249 RCC patients. And normal renal tissues were collected from patients without RCC who received nephrectomy. The RCC cell line ACHN was treated with miR-93 mimic, mimic-negative control (NC), miR-93 inhibitor, inhibitor-NC, and miR-93 inhibitor + small interfering RNA (siRNA) against RUNX3 (si-RUNX3). Expression of miR-93, RUNX3, TGF-β, and Smad4 were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Cell proliferation was assessed by the Metallothioneins (MTS) assay, cell invasion by the wound-healing assay, cell migration by the Transwell assay, and cell cycle and apoptosis by flow cytometry. Compared with normal renal tissues, the expression of miR-93 and TGF-β were higher while that of RUNX3 and Smad4 were low in RCC and adjacent normal tissues (all P<0.05). RUNX3 was confirmed as a target of miR-93 by the dual luciferase reporter gene assay. Compared with mimic-NC group, cell proliferation, invasion, migration and cells from G0/G1 to S phase enhanced but the apoptosis decreased in the miR-93 mimic group (all P<0.05). Compared with inhibitor-NC group, proliferation, invasion, and migration reduced, while apoptosis increased, and cells at G0/G1 phase arrested in the miR-93 inhibitor group (all P<0.05). Compared with miR-93 inhibitor group, cell proliferation, invasion, and migration increased with increasing cells from G1 to S phase while the apoptosis decreased, in miR-93 inhibitor + si-RUNX3 group (all P<0.05). In conclusion, miR-93 inhibits apoptosis and promotes proliferation, invasion, and migration of RCC cells via TGF-β/Smad signaling by inhibiting RUNX3.

PCA3 and TMPRSS2-ERG gene fusions as diagnostic biomarkers for prostate cancer

The incidence of prostate cancer (PCa) is rising steadily among males in many countries. Serum prostate-specific antigen (PSA) is widely applied to clinical diagnosis and screening of PCa. However, the so-called grey area of PSA levels 4.0-10.0 ng/mL has a low specificity of 25-40% resulting in a high rate of negative biopsy and overtreatment. So in order to treat PCa patients in early stage, there is an urgent need for new biomarkers in PCa diagnosis. The PCA3 gene, a non-coding RNA (ncRNA) that is highly expressed in prostate cancer (PCa) cells, has been identified as a molecular biomarkers to detect PCa, of which PCA3 has already under clinical application. PCA3 is strongly overexpressed in malignant prostate tissue compared to benign or normal adjacent one. Newly, PCA3 is considered to be a promising biomarker in clinical diagnosis and targeted therapy. The diagnostic significance of PCA3, however, is awaiting further researches. Moreover, it has been demonstrated recently that TMPRSS2-ERG gene fusion is identified as the predominant genetic change in patients diagnosed with PCa. Recent study revealed that combination of the PCA3 and TMPRSS2-ERG gene fusion test optimizes PCa detection compared with that of single biomarker, which would lead to a considerable reduction of the number of prostate biopsies. In this review, we focused on the potential use of PCA3 and TMPRSS2-ERG gene fusion detection in the diagnosis of PCa.

Molecular Mechanism of β-Catenin Signaling Pathway Inactivation in ETV1-Positive Prostate Cancers

In the United States of America, prostate cancer is the second most common age-related cancer among men. African-American men have the highest incidence of, and mortality rate from this disease in the United States. According to the American Cancer Society, 29% of all cancer cases and 9% of all cancer deaths are a result of prostate cancer. Individuals who are at highest risk include African-American men, men over 60 years of age, and those with a family history of the disease. African-Americans also have twice the risk of developing prostate cancer as compared to Caucasians. Erythroblastosis virus E26 transformation-specific (ETS) factors play an important role in human cancers. ETS Variant 1 (ETV1), an ETS factor, is notable for its association in prostate cancers, where truncated ETV1 (dETV1) or its full length counterpart is overexpressed in approximately 10% of the prostate cancer patients. Prostate cancer tumorigenesis may be initiated by deregulation of the Wnt/β-catenin pathway. Mutations that stabilize β-catenin were shown to contribute to the loss of cell-growth control in tumorigenesis. We hypothesized that ETV1's interaction with components of the Wnt/β-catenin pathway may alter β-catenin's interaction with downstream tumor-suppressor genes, which are critical in regulating apoptosis and cell-growth properties of prostate cells. Our results demonstrate for the first time that ETV1 alters β-catenin activity by activating kinases that regulate Wnt/β-catenin activity through post-translational modification in prostate cancer cells. We further demonstrate that therapeutic agents such as PD98059, that reverse effect of ETV1 on Wnt/β-catenin signaling pathway, can be used to target ETV1-positive prostate cancer cells. These therapeutic agents could have a profound impact on prevention and treatment of prostate cancer which may help to reduce health disparity seen in minority patients. Understanding the role of ETV1 in Wnt/β-catenin pathway will also allow us to develop better diagnostic tools, which can be used as a biomarker for ETV1-positive prostate cancers.

Ets Related Gene and Smad3 Proteins Collaborate to Activate Transforming Growth Factor-Beta Mediated Signaling Pathway in ETS Related Gene-Positive Prostate Cancer Cells

TGF-β/Smads signaling plays a significant role in the regulation of growth of normal and prostate cancer cells. Smad proteins function as important mediators of intracellular signal transduction of transforming growth factor-β (TGF-β). TGF-β signaling pathway is known to regulate cell proliferation, differentiation, apoptosis and play a major role in some human diseases and cancers. Following their phosphorylation by TGF-β receptor-I, Receptor-regulated Smads (including Smad2 and Smad3 proteins) form a heteromeric complex with co-Smad (Smad4) and then translocate into the nucleus where they bind and regulate the expression of target genes. ERG (Ets Related Gene) belongs to the ETS family of transcriptional factors. Chromosomal rearrangement of TMPRSS2 gene and ERG gene has been found in majority of prostate cancers. Over-expression of full length or truncated ERG proteins have been shown to associate with a higher rate of recurrent and unfavorable prognosis of prostate cancer. In order to understand how ERG oncoprotein regulates TGF-β/Smads signaling pathway, we have studied the effect of ERG on TGF-β/Smad3 signaling pathway. In this study, we demonstrate that ERG oncoprotein physically interacts with Smad3 protein and stabilizes phospho-Smad3 protein and thereby enhance TGF-β/Smad3 signaling pathway in prostate cells. Thus, ERG oncoprotein plays an important role in prostate tumorigenesis by using a novel mechanism to activate TGF-β/Smad3 signaling pathway.