Lentivirus-mediated SMO RNA interference inhibits SMO expression and cell proliferation, and affects the cell cycle in LNCaP and PC3 cancer cell lines

The miR-17-92 cluster in cardiac health and disease

MicroRNAs (miRs) are small noncoding RNAs that play important roles in both physiological and pathological processes through post-transcriptional regulation. The miR-17-92 cluster includes six individual members: miR-17, miR-18a, miR-19a, miR-19b-1, miR-20a, and miR-92a-1. The miR-17-92 cluster has been extensively studied and reported to broadly function in cancer biology, immunology, neurology, pulmonology, and cardiology. This review focuses on its roles in heart development and cardiac diseases. We briefly introduce the nature of the miR-17-92 cluster and its crucial roles in both normal development and the pathogenesis of various diseases. We summarize the recent progress in understanding the versatile roles of miR-17-92 during cardiac development, regeneration, and aging. Additionally, we highlight the indispensable roles of the miR-17-92 cluster in pathogenesis and therapeutic potential in cardiac birth defects and adult cardiac diseases.

A Novel Therapeutic siRNA Nanoparticle Designed for Dual-Targeting CD44 and Gli1 of Gastric Cancer Stem Cells

Purpose

Gastric cancer stem cells (CSCs) are important for the initiation, growth, recurrence, and metastasis of gastric cancer, due to their chemo-resistance and indefinite proliferation. Herein, to eliminate gastric CSCs, we developed novel CSC-targeting glioma-associated oncogene homolog 1 (Gli1) small interfering RNA (siRNA) nanoparticles that are specifically guided by a di-stearoyl-phosphatidyl-ethanolamine- hyaluronic-acid (DSPE-HA) single-point conjugate, as an intrinsic ligand of the CD44 receptor. We refer to these as targeting Gli1 siRNA nanoparticles.

Methods

We used the reductive amination reaction method for attaching amine groups of DSPE to aldehydic group of hyaluronic acid (HA) at the reducing end, to synthesize the DSPE-HA single-point conjugate. Next, targeting Gli1 siRNA nanoparticles were prepared using the layer-by-layer assembly method. We characterized the stem cellular features of targeting Gli1 siRNA nanoparticles, including their targeting efficiency, self-renewal capacity, the migration and invasion capacity of gastric CSCs, and the penetration ability of 3D tumor spheroids. Next, we evaluated the therapeutic efficacy of the targeting Gli1 siRNA nanoparticles by using in vivo relapsed tumor models of gastric CSCs.

Results

Compared with the multipoint conjugates, DSPE-HA single-point conjugates on the surface of nanoparticles showed significantly higher binding affinities with CD44. The targeting Gli1 siRNA nanoparticles significantly decreased Gli1 protein expression, inhibited CSC tumor spheroid and colony formation, and suppressed cell migration and invasion. Furthermore, in vivo imaging demonstrated that targeting Gli1 siRNA nanoparticles accumulated in tumor tissues, showing significant antitumor recurrence efficacy in vivo.

Conclusion

In summary, our targeting Gli1 siRNA nanoparticles significantly inhibited CSC malignancy features by specifically blocking Hedgehog (Hh) signaling both in vitro and in vivo, suggesting that this novel siRNA delivery system that specifically eliminates gastric CSCs provides a promising targeted therapeutic strategy for gastric cancer treatment.

Circular RNA SMO sponges miR-338-3p to promote the growth of glioma by enhancing the expression of SMO

Glioma is one of the most common tumors in the brain and complete cure still a challenge. The present research aimed to investigate the molecular mechanism of circular RNA SMO (circSMO742) in glioma, via targeting miR-338-3p and regulating SMO expression. QRT-PCR was utilized to examine the expression profiles of circSMO742 and microRNA-338-3p (miR-338-3p) in glioma. SMO protein in glioma was tested via western blot. RNA pulldown assay and dual luciferase reporter assays were used to explore the targeting correlation between RNAs. MTT assay, transwell assays and flow cytometry were used to investigate cell proliferation, migration and invasion, and apoptosis, respectively. Tumor xenograft was done to ascertain the effect of circSMO742 knocking down on tumor growth. CircSMO742 and SMO were highly expressed in glioma tissues, while miR-338-3p expression was reduced. CircSMO742 together with SMO could promote cells proliferation, migration and invasion while inhibit cells apoptosis, whereas miR-338-3p showed negative impacts on the cell activity. Knocking down of circSMO742 suppressed glioma growing in vivo. CircSMO742 promoted glioma growth by sponging miR-338-3p to regulate SMO expression. Our research revealed a new molecular mechanism of glioma growth and provide a fresh perspective on circRNAs in glioma progression.

In utero and lactational exposure of DEHP increases the susceptibility of prostate carcinogenesis in male offspring through PSCA hypomethylation

As an ubiquitous environmental endocrine disruptor, di(2-ethylhexyl) phthalate (DEHP) has been shown to interfere with the development of reproductive organs and induce pathological changes in prostate. Our previous finding showed that in utero and lactational (IUL) DEHP exposure could disrupt the balance of testosterone and estrogen and increase the susceptibility of prostate carcinogenesis. The purpose of this study is to investigate whether the early-life specific epigenetic modifications could mediate the effect of DEHP exposure on prostate carcinogenesis in rodents, for epigenetic modifications play important roles in regulating prostate carcinogenesis. The pregnant rats were treated with corn oil (negative control) or DEHP at 0.01, 0.1 and 1 mg/kg BW/day from GD7 to PND21. On PND21, the expression and DNA methylation change of six prostate carcinogenesis-related genes (ESR2/GSTP1/NKX3.1/PSCA/PTGS2/Rassf1a) were assessed through SYBR-Green real-time PCR combined with pyrosequencing assay in F1 male offspring. On PND196, the relationship b(STP1, PSCA and PTGS2 in a dose-dependent manner, which were positively correlated with PIN scores, Gleason scores, serum PSA concentrations and negatively correlated with prostate/body weight ratio on PND196. Meanwhile, 1 mg/kg BW/day DEHP markedly reduced DNA methylation level of PSCA in all studied CpG sites. Significant inverse correlations between methylation levels of the promoter CpG site and PSCA mRNA expression were observed. These results indicated that transcriptional changes of GSTP1, PSCA and PTGS2 induced by DEHP exposure might be contribute to the increasing susceptibility of prostate carcinogenesis in late life. Moreover, hypomethylation of PSCA could mediate the effect of DEHP on prostate carcinogenesis in rats.

miR-20a regulates proliferation, differentiation and apoptosis in P19 cell model of cardiac differentiation by targeting Smoothened

MicroRNA (miR)-20a, a member of the miR-17-92 cluster related to cardiac development, was obviously downregulated in myocardially differentiated P19 cells compared with normal P19 cells. Smoothened (SMO) is a member of the Hh pathway. Hh signaling induces cardiac differentiation in P19 cells, and SMO mediates the Hh pathway during embryonic development. Using bioinformatic prediction software Targetscan (http://www.targetscan.org/), PicTar (http://pictar.bio.nyu.edu), and miRBase (http://microrna.sanger.ac.uk/), miR-20a and the 3′-untranslated region (3′-UTR) of SMO mRNA were predicted to have complementary binding regions. Accordingly, we inferred that miR-20a might act as a regulator of SMO, and regulate proliferation, differentiation and apoptosis in P19 cells. We determined the expression of miR-20a, SMO and marker proteins of cardiomyocytes (cTnT, GATA4 and desmin) by quantitative real-time PCR (qRT-PCR) and western blot assays, and found that P19 cells had differentiated into cardiomyocytes successfully at differentiation day 10, and downregulation of miR-20a and upregulation of SMO existed in myocardially differentiated P19 cells. Cell proliferation, differentiation and apoptosis detection showed that miR-20a upregulation inhibited proliferation and differentiation and enhanced apoptosis in P19 cells. Moreover, we verified that miR-20a directly targeted SMO and knockdown of SMO and miR-20a overexpression had similar effects on P19 cell proliferation, differentiation and apoptosis, which verified the speculation that miR-20a inhibits proliferation and differentiation and enhances apoptosis in P19 cells by directly targeting SMO. Our results suggest that miR-20a may be a potential target against congenital heart diseases.

Summary: Our findings may bring a new viewpoint into the mechanisms of cardiac abnormalities and suggest that miR-20a may be a potential new therapeutic target for congenital heart diseases.

Mono-2-ethyhexyl phthalate advancing the progression of prostate cancer through activating the hedgehog pathway in LNCaP cells

Hedgehog (Hh) pathway plays a critical role in the progression of prostate cancer (PCa), the most commonly diagnosed non-cutaneous cancer in male adults. Studies showed that di-n-butyl phthalate (DBP) could interference with the Hh pathway. Di-2-ethylhexyl phthalate (DEHP), the congener of DBP, is the major plasticizer used in plastic materials that are inevitably exposed by patients with PCa. The aim of this in vitro study was to investigate whether mono-2-ethyhexyl phthalate (MEHP, the active metabolite of DEHP) could activate the Hh pathway of LNCaP cells. Results showed that the expression of the critical gene of Hh pathway PTCH and androgen-regulated gene KLK3 was significantly decreased on 3, 6 and 9 days with Hh pathway inhibitor cyclopamine's treatment. MEHP notably up-regulated the expression of PTCH with a dose-response relationship in the presence of cyclopamine, which indicate that MEHP might target on the downstream components of Hh pathway and advance the progression of PCa through activating the Hh pathway.

MicroRNA-338-3p inhibits colorectal carcinoma cell invasion and migration by targeting smoothened

OBJECTIVE

To investigate the regulative effect of microRNA-338-3p on colorectal carcinoma cell invasion and migration.

METHODS

The microRNA-338-3p expression pattern of colorectal carcinoma tissues and cell lines was detected by real-time reverse transcriptase polymerase chain reaction. The protein level of smoothened was detected by western blot analysis. Furthermore, colorectal carcinoma cells were pretreated with or without anti-smoothened-small interfering ribonucleic acid prior to the addition of pre-microRNA-338-3p or anti-microRNA-338-3p. The status of colorectal carcinoma cell invasion and that of migration were detected by transwell assay and wound healing assay, respectively.

RESULTS

The expression of microRNA-338-3p was significantly down-regulated in colorectal carcinoma tissues in comparison with those in the adjacent non-tumorous tissues, and the value was negatively related to advanced tumor, node, metastasis stage and local invasion. The expression of microRNA-338-3p in colorectal carcinoma cells transfected with pre-microRNA-338-3p p was significantly increased. Furthermore, over-expression of microRNA-338-3p inhibited the expression of smoothened protein in colorectal carcinoma cells, which showed obviously suppressed invasion and migration ability. The expression of microRNA-338-3p in colorectal carcinoma cells transfected with anti-microRNA-338-3p was significantly decreased. Moreover, the down-regulated expression of microRNA-338-3p caused the up-regulated expression of smoothened protein in colorectal carcinoma cells, which showed significantly enhanced invasion and migration ability. However, anti-smoothened-small interfering ribonucleic acid largely, but not completely, reversed the effects induced by blockage of microRNA-338-3p, suggesting that the regulative effect of microRNA-338-3p on colorectal carcinoma cell invasion and migration was indeed mediated by smoothened. Additionally, smoothened was identified as a direct target of microRNA-338-3p by luciferase assay.

CONCLUSIONS

MicroRNA-338-3p could inhibit colorectal carcinoma cell invasion and migration by inhibiting smoothened expression.