Targeting adenoviral vectors for enhanced gene therapy of uterine leiomyomas

EZH2 activates Wnt/β-catenin signaling in human uterine fibroids, which is inhibited by the natural compound methyl jasmonate

OBJECTIVE

To investigate the link between EZH2 and Wnt/β-catenin signaling and its role in uterine fibroids (UFs) pathogenesis and explore the potential effect of natural compound methyl jasmonate (MJ) against UFs.

DESIGN

EZH2 overexpression or inhibition was achieved in human uterine leiomyoma (HuLM) cells using EZH2-expressing adenovirus or chemical EZH2 inhibitor (DZNep), respectively. The HuLM and normal uterine smooth muscle cells were treated with 0.1-3 mM of MJ, and several experiments were employed.

SETTING

Laboratory study.

PATIENTS(S)

None.

INTERVENTION(S)

Methyl jasmonate.

MAIN OUTCOME MEASURE(S)

Protein expression of EZH2, β-catenin, and proliferating cell nuclear antigen (PCNA) was measured by Western blot as well as gene expression alterations of Wnt ligands (Wnt5A, Wnt5b, and Wnt9A), WISP1, CTNNB1, and its responsive gene PITX2 using quantitative real-time polymerase chain reaction. The protein and ribonucleic acid (RNA) levels of several markers were measured in MJ-treated or untreated HuLM cells, including EZH2 and β-catenin, extracellular matrix markers collagen type 1 (COL1A1) and fibronectin (FN), proliferation markers cyclin D1 (CCND1) and PCNA, tumor suppressor marker p21, and apoptotic markers (BAX, cytochrome c, and cleaved caspase 3).

RESULT(S)

EZH2 overexpression significantly increased the gene expression of several Wnt ligands (PITX2, WISP1, WNT5A, WNT5B, and WNT9A), which increased nuclear translocation of β-catenin and PCNA and eventually HuLM cell proliferation. EZH2 inhibition blocked Wnt/β-catenin signaling activation where the aforementioned genes significantly decreased as well as PCNA, cyclin D1, and PITX2 protein expression compared with those in untreated HuLM. Methyl jasmonate showed a potent antiproliferative effect on HuLM cells in a dose- and time-dependent manner. Interestingly, the dose range (0.1-0.5 mM) showed a selective growth inhibitory effect on HuLM cells, not on normal uterine smooth muscle cells. Methyl jasmonate treatment at 0.5 mM for 24 hours significantly decreased both protein and RNA levels of EZH2, β-catenin, COL1A1, FN, CCND1, PCNA, WISP1, and PITX2 but increased the protein levels of p21, BAX, cytochrome, c and cleaved caspase 3 compared with untreated HuLM. Methyl jasmonate-treated cells exhibited down-regulation in the RNA expression of 36 genes, including CTNNB1, CCND1, Wnt5A, Wnt5B, and Wnt9A, and up-regulation in the expression of 34 genes, including Wnt antagonist genes WIF1, PRICKlE1, and DKK1 compared with control, confirming the quantitative real-time polymerase chain reaction results.

CONCLUSION(S)

Our studies provide a novel link between EZH2 and the Wnt/β-catenin signaling pathway in UFs. Targeting EZH2 with MJ interferes with the activation of wnt/β-catenin signaling in our model. Methyl jasmonate may offer a promising therapeutic option as a nonhormonal and cost-effective treatment against UFs with favorable clinical utility, pending proven safe and efficient in human clinical trials.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

Gene Therapy for Malignant and Benign Gynaecological Disorders: A Systematic Review of an Emerging Success Story

Simple Summary

This review discusses all the major advances in gene therapy of gynaecological disorders, highlighting the novel and potentially therapeutic perspectives associated with such an approach. It specifically focuses on the gene therapy strategies against major gynaecological malignant disorders, such as ovarian, cervical, and endometrial cancer, as well as benign disorders, such as uterine leiomyomas, endometriosis, placental, and embryo implantation disorders. The above therapeutic strategies, which employ both viral and non-viral systems for mutation compensation, suicide gene therapy, oncolytic virotherapy, antiangiogenesis and immunopotentiation approaches, have yielded promising results over the last decade, setting the grounds for successful clinical trials.

Abstract

Despite the major advances in screening and therapeutic approaches, gynaecological malignancies still present as a leading cause of death among women of reproductive age. Cervical cancer, although largely preventable through vaccination and regular screening, remains the fourth most common and most lethal cancer type in women, while the available treatment schemes still pose a fertility threat. Ovarian cancer is associated with high morbidity rates, primarily due to lack of symptoms and high relapse rates following treatment, whereas endometrial cancer, although usually curable by surgery, it still represents a therapeutic problem. On the other hand, benign abnormalities, such as fibroids, endometriosis, placental, and embryo implantation disorders, although not life-threatening, significantly affect women’s life and fertility and have high socio-economic impacts. In the last decade, targeted gene therapy approaches toward both malignant and benign gynaecological abnormalities have led to promising results, setting the ground for successful clinical trials. The above therapeutic strategies employ both viral and non-viral systems for mutation compensation, suicide gene therapy, oncolytic virotherapy, antiangiogenesis and immunopotentiation. This review discusses all the major advances in gene therapy of gynaecological disorders and highlights the novel and potentially therapeutic perspectives associated with such an approach.

Magnetic Nanoparticles as a Component of Peptide-Based DNA Delivery System for Suicide Gene Therapy of Uterine Leiomyoma

Suicidegene therapy is considered a promising approach for the treatment of uterine leiomyoma (UL), a benign tumor in women characterized by precise localization. In this study, we investigate the efficiency of αvβ3 integrin-targeted arginine-rich peptide carrier R6p-cRGD electrostatically bound to magnetic nanoparticles (MNPs) for targeted DNA delivery into the UL cells. The physico–chemical and cytotoxic properties, transfection efficiency, and specificity of R6p-cRGD/DNA/MNPs polyplexes were evaluated. The addition of MNPs resulted in a decrease in the time needed for successful transfection with simultaneous increase in efficiency. We revealed a therapeutic effect on primary UL cells after delivery of plasmid encoding the herpes simplex virus type 1 (HSV-1) thymidine kinase gene. Treatment with ganciclovir resulted in 20% efficiency of suicide gene therapy in UL cells transfected with the pPTK-1 plasmid. Based on these results, we conclude that the use of cationic peptide carriers with MNPs can be promising for the development of modular non-viral carriers for suicide gene delivery to UL cells.

Polycondensed Peptide Carriers Modified with Cyclic RGD Ligand for Targeted Suicide Gene Delivery to Uterine Fibroid Cells

Suicide gene therapy was suggested as a possible strategy for the treatment of uterine fibroids (UFs), which are the most common benign tumors inwomen of reproductive age. For successful suicide gene therapy, DNAtherapeutics should be specifically delivered to UF cells. Peptide carriers are promising non-viral gene delivery systems that can be easily modified with ligands and other biomolecules to overcome DNA transfer barriers. Here we designed polycondensed peptide carriers modified with a cyclic RGD moiety for targeted DNA delivery to UF cells. Molecular weights of the resultant polymers were determined, and inclusion of the ligand was confirmed by MALDI-TOF. The physicochemical properties of the polyplexes, as well as cellular DNA transport, toxicity, and transfection efficiency were studied, and the specificity of αvβ3 integrin-expressing cell transfection was proved. The modification with the ligand resulted in a three-fold increase of transfection efficiency. Modeling of the suicide gene therapy by transferring the HSV-TK suicide gene to primary cells obtained from myomatous nodes of uterine leiomyoma patients was carried out. We observed up to a 2.3-fold decrease in proliferative activity after ganciclovir treatment of the transfected cells. Pro- and anti-apoptotic gene expression analysis confirmed our findings that the developed polyplexes stimulate UF cell death in a suicide-specific manner.

Development of iRGD-Modified Peptide Carriers for Suicide Gene Therapy of Uterine Leiomyoma

Uterine leiomyoma (UL) is one of the most common benign tumors in women that often leads to many reproductive complications. Suicide genetherapy was suggested as a promising approach for UL treatment. In the present study, we describe iRGD ligand-conjugated cysteine-rich peptide carrier RGD1-R6 for targeted DNA delivery to αvβ3 integrin-expressing primary UL cells. The physico-chemical properties, cytotoxicity, transfection efficiency and specificity of DNA/RGD1-R6 polyplexes were investigated. TheHSV-1thymidine kinase encoding plasmid delivery to PANC-1pancreatic carcinoma cells and primary UL cells resulted in significant suicide gene therapy effects. Subsequent ganciclovir treatment decreased cells proliferative activity, induced of apoptosis and promoted cells death.The obtained results allow us to concludethatthe developed RGD1-R6 carrier can be considered a promising candidate for suicide gene therapy of uterine leiomyoma.

Molecular Bio-Imaging Probe for Non-Invasive Differentiation Between Human Leiomyoma Versus Leiomyosarcoma

Leiomyosarcoma is the most frequent subtype of the deadly uterine sarcoma and shares many common clinical grounds with leiomyoma, which is in turn the most common solid benign uterine neoplasm. With the recent progress in minimally invasive techniques for managing leiomyomas, accurate preoperative diagnosis of uterine masses has become the most important selection criterion for the safest therapeutic option. Therefore, different imaging modalities would be playing a key role in management of uterine masses. Testing for a sarcoma-specific promoter that expresses its downstream reporter gene only in leiomyosarcoma and not in leiomyoma or healthy uterine tissue. Adenoviral vectors were utilized both in vitro and in vivo to test the specificity of the promoters. Quantitative studies of downstream gene expression of these promoters was carried out both in vitro and in vivo. Our data indicated that human leiomyosarcoma cells highly expressed the reporter gene downstream to survivin promoter (Ad-SUR-LUC) when compared with benign leiomyoma or normal cells (p value of 0.05). Our study suggested that survivin is the unique promoter capable of distinguishing between the deadly sarcoma and the benign counterparts.

Successes and failures of uterine leiomyoma drug discovery

INTRODUCTION

To-date, the only cure for symptomatic uterine fibroids (UFs) is surgical intervention. However, surgery may eliminate the hope of future pregnancies; moreover, the intrinsic risks of surgery make it a less favorable to women with UFs. Because of this, conservative medical therapies have become an attractive and prior option for those women. Leuprolide acetate (LA), a gonadotropin-releasing hormone (GnRH) agonist, is the only pharmacological agent currently approved for the short-term and pre-operative management of symptomatic UFs in the USA. Areas covered: This systematic review covers the successes and failures of prominent drugs that have been researched for UFs in the past and agents that have shown promise in recent clinical trials. The most recent clinical trials and advances in drug therapy are presented in a comprehensive overview outlining the direction UF drug discovery is heading. Expert opinion: Experts in the field are already on the forefront leading the responsibility to uncover potential drugs as long term fertility friendly viable options for non-invasive treatment/prevention of UFs. Indeed, a shift in the UF management is expected in the future.

Identification of Polycomb Group Protein EZH2-Mediated DNA Mismatch Repair Gene MSH2 in Human Uterine Fibroids

Uterine fibroids (UFs) are benign smooth muscle neoplasms affecting up to 70% of reproductive age women. Treatment of symptomatic UFs places a significant economic burden on the US health-care system. Several specific genetic abnormalities have been described as etiologic factors of UFs, suggesting that a low DNA damage repair capacity may be involved in the formation of UF. In this study, we used human fibroid and adjacent myometrial tissues, as well as an in vitro cell culture model, to evaluate the expression of MutS homolog 2 (MSH2), which encodes a protein belongs to the mismatch repair system. In addition, we deciphered the mechanism by which polycomb repressive complex 2 protein, EZH2, deregulates MSH2 in UFs. The RNA expression analysis demonstrated the deregulation of MSH2 expression in UF tissues in comparison to its adjacent myometrium. Notably, protein levels of MSH2 were upregulated in 90% of fibroid tissues (9 of 10) as compared to matched adjacent myometrial tissues. Human fibroid primary cells treated with 3-deazaneplanocin A (DZNep), chemical inhibitor of EZH2, exhibited a significant increase in MSH2 expression (P < .05). Overexpression of EZH2 using an adenoviral vector approach significantly downregulated the expression of MSH2 (P < .05). Chromatin immunoprecipitation assay demonstrated that enrichment of H3K27me3 in promoter regions of MSH2 was significantly decreased in DZNep-treated fibroid cells as compared to vehicle control. These data suggest that EZH2-H3K27me3 regulatory mechanism dynamically changes the expression levels of DNA mismatch repair gene MSH2, through epigenetic mark H3K27me3. MSH2 may be considered as a marker for early detection of UFs.

Magnetic nanoparticles as a new approach to improve the efficacy of gene therapy against differentiated human uterine fibroid cells and tumor-initiating stem cells

OBJECTIVE

To study whether efficient transduction and subsequent elimination of fibroid tumor-initiating stem cells during debulking of tumor cells will aid in completely eradicating the tumor as well as decreasing the likelihood of recurrence.

DESIGN

Case control study.

SETTING

Research laboratory.

PATIENT(S)

None.

INTERVENTION(S)

Magnetic nanoparticles (MNPs) complexed to adenovirus (Ad-GFP) or (Ad-LacZ) used to transfect differentiated human fibroid cells in vitro.

MAIN OUTCOME MEASURE(S)

Rate of transduction and tumor growth inhibition.

RESULT(S)

We have developed a localized nonsurgical adenovirus-based alternative for the treatment of uterine fibroids that combines viral-based gene delivery with nanotechnology for more efficient targeting. Magnetic nanoparticles complexed to adenovirus, in the presence of an external magnetic field, accelerate adenovirus transduction. We observed a statistically significant increase in transduction efficiency among differentiated human fibroid cells at two different multiplicities of infection (MOI), 1 and 10, respectively, with MNPs as compared with adenovirus alone. Human fibroid stem cells transfected with Ad-LacZ expressed β-galactosidaze at a MOI of 1, 10, and 50 at 19%, 62%, and 90%, respectively, which were statistically significantly enhanced with MNPs.

CONCLUSION(S)

When applied with adenovirus herpes simplex thymidine kinase, magnetofection statistically significantly suppressed proliferation and induced apoptosis in both cell types. Through the use of magnetofection, we will prove that a lower viral dose will effectively increase the overall safety profile of suicide gene therapy against fibroid tumors.

Targeted Adenoviral Vector Demonstrates Enhanced Efficacy for In Vivo Gene Therapy of Uterine Leiomyoma

BACKGROUND

Gene therapy is a potentially effective non-surgical approach for the treatment of uterine leiomyoma. We demonstrated that targeted adenovirus vector, Ad-SSTR-RGD-TK/GCV, was highly effective in selectively inducing apoptosis and inhibiting proliferation of human leiomyoma cells in vitro while sparing normal myometrial cells.

STUDY DESIGN

An in-vivo study, to compare efficacy and safety of modified adenovirus vector Ad-SSTR-RGD-TK/GCV versus untargeted vector for treatment of leiomyoma.

MATERIALS AND METHODS

Female nude mice were implanted with rat leiomyoma cells subcutaneously. Then mice were randomized into three groups. Group 1 received Ad-LacZ (marker gene), Group 2 received untargeted Ad-TK, and Group 3 received the targeted Ad-SSTR-RGD-TK. Tumors were measured weekly for 4 weeks. Then mice were sacrificed and tissue samples were collected. Evaluation of markers of apoptosis, proliferation, extracellular matrix, and angiogenesis was performed using Western Blot & Immunohistochemistry. Statistical analysis was done using ANOVA. Dissemination of adenovirus was assessed by PCR.

RESULTS

In comparison with the untargeted vector, the targeted adenoviral vector significantly shrank leiomyoma size (P < 0.05), reduced expression of proliferation marker (PCNA) (P < 0.05), induced expression of apoptotic protein, c-PARP-1, (P < 0.05) and inhibited expression of extracellular matrix-related genes (TGF beta 3) and angiogenesis-related genes (VEGF & IGF-1) (P < 0.01). There were no detectable adenovirus in tested tissues other than leiomyoma lesions with both targeted and untargeted adenovirus.

CONCLUSION

Targeted adenovirus, effectively reduces tumor size in leiomyoma without dissemination to other organs. Further evaluation of this localized targeted strategy for gene therapy is needed in appropriate preclinical humanoid animal models in preparation for a future pilot human trial.

Enhancing Adenoviral-Mediated Gene Transfer and Expression to Endometrial Cells

OBJECTIVE

Our aim was to screen a panel of modified adenoviral gene transfer vectors to identify those which can sustain high gene expression in human endometrial cells.

METHODS

Normal endometrial stromal cell cultures were established from endometrial lining of hysterectomy specimens performed for benign gynecologic indications. Human endometrial stromal cells were transfected by modified adenoviruses expressing luciferase reporter gene. Luciferase activity mediated by each virus was expressed as a percentage of adenovirus serotype 5 (Ad5-CMV-luc) activity. The 2-tailed Student t test was used to compare data.

RESULTS

At a multiplicity of infection (MOI) of 10 pfu/cell, of the transductionally modified adenoviruses, adenovirus-RGD (Ad-RGD-luc) mediated highest level of endometrial cell transduction with transgene expression around 4 times higher when compared to Ad5 (P < .001). Of the transcriptionally targeted adenoviruses, adenovirus under secretory leukocyte protease inhibitor promoter (Ad-SLPI-luc) and adenovirus under heparanase promoter (Ad-heparanase-luc)-mediated luciferase activation were 5.8- and 4.3-folds higher than Ad5-CMV-luc, respectively (P = .02 and .03, respectively). At MOI of 50 pfu/cell, Ad-RGD-luc and AD-SLPI-luc mediated significantly higher gene transfer efficiency compared to Ad5-CMV-luc (P values < .001, for each virus). Ad-heparanase-luc achieved higher gene activity, but difference was not significant (P = .1). Ad-SLPI-luc, at low viral dose (10 pfu/ cell), mediated gene expression effect comparable to Ad5-CMV-luc at a high dose (50 pfu/cell), with no significant difference.

CONCLUSIONS

We conclude that when compared to the wild-type adenovirus, Ad-RGD-luc, Ad-SLPI-luc, and Ad-heparanase-luc mediate higher reporter gene activity in endometrial cells and can work as effective gene transfer vectors in gene therapy applications to the endometrium.

Recent scientific advances in leiomyoma (uterine fibroids) research facilitates better understanding and management

Uterine leiomyomas (fibroids) are the most prevalent medical problem of the female reproductive tract, but there are few non-surgical treatment options. Although many advances in the understanding of the molecular components of these tumors have occurred over the past five years, an effective pharmaceutical approach remains elusive. Further, there is currently no clinical method to distinguish a benign uterine leiomyoma from a malignant leiomyosarcoma prior to treatment, a pressing need given concerns about the use of the power morcellator for minimally invasive surgery. This paper reviews current studies regarding the molecular biology of uterine fibroids, discusses non-surgical approaches and suggests new cutting-edge therapeutic and diagnostic approaches.

Somatostatin receptor based imaging and radionuclide therapy

Somatostatin (SST) receptors (SSTRs) belong to the typical 7-transmembrane domain family of G-protein-coupled receptors. Five distinct subtypes (termed SSTR1-5) have been identified, with SSTR2 showing the highest affinity for natural SST and synthetic SST analogs. Most neuroendocrine tumors (NETs) have high expression levels of SSTRs, which opens the possibility for tumor imaging and therapy with radiolabeled SST analogs. A number of tracers have been developed for the diagnosis, staging, and treatment of NETs with impressive results, which facilitates the applications of human SSTR subtype 2 (hSSTr2) reporter gene based imaging and therapy in SSTR negative or weakly positive tumors to provide a novel approach for the management of tumors. The hSSTr2 gene can act as not only a reporter gene for in vivo imaging, but also a therapeutic gene for local radionuclide therapy. Even a second therapeutic gene can be transfected into the same tumor cells together with hSSTr2 reporter gene to obtain a synergistic therapeutic effect. However, additional preclinical and especially translational and clinical researches are needed to confirm the value of hSSTr2 reporter gene based imaging and therapy in tumors.

Uterine fibroids: clinical manifestations and contemporary management

Uterine fibroids (leiomyomata) are extremely common lesions that are associated with detrimental effects including infertility and abnormal uterine bleeding. Fibroids cause molecular changes at the level of endometrium. Abnormal regulation of growth factors and cytokines in fibroid cells may contribute to negative endometrial effects. Understanding of fibroid biology has greatly increased over the last decade. Although the current armamentarium of Food and Drug Administration-approved medical therapies is limited, there are medications approved for use in heavy menstrual bleeding that can be used for the medical management of fibroids. Emergence of the role of growth factors in pathophysiology of fibroids has led researchers to develop novel therapeutics. Despite advances in medical therapies, surgical management remains a mainstay of fibroid treatment. Destruction of fibroids by interventional radiological procedures provides other effective treatments. Further experimental studies and clinical trials are required to determine which therapies will provide the greatest benefits to patients with fibroids.

Cell cultures in uterine leiomyomas: rapid disappearance of cells carrying MED12 mutations

Uterine leiomyomas (UL) are the most frequent symptomatic human tumors. Nevertheless, their molecular pathogenesis is not yet fully understood. To learn more about the biology of these common neoplasms and their response to treatment, cell cultures derived from UL are a frequently used model system, but until recently appropriate genetic markers confirming their origin from the tumor cell population were lacking for most UL, i.e., those not displaying karyotypic abnormalities. The identification of MED12 mutations in the majority of UL makes it possible to trace the tumor cell population during in vitro passaging in the absence of cytogenetic abnormalities. The present study is addressing the in vitro survival of cells carrying MED12 mutations and its association with karyotypic alterations. The results challenge numerous in vitro studies into the biology and behavior of leiomyomas. Cells of one genetic subtype of UL, i.e., those with rearrangements of the high mobility AT-hook 2 protein gene (HMGA2), seem to be able to proliferate in vitro for many passages whereas tumor cells from the much more frequent MED12-mutated lesions barely survive even the first passages. Apparently, for the most frequent type of human UL no good in vitro model seems to exist because cells do not survive culturing. On the other hand, this inability may point to an Achilles' heel of this type of UL.