Nutrition Alters the Stiffness of Adipose Tissue and Cell Signaling

Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM). The visceral adipose tissue (VAT) is dynamically altered in response to nutritional regimens that lead to local cues affecting the cells and ECM. The adipocytes are in conjunction with the surrounding ECM that maintains the tissue's niche, provides a scaffold for cells and modulates their signaling. In this study, we provide a better understanding of the crosstalk between nutritional regimens and the ECM's stiffness. Histological analyses showed that the adipocytes in mice fed a high-fat diet (HFD) were increased in size, while the ECM was also altered with changes in mass and composition. HFD-fed mice exhibited a decrease in elastin and an increase in collagenous proteins. Rheometer measurements revealed a stiffer ECM in whole tissue (nECM) and decellularized (deECM) in HFD-fed animals. These alterations in the ECM regulate cellular activity and influence their metabolic function. HFD-fed mice expressed high levels of the receptor for advanced-glycation-end-products (RAGE), indicating that AGEs might play a role in these processes. The cells also exhibited an increase in phosphoserine³³² of IRS-1, a decrease in the GLUT4 transporter levels at the cells' membrane, and a consequent reduction in insulin sensitivity. These results show how alterations in the stiffness of ECM proteins can affect the mechanical cues transferred to adipocytes and, thereby, influence the adipocytes' functionality, leading to metabolic disorders.

Pretreatment with gonadotropin-releasing hormone antagonist protects against chemotherapy-induced testicular damage 'in mice

Background

Testicular toxicity following chemotherapy is of increasing importance with the continuous improvement of survival rates. Gonadotropin-releasing hormone (GnRH) was suggested to protect testis against such toxicity; however, its suppressive quality and mechanism of action are still unclear. We examined whether and how pretreatment with GnRH antagonist protects against the testicular damage caused by chemotherapy.

Methods

Mature male mice were injected subcutaneously eight times in 2-day intervals with either saline or GnRH antagonist (Cetrotide; 1 g/mg), followed by an intraperitoneal injection with either saline or cyclophosphamide (CTX;100 mg/kg BW) and sacrificed 2 weeks or 3 months later. Testicular weight, epididymis weight, epididymal sperm count and sperm motility were measured. Serum anti-Müllerian hormone (AMH) was measured by enzyme-linked immunosorbent assay. Immunohistochemistry (Ki-67), immunofluorescence (PCNA, CD34), terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) and computerized analysis were performed to examine testicular proliferation, apoptosis and vascularization. Quantitative real-time PCR was used to assess the amount of spermatogonial reserve (Id4 and Gfra1 mRNAs).

Results

Pretreatment with GnRH antagonist transiently reduced testicular weight, epididymal weight, germinal proliferation and sperm count; it also abolished the permanent long-term effect of CTX on these parameters and prevented cyclophosphamide-induced testicular toxicity characterized by apoptosis and serum AMH increase and irreversible loss of spermatogonial reserve.

Conclusions

Our findings imply that pretreatment with GnRH antagonist temporarily reduces spermatogenesis and may be used as pretreatment for reducing chemotherapeutic testicular toxicity.

The Role of PEDF in Reproductive Aging of the Ovary

Reproductive aging is characterized by a decline in ovarian function and in oocytes’ quantity and quality. Pigment epithelium-derived factor (PEDF), a pivotal player in ovarian angiogenic and oxidative balance, was evaluated for its involvement in reproductive aging. Our work examines the initial stage of reproductive aging in women and mice, and the involvement of PEDF in the process. Granulosa cells from reproductively-aged (RA) women and mice (36–44 years old and 9–10 months old, respectively) indicated an increase in the level of PEDF mRNA (qPCR), with yet unchanged levels of AMH and FSHR mRNAs. However, the PEDF protein level in individual women showed an intra-cellular decrease (ELISA), along with a decrease in the corresponding follicular fluid, which reflects the secreted fraction of the protein. The in vitro maturation (IVM) rate in the oocytes of RA mice was lower compared with the oocytes of young mice, demonstrated by a reduced polar body extrusion (PBE) rate. The supplementation of PEDF improved the hampered PBE rate, manifested by a higher number of energetically-competent oocytes (ATP concentration and mtDNA copy number of individual oocytes). Our findings propose PEDF as an early marker of reproductive aging, and a possible therapeutic in vitro agent that could enhance the number of good-quality oocytes in older IVF patients.

Fyn and argonaute 2 participate in maternal-mRNA degradation during mouse oocyte maturation

Fertilization triggers physiological degradation of maternal-mRNAs, which are then replaced by embryonic transcripts. Ample evidence suggests that Argonaut 2 (AGO2) is a possible post-fertilization regulator of maternal-mRNAs degradation; but its role in degradation of maternal-mRNAs during oocyte maturation remains obscure. Fyn, a member of the Src family kinases (SFKs), and an essential factor in oocyte maturation, was reported to inhibit AGO2 activity in oligodendrocytes. Our aim was to examine the role of Fyn and AGO2 in degradation of maternal-mRNAs during oocyte maturation by either suppressing their activity with SU6656 - an SFKs inhibitor; or by microinjecting DN-Fyn RNA for suppression of Fyn and BCl-137 for suppression of AGO2. Batches of fifteen mouse oocytes or embryos were analyzed by qPCR to measure the expression level of nine maternal-mRNAs that were selected for their known role in oocyte growth, maturation and early embryogenesis. We found that Fyn/SFKs are involved in maintaining the stability of at least four pre-transcribed mRNAs in oocytes at the germinal vesicle (GV) stage, whereas AGO2 had no role at this stage. During in-vivo oocyte maturation, eight maternal-mRNAs were significantly degraded. Inhibition of AGO2 prevented the degreadation of at least five maternal-mRNAs, whereas inhibition of Fyn/SFK prevented degradation of at least five Fyn maternal-mRNAs and two SFKs maternal-mRNAs; pointing at their role in promoting the physiological degradation which occurs during in-vivo oocyte maturation. Our findings imply the involvement of Fyn/SFKs in stabilization of maternal-mRNA at the GV stage and the involvement of Fyn, SFKs and AGO2 in degradation of maternal mRNAs during oocyte maturation.

Irinotecan (CPT-11) Treatment Induces Mild Gonadotoxicity

BACKGROUND

Gonadal toxicity following chemotherapy is an important issue among the population of young cancer survivors. The inhibitor of DNA topoisomerase I, irinotecan (CPT-11), is widely used for several cancer types. However, little is known about the effect of irinotecan on the fertility of both genders. Thus, the aim of the present study was to evaluate irinotecan gonadotoxicity, using a mouse model.

METHODS

Mature male and female mice were injected intraperitoneally with either saline (), irinotecan (100 mg/kg) or cyclophosphamide (100 mg/kg); and sacrificed one week or three months later for an acute or long-term toxicity assessment, respectively. We used thorough and advanced fertility assessment by already established methods: Gonadal and epididymal weights, as well as sperm count and sperm motility were determined; serum anti-Müllerian hormone (AMH) was measured by ELISA. Immunohistochemistry (Ki-67), immunofluorescence (PCNA, CD34), terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) and computerized analysis were performed to examine gonadal proliferation, apoptosis and vascularization. qPCR was used to assess the amount of testicular spermatogonia (Id4 and Gafra1 mRNA) and ovarian primordial oocytes reserves (Sohlh2, Nobox and Figla mRNA).

RESULTS

Females: Irinotecan administration induced acute ovarian apoptosis and decreased vascularity, as well as a mild, statistically significant, long-term decrease in the number of growing follicles, ovarian weight, and ovarian reserve. Males: Irinotecan administration caused an acute testicular apoptosis and reduced testicular spermatogenesis, but had no effect on vascularity. Irinotecan induced long-term decrease of testicular weight, sperm count and testicular spermatogonia and caused elevated serum AMH.

CONCLUSION

Our findings imply a mild, though irreversible effect of irinotecan on mice gonads.

Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

Ultraviolet (UV) light affects endocrinological and behavioral aspects of sexuality via an unknown mechanism. Here we discover that ultraviolet B (UVB) exposure enhances the levels of sex-steroid hormones and sexual behavior, which are mediated by the skin. In female mice, UVB exposure increases hypothalamus-pituitary-gonadal axis hormone levels, resulting in larger ovaries; extends estrus days; and increases anti-Mullerian hormone (AMH) expression. UVB exposure also enhances the sexual responsiveness and attractiveness of females and male-female interactions. Conditional knockout of p53 specifically in skin keratinocytes abolishes the effects of UVB. Thus, UVB triggers a skin-brain-gonadal axis through skin p53 activation. In humans, solar exposure enhances romantic passion in both genders and aggressiveness in men, as seen in analysis of individual questionaries, and positively correlates with testosterone level. Our findings suggest opportunities for treatment of sex-steroid-related dysfunctions.

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UVB exposure increases circulating sex-steroid levels in mice and humans

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UVB exposure enhances female attractiveness and receptiveness toward males

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UVB exposure increases females’ estrus phase, HPG axis hormones, and follicle growth

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Skin p53 regulates UVB-induced sexual behavior and ovarian physiological changes

Pigment epithelium-derived factor negates oxidative stress in mouse oocytes

Molecular changes, caused by various environmental factors, affect the quality and developmental potential of oocytes. Oxidative stress (OS) is a major factor involved in various gynecologic disorders and/or in aging. Recent studies suggest that elevated reactive oxygen species (ROS) hamper oocyte quality and future embryonic development. Pigment epithelium-derived factor (PEDF) is a pleiotropic protein, known for its antiangiogenic, anti-inflammatory, and antioxidative properties. Our previous findings demonstrate the antioxidative role of rPEDF in maintaining granulosa cell viability. In the current study, we examined the ability of PEDF to negate the adverse impact of OS on oocytes. Maturation rate of oocytes exposed to OS was significantly lower than that of control oocytes. The number of mtDNA copies in OS-exposed oocytes was significantly higher than in control oocytes (>3 times), whereas ATP concentration was significantly lower. Oocytes exposed to OS demonstrated impaired chromosome arrangement at the metaphase plate. PEDF significantly improved maturation rate of untreated OS-exposed oocytes. Moreover, mtDNA copy number, ATP concentration, and chromosome arrangement at the metaphase plate in rPEDF-treated OS-exposed oocytes were restored to the level of control oocytes. Our findings demonstrate that OS hampers the ability of oocytes to undergo proper in vitro maturation. The energetic balance of OS-exposed oocyte is characterized by excessive mtDNA replication and reduced ATP concentration; it hampers the ability of oocytes to perform high fidelity chromosome segregation. PEDF alleviates this damage, improves the rate of oocyte maturation, and preserves mtDNA level and ATP content, thus enabling oocytes to form proper metaphase plate and improve oocyte competence.

Chemotherapy-induced acute vascular injury involves intracellular generation of ROS via activation of the acid sphingomyelinase pathway

Several categories of chemotherapy confer substantial risk for late-term vascular morbidity and mortality. In the present study, we aimed to investigate the mechanism of acute chemotherapy-induced vascular injury in normal tissues. Specifically, we looked at activation of the acid sphingomyelinase (ASMase)/ceramide pathway, which leads to generation of reactive oxygen species (ROS) and induction of oxidative stress that may result in vascular injury. In particular, we focused on two distinct drugs, doxorubicin (DOX) and cisplatin (CIS) and their effects on normal endothelial cells. In vitro, DOX resulted in increased ASMase activity, intra-cellular ROS production and induction of apoptosis. CIS treatment generated significantly reduced effects in endothelial cells. In-vivo, murine femoral arterial blood flow was measured in real-time, during and after DOX or CIS administration, using fluorescence optical imaging system. While DOX caused constriction of small vessels and disintegration of large vessels' wall, CIS induced minor vascular changes in arterial blood flow, correlating with the in vitro findings. These results demonstrate that DOX induces acute vascular injury by increased ROS production, via activation of ASMase/ceramide pathway, while CIS increases ROS production and its immediate extracellular translocation, without causing detectable acute vascular injury. Our findings may potentially lead to the development of new strategies to prevent long-term cardiovascular morbidity in cancer survivors.

Male sterility and reduced female fertility in SCAPER-deficient mice

Mutations in S-phase cyclin A-associated protein in the endoplasmic reticulum (SCAPER) cause a recessively inherited multisystemic disorder whose main features are retinal degeneration and intellectual disability. SCAPER, originally identified as a cell cycle regulator, was also suggested to be a ciliary protein. Because Scaper mutant males are sterile, we set up to characterize their phenotype. The testes of Scaper mutant mice are significantly smaller than those of WT mice. Histology revealed no signs of spermatogenesis, and seminiferous tubules contained mainly Sertoli cells with a few spermatogonia/spermatogonial stem cells (SSCs). In WT testes, SCAPER is expressed by SSCs and in the various stages of spermatogenesis, as well as in Sertoli cells. In WT spermatozoa SCAPER is not expressed in the flagellum but rather in the head compartment, where it is found both in the nucleus and in the perinuclear region. Scaper mutant females present reduced fertility, manifested by a significantly smaller litter size compared to WT females. Mutant ovaries are similar in size but comprised of significantly less primordial and antral follicles, compared to WT ovaries, while the number of atretic follicles is significantly higher. In WT ovarian follicles SCAPER is expressed in the somatic granulosa cells as well as in the oocyte. In conclusion, our data demonstrate that SCAPER is a crucial component in both male and female reproductive systems. We hypothesize that the reproductive phenotype observed in Scaper mutant mice is rooted in SCAPER's interaction with cyclin A/Cdk2, which play an important role, however different, in male and female gonads.

Cancer During Pregnancy: The Role of Vascular Toxicity in Chemotherapy-Induced Placental Toxicity

Breast cancer is diagnosed in ~0.3% of pregnant women. Studies that have addressed gestational and neonatal outcomes of chemotherapy during pregnancy have demonstrated increased gestational complications including preeclampsia and intrauterine growth retardation. We hypothesized that anthracycline-induced gestational complications could be derived from direct toxicity on the placenta vasculature. Pregnant ICR mice (day E12.5) were treated with doxorubicin (DXR; 8 mg/kg) or saline, while their umbilical cord blood flow was imaged by pulse-wave (PW) Doppler. Mice were euthanized on day E18.5, and their embryos and placentae were collected for further analysis. Unlike control mice, the DXR-treated mice presented an acute change in the umbilical cord’s blood flow parameters (velocity time integral and heart rate interval), reduced embryos’ weight, reduced placenta efficiency, and modulation in vascular-related pathways of treated placenta proteomics. Apoptosis and proliferation were also enhanced, as demonstrated by TUNEL and proliferating cell nuclear antigen (PCNA) analysis. We further examined the placentae of patients treated with epirubicin (EPI), who had been diagnosed with breast cancer during pregnancy (weeks 27–35). The immunohistochemistry of the EPI-treated human placentae showed enhanced proliferation and apoptosis as compared with matched chemo-naïve placentae, as well as reduced neovascularization (CD34). Our findings suggest that anthracycline-induced vascular insult promotes placental toxicity, and could point to potential agents designated to offset the damage and to reduce gestational complications in pregnant cancer patients.

Pigment epithelium-derived factor (PEDF) negates hyperandrogenic PCOS features

Polycystic ovary syndrome (PCOS), one of the most common female endocrine disorder, is a prevalent cause of infertility. Hyperandrogenism is a key feature in PCOS and is correlated with increased expression of VEGF and cytokines in the ovaries. We have previously shown that pigment epithelium-derived factor (PEDF), an endogenous protein, presents potent anti-angiogenic and anti-inflammatory activities in the ovary and negates the effects of cytokines and VEGF. Additionally, PEDF plays a role in both pathophysiology and treatment of ovarian-hyperstimulation syndrome (OHSS), frequently seen in PCOS patients. We established hyperandrogenic-PCOS models, both in vivo, using mice exposed prenatally to dihydrotestosterone (DHT) and, in vitro, using human primary granulosa cells (hpGCs) and human granulosa cell line (KGN). In PCOS-induced mice, the mRNA levels of I l-6, V egf and Amh were higher than those of control; yet, treatment with rPEDF decreased these levels. Moreover, treating OHSS-induced PCOS-mice with rPEDF alleviated all OHSS symptoms. Stimulation of hpGCs with DHT resulted in downregulation of PEDF mRNA expression, concomitantly with a significant increase in IL-6 and IL-8 mRNAs expression. However, co-stimulation of DHT with rPEDF attenuated the increase in cytokines expression. The anti-inflammatory effect of PEDF was found to be mediated via PPARγ pathway. Our findings suggest that rPEDF treatment may normalize the ovarian angiogenic-inflammatory imbalance, induced by PCOS-associated hyperandrogenism. Moreover, the therapeutic potency of PEDF in preventing OHSS symptomes offers a rationale for using PEDF as novel physiological treatment for PCOS sequels.

Pigment epithelium derived factor as a novel multi-target treatment for uterine fibroids

RESEARCH QUESTION

Does recombinant pigment epithelium derived factor (PEDF) have potential in treating uterine fibroids?

DESIGN

In-vitro models that used human leiomyoma and Eker rat uterine leiomyoma (ELT-3) cell lines. The ELT-3 cell line was used to examine cellular targets after adding recombinant PEDF to the culture media. Athymic nude female mice were used as an in-vivo model. They were injected with ELT-3 cells to induce ectopic fibroid lesions, then treated with recombinant PEDF.

RESULTS

RNA expression of PEDF and its receptors was found in both leiomyoma cell lines, as well as the expression of PEDF receptors. Addition of recombinant PEDF to the culture medium of leiomyoma cell lines activated ERK in a time-dependent manner, induced down-regulation of vascular endothelial growth factor mRNA and protein, as well as the mRNAs of oestrogen receptors alpha and beta and inhibited cellular proliferation. Treatment of mice-bearing fibroids with recombinant PEDF reduced fibroid growth rate and resulted in smaller tumours.

CONCLUSIONS

This study suggests that recombinant PEDF is a putative novel potent physiological treatment for uterine fibroids. It targets several cornerstones of fibroid pathobiology in parallel, including vascular endothelial growth factor and oestrogen receptors, which are needed for vascularization, and restricts fibroid growth and final size in an animal model.

miR-125a Induces HER2 Expression and Sensitivity to Trastuzumab in Triple-Negative Breast Cancer Lines

The EGFR/HER2 signaling network is an effective therapeutic target for HER2-positive cancers, which are known for their aggressive biological course. Evidence indicates that the EGFR/HER2 network plays a role in the aggressive basal-like subtype as well. Here, we studied the potential role of miR-125a-3p as a modulator of the EGFR/HER2 pathway in basal-like breast cancer. Over-expression of miR-125a-3p reduced the migratory capability of MDA-MB-231 cells and led to an increase in the expression of ErbB2 transcript and protein. The induced ErbB2 responded to trastuzumab and underwent internalization and subsequent intra-lysosomal degradation. Trastuzumab treatment further reduced the migratory capability and induced the apoptosis of the cells. An in-vivo mouse model, which supported the in-vitro findings, showed a synergistic effect for miR-125a-3p and trastuzumab. Trastuzumab-treated miR-125a-3p-induced tumors were significantly smaller than control induced tumors. Our findings indicate that, in the basal-like subtype of breast cancer, miR-125a-3p may act as a tumor suppressor. miR-125a-3p induces an increase in the expression of ErbB2 that may render the cells suitable for treatment with anti-HER2 therapies.

Pre-ovulatory intercellular regulation of miR-125a-3p within mouse ovarian follicles

miR-125a-3p, a post-transcription regulator of Fyn kinase, is expressed in mouse pre-ovulatory follicles; its expression within the follicle decreases toward ovulation. Our aim was to follow the synthesis of miR-125a-3p and regulation of its expression in all follicular compartments, focusing on intercellular communication. Mural granulosa cells (GCs) or cumulus cells (CCs) were transfected with either scrambled-miR (negative control) or miR-125a-3p mimic. Freshly isolated GCs or CCs were incubated overnight in culture media conditioned by transfected cells. To examine a possible role of gap junctions in the regulation of miR-125a-3p, we incubated large antral follicles in the presence of carbenoxolone, a gap-junction inhibitor, and triggered them to mature with hGC. Levels of miR-125a family members in GCs, CCs, oocytes, and culture media were measured by qPCR. We showed that miR-125a-3p is synthesized by all follicular components, but is regulated within the follicle as a whole. It is secreted by mural-GCs and taken up by CCs, where it remains functional, and vice versa, mural-GCs can take up miR-125a-3p secreted by CCs. miR-125a-3p is transcribed and accumulated in oocytes throughout oogenesis. Transcriptionally quiescent GV oocytes utilize their accompanying follicular cells to monitor the level of miR-125a-3p within them, as indicated in an ex vivo follicle culture. Our study reveals that miR-125a-3p expression is modulated by a network of intercellular communications within pre-ovulatory follicles, thus enabling a coordinated decrease of miR-125a-3p toward ovulation.

Elucidating the role of pigment epithelium-derived factor (PEDF) in metabolic PCOS models

PCOS is the most common endocrinopathy in women; associated with obesity and insulin resistance (IR). IR leads to accumulation of advanced-glycation-end-products (AGEs) and their receptor, RAGE. PCOS patients have increased levels of vascular endothelial growth factor (VEGF), interleukin 6/8 (IL-6/8) and anti-Mϋllerian-hormone (AMH). PEDF is a secreted-glycoprotein known for its anti-angiogenic and anti-inflammatory properties. We aimed to elucidate the role of PEDF in the pathogenesis and treatment of PCOS. We used a prenatal PCOS mouse model and fed the female offspring a high-fat diet, inducing metabolic PCOS (met.PCOS) characteristics. Female offspring were divided into three groups: control; met.PCOS; met.PCOS + recombinant PEDF (rPEDF). Met.PCOS mice gained more weight, had elevated serum IL-6 and higher mRNA levels of AMH, PEDF and RAGE in their granulosa cells (GCs) than met.PCOS + rPEDF mice. An in vitro Met.PCOS model in human GCs (KGN) line was induced by prolonged incubation with insulin/AGEs, causing development of IR. Under the same conditions, we observed an elevation of VEGF, IL-6/8 mRNAs, concomitantly with an increase in PEDF mRNA, intracellular protein levels, and an elevation of PEDF receptors (PEDF-Rs) mRNA and protein. Simultaneously, a reduction in the secretion of PEDF from GCs, was measured in the medium. The addition of rPEDF (5 nM) activated P38 signaling, implying that PEDF-Rs maintained functionality, and negated AGE-induced elevation of IL-6/8 and VEGF mRNAs. Decreased PEDF secretion may be a major contributor to hyperangiogenesis and chronic inflammation, which lie at the core of PCOS pathogenesis. rPEDF treatment may restore physiological angiogenesis inflammatory balance, thus suggesting a potential therapeutic role in PCOS.

Abstract 2768: Treosulfan induces differential gonadal toxicity profile compared with Busulfan

Background: Treosulfan (L-treitol-1,4-bis-methanesulfonate), an alkylating agent with myeloablative and immunosuppressive traits, has been increasingly incorporated as a main conditioning protocol for hematopoietic stem cell transplantation (HSCT) in pediatric malignant and non-malignant diseases. Treosulfan has been shown to present lower toxicity profile compared with conventional myeloablative regimens such as busulfan. Yet, while busulfan is considered highly gonadotoxic, the gonadal toxicity profile of treosulfan remains to be elucidated. Our aim was to study the short and long term gonadal effect of treosulfan in comparison to busulfan.

Methods: Mature 2 months old male and 3 months old female mice (“pubertal cohort”) were injected with treosulfan 2000 mg/kg or busulfan 40 mg/kg and were sacrificed one week, one month or six months post drug administration. Immature male and female mice (“prepubertal cohort”) were injected with treosulfan 750 mg/kg or busulfan 15 mg/kg and were sacrificed one week or three months post drug administration. Testicular function was assessed by measurements of sperm count and motility, testes and epididymides weight, serum anti-Mullerian Hormone (AMH) and testicular ID4 or GFRA1 mRNA (markers for stem spermatogonia). Immunohistochemistry was performed to evaluate testicular proliferation (Ki-67), apoptosis (TUNEL) and meiotic-active spermatocytes (DAZL-PCNA). Ovarian function was assessed by measurements of ovary weight, serum AMH, follicles count and ovarian SOHLH2, NOBOX of FIGLA mRNA (markers for primordial follicles). Immunohistochemistry was performed to evaluate ovarian proliferation (Ki-67), apoptosis (TUNEL) and growing follicles (AMH-PCNA).

Results: Treosulfan testicular toxicity was milder compared to busulfan toxicity, in both mature and immature male mice, while stem spermatogonia were spared. However, ovarian toxicity of both treosulfan and busulfan was severe and permanent in both mature and immature female mice; possibly by a short term irreversible reduction of reserve primordial follicles in the ovaries.

Conclusion: Our results indicate that treosulfan exerts a differential gonadal toxicity profile compared with busulfan, manifested by mild testicular toxicity and severe ovarian toxicity.

Citation Format: Mattan Levi, Salomon Stemmer, Jerry Stein, Ruth Shalgi, Irit Ben-Aharon. Treosulfan induces differential gonadal toxicity profile compared with Busulfan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2768. doi:10.1158/1538-7445.AM2017-2768

Interleukin 1-alpha deficiency increases the expression of Follicle-stimulating hormone receptors in granulosa cells

Follicle-stimulating hormone receptor (FSHR) is a pivotal regulator of ovarian response to hormonal stimulation. Inflammatory conditions have been linked to lower FSHR expression in granulosa cells (GCs) as well as an attenuated response to hormonal stimulation. The current study aimed to reveal if deficiency and/or blockage of the pro-inflammatory cytokine interleukin 1-alpha (IL1A) increased Fshr expression in rodent GCs. We found elevated Fshr transcript abundance, as assessed by quantitative PCR, in primary GCs isolated from Il1a-knockout compared to wild-type mice, and that the expression of FSHR is significantly higher in Il1a-knockout compared to wild-type ovaries. Supplementing GC cultures with recombinant IL1A significantly lowered Fshr expression in these cells. In accordance with the Fshr expression pattern, proliferation of GCs was higher in follicles from Il1a-knockout mice compared to wild-type mice, as indicated by the MKI67 immunohistochemical staining. Furthermore, treating wild-type mice with anakinra, an IL1 receptor 1 antagonist, significantly increased the expression of Fshr in primary GCs from treated compared to control mice. These data highlight an important interdependency between the potent pro-inflammatory cytokine IL1A and Fshr expression.

The Dual Role of PEDF in the Pathogenesis of OHSS: Negating Both Angiogenic and Inflammatory Pathways

CONTEXT

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of assisted reproductive technologies. This complex syndrome is known to involve massive angiogenesis and inflammation. We have previously established the anti-angiogenic involvement of pigment epithelium-derived factor (PEDF) in the pathophysiology and treatment of OHSS.

OBJECTIVE

Evaluate the anti-inflammatory role of PEDF in OHSS.

DESIGN

In vivo mouse OHSS model and in vitro cultures of granulosa cells.

MAIN OUTCOME

Changes in the expression of PEDF, IL-6, IL-8, and vascular endothelial growth factor (VEGF) were measured by quantitative PCR and ELISA; OHSS symptoms were recorded (body and ovarian weight gain and peritoneal vascular leakage quantified by the modified Miles's assay).

RESULTS

Rat granulosa cell-line stimulated with lysophosphatidic acid (LPA), exhibited a significant increase in IL-6 expression, concomitantly with a decrease in PEDF level (P < .01). Co-stimulation with recombinant PEDF (rPEDF) decreased the expression of IL-6 significantly (P < .05). Furthermore, the expression of IL-6 and IL-8 increased in LPA-stimulated human primary granulosa cells (P < .01). Co-stimulation with rPEDF decreased the expression of LPA-induced IL-6 and IL-8 mRNA and protein by 4- and 2- to 5-fold, respectively. IL-8-stimulated human primary granulosa cells exhibited increased expression of VEGF mRNA; co-stimulation with hCG induced a significantly higher increase in the expression of VEGF mRNA (P < .001), which was counteracted by rPEDF. Subcutaneous injection of 0.5 mg/kg rPEDF to OHSS-induced mice reduced the increased expression of IL-6 in the ovary (P < .01) and alleviated the severity of all OHSS parameters.

CONCLUSIONS

Our findings provide a framework that correlates down-regulation of OHSS symptoms caused by PEDF with both angiogenic and inflammatory pathways.

Pigment epithelium-derived factor regulation by human chorionic gonadotropin in granulosa cells

Human chorionic gonadotropin (hCG) is a known trigger of ovarian hyperstimulation syndrome (OHSS), a potentially life-threatening complication of assisted reproduction. Administration of hCG results in the release of vascular endothelial growth factor (VEGF) from the ovary. We have previously shown that expression of pigment epithelium-derived factor (PEDF) in granulosa cell line is regulated by hCG, reciprocally to VEGF, and that the PEDF–VEGF balance is impaired in OHSS. Our aim was to explore the signaling network by which hCG downregulates the expression of PEDF mRNA and protein in granulosa cells. We applied specific chemical inhibitors and stimuli to human primary granulosa cells and rat granulosa cell line. We found that PKA and protein kinase C, as well as EGFR, ERK1/2 and PI3K, participate in the signaling network. The finding that hCG-induced PEDF downregulation and VEGF upregulation are mediated by similar signaling cascades emphasizes the delicate regulation of ovarian angiogenesis.

A Role of MicroRNAs in Cell Differentiation During Gonad Development

MicroRNAs (miRNAs) are a group of small noncoding RNA molecules that play a major role in posttranscriptional regulation of gene expression and are expressed in an organ-specific manner. One miRNA can potentially regulate the expression of several genes, depending on cell type and differentiation stage. miRNAs are differentially expressed in the male and female gonads and have an organ-specific reproductive function. Exerting their affect through germ cells and gonadal somatic cells, miRNAs regulate key proteins necessary for gonad development. The role of miRNAs in the testes is only starting to emerge though they have been shown to be required for adequate spermatogenesis. Widely explored in the ovary, miRNAs were suggested to play a fundamental role in follicles' assembly, growth, differentiation, and ovulation. In this chapter, we focus on data obtained from mice in which distinct proteins that participate in the biosynthesis of miRNAs were conditionally knocked out from germ cells (spermatogonial cells or oocytes) or gonadal somatic cells (Sertoli or granulosa cells). We detail recent advances in identification of particular miRNAs and their significance in the development and function of male and female gonads. miRNAs can serve as biomarkers and therapeutic agents of pathological conditions; thus, elucidating the branched and complex network of reproduction-related miRNAs will aid understanding of gonads' physiology and managing reproduction disorders.

Abstract A57: miR-125a-induced cellular switch elicits a response to anti-HER2 targeted therapy in breast cancer cells

Background: The EGFR/HER2 signaling network emerges as an effective therapeutic target for Her2 enriched cancers, which is known by its aggressive biological course. Nevertheless, there is evidence that the EGFR/HER2 network may play a key role not only in the HER2-enriched subtype of breast cancer, but also in the similarly aggressive basal-like subtype. We had formerly demonstrated the involvement of miR-125a-3p in the EGFR pathway in prostate cancer. We aimed to study the effect of miR-125a-3p as a potential modulator of the ERBB2/HER2 pathway in basal-like breast cancer subtype.

Methods: Using qPCR we calibrated estrogen receptor (ER), ERBB2 (HER2), miR-125a-3p/5p (two isoforms) expression in three cell lines: MDA-MB-231, MCF-7 and SKBR3 (represent the basal-like subtype, ER positive subtype and HER2-enriched subtype respectively). We generated stable MDA-MB-231 cells that overexpress miR-125a-3p and control cells that overexpress scrambled miRNA. In parallel, we established an in vivo platform by injection of miR-125a-3p-overexpressing MDA-MB-231 breast cancer cells to the mammary pad of NUDE mice and evaluated traits of the induced tumors compared with scrambled miRNA-expressing cells (control mice) and response to potential targeted therapy.

Results: miR-125a-3p was endogenously expressed in all cell lines, though its expression in MDA-MB-231 cells was significantly lower than in MCF-7 or in SKBR3 cells. Following transfection of cells with miR-125a-3p, MDA-MB-231 cells showed a significant increase in the expression level of ERBB2 mRNA and protein as well as a stronger immunofluorescence staining of ErbB2 than in control cells. Combined treatment of miR-125a-3p-overexpressing cells and trastuzumab induces apoptosis and reduces migration of MDA-MB-231 cells. By tracking Erbb2 internalization and its localization to the lysosoms/the functionality of erbb2 receptor, we determined that trastuzumab caused internalization of ErbB2 and a subsequent lysosomal lysis. In the experimental in vivo platform, starting one week post cells injection/tumor formation?, mice were treated twice a week, for the next 28 days, with 10 mg/Kg trastuzumab or saline as a control. Response to treatment was evaluated by measurement of the tumor size/volume by computerized tomography (CT) or calliper. Both measurements indicated that that the tumors in the miR-125a-3p group that were treated with trastuzumab were significantly smaller than in other groups.

Conclusion: our results indicate that miR-125a-3p is capable of inducing a shift in the involvement of key cellular pathway - the ERBB2 pathway that may convert the cell fate and dispose it to anti-HER2 therapies. In an era of personalized medicine, our study proposes a means to enlarge the patient population that may benefit from anti-HER2 therapies.

Citation Format: Lihi Ninio-Many, Elad Hikri, Salomon M. Stemmer, Ruth Shalgi, Irit Ben-Aharon. miR-125a-induced cellular switch elicits a response to anti-HER2 targeted therapy in breast cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A57.

GnRH Agonist Triggering Modulates PEDF to VEGF Ratio Inversely to hCG in Granulosa Cells

CONTEXT

GnRH agonist (GnRH-a) triggering is associated with a reduced risk of ovarian hyperstimulation syndrome (OHSS) compared with human chorionic gonadotropin (hCG) in assisted reproduction technology cycles. We have shown that ovarian pigment epithelium derived factor (PEDF), a potent antiangiogenic factor, counteracts vascular endothelial growth factor (VEGF) expression and that OHSS is correlated with hCG-induced impaired PEDF to VEGF ratio.

OBJECTIVE

The objective of the study was to explore whether GnRH-a triggering could directly modulate PEDF/VEGF balance in granulosa cells.

DESIGN

The design of the study was a mouse model and cultured granulosa cells.

MAIN OUTCOME

Changes in PEDF and VEGF were measured by quantitative PCR and Western blot analysis. OHSS symptoms were recorded by changes in body weight and in peritoneal vascular leakage, quantified by the modified Miles vascular permeability assay.

RESULTS

GnRH-a stimulation significantly increased PEDF and decreased VEGF mRNA and protein levels both in rat granulosa cell line and human primary granulosa cells in vitro. GnRH-a and hCG triggering inversely modulated PEDF mRNA and protein level in human granulosa cells in vivo. In the GnRH-a triggering mouse model, we showed similar increase in PEDF to VEGF ratio as in the in vitro results. OHSS-predisposed mice did not develop OHSS parameters after GnRH-a triggering, opposed to hCG-triggered mice. Finally, GnRH-a triggering of OHSS-predisposed mice significantly increased ovarian PEDF to VEGF ratio compared with hCG-triggered mice and control mice.

CONCLUSIONS

GnRH-a triggering induces a direct effect on PEDF/VEGF balance in granulosa cells inversely to hCG. Our results suggest a novel elucidation to the GnRH-a triggering-mediated risk reduction of OHSS and may clarify the pros and cons of this triggering method.

The impact of oxaliplatin on the gonads: from bedside to the bench

STUDY HYPOTHESIS

What is the impact of oxaliplatin on gonadal function?

STUDY FINDING

Our results in both the clinical and pre-clinical settings indicate that oxaliplatin exerts moderate transient gonadal toxicity.

WHAT IS KNOWN ALREADY

Recent studies have indicated a significant increase in survivorship of colorectal cancer patients of reproductive age, who may then face fertility concerns. The impact of oxaliplatin on gonadal function is yet to be discovered.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Eleven female (<43 years) and eight male (<45 years) patients recently diagnosed with colorectal cancer, who were candidates for oxaliplatin-based protocol, were enrolled into the study. FSH, estradiol, anti-Müllerian hormone (AMH) and menstrual pattern were measured in female patients, whereas FSH, inhibin-B, testosterone, and steroid-hormone binding globulin were measured in male patients. Hormones were measured at baseline and 6 months post-treatment (last chemotherapy administration) in men and women. In the animal model, pubertal mice were injected with oxaliplatin and sacrificed 1 week, 1 month and 3 months later. Ovarian reserve was estimated by serum AMH measurements. Testicular function was evaluated by serum inhibin-B and sperm evaluation. Gonadal apoptosis (TUNEL), proliferation (Ki-67), repair (PCNA), ovarian reserve (AMH) and testicular reserve (DAZL) were measured by immunohistochemistry.

MAIN RESULTS AND THE ROLE OF CHANCE

In all women, AMH decreased post-treatment, but remained above the detection limit in 9/11 patients (P < 0.05). FSH was elevated, but did not exceed the premenopausal range in 9/11 patients. All patients remain menstruating or resumed menstruation post-treatment. In female mice oxaliplatin induced transient apoptosis at 1-month post-treatment. In men Inhibin-B was slightly reduced post-treatment. In male mice oxaliplatin did not affect spermatozoa concentration, but was associated with transient, moderate reductions of spermatocytes-spermatogonia numbers and spermatozoa motility.

LIMITATIONS, REASONS FOR CAUTION

Future prospective large-scale studies are warranted in order to affirm these outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Due to high survival rates of colorectal cancer patients of reproductive age that were diagnosed at early stages of the disease, the issue of treatment-induced gonadotoxicity gains significance. Since at the individual level there might be a risk of infertility, a detailed discussion and referral to fertility preservation prior to initiation of treatment is recommended. Nevertheless, oxaliplatin-based protocols appear to be less gonadotoxic than other chemotherapeutic protocols.

LARGE SCALE DATA

None.

STUDY FUNDING AND COMPETING INTERESTS

This study was supported by the Israeli Science Foundation (ISF) grant 13-1816 (I.B.-A.). There is no conflict of interest.

Anti-Müllerian Hormone Is a Marker for Chemotherapy-Induced Testicular Toxicity

Due to increased numbers of young cancer patients and improved survival, the impact of anticancer treatments on fertility has become a major health concern. Despite mounting research on ovarian toxicity, there is paucity of data regarding reliable biomarkers of testicular toxicity. Our aim was to evaluate anti-Müllerian hormone (AMH) as a marker for chemotherapy-induced testicular toxicity. Serum AMH and a panel of gonadal hormones were measured in male cancer patients at baseline and after chemotherapy. In the preclinical setting, mice were injected with diverse chemotherapies and were killed 1 week or 1, 3, or 6 months later. We evaluated spermatogenesis by AMH as well as qualitative and quantitative sperm parameters. Nineteen patients were enrolled, the median age was 38 years (21-44 y). Serum AMH was correlated with increased FSH and T and decreased inhibin-B in gonadotoxic protocols (cisplatin or busulfan) and remained unchanged in nongonadotoxic protocols (capecitabine). AMH expression had the same pattern in mice serum and testes; it was negatively correlated with testicular/epididymal weight and sperm motility. The increase in testicular AMH expression was also correlated with elevated apoptosis (terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling) and reduced proliferation (Ki67, proliferating cell nuclear antigen; all seminiferous tubules cells were analyzed). Severely damaged mice testes demonstrated a marked costaining of AMH and GATA-4, a Sertoli cell marker; staining that resembled the pattern of the Sertoli cell-only condition. Our study indicates that the pattern of serum AMH expression, in combination with other hormones, can delineate testicular damage, as determined in both experimental settings. Future large-scale clinical studies are warranted to further define the role of AMH as a biomarker for testicular toxicity.

Dexrazoxane exacerbates doxorubicin-induced testicular toxicity

Infertility induced by anti-cancer treatments pose a major concern for cancer survivors. Doxorubicin (DXR) has been previously shown to exert toxic effects on the testicular germinal epithelium. Based upon the cardioprotective traits of dexrazoxane (DEX), we studied its potential effect in reducing DXR-induced testicular toxicity. Male mice were injected with 5 mg/kg DXR, 100 mg/kg DEX, combination of both or saline (control) and sacrificed either 1, 3 or 6 months later. Testes were excised and further processed. Glutathione and apoptosis assays were performed to determine oxidative stress. Immunohistochemistry and confocal microscopy were used to study the effects of the drugs on testicular histology and on spermatogonial reserve. DXR and the combined treatment induced a striking decline in testicular weight. DEX prevented DXR-induced oxidative stress, but enhanced DXR-induced apoptosis within the testes. Furthermore, the combined treatment depleted the spermatogonial reserve after 1 month, with impaired recovery at 3 and 6 months post-treatment. This resulted in compromised sperm parameters, testicular and epididymal weights as well as significantly reduced sperm motility, all of which were more severe than those observed in DXR-treated mice. The activity of DEX in the testis may differ from its activity in cardiomyocytes. Adding DEX to DXR exacerbates DXR-induced testicular toxicity.

Gonadotrophin-releasing hormone agonists for fertility preservation: unraveling the enigma?

STUDY QUESTION

Can gonadotrophin-releasing hormone agonists (GnRH-a) preserve long-term fertility when administered prior to and concomitantly with chemotherapy?

SUMMARY ANSWER

GnRH-a display a differential protective effect on fertility, depending upon the specific chemotherapy-induced mechanism of ovarian injury.

WHAT IS KNOWN ALREADY

The role of GnRH-a in fertility preservation has been constantly debated and their use is considered experimental due to conflicting clinical evidence and paucity of data regarding their mechanism for ovarian protection.

STUDY DESIGN, SIZE, DURATION

In vivo model: 7-8 weeks old imprinting control region (ICR) mice were injected with GnRH-a (Leuprolide-acetate) or saline prior to and concomitantly with cyclophosphamide, doxorubicin or saline and sacrificed at various time-points on a longitudinal follow-up; 24 h (n = 36), 1 week (n = 40), 1 month (n = 36) and 9 months (n = 66) post chemotherapy treatment. Blood samples were drawn on Day 0 and on a monthly basis after chemotherapy treatment. On the day of sacrifice, blood samples were drawn and ovaries excised and processed for either immunohistochemistry (IHC), protein or RNA extraction. In vitro model: 21-23 days old Wistar-derived rats were sacrificed, their ovaries excised and primary granulosa cells (PGC) were either isolated for in vitro culture, or processed for immunofluorescence (IF) as well as for protein or RNA extraction.

MATERIALS, SETTING, METHODS

Ovarian reserve was estimated by serial measurements of serum anti-mullerian hormone (AMH), quantified by the AMH Gen II ELISA assay. Ovarian AMH and phosphorylated Akt (pAkt) were detected by immunoblotting. Vascular endothelial growth factor (VEGF) was measured by quantitative PCR. Ovarian GnRH receptor (GnRHR), AMH and CD34 were visualized by IHC, and apoptosis was evaluated using TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labeling (TUNEL).

MAIN RESULTS AND THE ROLE OF CHANCE

Cyclophosphamide-induced ovarian injury caused a prompt decrease in AMH level (P < 0.01) and a further long-term decline in serum AMH (P = 0.017), indicating damage to the ovarian reserve. Pretreatment with GnRH-a diminished AMH-decrease (P < 0.05) and maintained serum AMH level in the long run (P < 0.05). Doxorubicin-exerted ovarian-vascular-injury is also displayed by an acute increase in ovarian VEGF level (P < 0.05) and a sustained decrease in serum AMH level (P < 0.001). This was followed by ovarian recovery manifested by increased neovascularization. GnRH-a delayed the recovery in AMH level and decreased the level of VEGF (P < 0.001), thus interfering with the vascular recovery subsequent to doxorubicin-induced vascular damage.

LIMITATIONS, REASONS FOR CAUTION

To portray the differential mechanism of each chemotherapy, cyclophosphamide and doxorubicin were given separately, whereas most of the clinical protocols include several types of chemotherapies. Thus, future study should explore a prospective evaluation of various chemotherapies, as well as combined chemotherapeutic protocols.

WIDER IMPLICATIONS OF THE FINDINGS

Our study demonstrates that different chemotherapy agents affect the ovary via diverse mechanisms and thus the administration of GnRH-a concomitantly, could be beneficial to a subpopulation of patients treated with cyclophosphamide-based protocols.

STUDY FUNDING/COMPETING INTERESTS

This work was partially supported by a grant from the Israel Science Foundation (ISF) to I.B.-A. The authors have no conflict of interest to disclose.

The impact of oxaliplatin on the gonads: From bench to bedside

584

Background: Recent studies have indicated a significant increase of young colorectal cancer patients, who may then face unique survivorship issues as fertility concerns. The impact of oxaliplatin on gonadal function remains unclear. We prospectively evaluated oxaliplatin-induced gonadotoxicity in a cohort of young patients. In a preclinical setting, the impact of oxaliplatin on the gonads was prospectively studied in mice. Methods: Newly diagnosed female (< 43 years) and male (<45 years) patients who were candidates for oxaliplatin-based protocol were enrolled into the study. Hormonal profile (including AMH and menstrual pattern) was measured in female patients and in male patients at baseline and within 6 months post-treatment. In the pre-clinical setting, pubertal mice (female and male cohorts) were injected with oxaliplatin or saline (control) and sacrificed at various time-points (1 week, 1 or 3 months) post-treatment. Ovarian reserve was estimated by serial serum AMH. Testicular function was evaluated by serial serum inhibin and sperm count. Gonads had been retrieved at each time point for immunohistochemical study of apoptosis (TUNEL, Ki67) and repair (PCNA), ovarian reserve (AMH) and testicular reserve (DAZL). Results: Eighteen patients (10 women; 8 men) were enrolled. Median age for women was 34y (range 27-43) and for men 39y (33-44). AMH decreased in all women post-treatment, but was measurable in 8/10 patients (p<0.05). FSH was elevated yet in the premenopausal range in these patients. Three patients remain menstruating during treatment. Additional five patients resumed menstruation within 6 months post-treatment. In female mice oxaliplatin induced moderate apoptosis at 1-month post treatment with a recovery of the histology compared with control mice at later time points. Inhibin was slightly decreased in men post-treatment. In male mice oxaliplatin exerted moderate apoptosis and transient decrease in spermatocyte staining in histological sections and a non-significant decrease in sperm count. Conclusions: Our results in both the clinical and pre-clinical settings indicate that oxaliplatin exerts moderate transient gonadal toxicity. Future prospective large-scale studies are warranted in order to affirm these outcomes.

Chemotherapy-induced vascular toxicity--real-time in vivo imaging of vessel impairment

Certain classes of chemotherapies may exert acute vascular changes that may progress into long-term conditions that may predispose the patient to an increased risk of vascular morbidity. Yet, albeit the mounting clinical evidence, there is a paucity of clear studies of vascular toxicity and therefore the etiology of a heterogeneous group of vascular/cardiovascular disorders remains to be elucidated. Moreover, the mechanism that may underlie vascular toxicity can completely differ from the principles of chemotherapy-induced cardiotoxicity, which is related to direct myocyte injury. We have established a real-time, in vivo molecular imaging platform to evaluate the potential acute vascular toxicity of anti-cancer therapies. We have set up a platform of in vivo, high-resolution molecular imaging in mice, suitable for visualizing vasculature within confined organs and reference blood vessels within the same individuals whereas each individual serve as its own control. Blood vessel walls were impaired after doxorubicin administration, representing a unique mechanism of vascular toxicity that may be the early event in end-organ injury. Herein, the method of fibered confocal fluorescent microscopy (FCFM) based imaging is described, which provides an innovative mode to understand physiological phenomena at the cellular and sub-cellular levels in animal subjects.

Abstract 3840: Cetuximab-induced testicular toxicity

Background:

Cetuximab, an anti-EGFR monoclonal antibody, is the only targeted therapy approved for the treatment of head and neck squamous cell carcinoma (HNSCC) in patients with locally advanced tumors, in association with radiotherapy, and in patients with recurrent or metastatic disease, in association with cisplatin-based chemotherapy. We aimed to study the effect of cetuximab on testicular function and reserve.

Methods:

Male mice were injected intraperitoneally with cetuximab (1mg), or cisplatin (8mg/kg) or the combination of both and sacrificed either 1 week or 6 weeks later. Saline-injected mice served as controls. Testes were excised, weighed and further processed. Glutathione and apoptosis assays were performed on 6 weeks samples for determination of oxidative stress. Immunohistochemistry and confocal microscopy were used to study the effect of cetuximab, cisplatin and their combination on the testis histology as well as on the spermatogonial reserve.

Results:

Cetuximab induced mild apoptosis in the testis. Cisplatin induced enhanced apoptosis and depleted spermatogonial reserve, reflected by reduced DAZL staining (early spermatocyte marker). The combined treatment resulted in further decline in testicular weight compared with cisplatin-only treated mice at 1-month post treatment (p&lt;0.05). Cetuximab enhanced cisplatin-induced oxidative stress, and further depletion of spermatogonial reserve (p&lt;0.05).

Conclusions:

Cetuximab has a mild effect on testicular reserve. Nevertheless, the addition of cetuximab to cisplatin exacerbates cisplatin-induced testicular toxicity.

Citation Format: Mattan Levi, Aaron Popovtzer, Moran Tzabari, Salomon M. Stemmer, Ruth Shalgi, Irit Ben-Aharon. Cetuximab-induced testicular toxicity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3840. doi:10.1158/1538-7445.AM2014-3840

Role of pigment epithelium-derived factor in the reproductive system

The physiological function of the female reproductive organs is hormonally controlled. In each cycle, the reproductive organs undergo tissue modifications that are accompanied by formation and destruction of blood vessels. Proper angiogenesis requires an accurate balance between stimulatory and inhibitory signals, provided by pro- and anti-angiogenic factors. As with many other tissues, vascular endothelial growth factor (VEGF) appears to be one of the major pro-angiogenic factors in the female reproductive organs. Pigment epithelium-derived factor (PEDF) is a non-inhibitory member of the serine protease inhibitors (serpin) superfamily, possessing potent physiologic anti-angiogenic activity that negates VEGF activity. The role of PEDF in decreasing abnormal neovascularization by exerting its anti-angiogenic effect that inhibits pro-angiogenic factors, including VEGF, has been investigated mainly in the eye and in cancer. This review summarizes the function of PEDF in the reproductive system, showing its hormonal regulation and its anti-angiogenic activity. Furthermore, some pathologies of the female reproductive organs, including endometriosis, ovarian hyperstimulation syndrome, polycystic ovary syndrome, and others, are associated with a faulty angiogenic process. This review illuminates the role of PEDF in their pathogenesis and treatment. Collectively, we can conclude that although PEDF seems to play an essential role in the physiology and pathophysiology of the reproductive system, its full role and mechanism of action still need to be elucidated.

Hormonal regulation of pigment epithelium-derived factor (PEDF) expression in the endometrium

Pigment epithelium-derived factor (PEDF) is highly expressed in the female reproductive system and is subjected to regulation by steroid hormones in the ovary. As the uterine endometrium exhibits morphological and functional changes in response to estrogen (E2) and progesterone (P4), we aimed at characterizing the expression of PEDF in this component of the female reproductive tract and further at exploring the hormonal regulation of its expression. We found that PEDF is expressed in human and mouse endometrium. We further showed that this expression is subjected to regulation by steroid hormones, both in vivo and in vitro, as follows: E2 decreased PEDF expression and P4 increased its levels. In human endometrial samples, PEDF levels were dynamically altered along the menstrual cycle; they were low at the proliferative and early secretory phases and significantly higher at the late secretory phase. The expression levels of PEDF were inversely correlated to that of vascular endothelial growth factor (VEGF). We also showed that PEDF receptor was expressed in the endometrium and that its stimulation reduced VEGF expression. Illustrating the pattern of PEDF expression during the menstrual cycle may contribute to our understanding of the endometrial complexity.

MicroRNA miR-125a-3p modulates molecular pathway of motility and migration in prostate cancer cells

Fyn kinase is implicated in prostate cancer. We illustrate the role of miR-125a-3p in cellular pathways accounted for motility and migration of prostate cancer cells, probably through its regulation on Fyn expression and Fyn-downstream proteins. Prostate cancer PC3 cells were transiently transfected with empty miR-Vec (control) or with miR-125a-3p. Overexpression of miR-125a-3p reduced migration of PC3 cells and increased apoptosis. Live cell confocal imaging indicated that overexpression of miR-125a-3p reduced the cells' track speed and length and impaired phenotype. Fyn, FAK and paxillin, displayed reduced activity following miR-125a-3p overexpression. Accordingly, actin rearrangement and cells' protrusion formation were impaired. An inverse correlation between miR-125a-3p and Gleason score was observed in human prostate cancer tissues. Our study demonstrated that miR-125a-3p may regulate migration of prostate cancer cells.

Doxorubicin-induced vascular toxicity--targeting potential pathways may reduce procoagulant activity

INTRODUCTION

Previous study in mice using real-time intravital imaging revealed an acute deleterious effect of doxorubicin (DXR) on the gonadal vasculature, as a prototype of an end-organ, manifested by a reduction in blood flow and disintegration of the vessel wall. We hypothesized that this pattern may represent the formation of microthrombi. We aimed to further characterize the effect of DXR on platelets' activity and interaction with endothelial cells (EC) and to examine potential protectants to reduce DXR acute effect on the blood flow.

METHODS

The effect of DXR on platelet adhesion and aggregation were studied in vitro. For in vivo studies, mice were injected with either low molecular weight heparin (LMWH; Enoxaparin) or with eptifibatide (Integrilin(©)) prior to DXR treatment. Testicular arterial blood flow was examined in real-time by pulse wave Doppler ultrasound.

RESULTS

Platelet treatment with DXR did not affect platelet adhesion to a thrombogenic surface but significantly decreased ADP-induced platelet aggregation by up to 40% (p<0.001). However, there was a significant increase in GPIIbIIIa-mediated platelet adhesion to DXR-exposed endothelial cells (EC; 5.7-fold; p<0.001) reflecting the toxic effect of DXR on EC. The testicular arterial blood flow was preserved in mice pre-treated with LMWH or eptifibatide prior to DXR (P<0.01).

CONCLUSIONS

DXR-induced acute vascular toxicity may involve increased platelet-EC adhesion leading to EC-bound microthrombi formation resulting in compromised blood flow. Anti-platelet/anti-coagulant agents are effective in reducing the detrimental effect of DXR on the vasculature and thus may serve as potential protectants to lessen this critical toxicity.

Morphological and molecular markers are correlated with maturation-competence of human oocytes

STUDY QUESTION

Does the position of the germinal vesicle (GV) in human oocytes correlate with molecular and morphological parameters as well as with maturation-competence?

SUMMARY ANSWER

The position of GV in human oocytes correlates with density of microtubule (MT) filaments, concentration of Fyn, nucleolus localization and the ability of the oocytes to complete maturation following GV breakdown (GVBD).

WHAT IS KNOWN ALREADY

Our knowledge is confined to oocytes of young mice where maturation-competence is correlated with a central GV and regulated by MTs and the presence of a chromatin ring. Fyn kinase is localized at the spindle and cortex of mouse oocytes and plays a role in both maturation and MT stabilization.

STUDY DESIGN, SIZE, DURATION

Spatial localization of the GV and nucleolus (central or peripheral), the presence of a chromatin ring, the localization of Fyn, MT density and oocyte maturation were assessed in 153 human oocytes, 335 oocytes from young mice (2-month-old) and 146 oocytes from old mice (12-month-old).

PARTICIPANTS/MATERIALS, SETTING, METHODS

GV human oocytes were donated by consenting female patients (n = 57), 21-45-year-old undergoing IVF/ICSI. As a control, GV mouse oocytes were collected from female mice after injection of pregnant mares' serum gonadotrophin. Human and mouse GV oocytes allocated for immunocytochemistry were fixed on day of retrieval, stained with specific antibodies and imaged using a confocal laser-scanning microscope. Human and mouse oocytes allocated for maturation were incubated for 48 and 24 h, respectively. GVBD and extrusion of the first polar body (PBI) were assessed using differential interference contrast optics.

MAIN RESULTS AND THE ROLE OF CHANCE

GV location was peripheral and independent of age in 69.9% of the human oocytes, but GV location did vary with age in mice oocytes; it was central in 89.9% of the oocytes retrieved from young-mice and peripheral in 52.1% of the oocytes retrieved from old mice (P < 0.05). A central GV, whether in human or mouse oocytes, was highly correlated with a central nucleolus, absence of Fyn at the GV and a dense MT network (P < 0.05), whereas a peripheral GV correlated with peripheral nucleolus, presence of Fyn at the GV and a flimsy MT network. After 48 h in culture, no degeneration was observed in human central-GV oocytes, however, 12/95 (12.6%) of the peripheral-GV oocytes degenerated (P < 0.05). No correlation was observed between GV position and presence of a chromatin ring. The percentage of human oocytes that extruded the PBI after completing GVBD was significantly higher (73.7%) in central than in peripheral-GV oocytes (45.8%; P < 0.05). In mice oocytes, central location of the GV correlated with maturation competence in young (P < 0.05) but not old mice.

LIMITATIONS, REASONS FOR CAUTION

The fact that the human GV oocytes used in this study were exposed to gonadotrophic stimulation but failed to mature in vivo might be a sign of their low quality and this should be considered when drawing conclusions from the data. Furthermore, our observation that only peripheral-GV human oocytes were degraded may indicate that they are of a lower quality than central-GV human oocytes.

WIDER IMPLICATIONS OF THE FINDINGS

We suggest that the central location of GV within the oocytes, which is associated with an absence of Fyn at the GV and the presence of thick filamentous MTs in the ooplasm, may serve as a predictor of successful maturation and provide new insights for the use of IVM.

microRNA-125a-3p reduces cell proliferation and migration by targeting Fyn

Fyn, a member of the Src family kinases (SFKs), has a pivotal role in cell adhesion, proliferation, migration and survival, and its overexpression is associated with several types of cancer. MicroRNAs (miRNAs) play a major role in post-transcriptional repression of protein expression. In light of the significant functions of Fyn, together with studies demonstrating miR-125a as a tumor-suppressing miRNA that is downregulated in several cancer cell types and on our bioinformatics studies presented here, we chose to examine the post-transcription regulation of Fyn by miR-125a-3p in the HEK 293T cell line. We show that Fyn expression can be dramatically reduced by elevated levels of miR-125a-3p. Following this reduction, the activity of proteins downstream of Fyn, such as FAK, paxillin and Akt (proteins known to be overexpressed in various tumors), is also reduced. On a broader level, we show that miR-125a-3p causes an arrest of the cell cycle at the G2/M stage and decreases cell viability and migration, probably in a Fyn-directed manner. The results are reinforced by control experiments conducted using Fyn siRNA and anti-miR-125a-3p, as well as by the fact that numerous cancer cell lines show a significant downregulation of Fyn after mir-125a-3p overexpression. Collectively, we conclude that miR-125a-3p has an important role in the regulation of Fyn expression and of its signaling pathway, which implies that it has a therapeutic potential in overexpressed Fyn-related diseases.

Abstract 4168: The role of miRNA-125a-Fyn interplay in prostate cancer tumorigenesis

Background: The SRC-family of kinases (SFKs) has been broadly implicated in the pathogenesis of prostate cancer. Fyn, a member of the SFKs, mediates mitogenic signals and regulates proliferation, adhesion and motility. Cumulative data indicate that Fyn serves as a proto-oncogene and is known to be over-expressed in several types of malignancies. MicroRNAs are noncoding RNAs that are aberrantly expressed in cancer and seem to influence tumor behavior and progression. In a previous study performed in human embryonic kidney (HEK 293T) cells, we have validated the binding specificity of miR-125a-3p and Fyn 3’UTR using Luciferase assay and established the regulation of Fyn expression and signaling by miR-125a-3p. In the current study we aimed to characterize the interplay between miRNA-125a-3p and Fyn in prostate cancer. Methods: Prostate cancer (PC3) cell line, were transiently transfected with empty miR-vec (control) or with miR-125a-3p and their cell cycle and apoptotic rate were measured by fluorescence activated cell sorting (FACS). The migration ability was measured by transwell assay and scratch assay. Proliferation was assessed by MTT assay. Quantitative PCR and western blot analysis were implicated to determine the effect of miR-125a-3p on Fyn expression as well as on the activation state of its downstream effectors/proteins FAK, Akt and paxillin. Extraction of miRNA from formalin fixed paraffin-embedded (FFPE) cancerous and matched adjacent prostate tissues was performed with miRNeasy FFPE Kit on a cohort of 20 human prostate cancer specimens.

Results: Overexpression of miR-125a-3p in PC3 cells reduced significantly the expression of Fyn mRNA and protein and led to impaired cell viability to an arrest at the G2/M phase of the cell cycle. Moreover, overexpressing of miR-125a-3p reduced the activity of FAK, Akt and paxillin and the secretion of VEGF to the culture media. In miRNA125a-3p-overexpressing PC3 cells the migration was compromised by 50% and cell viability decreased by 50%. Moreover, we observed an inverse correlation between the expression of miR-125a-3p and the Gleason score of tissue samples obtained from patients diagnosed with prostate cancer, whereas the expression of miR-125a-3p was extremely reduced in Gleason score higher than 8.

Conclusions: Our study indicates miR-125a-3p signature in cellular pathways accounted for cell viability and migration of prostate cancer cells. The interplay between miR-125a-3p and Fyn may represent a new plausible therapeutic target in prostate cancer.

Citation Format: Lihi Ninio Many, Irit Ben-Aharon, Sofia Zilber, Mattan Levy, Salomon M. Stemmer, Ruth Shalgi. The role of miRNA-125a-Fyn interplay in prostate cancer tumorigenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4168. doi:10.1158/1538-7445.AM2013-4168

The role of pigment epithelium-derived factor in the pathophysiology and treatment of ovarian hyperstimulation syndrome in mice

CONTEXT

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of assisted reproduction. OHSS is induced by an ovarian release of vasoactive, angiogenic substances that results in vascular hyperpermeability, leakage, and shift of fluids from blood vessels into the extravascular space with consequent ascites and edema that are attributed to vascular endothelial growth factor (VEGF).

OBJECTIVE

Our objective was to examine a physiological approach for preventing and treating OHSS, based on negating the VEGF network.

DESIGN

We used a mouse OHSS model and cultured granulosa cells.

MAIN OUTCOME

Changes in pigment epithelium-derived factor (PEDF) and VEGF were measured by quantitative PCR and Western blot analysis. OHSS was recorded by changes in body weight and in peritoneal vascular leakage, quantified by the modified Miles vascular permeability assay.

RESULTS

Granulosa cells produced and secreted the anti-angiogenic factor, PEDF, in an inverse fashion to VEGF. The physiological PEDF-VEGF counterbalance was found to be impaired in the mouse OHSS model. Treatment of OHSS-induced mice with low doses of recombinant PEDF (rPEDF) alleviated OHSS signs including edema (P < .001) and vascular leakage (P < .001) and reduced the level of ovarian VEGF mRNA. Low doses of rPEDF also reduced VEGF mRNA levels in granulosa cells in vitro. However, these effects were not seen at higher doses of rPEDF, suggesting a hormetic mechanism of rPEDF action.

CONCLUSION

These observations provide a new perspective into the pathophysiology of OHSS, namely, high expression level of VEGF together with a nearly undetectable level of PEDF. A replacement therapy with rPEDF is suggested as an innovative physiological treatment for OHSS. Finally, control of the PEDF-VEGF reciprocal relationship could open new therapeutic avenues for other angiogenic-related fertility pathologies.

Hormonal regulation of pigment epithelium-derived factor (PEDF) in granulosa cells

Angiogenesis is critical for the development of ovarian follicles. Blood vessels are abrogated from the follicle until ovulation, when they invade it to support the developing corpus luteum. Granulosa cells are known to secrete anti-angiogenic factors that shield against premature vascularization; however, their molecular identity is yet to be defined. In this study we address the physiological role of pigment epithelium-derived factor (PEDF), a well-known angiogenic inhibitor, in granulosa cells. We have shown that human and mouse primary granulosa cells express and secrete PEDF, and characterized its hormonal regulation. Stimulation of granulosa cells with increasing doses of estrogen caused a gradual decrease in the PEDF secretion, while stimulation with progesterone caused an abrupt decrease in its secretion. Moreover, We have shown, by time- and dose-response experiments, that the secreted PEDF and vascular endothelial growth factor (VEGF) were inversely regulated by hCG; namely, PEDF level was nearly undetectable under high doses of hCG, while VEGF level was significantly elevated. The anti-angiogenic nature of the PEDF secreted from granulosa cells was examined by migration, proliferation and tube formation assays in cultures of human umbilical vein endothelial cells. Depleting PEDF from primary granulosa cells conditioned media accelerated endothelial cells proliferation, migration and tube formation. Collectively, the dynamic expression of PEDF that inversely portrays VEGF expression may imply its putative role as a physiological negative regulator of follicular angiogenesis.

De novo synthesis of protein phosphatase 1A, magnesium dependent, alpha isoform (PPM1A) during oocyte maturation

Oocyte maturation in mammals is a multiple-stage process that generates fertilizable oocytes. Ovarian oocytes are arrested at prophase of the first meiotic division characterized by the presence of a germinal vesicle. Towards ovulation, the oocytes resume meiosis and proceed to the second metaphase in a process known as maturation; they undergo nuclear and cytoplasmic changes that are accompanied by translation and degradation of mRNA. Protein phosphatase 1A, magnesium dependent, alpha isoform (PPM1A), which belongs to the metal-dependent serine/threonine protein phosphatase family, is highly conserved during evolution. PPM1A plays a significant role in many cellular functions such as cell cycle progression, apoptosis and cellular differentiation. It works through diverse signaling pathways, including p38 MAP kinase JNK and transforming growth factor beta (TGF-β). Herein we report that PPM1A is expressed in mouse oocytes and that its mRNA level rises during oocyte maturation. Using quantitative real-time polymerase chain reaction (qPCR) and western blot analysis, we found that PPM1A mRNA is synthesized at the beginning of the maturation process and remains elevated in the mature oocytes, promoting the accumulation of PPM1A protein. Since PPM1A function is mainly affected by its level, we propose that it might have an important role in oocyte maturation.