Stromal-epithelial Interactions Research Articles

Abstract 4499: Determining the role of discoidin domain receptors 1 and 2 in the pathogenesis of pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDA) is an aggressive and devastating cancer often characterized by an intense collagen-rich, fibrotic response. In the presence of an oncogenic Kras mutation, the pancreas undergoes an initial morphological event in which normal acinar cells transdifferentiate into a ductal-like phenotype in a process called acinar-ductal metaplasia (ADM). ADM advances into pre-cancerous lesions, followed by a subsequent replacement of epithelium with a collagen-dense stromal reaction as PDA progresses. Discoidin domain receptors, DDR1 and DDR2, are a unique family of tyrosine receptor kinases that bind to collagen and activate downstream cellular responses that affect cell proliferation, migration, and adhesion. Our preliminary data shows that during Kras-induced ADM in vitro DDR1 is downregulated and is accompanied by an upregulation of DDR2 expression. Immunohistochemistry on human tissue microarrays reveals DDR1 is expressed in normal epithelia and pre-neoplastic lesions, but downregulated during advanced PDA. Conversely, DDR2 is upregulated in metaplastic lesions and advanced carcinoma as well as in the stroma at all stages of progression, suggesting DDRs may play a differential role throughout the PDA. DDR1 is expressed in epithelial cells and associated with disease states such as fibrosis and various cancers, including PDA. To study the role of DDR1 in pancreatitis, a known risk factor of PDA, we used DDR1-null mice (DDR1-/-) with our cerulein-induced pancreatitis protocol. DDR1 ablation induces tissue damage and impairs recovery from extended cerulein treatment. To understand the role of DDR1 in tumorigenesis, we mated DDR1-/- mice in the KrasG12D/+; Ptf1aCre/+ (KC model) of pancreatic neoplasia. The absence of DDR1 in the KC model does not inhibit nor delay tumorigenesis, however, pancreata are smaller with less differentiated morphology than wild-type KC animals. In contrast, DDR2 is expressed in mesenchymal cells and has been implicated in EMT, cell proliferation, tumor invasion, and required for metastasis in breast cancer, however, its significance in PDA remains unknown. Our preliminary data shows DDR2 co-stains with neuroendocrine positive cells within neoplastic lesions that are associated with poor patient survival. To further investigate the role of DDR2 in tumor progression we have successfully mated a conditional, global DDR2 knockout mouse (DDR2fl/fl; β-actinCreERT2) with our novel KrasFSF-G12D/+;p53FRT/+ ;Ptf1a-FlpO/+ (KPF) aggressive PDA mouse model. Collectively, the results from these studies will help determine the role of DDRs throughout the initiation and progression of PDA and help define a potential point of regulation at the interface between the epithelial-stromal interactions. Citation Format: Jeanine Ruggeri, Christopher Halbrook, Anjum Sohail, Rafael Fridman, Howard Crawford. Determining the role of discoidin domain receptors 1 and 2 in the pathogenesis of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4499.

Abstract 5068: Distinct pro-inflammatory cytokines in prostate fibroblasts from African-Americans with prostate cancer increase the tumorigenicity of cancer cells

Abstract Introduction: African-American (AA) men are disproportionately affected by prostate cancer (PCa) compared with Caucasian (CA) men. AA men have higher PCa incidence and, once diagnosed, a higher stage-specific mortality rate (2.4 times higher) than CA men. Although socioeconomic factors partially explain such differences, a growing body of new scientific evidence suggests that biological factors, such as differences at the genetic and molecular level could be more critical than previously thought for the observed racial PCa disparities in incidence and outcome. Recent gene expression studies revealed that differences in the tumor microenvironment (TME) of AA vs. CA prostate tumors could affect the immune-inflammatory milieu. Fibroblasts are important regulators of stromal-epithelial paracrine interactions (SEI) in the TME. We isolated fibroblasts from AA and CA PCa patients and compared their biological effects in vitro and in vivo on PCa cell lines. Methods: Prostate fibroblasts were isolated from AA (PrF-AA) and CA (PrF-CA) patient tissues. Characterization of PrF included assaying their proliferation and expression of potential markers associated with the activation of carcinoma associated fibroblasts. In vitro effects of AA vs. CA fibroblasts on PCa cell proliferation and motility were studied. In vivo, the pro-tumorigenic properties of fibroblasts were tested using a subrenal xenograft model in SCID mice. RNA-Seq and cytokine array analysis of potential paracrine mediators of tumorigenesis was performed. Immunohistochemical analysis of a panel of putative stromal markers associated with racial differences was assessed in a cohort of PCa tissues from AA and CA. Results: Prostate fibroblasts from AA vs. CA men exhibit increased proliferation in response to known stromal mitogens. Expression of markers associated with myofibroblast activation (αSMA, vimentin and Tenascin-C) were significantly elevated in AA. Interestingly, expression of the androgen receptor (AR) and activation of AR signaling was significantly increased in PrF-AA compared to PrF-CA. The paracrine effects of PrF-AA on PCa cell proliferation and motility were significantly greater compared to those induced by PrF-CA. In an in vivo model, PRF-AA induced formation of larger and more invasive tumors by the AA PCa cell line E006AA compared to PRF-CA. Analysis of downstream regulatory pathways and potential paracrine mediators identified a panel of pro-inflammatory cytokines notably interleukins (IL6, IL11, IL17, IL18BP), growth factors (VEGF, FGF, BDNF), and other mediators enriched in PRF-AA. Conclusions: Prostate fibroblasts from African American men show enhanced secretion of pro-inflammatory and pro-proliferative mediators that can potentially increase the tumorigenicity of PCa cells through selective paracrine mechanisms. Citation Format: Marc Gillard, Alejandro Morales, Susan Crawford, Charles Brendler, Donald Vander Griend, Omar Franco. Distinct pro-inflammatory cytokines in prostate fibroblasts from African-Americans with prostate cancer increase the tumorigenicity of cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5068.

Abstract 1010: Establishing lobular-like and interlobular-like fibroblast cell lines from human breast reduction mammoplasties

Abstract Introduction: The importance of epithelial-stromal interactions for tissue homeostasis and maintenance is well documented. We have recently provided evidence that two distinct fibroblast lineages in the human breast stroma, lobular and interlobular, respectively, can be prospectively isolated and stably propagated in serial-passage subculture. The aim of the present study was to generate immortalized and stable cell lines derived from lobular and interlobular fibroblasts with preserved lineage identity and functionality. The availability of such cell lines will allow for an as of yet unprecedented detailed characterization of mammary fibroblast lineages including their specific interactions with normal and malignant breast epithelium. Results: Lobular- and interlobular-derived fibroblast cell strains in passage 8 were immortalized by retroviral introduction of human telomerase reverse transcriptase (hTERT) followed by neomycin selection. At abstract submission deadline, lobular and interlobular hTERT expressing fibroblasts had reached passage 56 corresponding to 60 and 100 population doublings, respectively, while mock-transfected controls had seized proliferating in passage 21. Lineage restriction of immortalized cells was maintained as lobular fibroblasts express higher levels of CD105 than interlobular fibroblasts. Also, lobular fibroblasts are able to undergo adipogenic and osteogenic differentiation upon relevant induction in culture, but fail to generate bone in an in vivo ectopic bone formation model, thus functionally distinguishing lobular fibroblasts from bone marrow-derived mesenchymal/skeletal stem cells. Upon co-culture with primary breast luminal progenitors, lobular fibroblasts support epithelial growth and branching morphogenesis, including correct apical-basal polarization. Conclusion: Lobular and interlobular fibroblasts have been successfully immortalized while preserving both lineage restriction and functional characteristics of their primary counterparts. With 80% of breast cancers arising in lobular epithelium, these established fibroblast models may prove instrumental to unravel such focal susceptibility to breast cancer development. Citation Format: Mikkel Morsing, Abbas Jafari, Moustapha Kassem, Ole William Petersen, Lone Rønnov-Jessen. Establishing lobular-like and interlobular-like fibroblast cell lines from human breast reduction mammoplasties [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1010.

Proliferation of prostate epithelia induced by IL-6 from stroma reacted with Trichomonasvaginalis.

Benign prostatic hyperplasia (BPH) is characterized by the proliferation of stromal and epithelial cell types in the prostate, and interactions between the two types of cells. We demonstrated previously that proliferation of prostate stromal cells was induced by BPH epithelial cells in response to Trichomonasvaginalis (Tv) infection via crosstalk with mast cells. In this study, we investigated whether IL-6 released by the proliferating stromal cells in turn induce the BPH epithelial cells to multiply. When culture supernatants of the proliferating prostate stromal cells were added to BPH epithelial cells, the latter multiplied, and expression of cyclin D1, FGF2 and Bcl-2 increased. Blocking the IL-6 signalling pathway with anti-IL-6R antibody or JAK1/2 inhibitor inhibited the proliferation of the BPH epithelial cells and reduced the expression of IL-6, IL-6R and STAT3. Also, epithelial-mesenchymal transition was detected in the proliferating BPH epithelial cells. In conclusion, IL-6 released from proliferating prostate stromal cells induced by BPH epithelial cells infected with Tv in turn induces multiplication of the BPH epithelial cells. This result provides first evidence that the inflammatory microenvironment of prostate stromal cells resulting from Tv infection induces the proliferation of prostate epithelial cells by stromal-epithelial interaction.

Crosstalk between YAP/TAZ and Notch Signaling.

How the behavior of cells in living tissues is orchestrated according to tissue needs, size, and developmental stage is still poorly understood. Advances in these directions are essential to understand morphogenesis, 'self-organization' phenomena, to build new tissues for regenerative medicine or to reverse the changes in deranged organs, such as in cancer or in genetic disorders. This review outlines a new scenario by which the crosstalk between the Yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ) transcription factors and Notch signaling influences cell self-renewal, stem cell differentiation, cell fate decisions, epithelial-stromal interactions, inflammation, morphogenesis, and large-scale gene oscillations.

Role of Stromal Paracrine Signals in Proliferative Diseases of the Aging Human Prostate.

Androgens are essential for the development, differentiation, growth, and function of the prostate through epithelial–stromal interactions. However, androgen concentrations in the hypertrophic human prostate decrease significantly with age, suggesting an inverse correlation between androgen levels and proliferative diseases of the aging prostate. In elderly males, age- and/or androgen-related stromal remodeling is spontaneously induced, i.e., increased fibroblast and myofibroblast numbers, but decreased smooth muscle cell numbers in the prostatic stroma. These fibroblasts produce not only growth factors, cytokines, and extracellular matrix proteins, but also microRNAs as stromal paracrine signals that stimulate prostate epithelial cell proliferation. Surgical or chemical castration is the standard systemic therapy for patients with advanced prostate cancer. Androgen deprivation therapy induces temporary remission, but the majority of patients eventually progress to castration-resistant prostate cancer, which is associated with a high mortality rate. Androgen deprivation therapy-induced stromal remodeling may be involved in the development and progression of castration-resistant prostate cancer. In the tumor microenvironment, activated fibroblasts stimulating prostate cancer cell proliferation are called carcinoma-associated fibroblasts. In this review, we summarize the role of stromal paracrine signals in proliferative diseases of the aging human prostate and discuss the potential clinical applications of carcinoma-associated fibroblast-derived exosomal microRNAs as promising biomarkers.

Human papillomavirus type 16 E5-mediated upregulation of Met in human keratinocytes

Human papillomaviruses (HPVs) cause benign lesions that can lead to malignancy. How cellular changes induced by viral oncogenes contribute to the progeny virion production is not always clear. Stromally-derived growth factors and their receptors are critical for development of malignancy, but their impact on the pre-malignant HPV life cycle is unknown. We show that HPV16 increases levels of Met, a growth factor receptor critical for tumor cell invasion, motility, and cancer metastasis. The viral oncogene E5 is primarily responsible for Met upregulation, with E6 playing a minor role. Met induction by E5 requires the epidermal growth factor receptor, which is also increased by E5 at the mRNA level. E5-induced Met contributes motility of HPV-containing cells. Finally, Met signaling is necessary for viral gene expression, particularly in the differentiation-dependent phase of the viral life cycle. These studies show a new role for E5 in epithelial-stromal interactions, with implications for cancer development.

Inhibition of Nox4-dependent ROS signaling attenuates prostate fibroblast activation and abrogates stromal-mediated protumorigenic interactions.

Carcinoma‐associated fibroblasts (CAFs) play a key onco‐supportive role during prostate cancer (PCa) development and progression. We previously reported that the reactive oxygen species (ROS)‐producing enzyme NADPH oxidase 4 (Nox4) is essential for TGFβ1‐mediated activation of primary prostate human fibroblasts to a CAF‐like phenotype. This study aimed to further investigate the functional relevance of prostatic Nox4 and determine whether pharmacological inhibition of stromal Nox4 abrogates paracrine‐mediated PCa‐relevant processes. RNA in situ hybridization revealed significantly elevated Nox4 mRNA levels predominantly in the peri‐tumoral stroma of clinical PCa with intense stromal Nox4 staining adjacent to tumor foci expressing abundant TGFβ protein levels. At pharmacologically relevant concentrations, the Nox1/Nox4 inhibitor GKT137831 attenuated ROS production, CAF‐associated marker expression and migration of TGFβ1‐activated but not nonactivated primary human prostate fibroblasts. Similar effects were obtained upon shRNA‐mediated silencing of Nox4 but not Nox1 indicating that GKT137831 primarily abrogates TGFβ1‐driven fibroblast activation via Nox4 inhibition. Moreover, inhibiting stromal Nox4 abrogated the enhanced proliferation and migration of PCa cell lines induced by TGFβ1‐activated prostate fibroblast conditioned media. These effects were not restricted to recombinant TGFβ1 as conditioned media from PCa cell lines endogenously secreting high TGFβ1 levels induced fibroblast activation in a stromal Nox4‐ and TGFβ receptor‐dependent manner. Importantly, GKT137831 also attenuated PCa cell‐driven fibroblast activation. Collectively, these findings suggest the TGFβ‐Nox4 signaling axis is a key interface to dysregulated reciprocal stromal–epithelial interactions in PCa pathophysiology and provide a strong rationale for further investigating the applicability of Nox4 inhibition as a stromal‐targeted approach to complement current PCa treatment modalities.

Abstract P6-07-08: Dual TGFβ/BMP inhibition allows in vitro expansion of multiple cell types from normal and cancerous breast

Abstract Functional modeling of breast epithelial hierarchy and stromal-epithelial cell interactions has been difficult due to inability to obtain sufficient stem-progenitor-mature epithelial cells and stromal cells. The recently developed epithelial reprogramming assay has partially overcome this limitation, allowing propagation of epithelial cells with stem, luminal progenitor and mature cell features. However, characterizing stromal cells using this assay is difficult because irradiated fibroblasts which can be difficult to distinguish from stromal cells are needed as feeder layer. A recent study demonstrated expansion of airway basal stem cells without a feeder layer through pharmacologic inhibition of TGFβ/BMP/SMAD signaling. We sought to develop this method for culture and expansion of cells from normal and cancerous breast samples. With appropriate modifications to growth media, we were able to obtain normal and stromal cells from breast biopsies of healthy women. The expanded cell population included CD10+/EpCAM- basal/myoepithelial cells, CD49f+/EpCAM+ luminal progenitor cells, CD49f-/EpCAM+ mature luminal cells, CD73+/EpCAM+/CD90- rare endogenous pluripotent somatic stem cells, CD73+/CD90+/EpCAM- mesenchymal stem cells, ALCAM (CD166)+/EpCAM+ cells, CD44+/CD24- cells, CD44+/CD24+ cells and ALDFLUOR+ stem/luminal progenitor cells. Epithelial cells were KRT14+, KRT19+ or both further documenting heterogeneity within epithelial cell population. We have extended this technique to grow breast epithelial cells from high-risk patients including BRCA1 mutant-carriers, tumor-adjacent normal and tumor cells from the same patient, pleural effusions and liver metastasis from breast cancer patients. Phenotypic characterization showed differences in the differentiation state of adjacent-normal and tumor cells. Tumor cells from pleural effusions showed remarkable phenotypic heterogeneity with a fraction of these cells expressing estrogen receptor. The assay described here, therefore, is versatile and provides resources to model epithelial-stromal interactions under normal and cancerous conditions as well as for genomics and screening of drugs to target metastasis on an individual level. Susan G. Komen for the Cure and Department of Defense supported this work. Citation Format: Nakshatri H, Ananappa M, Prasad MS, Kumar B, Liu Y, Storniolo AM, Miller KD, Bhat-Nakshatri P. Dual TGFβ/BMP inhibition allows in vitro expansion of multiple cell types from normal and cancerous breast [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-07-08.

Senescent fibroblasts drive ageing pigmentation: ​A potential therapeutic target for senile lentigo.

Cutaneous ageing is an important extrinsic process that modifies the pigmentary system. Because cellular senescence is a fundamental ageing mechanism, we examined the role of senescent cells in ageing pigmentation.Methods: Biopsies obtained from senile lentigo and perilesional normal skin were assayed for a marker of cellular senescence, p16INK4A. To determine the secretory phenotypes of senescent fibroblasts, we performed microarray, RNA sequencing and methylation array analyses in senile lentigo and senescent fibroblasts. To further investigate the impact of senescent cells on ageing-related pigmentation, an intervention that targeted senescent cells using radiofrequency was performed.Results: In vivo, senescent fibroblasts accumulated at the sites of age-related pigmentation. Phenotype switching of the cells resulted in the repression of stromal-derived factor 1 (SDF1) by promoter methylation. SDF1 induced melanocyte differentiation via stromal-epithelial interactions, ultimately driving skin pigmentation. Furthermore, the elimination of senescent fibroblasts from pigmented skin using radiofrequency was accompanied by skin lightening, rendering it a potential target for treatment.Conclusion: Aged pigmented skin contains an increasing proportion of senescent fibroblasts. Cells with phenotype switching exhibited a loss of SDF1, which stimulates the melanogenic process and thereby contributes to aging pigmentation. These data may promote the development of new therapeutic paradigms, such as a stroma-targeting therapy for pigmentary disorders.

Regulation of inflammatory gene expression in macrophages by epithelial-stromal interaction 1 (Epsti1)

Epithelial-stromal interaction 1 (EPSTI1) was first discovered as a gene induced in breast cancer epithelial cells by co-cultured stromal fibroblasts. There are many reports on the role of Epsti1 in cancer malignancy. Epsti1 is now well known in regulating cancer. Recently, the role of Epsti1 in the immune response has been reported; these reports suggest the role of Epsti1 in immune function, immune privilege, and autoimmune diseases. Furthermore, they show that Epsti1 is expressed in various types of immune cells. In this study, we observed that Epsti1 is highly expressed in macrophages exposed to IFNγ and lipopolysaccharide (LPS), which classically activates macrophages. Polarization of macrophage to classically activated (M1) or alternatively activated (M2) is important for mounting responses against various infections. The M1 and M2 types of macrophage have a distinct role in the immune system. However, the molecular mechanism of modulation of the macrophage type is not well defined. Our results showed that the M2 type macrophage phenotype is enhanced in Epsti1-deficient bone marrow-derived macrophages (BMDM). In addition, Epsti1 deficiency suppresses induction of pro-inflammatory genes in BMDMs via inhibition of Stat1 and p65 nuclear localization and phosphorylation. Surprisingly, Epsti1−/− mice show decreased numbers of M1 macrophages in the peritoneal cavity. These findings identify Epsti1 as a modulator of macrophage activation and polarization via the Stat1 and p65 pathways, and suggest a potentially important role of Epsti1 in immunotherapies against inflammatory diseases.

Adiponectin: A prosurvival and proproliferation signal that increases bovine mammary epithelial cell numbers and protects them from endoplasmic reticulum stress responses.

Cell-cell interactions between epithelial and stromal cells are predominant in the mammary gland, and various stromal cell-derived factors can elicit mitogenic responses in adjacent epithelial cells. Adiponectin is a hormone secreted mainly by adipocytes that mediates stromal-epithelial interactions in a number of tissues. Adiponectin receptors are expressed by bovine mammary epithelial cells, but the regulatory effects of adiponectin on the development and function of the mammary gland remain unclear. We therefore sought to investigate the effects of adiponectin on bovine mammary epithelial (MAC-T) cells and the regulatory mechanisms that underlie these adiponectin-induced actions. Our results revealed an increase in MAC-T cell proliferation and cell cycle progression in response to adiponectin. The expression of nuclear proliferating cell nuclear antigen (PCNA) and cyclin D1 was induced in MAC-T cells, and intracellular signaling molecules such as serine/threonine protein kinase (AKT), 70 kDa ribosomal S6 kinase (P70S6K), ribosomal protein S6 (S6), extracellular signal-regulated kinases 1 and 2 (ERK1/2), 90 kDa ribosomal S6 kinase (P90S6K), and cyclin D1 were activated in a dose-dependent manner. The abundance of adiponectin-induced signaling proteins was suppressed following inhibition of AKT or ERK1/2 mitogen-activated protein kinase (MAPK) signaling. In addition, inhibition of AKT or ERK1/2 signaling significantly reduced adiponectin-stimulated MAC-T cell proliferation. Furthermore, adiponectin reduced tunicamycin-induced expression and activation of endoplasmic reticulum stress-related proteins in MAC-T cells and attenuated the repressive effect of tunicamycin on proliferation of MAC-T cells. Collectively, these results suggest that adiponectin-mediated signaling may affect the development and function of the mammary gland in dairy cows by increasing mammary epithelial cell numbers. These findings may result in important implications for improving our fundamental understanding of lactation physiology in livestock species.

Nintedanib treatment delays prostate dorsolateral lobe cancer progression in the TRAMP model: contribution to the epithelial‐stromal interaction balance

Prostate cancer (PCa) progression mechanism has been linked to epithelial proliferation, tumor invasion ability, and growth factors. Nintedanib (BIBF 1120) has been reported as being FGF and VEGF pathway inhibitors, exhibiting antitumor activity. Thus, the objective herein was to characterize the early Nintedanib treatment effects on the structure and molecules involved in the basal membrane, the extracellular matrix (ECM) maintenance, in addition to the angiogenesis and mitogenic processes at different grades of prostatic tumor development in TRAMP mice. Therefore, 45 male TRAMP mice were divided into control groups: 8-week-old mice (TC8), 12-week-old mice (TC12), and 16-week-old mice (TC16); and treated groups with 10 mg/kg/day Nintedanib dose for 4 weeks. The treated groups were euthanized at 12 (TN12) and 16 (TN16) weeks of age. Samples from the dorsolateral lobe were collected and processed for light microscopy, immunohistochemistry, Western blotting, and microvessel density analysis. The results showed that early Nintedanib treatment led to an increase of healthy epithelium frequency and a reduction of LGPIN and a maximum vascularization density in the TN12 group. Also, treatment led to a well-differentiated adenocarcinoma decrease and an α and β dystroglycan and also laminin 1 increase in the TN16 group. IGFR1 decreased in the TN16 group. To conclude, early Nintedanib treatment led to a reduction in cancer severity, interfering in both ECM compounds and angiogenesis process to then contribute to a balance, not only in the prostatic epithelium and stroma, but also in the epithelial-stromal interaction during PCa progression.

Effect of adiantum capillus veneris against irradiation-induced oxidative stress in adult rats

Crosstalk between epithelial and stromal cells drives the morphogenesis of ectodermal organs during development and promotes normal mature adult epithelial tissue homeostasis. Epithelial-stromal interactions (ESIs) have historically been examined using mammalian models and ex vivo tissue recombination. Although these approaches have elucidated signaling mechanisms underlying embryonic morphogenesis processes and adult mammalian epithelial tissue function, they are limited by the availability of tissue, low throughput, and human developmental or physiological relevance. In this review, we describe how bioengineered ESIs, using either human stem cells or co-cultures of human primary epithelial and stromal cells, have enabled the development of human in vitro epithelial tissue models that recapitulate the architecture, phenotype, and function of adult human epithelial tissues. We discuss how the strategies used to engineer mature epithelial tissue models in vitro could be extrapolated to instruct the design of organotypic culture models that can recapitulate the structure of embryonic ectodermal tissues and enable the in vitro assessment of events critical to organ/tissue morphogenesis. Given the importance of ESIs towards normal epithelial tissue development and function, such models present a unique opportunity for toxicological screening assays to incorporate ESIs to assess the impact of chemicals on mature and developing epidermal tissues.

Abstract 2439: Establishment of six human colorectal cancer cell lines: identification of genes that have metastatic potential

Abstract A number of genes have been studied in accordance with their metastatic potential. Nevertheless, widely used metastatic colorectal cancer cell lines such as SW-620 or IS3 only show the influence of metastatic genes within limited mutational landscape. Here, three pairs of primary CRC (SNU-2335A, SNU-2335D, SNU-2404A, SNU-2404B, SNU-2414A, and SNU-2414B) and corresponding metastasis cell lines were established and analyzed by whole exome sequencing and microarray. Three pairs of primary CRC (SNU-2335A, SNU-2404A, and SNU-2414A) and corresponding matched metastasis cell lines (SNU-2335D, SNU-2404B, and SNU-2414B) were analyzed for gene expression by microarray and whole exome sequencing. Selected target genes from microarray were analyzed again by real-time PCR in order to confirm the mRNA expression level in the paired CRC cell lines. The genes selected for examination were calponin 3, acidic (CNN3); sorbin and SH3 domain containing 1(SORBS1); epithelial stromal interaction 1 (EPSTI1); bone marrow stromal cell antigen 2(BST2); kelch-like 5 (KLHL5); trypsinogen C (TRY6); and synaptotagmin-like 5 (SYTL5). We calculated the intersection of all three metastatic CRC cell lines. Five genes (BST2, SORBS1, CNN3, EPSTI1, and KLHL5) were up-regulated in metastatic cell lines compared to primary cell lines. Two genes (TRY6 and SYTL5) were down-regulated in metastatic cell lines compared to primary cell lines. Then, we ranked 15 genes that were up-regulated and 15 genes that were down-regulated in omental metastasis regardless of the 2-folds threshold. Of the 30 genes that were differently expressed, we selected three genes (CNN3, SORBS1, and TRY6) that showed the highest fold changes and are found in 2-fold change analysis. We identified 7 genes that were differently expressed in metastatic CRC cell lines compared to primary CRC cell lines. These genes may serve as diagnostic markers and therapeutic targets for patients with metastatic CRC. Note: This abstract was not presented at the meeting. Citation Format: Soon-Chan Kim, Chang-Won Hong, Sang-Geun Jang, Seung-Yong Jeong, Jae-Gahb Park, Ja-Lok Ku. Establishment of six human colorectal cancer cell lines: identification of genes that have metastatic potential [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 2439. doi:10.1158/1538-7445.AM2017-2439

Study of Proliferative Activity of Vaginal Epithelium in Women with Stress Urinary Incontinence Treated by Er:YAG Laser.

The expression of Ki-67 proliferation marker was studied in vaginal biopsy specimens from women with stress urinary incontinence treated using a Fotona nonablative erbium laser. Cells expressing Ki-67 were located in all cases in the parabasal and basal levels of stratified squamous epithelium, the index of labeled nuclei before Er:YAG laser exposure was 19.05±2.86%. After 1-2 months of laser therapy, the index of labeled nuclei in the epithelium increased significantly and reached 31.79±2.25%. These changes were interpreted as a result of epithelial-stromal interactions. Presumably, the increase in proliferative activity of the vaginal epithelium after exposure to Er:YAG laser was due to the presence of an appreciable level of synthetically active fibroblasts in the subepithelial stroma.

In Vivo Effects of Long-Term Cigarette Smoke Exposure on Mammary Tissue in Mice

Cigarette smoking is the leading cause of preventable death worldwide and has been linked to the development and progression of cancer. Many cohort studies have described the link between patients with breast cancer and those with long-term smoking history. Despite the claim of correlation, the mechanism by which cigarette smoke alters normal breast epithelial cells and stroma and contributes to tumor cell growth remains undefined. To investigate whether cigarette smoke promotes ductal epithelial cell hyperplasia by stimulating stromal endothelial cell proliferation, we exposed mice to cigarette smoke for 6 months. We observed epithelial proliferation, increased fibrosis, increased vascularity, and mast cell infiltration. This is the first study to look at the invivo changes in the breast after long-term cigarette smoke exposure and provides a novel insight to understanding how cigarette smoke contributes to early changes that may contribute to tumor formation and progression. In conclusion, this study suggests that cigarette smoke modulates key stromal-epithelial interactions to support increased angiogenesis, desmoplasia, and abnormal ductal epithelial cell growth.

An Engineered Cell-Instructive Stroma for the Fabrication of a Novel Full Thickness Human Cervix Equivalent In Vitro.

There is a growing interest for developing organotypic cervical models by using primary cervical cells that are able to reproduce the physiological relevant stromal microenvironment and the distinctive histology of the native cervical epithelium. Here for the first time it is reported the production of an organotypic cervical model featured by a scaffold-free stromal tissue resembling the extracellular matrix (ECM) composition and organization of the native counterpart as well as a completely well-differentiated epithelium. To reach this aim, human cervical microtissue precursors have been produced, characterized, and used as functional building units to fabricate a cell-synthesized cervical stroma equivalent by means of a bottom-up approach. Immunotypization, and molecular and morphological analyses reveal the extent of fundamental epithelial biomarkers and the presence of collagen and noncollagenous molecules, demonstrating that the natural tissue architecture and biological characteristics of cervical tissues are reproduced. The results of this study suggest that the bottom-up technology used to produce these 3D human cervical equivalents provides a fully functional organotypic cervical model that may be used as a valuable tool to investigate the epithelial-stromal interactions as well as for testing new therapeutics in vitro.

Metformin Ameliorates Uterine Defects in a Rat Model of Polycystic Ovary Syndrome

Adult rats treated concomitantly with insulin and human chorionic gonadotropin exhibit endocrine, metabolic, and reproductive abnormalities that are very similar to those observed in polycystic ovary syndrome (PCOS) patients. In this study, we used this rat model to assess the effects of metformin on PCOS-related uterine dysfunction. In addition to reducing androgen levels, improving insulin sensitivity, and correcting the reproductive cycle, metformin treatment induced morphological changes in the PCOS-like uterus. At the molecular and cellular levels, metformin normalized the androgen receptor-mediated transcriptional program and restored epithelial–stromal interactions. In contrast to glucose transport, uterine inflammatory gene expression was suppressed through the PI3K–Akt–NFκB network, but without affecting apoptosis. These effects appeared to be independent of AMPK subunit and autophagy-related protein regulation. We found that when metformin treatment partially restored implantation, several implantation-related genes were normalized in the PCOS-like rat uterus. These results improve our understanding of how metformin rescues the disruption of the implantation process due to the uterine defects that result from hyperandrogenism and insulin resistance. Our data provide insights into the molecular and functional clues that might help explain, at least in part, the potential therapeutic options of metformin in PCOS patients with uterine dysfunction.

Engineering epithelial-stromal interactions in vitro for toxicology assessment.

Crosstalk between epithelial and stromal cells drives the morphogenesis of ectodermal organs during development and promotes normal mature adult epithelial tissue homeostasis. Epithelial-stromal interactions (ESIs) have historically been examined using mammalian models and ex vivo tissue recombination. Although these approaches have elucidated signaling mechanisms underlying embryonic morphogenesis processes and adult mammalian epithelial tissue function, they are limited by the availability of tissue, low throughput, and human developmental or physiological relevance. In this review, we describe how bioengineered ESIs, using either human stem cells or co-cultures of human primary epithelial and stromal cells, have enabled the development of human in vitro epithelial tissue models that recapitulate the architecture, phenotype, and function of adult human epithelial tissues. We discuss how the strategies used to engineer mature epithelial tissue models in vitro could be extrapolated to instruct the design of organotypic culture models that can recapitulate the structure of embryonic ectodermal tissues and enable the in vitro assessment of events critical to organ/tissue morphogenesis. Given the importance of ESIs towards normal epithelial tissue development and function, such models present a unique opportunity for toxicological screening assays to incorporate ESIs to assess the impact of chemicals on mature and developing epidermal tissues.