Genomic and proteomic profiling II: comparative assessment of gene expression profiles in leiomyomas, keloids, and surgically-induced scars

Keloids, hypertrophic scars, and uterine fibroid development: a prospective ultrasound study of Black and African American women

OBJECTIVE

To examine the association between keloids, hypertrophic scars, and uterine fibroid incidence as well as growth. Both keloids and fibroids are fibroproliferative conditions that have been reported to be more prevalent among Blacks than Whites, and they share similar fibrotic tissue structures, including extracellular matrix composition, gene expression, and protein profiles. We hypothesized that women with a history of keloids would have greater uterine fibroid development.

DESIGN

A prospective community cohort study (enrollment 2010-2012) with 4 study visits over 5 years to conduct standardized ultrasounds to detect and measure fibroids ≥0.5 cm in diameter, assess the history of keloid and hypertrophic scars, and update covariates.

SETTING

Detroit, Michigan area.

PATIENTS

A total of 1,610 self-identified Black and/or African American women aged 23-35 years at enrollment without a previous clinical diagnosis of fibroids.

EXPOSURE(S)

Keloids (raised scars that grow beyond the margins of the original injury) and hypertrophic scars (raised scars that stay within the bounds of the original injury). Because of the difficulties in distinguishing keloids and hypertrophic scars, we separately examined the history of keloids and the history of either keloids or hypertrophic scars (any abnormal scarring) and their associations with fibroid incidence and growth.

MAIN OUTCOME MEASURE(S)

Fibroid incidence (new fibroid after a fibroid-free ultrasound at enrollment) was assessed using Cox proportional-hazards regression. Fibroid growth was assessed using linear mixed models. The estimates for the change in log volume per 18 months were converted to the estimated percentage difference in volume for scarring vs. no-scarring. Both incidence and growth models were adjusted for time-varying demographic, reproductive, and anthropometric factors.

RESULT(S)

Of the 1,230 fibroid-free participants, 199 (16%) reported ever having keloids, 578 (47%) reported keloids or hypertrophic scars, and 293 (24%) developed incident fibroids. Neither keloids (adjusted hazard ratio = 1.04; 95% confidence interval: 0.77, 1.40) nor any abnormal scarring (adjusted hazard ratio = 1.10; 95% confidence interval: 0.88, 1.38) were associated with fibroid incidence. Fibroid growth differed little by scarring status.

CONCLUSION(S)

Despite molecular similarities, self-reported keloid and hypertrophic scars did not show an association with fibroid development. Future research may benefit from the examination of dermatologist-confirmed keloids or hypertrophic scars; however, our data suggest little shared susceptibility for these 2 types of fibrotic conditions.

Differential Expression of Super-Enhancer-Associated Long Non-coding RNAs in Uterine Leiomyomas

Super-enhancer-associated long non-coding RNAs (SE-lncRNAs) are a specific set of lncRNAs transcribed from super-enhancer (SE) genomic regions. Recent studies have revealed that SE-lncRNAs play essential roles in tumorigenesis through the regulation of oncogenes. The objective of this study was to elucidate the expression profile of SE-lncRNAs with concurrent assessment of associated mRNAs in leiomyomas and paired myometrium. Arraystar SE-lncRNAs arrays were used to systematically profile the differentially expressed SE-lncRNAs along with the corresponding SE-regulated protein coding genes in eight leiomyomas and paired myometrium. The analysis indicated 7680 SE-lncRNAs were expressed, of which 721 SE-lncRNAs were overexpressed, while 247 SE-lncRNAs were underexpressed by 1.5-fold or greater in leiomyoma. Thirteen novel SE-lncRNAs and their corresponding protein coding genes were selected, and their expression was confirmed in eighty-one paired leiomyoma tissues by quantitative real-time PCR. The thirteen pairs of SE-lncRNAs and their corresponding protein coding genes included RP11-353N14.2/CBX4, SOCS2-AS1/SOCS2, RP1-170O19.14/HOXA11, CASC15/PRL, EGFLAM-AS1/EGFLAM, RP11-225H22/NEURL1, RP5-1086K13.1/CD58, AC092839.3/SPTBN1, RP11-69I8.3/CTGF, TM4SF1-AS1/TM4SF1, RP11-373D23/FOSL2, RP11-399K21.11/COMTD1, and CTB-113P19.1/SPARC. Among these SE-lncRNAs, the expression of SOCS2-AS1/SOCS2, RP11-353N14.2/CBX4, RP1-170O19.14/HOXA11, and RP11-225H22/NEURL1 was significantly higher in African Americans as compared with Caucasians. The expression of RP11-353N14.2/CBX4, SOCS2-AS1/SOCS2, CASC15/PRL, and CTB-113P19.1/SPARC was significantly higher in tumors with MED12-mutation-positive as compared with MED12-mutation-negative tumors. Collectively, our results indicate that the differential expression of SE in leiomyomas is another mechanism contributing to dysregulation of protein coding genes in leiomyomas and that race and MED12 mutation can influence the expression of a select group of SE.

Tranilast induces MiR-200c expression through blockade of RelA/p65 activity in leiomyoma smooth muscle cells

OBJECTIVE

To determine the mechanism by which tranilast induces miR-200c expression in leiomyoma smooth muscle cells (LSMCs).

DESIGN

Experimental study.

SETTING

Academic research laboratory.

PATIENT(S)

Women undergoing hysterectomy for leiomyoma.

INTERVENTION(S)

Blockade of RelA/p65.

MAIN OUTCOME MEASURE(S)

Effects of tranilast and blockade of RelA/p65 on miR-200c expression.

RESULT(S)

Tranilast, an inflammation inhibitor, dose-dependently induced miR-200c in LSMCs and myometrium smooth muscle cells (MSMCs), with a more profound effect in LSMCs than in MSMCs. The treatment of LSMCs with Bay 117082, an inhibitor of IκB phosphorylation, further enhanced miR-200c induction by tranilast. The knockdown of RelA/p65 by small interfering RNA also induced miR-200c expression in LSMCs. Although tranilast had no effect on total RelA/p65 protein levels in LSMCs, it significantly induced RelA/p65 phosphorylation at S536 while reducing its activity as well as its nuclear translocation. ChIP assay indicated that tranilast reduces the binding ability of RelA/p65 to miR-200c promoter, resulting in miR-200c induction. Tranilast also inhibited interleukin-8 (IL8) expression in LSMCs. The induction of miR-200c by tranilast partially mediates the inhibitory effect of tranilast on the expression of IL8 and cyclin-dependent kinase 2 in LSMCs.

CONCLUSION(S)

Induction of miR-200c by tranilast in LSMCs is mediated through a transcriptional mechanism involving inhibition of the nuclear factor κB signaling pathway. These results highlight the significance of inflammation in the pathogenesis of leiomyoma and the potential utility of antiinflammatory drugs for treatment of leiomyomas.

lncRNA-H19/miR-29a axis affected the viability and apoptosis of keloid fibroblasts through acting upon COL1A1 signaling

This study was intended to clarify the potential of applying the long-chain noncoding RNA H19/miR-29a axis in keloid treatment by elucidating its correlation with the activity of fibroblasts. In this study, 80 keloid tissues, 63 normal fibrous tissues, and 91 normal skin tissues were collected in advance, and concurrently, fibroblasts separated from the tissues were cultured. Besides this, the si-H19, pcDNA3.1-H19, miR-29a mimic, and miR-29a inhibitor were transfected to keloid fibroblasts, whose proliferation, apoptosis, and metastasis were appraised by employing the colony formation assay, flow cytometry, and transwell assay. In addition, the luciferase reporter gene assay was carried out to determine whether targeted regulation was present between H19 and miR-29a, as well as between miR-29a and COL1A1. The study results demonstrated that keloid tissues and fibroblasts exhibited observably upregulated H19 expression and downregulated miR-29a expression, relative to normal skin tissues and fibroblasts (P < .05). Also observed was a negative correlation between H19 expression and miR-29a expression among the gathered keloid tissues (r_s  = -.267, P = .017). Furthermore, in vitro transfection of pcDNA3.1-H19 or miR-29a inhibitor could intensify viability, proliferation, migration, and invasion of the fibroblasts (P < .05), while silencing of H19 and overexpression of miR-29a hindered both metastasis and multiplication of the fibroblasts significantly (P < .05). In addition, H19 was capable of altering miR-29a expression within fibroblasts by directly sponging it, and overexpression of COL1A1 could deter the impact of miR-29a on viability, proliferation, migration, and invasion of fibroblasts (P < .05). In conclusion, H19 might facilitate proliferation and metastasis of fibroblasts by modifying downstream miR-29a and COL1A1, which was expected to allow for development of keloid-targeted treatments.

Ginsenoside Rg3 targets cancer stem cells and tumor angiogenesis to inhibit colorectal cancer progression in vivo

Anti-angiogenic therapy has been successfully applied to treat colorectal cancer (CRC). Ginsenoside Rg3, derived from the Chinese herb ginseng, has anti-vascularization effects and can inhibit tumor growth and metastasis, and can sensitize cancer cells to chemotherapy. Therefore, in the present study, we investigated whether Rg3 could be appropriate for CRC treatment. Growth of CRC cells was assessed by an MTT (methyl thiazolyl tetrazolium) assay in vitro and using orthotopic xenograft models in vivo. mRNA expression was evaluated using real-time PCR. Protein levels were tested by western blotting, flow cytometry and immunohistochemistry. Migration was determined using a wound-healing assay. Stemness was further confirmed using a plate clone formation assay. We found that Rg3 repressed the growth and stemness of CRC cells both in vitro and in vivo. Rg3 also impaired the migration of CRC cells in vitro. Rg3 downregulated the expressions of angiogenesis-related genes, and repressed the vascularization of CRC xenografts. In addition, Rg3 strengthened the cytotoxicity of 5-Fluorouracil and oxaliplatin against orthotopic xenografts in vivo. Moreover, Rg3 downregulated the expressions of B7-H1 and B7-H3, high expressions of which were associated with reduced overall survival (OS) of CRC patients. Hence, Rg3 not only repressed the growth and stemness of CRC cells, but could also remodel the tumor microenvironment through repressing angiogenesis and promoting antitumor immunity. Therefore, Rg3 could be a novel therapeutic for the CRC treatment.

Abnormal expression of the vitamin D receptor in keloid scars

Keloids are abnormal fibroproliferative scars that pose a significant challenge to patients and clinicians. The molecular basis for keloid formation remains incompletely understood, and currently no universally effective treatments exist. It is well recognized that keloids are more prevalent in populations with darkly pigmented skin, such as African Americans, but the basis for the link between skin color and keloid risk is not known. Pigmentation reduces vitamin D production in the skin. Because most of the body's vitamin D is produced in the skin, rates of vitamin D deficiency are higher in populations with darker skin pigmentation. In addition to regulation of calcium homeostasis, vitamin D plays important roles in cell proliferation, differentiation, cancer progression, inflammation, and fibrosis. The activities of vitamin D are dependent on the vitamin D receptor (VDR), a member of the steroid nuclear receptor superfamily. The ligand-bound VDR acts as a transcription factor; thus, nuclear localization is required for ligand-dependent regulation of target gene expression. The current study investigated expression and nuclear localization of VDR in keloid scars (N=24) and biopsies of normal skin (N=24). Immunohistochemistry with two different antibodies demonstrated reduced VDR protein levels in a majority of keloid scars. Further, the percentage of epidermal cells displaying nuclear VDR localization was significantly lower in keloid scars compared with normal skin samples. Interestingly, analysis of VDR-positive nuclei among different normal skin samples showed a significant reduction in nuclear localization in epidermis of black donors compared with white donors. The results suggest that VDR may play a role in keloid pathology, and hint at a possible role for VDR in the increased susceptibility to keloid scarring in individuals with darkly pigmented skin.

Tranilast Inhibits Genes Functionally Involved in Cell Proliferation, Fibrosis, and Epigenetic Regulation and Epigenetically Induces miR-29c Expression in Leiomyoma Cells

Tranilast (N-3,4-dimethoxycinnamoyl anthranilic acid) is an antiallergic agent with inhibitory effects on cell proliferation and extracellular matrix production. Here we assess the effect of tranilast on the expression of miR-29c and genes functionally involved in cell proliferation, fibrosis, and epigenetic regulation in isolated leiomyoma smooth muscle cells (LSMC). Tranilast significantly inhibited the rate of LSMC proliferation, which was associated with downregulation of cell cycle progression genes cyclin D1 (CCND1) and cyclin-dependent kinase 2 (CDK2) expression at messenger RNA and protein levels ( P < .05). Tranilast also suppressed the expression of collagen type I (COL1), collagen type III alpha 1 chain (COL3A1), the profibrotic cytokine, transforming growth factor β-3 (TGF-β3), DNA (cytosine-5)-methyltransferase 1 (DNMT1), and enhancer of zeste homolog 2 (EZH2), which regulate epigenetic status of gene promoters ( P < .05). Tranilast also significantly induced the expression of cellular and secreted miR-29c through downregulation of methylation status of miR-29c promoter ( P < .05). In addition, tranilast suppressed the activity of luciferase reporter containing 3'UTR of COL3A1 and CDK2, which are downstream targets of miR-29c ( P < .05). Knockdown of miR-29c expression attenuated the inhibitory effects of tranilast on COL3A1 and CDK2 protein expression ( P < .05). Collectively, these findings suggest that tranilast could have therapeutic potential as an inhibitory agent for leiomyoma growth and its associated symptoms.

Long non-coding RNA H19 promotes the proliferation of fibroblasts in keloid scarring

The expression of the long non-coding RNA (lncRNA) H19 is associated with proliferation in tumors. In order to investigate whether H19 may additionally mediate the proliferation of fibroblasts in human keloid disease, the present study collected samples from 24 subjects, including 8 with keloids, 8 with normal scars and 8 normal skin controls. Reverse transcription-polymerase chain reaction revealed that H19 levels were markedly increased in human keloids compared with normal scars and normal skin controls (P=0.017). In order to identify a potential role for H19 in the proliferative activity of human keloid fibroblasts, small interfering (si)RNA-mediated silencing experiments were performed. H19 siRNA treatment markedly inhibited the proliferation of keloid fibroblasts, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (P=0.008). In order to identify the signaling mediators that are regulated by H19 in keloid fibroblasts, the expression levels of mammalian target of rapamycin (mTOR) and vascular endothelial growth factor (VEGF) were examined using western blotting. The results confirmed that knockdown of H19 inhibited mTOR and VEGF expression. In summary, the results indicate that H19 may be associated with increased proliferative activity of keloid fibroblasts, which may be mediated by mTOR and VEGF.

Clinical implications of single- versus multiple-site keloid disorder: a retrospective study in an Asian population

BACKGROUND

There is strong evidence of genetic susceptibility in individuals with keloid disorder. The purpose of this cross-sectional study was to determine the clinical relevance of our proposed variables on the multiplicity of keloids by further investigating the presence of other keloids and a family history.

METHODS

This was a retrospective review, using institutional review board-approved questionnaires, of patients with keloids who were seen at Kangbuk Samsung Hospital between December 2002 and February 2010. Eight hundred sixty-eight patients were included in our study. Comparisons between the 2 groups were made using Mann-Whitney tests for continuous variables and χ2 tests for categorical variables.

RESULTS

In our patient group, younger age of onset and the presence of family history were significantly associated with the occurrence of keloids at multiple sites. The locations of extra-auricular keloids, in order of frequency, included the shoulder; anterior chest, including the breasts; deltoid; trunk and pubic area; upper extremities; lower extremities; and other sites. As compared to secondary keloids, primary keloids were significantly associated with both a lower degree of recurrence and the presence of other keloids. The presence or absence of family history was significantly associated with the presence or absence of other keloids and primary or secondary keloids.

CONCLUSIONS

Keloid disorder is one of the most frustrating problems in wound healing and advances in our understanding of the differences of occurrence at a single site versus multiple sites might help in understanding pathogenesis and improving treatment.

RUNX3 expression is associated with sensitivity to pheophorbide a-based photodynamic therapy in keloids

Runt-related transcription factor 3 (RUNX3) has recently been reported to be a possible predictor of sensitivity of cancer cells for photodynamic therapy (PDT), a promising therapeutic modality for keloids. In this study, we aimed to elucidate the implications of RUNX3 for keloid pathogenesis and sensitivity to pheophorbide a-based PDT (Pa-PDT). RUNX3 and proliferating cell nuclear antigen (PCNA) expression were examined in 6 normal skin samples and 32 keloid tissue samples by immunohistochemistry. We found that RUNX3 expression was detected more often in keloid tissues than in dermis of normal skin. In keloid tissues, RUNX3 expression was significantly increased in patients presenting with symptoms of pain or pruritus, and was also significantly related to PCNA expression. The therapeutic effect of Pa-PDT was comparatively investigated in keloid fibroblasts (KFs) with and without RUNX3 expression. Significant differences were found after Pa-PDT between KFs with and without RUNX3 expression in cell viability, proliferative ability, type I collagen expression, generation of reactive oxygen species (ROS), and apoptotic cell death. In addition, RUNX3 expression was significantly decreased after Pa-PDT in KFs, and KFs with downregulation of RUNX3 showed significantly increased cell viability after Pa-PDT. Pa-PDT may be a potential therapeutic modality for keloids, and RUNX3, as a possible contributor to keloid pathogenesis, may improve sensitivity to Pa-PDT in KFs.

MicroRNAs in the development and pathobiology of uterine leiomyomata: does evidence support future strategies for clinical intervention?

BACKGROUND

Human leiomyomata (fibroids) are benign tumors of the uterus, represent the most common neoplasms of reproductive-aged women and have a prevalence of ∼70% in the general population. This disorder conveys a significant degree of morbidity and remains the leading indication for hysterectomy in the USA. Prior investigations of aberrant microRNA (miRNA) expression in various malignancies have provided invaluable insight into the role of this class of small non-coding RNAs in tumor growth. Evidence of irregular miRNA expression in uterine fibroids has garnered recent interest for diagnostic and therapeutic applications. Since miRNA gene targets modulate several processes implicated in the genesis of uterine fibroids, more focused investigation has the potential to elucidate the functional significance of miRNA in the genesis and pathology of the disease.

METHODS

Comprehensive electronic searches of peer reviewed published literature in PubMed (US National Library of Medicine, National Institute of Health; http://www.ncbi.nlm.nih.gov/pubmed/) were performed for content related to the biologic functions of miRNA, the roles of miRNA in human disease and studies investigating miRNA in the context of uterine leiomyomata. Herein, this article will review the current evidence supporting the use of miRNA expression profiling as an investigative tool to assess the pathobiology of uterine fibroids and will discuss potential future applications of miRNAs as biomarkers and therapeutic targets.

RESULTS

Mounting evidence supports a functional role for miRNA as either indirect or direct regulators of gene expression which impacts the pathobiology of uterine fibroids. Specifically, miRNAs let-7, 200a, 200c, 93, 106b and 21 have been implicated in cellular proliferation, apoptosis, extracellular matrix turnover, angiogenesis and inflammation. Preliminary data provide evidence to suggest that respective in vitro miRNA expression in leiomyomata and myometrium is regulated by sex steroids.

CONCLUSIONS

Collectively, the identification of aberrantly expressed miRNAs in uterine leiomyomata and accumulating data derived from mining of gene target prediction models and recent functional studies support the concept that miRNAs might impact the genesis and progression of disease. However, the specific biologic functions of differential miRNA expression have yet to be confirmed in vivo. Further functional studies and developing miRNA technology may provide the basis for future applications of miRNAs in clinical medicine as biomarkers and therapeutic targets.

Proceedings from the Third National Institutes of Health International Congress on Advances in Uterine Leiomyoma Research: comprehensive review, conference summary and future recommendations

BACKGROUND Uterine fibroids are the most common gynecologic tumors in women of reproductive age yet the etiology and pathogenesis of these lesions remain poorly understood. Age, African ancestry, nulliparity and obesity have been identified as predisposing factors for uterine fibroids. Symptomatic tumors can cause excessive uterine bleeding, bladder dysfunction and pelvic pain, as well as associated reproductive disorders such as infertility, miscarriage and other adverse pregnancy outcomes. Currently, there are limited noninvasive therapies for fibroids and no early intervention or prevention strategies are readily available. This review summarizes the advances in basic, applied and translational uterine fibroid research, in addition to current and proposed approaches to clinical management as presented at the 'Advances in Uterine Leiomyoma Research: 3rd NIH International Congress'. Congress recommendations and a review of the fibroid literature are also reported. METHODS This review is a report of meeting proceedings, the resulting recommendations and a literature review of the subject. RESULTS The research data presented highlights the complexity of uterine fibroids and the convergence of ethnicity, race, genetics, epigenetics and environmental factors, including lifestyle and possible socioeconomic parameters on disease manifestation. The data presented suggest it is likely that the majority of women with uterine fibroids will have normal pregnancy outcomes; however, additional research is warranted. As an alternative to surgery, an effective long-term medical treatment for uterine fibroids should reduce heavy uterine bleeding and fibroid/uterine volume without excessive side effects. This goal has not been achieved and current treatments reduce symptoms only temporarily; however, a multi-disciplined approach to understanding the molecular origins and pathogenesis of uterine fibroids, as presented in this report, makes our quest for identifying novel targets for noninvasive, possibly nonsystemic and effective long-term treatment very promising. CONCLUSIONS The Congress facilitated the exchange of scientific information among members of the uterine leiomyoma research and health-care communities. While advances in research have deepened our knowledge of the pathobiology of fibroids, their etiology still remains incompletely understood. Further needs exist for determination of risk factors and initiation of preventive measures for fibroids, in addition to continued development of new medical and minimally invasive options for treatment.

Keloids and ultrasound detected fibroids in young African American women

OBJECTIVE

Keloids and fibroids share a number of biologic and demographic similarities however there are no published reports of the association between them. The objective of this study was to investigate the association between self-reported keloids and ultrasound detected fibroids in a population of young African American women.

STUDY DESIGN

The Study of Environment, Life-style & Fibroids (SELF), is a volunteer cohort of over 1600 African American women aged 23-34 years recruited in Detroit, Michigan. Enrollment occurred between December 2010 and December 2012. Data are available for the first 1196 participants. Participants self-reported a history of raised (hypertrophic) scars or scars extending beyond the limits of the original injury (keloid) and had an enrollment pelvic ultrasound examination to detect prevalent fibroids. Log linear regression was used to model the association between abnormal scars and prevalent fibroids controlling for possible covariates. Among women with fibroids, associations between particular fibroid characteristics (tumor location, size or number) and scarring were assessed using chi-square and Mann Whitney U-tests.

RESULTS

Both abnormal scarring (keloids, 9.0%; hypertrophic scars, 28.3%) and fibroids (23.3%) were common in this cohort. There was no indication [adjusted Risk Ratio (95% Confidence Interval): 0.7 (0.5-1.1)] of an association between self-reported keloids and prevalent fibroids. Nor was there any association with hypertrophic scars. Specific characteristics of the prevalent fibroids were not associated with abnormal scarring.

CONCLUSION

Despite similarly dysregulated extracellular matrices in keloids and fibroids, these conditions did not tend to co-occur in this young African American population.

Extracellular matrix molecules implicated in hypertrophic and keloid scarring

Tissue regeneration repairs the fabric of the skin to maintain homeostasis after injury. The expression and proliferation of extracellular matrix (ECM) molecules in the dermis, mediated by a range of growth factors and cytokines, is a fundamental element of wound repair. Previous work focused on how these complex molecular mechanisms relate to the formation of raised dermal scars, including keloid and hypertrophic scars, characterized by excessive deposition of ECM molecules. However, the mechanisms in the wound repair pathway which lead to the differential expression and organization of ECM molecules observed in different types of scar tissue are not fully understood. To summarize what is known about the expression and composition of ECM molecules in abnormal scarring, an extensive search of the literature was conducted, focusing on keywords connected to skin scarring, hypertrophic scars and keloid disease. The transcription and translation of collagen I and III, fibronectin, laminin, periostin and tenascin are all increased in raised dermal scar tissue. However, hyaluronic acid, dermatopontin and decorin are decreased, and the expression and localisation of fibrillin and elastin fibres in the dermis are altered compared with normal skin and scars. Recent whole genome profiling and proteomic studies have led to the identification of regulatory elements with different expression profiles in hypertrophic and keloid tissue. If the mechanisms of raised dermal scar formation are to be elucidated and effective therapeutic treatments developed, an integrated approach to research is required, focussing on the interactions between ECM molecules, regulatory elements and pathways.

Prospective study of intraabdominal adhesions among women of different races with or without keloids

OBJECTIVE

We sought to evaluate postsurgical adhesions in women of different races with or without keloids.

STUDY DESIGN

This was a prospective study evaluating postsurgical adhesions after a cesarean delivery in 429 women with or without keloids. The outcome measures were the prevalence and extent of adhesions in women of different races with or without keloids.

RESULTS

There was no difference in the prevalence of adhesions and adhesion score in various sites among women of different races. Compared with whites (0.5%), keloids were significantly more common in African Americans (7.1%; P = .007; odds ratio, 16.5) and in Asians (5.2%; P = .02; odds ratio, 11.9). Women with keloids were found to have more dense adhesions between the uterus and the bladder (P = .028; 95% confidence interval, 0-12) and between the uterus and the anterior abdominal wall (P < .0001; 95% confidence interval, 8-12).

CONCLUSION

The prevalence and degree of postsurgical adhesions in women of different races are comparable. Women with keloids on the cesarean scar have increased adhesions between the uterus and the bladder and between the uterus and the abdominal wall.

Proinflammatory and profibrotic mediators: principal effectors of leiomyoma development as a fibrotic disorder

Leiomyomas are believed to derive from the transformation of myometrial smooth muscle cells/connective tissue fibroblasts. Although the identity of the molecule(s) that initiate such cellular transformation and orchestrate subsequent growth is still unknown, conventional evidence indicates that ovarian steroids are essential for leiomyoma growth. Ovarian steroid action in their target cell/tissue is mediated in part through local expression of various growth factors, cytokines, and chemokines. These autocrine/paracrine molecules with proinflammatory and profibrotic activities serve as major contributing factors in regulating cellular transformation, cell growth and apoptosis, angiogenesis, cellular hypertrophy, and excess tissue turnover, events central to leiomyoma growth. This review addresses the key regulatory functions of proinflammatory and profibrotic mediators and their molecular mechanisms, downstream signaling that regulates cellular events that result in transformation, and commitments of specific cells into forming a cellular environment with a possible role in development and subsequent growth of leiomyomas.

Molecular dissection of abnormal wound healing processes resulting in keloid disease

Keloids are locally aggressive scars that typically invade into healthy surrounding skin and cause both physical and psychosocial distress to the patient. These pathological scars occur following minimal skin trauma after a variety of causes including burns and trauma. Although the pathogenesis of keloid disease is not well understood, it is considered to be the end product of an abnormal healing process. The aim of this review was to investigate the molecular and cellular pathobiology of keloid disease in relation to the normal wound healing process. The molecular aberrances in keloids that correlate with the molecular mechanisms in normal wound healing can be categorized into three groups: (1) extracellular matrix proteins and their degradation, (2) cytokines and growth factors, and (3) apoptotic pathways. With respect to cellular involvements, fibroblasts are the most well-studied cell population. However, it is unclear whether the fibroblast is the causative cell; they are modulated by other cell populations in wound repair, such as keratinocytes and macrophages. This review presents a detailed account of individual phases of the healing process and how they may potentially be implicated in aberrant raised scar formation, which may help in clarifying the mechanisms involved in keloid disease pathogenesis.

Genetic susceptibility to raised dermal scarring

Raised skin scars, such as keloid and hypertrophic scars mostly occur post-wounding in the human dermis. There is compelling evidence for a genetic component to these conditions, given the familial predisposition, varied incidence in different ethnic populations and the presence in twins. The aim of this study was to perform a systematic review of the literature regarding genetic susceptibility to raised dermal scarring. We identified relevant articles by a systematic search of relevant search engines. Key search terms included: keloid disease, hypertrophic scarring, fibrosis, linkage analysis, gene expression, human leucocyte antigen system (HLA), twins, families, case-control association study and congenital syndromes. Numerous candidate genes have been identified, along with potential linkage regions on different chromosomes. Recent data also suggest that carriers of specific major histocompatibility complex (MHC) alleles, in particular HLA-DRB1*15, HLA-DQA1*0104, DQB1*0501 and DQB1*0503, are at increased risk of developing keloid scarring. In addition, distinct immunophenotypical profiles can distinguish between keloid and hypertrophic scars. Keloid and hypertrophic scars are multifaceted aberrations of the healing process with as yet incompletely understood aetiologies. Current data suggest a genetic susceptibility with a strong immunogenic component to dermal fibrosis with MHC genes being implicated. It appears unlikely that a single gene is responsible for the development of raised dermal scars. A likely scenario may involve the interaction of several gene pathways in addition to environmental factors. The ability to assess accurately an individual's potential genetic susceptibility to raised scarring may lead to a more personalized approach to their management in the future.

Molecular characterisation of the tumour microenvironment in breast cancer

The tumour microenvironment plays important roles in cancer initiation, growth, progression, invasion and metastasis, yet the molecular basis underlying these tumour-promoting effects is not fully delineated. Recent advances in gene expression, genetic and epigenetic profiling of stromal cells have improved our understanding of how mesenchymal-epithelial cell interactions may create a permissive microenvironment for malignancy and identified potential targets for cancer prevention and treatment including chemokine and cytokine networks. However, translating these findings into clinical practice may be difficult due to the complexity and redundancy of the interactions and the inherent ability of tumour epithelial cells to evolve and thrive in diverse environmental conditions.

The expression and potential regulatory function of microRNAs in the pathogenesis of leiomyoma

Leiomyomas are benign uterine tumors considered to arise from transformation of myometrial cells. What initiates the conversion of myometrial cells into leiomyoma is unknown, however cytogenetic analysis often shows occurrence of nonrandom chromosomal abnormalities that may account for their establishment. It is clear that ovarian steroids are essential for leiomyoma growth, and local expression of many autocrine/paracrine mediators serving as key regulators of cell-cycle progression, cellular hypertrophy, extracellular matrix accumulation, and apoptosis appear to play central roles in this capacity. However, the stability of the expression of these genes represents the hallmarks of leiomyoma establishment, growth, and regression. With the emergence of microRNA (miRNA) as a key regulator of gene expression stability, in this review we present evidence for the expression and potential regulatory functions on miRNAs in leiomyoma with particular emphasis on the expression of their selective target genes whose products influence various cellular activities critical to pathogenesis of leiomyomas.

Genomic and proteomic profiling I: leiomyomas in African Americans and Caucasians

BACKGROUND

Clinical observations indicate that leiomyomas occur more frequently in African Americans compared to other ethnic groups with unknown etiology. To identify the molecular basis for the difference we compared leiomyomas form A. Americans with Caucasians using genomic and proteomic strategies.

METHODS

Microarray, realtime PCR, 2D-PAGE, mass spectrometry, Western blotting and immunohistochemistry.

RESULTS

Using Affymetrix U133A array and analysis based on P ranking (P < 0.01) 1470 genes were identified as differentially expressed in leiomyomas compared to myometrium regardless of ethnicity. Of these, 268 genes were either over-expressed (177 genes) or under-expressed (91 genes) based on P < 0.01 followed by 2-fold cutoff selection in leiomyomas of A. Americans as compared to Caucasians. Among them, the expression E2F1, RUNX3, EGR3, TBPIP, ECM2, ESM1, THBS1, GAS1, ADAM17, CST6, CST7, FBLN5, ICAM2, EDN1 and COL18 was validated using realtime PCR low-density arrays. 2D PAGE coupled with image analysis identified 332 protein spots of which the density/volume of 31 varied by greater than or equal to 1.5 fold in leiomyomas as compared to myometrium. The density/volume of 34 protein-spots varied by greater than or equal to 1.5 fold (26 increased and 8 decreased) in leiomyomas of A. Americans as compared to Caucasians. Tandem mass spectrometric analysis of 15 protein spots identified several proteins whose transcripts were also identified by microarray, including 14-3-3 beta and mimecan, whose expression was confirmed using western blotting and immunohistochemistry.

CONCLUSION

These findings imply that the level rather than the ethnic-specific expression of a number of genes and proteins may account for the difference between leiomyomas and possibly myometrium, in A. Americans and Caucasians. Further study using larger sample size is required to confirm these findings.