MiR-130b modulates the invasive, migratory, and metastatic behavior of leiomyosarcoma.

Leiomyosarcoma (LMS) is an aggressive, often poorly differentiated cancer of the smooth muscle (SM) lineage for which the molecular drivers of transformation and progression are poorly understood. In microRNA (miRNA) profiling studies, miR-130b was previously found to be upregulated in LMS vs. normal SM, and down-regulated during the differentiation of mesenchymal stem cells (MSCs) into SM, suggesting a role in LMS tumor progression. In the present study, the effects of miR-130b on human LMS tumorigenesis were investigated. Stable miR-130b overexpression enhanced invasion of LMS cells in vitro, and led to the formation of undifferentiated, pleomorphic tumors in vivo, with increased growth and metastatic potential compared to control LMS cells. TSC1 was identified as a direct miR-130b target in luciferase-3'UTR assays, and shRNA-mediated knockdown of TSC1 replicated miR-130b effects. Loss-of-function and gain-of-function studies showed that miR-130b levels regulate cell morphology and motility. Following miR-130b suppression, LMS cells adopted a rounded morphology, amoeboid mode of cell movement and enhanced invasive capacity that was Rho/ROCK dependent. Conversely, miR-130b-overexpressing LMS cells exhibited Rho-independent invasion, accompanied by down-regulation of Rho-pathway effectors. In mesenchymal stem cells, both miR-130b overexpression and TSC1 silencing independently impaired SM differentiation in vitro. Together, the data reveal miR-130b as a pro-oncogenic miRNA in LMS and support a miR-130b-TSC1 regulatory network that enhances tumor progression via inhibition of SM differentiation.

Inflammatory Myofibroblastic Tumor in Female Genital Tract.

CONTEXT.­: Inflammatory myofibroblastic tumor is a mesenchymal neoplasm of low malignant potential. It was first described in lung, but is known to occur in many extrapulmonary sites including female genital organs, most commonly the uterus. It has a high recurrence rate and a low risk for metastasis. A more recently described aggressive variant, epithelioid myofibroblastic sarcoma with a predilection for the abdominal cavity of males, has also been recently reported to occur in the ovary. This tumor is composed of spindled and epithelioid myofibroblasts in a variably myxoid stroma and commonly shows a fascicular growth pattern with positive staining for desmin, smooth muscle actin, and CD10, which may mimic a smooth muscle or endometrial stromal neoplasm. In the female genital tract it has the potential for being misdiagnosed as a leiomyoma, endometrial stromal tumor, or as a myxoid leiomyosarcoma, resulting in undertreatment or overtreatment. It harbors rearrangements in the ALK gene, resulting in abnormal expression of ALK protein. Immunostaining for ALK is a helpful diagnostic tool. OBJECTIVE.­: To provide a brief review of clinical, histologic, immunohistochemical, and molecular features of inflammatory myofibroblastic tumor with emphasis on possible diagnostic pitfalls in the female genital tract. DATA SOURCES.­: Review of pertinent literature on inflammatory myofibroblastic tumor occurring in the female genital tract and personal experience of the authors. CONCLUSIONS.­: Inflammatory myofibroblastic tumor in the female genital tract can mimic other more common benign and malignant tumors like leiomyoma, leiomyosarcoma, and endometrial stromal sarcoma. Familiarity with clinical and histologic features and use of ALK immunostaining can be critical for correct diagnosis.

Arias-Stella Reaction With Signet Ring-Like Cell Histomorphology.

Cells with their nucleus pushed to the periphery in a crescent-like fashion by intracytoplasmic vacuole(s) are referred to as signet ring cells when the vacuole(s) contain mucin and signet ring-like cells when they are empty or contain a material other than mucin. Signet ring cells are commonly associated with adenocarcinomas. These cells are uncommon in the endometrium and have been found to be associated with both malignant and benign processes. We report the first case of signet ring-like cells within endometrial glands with Arias-Stella reaction.

Distribution and potential significance of intravillous and intrafibrinous particulate microcalcification.

Radiologic studies indicate that placental calcifications seen at 28-32 weeks' gestation are associated with adverse fetal outcome. One type of placental calcification is typically located at the basement membrane of chorionic villi. It has a fine particulate appearance and can only be seen microscopically. We have designated these calcifications as Intravillous and Intrafibrinous Particulate MicroCalcification (IPMC). In this study we examined the distribution and potential significance of IPMC. Placentas from 14 groups of fetal and maternal outcomes are examined histologically for IPMC. These groups were preterm birth, post term birth, intrauterine fetal demise, fetuses with non-reassuring heart rates, intrauterine growth restriction, fetal anomalies, mothers with gestational hypertension, gestational diabetes, placental abruption, pre-eclampsia and placentas of normal spontaneous vaginal births and placentas with chorioamnionitis, chronic villitis and infarcts. We observed fine dust-like particulates deposited in continuous and discrete patches. The particulates were predominantly located in the basement membranes of fibrotic chorionic villi and in perivillous fibrin. Compared to placentas without adverse outcomes, a higher incidence of IPMC was seen in intrauterine fetal demise cases and in cases with infarcts which suggests that hypoxia played a role in the etiology of IPMC.

Expression of Ezrin and Estrogen Receptors During Cervical Carcinogenesis.

RATIONALE: Development of cervical squamous carcinoma (CXCA) is accompanied by changes in estrogen receptors (ERs, ERα and ERß) and ezrin expression; however, reports have been conflicting. Using histologically documented staging of cervical biopsies, we determined ezrin and ER relationships during CXCA development. METHODS: Immunoreactive (ir) ezrin, ir-ERα, and ir-ERß were studied in normal epithelium, carcinoma in situ/cervical intraepithelial neoplasia (CIN) 1 to 3, and local invasion or metastatic CXCA. Results were compared using H scoring. Cultures of Caski metastatic CXCA cells were treated with estradiol and/or tamoxifen and studied for ER-driven ir-ezrin and the morphologic response. RESULTS: Koilocytosis was present and indicated viral presence. The ezrin H score increased from CIN1 to CIN3, reaching significant differences from normal by CIN3 ( P = .004) and 2× normal in metastatic CXCA. Estrogen receptor α and ERß H scores fell, reaching significance by CIN3 (ERα, P = .0001; ERß, P = .024). During estradiol treatment, ezrin in Caski cells increased and localized to the periphery, in ruffles and processes. The selective ER modulator tamoxifen blocked the estradiol-induced changes. CONCLUSIONS: During cervical carcinogenesis, the usual relationship between estrogen and ezrin induction is abridged. This is consistent with the effects of human papilloma virus viral proteins such as E6 and E7 that upregulate SIX1, a protein that induces ezrin. Cervical carcinogenesis is progressive but arrests at the preinvasive stage for varying lengths of time. These studies suggest that changes in ezrin may be associated with the development of the invasive phenotype and penetration of the basement membrane. They also raise the possibility that inhibiting ezrin expression could be a target for the prevention of invasive CXCA.

TGF-ß activates APC through Cdh1 binding for Cks1 and Skp2 proteasomal destruction stabilizing p27kip1 for normal endometrial growth.

We previously reported that aberrant TGF-ß/Smad2/3 signaling in endometrial cancer (ECA) leads to continuous ubiquitylation of p27(kip1)(p27) by the E3 ligase SCF-Skp2/Cks1 causing its degradation, as a putative mechanism involved in the pathogenesis of this cancer. In contrast, normal intact TGF-ß signaling prevents degradation of nuclear p27 by SCF-Skp2/Cks1 thereby accumulating p27 to block Cdk2 for growth arrest. Here we show that in ECA cell lines and normal primary endometrial epithelial cells, TGF-ß increases Cdh1 and its binding to APC/C to form the E3 ligase complex that ubiquitylates Cks1 and Skp2 prompting their proteasomal degradation and thus, leaving p27 intact. Knocking-down Cdh1 in ECA cell lines increased Skp2/Cks1 E3 ligase activity, completely diminished nuclear and cytoplasmic p27, and obviated TGF-ß-mediated inhibition of proliferation. Protein synthesis was not required for TGF-ß-induced increase in nuclear p27 and decrease in Cks1 and Skp2. Moreover, half-lives of Cks1 and Skp2 were extended in the Cdh1-depleted cells. These results suggest that the levels of p27, Skp2 and Cks1 are strongly or solely regulated by proteasomal degradation. Finally, an inverse relationship of low p27 and high Cks1 in the nucleus was shown in patients in normal proliferative endometrium and grade I-III ECAs whereas differentiated secretory endometrium showed the reverse. These studies implicate Cdh1 as the master regulator of TGF-ß-induced preservation of p27 tumor suppressor activity. Thus, Cdh1 is a potential therapeutic target for ECA and other human cancers showing an inverse relationship between Cks1/Skp2 and p27 and/or dysregulated TGF-ß signaling.

Utility of endometrial sampling prior to risk-reducing hysterectomy in a patient with Lynch syndrome.

Occult endometrial cancer is occasionally discovered in women with Lynch syndrome undergoing risk-reducing hysterectomy. The case presented here demonstrates that preoperative endometrial sampling can help detect these occult cancers; however, there are currently no recommendations for this preoperative intervention. A 50-year-old woman with Lynch syndrome underwent endometrial sampling prior to planned risk-reducing hysterectomy and bilateral salpingo-oophorectomy. The endometrial biopsy demonstrated a serous endometrial cancer. The patient was counselled regarding the diagnosis and revised operative plan, which now included staging, prior to surgery. Although the prevalence of occult endometrial cancer at the time of risk-reducing surgery in women with Lynch syndrome remains unknown, preoperative endometrial sampling may allow for improved patient counselling and surgical planning in this population, and can help avoid a subsequent surgery for staging.

Inhibitors of SCF-Skp2/Cks1 E3 ligase block estrogen-induced growth stimulation and degradation of nuclear p27kip1: therapeutic potential for endometrial cancer.

In many human cancers, the tumor suppressor, p27(kip1) (p27), a cyclin-dependent kinase inhibitor critical to cell cycle arrest, undergoes perpetual ubiquitin-mediated proteasomal degradation by the E3 ligase complex SCF-Skp2/Cks1 and/or cytoplasmic mislocalization. Lack of nuclear p27 causes aberrant cell cycle progression, and cytoplasmic p27 mediates cell migration/metastasis. We previously showed that mitogenic 17-ß-estradiol (E2) induces degradation of p27 by the E3 ligase Skp1-Cullin1-F-Box- S phase kinase-associated protein2/cyclin dependent kinase regulatory subunit 1 in primary endometrial epithelial cells and endometrial carcinoma (ECA) cell lines, suggesting a pathogenic mechanism for type I ECA, an E2-induced cancer. The current studies show that treatment of endometrial carcinoma cells-1 (ECC-1) with small molecule inhibitors of Skp2/Cks1 E3 ligase activity (Skp2E3LIs) stabilizes p27 in the nucleus, decreases p27 in the cytoplasm, and prevents E2-induced proliferation and degradation of p27 in endometrial carcinoma cells-1 and primary ECA cells. Furthermore, Skp2E3LIs increase p27 half-life by 6 hours, inhibit cell proliferation (IC50, 14.3µM), block retinoblastoma protein (pRB) phosphorylation, induce G1 phase block, and are not cytotoxic. Similarly, using super resolution fluorescence localization microscopy and quantification, Skp2E3LIs increase p27 protein in the nucleus by 1.8-fold. In vivo, injection of Skp2E3LIs significantly increases nuclear p27 and reduces proliferation of endometrial epithelial cells by 42%-62% in ovariectomized E2-primed mice. Skp2E3LIs are specific inhibitors of proteolytic degradation that pharmacologically target the binding interaction between the E3 ligase, SCF-Skp2/Cks1, and p27 to stabilize nuclear p27 and prevent cell cycle progression. These targeted inhibitors have the potential to be an important therapeutic advance over general proteasome inhibitors for cancers characterized by SCF-Skp2/Cks1-mediated destruction of nuclear p27.

Pigmented viral-associated conjunctival carcinoma.

A 54-year-old African-American woman developed a pigmented papillary squamous cell carcinoma in the palpebral and bulbar conjunctiva of the right eye in areas that received no sun exposure. In situ hybridization performed on the tumor showed human papilloma virus 16. The left eye showed a pedunculated nonpigmented conjunctival dysplasia. The tumors were extirpated by cryosurgery and topical interferon alfa 2b in the right eye and simple surgical excision in the left eye.

Dual Pten/Tp53 suppression promotes sarcoma progression by activating Notch signaling.

Soft tissue sarcomas are a heterogeneous group of tumors associated with poor clinical outcome. Although a subset of soft tissue sarcomas is characterized by simple karyotypes and recurrent chromosomal translocations, the mechanisms driving cytogenetically complex sarcomas are largely unknown. Clinical evidence led us to partially inactivate Pten and Tp53 in the smooth muscle lineage of mice, which developed high-grade undifferentiated pleomorphic sarcomas, leiomyosarcomas, and carcinosarcomas that widely recapitulate the human disease, including the aberrant karyotype and metastatic behavior. Pten was found haploinsufficient, whereas the wild-type allele of Tp53 invariably gained point mutations. Gene expression profiles showed up-regulated Notch signaling in Pten(Δ/+)Tp53(Δ/+) tumors compared with Pten(+/+)Tp53(Δ/+) tumors. Consistently, Pten silencing exacerbated the clonogenic and invasive potential of Tp53-deficient bone marrow-derived mouse mesenchymal stem cells and tumor cells and activated the Notch pathway. Moreover, the increased oncogenic behavior of Pten(Δ/+)Tp53(Δ/+) and shPten-transduced Pten(+/+)Tp53(Δ/+) tumor cells was counteracted by treatment with a γ-secretase inhibitor, suggesting that the aggressiveness of those tumors can be attributed, at least in part, to enhanced Notch signaling. This study demonstrates a cooperative role for Pten and Tp53 suppression in complex karyotype sarcomas while establishing Notch as an important functional player in the cross talk of these pathways during tumor progression. Our results highlight the importance of molecularly subclassifying patients with high-grade sarcoma for targeted treatments.

Estrogen and progesterone regulate p27kip1 levels via the ubiquitin-proteasome system: pathogenic and therapeutic implications for endometrial cancer.

The levels of proteins that control the cell cycle are regulated by ubiquitin-mediated degradation via the ubiquitin-proteasome system (UPS) by substrate-specific E3 ubiquitin ligases. The cyclin-dependent kinase inhibitor, p27kip1 (p27), that blocks the cell cycle in G1, is ubiquitylated by the E3 ligase SCF-Skp2/Cks1 for degradation by the UPS. In turn, Skp2 and Cks1 are ubiquitylated by the E3 ligase complex APC/Cdh1 for destruction thereby maintaining abundant levels of nuclear p27. We previously showed that perpetual proteasomal degradation of p27 is an early event in Type I endometrial carcinogenesis (ECA), an estrogen (E2)-induced cancer. The present studies demonstrate that E2 stimulates growth of ECA cell lines and normal primary endometrial epithelial cells (EECs) and induces MAPK-ERK1/2-dependent phosphorylation of p27 on Thr187, a prerequisite for p27 ubiquitylation by nuclear SCF-Skp2/Cks1 and subsequent degradation. In addition, E2 decreases the E3 ligase [APC]Cdh1 leaving Skp2 and Cks1 intact to cause p27 degradation. Furthermore, knocking-down Skp2 prevents E2-induced p27 degradation and growth stimulation suggesting that the pathogenesis of E2-induced ECA is dependent on Skp2-mediated degradation of p27. Conversely, progesterone (Pg) as an inhibitor of endometrial proliferation increases nuclear p27 and Cdh1 in primary EECs and ECA cells. Pg, also increases Cdh1 binding to APC to form the active E3ligase. Knocking-down Cdh1 obviates Pg-induced stabilization of p27 and growth inhibition. Notably, neither E2 nor Pg affected transcription of Cdh1, Skp2, Cks1 nor p27. These studies provide new insights into hormone regulation of cell proliferation through the UPS. The data implicates that preventing nuclear p27 degradation by blocking Skp2/Cks1-mediated degradation of p27 or increasing Cdh1 to mediate degradation of Skp2-Cks1 are potential strategies for the prevention and treatment of ECA.

Estradiol regulates expression of polysialated neural cell adhesion molecule by human vascular endothelial cells.

RATIONALE: The mechanism of atherogenesis includes leukocyte adhesion to endothelial cells followed by migration into the subendothelial space. The polysialylated neural cell adhesion molecules (PSA-nCAMs) are a group of hydrophilic neural cell adhesion molecule (NCAM) isoforms that inhibit NCAM: NCAM association, thereby blocking cell: cell adhesion. During previous studies, we demonstrated that sialylation of specific NCAMs are upregulated at proestrus in the rat and that PSA-nCAM is expressed by the rat vascular endothelium. METHODS AND RESULTS: In this study, we sought the presence of PSA-nCAM in human vessels and regulation of its expression in estradiol-treated human umbilical vascular endothelial cells (HUVEC). Immunoreactive PSA-nCAM (ir-PSA-nCAM) was shown in blood and lymph vessels of adult rats and human brain, skin, liver, lung, cervix, endometrium, and ovary. Staining for ir-PSA-nCAM was present on the glycocalyceal surface of estradiol-treated HUVEC, but not in the presence of the estrogen receptor (ER)-blocker fulvestrant. Western blotting confirmed these findings. CONCLUSIONS: PSA-nCAM is widely present in the glycocalyx of human and rat vascular endothelium. It also is expressed by HUVEC, in which it is induced by estradiol. The estrogen-regulated presence of vascular PSA-nCAM could diminish NCAM-dependent interactions between vessels and circulating leukocytes, thereby impeding vascular inflammation and atherogenesis, and, contributing to estrogen-induced cardioprotection. This hypothesized action is presently under study.

Utility of p16INK4a, CEA, Ki67, P53 and ER/PR in the differential diagnosis of benign, premalignant, and malignant glandular lesions of the uterine cervix and their relationship with Silverberg scoring system for endocervical glandular lesions.

Early detection of premalignant and malignant glandular lesions of the uterine cervix and their distinction from benign mimics is crucial but sometimes difficult. In this study, we investigated utility of expression of p16, CEA, Ki67, p53 and ER/PR in evaluating the benign, premalignant, and malignant glandular lesions of the uterine cervix. A total of 35 cervical cone or LEEP cases were collected including 14 adenocarcinoma in situ (AIS), 7 endocervical glandular dysplasia (EGD), and 14 benign mimics (BM). A histological score for each case according to the criteria proposed by Silverberg group was assigned independently by 4 pathologists. Formalin-fixed, paraffin-embedded sections were immunostained with p16, CEA, p53, Ki67, and ER/PR. Immunoreactivity was scored based on intensity (0 = none, 1 = mild, 2 = moderate, 3 = marked) and percentage of cells staining (0 = <1%,1 = 2-10%, 2 = 11-40%, 3 = >40%). A comparison of histological scores and immunoscores in 3 diagnostic categories was analysed. The histological scores assigned independently by 4 pathologists were all equal or above 6 for AIS, between 3 and 5 for EGD, and equal or below 3 for BM. There was increased expression of p16 and CEA in EGD compared with BM (P < 0.05), with further increase in expression of these markers in AIS compared with EGD (P < 0.05). Ki67 expression was significantly increased in AIS compared to EGD (P < 0.05) as well as compared to BM (P < 0.05). Ki67 expression was only slightly increased in EGD as compared to BM. There was a loss of ER/PR in cervical AIS, but not in EGD. Our results indicate that the Silverberg scoring system is a useful tool in differential diagnosis of cervical glandular lesions for increased diagnostic accuracy and interobserver agreement. Most cervical glandular lesions can be differentiated by using a combination of histological scores with a panel of immunomarkers.

Gene expression studies provide clues to the pathogenesis of uterine leiomyoma: new evidence and a systematic review.

BACKGROUND: Uterine leiomyomas are extremely common and a major cause of pelvic pain, bleeding, infertility, and the leading indication for hysterectomy. Familial and epidemiological studies provide compelling evidence that genetic alterations play an important role in leiomyoma development. METHODS: Using Affymetrix U133A GeneChip we analysed expression profiles of 22,283 genes in paired samples of leiomyoma and adjacent normal myometrium. We compared our results with previously published data on gene expression in uterine leiomyoma and identified the overlapping gene alterations. RESULTS: We detected 80 genes with average differences of > or = 2-fold and false discovery rates of < 5% (14 overexpressed and 66 underexpressed). A comparative analysis including eight previous gene expression studies revealed eight prominent genes (ADH1, ATF3, CRABP2, CYR61, DPT, GRIA2, IGF2, MEST) identified by at least five different studies, eleven genes (ALDH1, CD24, CTGF, DCX, DUSP1, FOS, GAGEC1, IGFBP6, PTGDS, PTGER3, TYMS) reported by four studies, twelve genes (ABCA, ANXA1, APM2, CCL21, CDKN1A, CRMP1, EMP1, ESR1, FY, MAP3K5, TGFBR2, TIMP3) identified by three studies, and 40 genes reported by two different studies. CONCLUSIONS: Review of gene expression data revealed concordant changes in genes regulating retinoid synthesis, IGF metabolism, TGF-beta signaling and extracellular matrix formation. Gene expression studies provide clues to the relevant pathways of leiomyoma development.