Claire M. Mach

On the Reproducibility of TCGA Ovarian Cancer MicroRNA Profiles

Dysregulated microRNA (miRNA) expression is a well-established feature of human cancer. However, the role of specific miRNAs in determining cancer outcomes remains unclear. Using Level 3 expression data from the Cancer Genome Atlas (TCGA), we identified 61 miRNAs that are associated with overall survival in 469 ovarian cancers profiled by microarray (p<0.01). We also identified 12 miRNAs that are associated with survival when miRNAs were profiled in the same specimens using Next Generation Sequencing (miRNA-Seq) (p<0.01). Surprisingly, only 1 miRNA transcript is associated with ovarian cancer survival in both datasets. Our analyses indicate that this discrepancy is due to the fact that miRNA levels reported by the two platforms correlate poorly, even after correcting for potential issues inherent to signal detection algorithms. Corrections for false discovery and microRNA abundance had minimal impact on this discrepancy. Further investigation is warranted.

The Small RNA Gene Activator Protein, SphI Postoctamer Homology-binding Factor/Selenocysteine tRNA Gene Transcription Activating Factor, Stimulates Transcription of the Human Interferon Regulatory Factor-3 Gene

Many small nuclear RNA gene promoters are activated by SphI postoctamer homology (SPH)-binding factor/selenocysteine tRNA gene transcription activating factor (SBF/Staf). Whereas this transcription factor was initially identified by its ability to bind to SPH elements in such promoters, it was more recently shown to have the capacity to activate transcription of a synthetic mRNA gene promoter through a distinct activation domain. Here, we show that the human interferon regulatory factor-3 (IRF-3) gene promoter contains a functional SPH element that is bound by SBF/Staf in vitro and in transfected cells.

Novel MicroRNAs regulating proliferation and apoptosis in uterine papillary serous carcinomas.

MicroRNAs (miRNAs) are endogenous, non-coding RNA transcripts that regulate gene expression. Here, we report 175 putative novel miRNAs identified in uterine cancers profiled by Next Generation Sequencing. Our data indicate that one of these putative miRNAs (BCM-173) is conserved across multiple species and is expressed at levels similar to known human miRNAs. Functionally, this miRNA promotes the growth and migration of uterine cancer cell lines by targeting vinculin and altering the distribution of focal adhesions. These results expand our insight into the repertoire of human miRNAs and identify novel pathways by which dysregulated miRNA expression promotes uterine cancer growth.

Bowel perforation associated with temsirolimus use in a recently irradiated patient

PURPOSE A probable case of bowel perforation associated with temsirolimus use in a patient with uterine leiomyosarcoma is reported. SUMMARY A 45-year-old Hispanic woman reported acute abdominal pain one day after receiving her third weekly i.v. infusion of temsirolimus, a mammalian target of rapamycin inhibitor increasingly used against a variety of cancers, including renal cell carcinoma and soft tissue sarcomas. Temsirolimus had been initiated three weeks previously in an attempt to control retroperitoneal metastases of uterine leiomyosarcoma, which had progressed despite surgical resection, six cycles of adjuvant chemotherapy, and pelvic irradiation. A computed tomography scan revealed a large pelvic mass with foci of gas, fluid collection, and other findings highly suggestive of an abscess due to bowel perforation. Application of the adverse drug reaction probability scale of Naranjo et al. in this case indicated a probable relationship between the bowel perforation and temsirolimus use; a literature search identified no other reported cases of temsirolimus-associated bowel perforation in association with uterine leiomyosarcoma. It is suspected that the patients recent course of pelvic radiotherapy may have played a role in predisposing her to bowel perforation during temsirolimus use. While the mechanism of bowel perforations associated with temsirolimus therapy remains unclear, it is possible that due to its inhibitory effects on vascular endothelial growth factor (VEGF), temsirolimus use may result in gastrointestinal stresses and weaknesses similar to those attributed to bevacizumab, a VEGF-targeted angiogenesis inhibitor that has been linked to chemotherapy-induced bowel perforation. CONCLUSION A woman who recently received pelvic radiation experienced a bowel perforation after three infusions of temsirolimus for the treatment of metastatic leiomyosarcoma.

Adjunct Histamine Blockers as Premedications to Prevent Carboplatin Hypersensitivity Reactions

The objective of this study was to evaluate the impact of premedications given as an adjunct to carboplatin on the incidence of hypersensitivity reactions in women with ovarian cancer. Medications of interest include a histamine1 (H1) and histamine2 (H2) blocker in addition to dexamethasone.

MicroRNAs and Recent Insights into Pediatric Ovarian Cancers

Ovarian cancer is the most common pediatric gynecologic malignancy. When diagnosed in children, ovarian cancers present unique challenges that differ dramatically from those faced by adults. Here, we review the spectrum of ovarian cancers found in young women and girls and discuss the biology of these diseases. A number of advances have recently shed significant new understanding on the potential causes of ovarian cancer in this unique population. Particular emphasis is placed on understanding how altered expression of non-coding RNA transcripts known as microRNAs play a key role in the etiology of ovarian germ cell and sex cord-stromal tumors. Emerging transgenic models for these diseases are also reviewed. Lastly, future challenges and opportunities for understanding pediatric ovarian cancers, delineating clinically useful biomarkers, and developing targeted therapies are discussed.

Molecular Targets and Emerging Therapeutic Options for Uterine Leiomyosarcoma.

Uterine leiomyosarcoma (uLMS) is an aggressive malignancy characterized by its early metastasis, high rates of recurrence, and poor prognosis. Multiple obstacles complicate the clinical management of uLMS. These include the fact that most uLMS are typically identified only after a woman has undergone hysterectomy or myomectomy, the limited efficacy of adjuvant therapy for early stage disease, and the poor response of metastatic disease to current treatments. Here, we discuss recent insights into the molecular basis of uLMS and discuss emerging options for its clinical management. Particular attention is given to the biologic basis of these strategies with the goal of understanding the rationale motivating their use.

Preferences and Outcomes for Chemotherapy Teaching in a Postgraduate Obstetrics and Gynecology Training Program.

PURPOSE To determine whether chemotherapy teaching is a desired component of postgraduate training programs in obstetrics and gynecology and assess its effect on practicing clinicians. METHOD After obtaining institutional review board approval, 99 individuals who completed postgraduate training at a single academic medical center between 2005 and 2013 were invited to complete an online survey. Descriptive statistics were used to summarize responses. RESULTS Of the 99 individuals, 68 (68%) completed the survey. Respondents included physicians currently practicing in both academic medicine (n = 36, 52.9%) and private practice (n = 24, 35.2%). Most respondents (n = 60, 88.2%) indicated that chemotherapy teaching was a desired feature of their training and expressed a preference for both formal didactics and direct clinical involvement (n = 55, 80.2%). Benefits identified by respondents included improved insight into the management of symptoms commonly associated with chemotherapy (n = 55, 82.1%) and an enhanced ability to counsel patients referred for oncology care (n = 48, 70.5%). All respondents who pursued training in gynecologic oncology following residency (n = 6) indicated that chemotherapy teaching favorably affected their fellowship experience. Of the 6 gynecologic oncologists, 3 (50%) who responded also indicated that chemotherapy teaching during residency improved their performance in fellowship interviews. CONCLUSION Chemotherapy teaching was a desired feature of postgraduate training in general obstetrics and gynecology at the institution studied. Consideration should be given to creating curricula that incorporate the principles and practice of chemotherapy and address the needs of obstetrics and gynecology trainees who intend to pursue both general and subspecialty practice.

Abstract 4448: Overexpression of ECT2 promotes proliferation and metastasis of UPSC

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Introduction: UPSC is a rare but aggressive malignancy that accounts for no more than 5 to 10% of uterine cancers, but more than 40% of associated uterine cancer deaths. The molecular events responsible for the poor clinical outcomes observed with UPSC are largely unknown. Epithelial cell transforming sequence 2 oncogene (ECT2) is a guanine nucleotide exchange factor (Rho-GEF) that catalyzes the exchange of GDP for GTP by Rho family GTPases. High levels of ECT2 expression have been reported in brain, lung and breast cancers, where they were shown promote metastasis. However, the role of ECT2 in UPSC has not been previously explored. Methods: After obtaining IRB permission, ECT2 mRNA and protein expression were measured in flash frozen specimens of normal proliferative endometrium (n=8) and UPSC (n =8) by quantitative real-time PCR (qPCR) and Western blot. Established cultures of UPSC cell lines (UPSC-ARK1, UPSC-ARK2) were transfected with either an siRNA targeting ECT2 or a non-targeting control (Dharmacon) using Lipofectamine 2000 (Invitrogen). Reduced expression of ECT2 following transfections with ECT2 siRNAs was confirmed by qPCR and Western blot. Standard MTS and Caspase 3/7 assays (Promega) were utilized to measure proliferation and apoptosis. Colony formation and Boyden chamber assays were used to measure metastatic capacity, migration and invasion in vitro. Results: Our data indicate that ECT2 is overexpressed >4-fold in nearly all UPSC specimens tested (n=8, p<0.001). We also found that ECT2 is robustly expressed in both the UPSC-ARK1 and UPSC-ARK2 cell lines. Utilizing these 2 cell lines, we found that knockdown of ECT2 significantly decreased proliferation (UPSC-ARK1: 0.62-fold versus control; n=3, p<0.05; UPSC-ARK2: 0.34-fold versus control, p<0.05) and increased rates of apoptosis (UPSC-ARK1: 1.3-fold; n=3, p<0.05; UPSC-ARK2: 2.2-fold, n=3, p<0.05) in both cell lines tested. Decreased ECT2 expression targeted by transfection with siRNAs led to decreased rates of colony formation in UPSC-ARK1 and UPSC-ARK2 cell lines. Knockdown of ECT2 also significantly reduced rates of migration and invasion observed in vitro with both cell lines. Conclusions: Overexpression of ECT2 plays a critical role in promoting the growth and metastasis of UPSC. Targeting ECT2 expression may provide an effective strategy for improving outcomes for UPSC and other human cancers where hyperactivation of metastasis-promoting Rho GTPases are observed. Citation Format: Claire M. Mach, Thomas J. Magliaro, Matthew L. Anderson. Overexpression of ECT2 promotes proliferation and metastasis of UPSC. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4448. doi:10.1158/1538-7445.AM2014-4448

Abstract 5242: miR-10b functions as a novel tumor suppressor in uterine leiomyosarcoma by promoting overexpression of SDC1

MicroRNAs (miRNAs) are endogenous RNA transcripts that play a critical role in regulating pleuripotency and differentiation. Altered miRNA expression is a well-established feature of nearly all human cancers. However, the mechanisms by which dysregulated miRNA expression promote tumorigenesis remain poorly understood.To evaluate the role of miRNAs in uterine leiomyosarcoma (uLMS), we profiled patterns of small RNA expression in matched specimens of healthy myometrium (n=34), uterine leiomyomas (n=34) and uterine leiomyosarcoma (n=12) using Next Generation Sequencing (NGS). After quantile normalization, patterns of mature miRNA transcripts were compared. We found that 37 individual miRNAs were differentially expressed >2-fold (p 8-fold, p 2-fold when uLMS were compared to myometrium (p Note: This abstract was not presented at the meeting. Citation Format: Matthew L. Anderson, Gyoung Eun Kim, Claire M. Mach, Chad J. Creighton, Dina Lev. miR-10b functions as a novel tumor suppressor in uterine leiomyosarcoma by promoting overexpression of SDC1. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5242. doi:10.1158/1538-7445.AM2014-5242