Sally A. Mullany

Loss of HSulf-1 expression enhances autocrine signaling mediated by amphiregulin in breast cancer.

Heparan sulfate (HS) glycosaminoglycans are the oligosaccharide chains of heparan sulfate proteoglycans. The sulfation of HS glycosaminoglycan residues is required for its interaction with various heparin-binding growth factors to promote their biological activities to activate their high affinity receptor tyrosine kinases. We have identified HS glycosaminoglycan-6-O-endosulfatase HSulf-1 as a down-regulated gene in ovarian, breast, and several other cancer cell lines. Here we have shown that HSulf-1 inhibits autocrine activation of the EGFR-ERK (epidermal growth factor receptor-extracellular signal-regulated kinase) pathway induced by serum withdrawal in MDA-MB-468 breast cancer cells. Short hairpin RNA-mediated down-regulation of HSulf-1 in HSulf-1 clonal lines of MDA-MB-468 led to a significant increase in autocrine activation of ERK compared with vector only control. The autocrine signaling was also inhibited with neutralization antibodies against amphiregulin and HB-EGF, the heparin-binding growth factor family of the EGF superfamily. Furthermore, HSulf-1-mediated inhibition of autocrine signaling was associated with reduced cyclin D1 levels, leading to decreased S phase fraction and increased G2–M fraction, as well as increased cell death. Finally, evaluation of HSulf-1 expression levels in primary invasive breast tumors by RNA in situ hybridization indicated that HSulf-1 is down-regulated in the majority (60%) of tumors, with a predominant association with lobular histology. These data suggest a potential role of HSulf-1 down-regulation in mammary carcinogenesis.

Effect of adding the topoisomerase I poison 7-ethyl-10-hydroxycamptothecin (SN-38) to 5-fluorouracil and folinic acid in HCT-8 cells: elevated dTTP pools and enhanced cytotoxicity

Purpose: To determine the effect of combined treatment with 7-ethyl-10-hydroxycamptothecin (SN-38, the active metabolite of irinotecan) and 5-fluorouracil/folinic acid (5FU/FA) in vitro using HCT-8 human intestinal adenocarcinoma cells. Methods: Cell survival was examined using colony forming assays. Cell cycle distribution before and after treatment was assessed by flow microfluorimetry. Levels of thymidylate synthase (TS) and topoisomerase I (topo I) in untreated and treated cells were determined by immunoblotting. Changes in deoxynucleotide pools were examined by high-performance liquid chromatography. Results: Clonogenic assays revealed that colony formation was decreased by 50% after a 24-h exposure to 8 ± 2 nM SN-38 or 12 ± 3 μM 5FU, the latter being assayed in the presence of 2 μM FA. When treatment with 5FU/FA was followed by SN-38, the cytotoxicity was similar to that observed with 5FU/FA alone. In contrast, when HCT-8 cells were exposed to both agents simultaneously or to SN-38 followed by 5FU/FA, the cytotoxicity was greater than that of SN-38 or 5FU/FA treatment alone. Investigation of the mechanistic basis for this sequence dependence revealed that SN-38 treatment was associated with a dose- and time-dependent decrease in conversion of [5-3H]-2′-deoxyuridine to [3H]-H2O and thymidylate in intact cells. Immunoblotting failed to reveal any decrease in TS protein that could account for the decreased activity. High-performance liquid chromatography revealed that SN-38 treatment was associated with increased levels of the deoxynucleotide dTTP and decreased levels of dUTP. Flow microfluorimetry revealed that a 24-h treatment with 10 nM SN-38 resulted in accumulation of HCT-8 cells in late S and G2 phases of the cell cycle, with a further increase in the G2 fraction during the 24 h after SN-38 removal. Conclusions: These observations are consistent with a model in which SN-38 sequentially induces diminished DNA synthesis, elevated dTTP pools, inhibition of dUMP synthesis and enhanced toxicity of 5FU/FA. Accordingly, sequencing of irinotecan and 5FU/FA might be important in combining these agents into an effective treatment for colorectal cancer.

Heterozygous ATR Mutations in Mismatch Repair–Deficient Cancer Cells Have Functional Significance

ATR (ataxia telangiectasia and Rad3-related) function is necessary for the proper response to commonly used chemotherapeutic agents. Heterozygous truncating mutations in exon 10 of the ATR gene have been described in numerous cancers exhibiting microsatellite instability. We show that truncating mutations of ATR are capable of acting in a dominant-negative manner to abrogate ATR-dependent Chk1 phosphorylation and cell-cycle arrests after DNA damage. In addition, endometrial cell lines harboring ATR mutations are defective for ATR-dependent responses. These findings imply that ATR mutations play an important role in the development and clinical behavior of a subset of microsatellite instability-positive endometrial, colon, and stomach cancers.

Expression and Functional Significance of HtrA1 Loss in Endometrial Cancer

Purpose: The purpose of this study was to determine if loss of serine protease HtrA1 in endometrial cancer will promote the invasive potential of EC cell lines. Experimental design: Western blot analysis and immunohistochemistry methods were used to determine HtrA1 expression in EC cell lines and primary tumors, respectively. Migration, invasion assays and in vivo xenograft experiment were performed to compare the extent of metastasis between HtrA1 expressing and HtrA1 knocked down clones. Results: Western blot analysis of HtrA1 in 13 EC cell lines revealed complete loss of HtrA1 expression in all seven papillary serous EC cell lines. Downregulation of HtrA1 in Hec1A and Hec1B cell lines resulted in a three- to fourfold increase in the invasive potential. Exogenous expression of HtrA1 in Ark1 and Ark2 cells resulted in three- to fourfold decrease in both invasive and migration potential of these cells. There was an increased rate of metastasis to the lungs associated with HtrA1 downregulation in Hec1B cells compared to control cells with endogenous HtrA1 expression. Enhanced expression of HtrA1 in Ark2 cells resulted in significantly less tumor nodules metastasizing to the lungs compared to parental or protease deficient (SA mutant) Ark2 cells. Immunohistochemical analysis showed 57% (105/184) of primary EC tumors had low HtrA1 expression. The association of low HtrA1 expression with high-grade endometrioid tumors was statistically significant (P = 0.016). Conclusions: Collectively, these data indicate loss of HtrA1 may contribute to the aggressiveness and metastatic ability of endometrial tumors. Clin Cancer Res; 17(3); 427–36. ©2010 AACR.

PG545 enhances anti-cancer activity of chemotherapy in ovarian models and increases surrogate biomarkers such as VEGF in preclinical and clinical plasma samples

BACKGROUND Despite the utility of antiangiogenic drugs in ovarian cancer, efficacy remains limited due to resistance linked to alternate angiogenic pathways and metastasis. Therefore, we investigated PG545, an anti-angiogenic and anti-metastatic agent which is currently in Phase I clinical trials, using preclinical models of ovarian cancer. METHODS PG545s anti-cancer activity was investigated in vitro and in vivo as a single agent, and in combination with paclitaxel, cisplatin or carboplatin using various ovarian cancer cell lines and tumour models. RESULTS PG545, alone, or in combination with chemotherapeutics, inhibited proliferation of ovarian cancer cells, demonstrating synergy with paclitaxel in A2780 cells. PG545 inhibited growth factor-mediated cell migration and reduced HB-EGF-induced phosphorylation of ERK, AKT and EGFR in vitro and significantly reduced tumour burden which was enhanced when combined with paclitaxel in an A2780 model or carboplatin in a SKOV-3 model. Moreover, in the immunocompetent ID8 model, PG545 also significantly reduced ascites in vivo. In the A2780 maintenance model, PG545 initiated with, and following paclitaxel and cisplatin treatment, significantly improved overall survival. PG545 increased plasma VEGF levels (and other targets) in preclinical models and in a small cohort of advanced cancer patients which might represent a potential biomarker of response. CONCLUSION Our results support clinical testing of PG545, particularly in combination with paclitaxel, as a novel therapeutic strategy for ovarian cancer.

Single cell sequencing reveals heterogeneity within ovarian cancer epithelium and cancer associated stromal cells

OBJECTIVES The purpose of this study was to determine the level of heterogeneity in high grade serous ovarian cancer (HGSOC) by analyzing RNA expression in single epithelial and cancer associated stromal cells. In addition, we explored the possibility of identifying subgroups based on pathway activation and pre-defined signatures from cancer stem cells and chemo-resistant cells. METHODS A fresh, HGSOC tumor specimen derived from ovary was enzymatically digested and depleted of immune infiltrating cells. RNA sequencing was performed on 92 single cells and 66 of these single cell datasets passed quality control checks. Sequences were analyzed using multiple bioinformatics tools, including clustering, principle components analysis, and geneset enrichment analysis to identify subgroups and activated pathways. Immunohistochemistry for ovarian cancer, stem cell and stromal markers was performed on adjacent tumor sections. RESULTS Analysis of the gene expression patterns identified two major subsets of cells characterized by epithelial and stromal gene expression patterns. The epithelial group was characterized by proliferative genes including genes associated with oxidative phosphorylation and MYC activity, while the stromal group was characterized by increased expression of extracellular matrix (ECM) genes and genes associated with epithelial-to-mesenchymal transition (EMT). Neither group expressed a signature correlating with published chemo-resistant gene signatures, but many cells, predominantly in the stromal subgroup, expressed markers associated with cancer stem cells. CONCLUSIONS Single cell sequencing provides a means of identifying subpopulations of cancer cells within a single patient. Single cell sequence analysis may prove to be critical for understanding the etiology, progression and drug resistance in ovarian cancer.

USP14 is a predictor of recurrence in endometrial cancer and a molecular target for endometrial cancer treatment

Endometrial adenocarcinoma is the most common gynecologic malignancy in the United States. Most endometrial cancer cases are diagnosed at an early stage and have good prognosis. Unfortunately a subset of patients with early stage and low grade disease experience recurrence for reasons that remain unclear. Recurrence is often accompanied by chemoresistance and high mortality. Deubiquitinating enzymes (DUBs) are key components of the ubiquitin-dependent protein degradation pathway and act as master regulators in a number of metabolic processes including cell growth, differentiation, and apoptosis. DUBs have been shown to be upregulated in a number of human cancers and their aberrant activity has been linked to cancer progression, initiation and onset of chemoresistance. Thus, selective inhibition of DUBs has been proposed as a targeted therapy for cancer treatment. This study suggests the DUB USP14 as a promising biomarker for stratifying endometrial cancer patients at diagnosis based on their risk of recurrence. Further USP14 is expressed along with the marker of proliferation Ki67 in endometrial cancer cells in situ. Lastly, pharmacological targeting of USP14 with the FDA approved small-molecule inhibitor VLX1570, decreases cell viability in chemotherapy resistant endometrial cancer cells with a mechanism consistent with cell cycle arrest and caspase-3 mediated apoptosis.

Enhanced recovery program and length of stay after laparotomy on a gynecologic oncology service: A randomized controlled trial

OBJECTIVE To estimate whether a rapid recovery program would reduce length of stay among patients undergoing laparotomy on a gynecologic oncology service. METHODS We conducted a prospective, randomized, controlled trial comparing an enhanced recovery after surgery protocol with routine postoperative care among women undergoing laparotomy on the gynecologic oncology service. Protocol elements included: preoperative counseling, regional anesthesia, intraoperative fluid restriction, and early postoperative ambulation and feeding. A sample size of 50 per group (N=100) was planned to achieve 80% power to detect a two-day difference in our primary outcome, length of hospital stay; secondary outcomes included: total daily narcotics used, time to postoperative milestones, and complications. RESULTS A total of 112 women were enrolled between 2013 and 2015. Nine patients did not undergo laparotomy and were excluded, leaving 52 and 51 patients in the control and intervention groups, respectively. There was no difference in length of stay between the two groups (median 3.0 in both groups; P=.36). Enhanced recovery after surgery patients used less narcotics on day 0 (10.0 compared with 5.5 morphine equivalents in the control and intervention arms, respectively, P=.09) and day 2 (10.0 compared with 7.5 morphine equivalents, respectively; P=.05); however, there was no statistically significant difference between groups in any of the secondary outcomes. Post hoc analysis based on actual anesthesia received also failed to demonstrate a difference in time to discharge. CONCLUSION When compared with usual care, introducing a formal enhanced recovery after surgery protocol did not significantly reduce length of stay. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, https://clinicaltrials.gov, NCT01705288.

The effect of photobiomodulation on chemotherapy-induced peripheral neuropathy: A randomized, sham-controlled clinical trial

BACKGROUND Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer therapy with few efficacious treatments. METHODS We enrolled 70 patients with CIPN in a randomized, double-blinded, sham-controlled, cross-over trial to determine if photobiomodulation (PBM)±physiotherapy reduced the symptoms of neuropathy compared to sham treatment. At the conclusion of follow-up, sham-arm patients could cross-over into a third arm combining PBM and physiotherapy to determine if multimodal treatment had additive effects. Treatment included 30minute sessions 3-times weekly for 6weeks using either PBM or sham therapy. Neuropathy was assessed using the modified total neuropathy score (mTNS) at initiation and 4, 8, and 16weeks after initiating treatment. RESULTS Sham-treated patients experienced no significant change in mTNS scores at any point during the primary analysis. PBM patients experienced significant reduction in mTNS scores at all time points. Mean changes in mTNS score (and corresponding percent drop from baseline) for sham and PBM-group patients respectively were -0.1 (-0.7%) and -4.2 (-32.4%) at 4weeks (p<0.001), 0.2 (0.0%) and -6.8 (-52.6%) at 8weeks (p<0.001), and 0.0 (0.1%) and -5.0 (-38.8%) at 16weeks (p<0.001). Patients who crossed over into the PBM/PT-group experienced similar results to those treated primarily; changes in mTNS score from baseline were -5.5 (-40.6%) 4weeks (p<0.001), -6.9 (-50.9%) at 8weeks (p<0.001), and -4.9 (-35.9%) at 16weeks (p<0.001). The addition of physiotherapy did not improve outcomes over PBM alone. CONCLUSION AND RELEVANCE Among patients with CIPN, PBM produced significant reduction in neuropathy symptoms.

Molecular characterization of endometrial cancer and therapeutic implications

Purpose of review This article reviews the emerging comprehensive genomic classification of endometrial carcinoma and discusses the therapeutic implications of these subgroups. Recent findings Comprehensive, multiplatform evaluation of endometrial cancers by the Cancer Genome Atlas stratified the molecular aberrations into four distinct subtypes: POLE mutations, microsatellite instability, copy-number low/microsatellite stable, and copy-number high/‘serous-like.’ POLE-mutant tumors have a favorable prognosis and may often be overtreated. Microsatellite instability hypermutated tumors commonly have alterations in the phosphatidylinositide 3-kinases/AKT/mechanistic target of rapamycin pathway and limiting targeted therapy to this group may lead to greater response rates. Copy-number low/microsatellite stable tumors represent the majority of grade 1 and grade 2 endometrioid cancers and have an intermediate prognosis, few TP53 mutations, but frequent mutations in genes involved with Wingless-related integration site signaling. Approximately 25% of high-grade endometrioid tumors have mutational profiles that classify as copy-number high/‘serous-like’ and might benefit from treatment approaches similar to those for serous tumors. Summary Molecular characterization of endometrial cancer classifies tumors into prognostically significant subtypes with a broad range of therapeutic implications.