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Background: The development of chemoresistance to paclitaxel and carboplatin represents a major therapeutic challenge in ovarian cancer, a disease frequently characterized by malignant ascites and extrapelvic metastasis. Microtentacles (McTNs) are tubulin-based projections observed in detached breast cancer cells. In this study, we investigated whether ovarian cancers exhibit McTNs and characterized McTN biology. Methods: We used an established lipid-tethering mechanism to suspend and image individual cancer cells. We queried a panel of immortalized serous (OSC) and clear cell (OCCC) cell lines as well as freshly procured ascites and human ovarian surface epithelium (HOSE). We assessed by Western blot β-tubulin isotype, α-tubulin post-translational modifications and actin regulatory proteins in attached/detached states. We studied clustering in suspended conditions. Effects of treatment with microtubule depolymerizing and stabilizing drugs were described. Results: Among cell lines, up to 30% of cells expressed McTNs. Four McTN morphologies (absent, symmetric-short, symmetric-long, tufted) were observed in immortalized cultures as well as ascites. McTN number/length varied with histology according to metastatic potential. Most OCCC overexpressed class III ß-tubulin. OCCC/OSC cell lines exhibited a trend towards more microtubule-stabilizing post-translational modifications of α-tubulin relative to HOSE. Microtubule depolymerizing drugs decreased the number/length of McTNs, confirming that McTNs are composed of tubulin. Cells that failed to form McTNs demonstrated differential expression of α-tubulin- and actin-regulating proteins relative to cells that form McTNs. Cluster formation is more susceptible to microtubule targeting agents in cells that form McTNs, suggesting a role for McTNs in aggregation. Conclusions: McTNs likely participate in key aspects of ovarian cancer metastasis. McTNs represent a new therapeutic target for this disease that could refine therapies, including intraperitoneal drug delivery.

Simple Summary Microtubule-interfering drugs have been used alone or in combination in the treatment of epithelial ovarian cancer. Over the years and with increasing chemoresistance to taxanes, epothilones (i.e., ixabepilone) have become of interest as alternatives to taxanes. In this review, we discuss the role of microtubule-interfering chemotherapeutic agents in treatment of newly diagnosed and recurrent ovarian cancer, as well as common mechanisms of chemoresistance. We also discuss future directions for the use of microtubule-interfering agents in ovarian cancer. Abstract Taxanes and epothilones are chemotherapeutic agents that ultimately lead to cell death through inhibition of normal microtubular function. This review summarizes the literature demonstrating their current use and potential promise as therapeutic agents in the treatment of epithelial ovarian cancer (EOC), as well as putative mechanisms of resistance. Historically, taxanes have become the standard of care in the front-line and recurrent treatment of epithelial ovarian cancer. In the past few years, epothilones (i.e., ixabepilone) have become of interest as they may retain activity in taxane-treated patients since they harbor several features that may overcome mechanisms of taxane resistance. Clinical data now support the use of ixabepilone in the treatment of platinum-resistant or refractory ovarian cancer. Clinical data strongly support the use of microtubule-interfering drugs alone or in combination in the treatment of epithelial ovarian cancer. Ongoing clinical trials will shed further light into the potential of making these drugs part of current standard practice.

Simple Summary Photodynamic priming is an emerging strategy that leverages subtherapeutic photochemistry for therapeutic benefits, often used as part of combination regimens. Our study aimed to couple photodynamically priming with antagonism of the prostaglandin E receptor 4, a therapeutic target linked to cancer-associated migration, invasion, angiogenesis, and immune evasion. Photodynamic priming and antagonism of the prostaglandin E receptor 4 independently attenuated OVCAR-5 ovarian cancer cell migration in a gap closure model, though their combination induced the most significant reductions. More potent combination effects were revealed when invasiveness was characterized using a transwell invasion model with CAOV3 ovarian cancer cells. Immunoblotting identified the epithelial growth factor receptor, cAMP-response element binding protein, and extracellular signal-regulated kinase 1/2 as potential mediators of these combinational effects. This work provides new evidence of a novel and clinically relevant combination strategy to address metastatic behavior, a major challenge in the treatment of cancer. Abstract The combination of photodynamic agents and biological inhibitors is rapidly gaining attention for its promise and approval in treating advanced cancer. The activity of photodynamic treatment is mainly governed by the formation of reactive oxygen species upon light activation of photosensitizers. Exposure to reactive oxygen species above a threshold dose can induce cellular damage and cancer cell death, while the surviving cancer cells are “photodynamically primed”, or sensitized, to respond better to other drugs and biological treatments. Here, we report a new combination regimen of photodynamic priming (PDP) and prostaglandin E2 receptor 4 (EP4) inhibition that reduces the migration and invasion of two human ovarian cancer cell lines (OVCAR-5 and CAOV3) in vitro. PDP is achieved by red light activation of the FDA-approved photosensitizer, benzoporphyrin derivative (BPD), or a chemical conjugate composed of the BPD linked to cetuximab, an anti-epithelial growth factor receptor (EGFR) antibody. Immunoblotting data identify co-inhibition of EGFR, cAMP-response element binding protein (CREB), and extracellular signal-regulated kinase 1/2 (ERK1/2) as key in the signaling cascades modulated by the combination of EGFR-targeted PDP and EP4 inhibition. This study provides valuable insights into the development of a molecular-targeted photochemical strategy to improve the anti-metastatic effects of EP4 receptor antagonists.

Ovarian cancer is the fifth most common cause of cancer deaths among American women. Platinum and taxane combination chemotherapy represents the first-line approach for ovarian cancer, but treatment success is often limited by chemoresistance. Therefore, it is necessary to find new drugs to sensitize ovarian cancer cells to chemotherapy. Persistent activation of Signal Transducer and Activator of Transcription 3 (STAT3) signaling plays an important role in oncogenesis. Using a novel approach called advanced multiple ligand simultaneous docking (AMLSD), we developed a novel nonpeptide small molecule, LLL12B, which targets the STAT3 pathway. In this study, LLL12B inhibited STAT3 phosphorylation (tyrosine 705) and the expression of its downstream targets, which are associated with cancer cell proliferation and survival. We showed that LLL12B also inhibits cell viability, migration, and proliferation in human ovarian cancer cells. LLL12B combined with either paclitaxel or with cisplatin demonstrated synergistic inhibitory effects relative to monotherapy in inhibiting cell viability and LLL12B-paclitaxel or LLL12B-cisplatin combination exhibited greater inhibitory effects than cisplatin-paclitaxel combination in ovarian cancer cells. Furthermore, LLL12B-paclitaxel or LLL12B-cisplatin combination showed more significant in inhibiting cell migration and growth than monotherapy in ovarian cancer cells. In summary, our results support the novel small molecule LLL12B as a potent STAT3 inhibitor in human ovarian cancer cells and suggest that LLL12B in combination with the current front-line chemotherapeutic drugs cisplatin and paclitaxel may represent a promising approach for ovarian cancer therapy.

The microtubule-stabilizing agent docetaxel in combination with gemcitabine represents one of the most effective regimens against the aggressive gynecologic tumor leiomyosarcoma (LMS). Upregulation of class III &beta, tubulin has previously been shown to confer taxane resistance in a variety of human cancers. Prostaglandin E2 receptor EP4 is linked to progression of a variety of human cancers and may represent a novel target for tumor inhibition in LMS. We evaluated the hypotheses that EP4 and class III &beta, tubulin have increased expression in LMS in comparison to normal myometrium or benign tumors and that expression of class III &beta, tubulin correlates with resistance to taxanes and poor clinical outcome. Gene expression was examined using TCGA data and correlated with clinicopathologic outcome which demonstrated that class III &beta, tubulin is more highly expressed in more aggressive sarcomas with EP4 being widely expressed in all subtypes of sarcoma. Immunohistochemistry for EP4 and class III &beta, tubulin was performed on patients with LMS, leiomyomatosis/STUMP, leiomyoma, and normal myometrium. Expression of EP4 and class III &beta, tubulin were characterized for cell lines SK-UT-1, SK-UT-1B, and PHM-41 and these cell lines were treated with docetaxel alone and in combination with EP4 inhibitors. In taxane-resistant cell lines that overexpress class III &beta, tubulin and EP4, treatment with EP4 inhibitor resulted in at least 2-fold sensitization to docetaxel. Expression of class III &beta, tubulin and EP4 in LMS may identify patients at risk of resistance to standard chemotherapies and candidates for augmentation of therapy through EP4 inhibition.

Dana M Roque,1 Masoud Azodi1,2 1Division of Gynecologic Oncology, 2Division of Minimally Invasive and Robotic Surgery, Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University, New Haven, CT, USALeonardo da Vinci has been credited with the design in 1495 of the first known robot, which was capable of human-like motions through the manipulation of multiple coordinated pulleys.1 The term "robot" stems from the Czech word "robota", referring to compulsory labor, and was popularized in English vocabulary as early as 1923. Today, the Robotics Institute of America defines "robots" as "reprogrammable, multifunctional manipulators designed to move material, parts, tools, or specialized devices through various programmed functions for the performance of a variety of tasks".2Robotic technology entered the surgical industry as early as 1985, beginning with applications to improve accuracy and precision in neurosurgery during stereotactic brain biopsies3 and in the field of orthopedics for joint alignment.4 Robotic assistance soon emerged as a tool to overcome problematic ergonomics limiting dexterity and the pitfalls of bi-dimensional imaging associated with traditional laparoscopic approaches, with roles quickly expanding to urologic, gastrointestinal, cardiac, maxillofacial, ophthalmologic, and gynecologic subspecialties, among others.5

Background The aim of the present study was to investigate within ovarian carcinoma and normal ovarian biopsies the gene expression of multiple secretoglobin family members relative to mammaglobin B, which we previously reported as a promising novel ovarian carcinoma prognostic marker. Methods Using quantitative real-time Reverse Transcription PCR we tested 53 ovarian carcinoma and 30 normal ovaries for the expression of 8 genes belonging to the secretoglobin family: mammaglobin A, lipophilin A, lipophilin B, uteroglobin, HIN-1, UGRP-1, RYD5 and IIS. Next, we decided to expand the LipB gene expression analysis to a further 48 ovarian carcinoma samples, for a total of 101 tumor tissues of various histologies and to study its protein expression by immunohistochemistry in formalin-fixed paraffin-embedded tumors and normal ovaries. Finally, we correlated lipophilin B gene and protein expression to conventional patient clinico-pathological features and outcome. Results We found significant mammaglobin A, lipophilin A, lipophilin B and RYD5 gene overexpression in ovarian carcinomas compared to normal ovaries. Lipophilin B mRNA showed a higher presence in tumors (75.4%) compared to normal ovaries (16.6%) and the most significant correlation with mammaglobin B mRNA (rs =0.77, p, This investigation was supported by grants from the Nocivelli Foundation, Brescia, Italy, and by grants from the Istituto Superiore di Sanità (Programma onco-proteomica Italia-USA 527B4/4), Rome, Italy. Dr Elisa Rossi is supported by the JAE-Doc program of CSIC funded by FEDER. Moreover, this work was supported in part by grants from NIH R01 CA122728-01A4 and R01 CA154460-01A1, the Honorable Tina Brozman Foundation and Deborah Bunn Alley Ovarian Cancer Research Foundation to ADS

Uterine serous carcinoma (USC) is a biologically aggressive subtype of endometrial cancer. We analyzed the mutational landscape of USC by whole-exome sequencing of 57 cancers, most of which were matched to normal DNA from the same patients. The distribution of the number of protein-altering somatic mutations revealed that 52 USC tumors had fewer than 100 (median 36), whereas 5 had more than 3,000 somatic mutations. The mutations in these latter tumors showed hallmarks of defects in DNA mismatch repair. Among the remainder, we found a significantly increased burden of mutation in 14 genes. In addition to well-known cancer genes (i.e., TP53 , PIK3CA , PPP2R1A , KRAS , FBXW7 ), there were frequent mutations in CHD4/Mi2b , a member of the NuRD–chromatin-remodeling complex, and TAF1 , an element of the core TFIID transcriptional machinery. Additionally, somatic copy-number variation was found to play an important role in USC, with 13 copy-number gains and 12 copy-number losses that occurred more often than expected by chance. In addition to loss of TP53 , we found frequent deletion of a small segment of chromosome 19 containing MBD3 , also a member of the NuRD–chromatin-modification complex, and frequent amplification of chromosome segments containing PIK3CA , ERBB2 (an upstream activator of PIK3CA), and CCNE1 (a target of FBXW7-mediated ubiquitination). These findings identify frequent mutation of DNA damage, chromatin remodeling, cell cycle, and cell proliferation pathways in USC and suggest potential targets for treatment of this lethal variant of endometrial cancer.

To compare the in vitro sensitivity/resistance to patupilone versus paclitaxel in uterine and ovarian carcinosarcomas (CS).Five primary carcinosarcoma cell lines, two from uterine and three of ovarian origin, were evaluated for growth rate and tested for their in vitro sensitivity/resistance to patupilone versus paclitaxel by MTS assays. To identify potential mechanisms underlying the differential sensitivity/resistance to patupilone, expression levels of β-tubulin III (TUBB3) were determined with quantitative-real-time-polymerase-chain-reaction (q-RT-PCR) in primary uterine and ovarian CS cell lines and in 26 uterine and 9 ovarian CS fresh-frozen-tissues.No appreciable difference in sensitivity to patupilone versus paclitaxel was noted in ovarian CS cell lines, or when uterine and ovarian CS cell lines were compared in their response to paclitaxel. In contrast, uterine CS cell lines were found to be significantly more sensitive to patupilone than to paclitaxel (P0.002) and demostrated lower IC(50s) to patupilone (range 0.76-0.93nM) when compared to ovarian CS (range 1.9-3.4 nM, p0.05). Higher levels of TUBB3 were detected in uterine CS cell lines and fresh frozen tissues when compared to ovarian CS (P0.05).Uterine CS cell lines are significantly more sensitive than ovarian CS cell lines to patupilone versus paclitaxel. High expression of TUBB3 is associated with sensitivity to patupilone in primary CS cell lines and may act as a genetic marker to predict chemotherapy efficacy. Patupilone may represent a promising drug in the treatment of this subset of rare but highly aggressive gynecological tumors.