Avascular spaces in radical hysterectomy.

The most common cancer in women worldwide is cervical cancer. For early-stage disease the standard treatment is radical hysterectomy. One of the main issues faced by surgeons performing a radical hysterectomy is the wide variation in the terminology used to define the procedure and the nomenclature used to describe the anatomical spaces critical to the success of the surgery. The aim of this review was to synthesize currently used anatomical landmarks with relation to surgical avascular spaces for the performance of radical hysterectomy.A computer-based comprehensive review of the MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and SciSearch databases, as well as National Comprehensive Cancer Network and European Society of Gynaecological Oncology guidelines, was performed. With all relevant data collected, and previous anatomical studies during surgeries and on cadavers performed by authors, a manuscript of the definition of avascular spaces, methods of dissection, and anatomical limits was prepared.Avascular pelvic spaces developed during radical hysterectomy, such as the paravesical, pararectal, ureter tunnel, and paravaginal, were considered and included in the manuscript. A clear definition of avascular spaces may aid a better understanding of the anatomical aspects of the radical hysterectomy. It could improve surgeon knowledge of the structures that need to be preserved and those that need to be resected during a radical hysterectomy. Additionally, the detailed exposure of anatomical boundaries will facilitate the appropriate tailored radicality depending on the risk factors of the disease. Moreover, knowledge of these spaces could make pelvic surgery safer and easier for other types of gynecological and non-gynecological procedures.

Processing closely spaced lesions during Nucleotide Excision Repair triggers mutagenesis in E. coli.

It is generally assumed that most point mutations are fixed when damage containing template DNA undergoes replication, either right at the fork or behind the fork during gap filling. Here we provide genetic evidence for a pathway, dependent on Nucleotide Excision Repair, that induces mutations when processing closely spaced lesions. This pathway, referred to as Nucleotide Excision Repair-induced Mutagenesis (NERiM), exhibits several characteristics distinct from mutations that occur within the course of replication: i) following UV irradiation, NER-induced mutations are fixed much more rapidly (t ½ ≈ 30 min) than replication dependent mutations (t ½ ≈ 80-100 min) ii) NERiM specifically requires DNA Pol IV in addition to Pol V iii) NERiM exhibits a two-hit dose-response curve that suggests processing of closely spaced lesions. A mathematical model let us define the geometry (infer the structure) of the toxic intermediate as being formed when NER incises a lesion that resides in close proximity of another lesion in the complementary strand. This critical NER intermediate requires Pol IV / Pol II for repair, it is either lethal if left unrepaired or mutation-prone when repaired. Finally, NERiM is found to operate in stationary phase cells providing an intriguing possibility for ongoing evolution in the absence of replication.

Nerve-sparing radical hysterectomy: steps to standardize surgical technique.

AIM: The primary objective of this review was to study and analyze techniques of nerve-sparing radical hysterectomy so as to be able to characterize and elucidate intricate steps for the dissection of each component of the pelvic autonomic nerve plexuses during nerve-sparing radical hysterectomy. METHODS: This review was based on a five-step study design that included searching for relevant publications, selecting publications by applying inclusion and exclusion criteria, quality assessment of the identified studies, data extraction, and data synthesis. RESULTS: There are numerous differences in the published literature concerning nerve-sparing radical hysterectomy including variations in techniques and surgical approaches. Techniques that claim to be nerve-sparing by staying above the dissection level of the hypogastric nerves do not highlight the pelvic splanchnic nerve, do not take into account the intra-operative patient position, nor the fact that the bladder branches leave the inferior hypogastric plexus in a ventrocranial direction, and the fact that inferior hypogastric plexus will be drawn cranially with the vaginal walls (if this is not recognized and isolated earlier) above the level of hypogastric nerves by drawing the uterus cranially during the operation. CONCLUSIONS: The optimal nerve-sparing radical hysterectomy technique has to be radical (type C1) and must describe surgical steps to highlight all three components of the pelvic autonomic nervous system (hypogastric nerves, pelvic splanchnic nerves, and the bladder branches of the inferior hypogastric plexus). Recognizing the pelvic splanchnic nerves in the caudal parametrium and the isolation of the bladder branches of the inferior hypogastic plexus requires meticulous preparation of the caudal part of the ventral parametrium.

Surgical and systemic management of endometrial cancer: an international survey.

PURPOSE: To ascertain the spectrum of clinical management of endometrial carcinoma (EC) the largest international survey was conducted to evaluate and identify differences worldwide. METHODS: After validation of a 15-item questionnaire regarding surgical and adjuvant treatment of EC in Germany, an English-adapted questionnaire was put online and posted to all the major gynecological cancer Societies worldwide for further distribution commencing in 2010 and continued for 26 months. RESULTS: A total of 618 Institutions around the world participated: Central Europe (CE), Southern Europe (SE), Northern Europe (NE), Asia and USA/Canada/UK. Both a therapeutic and staging value was attributed to systematic pelvic and paraaortic lymph node dissection (LND) in CE (74.6%) and in Asia (67.2%), as opposed to USA/UK where LND was mainly for staging purposes (53.5%; p < 0.001). LND was performed up to the renal veins in CE in 86.8%, in Asia in 80.8%, in USA/UK in 51.2% and in SE in 45.1% (p < 0.001) of cases. In advanced disease, centers from Asia were treated most with adjuvant chemotherapy alone (93.6%), as opposed to centers in SE, CE and UK/USA that employed combination chemo-radiotherapy in 90.9% (p < 0.001) of cases. Paclitaxel/carboplatin was mostly used followed by doxorubicin/cisplatin (75 vs. 23.3%; p < 0.001). In total, 94% of all participants supported the concept of treating EC patients within appropriate clinical trials. CONCLUSIONS: There is broad range in both the surgical and adjuvant treatment of EC across different countries. Large-scale multicenter prospective trials are warranted to establish consistent, evidence-based guidelines to optimize treatment worldwide.

Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.

Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 39 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis.

Escherichia coli DNA polymerase III is responsible for the high level of spontaneous mutations in mutT strains.

Reactive oxygen species induce oxidative damage in DNA precursors, i.e. dNTPs, leading to point mutations upon incorporation. Escherichia coli mutT strains, deficient in the activity hydrolysing 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP), display more than a 100-fold higher spontaneous mutation frequency over the wild-type strain. 8-oxo-dGTP induces A to C transversions when misincorporated opposite template A. Here, we report that DNA pol III incorporates 8-oxo-dGTP ≈ 20 times more efficiently opposite template A compared with template C. Single, double or triple deletions of pol I, pol II, pol IV or pol V had modest effects on the mutT mutator phenotype. Only the deletion of all four polymerases led to a 70% reduction of the mutator phenotype. While pol III may account for nearly all 8-oxo-dGTP incorporation opposite template A, it only extends ≈ 30% of them, the remaining 70% being extended by the combined action of pol I, pol II, pol IV or pol V. The unique property of pol III, a C-family DNA polymerase present only in eubacteria, to preferentially incorporate 8-oxo-dGTP opposite template A during replication might explain the high spontaneous mutation frequency in E. coli mutT compared with the mammalian counterparts lacking the 8-oxo-dGTP hydrolysing activities.

Anatomical location of the surgically identifiable bladder branch of the inferior hypogastric plexus for nerve-sparing radical hysterectomy.

Objective: We aimed to demonstrate the entire structure of the inferior hypogastric plexus in the female pelvis focusing on surgically identifiable nerve bundles to the urinary bladder. Methods: Surgical videos of transabdominal nerve-sparing radical hysterectomy for 10 patients with cervical cancer at International Federation of Gynecology and Obstetrics (FIGO 2009) stage IB1-IIB were retrospectively analyzed. The paracervical tissue dorsal to the ureter was separated into the lateral component (dorsal layer of the vesicouterine ligament) and medial component (paracolpium) using Okabayashi's technique. Any bundle-like structures in the paracervical area were isolated and divided using cold scissors, and each cut edge was inspected to determine whether the bundle was a blood vessel or a nerve. Results: In all cases, the surgically identifiable nerve bundle of the bladder branch was identified on the rectovaginal ligament running parallel and dorsal to the vaginal vein of the paracolpium. The bladder branch was revealed only after complete division of the vesical veins in the dorsal layer of the vesicouterine ligament where no definitive nerve bundles were observed. The bladder branch was derived laterally from the pelvic splanchnic nerve and medially from the inferior hypogastric plexus. Conclusions: The surgical identification of the nerve bundle of the bladder branch is essential for a safe and secure nerve-sparing radical hysterectomy. The preservation of the surgically identifiable bladder branch from the pelvic splanchnic nerve as well as from the inferior hypogastric plexus can provide satisfactory postoperative voiding function.

A novel protein overexpressed in hepatoma accelerates export of NF-kappa B from the nucleus and inhibits p53-dependent apoptosis.

NF-kappa B is a transcription factor that can protect from or contribute to apoptosis. Here we report identification of HSCO that binds to NF-kappa B and inhibits apoptosis. HSCO mRNA was overexpressed in 20 of 30 hepatocellular carcinomas analyzed. Overexpression of HSCO inhibited caspase 9 activation and apoptosis induced by DNA damaging agents, while it augmented apoptosis induced by TNFalpha. Like I kappa B alpha, HSCO inhibited NF-kappa B activity and abrogated p53-induced apoptosis. However, the underlying mechanism was different. HSCO is a nuclear-cytoplasmic shuttling protein, bound to RelA NF-kappa B, and HSCO sequestered it in the cytoplasm by accelerating its export from the nucleus. These results suggest that overexpression of HSCO suppresses p53-induced apoptosis by preventing nuclear localization of NF-kappa B during signaling and thus contributes to hepatocarcinogenesis.

Biochemical basis for the essential genetic requirements of RecA and the beta-clamp in Pol V activation.

In Escherichia coli, it is genetically well established that the beta-clamp and RecA are essential cofactors that endow DNA polymerase (Pol) V with lesion bypass activity. However, the biochemical basis for these requirements is still largely unknown. Because the process of translesion synthesis (TLS) requires that the specialized DNA polymerase synthesize in a single binding event a TLS patch that is long enough to resist external proofreading, it is critical to monitor Pol V burst synthesis. Here, we dissect the distinct roles that RecA and the beta-clamp perform during the Pol V activation process using physiologically relevant long single-stranded template DNA, similar to those used in genetic assays. Our data show that the beta-clamp endows the complex between Pol V and the template DNA with increased stability. Also, the RecA filament formed in cis on the single-stranded DNA produced downstream from the lesion stretches the template DNA to allow smooth elongation of the nascent strand by Pol V. The concurrent action of both cofactors is required for achieving productive TLS events. The present article presents an integrated view of TLS under physiologically relevant conditions in E. coli that may represent a paradigm for lesion bypass in other organisms.

Expression of p53 and p21(WAF-1), apoptosis, and proliferation of smooth muscle cells in normal myometrium during the menstrual cycle: implication of DNA damage and repair for leiomyoma development.

Uterine leiomyoma is the most common tumor in the female genital tract, although its pathogenesis remains unclear. Molecular analyses have demonstrated that each leiomyoma nodule is monoclonal and harbors various DNA abnormalities, suggesting that DNA damage in normal smooth muscle cells plays an important role in the pathogenesis of leiomyoma. The aim of this study is to evaluate precisely when and where DNA damage occurs in the myometrium. The localization of damaged, apoptotic, and proliferating cells was evaluated by immunohistochemical staining of p53, p21(WAF-1), TUNEL, and the cell proliferation marker, Ki-67, in normal myometrium during the menstrual cycle. p53-positive cells and p21(WAF-1)-positive cells were observed during the follicular phase, mostly in the submucosal layer of the myometrium. TUNEL-positive cells were sporadically identified in this layer during either the menstrual or follicular phase. In contrast, the number of Ki-67-positive cells was higher in the luteal phase. These results suggest that DNA damage, repair, and apoptosis occur cyclically in normal myometrium during the follicular phase. In addition, smooth muscle cells proliferate in the luteal phase, which may be a vulnerable period for DNA damage. Thus, these cyclic events during the menstrual cycle may contribute to a high incidence of leiomyoma development.

Double-strand breaks: When DNA repair events accidentally meet.

The cellular response to alkylation damage is complex, involving multiple DNA repair pathways and checkpoint proteins, depending on the DNA lesion, the cell type, and the cellular proliferation state. The repair of and response to O-alkylation damage, primarily O6-methylguaine DNA adducts (O6-mG), is the purview of O6-methylguanine-DNA methyltransferase (MGMT). Alternatively, this lesion, if left un-repaired, induces replication-dependent formation of the O6-mG:T mis-pair and recognition of this mis-pair by the post-replication mismatch DNA repair pathway (MMR). Two models have been suggested to account for MMR and O6-mG DNA lesion dependent formation of DNA double-strand breaks (DSBs) and the resulting cytotoxicity - futile cycling and direct DNA damage signaling. While there have been hints at crosstalk between the MMR and base excision repair (BER) pathways, clear mechanistic evidence for such pathway coordination in the formation of DSBs has remained elusive. However, using a novel protein capture approach, Fuchs and colleagues have demonstrated that DSBs result from an encounter between MMR-induced gaps initiated at alkylation induced O6-mG:C sites and BER-induced nicks at nearby N-alkylation adducts in the opposite strand. The accidental encounter between these two repair events is causal in the formation of DSBs and the resulting cellular response, documenting a third model to account for O6-mG induced cell death in non-replicating cells. This graphical review highlights the details of this Repair Accident model, as compared to current models, and we discuss potential strategies to improve clinical use of alkylating agents such as temozolomide, that can be inferred from the Repair Accident model.

Activated local immunity by CC chemokine ligand 19-transduced embryonic endothelial progenitor cells suppresses metastasis of murine ovarian cancer.

Although tumor microenvironments play a key role in successful tumor immunotherapy, effective manipulation of local immunity is difficult because of the lack of an appropriate target system. It is well known that bone marrow-derived endothelial progenitor cells (EPCs) are actively recruited during tumor angiogenesis. Using this feature, we attempted to establish a novel therapeutic modality that targets tumor vessels of multiple metastases using embryonic endothelial progenitor cells (eEPCs) transduced with an immune-activating gene. The eEPCs were retrovirally transduced with the mouse CC chemokine ligand 19 (CCL19) gene, a lymphocyte-migrating chemokine. The mouse ovarian cancer cell line OV2944-HM-1 (HM-1) was inoculated subcutaneously into B6C3F1 mice, along with CCL19-tranduced eEPCs (eEPC-CCL19), resulting in immunologic activity and tumor-inhibitory effects. In this model, eEPC-CCL19 showed tumor repression accompanied by increased tumor-infiltrating CD8+ lymphocytes compared with the control group. In contrast, no tumor repression was observed when the same experiment was done in immunodeficient (SCID) mice, suggesting a crucial role of T-cell function in this system. Next, we established a lung metastasis model by injecting HM-1 cells or B16 melanoma cells via the tail vein. Subsequent intravenous injection of eEPC-CCL19 leads to a decrease in the number of lung metastasis and prolonged survival. Antitumor effects were also observed in a peritoneal dissemination model using HM-1. These results suggest that systemic delivery of an immune-activating signal using EPCs can alter the tumor immune microenvironment and lead to a therapeutic effect, which may provide a novel strategy for targeting multiple metastases of various malignancies.

Enrichment of plasmid pool from E. coli for mass sequencing to detect untargeted mutagenic events.

Translesion synthesis (TLS) is an event to cope with DNA damages. During TLS, the responsible TLS polymerase frequently elicits untargeted mutagenesis as potentially a source of genetic diversity. Identifying such untargeted mutations in vivo is challenging due to the bulk of DNA that does not undergo TLS. Here, we present a protocol to enrich a plasmid pool that underwent Pol V-mediated TLS in Escherichia coli for mass sequencing. The concept of this protocol could be applied into any species. For complete details on the use and execution of this protocol, please refer to Isogawa et al. (2018).

Crosstalk between repair pathways elicits double-strand breaks in alkylated DNA and implications for the action of temozolomide.

Temozolomide (TMZ), a DNA methylating agent, is the primary chemotherapeutic drug used in glioblastoma treatment. TMZ induces mostly N-alkylation adducts (N7-methylguanine and N3-methyladenine) and some O6-methylguanine (O6mG) adducts. Current models propose that during DNA replication, thymine is incorporated across from O6mG, promoting a futile cycle of mismatch repair (MMR) that leads to DNA double-strand breaks (DSBs). To revisit the mechanism of O6mG processing, we reacted plasmid DNA with N-methyl-N-nitrosourea (MNU), a temozolomide mimic, and incubated it in Xenopus egg-derived extracts. We have shown that in this system, MMR proteins are enriched on MNU-treated DNA and we observed robust, MMR-dependent, repair synthesis. Our evidence also suggests that MMR, initiated at O6mG:C sites, is strongly stimulated in cis by repair processing of other lesions, such as N-alkylation adducts. Importantly, MNU-treated plasmids display DSBs in extracts, the frequency of which increases linearly with the square of alkylation dose. We suggest that DSBs result from two independent repair processes, one involving MMR at O6mG:C sites and the other involving base excision repair acting at a nearby N-alkylation adduct. We propose a new, replication-independent mechanism of action of TMZ, which operates in addition to the well-studied cell cycle-dependent mode of action.

Targeting Dormant Ovarian Cancer Cells In Vitro and in an In Vivo Mouse Model of Platinum Resistance.

Spheroids exhibit drug resistance and slow proliferation, suggesting involvement in cancer recurrence. The protein kinase C inhibitor UCN-01 (7-hydroxystaurosporine) has shown higher efficacy against slow proliferating and/or quiescent ovarian cancer cells. In this study, tumorigenic potential was assessed using anchorage-independent growth assays and spheroid-forming capacity, which was determined with ovarian cancer cell lines as well as primary ovarian cancers. Of 12 cell lines with increased anchorage-independent growth, 8 formed spheroids under serum-free culture conditions. Spheroids showed reduced proliferation (P < 0.0001) and Ki-67 immunostaining (8% vs. 87%) relative to monolayer cells. Spheroid formation was associated with increased expression of mitochondrial pathway genes (P ≤ 0.001) from Affymetrix HT U133A gene expression data. UCN-01, a kinase inhibitor/mitochondrial uncoupler that has been shown to lead to Puma-induced mitochondrial apoptosis as well as ATP synthase inhibitor oligomycin, demonstrated effectiveness against spheroids, whereas spheroids were refractory to cisplatin and paclitaxel. By live in vivo imaging, ovarian cancer xenograft tumors were reduced after primary treatment with carboplatin. Continued treatment with carboplatin was accompanied by an increase in tumor signal, whereas there was little or no increase in tumor signal observed with subsequent treatment with UCN-01 or oltipraz. Taken together, our findings suggest that genes involved in mitochondrial function in spheroids may be an important therapeutic target in preventing disease recurrence.

Role of premature leptin surge in obesity resulting from intrauterine undernutrition.

Intrauterine undernutrition is closely associated with obesity related to detrimental metabolic sequelae in adulthood. We report a mouse model in which offspring with fetal undernutrition (UN offspring), when fed a high-fat diet (HFD), develop pronounced weight gain and adiposity. In the neonatal period, UN offspring exhibited a premature onset of neonatal leptin surge compared to offspring with intrauterine normal nutrition (NN offspring). Unexpectedly, premature leptin surge generated in NN offspring by exogenous leptin administration led to accelerated weight gain with an HFD. Both UN offspring and neonatally leptin-treated NN offspring exhibited an impaired response to acute peripheral leptin administration on a regular chow diet (RCD) with impaired leptin transport to the brain as well as an increased density of hypothalamic nerve terminals. The present study suggests that the premature leptin surge alters energy regulation by the hypothalamus and contributes to "developmental origins of health and disease."

Elevated MAL expression is accompanied by promoter hypomethylation and platinum resistance in epithelial ovarian cancer.

We previously found that the gene encoding the Myelin and Lymphocyte protein, MAL, was among the most highly expressed genes in serous ovarian cancers from short-term survivors (<3 years) relative to those of long-term survivors (>7 years). In the present study, we have found that this difference in expression is partially attributable to differences in DNA methylation at a specific region within the MAL promoter CpG island. While MAL was largely unmethylated at the transcription start site (Region 1; -48 to +73 bp) in primary serous ovarian cancers, methylation of an upstream region (Region 2; -452 to -266 bp) was inversely correlated with MAL transcription in the primary cancers (R = -0.463) and ovarian cancer cell lines (R = -0.444). Following treatment of the OVCA432 cell line with 5-azacytidine, methylation of Region 2 decreased from 73.3% to 34.7% (p = 0.007) while Region 1 was unaffected. This was accompanied by a 10-fold increase in MAL expression. Since MAL transcripts are elevated in tumors from short-term survivors, all of whom were treated with platinum-based therapy, MAL may have a role in cisplatin response. We therefore determined the 50% growth inhibitory dose of cisplatin in 30 ovarian cancer cell lines and compared this to MAL expression. MAL transcript levels were higher in the resistant ovarian cell lines (p = 0.04). MAL methylation status may therefore serve as a marker of platinum sensitivity while MAL protein may be a target for development of novel therapies aimed at enhancing sensitivity to platinum-based drugs in ovarian cancer.

Targeting slow-proliferating ovarian cancer cells.

Advanced ovarian cancer has a high rate of recurrence and mortality despite relative chemosensitivity at the time of initial treatment. Conventional chemotherapeutic agents typically target rapidly dividing cells. Disease relapse may therefore result from the survival and later emergence of latent slow-proliferating and/or quiescent cancer cells. We sought to identify drugs that target this cell population and to investigate the influence of these cells on outcome of patients in remission from advanced ovarian cancer. Drugs with increased efficacy against slower proliferating cells were identified using correlation-based screening of 44,657 compounds tested on the NCI-60 panel of cancer cell lines. Validation of candidates was performed in comparison with Cisplatin or Paclitaxel and by manipulation of proliferation rates by serum deprivation. Cytostatic and cytocidal effects were evaluated using MTT assays and active caspase-3 immunocytochemistry. Ki-67 proliferation indices were determined for tumors from 104 patients in remission. UCN-01 efficacy was correlated with longer doubling time among the NCI-60 cell lines (R = 0.54, p < 0.0001) and in a panel of 24 ovarian cancer cell lines (R = 0.42, p = 0.04), whereas this was not the case for Cisplatin (R = -0.10, p = 0.65) and Paclitaxel efficacy correlated with shorter doubling time (R = -0.52, p = 0.009). Cytostatic and cytocidal effects of UCN-01 were increased in serum-deprived cells. A low proliferation index was associated with presence of persistent disease at second-look surgery (p = 0.01) and poor survival (disease-free survival, p = 0.002; overall survival, p = 0.04). These results suggest that targeting quiescent ovarian cancer cells may be a worthwhile therapeutic approach to improving survival of women with ovarian cancer.

Yin yang 1 modulates taxane response in epithelial ovarian cancer.

Survival of ovarian cancer patients is largely dictated by their response to chemotherapy, which depends on underlying molecular features of the malignancy. We previously identified YIN YANG 1 (YY1) as a gene whose expression is positively correlated with ovarian cancer survival. Herein, we investigated the mechanistic basis of this association. Epigenetic and genetic characteristics of YY1 in serous epithelial ovarian cancer were analyzed along with YY1 mRNA and protein. Patterns of gene expression in primary serous epithelial ovarian cancer and in the NCI60 database were investigated using computational methods. YY1 function and modulation of chemotherapeutic response in vitro was studied using small interfering RNA knockdown. Microarray analysis showed strong positive correlation between expression of YY1 and genes with YY1 and transcription factor E2F binding motifs in ovarian cancer and in the NCI60 cancer cell lines. Clustering of microarray data for these genes revealed that high YY1/E2F3 activity positively correlates with survival of patients treated with the microtubule-stabilizing drug paclitaxel. Increased sensitivity to taxanes, but not to DNA cross-linking platinum agents, was also characteristic of NCI60 cancer cell lines with a high YY1/E2F signature. YY1 knockdown in ovarian cancer cell lines results in inhibition of anchorage-independent growth, motility, and proliferation but also increases resistance to taxanes, with no effect on cisplatin sensitivity. These results, together with the prior demonstration of augmentation of microtubule-related genes by E2F3, suggest that enhanced taxane sensitivity in tumors with high YY1/E2F activity may be mediated by modulation of putative target genes with microtubule function.