Endocervical-type mucinous adenocarcinoma (ECA) of the uterine cervix is defined as a tumor composed of cells resembling those of the endocervical glands, but recent studies have demonstrated that a minority of ECAs displays a gastric immunophenotype. The aim of this study was to assess the significance of the gastric phenotype. Fifty-three cases of mucinous adenocarcinoma of the uterine cervix (37 FIGO stage IB, 4 stage IIA, and 12 stage IIB) were reviewed and reevaluated using a newly established morphologic criteria for distinguishing gastric type adenocarcinoma, which was defined as a tumor showing clear and/or pale eosinophilic and voluminous cytoplasm, with distinct cell borders. The results were correlated with gastric immunophenotype, determined by HIK1083 and MUC6 immunostaining, and patient outcome. Following the current World Health Organization scheme (2003), 47 tumors (89%) were classified as ECA, 1 (2%) as intestinal type, 1 (2%) as mixed endocervical and intestinal type, and 4 (8%) as minimal deviation adenocarcinoma. Twelve of 47 (26%) ECAs and all 4 minimal deviation adenocarcinomas, reclassified as gastric type using the novel criteria, were frequently positive for HIK1083 with a rate of 75% (12/16), whereas only 11% (4/37) of nongastric tumors were positive. There was no significant difference in MUC6 reactivity between gastric and nongastric type tumors (31%, 5/16 vs. 16%, 6/37; P=0.4). Patients with gastric-type adenocarcinomas had a significantly decreased 5-year disease-specific survival rate (30 vs. 77%; P<0.0001), and the gastric type morphology was related to a significant risk for disease recurrence compared with the nongastric type (P=0.001; HR, 4.5; 95% confidence interval, 1.42-14.2). HIK1083-positivity was also related to decreased 5-year disease-specific survival rate (38% vs. 74%; P<0.005). Mucinous adenocarcinoma of the uterine cervix with gastric immunophenotype can be a distinct morphologic variant showing an aggressive clinical course.

Paclitaxel stabilizes microtubules, causing mitotic arrest and activating the spindle assembly checkpoint. We determined whether suppression of the checkpoint genes Mad2 and BubR1 affects paclitaxel resistance and whether overexpression of Mad2 protein in checkpoint-defective cells enhances paclitaxel sensitivity. Suppression of Mad2 and BubR1 in paclitaxel-treated cancer cells abolished checkpoint function, resulting in paclitaxel resistance that correlated with suppression of cyclin-dependent kinase-1 activity. In contrast, overexpression of Mad2 in cells with a checkpoint defect attributable to low Mad2 expression restored checkpoint function, resulting in enhanced paclitaxel sensitivity that correlated with enhanced cyclin-dependent kinase-1 activity. However, overexpression of Mad2 failed to enhance paclitaxel sensitivity via checkpoint activation in Mad2-independent checkpoint-defective and -intact cells. Thus, checkpoint function is required for paclitaxel sensitivity. These findings show that any molecules that could interfere with the spindle assembly checkpoint could generate paclitaxel resistance in any patient.

Purpose: High-grade serous ovarian cancers are heterogeneous not only in terms of clinical outcome but also at the molecular level. Our aim was to establish a novel risk classification system based on a gene expression signature for predicting overall survival, leading to suggesting novel therapeutic strategies for high-risk patients.Experimental Design: In this large-scale cross-platform study of six microarray data sets consisting of 1,054 ovarian cancer patients, we developed a gene expression signature for predicting overall survival by applying elastic net and 10-fold cross-validation to a Japanese data set A (n ¼ 260) and evaluated the signature in five other data sets. Subsequently, we investigated differences in the biological characteristics between high-and low-risk ovarian cancer groups.Results: An elastic net analysis identified a 126-gene expression signature for predicting overall survival in patients with ovarian cancer using the Japanese data set A (multivariate analysis, P ¼ 4 Â 10 À20 ). We validated its predictive ability with five other data sets using multivariate analysis (Tothill's data set, P ¼ 1 Â 10 À5 ; Bonome's data set, P ¼ 0.0033; Dressman's data set, P ¼ 0.0016; TCGA data set, P ¼ 0.0027; Japanese data set B, P ¼ 0.021). Through gene ontology and pathway analyses, we identified a significant reduction in expression of immune-response-related genes, especially on the antigen presentation pathway, in high-risk ovarian cancer patients.Conclusions: This risk classification based on the 126-gene expression signature is an accurate predictor of clinical outcome in patients with advanced stage high-grade serous ovarian cancer and has the potential to develop new therapeutic strategies for high-grade serous ovarian cancer patients.

Anaphase‐promoting complex (APC) is activated by two regulatory proteins, Cdc20 and Cdh1. In yeast and Drosophila, Cdh1‐dependent APC (Cdh1–APC) activity targets mitotic cyclins from the end of mitosis to the G1 phase. To investigate the function of Cdh1 in vertebrate cells, we generated clones of chicken DT40 cells disrupted in their Cdh1 loci. Cdh1 was dispensable for viability and cell cycle progression. However, similarly to yeast and Drosophila, loss of Cdh1 induced unscheduled accumulation of mitotic cyclins in G1, resulting in abrogation of G1 arrest caused by treatment with rapamycin, an inducer of p27Kip1. Further more, we found that Cdh1−/− cells fail to maintain DNA damage‐induced G2 arrest and that Cdh1–APC is activated by X‐irradiation‐induced DNA damage. Thus, activation of Cdh1–APC plays a crucial role in both cdk inhibitor‐dependent G1 arrest and DNA damage‐induced G2 arrest.

Although the majority of smooth muscle neoplasms found in the uterus are benign, uterine leiomyosarcoma (LMS) is extremely malignant, with high rates of recurrence and metastasis. We earlier reported that mice with a homozygous deficiency for LMP2, an interferon (IFN)-γ-inducible factor, spontaneously develop uterine LMS. The IFN-γ pathway is important for control of tumor growth and invasion and has been implicated in several cancers. In this study, experiments with human and mouse uterine tissues revealed a defective LMP2 expression in human uterine LMS that was traced to the IFN-γ pathway and the specific effect of JAK-1 somatic mutations on the LMP2 transcriptional activation. Furthermore, analysis of a human uterine LMS cell line clarified the biological significance of LMP2 in malignant myometrium transformation and cell cycle, thus implicating LMP2 as an anti-tumorigenic candidate. This role of LMP2 as a tumor suppressor may lead to new therapeutic targets in human uterine LMS.

A subset of endocervical-type mucinous adenocarcinomas (ACs) of the uterine cervix exhibit a gastric phenotype and morphology, as reported in cases of minimal deviation AC in which the presence of human papillomavirus (HPV) has been rarely detected. To investigate the HPV-independent pathway of carcinogenesis in cases of gastric-type AC, we investigated the common high-risk HPV (hr-HPV) status in 52 nonsquamous cell carcinomas , using a PCRbased typing method and immunohistochemistry of p16INK4a (a cyclin-dependent kinase inhibitor that is overexpressed in both cancerous and precancerous cervical tissue, making it an ideal biomarker for cervical cancer cases). Using novel morphological criteria, seven of 52 (13.5%) carcinomas were designated as gastric-type ACs, all of which were negative for both hr-HPV DNA and p16INK4a . Nongastric-type ACs were frequently positive for both hr-HPV DNA (90%, 28/31) and p16INK4a (94%, 29/31) with adenosquamous and neuroendocrine carcinomas demonstrating the presence of hr-HPV DNA in 86% (6/7) and 83% (5/6) of cases , respectively. In these two types of carcinoma , 86% (6/7) and 100% (6/6) were positive for p16 INK4a , respectively. Our data suggests that gastric-type AC appears to represent an oncogenic hr-HPV-independent neoplasm and therefore is a potential pitfall of HPV DNA testing and vaccination.

IntroductionPaclitaxel is used widely in the treatment of breast cancer. Not all tumors respond to this drug, however, and the characteristics that distinguish resistant tumors from sensitive tumors are not well defined. Activation of the spindle assembly checkpoint is required for paclitaxel-induced cell death. We hypothesized that cyclin-dependent kinase (CDK) 1 activity and CDK2 activity in cancer cells, which reflect the activation state of the spindle assembly checkpoint and the growth state, respectively, predict sensitivity to paclitaxel.MethodsCell viability assays and DNA and chromatin morphology analyses were performed in human breast cancer cell lines to evaluate sensitivity to paclitaxel and the cell cycle response to paclitaxel. We then examined the specific activities of CDK1 and CDK2 in these cell lines and in xenograft models of human breast cancer before and after paclitaxel treatment. Protein expression and kinase activity of CDKs and cyclins were analyzed using a newly developed assay system.ResultsIn the cell lines, biological response to paclitaxel in vitro did not accurately predict sensitivity to paclitaxel in vivo. Among the breast cancer xenograft tumors, however, tumors with significantly increased CDK1 specific activity after paclitaxel treatment were sensitive to paclitaxel in vivo, whereas tumors without such an increase were resistant to paclitaxel in vivo. Baseline CDK2 specific activity was higher in tumors that were sensitive to paclitaxel than in tumors that were resistant to paclitaxel.ConclusionsThe change in CDK1 specific activity of xenograft tumors after paclitaxel treatment and the CDK2 specific activity before paclitaxel treatment are both associated with the drug sensitivity in vivo. Analysis of cyclin-dependent kinase activity in the clinical setting could be a powerful approach for predicting paclitaxel sensitivity.

Inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinases, such as erlotinib and gefitinib, have not been very effective in the treatment of breast cancer although many breast cancer cells express EGFR. To address this apparent paradox, we examined possible predictors of the sensitivity of 10 breast cancer cell lines to erlotinib in light of cyclin-dependent kinase 2 (CDK2), considered the farthest downstream kinase that controls cell cycling in the EGFR signaling pathway. Expression of EGFR and HER2 were not associated with sensitivity to erlotinib. Expression of phosphorylated (p-)tyrosine, p-Akt, phosphorylated extracellular signal-regulated kinase (p-ERK) 1/ERK2 (p42/p44), and p27 after treatment of erlotinib was not associated with erlotinib sensitivity. However, suppression of CDK2 activity after erlotinib treatment correlated with erlotinib sensitivity (P < 0.0001). Restoration of CDK2 activity partially restored proliferation and induced erlotinib resistance in erlotinibsensitive cell lines, indicating that sensitivity to erlotinib in these breast cancer cells depends, at least in part, on CDK2 activity. p27, an inhibitor of CDK2, was not translocated into the nucleus in erlotinib-resistant cell lines. Knocking down p27 protein partially blocked erlotinib-induced cell death and cell cycle arrest. These findings indicate that the ability of erlotinib to suppress CDK2 activity is critical for cellular sensitivity to erlotinib, regardless of EGFR expression level, and that the presence of p27 in the cytoplasm also participates in erlotinib resistance.