ZNF671 DNA methylation as a molecular predictor for the early recurrence of serous ovarian cancer.

Serous ovarian cancer is the most frequent type of epithelial ovarian cancer. Despite the use of surgery and platinum-based chemotherapy, many patients suffer from recurrence within 6 months, termed platinum resistance. Currently, the lack of relevant molecular biomarkers for the prediction of the early recurrence of serous ovarian cancers is linked to the poor prognosis. To identify an effective biomarker for early recurrence, we analyzed the genome-wide DNA methylation status characteristic of early recurrence after treatment. The patients in The Cancer Genome Atlas (TCGA) dataset who showed a complete response after the first therapy were categorized into 2 groups: early recurrence serous ovarian cancer (ERS, recurrence ≤12 months, n = 51) and late recurrence serous ovarian cancer (LRS, recurrence >12 months, n = 158). Among the 12 differently methylated probes identified between the 2 groups, we found that ZNF671 was the most significantly methylated gene in the early recurrence group. A validation cohort of 78 serous ovarian cancers showed that patients with ZNF671 DNA methylation had a worse prognosis (P < .05). The multivariate analysis revealed that the methylation status of ZNF671 was an independent factor for predicting the recurrence of serous ovarian cancer patients both in the TCGA dataset and our cohort (P = .049 and P = .021, respectively). Functional analysis revealed that the depletion of ZNF671 expression conferred a more migratory and invasive phenotype to the ovarian cancer cells. Our data indicate that ZNF671 functions as a tumor suppressor in ovarian cancer and that the DNA methylation status of ZNF671 might be an effective biomarker for the recurrence of serous ovarian cancer after platinum-based adjuvant chemotherapy.

Characteristic DNA methylation profiles of chorionic villi in recurrent miscarriage.

Dysregulation of transcriptional programs that are tightly regulated by DNA methylation during placental and fetal development at different gestational stages, may cause recurrent miscarriage. Here, we examined genome-wide DNA methylation in chorionic villi and decidual tissues from patients suffering RM and from healthy women who had undergone artificial abortion (n = 5 each). We found that 13,426 and 5816 CpG sites were differentially methylated in chorionic villi and decidua, respectively. DNA methylation profiles of chorionic villi, but not decidua, in RM patients was clearly distinct from AA controls. Among the differentially methylated genes, the enhancer region of SPATS2L was significantly more highly methylated in RM patients (n = 19) than AA controls (n = 19; mean methylation level, 52.0%-vs.-28.9%, P < 0.001), resulting in reduced expression of SPATS2L protein in the former. Functionally, depletion of SPATS2L in extravillous trophoblast cells decreased their invasion and migration abilities. Our data indicate that particularly the chorionic villi in RM patients exhibit distinct DNA methylation profiles compared with normal pregnancies and that this changed DNA methylation status may impede the progression of embryo development via the altered expression of genes such as SPATS2L in the villi.

Abnormal accumulation of OFD1 in endometrial cancer with poor prognosis inhibits ciliogenesis.

The aim of the present study was to examine primary cilia in endometrial tissue during the menstrual cycle and to clarify their morphological changes with different grades of endometrial cancer. Images of fluorescence immunostaining taken by confocal microscopy were used to count the number of primary cilia in normal endometrium and endometrioid carcinoma Grade 1 and Grade 3 specimens. To examine the association between autophagy and ciliogenesis in endometrioid carcinoma, the expression of p62/Sequestosome-1, a selective substrate for autophagy, and oral-facial-digital syndrome 1 protein (OFD1), a protein associated with ciliogenesis, were examined using images of fluorescence immunostaining taken by confocal microscopy. The level of p62 expression was confirmed by western blotting. In proliferative and secretory endometrial stromal cells, the percentage of cells that were ciliated was 7.2 and 32.7% (95% confidence interval=21.61-39.79; P<0.01), and the length of the primary cilia was 1.24 µm and 2.34 µm (0.92-1.26; P<0.01), respectively. In stromal cells of endometrioid carcinoma Grade 1 and Grade 3, the percentage of ciliated cells was 13.5 and 2.9% (7.89-15.05; P<0.001), and the length of the primary cilia was 2.02 and 1.14 µm (0.76-0.99; P<0.001), respectively. In both normal menstrual cycle tissue and endometrial carcinomas, the percentage of primary cilia was lower and their length was shorter in tissues with higher proliferative potential. The expression of OFD1 was significantly higher in Grade 3 compared with Grade 1 as indicated by quantifying the intensity of the fluorescence images (133-12248; P=0.046). To the best of our knowledge, this is the first study concerning the distribution of primary cilia in normal endometrium and endometrial cancer tissues. Overall, fewer ciliated cells in the highly malignant endometrial cancer tissues may be associated not only to the proliferation of cancer cells, but also to the excessive accumulation of OFD1 due to dysfunctional autophagy.

Autocrine HGF/c-Met signaling pathway confers aggressiveness in lymph node adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive T-cell neoplasm. While ATL cells in peripheral blood (PB-ATL) are sensitive to anti-CC chemokine receptor 4 treatment, non-PB-ATLs, including lymph node ATLs (LN-ATLs), are more aggressive and resistant. We examined characteristic cytokines and growth factors that allow non-PB-ATLs to proliferate and invade compared with PB-ATLs. Protein array analysis revealed hepatocyte growth factor (HGF) and C-C motif chemokine 2 (CCL2) were significantly upregulated in non-PB-ATLs compared with PB-ATLs. The HGF membrane receptor, c-Met, was expressed in PB-ATL and non-PB-ATL cell lines, but CCR2, a CCL2 receptor, was not. Immunohistochemical analysis in clinical ATLs revealed high HGF expression in LNs, pharynx, bone marrow, and tonsils. The HGF/c-Met signaling pathway was active downstream in non-PB-ATLs. Downregulation of HGF/c-Met by siRNA or chemical inhibitors decreased in vitro and in vivo proliferation and invasion by non-PB-ATLs. Treatment with bromodomain and extra-terminal motif inhibitor suppressed HGF expression and decreased levels of histone H3 lysine 27 acetylation (H3K27Ac) and bromodomain-containing protein 4 (BRD4) binding promoter and enhancer regions, suppressing non-PB-ATL cellular growth. Our data indicate H3K27Ac/BRD4 epigenetics regulates the HGF/c-MET pathway in ATLs; targeting this pathway may improve treatment of aggressive non-PB-ATLs.

Expression of P-REX2a is associated with poor prognosis in endometrial malignancies.

P-REX2a is a PTEN inhibitor that also activates Rac 1. No associations with P-REX2a and human endometrial cancers have been reported to date. In this study, we immunohistochemically analyzed 155 uterine endometrial malignancies for P-REX2a expression. The P-REX2a-positive tumors displayed worse prognosis independent of PTEN expression. Then, we transduced either P-REX2a expression vector or short hairpin RNAs targeting P-REX2a into 2 uterine endometrioid carcinoma cell lines, OMC-2 and JHUEM-14. Ectopic expression of P-REX2a led to increased cell proliferation only in the PTEN-expressing OMC-2 cells but did not show any change in the PTEN-negative JHUEM-14 cells or the P-REX2a-knockdown cells. Induction of P-REX2a increased and knockdown of P-REX2a decreased cell migration in both cell lines. Then, we performed expression microarray analysis using these cells, and pathway analysis revealed that the expression of members of the GPCR downstream pathway displayed the most significant changes induced by the knockdown of P-REX2a. Immunohistochemical analysis revealed that Vav1, a member of the GPCR downstream pathway, was expressed in 139 of the 155 endometrial tumors, and the expression levels of Vav1 and P-REX2a showed a positive correlation (r = 0.44, p < 0.001). In conclusion, P-REX2a enhanced cell motility via the GPCR downstream pathway independently of PTEN leading to progression of uterine endometrioid malignancies and poor prognosis of the patients.