PTEN loss and HOXA10 expression are associated with ovarian endometrioid adenocarcinoma differentiation and progression

Apolipoprotein B100 acts as a tumor suppressor in ovarian cancer via lipid/ER stress axis-induced blockade of autophagy

Ovarian cancer presents a significant treatment challenge due to its insidious nature and high malignancy. As autophagy is a vital cellular process for maintaining homeostasis, targeting the autophagic pathway has emerged as an avenue for cancer therapy. In the present study, we identify apolipoprotein B100 (ApoB100), a key modulator of lipid metabolism, as a potential prognostic biomarker of ovarian cancer. ApoB100 functioned as a tumor suppressor in ovarian cancer, and the knockdown of ApoB100 promoted ovarian cancer progression in vivo. Moreover, ApoB100 blocked autophagic flux, which was dependent on interfering with the lipid accumulation/endoplasmic reticulum (ER) stress axis. The effects of LFG-500, a novel synthetic flavonoid, on ApoB100 induction were confirmed using proteomics and lipidomics analyses. Herein, LFG-500 induced lipid accumulation and ER stress and subsequently blocked autophagy by upregulating ApoB100. Moreover, data from in vivo experiments further demonstrated that ApoB100, as well as the induction of the lipid/ER stress axis and subsequent blockade of autophagy, were responsible for the anti-tumor effects of LFG-500 on ovarian cancer. Hence, our findings support that ApoB100 is a feasible target of ovarian cancer associated with lipid-regulated autophagy and provide evidence for using LFG-500 for ovarian cancer treatment.

Integrated Bioinformatic Analysis of the Correlation of HOXA10 Expression with Survival and Immune Cell Infiltration in Lower Grade Glioma

Homeobox A10 (HOXA10) encodes a transcription factor that regulates developmental processes. Whether HOXA10 mRNA levels in lower grade glioma (LGG) correlate with survival and immune cell infiltration has not been evaluated. The differential expression of HOXA10 in different tumors and their corresponding normal tissues was evaluated by exploring public datasets. The correlations between HOXA10 and survival, tumor immune cell infiltration, diverse gene mutation characteristics, and tumor mutation burden in LGG were also investigated using several independent datasets. Pathway enrichment analysis was conducted to identify HOXA10-associated signaling pathways. We found that HOXA10 expression levels did not significantly differ between LGG tumors and normal tissues. Upon assessing the association between HOXA10 expression and immune cell infiltration in LGG, as expected, HOXA10 gene mRNA levels were positively associated with B-cell and dendritic cell infiltration levels in public online datasets. Different HOXA10 expression groups showed diverse gene mutation characteristics and TMB, and low HOXA10 expression was closely related to improved LGG patient survival. Pathway enrichment analysis of HOXA10-associated genes indicated that the cell cycle signaling pathway may participate in affecting the outcomes of LGG patients. Our findings showed that HOXA10 expression was associated with LGG prognosis and tumor immunity.

Loss of HOXA10 causes endometrial hyperplasia progressing to endometrial cancer

Endometrial cancer is the fourth most common malignancy in women and the precursor lesion is endometrial hyperplasia. HOXA10 is a transcription factor that plays key roles in endometrial functions such as the endowment of receptivity, embryo implantation, and trophoblast invasion. Herein, using testicular transgenesis, we developed transgenic mice that expressed a shRNA against HOXA10 and there was a nearly 70% reduction in the expression of HOXA10 in these animals. We observed that downregulation of HOXA10 led to the development of endometrial hyperplasia in the young animals (3 months), and as they aged (>1 year), most animals developed well-differentiated endometrial adenocarcinoma. In the endometrium of animals with reduced HOXA10, there was increased proliferation and elevated levels of ERα and ERβ. In parallel, there was increased expression of Wnt4 and β-Catenin, SOX9, and YAP1. We propose that chronic reduction in HOXA10 expression disrupts multiple pathways in the uterus that aids in the development of endometrial hyperplasia which progresses to endometrial cancer with age.

HOXA10 promote pancreatic cancer progression via directly activating canonical NF-κB signaling pathway

BACKGROUND

Although transcription factor homeobox A10 (HOXA10) plays an important role in regulating the development of the pancreas, a pathway of HOXA10 participates in pancreatic ductal adenocarcinoma (PDAC) progression has not been revealed.

METHODS

Immunohistochemistry assays were applied to demonstrate the relationship between HOXA10 expression and PDAC progression. Functional assays were used to illustrate the oncogenic role of HOXA10 in PDAC progression. Regulatory mechanisms of HOXA10 induced IKKβ gene transcription and the nuclear transcription factor kappa B (NF-κB) signal pathways activation were also investigated in PDAC cells.

RESULTS

In the current study, we show that HOXA10 expression increased in PDAC with higher tumor stage and poor patient survival in public RNA-seq data suggesting HOXA10 is associated with PDAC progression. HOXA10 promotes PDAC cell proliferation, anchorage colony formation, and xenograft growth by activating canonical NF-κB signaling both in vitro and in vivo. Mechanically, HOXA10 up-regulates IKKβ gene transcription directly and subsequently sustain the activation of NF-κB independent of tumor necrosis factor-alpha in PDAC cells.

CONCLUSION

Collectively, up-regulation of HOXA10 gene expression promote cell growth and tumor progression through directly activating canonical NF-κB signaling in PDAC.

Crosstalk between miRNA and PI3K/AKT/mTOR signaling pathway in cancer

Phosphoinositide-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important proliferative signaling pathways with critical undeniable function in various aspects of cancer initiation/progression, including proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. On the other hand, numerous genetic alterations in the key genes involved in the PI3K/AKT/mTOR signaling pathway have been identified in multiple solid and hematological tumors. In addition, accumulating recent evidences have demonstrated a reciprocal interaction between this signaling pathway and microRNAs, a large group of small non-coding RNAs. Therefore, in this review, it was attempted to discuss about the interaction between key components of PI3K/AKT/mTOR signaling pathway with various miRNAs and their importance in cancer biology.

HOXA10 inhibit the osteogenic differentiation of periodontal ligament stem cells by regulating β-catenin localization and DKK1 expression

Introduction: Human periodontal ligament stem cells (hPDLSCs) are stem cells found near the tooth periodontal ligament. These cels are involved in the regeneration of the periodontal ligament and alveolar bone during orthodontic treatment and chronic periodontitis.Objectives: The Homeobox gene HOXA10 regulates the osteogenic differentiation of stem cells. However, the role of HOXA10 in hPDLSCs remains unclear. Therefore, we studied the effects of HOXA10 on human PDLSC osteogenic differentiation in vitro.Methods: First, hPDLSCs were isolated and characterized. Second, we assessed the effects of overexpression and knockdown of HOXA10 on PDLSC osteogenic differentiation. Finally, the specific Wnt signaling pathway activator lithium chloride (LiCl) and inhibitor ICG-001 were used to investigate the involvement of the Wnt signaling pathway in HOXA10-induced regulation of osteogenic differentiation.Results: Overexpressing HOXA10 inhibited PDLSC osteogenic differentiation in vitro, shown by ALP and Alizarin Red staining, while HOXA10 knockdown demonstrated the opposite effects. HOXA10 negatively regulated nuclear β-catenin and osteogenic differentiation markers including alkaline phosphatase (ALPL) and integrin-binding sialoprotein (IBSP). Upregulating HOXA10 reduced nuclear β-catenin and increased DKK1 expression. However, HOXA10 knockdown enhanced nuclear β-catenin accumulation and reduced DKK1 expression. These negative effects on osteogenic differentiation by HOXA10 overexpression were restored by the Wnt/β-catenin pathway activator LiCl. The increased osteogenic differentiation effects of HOXA10 knockdown were antagonized by ICG-001, a Wnt pathway inhibitor.Conclusion: These data demonstrate that HOXA10 inhibits the osteogenic differentiation of periodontal ligament stem cells by regulating β-catenin localization and DKK1.

Non-target genetic manipulation induces rhabdomyosarcoma in KrasPten-driven mouse model of ovarian cancer

Background

Genetically engineered mice are ideal models to advance our understanding the tumorigenesis of ovarian cancer. Our original objective was to establish an ovarian cancer model induced by Kras activation and Pten deletion. However, proficiently establishing the model remains a technical problem, which limits its application.

Methods

We established the Kras activation/Pten deletion-induced mouse model of ovarian cancer by injecting Cre recombinase-expressing adenovirus in the ovarian bursa. PCR analysis, Western blotting, and immunohistochemistry staining were performed to verify the alteration of conditional genes. We detected expression of canonical molecular markers in order to examine the origin of the tumors.

Results

Subcutaneous lumps developed accidentally in mice with ovarian cancer, as early as 2 weeks post in vivo genetic manipulation, far before the destructive growth of ovarian cancer. PCR analysis confirmed the efficient Cre-mediated recombination of Kras and Pten in tumor tissues, which are consistent with the activation of the MAPK and PI3K/Akt/mTOR pathways. Histomorphological and histological analysis showed that the lumps were actually rhabdomyosarcoma (RMS). We confirmed that the leakage of adenovirus transformed healthy adjacent tissues into RMS.

Conclusions

Avoiding accidental exposure of non-target tissues to adenovirus is crucial to successfully establish the ovarian cancer mouse model. Moreover, non-specific genetic manipulations can induce the development of RMS.

Transcription factors in epithelial ovarian cancer: histotype-specific drivers and novel therapeutic targets

Transcription factors (TFs) are major contributors to cancer risk and somatic development. In preclinical and clinical studies, direct or indirect inhibition of TF-mediated oncogenic gene expression profiles have proven to be effective in many tumor types, highlighting this group of proteins as valuable therapeutic targets. In spite of this, our understanding of TFs in epithelial ovarian cancer (EOC) is relatively limited. EOC is a heterogeneous disease composed of five major histologic subtypes; high-grade serous, low-grade serous, endometrioid, clear cell and mucinous. Each histology is associated with unique clinical etiologies, sensitivity to therapies, and molecular signatures - including diverse transcriptional regulatory programs. While some TFs are shared across EOC subtypes, a set of TFs are expressed in a histotype-specific manner and likely explain part of the histologic diversity of EOC subtypes. Targeting TFs present with unique opportunities for development of novel precision medicine strategies for ovarian cancer. This article reviews the critical TFs in EOC subtypes and highlights the potential of exploiting TFs as biomarkers and therapeutic targets.

APC2 is critical for ovarian WNT signalling control, fertility and tumour suppression

BACKGROUND

Canonical WNT signalling plays a critical role in the regulation of ovarian development; mis-regulation of this key pathway in the adult ovary is associated with subfertility and tumourigenesis. The roles of Adenomatous polyposis coli 2 (APC2), a little-studied WNT signalling pathway regulator, in ovarian homeostasis, fertility and tumourigenesis have not previously been explored. Here, we demonstrate essential roles of APC2 in regulating ovarian WNT signalling and ovarian homeostasis.

METHODS

A detailed analysis of ovarian histology, gene expression, ovulation and hormone levels was carried out in 10 week old and in aged constitutive APC2-knockout (Apc2-/-) mice (mixed background). Statistical significance for qRT-PCR data was determined from 95% confidence intervals. Significance testing was performed using 2-tailed Student's t-test, when 2 experimental cohorts were compared. When more were compared, ANOVA test was used, followed by a post-hoc test (LSD or Games-Howell). P-values of < 0.05 were considered statistically significant.

RESULTS

APC2-deficiency resulted in activation of ovarian WNT signalling and sub-fertility driven by intra-ovarian defects. Follicular growth was perturbed, resulting in a reduced rate of ovulation and corpora lutea formation, which could not be rescued by administration of gonadotrophins. Defects in steroidogenesis and follicular vascularity contributed to the subfertility phenotype. Tumour incidence was assessed in aged APC2-deficient mice, which also carried a hypomorphic Apc allele. APC2-deficiency in these mice resulted in predisposition to granulosa cell tumour (GCT) formation, accompanied by acute tumour-associated WNT-signalling activation and a histologic pattern and molecular signature seen in human adult GCTs.

CONCLUSIONS

Our work adds APC2 to the growing list of WNT-signalling members that regulate ovarian homeostasis, fertility and suppress GCT formation. Importantly, given that the APC2-deficient mouse develops tumours that recapitulate the molecular signature and histological features of human adult GCTs, this mouse has excellent potential as a pre-clinical model to study ovarian subfertility and transitioning to GCT, tumour biology and for therapeutic testing.

The Role of HOX Transcription Factors in Cancer Predisposition and Progression

Homeobox (HOX) transcription factors, encoded by a subset of homeodomain superfamily genes, play pivotal roles in many aspects of cellular physiology, embryonic development, and tissue homeostasis. Findings over the past decade have revealed that mutations in HOX genes can lead to increased cancer predisposition, and HOX genes might mediate the effect of many other cancer susceptibility factors by recognizing or executing altered genetic information. Remarkably, several lines of evidence highlight the interplays between HOX transcription factors and cancer risk loci discovered by genome-wide association studies, thereby gaining molecular and biological insight into cancer etiology. In addition, deregulated HOX gene expression impacts various aspects of cancer progression, including tumor angiogenesis, cell autophagy, proliferation, apoptosis, tumor cell migration, and metabolism. In this review, we will discuss the fundamental roles of HOX genes in cancer susceptibility and progression, highlighting multiple molecular mechanisms of HOX involved gene misregulation, as well as their potential implications in clinical practice.

HOXA10 expression profiling in prostate cancer

BACKGROUND

HOX genes encode transcription factors that play key roles in modulating normal tissue morphogenesis, differentiation and homeostasis. Disruption of normal HOX gene expression occurs frequently in human cancers and is associated with both tumor promoting and suppressing activities. Among these is, HOXA10, a pleiotropic gene that is critical for normal prostate development. In this study we characterized HOXA10 expression in human and mouse PCa to gain insights into its clinical significance.

METHODS

A meta-analysis of HOXA10 mRNA expression was carried out across several publicly available data sets. Expression of HOXA10 protein expression was assessed by immunohistochemistry (IHC) using human radical prostatectomy (RP) cases. We correlated HOXA10 expression to clinicopathological features and investigated its relationship to biochemical recurrence (BCR) after RP by the Kaplan-Meier method. HOXA10 mRNA and IHC protein expression was also examined in a mouse model of Pten-null PCa.

RESULTS

A meta-analysis of HOXA10 gene expression indicated dysregulated expression of HOXA10 in human PCa. IHC profiling of HOXA10 revealed inverse correlations between HOXA10 expression and Gleason pattern, Gleason score, and pathological stage (P < 0.01). Patients with low expression profiles of HOXA10 were associated with a higher risk of BCR, (OR, 3.54; 95%CI, 1.21-16.14; P = 0.049) whereas patients with high HOXA10 expression experienced longer times to BCR (P = 0.045). However, HOXA10 was not an independent predictor of BCR (OR, 1.52; 95%CI, 0.42-5.54; P = 0.52). Evaluation of expression patterns of HOXA10 in mouse prostate tumors mimicked that of humans.

CONCLUSIONS

Our findings show that HOXA10 expression is inversely associated with tumor differentiation and high HOXA10 expression is associated with improved BCR-free survival. This study provides human and mouse evidence to suggest tumor suppressive roles for HOXA10 in the context of prostate cancer.

HoxA10 Facilitates SHP-1-Catalyzed Dephosphorylation of p38 MAPK/STAT3 To Repress Hepatitis B Virus Replication by a Feedback Regulatory Mechanism

Hepatitis B virus (HBV) infection is the leading cause of chronic hepatitis B (CHB), liver cirrhosis (LC), and hepatocellular carcinoma (HCC). This study reveals a distinct mechanism underlying the regulation of HBV replication. HBV activates homeobox A10 (HoxA10) in human hepatocytes, leukocytes, peripheral blood mononuclear cells (PBMCs), HepG2-NTCP cells, leukocytes isolated from CHB patients, and HBV-associated HCC tissues. HoxA10 in turn represses HBV replication in human hepatocytes, HepG2-NTCP cells, and BALB/c mice. Interestingly, we show that during early HBV infection, p38 mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) were activated to facilitate HBV replication; however, during late HBV infection, HoxA10 was induced to attenuate HBV replication. Detailed studies reveal that HoxA10 binds to p38 MAPK, recruits SH2-containing protein tyrosine phosphatase 1 (SHP-1) to facilitate SHP-1 in catalyzing dephosphorylation of p38 MAPK/STAT3, and thereby attenuates p38 MAPK/STAT3 activation and HBV replication. Furthermore, HoxA10 binds to the HBV enhancer element I (EnhI)/X promoter, competes with STAT3 for binding of the promoter, and thereby represses HBV transcription. Taken together, these results show that HoxA10 attenuates HBV replication through repressing the p38 MAPK/STAT3 pathway by two approaches: HoxA10 interacts with p38 MAPK and recruits SHP-1 to repress HBV replication, and HoxA10 binds to the EnhI/X promoter and competes with STAT3 to attenuate HBV transcription. Thus, the function of HoxA10 is similar to the action of interferon (IFN) in terms of inhibition of HBV infection; however, the mechanism of HoxA10-mediated repression of HBV replication is different from the mechanism underlying IFN-induced inhibition of HBV infection.IMPORTANCE Two billion people have been infected with HBV worldwide; about 240 million infected patients developed chronic hepatitis B (CHB), and 650,000 die each year from liver cirrhosis (LC) or hepatocellular carcinoma (HCC). This work elucidates a mechanism underlying the control of HBV replication. HBV infection activates HoxA10, a regulator of cell differentiation and cancer progression, in human cells and patients with CHB and HCC. HoxA10 subsequently inhibits HBV replication in human tissue culture cells and mice. Additionally, HoxA10 interacts with p38 MAPK to repress the activation of p38 MAPK and STAT3 and recruits and facilitates SHP-1 to catalyze the dephosphorylation of p38 MAPK and STAT3. Moreover, HoxA10 competes with STAT3 for binding of the HBV X promoter to repress HBV transcription. Thus, this work reveals a negative regulatory mechanism underlying the control of HBV replication and provides new insights into the development of potential agents to control HBV infection.

LncRNA MEG3 impacts proliferation, invasion, and migration of ovarian cancer cells through regulating PTEN

OBJECTIVE AND DESIGN

We investigated the expressions of lncRNA MEG3 and PTEN in ovarian cancer tissues and their effects on cell proliferation, cycle and apoptosis of ovarian cancer.

METHODS

Expression levels of MEG3 in ovarian cancer cell lines and normal ovarian cell lines were detected by qRT-PCR. Cell viability was detected by MTT assay. Cell apoptosis and cell cycle distribution were measured by flow cytometry. Cell invasion capability was tested by transwell assay. Cell migration capacity was tested by wound healing. The xenograft model was constructed to explore the effect of lncRNA MEG3 on ovarian cancer in vivo.

RESULT

Compared with normal ovarian cells, expression levels of MEG3 and PTEN were relatively lower in ovarian cancer cells. There was a positive correlation between the expression of PTEN and the expression of MEG3. Enhanced expression level of PTEN suppressed SKOV3 cell proliferation, increased cell apoptosis rate, and decreased cell invasion and migration.

CONCLUSION

LncRNA MEG3 and PTEN were down-regulated in ovarian cancer cells. LncRNA MEG3 regulated the downstream gene PTEN in ovarian cancer cells to prohibit cell proliferation, promote apoptosis and block cell cycle progression.

Upregulation of HOXA10 Protein Expression Predicts Poor Prognosis for Colorectal Cancer

AIMS

The homeobox (HOX) genes function as transcriptional factors that can promote tumorigenesis. However, the expression profile of HOXA10 and the role this protein plays in solid tumors are unclear. Here we examined HOXA10 protein expression in samples from colorectal cancer (CRC) patients to address the clinical significance of this protein.

MATERIALS AND METHODS

Seven independent investigations from the Oncomine database were retrieved. A total of 85 patients who underwent radical excision followed by 5-fluorouracil (5-FU)-based adjuvant chemotherapy were enrolled. Immunohistochemistry was performed on pairs of cancerous and normal tissues to detect the expression of both HOXA10, and the phosphatase and tensin homolog deleted on chromosome ten (PTEN). Lentivirus-mediated RNA interference was used to knock down HOXA10 expression in LoVo and HT-29 cell lines, then cells' proliferation, apoptosis, and tumor growth in vivo were detected.

RESULTS

Oncomine data showed that HOXA10 expression was significantly upregulated in CRC tissues compared with relevant normal controls. In our study, 58 cases (68.2%) showed positive HOXA10 protein expression in tumor tissue and negative expression in normal tissues. HOXA10 protein upregulation was consistent with PTEN downregulation. Although not related to clinicopathological parameters, a significant correlation was found between HOXA10 upregulation and a decreased 5-year disease-free survival (DFS). A Cox proportional hazards model further suggested that HOXA10 overexpression was an independent factor to predict DFS of CRC patients. Furthermore, HOXA10 knockdown significantly increased sensitivity to 5-FU chemotherapy in vitro and in vivo.

CONCLUSIONS

Significant HOXA10 overexpression in CRC may be a potential biomarker indicating poor prognosis and 5-FU resistance.

Dysregulation of mitotic machinery genes precedes genome instability during spontaneous pre-malignant transformation of mouse ovarian surface epithelial cells

Background

Based in epidemiological evidence, repetitive ovulation has been proposed to play a role in the origin of ovarian cancer by inducing an aberrant wound rupture-repair process of the ovarian surface epithelium (OSE). Accordingly, long term cultures of isolated OSE cells undergo in vitro spontaneous transformation thus developing tumorigenic capacity upon extensive subcultivation. In this work, C57BL/6 mouse OSE (MOSE) cells were cultured up to passage 28 and their RNA and DNA copy number profiles obtained at passages 2, 5, 7, 10, 14, 18, 23, 25 and 28 by means of DNA microarrays. Gene ontology, pathway and network analyses were focused in passages earlier than 20, which is a hallmark of malignancy in this model.

Results

At passage 14, 101 genes were up-regulated in absence of significant DNA copy number changes. Among these, the top-3 enriched functions (>30 fold, adj p < 0.05) comprised 7 genes coding for centralspindlin, chromosome passenger and minichromosome maintenance protein complexes. The genes Ccnb1 (Cyclin B1), Birc5 (Survivin), Nusap1 and Kif23 were the most recurrent in over a dozen GO terms related to the mitotic process. On the other hand, Pten plus the large non-coding RNAs Malat1 and Neat1 were among the 80 down-regulated genes with mRNA processing, nuclear bodies, ER-stress response and tumor suppression as relevant terms. Interestingly, the earliest discrete segmental aneuploidies arose by passage 18 in chromosomes 7, 10, 11, 13, 15, 17 and 19. By passage 23, when MOSE cells express the malignant phenotype, the dysregulated gene expression repertoire expanded, DNA imbalances enlarged in size and covered additional loci.

Conclusion

Prior to early aneuploidies, overexpression of genes coding for the mitotic apparatus in passage-14 pre-malignant MOSE cells indicate an increased proliferation rate suggestive of replicative stress. Concomitant down-regulation of nuclear bodies and RNA processing related genes suggests altered control of nuclear RNA maturation, features recently linked to impaired DNA damage response leading to genome instability. These results, combined with cytogenetic analysis by other authors in this model, suggest that transcriptional profile at passage 14 might induce cytokinesis failure by which tetraploid cells approach a near-tetraploid stage containing primary chromosome aberrations that initiate the tumorigenic drive.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3068-5) contains supplementary material, which is available to authorized users.

Expression and mechanism of action of miR-196a in epithelial ovarian cancer

OBJECTIVE

To explore the expression, biological function and possible mechanism of action of microRNA molecular-196a (miR-196a) in epithelial ovarian cancer.

METHODS

RT-PCR was used to detect the expression quantities of epithelial ovarian tissue, benign ovarian tissue, normal ovary epithelial tissue, ovarian cancer cell lines and miR-196a in normal ovarian epithelial cells to analyze the relationship between the expression of miR-196a and the clinical pathologic parameters of ovarian cancer. Among those cell lines, the cell line of which miR-196a expressed the most or least was selected and transfected the ovarian cancer cell line by using negative control plasma and miR-196a inhibitor. After transfection, RT-PCR was used to test the expression quantity of miR-196a, Transwell chamber method was applied to determine the migration and invasion abilities of ovarian carcinoma cells and Western blot was employed to detect the expression of HOXA10 protein.

RESULTS

The relative expression quantities of miR-196a in ovarian cancer tissue and benign ovarian tissue were significantly higher than that in normal ovarian epithelial tissue, and the expression quantity of miR-196a in ovarian cancer tissue was distinctively higher than that in benign ovarian tissue (P < 0.05). Among 78 cases of epithelial ovarian cancer, the expression quantities of miR-196a in patients with low differentiation were all significantly higher than those in patients with high differentiation (P < 0.05). The expression of miR-196a showed no significant relation with age, clinical stage and whether CA125 was positive or not in patients (P > 0.05). Compared with normal ovarian epithelial cell line IOSE80, the expression quantities of miR-196a of all ovarian cancer cell lines increased obviously and differences were statistically significant (P < 0.05). Among them, the expression of miR-196a of ovarian cancer cell line SKOV3 was the highest, while it decreased significantly (4.678 ± 0.785 vs. 2.131 ± 0.345, t = 2.938, P < 0.05) after the ovarian cancer cell line SKOV3 was transfected by miR-196a inhibitor. The results of Transwell chamber method showed that the migration and invasion abilities of ovarian cancer cells SKOV3 were declined significantly after the expression of miR-196a was down-regulated and the difference showed statistical significance (P < 0.05). The results of Western blot revealed that the relative expression of HOXA10 decreased distinctly after the expression of miR-196a was down-regulated and also the difference showed statistical significance (P < 0.05).

CONCLUSIONS

The miR-196a might serve as a cancer-promoting gene to promote the migration and invasion of epithelial ovarian cancer by downstream target gene HOXA10.

Germ cell specific overactivation of WNT/βcatenin signalling has no effect on folliculogenesis but causes fertility defects due to abnormal foetal development

All the major components of the WNT signalling pathway are expressed in female germ cells and embryos. However, their functional relevance in oocyte biology is currently unclear. We examined ovaries collected from TCFGFP mice, a well-known Wnt reporter mouse model, and found dynamic changes in the Wnt/βcatenin signalling activity during different stages of oocyte development and maturation. To understand the functional importance of Wnt signalling in oocytes, we developed a mouse model with the germ cell-specific constitutive activation of βcatenin using cre recombinase driven by the DEAD (Asp-Glu-Ala-Asp) box protein 4 (Ddx4) gene promoter. Histopathological and functional analysis of ovaries from these mutant mice (Ctnnb1^ex3cko) showed no defects in ovarian functions, oocytes, ovulation and early embryonic development. However, breeding of the Ctnnb1^ex3cko female mice with males of known fertility never resulted in birth of mutant pups. Examination of uteri from time pregnant mutant females revealed defects in ectoderm differentiation leading to abnormal foetal development and premature death. Collectively, our work has established the role of active WNT/βcatenin signalling in oocyte biology and foetal development, and provides novel insights into the possible mechanisms of complications in human pregnancy such as repeated spontaneous abortion, sudden intrauterine unexpected foetal death syndrome and stillbirth.

miR-93 promotes cell proliferation in gliomas through activation of PI3K/Akt signaling pathway

The PI3K/Akt signaling pathway is frequently activated in various human cancer types and plays essential roles in development and progression of cancers. Multiple regulators, such as phosphatase and tensin homolog (PTEN) and PH domain leucine rich repeat protein phosphatases (PHLPP), have also found to be involved in suppression of the PI3K/Akt signaling pathway. However, how suppressive effects mediated by these regulators are concomitantly disrupted in cancers, which display constitutively activated PI3K/Akt signaling, remains puzzling. In the present study, we reported that the expression of miR-93 was markedly upregulated in glioma cell lines and clinical glioma tissues. Statistical analysis revealed that miR-93 levels significantly correlated with clinicopathologic grade and overall survival in gliomas. Furthermore, we found that overexpressing miR-93 promoted, but inhibition of miR-93 reduced, glioma cell proliferation and cell-cycle progression. We demonstrated that miR-93 activated PI3K/Akt signaling through directly suppressing PTEN, PHLPP2 and FOXO3 expression via targeting their 3'UTRs. Therefore, our results suggest that miR-93 might play an important role in glioma progression and uncover a novel mechanism for constitutive PI3K/Akt activation in gliomas.

Integration and bioinformatics analysis of DNA-methylated genes associated with drug resistance in ovarian cancer

The main obstacle to the successful treatment of ovarian cancer is the development of drug resistance to combined chemotherapy. Among all the factors associated with drug resistance, DNA methylation apparently plays a critical role. In this study, we performed an integrative analysis of the 26 DNA-methylated genes associated with drug resistance in ovarian cancer, and the genes were further evaluated by comprehensive bioinformatics analysis including gene/protein interaction, biological process enrichment and annotation. The results from the protein interaction analyses revealed that at least 20 of these 26 methylated genes are present in the protein interaction network, indicating that they interact with each other, have a correlation in function, and may participate as a whole in the regulation of ovarian cancer drug resistance. There is a direct interaction between the phosphatase and tensin homolog (PTEN) gene and at least half of the other genes, indicating that PTEN may possess core regulatory functions among these genes. Biological process enrichment and annotation demonstrated that most of these methylated genes were significantly associated with apoptosis, which is possibly an essential way for these genes to be involved in the regulation of multidrug resistance in ovarian cancer. In addition, a comprehensive analysis of clinical factors revealed that the methylation level of genes that are associated with the regulation of drug resistance in ovarian cancer was significantly correlated with the prognosis of ovarian cancer. Overall, this study preliminarily explains the potential correlation between the genes with DNA methylation and drug resistance in ovarian cancer. This finding has significance for our understanding of the regulation of resistant ovarian cancer by methylated genes, the treatment of ovarian cancer, and improvement of the prognosis of ovarian cancer.

ARID1A gene mutation in ovarian and endometrial cancers (Review)

The AT-rich interacting domain-containing protein 1A gene (ARID1A) encodes ARID1A, a member of the SWI/SNF chromatin remodeling complex. Mutation of ARID1A induces changes in expression of multiple genes (CDKN1A, SMAD3, MLH1 and PIK3IP1) via chromatin remodeling dysfunction, contributes to carcinogenesis, and has been shown to cause transformation of cells in association with the PI3K/AKT pathway. Information on ARID1A has emerged from comprehensive genome-wide analyses with next-generation sequencers. ARID1A mutations have been found in various types of cancer and occur at high frequency in endometriosis-associated ovarian cancer, including clear cell adenocarcinoma and endometrioid adenocarcinoma, and also occur at endometrial cancer especially in endometrioid adenocarcinoma. It has also been suggested that ARID1A mutation occurs at the early stage of canceration from endometriosis to endometriosis-associated carcinoma in ovarian cancer and also from atypical endo-metrial hyperplasia to endometrioid adenocarcinoma in endometrial cancer. Therefore, development of a screening method that can detect mutations of ARID1A and activation of the PI3K/AKT pathway might enable early diagnosis of endometriosis-associated ovarian cancers and endometrial cancers. Important results may also emerge from a current clinical trial examining a multidrug regimen of temsirolimus, a small molecule inhibitor of the PI3K/AKT pathway, for treatment of advanced ovarian clear cell adenocarcinoma with ARID1A mutation and PI3K/AKT pathway activation. Also administration of sorafenib, a multikinase inhibitor, can inhibit cancer proliferation with PIK3CA mutation and resistance to mTOR inhibitors and GSK126, a molecular-targeted drug can inhibit proliferation of ARID1A-mutated ovarian clear cell adenocarcinoma cells by targeting and inhibiting EZH2. Further studies are needed to determine the mechanism of chromatin remodeling dysregulation initiated by ARID1A mutation, to develop methods for early diagnosis, to investigate new cancer therapy targeting ARID1A, and to examine the involvement of ARID1A mutations in development, survival and progression of cancer cells.

HOXA10 promotes cell invasion and MMP-3 expression via TGFβ2-mediated activation of the p38 MAPK pathway in pancreatic cancer cells

BACKGROUND

HOXA10 is closely related to tumor progression in many human cancers. However, the role of HOXA10 in pancreatic cancer remains unclear. The aim of this study was to determine the involvement of HOXA10 in pancreatic cancer cell invasion and migration.

METHODS

The effect of HOXA10 on the invasion and migration of pancreatic cancer cells was assessed by invasion and migration assays. The protein of transforming growth factor beta-2 (TGFβ2) was neutralized by TGFβ2 blocking antibody. The activation of p38 was inhibited by SB239063.

RESULTS

HOXA10 could promote the invasion and migration of pancreatic cancer cells. Knockdown of HOXA10 decreased the expressions of TGFβ2 and matrix metallopeptidase-3 (MMP-3) and suppressed the activation of p38. Conversely, overexpression of HOXA10 increased the levels of TGFβ2 and MMP-3. Further experiments identified that TGFβ2 contributed to the HOXA10-promoted invasion and migration and regulated MMP-3 expression and p38 activation. Additionally, inhibition of p38 suppressed cell invasion and MMP-3 expression in pancreatic cancer cells.

CONCLUSIONS

HOXA10 promotes cell invasion and MMP-3 expression of pancreatic cancer cells via TGFβ2-p38 MAPK pathway. Thus, HOXA10 could be a useful target for the treatment of pancreatic cancer.

Genetically engineered mouse models for epithelial ovarian cancer: are we there yet?

The development of preclinical spontaneous genetically engineered mouse models (GEMMs) requires an understanding of the genetic basis of the human disease. Such robust models have proven invaluable for increasing understanding of human malignancies as well as identifying new biomarkers and testing new therapies for these diseases. While GEMMs have been reported for ovarian cancer, the majority have proven disappointing overall in their recapitulation of paired genetic and histological features especially for serous ovarian epithelial cancer. This review describes GEMMs for ovarian cancer, in particular, high grade serous ovarian cancer and assesses these in light of recent changes in our understanding of the human malignancy.

Ribonucleotide reductase large subunit M1 predicts poor survival due to modulation of proliferative and invasive ability of gastric cancer

OBJECTIVES

We aimed to investigate the prognostic value of RRM1 in GC patients.

METHODS

A total of assessable 389 GC patients with clinicopathological and survival information were enrolled from City of Hope (COH, n = 67) and Zhejiang University (ZJU, n = 322). RRM1 protein expression was determined by immunohistochemistry on FFPE tissue samples. Kaplan-Meier and Cox analyses were used to measure survival. Ras/Raf activity and invasion assays were used to evaluate the role of RRM1 in GC cell lines.

RESULTS

In vitro experiments demonstrated RRM1 activated Ras/Raf/MAPK signal transduction and promoted GC cell proliferation. Meanwhile, RRM1 expression was significantly associated with lymph node involvement, tumor size, Ki67 expression, histological subtype and histological grade in the GC tissue samples (p<0.05). Kaplan-Meier analysis illustrated that high RRM1 expression predicted poor survival in GC patients in the COH and ZJU cohorts (log-rank p<0.01). In multivariate Cox analysis, the hazard ratios of RRM1 for overall survival were 2.55 (95% CI 1.27-5.15) and 1.51 (95% CI 1.07-2.13) in the COH and ZJU sets, respectively. In particular, RRM1 specifically predicted the outcome of advanced GCs with poor differentiation and high proliferative ability. Furthermore, inhibition of RRM1 by siRNA significantly reduced the dNTP pool, Ras/Raf and MMP-9 activities and the levels of p-MEK, p-ERK and NF-κB, resulting in growth retardation and reduced invasion in AGS and NCI-N87 cells.

CONCLUSIONS

RRM1 overexpression predicts poor survival in GC patients with advanced TNM stage. RRM1 could potentially serve as prognostic biomarker and therapeutic target for GCs.

The RUNX1 transcription factor is expressed in serous epithelial ovarian carcinoma and contributes to cell proliferation, migration and invasion

Previously, we have identified the RUNX1 gene as hypomethylated and overexpressed in post-chemotherapy (CT) primary cultures derived from epithelial ovarian cancer (EOC) patients, when compared with primary cultures derived from matched primary (prior to CT) tumors. Here we show that RUNX1 displays a trend of hypomethylation, although not significant, in omental metastases compared with primary EOC tumors. Surprisingly, RUNX1 displayed significantly higher expression not only in metastatic tissue, but also in high-grade primary tumors and even in low malignant potential tumors. The RUNX1 expression levels were almost identical in primary tumors and omental metastases, suggesting that RUNX1 hypomethylation might have a limited impact on its overexpression in advanced (metastatic) stage of the disease. Knockdown of the RUNX1 expression in EOC cells led to sharp decrease of cell proliferation and induced G 1 cell cycle arrest. Moreover, RUNX1 suppression significantly inhibited EOC cell migration and invasion. Gene expression profiling and consecutive network and pathway analyses confirmed these findings, as numerous genes and pathways known previously to be implicated in ovarian tumorigenesis, including EOC tumor invasion and metastasis, were found to be downregulated upon RUNX1 suppression, while a number of pro-apoptotic genes and some EOC tumor suppressor genes were induced. Taken together, our data are indicative for a strong oncogenic potential of the RUNX1 gene in EOC progression and suggest that RUNX1 might be a novel EOC therapeutic target. Further studies are needed to more completely elucidate the functional implications of RUNX1 and other members of the RUNX gene family in ovarian tumorigenesis.