Elevated expression of FoxM1 promotes the tumor cell proliferation in hepatocellular carcinoma

Pan-Cancer landscape of protein activities identifies drivers of signalling dysregulation and patient survival

Genetic alterations in cancer cells trigger oncogenic transformation, a process largely mediated by the dysregulation of kinase and transcription factor (TF) activities. While the mutational profiles of thousands of tumours have been extensively characterised, the measurements of protein activities have been technically limited until recently. We compiled public data of matched genomics and (phospho)proteomics measurements for 1,110 tumours and 77 cell lines that we used to estimate activity changes in 218 kinases and 292 TFs. Co-regulation of kinase and TF activities reflects previously known regulatory relationships and allows us to dissect genetic drivers of signalling changes in cancer. We find that loss-of-function mutations are not often associated with the dysregulation of downstream targets, suggesting frequent compensatory mechanisms. Finally, we identified the activities most differentially regulated in cancer subtypes and showed how these can be linked to differences in patient survival. Our results provide broad insights into the dysregulation of protein activities in cancer and their contribution to disease severity.

Dissecting novel mechanisms of hepatitis B virus related hepatocellular carcinoma using meta-analysis of public data

BACKGROUND

Hepatitis B virus (HBV) is a cause of hepatocellular carcinoma (HCC). Interestingly, this process is not necessarily mediated through cirrhosis and may in fact involve oncogenic processes. Prior studies have suggested specific oncogenic gene expression pathways were affected by viral regulatory proteins. Thus, identifying these genes and associated pathways could highlight predictive factors for HCC transformation and has implications in early diagnosis and treatment.

AIM

To elucidate HBV oncogenesis in HCC and identify potential therapeutic targets.

METHODS

We employed our Search, Tag, Analyze, Resource platform to conduct a meta-analysis of public data from National Center for Biotechnology Information’s Gene Expression Omnibus. We performed meta-analysis consisting of 155 tumor samples compared against 185 adjacent non-tumor samples and analyzed results with ingenuity pathway analysis.

RESULTS

Our analysis revealed liver X receptors/retinoid X receptor (RXR) activation and farnesoid X receptor/RXR activation as top canonical pathways amongst others. Top upstream regulators identified included the Ras family gene rab-like protein 6 (RABL6). The role of RABL6 in oncogenesis is beginning to unfold but its specific role in HBV-related HCC remains undefined. Our causal analysis suggests RABL6 mediates pathogenesis of HBV-related HCC through promotion of genes related to cell division, epigenetic regulation, and Akt signaling. We conducted survival analysis that demonstrated increased mortality with higher RABL6 expression. Additionally, homeobox A10 (HOXA10) was a top upstream regulator and was strongly upregulated in our analysis. HOXA10 has recently been demonstrated to contribute to HCC pathogenesis in vitro. Our causal analysis suggests an in vivo role through downregulation of tumor suppressors and other mechanisms.

CONCLUSION

This meta-analysis describes possible roles of RABL6 and HOXA10 in the pathogenesis of HBV-related HCC. RABL6 and HOXA10 represent potential therapeutic targets and warrant further investigation.

miR-199a-3p increases the anti-tumor activity of palbociclib in liver cancer models

Palbociclib is in early-stage clinical testing in advanced hepatocellular carcinoma (HCC). Here, we investigated whether the anti-tumor activity of palbociclib, which prevents the CDK4/6-mediated phosphorylation of RB1 but simultaneously activates AKT signaling, could be improved by its combination with a PI3K/AKT/mTOR inhibitor in liver cancer models. The selective pan-AKT inhibitor, MK-2206, or the microRNA-199a-3p were tested in combination with palbociclib in HCC cell lines and in the TG221 HCC transgenic mouse model. The combination palbociclib/MK-2206 was highly effective, but too toxic to be tolerated by mice. Conversely, the combination miR-199a-3p mimics/palbociclib not only induced a complete or partial regression of tumor lesions, but was also well tolerated. After 3 weeks of treatment, the combination produced a significant reduction in number and size of tumor nodules in comparison with palbociclib or miR-199a-3p mimics used as single agents. Moreover, we also reported the efficacy of this combination against sorafenib-resistant cells in vitro and in vivo. At the molecular level, the combination caused the simultaneous decrease of the phosphorylation of both RB1 and of AKT. Our findings provide pre-clinical evidence for the efficacy of the combination miR-199a-3p/palbociclib as anti-HCC treatment or as a new approach to overcome sorafenib resistance.

Expression of FOXM1 and Aurora-A predicts prognosis and sorafenib efficacy in patients with hepatocellular carcinoma

BACKGROUND:

Effective prognostic biomarkers and powerful target-therapeutic drugs are needed for improving the treatment of Hepatocellular carcinoma (HCC).

OBJECTIVE:

This study aimed to evaluate the expression of FOXM1 and Aurora-A and their prognostic value in HCC.

METHODS:

We determined the differentially expressed genes signature in HCC using the Gene Set Enrichment Analysis (GSEA), and then evaluated the expression of FOXM1 and Aurora-A in TCGA and KMUH cohort. Associations between co-expression of FOXM1 and Aurora-A and clinical variables were calculated. Overall survival (OS) and recurrence-free survival (RFS) were estimated with different FOXM1 and Aurora-A expression status.

RESULTS:

FOXM1-related gene sets were mostly associated with cell cycle regulation in HCC tissues. We found a positive correlation between the expression of FOXM1 and Aurora-A. Overexpression of FOXM1 and Aurora-A was associated with larger tumor size, advanced stage, higher grade, and double-positive for HBV and HCV. The coordinated overexpression of FOXM1 and Aurora-A was the most significant independent prognostic factor for OS and RFS. Furthermore, the concomitant high expression of FOXM1 and Aurora-A predicted the worst OS of sorafenib-treated patients with HCC.

CONCLUSIONS:

The co-expression of FOXM1 and Aurora-A could be a reliable biomarker to predict the sorafenib response and prognosis of HCC patients.

Reciprocal Regulation Between Forkhead Box M1/NF-κB and Methionine Adenosyltransferase 1A Drives Liver Cancer

BACKGROUND AND AIMS

Forkhead box M1 (FOXM1) and nuclear factor kappa B (NF-ĸB) are oncogenic drivers in liver cancer that positively regulate each other. We showed that methionine adenosyltransferase 1A (MAT1A) is a tumor suppressor in the liver and inhibits NF-ĸB activity. Here, we examined the interplay between FOXM1/NF-κB and MAT1A in liver cancer.

APPROACH AND RESULTS

We examined gene and protein expression, effects on promoter activities and binding of proteins to promoter regions, as well as effects of FOXM1 inhibitors T0901317 (T0) and forkhead domain inhibitory-6 (FDI-6) in vitro and in xenograft and syngeneic models of liver cancer. We found, in both hepatocellular carcinoma and cholangiocarcinoma, that an induction in FOXM1 and NF-κB expression is accompanied by a fall in MATα1 (protein encoded by MAT1A). The Cancer Genome Atlas data set confirmed the inverse correlation between FOXM1 and MAT1A. Interestingly, FOXM1 directly interacts with MATα1 and they negatively regulate each other. In contrast, FOXM1 positively regulates p50 and p65 expression through MATα1, given that the effect is lost in its absence. FOXM1, MATα1, and NF-κB all bind to the FOX binding sites in the FOXM1 and MAT1A promoters. However, binding of FOXM1 and NF-κB repressed MAT1A promoter activity, but activated the FOXM1 promoter. In contrast, binding of MATα1 repressed the FOXM1 promoter. MATα1 also binds and represses the NF-κB element in the presence of p65 or p50. Inhibiting FOXM1 with either T0 or FDI-6 inhibited liver cancer cell growth in vitro and in vivo. However, inhibiting FOXM1 had minimal effects in liver cancer cells that do not express MAT1A.

CONCLUSIONS

We have found a crosstalk between FOXM1/NF-κB and MAT1A. Up-regulation in FOXM1 lowers MAT1A, but raises NF-κB, expression, and this is a feed-forward loop that enhances tumorigenesis.

Matrix metalloproteinase-14 (MMP-14) downregulation inhibits esophageal squamous cell carcinoma cell migration, invasion, and proliferation

Background

Matrix metalloproteinase‐14 (MMP‐14) is known to be a key regulator of oncogenesis and tumor progression. The present study was designed to assess the relationship between the downregulation of MMP‐14 and the in vitro proliferative, migratory, and invasive activity of esophageal squamous cell carcinoma (ESCC) cells.

Methods

MMP‐14 expression in human ESCC and paracancerous normal esophageal tissue samples was evaluated via immunohistochemistry, and correlations between MMP‐14 staining and patient clinicopathological features were examined. In addition, siRNA was used to knockdown MMP‐14 in ESCC cells, and the proliferation and invasive activity of these cells were then evaluated via MTT and Transwell assays, respectively. Flow cytometry was additionally used to assess cell cycle progression, while Western blotting was employed to measure protein levels within these cells.

Results

ESCC samples were found to exhibit MMP‐14 overexpression relative to paracancerous tissue samples, and this overexpression was positively correlated with tumor T classification (T1‐2 vs. T3; P < 0.05), N classification (negative vs. positive; P < 0.001), degree of differentiation (G1 vs. G3, P < 0.05; G2 vs. G3, P < 0.05) and clinical stage (I–IIA vs. IIB–III; P < 0.05). When MMP‐14 was knocked down in ESCC cells, this induced cell cycle arrest, impairing their proliferative and invasive activity.

Conclusions

MMP‐14 is a key regulator of the proliferation and invasion of ESCC cells, making it a viable therapeutic target for the treatment of this cancer.

Liver Fibrosis and Inflammation under the Control of ERK2

Chronic liver injury could lead the formation of liver fibrosis, eventually some would develop to hepatocellular carcinoma (HCC), one of the leading malignancies worldwide. The aim of the study is to dissect the role of extracellular signal-regulated kinase 2 (ERK2) signaling in liver fibrosis and inflammation. The choline-deficient, ethionine-supplemented (CDE) diet could lead to fatty livers and generate oval cells, activate hepatocyte stellate cell (HSC) and recruit immune cells as the liver fibrosis model mice. WT and ERK2 deficient (ERK2^−/−) mice were compared in terms of liver weight/body weight, liver function, liver fibrosis markers and the differential gene expression in hepatotoxicity. ERK2^−/− mice display the less degree of liver fibrosis when compared to WT mice. The protein level of alpha smooth muscle (α-SMA) was reduced and several hepatocellular carcinoma-related genes such as MMP9, FoxM1 were down-regulated. In addition, the cell proliferation and the percentages of activated T cells were reduced in ERK2^−/− mice upon liver injury. Therefore, ERK2 plays an important role in regulating liver cirrhosis and inflammation.

FOX transcription factor family in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) is a multistep process, involving the progressive accumulation of molecular alterations and transcriptomic alterations. The Forkhead-box (FOX) transcription factor family is characterized by its unique DNA binding domain (FKH or winged-helix domain). Human FOX family consists of about 17 subfamilies, at least 43 members. Some of them are liver-enriched transcription factors, suggesting that they may play a crucial role in the development or/and functions of the liver. Dysregulation of FOX transcription factors may contribute to the pathogenesis of HCC because they can activate or suppress the expression of various tumor-related molecules, and pinpoint different molecular and cellular events. Here we summarized, analyzed and discussed the status and the functions of the human FOX family of transcription factors in HCC, aiming to help the further development of them as potential therapeutic targets or/and diagnostic/prognostic markers for HCC.

High expression of FOXM1 critical for sustaining cell proliferation in mitochondrial DNA-less liver cancer cells

The copy number of mitochondrial DNA (mtDNA) is decreased in most cancer types, including hepatocellular carcinoma (HCC), compared to normal counterparts. However, a decrease in mtDNA usually leads to defects in cell proliferation, which contradicts the robustness of cancer cell proliferation. In this study, we found that four out of seven HCC cell lines were of the mtDNA-less type. Interestingly, FOXM1, a member of the FOX transcription factor family, was highly expressed in a subset of them with proliferative potential maintained. B-MYB, a partner of FOXM1, was also expressed in the same cell lines. RNAi-mediated experiments demonstrated that when FOXM1/B-MYB was silenced in the cell lines, cell cycle-related genes were downregulated, while p21^Cip1 was induced with senescence-associated β-galactosidase, resulting in G₁/S cell cycle arrest. These results suggest that high expression of FOXM1/B-MYB is critical for sustaining cell proliferation in mtDNA-less cells. In addition, we found that high expression of FOXM1 was mediated by the deubiquitinating enzyme, OTUB1, in one cell line. Thus, interference with FOXM1/B-MYB expression, such as through OTUB1 inhibition, may induce a dormant state of senescence-like proliferation arrest in mtDNA-less cancer cells. This finding may be utilized for the development of precision medicine for relevant cancers.

FOXM1 functions collaboratively with PLAU to promote gastric cancer progression

Background: Gastric cancer (GC) is one of the main mortality cause worldwide. Previously, we found Forkhead box protein (FOXM1) or Urokinase-type plasminogen activator (PLAU) are independent prognostic markers of GC. This study aims to explore the combining prognostic efficacy and the potential insights underlying additive effect of FOXM1 to PLAU in GC progression through in-silico analyses. Method: The expression of FOXM1 and PLAU were profiled in 33 cancer types using public data. A merged GC expression dataset containing 598 samples was used for evaluating prognostic significance of FOXM1/PLAU. Gene Set Enrichment Analysis (GSEA) was performed to elucidate the mechanisms underlying FOXM1/PLAU promoted GC progression. The Cancer Genome Atlas (TCGA) was used for analyzing the association between FOXM1/PLAU and tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were also computed using TCGA GC data. Drugs targeting FOXM1/PLAU associated gene expression pattern was analyzed using LINCs database. Results: FOXM1 and PLAU are overexpressed in 17/33 cancer types including GC. Kaplan-Meier analyses indicate that the FOXM1+PLAU+ subgroup have the worst prognosis, while FOXM1-PLAU- subgroup have the best survival. Bioinformatics analysis indicated that FOXM1+PLAU+ associated genes are enriched in TGF-beta, DNA repair and drug resistance signaling pathways; FOXM1 and PLAU expression are negatively correlated with tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were presented. Data mining from LINCs suggested several chemicals or drugs that could target the gene expression pattern of FOXM1+PLAU+ patients. Conclusion: FOXM1+PLAU+ can serve as effective prognostic biomarkers and potential therapeutic targets for GC. Due to the additive effect of these two genes, screening for drugs or chemicals that targeting the expression patterns PLAU+FOXM1+ subgroup may exert important clinical impact on GC management.

The Clinical and Experimental Research on the Treatment of Endometriosis with Thiostrepton

BACKGROUND/OBJECTIVE

Forkhead Box M1 (FOXM1) is frequently activated in tumors. We studied the expression and the possible mechanism of FOXM1 and evaluated the effects of thiostrepton in an endometriotic rat model.

METHODS AND MATERIAL

This was a randomized study in a rat model of endometriosis. Fifty female Wistar rats were surgically induced with endometriosis. After 4 weeks of observation, twenty and thirty rats were randomly allocated to an ovariectomized (OVX) group and a treatment group, respectively. The OVX group was ovariectomized and randomly divided into an OVX-estrogen group and a control (OVX -oil) group. All rats were allowed a resting period of 3 days prior to any operation. The rats in the estrogen group were given estradiol (20 µg/kg, 0.1 ml /d), while the control group was treated with an equivalent amount of sesame oil. Every group was injected with subcutaneous injection for 7 days. The treatment group was randomly divided into three groups to receive the following: TST at 150 mg/kg, ip.; TST at 250 mg/kg, ip.; or sterile normal saline, ip. The groups received these dosages every 2 days for 2 weeks. Lesion growth, histological examination, and protein expression were subsequently analyzed using caliper measurement, histology, immunostaining, and Western blot after each rat received an injection in its own group.

RESULTS

Our results showed that FOXM1 is enriched in nucleus of an ectopic endometrium when compared with a eutopic uterus. Furthermore, we found that an ERK/FOXM1/matrix metalloproteinase-9 (MMP9) signaling pathway might result in the establishment and development of endometriosis. Finally, a thiostrepton concentration dependently reduced the expression of FOXM1, MMP9 and Bcl-2 in endometriotic lesions of the treated rats. Statistical significance was accepted for a value of P < 0.05.

CONCLUSION

We postulate that thiostrepton could inhibit the endometriotic lesions, at least in part, by decreasing the FOXM1 expression and exerting a pro-apoptotic effect. We reported for the first time that FOXM1 expresses in experimental endometriosis rat and thiostrepton may also be suitable for the administration of endometriosis by inhibiting the growth of endometriotic implants. More studies are needed to further evaluate thiostrepton's effect.

Disruption of crosstalk between LX-2 and liver cancer stem-like cells from MHCC97H cells by DFOG via inhibiting FOXM1

Hepatic stellate cell (HSC) line LX-2 is activated by liver cancer stem-like cells (LCSLCs) and produces various cytokines that make up most of the hepatocellular carcinoma (HCC) microenvironment. The new genistein derivative, 7-difluoromethoxyl-5,4'-di-n-octylgenistein (DFOG), shows anticancer effects in multiple malignancies by controlling forkhead box M1 (FOXM1). In this study, we aimed to assess whether DFOG disrupts the crosstalk between human HSC LX-2 cells and LCSLCs. Distinct generations of MHCC97H-derived spheres were obtained with the second generation considered as LCSLCs which displayed enhanced self-renewal ability and elevated expression levels of CD133, CD44, and EpCAM proteins, as well as tumorigenicity, as revealed by colony formation assay in vitro and tumorigenicity assay in vivo. LX-2 and MHCC97H cells were co-cultured with/without DFOG (1, 5, and 10 μM, respectively) using the transwell system. FOXM1 overexpression and/or knockdown were employed for mechanistic investigations. Our results suggested that Co-CM promoted LX-2 cell transformation into liver cancer-associated HSCs. Meanwhile, FOXM1 was up-regulated and the level of hepatocyte growth factor (HGF) was increased in LX-2 cells and in the supernatant after Co-CM stimulation. Sphere and colony formation abilities in MHCC97H cells, and protein levels of CD133, CD44, and EpCAM, were also markedly elevated. DFOG dose-dependently inhibited the above effects, similar to FOXM1 knockdown in LX-2 cells. FOXM1 overexpression reversed the inhibitory effects of DFOG or FOXM1 knockdown or both on LX-2 cell activation and LCSLC feature induction in MHCC97H cells by LCSLC/LX-2 co-culture. This study demonstrated that DFOG disrupts the crosstalk between HSCs and LCSLCs to suppress LCSLC features via down-regulating FOXM1 expression and reducing HGF secretion in HSCs.

The inhibitory effect and safety of GANT61 on HeLa cells in nude mice

The Hedgehog (Hh) pathway effector Gli1 plays an important role in cervical cancer, and GANT61 is an Hh signaling inhibitor. In this study, we aimed to investigate the inhibitory effect of GANT61 on cervical cancer and to study its safety in nude mice. We used in vivo experiments to assess the effect of GANT61 on the growth of cervical cancer HeLa cells, and we measured the WBC, HGB, PLT, ALT, AST and Cre levels in nude mice. Next, we examined the organ and tumor morphology and distant metastasis by HE staining. We used immunohistochemistry to monitor the expression levels of Gli1, FoxM1, Ki-67, cyclinD1, E-cadherin, vimentin, survivin, caspase-3 and CD34+. Western blotting and RT-RCR were used to measure Gli1 expression. GANT61 inhibited the growth and metastasis of HeLa cervical cancer cells upon their transplantation into nude mice, and we preliminarily propose that GANT61 is safe for nude mice. These findings suggest that GANT61 could be used as a Hedgehog inhibitor to inhibit EMT and proliferation and to promote apoptosis via Gli1 downregulation.

Combined Aberrant Expression of NDRG2 and LDHA Predicts Hepatocellular Carcinoma Prognosis and Mediates the Anti-tumor Effect of Gemcitabine

The Warburg effect is one of the important hallmarks of cancer. The activation of oncogene and inactivation of tumor suppressor gene contribute to the enhancement of glycolytic enzymes and the Warburg effect. The N-myc downstream regulated gene 2 (NDRG2) is a tumor suppressor gene and is frequently lost in various types of cancer. However, little is known about glycolytic function and therapeutic value of NDRG2 in hepatocellular carcinoma (HCC). In this study, we found that NDRG2 and lactate dehydrogenase A (LDHA) were aberrantly expressed in HCC and were closely related to the Warburg effect. The correlation between NDRG2 and LDHA expression predicted HCC prognosis and the clinical response to chemotherapy. NDRG2 expression was significantly decreased while LDHA expression was increased in HCC specimens. NDRG2 and LDHA expression was significantly correlated with differentiation status, vascular invasion, and TNM stage of HCC. NDRG2 inhibited LDHA expression, the Warburg effect and the growth of HCC cells. Furthermore, NDRG2 mediated gemcitabine-induced inhibition of LDHA expression and the Warburg effect in HCC cells. Taken together, our data suggest that NDRG2 plays an important role in inhibiting the Warburg effect and the malignant growth of HCC via LDHA. NDRG2 combined with LDHA might be powerful prognostic biomarkers and targets for chemotherapy treatment of HCC.

Widespread epigenetic changes to the enhancer landscape of mouse liver induced by a specific xenobiotic agonist ligand of the nuclear receptor CAR

CAR (Nr1i3), a liver nuclear receptor and xenobiotic sensor, induces drug, steroid and lipid metabolism and dysregulates genes linked to hepatocellular carcinogenesis, but its impact on the liver epigenome is poorly understood. TCPOBOP, a halogenated xenochemical and highly specific CAR agonist ligand, induces localized chromatin opening or closing at several thousand mouse liver genomic regions, discovered as differential DNase-hypersensitive sites (ΔDHS). Active enhancer and promoter histone marks induced by TCPOBOP were enriched at opening DHS and TCPOBOP-inducible genes. Enrichment of CAR binding and CAR motifs was seen at opening DHS and their inducible drug/lipid metabolism gene targets, and at many constitutively open DHS located nearby. TCPOBOP-responsive cell cycle and DNA replication genes co-dependent on MET/EGFR signaling for induction were also enriched for CAR binding. A subset of opening DHS and many closing DHS mapping to TCPOBOP-responsive target genes did not bind CAR, indicating an indirect mechanism for their changes in chromatin accessibility. TCPOBOP-responsive DHS were also enriched for induced binding of RXRA, CEBPA and CEBPB, and for motifs for liver-enriched factors that may contribute to liver-specific transcriptional responses to TCPOBOP exposure. These studies elucidate the enhancer landscape of TCPOBOP-exposed liver and the widespread epigenetic changes that are induced by both direct and indirect mechanisms linked to CAR activation. The global maps of thousands of environmental chemical-induced epigenetic changes described here constitute a rich resource for further research on xenochemical effects on liver chromatin states and the epigenome.

Transcriptome Responses to Dexamethasone Depending on Dose and Glucocorticoid Receptor Sensitivity in the Liver

Tissue sensitivity to glucocorticoids is a key factor dictating outcome of their homeostatic and therapeutic action, whereby liver represents one of the major peripheral targets. Here, we used pigs carrying a natural gain-of-function glucocorticoid receptor (GR) variant Ala610Val (GR_Ala610Val) as a model to identify genes and pathways related to differential glucocorticoid sensitivity. Animals with different GR_Ala610Val genotypes were treated either with saline or two different doses of dexamethasone. Genome-wide transcriptional responses depending on treatment, genotype, and their interaction in the liver were investigated using mRNA sequencing. Dexamethasone induced vast transcriptional responses, with more than 30% of present genes being affected. Functional annotation of genes differentially expressed due to dexamethasone treatment suggested that genes related to inflammation respond more sensitively, despite absence of an immune stimulus. In contrast, genes involved in glucose metabolism and cancer appeared to be less sensitive. Analysis of genotype and genotype × treatment interaction revealed that clustered protocadherins, particularly PCDHB7, are most prominently affected by GR_Ala610Val, mainly depending on dose. GR_Ala610Val influenced also expression of a set of glucose metabolism related genes, including PPARGC1A and CEBPB, in the absence of dexamethasone though no differences in basal plasma glucose level were observed. This might represent an adaptive response, keeping balance between receptor sensitivity, and level of circulating endogenous glucocorticoids. Administration of low dexamethasone dose changed their expression pattern and induced higher glucose response in carriers of the hypersensitive Val receptor. Our findings suggest that GR_Ala610Val modulates tissue responses to glucocorticoids dynamically, depending on their circulating level.

Clinicopathological and prognostic significance of FoxM1 in hepatocellular carcinoma patients: a meta-analysis

Background and aims

Recently, the abnormal expression of FoxM1 has been found in many malignant tumors. However, the clinicopathological and prognostic value of FoxM1 expression in hepatocellular carcinoma (HCC) patients remains controversial. We conducted a meta-analysis to establish the relationship between FoxM1 expression and the clinicopathological features and prognostic value in patients with HCC.

Methods

An electronic search for relevant articles was conducted according to a set of criteria in the PubMed, Cochrane Library, Web of Science, EMBASE, Chinese CNKI and Chinese WanFang databases. The correlation data between FoxM1 expression and clinicopathological features and survival outcomes were analyzed. Pooled odds ratios (ORs) and hazard ratios (HRs) with 95% CIs were calculated using STATA14.2.

Results

A total of 14 studies comprising of 2,036 patients were enrolled in this meta-analysis. The results showed that FoxM1 expression was related to the incidence, tumor size (>5 cm), vascular invasion, differentiation and TNM stage. Moreover, overexpression of FoxM1 indicated a poor 3- and 5-year overall survival rate (OS) and recurrence-free survival rate (disease-free survival rate).

Conclusion

Our meta-analysis indicated that FoxM1 expression was associated with incidence, tumor size (>5 cm), vascular invasion, differentiation and TNM stage. Accordingly, FoxM1 may be a reliable prognostic biomarker for patients with HCC. However, additional high-quality studies are still needed to further support these findings.

miR-199a-3p Modulates MTOR and PAK4 Pathways and Inhibits Tumor Growth in a Hepatocellular Carcinoma Transgenic Mouse Model

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Prognosis is poor, and therapeutic options are limited. MicroRNAs (miRNAs) have emerged as potential therapeutic molecules against cancer. Here, we investigated the therapeutic efficacy of miR-199a-3p, an miRNA highly expressed in normal liver and downregulated in virtually all HCCs. The therapeutic value of miR-199a-3p mimic molecules was assayed in the TG221 mouse, a transgenic model highly predisposed to the development of liver cancer. Administration of miR-199a-3p mimics in the TG221 transgenic mouse showing liver cancer led to a significant reduction of number and size of tumor nodules compared to control animals. In vivo delivery confirmed protein downregulation of the miR-199a-3p direct targets, mechanistic target of rapamycin (MTOR) and p21 activated kinase 4 (PAK4), ultimately leading to the repression of FOXM1. Remarkably, the anti-tumor activity of miR-199a-3p mimics was comparable to that obtained with sorafenib. These results suggested that miR-199a-3p may be considered a promising HCC therapeutic option.

miR-6883 Family miRNAs Target CDK4/6 to Induce G1 Phase Cell-Cycle Arrest in Colon Cancer Cells

CDK4/6 targeting is a promising therapeutic strategy under development for various tumor types. In this study, we used computational methods and The Cancer Genome Atlas dataset analysis to identify novel miRNAs that target CDK4/6 and exhibit potential for therapeutic development in colorectal cancer. The 3'UTR of CDK4/6 mRNAs are targeted by a family of miRNAs, which includes miR-6883-5p, miR-149*, miR-6785-5p, and miR-4728-5p. Ectopic expression of miR-6883-5p or miR-149* downregulated CDK4 and CDK6 levels in human colorectal cancer cells. RNA-seq analysis revealed an inverse relationship between the expression of CDK4/6 and miR-149* and intronic miRNA-6883-5p encoding the clock gene PER1 in colorectal cancer patient samples. Restoring expression of miR-6883-5p and miR-149* blocked cell growth leading to G₀-G₁ phase cell-cycle arrest and apoptosis in colorectal cancer cells. CDK4/6 targeting by miR-6883-5p and miR-149* could only partially explain the observed antiproliferative effects. Notably, both miRNAs synergized with the frontline colorectal cancer chemotherapy drug irinotecan. Further, they resensitized mutant p53-expressing cell lines resistant to 5-fluorouracil. Taken together, our results established the foundations of a candidate miRNA-based theranostic strategy to improve colorectal cancer management. Cancer Res; 77(24); 6902-13. ©2017 AACR.

Increased expression of Forkhead box M1 transcription factor is associated with clinicopathological features and confers a poor prognosis in human hepatocellular carcinoma

AIM

Forkhead Box M1 (FoxM1) is a proliferation-specific transcription factor. In this study, we aimed to elucidate the clinicopathological and prognostic values of FoxM1 expression in human hepatocellular carcinoma (HCC) and correlate FoxM1 expression with various etiologies of liver diseases. We also investigated its therapeutic value in HCC.

METHODS

We investigated the expression of FoxM1 in tumor tissues and adjacent non-tumor tissues of 79 Japanese HCC patients by quantitative real-time reverse transcription-polymerase chain reaction analysis. Depletion by siRNA or specific inhibition by siomycin A were also used to investigate the effect of FoxM1 inhibition on stem-like features of human HCC cells.

RESULTS

Quantitative real-time reverse transcription-polymerase chain reaction analysis showed that tumor tissues displayed an approximately 14-fold increase in FoxM1 expression compared with adjacent non-tumor tissues. Interestingly, the expression levels of FoxM1in tumor tissues did not depend on the etiology of liver disease. The expression of FoxM1 in tumor tissues was associated with serum α-fetoprotein level, maximum tumor size, histological grade, TNM staging, and portal involvement. Kaplan-Meier analysis indicated that the high FoxM1 expression (≥median) group had a poor prognosis compared with the low FoxM1 expression (<median) group. Using multivariate analysis, the expression of FoxM1 in tumor tissues was shown to be an independent prognostic factor that affected overall survival and disease-free survival. Furthermore, FoxM1 inhibition by siRNA or siomycin A reduced spheroid colony formation of HCC cells in vitro.

CONCLUSION

Our data suggest that FoxM1 might be a prognostic biomarker and a promising therapeutic target for HCC.

FoxM1: Repurposing an oncogene as a biomarker

The past few decades have witnessed a tremendous progress in understanding the biology of cancer, which has led to more comprehensive approaches for global gene expression profiling and genome-wide analysis. This has helped to determine more sophisticated prognostic and predictive signature markers for the prompt diagnosis and precise screening of cancer patients. In the search for novel biomarkers, there has been increased interest in FoxM1, an extensively studied transcription factor that encompasses most of the hallmarks of malignancy. Considering the attractive potential of this multifarious oncogene, FoxM1 has emerged as an important molecule implicated in initiation, development and progression of cancer. Bolstered with the skill to maneuver the proliferation signals, FoxM1 bestows resistance to contemporary anti-cancer therapy as well. This review sheds light on the large body of literature that has accumulated in recent years that implies that FoxM1 neoplastic functions can be used as a novel predictive, prognostic and therapeutic marker for different cancers. This assessment also highlights the key features of FoxM1 that can be effectively harnessed to establish FoxM1 as a strong biomarker in diagnosis and treatment of cancer.

Expression of OTUB1 in hepatocellular carcinoma and its effects on HCC cell migration and invasion

OTUB1 (OTU domain-containing ubiquitin aldehyde binding protein 1) is a deubiquitinating enzyme (DUB) that belongs to the ovarian tumor (OTU) domain protease superfamily. Although it has been demonstrated to play important roles in the development of many kinds of cancer, the mechanism of OTUB1 in hepatocellular carcinoma (HCC) is not clear. The aim of this study was to explore the roles of OTUB1 in HCC progression using cell lines and 115 archived HCC samples. In addition, the clinical outcomes were also analyzed with a special focus on OTUB1 expression in HCC samples. In the immunohistochemical study, OTUB1 showed high expression in 60 of the 115 cases (52.2%). The OTUB1 expression level was significantly correlated with many clinicopathological parameters, including TNM stage (P = 0.002), histology stage (P = 0.002), and metastasis/recurrence (P = 0.016). Survival analysis showed that the group with OTUB1 overexpression had significantly shorter overall survival time than the group with OTUB1 downregulation (hazard ratio [HR] = 0.482; confidence interval [CI]: 0.311-0.748; P = 0.001). Multivariate analysis indicated that OTUB1 expression was a significant and independent prognostic parameter (HR = 0.214; CI: 0.126-0.364; P < 0.001) for HCC patients. The ability of HCC cells to undergo proliferation, migration, and invasion was suppressed by disruption of endogenous OTUB1 using short hairpin RNA (shRNA). OTUB1 expression appears to be a new and independent predictor for the prognosis of HCC patients. Overexpression of OTUB1 in HCC could be a novel, effective, and supplementary biomarker for HCC because it plays a vital role in the progression of HCC.

Knockdown of the differentially expressed gene TNFRSF12A inhibits hepatocellular carcinoma cell proliferation and migration in vitro

Human hepatocellular carcinoma (HCC) has been reported to be highly insensitive to conventional chemotherapy. In the current study, the Agilent Whole Human Genome Oligo Microarray (4×44 K) was used in order to identify the differentially expressed genes between HCC and adjacent tissues, and the top 22 differentially expressed genes were confirmed through reverse transcription-quantitative polymerase chain reaction. Among the identified differences in gene expression, expression of tumor necrosis factor receptor superfamily member 12A (TNFRSF12A) was markedly higher in HCC tissue than in adjacent tissue. Previous studies have suggested that TNFRSF12A may serve a role in tumor growth and metastasis, thus in the current study, TNFRSF12A was knocked down in the SMMC7721 cell line through siRNA. This demonstrated that cells exhibited reduced reproductive and metastatic capacity ex vivo. Thus, the results of the current study suggest that TNFRSF12A may be a candidate therapeutic target for cancer including HCC, and additional genes that exhibited significantly different expression from normal adjacent tissues require further study.

A novel peptide, 9R-P201, strongly inhibits the viability, proliferation and migration of liver cancer HepG2 cells and induces apoptosis by down-regulation of FoxM1 expression

Overexpression of FoxM1 was closely related to the proliferation, metastasis, chemo-resistance and poor prognosis of various cancers. FoxM1 was regarded as the Achilles' heel of cancer and a potential target for anti-cancer drug discovery. We previously obtained several high affinity peptides from the phage random library against the DNA binding domain of FoxM1c (FoxM1c-DBD) protein. Here in this paper, we found that 9R-P201, one of the novel peptides, showed stronger inhibition to HepG2 cancer cells than those of DU145, HUVEC and L-02 cells with an IC₅₀ of 43.6µg/ml (13.1µM). The peptide was highly effective to liver cancer cells with an IC₅₀ for L-02 cells of 2855.9µg/ml. We confirmed that 9R-P201 aggregated in the cell nucleus and the expression of FoxM1 was significantly down-regulated at both transcriptional and translational levels in HepG2 cells, leading to the suppression of cell proliferation, migration, angiogenesis, and induction of apoptosis. Whole genomic RNA sequencing analysis revealed that 357 genes were significantly and differentially expressed, most of them were enriched in cancer-associated biological processes. Finally, treatment of HepG2 xenografts with 9R-P201 resulted in growth inhibition and down-regulation of foxM1 expression in tumors. Collectively, our findings suggested that 9R-P201 could strongly inhibit the viability, proliferation and migration of liver cancer HepG2 cells and induce apoptosis by down-regulation of FoxM1 and regulation of related gene expression in signal transduction passways. Thus, 9R-P201 holds great potential as a lead anti-cancer drug targeting FoxM1.