FOXM1 promotes invasion and migration of colorectal cancer cells partially dependent on HSPA5 transactivation

Diagnostic, prognostic, and therapeutic potential of exosomal microRNAs in renal cancer

Renal cell carcinoma (RCC) arises from the tubular epithelial cells of the nephron. It has the highest mortality rate among urological cancers. There are no effective therapeutic approaches and no non-invasive biomarkers for diagnosis and follow-up. Thus, suitable novel biomarkers and therapeutic targets are essential for improving RCC diagnosis/prognosis and treatment. Circulating exosomes such as exosomal microRNAs (Exo-miRs) provide non-invasive prognostic/diagnostic biomarkers and valuable therapeutic targets, as they can be easily isolated and quantified and show high sensitivity and specificity. Exosomes secreted by an RCC can exhibit alterations in the miRs' profile that may reflect the cellular origin and (patho)physiological state, as a ''signature'' or ''fingerprint'' of the donor cell. It has been shown that the transportation of renal-specific miRs in exosomes can be rapidly detected and measured, holding great potential as biomarkers in RCC. The present review highlights the studies reporting tumor microenvironment-derived Exo-miRs with therapeutic potential as well as circulating Exo-miRs as potential diagnostic/prognostic biomarkers in patients with RCC.

FOXM1: a new therapeutic target of extramammary Paget disease

Extramammary Paget disease (EMPD) is a rare skin cancer that primarily affects older individuals predominantly in areas with apocrine sweat glands. Although most early EMPD lesions are indolent, patients with metastatic EMPD have a poor prognosis due to the lack of effective systemic treatment. In this study, we investigated the role of forkhead box M1 (FOXM1), a potent transcription factor, in EMPD and assessed the potential of FOXM1 as a therapeutic target. Immunohistochemistry of 112 primary and 17 metastatic EMPD samples revealed that FOXM1 expression increased with tumor progression. Patients in whom FOXM1 was expressed in more than 10% of tumor cells had significantly shorter disease-specific survival than the other patients (p = 0.0397). In in vitro studies using our newly established EMPD cell line, KS-EMPD-1, we found high expression of FOXM1. Knockdown of FOXM1 impaired tumor cell viability, migration, and invasion. Inhibition of FOXM1 using thiostrepton also reduced tumor cell viability in a dose-dependent manner. These findings suggest that FOXM1 is a promising therapeutic target for patients with EMPD.

Flavopiridol Suppresses Cell Proliferation and Migration and Induces Apoptotic Cell Death by Inhibiting Oncogenic FOXM1 Signaling in IDH Wild-Type and IDH-Mutant GBM Cells

Glioblastoma multiforme (GBM) remains one of the most challenging solid cancers to treat due to its highly aggressive and drug-resistant nature. Flavopiridol is synthetic flavone that was recently approved by the FDA for the treatment of acute myeloid leukemia. Flavopiridol exhibits antiproliferative activity in several solid cancer cells and currently evaluated in clinical trials in several solid and hematological cancers. In this study, we investigated the molecular mechanisms underlying antiproliferative effects of flavopiridol in GBM cell lines with wild-type and mutant encoding isocitrate dehydrogenase 1 (IDH1). We found that flavopiridol inhibits proliferation, colony formation, and migration and induces apoptosis in IDH1 wild-type and IDH-mutant cells through inhibition of FOXM1 oncogenic signaling. Furthermore, flavopiridol treatment also inhibits of NF-KB, mediators unfolded protein response (UPR), including, GRP78, PERK and IRE1α, and DNA repair enzyme PARP, which have been shown to be potential therapeutic targets by downregulating FOXM1 in GBM cells. Our findings suggest for the first time that flavopiridol suppresses proliferation, survival, and migration and induces apoptosis in IDH1 wild-type and IDH1-mutant GBM cells by targeting FOXM1 oncogenic signaling which also regulates NF-KB, PARP, and UPR response in GBM cells. Flavopiridol may be a potential novel therapeutic strategy in the treatment of patients IDH1 wild-type and IDH1-mutant GBM.

High-accuracy prediction of colorectal cancer chemotherapy efficacy using machine learning applied to gene expression data

Introduction: FOLFOX and FOLFIRI chemotherapy are considered standard first-line treatment options for colorectal cancer (CRC). However, the criteria for selecting the appropriate treatments have not been thoroughly analyzed. Methods: A newly developed machine learning model was applied on several gene expression data from the public repository GEO database to identify molecular signatures predictive of efficacy of 5-FU based combination chemotherapy (FOLFOX and FOLFIRI) in patients with CRC. The model was trained using 5-fold cross validation and multiple feature selection methods including LASSO and VarSelRF methods. Random Forest and support vector machine classifiers were applied to evaluate the performance of the models. Results and Discussion: For the CRC GEO dataset samples from patients who received either FOLFOX or FOLFIRI, validation and test sets were >90% correctly classified (accuracy), with specificity and sensitivity ranging between 85%-95%. In the datasets used from the GEO database, 28.6% of patients who failed the treatment therapy they received are predicted to benefit from the alternative treatment. Analysis of the gene signature suggests the mechanistic difference between colorectal cancers that respond and those that do not respond to FOLFOX and FOLFIRI. Application of this machine learning approach could lead to improvements in treatment outcomes for patients with CRC and other cancers after additional appropriate clinical validation.

FOXM1 maintains fatty acid homoeostasis through the SET7-H3K4me1-FASN axis

Reprogramming of metabolic genes and subsequent alterations in metabolic phenotypes occur widely in malignant tumours, including glioblastoma (GBM). FOXM1 is a potent transcription factor that plays an oncogenic role by regulating the expression of many genes. As a SET domain containing protein, SET7 is a protein lysine methyltransferase which monomethylates histone proteins and other proteins. The epigenetic modification of histones regulates gene expressions by epigenetically modifying promoters of DNAs and inter vening in tumor development. Activation of FASN increased de novo fatty acid (FA) synthesis, a hallmark of cancer cells. Here, we report that FOXM1 may directly promote the transcription of SET7 and activate SET7-H3K4me1-FASN axis, which results in the maintenance of de novo FA synthesis.

FOXM1: A small fox that makes more tracks for cancer progression and metastasis

Transcription factors (TFs) are indispensable for the modulation of various signaling pathways associated with normal cell homeostasis and disease conditions. Among cancer-related TFs, FOXM1 is a critical molecule that regulates multiple aspects of cancer cells, including growth, metastasis, recurrence, and stem cell features. FOXM1 also impact the outcomes of targeted therapies, chemotherapies, and immune checkpoint inhibitors (ICIs) in various cancer types. Recent advances in cancer research strengthen the cancer-specific role of FOXM1, providing a rationale to target FOXM1 for developing targeted therapies. This review compiles the recent studies describing the pivotal role of FOXM1 in promoting metastasis of various cancer types. It also implicates the contribution of FOXM1 in the modulation of chemotherapeutic resistance, antitumor immune response/immunotherapies, and the potential of small molecule inhibitors of FOXM1.

Autophagy as a self-digestion signal in human cancers: Regulation by microRNAs in affecting carcinogenesis and therapy response

Autophagy is defined as a "self-digestion" signal, and it is a cell death mechanism its primary function is degrading toxic agents and aged organelles to ensure homeostasis in cells. The basic leve ls of autophagy are found in cells, and when its levels exceed to standard threshold, cell death induction is observed. Autophagy dysregulation in cancer has been well-documented, and regulation of this pathway by epigenetic factors, especially microRNAs (miRNAs), is interesting and noteworthy. miRNAs are considered short endogenous RNAs that do not encode functional proteins, and they are essential regulators of cell death pathways such as apoptosis, necroptosis, and autophagy. Accumulating data has revealed miRNA dysregulation (upregulation or downregulation) during tumor progression, and their therapeutic manipulation provides new insight into cancer therapy. miRNA/autophagy axis in human cancers has been investigated an exciting point is the dual function of both autophagy and miRNAs as oncogenic and onco-suppressor factors. The stimulation of pro-survival autophagy by miRNAs can increase the survival rate of tumor cells and mediates cancer metastasis via EMT inductionFurthermore, pro-death autophagy induction by miRNAs has a negative impact on the viability of tumor cells and decreases their survival rate. The miRNA/autophagy axis functions beyond regulating the growth and invasion of tumor cells, and they can also affect drug resistance and radio-resistance. These subjects are covered in the current review regarding the new updates provided by recent experiments.

Dioscin induces M1 macrophage polarization through Connexin-43 Channels in Tumor-associated-macrophages-mediated melanoma metastasis

BACKGROUND

Tumor-associated macrophages (TAMs) are important constituent parts of tumor microenvironment that connected with tumor metastasis in melanoma. Connexin 43 (Cx43) was expressed in all the immune cells which modulated different aspects of immune response. However, the concrete molecular mechanism maintains unclear.

PURPOSE

The study aimed to find a natural drug monomer effectively reversed the polarity of tumor-associated macrophages inhibiting melanoma metastasis and improving survival time.

METHODS

Flow cytometry was used to determine the effects of dioscin on the macrophage phenotype. Western bolt and ELISA were performed to explore the underlying mechanism of dioscin and a co-culture experiment in vitro was applied to assess the role of dioscin on TAMs-mediated melanoma proliferation, invasion and migration. Moreover, in vivo melanoma metastasis models were established for examining effects of dioscin on TAMs-mediated melanoma metastasis.

RESULTS

Dioscin repolarized macrophages from M2 towards M1-like phenotype. Dioscin suppressed M2-like phenotype macrophages through enhanced the expression and transport function of Cx43. Furthermore, the stimulation IFN-γ/STAT1 pathway and suppression IL-4/JAK2/STAT3 pathway were major mechanism of dioscin. Importantly, dioscin suppressed Cx43^G21R mutation TAMs induced proliferation, invasion, migration and metastasis of melanoma cells. It worthily noting that dioscin ameliorated tumor-associated-macrophages-mediated melanoma metastasis in vitro and vivo.

CONCLUSION

Dioscin re-polarized macrophages from M2 to M1 phenotype through activation of Cx43-gap-junction-intercellular-communications (Cx43-GJs)/IFN-γ/STAT1 pathway and inhibition of Cx43-GJs/IL-4/JAK2/STAT3 suppressing migration, invasion and metastasis of melanoma, which provided a theoretical and experimental basis for treating melanoma metastasis.

Ascendancy of unfolded protein response over glioblastoma: estimating progression, prognosis and survival

Glioblastoma (GBM) is presented with a poor prognosis. The endoplasmic reticulum stress (ERS) has been implicated as a major contributor to disease progression and chemoresistance in GBM. Triggering ERS by chemical agents or genetic modulations is identified as some of the reasons for regulating gene expression and the pathogenesis of GBM. ERS initiates unfolded protein response (UPR), an integrated system useful in restoring homeostasis or inducing apoptosis. Modulation of UPR might have positive outcomes in GBM treatment as UPR inducers have been shown to alter cell survival and migration. In the current review, we have utilized GSE7806, a publicly available dataset from Gene Expression Omnibus (GEO), to evaluate the genes expressed during 6.5 hr and 18 hr, which can be comparable to the early and late-onset of the disease. Subsequently, we have elucidated the prognosis and survival information whilst the expression of these genes in the GBM was noted in previous studies. This is the first of its kind review summarizing the most recent gene information correlating UPR and GBM.

Using Next-Generation Sequencing and Bioinformatic Methods to Predict New Genes That May Be Regulated by CD47 in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common cancers in the world, and the incidence and death rate of OSCC in men is twice that of women. CD47 is a ubiquitous cell surface transmembrane protein, also known as integrin-related protein (IAP). Previous studies have pointed out that CD47 can inhibit the growth of OSCC, but the detailed mechanism is not clear. This study aimed to explore the effect of CD47 gene expression profiles in OSCC. The OSCC cell lines, OECM-1 and OC-2, overexpressed CD47, and the expression profiles of mRNAs were analyzed through next-generation sequencing (NGS) with a bioinformatic approach. A total of 14 differentially expressed genes (DEGs) were listed. In addition, ingenuity pathway analysis (IPA) was used to analyze the molecular function (MF), biological process (BP), and cellular component (CC) network signaling. The human protein atlas (HPA) database was used to analyze gene expression and the survivability of human cancer. The results found that HSPA5, HYOU1, and PDIA4 were involved in the IPA network and when highly expressed, mediated the survivability of cancer. In addition, HSPA5 was positively and significantly correlated with CD47 expression (p < 0.0001) and induced by CD47-overexpression in the OECM-1 and OC-2 OSCC cancer cell lines. These findings provide important insights into possible new diagnostic strategies, including unfolded protein for OSCC-targeting CD47.

FOXM1 and Cancer: Faulty Cellular Signaling Derails Homeostasis

Forkhead box transcription factor, FOXM1 is implicated in several cellular processes such as proliferation, cell cycle progression, cell differentiation, DNA damage repair, tissue homeostasis, angiogenesis, apoptosis, and redox signaling. In addition to being a boon for the normal functioning of a cell, FOXM1 turns out to be a bane by manifesting in several disease scenarios including cancer. It has been given an oncogenic status based on several evidences indicating its role in tumor development and progression. FOXM1 is highly expressed in several cancers and has also been implicated in poor prognosis. A comprehensive understanding of various aspects of this molecule has revealed its role in angiogenesis, invasion, migration, self- renewal and drug resistance. In this review, we attempt to understand various mechanisms underlying FOXM1 gene and protein regulation in cancer including the different signaling pathways, post-transcriptional and post-translational modifications. Identifying crucial molecules associated with these processes can aid in the development of potential pharmacological approaches to curb FOXM1 mediated tumorigenesis.

Rosmarinic Acid Methyl Ester Regulates Ovarian Cancer Cell Migration and Reverses Cisplatin Resistance by Inhibiting the Expression of Forkhead Box M1

Rosmarinic acid methyl ester (RAME), a derivative of rosmarinic acid (RA), is reported to have several therapeutic effects, including anti-tumor effects against cervical cancer. However, its anti-tumor effects in ovarian cancer is unclear. In this study, we studied the molecular pathways associated with the anti-tumor effects of RAME in ovarian cancer. To identify the effects of RAME in ovarian cancer, RNA sequencing was performed in RAME-treated ovarian cancer cells; we found that RAME treatment downregulated the genes closely involved with the target genes of the transcription factor Forkhead box M1 (FOXM1). It was reported that FOXM1 is overexpressed in a variety of cancer cells and is associated with cell proliferation and tumorigenesis. Therefore, we hypothesized that FOXM1 is a key target of RAME; this could result in its anti-tumor effects. Treatment of ovarian cancer cells with RAME-inhibited cell migration and invasion, as shown by wound healing and transwell migration assays. To examine whether RAME represses the action of FOXM1, we performed quantitative RT-PCR and ChIP-qPCR. Treatment of ovarian cancer cells with RAME decreased the mRNA expression of FOXM1 target genes and the binding of FOXM1 to its target genes. Moreover, FOXM1 expression was increased in cisplatin-resistant ovarian cancer cells, and combination treatment with RAME and cisplatin sensitized the cisplatin-resistant ovarian cancer cells, which was likely due to FOXM1 inhibition. Our research suggests that RAME is a promising option in treating ovarian cancer patients, as it revealed a novel molecular pathway underlying its anti-tumor effects.

HMGB1: an overview of its versatile roles in the pathogenesis of colorectal cancer

BACKGROUND

In recent years, the high mobility group box-1 (HMGB1) protein, a damage-associated molecular pattern (DAMP) molecule, has been found to play multifunctional roles in the pathogenesis of colorectal cancer. Although much attention has been given to the diagnostic and prognostic values of HMGB1 in colorectal cancer, the exact functional roles of the protein as well as the mechanistic pathways involved have remained poorly defined. This systematic review aims to discuss what is currently known about the roles of HMGB1 in colorectal cancer development, growth and progression, and to highlight critical areas for future investigations. To achieve this, the bibliographic databases Pubmed, Scopus, Web of Science and ScienceDirect were systematically screened for articles from inception till June 2018, which address associations of HMGB1 with colorectal cancer.

CONCLUSIONS

HMGB1 plays multiple roles in promoting the pathogenesis of colorectal cancer, despite a few contradicting studies. HMGB1 may differentially regulate disease-related processes, depending on the redox status of the protein in colorectal cancer. Binding of HMGB1 to various protein partners may alter the impact of HMGB1 on disease progression. As HMGB1 is heavily implicated in the pathogenesis of colorectal cancer, it is crucial to further improve our understanding of the functional roles of HMGB1 not only in colorectal cancer, but ultimately in all types of cancers.

Tumor-associated macrophages: an accomplice in solid tumor progression

In many solid tumor types, tumor-associated macrophages (TAMs) are important components of the tumor microenvironment (TME). Moreover, TAMs infiltration is strongly associated with poor survival in solid tumor patients. In this review, we describe the origins of TAMs and their polarization state dictated by the TME. We also specifically focus on the role of TAMs in promoting tumor growth, enhancing cancer cells resistance to chemotherapy and radiotherapy, promoting tumor angiogenesis, inducing tumor migration and invasion and metastasis, activating immunosuppression. In addition, we discuss TAMs can be used as therapeutic targets of solid tumor in clinics. The therapeutic strategies include clearing macrophages and inhibiting the activation of TAMs, promoting macrophage phagocytic activity, limiting monocyte recruitment and other targeted TAMs therapies.

Dihydroartemisinin-induced unfolded protein response feedback attenuates ferroptosis via PERK/ATF4/HSPA5 pathway in glioma cells

Background

Dihydroartemisinin (DHA) has been shown to exert anticancer activity through iron-dependent reactive oxygen species (ROS) generation, which is similar to ferroptosis, a novel form of cell death. However, whether DHA causes ferroptosis in glioma cells and the potential regulatory mechanisms remain unclear.

Methods

Effects of DHA on the proliferation, cell death, ROS and lipid ROS generation as well as reduced gluthione consumption were assessed in glioma cells with or without ferroptosis inhibitor. The biological mechanisms by which glioma cells attenuate the pro-ferroptotic effects of DHA were assessed using molecular methods.

Results

DHA induced ferroptosis in glioma cells, as characterized by iron-dependent cell death accompanied with ROS generation and lipid peroxidation. However, DHA treatment simultaneously activated a feedback pathway of ferroptosis by increasing the expression of heat shock protein family A (Hsp70) member 5 (HSPA5). Mechanistically, DHA caused endoplasmic reticulum (ER) stress in glioma cells, which resulted in the induction of HSPA5 expression by protein kinase R-like ER kinase (PERK)-upregulated activating transcription factor 4 (ATF4). Subsequent HSPA5 upregulation increased the expression and activity of glutathione peroxidase 4 (GPX4), which neutralized DHA-induced lipid peroxidation and thus protected glioma cells from ferroptosis. Inhibition of the PERK-ATF4-HSPA5-GPX4 pathway using siRNA or small molecules increased DHA sensitivity of glioma cells by increasing ferroptosis both in vitro and in vivo.

Conclusions

Collectively, these data suggested that ferroptosis might be a novel anticancer mechanism of DHA in glioma and HSPA5 may serve as a negative regulator of DHA-induced ferroptosis. Therefore, inhibiting the negative feedback pathway would be a promising therapeutic strategy to strengthen the anti-glioma activity of DHA.

Stage-Dependent Gene Expression Profiling in Colorectal Cancer

Temporal gene expression profiles have been widely considered to uncover the mechanism of cancer development and progression. Gene expression patterns, however, have been analyzed for limited stages with small samples, without proper data pre-processing, in many cases. With those approaches, it is difficult to unveil the mechanism of cancer development over time. In this study, we analyzed gene expression profiles of two independent colorectal cancer sample datasets, each of which contained 556 and 566 samples, respectively. To find specific gene expression changes according to cancer stage, we applied the linear mixed-effect regression model (LMER) that controls other clinical variables. Based on this methodology, we found two types of gene expression patterns: continuously increasing and decreasing genes as cancer develops. We found that continuously increasing genes are related to the nervous and developmental system, whereas the others are related to the cell cycle and metabolic processes. We further analyzed connected sub-networks related to the two types of genes. From these results, we suggest that the gene expression profile analysis can be used to understand underlying the mechanisms of cancer development such as cancer growth and metastasis. Furthermore, our approach can provide a good guideline for advancing our understanding of cancer developmental processes.

Urinary exosome miR-30c-5p as a biomarker of clear cell renal cell carcinoma that inhibits progression by targeting HSPA5

Exosome-derived miRNAs are regarded as biomarkers for the diagnosis and prognosis of many human cancers. However, its function in clear cell renal cell carcinoma (ccRCC) remains unclear. In this study, differentially expressed miRNAs from urinal exosomes were identified using next-generation sequencing (NGS) and verified using urine samples of ccRCC patients and healthy donors. Then, the exosomes were analysed in early-stage ccRCC patients, healthy individuals and patients suffering from other urinary system cancers. Thereafter, the target gene of the miRNA was detected. Its biological function was investigated in vitro and in vivo. The results showed that miR-30c-5p could be amplified in a stable manner. Its expression pattern was significantly different only between ccRCC patients and healthy control individuals, but not compared with that of other urinary system cancers, which indicated its specificity for ccRCC. Additionally, the overexpression of miR-30c-5p inhibited ccRCC progression in vitro and in vivo. Heat-shock protein 5 (HSPA5) was found to be a direct target gene of miR-30c-5p. The depletion of HSPA5 caused by miR-30c-5p inhibition reversed the promoting effect of ccRCC growth. In conclusion, urinary exosomal miR-30c-5p acts as a potential diagnostic biomarker of early-stage ccRCC and may be able to modulate the expression of HSPA5, which is correlated with the progression of ccRCC.

The forkhead-box family of transcription factors: key molecular players in colorectal cancer pathogenesis

Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide and the fourth most frequent cause of death having an oncological origin. It has been found that transcription factors (TF) dysregulation, leading to the significant expression modifications of genes, is a widely distributed phenomenon regarding human malignant neoplasias. These changes are key determinants regarding tumour’s behaviour as they contribute to cell differentiation/proliferation, migration and metastasis, as well as resistance to chemotherapeutic agents. The forkhead box (FOX) transcription factor family consists of an evolutionarily conserved group of transcriptional regulators engaged in numerous functions during development and adult life. Their dysfunction has been associated with human diseases. Several FOX gene subgroup transcriptional disturbances, affecting numerous complex molecular cascades, have been linked to a wide range of cancer types highlighting their potential usefulness as molecular biomarkers. At least 14 FOX subgroups have been related to CRC pathogenesis, thereby underlining their role for diagnosis, prognosis and treatment purposes.

This manuscript aims to provide, for the first time, a comprehensive review of FOX genes’ roles during CRC pathogenesis. The molecular and functional characteristics of most relevant FOX molecules (FOXO, FOXM1, FOXP3) have been described within the context of CRC biology, including their usefulness regarding diagnosis and prognosis. Potential CRC therapeutics (including genome-editing approaches) involving FOX regulation have also been included. Taken together, the information provided here should enable a better understanding of FOX genes’ function in CRC pathogenesis for basic science researchers and clinicians.

MicroRNA‑320a suppresses tumour cell proliferation and invasion of renal cancer cells by targeting FoxM1

An increasing body of evidence has indicated that microRNAs (miRNAs/miRs) may play an important role in tumourigenesis and tumour progression. Recent studies have demonstrated that miR‑320a is aberrantly expressed in a variety of different types of human cancer. The results of the present study confirmed that the expression of miR‑320a was decreased in clinical specimens and cell lines. Expression of miR‑320a inhibited the growth and invasive ability of ACHN and Caki‑1 cells. Bioinformatics analysis and a luciferase reporter assay demonstrated that forkhead box protein M1 (FoxM1) was directly regulated by miR‑320a. Rescue experiments in vitro revealed that the upregulation of FoxM1 antagonized the miR‑320a‑mediated malignant phenotype in renal cancer. Furthermore, experiments employing a xenograft mouse model revealed that the upregulation of miR‑320a inhibited the proliferation of renal cancer cells in nude mice when FoxM1 protein expression was reduced. Collectively, the present study demonstrated a novel molecular interaction regulated by miR‑320a, which may provide a novel insight into the treatments for renal cancer.

Delineating the HMGB1 and HMGB2 interactome in prostate and ovary epithelial cells and its relationship with cancer

High Mobility Group B (HMGB) proteins are involved in cancer progression and in cellular responses to platinum compounds used in the chemotherapy of prostate and ovary cancer. Here we use affinity purification coupled to mass spectrometry (MS) and yeast two-hybrid (Y2H) screening to carry out an exhaustive study of HMGB1 and HMGB2 protein interactions in the context of prostate and ovary epithelia. We present a proteomic study of HMGB1 partners based on immunoprecipitation of HMGB1 from a non-cancerous prostate epithelial cell line. In addition, HMGB1 and HMGB2 were used as baits in yeast two-hybrid screening of libraries from prostate and ovary epithelial cell lines as well as from healthy ovary tissue. HMGB1 interacts with many nuclear proteins that control gene expression, but also with proteins that form part of the cytoskeleton, cell-adhesion structures and others involved in intracellular protein translocation, cellular migration, secretion, apoptosis and cell survival. HMGB2 interacts with proteins involved in apoptosis, cell motility and cellular proliferation. High confidence interactors, based on repeated identification in different cell types or in both MS and Y2H approaches, are discussed in relation to cancer. This study represents a useful resource for detailed investigation of the role of HMGB1 in cancer of epithelial origins, as well as potential alternative avenues of therapeutic intervention.

Role of microRNAs in the resistance of colorectal cancer to chemoradiotherapy

Colorectal cancer (CRC) is among the main tumor-related causes of death worldwide. The fact that the majority of the patients develop resistance to chemoradiotherapy (CRT) is a major obstacle for the treatment of CRC. In order to develop more effective treatment strategies, it is crucial to elucidate the mechanisms underlying the development of resistance to CRT. Several studies have recently indicated the regulatory effects of microRNAs (miRNAs) in response to antitumor agents. For example, miR-34a attenuates the chemoresistance of colon cancer to 5-FU by inhibiting E2F3 and SIRT1. The miR-34a mimic MRX34 is the first synthetic miRNA to have been entered into clinical trials. miR-21 prevents tumor cell stemness, invasion and drug resistance, which are required for the development of CRC. These findings suggest that miRNAs represent a focus in the research of novel cancer treatments aimed at sensitizing cancer cells to chemotherapeutic drugs. The aim of the present study was to review the functions of miRNAs and investigate the roles of miRNAs in CRC radioresistance or chemoresistance. Furthermore, the potential of including miRNAs in therapeutic strategies and using them as molecular biomarkers for predicting radiosensitivity and chemosensitivity was discussed.

ER stress and cancer: The FOXO forkhead transcription factor link

The endoplasmic reticulum (ER) is a cellular organelle with central roles in maintaining proteostasis due to its involvement in protein synthesis, folding, quality control, distribution and degradation. The accumulation of misfolded proteins in the ER lumen causes 'ER stress' and threatens overall cellular proteostasis. To restore ER homeostasis, cells evoke an evolutionarily conserved adaptive signalling and gene expression network collectively called the 'unfolded protein response (UPR)', a complex biological process which aims to restore proteostasis. When ER stress is overwhelming and beyond rectification, the normally pro-survival UPR can shift to induce cell termination. Emerging evidence from mammalian, fly and nematode worm systems reveals that the FOXO Forkhead proteins integrate upstream ER stress and UPR signals with the transcriptional machinery to decrease translation, promote cell survival/termination and increase the levels of ER-resident chaperones and of ER-associated degradation (ERAD) components to restore ER homeostasis. The high rates of protein synthesis/translation associated with cancer cell proliferation and metabolism, as well as mutations resulting in aberrant proteins, also induce ER stress and the UPR. While the pro-survival side of the UPR underlies its ability to sustain and promote cancers, its apoptotic functions can be exploited for cancer therapies by offering the chance to 'flick the proteostatic switch'. To this end, further studies are required to fully reevaluate the roles and regulation of these UPR signalling molecules, including FOXO proteins and their targets, in cancer initiation and progression as well as the effects on inhibiting their functions in cancer cells. This information will help to establish these UPR signalling molecules as possible therapeutic targets and putative biomarkers in cancers.

Paeoniflorin inhibits cell growth and induces cell cycle arrest through inhibition of FoxM1 in colorectal cancer cells

Paeoniflorin (PF) exhibits tumor suppressive functions in a variety of human cancers. However, the function of PF and molecular mechanism in colorectal cancer are elusive. In the present study, we investigated whether PF could exert its antiproliferative activity, anti-migration, and anti-invasive function in colorectal cancer cells. We found that PF inhibited cell growth and induced apoptosis and blocked cell cycle progression in the G0/G1 phase in colorectal cancer cells. Moreover, we found that PF suppressed cell migration and invasion in colorectal cancer cells. FoxM1 has been reported to play an important oncogenic role in human cancers. We also determine whether PF inhibited the expression of FoxM1, leading to its anti-cancer activity. We found that PF treatment in colorectal cancer cells resulted in down-regulation of FoxM1. The rescue experiments showed that overexpression of FoxM1 abrogated the tumor suppressive function induced by PF treatment. Notably, depletion of FoxM1 promoted the anti-tumor activity of PF in colorectal cancer cells. Therefore, inhibition of FoxM1 could participate in the anti-tumor activity of PF in colorectal cancer cells.

Decanoic acid suppresses proliferation and invasiveness of human trophoblast cells by disrupting mitochondrial function

Decanoic acid (DA) is a medium-chain fatty acid used in the manufacture of various products including plastics, cosmetics, and lubricants. In addition to antiviral and antibacterial effects, DA's, reported biological activities include regulation of signaling pathways and redox homeostasis in various human cell types. The influence of DA on functional properties of human trophoblasts, including proliferation, invasion and apoptosis is currently unknown. In the present study, we evaluated the anti-proliferative and anti-invasive effects of DA on the human trophoblast cell line HTR8/SVneo. In addition, DA induced oxidative stress, as evidenced by generation of reactive oxygen species (ROS) and induction of lipid peroxidation (LPO). This oxidative stress was accompanied by activation of the mitochondria-dependent apoptotic pathway in HTR8/SVneo cells. We also observed elevated mitochondrial Ca²⁺, and loss of mitochondrial membrane potential in response to DA treatment. Chelation of mitochondrial Ca²⁺ using BAPTA-AM rescued cellular proliferation suppressed by DA. We also verified that signaling proteins including AKT, P70S6K, S6, and ERK1/2 and their targets were significantly reduced in HTR8/SVneo cells by DA treatment. Pre-treatment of cells with selective inhibitors of AKT (LY294002) and ERK1/2 (U0126) revealed that the AKT and ERK1/2 signaling pathways regulated by DA displayed cross-talk in HTR8/SVneo cells. Collectively, these results suggest that personal products containing DA will have harmful effects on human trophoblasts, and could cause implantation and placentation failure during early pregnancy.

Induction of reactive oxygen species: an emerging approach for cancer therapy

Reactive oxygen species (ROS), a group of ions and molecules, include hydroxyl radicals (·OH), alkoxyl radicals, superoxide anion (O2·-), singlet oxygen (1O2) and hydrogen peroxide (H2O2). Hydroxyl radicals and alkoxyl radicals are extremely and highly reactive species respectively. Endogenous ROS are mainly formed in mitochondrial respiratory chain. Low levels of ROS play important roles in regulating biological functions in mammalian cells. However, excess production of ROS can induce cell death by oxidative damaging effects to intracellular biomacromolecules. Cancer cell death types induced by ROS include apoptotic, autophagic, ferroptotic and necrotic cell death. Since abnormal metabolism in cancer cells, they have higher ROS content compared to normal cells. The higher endogenous ROS levels in cancer cells endow them more susceptible to the ROS-induction treatment. Indeed, some anticancer drugs currently used in clinic, such as molecular targeted drugs and chemotherapeutic agents, effectively kill cancer cells by inducing ROS generation. In addition, photodynamic therapy (PDT) is mainly based on induction of ROS burst to kill cancer cells. The mechanism of cell death induced by radiotherapy using ionizing radiation also refers to ROS production. Moreover, ROS play an important role in tumor immune therapy. Altogether, combining above traditional treatments with ROS-induced agents will be considered as a promising strategy in cancer therapy. In this review, we focus on our current understanding of the anticancer effects of ROS.

miR-216b inhibits glioma cell migration and invasion through suppression of FoxM1

MicroRNAs (miRNAs) play a vital role in tumour biological and pathologic processes. In the present study, we aimed to detect the expression and biological role of miR-216b in glioma. Our data showed that miR-216b was significantly downregulated in human glioma tissues and cells. Ectopic expression of miR-216b inhibited the proliferation and invasion of U87 and U251 cells and suppressed the growth of xenograft tumours in vivo. Bioinformatic and luciferase reporter analyses identified Forkhead box protein M1 (FoxM1) as a direct target of miR-216b. Overexpression of miR-216b inhibited the expression of FoxM1 in glioma cells. Rescue experiments demonstrated that co-transfection of FoxM1 lacking the 3'-untranslated region partially prevented miR‑216b-induced inhibition of glioma cell growth and invasion. In vivo studies indicated that ectopic expression of miR-216b impeded the proliferation of glioma xenograft tumours in nude mice, coupled with a decreased in FoxM1 protein expression and the percentage of Ki-67-positive tumour cells. Taken together, our results provide evidence of the suppressive activity of miR‑216b in glioma, which is largely ascribed to downregulation of FoxM1. Restoration of miR-216b may provide a novel potential therapeutic agent for glioma.

A novel integrative risk index of papillary thyroid cancer progression combining genomic alterations and clinical factors

Although the majority of papillary thyroid cancer (PTC) is indolent, a subset of PTC behaves aggressively despite the best available treatment. A major clinical challenge is to reliably distinguish early on between those patients who need aggressive treatment from those who do not. Using a large cohort of PTC samples obtained from The Cancer Genome Atlas (TCGA), we analyzed the association between disease progression and multiple forms of genomic data, such as transcriptome, somatic mutations, and somatic copy number alterations, and found that genes related to FOXM1 signaling pathway were significantly associated with PTC progression. Integrative genomic modeling was performed, controlling for demographic and clinical characteristics, which included patient age, gender, TNM stages, histological subtypes, and history of other malignancy, using a leave-one-out elastic net model and 10-fold cross validation. For each subject, the model from the remaining subjects was used to determine the risk index, defined as a linear combination of the clinical and genomic variables from the elastic net model, and the stability of the risk index distribution was assessed through 2,000 bootstrap resampling. We developed a novel approach to combine genomic alterations and patient-related clinical factors that delineates the subset of patients who have more aggressive disease from those whose tumors are indolent and likely will require less aggressive treatment and surveillance (p = 4.62 × 10-10, log-rank test). Our results suggest that risk index modeling that combines genomic alterations with current staging systems provides an opportunity for more effective anticipation of disease prognosis and therefore enhanced precision management of PTC.

FoxM1 promotes epithelial-mesenchymal transition of hepatocellular carcinoma by targeting Snai1

Forkhead box protein M1 (FoxM1) is aberrantly expressed in several types of human malignancy, and serves an important role in tumor metastasis. Epithelial-mesenchymal transition (EMT) of cancer cells has been associated cancer metastasis; however, the implication of FoxM1 in EMT and its putative roles in the regulation of cancer metastasis remain to be elucidated. In the present study, the expression of FoxM1, Snai1 and E-cadherin in hepatocellular carcinoma (HCC) cell lines with various metastatic potentials, and in normal liver cells, was investigated using western blot analysis and reverse transcription-quantitative polymerase chain reaction. The effects of FoxM1 on the invasive and migratory capabilities of HCC cells were evaluated using wound healing and Transwell migration assays. The present results demonstrated that FoxM1 expression was significantly upregulated in HCC cells compared with in normal hepatocytes (P<0.05). In addition, FoxM1 expression was significantly increased in MHCC-LM3 cells, characterized by higher metastatic potential, compared with in SMMC-7721 cells, which have a lower metastatic potential. Furthermore, overexpression of FoxM1 was demonstrated to be negatively correlated with E-cadherin (P<0.05) and positively associated with Snai1 (P<0.05) expression. These observations suggested that FoxM1 may enhance the invasion and migration of cancer cells, and thus promotes their EMT, in a mechanism that may involve the regulation of Snai1. Therefore, it may be hypothesized that FoxM1 has potential as a novel diagnostic marker and therapeutic target for the treatment of patients with HCC.

CQ synergistically sensitizes human colorectal cancer cells to SN-38/CPT-11 through lysosomal and mitochondrial apoptotic pathway via p53-ROS cross-talk

Autophagy plays a key role in supporting cell survival against chemotherapy-induced apoptosis. In this study, we found the chemotherapy agent SN-38 induced autophagy in colorectal cancer (CRC) cells. However, inhibition of autophagy using a small molecular inhibitor 3-methyladenine (3-MA) and ATG5 siRNA did not increase SN-38-induced cytotoxicity in CRC cells. Notably, another autophagy inhibitor chloroquine (CQ) synergistically enhanced the anti-tumor activity of SN-38 in CRC cells with wild type (WT) p53. Subsequently, we identified a potential mechanism of this cooperative interaction by showing that CQ and SN-38 acted together to trigger reactive oxygen species (ROS) burst, upregulate p53 expression, elicit the loss of lysosomal membrane potential (LMP) and mitochondrial membrane potential (∆ψm). In addition, ROS induced by CQ plus SN-38 upregulated p53 levels by activating p38, conversely, p53 stimulated ROS. These results suggested that ROS and p53 reciprocally promoted each other's production and cooperated to induce CRC cell death. Moreover, we showed induction of ROS and p53 by the two agents provoked the loss of LMP and ∆ψm. Altogether, all results suggested that CQ synergistically sensitized human CRC cells with WT p53 to SN-38 through lysosomal and mitochondrial apoptotic pathway via p53-ROS cross-talk. Lastly, we showed that CQ could enhance CRC cells response to CPT-11 (a prodrug of SN-38) in xenograft models. Thus the combined treatment might represent an attractive therapeutic strategy for the treatment of CRC.

Forkhead Box Protein J1 (FOXJ1) is Overexpressed in Colorectal Cancer and Promotes Nuclear Translocation of β-Catenin in SW620 Cells

Background

FOXJ1, which is a forkhead transcription factor, has been previously studied mostly as a ciliary transcription factor. The role of FOXJ1 in cancer progression is still elusive and controversial. In the present study, the effect of FOXJ1 in progression of colorectal cancer (CRC) was investigated.

Material/Methods

The pattern of FOXJ1 expression was investigated using the method of immunohistochemistry (IHC) in a tissue microarray (TMA) incorporating 50 pairs of colon cancer specimens and adjacent normal tissue. In addition, the correlation of FOXJ1 expression with clinicopathological characteristics was evaluated in the other TMA containing 208 cases of colon cancer. Moreover, the influence of regulating FOXJ1 level on the proliferation, migration, and invasion ability of colorectal cancer (CRC) cells was evaluated.

Results

Increased expression of FOXJ1was significantly associated with clinical stage (p<0.05), metastasis of lymph node (p<0.05), and invasion depth (p<0.001) in colon cancer, suggesting FOXJ1 is a tumor promoter in CRC. Consistently, FOXJ1 overexpression significantly enhanced the proliferation, migration, and invasion of CRC cells, while silencing of FOXJ1 induced the opposite effect. Furthermore, up-regulation of FOXJ1 in SW620 cells markedly inhibited the level of truncated APC and the phosphorylation of β-catenin, while the level of cyclinD1 was decreased. In addition, overexpression of FOXJ1 significantly promoted nuclear translocation of β-catenin in SW620 cells.

Conclusions

These findings demonstrate that increased FOXJ1 contributes to the progression of CRC, which might be associated with the promotion effect of β-catenin nuclear translocation. FOXJ1 may be a novel therapeutic target in CRC.

Decreased expression of microRNA-17 and microRNA-20b promotes breast cancer resistance to taxol therapy by upregulation of NCOA3

Chemoresistance is a major obstacle to effective breast cancer chemotherapy. However, the underlying molecular mechanisms remain unclear. In this study, nuclear receptor coactivator 3 (NCOA3) was found to be significantly increased in taxol-resistant breast cancer tissues and cells. Moreover, overexpression of NCOA3 enhanced breast cancer cell resistance to taxol, whereas depletion of NCOA3 decreased taxol resistance. Subsequently, we investigated whether NCOA3 expression was regulated by miRNAs in breast cancer. By bioinformatics prediction in combination with the data of previous report, miR-17 and miR-20b were selected as the potential miRNAs targeting NCOA3. By real-time PCR analysis, we found that miR-17 and miR-20b were significantly reduced in taxol-resistant breast cancer tissues and cells. In addition, we provided some experimental evidences that miR-17 and miR-20b attenuated breast cancer resistance to taxol in vitro and in vivo models. Furthermore, by luciferase reporter assays, we further validated that both miR-17 and miR-20b directly binded the 3'-untranslated region of NCOA3 mRNA and inhibited its expression in breast cancer cells. Finally, both miR-17 and miR-20b levels were found to be significantly negatively correlated with NCOA3 mRNA levels in breast cancer tissues. Together, our results indicated that loss of miR-17 and miR-20b enhanced breast cancer resistance to taxol by upregulating NCOA3 levels. Our study suggested miR-17, miR-20b and NCOA3 may serve as some predictive biomarkers and potential therapeutic targets in taxol-resistant breast cancer treatment.

Downregulation of microRNA-27b-3p enhances tamoxifen resistance in breast cancer by increasing NR5A2 and CREB1 expression

Estrogen-dependent breast cancer is often treated with the aromatase inhibitors or estrogen receptor (ER) antagonists. Tamoxifen as a major ER antagonist is usually used to treat those patients with ERα-positive breast cancer. However, a majority of patients with ERα positive fail to respond to tamoxifen due to the presence of intrinsic or acquired resistance to the drug. Altered expression and functions of microRNAs (miRNAs) have been reportedly associated with tamoxifen resistance. In this study, we investigated the role of miR-27b-3p in resistance of breast cancer to tamoxifen. MiR-27b-3p levels were remarkably reduced in the tamoxifen-resistant breast cancer cells compared with their parental cells. In addition, miR-27b-3p was also significantly downregulated in breast tumor tissues relative to adjacent non-tumor tissues. Moreover, the expression levels of miR-27b-3p were lower in the breast cancer tissues from tamoxifen-resistant patients compared with that from untreated-tamoxifen patients. Notably, tamoxifen repressed miR-27b-3p expression, whereas estrogen induced miR-27b-3p expression in breast cancer cells. Besides, we provided experimental evidences that miR-27b-3p enhances the sensitivity of breast cancer cells to tamoxifen in vitro and in vivo models. More importantly, we validated that miR-27b-3p directly targeted and inhibited the expression of nuclear receptor subfamily 5 group A member 2 (NR5A2) and cAMP-response element binding protein 1 (CREB1) and therefore augmented tamoxifen-induced cytotoxicity in breast cancer. Lastly, miR-27b-3p levels were found to be significantly negatively correlated with both NR5A2 and CREB1 levels in breast cancer tissues. Our findings provided further evidence that miR-27b-3p might be considered as a novel and potential target for the diagnosis and treatment of tamoxifen-resistant breast cancer.