Decreased expression of BATF2 is significantly associated with poor prognosis in oral tongue squamous cell carcinoma

miR-939-3p induces sarcoma proliferation and poor prognosis via suppressing BATF2

Background

Sarcoma is a rare and aggressive malignancy with poor prognosis, in which oncogene activation and tumor suppressor inactivation are involved. Accumulated studies suggested basic leucine zipper transcription factor ATF-like 2 (BATF2) as a candidate tumor suppressor, but its specific role and mechanism in sarcoma remain unclear.

Methods

The expression levels of BATF2 and miR-939-3p were evaluated by using human sarcoma samples, cell lines and xenograft mouse models. Bioinformatics analysis, qPCR, Western blot, cell proliferation assay, overexpression plasmid construction, point mutation and dual luciferase reporter assay were utilized to investigate the role and mechanism of miR-939-3p in sarcoma.

Results

In this study, we demonstrated that the expression of BATF2 was downregulated in human sarcoma tissues and cell lines. The downregulation of BATF2 was negatively associated with the prognosis of sarcoma patients. Subsequent bioinformatic prediction and experimental validations showed that BATF2 expression was reduced by microRNA (miR)-939-3p mimic and increased by miR-939-3p inhibitor. Additionally, miR-939-3p was upregulated in sarcoma tissues and cells, correlating with a poor prognosis of sarcoma patients. Moreover, miR-939-3p overexpression suppressed sarcoma cell proliferation, which was significantly attenuated by the restoration of BATF2, while siRNA-mediated knockdown of BATF2 aggravated the miR-939-3p-induced promotion of sarcoma cell proliferation. Further computational algorithms and dual-luciferase reporter assays demonstrated that miR-939-3p repressed BATF2 expression via directly binding to its 3' untranslated region (3' UTR).

Conclusion

Collectively, these findings identified miR-939-3p as a novel regulator of BATF2, as well as a prognostic biomarker in sarcoma, and revealed that suppressing miR-939-3p or inducing BATF2 expression may serve as a promising therapeutic strategy against sarcoma.

Nuclear export of BATF2 enhances colorectal cancer proliferation through binding to CRM1

BACKGROUND

During the tumourigenesis and development of colorectal cancer (CRC), the inactivation of tumour suppressor genes is closely involved, although detailed molecular mechanisms remain elusive. Accumulating studies, including ours, have demonstrated that basic leucine zipper transcription factor ATF (activating transcription factor)-like 2 (BATF2) is a capable tumour suppressor that localises in the nucleus. However, its different subcellular localisation, potential functions and underlying mechanisms are unclear.

METHODS

The translocation of BATF2 and its clinical relevance were detected using CRC samples, cell lines and xenograft nude mice. Candidate BATF2-binding proteins were screened using co-immunoprecipitation, quantitative label-free liquid chromatography-tandem mass spectrometry proteomic analysis, Western blotting and immunofluorescence. Recombinant plasmids, point mutations and siRNAs were applied to clarify the binding sites between BATF2 and chromosome region maintenance 1 (CRM1).

RESULTS

The present study found that BATF2 was mainly localised in the cytoplasm, rather than nucleus, of CRC cells in vitro and in vivo, while cytoplasmic BATF2 expression was inversely correlated with the prognosis of CRC patients. Furthermore, we identified the nuclear export and subsequent ubiquitin-mediated degradation of BATF2 in CRC cells. Mechanistically, a functional nuclear export sequence (any amino acid) was characterised in BATF2 protein, through which BATF2 bound to CRM1 and translocated out of nucleus, ultimately enhancing CRC growth via inducing activator protein 1 (AP-1)/cyclin D1/phosphorylated retinoblastoma protein (pRb) signalling pathway. Additionally, nuclear export of BATF2 can be retarded by the mutation of NES in BATF2 or the knockdown of CRM1, whereas CRM1 expression was negatively associated with nuclear BATF2 expression and the prognosis of CRC patients.

CONCLUSION

These findings revealed the biological effects and underlying mechanisms of cytoplasmic localisation of BATF2. Furthermore, suppressing nuclear export of BATF2 via mutating its NES region or inhibiting CRM1 expression may serve as a promising therapeutic strategy against CRC.

m6A modification-mediated BATF2 suppresses metastasis and angiogenesis of tongue squamous cell carcinoma through inhibiting VEGFA

The aim is to explore the underlying mechanism of basic leucine zipper ATF-like transcription factor 2 (BATF2) in tongue squamous cell carcinoma (TSCC). The expression of BATF2 in TSCC tissues and corresponding adjacent normal TSCC tissues, human TSCC cell lines (SCC-15 and CAL-27) and human normal tongue epithelial cells NTEC was detected. Then, SCC-15 cells with stable BATF2 knockdown and CAL-27 cells with BATF2 overexpression were established to investigate the functional effect of BATF2 on TSCC. Thereafter, the effect of BATF2 on TSCC angiogenesis and BATF2 m6A methylation was also examined. BATF2 was significantly downregulated in TSCC tissues and cell lines, and BATF2 overexpression could suppress growth, metastasis and angiogenesis of TSCC. Mechanistically, vascular endothelial growth factor A (VEGFA) was identified as a downstream gene of BATF2, and it was confirmed that BATF2 suppressed growth, metastasis and angiogenesis of TSCC via inhibiting VEGFA. In addition, the N6-methyladenosine (m6A) modification of BATF2 mRNA mediated by METTL14 suppressed its expression in TSCC. METTL14/BATF2 axis could serve as a novel promising therapeutic candidate against angiogenesis for TSCC.

Single-Molecule RNA Sequencing Reveals IFNγ-Induced Differential Expression of Immune Escape Genes in Merkel Cell Polyomavirus-Positive MCC Cell Lines

Merkel cell carcinoma (MCC) is a rare and highly aggressive cancer, which is mainly caused by genomic integration of the Merkel cell polyomavirus and subsequent expression of a truncated form of its large T antigen. The resulting primary tumor is known to be immunogenic and under constant pressure to escape immune surveillance. Because interferon gamma (IFNγ), a key player of immune response, is secreted by many immune effector cells and has been shown to exert both anti-tumoral and pro-tumoral effects, we studied the transcriptomic response of MCC cells to IFNγ. In particular, immune modulatory effects that may help the tumor evade immune surveillance were of high interest to our investigation. The effect of IFNγ treatment on the transcriptomic program of three MCC cell lines (WaGa, MKL-1, and MKL-2) was analyzed using single-molecule sequencing via the Oxford Nanopore platform. A significant differential expression of several genes was detected across all three cell lines. Subsequent pathway analysis and manual annotation showed a clear upregulation of genes involved in the immune escape of tumor due to IFNγ treatment. The analysis of selected genes on protein level underlined our sequencing results. These findings contribute to a better understanding of immune escape of MCC and may help in clinical treatment of MCC patients. Furthermore, we demonstrate that single-molecule sequencing can be used to assess characteristics of large eukaryotic transcriptomes and thus contribute to a broader access to sequencing data in the community due to its low cost of entry.

Identification of prognostic immune genes in laryngeal cancer

Objective

In this study, we aimed to identify prognostic immune-related genes and establish a prognostic model for laryngeal cancer based on these genes.

Methods

Transcriptome profiles and clinical data of patients with laryngeal cancer were downloaded from The Cancer Genome Atlas database. Integrated bioinformatics analyses were performed to identify genes associated with prognosis.

Results

Thirty prognostic immune-related genes for laryngeal cancer were identified. We constructed a regulatory network of prognosis comprising transcription factors and immune-related genes. Multivariate Cox regression analyses identified 15 immune-related genes in the network that were used to establish the prognostic model. The model exhibited excellent prognostic prediction ability with a high area under the curve value (0.916). The calculated risk score based on expression of the 15 immune-related genes was shown to be an independent prognostic factor for laryngeal cancer.

Conclusion

We identified prognostic immune-related genes and established a prognostic model for laryngeal cancer, which might help identify novel predictive biomarkers and therapeutic targets of laryngeal cancer.

Deregulation of extracellular matrix modeling with molecular prognostic markers revealed by transcriptome sequencing and validations in Oral Tongue squamous cell carcinoma

Oral Tongue Squamous Cell Carcinoma (OTSCC), a distinct sub-group of head and neck cancers, is characteristically aggressive in nature with a higher incidence of recurrence and metastasis. Recent advances in therapeutics have not improved patient survival. The phenomenon of occult node metastasis, even among the purportedly good prognosis group of early-stage and node-negative tongue tumors, leads to a high incidence of locoregional failure in OTSCC which needs to be addressed. In the current study, transcriptome analysis of OTSCC patients identified the key genes and deregulated pathways. A panel of 26 marker genes was shortlisted and validated using real-time PCR in a prospective cohort of 100 patients. The gene expression was correlated with clinicopathological features including occult node metastasis, survival, and therapeutic outcome. The up-regulation of a panel of 6 genes namely, matrix metalloproteinase 9 (MMP9), Laminin subunit Gamma 2 (LAMC2), Desmoglein 2 (DSG2), Plasminogen Activator Urokinase (PLAU), Forkhead Box M1 (FOXM1), and Myosin 1B (MYO1B) was associated with failure of treatment in the early stage (T1, T2). Up-regulation of Tenacin C (TNC) and Podoplanin (PDPN) was significantly correlated with occult node positivity. Immunohistochemical analysis of LAMC2, MMP9, and E-Cadherin (ECAD) confirmed these markers to be indicators of poor prognosis. We propose this panel of valuable prognostic markers can be clinically useful to identify poor prognosis and occult node metastasis in OTSCC patients.

A novel immune checkpoint-related seven-gene signature for predicting prognosis and immunotherapy response in melanoma

BACKGROUND

New emergence of immunotherapy has significantly improved clinical outcome of melanoma patients with advanced and metastatic diseases. We aimed to develop a gene signature based on the expression of PD-1/PD-L1 signaling pathway genes to predict prognosis and immunotherapy response in melanoma patients.

METHODS

Melanoma samples from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) were used as the training set and external validation sets respectively. Prognostic genes for overall survival (OS) were identified by univariate Cox regression analysis. Then a multi-gene risk signature was established with the Least Absolute Shrinkage and Selector Operation (LASSO) regression and multivariate Cox regression. The predictive and prognostic value of gene signature was evaluated by Kaplan Meier curve, Time-dependent receiver operating characteristic (ROC) curve, and area under curve (AUC). Gene set enrichment analysis (GSEA) was performed to investigate the discrepantly enriched biological processes between low-risk and high-risk group of melanoma patients.

RESULTS

A seven-gene risk signature (BATF2, CTLA4, EGFR, HLA-DQB1, IKBKG, PIK3R2, PPP3CA) was constructed. The signature was an independent risk factor for OS (hazard ratio = 1.544, p < 0.001) and it could robustly predict OS in both training and validation sets. Besides, high risk scores indicated advanced clinical stage and no response to immunotherapy for melanoma patients. GSEA demonstrated that high risk score was intimately associated with immune response and immune regulation. In conclusion, the novel seven-gene signature could serve as a robust biomarker for prognosis and a potential indicator of immunotherapy response in melanoma.

Suppressor of activator protein-1 regulated by interferon expression in prostate cancer tissues and cells

PURPOSE

The aim of this study was to investigate the role of the suppressor of activator protein-1 regulated by interferon (SARI), in the development and progression of prostate cancer.

METHODS

Sixty-seven prostate cancer tissue specimens and 20 benign prostatic hyperplasia specimens were used to investigate the correlation between SARI expression and clinicopathologic parameters. Immunohistochemistry was used to detect the SARI and E-cadherin protein expression in the prostate cancer and benign prostatic hyperplasia specimens, and their correlation was established. Quantitative PCR (qPCR) was used to determine the SARI mRNA expression in a normal prostate cell line (RWPE-1) and prostate cancer cell lines (LNCaP and PC3). Western blotting was used to detect the SARI protein expression in the RWPE-1, LNCaP, and PC3 cell lines.

RESULTS

SARI protein expression did not correlate with the prostate cancer patients' age or serum Prostate-Specific Antigen value but did show a correlation with the tumor stage of prostate cancer and Gleason score. SARI and E-cadherin expression in the prostate cancer tissue was significantly lower than in the benign prostatic hyperplasia specimens, suggesting a positive correlation between the SARI and E-cadherin expression. SARI mRNA and protein were highly expressed in RWPE-1, the normal prostate cell line, but SARI mRNA and protein expression were reduced in the prostate cancer cell lines, LNCaP and PC3. Significant differences in the expression were found between the prostate cancer cell lines and the normal prostate cell line.

CONCLUSION

In this study, high SARI expression was found to be negatively correlated with the development and progression of prostate cancer.

Calycosin suppresses TGF-β-induced epithelial-to-mesenchymal transition and migration by upregulating BATF2 to target PAI-1 via the Wnt and PI3K/Akt signaling pathways in colorectal cancer cells

OBJECTIVES

To determine whether the upregulation of basic leucine zipper ATF-like transcription factor 2 (BATF2) by calycosin suppresses the growth and epithelial-to-mesenchymal transition (EMT) in human colorectal cancer (CRC) cells.

METHOD

Cells were cultured and treated with different concentrations of calycosin for different periods of time. Protein and mRNA expression was determined by western blotting and quantitative PCR. Cell migration was assessed by Transwell experiments. Co-immunoprecipitation and luciferase assays were used to analyze the association between BATF2 and plasminogen activator inhibitor-1. (PAI-1). Cell apoptosis was determined by flow cytometry; β-catenin cellular localization was visualized by immunofluorescent staining.

RESULTS

Calycosin up-regulated the expression of BATF2 via the signal transducer and activator of transcription 3 (STAT3) pathway, which was antagonized by transforming growth factor beta (TGF-β), calycosin promoted the cell apoptosis and growth inhibition via phosphoinositide 3-kinase (PI3K)/Akt pathway. TGF-β promoted cell growth, which was inhibited by calycosin regulating the expression of proliferating cell nuclear antigen (PCNA) via the phosphoinositide 3-kinase pathway. TGF-β suppressed expression of BAX via the phosphoinositide 3-kinase pathway but induced cell apoptosis .calycosin enhanced the effect of TGF-β on cell apoptosis,In addition, calycosin suppressed TGF-β-induced cell migration by increasing BATF2 to target PAI-1. TGF-β-induced EMT was inhibited by calycosin in human CRC LoVo and HCT116 cell lines via the Wnt signaling pathway.

CONCLUSIONS

The induction of BATF2 by calycosin may be a feasible therapeutic option for CRC. .

A review of the most promising biomarkers for early diagnosis and prognosis prediction of tongue squamous cell carcinoma

BACKGROUND

There is a great interest in developing biomarkers to enhance early detection and clinical management of tongue squamous cell carcinoma (TSCC). However, the developmental path towards a clinically valid biomarker remains extremely challenging. Ideally, the initial key step in moving a newly discovered biomarker towards clinical implementation is independent replication. Therefore, the focus of this review is on biomarkers that consistently showed clinical relevance in two or more publications.

METHODS

We searched PubMed database for relevant papers across different TSCC sample sources, i.e., body fluids (saliva, serum/plasma) and tissues. No restriction regarding the date of publication was applied except for immunohistochemistry (IHC); only studies published between 2010 and June 2017 were included.

RESULTS

The search strategy identified 1429 abstracts, of which 96 papers, examining 150 biomarkers, were eventually included. Of these papers, 66% were exploratory studies evaluating single or a panel of biomarkers in one publication. Ultimately, based on studies that had undergone validation for their clinical relevance in at least two independent studies, we identified 10 promising candidates, consisting of different types of molecules (IL-6, IL-8, and Prolactin in liquid samples; HIF-1α, SOX2, E-cadherin, vimentin, MALAT1, TP53, and NOTCH1 in tissue biopsies) CONCLUSIONS: Although more exploratory research is needed with newer methods to identify biomarkers for TSCC, rigorous validation of biomarkers that have already shown unbiased assessment in at least two publications should be considered a high priority. Further research on these promising biomarkers or their combination in multi-institutional studies, could provide new possibilities to develop a specific panel for early diagnosis, prognosis, and individualized treatments.

Antitumor effect of Batf2 through IL-12 p40 up-regulation in tumor-associated macrophages

The development of effective treatments against cancers is urgently needed, and the accumulation of CD8⁺ T cells within tumors is especially important for cancer prognosis. Although their mechanisms are still largely unknown, growing evidence has indicated that innate immune cells have important effects on cancer progression through the production of various cytokines. Here, we found that basic leucine zipper transcription factor ATF-like 2 (Batf2) has an antitumor effect. An s.c. inoculated tumor model produced fewer IL-12 p40⁺ macrophages and activated CD8⁺ T cells within the tumors of Batf2^-/- mice compared with WT mice. In vitro studies also revealed that the IL-12 p40 expression was significantly lower in Batf2^-/- macrophages following their stimulation by toll-like receptor ligands, such as R848. Additionally, we found that BATF2 interacts with p50/p65 and promotes IL-12 p40 expression. In conclusion, Batf2 has an antitumor effect through the up-regulation of IL-12 p40 in tumor-associated macrophages, which eventually induces CD8⁺ T-cell activation and accumulation within the tumor.

Effects and mechanisms of action of SARI on androgen-independent prostate cancer (DU145) cells

This study aimed to characterize the role and mechanisms of action of suppressor of AP-1, regulated by IFN (SARI) in androgen-independent prostate cancer cells using the DU145 cell line. Prostate cancer cell lines were transfected to permit both the overexpression and inhibition of SARI. MTT assays and Transwell assays were performed to detect the effects of SARI overexpression and inhibition on the proliferation activity, invasiveness, and metastatic ability of DU145 cells. Expression of vascular endothelial growth factor (VEGF) and tyrosine-phosphorylated signal transducer and activator of transcription 3 (p-STAT3) was monitored in the experimental groups using a qPCR assay and western blot analysis. Additionally, DU145 cells were separately treated with 5, 50, and 100 μmol/L AG490 for 48 h and SARI expression was detected using the qPCR assay and western blot analysis. We also monitored the effects of AG490 treatment (100 μmol/L for 48 h) on both the SARI-SiRNA DU145 cells and empty vector DU145 (DU145-V) cells using the MTT assay and a Transwell migration assay. SARI overexpression and SARI-SiRNA DU145 prostate cancer cell lines were successfully established. The proliferation activity and the invasion and migration abilities of DU145-SARI cells were significantly lower compared with the DU145-V group (P < 0.05). Conversely, the proliferation activity and the invasion and migration abilities of SARI-SiRNA cells were significantly higher compared with the DU145-V group (P < 0.05). VEGF and p-STAT3 expression levels were lower in the SARI overexpression group compared with the DU145-V group and the control group (P < 0.05). In contrast, VEGF and p-STAT3 expression levels were higher in the SARI-SiRNA group compared with both the DU145-V group and the control group (P < 0.05). In comparison with the control group, SARI expression levels were higher in DU145 cells treated with 50 and 100 μmol/L AG490. Upon treatment with 100 μmol/L AG490 for 48 h, the proliferation activity and invasiveness and migration abilities of SARI-SiRNA cells were significantly higher compared with the DU145-V group (P < 0.05). SARI significantly affects the proliferation, invasion, and metastasis of DU145 cells. It is possible that SARI inhibits the proliferation, invasion, and migration of androgen-independent prostate cancer cells by regulating downstream genes through the SARI/STAT3/VEGF pathways.

BCL-2 inhibition impairs mitochondrial function and targets oral tongue squamous cell carcinoma

Purpose

To understand the role of Bcl-2 overexpression in oral tongue squamous cell carcinoma (OTSCC) patients and investigate the efficacy of targeting Bcl-2 in OTSCC.

Methods

The expression level of Bcl-2 on normal tongue cells and OTSCC cells were measured by real-time PCR and western blotting. The functional roles of Bcl-2 were examined by MTS, flow cytometry and xenograft cancer mouse model. Mechanism studies were performed by analyzing mitochondrial functions in a panel of OTSCC cell lines.

Results

Bcl-2 is up-regulated at mRNA and protein levels in a panel of OTSCC cell lines compared to normal tongue epithelial cells (NTEC). Importantly, overexpression of Bcl-2 confers resistance of OTSCC cells to chemotherapeutic drug cisplatin treatment. Overexpression of Bcl-2 in NTEC significantly increased cell growth. In contrast, inhibition of Bcl-2 by genetic and pharmacological approaches inhibits proliferation and induces apoptosis in OTSCC cells. Mechanistically, Bcl-2 inhibitor ABT-199 impairs mitochondrial functions as shown by the decreased levels of mitochondrial membrane potential, mitochondrial respiration and ATP, and the increased levels of ROS in OTSCC cells. In addition, ABT-199 inhibits proliferation and induces apoptosis and mitochondrial dysfunctions in NTEC cells, but to a less extent than in OTSCC cells. We further show that ABT-199 augments the effects of cisplatin in eliminating OTSCC cells in in vitro tongue cancer cellular system and in vivo tongue cancer xenograft mouse model.

Conclusions

Inhibition of Bcl-2 effectively targets OTSCC cells through inhibiting proliferation and inducing apoptosis. Inhibition of Bcl-2 also augments the inhibitory effects of cisplatin in vitro and in vivo.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-3310-2) contains supplementary material, which is available to authorized users.

Targeting Batf2 for infectious diseases and cancer

The family members Batf, Batf2 and Batf3 belong to a class of transcription factors containing basic leucine zipper domains that regulate various immunological functions and control the development and differentiation of immune cells. Functional studies by others demonstrated a predominant role for Batf in controlling Th2 cell functions and lineage development of T lymphocytes as well as a critical role of Batf, Batf2 and Batf3 in CD8α+dendritic cell development. Moreover, Batf family member expression was measured in a vast collection of mouse and human cell types by cap analysis gene expression (CAGE), a recent developed sequencing technology, showing reasonable expression spectrum in immune cells consistent with previously published expression profiles. Batf and Batf3 were highly expressed in lymphocytes and the earlier moderately expressed in myeloid lineages. Batf2 was predominantly expressed in monocytes/macrophages. Functional studies in mice demonstrated that Batf2 has a central role in macrophage activation by regulating inflammatory responses during lipopolysaccharides stimulation and mycobacterial infection. Hence, Batf2 could be used as a biomarker and a potential host directed drug target in tuberculosis. Moreover, Batf2 act as a tumor suppressor gene and augmenting Batf2 in malignant cells might be an encouraging therapeutic treatment against cancer.

SARI inhibits angiogenesis and tumour growth of human colon cancer through directly targeting ceruloplasmin

SARI, also called as BATF2, belongs to the BATF family and has been implicated in cancer cell growth inhibition. However, the role and mechanism of SARI in tumour angiogenesis are elusive. Here we demonstrate that SARI deficiency facilitates AOM/DSS-induced colonic tumorigenesis in mice. We show that SARI is a novel inhibitor of colon tumour growth and angiogenesis in mice. Antibody array and HUVEC-related assays indicate that VEGF has an essential role in SARI-controlled inhibition of angiogenesis. Furthermore, Co-IP/PAGE/mass spectrometry indicates that SARI directly targets ceruloplasmin (Cp), and induces protease degradation of Cp, thereby inhibiting the activity of the HIF-1α/VEGF axis. Tissue microarray results indicate that SARI expression inversely correlates with poor clinical outcomes in colon cancer patients. Collectively, our results indicate that SARI is a potential target for therapy by inhibiting angiogenesis through the reduction of VEGF expression and is a prognostic indicator for patients with colon cancer.

Apoptosis transcriptional mechanism of feline infectious peritonitis virus infected cells

Apoptosis has been postulated to play an important role during feline infectious peritonitis virus (FIPV) infection; however, its mechanism is not well characterized. This study is focused on apoptosis and transcriptional profiling of FIPV-infected cells following in vitro infection of CRFK cells with FIPV 79-1146 WSU. Flow cytometry was used to determine mode of cell death in first 42 h post infection (hpi). FIPV infected cells underwent early apoptosis at 9 hpi (p < 0.05) followed by late apoptosis at 12 hpi (p < 0.05) and necrosis from 24 hpi (p < 0.05). Then, next generation sequencing was performed on 9 hpi and control uninfected cells by Illumina analyzer. An aggregate of 4546 genes (2229 down-regulated and 2317 up-regulated) from 17 cellular process, 11 molecular functions and 130 possible biological pathways were affected by FIPV. 131 genes from apoptosis cluster (80 down-regulated and 51 up-regulated) along with increase of apoptosis, p53, p38 MAPK, VEGF and chemokines/cytokines signaling pathways were probably involved in apoptosis process. Six of the de-regulated genes expression (RASSF1, BATF2, MAGEB16, PDCD5, TNFα and TRAF2) and TNFα protein concentration were analyzed by RT-qPCR and ELISA, respectively, at different time-points. Up-regulations of both pro-apoptotic (i.e. PDCD5) and anti-apoptotic (i.e. TRAF2) were detected from first hpi and continuing to deregulate during apoptosis process in the infected cells.

BATF2 Deficiency Promotes Progression in Human Colorectal Cancer via Activation of HGF/MET Signaling: A Potential Rationale for Combining MET Inhibitors with IFNs

PURPOSE

BATF2, a novel IFN-stimulated gene, inhibits tumor cell proliferation, invasion, and migration. The objectives of this study were to determine how BATF2 expression is associated with colorectal cancer progression and patient outcome, to investigate how BATF2 overexpression inhibits hepatocyte growth factor (HGF)/MET signaling, and to elucidate the rationale for combining MET inhibitors with IFN.

EXPERIMENTAL DESIGN

BATF2 expression in colorectal cancer tissues was determined and correlated with colorectal cancer patient prognosis. Cultured colorectal cancer cells were used to investigate the effects of BATF2 overexpression on the malignant phenotype of colorectal cancer cells and HGF/MET signaling. Tumor xenograft models were used to validate the effects of BATF2 on colorectal cancer xenograft growth and assess the efficacy of the combination of MET inhibitors with IFNs in colorectal cancer.

RESULTS

In colorectal cancer tissues, BATF2 was found to be significantly downregulated, and its expression negatively correlated with MET expression. Decreased BATF2 expression was associated with progression and shorter patient survival in colorectal cancer. BATF2 overexpression promoted apoptosis and inhibited proliferation, migration, and invasion in colorectal cancer cells, as well as dramatically blunted tumor xenograft growth. In addition, MET inhibitors in combination with IFNβ produced synergistic cytotoxicity both in vitro and in vivo.

CONCLUSIONS

Together, these novel findings suggest that BATF2, a tumor suppressor gene, is a potent negative regulator of HGF/MET signaling in colorectal cancer and may serve as a prognostic tumor marker. Furthermore, these results provide a rationale for combining MET inhibitors with IFNs in preclinical trials.