Inhibition of transforming growth factor-β-activated kinase-1 blocks cancer cell adhesion, invasion, and metastasis

Comprehensive analyses reveal the prognosis and biological function roles of chromatin regulators in lung adenocarcinoma

The present study explored the prognosis and biological function roles of chromatin regulators (CRs) in patients with lung adenocarcinoma (LUAD). Using transcriptome profile and clinical follow-up data of LUAD dataset, we explored the molecular classification, developed, and validated a CR prognostic model, built an individual risk scoring system in LUAD, and compared the clinical and molecular characteristics between different subtypes and risk stratifications. We investigated the chemotherapy sensitivity and predicted potential immunotherapy response. Lastly, we collected the clinical samples and validated the prognosis and potential function role of NAPS2. Our study indicated that LUAD patients could be classified into two subtypes that had obviously different clinical background and molecular features. We constructed a prognostic model with eight CR genes, which was well validated in several other population cohort. We built high- and low-risk stratifications for LUAD patients. Patients from high-risk group were totally different from low-risk groups in clinical, biological function, gene mutation, microenvironment, and immune infiltration levels. We idented several potential molecular compounds for high-risk group treatment. We predicted that high-risk group may have poor immunotherapy response. We finally found that Neuronal PAS Domain Protein 2 (NPAS2) involved in the progression of LUAD via regulating cell adhesion. Our study indicated that CR involved in the progression of LUAD and affect their prognosis. Different therapeutic strategies should be developed for different molecular subtypes and risk stratifications. Our comprehensive analyses uncover specific determinants of CRs in LUAD and provides implications for investigating disease-associated CRs.

HDAC6-dependent deacetylation of TAK1 enhances sIL-6R release to promote macrophage M2 polarization in colon cancer

Histone deacetylase 6 (HDAC6), a member of the HDAC family, has been identified as a potential therapeutic target for tumor therapy, but the function and underlying mechanisms of HDAC6 in colon cancer are incompletely characterized. Our study showed that the infiltration ratio of M2 macrophages was increased in colon cancer tissues with high HDAC6 expression. Similarly, the knockdown of HDAC6 in colon cancer cells inhibited cocultured macrophage M2 polarization in vitro. Analysis of the antibody chip revealed that HDAC6 promoted sIL-6R release to enhance macrophage M2 polarization. Mass spectrometry and immunoprecipitation demonstrated that, mechanistically, HDAC6 interacted with transforming growth factor β-activated kinase 1 (TAK1), deacetylated TAK1 at T178 and promoted TAK1 phosphorylation. TAK1-p38 MAPK signaling could further increase the phosphorylation and activity of ADAM17, which is responsible for shedding of IL-6R. Notably, the expression of phosphorylated TAK1 was positively correlated with HDAC6 expression and macrophage M2 polarization in human colon cancer tissues. Our study revealed a new HDAC6-TAK1-ADAM17 regulatory axis that mediates sIL-6R release and macrophage polarization in colon cancer.

Transforming Growth Factor-β Activated Kinase 1 (Tak1) Is Activated in Hepatocellular Carcinoma, Mediates Tumor Progression, and Predicts Unfavorable Outcome

Simple Summary

Chronic inflammation is known to drive cancer initiation and progression in the liver and other organs. In different genetic mouse models, the role of the pro-inflammatory kinase Tak1 in liver cancer development has been controversial so far. To clarify the role of Tak1 in human hepatocellular carcinoma (HCC), we investigated the expression of Tak1 in a large and clinicopathologically well-characterized patient cohort with HCC. In human livers and HCCs, Tak1 is predominantly present in its isoform Tak1A localizing to the cell nucleus. Tak1 is upregulated in HCCs of the diethylnitrosamine mouse model as well as in human HCCs, independent of etiology, and is further induced in distant metastases. Overexpression of the isoform Tak1A in the HCC cell line Huh7 resulted in increased tumor cell migration, whereas overexpression of full-length Tak1 had no significant effect. In human HCCs, high nuclear Tak1 expression is associated with vascular invasion and short overall survival.

Abstract

Although knowledge on inflammatory signaling pathways driving cancer initiation and progression has been increasing, molecular mechanisms in hepatocarcinogenesis are still far from being completely understood. Hepatocyte-specific deletion of the MAPKKK Tak1 in mice recapitulates important steps of hepatocellular carcinoma (HCC) development, including the occurrence of cell death, steatohepatitis, dysplastic nodules, and HCCs. However, overactivation of Tak1 in mice upon deletion of its deubiquitinase Cyld also results in steatohepatitis and HCC development. To investigate Tak1 and Cyld in human HCCs, we created a tissue microarray to analyze their expression by immunohistochemistry in a large and well-characterized cohort of 871 HCCs of 561 patients. In the human liver and HCC, Tak1 is predominantly present as its isoform Tak1A and predominantly localizes to cell nuclei. Tak1 is upregulated in diethylnitrosamine-induced mouse HCCs as well as in human HCCs independent of etiology and is further induced in distant metastases. A high nuclear Tak1 expression is associated with short survival and vascular invasion. When we overexpressed Tak1A in Huh7 cells, we observed increased tumor cell migration, whereas overexpression of full-length Tak1 had no significant effect. A combined score of low Cyld and high Tak1 expression was an independent prognostic marker in a multivariate Cox regression model.

PCAT-1 promotes cell growth by sponging miR-129 via MAP3K7/NF-κB pathway in multiple myeloma

Loss of one or some specific miRNA-mediated regulation is closely associated with malignant progression of multiple myeloma (MM). But how these miRNAs work and what role the specific miRNA plays in this process of malignant progression remain unclear. It was found in this study that the expression of miR-129 was decreased in both MM cell lines and newly diagnosed MM patients. Further clinicopathological statistics showed that miR-129 was correlated with the isotype of MM patients. MiR-129 overexpression disturbed cell proliferation, cell cycle evolution and spurred apoptosis both in vitro and in vivo. MAP3K7, a kinase able to activate NF-κB circuit, was found to be up-regulated in MM and contain a binding target of miR-129. In addition, lncRNA PCAT-1 functioned to sponge miR-129 and thereby lowered its expression. PCAT-1 knockdown eliminated the tumour-promoting effect caused by miR-129 inhibition, probably through repressing MAP3K7 and subsequent NF-κB activation. To the best of our knowledge, this is the first study to have discovered that increased expression of PCAT-1 could augment cell proliferation and cycle procession and inhibit apoptosis by down-regulating miR-129 via the MAP3K7/NF-κB pathway in MM.

Multifaceted roles of TAK1 signaling in cancer

Context-specific signaling is a prevalent theme in cancer biology wherein individual molecules and pathways can have multiple or even opposite effects depending on the tumor type. TAK1 represents a particularly notable example of such signaling diversity in cancer progression. Originally discovered as a TGF-β-activated kinase, over the years it has been shown to respond to numerous other stimuli to phosphorylate a wide range of downstream targets and elicit distinct cellular responses across cell and tissue types. Here we present a comprehensive review of TAK1 signaling and provide important therapeutic perspectives related to its function in different cancers.

MAP3K7 is recurrently deleted in pediatric T-lymphoblastic leukemia and affects cell proliferation independently of NF-κB

BACKGROUND

Deletions of 6q15-16.1 are recurrently found in pediatric T-cell acute lymphoblastic leukemia (T-ALL). This chromosomal region includes the mitogen-activated protein kinase kinase kinase 7 (MAP3K7) gene which has a crucial role in innate immune signaling and was observed to be functionally and prognostically relevant in different cancer entities. Therefore, we correlated the presence of MAP3K7 deletions with clinical parameters in a cohort of 327 pediatric T-ALL patients and investigated the function of MAP3K7 in the T-ALL cell lines CCRF-CEM, Jurkat and MOLT-4.

METHODS

MAP3K7 deletions were detected by multiplex ligation-dependent probe amplification (MLPA). T-ALL cell lines were transduced with adeno-associated virus (AAV) vectors expressing anti-MAP3K7 shRNA or a non-silencing shRNA together with a GFP reporter. Transduction efficiency was measured by flow cytometry and depletion efficiency by RT-PCR and Western blots. Induction of apoptosis was measured by flow cytometry after staining with PE-conjugated Annexin V. In order to assess the contribution of NF-κB signaling to the effects of MAP3K7 depletion, cells were treated with TNF-α and cell lysates analyzed for components of the NF-κB pathway by Western blotting and for expression of the NF-κB target genes BCL2, CMYC, FAS, PTEN and TNF-α by RT-PCR.

RESULTS

MAP3K7 is deleted in approximately 10% and point-mutated in approximately 1% of children with T-ALL. In 32 of 33 leukemias the deletion of MAP3K7 also included the adjacent CASP8AP2 gene. MAP3K7 deletions were associated with the occurrence of SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and outcome. Depletion of MAP3K7 expression in T-ALL cell lines by shRNAs slowed down proliferation and induced apoptosis, but neither changed protein levels of components of NF-κB signaling nor NF-κB target gene expression after stimulation with TNF-α.

CONCLUSIONS

This study revealed that the recurrent deletion of MAP3K7/CASP8AP2 is associated with SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and risk of relapse. Homozygous deletions of MAP3K7 were not observed, and efficient depletion of MAP3K7 interfered with viability of T-ALL cells, indicating that a residual expression of MAP3K7 is indispensable for T-lymphoblasts.

TAK1 mediates microenvironment-triggered autocrine signals and promotes triple-negative breast cancer lung metastasis

Triple-negative breast cancer (TNBC) is a highly metastatic subtype of breast cancer that has limited therapeutic options. Thus, developing novel treatments for metastatic TNBC is an urgent need. Here, we show that nanoparticle-mediated delivery of transforming growth factor-β1-activated kinase-1 (TAK1) inhibitor 5Z-7-Oxozeaenol can inhibit TNBC lung metastasis in most animals tested. P38 is a central signal downstream of TAK1 in TNBC cells in TAK1-mediated response to multiple cytokines. Following co-culturing with macrophages or fibroblasts, TNBC cells express interleukin-1 (IL1) or tumor necrosis factor-α (TNFα), respectively. Compared to TAK1 inhibition, suppressing IL1 signaling with recombinant IL1 receptor antagonist (IL1RA) is less efficient in reducing lung metastasis, possibly due to the additional TAK1 signals coming from distinct stromal cells. Together, these observations suggest that TAK1 may play a central role in promoting TNBC cell adaptation to the lung microenvironment by facilitating positive feedback signaling mediated by P38. Approaches targeting the key TAK1-P38 signal could offer a novel means for suppressing TNBC lung metastasis.

Therapeutic options for triple-negative breast cancer (TNBC) metastasis are limited. Here they show nanoparticle-mediated delivery of TAK1 inhibitor 5Z-7-Oxozeaenol to inhibit TNBC lung metastasis in mice, and that TAK1 might promote TNBC cell adaptation in lung microenvironment by positive feedback mediated by P38 signaling.

Nuclear Met promotes hepatocellular carcinoma tumorigenesis and metastasis by upregulation of TAK1 and activation of NF-κB pathway

Presence of Met receptor tyrosine kinase in the nucleus of cells has been reported. However, the functions of Met which expresses in the nucleus (nMet) remain elusive. In this study, we found that nMet was increased in 89% of HCC tumorous tissues when compared with the corresponding non-tumorous liver tissues. nMet expression increased progressively along HCC development and significantly correlated with cirrhosis, poorer cellular differentiation, venous invasion, late stage HCC and poorer overall survival. Western blot analysis revealed that nMet is a 48-kDa protein comprising the carboxyl terminal of Met receptor. Induced expression of nMet promoted HCC cell growth, migration and invasiveness in vitro and tumorigenesis and pulmonary metastasis in vivo. Luciferase assay showed that nMet activated NF-κB pathway. Indeed, p-IKKα/β and nuclear p-p65 were higher in nMet stable cells than in the control cells. Perturbation of TAK1/NF-κB axis abrogated the aggressiveness of HCC cells, both in vitro and in vivo. In conclusion, nMet was overexpressed and as a potential prognostic biomarker of HCC. Functionally, nMet accelerated HCC tumorigenesis and metastasis via the activation of TAK1/NF-κB pathway.

MicroRNA-143 inhibits cell growth by targeting ERK5 and MAP3K7 in breast cancer

This study aimed to investigate the function and mechanism of microRNA-143 (miR-143) in the occurrence and development of breast cancer (BC). A total of 30 BC tissues, 30 corresponding noncancerous tissues, and 10 normal control (NC) breast tissues were obtained to detect the levels of miR-143, extracellular signal-regulated kinase 5 (ERK5) and mitogen-activated protein 3 kinase 7 (MAP3K7) using RT-qPCR, western blotting or immunohistochemistry. The correlation of miR-143 with ERK5 or MAP3K7 was evaluated using Pearson correlation analysis. MCF-7 cells were transiently transfected with miR-143 mimic, miR-143 inhibitor, miR-143 mimic/inhibitor + si-ERK5, si-MAP3K7 or si-cyclin D1. Then, cell growth was evaluated by MTT assay and the expressions of phospho-ERK5 (p-ERK5), ERK5, p-MAP3K7, MAP3K7 and cyclin D1 were detected by western blotting. Results showed that, compared with noncancerous tissues or NC breast tissues, miR-143 level was decreased, while p-ERK5, ERK5, p-MAP3K7 and MAP3K7 expressions were increased in BC tissues (all P<0.01). The miR-143 level was negatively correlated with the mRNA level of ERK5 or MAP3K7 (r=-4.231 or r=-4.280, P<0.01). In addition, up-regulated miR-143 significantly decreased the expressions of p-ERK5, ERK5, p-MAP3K7, MAP3K7 and cyclin D1 (all P<0.01), as well as cell viability in MCF-7 cells (all P<0.05) while the effect of down-regulated miR-143 was the opposite. In conclusion, both ERK5 and MAP3K7 may be the target genes of miR-143. Increased expression of miR-143 can inhibit cell growth, which may be associated with ERK5 and MAP3K7 expressions in BC.

Transforming growth factor β-activated kinase 1 inhibitor suppresses the proliferation in triple-negative breast cancer through TGF-β/TGFR pathway

Breast cancer is one of the most invasive cancer types in female population. The functional activity of Transforming growth factor β-activated kinase 1 (TAK1) in breast cancer progression increasingly attracts attention as it provides a potential target for antibreast cancer drug development. However, the fundamental role of TAK1 for triple-negative breast cancer (TNBC) progression and the effect of potential anti-TAK1 drug candidate needs to be further evaluated. Herein, we focused on the role of TAK1 in human breast cancer cells, and we hypothesized that the inhibition of TAK1 activation can repress the growth of human TNBC cells. We found that the TAK1 is robustly activated within cancer cell population of clinic-derived TNBC samples and the human breast cancer cell lines in culture. Furthermore, we determined the effect of 5Z-7-oxozeaenol (5Z-O), a TAK1-specific small molecule inhibitor, on proliferation of human TNBC cell line. 5Z-O treatment significantly suppressed the proliferation of human TNBC cells. Collectively, these demonstrate the role of TAK1 in human breast cancer and the antiproliferate effect of TAK1 inhibitor. Our study sets the stage for further research on TAK1 as a promising target for development of anti-TNBC drugs and therapeutic strategies.

Inhibition of ovarian cancer cell growth by a novel TAK1 inhibitor LYTAK1

PURPOSE

Transforming growth factor-β-activating kinase 1 (TAK1) has been implicated in promoting ovarian cancer progression. Here, we evaluated the anti-ovarian cancer effect of LYTAK1, a novel and specific TAK1 inhibitor.

METHODS

Established or primary human ovarian cancer cells were treated with LYTAK1, and its cytotoxicity and underlying mechanisms were analyzed using in vitro and in vivo assays.

RESULTS

We demonstrated that LYTAK1 blocked TAK1-nuclear factor kappa B activation, and potently inhibited growth of established (SKOV3, CaOV3 and A2780 lines) or primary (patient-derived) human ovarian cancer cells, where TAK1 was over-expressed and over-activated. While the normal ovarian epithelial cells (IOSE-80), with low TAK1 expression, were minimally affected by the same LYTAK1 treatment. In ovarian cancer cells, LYTAK1 mainly induced necrosis (but not apoptosis), which was associated with mitochondrial permeability transition pore (mPTP) opening, the latter was evidenced by mitochondrial membrane potential reduction. Inhibition of mPTP, either by its inhibitor sanglifehrin A or cyclosporine A, as well as by siRNA-mediated knockdown of cyclophilin-D or voltage-dependent anion channel, attenuated LYTAK1-induced necrosis and cytotoxicity in ovarian cancer cells. In vivo, LYTAK1 oral administration suppressed growth of SKOV3 xenografts in nude mice, and its activity could be further enhanced by co-treatment of paclitaxel (Taxol).

CONCLUSIONS

These data reveal the therapeutic potential of LYTAK1 as an agent targeting the pro-oncogenic TAK1 in ovarian cancer.

MiR-377 targets E2F3 and alters the NF-kB signaling pathway through MAP3K7 in malignant melanoma

Background

The incidence of cutaneous malignant melanoma continues to rise, and once the disease metastasizes it is almost inevitably fatal. We recently reported that a large miRNAs cluster on human chromosome 14q32, implicated in many types of cancers, is significantly down-regulated in melanoma. miR-377, one of the miRNAs located within this cluster, was studied here.

Methods

qRT-pCR was used to quantify miR-377 levels in melanoma cell lines and samples. Melanoma cell lines ectopically expressing miR-377 were generated by stable transfection, mRNA expression was assessed using mRNA arrays and protein expression was assessed by Western blot analysis. Potential targets of miR-377 were identified through luciferase reporter assays. Cellular proliferation, migration and soft-agar colony formation were monitored in control and miR-377-expressing cells using cell biology techniques.

Results

miR-377 is expressed in normal melanocytes but not in melanoma cell lines or samples. Its ectopic stable expression in melanoma cell lines decreased their proliferative and migratory capacity and their colony-forming capability. mRNA arrays of melanoma cells over-expressing miR-377 pointed to several down-regulated mRNAs that have putative binding sites for miR-377 in their 3′UTR, of which both E2F3 and MAP3K7 were found to be direct targets of miR-377.

E2F3, a potent transcriptional inducer of cell-cycle progression, was found to be elevated in melanoma cell lines, but decreased following ectopic expression of miR-377. Ectopic miR-377 also led to a decrease in the activity of a reporter plasmid containing three E2F DNA-binding sites linked to a luciferase cDNA sequence, demonstrating that miR-377 down-regulates E2F3-induced transcription.

MAP3K7 (known as TAK1), a serine/threonine kinase along the MAPK signaling pathway, was over-expressed in melanoma but decreased following ectopic expression of miR-377. MAP3K7 is involved in the activation of NF-κB. MiR-377 over-expression led to decreased activity of a reporter plasmid containing two NF-κB DNA-binding sites and to decreased output along the NF-kB signaling pathway.

Conclusion

Our results suggest that miR-377 is an important negative regulator of E2F and MAP3K7/NF-kB signaling pathway in melanoma cells; it is tempting to speculate that its silencing in melanoma promotes the tumorigenic and metastatic potential of the cells through activation of these pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0338-9) contains supplementary material, which is available to authorized users.

MUC1-C activates the TAK1 inflammatory pathway in colon cancer

The mucin 1 (MUC1) oncoprotein has been linked to the inflammatory response by promoting cytokine-mediated activation of the NF-κB pathway. The TGF-β-activated kinase 1 (TAK1) is an essential effector of proinflammatory NF-κB signaling that also regulates cancer cell survival. The present studies demonstrate that the MUC1-C transmembrane subunit induces TAK1 expression in colon cancer cells. MUC1 also induces TAK1 in a MUC1(+/-)/IL-10(-/-) mouse model of colitis and colon tumorigenesis. We show that MUC1-C promotes NF-κB-mediated activation of TAK1 transcription and, in a positive regulatory loop, MUC1-C contributes to TAK1-induced NF-κB signaling. In this way, MUC1-C binds directly to TAK1 and confers the association of TAK1 with TRAF6, which is necessary for TAK1-mediated activation of NF-κB. Targeting MUC1-C thus suppresses the TAK1NF-κB pathway, downregulates BCL-XL and in turn sensitizes colon cancer cells to MEK inhibition. Analysis of colon cancer databases further indicates that MUC1, TAK1 and TRAF6 are upregulated in tumors associated with decreased survival and that MUC1-C-induced gene expression patterns predict poor outcomes in patients. These results support a model in which MUC1-C-induced TAK1NF-κB signaling contributes to intestinal inflammation and colon cancer progression.

LYTAK1, a novel TAK1 inhibitor, suppresses KRAS mutant colorectal cancer cell growth in vitro and in vivo

KRAS mutation in colorectal cancer (CRC) activates transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) to promote tumor progression. In the current study, we explored the potential effect of LYTAK1, a novel TAK1 inhibitor, against KRAS mutant CRC cells in vitro and in vivo. We found that LYTAK1 dose-dependently inhibited KRAS mutant CRC cell (HT-29 and SW-620 lines) growth, and induced cell cycle G1-S arrest. Further, LYTAK1 activated apoptosis in HT-29 cells and SW-620 cells, and apoptosis inhibitors almost reversed LYTAK1-mediated growth inhibition. While in KRAS wild-type (WT) CRC cell lines (DLD-1 and HCT-116), LYTAK1 had almost no effect on cell growth, cell cycle progression, or cell apoptosis. In KRAS mutant HT-29 cells and SW-260 cells, LYTAK1 blocked TAK1 activation or phosphorylation at Thr-184/187. Activation of nuclear factor κB (NF-κB) in these cells, detected by phosphorylations of p65 and IκB kinase α (IKKα) as well as expression of NF-κB-regulated gene cyclin D1, was significantly inhibited by LYTAK1. Further, LYTAK1 treatment resulted in downregulation of β-catenin and Wnt response gene Axin 2, indicating Wnt inactivation. In vivo, oral LYTAK1 significantly inhibited HT-29 xenograft growth in nude mice. Together, these results show that LYTAK1 inhibits KRAS mutant CRC cell growth both in vitro and in vivo. LYTAK1 might be investigated as a novel agent against CRC with KRAS mutation.

The TAK1-NF-κB axis as therapeutic target for AML

Development and maintenance of leukemia can be partially attributed to alterations in (anti)-apoptotic gene expression. Genome-wide transcriptome analyses revealed that 89 apoptosis-associated genes were differentially expressed between patient acute myeloid leukemia (AML) CD34(+) cells and normal bone marrow (NBM) CD34(+) cells. Among these, transforming growth factor-β activated kinase 1 (TAK1) was strongly upregulated in AML CD34(+) cells. Genetic downmodulation or pharmacologic inhibition of TAK1 activity strongly impaired primary AML cell survival and cobblestone formation in stromal cocultures. TAK1 inhibition was mainly due to blockade of the nuclear factor κB (NF-κB) pathway, as TAK1 inhibition resulted in reduced levels of P-IκBα and p65 activity. Overexpression of a constitutive active variant of NF-κB partially rescued TAK1-depleted cells from apoptosis. Importantly, NBM CD34(+) cells were less sensitive to TAK1 inhibition compared with AML CD34(+) cells. Knockdown of TAK1 also severely impaired leukemia development in vivo and prolonged overall survival in a humanized xenograft mouse model. In conclusion, our results indicate that TAK1 is frequently overexpressed in AML CD34(+) cells, and that TAK1 inhibition efficiently targets leukemic stem/progenitor cells in an NF-κB-dependent manner.

A meta analysis of pancreatic microarray datasets yields new targets as cancer genes and biomarkers

The lack of specific symptoms at early tumor stages, together with a high biological aggressiveness of the tumor contribute to the high mortality rate for pancreatic cancer (PC), which has a five year survival rate of less than 5%. Improved screening for earlier diagnosis, through the detection of diagnostic and prognostic biomarkers provides the best hope of increasing the rate of curatively resectable carcinomas. Though many serum markers have been reported to be elevated in patients with PC, so far, most of these markers have not been implemented into clinical routine due to low sensitivity or specificity. In this study, we have identified genes that are significantly upregulated in PC, through a meta-analysis of large number of microarray datasets. We demonstrate that the biological functions ascribed to these genes are clearly associated with PC and metastasis, and that that these genes exhibit a strong link to pathways involved with inflammation and the immune response. This investigation has yielded new targets for cancer genes, and potential biomarkers for pancreatic cancer. The candidate list of cancer genes includes protein kinase genes, new members of gene families currently associated with PC, as well as genes not previously linked to PC. In this study, we are also able to move towards developing a signature for hypomethylated genes, which could be useful for early detection of PC. We also show that the significantly upregulated 800+ genes in our analysis can serve as an enriched pool for tissue and serum protein biomarkers in pancreatic cancer.

Multimodality imaging of RNA interference

The discovery of small interfering RNAs (siRNAs) and their potential to knock down virtually any gene of interest has ushered in a new era of RNA interference (RNAi). Clinical use of RNAi faces severe limitations due to inefficiency delivery of siRNA or short hairpin RNA (shRNA). Many molecular imaging techniques have been adopted in RNAi-related research for evaluation of siRNA/shRNA delivery, biodistribution, pharmacokinetics, and the therapeutic effect. In this review article, we summarize the current status of in vivo imaging of RNAi. The molecular imaging techniques that have been employed include bioluminescence/fluorescence imaging, magnetic resonance imaging/ spectroscopy, positron emission tomography, single-photon emission computed tomography, and various combinations of these techniques. Further development of non-invasive imaging strategies for RNAi, not only focusing on the delivery of siRNA/shRNA but also the therapeutic efficacy, is critical for future clinical translation. Rigorous validation will be needed to confirm that biodistribution of the carrier is correlated with that of siRNA/shRNA, since imaging only detects the label (e.g. radioisotopes) but not the gene or carrier themselves. It is also essential to develop multimodality imaging approaches for realizing the full potential of therapeutic RNAi, as no single imaging modality may be sufficient to simultaneously monitor both the gene delivery and silencing effect of RNAi.

TAK1 regulates hepatic cell survival and carcinogenesis

TGF-β-activated kinase 1 (TAK1 or MAP3K7) is an intracellular hub molecule that regulates both nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways that play key roles in development, cell survival, immune response, metabolism, and carcinogenesis. TAK1 activity is tightly regulated by its binding proteins, TAB1 and TAB2/TAB3, as well as by post-translational modification including ubiquitination and phosphorylation. Accumulating evidence demonstrates that TAK1 plays a role in tumor initiation, progression, and metastasis as a tumor prompter or tumor suppressor. An understanding of the role of TAK1 in liver physiology and diseases is required for the development of therapeutic agencies targeting TAK1. In this review, we highlight the activation mechanism and pathophysiological roles of TAK1 in the liver.

Fibroblast growth factor receptor 3 interacts with and activates TGFβ-activated kinase 1 tyrosine phosphorylation and NFκB signaling in multiple myeloma and bladder cancer

Cancer is a major public health problem worldwide. In the United States alone, 1 in 4 deaths is due to cancer and for 2013 a total of 1,660,290 new cancer cases and 580,350 cancer-related deaths are projected. Comprehensive profiling of multiple cancer genomes has revealed a highly complex genetic landscape in which a large number of altered genes, varying from tumor to tumor, impact core biological pathways and processes. This has implications for therapeutic targeting of signaling networks in the development of treatments for specific cancers. The NFκB transcription factor is constitutively active in a number of hematologic and solid tumors, and many signaling pathways implicated in cancer are likely connected to NFκB activation. A critical mediator of NFκB activity is TGFβ-activated kinase 1 (TAK1). Here, we identify TAK1 as a novel interacting protein and target of fibroblast growth factor receptor 3 (FGFR3) tyrosine kinase activity. We further demonstrate that activating mutations in FGFR3 associated with both multiple myeloma and bladder cancer can modulate expression of genes that regulate NFκB signaling, and promote both NFκB transcriptional activity and cell adhesion in a manner dependent on TAK1 expression in both cancer cell types. Our findings suggest TAK1 as a potential therapeutic target for FGFR3-associated cancers, and other malignancies in which TAK1 contributes to constitutive NFκB activation.

c-MYC overexpression overrides TAK1 dependency in efficient tumorigenicity of AKT-transformed cells

Transforming growth factor activated kinase 1 (TAK1) provides prosurvival signals in various types of cells, and emerging evidence indicates that targeting TAK1 is a promising means to eliminate certain types of cancer cells. Here, we show that TAK1 is required for efficient tumorigenicity of AKT-transformed cells. TAK1 inhibition accelerates cell apoptosis of AKT-transformed cells in anchorage-independent cell growth accompanying by the downregulation of Mcl-1 and Bcl-2 expression. On the contrary, the tumorigenicity of c-Myc-transformed cells is not significantly affected by TAK1 inhibition. Moreover, AKT-transformed cells with c-Myc overexpression tolerate TAK1 inhibition in anchorage-independent growth and tumorigenicity in vivo. Together, our results provide evidence that TAK1-dependency in the tumorigenicity of AKT-transformed cells can be alleviated by c-Myc overexpression. These findings suggest that dual-targeting TAK1 and c-Myc might be a rational therapeutic strategy for treatment of certain types of cancer.

Inhalation delivery of Telmisartan enhances intratumoral distribution of nanoparticles in lung cancer models

The purpose of the present study was to evaluate the effect of Telmisartan (Tel) and Losartan (Los) on nanoparticle intratumoral distribution and anticancer effects in lung cancer. A549 lung tumor cells were orthotopically and metastatically administered to Nu/nu mice. Fluorescent polystyrene nanoparticles (FPNPs, size ~200 nm) beads were used to study their intratumoral distribution after Tel and Los treatments. Animals were administered with FPNPs and after 2h, FPNPs intratumoral distribution was studied by fluorescent microscopy. Tel (~1.12 mg/kg) and Los (~4.5mg/kg) were administered by inhalation delivery at alternative days for 4 weeks to tumor bearing animals. Collagen-1, transforming growth factor beta 1 (TGF-β1), cleaved caspase-3, Vimentin and E-Cadherin expressions were studied by western blotting. To correlate the AT1 receptor blockage to anticancer effects, VEGF levels and microvessel densities (MVD) were quantified. Los and Tel treated group resulted in the 5.33 and 14.33 fold increase respectively in the FPNPs intratumoral distribution as compared to the controls. Tel treatment attenuated 2.23 and 1.70 fold Collagen 1 expression compared to untreated control and Los groups, respectively. Further, in Tel and Los treated groups, the TGF-β1 active levels were significantly (p<0.05) decreased. Tel (at four times less dose) was 1.89 and 1.92 fold superior in anticancer activity to Los respectively in A549 orthotopic and metastatic tumor models (p<0.05) when given by inhalation route. Tel, by virtue of its dual pharmacophoric nature could be an ideal candidate for combination therapy to improve the nanoparticle intratumoral distribution and anticancer effects.

Cell type-specific function of TAK1 in innate immune signaling

Transforming growth factor β-activated kinase 1 (TAK1 or MAP3K7) is a key signaling component of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Activation of TAK1 is tightly regulated through its binding partners and protein modifications. Although TAK1 functions as an essential and positive regulator of innate immune signaling and apoptosis in mouse embryonic fibroblasts (MEFs), T cells, and other cells, it negatively regulates cell development and activation of proinflammatory signaling pathways in neutrophils. However, the molecular mechanisms responsible for the opposite roles of TAK1 in different cell types remain to be addressed. In this article, we discuss the latest progresses in our understanding of TAK1 regulation, function, and mechanisms in a cell-type specific manner.

The janus face of lipids in human breast cancer: how polyunsaturated Fatty acids affect tumor cell hallmarks

For several years, lipids and especially n - 3 and n - 6 polyunsaturated fatty acids (PUFAs) receive much attention in human health. Epidemiological studies tend to correlate a PUFA-rich diet with a reduced incidence of cancer, including breast cancer. However, the molecular and cellular mechanisms supporting the effect of PUFAs in breast cancer cells remain relatively unknown. Here, we review some recent progress in understanding the impact that PUFA may have on breast cancer cell proliferation, apoptosis, migration, and invasion. While most of the results obtained with docosahexaenoic acid and/or eicosapentaenoic acid show a decrease of tumor cell proliferation and/or aggressivity, there is some evidence that other lipids, which accumulate in breast cancer tissues, such as arachidonic acid may have opposite effects. Finally, lipids and especially PUFAs appear as potential adjuvants to conventional cancer therapy.