HYAL-2-WWOX-SMAD4 Signaling in Cell Death and Anticancer Response

Hyaluronic acid/dextran-based polymeric micelles co-delivering ursolic acid and doxorubicin to mitochondria for potentiating chemotherapy in MDR cancer

Cancer multidrug resistance (MDR) dramatically hindered the efficiency of standard chemotherapy. Mitochondria are highly involved in the occurrence and development of MDR; thus, inducing its malfunction will be an appealing strategy to treat MDR tumors. In this paper, a natural polysaccharides-based nanoplatform (TDTD@UA/HA micelles) with cell and mitochondria dual-targeting ability was facilely fabricated to co-deliver ursolic acid (UA) and doxorubicin (DOX) for combinatorial MDR therapy. TDTD@UA/HA micelles featured a spherical morphology, narrow size distribution (∼140 nm), as well as favorable drug co-loading capacity (DOX: 8.41 %, UA: 9.06 %). After hyaluronic acid (HA)-mediated endocytosis, the lysosomal hyaluronidase promoted the degradation of HA layer and then the positive triphenylphosphine groups were exposed, which significantly enhanced the mitochondria-accumulation of nano micelles. Subsequently, DOX and UA were specifically released into mitochondria under the trigger of endogenous reactive oxygen species (ROS), followed by severe mitochondrial destruction through generating ROS, exhausting mitochondrial membrane potential, and blocking energy supply, etc.; ultimately contributing to the susceptibility restoration of MCF-7/ADR cells to chemotherapeutic agents. Importantly, TDTD@UA/HA micelles performed potent anticancer efficacy without distinct toxicity on the MDR tumor-bearing nude mice model. Overall, the versatile nanomedicine represented a new therapeutic paradigm and held great promise in overcoming MDR-related cancer.

Zfra Inhibits the TRAPPC6AΔ-Initiated Pathway of Neurodegeneration

When WWOX is downregulated in middle age, aggregation of a protein cascade, including TRAPPC6AΔ (TPC6AΔ), TIAF1, and SH3GLB2, may start to occur, and the event lasts more than 30 years, which results in amyloid precursor protein (APP) degradation, amyloid beta (Aβ) generation, and neurodegeneration, as shown in Alzheimer's disease (AD). Here, by treating neuroblastoma SK-N-SH cells with neurotoxin MPP+, upregulation and aggregation of TPC6AΔ, along with aggregation of TIAF1, SH3GLB2, Aβ, and tau, occurred. MPP+ is an inducer of Parkinson's disease (PD), suggesting that TPC6AΔ is a common initiator for AD and PD pathogenesis. Zfra, a 31-amino-acid zinc finger-like WWOX-binding protein, is known to restore memory deficits in 9-month-old triple-transgenic (3xTg) mice by blocking the aggregation of TPC6AΔ, SH3GLB2, tau, and amyloid β, as well as inflammatory NF-κB activation. The Zfra4-10 peptide exerted a strong potency in preventing memory loss during the aging of 3-month-old 3xTg mice up to 9 months, as determined by a novel object recognition task (ORT) and Morris water maize analysis. Compared to age-matched wild type mice, 11-month-old Wwox heterozygous mice exhibited memory loss, and this correlates with pT12-WWOX aggregation in the cortex. Together, aggregation of pT12-WWOX may link to TPC6AΔ aggregation for AD progression, with TPC6AΔ aggregation being a common initiator for AD and PD progression.

WWOX Controls Cell Survival, Immune Response and Disease Progression by pY33 to pS14 Transition to Alternate Signaling Partners

Tumor suppressor WWOX inhibits cancer growth and retards Alzheimer’s disease (AD) progression. Supporting evidence shows that the more strongly WWOX binds intracellular protein partners, the weaker is cancer cell growth in vivo. Whether this correlates with retardation of AD progression is unknown. Two functional forms of WWOX exhibit opposite functions. pY33-WWOX is proapoptotic and anticancer, and is essential for maintaining normal physiology. In contrast, pS14-WWOX is accumulated in the lesions of cancers and AD brains, and suppression of WWOX phosphorylation at S14 by a short peptide Zfra abolishes cancer growth and retardation of AD progression. In parallel, synthetic Zfra4-10 or WWOX7-21 peptide strengthens the binding of endogenous WWOX with intracellular protein partners leading to cancer suppression. Indeed, Zfra4-10 is potent in restoring memory loss in triple transgenic mice for AD (3xTg) by blocking the aggregation of amyloid beta 42 (Aβ42), enhancing degradation of aggregated proteins, and inhibiting activation of inflammatory NF-κB. In light of the findings, Zfra4-10-mediated suppression of cancer and AD is due, in part, to an enhanced binding of endogenous WWOX and its binding partners. In this perspective review article, we detail the molecular action of WWOX in the HYAL-2/WWOX/SMAD4 signaling for biological effects, and discuss WWOX phosphorylation forms in interacting with binding partners, leading to suppression of cancer growth and retardation of AD progression.

Cannabidiol Antiproliferative Effect in Triple-Negative Breast Cancer MDA-MB-231 Cells Is Modulated by Its Physical State and by IGF-1

Cannabidiol (CBD) is a non-psychoactive phytocannabinoid that has been discussed for its safety and efficacy in cancer treatments. For this reason, we have inquired into its use on triple-negative human breast cancer. Analyzing the biological effects of CBD on MDA-MB-231, we have demonstrated that both CBD dosage and serum concentrations in the culture medium influence its outcomes; furthermore, light scattering studies demonstrated that serum impacts the CBD aggregation state by acting as a surfactant agent. Pharmacological studies on CBD in combination with chemotherapeutic agents reveal that CBD possesses a protective action against the cytotoxic effect exerted by cisplatin on MDA-MB-231 grown in standard conditions. Furthermore, in a low serum condition (0.5%), starting from a threshold concentration (5 µM), CBD forms aggregates, exerts cytostatic antiproliferative outcomes, and promotes cell cycle arrest activating autophagy. At doses above the threshold, CBD exerts a highly cytotoxic effect inducing bubbling cell death. Finally, IGF-1 and EGF antagonize the antiproliferative effect of CBD protecting cells from harmful consequences of CBD aggregates. In conclusion, CBD effect is strongly associated with the physical state and concentration that reaches the treated cells, parameters not taken into account in most of the research papers.

Finding New Ways How to Control BACE1

Recently, all applications of BACE1 inhibitors failed as therapeutical targets for Alzheimer´s disease (AD) due to severe side effects. Therefore, alternative ways for treatment development are a hot research topic. The present analysis investigates BACE1 protein-protein interaction networks and attempts to solve the absence of complete knowledge about pathways involving BACE1. A bioinformatics analysis matched the functions of the non-substrate interaction network with Voltage-gated potassium channels, which also appear as top priority protein nodes. Targeting BACE1 interactions with PS1 and GGA-s, blocking of BACE1 access to APP by BRI3 and RTN-s, activation of Wnt signaling and upregulation of β-catenin, and brain delivery of the extracellular domain of p75^NTR, are the main alternatives to the use of BACE 1 inhibitors highlighted by the analysis. The pathway enrichment analysis also emphasized substrates and substrate candidates with essential biological functions, which cleavage must remain controlled. They include ephrin receptors, ROBO1, ROBO2, CNTN-s, CASPR-s, CD147, CypB, TTR, APLP1/APLP2, NRXN-s, and PTPR-s. The analysis of the interaction subnetwork of BACE1 functionally related to inflammation identified a connection to three cardiomyopathies, which supports the hypothesis of the common molecular mechanisms with AD. A lot of potential shows the regulation of BACE1 activity through post-translational modifications. The interaction network of BACE1 and its phosphorylation enzyme CSNK1D functionally match the Circadian clock, p53, and Hedgehog signaling pathways. The regulation of BACE1 glycosylation could be achieved through N-acetylglucosamine transferases, α-(1→6)-fucosyltransferase, β-galactoside α-(2→6)-sialyltransferases, galactosyltransferases, and mannosidases suggested by the interaction network analysis of BACE1-MGAT3. The present analysis proposes possibilities for the alternative control of AD pathology.

TGFα-EGFR pathway in breast carcinogenesis, association with WWOX expression and estrogen activation

WWOX is a tumor-suppressive steroid dehydrogenase, which relationship with hormone receptors was shown both in animal models and breast cancer patients. Herein, through nAnT-iCAGE high-throughput gene expression profiling, we studied the interplay of estrogen receptors and the WWOX in breast cancer cell lines (MCF7, T47D, MDA-MB-231, BT20) under estrogen stimulation and either introduction of the WWOX gene by retroviral transfection (MDA-MB-231, T47D) or silenced with shRNA (MCF7, BT20). Additionally, we evaluated the consequent biological characteristics by proliferation, apoptosis, invasion, and adhesion assays. TGFα-EGFR signaling was found to be significantly affected in all examined breast cancer cell lines in response to estrogen and strongly associated with the level of WWOX expression, especially in ER-positive MCF7 cells. Under the influence of 17β-estradiol presence, biological characteristics of the cell lines were also delineated. The study revealed modulation of adhesion, invasion, and apoptosis. The obtained results point at a complex role of the WWOX gene in the carcinogenesis of the breast tissue, which seems to be closely related to the presence of estrogen α and/or β receptors.

WWOX and Its Binding Proteins in Neurodegeneration

WW domain-containing oxidoreductase (WWOX) is known as one of the risk factors for Alzheimer's disease (AD), a neurodegenerative disease. WWOX binds Tau via its C-terminal SDR domain and interacts with Tau phosphorylating enzymes ERK, JNK, and GSK-3β, and thereby limits AD progression. Loss of WWOX in newborns leads to severe neural diseases and early death. Gradual loss of WWOX protein in the hippocampus and cortex starting from middle age may slowly induce aggregation of a protein cascade that ultimately causes accumulation of extracellular amyloid beta plaques and intracellular tau tangles, along with reduction in inhibitory GABAergic interneurons, in AD patients over 70 years old. Age-related increases in pS14-WWOX accumulation in the brain promotes neuronal degeneration. Suppression of Ser14 phosphorylation by a small peptide Zfra leads to enhanced protein degradation, reduction in NF-κB-mediated inflammation, and restoration of memory loss in triple transgenic mice for AD. Intriguingly, tumor suppressors p53 and WWOX may counteract each other in vivo, which leads to upregulation of AD-related protein aggregation in the brain and lung. WWOX has numerous binding proteins. We reported that the stronger the binding between WWOX and its partners, the better the suppression of cancer growth and reduction in inflammation. In this regard, the stronger complex formation between WWOX and partners may provide a better blockade of AD progression. In this review, we describe whether and how WWOX and partner proteins control inflammatory response and protein aggregation and thereby limit AD progression.

Normal cells repel WWOX-negative or -dysfunctional cancer cells via WWOX cell surface epitope 286-299

Metastatic cancer cells are frequently deficient in WWOX protein or express dysfunctional WWOX (designated WWOXd). Here, we determined that functional WWOX-expressing (WWOXf) cells migrate collectively and expel the individually migrating WWOXd cells. For return, WWOXd cells induces apoptosis of WWOXf cells from a remote distance. Survival of WWOXd from the cell-to-cell encounter is due to activation of the survival IκBα/ERK/WWOX signaling. Mechanistically, cell surface epitope WWOX286-299 (repl) in WWOXf repels the invading WWOXd to undergo retrograde migration. However, when epitope WWOX7-21 (gre) is exposed, WWOXf greets WWOXd to migrate forward for merge. WWOX binds membrane type II TGFβ receptor (TβRII), and TβRII IgG-pretreated WWOXf greet WWOXd to migrate forward and merge with each other. In contrast, TβRII IgG-pretreated WWOXd loses recognition by WWOXf, and WWOXf mediates apoptosis of WWOXd. The observatons suggest that normal cells can be activated to attack metastatic cancer cells. WWOXd cells are less efficient in generating Ca²⁺ influx and undergo non-apoptotic explosion in response to UV irradiation in room temperature. WWOXf cells exhibit bubbling cell death and Ca²⁺ influx effectively caused by UV or apoptotic stress. Together, membrane WWOX/TβRII complex is needed for cell-to-cell recognition, maintaining the efficacy of Ca²⁺ influx, and control of cell invasiveness.

Therapeutic Zfra4-10 or WWOX7-21 Peptide Induces Complex Formation of WWOX with Selective Protein Targets in Organs that Leads to Cancer Suppression and Spleen Cytotoxic Memory Z Cell Activation In Vivo

Synthetic Zfra4-10 and WWOX7-21 peptides strongly suppress cancer growth in vivo. Hypothetically, Zfra4-10 binds to the membrane Hyal-2 of spleen Z cells and activates the Hyal-2/WWOX/SMAD4 signaling for cytotoxic Z cell activation to kill cancer cells. Stimulation of membrane WWOX in the signaling complex by a WWOX epitope peptide, WWOX7-21, is likely to activate the signaling. Here, mice receiving Zfra4-10 or WWOX7-21 peptide alone exhibited an increased binding of endogenous tumor suppressor WWOX with ERK, C1qBP, NF-κB, Iba1, p21, CD133, JNK1, COX2, Oct4, and GFAP in the spleen, brain, and/or lung which led to cancer suppression. However, when in combination, Zfra4-10 and WWOX7-21 reduced the binding of WWOX with target proteins and allowed tumor growth in vivo. In addition to Zfra4-10 and WWOX7-21 peptides, stimulating the membrane Hyal-2/WWOX complex with Hyal-2 antibody and sonicated hyaluronan (HAson) induced Z cell activation for killing cancer cells in vivo and in vitro. Mechanistically, Zfra4-10 binds to membrane Hyal-2, induces dephosphorylation of WWOX at pY33 and pY61, and drives Z cell activation for the anticancer response. Thus, Zfra4-10 and WWOX7-21 peptides, HAson, and the Hyal-2 antibody are of therapeutic potential for cancer suppression.

Pleiotropic tumor suppressor functions of WWOX antagonize metastasis

Tumor progression and metastasis are the major causes of death among cancer associated mortality. Metastatic cells acquire features of migration and invasion and usually undergo epithelia-mesenchymal transition (EMT). Acquirement of these various hallmarks rely on different cellular pathways, including TGF-β and Wnt signaling. Recently, we reported that WW domain-containing oxidoreductase (WWOX) acts as a tumor suppressor and has anti-metastatic activities involving regulation of several key microRNAs (miRNAs) in triple-negative breast cancer (TNBC). Here, we report that WWOX restoration in highly metastatic MDA-MB435S cancer cells alters mRNA expression profiles; further, WWOX interacts with various proteins to exert its tumor suppressor function. Careful alignment and analysis of gene and miRNA expression in these cells revealed profound changes in cellular pathways mediating adhesion, invasion and motility. We further demonstrate that WWOX, through regulation of miR-146a levels, regulates SMAD3, which is a member of the TGF-β signaling pathway. Moreover, proteomic analysis of WWOX partners revealed regulation of the Wnt-signaling activation through physical interaction with Disheveled. Altogether, these findings underscore a significant role for WWOX in antagonizing metastasis, further highlighting its role and therapeutic potential in suppressing tumor progression.

Functional role of WW domain-containing proteins in tumor biology and diseases: Insight into the role in ubiquitin-proteasome system

The ubiquitin-proteasome system (UPS) governs the protein degradation process and balances proteostasis and cellular homeostasis. It is a well-controlled mechanism, in which removal of the damaged or excessive proteins is essential in driving signal pathways for cell survival or death. Accumulation of damaged proteins and failure in removal may contribute to disease initiation such as in cancers and neurodegenerative diseases. In this notion, specific protein-protein interaction is essential for the recognition of targeted proteins in UPS. WW domain plays an indispensable role in the protein-protein interactions during signaling. Among the 51 WW domain-containing proteins in the human proteomics, near one-quarter of them are involved in the UPS, suggesting that WW domains are crucial modules for driving the protein-protein binding and subsequent ubiquitination and degradation. In this review, we detail a broad spectrum of WW domains in protein-protein recognition, signal transduction, and relevance to diseases. New perspectives in dissecting the molecular interactions are provided.

WWOX Possesses N-Terminal Cell Surface-Exposed Epitopes WWOX7-21 and WWOX7-11 for Signaling Cancer Growth Suppression and Prevention In Vivo

Membrane hyaluronidase Hyal-2 supports cancer cell growth. Inhibition of Hyal-2 by specific antibody against Hyal-2 or pY216-Hyal-2 leads to cancer growth suppression and prevention in vivo. By immunoelectron microscopy, tumor suppressor WWOX is shown to be anchored, in part, in the cell membrane by Hyal-2. Alternatively, WWOX undergoes self-polymerization and localizes in the cell membrane. Proapoptotic pY33-WWOX binds Hyal-2, and TGF-β induces internalization of the pY33-WWOX/Hyal-2 complex to the nucleus for causing cell death. In contrast, when pY33 is downregulated and pS14 upregulated in WWOX, pS14-WWOX supports cancer growth in vivo. Here, we investigated whether membrane WWOX receives extracellular signals via surface-exposed epitopes, especially at the S14 area, that signals for cancer growth suppression and prevention. By using a simulated 3-dimentional structure and generated specific antibodies, WWOX epitopes were determined at amino acid #7 to 21 and #286 to 299. Synthetic WWOX7-21 peptide, or truncation to 5-amino acid WWOX7-11, significantly suppressed and prevented the growth and metastasis of melanoma and skin cancer cells in mice. Time-lapse microscopy revealed that WWOX7-21 peptide potently enhanced the explosion and death of 4T1 breast cancer stem cell spheres by ceritinib. This is due to rapid upregulation of proapoptotic pY33-WWOX, downregulation of prosurvival pERK, prompt increases in Ca²⁺ influx, and disruption of the IkBα/WWOX/ERK prosurvival signaling. In contrast, pS14-WWOX7-21 peptide dramatically increased cancer growth in vivo and protected cancer cells from ceritinib-mediated apoptosis in vitro, due to a prolonged ERK phosphorylation. Further, specific antibody against pS14-WWOX significantly enhanced the ceritinib-induced apoptosis. Together, the N-terminal epitopes WWOX7-21 and WWOX7-11 are potent in blocking cancer growth in vivo. WWOX7-21 and WWOX7-11 peptides and pS14-WWOX antibody are of therapeutic values in suppressing and preventing cancer growth in vivo.

The WWOX Gene Influences Cellular Pathways in the Neuronal Differentiation of Human Neural Progenitor Cells

The brain is the most functionally organized structure of all organs. It manages behavior, perception and higher cognitive functions. The WWOX gene is non-classical tumor suppressor gene, which has been shown to have an impact on proliferation, apoptosis and migration processes. Moreover, genetic aberrations in WWOX induce severe neuropathological phenotypes in humans and rodents. The aim of the present study was to investigate in detail the impact of WWOX on human neural progenitor cell (hNPC) maintenance and how depletion of WWOX disturbs signaling pathways playing a pivotal role in neuronal differentiation and central nervous system (CNS) organogenesis. hNPC with a silenced WWOX gene exhibited lowered mitochondrial redox potential, enhanced adhesion to fibronectin and extracellular matrix protein mixture, downregulation of MMP2/9 expression and impaired 3D growth. Global transcriptome analysis using cap analysis of gene expression (CAGE) found that WWOX downregulation significantly changes the expression of multiple genes engaged in cytoskeleton organization, adhesion, cell signaling and chromatin remodeling. The massive changes in gene expression caused by WWOX silencing may strongly affect the differentiation and migration of neurons in organogenesis, brain injury, cancerogenesis or neurodifferentiation. WWOX gene appears to be an important regulator of neural tissue architecture and function.

Differentiation of Intracellular Hyaluronidase Isoform by Degradable Nanoassembly Coupled with RNA-Binding Fluorescence Amplification

Hyaluronidase has two cruical isoforms, hyaluronidase-1 (Hyal-1) and hyaluronidase-2 (Hyal-2), which are essential for cellular hyaluronic acid (HA) catabolism to generate different-sized oligosaccharide fragments for performing different physiological functions. In particular, Hyal-1 is the major tumor-derived hyaluronidase. Thus, specific detection of one hyaluronidase isoform, especially Hyal-1, in live cells is of scientific significance but remains challenging. Herein, by use of differentiated tolerance capability of an amphiphilic HA-based nanoassembly to Hyal-1 and Hyal-2, we rationally design a Hyal-1 specific nanosensor, consisting of cholesterylamine-modified HA nanoassembly (CHA) and RNA-binding fluorophores (RBF). The RBF molecules were entrapped in CHA to switch off their fluorescence via aggregation caused quenching. However, CHA can be disassembled by Hyal-1 to release RBF, resulting in fluorescence activation. Moreover, the fluorescence of the released RBF is further enhanced by cytoplasm RNA. Owing to this cascade signal amplification, this nanosensor RBF@CHA displays a significant change of signal-to-background-noise ratio (120-fold) toward 16 μg/mL Hyal-1 in cellular lysates. In contrast, it is resistant to Hyal-2. By virtue of its selective and sensitive characteristics under a complicated matrix, RBF@CHA had been successfully applied for specifically visualizing Hyal-1 over Hyal-2 inside live cells for the first time, detecting a low level of intracellular Hyal-1 and distinguishing normal and cancer cells with different expressions of Hyal-1. This approach would be useful to better understand biological functions and related diseases of intracellular Hyal-1.

Strategies by which WWOX-deficient metastatic cancer cells utilize to survive via dodging, compromising, and causing damage to WWOX-positive normal microenvironment

Proapoptotic tumor suppressor WWOX is upregulated in the early stage of cancer initiation, which probably provides limitation to cancer growth and progression. Later, WWOX protein is reduced to enhance cancer cell growth, migration, invasiveness and metastasis. To understand how WWOX works in controlling cancer progression, here we demonstrate that apoptotic stress mediated by ectopic WWOX stimulated cancer cells to secrete basic fibroblast growth factor (bFGF) in order to support capillary microtubule formation. This event may occur in the cancer initiation stage. Later, when WWOX loss occurs in cancer cells, hyaluronidase production is then increased in the cancer cells to facilitate metastasis. We determined that inhibition of membrane hyaluronidase Tyr216-phosphorylated Hyal-2 by antibody suppresses cancer growth in vivo. WWOX-negative (WWOX-) cells dodged WWOX+cells in the microenvironment by migrating individually backward to avoid physical contacts and yet significantly upregulating the redox activity of WWOX+parental cells or other WWOX+cell types for causing apoptosis. Upon detecting the presence of WWOX+cells from a distance, WWOX- cells exhibit activation of MIF, Hyal-2, Eph, and Wnt pathways, which converges to MEK/ERK signaling and enables WWOX- cells to evade WWOX+cells. Inhibition of each pathway by antibody or specific chemicals enables WWOX- cells to merge with WWOX+cells. In addition, exogenous TGF-β assists WWOX- cells to migrate collectively forward and merge with WWOX+cells. Metastatic WWOX- cancer cells frequently secrete high levels of TGF-β, which conceivably assists them to merge with WWOX+cells in target organs and secure a new home base in the WWOX+microenvironment. Together, loss of WWOX allows cancer cells to develop strategies to dodge, compromise and even kill WWOX-positive cells in microenvironment.

WW Domain-Containing Proteins YAP and TAZ in the Hippo Pathway as Key Regulators in Stemness Maintenance, Tissue Homeostasis, and Tumorigenesis

The Hippo pathway is a conserved signaling pathway originally defined in Drosophila melanogaster two decades ago. Deregulation of the Hippo pathway leads to significant overgrowth in phenotypes and ultimately initiation of tumorigenesis in various tissues. The major WW domain proteins in the Hippo pathway are YAP and TAZ, which regulate embryonic development, organ growth, tissue regeneration, stem cell pluripotency, and tumorigenesis. Recent reports reveal the novel roles of YAP/TAZ in establishing the precise balance of stem cell niches, promoting the production of induced pluripotent stem cells (iPSCs), and provoking signals for regeneration and cancer initiation. Activation of YAP/TAZ, for example, results in the expansion of progenitor cells, which promotes regeneration after tissue damage. YAP is highly expressed in self-renewing pluripotent stem cells. Overexpression of YAP halts stem cell differentiation and yet maintains the inherent stem cell properties. A success in reprograming iPSCs by the transfection of cells with Oct3/4, Sox2, and Yap expression constructs has recently been shown. In this review, we update the current knowledge and the latest progress in the WW domain proteins of the Hippo pathway in relevance to stem cell biology, and provide a thorough understanding in the tissue homeostasis and identification of potential targets to block tumor development. We also provide the regulatory role of tumor suppressor WWOX in the upstream of TGF-β, Hyal-2, and Wnt signaling that cross talks with the Hippo pathway.

WWOX Phosphorylation, Signaling, and Role in Neurodegeneration

Homozygous null mutation of tumor suppressor WWOX/Wwox gene leads to severe neural diseases, metabolic disorders and early death in the newborns of humans, mice and rats. WWOX is frequently downregulated in the hippocampi of patients with Alzheimer’s disease (AD). In vitro analysis revealed that knockdown of WWOX protein in neuroblastoma cells results in aggregation of TRAPPC6AΔ, TIAF1, amyloid β, and Tau in a sequential manner. Indeed, TRAPPC6AΔ and TIAF1, but not tau and amyloid β, aggregates are present in the brains of healthy mid-aged individuals. It is reasonable to assume that very slow activation of a protein aggregation cascade starts sequentially with TRAPPC6AΔ and TIAF1 aggregation at mid-ages, then caspase activation and APP de-phosphorylation and degradation, and final accumulation of amyloid β and Tau aggregates in the brains at greater than 70 years old. WWOX binds Tau-hyperphosphorylating enzymes (e.g., GSK-3β) and blocks their functions, thereby supporting neuronal survival and differentiation. As a neuronal protective hormone, 17β-estradiol (E2) binds WWOX at an NSYK motif in the C-terminal SDR (short-chain alcohol dehydrogenase/reductase) domain. In this review, we discuss how WWOX and E2 block protein aggregation during neurodegeneration, and how a 31-amino-acid zinc finger-like Zfra peptide restores memory loss in mice.

Chasing the signaling run by tri-molecular time-lapse FRET microscopy

A feasible design is made to measure three protein/protein interactions to visualize signal pathways by time-lapse Förster resonance energy transfer (FRET) microscopy. When interacting proteins are in close proximity, excitation energy is provided to allow the energy flow from the first molecule to excite the second, followed by energy transfer to the third. By phorbol ester/calcium ionophore stimulation, for example, a real-time complex formation of ectopic IκBα/ERK/WWOX occurs as measured by FRET microscopy, indicative of an ongoing functional signaling. Hyaluronan induces membrane Hyal-2 signaling, which allows FRET measurement of the complex formation of ectopic Smad4/WWOX/Hyal-2 for causing bubbling cell death. If ectopic p53 is recruited to replace Hyal-2, the resulting ectopic Smad4/WWOX/p53 complex induces membrane blebbing without cell death. Together, in this perspective review article, we demonstrate the utilization of time-lapse FRET microscopy to visualize the signaling event via the tri-molecular protein complex formation and their biological outcomes. We show an initial two-protein binding to form the driving force to jumpstart the tri-molecular execution for the signal pathway.

Correlation of expression of WWOX and JNK with clinicopathologic features in human breast carcinoma

The aim of our study was to compare the expression levels of c-Jun N-terminal kinase (JNK) and WW domain-containing oxidoreductase (WWOX) in human breast carcinoma, to analyze the correlation between the expression of WWOX and JNK with the clinicopathologic features of human breast carcinoma, and to explore the potential mechanism of their antitumor effects. The mRNA and protein levels of WWOX and JNK in forty paired breast carcinoma tissues and the adjacent normal tissues were detected by real-time quantitative polymerase chain reaction (RT-PCR) and Western blot analysis. Protein expression was further confirmed by immunohistochemistry (IHC). The mRNA expression levels of both JNK and WWOX were downregulated in carcinoma tissues relative to those in the adjacent normal tissues, as determined by Western blot analysis and IHC (P<0.01). JNK expression was positively correlated with WWOX expression (r=0.47, P=0.002). Both WWOX and JNK play important roles in breast cancer. Therefore, the antitumor ability of WWOX and JNK could supply significant information for therapeutic strategy.

Phosphorylation/de-phosphorylation in specific sites of tumor suppressor WWOX and control of distinct biological events

Abnormal differentiation and growth of hematopoietic stem cells cause the development of hematopoietic diseases and hematopoietic malignancies. However, the molecular events underlying leukemia development are not well understood. In our recent study, we have demonstrated that calcium ionophore and phorbol ester force the differentiation of T lymphoblastic leukemia. The event involves a newly identified IκBα/WWOX/ERK signaling, in which WWOX is Ser14 phosphorylated. Additional evidence also reveals that pS14-WWOX is involved in enhancing cancer progression and metastasis and facilitating neurodegeneration. In this mini-review, we update the current knowledge for the functional roles of WWOX under physiological and pathological settings, and provide new insights regarding pS14-WWOX in T leukemia cell maturation, and switching the anticancer pY33-WWOX to pS14-WWOX for cancer promotion and disease progression. Impact statement WWOX was originally designated as a tumor suppressor. However, human newborns deficient in WWOX do not spontaneously develop tumors. Activated WWOX with Tyr33 phosphorylation is present in normal tissues and organs. However, when pY33-WWOX is overly induced under stress conditions, it becomes apoptotic to eliminate damaged cells. Notably, WWOX with Ser14 phosphorylation is upregulated in the lesions of cancer, as well as in the brain hippocampus and cortex with Alzheimer's disease. Suppression of pS14-WWOX by Zfra reduces cancer growth and mitigates Alzheimer's disease progression, suggesting that pS14-WWOX facilitates disease progression. pS14-WWOX can be regarded as a marker of disease progression.

Relationship of genetic variant distributions of WW domain-containing oxidoreductase gene with uterine cervical cancer

To our knowledge, no study investigates the association of genetic variant distributions of WW domain-containing oxidoreductase (WWOX) gene with development of invasive cancer, clinicopathologic variables and patient survival in uterine cervical cancer for Taiwanese women. We therefore conducted this study to explore the clinical involvements of WWOX single nucleotide polymorphisms (SNPs) in cervical cancer. One hundred and thirty-one patients with cervical invasive cancer and 93 patients with precancerous lesions as well as 316 control women were consecutively enrolled. The genotypic frequencies of WWOX genetic variants rs73569323, rs383362, rs11545028, rs3764340 and rs12918952 were determined by real-time polymerase chain reaction. The results revealed that only WWOX SNP rs3764340 was associated between patients with cervical invasive cancer and normal controls among 5 WWOX genetic variants. Cervical cancer patients with genotypes GA/AA in WWOX SNP rs12918952 were associated with parametrium invasion and pelvic lymph node metastasis. Univariate analysis found that WWOX SNPs rs73569323 and rs11545028 were associated with patient survival, whereas multivariate analysis revealed CT/TT in rs11545028 was the only genetic variant, which could predict better overall survival, among 5 WWOX SNPs in Taiwan. In conclusion, Taiwanese women with CG/GG in WWOX SNP rs3764340 are susceptible to cervical invasive cancer. Cervical cancer patients with GA/AA in rs12918952 tend to have more risk to develop parametrium invasion and pelvic lymph node metastasis. Among 5 WWOX SNPs, rs11545028 is the only genetic variant associated with patient survival, in which CT/TT could predict better overall survival in Taiwanese women.

A Trickster in Disguise: Hyaluronan's Ambivalent Roles in the Matrix

Hyaluronan (HA) is a simple but diverse glycosaminoglycan. It plays a major role in aging, cellular senescence, cancer, and tissue homeostasis. In which way HA affects the surrounding tissues greatly depends on the molecular weight of HA. Whereas high molecular weight HA is associated with homeostasis and protective effects, HA fragments tend to be linked to the pathologic state. Furthermore, the interaction of HA with its binding partners, the hyaladherins, such as CD44, is essential for sustaining tissue integrity and is likewise related to cancer. The naked mole rat, a rodent species, possesses a special form of very high molecular weight (vHMW) HA, which is associated with the extraordinary cancer resistance and longevity of those animals. This review addresses HA and its diverse facets: from HA synthesis to degradation, from oligomeric HA to vHMW-HA and from its beneficial properties to the involvement in pathologies. We further discuss the functions of HA in the naked mole rat and compare them to human conditions. Though intensively researched, this simple polymer bears some secrets that may hold the key for a better understanding of cellular processes and the development of diseases, such as cancer.

Functional genetic variant of WW domain-containing oxidoreductase (WWOX) gene is associated with hepatocellular carcinoma risk

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Human WW domain-containing oxidoreductase (WWOX) gene has been identified as a tumor suppressor gene in multiple cancers. We hypothesize that genetic variations in WWOX are associated with HCC risk.

METHODOLOGY/PRINCIPAL FINDINGS

Five single-nucleotide polymorphisms (SNPs) of the WWOX gene were evaluated from 708 normal controls and 354 patients with HCC. We identified a significant association between a WWOX single nucleotide polymorphism (SNP), rs73569323, and decreased risk of HCC. After adjustment for potential confounders, patients with at least one T allele at rs11545028 of WWOX may have a significantly smaller tumor size, reduced levels of α-fetoprotein and alanine aminotransferase (ALT). Moreover, the A allele at SNP rs12918952 in WWOX conferred higher risk of vascular invasion. Additional in silico analysis also suggests that WWOX rs12918952 polymorphism tends to affect WWOX expression, which in turn contributes to tumor vascular invasion.

CONCLUSIONS

In conclusion, genetic variations in WWOX may be a significant predictor of early HCC occurrence and a reliable biomarker for disease progression.

Zfra restores memory deficits in Alzheimer's disease triple-transgenic mice by blocking aggregation of TRAPPC6AΔ, SH3GLB2, tau, and amyloid β, and inflammatory NF-κB activation

Introduction

Zinc finger-like protein that regulates apoptosis (Zfra) is a naturally occurring 31-amino-acid protein. Synthetic peptides Zfra1–31 and Zfra4–10 are known to effectively block the growth of many types of cancer cells.

Methods

Ten-month-old triple-transgenic (3×Tg) mice for Alzheimer's disease (AD) received synthetic Zfra peptides via tail vein injections, followed by examining restoration of memory deficits.

Results

Zfra significantly downregulated TRAPPC6AΔ, SH3GLB2, tau, and amyloid β (Αβ) aggregates in the brains of 3×Tg mice and effectively restored their memory capabilities. Zfra inhibited melanoma-induced neuronal death in the hippocampus and plaque formation in the cortex. Mechanistically, Zfra blocked the aggregation of amyloid β 42 and many serine-containing peptides in vitro, suppressed tumor necrosis factor–mediated NF-κB activation, and bound cytosolic proteins for accelerating their degradation in ubiquitin/proteasome-independent manner.

Discussion

Zfra peptides exhibit a strong efficacy in blocking tau aggregation and amyloid Αβ formation and restore memory deficits in 3×Tg mice, suggesting its potential for treatment of AD.