p120-Catenin modulating nuclear factor-κB activation is partially RhoA/ROCKdependent in scratch injury.

p120-catenin (p120) is known as a cadherin-associated protein that participates in tumor metastasis and invasion, as well as an anti-inflammatory mediator. Recently, its anti-inflammatory role is drawing increasing attention, but the regulatory mechanisms are still unknown. Here, we report that p120 modulated inflammatory responses partially depends on RhoA/ROCK pathway in scratch-induced injury in human bronchial epithelial cells (BECs). For the first time, we found that p120 was significantly reduced in BECs after scratching, which could induce interleukin-8 (IL-8) production through nuclear factor-κB (NF-κB) activation accompanied with IκBα phosphorylation. Over-expression of p120 3A could inhibit NF-κB activation and IL-8 mRNA expression and protein synthesis after scratching, while p120 knockdown by small interfering RNA could promote NF-κB activation and IL-8 mRNA expression and protein synthesis after scratching. Furthermore, we found that RhoA was the binding partner of p120 in BECs. Although total RhoA and p120-binded RhoA remained unchanged, the RhoA activity was increased after scratching. Chemical blockade of RhoA/ROCK signaling (Y27632) inhibited scratch-induced nuclear translocation of NF-κB p65. Over-expression of p120 3A attenuated scratch-induced RhoA activation, whereas silence of p120 significantly elevated scratch-induced RhoA activation in BCEs. Conclusively, these results indicate an anti-inflammatory effect of p120 in bronchial epithelial cells through its modulation of NF-κB signaling depending on RhoA/ROCK pathway.

The value of tumor markers in the diagnosis of papillary thyroid carcinoma alone and in combination.

Aim of the study is to evaluate the expression of CK19, galectin-3, HBME-1, CD56, claudin-1 and neutrophil gelatinase-associated lipocalin (NGAL) in papillary thyroid carcinoma (PTC), including classic, follicular variant and micro-carcinoma. Peritumoral benign thyroid tissues were used as a control (C). Immunohistochemical staining with the EnVision detection system was performed on 59 formalin-fixed, paraffin-embedded thyroid tissues, including 43 PTC and 16 C. CK19, galectin-3, HBME-1, claudin-1 and NGAL were positive in most PTC, but were negative or showed focal weak staining in C. CD56 was positive in C, but absent in PTC. For a single analyzed tumor marker, the sensitivity of the above six thyroid tumor markers was 100%, 95.3%, 86%, 79.1%, 90.7%, 93%, respectively. The specificity was 56.25%, 100%, 100%, 100%, 100%, 100%, respectively. For the combination of the six tumor markers, the sensitivity, specificity, positive predictive value, negative predictive value and the diagnostic accuracy were all 100%, with co-expression of at least four indices. In the diagnosis of PTC, combined application of the above tumor markers is recommended. It can be diagnosed as PTC clearly when thyroid lesions are positive for at least four of the above tumor markers [CD56⁻], and can be excluded as PTC definitely when at least four tumor markers are negative [CD56⁺].

The Role of Innate Immunity in Osteoarthritis and the Connotation of "Immune-joint" Axis: A Narrative Review.

Osteoarthritis (OA) is a degenerative disease that results in constriction of the joint space due to the gradual deterioration of cartilage, alterations in subchondral bone, and synovial membrane. Recently, scientists have found that OA involves lesions in the whole joint, in addition to joint wear and tear and cartilage damage. Osteoarthritis is often accompanied by a subclinical form of synovitis, which is a chronic, relatively low-grade inflammatory response mainly mediated by the innate immune system. The "immune-joint" axis refers to an interaction of an innate immune response with joint inflammation and the whole joint range. Previous studies have underestimated the role of the immune-joint axis in OA, and there is no related research. For this reason, this review aimed to evaluate the existing evidence on the influence of innate immune mechanisms on the pathogenesis of OA. The innate immune system is the body's first line of defense. When the innate immune system is triggered, it instantly activates the downstream inflammatory signal pathway, causing an inflammatory response, while also promoting immune cells to invade joint synovial tissue and accelerate the progression of OA. We have proposed the concept of the "immune-joint" axis and explored it from two aspects of Traditional Chinese Medicine (TCM) theory and modern medical research, such as the innate immunity and OA, macrophages and OA, complement and OA, and other cells and OA, to enrich the scientific connotation of the "immune-joint" axis.

Prebiotics alleviate cartilage degradation and inflammation in post-traumatic osteoarthritic mice by modulating the gut barrier and fecal metabolomics.

Osteoarthritis (OA) is a degenerative joint disease characterized by articular cartilage degeneration, subchondral bone sclerosis, synovial hyperplasia and inflammation as the main pathological manifestations. This study aims to investigate the protective effect of prebiotics in post-traumatic osteoarthritic (PTOA) mice by modulating the gut barrier and fecal metabolomics. The results suggested that cartilage degeneration, osteophyte formation and inflammation were significantly reduced by prebiotics in PTOA mice. In addition, the gut barrier was protected by the increased expression of tight junction proteins ZO-1 and occludin in the colon. High-throughput sequencing found that 220 fecal metabolites were affected by joint trauma, 81 of which were significantly recovered after probiotic intervention, and some metabolites (valerylcarnitine, adrenic acid, oxoglutaric acid, etc.) were closely associated with PTOA. Our study demonstrates that prebiotics can delay the progression of PTOA by regulating the metabolites of the gut microbiota and protecting the gut barrier, which is expected to be an intervention method for PTOA.

Zhuifeng tougu capsules inhibit the TLR4/MyD88/NF-κB signaling pathway and alleviate knee osteoarthritis: In vitro and in vivo experiments.

Background: Knee osteoarthritis (KOA), a chronic degenerative disease, is mainly characterized by destruction of articular cartilage and inflammatory reactions. At present, there is a lack of economical and effective clinical treatment. Zhuifeng Tougu (ZFTG) capsules have been clinically approved for treatment of OA as they relieve joint pain and inflammatory manifestations. However, the mechanism of ZFTG in KOA remains unknown. Purpose: This study aimed to investigate the effect of ZFTG on the TLR4/MyD88/NF-κB signaling pathway and its therapeutic effect on rabbits with KOA. Study design: In vivo, we established a rabbit KOA model using the modified Videman method. In vitro, we treated chondrocytes with IL-1ß to induce a pro-inflammatory phenotype and then intervened with different concentrations of ZFTG. Levels of IL-1ß, IL-6, TNF-α, and IFN-γ were assessed with histological observations and ELISA data. The effect of ZFTG on the viability of chondrocytes was detected using a Cell Counting Kit-8 and flow cytometry. The protein and mRNA expressions of TLR2, TLR4, MyD88, and NF-κB were detected using Western blot and RT-qPCR and immunofluorescence observation of NF-κB p65 protein expression, respectively, to investigate the mechanism of ZFTG in inhibiting inflammatory injury of rabbit articular chondrocytes and alleviating cartilage degeneration. Results: The TLR4/MyD88/NF-κB signaling pathway in rabbits with KOA was inhibited, and the levels of IL-1ß, IL-6, TNF-α, and IFN-γ in blood and cell were significantly downregulated, consistent with histological results. Both the protein and mRNA expressions of TLR2, TLR4, MyD88, NF-κB, and NF-κB p65 proteins in that nucleus decreased in the ZFTG groups. Moreover, ZFTG promotes the survival of chondrocytes and inhibits the apoptosis of inflammatory chondrocytes. Conclusion: ZFTG alleviates the degeneration of rabbit knee joint cartilage, inhibits the apoptosis of inflammatory chondrocytes, and promotes the survival of chondrocytes. The underlying mechanism may be inhibition of the TLR4/MyD88/NF-kB signaling pathway and secretion of inflammatory factors.

Nodakenin attenuates cartilage degradation and inflammatory responses in a mice model of knee osteoarthritis by regulating mitochondrial Drp1/ROS/NLRP3 axis.

Osteoarthritis (OA) is a common degenerative disease with few treatments. In traditional Chinese medicine (TCM), Radix Angelicae biseratae (RAB) is commonly used to treat OA. Nodakenin (Nod) is one main coumarin active component in RAB and exhibits anti-inflammatory, anti-oxidative, and anti-apoptotic effects. Reactive oxygen species (ROS) produced by mitochondria play a vital role in the pathogenesis of OA. We hypothesized that Nod might ameliorate cartilage degradation and inflammatory responses by regulating the mitochondrial Drp1/ROS/NLRP3 axis. With this, the effects of Nod on a mouse model of knee OA and activated primary chondrocytes were assessed. The results showed that Nod intervention improved bone volume, lowered trabecular separation, and increased trabecular number in the subchondral bone. Nod decreased the Osteoarthritis Research Society International (OARSI) scores and increased collagen II-positive areas in the articular cartilage of the tibial plateau. Compared with OA mice, Nod-treated animals exhibited lower levels of inflammatory factors in the serum and synovitis of the knee joint. In vitro results indicated that Nod suppressed dynamin-related protein 1 (Drp1) phosphorylation and massive ROS production by Drp1-dependent mitochondrial fission in lipopolysaccharide-stimulated chondrocytes. Moreover, Nod inhibited the mRNA levels of inflammatory cytokines (COX 2, IL-1ß, and TNF-α), nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, and matrix metalloproteinase 13 expression in activated chondrocytes. In conclusion, Nod attenuates cartilage degradation and inflammatory responses in mice with OA by regulating the mitochondrial Drp1/ROS/NLRP3 axis, suggesting its potential for OA therapy.

Baicalein Alleviates Osteoarthritis Progression in Mice by Protecting Subchondral Bone and Suppressing Chondrocyte Apoptosis Based on Network Pharmacology.

As life expectancy increases, Osteoarthritis (OA) is becoming a more frequently seen chronic joint disease. The main characteristics of OA are loss of articular cartilage, subchondral bone sclerosis, and synovial inflammation. Baicalein (Bai), a traditional Chinese medicine extracted from Scutellaria baicalensis Georgi, has been demonstrated to exert notable anti-inflammatory effects in previous studies, suggesting its potential effect in the treatment of OA. In this study, we first predicted the action targets of Bai, mapped target genes related to OA, identified potential anti-OA targets for Bai, performed gene ontology (GO) enrichment, and KEGG signaling pathway analyses of the action targets, and analyzed the molecular docking of key Bai targets. Additionally, the effect and potential mechanism of Bai against OA were verified in mouse knee OA models induced by destabilized medial meniscus (DMM) surgery. GO and KEGG analyses showed that 19 anti-OA targets were mainly involved in the response to oxidative stress, the response to hypoxia and apoptosis, and the PI3K-Akt and p53 signaling pathways. Molecular docking results indicated that BAX, BCL 2, and Caspase 3 enriched in the apoptotic signaling pathway have high binding affinity with Bai. Validation experiments showed that Bai can significantly attenuate the loss of articular cartilage (OARSI score), suppress synovial inflammation (synovitis score), and ameliorate subchondral bone resorption measured by micro-CT. In addition, Bai notably inhibited the expression of apoptosis-related proteins in articular cartilage (BAX, BCL 2, and Caspase 3). By combining network pharmacology with experimental validation, our study identifies and verifies the importance of the apoptotic signaling pathway in the treatment of OA by Bai. Bai may have promising application and potential therapeutic value in OA treatment.

Bleomycin-induced nuclear factor-kappaB activation in human bronchial epithelial cells involves the phosphorylation of glycogen synthase kinase 3beta.

Nuclear factor-kappaB (NF-kappaB) plays a central role in the development of bleomycin (BLM) lung toxicity, but the regulatory mechanisms are still unknown. In the present study, we investigated the cytotoxic effect of BLM on cultured human bronchial epithelial cells (BECs) and first confirmed that BLM induced the transcriptional activation of NF-kappaB signaling in BECs. We also found that BLM activated Akt (protein kinase B, PKB) and increased the phosphorylation level of glycogen synthase kinase 3beta (GSK3beta). GSK3beta is known to be a key downstream target of Akt, and LY294002, the PI3K (phosphatidylinositol 3-kinase)/Akt inhibitor, which promoted the dephosphorylation of GSK3beta, significantly attenuated BLM-induced NF-kappaB activation. Next, we further observed that constitutively active GSK3beta stabilized the inhibitor of NF-kappaB (IkappaBalpha), inhibited p65 nuclear translocation and partially blocked BLM-induced NF-kappaB activation. Importantly, a co-immunoprecipitation assay revealed that GSK3beta formed a complex with IkappaBalpha, while GSK3beta phosphorylation caused by BLM led to their dissociation. These results suggest that BLM can induce the activation of NF-kappaB signaling in BECs and this process is tightly associated with the phosphorylation status of GSK3beta, implying a possible regulatory mechanism of NF-kappaB signaling in BECs during the toxic lung injury induced by BLM.

[Spatial-temporal distribution of glycogen synthase kinase 3beta and adenomatous polyposis coli protein are involved in the injury and repair of airway epithelial cells induced by scratching].

To investigate the roles of glycogen synthase kinase 3beta (GSK3beta) and adenomatous polyposis coli (APC) protein in wound repair of airway epithelial cells (AECs), we established a wound model of airway epithelium in vitro. Then the following tests were undertaken: (1) Western blot was used to detect the levels of total GSK3beta and phosphorylated GSK3beta in human bronchial epithelial (16HBE) cells; (2) The localizations of APC protein was observed by using immunofluorescence technique; (3) Immunoprecipitation was used to investigate the relationship between APC protein and GSK3beta during the repair of 16HBE cells. The results were as follows: (1) The level of phosphorylated GSK3beta increased 0.5 h after scratching (P<0.05), reached a maximum at 6 h (P<0.05), and maintained until 12 h, while the total level of GSK3beta remained constant; (2) Results of immunofluorescence study showed that APC protein clustered with tubulin in the region of the migrating leading cells 6 h after scratching, which was dissimilar with that in the cells 0 h after scratching; (3) GSK3beta and APC protein were immunoprecipitated and analysed on SDS-PAGE. We found that GSK3beta and APC protein were precipitated, indicating that the two proteins existed in a complex. After scratching, dissociation of the two proteins occurred. Taken together, we conclude that scratching caused a decrease in phosphorylation of GSK3beta, and that reduced phosphorylation of GSK3beta promoted APC protein to bind to the plus ends of microtubules and stabilize the growing ends. These observations suggest that APC protein and GSK3beta may synergistically play an important role in the repair of airway epithelium.

Glycogen synthase kinase 3beta induces cell cycle arrest in a cyclin D1-dependent manner in human lung adenocarcinoma cell line A549.

The effect of glycogen synthase kinase 3beta (GSK3beta) has been repeatedly implicated in cell proliferation, but studies on the effect of GSK3beta in different cell lines with different stimuli have drawn different conclusions. To investigate the direct effect of GSK3beta on cell growth in human lung adenocarcinoma cell line A549, we changed its activity by transient transfection with two kinds of GSK3beta mutant plasmids, constitutively active form S9A-GSK3beta and dominant negative form KM-GSK3beta. Twenty-four hours later, cell counting, flow cytometry and Western blot detection were made respectively. The results showed that enhancing GSK3beta activity caused a decrease in cell number, as well as a higher percentage of cells at G(1) phase. Further, the expression of cyclin D1 was down-regulated by GSK3beta. Taken together, our observations suggest that GSK3beta may induce G(1) cell cycle arrest in a cyclin D1-dependent fashion and therefore possibly plays a growth-inhibitory role in A549 cells.

Erdheim-Chester Disease with Emperipolesis: A Unique Case Involving the Heart.

Histiocytosis is an uncommon disease characterized by excessive accumulation of histiocytes. Here, we report a rare case of non-Langerhans-cell histiocytosis in a 51-year-old woman who presented with severe symptoms of pericardial effusion. Radiologic investigation also detected multiple bone (lower limbs, vertebrae, ribs, and ilium) lesions. Resected pericardium showed abundant mono- or multi-nucleated non-foamy histiocytes (CD68+/CD163+/S-100+/CD1α-/langerin-) in a fibroinflammatory background. The histiocytes demonstrated emperipolesis of lymphocytes, a hallmark feature of Rosai-Dorfman disease (RDD). However, molecular analysis revealed a BRAF V600E mutation of the proliferating histiocytes, highlighting the neoplastic features frequently observed in another non-Langerhans-cell histiocytosis known as Erdheim-Chester Disease (ECD). We consider this case to be a unique presentation of ECD harboring some RDD-like cells with emperipolesis, but not a case of RDD with a BRAF mutation concerning its clinical manifestation (involvement of the heart and bones) and neoplastic features.

Clinical pathological feature of early tongue amyloidosis.

OBJECTIVE: To investigate the clinical pathological feature and diagnostic criteria of tongue amyloidosis (AL). METHODS: During 1992 to 2005, 25 patients pathologically diagnosed as tongue AL in our hospital were reviewed retrospectively, and all of them had no enlarged tongue. Haematoxylin and eosin (HE) and immunohistochemical staining were used to detect the amyloid deposition on the tongue. RESULTS: Totally 84% (21/25) patients had symptoms of xerostomia and taste-blindness, 44% (11/25) patients complained of activity limitation of tongue. Macroscopic observation showed mucosa pallescence, punctuate hemorrhage, red grain particles, and ulcers on the tongue. HE staining indicated amyloid depositions in basement membrane, muscle cell, vessel wall, and nerve fiber. Immunohistochemical study demonstrated kappa light-chain deposition in 64% (16/25) cases, and lambda light-chain deposition in 36% (9/25) cases. They presented in vessel wall, nerve fiber, and muscle cells. CONCLUSION: The biopsy is an important means for the diagnosis of early tongue AL, and the wide variety of amyloid light chain is helpful to differential diagnosis.

[Dynamic changes of adenomatous polyposis coli protein and glycogen synthase kinase 3beta in the repair of the injured airway epithelial cells in smoking mice].

To investigate the roles of adenomatous polyposis coli (APC) protein and glycogen synthase kinase 3beta (GSK3beta) of smoking murine model in the repair of the injured airway epithelial cells (AECs) in different stages, 30 male Kun-Ming mice were randomly divided into two groups, the control group and the smoking group. There were 24 mice in smoking group, and 6 animals were separately killed at the end of the 1st, 4th, 8th and 12th week after smoking. Then the following tests were undertaken: (1) HE staining of lung section to observe the morphological changes of the bronchi in the smoking mice. (2) Immunohistochemical staining of APC protein and GSK3beta in the AECs. (3) Western blot was used to detect the levels of APC protein, GSK3beta and phosphorated GSK3beta (p-GSK3beta) in pulmonary tissue. (4) Observing the localizations of APC protein and GSK3beta in the AECs by immunofluorescence technique. The results showed: (1) AECs showed changes of predominant injury (1-, 4-week), repair (8-week) and reinjury (12-week) along with smoking time prolonged. The experimental results indicated that the model of smoking mice was duplicated successfully. (2) Immunohistochemical results showed that the expression of APC protein in the AECs increased after 1-week smoking (0.458 +/- 0.062 vs 0.399 +/- 0.060, P< 0.05 vs control), but was significantly decreased at the end of the 4th week (0.339+/- 0.056, P<0.01 vs control) and increased at the end of the 8th and 12th week (0.387 +/- 0.041, 0.378 +/- 0.037, P<0.05 vs 4-week). The expression of GSK3beta in the AECs of smoking mice obviously decreased (P<0.01 or P<0.05 vs control). (3) Western blot showed that the expressions of APC protein and GSK3beta in lung tissue were consistent with the results of immunohistochemistry; and the levels of p-GSK3beta in all smoking models were higher than that in control. (4) The results of immunofluorescence showed that APC protein was localized mainly near the regions of epithelial cell membrane at the end of the 1st and 8th week after smoking, which were dissimilar with the localization in control, and this change was not seen in the location of GSK3beta. Taken together, these results demonstrate that the expressions and localizations of APC protein, GSK3beta and the activity of GSK3beta are dynamically changed in the AECs with experimental smoking injury at different phases, suggesting that APC protein and GSK3beta may be involved in the regulation of migration and proliferation of AECs, and play an important role in the process of repair of airway epithelium injury.

Cigarette smoke extract-induced p120-mediated NF-κB activation in human epithelial cells is dependent on the RhoA/ROCK pathway.

Cigarette smoke exposure is a major cause of chronic obstructive pulmonary disease (COPD), but the underlying molecular inflammatory mechanisms remain poorly understood. Previous studies have found that smoke disrupts cell-cell adhesion by inducing epithelial barrier damage to the adherens junction proteins, primarily E-cadherin (E-cad) and p120-catenin (p120). Recently, the anti-inflammatory role of p120 has drawn increasing attention. In this study, we demonstrate that p120 has a role in the cigarette smoke extract-induced inflammatory response, presumably by regulating NF-κB signaling activation. Mechanistically, we show that p120-mediated NF-κB signaling activation in airway epithelial inflammation is partially RhoA dependent and is independent of E-cad. These results provide novel evidence for the role of p120 in the anti-inflammatory response.

Expression of papillary thyroid carcinoma-associated molecular markers and their significance in follicular epithelial dysplasia with papillary thyroid carcinoma-like nuclear alterations in Hashimoto's thyroiditis.

The aim of this study was to evaluate the expression of papillary thyroid carcinoma (PTC)-associated tumor markers in follicular epithelial dysplasia showing PTC-like nuclear alterations (FED) in Hashimoto's thyroiditis (HT) and to explore the relationship between HT and PTC. In this study, 43 PTC, 18 HT with FED and 16 peritumoral benign thyroid tissues were immunohistochemically analyzed for CK19, galectin-3, HBME-1, CD56, claudin-1 and NGAL expression. Our research revealed that in HT, the expression of CK19, galectin-3, HBME-1, claudin-1 and NGAL was focal and limited to FED, while CD56 was strongly positive in FED and most Hürthle cells. The stain intensity of CK19, claudin-1 and NGAL in FED decreased compared with PTC, but were significantly higher than that in peritumoral benign thyroid tissues (all P < 0.0125). For galectin-3, HBME-1 and CD56, no statistically significant difference was detected between HT and peritumoral benign thyroid tissues (all P > 0.05). In conclusion, In HT, FED might be a precancerous condition closely associated with PTC development as they have overlaps in cytological and immunomarker profiles, indicating that in patients with HT, under prolonged stimuli from chronic inflammation, part of follicular epithelia may show regeneration, hyperplasia, Hürthle cell metaplasia and dysplasia, eventually malignant transformation. Hence, long term follow-up and regular inspection would be necessary for Hashimoto's thyroiditis with FED.

p120 modulates LPS-induced NF-κB activation partially through RhoA in bronchial epithelial cells.

p120-Catenin (p120) is an adherens junction protein recognized to regulate cell-cell adhesion. Emerging evidence indicates that p120 may also play an important role in inflammatory responses, and the regulatory mechanisms are still unknown. In the present study, we showed that p120 was associated with airway inflammation. p120 downregulation induced nuclear factor-κB (NF-κB) activation, accompanied with I κ B α degradation, p65 nuclear translocation, and increased expression of interleukin-8 (IL-8) in lipopolysaccharide (LPS)- treated C57BL mice and human bronchial epithelial cells (BECs). Moreover, we first found that p120 directly coprecipitated with RhoA in BECs. After LPS stimulation, although total RhoA and p120-bound RhoA were unchanged, RhoA activity was increased. Y27632, a ROCK inhibitor, could partially inhibit nuclear translocation of p65. Overexpression of p120 inactivated RhoA and NF-κB in BECs, whereas p120 loss significantly increased RhoA activity, p65 nuclear translocation, and IL-8 expression. Taken together, our study supports the regulatory role of p120 in airway inflammation and reveals that p120 may modulate NF-κB signaling partially through RhoA.

Involvement of p120 in LPS-induced NF-kappaB activation and IL-8 production in human bronchial epithelial cells.

P120-catenin (p120), a prototypic member of a subfamily of Armadillo repeat domain (Arm domain) proteins, not only participates in cell-cell adhesion, but also mediates inflammatory responses in the skin. In the present study, we demonstrated the effect of p120 on lipopolysaccharide (LPS)-induced inflammatory responses in human bronchial epithelial cells (BECs). We first confirmed that p120 expression was significantly reduced after LPS stimulation in BECs, the p65 subunit of nuclear factor-kappaB (NF-kappaB) nuclear translocation was promoted and NF-kappaB activity was rapidly induced. Moreover, the expression level of interleukin-8 (IL-8) increased after LPS treatment. Over-expression of p120 attenuated LPS-stimulated NF-kappaB reporter gene expression and IL-8 mRNA expression and protein synthesis. On the contrary, transfection with p120 small interfering RNA (siRNA) significantly elevated LPS-stimulated NF-kappaB transcriptional activity, p65 nuclear translocation and IL-8 expression. Collectively, these results indicate an anti-inflammatory effect of p120 in BECs, through its modulation of NF-kappaB signaling.

Glycogen synthase kinase 3beta induces apoptosis in cancer cells through increase of survivin nuclear localization.

Glycogen synthase kinase 3beta (GSK3beta) regulates numerous signaling pathways that control a wide range of cellular processes, including cell proliferation, differentiation, apoptosis and metabolism. We report a novel function of GSK3beta: It interacts with the inhibitor-of-apoptosis protein (IAP) survivin to modulate its expression, thus regulating apoptosis in human lung cancer cells. A co-immunoprecipitation assay revealed that GSK3beta can bind survivin. Activation of GSK3beta induced translocation of survivin from the cytoplasm to the nucleus, resulting in G1 cell-cycle arrest and apoptosis, as well as sensitization to the chemotherapeutic drug doxorubicin. In contrast, inactivation of GSK3beta, either by transfection of a dominant-negative mutant inhibitor DN-GSK3beta or with selective inhibitor LiCl, increased cytoplasmic survivin expression, leading to cell-cycle progression and resistance to apoptosis. These results identify a pro-apoptotic role for GSK3beta in cancer cells, through its modulation of survivin in subcellular redistribution. This new role suggests that there is a potential for pharmacologic activation of GSK3beta to enhance treatment of cancer patients, including those with resistance.