Epithelial-mesenchymal transition, regulated by ß-catenin and Twist, leads to esophageal wall remodeling in pediatric eosinophilic esophagitis.

Eosinophilic Esophagitis (EoE) is an antigen-triggered inflammatory condition of the esophageal lining characterized by eosinophilic infiltration. EoE is associated with significant remodeling, and although this remodeling is reversed by current treatment regimens, symptoms of EoE and associated remodeling reappear upon cessation of therapies. We hypothesized that structural remodeling of cell-cell adhesion is a key factor in the pathogenesis of EoE and that epithelial to mesenchymal transition (EMT) was a viable molecular process to lead to this remodeling. Endoscopically obtained biopsy samples from 18 EoE and 18 control pediatric patients were evaluated by transmission electron microscopy to measure intercellular spaces (IS) between cells. Biopsy samples from all groups were analyzed for cellular levels of cell-cell adhesion proteins: E-cadherin, zonula occludens associated protein-1 (ZO-1), and N-cadherin. We also analyzed for cellular levels and localization two of transcription factors, Twist1 and ß-catenin, that are associated with promoting EMT. The IS was significantly increased in the EoE group compared to the control. We observed a significant decrease in E-cadherin and ZO-1 levels and a concomitant increase in N-cadherin levels in EoE samples compared to control. Further, while there was no significant change in cellular levels of ß-catenin, we observed an altered localization of the protein from the cell membrane in control tissue to a nuclear/perinuclear localization in EoE. We observed higher levels of the transcription factor Twist1 in the EoE group compared to normal which was localized mainly at the nucleus. Our results suggest that the integrity of normally sealed esophageal epithelia is compromised in the EoE patients compared to control subjects, and this is due to alterations in the expression of cell adhesion molecules at the esophageal epithelium. Our data also suggest that EMT, potentially regulated by transcription factors ß-catenin and Twist1, may be responsible for the molecular alteration which leads to the remodeling of esophageal epithelia in EoE.

Wnt/ß-Catenin Participates in the Repair of Acute Respiratory Distress Syndrome-Associated Early Pulmonary Fibrosis via Mesenchymal Stem Cell Microvesicles.

PURPOSE: The main aim of the present study was to establish whether mesenchymal stem cell microvesicles (MSC MVs) exert anti-fibrotic effects and investigate the mechanisms underlying these effects in a mouse model of acute respiratory distress syndrome (ARDS)-associated early pulmonary fibrosis. METHODS: An ARDS-associated pulmonary fibrosis model was established in mice by an intratracheal injection of lipopolysaccharide (LPS). At 1, 3, and 7 days after LPS-mediated injury, the lungs of mice treated with MSC MVs and untreated controls were carefully excised and fibrosis was assessed based on the extent of collagen deposition. In addition, the development of epithelial-mesenchymal transition (EMT) was evaluated based on loss of E-cadherin and zona occludens-1 (ZO-1) along with the acquisition of α-smooth muscle actin (α-SMA) and N-cadherin. Nuclear translocation and ß-catenin expression analyses were also used to evaluate activation of the Wnt/ß-catenin signaling pathway. RESULTS: Blue-stained collagen fibers were evident as early as 7 days after LPS injection. Treatment with MSC MVs suppressed pathological progression to a significant extent. MSC MVs markedly reversed the upregulation of N-cadherin and α-SMA and attenuated the downregulation of E-cadherin and ZO-1. The expression and nuclear translocation of ß-catenin were clearly decreased on day 7 after MSC MV treatment. CONCLUSION: Analyses indicated that MSC MVs could ameliorate ARDS-associated early pulmonary fibrosis via the suppression of EMT and might be related to Wnt/ß-catenin transition signaling.

LncRNA SNHG16 promotes proliferation and migration in laryngeal squamous cell carcinoma via the miR-140-5p/NFAT5/Wnt/ß-catenin pathway axis.

BACKGROUND: Recent studies demonstrate that long noncoding RNAs (lncRNAs) are involved in the development of various cancers. Many lncRNAs were reported to abnormally express in laryngeal squamous cell carcinoma (LSCC) and play pivotal roles in its development. LncRNA small nucleolar RNA host gene 16 (SNHG16) was previously validated as an oncogene in hepatocellular carcinoma. Nevertheless, the biological role of SNHG16 in LSCC still needs more explorations. The goal of this assay is to explore the function and molecular mechanism of lncRNA SNHG16 in the development of LSCC. METHODS AND RESULTS: First, RT-qPCR demonstrated the upregulation of SNHG16 in LSCC cells and tissues. Loss-of-function assays determined the inhibitive influence of SNHG16 downregulation on cell viability, growth, and migration in LSCC. Furthermore, SNHG16 bound with miR-140-5p in LSCC. MiR-140-5p overexpression suppressed LSCC cell proliferation and migration. NFAT5 was identified as a direct target of miR-140-5p. Through rescue experiments, overexpression of NFAT5 reversed SNHG16 knockdown-mediated suppression on cell viability, growth, and migration in LSCC. Additionally, NFAT5 overexpression activated while NFAT5 downregulation inhibited the Wnt/ß-catenin signaling pathway. CONCLUSION: LncRNA SNHG16 is upregulated in LSCC and contributes to the development of LSCC via regulating the miR-140-5p/NFAT5/Wnt/ß-catenin pathway axis. The SNHG16/miR-140-5p/NFAT5/Wnt/ß-catenin pathway axis might provide a novel strategy for LSCC treatment.

MiR-93 inhibits the vascular calcification of chronic renal failure by suppression of Wnt/ß-catenin pathway.

OBJECTIVE: To explore the effect of miR-93-mediated Wnt/ß-catenin pathway on the vascular calcification (VC) of chronic renal failure (CRF). METHODS: SD rats were utilized to construct CRF models and divided into Control, CRF, CRF + LV (lentiviral vector)-miR-93 and CRF + LV-Con groups. Renal tissues collected from rats were performed hematoxylin and eosin (HE) staining and Masson staining, while the abdominal aorta was dissected for alizarin red staining and Von Kossa staining. VC-related genes were determined by qRT-PCR while Wnt/ß-catenin pathway-related proteins were examined by Western blotting. RESULTS: As compared to Control group, the serum levels of blood urea nitrogen (BUN), serum creatinine (Scr), phosphorus (P), cystatin C (Cys-C) and 24-h urea protein (24 h Upro), and the scores of renal interstitial lesion and fibrotic area in rats from CRF group were elevated, with the increased calcified area of aorta as well as the enhanced calcium content and ALP. Meanwhile, rats in the CRF group had up-regulated expression of OPN, OCN, RUNX2 and BMP-2 and down-regulated expression of miR-93. As for the expression of Wnt/ß-catenin pathway, rats in the CRF group had sharp increases in the protein expression of TCF4 and ß-catenin, while α-SMA was down-regulated. However, changes of the above were reversed in rats from CRF + LV-miR-93 group, and TCF4 was confirmed to be a target gene of miR-93. CONCLUSION: MiR-93, via inhibiting the activity of Wnt/ß-catenin pathway by targeting TCF4, can improve the renal function of CRF rats, thereby mitigating the vascular calcification of CRF.

The Akt/GSK3ß/ß-catenin signaling regulated by ZCCHC14 is responsible for accelerating the proliferation of hepatocellular carcinoma.

PURPOSE: To clarify how ZCCHC14 affects the development of hepatocellular carcinoma (HCC). METHODS: Differential levels of ZCCHC14 in HCC tissues and cells were examined. Proliferative and migratory changes in HCC cells with overexpression or knockdown of ZCCHC14 were detected using 5-Ethynyl-2'- deoxyuridine (EdU) and Transwell assay, respectively. Expression changes of p-Akt/Akt, p-GSK3ß/GSK3ß and ß-catenin in HCC cells mediated by ZCCHC14 were determined. Intervened by the p-Akt activator SC79 or overexpression of ß-catenin, further validated the involvement of the Akt/GSK3ß/ß-catenin signaling in HCC cell phenotypes mediated by ZCCHC14. RESULTS: Upregulated ZCCHC14 in HCC accelerated in vitro proliferative potential of HCC cells. Knockdown of ZCCHC14 inactivated the Akt/GSK3ß/ß-catenin signaling and inhibited malignant phenotypes of HCC, which were partially reversed by SC79 induction or overexpression of ß-catenin. CONCLUSIONS: By activating the Akt/GSK3ß/ß-catenin signaling, ZCCHC14 accelerates HCC cells proliferation.

Atorvastatin inhibits proliferation and promotes apoptosis of colon cancer cells via COX-2/PGE2/ß-Catenin Pathway.

PURPOSE: To explore the effects of atorvastatin (ATST) on the proliferation and apoptosis of colon cancer cells through the cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2)/ß-catenin pathway. METHODS: HCT116 cells were cultured and transfected, and they were treated with ATST at different concentrations for different time. The association between the expressions of COX-2 and PGE2 and the survival time of patients with colon cancer was analyzed via Kaplan-Meier survival analysis. Then the protein expressions of COX-2, ß-catenin and apoptosis-related molecules in HCT116 cells were determined using Western blotting, and the proliferation of HCT116 cells was detected via cell counting kit-8 (CCK-8) assay. RESULTS: There was a significant difference in the survival rate between HCT116 cells treated with 30 µM ATST and those treated with 0 µM ATST. The survival time was obviously longer in patients with low expressions of COX-2 and PGE2 than that those with high expressions of COX-2 and PGE2. Low expressions of COX-2 and PGE2 in colon cancer tissues indicate a longer survival time. Moreover, a positive correlation was found between HCT116 cell density and COX-2 level, HCT116 cell density and PGE2 level, and COX-2 and PGE2 levels. ATST could down-regulate COX-2 and ß-catenin, and knocking down COX-2 could lower ß-catenin. After treatment with ATST and ATST + anti-COX-2, the activity of cleaved caspase-9, caspase-3 and PARP was remarkably enhanced, suggesting that ATST and ATST + anti-COX-2 can promote apoptosis of HCT116 cells. It was found that ATST and ATST + anti-COX-2 could also inhibit the proliferation of HCT116 cells.

ß-Catenin Attenuation Inhibits Tumor Growth and Promotes Differentiation in a BRAFV600E-Driven Thyroid Cancer Animal Model.

BRAFV600E mutation is the most frequent genetic alteration in papillary thyroid cancer (PTC). ß-Catenin (Ctnnb1) is a key downstream component of canonical Wnt signaling pathway and is frequently overexpressed in PTC. BRAF V600E-driven tumors have been speculated to rely on Wnt/ß-catenin signaling to sustain its growth, although many details remain to be elucidated. In this study, we investigated the role of ß-catenin in BrafV600E -driven thyroid cancer in a transgenic mouse model. In Braf V600E mice with wild-type (WT) Ctnnb1 (BVE-Ctnnb1WT or BVE), overexpression of ß-catenin was observed in thyroid tumors. In Braf V600E mice with Ctnnb1 knockout (BVE-Ctnnb1null), thyroid tumor growth was slowed with significant reduction in papillary architecture. This was associated with increased expression of genes involved in thyroid hormone synthesis, elevated 124iodine uptake, and serum T4. The survival of BVE-Ctnnb1null mice was increased by more than 50% during 14-month observation. Mechanistically, downregulation of MAPK, PI3K/Akt, and TGFß pathways and loss of epithelial-mesenchymal transition (EMT) were demonstrated in the BVE-Ctnnb1null tumors. Treatment with dual ß-catenin/KDM4A inhibitor PKF118-310 dramatically improved the sensitivity of BVE-Ctnnb1WT tumor cells to BRAFV600E inhibitor PLX4720, resulting in significant growth arrest and apoptosis in vitro, and tumor regression and differentiation in vivo These findings indicate that ß-catenin signaling plays an important role in thyroid cancer growth and resistance to BRAFV600E inhibitors. Simultaneously targeting both Wnt/ß-catenin and MAPK signaling pathways may achieve better therapeutic outcome in BRAFV600E inhibitor-resistant and/or radioiodine-refractory thyroid cancer.

ß-Catenin Signaling Regulates the In Vivo Distribution of Hepatitis B Virus Biosynthesis across the Liver Lobule.

ß-Catenin (Ctnnb1) supports high levels of liver gene expression in hepatocytes in proximity to the central vein functionally defining zone 3 of the liver lobule. This region of the liver lobule supports the highest levels of viral biosynthesis in wild-type hepatitis B virus (HBV) transgenic mice. Liver-specific ß-catenin-null HBV transgenic mice exhibit a stark loss of high levels of pericentral viral biosynthesis. Additionally, viral replication that does not depend directly on ß-catenin activity appears to expand to include hepatocytes of zone 1 of the liver lobule in proximity to the portal vein, a region of the liver that typically lacks significant HBV biosynthesis in wild-type HBV transgenic mice. While the average amount of viral RNA transcripts does not change, viral DNA replication is reduced approximately 3-fold. Together, these observations demonstrate that ß-catenin signaling represents a major determinant of HBV biosynthesis governing the magnitude and distribution of viral replication across the liver lobule in vivo. Additionally, these findings reveal a novel mechanism for the regulation of HBV biosynthesis that is potentially relevant to the expression of additional liver-specific genes. IMPORTANCE Viral biosynthesis is highest around the central vein in the hepatitis B virus (HBV) transgenic mouse model of chronic infection. The associated HBV biosynthetic gradient across the liver lobule is primarily dependent upon ß-catenin. In the absence of ß-catenin, the gradient of viral gene expression spanning the liver lobule is absent, and HBV replication is reduced. Therefore, therapeutically manipulating ß-catenin activity in the livers of chronic HBV carriers may reduce circulating infectious virions without greatly modulating viral protein production. Together, these changes in viral biosynthesis might limit infection of additional hepatocytes while permitting immunological clearance of previously infected cells, potentially limiting disease persistence.

Canonical Wnt Signaling Pathway on Polarity Formation of Utricle Hair Cells.

As part of the inner ear, the vestibular system is responsible for sense of balance, which consists of three semicircular canals, the utricle, and the saccule. Increasing evidence has indicated that the noncanonical Wnt/PCP signaling pathway plays a significant role in the development of the polarity of the inner ear. However, the role of canonical Wnt signaling in the polarity of the vestibule is still not completely clear. In this study, we found that canonical Wnt pathway-related genes are expressed in the early stage of development of the utricle and change dynamically. We conditionally knocked out ß-catenin, a canonical Wnt signaling core protein, and found that the cilia orientation of hair cells was disordered with reduced number of hair cells in the utricle. Moreover, regulating the canonical Wnt pathway (Licl and IWP2) in vitro also affected hair cell polarity and indicated that Axin2 may be important in this process. In conclusion, our results not only confirm that the regulation of canonical Wnt signaling affects the number of hair cells in the utricle but also provide evidence for its role in polarity development.

Wnt Signaling: From Mesenchymal Cell Fate to Lipogenesis and Other Mature Adipocyte Functions.

Wnt signaling is an ancient and evolutionarily conserved pathway with fundamental roles in the development of adipose tissues. Roles of this pathway in mesenchymal stem cell fate determination and differentiation have been extensively studied. Indeed, canonical Wnt signaling is a significant endogenous inhibitor of adipogenesis and promoter of other cell fates, including osteogenesis, chondrogenesis, and myogenesis. However, emerging genetic evidence in both humans and mice suggests central roles for Wnt signaling in body fat distribution, obesity, and metabolic dysfunction. Herein, we highlight recent studies that have begun to unravel the contributions of various Wnt pathway members to critical adipocyte functions, including carbohydrate and lipid metabolism. We further explore compelling evidence of complex and coordinated interactions between adipocytes and other cell types within adipose tissues, including stromal, immune, and endothelial cells. Given the evolutionary conservation and ubiquitous cellular distribution of this pathway, uncovering the contributions of Wnt signaling to cell metabolism has exciting implications for therapeutic intervention in widespread pathologic states, including obesity, diabetes, and cancers.

MiR-145-5p modulates lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating ß-catenin signaling in hyperlipidemia.

The present study aims to explore the role of microRNA 145-5p (miR-145-5p) in hyperlipidemia. Using bioinformatics tools and a wide range of function and mechanism assays, we attempted to understand the specific function and potential mechanism of miR-145-5p in hyperlipidemia. A cholesterol-enriched diet induced an increase of serum cholesterol and triacylglycerol but a decrease of serum high-density lipoprotein. MiR-145-5p level was decreased in hyperlipidemia rat models. MiR-145-5p regulated lipid metabolism by antagonizing the alteration of high-density lipoprotein, cholesterol, and triacylglycerol in serum mediated by a cholesterol-enriched diet. In mechanism, miR-145-5p directly bound with p21 protein (RAC1)-activated kinase 7 (PAK7) and negatively regulated mRNA and protein levels of PAK7 in THP-1 cells. Furthermore, miR-145-5p level was negatively associated with PAK7 level in rat cardiac tissues. Finally, overexpression of PAK7 reversed the effects of miR-145-5p on ß-catenin activation and M2 macrophages polarization in THP-1 cells. In conclusion, MiR-145-5p modulated lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating ß-catenin signaling in hyperlipidemia, which may provide a potential biomarker for the treatment of hyperlipidemia-induced cardiovascular diseases.

Investigating function of long noncoding RNA of HOTAIRM1 in progression of SKOV3 ovarian cancer cells.

Ovarian cancer is one of the most heterogeneous malignancies in the field of gynecologic oncology. Deregulation of long noncoding RNAs (lncRNAs) is implicated in carcinogenesis. Therefore, the present study was conducted to investigate the possible role of lncRNA of HOXA transcript antisense intergenic RNA myeloid-specific 1(HOTAIRM1) in progression of SKOV3 cells in ovarian cancer and also its underlying molecular mechanisms. HOTAIRM1 expression level will be measured by real-time polymerase chain reaction (PCR) in SKOV3 cells. For determining the effect of HOTAIRM1 silencing on progression of SKOV3 cells, siHOTAIRM1 will be designed and transfected into cells using a liposomal approach. MTT and trypan blue assays will be used to determine the effect of HOTAIRM1 silencing on cell proliferation. Apoptosis of the cells will be detected by flow cytometry. Furthermore, expressions of apoptosis-related genes and Wnt pathway-related proteins and genes will be analyzed by Western blot and real-time PCR. HOTAIRM1 was overexpressed in SKOV3 cells. Silencing of HOTAIRM1 alleviated cell proliferation, and increased cell apoptosis of SKOV3 cells. Moreover, siHOTAIRM1 significantly increased expression of pro-apoptotic agents, such as Bad and Bax, while it decreased expressions of Bid and Bcl-2 (anti-apoptotic agents). Also, silencing of HOTAIRM1 resulted in a suppressed expression of Wnt pathway-related proteins and also expression of its downstream target gene, matrix metalloproteinase 9(MMP9). Our findings provided new insights into function of lncRNA of HOTAIRM1 in progression of ovarian cancer by modulating Wnt pathway and its downstream target gene, MMP9.

Loss of CTNNB1 exon 3 in sclerosing angiomatoid nodular transformation of the spleen.

Sclerosing angiomatoid nodular transformation (SANT) is a rare vascular lesion of the spleen. Although several hypotheses have been suggested, the etiopathogenesis of SANT remains unknown. It is also unclear whether SANT is a reactive or a neoplastic lesion. Since CTNNB1 (ß-catenin gene) exon 3 mutations were frequently detected in some rare fibrovascular lesions, we aimed to investigate the presence of oncogenic CTNNB1 mutations in SANT cases. For this purpose, 7 cases of SANT with typical histopathological features were retrieved. First, the presence of CTNNB1 exon 3 alterations was examined with a recently described immunohistochemistry-based method. Then, the findings were confirmed with polymerase chain reaction (PCR), reverse transcription PCR (RT-PCR), and Sanger sequencing. In all cases, immunochemistry of ß-catenin gave a staining pattern that was suggestive of exon 3 alteration; however, no missense mutations were found in any case at the CTNNB1 exon 3 hotspot region. Subsequently, we screened for large interstitial deletions of CTNNB1 exon 3 which revealed short PCR products in three cases. Sequencing confirmed that these cases had large interstitial deletions, resulting in loss of the entire exon 3 of CTNNB1. In the remaining four cases, loss of exon 3 was documented at the cDNA level, although genomic deletion was not identified. These results demonstrate that loss of CTNNB1 exon 3 and stabilization of ß-catenin with activation of Wnt signaling pathway might have a significant role in the pathogenesis of SANT. Through this study, we provided important evidence for the neoplastic nature and pathogenesis of this disorder.

Pannexin 1 binds ß-catenin to modulate melanoma cell growth and metabolism.

Melanoma is the most aggressive skin malignancy with increasing incidence worldwide. Pannexin1 (PANX1), a member of the pannexin family of channel-forming glycoproteins, regulates cellular processes in melanoma cells including proliferation, migration, and invasion/metastasis. However, the mechanisms responsible for coordinating and regulating PANX1 function remain unclear. Here, we demonstrated a direct interaction between the C-terminal region of PANX1 and the N-terminal portion of ß-catenin, a key transcription factor in the Wnt pathway. At the protein level, ß-catenin was significantly decreased when PANX1 was either knocked down or inhibited by two PANX1 blockers, Probenecid and Spironolactone. Immunofluorescence imaging showed a disrupted pattern of ß-catenin localization at the cell membrane in PANX1-deficient cells, and transcription of several Wnt target genes, including MITF, was suppressed. In addition, a mitochondrial stress test revealed that the metabolism of PANX1-deficient cells was impaired, indicating a role for PANX1 in the regulation of the melanoma cell metabolic profile. Taken together, our data show that PANX1 directly interacts with ß-catenin to modulate growth and metabolism in melanoma cells. These findings provide mechanistic insight into PANX1-mediated melanoma progression and may be applicable to other contexts where PANX1 and ß-catenin interact as a potential new component of the Wnt signaling pathway.

Wnt/ß-catenin/Slug pathway contributes to tumor invasion and lymph node metastasis in head and neck squamous cell carcinoma.

The canonical Wnt/ß-catenin pathway is involved in diverse cancer development mechanisms, such as proliferation, migration, and invasion. However, its role in head and neck squamous cell carcinoma (HNSCC) remains largely unknown. We investigated whether the canonical Wnt/ß-catenin signaling pathway acts as a controller of invasion and lymph node metastasis (LNM) in HNSCC. Loss of function experiments against the canonical Wnt/ß-catenin pathway were conducted to evaluate its invasive and metastatic role in HNSCC cells. Slug was evaluated as a downstream protein in canonical Wnt/ß-catenin-mediated invasion. In addition, canonical Wnt/ß-catenin and Slug expression levels were examined in 119 HNSCC tissue samples to study the relevance of these proteins in LNM and prognosis of patients post-treatment. In vitro suppression of ß-catenin expression led to decreased migration and invasion of HNSCC cells. Using an in vivo mouse orthotopic LNM model, a decrease in LNM was observed with mitigated ß-catenin expression. Slug expression upregulation mediates invasion and LNM by the canonical Wnt/ß-catenin pathway. Simultaneous expression of ß-catenin and Slug is the major predictive factor of LNM and survival rate in patients with HNSCC. In conclusion, the canonical Wnt/ß-catenin/Slug signaling axis significantly contributes to cancer cell invasion and LNM. Its blockade may be a treatment strategy for LNM and tumor recurrence in HNSCC.

Association of beta-catenin and CD44 in the development of renal cell carcinoma.

INTRODUCTION AND OBJECTIVE: Renal cell carcinoma (RCC) accounts for approximately 3% of all cancers. Approximately 25%-30% of patients present with metastatic disease at the time of diagnosis, and metastatic RCC is a treatment-resistant malignancy. Altered expression of cell adhesion molecules such as CD44 on tumor cells suggests a pathogenetic mechanism for tumor metastasis and may provide prognostic information for particular tumors. These cell matrix interactions of CD44 play a role in tumor cell invasion and metastasis. The Wnt/beta-catenin pathway turned out to be a promising target as it is involved in the regulation of cell proliferation, differentiation and apoptosis induction. METHOD: In this study, the expression of beta-catenin and CD44 was analyzed in primary renal cell carcinoma (RCC) samples to understand their association with development of the disease. For this purpose, immunohistochemical expression analysis of beta-catenin and CD44 was performed in 30 primary RCC histological samples and normal kidney tissues in different subtypes at different clinical stages of Indian patients (year: 2017-2019). RESULT: Most of the patients who presented were diagnosed as clear cell carcinoma and it was observed that expression of CD44 was high in patients with high stage tumors. Also beta-catenin was increased in advanced grade tumors, but there was insignificant correlation between high expression of molecules and survival or recurrence of disease. CONCLUSION: Both cd44 and beta-catenin activation was noted in patients with clear cell carcinoma, more in advanced tumors. Both can be promising targets for treatment in clear cell RCCs.

Rapamycin inhibits lung squamous cell carcinoma growth by downregulating glypican-3/Wnt/ß-catenin signaling and autophagy.

PURPOSE: There is not much progress in the treatment for lung squamous cell carcinoma LSCC in the past few years. Rapamycin Rapa, an inhibitor of mammalian target of rapamycin mTOR, has exhibited antitumor efficacy in a variety of malignant tumors. It has recently been reported that Rapamycin can induce autophagy signaling pathway in lung cancer and Glypican-3GPC3 can promote the growth of hepatocellular carcinoma by stimulating canonical Wnt signaling pathway. The aim of this study is to investigate the mechanisms of rapamycin's antitumor efficacy in relation to GPC3/Wnt/ß-catenin pathway and autophagy in LSCC. METHODS: SK-MES-1 cells, a LSCC cell line, were treated with various concentrations of rapamycin with or without Glypican-3 GPC3-targeting siRNA. SK-MES-1 cell proliferation was determined by MTT assay. Protein expression levels of GPC3, ß-catenin, Beclin-1 were checked via western blotting. We established the xenograft mice model to investigate the suppression effect of rapamycin on LSCC. In addition, we further testified the metabolism protein of autophagy process using the xenograft tumor tissue. RESULTS: Rapamycin could inhibit the SK-MES-1 cell proliferation in a concentration-dependent manner both in vitro and in vivo by decreasing the GPC3 expression and downregulating the glypican-3/Wnt/ß-catenin signaling pathway. In addition, we found that GPC3 silencing can activate the glypican-3/Wnt/ß-catenin pathway and autophagy, which contribute to the suppression of tumor growth both in vitro and in vivo. CONCLUSION: Rapamycin suppresses the growth of lung cancer through down-regulating glypican-3/Wnt/ß-catenin signaling, which mediates with activation of autophagy. This study suggests GPC3 is a new promising target for rapamycin in the treatment of lung cancer.

RPN2 is targeted by miR-181c and mediates glioma progression and temozolomide sensitivity via the wnt/ß-catenin signaling pathway.

Accumulating evidence indicates that the dysregulation of the miRNAs/mRNA-mediated carcinogenic signaling pathway network is intimately involved in glioma initiation and progression. In the present study, by performing experiments and bioinformatics analysis, we found that RPN2 was markedly elevated in glioma specimens compared with normal controls, and its upregulation was significantly linked to WHO grade and poor prognosis. Knockdown of RPN2 inhibited tumor proliferation and invasion, promoted apoptosis, and enhanced temozolomide (TMZ) sensitivity in vitro and in vivo. Mechanistic investigation revealed that RPN2 deletion repressed ß-catenin/Tcf-4 transcription activity partly through functional activation of glycogen synthase kinase-3ß (GSK-3ß). Furthermore, we showed that RPN2 is a direct functional target of miR-181c. Ectopic miR-181c expression suppressed ß-catenin/Tcf-4 activity, while restoration of RPN2 partly reversed this inhibitory effect mediated by miR-181c, implying a molecular mechanism in which TMZ sensitivity is mediated by miR-181c. Taken together, our data revealed a new miR-181c/RPN2/wnt/ß-catenin signaling axis that plays significant roles in glioma tumorigenesis and TMZ resistance, and it represents a potential therapeutic target, especially in GBM.