RGL2 Drives the Metastatic Progression of Colorectal Cancer via Preventing the Protein Degradation of β-Catenin and KRAS.
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ABSTRACT:
SUBMITTER: Sun MS
PROVIDER: S-EPMC8067854 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Introduction: Serine hydroxymethyltransferase 2 (SHMT2) plays a critical role in serine-glycine metabolism to drive cancer cell proliferation. However, the nonmetabolic function of SHMT2 in tumorigenesis, especially in human colorectal cancer (CRC) progression, remains largely unclear. Methods: SHMT2 expression in human CRC cells was identified by western blot and immunofluorescence assay. The CRC cell proliferation, migration, and invasion after SHMT2 knockdown or overexpression were explored through in vitro and in vivo assays. Immunofluorescence, mRNA-seq, co-immunoprecipitation, chromatin immunoprecipitation-qPCR and immunohistochemistry assays were used to investigate the underlying mechanisms behind the SHMT2 nonmetabolic function. Results: We demonstrated that SHMT2 was distributed in the cytoplasm and nucleus of human CRC cells. SHMT2 knockdown resulted in the significant inhibition of CRC cell proliferation, which was not restored by serine, glycine, or formate supplementation. The invasion and migration of CRC cells were suppressed after SHMT2 knockdown. Mechanistically, SHMT2 interacted with β-catenin in the cytoplasm. This interaction inhibited the ubiquitylation-mediated degradation of β-catenin and subsequently modulated the expression of its target genes, leading to the promotion of CRC cell proliferation and metastasis. Notably, the lysine 64 residue on SHMT2 (SHMT2K64) mediated its interaction with β-catenin. Moreover, transcription factor TCF4 interacted with β-catenin, which in turn increased SHMT2 expression, forming an SHMT2/β-catenin positive feedback loop. In vivo xenograft experiments confirmed that SHMT2 promoted the growth and metastasis of CRC cells. Finally, the level of SHMT2 was found to be significantly increased in human CRC tissues. The SHMT2 level was correlated with an increased level of β-catenin, associated with CRC progression and predicted poor patient survival. Conclusion: Taken together, our findings reveal a novel nonmetabolic function of SHMT2 in which it stabilizes β-catenin to prevent its ubiquitylation-mediated degradation and provide a potential therapeutic strategy for CRC therapy.
| S-EPMC7806468 | biostudies-literature
Project description:Background Hypoxia, a typical hallmark of solid tumors, exhibits an essential role in the progression of colorectal cancer (CRC), in which the dysregulation of long non-coding RNAs (lncRNAs) is frequently observed. However, the underlying mechanisms are not clearly defined. Methods The TCGA database was analyzed to identify differential lncRNA expression involved in hypoxia-induced CRC progression. qRT-PCR was conducted to validate the upregulation of lncRNA STEAP3-AS1 in CRC cell lines and tumor-bearing mouse and zebrafish models under hypoxia. ChIP-qRT-PCR was used to detect the transcriptional activation of STEAP3-AS1 mediated by HIF-1α. RNA-seq, fluorescent in situ hybridization, RNA pulldown, RNA immunoprecipitation, co-immunoprecipitation, immunofluorescence and immunoblot experiments were used to ascertain the involved mechanisms. Functional assays were performed in both in vitro and in vivo models to investigate the regulatory role of STEAP3-AS1/STEAP3/Wnt/β-catenin axis in CRC proliferation and metastasis. Results Here, we identified a hypoxia-induced antisense lncRNA STEAP3-AS1 that was highly expressed in clinical CRC tissues and positively correlated with poor prognosis of CRC patients. Upregulation of lncRNA STEAP3-AS1, which was induced by HIF-1α-mediated transcriptional activation, facilitated the proliferation and metastasis of CRC cells both in vitro and in vivo. Mechanistically, STEAP3-AS1 interacted competitively with the YTH domain-containing family protein 2 (YTHDF2), a N6-methyladenosine (m6A) reader, leading to the disassociation of YTHDF2 with STEAP3 mRNA. This effect protected STEAP3 mRNA from m6A-mediated degradation, enabling the high expression of STEAP3 protein and subsequent production of cellular ferrous iron (Fe2+). Increased Fe2+ levels elevated Ser 9 phosphorylation of glycogen synthase kinase 3 beta (GSK3β) and inhibited its kinase activity, thus releasing β-catenin for nuclear translocation and subsequent activation of Wnt signaling to support CRC progression. Conclusions Taken together, our study highlights the mechanisms of lncRNA STEAP3-AS1 in facilitating CRC progression involving the STEAP3-AS1/STEAP3/Wnt/β-catenin axis, which may provide novel diagnostic biomarkers or therapeutic targets to benefit CRC treatment. Graphical abstract Hypoxia-induced HIF-1α transcriptionally upregulates the expression of lncRNA STEAP3-AS1, which interacts competitively with YTHDF2, thus upregulating mRNA stability of STEAP3 and consequent STEAP3 protein expression. The enhanced STEAP3 expression results in production of cellular ferrous iron (Fe2+), which induces the Ser 9 phosphorylation and inactivation of GSK3β, releasing β-catenin for nuclear translocation and contributing to subsequent activation of Wnt signaling to promote CRC progression. Supplementary Information The online version contains supplementary material available at 10.1186/s12943-022-01638-1.
| S-EPMC9392287 | biostudies-literature
Project description:The K+ channel KCNQ1 has been proposed as a tumor suppressor in colorectal cancer (CRC). We investigated the molecular mechanisms regulating KCNQ1:β-catenin bidirectional interactions and their effects on CRC differentiation, proliferation, and invasion. Molecular and pharmacologic approaches were used to determine the influence of KCNQ1 expression on the Wnt/β-catenin signaling and epithelial-to-mesenchymal transition (EMT) in human CRC cell lines of varying stages of differentiation. The expression of KCNQ1 was lost with increasing mesenchymal phenotype in poorly differentiated CRC cell lines as a consequence of repression of the KCNQ1 promoter by β-catenin:T-cell factor (TCF)-4. In well-differentiated epithelial CRC cell lines, KCNQ1 was localized to the plasma membrane in a complex with β-catenin and E-cadherin. The colocalization of KCNQ1 with adherens junction proteins was lost with increasing EMT phenotype. ShRNA knock-down of KCNQ1 caused a relocalization of β-catenin from the plasma membrane and a loss of epithelial phenotype in CRC spheroids. Overexpression of KCNQ1 trapped β-catenin at the plasma membrane, induced a patent lumen in CRC spheroids, and slowed CRC cell invasion. The KCNQ1 ion channel inhibitor chromanol 293B caused membrane depolarization, redistribution of β-catenin into the cytosol, and a reduced transepithelial electrical resistance, and stimulated CRC cell proliferation. Analysis of human primary CRC tumor patient databases showed a positive correlation between KCNQ1:KCNE3 channel complex expression and disease-free survival. We conclude that the KCNQ1 ion channel is a target gene and regulator of the Wnt/β-catenin pathway, and its repression leads to CRC cell proliferation, EMT, and tumorigenesis.
| S-EPMC5402468 | biostudies-literature
Project description:BRAF V600E attracts wide attention in the treatment of colorectal cancer (CRC) as stratifying and predicting a refractory classification of CRC. Recent evidence indicates that Wnt/β-catenin signaling is broadly activated and participates in the refractoriness of BRAF V600E CRC, but the underlying molecular mechanism needs to be elucidated. Here, heat shock 70 kDa protein 8 (HSPA8), an essential regulator in chaperone-mediated autophagy (CMA), is identified as a potential therapeutic target for advanced BRAF V600E CRC. These results show that HSPA8 is transcriptionally upregulated in BRAF V600E CRC, which promotes CMA-dependent degradation of caveolin-1 (CAV1) to release β-catenin into the nucleus and thus activates the Wnt/β-catenin pathway, contributing to metastasis and progression of BRAF V600E CRC. Of note, HSPA8 directly interacts with the KIFSN motif on CAV1, the interaction can be enhanced by p38 MAPK-mediated CAV1 S168 phosphorylation. Furthermore, pharmacological targeting HSPA8 by VER155008 exhibits synergistic effects with BRAF inhibitors on CRC mouse models. In summary, these findings discover the important role of the HSPA8/CAV1/β-catenin axis in the development of refractory BRAF V600E CRC and highlight HSPA8 as a predictive biomarker and therapeutic target in clinical practice.
| S-EPMC10797426 | biostudies-literature
Project description:Aberrant regulation of the Wnt/β-catenin signaling pathway is one of the major causes of colorectal cancer (CRC). Loss-of-function mutations in APC are commonly found in CRC, leading to inappropriate activation of canonical Wnt signaling. Conversely, gain-of-function mutations in KRAS and BRAF genes are detected in up to 60% of CRCs. Whereas KRAS/mitogen-activated protein kinase (MAPK) and canonical Wnt/β-catenin pathways are critical for intestinal tumorigenesis, mechanisms integrating these two important signaling pathways during CRC development are unknown. Results herein demonstrate that transformation of normal intestinal epithelial cells (IECs) by oncogenic forms of KRAS, BRAF or MEK1 was associated with a marked increase in β-catenin/TCF4 and c-MYC promoter transcriptional activities and mRNA levels of c-Myc, Axin2 and Lef1. Notably, expression of a dominant-negative mutant of T-Cell Factor 4 (ΔNTCF4) severely attenuated IEC transformation induced by oncogenic MEK1 and markedly reduced their tumorigenic and metastatic potential in immunocompromised mice. Interestingly, the Frizzled co-receptor LRP6 was phosphorylated in a MEK-dependent manner in transformed IECs and in human CRC cell lines. Expression of LRP6 mutant in which serine/threonine residues in each particular ProlineProlineProlineSerine/ThreonineProline motif were mutated to alanines (LRP6-5A) significantly reduced β-catenin/TCF4 transcriptional activity. Accordingly, MEK inhibition in human CRC cells significantly diminished β-catenin/TCF4 transcriptional activity and c-MYC mRNA and protein levels without affecting β-catenin expression or stability. Lastly, LRP6 phosphorylation was also increased in human colorectal tumors, including adenomas, in comparison with healthy adjacent normal tissues. Our data indicate that oncogenic activation of KRAS/BRAF/MEK signaling stimulates the canonical Wnt/β-catenin pathway, which in turn promotes intestinal tumor growth and invasion. Moreover, LRP6 phosphorylation by ERK1/2 may provide a unique point of convergence between KRAS/MAPK and Wnt/β-catenin signalings during oncogenesis.
| S-EPMC4687460 | biostudies-literature
Project description:Aberrant regulation of the Wnt/β-catenin pathway plays important roles in colorectal carcinogenesis, with over 90% of cases of sporadic colon cancer featuring β-catenin accumulation. While ubiquitination-mediated degradation is widely accepted as a major route for β-catenin protein turnover, little is known about the regulation of β-catenin in transcriptional level. Here we show that Elf3, a member of the E-twenty-six family of transcription factors, drives β-catenin transactivation and associates with poor survival of colorectal cancer (CRC) patients. We first found recurrent amplification and upregulation of Elf3 in CRC tissues, and further Gene Set Enrichment Analysis identified significant association between Elf3 expression and activity of WNT/β-catenin pathway. Chromatin immunoprecipitation and electrophoretic mobility shift assay consistently revealed that Elf3 binds to and transactivates β-catenin promoter. Ectopic expression of Elf3 induces accumulation of β-catenin in both nucleus and cytoplasm, causing subsequent upregulation of several effector genes including c-Myc, VEGF, CCND1, MMP-7 and c-Jun. Suppressing Elf3 in CRC cells attenuates β-catenin signaling and decreases cell proliferation, migration and survival. Targeting Elf3 in xenograft tumors suppressed tumor progression in vivo. Taken together, our data identify Elf3 as a pivotal driver for β-catenin signaling in CRC, and highlight potential prognostic and therapeutic significance of Elf3 in CRC.
| S-EPMC4047871 | biostudies-literature
Project description:BackgroundThe sperm-associated antigen 5 (SPAG5) plays a key role in controlling various cellular phenomena, including cell cycle progression and proliferation. However, the role of SPAG5 in hepatocellular carcinoma (HCC) remains unknown.MethodsThis study investigated the function and clinical significance of SPAG5 protein expression in hepatocellular carcinoma. We analyzed SPAG5 expression in surgical specimens from 136 HCC patients. The correlation between the clinical characteristics and prognosis was also determined. Furthermore, the SPAG5 was overexpressed in HCC cell and silenced with shRNA in HCC cells. Moreover, cell proliferation and apoptosis were measured using Edu assay and flow cytometry and a molecular mechanism of SPAG5 promotes HCC progression was explored.ResultsHerein, our study showed that upregulation of SPAG5 was detected frequently in primary HCC tissues, and was associated with significantly worse survival among the HCC patients. Multivariate analyses revealed that high SPAG5 expression was an independent predictive marker for the poor prognosis of HCC. SPAG5 silence effectively abolished the proliferation abilities of SPAG5 in vivo and in vitro, while induced apoptosis in HCC cells. Furthermore, our results indicate that SPAG5 promoted cell progression by decreasing SCARA5 expression, which has been reported to control the progression of HCC, and our data demonstrated that SCARA5 is crucial for SPAG5-mediated HCC cell progression in vitro and in vivo. Moreover, we found that the expression of SPAG5 and SCARA5 are inversely correlated in HCC tissues. In addition, we demonstrated that SPAG5 promoted progression in HCC via downregulating SCARA5 depended on the β-catenin/TCF4 signaling pathway. Interestingly, the underlying mechanism is which SPAG5 regulates SCARA5 expression by modulating β-catenin degradation.ConclusionsTaken together, our data provide a novel evidence for the biological and clinical significance of SPAG5 as a potential biomarker, and we demonstrate that SPAG5-β-catenin-SCARA5 might be a novel pathway involved in HCC progression.
| S-EPMC6154423 | biostudies-literature
Project description:Colorectal cancer (CRC) pathogenesis is mainly driven by alterations in WNT signaling, which results in altered transcriptional activity of β-Catenin. Mutations in APC (Adenomatous Polyposis Coli) are reflected in β-Catenin hyperactivation and loss of proliferation control. Certain intestinal bacteria metabolites have shown the ability to limit CRC cell proliferation and CRC pathogenesis. Here, we investigated the molecular mechanism underlying the anti-proliferative activity of butyrate, a microbiota-derived short chain fatty acid, in two CRC cell lines, namely HCT116 and SW620, which bear a mutation in β-Catenin and APC, respectively. In particular, we focused on autophagy, a lysosome-dependent degradation pathway, which was shown to control intestinal tissue homeostasis. Butyrate reduced CRC cell proliferation, as witnessed by the downregulation of proliferation markers. TCGA bioinformatic transcriptomic analysis of CTNNB1 (β-Catenin) gene correlation in CRC patients showed that β-Catenin negatively correlates with the autophagy gene ATG4D. In CRC cells, regardless of the mutational state of APC or β-Catenin genes, butyrate caused the autophagy-mediated degradation of β-Catenin; thus, preventing its transcriptional activity. Autophagy gene silencing restored β-Catenin levels, allowing it to translocate into the nucleus to promote the expression of downstream genes associated with cancer cell proliferation. CRC-affected patients show driver mutations in the WNT pathway; thus, targeting its crucial effector may be a promising therapeutic strategy in CRC treatment; for instance, by using ad hoc probiotics that stimulate autophagy.
| S-EPMC9138675 | biostudies-literature
Project description:In colorectal cancer, APC-mediated induction of unregulated cell growth involves posttranslational mechanisms that prevent proteasomal degradation of proto-oncogene β-catenin (CTNNB1) and its eventual translocation to the nucleus. However, about 10% of colorectal tumors also exhibit increased CTNNB1 mRNA. Here, we show in colorectal cancer that increased expression of ZNF148, the gene coding for transcription factor ZBP-89, correlated with reduced patient survival. Tissue arrays showed that ZBP-89 protein was overexpressed in the early stages of colorectal cancer. Conditional deletion of Zfp148 in a mouse model of Apc-mediated intestinal polyps demonstrated that ZBP-89 was required for polyp formation due to induction of Ctnnb1 gene expression. Chromatin immunoprecipitation (ChIP) and EMSA identified a ZBP-89-binding site in the proximal promoter of CTNNB1 Reciprocally, siRNA-mediated reduction of CTNNB1 expression also decreased ZBP-89 protein. ChIP identified TCF DNA binding sites in the ZNF148 promoter through which Wnt signaling regulates ZNF148 gene expression. Suppression of either ZNF148 or CTNNB1 reduced colony formation in WNT-dependent, but not WNT-independent cell lines. Therefore, the increase in intracellular β-catenin protein initiated by APC mutations is sustained by ZBP-89-mediated feedforward induction of CTNNB1 mRNA. Cancer Res; 76(23); 6877-87. ©2016 AACR.
| S-EPMC5379474 | biostudies-literature
Project description:Recent studies suggest that long noncoding RNAs (lncRNAs) play essential roles in tumor progression. However, the functional roles and underlying mechanisms of lncRNAs in neuroblastoma (NB), the most common malignant solid tumor in pediatric population, still remain elusive. Herein, through integrating analysis of a public RNA sequencing dataset, neuroblastoma highly expressed 1 (NHEG1) was identified as a risk-associated lncRNA, contributing to an unfavorable outcome of NB. Depletion of NHEG1 led to facilitated differentiation and decreased growth and aggressiveness of NB cells. Mechanistically, NHEG1 bound to and stabilized DEAD-box helicase 5 (DDX5) protein through repressing proteasome-mediated degradation, resulting in β-catenin transactivation that altered target gene expression associated with NB progression. We further determined a lymphoid enhancer binding factor 1 (LEF1)/transcription factor 7-like 2 (TCF7L2)/NHEG1/DDX5/β-catenin axis with a positive feedback loop and demonstrated that NHEG1 harbored oncogenic properties via its interplay with DDX5. Administration of small interfering RNAs against NHEG1 or DDX5 reduced tumor growth and prolonged survival of nude mice bearing xenografts. High NHEG1 or DDX5 expression was associated with poor survival of NB patients. These results indicate that lncRNA NHEG1 exhibits oncogenic activity that affects NB progression via stabilizing the DDX5 protein, which might serve as a potential therapeutic target for NB.
| S-EPMC7054727 | biostudies-literature