A Peptide Encoded by a Putative lncRNA HOXB-AS3 Suppresses Colon Cancer Growth.

A substantial fraction of eukaryotic transcripts are considered long non-coding RNAs (lncRNAs), which regulate various hallmarks of cancer. Here, we discovered that the lncRNA HOXB-AS3 encodes a conserved 53-aa peptide. The HOXB-AS3 peptide, not lncRNA, suppresses colon cancer (CRC) growth. Mechanistically, the HOXB-AS3 peptide competitively binds to the ariginine residues in RGG motif of hnRNP A1 and antagonizes the hnRNP A1-mediated regulation of pyruvate kinase M (PKM) splicing by blocking the binding of the ariginine residues in RGG motif of hnRNP A1 to the sequences flanking PKM exon 9, ensuring the formation of lower PKM2 and suppressing glucose metabolism reprogramming. CRC patients with low levels of HOXB-AS3 peptide have poorer prognoses. Our study indicates that the loss of HOXB-AS3 peptide is a critical oncogenic event in CRC metabolic reprogramming. Our findings uncover a complex regulatory mechanism of cancer metabolism reprogramming orchestrated by a peptide encoded by an lncRNA.

Down-regulation of TRPS1 stimulates epithelial-mesenchymal transition and metastasis through repression of FOXA1.

The tricho-rhino-phalangeal syndrome 1 gene (TRPS1), which was initially found to be associated with tricho-rhino-phalangeal syndrome, is critical for the development and differentiation of bone, hair follicles and kidney. However, its role in cancer progression is largely unknown. In this study, we demonstrated that down-regulation of TRPS1 correlated with distant metastasis, tumour recurrence and poor survival rate in cancer patients. TRPS1 was frequently down-regulated in high-metastatic cancer cell lines from the breast, colon and nasopharynx. Silencing of TRPS1 stimulated epithelial-mesenchymal transition (EMT), migration and invasion in vitro and metastasis in vivo, while TRPS1 over-expression exhibited the opposite effects. Using quantitative proteomics, FOXA1, a negative regulator of epithelial-mesenchymal transition (EMT), was shown to be down-regulated by TRPS1 knockdown. Ectopic expression of FOXA1 blocked the enhancement of EMT, migration and invasion induced by TRPS1 silencing. Mechanistically, TRPS1, acting as a transcription activator, directly induced FOXA1 transcription by binding to the FOXA1 promoter. We further showed that down-regulation of TRPS1 was induced by miR-373 binding to the 3' UTR of TRPS1. Over-expression of TRPS1, but not TRPS1 3' UTR, blocked the enhancement of migration and invasion induced by miR-373. Taken together, we consider that down-regulation of TRPS1 by miR-373, acting as a transcriptional activator, promotes EMT and metastasis by repressing FOXA1 transcription, expanding upon its previously reported role as a transcription repressor. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

ACK1 promotes gastric cancer epithelial-mesenchymal transition and metastasis through AKT-POU2F1-ECD signalling.

Amplification of the activated Cdc42-associated kinase 1 (ACK1) gene is frequent in gastric cancer (GC). However, little is known about the clinical roles and molecular mechanisms of ACK1 abnormalities in GC. Here, we found that the ACK1 protein level and ACK1 phosphorylation at Tyr 284 were frequently elevated in GC and associated with poor patient survival. Ectopic ACK1 expression in GC cells induced epithelial-mesenchymal transition (EMT) and promoted migration and invasion in vitro, and metastasis in vivo; the depletion of ACK1 induced the opposite effects. We utilized SILAC quantitative proteomics to discover that the level of the cell cycle-related protein ecdysoneless homologue (ECD) was markedly altered by ACK1. Overexpression of ECD promoted EMT, migration, and invasion in GC, similar to the effects of ACK1 overexpression. Silencing of ECD completely blocked the augmentation of ACK1 overexpression-induced EMT, migration, and invasion. Mechanistically, ACK1 phosphorylated AKT at Thr 308 and Ser 473 and activated the AKT pathway to up-regulate the transcription factor POU2F1, which directly bound to the promoter region of its novel target gene ECD and thus regulated ECD expression in GC cells. Furthermore, the phosphorylation levels of AKT at Thr 308 and Ser 473 and POU2F1 and ECD levels were positively associated with ACK1 levels in clinical GC specimens. Collectively, we have demonstrated that ACK1 promotes EMT, migration, and invasion by activating AKT-POU2F1-ECD signalling in GC cells. ACK1 may be employed as a new prognostic factor and therapeutic target for GC.

TaoHe ChengQi decoction ameliorates sepsis-induced cardiac dysfunction through anti-ferroptosis via the Nrf2 pathway.

BACKGROUND: Sepsis-induced cardiac dysfunction (SICD) is a serious complication of sepsis that is associated with increased mortality. Ferroptosis has been reported in the SICD. TaoHe ChengQi decoction (THCQD), a classical traditional Chinese medicinal formula, has multiple beneficial pharmacological effects. The potential effects of THCQD on the SICD remain unknown. PURPOSE: To investigate the effect of THCQD on SICD and explore whether this effect is related to the regulation of myocardial ferroptosis through nuclear factor erythroid 2-related factor 2 (Nrf2) activation. METHODS: We induced sepsis in a mouse model using cecal ligation and puncture (CLP) and administered THCQD (2 and 4 g/kg) and dexamethasone (40 mg/kg). Mice mortality was recorded and survival curves were plotted. Echocardiography, hematoxylin and eosin staining, and analysis of serum myocardial injury markers and inflammatory factors were used to evaluate cardiac pathology. Myocardial ferroptosis was detected by quantifying specific biomarker content and protein levels. Through HPLC-Q-Exactive-MS analysis, we identified the components of the THCQD. Network pharmacology analysis and Cellular Thermal Shift Assay (CETSA) were utilized to predict the targets of THCQD for treating SICD. We detected the expression of Nrf2 using Western blotting or immunofluorescence. An RSL3-induced ferroptosis model was established using neonatal rat cardiomyocytes (NRCMs) to further explore the pharmacological mechanism of THCQD. In addition to measuring cell viability, we observed changes in NRCM mitochondria using electron microscopy and JC-1 staining. NRF2 inhibitor ML385 and Nrf2 knockout mice were used to validate whether THCQD exerted protective effects against SICD through Nrf2-mediated ferroptosis signaling. RESULTS: THCQD reduced mortality in septic mice, protected against CLP-induced myocardial injury, decreased systemic inflammatory response, and prevented myocardial ferroptosis. Network pharmacology analysis and CETSA experiments predicted that THCQD may protect against SICD by activating the Nrf2 signaling pathway. Western blotting and immunofluorescence showed that THCQD activated Nrf2 in cardiac tissue. THCQDs consistently mitigated RSL3-induced ferroptosis in NRCM, which is related to Nrf2. Furthermore, the pharmacological inhibition of Nrf2 and genetic Nrf2 knockout partially reversed the protective effects of THCQD on SICD and ferroptosis. CONCLUSION: The effect of THCQD on SICD was achieved by activating Nrf2 and its downstream pathways.

ECD promotes gastric cancer metastasis by blocking E3 ligase ZFP91-mediated hnRNP F ubiquitination and degradation.

The human ortholog of the Drosophila ecdysoneless gene (ECD) is required for embryonic development and cell-cycle progression; however, its role in cancer progression and metastasis remains unclear. Here, we found that ECD is frequently overexpressed in gastric cancer (GC), especially in metastatic GC, and is correlated with poor clinical outcomes in GC patients. Silencing ECD inhibited GC migration and invasion in vitro and metastasis in vivo, while ECD overexpression promoted GC migration and invasion. ECD promoted GC invasion and metastasis by protecting hnRNP F from ubiquitination and degradation. We identified ZFP91 as the E3 ubiquitin ligase that is responsible for hnRNP F ubiquitination at Lys 185 and proteasomal degradation. ECD competitively bound to hnRNP F via the N-terminal STG1 domain (13-383aa), preventing hnRNP F from interacting with ZFP91, thus preventing ZFP91-mediated hnRNP F ubiquitination and proteasomal degradation. Collectively, our findings indicate that ECD promotes cancer invasion and metastasis by preventing E3 ligase ZFP91-mediated hnRNP F ubiquitination and degradation, suggesting that ECD may be a marker for poor prognosis and a potential therapeutic target for GC patients.

Amplification of ACK1 promotes gastric tumorigenesis via ECD-dependent p53 ubiquitination degradation.

Amplification or over-expression of an activated Cdc42-associated kinase 1 (ACK1) gene is common in breast, lung and ovarian cancers. However, little is known about the role of ACK1 in gastric tumorigenesis. Here, we found that DNA copy numbers of the ACK1 gene and its mRNA expression levels were significantly increased in gastric cancer (GC) compared to normal gastric tissues. Additionally, silencing ACK1 inhibited GC cell proliferation and colony formation, induced G2/M arrest and cellular apoptosis in vitro, and suppressed tumor growth in vivo. Gene Ontology annotation revealed that 147 differential proteins regulated by ACK1 knockdown were closely related with cellular survival. A cell cycle regulator, ecdysoneless homolog (ECD), was found to be significantly down-regulated by ACK1 knockdown. Silencing of ECD inhibited colony formation and induced G2/M arrest and cell apoptosis, which is similar to the effects of ACK1 knockdown. Silencing of ECD did not further enhance the effects of ACK1 knockdown on G2/M arrest and apoptosis, while silencing of ECD blocked the enhancement of colony formation by ACK1 over-expression. Over-expression of ACK or ECD promoted the ubiquitination of tumor suppressor p53 protein and decreased p53 levels, while silencing of ACK1 or ECD decreased the p53 ubiquitination level and increased p53 levels. Silencing of ECD attenuated the ubiquitination enhancement of p53 induced by ACK1 over-expression. Collectively, we demonstrate that amplification of ACK1 promotes gastric tumorigenesis by inducing an ECD-dependent ubiquitination degradation of p53.

MiR-373 drives the epithelial-to-mesenchymal transition and metastasis via the miR-373-TXNIP-HIF1α-TWIST signaling axis in breast cancer.

Our previous proteomics study revealed that thioredoxin-interacting protein (TXNIP) was down-regulated by miR-373. However, little is known of the mechanism by which miR-373 decreases TXNIP to stimulate metastasis. In this study, we show that miR-373 promotes the epithelial-to-mesenchymal transition (EMT) in breast cancer. MiR-373 suppresses TXNIP by binding to the 3'UTR of TXNIP, which in turn, induces cancer cell EMT and metastasis. TXNIP co-expression, but not the TXNIP-3'UTR, reverses the enhancement of EMT, migration, invasion and metastasis induced by miR-373. MiR-373 stimulates EMT, migration and invasion through TXNIP-dependent reactive oxygen species (ROS) reduction. Mechanistically, miR-373 up-regulates and activates the HIF1α-TWIST signaling axis via the TXNIP pathway. Consequently, TWIST induces miR-373 expression by binding to the promoter of the miR-371-373 cluster. Clinically, miR-373 is negatively associated with TXNIP and positively associated with HIF1α and TWIST, and activation of the miR-373-TXNIP-HIF1α-TWIST signaling axis is correlated with a worse outcome in patients with breast cancer. This signaling axis may be an independent prognostic factor for patients with breast cancer.

Epigenetic silencing of ITGA2 by MiR-373 promotes cell migration in breast cancer.

The loss of ITGA2 plays an important role in cancer metastasis in several solid cancers. However, the molecular mechanism of ITGA2 loss in primary cancers remains unclear. In this study, we found that a lower ITGA2 protein level was observed in breast cancers compared to adjacent non-cancerous breast tissues. Interestingly, the reduction degree of ITGA2 at the protein level was far more than that at the mRNA level. We further showed that the translation of ITGA2 mRNA was directly inhibited by miR-373 through binding to ITGA2-3'UTR. Silencing of ITGA2 detached cell-cell interactions, induced the deploymerization of stress fiber F-actin and stimulated cancer cell migration, similar to the effect of miR-373 over-expression. The co-expression of ITGA2, not ITGA2-3'UTR, could abrogate miR-373-induced cancer cell migration because that the expression of ITGA2-3'UTR was inhibited by co-transfected miR-373. ITGA2 protein level was inversely associated with miR-373 level in breast cancers (r = -0.663, P<0.001). 73.33% of breast cancer patients with high miR-373 and low ITGA2 expression exhibited the lymph node-positive metastases. Together, our results show that epigenetic silencing of ITGA2 by miR-373 stimulates breast cancer migration, and miR-373high/ITGA2low may be as a prognosis biomarker for breast cancer patients.