Targeting lncRNA16 by GalNAc-siRNA conjugates facilitates chemotherapeutic sensibilization via the HBB/NDUFAF5/ROS pathway

Chemoresistance is a significant barrier to effective cancer treatment. Potential mechanisms for chemoresistance include reactive oxygen species (ROS) accumulation and expression of chemoresistance-promoting genes. Here, we report a novel function of lncRNA16 in the inhibition of ROS generation and the progression of chemoresistance. By analyzing the serum levels of lncRNA16 in a cohort of 35 patients with non-small cell lung cancer (NSCLC) and paired serum samples pre- and post-treatment from 10 NSCLC patients receiving neoadjuvant platinum-based chemotherapy, performing immunohistochemistry (IHC) assays on 188 NSCLC tumor samples, using comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) assays, as well as RNA immunoprecipitation (RIP) and RNA pull-down analyses, we discovered that patients with increased serum levels of lncRNA16 exhibited a poor response to platinum-based chemotherapy. The expression of hemoglobin subunit beta (HBB) and NDUFAF5 significantly increases with the development of chemoresistance. LncRNA16 binds to HBB and promotes HBB accumulation by inhibiting autophagy. LncRNA16 can also inhibit ROS generation via the HBB/NDUFAF5 axis and function as a scaffold to facilitate the colocalization of HBB and NDUFAF5 in the mitochondria. Importantly, preclinical studies in mouse models of chemo-resistant NSCLC have suggested that lncRNA16 targeting by trivalent N-acetylgalactosamine (GalNAc)-conjugated siRNA restores chemosensitivity and results in tumor growth inhibition with no detectable toxicity in vivo. Overall, lncRNA16 is a promising therapeutic target for overcoming chemoresistance, and the combination of first-line platinum-based chemotherapy with lncRNA16 intervention can substantially enhance anti-tumor efficacy.

Tumor-associated macrophage (TAM)-secreted CCL22 confers cisplatin resistance of esophageal squamous cell carcinoma (ESCC) cells via regulating the activity of diacylglycerol kinase α (DGKα)/NOX4 axis

Tumor-associated macrophages (TAMs) are often associated with chemoresistance and resultant poor clinical outcome in solid tumors. Here, we demonstrated that TAMs-released chemokine-C-C motif chemokine 22 (CCL22) in esophageal squamous cell carcinoma (ESCC) stroma was tightly correlated with the chemoresistance of ESCC patients. TAMs-secreted CCL22 was able to block the growth inhibitory and apoptosis-promoting effects of cisplatin on ESCC cells. Mechanistically, CCL22 stimulated intratumoral diacylglycerol kinase α (DGKα) to produce phosphatidic acid (PA), which suppressed the activity of NADPH oxidase 4 (NOX4) and then blocked the overproduction of intratumoral reactive species oxygen (ROS) induced by cisplatin. CCL22 activated DGKα/nuclear factor-κB (NF-κB) axis to upregulate the level of several members of ATP binding cassette (ABC) transporter superfamily, including ABC sub-family G member 4 (ABCG4), ABC sub-family A member 3 (ABCA3), and ABC sub-family A member 5 (ABCA5), to lower the intratumoral concentration of cisplatin. Consequently, these processes induced the cisplatin resistance in ESCC cells. In xenografted models, targeting DGKα with 5'-cholesterol-conjugated small-interfering (si) RNA enhanced the chemosensitivity of cisplatin in ESCC treatment, especially in the context of TAMs. Our data establish the correlation between the TAMs-induced intratumoral metabolic product/ROS axis and chemotherapy efficacy in ESCC treatment and reveal relevant molecular mechanisms.

AKT2S128/CCTαS315/319/323-positive cancer-associated fibroblasts (CAFs) mediate focal adhesion kinase (FAK) inhibitors resistance via secreting phosphatidylcholines (PCs)

Abnormal metabolism is regarded as an oncogenic hallmark related to tumor progression and therapeutic resistance. Present study employed multi-omics, including phosphoproteomics, untargeted metabolomics and lipidomics, to demonstrate that the pAKT2 Ser128 and pCCTα Ser315/319/323-positive cancer-associated fibroblasts (CAFs) substantially release phosphatidylcholines (PCs), contributing to the resistance of focal adhesion kinase (FAK) inhibitors in esophageal squamous cell carcinoma (ESCC) treatment. Additionally, we observed extremely low levels of FAK Tyr397 expression in CAFs, potentially offering no available target for FAK inhibitors playing their anti-growth role in CAFs. Consequently, FAK inhibitor increased the intracellular concentration of Ca2+ in CAFs, promoting the formation of AKT2/CCTα complex, leading to phosphorylation of CCTα Ser315/319/323 sites and eventually enhancing stromal PC production. This activation could stimulate the intratumoral Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (STAT3) pathway, triggering resistance to FAK inhibition. Analysis of clinical samples demonstrated that stromal pAKT2 Ser128 and pCCTα Ser315/319/323 are related to the tumor malignancy and reduced patient survival. Pseudo-targeted lipidomics and further validation cohort quantitatively showed that plasma PCs enable to distinguish the malignant extent of ESCC patients. In conclusion, inhibition of stroma-derived PCs and related pathway could be possible therapeutic strategies for tumor therapy.

Co-targeting FAK and Gli1 inhibits the tumor-associated macrophages-released CCL22-mediated esophageal squamous cell carcinoma malignancy

Esophageal squamous cell carcinoma (ESCC) is a frequently seen esophageal tumor type in China. Activation of signaling proteins and relevant molecular mechanisms in ESCC are partially explored, impairing the antitumor efficiency of targeted therapy in ESCC treatment. Tumor-associated macrophages (TAMs)-released C-C motif chemokine 22 (CCL22) can activate intratumoral focal adhesion kinase (FAK), thus promoting the progression of ESCC. Here, we demonstrated that highly secreted CCL22 by TAMs (CCL22-positive TAMs) induced ESCC cell stemness and invasion through facilitating transcriptional activity of intratumoral glioma-associated oncogene 1 (Gli1), a downstream effector for Hedgehog (HH) pathway. Mechanistically, FAK-activated protein kinase B (AKT) mediated Gli1 phosphorylation at its Ser112/Thr115/Ser116 sites and released Gli1 from suppressor of fused homolog, the endogenous inhibitor of Gli1 to activate downstream stemness-associated factors, such as SRY-box transcription factor 2 (SOX2), Nanog homeobox (Nanog), or POU class 5 homeobox (OCT4). Furthermore, inhibition of FAK activity by VS-4718, the FAK inhibitor, enhanced antitumor effect of GDC-0449, the HH inhibitor, both in xenografted models and in vitro assays. Clinically, CCL22/Gli1 axis is used to evaluate ESCC prognosis. Overall, our study establishes the communication of FAK with HH pathway and offers the novel mechanism related to Gli1 activation independent of Smoothened as well as the rationale for the anti-ESCC combination treatment.

Dysregulation of cholesterol metabolism in cancer progression

Cholesterol homeostasis has been implicated in the regulation of cellular and body metabolism. Hence, deregulated cholesterol homeostasis leads to the development of many diseases such as cardiovascular diseases, and neurodegenerative diseases, among others. Recent studies have unveiled the connection between abnormal cholesterol metabolism and cancer development. Cholesterol homeostasis at the cellular level dynamically circulates between synthesis, influx, efflux, and esterification. Any dysregulation of this dynamic process disrupts cholesterol homeostasis and its derivatives, which potentially contributes to tumor progression. There is also evidence that cancer-related signals, which promote malignant progression, also regulate cholesterol metabolism. Here, we described the relationship between cholesterol metabolism and cancer hallmarks, with particular focus on the molecular mechanisms, and the anticancer drugs that target cholesterol metabolism.

Long non-coding RNA colon cancer-associated transcript 1-Vimentin axis promoting the migration and invasion of HeLa cells

BACKGROUND

Long non-coding RNA colon cancer-associated transcript 1 (CCAT1) is involved in transforming multiple cancers into malignant cancer types. Previous studies underlining the mechanisms of the functions of CCAT1 primarily focused on its decoy for miRNAs (micro RNAs). However, the regulatory mechanism of CCAT1-protein interaction associated with tumor metastasis is still largely unknown. The present study aimed to identify proteome-wide CCAT1 partners and explored the CCAT1-protein interaction mediated tumor metastasis.

METHODS

CCAT1-proteins complexes were purified and identified using RNA antisense purification coupled with the mass spectrometry (RAP-MS) method. The database for annotation, visualization, and integrated discovery and database for eukaryotic RNA binding proteins (EuRBPDB) websites were used to bioinformatic analyzing CCAT1 binding proteins. RNA pull-down and RNA immunoprecipitation were used to validate CCAT1-Vimentin interaction. Transwell assay was used to evaluate the migration and invasion abilities of HeLa cells.

RESULTS

RAP-MS method worked well by culturing cells with nucleoside analog 4-thiouridine, and cross-linking was performed using 365 nm wavelength ultraviolet. There were 631 proteins identified, out of which about 60% were RNA binding proteins recorded by the EuRBPDB database. Vimentin was one of the CCAT1 binding proteins and participated in the tumor metastasis pathway. Knocked down vimetin ( VIM ) and rescued the downregulation by overexpressing CCAT1 demonstrated that CCAT1 could enhance tumor migration and invasion abilities by stabilizing Vimentin protein.

CONCLUSION

CCAT1 may bind with and stabilize Vimentin protein, thus enhancing cancer cell migration and invasion abilities.

Spatial transcriptomics delineates molecular features and cellular plasticity in lung adenocarcinoma progression

Indolent (lepidic) and aggressive (micropapillary, solid, and poorly differentiated acinar) histologic subtypes often coexist within a tumor tissue of lung adenocarcinoma (LUAD), but the molecular features associated with different subtypes and their transitions remain elusive. Here, we combine spatial transcriptomics and multiplex immunohistochemistry to elucidate molecular characteristics and cellular plasticity of distinct histologic subtypes of LUAD. We delineate transcriptional reprogramming and dynamic cell signaling that determine subtype progression, especially hypoxia-induced regulatory network. Different histologic subtypes exhibit heterogeneity in dedifferentiation states. Additionally, our results show that macrophages are the most abundant cell type in LUAD, and identify different tumor-associated macrophage subpopulations that are unique to each histologic subtype, which might contribute to an immunosuppressive microenvironment. Our results provide a systematic landscape of molecular profiles that drive LUAD subtype progression, and demonstrate potentially novel therapeutic strategies and targets for invasive lung adenocarcinoma.

MTA1, a Novel ATP Synthase Complex Modulator, Enhances Colon Cancer Liver Metastasis by Driving Mitochondrial Metabolism Reprogramming

Liver metastasis is the most fatal event of colon cancer patients. Warburg effect has been long challenged by the fact of upregulated oxidative phosphorylation (OXPHOS), while its mechanism remains unclear. Here, metastasis-associated antigen 1 (MTA1) is identified as a newly identified adenosine triphosphate (ATP) synthase modulator by interacting with ATP synthase F1 subunit alpha (ATP5A), facilitates colon cancer liver metastasis by driving mitochondrial bioenergetic metabolism reprogramming, enhancing OXPHOS; therefore, modulating ATP synthase activity and downstream mTOR pathways. High-throughput screening of an anticancer drug shows MTA1 knockout increases the sensitivity of colon cancer to mitochondrial bioenergetic metabolism-targeted drugs and mTOR inhibitors. Inhibiting ATP5A enhances the sensitivity of liver-metastasized colon cancer to sirolimus in an MTA1-dependent manner. The therapeutic effects are verified in xenograft models and clinical cases. This research identifies a new modulator of mitochondrial bioenergetic reprogramming in cancer metastasis and reveals a new mechanism on upregulating mitochondrial OXPHOS as the reversal of Warburg effect in cancer metastasis is orchestrated.

Combined Wee1 and EGFR inhibition reveals synergistic antitumor effect in esophageal squamous cell carcinoma

Epidermal growth factor receptor (EGFR) is one of the most common amplified and overexpressed oncogenes in esophageal squamous cell carcinoma (ESCC), while the clinical efficacy of EGFR-targeted therapy in ESCC is dismal. Here, we evaluated the efficacy of dual blockage using monoclonal antibody against EGFR (Nimotuzumab) and an Wee1 inhibitor (AZD1775) in ESCC. We found that the mRNA and protein expression of EGFR and Wee1 were positively correlated in ESCC. Nimotuzumab-AZD1775 co-treatment inhibited tumor growth in PDX models with different drug susceptibility. Transcriptome sequencing and mass spectrometry analysis indicated that higher sensitive models showed enrichment of the PI3K/Akt or MAPK signaling pathway in Nimotuzumab-AZD1775 group compared with control group. In vitro experiments showed that the combination further inhibit PI3K/Akt and MAPK pathways compared to their monotherapy as indicated by downregulation of pAKT, pS6, pMEK, pErk and p-p38 MAPK. Furthermore, AZD1775 potentiated Nimotuzumab's antitumor effect through inducing apoptosis. Meanwhile, the bioinformatics analysis suggests the POLR2A might be candidate molecule of EGFR/Wee1 downstream. In conclusion, our work uncovers that EGFR-mAb Nimotuzumab combined with Wee1 inhibitor AZD1775 elicited potentiated anticancer activity against ESCC cell line and PDXs partially through PI3K/Akt and MAPK pathways blockade. These preclinical data raise the promising that ESCC patients may benefit from dual target EGFR and Wee1.

CDK7-YAP-LDHD axis promotes D-lactate elimination and ferroptosis defense to support cancer stem cell-like properties

Reprogrammed cellular metabolism is essential for maintaining cancer stem cells (CSCs) state. Here, we report that mitochondrial D-lactate catabolism is a necessary initiating oncogenic event during tumorigenesis of esophageal squamous cell carcinoma (ESCC). We discover that cyclin-dependent kinase 7 (CDK7) phosphorylates nuclear Yes-associated protein 1 (YAP) at S127 and S397 sites and enhances its transcription function, which promotes D-lactate dehydrogenase (LDHD) protein expression. Moreover, LDHD is enriched significantly in ESCC-CSCs rather than differentiated tumor cells and high LDHD status is connected with poor prognosis in ESCC patients. Mechanistically, the CDK7-YAP-LDHD axis helps ESCC-CSCs escape from ferroptosis induced by D-lactate and generates pyruvate to satisfy energetic demands for their elevated self-renewal potential. Hence, we conclude that esophageal CSCs adopt a D-lactate elimination and pyruvate accumulation mode dependent on CDK7-YAP-LDHD axis, which drives stemness-associated hallmarks of ESCC-CSCs. Reasonably, targeting metabolic checkpoints may serve as an effective strategy for ESCC therapy.

Comparative transcriptome characterization of esophageal squamous cell carcinoma and adenocarcinoma

Background

Esophageal cancers are primarily categorized as esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). While various (epi) genomic alterations associated with tumor development in ESCC and EAC have been documented, a comprehensive comparison of the transcriptomes in these two cancer subtypes remains lacking.

Methods

We collected 551 gene expression profiles from publicly available sources, including normal, ESCC, and EAC tissues or cell lines. Subsequently, we conducted a systematic analysis to compare the transcriptomes of these samples at various levels, including gene expression, promoter activity, alternative splicing (AS), alternative polyadenylation (APA), and gene fusion.

Results

Seven distinct cluster gene expression patterns were identified among the differentially expressed genes in normal, ESCC, and EAC tissues. These patterns were enriched in the PI3K-Akt signaling pathway and the activation of extracellular matrix organization and exhibited repression of epidermal development. Notably, we observed additional genes or unique expression levels enriched in these shared pathways and biological processes related to tumor development and immune activation. In addition to the differentially expressed genes, there was an enrichment of lncRNA co-expression networks and downregulation of promoter activity associated with the repression of epidermal development in both ESCC and EAC. This indicates a common feature between these two cancer subtypes. Furthermore, differential AS and APA patterns in ESCC and EAC appear to partially affect the expression of host genes associated with bacterial or viral infections in these subtypes. No gene fusions were observed between ESCC and EAC, thus highlighting the distinct molecular mechanisms underlying these two cancer subtypes.

Conclusions

We conducted a comprehensive comparison of ESCC and EAC transcriptomes and uncovered shared and distinct transcriptomic signatures at multiple levels. These findings suggest that ESCC and EAC may exhibit common and unique mechanisms involved in tumorigenesis.

Aqueous-soluble components of sporoderm-removed Ganoderma lucidum spore powder promote ferroptosis in oral squamous cell carcinoma

Objective

Ferroptosis is a novel cell death process which displays a promising role in cancer treatment. However, clinically available drugs targeting ferroptosis are rarely used, and yet there are no studies reporting on inducing ferroptosis via Chinese herbal extracts. Here we explored the tumor inhibition effects of Ganoderma lucidum (G. lucidum) on oral squamous cell carcinoma (OSCC). Specifically, we aimed to clarify the biological mechanism of components in the dietary, aqueous-soluble sporoderm-removed G. lucidum spore powder (A-GSP).

Methods

Preliminary transcriptome analysis revealed the significant enrichment of the ferroptosis pathway. Cellular Fe2+, glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS) and lipid peroxide levels were measured to identify ferroptosis occurrence. Western blotting was used to measure ferroptosis-related proteins. Changes in mitochondria morphology and function were observed with transmission electron microscopy (TEM) and ATP detection assays. Ferroptosis inhibitor ferrostatin-1 was then used to verify the anti-tumor effects of A-GSP. Finally, nude mice xenograft models of oral cancer confirmed that A-GSP inhibited tumor growth.

Results

A-GSP promoted ferroptosis in oral cancer cells by inducing Fe2+ influx, GSH depletion, as well as lipid peroxide and ROS accumulation. Ferroptosis-related proteins exhibited corresponding changes, particularly Acyl-coA synthetase long chain family member 4 (ACSL4) increase and glutathione peroxidase 4 (GPX4) decrease. A-GSP considerably lowered mitochondrial volume and ridge number, while significantly decreasing ATP production. Ferrostatin-1 reversed all of these A-GSP-induced changes. In vivo, A-GSP exerted a ferroptosis-mediated tumor-suppressing effect without observable adverse reactions.

Conclusions

Our findings demonstrate the therapeutic potential of A-GSP for treating patients with OSCC by targeting ferroptosis.

PAFR/Stat3 axis maintains the symbiotic ecosystem between tumor and stroma to facilitate tumor malignancy

Stroma surrounding the tumor cells plays crucial roles for tumor progression. However, little is known about the factors that maintain the symbiosis between stroma and tumor cells. In this study, we found that the transcriptional regulator-signal transducer and activator of transcription 3 (Stat3) was frequently activated in cancer-associated fibroblasts (CAFs), which was a potent facilitator of tumor malignancy, and formed forward feedback loop with platelet-activating factor receptor (PAFR) both in CAFs and tumor cells. Importantly, PAFR/Stat3 axis connected intercellular signaling crosstalk between CAFs and cancer cells and drove mutual transcriptional programming of these two types of cells. Two central Stat3-related cytokine signaling molecules-interleukin 6 (IL-6) and IL-11 played the critical role in the process of PAFR/Stat3 axis-mediated communication between tumor and CAFs. Pharmacological inhibition of PAFR and Stat3 activities effectively reduced tumor progression using CAFs/tumor co-culture xenograft model. Our study reveals that PAFR/Stat3 axis enhances the interaction between tumor and its associated stroma and suggests that targeting this axis can be an effective therapeutic strategy against tumor malignancy.

Gut microbiota-mediated nucleotide synthesis attenuates the response to neoadjuvant chemoradiotherapy in rectal cancer

Preoperative neoadjuvant chemoradiotherapy (nCRT) is a standard treatment for locally advanced rectal cancer (LARC) patients, yet little is known about the mediators underlying the heterogeneous patient response. In this longitudinal study, we performed 16S rRNA sequencing on 353 fecal specimens and find reduced microbial diversity after nCRT. Multi-omics data integration reveals that Bacteroides vulgatus-mediated nucleotide biosynthesis associates with nCRT resistance in LARC patients, and nonresponsive tumors are characterized by the upregulation of genes related to DNA repair and nucleoside transport. Nucleosides supplementation or B. vulgatus gavage protects cancer cells from the 5-fluorouracil or irradiation treatment. An analysis of 2,205 serum samples from 735 patients suggests that uric acid is a potential prognosis marker for LARC patients receiving nCRT. Our data unravel the role of intestinal microbiota-mediated nucleotide biosynthesis in the response of rectal tumors to nCRT, and highlight the importance of deciphering the cross-talk between cancer cells and gut microorganisms during cancer therapies.

Integrated multi-omics profiling yields a clinically relevant molecular classification for esophageal squamous cell carcinoma

Integrated molecular analysis of human cancer has yielded molecular classification for precise management of cancer patients. Here, we analyzed the whole genomic, epigenomic, transcriptomic, and proteomic data of 155 esophageal squamous cell carcinomas (ESCCs). Multi-omics analysis led to the classification of ESCCs into four subtypes: cell cycle pathway activation, NRF2 oncogenic activation, immune suppression (IS), and immune modulation (IM). IS and IM cases were highly immune infiltrated but differed in the type and distribution of immune cells. IM cases showed better response to immune checkpoint blockade therapy than other subtypes in a clinical trial. We further developed a classifier with 28 features to identify the IM subtype, which predicted anti-PD-1 therapy response with 85.7% sensitivity and 90% specificity. These results emphasize the clinical value of unbiased molecular classification based on multi-omics data and have the potential to further improve the understanding and treatment of ESCC.

Erratum: Transcriptional Downregulation of miR-4306 serves as a New Therapeutic Target for Triple Negative Breast Cancer: Erratum

[This corrects the article DOI: 10.7150/thno.30701.].

Identification of RNA-splicing factor Lsm12 as a novel tumor-associated gene and a potent biomarker in Oral Squamous Cell Carcinoma (OSCC)

Background

Oral squamous cell carcinoma (OSCC) is one of the common cancers worldwide. The lack of specific biomarkers and therapeutic targets leads to delayed diagnosis and hence the poor prognosis of OSCC patients. Thus, it is urgent to identify effective biomarkers and therapeutic targets for OSCC.

Methods

We established the golden hamster carcinogenic model of OSCC induced by 7,12-dimethylbenz(a) anthrancene (DMBA) and used mRNA microarrays to detect the differentially expressed genes (DEGs). DEGs were validated in OSCC clinical tissue microarrays using immunohistochemistry method. Whole transcriptome sequencing was performed to obtain an overview of biological functions of Lsm12. PCR assay and sequencing were employed to investigate the alternative splicing of genes regulated by Lsm12. Cell proliferation, colony formation, Transwell migration and invasion assay and in vivo tumor formation assay were performed to investigate the roles of Lsm12 and two transcript variants of USO1 in OSCC cells.

Results

Lsm12 was identified to be significantly up-regulated in the animal model of OSCC tumorigenesis, which was validated in the clinical OSCC samples. In the paired normal tissues, Lsm12 staining was negative (91%, 92/101) or weak, while in OSCC tissues, positive rate is 100% and strong staining spread over the whole tissues in 93 (93/101, 92%) cases. Lsm12 overexpression significantly promoted OSCC cell growth, colony formation, migration and invasion abilities, while Lsm12 knockdown showed the opposite trends on these phenotypes and obviously inhibited the tumor formation in vivo. Furthermore, Lsm12 overexpression caused the inclusion of USO1 exon 15 and Lsm12 knockdown induced exon 15 skipping. Exon 15-retained USO1 significantly promoted the malignant phenotypes of OSCC cells when compared with the exon 15-deleted USO1.

Conclusions

We identified Lsm12, a novel tumorigenesis-related gene, as an important regulator involved in OSCC tumorigenesis. Lsm12 is a novel RNA-splicing related gene and can regulate the alternative splicing of USO1 exon 15 which was associated closely with OSCC carcinogenesis. Our findings thus provide that Lsm12 might be a potent biomarker and potential therapeutic target for OSCC.

Liver tumour immune microenvironment subtypes and neutrophil heterogeneity

The heterogeneity of the tumour immune microenvironment (TIME), organized by various immune and stromal cells, is a major contributing factor of tumour metastasis, relapse and drug resistance^1-3, but how different TIME subtypes are connected to the clinical relevance in liver cancer remains unclear. Here we performed single-cell RNA-sequencing (scRNA-seq) analysis of 189 samples collected from 124 patients and 8 mice with liver cancer. With more than 1 million cells analysed, we stratified patients into five TIME subtypes, including immune activation, immune suppression mediated by myeloid or stromal cells, immune exclusion and immune residence phenotypes. Different TIME subtypes were spatially organized and associated with chemokine networks and genomic features. Notably, tumour-associated neutrophil (TAN) populations enriched in the myeloid-cell-enriched subtype were associated with an unfavourable prognosis. Through in vitro induction of TANs and ex vivo analyses of patient TANs, we showed that CCL4⁺ TANs can recruit macrophages and that PD-L1⁺ TANs can suppress T cell cytotoxicity. Furthermore, scRNA-seq analysis of mouse neutrophil subsets revealed that they are largely conserved with those of humans. In vivo neutrophil depletion in mouse models attenuated tumour progression, confirming the pro-tumour phenotypes of TANs. With this detailed cellular heterogeneity landscape of liver cancer, our study illustrates diverse TIME subtypes, highlights immunosuppressive functions of TANs and sheds light on potential immunotherapies targeting TANs.

A liquid biopsy signature predicts lymph node metastases in T1 oesophageal squamous cell carcinoma: implications for precision treatment strategy

BACKGROUND

The treatment strategies for T1 oesophageal squamous cell carcinoma (ESCC) patients with or without lymph node metastasis (LNM) are different. Given the advantages of the minimally invasive, sensitive and real-time detection, liquid biopsy has become an important cancer diagnostic and prognostic tool.

METHODS

MiRNA array and small-RNA sequencing were performed. Then, 222 formalin-fixed and paraffin-embedded tumour samples and 229 pretreatment serum samples from T1 ESCC patients were used to verify and evaluate the results.

RESULTS

We demonstrated that serum miR-20b-5p could predict LNM in T1 ESCC patients. The AUC for serum miR-20b-5p was higher (0.827) than those for lymphovascular invasion (LVI) (0.751, P = 0.2128), invasion depth (0.662, P = 0.0027) and tumour differentiation grade (0.634, P = 0.0019). A nomogram for predicting LNM with three independent significant predictors (miR-20b-5p, LVI and invasion depth) was constructed with a concordance index of 0.931. Serum miR-20b-5p was also significantly correlated with disease-free survival (P < 0.001). An algorithm of improved T1 ESCC treatment strategy after biopsy and/or after endoscopic resection based on serum miR-20b-5p level was constructed.

CONCLUSIONS

This study suggests that serum miR-20b-5p is a potential biomarker for predicting LNM and can be helpful for precise clinical decision-making strategies and improve treatment outcomes for T1 ESCC patients.

FAM135B sustains the reservoir of Tip60-ATM assembly to promote DNA damage response

BACKGROUND

Recently, the mechanism by which cells adapt to intrinsic and extrinsic stresses has received considerable attention. Tat-interactive protein 60-kDa/ataxia-telangiectasia-mutated (TIP60/ATM) axis-mediated DNA damage response (DDR) is vital for maintaining genomic integrity.

METHODS

Protein levels were detected by western blot, protein colocalisation was examined by immunofluorescence (IF) and protein interactions were measured by co-immunoprecipitation, proximity ligation assay and GST pull-down assays. Flow cytometry, comet assay and IF assays were used to explore the biological functions of sequence similarity 135 family member B (FAM135B) in DDR. Xenograft tumour, FAM135B transgenic mouse models and immunohistochemistry were utilised to confirm in vitro observations.

RESULTS

We identified a novel DDR regulator FAM135B which could protect cancer cells from genotoxic stress in vitro and in vivo. The overexpression of FAM135B promoted the removal of γH2AX and 53BP1 foci, whereas the elimination of FAM135B attenuated these effects. Consistently, our findings revealed that FAM135B could promote homologous recombination and non-homologous end-joining repairs. Further study demonstrated that FAM135B physically bound to the chromodomain of TIP60 and improved its histone acetyltransferase activity. Moreover, FAM135B enhanced the interactions between TIP60 and ATM under resting conditions. Intriguingly, the protein levels of FAM135B dramatically decreased following DNA damage stress but gradually increased during the DNA repair period. Thus, we proposed a potential DDR mechanism where FAM135B sustains a reservoir of pre-existing TIP60-ATM assemblies under resting conditions. Once cancer cells suffer DNA damage, FAM135B is released from TIP60, and the functioning pre-assembled TIP60-ATM complex participates in DDR.

CONCLUSIONS

We characterised FAM135B as a novel DDR regulator and further elucidated the role of the TIP60-ATM axis in response to DNA damage, which suggests that targeting FAM135B in combination with radiation therapy or chemotherapy could be a potentially effective approach for cancer treatment.

PTBP1 promotes IRES-mediated translation of cyclin B1 in cancer

Cyclin B1 is an essential cyclin-dependent protein that involves in the G2/M transition. Multiple studies report that cyclin B1 is upregulated in cancers and promotes cancer progression. However, the mechanism of cyclin B1 upregulation remains unclear. Here we report that the 5'UTR of cyclin B1 mRNA contains an internal ribosome entry site (IRES) by using a bicistronic fluorescent reporter. We show that IRES can initiate the translation of cyclin B1, and the IRES-mediated translation is further activated under cell stress. Interacting trans-acting factors (ITAFs) are required by most IRES to initiate the translation. We find that PTBP1 promotes the IRES-mediated translation of cyclin B1 by binding to the 5'UTR of cyclin B1. On top of that, PTBP1 promotes the malignancy of ESCC cells. Our data suggest that the IRES-mediated translation of cyclin B1 plays an essential role in the cyclin B1 upregulation in cancers.

Nuclear genome-derived circular RNA circPUM1 localizes in mitochondria and regulates oxidative phosphorylation in esophageal squamous cell carcinoma

Circular RNAs (circRNAs) were shown to play an important role in the occurrence and progression of tumors. However, the functions of nuclear genome-derived circRNAs localized in mitochondria of tumor cells remain largely elusive. Here, we report that circPUM1, a circular RNA derived from back-splicing of pre-mRNAs of nuclear genome PUM1, localizes in mitochondria. The expression level of circPUM1 is positively correlated with HIF1α accumulation under CoCl₂-induced intracellular hypoxic-like condition in esophageal squamous cell carcinoma (ESCC) cell lines. Importantly, circPUM1 acts as a scaffold for the interaction between UQCRC1 and UQCRC2 in ESCC cell lines. Knock-down of circPUM1 would result in lower intracellular oxygen concentration, downregulated oxidative phosphorylation, decrease of mitochondrial membrane potential, increase of ROS generation and shrinking of mitochondria, respectively. CircPUM1 depletion induces dysfunction of the mitochondrial complex III and the cleavage of caspase3 spontaneously. Interestingly, disruption of circPUM1 led to pyroptosis that initiates the cell death of ESCC cell lines. Therefore, we conclude that circPUM1 plays a critical role in maintaining the stability of mitochondrial complex III to enhance oxidative phosphorylation for ATP production of ESCC cells and moreover propose that ESCC cells exploit circPUM1 during cell adaptation.

The metabolic genomic atlas reveals potential drivers and clinically relevant insights into the etiology of esophageal squamous cell carcinoma

Background: Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers globally, with a poor prognosis and ambiguous therapy target. As a hallmark of cancer, metabolism reprogramming plays a critical role in the development of ESCC; however, the genomic alterations underlying this reconfiguration are still largely unknown.

Methods: We have comprehensively studied the metabolic genomic variations in an integrated ESCC cohort of 490 patients and characterized the somatic alterations associated with various metabolic pathways.

Results: The somatic mutations and copy number alterations (CNAs) occurred heterogeneously in all patients. Using CNA-based clustering, we stratified patients into three clusters and Cluster3 with more deletions marked for worse prognosis. Our findings revealed detailed genetic alterations in components of metabolic pathways and highlighted the role of metal ion channel transporters and non-neuronal/neuronal synapse systems in the development of ESCC. We found a subset of potential metabolic drivers and functionally validated RYR2, MGST3, and CYP8B1 involved in the ESCC-associated malignancy. Another key finding was that we identified 27 metabolic genes with genomic alterations that could serve as independent prognostic factors and figured out two genetic panels that could stratify patients into distinct prognostic groups.

Conclusion: Collectively, our study provided a deep insight into the metabolic landscape in ESCC, extending our understanding of the metabolic reconfiguration underlying the genomic basis of ESCC. Furthermore, our findings revealed potential prognostic factors of ESCC, which are expected to contribute to the accurate determination of the prognosis in the clinic.

The m6A-induced lncRNA CASC8 promotes proliferation and chemoresistance via upregulation of hnRNPL in esophageal squamous cell carcinoma

Long noncoding RNAs (lncRNAs) are dysregulated in many cancers. Here, we identified the molecular mechanisms of lncRNA Cancer Susceptibility Candidate 8 (CASC8) in promoting the malignancy of esophageal squamous cell carcinoma (ESCC). CASC8 was highly overexpressed in ESCC tissues and upregulation of CASC8 predicted poor prognosis in ESCC patients. Moreover, CASC8 decreased the cisplatin sensitivity of ESCC cells and promoted ESCC tumor growth in vivo. Mechanistically, CASC8 interacted with heterogeneous nuclear ribonucleoprotein L (hnRNPL) and inhibited its polyubiquitination and proteasomal degradation, thus stabilizing hnRNPL protein levels and activating the Bcl2/caspase3 pathway. Additionally, AlkB Homolog 5, RNA demethylase (ALKBH5)-mediated m6A demethylation stabilized the CASC8 transcript, resulting in CASC8 upregulation. Taken together, these findings identified an oncogenic function of CASC8 in the progression of ESCC, which suggest that CASC8 might become a potential prognostic biomarker in ESCC.

[Study of abnormal lipid metabolism analysis and significance of fatty acid binding protein expression in patients with hepatocellular carcinoma]

Objective: Hepatocellular carcinoma (HCC) is the fourth most dominant cancer in the world and the second leading cause of cancer-related deaths in the China. With the increase in the incidence of metabolic syndrome (MS) in the population, the correlation between MS and HCC has gradually been recognized. MS manifests as non-alcoholic fatty liver disease (shortly known as NAFLD) in the liver. A large number of research results has shown that the development of fatty liver is closely related to the occurrence of HCC, in which lipid metabolism plays a key regulatory role, and lipid metabolism is regulated by fatty acid binding protein (FABP). This study signifies the lipid metabolism analysis and the key FABP expression conditions in HCC. Methods: Data of patients who were first diagnosed with primary HCC between January 2016 to July 2019 were collected, and were divided into two groups according to the etiology, namely the viral and non-viral hepatitis-related HCC group. The relationship between MS-related factors and HCC was analyzed by t-test and chi square test. The expressions of FABP1, FABP4 and FABP5 were detected in cancer and adjacent tissues by immunohistochemistry, and the expressions of FABP1, FABP4 and FABP5 in HCC with fatty liver were detected by immunofluorescence. Finally, the expressional characteristics of the above-mentioned FABPs in HCC patients were analyzed with different clinicopathological features. Results: There were statistically significant differences in the rate of abnormal lipid metabolism and the number of abnormalities in MS-related factors between the viral and non-viral hepatitis-related HCC group. FABP1, FABP4, and FABP5 expression in HCC tissues were lower than the corresponding adjacent tumor tissues. Compared with simple HCC, FABP1, FABP4, FABP5 expression were increased in HCC tissues with steatosis, and the expression of FABP was closely related to the clinical characteristics of patients. Conclusion: Abnormal lipid metabolism is closely related to non-viral hepatitis-related HCC. The expression of lipid metabolism regulatory proteins FABP1, FABP4, and FABP5 are down-regulated in HCC tissues, but up-regulated in HCC with fatty liver, suggesting that the relationship between MS, especially dyslipidemia, and HCC should be paid attention to in clinical practice for early intervention. FABP1, FABP4, FABP5 may regulate HCC occurrence and development.

Genomic and epigenomic evolution of acquired resistance to combination therapy in esophageal squamous cell carcinoma

BACKGROUNDTargeted arterial infusion of verapamil combined with chemotherapy (TVCC) is an effective clinical interventional therapy for esophageal squamous cell carcinoma (ESCC), but multidrug resistance (MDR) remains the major cause of relapse or poor prognosis, and the underlying molecular mechanisms of MDR, temporal intratumoral heterogeneity, and clonal evolutionary processes of resistance have not been determined.METHODSTo elucidate the roles of genetic and epigenetic alterations in the evolution of acquired resistance during therapies, we performed whole-exome sequencing on 16 serial specimens from 7 patients with ESCC at every cycle of therapeutic intervention from 3 groups, complete response, partial response, and progressive disease, and we performed whole-genome bisulfite sequencing for 3 of these 7 patients, 1 patient from each group.RESULTSPatients with progressive disease exhibited a substantially higher genomic and epigenomic temporal heterogeneity. Subclonal expansions driven by the beneficial new mutations were observed during combined therapies, which explained the emergence of MDR. Notably, SLC7A8 was identified as a potentially novel MDR gene, and functional assays demonstrated that mutant SLC7A8 promoted the resistance phenotypes of ESCC cell lines. Promoter methylation dynamics during treatments revealed 8 drug resistance protein-coding genes characterized by hypomethylation in promoter regions. Intriguingly, promoter hypomethylation of SLC8A3 and mutant SLC7A8 were enriched in an identical pathway, protein digestion and absorption, indicating a potentially novel MDR mechanism during treatments.CONCLUSIONOur integrated multiomics investigations revealed the dynamics of temporal genetic and epigenetic inter- and intratumoral heterogeneity, clonal evolutionary processes, and epigenomic changes, providing potential MDR therapeutic targets in treatment-resistant patients with ESCC during combined therapies.FUNDINGNational Natural Science Foundation of China, Science Foundation of Peking University Cancer Hospital, CAMS Innovation Fund for Medical Sciences, Major Program of Shenzhen Bay Laboratory, Guangdong Basic and Applied Basic Research Foundation, and the third round of public welfare development and reform pilot projects of Beijing Municipal Medical Research Institutes.

Glutathione peroxidase 4-dependent glutathione high-consumption drives acquired platinum chemoresistance in lung cancer-derived brain metastasis

BACKGROUND

Platinum-based chemotherapy is effective in inducing shrinkage of primary lung cancer lesions; however, it shows finite therapeutic efficacy in patients suffering from brain metastasis (BM). The intrinsic changes of BM cells, which contribute to the poor results remain unknown.

METHODS

Platinum drug-sensitivity was assessed by utilizing a preclinical BM model of PC9 lung adenocarcinoma cells in vitro and in vivo. High consumption of glutathione (GSH) and two associated upregulated proteins (GPX4 and GSTM1) in BM were identified by integrated metabolomics and proteomics in cell lines and verified by clinical serum sample. Gain-of-function and rescue experiments were implemented to reveal the impact and mechanism of GPX4 and GSTM1 on the chemosensitivity in BM. The interaction between GPX4 and GSTM1 was examined by immunoblotting and immunoprecipitation. The mechanism of upregulation of GPX4 was further uncovered by luciferase reporter assay, immunoprecipitation, and electrophoretic mobility shift assay.

RESULTS

The derivative brain metastatic subpopulations (PC9-BrMs) of parental cells PC9 developed obvious resistance to platinum. Radically altered profiles of BM metabolism and protein expression compared with primary lung cancer cells were described and GPX4 and GSTM1 were identified as being responsible for the high consumption of GSH, leading to decreased chemosensitivity by negatively regulating ferroptosis. Besides, GSTM1 was found regulated by GPX4, which was transcriptionally activated by the Wnt/NR2F2 signaling axis in BM.

CONCLUSIONS

Collectively, our findings demonstrated that Wnt/NR2F2/GPX4 promoted acquired chemoresistance by suppressing ferroptosis with high consumption of GSH. GPX4 inhibitor was found to augment the anticancer effect of platinum drugs in lung cancer BM, providing novel strategies for lung cancer patients with BM.

P–165 Using Artificial Intelligence to Classify Embryo Shape: An International Perspective

Study question

Is a pre-trained machine learning algorithm able to accurately detect cellular arrangement in 4-cell embryos from a different continent?

Summary answer

Artificial Intelligence (AI) analysis of 4-cell embryo classification is transferable across clinics globally with 79% accuracy.

What is known already

Previous studies observing four-cell human embryo configurations have demonstrated that non-tetrahedral embryos (embryos in which cells make contact with fewer than 3 other cells) are associated with compromised blastulation and implantation potential. Previous research by this study group has indicated the efficacy of AI models in classification of tetrahedral and non-tetrahedral embryos with 87% accuracy, with a database comprising 2 clinics both from the same country (Brazil). This study aims to evaluate the transferability and robustness of this model on blind test data from a different country (France).

Study design, size, duration

The study was a retrospective cohort analysis in which 909 4-cell embryo images (“tetrahedral”, n = 749; “non-tetrahedral”, n = 160) were collected from 3 clinics (2 Brazilian, 1 French). All embryos were captured at the central focal plane using Embryoscope™ time-lapse incubators. The training data consisted solely of embryo images captured in Brazil (586 tetrahedral; 87 non-tetrahedral) and the test data consisted exclusively of embryo images captured in France (163 tetrahedral; 72 non-tetrahedral).

Participants/materials, setting, methods

The embryo images were labelled as either “tetrahedral” or “non-tetrahedral” at their respective clinics. Annotations were then validated by three operators. A ResNet–50 neural network model pretrained on ImageNet was fine-tuned on the training dataset to predict the correct annotation for each image. We used the cross entropy loss function and the RMSprop optimiser (lr = 1e–5). Simple data augmentations (flips and rotations) were used during the training process to help counteract class imbalances.

Main results and the role of chance

Our model was capable of classifying embryos in the blind French test set with 79% accuracy when trained with the Brazilian data. The model had sensitivity of 91% and 51% for tetrahedral and non-tetrahedral embryos respectively; precision was 81% and 73%; F1 score was 86% and 60%; and AUC was 0.61 and 0.64. This represents a 10% decrease in accuracy compared to when the model both trained and tested on different data from the same clinics.

Limitations, reasons for caution

Although strict inclusion and exclusion criteria were used, inter-operator variability may affect the pre-processing stage of the algorithm. Moreover, as only one focal plane was used, ambiguous cases were interpoloated and further annotated. Analysing embryos at multiple focal planes may prove crucial in improving the accuracy of the model.

Wider implications of the findings: Though the use of machine learning models in the analysis of embryo imagery has grown in recent years, there has been concern over their robustness and transferability. While previous results have demonstrated the utility of locally-trained models, our results highlight the potential for models to be implemented across different clinics.

Trial registration number

Not applicable

MAGE-C3 promotes cancer metastasis by inducing epithelial-mesenchymal transition and immunosuppression in esophageal squamous cell carcinoma

Background

Evading immune surveillance is necessary for tumor metastasis. Thus, there is an urgent need to better understand the interaction between metastasis and mechanisms of tumor immune evasion. In this study, we aimed to clarify a novel mechanism that link tumor metastasis and immunosuppression in the development of esophageal squamous cell carcinoma (ESCC).

Methods

The expression of melanoma‐associated antigen C3 (MAGE‐C3) was detected using immunohistochemistry. Transwell assays were used to evaluate the migration and invasion ability of esophageal squamous cell carcinoma (ESCC) cells. Metastasis assays in mice were used to evaluate metastatic ability in vivo. Lymphocyte‐mediated cytotoxicity assays were performed to visualize the immune suppression function on tumor cells. RNA sequencing was performed to identify differentially expressed genes between MAGE‐C3 overexpressing ESCC cells and control cells. Gene ontology (GO) enrichment analyses was performed to identify the most altered pathways influenced by MAGE‐C3. The activation of the interferon‐γ (IFN‐γ) pathway was analyzed using Western blotting, GAS luciferase reporter assays, immunofluorescence, and flow cytometry. The role of MAGE‐C3 in the IFN‐γ pathway was determined by Western blotting and immunoprecipitation. Furthermore, immunohistochemistry and flow cytometry analysis monitored the changes of infiltrated T cell populations in murine lung metastases.

Results

MAGE‐C3 was overexpressed in ESCC tissues. High expression of MAGE‐C3 had a significant association with the risk of lymphatic metastasis and poor survival in patients with ESCC. Functional experiments revealed that MAGE‐C3 promoted tumor metastasis by activating the epithelial‐mesenchymal transition (EMT). MAGE‐C3 repressed antitumor immunity and regulated cytokine secretion of T cells, implying an immunosuppressive function. Mechanistically, MAGE‐C3 facilitated IFN‐γ signaling and upregulated programmed cell death ligand 1 (PD­L1) by binding with IFN‐γ receptor 1 (IFNGR1) and strengthening the interaction between IFNGR1 and signal transducer and activator of transcription 1 (STAT1). Interestingly, MAGE‐C3 displayed higher tumorigenesis in immune‐competent mice than in immune‐deficient nude mice, confirming the immunosuppressive role of MAGE‐C3. Furthermore, mice bearing MAGE‐C3‐overexpressing tumors showed worse survival and more lung metastases with decreased CD8⁺ infiltrated T cells and increased programmed cell death 1 (PD‐1)⁺CD8⁺ infiltrated T cells.

Conclusion

MAGE‐C3 enhances tumor metastasis through promoting EMT and protecting tumors from immune surveillance, and could be a potential prognostic marker and therapeutic target.

NOX5 mediates the crosstalk between tumor cells and cancer-associated fibroblasts via regulating cytokine network

Activation of cancer-associated fibroblasts (CAFs) is a crucial feature for tumor malignancy. The reciprocal interplay between tumor cells and CAFs not only facilitates tumor progression and metastasis but also sustains the tumor-promoting function of CAFs. Nevertheless, how tumor cells readily adapt to these functional CAFs is still unclear. NADPH oxidase 5 (NOX5) is a strong reactive oxygen species producer overexpressed in esophageal squamous cell carcinoma (ESCC) cells. In this study, we showed that NOX5-positive ESCC cells induced normal fibroblasts (NFs) or adipose-derived mesenchymal stem cells (MSCs) to express the marker of CAFs-α smooth muscle actin. Moreover, these tumor cells reprogrammed the cytokine profile of the activated CAFs, which further stimulated NFs or MSCs to CAFs and induced lymphangiogenesis to facilitate ESCC malignancy. NOX5 activated intratumoral Src/nuclear factor-κB signaling to stimulate secretion of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and lactate from tumor cells. Subsequently, TNF-α, IL-1β, and lactate activated CAFs, and facilitated the secretion of IL-6, IL-7, IL-8, CCL5, and transforming growth factor-β1 from CAFs. These CAFs-derived cytokines reciprocally induced the progression of NOX5-positive ESCC cells. Our findings together indicate that NOX5 serves as the driving oncoprotein to provide a niche that is beneficial for tumor malignant progression.

Feed-forward activation of STAT3 signaling limits the efficacy of c-Met inhibitors in esophageal squamous cell carcinoma (ESCC) treatment

c-Hepatocyte growth factor receptor (Met) inhibitors have demonstrated clinical benefits in some types of solid tumors. However, the efficacy of c-Met inhibitors in esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we discovered that c-Met inhibitors induced "Signal Transducer and Activator of Transcription (STAT3)-addiction" in ESCC cells, and the feedback activation of STAT3 in ESCC cells limits the tumor response to c-Met inhibition. Mechanistically, c-Met inhibition increased the autocrine of several cytokines, including CCL2, interleukin 8, or leukemia inhibitory factor, and facilitated the interactions between the receptors of these cytokines and Janus Kinase1/2 (JAK1/2) to resultantly activate JAKs/STAT3 signaling. Pharmacological inhibition of c-Met together with cytokines/JAKs/STAT3 axis enhanced cancer cells regression in vitro. Importantly, combined c-Met and STAT3 inhibitors synergistically suppressed tumor growth and promoted the apoptosis of tumor cells without producing systematic toxicity. These findings suggest that inhibition of the STAT3 feedback loop may augment the response to c-Met inhibitors via the STAT3-mediated oncogene addiction in ESCC cells.

Long Noncoding RNA VESTAR Regulates Lymphangiogenesis and Lymph Node Metastasis of Esophageal Squamous Cell Carcinoma by Enhancing VEGFC mRNA Stability

Lymph node metastasis is one of the most malignant clinical features in patients with esophageal squamous cell carcinoma (ESCC). Understanding the mechanism of lymph node metastasis will provide treatment strategies for patients with ESCC. Long noncoding RNAs (lncRNA) play a critical role in the development and progression of human cancers. However, the role and mechanism of lncRNAs in lymph node metastasis remain largely unknown. Here we show that VEGFC mRNA stability-associated long noncoding RNA (VESTAR) is involved in lymph node metastasis of ESCC. VESTAR was overexpressed in ESCC tissues and was predictive of poor prognosis in patients with ESCC. In ESCC, NXF1 and SRSF3 facilitated nuclear export of VESTAR to the cytoplasm, which was associated with lymph node metastasis. Depletion of VESTAR inhibited ESCC-associated lymphangiogenesis and lymphatic metastasis. Mechanistically, VESTAR directly bound and stabilized VEGFC mRNA. VESTAR also interacted with HuR, a positive regulator of VEGFC mRNA stability, and increased HuR binding to VEGFC mRNA. Our study reveals a novel lncRNA-guided mechanism of lymph node metastasis in ESCC and may provide a potential target for treatment of ESCC lymphatic metastasis. SIGNIFICANCE: These findings illustrate the lncRNA-guided regulation of VEGFC mRNA stability via direct RNA-RNA interactions, highlighting a therapeutic target for patients with ESCC with lymphatic metastasis.

Extracellular vesicles derived from oesophageal cancer containing P4HB promote muscle wasting via regulating PHGDH/Bcl-2/caspase-3 pathway

Cachexia, characterized by loss of skeletal muscle mass and function, is estimated to inflict the majority of patients with oesophageal squamous cell carcinoma (ESCC) and associated with their poor prognosis. However, its underlying mechanisms remain elusive. Here, we developed an ESCC‐induced cachexia mouse model using human xenograft ESCC cell lines and found that ESCC‐derived extracellular vesicles (EVs) containing prolyl 4‐hydroxylase subunit beta (P4HB) induced apoptosis of skeletal muscle cells. We further identified that P4HB promoted apoptotic response through activating ubiquitin‐dependent proteolytic pathway and regulated the stability of phosphoglycerate dehydrogenase (PHGDH) and subsequent antiapoptotic protein Bcl‐2. Additionally, we proved that the P4HB inhibitor, CCF642, not only rescued apoptosis of muscle cells in vitro, but also prevented body weight loss and muscle wasting in ESCC‐induced cachexia mouse model. Overall, these findings demonstrate a novel pathway for ESCC‐induced muscle wasting and advocate for the development of P4HB as a potential intervention target for cachexia in patients with ESCC.

Advancing science and education through a novel collaboration platform between the University of Michigan and Peking University Health Science Center

Research in China has been advancing over the past decade with increasing investments from government and private entities. Collaboration with Chinese investigators and those in the United States has also increased as reflected in the growth of scientific papers with Chinese authors. Collaborations are more commonly based on faculty‐to‐faculty relationships which can be challenged by institutional or governmental policies. This paper reports on an institution‐to‐ institution collaboration, the Joint Institute for Translational and Clinical Research initiated in 2010 between the University of Michigan Medical School and Peking University Health Science Center, to enable and support collaborative faculty‐initiated research. Concomitant education and training programs have also been co‐developed. Beginning in 2011, 190 proposals from faculty‐to‐faculty partnerships have been submitted from which 59 have been selected for funding. These projects have involved over 138,000 patient subjects and resulted in 86 peer‐reviewed publications to date. Pilot data has been leveraged to secure $27.3 million dollars of extramural funding outside of China. Faculty and trainee exchanges take place regularly including an annual symposium with mechanisms to link faculty who are seeking partnerships by utilizing each other's complementary strengths and resources. As the collaboration enters its second decade, both institutions believe that the model offers a unique platform to promote faculty‐initiated collaborative research. Next steps include funding studies in prioritized scientific themes, and promoting access to high‐quality cohorts to attract industry partners and to develop sustainable financial models.

Utility of Contrast-Enhanced T2 FLAIR for Imaging Brain Metastases Using a Half-dose High-Relaxivity Contrast Agent

BACKGROUND AND PURPOSE

Efficient detection of metastases is important for patient' treatment. This prospective study was to explore the clinical value of contrast-enhanced T2 FLAIR in imaging brain metastases using half-dose gadobenate dimeglumine.

MATERIALS AND METHODS

In vitro signal intensity of various gadolinium concentrations was explored by spin-echo T1-weighted imaging and T2 FLAIR. Then, 46 patients with lung cancer underwent nonenhanced T2 FLAIR before administration of half-dose gadobenate dimeglumine and 3 consecutive contrast-enhanced T2 FLAIR sequences followed by 1 spin-echo T1WI after administration of half-dose gadobenate dimeglumine. After an additional dose of 0.05 mmol/kg, 3D brain volume imaging was performed. All brain metastases were classified as follows: solid-enhancing, ≥ 5 mm (group A); ring-enhancing, ≥ 5 mm (group B); and lesion diameter of <5 mm (group C). The contrast ratio of the lesions on 3 consecutive phases of contrast-enhanced T2 FLAIR was measured, and the percentage increase of contrast-enhanced T2 FLAIR among the 3 groups was compared.

RESULTS

In vitro, the maximal signal intensity was achieved in T2 FLAIR at one-eighth to one-half of the contrast concentration needed for maximal signal intensity in T1WI. In vivo, the mean contrast ratio values of metastases on contrast-enhanced T2 FLAIR for the 3 consecutive phases ranged from 63.64% to 83.05%. The percentage increase (PI) values of contrast-enhanced T2 FLAIR were as follows: PI_A < PI_B (P = .001) and PI_A < PI_C (P < .001). The degree of enhancement of brain metastases on contrast-enhanced T2 FLAIR was lower than on 3D brain volume imaging (P < .001) in group A, and higher than on 3D brain volume imaging (P < .001) in group C.

CONCLUSIONS

Small or ring-enhancing metastases can be better visualized on delayed contrast-enhanced T2 FLAIR using a half-dose high-relaxivity contrast agent.