EphB6 deficiency in intestinal neurons promotes tumor growth in colorectal cancer by neurotransmitter GABA signaling.

EphB6 belongs to the receptor tyrosine kinase, whose low expression is associated with shorter survival of colorectal cancer (CRC) patients. But the role and mechanism of EphB6 in the progression of CRC need further study. In addition, EphB6 was mainly expressed in intestinal neurons. But how EphB6 is involved in functions of intestinal neurons has not been known. In our study, we constructed a mouse xenograft model of CRC by injecting CMT93 cells into the rectum of EphB6-deficient mice. We found that the deletion of EphB6 in mice promoted tumor growth of CMT93 cells in a xenograft model of CRC, which was independent of changes in the gut microbiota. Interestingly, inhibition of intestinal neurons by injecting botulinum toxin A into rectum of EphB6-deficient mice could eliminate the promotive effect of EphB6 deficiency on tumor growth in the xenograft model of CRC. Mechanically, the deletion of EphB6 in mice promoted the tumor growth in CRC by increasing GABA in the tumor microenvironment. Furthermore, EphB6 deficiency in mice increased the expression of synaptosomal-associated protein 25 in the intestinal myenteric plexus, which mediated the release of GABA. Our study concluded that EphB6 knockout in mice promotes tumor growth of CMT93 cells in a xenograft model of CRC by modulating GABA release. Our study found a new regulating mechanism of EphB6 on the tumor progression in CRC that is dependent on intestinal neurons.

Machine learning-based automated sponge cytology for screening of oesophageal squamous cell carcinoma and adenocarcinoma of the oesophagogastric junction: a nationwide, multicohort, prospective study.

BACKGROUND: Oesophageal squamous cell carcinoma and adenocarcinoma of the oesophagogastric junction have a dismal prognosis, and early detection is key to reduce mortality. However, early detection depends on upper gastrointestinal endoscopy, which is not feasible to implement at a population level. We aimed to develop and validate a fully automated machine learning-based prediction tool integrating a minimally invasive sponge cytology test and epidemiological risk factors for screening of oesophageal squamous cell carcinoma and adenocarcinoma of the oesophagogastric junction before endoscopy. METHODS: For this multicohort prospective study, we enrolled participants aged 40-75 years undergoing upper gastrointestinal endoscopy screening at 39 tertiary or secondary hospitals in China for model training and testing, and included community-based screening participants for further validation. All participants underwent questionnaire surveys, sponge cytology testing, and endoscopy in a sequential manner. We trained machine learning models to predict a composite outcome of high-grade lesions, defined as histology-confirmed high-grade intraepithelial neoplasia and carcinoma of the oesophagus and oesophagogastric junction. The predictive features included 105 cytological and 15 epidemiological features. Model performance was primarily measured with the area under the receiver operating characteristic curve (AUROC) and average precision. The performance measures for cytologists with AI assistance was also assessed. FINDINGS: Between Jan 1, 2021, and June 30, 2022, 17 498 eligible participants were involved in model training and validation. In the testing set, the AUROC of the final model was 0·960 (95% CI 0·937 to 0·977) and the average precision was 0·482 (0·470 to 0·494). The model achieved similar performance to consensus of cytologists with AI assistance (AUROC 0·955 [95% CI 0·933 to 0·975]; p=0·749; difference 0·005, 95% CI, -0·011 to 0·020). If the model-defined moderate-risk and high-risk groups were referred for endoscopy, the sensitivity was 94·5% (95% CI 88·8 to 97·5), specificity was 91·9% (91·2 to 92·5), and the predictive positive value was 18·4% (15·6 to 21·6), and 90·3% of endoscopies could be avoided. Further validation in community-based screening showed that the AUROC of the model was 0·964 (95% CI 0·920 to 0·990), and 92·8% of endoscopies could be avoided after risk stratification. INTERPRETATION: We developed a prediction tool with favourable performance for screening of oesophageal squamous cell carcinoma and adenocarcinoma of the oesophagogastric junction. This approach could prevent the need for endoscopy screening in many low-risk individuals and ensure resource optimisation by prioritising high-risk individuals. FUNDING: Science and Technology Commission of Shanghai Municipality.

A single-cell atlas of liver metastases of colorectal cancer reveals reprogramming of the tumor microenvironment in response to preoperative chemotherapy.

Metastasis is the primary cause of cancer-related mortality in colorectal cancer (CRC) patients. How to improve therapeutic options for patients with metastatic CRC is the core question for CRC treatment. However, the complexity and diversity of stromal context of the tumor microenvironment (TME) in liver metastases of CRC have not been fully understood, and the influence of stromal cells on response to chemotherapy is unclear. Here we performed an in-depth analysis of the transcriptional landscape of primary CRC, matched liver metastases and blood at single-cell resolution, and a systematic examination of transcriptional changes and phenotypic alterations of the TME in response to preoperative chemotherapy (PC). Based on 111,292 single-cell transcriptomes, our study reveals that TME of treatment-naïve tumors is characterized by the higher abundance of less-activated B cells and higher heterogeneity of tumor-associated macrophages (TAMs). By contrast, in tumors treated with PC, we found activation of B cells, lower diversity of TAMs with immature and less activated phenotype, lower abundance of both dysfunctional T cells and ECM-remodeling cancer-associated fibroblasts, and an accumulation of myofibroblasts. Our study provides a foundation for future investigation of the cellular mechanisms underlying liver metastasis of CRC and its response to PC, and opens up new possibilities for the development of therapeutic strategies for CRC.

Pregnancy and birth outcomes of multiple gestations with PPROM occurred within 24 h after fetal reduction: A case series.

OBJECTIVE: The study aims to analyze the pregnancy outcomes of multiple gestations with preterm premature rupture of membranes (PPROM) that occurred within 24 h after fetal reduction with potassium chloride (KCL). MATERIALS AND METHODS: We identified and evaluated the outcomes of 16 retrospectively recorded multigestational pregnancies that met the inclusion criteria between 2006 and 2016, from the Obstetrics Department of Shandong Provincial Hospital. A total of 16 patients carrying twins or higher order multiple gestations experienced PPROM within 24 h after fetal reduction, and all of them received expectant management after understanding the relevant risks. The maternal and neonatal records were retrospectively collected and reviewed. Every surviving child was followed up to at least 2 years old. RESULT: Of the 16 cases, 12 cases (75%) ended in successful pregnancy, resulting in the delivery of at least 1 child surviving from a multiple gestational pregnancy. All cases of successful pregnancies were either term (≥37 weeks) or near-term (36+5 weeks) at delivery. And of those 20 infants delivered, only 3 were low birth weight infants (<2500g) (15%), None of the 16 women had fever, or other clinical symptoms and signs of chorioamnionitis during hospital stay. Postnatal follow-up of the surviving babies showed no obvious sequelae thus far. No newborn baby had neonatal complications, or needed to be transferred to neonatal intensive care unit. CONCLUSION: Overall, our data demonstrate that dichorionic diamniotic (DCDA) twins or higher-order gestations who experienced PPROM of the reduced fetus within 24 h after selective reduction with KCL had relatively good outcomes with expectant management alone.

The gut microbiota regulates autism-like behavior by mediating vitamin B6 homeostasis in EphB6-deficient mice.

BACKGROUND: Autism spectrum disorder (ASD) is a developmental disorder, and the effective pharmacological treatments for the core autistic symptoms are currently limited. Increasing evidence, particularly that from clinical studies on ASD patients, suggests a functional link between the gut microbiota and the development of ASD. However, the mechanisms linking the gut microbiota with brain dysfunctions (gut-brain axis) in ASD have not yet been full elucidated. Due to its genetic mutations and downregulated expression in patients with ASD, EPHB6, which also plays important roles in gut homeostasis, is generally considered a candidate gene for ASD. Nonetheless, the role and mechanism of EPHB6 in regulating the gut microbiota and the development of ASD are unclear. RESULTS: Here, we found that the deletion of EphB6 induced autism-like behavior and disturbed the gut microbiota in mice. More importantly, transplantation of the fecal microbiota from EphB6-deficient mice resulted in autism-like behavior in antibiotic-treated C57BL/6J mice, and transplantation of the fecal microbiota from wild-type mice ameliorated the autism-like behavior in EphB6-deficient mice. At the metabolic level, the disturbed gut microbiota in EphB6-deficient mice led to vitamin B6 and dopamine defects. At the cellular level, the excitation/inhibition (E/I) balance in the medial prefrontal cortex was regulated by gut microbiota-mediated vitamin B6 in EphB6-deficient mice. CONCLUSIONS: Our study uncovers a key role for the gut microbiota in the regulation of autism-like social behavior by vitamin B6, dopamine, and the E/I balance in EphB6-deficient mice, and these findings suggest new strategies for understanding and treating ASD. Video abstract.

ZIC2 is downregulated and represses tumor growth via the regulation of STAT3 in breast cancer.

Although early detection and systemic therapies have improved the diagnosis and clinical cure rate of breast cancer, breast cancer remains the most frequently occurring malignant cancer in women due to a lack of sufficiently effective treatments. Thus, to develop potential targeted therapies and thus benefit more patients, it is helpful to understand how cancer cells work. ZIC family members have been shown to play important roles in neural development and carcinogenesis. In our study, we found that ZIC2 is downregulated in breast cancer tissues at both the mRNA and protein levels. Low expression of ZIC2 was correlated with poor outcome in breast cancer patients and serves as an independent prognostic marker. Furthermore, overexpression of ZIC2 repressed, whereas knockdown of ZIC2 promoted, cell proliferation and colony formation ability in vitro and tumor growth in vivo. Using ChIP-seq and RNA-seq analysis, we screened and identified STAT3 as a potential target for ZIC2. ZIC2 bound to the STAT3 promoter and repressed the promoter activities of STAT3. ZIC2 knockdown induced the expression of STAT3, increasing the level of phosphorylated STAT3. These results suggest that ZIC2 regulates the transcription of STAT3 by directly binding to the STAT3 promoter. Additionally, interfering STAT3 with siRNAs or inhibitors abrogated the oncogenic effects induced by decreased ZIC2. Taken together, our results indicate that ZIC2 serves as a useful prognostic marker in breast cancer and acts as a tumor suppressor by regulating STAT3, implying that STAT3 inhibitors might provide an alternative treatment option for breast cancer patients with ZIC2 downregulation.

Comparisons between two methods of multifetal pregnancy reduction in women with a dichorionic triamniotic triplet pregnancy.

OBJECTIVE: To compare the different pregnancy outcomes of women with a reduced dichorionic triamniotic (DCTA) triplet managed with radiofrequency ablation (RFA) or potassium chloride (KCL). MATERIALS AND METHODS: This was a retrospective cohort study. We studied 30 women of DCTA triplets managed with RFA as well as 85 managed with KCL. We compared the mean neonatal birthweight, median gestational age and perinatal mortality of two groups. RESULTS: The mean neonatal birthweight of children in RFA group was 2572.4 g (SD, 407.0), vs 2899.3 g (SD, 554.9) in KCL group (P < 0.001). The rate of low birth weight infants was 23 (42.6%) vs. 16 (18.0%), respectively, (p < 0.005). However, there was no statistically significant difference in the median gestational age of delivery, premature birth before 32&37 weeks' gestation, neonatal brain injury or successful pregnancy between two groups. (We define the successful pregnancy as the condition that at least one child survives for a specific woman, while the failed one as no child survives.) CONCLUSION: What we took it for granted was that pregnancy outcomes in women with a reduced DCTA triplet managed with RFA was riskier than with KCL, however, we proved that it is not accurate. For women with a reduced DCTA triplet, managed with RFA is not much riskier than with KCL. What's more, most women have two children survived in RFA group, while in KCL group, only one child survives for most women. This result may change the management alternative for those women with DCTA triplet pregnancies who choose reduction, especially for women who desire to have two surviving and healthy fetuses.

Correction to: Elevated expression of CST1 promotes breast cancer progression and predicts a poor prognosis.

In Figure 7f the panel for c-myc of MDA-MB-468 was erroneously duplicated. The corrected version of the figure is shown in this paper. This correction does not influence the conclusion of the study and we sincerely apologize for this oversight.

[Pharmacokinetics of eight constituents in rat plasma after oral administration of Modified Xiaochaihu Granules for gastric ulcer based on UPLC-MS/MS].

An ultra-performance liquid chromatography-tandem mass spectrometric method (UPLC-MS/MS) was developed in this study to simultaneously determine the contents of eight effective constituents in rat plasma, including baicalin, wogonoside, baicalein, liquiritin, glycyrrhizic acid, berberine hydrochloride, saikosaponin a and saikosaponin d in plasma of gastric ulcer rats, and investigate the pharmacokinetics of Modified Xiaochaihu Granules. Chromatographic separation was conducted on Zorbax SB-C18 column (2.1 mm×100 mm, 1.8 µm) with acetonitrile -0.1% formic acid aqueous solution as the mobile phase for gradient elution, at a flow rate of 0.4 mL·min⁻¹ and column temperature of 40 °C. Detection was performed in the multiple reaction monitoring (MRM) mode with ESI ion source. All calibration curves showed good linearity (r>0.996) over a wide concentration range for all constituents. RSDs of intra-day and inter-day precision were all within 15% and the extraction recoveries of all the constituents were in the range of 81.92% to 104.8%. The time to peak (tmax) of these eight constituents was (2.69±2.02), (5.17±2.04), (0.25±0), (0.83±0.26), (0.92±0.20), (0.92±0.20), (0.58±0.20), and (0.083±0) h, respectively; the half-life (t1/2) of them was (7.85±0.34), (10.16±2.21), (6.79±0.21), (8.32±0.48), (11.05±1.78), (11.56±3.46), (15.30±1.84), and (5.54±1.91) h, respectively; the peak concentration (Cmax) of them was (55.02±1.67), (213.66±4.62), (62.61±0.69), (68.43±1.42), (62.22±0.39), (30.17±1.89), (61.79±4.81), and (38.02±1.75) µg·L⁻¹, respectively. This established method is simple and accurate with good repeatability and strong specificity, which could provide modern experimental basis for modified Xiaochaihu granules in clinical treatment of gastric ulcer.

MiR-324-5p reduces viability and induces apoptosis in gastric cancer cells through modulating TSPAN8.

OBJECTIVES: The purpose of this study was to further clarify the role and underlying mechanism of miR-324-5p in gastric cancer. METHODS: The expressions of miR-324-5p and TSPAN8 as determined by qRT-PCR or Western blot were compared between the gastric cancer tissues and normal tissues. Human gastric cancer cell line SGC-7901 was cultured and transfected with miR-324-5p mimic/inhibitor or pcDNA-TSPAN8. The cell survival was assessed by the cell viability and apoptosis. Luciferase reporter gene assays were performed to explore the interaction between miR-324-5p and TSPAN8 in SGC-7901 cells. KEY FINDINGS: MiR-324-5p was decreased in human gastric carcinoma tissues (n = 33), but TSPAN8 protein expression was increased in the gastric carcinoma tissues (n = 33). Moreover, miR-324-5p inhibited the viability and induced the apoptosis of gastric cancer cells in vitro. TSPAN8 is a functional target of miR-324-5p in gastric cancer. MiR-324-5p was further confirmed to reduce gastric cancer cell viability and induce apoptosis via downregulating TSPAN8 in SGC-7901 cells in vitro. Additionally, miR-324-5p overexpression markedly inhibited the tumorigenesis of gastric cancer cells in vivo, as shown by the smaller tumour volume compared with the control. CONCLUSIONS: This study suggested a novel, probable mechanism of miR-324-5p in gastric cancer context and revealed that miR-324-5p inhibited gastric cancer cell survival by targeting TSPAN8.

[Studies on serum pharmacochemistry of effective parts of modified Xiaochaihu Tang for treatment of gastric ulcer].

To conduct the studies on serum pharmacochemistry of effective parts of modified Xiaochaihu Tang for treatment of gastric ulcer by using chromatography-mass spectrometry. Absolute ethyl alcohol induced-gastric ulcer model of mouse was used in this study to investigate the pharmacology of modified Xiaochaihu Tang and its effective parts. Both groups could significantly decrease the absolute ethyl alcohol induced-ulcer. Gasphase-mass spectrometry (GC-MS) was used to detect chemical compositions of volatile fractions and the drug components after gastric administration. A total of 63 compounds were identified in extracts, accounting for more than 93% of the all volatile oil, including 23.51% α-curcumene, 11.96% zingiberene, 9.56% curzerene, 6.54% ß-sesquinene, 4.77% camphene, and 6 prototype components were also detected in serum for gastric ulcer model. In liquid chromatography-mass spectrometry (LC-MS), a total of 17 compounds were identified in extracts, 6 prototype components and 2 metabolites (3,5-O-feruloylquinic acid and palmatine) were obtained in serum. In a conclusion, this study provides an important scientific basis for identifying the active ingredients in modified Xiaochaihu Tang, and also helps to reveal the pharmacological effect of modified Xiaochaihu Tang for treatment of gastric ulcer.

Author Correction: Ephrin receptor A2 is an epithelial cell receptor for Epstein-Barr virus entry.

In the version of this Letter originally published, the authors reported on the use of 2,5-dimethylpyrrolyl benzoic acid to block Ephrin receptors. In 2011, it was reported that newly synthesized 2,5-dimethylpyrrolyl benzoic acid lacked the previously reported EphA2 antagonizing activity1. However, the purchased compound did in fact have the activity initially reported, suggesting that an uncharacterized alteration occurred during storage. The authors therefore wish to clarify that the compound used in their study should be more accurately referred to as a 2,5-dimethylpyrrolyl benzoic acid derivative. All references to 2,5-dimethylpyrrolyl benzoic acid in the Letter have now been changed to reflect this.Although 2,5-dimethylpyrrolyl benzoic acid derivatives have been reported to have off-target effects2, as do most small-molecule inhibitors, the multiple complementary methods and techniques used demonstrate that EphA2 is a key Epstein-Barr virus epithelial cell receptor. The conclusions of the study are therefore unchanged.

Overexpression of Nogo receptor 3 (NgR3) correlates with poor prognosis and contributes to the migration of epithelial cells of nasopharyngeal carcinoma patients.

Lymph node metastasis (N classification) is one of the most important prognostic factors of nasopharyngeal carcinoma (NPC), and nerve involvement is associated with the transition of the N category in NPC patients. Although the nervous system has been reported to participate in many types of cancer progression, its functions in NPC progression remains unknown. Through analysis of gene profiling data, we demonstrate an enrichment of genes associated with neuronal development and differentiation in NPC tissues and cell lines. Among these genes, Nogo receptor 3 (NgR3), which was originally identified in the nervous system and plays a role in nerve development and regeneration, was inappropriately overexpressed in NPC cells and tissues. Immunohistochemical analysis demonstrated that the overexpression of NgR3 was correlated with poor prognosis in NPC patients. Overexpression of NgR3 promoted, and knocking down NgR3 inhibited, NPC cell migration and invasion in vitro and metastasis in vivo. The ability of NgR3 to promote cell migration was triggered by the downregulation of E-cadherin and enhanced cytoskeletal rearrangement and cell polarity, which were correlated with the activation of focal adhesion kinase (FAK). Collectively, NgR3 is a novel indicator of poor outcomes in NPC patients and plays an important role in driving the progression of NPC. These results suggest a potential link between the nervous system and NPC progression. KEY MESSAGES: Genes involved in the neuronal biological process are enriched in nasopharyngeal carcinoma. Overexpression of NgR3 correlates with poor prognosis of nasopharyngeal carcinoma. NgR3 promotes NPC cell migration by downregulating E-cadherin. NgR3 promotes NPC cell polarity and enhances the formation of NPC cell pseudopodia by activating FAK/Src pathway.

Ephrin receptor A2 is an epithelial cell receptor for Epstein-Barr virus entry.

Epstein-Barr virus (EBV) is causally associated with nasopharyngeal carcinoma, 10% of gastric carcinoma and various B cell lymphomas 1 . EBV infects both B cells and epithelial cells 2 . Recently, we reported that epidermal growth factor and Neuropilin 1 markedly enhanced EBV entry into nasopharyngeal epithelial cells 3 . However, knowledge of how EBV infects epithelial cells remains incomplete. To understand the mechanisms through which EBV infects epithelial cells, we integrated microarray and RNA interference screen analyses and found that Ephrin receptor A2 (EphA2) is important for EBV entry into the epithelial cells. EphA2 short interfering RNA knockdown or CRISPR-Cas9 knockout markedly reduced EBV epithelial cell infection, which was mostly restored by EphA2 complementary DNA rescue. EphA2 overexpression increased epithelial cell EBV infection. Soluble EphA2 protein, antibodies against EphA2, soluble EphA2 ligand EphrinA1, or the EphA2 inhibitor 2,5-dimethylpyrrolyl benzoic acid efficiently blocked EBV epithelial cell infection. Mechanistically, EphA2 interacted with EBV entry proteins gH/gL and gB to facilitate EBV internalization and fusion. The EphA2 Ephrin-binding domain and fibronectin type III repeats domain were essential for EphA2-mediated EBV infection, while the intracellular domain was dispensable. This is distinct from Kaposi's sarcoma-associated herpesvirus infection through EphA2 4 . Taken together, our results identify EphA2 as a critical player for EBV epithelial cell entry.

The RARS-MAD1L1 Fusion Gene Induces Cancer Stem Cell-like Properties and Therapeutic Resistance in Nasopharyngeal Carcinoma.

Purpose: Nasopharyngeal carcinoma (NPC) is the most common head and neck cancer in Southeast Asia. Because local recurrence and distant metastasis are still the main causes of NPC treatment failure, it is urgent to identify new tumor markers and therapeutic targets for advanced NPC.Experimental Design: RNA sequencing (RNA-seq) was applied to look for interchromosome translocation in NPC. PCR, FISH, and immunoprecipitation were used to examine the fusion gene expression at RNA, DNA, and protein levels in NPC biopsies. MTT assay, colony formation assay, sphere formation assay, co-immunoprecipitation, chromatin immunoprecipitation assay, and in vivo chemoresistance assay were applied to explore the function of RARS-MAD1L1 in NPC.Results: We demonstrated that RARS-MAD1L1 was present in 10.03% (35/349) primary NPC biopsies and 10.7% (9/84) in head and neck cancer (HNC) samples. RARS-MAD1L1 overexpression increased cell proliferation, colony formation, and tumorigenicity in vitro, and the silencing of endogenous RARS-MAD1L1 reduced cancer cell growth and colony formation in vitro In addition, RARS-MAD1L1 increased the side population (SP) ratio and induced chemo- and radioresistance. Furthermore RARS-MAD1L1 interacted with AIMP2, which resulted in activation of FUBP1/c-Myc pathway. The silencing of FUBP1 or the administration of a c-Myc inhibitor abrogated the cancer stem cell (CSC)-like characteristics induced by RARS-MAD1L1. The expression of c-Myc and ABCG2 was higher in RARS-MAD1L1-positive HNC samples than in negative samples.Conclusions: Our findings indicate that RARS-MAD1L1 might contribute to tumorigenesis, CSC-like properties, and therapeutic resistance, at least in part, through the FUBP1/c-Myc axis, implying that RARS-MAD1L1 might serve as an attractive target for therapeutic intervention for NPC. Clin Cancer Res; 24(3); 659-73. ©2017 AACR.

Genomic comparison of esophageal squamous cell carcinoma and its precursor lesions by multi-region whole-exome sequencing.

Esophageal squamous dysplasia is believed to be the precursor lesion of esophageal squamous cell carcinoma (ESCC); however, the genetic evolution from dysplasia to ESCC remains poorly understood. Here, we applied multi-region whole-exome sequencing to samples from two cohorts, 45 ESCC patients with matched dysplasia and carcinoma samples, and 13 tumor-free patients with only dysplasia samples. Our analysis reveals that dysplasia is heavily mutated and harbors most of the driver events reported in ESCC. Moreover, dysplasia is polyclonal, and remarkable heterogeneity is often observed between tumors and their neighboring dysplasia samples. Notably, copy number alterations are prevalent in dysplasia and persist during the ESCC progression, which is distinct from the development of esophageal adenocarcinoma. The sharp contrast in the prevalence of the 'two-hit' event on TP53 between the two cohorts suggests that the complete inactivation of TP53 is essential in promoting the development of ESCC.The pathogenesis of oesophageal squamous cell carcinoma is a multi-step process but the genetic determinants behind this progression are unknown. Here the authors use multi-region exome sequencing to comprehensively investigate the genetic evolution of precursor dysplastic lesions and untransformed oesophagus.

Elevated expression of CST1 promotes breast cancer progression and predicts a poor prognosis.

Cystatin SN (CST1) belongs to the type 2 cystatin (CST) superfamily, which restricts the proteolytic activities of cysteine proteases. CST1 has been recently considered to be involved in the development of several human cancers. However, the prognostic significance and function of CST1 in breast cancer remains unknown. In the current study, we found that CST1 was generally upregulated in breast cancer at both mRNA and protein level. Furthermore, overall survival (OS) and disease-free survival (DFS) in the low CST1 expression subgroup were significantly superior to the high CST1 expression subgroup (OS, p < 0.001; DFS, p < 0.001), which indicated that CST1 expression level was closely correlated to the survival risk of these patients. Univariate and multivariate analyses demonstrated that CST1 expression was an independent prognostic factor, the same as ER status and nodal status. Next, CST1 overexpression promoted breast cancer cell proliferation, clonogenicity, migration, and invasion abilities. By contrast, knockdown of CST1 attenuated these malignant characteristics in breast cancer cells. Collectively, our study indicates that CST1 cannot only serve as a significant prognostic indicator but also as a potential therapeutic target for breast cancer. KEY MESSAGES: High CST1 expression is negatively correlated with survival of breast cancer patients. CST1 promotes cell proliferation, clone formation, and metastasis in breast cancer cells. CST1 is a novel potential prognostic biomarker and therapeutic target for breast cancer.

RBM24 suppresses cancer progression by upregulating miR-25 to target MALAT1 in nasopharyngeal carcinoma.

Abnormal interaction between non-coding RNAs has been demonstrated to be a common molecular event in various human cancers, but its significance and underlying mechanisms have not been well documented. RNA-binding proteins (RBPs) are key regulators of RNA transcription and post-transcriptional processing. In this study, we found that RNA-binding protein 24 (RBM24) was frequently downregulated in nasopharyngeal carcinoma (NPC). The restoration of RBM24 expression suppressed NPC cellular proliferation, migration and invasion and impeded metastatic colonization in mouse models. Microarray analyses revealed that miR-25 expression was upregulated by RBM24 expression in NPC cells. Similarly, ectopic miR-25 expression suppressed NPC cellular growth and motility by targeting the pro-oncogenic lncRNA MALAT1, and the knockdown of MALAT1 expression exhibited similar effects as RBM24 restoration in NPC cells. Overall, these findings suggest a novel role of RBM24 as a tumor suppressor. Mechanistically, RBM24 acts at least in part through upregulating the expression of miR-25, which in turn targets MALAT1 for degradation.

ISG15 predicts poor prognosis and promotes cancer stem cell phenotype in nasopharyngeal carcinoma.

Interferon-stimulated gene 15 (ISG15), the first identified ubiquitin-like protein, is known for its anti-viral capacity. However, its role in tumorigenesis remains controversial. Here, using RNA-seq profiling analysis, we identified ISG15 as a differentially expressed gene in nasopharyngeal carcinoma (NPC) and validated its overexpression in NPC samples and cells. High ISG15 levels in NPC tissues were correlated with more frequent local recurrence and shorter overall survival and disease-free survival. ISG15 overexpression promoted a cancer stem cell phenotype in NPC cells, including increased colony and tumorsphere formation abilities, pluripotency-associated genes expression, and in vivo tumorigenicity. By contrast, knockdown of ISG15 attenuated stemness characteristics in NPC cells. Furthermore, overexpression of ISG15 increased NPC cell resistance to radiation and cisplatin (DDP) treatment. Our study demonstrates a protumor role of ISG15, and suggests that ISG15 is a prognostic predictor and a potential therapeutic target for NPC.