IL-24 improves efficacy of CAR-T cell therapy by targeting stemness of tumor cells

BACKGROUND

Cancer stem cells (CSCs) induce therapeutic resistance and may be an important barrier to cancer immunotherapy. Chimeric antigen receptor T (CAR-T) cell therapy has demonstrated remarkable efficacy in clinical settings. However, CAR-T cell therapy fails in a large proportion of patients, especially in those with solid tumors. It is unclear how CSCs mediate resistance to CAR-T cells, and whether CAR-T cells can more effectively eradicate CSCs.

METHODS

In this study, the effect of CSCs on CAR-T cell therapy was determined using in vitro and in vivo assays. Subsequently, Interleukin-24 (IL-24) was expressed along with CAR in T cells. Further in vitro and in vivo tests were performed to determine the effects of IL-24 on CSCs and CAR-T cell therapy.

RESULTS

IL-24 induced apoptosis in CSCs and contributed to T cell activation, differentiation, and proliferation. CAR.IL-24-T cells inhibited CSC enrichment and exhibited stronger antitumor activity in vitro and in vivo.

CONCLUSIONS

IL-24 helps eliminate CSCs and endows CAR-T cells with improved antitumor reactivity.

KCNH2A561V Heterozygous Mutation Inhibits KCNH2 Protein Expression via The Activation of UPR Mediated by ATF6

The potassium channel protein KCNH2 is encoded by KCNH2 gene, and there are more than 300 mutations of KCNH2. Unfolded protein response (UPR) is typically initiated in response to an accumulation of unfolded and/or misfolded proteins in the endoplasmic reticulum (ER). The present study aimed to explore the UPR process and the role of activating transcription factor 6 (ATF6) in the abnormal expression of potassium voltage-gated channel subfamily H member 2 (KCNH2)A561V. The wild-type (wt) KCNH2 and A561V mutant KCNH2 was constructed with his-tag. The 293 cells were used and divided into KCNH2wt+KCNH2A561V, KCNH2wt and KCNH2A561V groups. The expression levels of ATF6 and KCNH2 in different groups were detected by Western blotting, reverse transcription-quantitative PCR, immunofluorescence and immuno-coprecipitation assays. The protein types and abundance of immuno-coprecipitation samples were analyzed by mass spectrometry. The proteomic analysis of the mass spectrometry results was carried out by using the reactome database and GO (Gene Ontology) tool. The mRNA expression levels of KCNH2 and ATF6 in the KCNH2wt+KCNH2A561V group were higher compared with the KCNH2A561V group. However, the full-length protein expression of ATF6 was inhibited, indicating that ATF6 was highly activated and a substantial number of ATF6 was sheared in KCNH2wt+KCNH2A561V group compared with control group. Furthermore, A561V-KCNH2 mutation leading to the accumulation of the immature form of KCNH2 (135 kDa bands) in ER, resulting in the reduction of the ratio of 155 kDa/135 kDa. In addition, the abundance of UPR-related proteins in the KCNH2A561V group was higher compared with the KCNH2wt+KCNH2A561V group. The 'cysteine biosynthetic activity' of GO:0019344 process and the 'positive regulation of cytoplasmic translation activity' of GO:2000767 process in the KCNH2A561V group were higher compared with the KCNH2wt+KCNH2A561V group. Hence, co-expression of wild-type and A561V mutant KCNH2 in 293 cells activated the UPR process, which led to the inhibition of protein translation and synthesis, in turn inhibiting the expression of KCNH2. These results provided a theoretical basis for clinical treatment of Long QT syndrome.

An Automated Brain Metastasis Detection and Segmentation System from MRI with a Large Multi-Institutional Dataset

PURPOSE/OBJECTIVE(S)

Developments of automated systems for brain metastasis (BM) detection and segmentation from MRI for assisting early detection and stereotactic radiosurgery (SRS) have been reported but most based upon relatively small datasets from single institutes. This work aims to develop and evaluate a system using a large multi-institutional dataset, and to improve both identification of small/subtle BMs and segmentation accuracy of large BMs.

MATERIALS/METHODS

A 3D U-Net system was trained and evaluated to detect and segment intraparenchymal BMs with a size > 2mm using 1856 MRI volumes from 1791 patients treated with SRS from seven institutions (1539 volumes for training, 183 for validation, and 134 for testing). All patients had 3D post-Gd T1w MRI scans pre-SRS. Gross tumor volumes (GTVs) of BMs for SRS were curated by each institute first. Then, additional efforts were spent to create GTVs for the untreated and/or uncontoured BMs, including central reviews by two radiologists, to improve accuracy of ground truth. The training dataset was augmented with synthetic BMs of 3773 MRIs using a 3D generative pipeline. Our system consists of two U-Nets with one using small 3D patches dedicated for detecting small BMs and another using large 3D patches for segmenting large BMs, and a random-forest based fusion module for combining the two network outputs. The first U-Net was trained with 3D patches containing at least one BM < 0.1 cm3. For detection performance, we measured BM-level sensitivity and case-level false-positive (FP) rate. For segmentation performance, we measured BM-level Dice similarity coefficient (DSC) and 95-percentile Hausdorff distance (HD95). We also stratified performances based upon BM sizes.

RESULTS

For 739 BMs in the 134 testing cases, the overall lesion-level sensitivity was 0.870 with an average case-level FP of 1.34±1.92 (95% CI: 1.02-1.67). The sensitivity was >0.969 for the BMs >0.1 cm3, but dropped to 0.755 for the BMs < 0.1 cm3 (Table 1). The average DSC and HD95 for all detected BMs were 0.786 and 1.35mm. The worse performance for BMs > 20 cm3 was caused by a case with 83 cm3 GTV and artifacts in the MRI volume.

CONCLUSION

We achieved excellent detection sensitivity and segmentation accuracy for BMs > 0.1 cm3, and promising performance for small BMs (<0.1cm3) with a controlled FP rate using a large multi-institutional dataset. Clinical utility for assisting early detection and SRS planning will be investigated. Table 1: Per-lesion detection and segmentation performance stratified by individual BM size. N is the number of BMs in each category.

Loss of miR-637 promotes cancer cell stemness via WASH/IL-8 pathway and serves as a novel prognostic marker in esophageal squamous cell carcinoma

BACKGROUND

Esophageal carcinoma is the highly lethal cancer in the world, predominantly in some areas of East Asia. We previously reported that overexpression of cytoskeleton regulator Wiskott-Aldrich syndrome protein and SCAR Homolog (WASH) associates with poor prognosis of patients with esophageal squamous cell carcinoma (ESCC). However, the molecular mechanism and clinical significance involved in WASH overexpression have not been fully elucidated.

METHODS

Bioinformatics analysis and luciferase reporter assay were used to predict and validate miR-637 as a regulator of WASH in ESCC cell lines. qRT-PCR, Western blotting and ELISA assays were performed to examine RNA expression and protein levels, respectively. Next, the biological functions of miR-637 were explored by tumor sphere formation assay in vitro and nude mouse tumor xenograft in vivo. Finally, we evaluated the association of miR-637 levels with clinical features in ESCC patients.

RESULTS

We identified miR-637 as a WASH-targeting miRNA. miR-637 mimic strongly attenuated the downstream IL-8 production and tumor sphere formation in esophageal cancer cells, whereas miR-637 inhibitor displayed an opposite effect. IL-8 could facilitate stem-like properties and partially rescue the phenotypes induced by miR-637 mimic. Furthermore, miR-637 inhibitor dramatically promoted IL-8 expression and cancer stemness properties in a WASH-dependent manner. Ectopic expression of miR-637 also inhibited tumor growth in a mouse model. Clinically, low expression of miR-637 was observed in tumor tissues and the low expression levels of miR-637 were correlated with poor survival of ESCC patients. In particular, plasma miR-637 could be used as a noninvasive biomarker for ESCC patients.

CONCLUSIONS

These results implicate the potential application of miR-637 for diagnosis and prognosis of esophageal cancer.

Loss of Raptor induces Sertoli cells into an undifferentiated state in mice

In mammals, testis development is triggered by the expression of the sex-determining Y-chromosome gene SRY to commit the Sertoli cell (SC) fate at gonadal sex determination in the fetus. Several genes have been identified to be required to promote the testis pathway following SRY activation (i.e., SRY box 9 (SOX9)) in an embryo; however, it largely remains unknown about the genes and the mechanisms involved in stabilizing the testis pathway after birth and throughout adulthood. Herein, we report postnatal males with SC-specific deletion of Raptor demonstrated the absence of SC unique identity and adversely acquired granulosa cell-like characteristics, along with loss of tubular architecture and scattered distribution of SCs and germ cells. Subsequent genome-wide analysis by RNA sequencing revealed a profound decrease in the transcripts of testis genes (i.e., Sox9, Sox8, and anti-Mullerian hormone (Amh)) and, conversely, an increase in ovary genes (i.e., LIM/Homeobox gene 9 (Lhx9), Forkhead box L2 (Foxl2) and Follistatin (Fst)); these changes were further confirmed by immunofluorescence and quantitative reverse-transcription polymerase chain reaction. Importantly, co-immunofluorescence demonstrated that Raptor deficiency induced SCs dedifferentiation into a progenitor state; the Raptor-mutant gonads showed some ovarian somatic cell features, accompanied by enhanced female steroidogenesis and elevated estrogen levels, yet the zona pellucida 3 (ZP3)-positive terminally feminized oocytes were not observed. In vitro experiments with primary SCs suggested that Raptor is likely involved in the fibroblast growth factor 9 (FGF9)-induced formation of cell junctions among SCs. Our results established that Raptor is required to maintain SC identity, stabilize the male pathway, and promote testis development.

High mobility group protein B1 decreases surface localization of PD-1 to augment T-cell activation

High-mobility group protein B1 (HMGB1) is a danger signaling molecule that has been found to trigger an effective antitumor immune response. However, the mechanisms underlying its antitumor effects are not fully understood. Here, we found that HMGB1 release induced by chemotherapy in patients with non-small cell lung cancer (NSCLC) was negatively correlated with PD-1 expression on CD8+ T cells. In vitro analysis indicated that treatment with HMGB1 led to a significant decrease in the level of expression of PD-1 on CD8+ T cells. Further analysis demonstrated that HMGB1 reduced PD-1 expression by inducing dynamin-mediated internalization of the protein, leading to early endocytosis in the cytoplasm, and subsequently degradation in the lysosomes. In a xenograft model, HER2-targeted chimeric-antigen receptor (CAR) T cells had enhanced function in the presence of HMGB1. These data identify a role for HMGB1 as a negative regulator of PD-1 signaling in lung cancer cells and the observed antitumor effect of HMGB1 on chimeric-antigen receptor (CAR) T cells may provide a theoretical foundation for a new immunotherapy combination.

Long Noncoding RNA lncNDEPD1 Regulates PD-1 Expression via miR-3619-5p in CD8+ T Cells

Therapies targeting programmed cell death protein 1 (PD-1) have gained great success in patients with multiple types of cancer. The regulatory mechanisms underlying PD-1 expression have been extensively explored. However, the impact of long noncoding RNAs on PD-1 expression remains elusive. In this study, we identified the Notch1/lncNDEPD1 axis, which plays a critical role in PD-1 expression in human CD8⁺ T cells. RNA sequencing and quantitative reverse transcription PCR data showed that lncNDEPD1 was upregulated in activated T cells, especially in PD-1^high subsets. Fluorescence in situ hybridization demonstrated that lncNDEPD1 was localized in the cytoplasm. A mechanistic study showed that lncNDEPD1 could bind with miR-3619-5p and PDCD1 mRNA to prevent PDCD1 mRNA degradation and then upregulate PD-1 expression. A chromatin immunoprecipitation assay showed that Notch1 directly binds to the promoter of lncNDEPD1 instead of PDCD1 Furthermore, chimeric Ag receptor T cells expressing lncNDEPD1-specific short hairpin RNAs were generated. Chimeric Ag receptor T cells with decreased lncNDEPD1 expression showed enhanced tumoricidal effects when PD-L1 was present. Our work uncovered a new regulatory mechanism of PD-1 expression and thus provided a potential target to decrease PD-1 without affecting T cell function.

[Analysis of the effect of preventive intervention on occupational exposure of nurses after tumor particle implantation in thoracic surgery]

Objective: To study the effect of preventive intervention on occupational exposure of nurses after tumor particle implantation in thoracic surgery. Methods: In March 2020, 99 nurses who were engaged in postoperative nursing of tumor particle implantation in thoracic surgery department of our hospital from February 2019 to February 2020 were selected as the research objects. According to different preventive interventions, they were divided into observation group (51 cases) and control group (48 cases) . The observation group received preventive intervention, while the control group received routine intervention. The differences of radiation dose, psychological state and abnormal rate of important organ function between the two groups were analyzed. Results: Compared with the control group, the radiation dose of the observation group was significantly less, and the scores of anxiety and depression were lower after the intervention, the difference were statistically significant (P<0.05) . There was no significant difference of the abnormal rate of important organ function between the two groups (P>0.05) . Conclusion: Preventive intervention can reduce the risk of occupational exposure and improve the psychological status of nurses after tumor particle implantation in thoracic surgery.

LINC00641 induces the malignant progression of colorectal carcinoma through the miRNA-424-5p/PLSCR4 feedback loop

OBJECTIVE

To illustrate the role of LINC00641 in inducing the malignant progression of colorectal cancer (CRC) through the miRNA-424-5p/PLSCR4 feedback loop.

PATIENTS AND METHODS

LINC00641 levels in paired CRC and non-tumoral tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Its prognostic potential in CRC was assessed by Kaplan-Meier method. Changes in proliferative and migratory abilities of HCT116 and SW620 cells transfected with si-LINC00641 were evaluated by 5-Ethynyl-2'- deoxyuridine (EdU), cell counting kit-8 (CCK-8) and transwell assay. The feedback loop LINC00641/miRNA-424-5p/PLSCR4 was identified through Dual-Luciferase reporter assay and its involvement in CRC progression was finally explored by rescue experiments.

RESULTS

LINC00641 was upregulated in CRC tissues, which was an unfavorable factor to the overall survival of CRC. Proliferative and migratory abilities of HCT116 and SW620 cells were inhibited by knockdown of LINC00641. LINC00641 could competitively bind miRNA-424-5p, thereby abolishing its inhibitory effect on PLSCR4 expression. Knockdown of PLSCR4 could inhibit proliferative and migratory abilities of HCT116 and SW620 cells.

CONCLUSIONS

LINC00641 stimulates proliferative and migratory abilities of CRC through the miRNA-424-5p/PLSCR4 feedback loop.

IL-33/ST2 as a potential target for tumor immunotherapy

IL-33, a member of the IL-1 family, was initially reported to be expressed constitutively in the nucleus of tissue-lining and structural cells. However, upon tissue damage or injury, IL-33 can be released quickly to bind with its cognate receptor ST2 in response to wound healing and inflammation and act as a DAMP. As a key regulator of Th2 responses, IL-33/ST2 signal is primarily associated with immunity and immune-related disorders. In recent years, IL-33/ST2 signaling pathway has been reported to promote the development of cancer and remodel the tumor microenvironment by expanding immune suppressive cells such as myeloid-derived suppressor cells or regulatory T cells. However, its role remains controversial in some tumor settings. IL-33 could also promote effective infiltration of immune cells such as CD8⁺ T and NK cells, which act as antitumor. These dual effects may limit the clinical application to target this cytokine axis. Therefore, more comprehensive exploration and deeper understanding of IL-33 are required. In this review, we summarized the IL-33/ST2 axis versatile roles in the tumor microenvironment with a focus on the IL-33-target immune cells and downstream signaling pathways. We also discuss how the IL-33/ST2 axis could be used as a potential therapeutic target for cancer immunotherapy.

Targeting CD276 by CAR-T cells induces regression of esophagus squamous cell carcinoma in xenograft mouse models

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CD276 is homogeneously overexpressed in ESCC and EAC.

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CD276-directed CAR-T cells demonstrate remarkable anti-tumor effects in ESCC PDX model.

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CD276-targeting CAR-T cells are successfully generated with patients T cells and show potent cytotoxicity against autologous tumor cells.

Esophageal cancer, including esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), has a poor prognosis and limited therapeutic options. Chimeric antigen receptor (CAR)-T cells represent a potential ESCC treatment. In this study, we examined CD276 expression in healthy and esophageal tumor tissues and explored the tumoricidal potential of CD276-targeting CAR-T cells in ESCC. CD276 was strongly and homogenously expressed in ESCC and EAC tumor lesions but mildly in healthy tissues, representing a good target for CAR-T cell therapy. We generated CD276-directed CAR-T cells with a humanized antigen-recognizing domain and CD28 or 4–1BB co-stimulation. CD276-specific CAR-T cells efficiently killed ESCC tumor cells in an antigen-dependent manner both in vitro and in vivo. In patient-derived xenograft models, CAR-T cells induced tumor regression and extended mouse survival. In addition, CAR-T cells generated from patient T cells demonstrated potent cytotoxicity against autologous tumor cells. Our study indicates that CD276 is an attractive target for ESCC therapy, and CD276-targeting CAR-T cells are worth testing in ESCC clinical trials.

[HIV infection and related factors among men who have sex with men aged 50 and above]

Objectives: To explore the HIV prevalence and related factors among MSM aged 50 and above and provide evidence on the prevention and control of HIV/AIDS. Methods: Based on an MSM social application software Blued 7.1.6, we recruited participants through online convenience sampling to collect demographic variables, behavioral and self-reported HIV infection status, etc. Univariate χ2 test and multivariate logistic regression were used to analyze the related factors of self-reported HIV infection. Results: Self-reported HIV infection rate was 17.6%(126/714) among the participants. In multivariable analysis, participants who got divorced or widowed had a 2.07(95%CI: 1.34-3.21) times greater risk of self-reported HIV-positive than those who were married. Participants unaware of HIV-related knowledge showed a 1.92(95%CI:1.21-3.04) times greater risk of self-reported HIV-positive than those with better HIV-related knowledge. Participants who have ever been diagnosed with sexually transmitted disease (STD) showed a 3.17(95%CI:2.09-4.83) times greater risk of self-reported HIV-positive than those without STD infection history. Conclusion: Our findings indicated that the self-reported HIV infection rate was high among MSM aged 50 and above. Being divorced or widowed, being unaware of HIV-related knowledge and STD infection history was proved related with self-reported HIV infection.

[Role of Orai 1-mediated store-operated calcium entry in the immune function of CD4+ T cells in septic mice]

Objective: To investigate the role of Orai1-mediated store-operated calcium entry in the immune damage of CD4⁺ T cells in septic mice. Methods: Sepsis mouse model was established by cecal ligation and puncture(CLP). Balb/c mice of clean grade were sacrificed 1, 3, and 5 days after operation. Spleen samples were harvested at given intervals. Splenic CD4⁺ T cells were selected by immunomagnetic beads and the expression of Orai1 protein was detected by western blotting, the storage operated calcium entry (SOCE) was detected by flow cytometry, the apoptosis of CD4⁺ T cells was detected by flow cytometry, the proliferation of CD4⁺ T cells was detected by CCK-8, and the IFN-γ and IL-4 were detected by enzyme-linked immunosorbent assay (ELISA). Then the expression of Orai1 protein was regulated to further detect the SOCE and immune function of splenic CD4⁺ T cells in mice. The experiment was divided into 4 groups, sham group, CLP3 group, Orai1 down group (Orai1-down group) and Orai1 up regulation group (Orai1-up group). Results: The relative expression of Orai1 protein in splenic CD4⁺ T cells in sham group was 1.03±0.16. Compared with sham group, Orai1 protein levels in CLP Group were all significantly lower (F=19.64, P=0.000 5). The increased value of splenic CD4⁺ T cells fluorescence intensity in sham group was 494±41. Compared with sham group, the levels of SOCE in CLP Group were all lower (F=30.01, P=0.001). The ratio of early and late apoptosis of CD4⁺ T cells in sham group was 8.7%±1.5%. Compared with sham group, the early and late apoptosis rates of CLP Group were significantly higher (F=32.29, P=0.000 1). The OD of sham group was 0.81±0.10 at 450 nm. Compared with sham group, the proliferation ability of splenic CD4⁺ T cells in CLP Group were significantly decreased (F=7.26, P=0.001 8). Compared with sham group, the secretion of IFN-γ and IL-4 by CD4⁺ T cells and the ratio of IFN-γ/IL-4 in CLP Group were all significantly decreased (F=19.690, 6.183, 11.230, all P<0.05). Compared with CLP3 group, the increased value of fluorescence intensity of CD4⁺ T cells was significantly decreased, the early and late apoptosis ratio of CD4⁺ T cells was significantly increased, the OD450 nm value of CD4⁺ T cells was decreased, the multiplication capacity of splenic CD4⁺ T cells were decreased, the level of IFN-γ and IL-4 secreted by T cells were decreased, and the value of IFN-γ/IL-4 in orai1-down group was decreased (t=4.819, 7.952, 2.988, 28.760, 3.140, 7.670, all P<0.05). However, Orail-up group showed the opposite trend. Conclusion: Orai1-mediated store-operated calcium entry can alleviate the immune dysfunction of CD4⁺ T cells in septic mice.

Regulatory T cells promote glioma cell stemness through TGF-β-NF-κB-IL6-STAT3 signaling

Glioma stem cells (GSCs) contribute to the malignant growth of glioma, but little is known about the interaction between GSCs and tumor microenvironment. Here, we found that intense infiltration of regulatory T cells (Tregs) facilitated the qualities of GSCs through TGF-β secretion that helped coordinately tumor growth. Mechanistic investigations indicated that TGF-β acted on cancer cells to induce the core cancer stem cell-related genes CD133, SOX2, NESTIN, MUSASHI1 and ALDH1A expression and spheres formation via NF-κB–IL6–STAT3 signaling pathway, resulting in the increased cancer stemness and tumorigenic potential. Furthermore, Tregs promoted glioma tumor growth, and this effect could be abrogated with blockade of IL6 receptor by tocilizumab which also demonstrated certain level of therapeutic efficacy in xenograft model. Additionally, expression levels of CD133, IL6 and TGF-β were found to serve as prognosis markers of glioma patients. Collectively, our findings reveal a new immune-associated mechanism underlying Tregs-induced GSCs. Moreover, efforts to target this network may be an effective strategy for treating glioma.

Eomes promotes esophageal carcinoma progression by recruiting Treg cells through the CCL20-CCR6 pathway

Eomesodermin (Eomes) is a T‐box transcription factor that drives the differentiation and function of cytotoxic lymphocytes. However, the underlying function and mechanism of Eomes in tumor cells remains elusive. Here, we studied the role of Eomes in human esophageal squamous cell carcinoma (ESCC). Using 2 human ESCC cell lines, we found that Eomes knockdown reduced esophageal cancer cell proliferation and that the esophageal cancer cell cycle was blocked in the G2/M phase. Mechanistically, we identified CCL20 as the main downstream target of Eomes. Furthermore, we found that CCL20 could chemoregulate regulatory T cells (Tregs) through their specific receptor CCR6, then promoting the proliferation of esophageal cancer cells. Eomes knockdown also delayed the growth of human ESCC xenografts in BALB/c nude mice. Importantly, in 133 human ESCC tissues, high Eomes levels were associated with poor clinical prognosis. Overall, our findings suggested that the Eomes‐CCL20‐CCR6 pathway plays a vital role in human ESCC progress. Therefore, targeting this pathway may represent a promising strategy for controlling human ESCC.

Immunosenescence: a key player in cancer development

Immunosenescence is a process of immune dysfunction that occurs with age and includes remodeling of lymphoid organs, leading to changes in the immune function of the elderly, which is closely related to the development of infections, autoimmune diseases, and malignant tumors. T cell-output decline is an important feature of immunosenescence as well as the production of senescence-associated secretory phenotype, increased glycolysis, and reactive oxygen species. Senescent T cells exhibit abnormal phenotypes, including downregulation of CD27, CD28, and upregulation of CD57, killer cell lectin-like receptor subfamily G, Tim-3, Tight, and cytotoxic T-lymphocyte-associated protein 4, which are tightly related to malignant tumors. The role of immunosenescence in tumors is sophisticated: the many factors involved include cAMP, glucose competition, and oncogenic stress in the tumor microenvironment, which can induce the senescence of T cells, macrophages, natural killer cells, and dendritic cells. Accordingly, these senescent immune cells could also affect tumor progression. In addition, the effect of immunosenescence on the response to immune checkpoint blocking antibody therapy so far is ambiguous due to the low participation of elderly cancer patients in clinical trials. Furthermore, many other senescence-related interventions could be possible with genetic and pharmacological methods, including mTOR inhibition, interleukin-7 recombination, and NAD⁺ activation. Overall, this review aims to highlight the characteristics of immunosenescence and its impact on malignant tumors and immunotherapy, especially the future directions of tumor treatment through senescence-focused strategies.

Th17 cells inhibit CD8+ T cell migration by systematically downregulating CXCR3 expression via IL-17A/STAT3 in advanced-stage colorectal cancer patients

Background

CD8⁺ T cell trafficking to the tumor site is essential for effective colorectal cancer (CRC) immunotherapy. However, the mechanism underlying CD8⁺ T cell infiltration in colorectal tumor tissues is not fully understood. In the present study, we investigated CD8⁺ T cell infiltration in CRC tissues and the role of chemokine–chemokine receptor signaling in regulation of T cell recruitment.

Methods

We screened chemokines and cytokines in healthy donor and CRC tissues from early- and advanced-stage patients using multiplex assays and PCR screening. We also utilized transcription factor activation profiling arrays and established a xenograft mouse model.

Results

Compared with tumor tissues of early-stage CRC patients, CD8⁺ T cell density was lower in advanced-stage tumor tissues. PCR screening showed that CXCL10 levels were significantly increased in advanced-stage tumor tissues. CXCR3 (the receptor of CXCL10) expression on CD8⁺ T cells was lower in the peripheral blood of advanced-stage patients. The migratory ability of CD8⁺ T cells to CXCL10 depended on CXCR3 expression. Multiplex arrays showed that IL-17A was increased in advanced-stage patient sera, which markedly downregulated CXCR3 expression via activating STAT3 signaling and reduced CD8⁺ T cell migration. Similar results were found after CD8⁺ T cells were treated with Th17 cell supernatant. Adding anti-IL-17A or the STAT3 inhibitor, Stattic, rescued these effects in vitro and in vivo. Moreover, survival analysis showed that patients with low CD8 and CXCR3 expression and high IL-17A levels had significantly worse prognosis.

Conclusions

CD8⁺ T cell infiltration in advanced-stage tumor was systematically inhibited by Th17 cells via IL-17A/STAT3/CXCR3 axis. Our findings indicate that the T cell infiltration in the tumor microenvironment may be improved by inhibiting STAT3 signaling.

Interleukin-33-nuclear factor-κB-CCL2 signaling pathway promotes progression of esophageal squamous cell carcinoma by directing regulatory T cells

Esophageal cancer is currently one of the most fatal cancers. However, there is no effective treatment. Increasing evidence suggests that interleukin (IL)‐33 has a significant role in tumor progression and metastasis. Currently, the underlying cellular and molecular mechanism of IL‐33 in promoting esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we investigated whether IL‐33 could induce the epithelial‐mesenchymal transition (EMT) in ESCC. Interleukin‐33 expression was examined in ESCC and corresponding adjacent normal tissues by immunohistochemistry and quantitative real‐time PCR experiments. Elevated IL‐33 levels were observed in ESCC tissues. Further in vitro experiments were undertaken to elucidate the effect of IL‐33 on migration and invasion in KYSE‐450 and Eca‐109 esophageal cancer cells. Knockdown of IL‐33 decreased the metastasis and invasion capacity in esophageal cancer cells, whereas IL‐33 overexpression showed the opposite effect. We then screened CCL2 which is a downstream molecule of IL‐33, and proved that IL‐33 could promote tumor development and metastasis by recruiting regulatory T cells (Tregs) through CCL2, and IL‐33 regulated the expression of CCL2 through transforming growth factor‐β in Treg cells. Knockdown of IL‐33 decreased the development of human ESCC xenografts in BALB/c nude mice. Collectively, we found that the IL‐33/nuclear factor‐κB/CCL2 pathway played an essential role in human ESCC progress. Hence, IL‐33 should be considered as an effective therapy target for ESCC.

Systematic construction and validation of an immune prognostic model for lung adenocarcinoma

Lung adenocarcinoma (LUAD), the most common non‐small‐cell lung cancer, is characterized by a dense lymphocytic infiltrate, which indicates that the immune system plays an active role in the development and growth of this cancer. However, no investigations to date have proposed robust models for predicting survival outcome for patients with LUAD in terms of tumour immunology. A total of 761 LUAD patients were included in this study, in which the database of The Cancer Genome Atlas (TCGA) was utilized for discovery, and the Gene Expression Omnibus (GEO) database was utilized for validation. Bioinformatics analysis and R language tools were utilized to construct an immune prognostic model and annotate biological functions. Lung adenocarcinoma showed a weakened immune phenotype compared with adjacent normal tissues. Immune‐related gene sets were profiled, an immune prognostic model based on 2 immune genes (ANLN and F2) was developed with the TCGA database to distinguish cases as having a low or high risk of unfavourable prognosis, and the model was verified with the GEO database. The model was prognostically significant in stratified cohorts, including stage I‐II, stage III‐IV and epidermal growth factor receptor (EGFR) mutant subsets, and was considered to be an independent prognostic factor for LUAD. Furthermore, the low‐ and high‐risk groups showed marked differences in tumour‐infiltrating leucocytes, tumour mutation burden, aneuploidy and PD‐L1 expression. In conclusion, an immune prognostic model was proposed for LUAD that is capable of independently identifying patients at high risk for poor survival, suggesting a relationship between local immune status and prognosis.

[Baicalin regulates STIM1-mediated calcium overload and reduces apoptosis of cardiomyocytes induced by lipopolysaccharide]

Objective: To investigate the protective effect of Baicalin on apoptosis induced by lipopolysaccharide in H9C2 cardiomyocytes and its possible mechanism. Methods: In order to establish apoptosis model of H9C2 cardiomyocytes, H9C2 cardiomyocytes were cultured and divided into four groups: the control group; the baicalin group was treated with baicalin at the final concentration of 10μmol/L for 12 hours; the LPS group was stimulated with LPS at the final concentration of 1 μg/ml for 6 hours; The LPS+baicalin group was stimulated with LPS at the final concentration of 1 μg/ml for 6 hours within treated with baicalin at the final concentration of 10μmol/L for 12 hours. Collecting cell samples, CCK-8 (The Cell Counting Kit-8) was used to detect cell activity, and Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) was used to detect the expression levels of apoptosis. Laser Scanning Confocal Microscopy was used to detect the expression levels of store-operated calcium entry in H9C2 cardiomyocytes. Western blot was used to detect the protein expression levels of STIM1, cleaved-caspase3, Bax and Bcl-2. Fluorogenic quantitative PCR was used to detect the mRNA expression level of STIM1. Results: Compared with the control group, LPS-induced H9C2 cardiomyocyte survival rate decreased (P<0.05), the expression level of apoptosis increased (P<0.05), the internal flow of calcium increased (P<0.05), the expression levels of cleaved-caspase3, Bax protein levels increased (P<0.05), Bcl-2 protein level decreased (P<0.05), the expression of STIM1 mRNA and protein level increased (P<0.05). Compared with LPS group, the survival rate of H9C2 cardiomyocytes in baicalin intervention group increased (P<0.05), the expression level of apoptosis decreased (P<0.05), the internal flow of calcium decreased (P<0.05), the expression levels of cleaved-caspase3, Bax protein decreased (P<0.05), and the level of Bcl-2 protein increased (P<0.05), the expression of STIM1 mRNA and protein level decreased (P<0.05). Conclusion: Baicalin may alleviate LPS-induced cardiomyocyte apoptosis by alleviating calcium overload, and improve cell survival.

TNF-α-induced Tim-3 expression marks the dysfunction of infiltrating natural killer cells in human esophageal cancer

BACKGROUND

Impairment of natural killer (NK) cell activity is an important mechanism of tumor immunoevasion. T cell immunoglobulin domain and mucin domain-3 (Tim-3) is an activation-induced inhibitory molecule, inducing effector lymphocyte exhaustion in chronic viral infection and cancers. However, its function in NK cells in human esophageal cancer remains unclear.

METHODS

We prospectively collected peripheral blood and tumor samples from 53 patients with esophageal cancer. Peripheral and tumor-infiltrating NK cells were analyzed for Tim-3, Annexin V, CD69, CD107a and IFN-γ expression by flow cytometry. Quantitative real-time PCR was used to test relative mRNA expression of IFN-γ, granzyme B, perforin and NKG2D in sorted Tim-3⁺ NK cells and Tim-3^- NK cells, respectively. NK cells isolated from healthy donors were treated with recombinant TNF-α to induce Tim-3 expression. Tim-3 and TNF-α mRNA levels in tumor tissues were measured in both humans and mice. Finally, associations between NK cell frequencies with pathological parameters were investigated.

RESULTS

We observed up-regulation of Tim-3 expression on NK cells from esophageal cancer patients, especially at the tumor site. Furthermore, tumor-infiltrating NK cells with high Tim-3 expression exhibited a phenotype with enhanced dysfunction. In vitro, Tim-3 expression on NK cells isolated from blood of healthy donors can be induced by recombinant TNF-α via NF-κB pathway. In both animal models and patients, the Tim-3 level was positively correlated with TNF-α expression in esophageal cancer tissues. Finally, higher Tim-3 level on tumor-infiltrating NK cells is correlated with tumor invasion, nodal status and poor stage in patients with esophageal cancer.

CONCLUSIONS

Taken together, Tim-3 may play a crucial role to induce NK cell dysfunction in tumor microenvironment and could serve as a potential biomarker for prognosis of esophageal cancer.

An Adiponectin Receptor Agonist Reduces Type 2 Diabetic Periodontitis

Periodontitis is twice as prevalent in diabetics as in nondiabetics, and type 2 diabetes (T2D)-associated periodontitis is severe in many cases due to the altered and aberrant functions of bone cells in hyperglycemic conditions. Therefore, developing an effective method to halt the disease process, as well as restore and regenerate lost alveolar bone to reserve the natural teeth in diabetics, is critically important. In the current study, we applied a newly discovered adiponectin receptor agonist AdipoRon (APR) in experimental periodontitis in diabetic animal models and demonstrated the underlying molecular mechanisms. We found that when APR systemically quenched the blood sugar level in diet-induced obesity (DIO) diabetic mice, it reduced osteoclast numbers and alveolar bone loss significantly due to APR's inhibition on osteoclast differentiation shown in our in vitro studies. APR also decreased the production of proinflammatory molecules CC chemokine ligand 2 and interleukin 6 in diseased gingival tissues. On the other hand, APR promoted alveolar bone regeneration through enhancing osteogenic differentiation and decreasing stromal cell-derived factor 1 in the bone marrow that facilitates stem cell migration. Same results were achieved by APR treatment of periodontitis induced in adiponectin (APN) knockout mice, indicating the ability of APR to activate the endogenous APN receptors to exert osteoanabolic effects. In summary, our study supports the notion that APR could be used as an effective multipronged approach to target T2D-associated periodontitis.

Integrated analysis of dysregulated long non-coding RNAs/microRNAs/mRNAs in metastasis of lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD), largely remains a primary cause of cancer-related death worldwide. The molecular mechanisms in LUAD metastasis have not been completely uncovered.

METHODS

In this study, we identified differentially expressed genes (DEGs), miRNAs (DEMs) and lncRNAs (DELs) underlying metastasis of LUAD from The Cancer Genome Atlas database. Intersection mRNAs were used to perform gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and co-expression network analysis. In addition, survival analyses of intersection mRNAs were conducted. Finally, intersection mRNAs, miRNAs and lncRNAs were subjected to construct miRNA-mRNA-lncRNA network.

RESULTS

A total of 1015 DEGs, 54 DEMs and 22 DELs were identified in LUAD metastasis and non-metastasis samples. GO and KEGG pathway analysis had proven that the functions of intersection mRNAs were closely related with many important processes in cancer pathogenesis. Among the co-expression interactions network, 22 genes in the co-expression network were over the degree 20. These genes imply that they have connections with many other gene nodes. In addition, 14 target genes (ARHGAP11A, ASPM, HELLS, PRC1, TMPO, ARHGAP30, CD52, IL16, IRF8, P2RY13, PRKCB, PTPRC, SASH3 and TRAF3IP3) were found to be associated with survival in patients with LUAD significantly (log-rank P < 0.05). Two lncRNAs (LOC96610 and ADAM6) acting as ceRNAs were identified based on the miRNA-mRNA-lncRNA network.

CONCLUSIONS

Taken together, the results may provide a novel perspective to develop a multiple gene diagnostic tool for LUAD prognosis, which might also provide potential biomarkers or therapeutic targets for LUAD.

Interleukin 8 (CXCL8)-CXC chemokine receptor 2 (CXCR2) axis contributes to MiR-4437-associated recruitment of granulocytes and natural killer cells in ischemic stroke

Granulocytes and natural killer (NK) cells have been linked to brain injury in ischemic stroke. However, their recruitment from peripheral leucocytes in stroke patients is not well understood. Here, the expression of the interleukin 8 (CXCL8) in plasma, and CXC chemokine receptor 2 (CXCR2) in peripheral leucocytes of patients with ischemic stroke were evaluated. Based on the results, CXCR2 expression positively correlated with granulocytes and NK cells, which were in turn attracted by CXCL8. The results also indicated that CXCR2 was a direct target of microRNA (miR)-4437, a negative regulator of CXCR2, which was downregulated in peripheral leucocytes from patients with ischemic stroke. Furthermore, serum CXCL8 levels were associated with the infarct volume and functional outcomes in patients with ischemic stroke. The results of the receiver operating characteristic curve analysis with an optimal cut-off value of 34 pg/mL indicated serum CXCL8 levels could be a prognostic indicator for ischemic stroke. In conclusion, these data highlighted the involvement of the CXCL8-CXCR2 chemotactic axis in the recruitment of granulocytes and NK cells in ischemic stroke. Furthermore, miR-4437 was suggested as a novel target for treating ischemic stroke, while the serum CXCL8 level could be a prognostic factor for ischemic stroke.

Maelstrom Directs Myeloid-Derived Suppressor Cells to Promote Esophageal Squamous Cell Carcinoma Progression via Activation of the Akt1/RelA/IL8 Signaling Pathway

Maelstrom (MAEL) is a novel cancer/testis-associated gene, which is not only expressed in the male testicular germ cells among human normal tissues, but is also aberrantly expressed in various cancer tissues. In our study, MAEL was characterized as a tumor-promoting gene and was significantly associated with esophageal squamous cell carcinoma (ESCC) recurrence and unfavorable prognosis. Kaplan-Meier analysis showed that patients with high MAEL expression had a shorter survival time. Functional experiments showed that MAEL promoted tumor cell growth and inhibited cell apoptosis. These results prompted us to investigate the factors affecting the tumorigenicity of MAEL Further experimentation demonstrated that MAEL enhanced the expression of phosphorylated Akt1, with subsequent phosphorylation of nuclear factor kappa B (NF-κB) subunit RelA in tumor cells, and chemoattracted myeloid-derived suppressor cells (MDSCs) by upregulating interleukin-8 (IL8) to accelerate tumor progression in the tumor microenvironment. We also found that TGFβ secreted by MDSCs could upregulate MAEL by inducing Smad2/Smad3 phosphorylation. In summary, this study revealed a mechanism by which MAEL could upregulate IL8 through Akt1/RelA to direct MDSCs homing into the tumor, suggesting that MAEL could be an attractive therapeutic target and a prognostic marker against ESCC. Cancer Immunol Res; 6(10); 1246-59. ©2018 AACR.

Alkannin Inhibited Hepatic Inflammation in Diabetic Db/Db Mice

Background/Aims: The current study was designed to investigate the protective role of alkannin (ALK) on liver injury in diabetic C57BL/KsJ-db/db mice and explore its potential mechanisms. Methods: An oral glucose tolerance test (OGTT) was performed. The levels of insulin, alanine aminotransferase (ALT), aspartate aminotransaminase (AST), total cholesterol (TC) and triglyceride (TG) were determined by commercial kits. The pro-inflammatory cytokines interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α were determined by ELISA. The levels of the ROCK/NF-κB pathway were determined by Western blotting. Results: The contents of pro-inflammatory cytokines interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α were inhibited by ALK, metformin or fasudil in diabetic db/db mice. Further, Western blotting analysis showed that the expression of Rho, ROCK1, ROCK2, p-NF-κBp65, and p-IκBα was significantly reversed by ALK treatment. In human hepatic HepG2 cells, the hepatoprotective effects of ALK were further characterized. With response to palmitic acid-challenge, increased amounts of insulin, ALT, AST, TG, and TC were observed, whereas ALK pretreatment significantly inhibited their leakage in HepG2 cells without appreciable cytotoxic effects. The inflammation condition was recovered with ALK treatment as shown by changes of IL-1β, IL-6 and TNF-α. Further, Western blotting analysis also suggested that ALK improves hepatic inflammation in a Rho-kinase pathway. Conclusion: The present study successfully investigated the role of Rho-kinase signalling in diabetic liver injury. ALK exhibited hepatoprotective effects in diabetic db/db mice, and it might act through improving hepatic inflammation through the Rho-kinase pathway.

Metformin blocks myeloid-derived suppressor cell accumulation through AMPK-DACH1-CXCL1 axis

Purpose: Tumor development has been closely linked to tumor microenvironment, particularly in terms of myeloid-derived suppressive cells (MDSCs), a heterogeneous population of immature myeloid cells that protect tumors from elimination by immune cells. Approaches aimed at blocking MDSC accumulation could improve cancer clinical outcome. Experimental Design: We investigated that metformin suppressed MDSC migration to inhibit cancer progression. Primary tumor tissues were incubated with metformin, and proinflammatory chemokine production was measured. To study MDSC chemotaxis in vivo, BALB/C nude mice were injected subcutaneously with TE7 cells and treated with metformin. Migration of adoptively transferred MDSCs was analyzed using flow cytometry and immunohistochemistry. Results: The frequency of tumor-infiltrated polymorphonuclear (PMN)-MDSCs was increased compared to their circulating counterparts. There was a significant correlation between PMN-MDSCs accumulation in tumors and ESCC prognosis. Moreover, PMN-MDSCs displayed immunosuppressive activity in vitro. Treatment with metformin reduced MDSC migration in patients. Metformin inhibited CXCL1 secretion in ESCC cells and tumor xenografts by enhancing AMPK phosphorylation and inducing DACH1 expression, leading to NF-κB inhibition and reducing MDSC migration. Knockdown of AMPK and DACH1 expression blocked the effect of metformin on MDSC chemotaxis. Conclusions: A novel anti-tumor effect of metformin, which is mediated by reducing PMN-MDSC accumulation in the tumor microenvironment via AMPK/DACH1/CXCL1 axis.

IL6 derived from cancer-associated fibroblasts promotes chemoresistance via CXCR7 in esophageal squamous cell carcinoma

Various factors and cellular components in the tumor microenvironment are key drivers associated with drug resistance in many cancers. Here, we analyzed the factors and molecular mechanisms involved in chemoresistance in patients with esophageal squamous cell carcinoma (ESCC). We found that interleukin 6 (IL6) derived mainly from cancer-associated fibroblasts played the most important role in chemoresistance by upregulating C-X-C motif chemokine receptor 7 (CXCR7) expression through signal transducer and activator of transcription 3/nuclear factor-κB pathway. CXCR7 knockdown resulted in the inhibition of IL6-induced proliferation and chemoresistance. In addition, CXCR7 silencing significantly decreased gene expression associated with stemness, chemoresistance and epithelial-mesenchymal transition and suppressed the proliferation ability of ESCC cells in three-dimensional culture systems and angiogenesis assay. In clinical samples, ESCC patients with high expression of CXCR7 and IL6 presented a significantly worse overall survival and progression-free survival upon receiving cisplatin after operation. These results suggest that the IL6-CXCR7 axis may provide a promising target for the treatment of ESCC.

Cortical Potential Imaging of Brain Electrical Activity by Means of Parametric Projection Filter

Objectives: The objective of this study was to explore suitable spatial filters for inverse estimation of cortical potentials from the scalp electroencephalogram. The effect of incorporating noise covariance into inverse procedures was examined by computer simulations and tested in human experiment.

Methods: The parametric projection filter, which allows inverse estimation with the presence of information on the noise, was applied to an inhomogeneous three-concentric-sphere model under various noise conditions in order to estimate the cortical potentials from the scalp potentials. The method for determining the optimum regularization parameter, which can be applied for parametric inverse techniques, is also discussed.

Results: Human visual evoked potential experiment was carried out to examine the performance of the proposed restoration method. The parametric projection filter gave more localized inverse solution of cortical potential distribution than the truncated SVD and Tikhonov regularization.

Conclusion: The present simulation results suggest that incorporation of information on the noise covariance allows better estimation of cortical potentials, than inverse solutions without knowledge about the noise covariance, when the correlation between the signal and noise is low.

Mechanism of iodine release from iodoapatite in aqueous solution

Incongruent release of iodine from iodoapatite (Pb₅(VO₄)₃I) for immobilization of¹²⁹iodine, controlled by exchange of iodide and hydroxide in solution.

Identification of liver metastasis-associated genes in human colon carcinoma by mRNA profiling

Objective

Liver metastasis, which contributes substantially to high mortality, is the most common recurrent mode of colon carcinoma. Thus, it is necessary to identify genes implicated in metastatic colonization of the liver in colon carcinoma.

Methods

We compared mRNA profiling in 18 normal colon mucosa (N), 20 primary tumors (T) and 19 liver metastases (M) samples from the dataset GSE49355 and GSE62321 of Gene Expression Omnibus (GEO) database. Gene ontology (GO) and pathways of the identified genes were analyzed. Co-expression network and protein-protein interaction (PPI) network were employed to identify the interaction relationship. Survival analyses based on The Cancer Genome Atlas (TCGA) database were used to further screening. Then, the candidate genes were validated by our data.

Results

We identified 22 specific genes related to liver metastasis and they were strongly associated with cell migration, adhesion, proliferation and immune response. Simultaneously, the results showed that C-X-C motif chemokine ligand 14 (CXCL14) might be a favorable prediction factor for survival of patients with colon carcinoma. Importantly, our validated data further suggested that lower CXCL14 represented poorer outcome and contributed to metastasis. Gene set enrichment analysis (GSEA) showed that CXCL14 was negatively related to the regulation of stem cell proliferation and epithelial to mesenchymal transition (EMT).

Conclusions

CXCL14 was identified as a crucial anti-metastasis regulator of colon carcinoma for the first time, and might provide novel therapeutic strategies for colon carcinoma patients to improve prognosis and prevent metastasis.

Gene function analysis and underlying mechanism of esophagus cancer based on microarray gene expression profiling

Esophageal cancer (EC) is one of the most common digestive malignant tumors worldwide. Over the past decades, there have been minimal improvements in outcomes for patients with EC. New targets and novel therapies are needed to improve outcomes for these patients. This study aimed to explore the molecular mechanisms of EC by integrated bioinformatic analyses of the feature genes associated with EC and correlative gene functions which can distinguish cancerous tissues from non-cancerous tissues. Gene expression profile GSE20347 was downloaded from Gene Expression Omnibus (GEO) database, including 17 EC samples and their paired adjacent non-cancerous samples. The differentially expressed genes (DEGs) between EC and normal specimens were identified and then applied to analyze the GO enrichment on gene functions and KEGG pathways. Corresponding Pathway Relation Network (Pathway-net) and Gene Signal Network (signal-net) of DEGs were established based on the data collected from GCBI datasets. The results showed that DEGs mainly participated in the process of cell adhesion, cell proliferation, survival, invasion, metastasis and angiogenesis. Aberrant expression of PTK2, MAPK signaling pathway, PI3K-Akt signaling pathway, p53 signaling pathway and MET were closely associated with EC carcinogenesis. Importantly, Interleukin 8 (IL8) and C-X-C chemokine receptor type 7 (CXCR-7) were predicted to be significantly related to EC. These findings were further validated by analyzing both TCGA database and our clinical samples of EC. Our discovery provides a registry of genes and pathways that are disrupted in EC, which has the potential to be used in clinic for diagnosis and target therapy of EC in future.

WASH overexpression enhances cancer stem cell properties and correlates with poor prognosis of esophageal carcinoma

There is increasing evidence that cytoskeleton remodeling is involved in cancer progression. Wiskott-Aldrich syndrome protein (WASP) family represents a key regulator of actin cytoskeleton remodeling. However, the underlying mechanism of the WASP family in cancer progression remains elusive. Here, we studied the role of WASP and SCAR Homolog (WASH), a recently identified WASP family member, in human esophageal squamous cell carcinoma (ESCC). Using three human ESCC cell lines, we found that WASH expression was significantly elevated in cancer stem-like cells enriched by sphere formation assay. WASH knockdown decreased the sphere-forming capacity of esophageal cancer cells whereas WASH over-expression exhibited the opposite effect. Mechanistically, we identified interleukin-8 (IL-8) as a key downstream target of WASH. IL-8 knockdown completely attenuated tumor sphere formation induced by WASH overexpression. WASH knockdown also delayed the growth of human ESCC xenografts in BALB/c nude mice. Importantly, high WASH levels were associated with poor clinical prognosis in a total of 145 human ESCC tissues. Collectively, our results suggest an essential role of the WASH/IL-8 pathway in human ESCC by maintaining the stemness of cancer cells. Hence, targeting this pathway might represent a promising strategy to control human esophageal carcinoma.

Musashi1, a potential prognostic marker in esophageal squamous cell carcinoma

Esophageal cancer ranks as the sixth leading cause of cancer-related deaths worldwide. Cancer stemness is mainly considered to be the key factor for cancer recurrence particularly in esophageal cancer. It is important to identify cancer stem cell markers as targets in future therapies. The present study aimed to investigate the expression of putative cancer stem cell-related marker musashi1 (Msi1) and assess the correlation with clinicopathologcal status of esophageal squamous cell carcinoma (ESCC) cases. We then clarified the role of Msi1 in esophageal cancer cells during proliferation, apoptosis, sphere formation and migration. Finally, we investigated the relationship of Msi1 with the prognosis of ESCC patients. ESCC tissue samples from 93 patients and 20 paired histologically normal tissues were procured for immunohistochemical analysis. We analyzed the characteristics of Msi1, using sphere formation and anchorage independent growth. Moreover, using flow cytometry and Cell Counting Kit-8 (CCK-8) assay, we investigated the role of Msi1 in cancer cell proliferation and apoptosis. Furthermore, we clarified the role of Msi1 in the process of sphere formation and migration of ESCC cells through knockdown of Msi1 expression by siRNA in ESCC cell lines. The results revealed that there was a higher expression of Msi1 in ESCC specimens compared with normal tissues. In addition, Msi1 expression was significantly associated with clinical stage and lymph node metastasis. Most importantly, the increased immunocytochemical staining of Msi1 in spheroid cells revealed the stemness characteristics of Msi1 in ESCC. In addition, we found that silencing of Msi1 decreased cell proliferation, migration and induced apoptosis in TE-7 and KYSE70 cells. Furthermore, downregulation of Msi1 attenuated the sphere formation ability of ESCC cells. Patients with higher expression of Msi1 had a shorter survival. In conclusion, Msi1 acts as a stemness-associated gene in esophageal cancer cell lines and could serve as a prognostic marker in patients with ESCC.