Detection and identification of circulating tumor cells in parathyroid tumors and correlation analysis with clinicopathological features.

INTRODUCTION: The differential diagnosis of parathyroid carcinoma (PC)/parathyroid adenoma (PA) in parathyroid tumors is critical for their management and prognosis. Circulating tumor cells (CTCs) identification in the peripheral blood of parathyroid tumors remains unknown. In this study, we proposed to investigate the differences of CTCs in PC/PA and the relationship with clinicopathologic features to assess its relevance to PC and value in identifying PC/PA. METHODS AND MATERIALS: Peripheral blood was collected from 27 patients with PC and 37 patients with PA treated in our hospital, and the number of chromosome 8 aberrant CTCs was detected by negative magnetic bead sorting fluorescence in situ hybridization (NE-FISH). The differences of CTCs in PC/PA peripheral blood were compared and their diagnostic efficacy was evaluated, and the correlation between CTCs and clinicopathological features of PC was further explored. RESULTS: CTCs differed significantly in PC/PA (p = 0.0008) and were up-regulated in PC, with good diagnostic efficacy. CTCs combined with alkaline phosphatase (ALP) assay improved the diagnostic efficacy in identifying PC/PA (AUC = 0.7838, p = 0.0001). The number of CTCs was correlated with tumor dimensions, but not significantly correlated with clinical markers such as calcium and PTH and pathological features such as vascular invasion, lymph node metastasis and distant metastasis. CONCLUSION: As a non-invasive liquid biopsy method, CTCs test combined with ALP test can be used as an important reference basis for timely and accurate identification and treatment of PC. It is of great significance to improve the current situation of PC diagnosis, treatment and prognosis.

DNA methylation profiling identifies epigenetic signatures of early gastric cancer.

Research on the DNA methylation status of gastric cancer (GC) has primarily focused on identifying invasive GC to develop biomarkers for diagnostic. However, DNA methylation in noninvasive GC remains unclear. We conducted a comprehensive DNA methylation profiling study of differentiated-type intramucosal GCs (IMCs). Illumina 850K microarrays were utilized to assess the DNA methylation profiles of formalin-fixed paraffin-embedded tissues from eight patients who were Epstein-Barr virus-negative and DNA mismatch repair proficient, including IMCs and paired adjacent nontumor mucosa. Gene expression profiling microarray data from the GEO database were analyzed via bioinformatics to identify candidate methylation genes. The final validation was conducted using quantitative real-time PCR, the TCGA methylation database, and single-sample gene set enrichment analysis (GSEA). Genome-wide DNA methylation profiling revealed a global decrease in methylation in IMCs compared with nontumor tissues. Differential methylation analysis between IMCs and nontumor tissues identified 449 differentially methylated probes, with a majority of sites showing hypomethylation in IMCs compared with nontumor tissues (66.1% vs 33.9%). Integrating two RNA-seq microarray datasets, we found one hypomethylation-upregulated gene: eEF1A2, overlapped with our DNA methylation data. The mRNA expression of eEF1A2 was higher in twenty-four IMC tissues than in their paired adjacent nontumor tissues. GSEA indicated that the functions of eEF1A2 were associated with the development of IMCs. Furthermore, TCGA data indicated that eEF1A2 is hypomethylated in advanced GC. Our study illustrates the implications of DNA methylation alterations in IMCs and suggests that aberrant hypomethylation and high mRNA expression of eEF1A2 might play a role in IMCs development.

Reticular fibre structure in the differential diagnosis of parathyroid neoplasms.

BACKGROUND: To investigate the characteristics of reticular fibre structure (RFS) in parathyroid adenoma (PTA), atypical parathyroid tumour (APT), and parathyroid carcinoma (PTC), and to assess its value as a diagnostic indicator. METHODS: Clinical data and pathological specimens of patients with PTA, APT or PTC were collected. Reticular fibre staining was performed to observe the characteristics of RFS. This study evaluated the incidence of RFS destruction in parathyroid tumours, compared RFS destruction between primary PTC and recurrent and metastatic PTC, and explored the association between RFS destruction and clinicopathological features of APT and primary PTC. RESULTS: Reticular fibre staining was performed in 50 patients with PTA, 25 patients with APT, and 36 patients with PTC. In PTA cases, a delicate RFS was observed. In both the APT and PTC groups, incomplete RFS areas were observed. The incidence of RFS destruction was different among the PTA, APT, and PTC groups (P < 0.001, χ2-test), at 0% (0/50), 44% (11/25), and 86% (31/36), respectively. When differentiating PTC from APT, the sensitivity and specificity of RFS destruction were 81% and 56%, respectively. The incidence of RFS destruction was 73% (8/11) in the primary PTC group and 92% (23/25) in the recurrent and metastatic PTC groups. In both the APT group and primary PTC group, no correlation was found between RFS destruction and clinicopathological features. CONCLUSION: RFS destruction may indicate that parathyroid tumours have unfavourable biological behaviours.Reticular fibre staining may be a valuable tool for improving the diagnostic accuracy in parathyroid tumours.

The association between ROS1 rearrangement and risk of thromboembolic events in patients with advanced non-small cell lung cancer: a multicenter study in China.

BACKGROUND: According to several studies, ROS1 rearrangement is associated with thrombotic risk in non-small cell lung cancer (NSCLC). However, there is no clear understanding of the predictors and prognostic impact of thromboembolic events (TEEs) in patients with advanced ROS1 rearrangement NSCLC. METHODS: A total of 47 newly diagnosed advanced NSCLC patients with ROS1 rearrangement from four Chinese hospitals were retrospectively included and were evaluated for TEEs incidence, characteristics, predictors, as well as response to therapies and overall survival (OS). RESULTS: Of the 47 enrolled patients, 23.4% (n = 11) patients developed TEEs. Among them, 7 of 11 patients (64%) developed pulmonary embolism (PE), and 5 patients (45%) experienced recurrent TEEs. In multivariate analysis, D-dimer was associated with the occurrence of TEEs in ROS1 rearranged NSCLC (HR 1.16, 95% CI 1.08-1.23, P < 0.001). Median progression-free survival (PFS) after first-line ROS1 tyrosine kinase inhibitors (TKIs) therapy was significantly longer in patients without TEEs than in those developing TEEs (26 months vs. 12 months, P = 0.0383). Furthermore, patients with TEEs had a shorter OS period than those without TEEs (29.8 months vs. not estimable, P = 0.0647). CONCLUSION: The results of this multicenter study indicated that advanced NSCLC patients with ROS1 rearrangement were more likely to experience PE and TEEs recurrence. And patients with TEEs tended to have a worse prognosis. Furthermore, an elevated D-dimer level suggested a hypercoagulable state in NSCLC patients with ROS1 rearrangement.

Real-world data of EGFR mutation testing in Chinese non-small cell carcinoma: Low tumor cell number and tumor cellularity can be accepted.

INTRODUCTION: Molecular testing on advanced non-small cell lung cancer (NSCLC) often confront of limited specimen.The aim of the study is to compare the mutation frequency in adenocarcinoma samples with poor tumor cell content and the optimal samples, making the optimal strategy of mutation analysis. METHODS: In this retrospective study, mutation status of EGFR, ALK, ROS1, BRAF, KRAS, RET, HER2, CMET, NRAS and PIK3CA in 1594 NSCLCs were tested by ARMS-PCR and qRT-PCR, consists of 790 cases of surgical specimens, 741 cases of small biopsies, 63 cases of cytology cell blocks. We analyzed the discrepancies in mutation frequency with optimal specimens and the suboptimal ones. RESULTS: Comparing the gene mutation frequency in optimal and suboptimal samples, only the EGFR mutation rates of surgical samples (12.5 %, 1 out of 8) with < 10 % tumor cellularity was lower than in those with ≥ 10 % (57.1 %, 385 out of 674， p = 0.015). However, surgical specimens with low tumor cellularity (<20 %) were comparable to the qualified samples. The mutation frequency of EGFR in biopsy specimens with poor specimen adequacy( <20 %, <10 %, <5 %, <200, <100, <50) were comparable to the qualified samples. Low tumor cellularity (<20 %, <10 %, <5 %) and low tumor cell number (<200, <100, <50) was not associated with mutational rate for ALK, ROS1, BRAF, KRAS, RET, HER2, CMET, NRAS and PIK3CA mutations in small biopsy samples. CONCLUSIONS: In clinical practice, specimen with low adequacy could attempt in gene mutation testing, including biopsy and surgical specimen. However, the amount of tumor for molecular testing should be reported and suboptimal samples with a negative EGFR mutation result should be considered for combination using of other mutation test method or repeat testing of an alternate tumor sample, especially for the surgical samples.

Deep learning for automatic diagnosis of gastric dysplasia using whole-slide histopathology images in endoscopic specimens.

BACKGROUND: Distinguishing gastric epithelial regeneration change from dysplasia and histopathological diagnosis of dysplasia is subject to interobserver disagreement in endoscopic specimens. In this study, we developed a method to distinguish gastric epithelial regeneration change from dysplasia and further subclassify dysplasia. Meanwhile, optimized the cross-hospital diagnosis using domain adaption (DA). METHODS: 897 whole slide images (WSIs) of endoscopic specimens from two hospitals were divided into training, internal validation, and external validation cohorts. We developed a deep learning (DL) with DA (DLDA) model to classify gastric dysplasia and epithelial regeneration change into three categories: negative for dysplasia (NFD), low-grade dysplasia (LGD), and high-grade dysplasia (HGD)/intramucosal invasion neoplasia (IMN). The diagnosis based on the DLDA model was compared to 12 pathologists using 100 gastric biopsy cases. RESULTS: In the internal validation cohort, the diagnostic performance measured by the macro-averaged area under the receiver operating characteristic curve (AUC) was 0.97. In the independent external validation cohort, our DLDA models increased macro-averaged AUC from 0.67 to 0.82. In terms of the NFD and HGD cases, our model's diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were significantly higher than junior and senior pathologists. Our model's diagnostic sensitivity, NPV, was higher than specialist pathologists. CONCLUSIONS: We demonstrated that our DLDA model could distinguish gastric epithelial regeneration change from dysplasia and further subclassify dysplasia in endoscopic specimens. Meanwhile, achieved significant improvement of diagnosis cross-hospital.

High expression of nuclear NRF2 combined with NFE2L2 alterations predicts poor prognosis in esophageal squamous cell carcinoma patients.

Nuclear factor erythroid-2 related factor-2 (NFE2L2 or NRF2) is a frequently mutated gene in esophageal squamous cell carcinoma (ESCC). However, the roles of NFE2L2 alterations in ESCC remain elusive. In order to elucidate this issue, 130 ESCC patients who underwent esophagectomy were enrolled. The majority of tumor tissues were positive for NRF2, which was significantly enriched in the nucleus of the primary tumor tissues compared with the noncancerous mucosae. Primary ESCC tumors positive for NRF2 tended to be positive for NAD(P)H quinone oxidoreductase 1 (NQO1) as the downstream target of NRF2. There was a positive correlation between NRF2 and NQO1 expression level in primary tumors. NQO1 staining in primary tumors with NRF2 nuclear expression was significantly stronger than that with NRF2 cytoplasmic expression. In addition, high concordance for the status of NRF2 expression between primary tumors and corresponding metastatic lesions was observed. Next, we found high expression of nuclear NRF2 (the proportion of nuclear NRF2 expression >20% or nuclear NRF2 immunohistochemistry score >20) predicted shorter overall survival in patients with dual-positive expression of NRF2 and NQO1. Captured-based targeted sequencing revealed that NFE2L2 somatic alterations were observed in 52.8% of ESCC patients with dual-positive expression of NRF2 and NQO1. NFE2L2 amplification and mutations within the DLG/ETGE motifs were seen more frequently in ESCC tumors with nuclear or nucleocytoplasmic expression of NRF2 compared with those with cytoplasmic expression of NRF2. We also found high expression of nuclear NRF2 plus the status of NFE2L2 alteration exhibited high performance in predicting prognosis of ESCC patients. Our study demonstrated that high nuclear NRF2 expression and NFE2L2 alterations were associated with poor prognosis of ESCC patients. These findings suggest that NRF2 signaling pathway might play vital roles in ESCC malignancy and the aberrant activation of NRF2 pathway predicts unfavorable prognosis in ESCC.

Clinicopathological and molecular characteristics of the alpha-fetoprotein-producing gastric cancer: emphasis on two major subtypes.

Alpha-fetoprotein-producing gastric cancer (AFPGC) is associated with high invasion and poor prognosis, but has not been well-documented due to its rarity. To develop the understanding of AFPGC, and further facilitate its clinical decision-making and treatment, we performed clinicopathological and molecular characterization of AFPGC and its two major subtypes, namely, gastric adenocarcinoma with enteroblastic differentiation (GAED) and hepatoid adenocarcinoma (HAC). The clinicopathological and molecular characteristics of AFPGC patients (n = 54) were mainly investigated by immunohistochemistry and next-generation sequencing (NGS) approaches. AFPGC exhibited a higher incidence of lymphatic and vascular invasion than conventional gastric adenocarcinoma (CGA). Despite various morphological patterns, there was mostly no evident difference in clinicopathological characteristics between the GAED and HAC subtypes. Target-enriched NGS profiling of disease mutation landscapes discovered 17 differentially mutated genes between AFPGC and CGA. The AFPGC patients carrying ZNF217 mutations had poorer overall survival than the ZNF217 wildtype. Furthermore, ATR showed a significantly higher mutation rate in GAED than in HAC. Overall, our study of clinicopathological characteristics shed light on the differences between CGA and AFPGC, as well as the relationships between the GAED and HAC subtypes of AFPGC. Furthermore, mutation landscape profiling revealed potential diagnostic and prognostic markers for AFPGC and its two subtypes.

Homologous recombination repair gene mutations in Chinese localized and locally advanced prostate cancer patients.

BACKGROUND: Homologous recombination repair gene (HRR) mutations have been proven to be effective biomarkers for PARP inhibitor therapy for metastatic castration resistant prostate cancer. However, the frequency of HRR mutations in patients with localized and locally advanced prostate cancer is still unclear. This study investigated the profile of HRR gene mutations in Chinese localized and locally advanced prostate cancer patients. MATERIALS AND METHODS: 74 patients with localized and locally advanced prostate cancer patients in Beijing Chaoyang Hospital between May 2018 and September 2019 were retrospectively included. Matched prostate cancer and histologically normal tissues were subjected to next-generation sequencing. Pathogenic alterations of 19 HRR genes were examined. RESULTS: Ten deleterious and suspected deleterious mutations (4 germline and 6 somatic mutations) were detected in 9 of 74 (12.16 %) patients, occurred in seven HRR-related genes, including CDK12, NBN, ATM, ATR, BRCA2, PALB2 and RAD51C. The mutation frequency of HRR genes in this study (12.16 %) was higher than TCGA cohort (7.29 %), and the mutation sites in 7 HRR genes detected in this cohort were different from those of TCGA data. Patients with HRR gene mutations had higher Gleason grade (≥ 3) (P = 0.03) and risk level (very-high) (P = 0.03). Postoperative prostate specific antigen level and positive surgical margin rate was not associated with HRR gene mutation status. CONCLUSIONS: This study illustrated the mutation patterns of HRR genes in Chinese population with localized and locally advanced prostate cancer. These results provide further evidence that HRR gene mutations were more prevalent in patients with higher Gleason grade, or with very-high-risk level. Patients with these clinicopathologic characteristics may need more precise stratification through molecular detection.

Genome-Wide DNA Methylation Pattern of Cancer Stem Cells in Esophageal Cancer.

BACKGROUND: Cancer stem cells (CSCs) are considered the main cause of cancer recurrence and metastasis, and DNA methylation is involved in the maintenance of CSCs. However, the methylation profile of esophageal CSCs remains unknown. METHODS: Side population (SP) cells were isolated from esophageal squamous cell carcinoma (ESCC) cell lines KYSE150 and EC109. Sphere-forming cells were collected from human primary esophageal cancer cells. SP cells and sphere-forming cells were used as substitutes for cancer stem-like cells. We investigated the genome-wide DNA methylation profile in esophageal cancer stem-like cells using reduced representation bisulfite sequencing (RRBS). RESULTS: Methylated cytosine (mC) was found mostly in CpG dinucleotides, located mostly in the intronic, intergenic, and exonic regions. Forty intersected differentially methylated regions (DMRs) were identified in these 3 groups of samples. Thirteen differentially methylated genes with the same alteration trend were detected; these included OTX1, SPACA1, CD163L1, ST8SIA2, TECR, CADM3, GRM1, LRRK1, CHSY1, PROKR2, LINC00658, LOC100506688, and NKD2. DMRs covering ST8SIA2 and GRM1 were located in exons. These differentially methylated genes were involved in 10 categories of biological processes and 3 cell signaling pathways. CONCLUSIONS: When compared to non-CSCs, cancer stem-like cells have a differential methylation status, which provides an important biological base for understanding esophageal CSCs and developing therapeutic targets for esophageal cancer.

Genetic features and application value of next generation sequencing in the diagnosis of synchronous multifocal lung adenocarcinoma.

The present study aimed to elucidate the genetic features of multiple lung cancer (MLC) and identify effective molecular markers for diagnosis using next generation sequencing (NGS). The present data may also inform patient treatment and prognosis. A total of 35 lesions were obtained from 17 patients with MLC. Based on lesion histology and NGS, 13 cases of multiple primary lung cancer (MPLC) were identified and 4 cases were classified as intrapulmonary metastasis (IPM). All 4 patients with IPM exhibited an epidermal growth factor receptor (EGFR) mutation and synchronous mutation of at least one tumor suppressor gene. The frequency and percentage of EGFR mutations, accompanied with tumor suppressor genes, were significantly higher in patients with IPM compared with MPLC. Furthermore, a high EGFR-heterogeneity score and male sex were risk factors of IPM occurrence. There were significant differences in mean EGFR mutation abundance alone, mutations of tumor suppressor genes and mutations of EGFR combined with tumor suppressor genes between patients with adenocarcinoma (ADC) and adenocarcinoma in situ (AIS). In conclusion, histological characteristics combined with genetic alterations may be an effective method for the diagnosis of MPLC and IPM, and NGS may serve as a useful diagnostic tool. MLC exhibited unique molecular characteristics, including higher rates of EGFR mutations, EGFR driver mutations accompanied with tumor suppressor gene mutations and the absence of anaplastic lymphoma kinase mutations, which may help distinguish between patients with MPLC or IPM. The present study hypothesized that the mean frequency of EGFR mutations, mutations of tumor suppressor genes and mutations of both EGFR and tumor suppressor genes may serve an important role in the development of AIS to ADC. The results of the present study highlight the potential underlying mechanisms of lung ADC development, which may assist with future elucidation of effective treatments to prevent the progression of lung cancer.

Apatinib induces apoptosis and autophagy via the PI3K/AKT/mTOR and MAPK/ERK signaling pathways in neuroblastoma.

The clinical outcome of neuroblastoma (NB) has significantly improved in the last 30 years for patients with localized disease; however, the overall survival (OS) for patients with metastasis remains poor. Apatinib, a selective inhibitor of the vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase, which was discovered to be highly associated with metastasis, has been reported to exert antitumor effects in numerous types of cancer. However, the effect of apatinib in NB remains relatively unknown. The present study aimed to investigate the antitumor effects of apatinib in NB cells in vitro. The results revealed that apatinib inhibited cell viability and colony formation, whilst inducing cell cycle arrest and the apoptosis of NB cells. Additionally, apatinib inhibited the migration and invasion of NB cells, in addition to promoting the autophagy of NB cells. Western blotting demonstrated that the protein expression levels of phosphorylated (p)-AKT, p-mTOR and p-P70S6K, and downstream molecules associated with the cell cycle and apoptosis, such as cyclin D1 and the Bcl-2/Bax ratio of NB cells, were significantly decreased following treatment with apatinib. In addition, western blotting and immunofluorescence assays identified that the expression level of microtubule-associated protein 1A/1B-light chain 3-II, which is expressed in autophagosomes, was upregulated following apatinib treatment. In conclusion, the findings of the present study suggested that apatinib may induce apoptosis and autophagy via the PI3K/AKT/mTOR and mitogen-activated protein kinase/ERK signaling pathways in NB cells. Thus, apatinib may be a potential antitumor agent for the clinical treatment of NB.

TM4SF1 promotes the self-renewal of esophageal cancer stem-like cells and is regulated by miR-141.

Cancer stem-like cells have been identified in primary human tumors and cancer cell lines. Previously we found TM4SF1 gene was highly expressed in side population (SP) cells from esophageal squamous cell carcinoma (ESCC) cell lines, but the role and underlying mechanism of TM4SF1 in ESCC remain unclear. In this study, we observed TM4SF1 was up-regulated but miR-141 was down-regulated in SP cells isolated from ESCC cell lines. TM4SF1 could stimulate the self-renewal ability and carcinogenicity of esophageal cancer stem-like cells, and promote cell invasion and migration. In miR-141 overexpression cells, the expression of TM4SF1 was significantly reduced. We also found that overexpression of miR-141 could abolish the self-renewal ability and carcinogenicity of esophageal cancer stem-like cells and decrease cell invasion and migration by suppressing TM4SF1. Consequently, TM4SF1 is a direct target gene of miR-141. The regulation of TM4SF1 by miR-141 may play an important role in controlling self-renewals of esophageal cancer stem-like cells. It may also promote the development of new therapeutic strategies and efficient drugs to target ESCC stem-like cells.

RFT2 is overexpressed in esophageal squamous cell carcinoma and promotes tumorigenesis by sustaining cell proliferation and protecting against cell death.

Human riboflavin transporter 2 (RFT2, also termed as SLC52A3) was recently identified as a susceptibility gene to esophageal squamous cell carcinoma (ESCC), however, its expression and biologic function has remained unclear in ESCC. In this study, we demonstrated that RFT2 was frequently overexpressed in tumor samples compared with normal adjacent tissue in ESCC patients. Knockdown of RFT2 in ESCC cells resulted in decreases of intracellular flavin status, mitochondrial membrane potential and cellular ATP levels, and inhibitions of cell proliferation, colony formation and anchorage-independent growth. Knockdown of RFT2 increased p21 and p27 protein levels, decreased their downstream targets cyclin E1 and Cdk2 protein levels and caused pRb hypophosphorylation, leading to cell cycle arrest at G1-G1/S. Knockdown of RFT2 also reduced anti-apoptotic proteins Bcl-2, Bcl-xl and survivin levels, caused activation of caspase-3 and apoptosis. In contrast, ectopic overexpression of RFT2 in ESCC cells promoted cell proliferation under restricted conditions (soft agar), conferred resistance to cisplatin, and enhanced tumorigenicity in nude mice. These results suggest that RFT2 contributes to ESCC tumorigenesis and may serve as a potential therapeutic target.

Macrophage inhibitory factor 1 acts as a potential biomarker in patients with esophageal squamous cell carcinoma and is a target for antibody-based therapy.

Macrophage inhibitory factor 1 (MIC1) is frequently altered in various cancers. The aim of this study was to investigate the clinical significance of MIC1 for esophageal squamous cell carcinoma (ESCC). Serum MIC1 of 286 ESCC and 250 healthy subjects was detected, the diagnostic performance was assessed and compared with SCC, CEA, CA199 and CA724, and the value as a prognostic indicator was also evaluated. The expression of MIC1 in ESCC cell lines, tissues were detected, and the inhibition of MIC1 antibody on ESCC was carried out in vitro and in vivo. The results showed that the serum MIC1 of ESCC was significantly higher than normal groups (P < 0.001), and was positively associated with tumor invasion (P = 0.030) as well as lymph node metastasis (P = 0.007). The sensitivity of MIC1 was significantly better than SCC, CEA, CA199 and CA724, especially for stage I ESCC. Patients with higher serum MIC1 also had a poorer prognosis in relapse-free (P = 0.050) and tumor-specific survival (P = 0.005). In vitro studies showed that the expression of MIC1 was upregulated in 37.5% (3/8) ESCC cell lines and 45% (18/40) tissues, and the transcription of MIC1 in tumor tissues was significantly higher than paired adjacent normal tissues (P = 0.001). The antibody of MIC1 inhibited the tumor growth (P < 0.001), and showing preference for tumor tissues in xenograft model. The decreased formation of neovascularization lumen may be involved in the mechanism. We conclude that MIC1 plays an important role in the progression of ESCC and can serve as a potential biomarker and therapeutic target for ESCC.

miR-203 inhibits the proliferation and self-renewal of esophageal cancer stem-like cells by suppressing stem renewal factor Bmi-1.

Cancer stem-like cells exist in many malignancies and several stem cell-related genes and microRNAs, such as Bmi-1 and miR-203, have been identified as cancer stem-like cell regulators using gene microarray or sequencing analysis. Previously, we used side population (SP) sorting to enrich cancer stem-like cells from esophageal squamous cell carcinoma (ESCC) cell line EC9706. Our results demonstrated that EC9706 SP cells shared common features of cancer stem-like cells. In this study, we examined the expression of Bmi-1 and miR-203 in ESCC SP and non-SP (NSP) cells. Our results showed that, when compared with NSP cells, Bmi-1 was up-regulated and miR-203 was down-regulated in SP cells. During the differentiation from SP to NSP cells, the expression levels of Bmi-1 were gradually decreased. Overexpression of miR-203 resulted in a significant reduction of endogenous Bmi-1 protein level in EC9706 cells. SP and NSP analyses revealed that the SP cell fraction was markedly decreased in miR-203 overexpressed cells. miR-203 overexpressed cells also showed a significant reduction in colony formation, which was resistant to chemotherapeutic drug treatment and tumorigenicity in nude mice. Rescue experiments demonstrated that ectopic expression of Bmi-1 in miR-203 overexpressed cells increased the SP fraction and restored cell proliferation. Taken together, these results indicated that stem renewal factor Bmi-1 was a direct target of miR-203. The regulation of Bmi-1 by miR-203 may play an important role in controlling cell proliferation and self-renewal of esophageal cancer stem-like cells. It may also promote the development of new therapeutic strategies and efficient drugs that target ESCC stem-like cells.

Multiple tumor-associated microRNAs modulate the survival and longevity of dendritic cells by targeting YWHAZ and Bcl2 signaling pathways.

Tumors use a wide array of immunosuppressive strategies, such as reducing the longevity and survival of dendritic cells (DCs), to diminish immune responses and limit the effect of immunotherapy. In this study, we found that tumors upregulate the expression of multiple microRNAs (miRNAs), such as miR-16-1, miR-22, miR-155, and miR-503. These tumor-associated miRNAs influenced the survival and longevity of DCs by affecting the expression of multiple molecules that are associated with apoptotic signaling pathways. Specifically, miR-22 targeted YWHAZ to interrupt the PI3K/Akt and MAPK signaling pathways, and miR-503 downregulated Bcl2 expression. The result of the increased expression of miR-22 and miR-503 in the tumor-associated DCs was their reduced survival and longevity. Thus, tumor-associated miRNAs can target multiple intracellular signaling molecules to cause the apoptosis of DCs in the tumor environment. Use of miR-22 and miR-503 as inhibitors may therefore represent a new strategy to improve DC-based immunotherapies against tumors.

[Research advances in induced pluripotent stem cells].

Differentiated somatic cells can be directly reprogrammed into induced pluripotent stem (iPS) cells in vitro. Similarly to embryonic stem (ES) cells, iPS cells have pluripotency to differentiate into all cell types and capability to self-renew themselves indefinitely. Without immune rejection and ethical issues, patient-specific iPS cells promise to be an ideal tool for regenerative medicine, drug screening, and toxicity testing.

miR-223 suppresses differentiation of tumor-induced CD11b⁺ Gr1⁺ myeloid-derived suppressor cells from bone marrow cells.

Tumor-associated factors are related to increased accumulation of CD11b(+) Gr1(+) myeloid-derived suppressor cells (MDSCs). However, the exact mechanism of how genetic factors control the expansion of MDSCs in tumor-bearing hosts remains elusive. Herein, we found that tumor-associated MDSCs and their subsets, mononuclear MDSCs and polymorphonuclear MDSCs, have decreased expression of miR-223 when compared to CD11b(+) Gr1(+) cells from the spleen of disease-free mice. With the differentiation of CD11b(+) Gr1(+) MDSCs from bone marrow cells (BMCs) upon exposure to tumor-associated factors, the expression of both pri-miR-223 and mature miR-223 was downregulated, indicating that the expression of miR-223 could be regulated by tumor-associated factors. Interestingly, miR-223 remarkably inhibits differentiation of BMCs into CD11b(+) Gr1(+) MDSCs in the presence of tumor-associated factors by targeting myocyte enhancer factor 2C (MEF2C). Using reconstituted s.c. tumor models, miR-223 also suppresses accumulation of CD11b(+) Gr1(+) MDSCs, whereas its targeting molecule MEF2C increases the number of MDSCs. Tumor growth is slower in mice infused by miR223-engineered BMCs than in mice infused with control transfected BMCs. As miR-223 and its target molecule MEF2C are highly conserved between mice and humans, the modulation of miR-223 in tumor-induced CD11b(+) Gr1(+) MDSCs may exert an important role in controlling the increased accumulation of CD11b(+) Gr1(+) MDSCs in patients with tumor.