Cancer stem cell biomarkers SOX2 and Oct4 in cervical cancer patients undergoing chemoradiotherapy.

BACKGROUND: Cancer stem cell biomarkers SRY (sex-determining region Y)-box 2 (SOX2) and octamer-binding transcription factor 4 (Oct4) account for radioresistance in cervical squamous cell cancers (CSCCs). Their clinical implications are limited and contradictory. METHODS: In this prospective cohort study, we recruited patients with FIGO IB2-IVA CSCC treated with primary chemoradiotherapy on regular follow-up. Tissue biopsy specimens were evaluated for SOX2 and Oct4 expression by immunohistochemistry, quantified by a product of proportion and intensity scores. RESULTS: A total of 59 patients were included. Most had a moderately differentiated (81%), keratinizing (59%) CSCC, and ≥FIGO stage IIB disease (95%). SOX2 expression (high:low 21:38 patients) and Oct4 expression (high:low 4:55 patients) had a significant interrelation (p = 0.005, odds ratio (95% CI) - 1.23 (1.004-1.520)). At a median follow-up of 36 months, the 3-year overall survival (OS) was 60% and 53% for low and high SOX2 expression (p = 0.856), and 54% and 100% for low and high Oct4 expression (p = 0.114). The 3-year disease-frese survival (DFS) was 65% and 50% in the low and high SOX2 expression (p = 0.259), and 59% and 75% for low and high Oct4 expression (p = 0.598). SOX2 expression was the only variable significantly associated with a lower OS and DFS on regression analysis. CONCLUSION: Our study demonstrated a trend toward improved OS and DFS with low SOX2 and high Oct4 expression in CSCC patients undergoing chemoradiotherapy.

In high-grade ovarian carcinoma, platinum-sensitive tumor recurrence and acquired-resistance derive from quiescent residual cancer cells that overexpress CRYAB, CEACAM6, and SOX2.

Most high-grade ovarian carcinomas (HGOCs) are sensitive to carboplatin (CBP)-based chemotherapy but frequently recur within 24 months. Recurrent tumors remain CBP-sensitive and acquire resistance only after several treatment rounds. Recurrences arise from a small number of residual tumor cells not amenable to investigation in patients. We developed patient-derived xenografts (PDXs) that allow the study of these different stages of CBP-sensitive recurrence and acquisition of resistance. We generated PDX models from CBP-sensitive and intrinsically resistant HGOC. PDXs were CBP- or mock-treated and tumors were sampled, after treatment and at recurrence. We also isolated models with acquired-resistance from CBP-sensitive PDXs. Tumors were characterized at the histological and transcriptome levels. PDX models reproduced treatment response seen in the patients. CBP-sensitive residual tumors contained nonproliferating tumor cell clusters embedded in a fibrotic mesh. In nontreated PDX tumors and treated CBP-resistant tumors, fibrotic tissue was not prevalent. Residual tumors had marked differences in gene expression when compared to naïve and recurrent tumors, indicating downregulation of the cell cycle and proliferation and upregulation of interferon response and the epithelial-mesenchymal transition. This gene expression pattern resembled that described in embryonal diapause and 'drug-tolerant persister' states. Residual and acquired-resistance tumors share the overexpression of three genes: CEACAM6, CRYAB, and SOX2. Immunostaining analysis showed strong CEACAM6, CRYAB, and SOX2 protein expression in CBP-sensitive residual and acquired-resistance PDX, thus confirming the RNA profiling results. In HGOC PDX, CBP-sensitive recurrences arise from a small population of quiescent, drug-tolerant, residual cells embedded in a fibrotic mesh. These cells overexpress CEACAM6, CRYAB, and SOX2, whose overexpression is also associated with acquired resistance and poor patient prognosis. CEACAM6, CRYAB, and SOX2 may thus serve as a biomarker to predict recurrence and emergence of resistant disease in CBP-treated HGOC patients. © 2022 The Pathological Society of Great Britain and Ireland.

Quantitative analysis of KLF4 and SOX2 expression in oral carcinomas reveals independent association with oral tongue subsite location and histological grade.

BACKGROUND: Stemness factors associated with tumorigenesis in different types of cancers have not been specifically studied in oral tongue SCC (OTSSC). Here, we aimed to quantify expression levels and distribution of KLF4 and SOX2, two relevant stemness factors, in oral SCC including OTSCC samples from different subsites. METHODS AND RESULTS: We determined KLF4 and SOX2 expression levels by immunostaining 35 biopsies of OSCC. Stained wholeslide images were digitized and subjected to automatic cell detection and unbiased quantification using Qupath software. We found statistically significant reduction in KLF4 positive cells density (p= 0.024), and fraction (p= 0.022) in OTSCC from tongue borders compared with other tongue subsites. Instead, quantitative SOX2 analysis did not show differences in expression levels between OTSCC from the borders versus OTSCC developed in others subsites. Notably SOX2 expression was revealed increased in moderately and poorly differentiated OSCC compared with well differentiated ones (positive cells density p= 0.025, fraction p= 0.006). No significant correlation between KLF4 and SOX2 expression was observed, neither in OSCC nor in OTSCC. CONCLUSIONS: KLF4 and SOX2 exhibit opposite expression profiles regarding subsite localization and differentiation level in OSCC. Our study prompts future OTSCC prospective studies looking for clinical prognosis to incorporate detailed subsite information in the analysis.

The Prognostic Value of Sex-Determining Region Y-Box 2 and CD8+ Tumor-Infiltrating Lymphocytes in Limited-Stage Small-Cell Lung Cancer.

BACKGROUND: Sex-determining region Y-box 2 (SOX2) is a transcriptional factor that drives embryonic stem cells to neuroendocrine cells in lung development and is highly expressed in small-cell lung cancer (SCLC). However, the prognostic role of SOX2 and its relationship with tumor-infiltrating lymphocytes (TILs) has not been determined in SCLC. Herein, we assessed the expression of SOX2 and CD8+ TILs to obtain insights into the prognostic role of SOX2 and CD8+ TILs in limited-stage (LS)-SCLC. METHODS: A total of 75 patients with LS-SCLC was enrolled. The SOX2 expression and CD8+ TILs were evaluated by immunohistochemistry. RESULTS: High SOX2 and CD8+ TIL levels were identified in 52 (69.3%) and 40 (53.3%) patients, respectively. High SOX2 expression was correlated with increased density of CD8+ TILs (p = 0.041). Unlike SOX2, high CD8+ TIL numbers were associated with significantly longer progression-free survival (PFS; 13.9 vs. 8.0 months, p = 0.014). Patients with both high SOX2 expression and CD8+ TIL numbers (n = 29, 38.7%) had significantly longer PFS and overall survival (OS) compared to those from the other groups (median PFS 19.3 vs. 8.4 months; p = 0.002 and median OS 35.7 vs. 17.4 months; p = 0.004, respectively). Multivariate Cox regression analysis showed that the combination of high SOX2 expression and CD8+ TIL levels was an independent good prognostic factor for OS (HR = 0.471, 95% CI, 0.250-0.887, p = 0.02) and PFS (HR = 0.447, 95% CI, 0.250-0.801, p = 0.007) in SCLC. CONCLUSIONS: Evaluation of the combination of SOX2 and CD8+ TIL levels may be of a prognostic value in LS-SCLC.

Clinical Significance and Prognostic Value of SOX2 Protein Expression in Patients With Oral Squamous Cell Carcinoma.

OBJECTIVES: Cancer stem cells are a small group of highly tumorigenic cells with the trend of self-renewal, tumor progression, metastasis, recurrence, and therapeutic resistance. SOX2 is an important cancer stem cell marker that is involved in tumorigenesis and correlated with aggressive features in various types of malignancies. The present study was aimed to investigate the expression of this biomarker in neoplastic tissues of oral squamous cell carcinoma (OSCC) to determine whether it has the potential to predict the outcomes and survival of the affected patients. MATERIALS AND METHODS: The medical records of 73 patients diagnosed with OSCC were retrospectively studied. Clinical and pathologic features included age, sex, tumor size, histologic grade, lymph node involvement, recurrence, metastasis, and follow up. Immunohistochemical analysis for SOX2 protein expression was performed, and its correlations with clinicopathologic features were evaluated. RESULTS: SOX2 was significantly associated with tumor size, lymph node metastasis, and patients' survival. We found no apparent correlation between SOX2 and tumor recurrence, distant metastasis, or differentiation. The multivariate analysis identifies patients' age, sex, and SOX2 expression as independent prognostic factors for overall survival. CONCLUSION: SOX2 may worsen the prognosis and be a progressive malignant factor, which can help clinicians investigate OSCC patients' survival and plan the appropriate treatment accordingly.

Co-expression of SOX2 and HR-HPV RISH predicts poor prognosis in small cell neuroendocrine carcinoma of the uterine cervix.

BACKGROUND: Small cell neuroendocrine carcinoma of the uterine cervix (SCNEC) is a rare cancer involving the human papilloma virus (HPV), and has few available treatments. The present work aimed to assess the feasibility of SOX2 and HPV statuses as predictive indicators of SCNEC prognosis. METHODS: The associations of SOX2 and/or high-risk (HR)-HPV RNA in situ hybridization (RISH) levels with clinicopathological characteristics and prognostic outcomes for 88 neuroendocrine carcinoma (NEC) cases were analyzed. RESULTS: Among these patients with SCNEC, SOX2, P16INK4A and HR-HPV RISH expression and SOX2/HR-HPV RISH co-expression were detected in 68(77.3%), 76(86.4%), 73(83.0%), and 48(54.5%), respectively. SOX2-positive and HR-HPV RISH-positive SCNEC cases were associated with poorer overall survival (OS, P = 0.0170, P = 0.0451) and disease-free survival (DFS, P = 0.0334, P = 0.0309) compared with those expressing low SOX2 and negative HR-HPV RISH. Alternatively, univariate analysis revealed that SOX2 and HR-HPV RISH expression, either separately or in combination, predicted the poor prognosis of SCNEC patients. Multivariate analysis revealed that the co-expression of SOX2 with HR-HPV RISH may be an independent factor of OS [hazard ratio = 3.597; 95% confidence interval (CI): 1.085-11.928; P = 0.036] and DFS [hazard ratio = 2.880; 95% CI: 1.199-6.919; P = 0.018] prediction in SCNEC. CONCLUSIONS: Overall, the results of the present study suggest that the co-expression of SOX2 with HR-HPV RISH in SCNEC may represent a specific subgroup exhibiting remarkably poorer prognostic outcomes compared with the expression of any one marker alone.

A Comparative Assessment of Marker Expression Between Cardiomyocyte Differentiation of Human Induced Pluripotent Stem Cells and the Developing Pig Heart.

The course of differentiation of pluripotent stem cells into cardiomyocytes and the intermediate cell types are characterized using molecular markers for different stages of development. These markers have been selected primarily from studies in the mouse and from a limited number of human studies. However, it is not clear how well mouse cardiogenesis compares with human cardiogenesis at the molecular level. We tackle this issue by analyzing and comparing the expression of common cardiomyogenesis markers [platelet-derived growth factor receptor, alpha polypeptide (PDGFR-α), fetal liver kinase 1 (FLK1), ISL1, NK2 homeobox 5 (NKX2.5), cardiac troponin T (CTNT), connexin43 (CX43), and myosin heavy chain 7 (MYHC-B)] in the developing pig heart at embryonic day (E)15, E16, E18, E20, E22, and E24 and in differentiating cardiomyocytes from human induced pluripotent stem cells (hiPSCs). We found that porcine expression of the mesoderm marker FLK1 and the cardiac progenitor marker ISL1 was in line with our differentiating hiPSC and reported murine expression. The cardiac lineage marker NKX2.5 was expressed at almost all stages in the pig and hiPSC, with an earlier onset in the hiPSC compared with reported murine expression. Markers of immature cardiomyocytes, CTNT, and MYHC-B were consistently expressed throughout E16-E70 in the pig, which is comparable with mouse development, whereas the markers increased over time in the hiPSC. However, the commonly used mature cardiomyocyte marker, CX43, should be used with caution, as it was also expressed in the pig mesoderm, as well as hiPSC immature cardiomyocytes, while this has not been reported in mice. Based on our observations in the various species, we suggest to use FLK1/PDGFR-α for identifying cardiac mesoderm and ISL1/NKX2.5 for cardiac progenitors. Furthermore, a combination of two or more of the following, CTNT+/MYHC-B+/ISL1+ could mark immature cardiomyocytes and CTNT+/ISL1- mature cardiomyocytes. CX43 should be used together with sarcomeric proteins. This knowledge may help improving differentiation of hiPSC into more in vivo-like cardiac tissue in the future.

Modeling tumor development and metastasis using paired organoids derived from patients with colorectal cancer liver metastases.

Tumor metastasis accounts for the majority of cancer-related deaths; it is therefore important to develop preclinical models that faithfully recapitulate disease progression. Here, we generated paired organoids derived from primary tumors and matched liver metastases in the same colorectal cancer (CRC) patients. Despite the fact that paired organoids exhibit comparable gene expression and cell morphology, organoids from metastatic lesions demonstrate more aggressive phenotypes, tumorigenesis, and metastatic capacity than those from primary lesions. Transcriptional analyses of the paired organoids reveal signature genes and pathways altered during the progression of CRC, including SOX2. Further study shows that inducible knockdown of SOX2 attenuated invasion, proliferation, and liver metastasis outgrowth. Taken together, we use patient-derived paired primary and metastatic cancer organoids to model CRC metastasis and illustrate that SOX2 is associated with CRC progression and may serve as a potential prognostic biomarker and therapeutic target of CRC.

Development and regeneration of the crushing dentition in skates (Rajidae).

Sharks and rays (elasmobranchs) have the remarkable capacity to continuously regenerate their teeth. The polyphyodont system is considered the ancestral condition of the gnathostome dentition. Despite this shared regenerative ability, sharks and rays exhibit dramatic interspecific variation in their tooth morphology. Ray (batoidea) teeth typically constitute crushing pads of flattened teeth, whereas shark teeth are pointed, multi-cuspid units. Although recent research has addressed the molecular development of the shark dentition, little is known about that of the ray. Furthermore, how dental diversity within the elasmobranch lineage is achieved remains unknown. Here, we examine dental development and regeneration in two Batoid species: the thornback skate (Raja clavata) and the little skate (Leucoraja erinacea). Using in situ hybridization and immunohistochemistry, we examine the expression of a core gnathostome dental gene set during early development of the skate dentition and compare it to development in the shark. Elasmobranch tooth development is highly conserved, with sox2 likely playing an important role in the initiation and regeneration of teeth. Alterations to conserved genes expressed in an enamel knot-like signalling centre may explain the morphological diversity of elasmobranch teeth, thereby enabling sharks and rays to occupy diverse dietary and ecological niches.

SOX2 and p53 Expression Control Converges in PI3K/AKT Signaling with Versatile Implications for Stemness and Cancer.

Stemness and reprogramming involve transcriptional master regulators that suppress cell differentiation while promoting self-renewal. A distinguished example thereof is SOX2, a high mobility group (HMG)-box transcription factor (TF), whose subcellular localization and turnover regulation in embryonic, induced-pluripotent, and cancer stem cells (ESCs, iPSCs, and CSCs, respectively) is mediated by the PI3K/AKT/SOX2 axis, a stem cell-specific branch of the PI3K/AKT signaling pathway. Further effector functions associated with PI3K/AKT induction include cell cycle progression, cellular (mass) growth, and the suppression of apoptosis. Apoptosis, however, is a central element of DNA damage response (DDR), where it provides a default mechanism for cell clearance when DNA integrity cannot be maintained. A key player in DDR is tumor suppressor p53, which accumulates upon DNA-damage and is counter-balanced by PI3K/AKT enforced turnover. Accordingly, stemness sustaining SOX2 expression and p53-dependent DDR mechanisms show molecular-functional overlap in PI3K/AKT signaling. This constellation proves challenging for stem cells whose genomic integrity is a functional imperative for normative ontogenesis. Unresolved mutations in stem and early progenitor cells may in fact provoke transformation and cancer development. Such mechanisms are also particularly relevant for iPSCs, where genetic changes imposed through somatic cell reprogramming may promote DNA damage. The current review aims to summarize the latest advances in the understanding of PI3K/AKT/SOX2-driven stemness and its intertwined relations to p53-signaling in DDR under conditions of pluripotency, reprogramming, and transformation.

Cancer-driven IgG promotes the development of prostate cancer though the SOX2-CIgG pathway.

BACKGROUND: Although androgen deprivation therapy (ADT) is the initial treatment strategy for prostate cancer (PCa), recurrent castration-resistant prostate cancer (CRPC) eventually ensues. In this study, cancer-derived immunoglobulin G (CIgG) is found to be induced after ADT, identifying CIgG as a potential CRPC driver gene. METHODS: The expression of CIgG and its clinical significance in PCa tissue was analyzed by The Cancer Genome Atlas database and immunohistochemistry. Subsequently, the sequence features of prostate cell line VHDJH rearrangements were analyzed. We also assessed the effect of CIgG on the migratory, invasive and proliferative abilities of PCa cells in vitro and vivo. Suspended microsphere, colony formation and drug-resistant assays were performed using PC3 cells with high CIgG expression (CIgGhigh ) and low CIgG expression (CIgG-/low ), and A nonobese diabetic/severe combined immunodeficiency mouse tumor xenograft model was developed for the study of the tumorigenic effects of the different cell populations. The SOX2-CIgG signaling pathway was validated by immunohistochemistry, immunofluorescence, quantitative reverse transcription-polymerase chain reaction, Western blot, luciferase, and chromatin immunoprecipitation assays and bioinformatics analyses. Finally, we investigated the effect of RP215 inhibition on the progression of PCa in vivo using a Babl/c nude mouse xenograft model. RESULTS: CIgG is frequently expressed in PCa and associated with clinicopathological characteristics, moreover, CIgG transcripts with unique patterns of VHDJH rearrangements are found in PCa cells. Functional analyses identified that CIgG was induced by ADT and upregulated by SOX2 (SRY (sex determining region Y)-box 2) in PCa, promoting the development of PCa. In addition, our findings underscore a novel role of CIgG signaling in the maintenance of stemness and the progression of cancer through mitogen activated protein kinase/extracellular-signal-regulated kinase and AKT in PCa. In vivo experiments further demonstrated that depleting CIgG significantly suppressed the growth of PCa cell xenografts. Furthermore, a CIgG monoclonal antibody named RP215 exhibits tumor inhibitory effect as well. CONCLUSION: Our data suggests that CIgG could be a driver of PCa development, and that targeting the SOX2-CIgG axis may therefore inhibit PCa development after ADT.

The role of SOX2 overexpression in prognosis of patients with solid tumors: A meta-analysis and system review.

BACKGROUND: Many studies have been done to reported the value of SRY-related HMG-box Gene 2 (SOX2) in prognosis of solid tumors. But results were not particularly consistent among these studies because of the limitations of the small sample data. METHODS: We searched relevant studies published before November 2018 by PubMed, Web of Science and EMBASE. In this meta-analysis, hazard ratio (HR) values for overall survival (OS) were cumulatively pooled and quantitatively analyzed. RESULTS: A meta-analysis based on 12 studies with 3318 patients was conducted to assess the potential correlation between SOX2 overexpression and OS in human solid tumors. A total of 12 studies (n = 3318) were assessed in the meta-analysis. It suggested that the high expression of SOX2 obviously indicates poor survival and prognosis in both univariate and multivariate analysis. In the univariate analysis, the combined HR for OS was 1.66 (95% confidence interval [CI]: 1.46-1.89, P < .001). The pooled HR of multivariate analysis for OS was 1.51 (95% confidence interval [CI]: 1.32-1.71, P < .001). CONCLUSIONS: This meta-analysis indicated that the high expression level of SOX2 is significantly associated with a decline in survival of human with solid tumors. On the basis of the expression level in solid tumors, SOX2 is expected to be a meaningful prognostic biomarker and effective therapeutic target.

Association of SOX2, OCT4 and WNT5A Expression in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma: An Immunohistochemical Study.

The cancer stem cells deliver uncontrolled proliferative capacity within the tumor imparting to increasing size while epithelial mesenchymal transition adds to the invasive potential. Studies using specific markers elucidating the role of these phenomena may bring advancement in the targeted therapy of tumor. SOX2 and OCT4 are two among few stem cell markers indicative of proliferative potential and WNT5A is an epithelial mesenchymal transition marker indicative of invasive potential. We aimed to determine the association between expression of SOX2, OCT4 and WNT5A in oral epithelial dysplasia, oral squamous cell carcinoma and normal oral mucosa. 20 cases of oral squamous cell carcinoma, 20 cases of oral epithelial dysplasia (leukoplakia with dysplasia) and 25 normal oral mucosa tissues specimens were immunohistochemically stained to assess SOX2, OCT4 and WNT5A expression. SOX2 expression was higher in oral squamous cell carcinoma than in oral epithelial dysplasia and very low in normal oral mucosa. OCT4 was very low in oral squamous cell carcinoma and oral epithelial dysplasia when compared to SOX2, while negative in normal tissues. Co-expression of SOX2 and OCT4 showed statistically non-significant difference for tumor proliferation. WNT5A expression was found to be increasing from normal oral mucosa to oral epithelial dysplasia and oral squamous cell carcinoma. In conformity with present study, SOX2 itself can act as a potential marker for proliferation in tumor cells while OCT4 has non-significant role in regulation of tumor behavior in oral squamous cell carcinoma as well as in oral epithelial dysplasia. WNT5A can be a putative marker in studying invasive potential of oral squamous cell carcinoma.

The Evaluation of TUNEL, PCNA and SOX2 Expressions in Lens Epithelial Cells of Cataract Patients with Pseudoexfoliation Syndrome.

Purpose: This study aims to determine the expression patterns of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), proliferating cell nuclear antigen (PCNA) and SOX2 in lens epithelial cells (LEC) of cataract patients with pseudoexfoliation syndrome (PEX), and to determine the effect of apoptosis, proliferative activity and stem/progenitor cells on cataract formation in patients with PEX. This is a prospective, randomized clinical trial.Materials and Methods: Setting: institutional. 50 eyes of 50 patients were included. Anterior capsule samples were obtained during phacoemulsification surgery. The specimens of LEC were also examined using the TUNEL, PCNA and SOX2 immunohistochemical staining method. To detect the number of immunopositive cells, the total number of cells in a 3 mm2 area was counted using a microscope under x20 magnification and the percentage of cells stained positive was determined.Results: In Group 1, increased expression was observed with TUNEL, while decreased expression was detected with PCNA (p = .008, p = .015). The average percentage of TUNEL immunopositive cells was significantly higher in Group 1 than in Group 2, but there was no statistically meaningful SOX2 expression in Group 1 and Group 2 (P = .44). Apoptosis rates were 61.75 ± 14.5% and 36.91 ± 14.6% in Groups 1 and 2, respectively. Proliferation rates were 40.96 ± 16.8% and 65.45 ± 16.9% in Groups 1 and 2, respectively.Conclusion: We found increased apoptosis and decreased proliferation of LECs in cataract patients with PEX. We suspected that this could be related to oxidative stress.

circ_0005273 promotes thyroid carcinoma progression by SOX2 expression.

Papillary thyroid carcinoma (PTC) is one of the most prevalent tumors in endocrine system. CircRNAs (circular RNAs) are widely known as critical regulators in tumorigenesis of papillary thyroid carcinoma (PTC). The present study focused on the functional investigation and potential molecular mechanism toward circ_0005273 in PTC progression. Gene Expression Omnibus datasets (GSE93522) and qRT-PCR (quantitative real-time PCR) analyses showed that circ_0005273 were upregulated in PTC tissues and cell lines. Moreover, circ_0005273 was located in the cytoplasm of PTC cells and suggested poor prognosis in PTC patients. In vivo and in vitro functional assays indicated that knockdown of circ_0005273 inhibited PTC tumor growth and progression, respectively. Mechanistically, miR-1183 was identified as functional target of circ_0005273, and circ_0005273 could directly bind to miR-1138 and relieve inhibition of SRY (sex-determining region Y)-box 2 (SOX2). Data from Cell Counting Kit-8, colony formation assays and transwell assays revealed that the oncogenic role of circ_0005273 on PTC progression dependent on miR-1183-mediated SOX2 expression. In conclusion, circ_0005273 functioned as a tumor promoter of PTC via circ_0005273/miR-1183/SOX2 axis, suggesting a novel biomarker and therapeutic target for PTC.

Chlorogenic acid inhibits esophageal squamous cell carcinoma growth in vitro and in vivo by downregulating the expression of BMI1 and SOX2.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in China, accompanied by an extremely high mortality rate. Chlorogenic acid (CGA) is a small-molecule compound, that has been shown to have a wide range of biological activities, including antitumor. However, the efficacy and molecular mechanism of CGA on ESCC remains unknown. In this study, we confirmed the inhibition of proliferation by CGA in ESCC cells, as well as the reduction of ESCC xenograft volume by CGA in vivo. In addition, CGA also suppressed both the migration and invasion of ESCC cells in vitro. In a carcinogen-induced murine model of ESCC, hyperplasia of the esophagus was slowed by CGA, while mice suffering from ESCC that were treated with CGA had longer survival times than mice in the control group. The measurement of pluripotency factors (BMI1, SOX2, OCT4 and Nanog) that are related to poor prognosis revealed reduced expression of both BMI1 and SOX2, but not of OCT4 or Nanog, in ESCC cells, in both a dose- and time-dependent manner. Together, our initial findings demonstrate that CGA suppresses ESCC progression, downregulates the expression of BMI1 and SOX2, and provide an anti-tumor candidate for ESCC therapy.

Comprehensive in situ analysis of ALDH1 and SOX2 reveals increased expression of stem cell markers in high-grade serous carcinomas compared to low-grade serous carcinomas and atypical proliferative serous tumors.

Recent studies have shown that re-expression of stem cell factors contribute to pathogenesis, therapy resistance, and recurrent disease in ovarian carcinomas. In this study, we compare the expression and co-expression of stem cell markers ALDH1 and SOX2 in different types of serous ovarian tumors. A total of 215 serous ovarian tumors (161 high-grade serous carcinomas (HGSC), 17 low-grade serous carcinomas (LGSC), 37 atypical proliferative serous tumors (APST)), and 10 cases of serous tubal intraepithelial carcinoma (STIC) were analyzed. Double immunostaining experiments addressed the association of cell proliferation (Ki67) with ALDH1 and the potential co-expression of SOX2 and ALDH1. The prognostic effect was analyzed in the cohort of HGSC. Expression of ALDH1and/or SOX2 was detected with increased frequency in HGSC (88.8%), compared with LGSC (70.5%) and APST (36.4%), while ALDH1 alone was significantly more frequently expressed in LGSC. The majority of all tumor types showed expression of ALDH1 and SOX2 in different cells. Only a minority of HGSC (4.6%) and STIC (20%) showed SOX2/ALDH1 co-expression in > 10% of tumor cells. Double staining also revealed that ALDH1 is associated with the non-proliferating Ki67-negative fraction consistent with a stem cell phenotype. Co-expression of ALDH1 and SOX2 or ALDH1 and Ki67 has no effect on survival. Expression of stem cell factors ALDH1 and/or SOX2 shows increased frequency in high-grade serous ovarian carcinomas compared to low-grade carcinomas and borderline tumors, supporting the concept that stem cell markers play different biological roles in low-grade versus high-grade serous neoplasia of the ovary.

miR-126-3p sensitizes glioblastoma cells to temozolomide by inactivating Wnt/ß-catenin signaling via targeting SOX2.

AIMS: The acquired drug resistance has been regarded as a main barrier for the effective treatment of temozolomide (TMZ) in glioblastoma (GBM). MiR-126-3p is commonly down-regulated and exerts tumor-suppressive roles in kinds of human cancers, including GBM. This study was designed to investigate the functions and mechanisms of miR-126-3p in regulating TMZ resistance in GBM. MATERIALS AND METHODS: qRT-PCR analysis was used to measure the expressions of miR-126-3p and SOX2 mRNA in GBM tissues and cells. Cell viability, colony forming ability and apoptosis were detected to evaluate the effect of miR-126-3p or SOX2 on TMZ resistance. Luciferase reporter experiments were applied to identify the target genes of miR-126-3p. Western blot analysis was performed to determine the protein levels associated with Wnt/ß-catenin signaling. TOP/FOP Flash assays were conducted to determine the effects of miR-126-3p or SOX2 on Wnt/ß-catenin signaling. KEY FINDINGS: miR-126-3p expression was decreased in TMZ-resistant GBM tissues and cells. High levels of miR-126-3p enhanced TMZ sensitivity by inhibiting cell viability, reducing colony forming potential and inducing apoptosis. Additionally, SOX2 was identified as a downstream target of miR-126-3p. On the contrary, SOX2 overexpression conferred TMZ resistance of GBM cells. Moreover, miR-126-3p-mediated TMZ sensitivity was reversed following increased expression of SOX2. Furthermore, miR-126-3p-induced inactivation of Wnt/ß-catenin signaling was greatly abrogated by SOX2 up-regulation. SIGNIFICANCE: MiR-126-3p sensitizes GBM cells to TMZ possibly by repressing SOX2 expression and blocking Wnt/ß-catenin signaling. This study provides novel targets to overcome TMZ resistance in GBM chemotherapy.

Protective autophagy decreases osimertinib cytotoxicity through regulation of stem cell-like properties in lung cancer.

Osimertinib, a third-generation epidermal growth factor receptor - tyrosine kinase inhibitor (EGFR-TKI), shows great efficacy in EGFR-mutant non-small cell lung cancer (NSCLC); however, the resistance is inevitable. Osimertinib induces autophagy in NSCLC cells, but the role of autophagy in osimertinib resistance is not clear. We discovered that enhanced autophagy is associated with osimertinib resistance in vitro and in vivo. Inhibition of autophagy enhanced osimertinib cytotoxicity in both osimertinib-resistant and sensitive cells. Moreover, osimertinib-resistant cells exhibited stem cell-like properties, whereas autophagy inhibition decreased the stemness by downregulating the expression of SOX2 and ALDH1A1. Further, we found that knockdown of Beclin-1 inhibited the stem cell-like properties and restored osimertinib cytotoxicity. Osimertinib combined with chloroquine inhibited tumor growth more effectively than alone in xenograft mice. These results reveal that autophagy plays an adverse role in osimertinib cytotoxicity through inducing stem cell-like properties. Combination therapy of EGFR-TKI and autophagy inhibitor could provide a promising strategy to improve osimertinib cytotoxicity.

Direct and selective lineage conversion of human fibroblasts to dopaminergic precursors.

Transplantation of dopaminergic precursors (DPs) is a promising therapeutic strategy of Parkinson's disease (PD). However, limited cell source for dopaminergic precursors has become a major obstacle for transplantation therapy. Our group demonstrated previously that mouse fibroblasts can be reprogrammed into induced dopaminergic precursors (iDPs) with high differentiation efficiency. In the current study, we hypothesized that a similar strategy can be applied to generate human iDPs for future cell therapy of PD. We overexpressed transcription factors Brn2, Sox2, and Foxa2 in human fibroblasts and observed formation of neurospheres. Subsequent characterization of the precursor colonies confirmed the generation of human induced dopaminergic precursors (hiDPs). These hiDPs were capable of self-renewal, proliferation, and differentiation. The hiDPs demonstrated high immunoreactivity for neural progenitor markers and high levels of gene expression for ventral mesencephalon-related neural progenitor markers such as Lmx1a, NIKX6.1, Corin, Otx2 and Mash1. Furthermore, the hiDPs could be differentiated into dopaminergic neurons with ˜80% efficiency, which significantly increased major functionally relevant proteins such as TH, DAT, AADC, Lmx1B, and VMAT2 compared to hiDPs. Additionally, hiDPs are more dopaminergic progenitor-restricted compare to those hiDP-like cells reprogrammed only by Brn2 and Sox2. Together, these results suggest that hiDPs with high differentiation efficiency can be generated by direct lineage reprogramming of fibroblasts with transcription factors Brn2, Sox2, and Foxa2. These hiDPs may serve as a safe and effective cell source for transplantation treatment of PD.