Beta hydroxybutyrate induces lung cancer cell death, mitochondrial impairment and oxidative stress in a long term glucose-restricted condition

BACKGROUND

Metabolic plasticity gives cancer cells the ability to shift between signaling pathways to facilitate their growth and survival. This study investigates the role of glucose deprivation in the presence and absence of beta-hydroxybutyrate (BHB) in growth, death, oxidative stress and the stemness features of lung cancer cells.

METHODS AND RESULTS

A549 cells were exposed to various glucose conditions, both with and without beta-hydroxybutyrate (BHB), to evaluate their effects on apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS) levels using flow cytometry, and the expression of CD133, CD44, SOX-9, and β-Catenin through Quantitative PCR. The activity of superoxide dismutase, glutathione peroxidase, and malondialdehyde was assessed using colorimetric assays. Treatment with therapeutic doses of BHB triggered apoptosis in A549 cells, particularly in cells adapted to glucose deprivation. The elevated ROS levels, combined with reduced levels of SOD and GPx, indicate that oxidative stress contributes to the cell arrest induced by BHB. Notably, BHB treatment under glucose-restricted conditions notably decreased CD133 expression, suggesting a potential inhibition of cell survival through the downregulation of CD133 levels. Additionally, the simultaneous decrease in mitochondrial membrane potential and increase in ROS levels indicate the potential for creating oxidative stress conditions to impede tumor cell growth in such environmental settings.

CONCLUSION

The induced cell death, oxidative stress and mitochondria impairment beside attenuated levels of cancer stem cell markers following BHB administration emphasize on the distinctive role of metabolic plasticity of cancer cells and propose possible therapeutic approaches to control cancer cell growth through metabolic fuels.

High CD133 expression in proximal tubular cells in diabetic kidney disease: good or bad?

BACKGROUND

Proximal tubular cells (PTCs) play a critical role in the progression of diabetic kidney disease (DKD). As one of important progenitor markers, CD133 was reported to indicate the regeneration of dedifferentiated PTCs in acute kidney disease. However, its role in chronic DKD is unclear. Therefore, we aimed to investigate the expression patterns and elucidate its functional significance of CD133 in DKD.

METHODS

Data mining was employed to illustrate the expression and molecular function of CD133 in PTCs in human DKD. Subsequently, rat models representing various stages of DKD progression were established. The expression of CD133 was confirmed in DKD rats, as well as in human PTCs (HK-2 cells) and rat PTCs (NRK-52E cells) exposed to high glucose. The immunofluorescence and flow cytometry techniques were utilized to determine the expression patterns of CD133, utilizing proliferative and injury indicators. After overexpression or knockdown of CD133 in HK-2 cells, the cell proliferation and apoptosis were detected by EdU assay, real-time cell analysis and flow analysis. Additionally, the evaluation of epithelial, progenitor cell, and apoptotic indices was performed through western blot and quantitative RT-PCR analyses.

RESULTS

The expression of CD133 was notably elevated in both human and rat PTCs in DKD, and this expression increased as DKD progressed. CD133 was found to be co-expressed with CD24, KIM-1, SOX9, and PCNA, suggesting that CD133+ cells were damaged and associated with proliferation. In terms of functionality, the knockdown of CD133 resulted in a significant reduction in proliferation and an increase in apoptosis in HK-2 cells compared to the high glucose stimulus group. Conversely, the overexpression of CD133 significantly mitigated high glucose-induced cell apoptosis, but had no impact on cellular proliferation. Furthermore, the Nephroseq database provided additional evidence to support the correlation between CD133 expression and the progression of DKD. Analysis of single-cell RNA-sequencing data revealed that CD133+ PTCs potentially play a role in the advancement of DKD through multiple mechanisms, including heat damage, cell microtubule stabilization, cell growth inhibition and tumor necrosis factor-mediated signaling pathway.

CONCLUSION

Our study demonstrates that the upregulation of CD133 is linked to cellular proliferation and protects PTC from apoptosis in DKD and high glucose induced PTC injury. We propose that heightened CD133 expression may facilitate cellular self-protective responses during the initial stages of high glucose exposure. However, its sustained increase is associated with the pathological progression of DKD. In conclusion, CD133 exhibits dual roles in the advancement of DKD, necessitating further investigation.

A Validation Study of CD133 as a Reliable Marker for Identification of Colorectal Cancer Stem-Like Cells

Colorectal carcinoma (CRC) is maintained by putative colorectal cancer stem-like cells (CRC-CSCs) that are responsible for CRC metastasis and relapse. Targeting these CSCs can be an effective treatment of CRC. However, reliable identification of CRC-CSCs remains controversial due to the absence of specific markers. It is assumed that glycoprotein CD133 can serve as a useful marker for identification of CRC-CSCs. In this study, we employed CD133 as a marker to identify CRC-CSCs in human (LoVo, HCT116, and SW620) and mouse (CT26) CRC cell lines. In these lines, CD133+ cells were isolated and identified by magnetic-activated cell sorting and flow cytometry. Proliferation, colony formation, and drug resistance of CD133+ cells were analyzed in vitro, and their tumorigenicity was determined in vivo on mice. Proliferation, colony-forming ability, drug resistance, and tumorigenicity of CD133+ cells were higher than those of CD133- cells. Thus, cultured CD133+ cells had the characteristics of CSCs. Hence, glycoprotein CD133 is a reliable marker to identify CRC-CSCs. These results can be used for designing a novel therapeutic target in CRC treatment.

Genetic and clinical characteristics of PROM1-related retinal degeneration in Korean

This scientific report aims to comprehensively describe the genetic and clinical characteristics of PROM1-related retinal degeneration in Korean patients. Medical records of patients diagnosed with retinal dystrophy who underwent comprehensive ophthalmologic examination and genetic testing at Samsung Medical Center between January 2016 and April 2023 were retrospectively reviewed. Genetic testing included targeted gene panel sequencing and Sanger sequencing, with diagnosis based on the presence of a "Likely Pathogenic" or "Pathogenic Variant" in the PROM1 gene, as determined by the ACMG criteria. The study identified seven patients from five unrelated families with PROM1-related retinal degeneration, all carrying the autosomal dominant variant PROM1 p.R373C; no other PROM1 gene variants were detected. All patients exhibited degenerative retinal area within the macula, with peripheral retinal degeneration observed in five patients. Substantial interfamilial and intrafamilial variability was observed in the extent of macular and peripheral degeneration. Ultra-widefield autofluorescence imaging and fluorescein angiography aided in the detection of mild peripheral degeneration in one case. In conclusion, the autosomal dominant variant PROM1 p.R373C constitutes a significant proportion of PROM1-related retinal degeneration cases in the Korean population. The observed clinical heterogeneity may suggests the potential influence of additional genetic, epigenetic, and environmental factors on disease phenotypes.

Clinical Characteristics and Genetic Variants in Taiwanese Patients With PROM1-Related Inherited Retinal Disorders

Purpose

This study investigated the clinical characteristics of patients with PROM1-related inherited retinal diseases (IRDs).

Methods

Patients diagnosed with IRDs who had mutations in PROM1 were identified at Linkou Chang Gung Memorial Hospital and Kaohsiung Medical University Hospital in Taiwan. Information on clinical characteristics and best-corrected visual acuity was recorded. Color fundus (CF) images, fundus autofluorescence photography (FAF), spectral-domain optical coherence tomography (SD-OCT), and electroretinograms (ERGs) were analyzed to examine patient phenotypes. PROM1 variants were detected using whole exome sequencing and verified by Sanger sequencing.

Results

Fourteen patients from nine families with PROM1-related IRDs were analyzed. Most patients exhibited chorioretinal atrophy in the macular area, with or without extramacular involvement on CF. Similarly, hypo-autofluorescence confined to the macular area, with or without extramacular involvement, was present for most patients on FAF. Furthermore, SD-OCT revealed outer retinal tubulations and focal or diffuse retinal thinning. ERGs showed variable findings, including maculopathy with normal ERG, subnormal cone response, and extinguished rod and cone responses. We detected five variants of the PROM1 gene, including c.139del, c.794del, c.1238T>A, c.2110C>T, and c.1117C>T.

Conclusions

In this study, we evaluated 14 Taiwanese patients with five PROM1 variants. Additionally, incomplete penetrance of heterozygous PROM1 variants was observed. Furthermore, patients with autosomal dominant PROM1 variants had lesions in the macular area and the peripheral region of the retina. SD-OCT serves as a useful tool for early detection of PROM1-related IRDs, as it captures certain signs of such diseases.

Exosomes from metastatic colon cancer cells drive the proliferation and migration of primary colon cancer through increased expression of cancer stem cell markers CD133 and DCLK1

The exchange of biological material between the neighbouring cells is essential for homeostasis. In pathological conditions, such as cancer, the major challenge in cancer treatment is the abnormal expression of crucial proteins and miRNA exchanged between the cancer cells through extracellular vesicles called exosomes. Clinically, it has been noticed that the primary tumour and the distal metastases are interconnected and co-dependent. The exosomes are key factors responsible for preparing the pre-metastatic niche and communicating between the tumour and the distal metastatic site. Cancer stem cells (CSCs) are a subpopulation of cancer cells with self-renewal characteristics and are shown to be responsible for metastasis. This study aims to understand the effect of metastatic cell line-derived exosomes and their regulation of CSC marker expressions on primary colon cancer cell lines. We have identified that treatment of primary colon cancer cell lines with metastatic colon cancer cell-derived exosomes has significantly increased the proliferation, colony formation, cell migration, and invasion. In addition, there was a significant increase in the number and size of spheroids following the exosomes treatment. We found that this metastatic phenotype is due to the increased expression of CD133 and DCLK1 in primary colon cancer cells.

CD133/Prom1 marks proximal mouse oviduct epithelial progenitors and adult epithelial cells with a low generative capacity

The epithelium lining the oviduct or fallopian tube consists of multiciliated and secretory cells, which support fertilization and preimplantation development, however, its homeostasis remains poorly understood. CD133/Prom1 expression has been used as a marker to identify adult stem cell populations in various organs and often associated with cancer cells that have stem-like properties. Using an antibody targeted to CD133 and a Cre recombinase-based lineage tracing strategy, we found that CD133/Prom1 expression is not associated with a stem/progenitor population in the oviduct but marked predominantly multiciliated cells with a low generative capacity. Additionally, we have shown that CD133 is disparately localised along the oviduct during neonatal development, and that Prom1 expressing secretory cells in the ampulla rapidly transitioned to multiciliated cells and progressively migrated to the ridge of epithelial folds.

MACULAR ATROPHY AND PHENOTYPIC VARIABILITY IN AUTOSOMAL DOMINANT STARGARDT-LIKE MACULAR DYSTROPHY DUE TO PROM1 MUTATION

PURPOSE

To describe the phenotypic variability and rates of progression of atrophy in patients with PROM1 -associated macular dystrophy.

METHODS

Patients in this retrospective, longitudinal case series from a tertiary center had clinical examination and multimodal imaging performed. Areas of retinal pigment epithelium and ellipsoid zone loss over time by optical coherence tomography were calculated by two independent graders.

RESULTS

Fifteen patients from five kindreds with an Arg373Cys mutation in PROM1 were studied. The average age was 39 years, and 80% were women. The visual acuity was 20/40 at presentation and 20/57 at last follow-up (average 4.8 years). Three distinct macular phenotypes were observed: 1) central geographic atrophy (13%), 2) multifocal geographic atrophy (20%), and 3) bull's eye maculopathy (67%). The overall rate of atrophy progression was 0.36 mm 2 /year, but the average rate of atrophy progression varied by macular phenotype: 1.08 mm 2 /year for central geographic atrophy, 0.53 mm 2 /year for multifocal geographic atrophy, and 0.23 mm 2 /year for bull's eye maculopathy.

CONCLUSION

Patients with PROM1 -associated macular dystrophy demonstrate distinct phenotypes, with bull's eye maculopathy being the most common. The average rate of atrophy progression may be similar to reported rates for ABCA4 -related Stargardt disease and less than age-related macular degeneration. These results provide important measures for following treatment response in future gene and stem cell-based therapies.

Prominin-1 promotes restitution of the murine extrahepatic biliary luminal epithelium following cholestatic liver injury

BACKGROUND AND AIMS

Restitution of the extrahepatic biliary luminal epithelium in cholangiopathies is poorly understood. Prominin-1 (Prom1) is a key component of epithelial ciliary body of stem/progenitor cells. Given that intrahepatic Prom1-expressing progenitor cells undergo cholangiocyte differentiation, we hypothesized that Prom1 may promote restitution of the extrahepatic bile duct (EHBD) epithelium following injury.

APPROACH AND RESULTS

Utilizing various murine biliary injury models, we identified Prom1-expressing cells in the peribiliary glands of the EHBD. These Prom1-expressing cells are progenitor cells which give rise to cholangiocytes as part of the normal maintenance of the EHBD epithelium. Following injury, these cells proliferate significantly more rapidly to re-populate the biliary luminal epithelium. Null mutation of Prom1 leads to significantly >10-fold dilated peribiliary glands following rhesus rotavirus-mediated biliary injury. Cultured organoids derived from Prom1 knockout mice are comprised of biliary progenitor cells with altered apical-basal cellular polarity, significantly fewer and shorter cilia, and decreased organoid proliferation dynamics consistent with impaired cell motility.

CONCLUSIONS

We, therefore, conclude that Prom1 is involved in biliary epithelial restitution following biliary injury in part through its role in supporting cell polarity.

Clinical Characterization of Autosomal Dominant and Autosomal Recessive PROM1 Mutation With a Report of Novel Mutation

BACKGROUND AND OBJECTIVE

This study aims to provide clinical characterization of PROM1 mutation with a report of novel mutation.

PATIENTS AND METHODS

This study is a retrospective case series of six patients from a single institution with multimodal imaging, electroretinography, and genetic testing.

RESULTS

Six patients aged 12 to 47 years were identified. Patients with autosomal recessive (AR) variants showed more severe panretinal dystrophy with symmetrical macular involvement and peripheral retinal pigment epithelium atrophy. The autosomal dominant (AD) variants, on the other hand, showed milder macular involvement with bull's eye maculopathy phenotype with minimal peripheral involvement. Among patients with AR variants, a younger patient with aberrant splicing showed a milder phenotype compared with patients with a nonsense mutation and an additional ABCA4 mutation.

CONCLUSION

The authors describe patients with PROM1 retinopathy inherited AD and AR inherited patterns. Novel mutations of c.1909C>T and c.2050C>T were identified, leading to truncation of the protein at sequence p.Gln637* and p.Arg684*, respectively. [Ophthalmic Surg Lasers Imaging Retina 2022;53:422-428.].

Effect of CD133 Polymorphisms on the Risk of Developing Liver Cirrhosis and hepatocellular carcinoma Induced by Viral Hepatitis

BACKGROUND

CD133 has been postulated to identify cancer stem cells (CSCs) and to play a role in tumorigenesis and cancer progression. The purpose of this study was to explore the impact of CD133 polymorphisms on viral hepatitis-induced liver cirrhosis, as well as hepatocellular carcinoma (HCC) susceptibility and prognosis.

METHODOLOGY

Cd133⁺ cells were counted and CD133 SNPs (rs3130, rs1029728, rs2240688, and rs2286455) were genotyped in HCV, HCV-liver cirrhosis, HCV-HCC, HBV, HBV-liver cirrhosis, and HBV-HCC patients and disease-free controls.

RESULTS

The percentage of CD133⁺ cells was observed to be significantly higher in HCV- and HBV-associated liver cirrhosis and HCC. Also, the CD133 rs3130 (C > T) TT, rs1029728 (A > G) GG, and rs2240688 (G > T) SNP TT genotypes were associated with a greater risk of liver cirrhosis and HCC development in viral hepatitis patients. Furthermore, in HCV-related HCC, rs3130 TT, rs1029728 GG, or rs2240688 TT genotypes were significantly associated with an increased number and size of focal lesions, but only the rs3130 TT genotype was associated with higher lesion size in HBV-associated HCC. In addition, individuals having rs3130 TT and rs1029728 GG genotypes had a significantly higher percentage of CD133⁺ cells. However, only HCV-infected individuals, carrying rs2240688 TT genotype, had an elevated level of CD133⁺ cells.

CONCLUSIONS

CD133 rs3130, rs1029728, and rs2240688 are genetic factors that can influence the susceptibility to liver cirrhosis and cancer, as well as the prognosis. As a result, CD133⁺ cells and CD133 polymorphisms might serve as potential predictors of these illnesses, laying the groundwork for the discovery of novel therapeutic targets.

Emerging roles of CD133 in the treatment of gastric cancer, a novel stem cell biomarker and beyond

Gastric cancer (GC) is an aggressive disease with one of the highest mortality rates in the world. In the early stage, most patients are asymptomatic and early diagnosis is difficult. Recently, cancer stem cells (CSCs) have been highlighted as crucial emerging factors in the initiation or invasiveness of solid tumors. CD133, a CSC marker, is highly expressed in various tumors including gastric cancer. CD133-positive cells showed elevated malignant biological behaviors and CD133 upregulation is related to chemoresistance, cancer relapse, and poor prognosis. CD133 also plays an important role in the progression of tumors and metastasis. This review summarizes the current knowledge of the role of CD133 expression in GC and aims to contribute at identifying promising new strategies for treatment and management of gastric cancer.

HN1L promotes stem cell-like properties by regulating TGF-β signaling pathway through targeting FOXP2 in prostate cancer

Dysregulated hematological and neurological expressed 1-like (HN1L) has been implicated in carcinogenesis of difference cancers, including hepatocellular carcinoma and breast cancer. However, the role of HN1L in the progression of prostate cancer (PCA) remains unknown. Therefore, we aimed to investigate the role of HN1L in stemness and progression of PCA. The expression of HN1L in PCA tissues and cells was determined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), western blot analysis, and/or immunohistochemistry (IHC). CD133+ cells were sorted from PCA cells using magnetic fluorescence cell sorting technology and were considered as cancer stem cells (CSCs). Sphere formation assays, transwell assays, and animal experiments were conducted to assess cell stemness, migration, invasion, and in vivo tumorigenesis, respectively. The results showed that HN1L expression was higher in PCA tissues and cells as compared with normal tissues and cells, as well as in CD133+ cells as compared with CD133- cells. HN1L knockdown significantly decreased the expression levels of CSC markers including OCT4 (POU class 5 homeobox 1), CD44, and SRY-box transcription factor 2, inhibited cell migration, invasion, and tumorigenesis and decreased the number of tumor spheroids and CD133+ cell population. Furthermore, we found that HN1L could bind to forkhead box P2 (FOXP2) and positively regulated transforming growth factor-β (TGF-β) expression via upregulation of FOXP2. In addition, the overexpression of TGF-β in HN1L-knockdown PCA cells increased the number of tumor spheroids and CD133+ cell population, as well as enhanced cell migration and invasion. Collectively, this study demonstrates that HN1L promotes stem cell-like properties and cancer progression by targeting FOXP2 through TGF-β signaling pathway in PCA.

An Enhancer-Driven Stem Cell-Like Program Mediated by SOX9 Blocks Intestinal Differentiation in Colorectal Cancer

BACKGROUND AND AIMS

Genomic alterations that encourage stem cell activity and hinder proper maturation are central to the development of colorectal cancer (CRC). Key molecular mediators that promote these malignant properties require further elucidation to galvanize translational advances. We therefore aimed to characterize a key factor that blocks intestinal differentiation, define its transcriptional and epigenetic program, and provide preclinical evidence for therapeutic targeting in CRC.

METHODS

Intestinal tissue from transgenic mice and patients were analyzed by means of histopathology and immunostaining. Human CRC cells and neoplastic murine organoids were genetically manipulated for functional studies. Gene expression profiling was obtained through RNA sequencing. Histone modifications and transcription factor binding were determined with the use of chromatin immunoprecipitation sequencing.

RESULTS

We demonstrate that SRY-box transcription factor 9 (SOX9) promotes CRC by activating a stem cell-like program that hinders intestinal differentiation. Intestinal adenomas and colorectal adenocarcinomas from mouse models and patients demonstrate ectopic and elevated expression of SOX9. Functional experiments indicate a requirement for SOX9 in human CRC cell lines and engineered neoplastic organoids. Disrupting SOX9 activity impairs primary CRC tumor growth by inducing intestinal differentiation. By binding to genome wide enhancers, SOX9 directly activates genes associated with Paneth and stem cell activity, including prominin 1 (PROM1). SOX9 up-regulates PROM1 via a Wnt-responsive intronic enhancer. A pentaspan transmembrane protein, PROM1 uses its first intracellular domain to support stem cell signaling, at least in part through SOX9, reinforcing a PROM1-SOX9 positive feedback loop.

CONCLUSIONS

These studies establish SOX9 as a central regulator of an enhancer-driven stem cell-like program and carry important implications for developing therapeutics directed at overcoming differentiation defects in CRC.

RASSF1C oncogene elicits amoeboid invasion, cancer stemness, and extracellular vesicle release via a SRC/Rho axis

Cell plasticity is a crucial hallmark leading to cancer metastasis. Upregulation of Rho/ROCK pathway drives actomyosin contractility, protrusive forces, and contributes to the occurrence of highly invasive amoeboid cells in tumors. Cancer stem cells are similarly associated with metastasis, but how these populations arise in tumors is not fully understood. Here, we show that the novel oncogene RASSF1C drives mesenchymal-to-amoeboid transition and stem cell attributes in breast cancer cells. Mechanistically, RASSF1C activates Rho/ROCK via SRC-mediated RhoGDI inhibition, resulting in generation of actomyosin contractility. Moreover, we demonstrate that RASSF1C-induced amoeboid cells display increased expression of cancer stem-like markers such as CD133, ALDH1, and Nanog, and are accompanied by higher invasive potential in vitro and in vivo. Further, RASSF1C-induced amoeboid cells employ extracellular vesicles to transfer the invasive phenotype to target cells and tissue. Importantly, the underlying RASSF1C-driven biological processes concur to explain clinical data: namely, methylation of the RASSF1C promoter correlates with better survival in early-stage breast cancer patients. Therefore, we propose the use of RASSF1 gene promoter methylation status as a biomarker for patient stratification.

Wnt/β-catenin Signaling Inhibitors suppress the Tumor-initiating properties of a CD44+CD133+ subpopulation of Caco-2 cells

Tumor-initiating cells or cancer stem cells are a subset of cancer cells that have tumorigenic potential in human cancer. Although several markers have been proposed to distinguish tumor-initiating cells from colorectal cancer cells, little is known about how this subpopulation contributes to tumorigenesis. Here, we characterized a tumor-initiating cell subpopulation from Caco-2 colorectal cancer cells. Based on the findings that Caco-2 cell subpopulations express different cell surface markers, we were able to discriminate three main fractions, CD44-CD133-, CD44-CD133+, and CD44+CD133+ subsets, and characterized their biochemical and tumorigenic properties. Our results show that CD44+CD133+ cells possessed an unusual capacity to proliferate and could form tumors when transplanted into NSG mice. Additionally, primary tumors grown from CD44+CD133+ Caco-2 cells contained mixed populations of CD44+CD133+ and non-CD44+CD133+ Caco-2 cells, indicating that the full phenotypic heterogeneity of the parental Caco-2 cells was re-created. Notably, only the CD44+CD133+ subset of Caco-2-derived primary tumors had tumorigenic potential in NSG mice, and the tumor growth of CD44+CD133+ cells was faster in secondary xenografts than in primary transplants. Gene expression analysis revealed that the Wnt/β-catenin pathway was over-activated in CD44+CD133+ cells, and the growth and tumorigenic potential of this subpopulation were significantly suppressed by small-molecule Wnt/β-catenin signaling inhibitors. Our findings suggest that the CD44+CD133+ subpopulation from Caco-2 cells was highly enriched in tumorigenic cells and will be useful for investigating the mechanisms leading to human colorectal cancer development.

Elevated glucose represses lysosomal and mTOR-related genes in renal epithelial cells composed of progenitor CD133+ cells

Hyperglycemia is one of the major health concern in many parts of the world. One of the serious complications of high glucose levels is diabetic nephropathy. The preliminary microarray study performed on primary human renal tubular epithelial (hRTE) cells exposed to high glucose levels showed a significant downregulation of mTOR as well as its associated genes as well as lysosomal genes. Based on this preliminary data, the expression of various lysosomal genes as well as mTOR and its associated genes were analyzed in hRTE cells exposed to 5.5, 7.5, 11 and 16 mM glucose. The results validated the microarray analysis, which showed a significant decrease in the mRNA as well as protein expression of the selected genes as the concentration of glucose increased. Co-localization of lysosomal marker, LAMP1 with mTOR showed lower expression of mTOR as the glucose concentration increased, suggesting decrease in mTOR activity. Although the mechanism by which glucose affects the regulation of lysosomal genes is not well known, our results suggest that high levels of glucose may lead to decrease in mTOR expression causing the cells to enter an anabolic state with subsequent downregulation of lysosomal genes.

Human CD34-negative hematopoietic stem cells: The current understanding of their biological nature

Hematopoietic stem cell (HSC) heterogeneity and hierarchy are a current topic of interest, having major implications for clinical HSC transplantation and basic research on human HSCs. It was long believed that the most primitive HSCs in mammals, including mice and humans, were CD34 antigen positive (CD34⁺). However, 2 decades ago, it was reported that murine long-term multilineage reconstituting HSCs were lineage marker negative (Lin^-, i.e., c-kit⁺Sca-1⁺CD34^low/-), known as CD34^low/- KSL cells. In contrast, human CD34^- HSCs, a counterpart of murine CD34^low/- KSL cells, were hard to identify for a long time mainly because of their rarity. We previously identified very primitive human cord blood (CB)-derived CD34^- severe combined immunodeficiency (SCID)-repopulating cells (SRCs) using the intra-bone marrow injection method and proposed the new concept that CD34^- SRCs (HSCs) reside at the apex of the human HSC hierarchy. Through a series of studies, we identified two positive/enrichment markers: CD133 and GPI-80. The combination of these two markers enabled the development of an ultrahigh-resolution purification method for CD34^- as well as CD34⁺ HSCs and the successful purification of both HSCs at the single-cell level. Cell population purity is a crucial prerequisite for reliable biological and molecular analyses. Clonal analyses of highly purified human CD34^- HSCs have revealed their potent megakaryocyte/erythrocyte differentiation potential. Based on these observations, we propose a revised road map for the commitment of human CB-derived CD34^- HSCs. This review updates the current understanding of the stem cell nature of human CB-derived primitive CD34^- as well as CD34⁺ HSCs.

Distinct roles for prominin-1 and photoreceptor cadherin in outer segment disc morphogenesis in CRISPR-altered X. laevis

Mutations in prominin-1 (prom1) and photoreceptor cadherin (cdhr1) are associated with inherited retinal degenerative disorders but their functions remain unknown. Here, we used CRISPR-Cas9 to generate prom1-null, cdhr1-null, and prom1 plus cdhr1 double-null Xenopuslaevis and then documented the effects of these mutations on photoreceptor structure and function. Prom1-null mutations resulted in severely dysmorphic photoreceptors comprising overgrown and disorganized disc membranes. Cone outer segments were more severely affected than rods and had an impaired electroretinogram response. Cdhr1-null photoreceptors did not appear grossly dysmorphic, but ultrastructural analysis revealed that some disc membranes were overgrown or oriented vertically within the plasma membrane. Double-null mutants did not differ significantly from prom1-null mutants. Our results indicate that neither prom1 nor cdhr1 are necessary for outer segment disc membrane evagination or the fusion event that controls disc sealing. Rather, they are necessary for the higher-order organization of the outer segment. Prom1 may align and reinforce interactions between nascent disc leading edges, a function more critical in cones for structural support. Cdhr1 may secure discs in a horizontal orientation prior to fusion and regulate cone lamellae size.This article has an associated First Person interview with the first author of the paper.

An aptamer-based drug delivery agent (CD133-apt-Dox) selectively and effectively kills liver cancer stem-like cells

Liver cancer has no effective therapies, hence a poor survival. Cancer stem-like cells not only contribute to cancer initiation and progression, but also to drug resistance, cancer metastasis, and eventually treatment failure. Hence, any approaches that can effectively kill cancer stem-like cells hold a great potential for cancer treatment. CD133 is a robust marker for liver cancer stem-like cells. We developed a specific aptamer against CD133 (CD133-apt), and then loaded this aptamer with an anticancer drug doxorubicin (CD133-apt-Dox). The efficacy of CD133-apt-Dox in targeting liver cancer stem-like cells and its overall effect in treating liver cancer were investigated using multiple in vitro and in vivo studies including in patients-derived liver cancer organoids. We have observed that CD133-apt could preferably delivered doxorubicin to CD133-expressing cells with efficient drug accumulation and retention. CD133-apt-Dox impaired the self-renewal capacity of liver cancer stem-like cells and attenuated their stem-ness phenotypes in vitro or in vivo. CD133-apt-Dox significantly inhibited the growth of liver cancer cells and patients-derived organoids and reduced the growth of xenograft tumours in nude mice inhibited the growth of DEN-induced liver cancer in immunocompetent mice. Hence, aptamer-mediated targeting of CD133 is a highly promising approach for liver cancer therapy.

Prominin-1-Radixin axis controls hepatic gluconeogenesis by regulating PKA activity

Prominin-1 (Prom1) is a major cell surface marker of cancer stem cells, but its physiological functions in the liver have not been elucidated. We analyzed the levels of mRNA transcripts in serum-starved primary WT (Prom1+/+ ) and KO (Prom1-/- ) mouse hepatocytes using RNA sequencing (RNA-seq) data, and found that CREB target genes were downregulated. This initial observation led us to determine that Prom1 deficiency inhibited cAMP response element-binding protein (CREB) activation and gluconeogenesis, but not cyclic AMP (cAMP) accumulation, in glucagon-, epinephrine-, or forskolin-treated liver tissues and primary hepatocytes, and mitigated glucagon-induced hyperglycemia. Because Prom1 interacted with radixin, Prom1 deficiency prevented radixin from localizing to the plasma membrane. Moreover, systemic adenoviral knockdown of radixin inhibited CREB activation and gluconeogenesis in glucagon-treated liver tissues and primary hepatocytes, and mitigated glucagon-elicited hyperglycemia. Based on these results, we conclude that Prom1 regulates hepatic PKA signaling via radixin functioning as an A kinase-anchored protein (AKAP).

CD133 Expression in Medullary Thyroid Cancer Cells Identifies Patients with Poor Prognosis

CONTEXT

The identification of markers able to determine medullary thyroid cancer (MTC) patients at high-risk of disease progression is critical to improve their clinical management and outcome. Previous studies have suggested that expression of the stem cell marker CD133 is associated with MTC aggressiveness.

OBJECTIVE

To evaluate CD133 impact on disease progression in MTC and explore the regulatory mechanisms leading to the upregulation of this protein in aggressive tumors.

PATIENTS

We compiled a series of 74 MTCs with associated clinical data and characterized them for mutations in RET and RAS proto-oncogenes, presumed to be related with disease clinical behavior.

RESULTS

We found that CD133 immunohistochemical expression was associated with adverse clinicopathological features and predicted a reduction in time to disease progression even when only RET-mutated cases were considered in the analysis (log-rank test P < 0.003). Univariate analysis for progression-free survival revealed CD133 expression and presence of tumor emboli in peritumoral blood vessels as the most significant prognostic covariates among others such as age, gender, and prognostic stage. Multivariate analysis identified both variables as independent factors of poor prognosis (hazard ratio = 16.6 and 2; P = 0.001 and 0.010, respectively). Finally, we defined hsa-miR-30a-5p, a miRNA downregulated in aggressive MTCs, as a CD133 expression regulator. Ectopic expression of hsa-miR-30a-5p in MZ-CRC-1 (RETM918T) cells significantly reduced CD133 mRNA expression.

CONCLUSIONS

Our results suggest that CD133 expression may be a useful tool to identify MTC patients with poor prognosis, who may benefit from a more extensive primary surgical management and follow-up.

Osthole resensitizes CD133+ hepatocellular carcinoma cells to cisplatin treatment via PTEN/AKT pathway

The population of CD133 positive cancer cells has been reported to be responsible for drug resistance of hepatocellular carcinoma (HCC). However, the potential molecular mechanism by which CD133⁺ HCC cells develop drug resistance is still unclear. In this study, we found that CD133⁺ HepG2 and Huh7 cells were resistant to cisplatin treatment, compared to the CD133^- HepG2 and Huh7 cells. However, treatment with osthole, a natural coumarin isolated from umbelliferae plant monomers, was found to resensitize CD133⁺ HepG2 and Huh7 cells to cisplatin treatment. In the mechanism research, we found that treatment with osthole increased the expression of PTEN. As a result, osthole inhibited the phosphorylation of AKT and Bad to decrease the amount of free Bcl-2 in CD133⁺ HepG2 and Huh7 cells. Finally, cisplatin-induced mitochondrial apoptosis was expanded. In conclusion, combination treatment with osthole can resensitize CD133⁺ HCC cells to cisplatin treatment via the PTEN/AKT pathway.

The protoapigenone analog WYC0209 targets CD133+ cells: A potential adjuvant agent against cancer stem cells in urothelial cancer therapy

Urothelial carcinoma (UC) is one of the highest incidence cancers that rank the fourth commonly diagnosed tumors worldwide. The unresectable lesions that are resistant to therapeutic interventions is the major cause leading to death. Previous studies had shown that the resistance and metastatic consequence may arise from cancer stem-like cells population. The phytochemical flavonoids have promised bioactivity and potent anti-carcinogenic effects, and trap great attentions for cancer chemoprevention and/or adjuvant chemotherapy. However, the mechanisms of flavonoids on cancer stemness is still obscured. In this study, we analyzed the biofunctional effects of as-prepared flavonoid derivative-WYC0209 on T24, BFTC905 and BFTC909 human UC cell lines. Our results demonstrated that WYC0209 significantly induced anti-cell viability on UC cells through decreased Akt/NFkB signaling. Moreover, WYC0209 enhanced the cell apoptosis through activated the caspase-3 activity and inactivated Bcl-xL expression. Interestingly, WYC0209 dramatically inhibited the cancer stem cells (CSCs) traits, including attenuation of side population and tumorsphere formation in which were through declined EMT-CSCs markers including MDR1, ABCG2 and BMI-1. We further validated the effects of WYC0209 on several CSC surface markers including CD133, CD44, SOX-2 and Nanog. Our results showed that WYC0209 markedly inhibited CD133 expressions in both transcriptional and translational levels. High expression levels of CD133 was also demonstrated in human upper tract UC specimens. In summary, our study showed that WYC0209 may potentially as an adjuvant agent to against CD133-driven UC CSCs and provide a beneficial strategy to against UC cancer therapeutics resistant.

The stem cell marker Prom1 promotes axon regeneration by down-regulating cholesterol synthesis via Smad signaling

Axon regeneration is regulated by a neuron-intrinsic transcriptional program that is suppressed during development but that can be reactivated following peripheral nerve injury. Here we identify Prom1, which encodes the stem cell marker prominin-1, as a regulator of the axon regeneration program. Prom1 expression is developmentally down-regulated, and the genetic deletion of Prom1 in mice inhibits axon regeneration in dorsal root ganglion (DRG) cultures and in the sciatic nerve, revealing the neuronal role of Prom1 in injury-induced regeneration. Elevating prominin-1 levels in cultured DRG neurons or in mice via adeno-associated virus-mediated gene delivery enhances axon regeneration in vitro and in vivo, allowing outgrowth on an inhibitory substrate. Prom1 overexpression induces the consistent down-regulation of cholesterol metabolism-associated genes and a reduction in cellular cholesterol levels in a Smad pathway-dependent manner, which promotes axonal regrowth. We find that prominin-1 interacts with the type I TGF-β receptor ALK4, and that they synergistically induce phosphorylation of Smad2. These results suggest that Prom1 and cholesterol metabolism pathways are possible therapeutic targets for the promotion of neural recovery after injury.

Astrocytes influence medulloblastoma phenotypes and CD133 surface expression

The medulloblastoma (MB) microenvironment is diverse, and cell-cell interactions within this milieu is of prime importance. Astrocytes, a major component of the microenvironment, have been shown to impact primary tumor cell phenotypes and metastasis. Based on proximity of MB cells and astrocytes in the brain microenvironment, we investigated whether astrocytes may influence MB cell phenotypes directly. Astrocyte conditioned media (ACM) increased Daoy MB cell invasion, adhesion, and in vivo cellular protrusion formation. ACM conditioning of MB cells also increased CD133 surface expression, a key cancer stem cell marker of MB. Additional neural stem cell markers, Nestin and Oct-4A, were also increased by ACM conditioning, as well as neurosphere formation. By knocking down CD133 using short interfering RNA (siRNA), we showed that ACM upregulated CD133 expression in MB plays an important role in invasion, adhesion and neurosphere formation. Collectively, our data suggests that astrocytes influence MB cell phenotypes by regulating CD133 expression, a key protein with defined roles in MB tumorgenicity and survival.

Hematopoietic stem-cell senescence and myocardial repair - Coronary artery disease genotype/phenotype analysis of post-MI myocardial regeneration response induced by CABG/CD133+ bone marrow hematopoietic stem cell treatment in RCT PERFECT Phase 3

Background

Bone marrow stem cell clonal dysfunction by somatic mutation is suspected to affect post-infarction myocardial regeneration after coronary bypass surgery (CABG).

Methods

Transcriptome and variant expression analysis was studied in the phase 3 PERFECT trial post myocardial infarction CABG and CD133⁺ bone marrow derived hematopoetic stem cells showing difference in left ventricular ejection fraction (∆LVEF) myocardial regeneration Responders (n=14; ∆LVEF +16% day 180/0) and Non-responders (n=9; ∆LVEF -1.1% day 180/0). Subsequently, the findings have been validated in an independent patient cohort (n=14) as well as in two preclinical mouse models investigating SH2B3/LNK antisense or knockout deficient conditions.

Findings

1. Clinical: R differed from NR in a total of 161 genes in differential expression (n=23, q<0•05) and 872 genes in coexpression analysis (n=23, q<0•05). Machine Learning clustering analysis revealed distinct RvsNR preoperative gene-expression signatures in peripheral blood acorrelated to SH2B3 (p<0.05). Mutation analysis revealed increased specific variants in RvsNR. (R: 48 genes; NR: 224 genes). 2. Preclinical:SH2B3/LNK-silenced hematopoietic stem cell (HSC) clones displayed significant overgrowth of myeloid and immune cells in bone marrow, peripheral blood, and tissue at day 160 after competitive bone-marrow transplantation into mice. SH2B3/LNK^−/− mice demonstrated enhanced cardiac repair through augmenting the kinetics of bone marrow-derived endothelial progenitor cells, increased capillary density in ischemic myocardium, and reduced left ventricular fibrosis with preserved cardiac function. 3. Validation: Evaluation analysis in 14 additional patients revealed 85% RvsNR (12/14 patients) prediction accuracy for the identified biomarker signature.

Interpretation

Myocardial repair is affected by HSC gene response and somatic mutation. Machine Learning can be utilized to identify and predict pathological HSC response.

Funding

German Ministry of Research and Education (BMBF): Reference and Translation Center for Cardiac Stem Cell Therapy - FKZ0312138A and FKZ031L0106C, German Ministry of Research and Education (BMBF): Collaborative research center - DFG:SFB738 and Center of Excellence - DFG:EC-REBIRTH), European Social Fonds: ESF/IV-WM-B34-0011/08, ESF/IV-WM-B34-0030/10, and Miltenyi Biotec GmbH, Bergisch-Gladbach, Germany. Japanese Ministry of Health : Health and Labour Sciences Research Grant (H14-trans-001, H17-trans-002)

Trial registration

ClinicalTrials.gov NCT00950274

Prominin-1-expressing hepatic progenitor cells induce fibrogenesis in murine cholestatic liver injury

Cholestatic liver injury is associated with intrahepatic biliary fibrosis, which can progress to cirrhosis. Resident hepatic progenitor cells (HPCs) expressing Prominin-1 (Prom1 or CD133) become activated and participate in the expansion of cholangiocytes known as the ductular reaction. Previously, we demonstrated that in biliary atresia, Prom1(+) HPCs are present within developing fibrosis and that null mutation of Prom1 significantly abrogates fibrogenesis. Here, we hypothesized that these activated Prom1-expressing HPCs promote fibrogenesis in cholestatic liver injury. Using Prom1CreERT2-nLacZ/+ ;Rosa26Lsl-GFP/+ mice, we traced the fate of Prom1-expressing HPCs in the growth of the neonatal and adult livers and in biliary fibrosis induced by bile duct ligation (BDL). Prom1-expressing cell lineage labeling with Green Fluorescent Protein (GFP) on postnatal day 1 exhibited an expanded population as well as bipotent differentiation potential toward both hepatocytes and cholangiocytes at postnatal day 35. However, in the adult liver, they lost hepatocyte differentiation potential. Upon cholestatic liver injury, adult Prom1-expressing HPCs gave rise to both PROM1(+) and PROM1(-) cholangiocytes contributing to ductular reaction without hepatocyte or myofibroblast differentiation. RNA-sequencing analysis of GFP(+) Prom1-expressing HPC lineage revealed a persistent cholangiocyte phenotype and evidence of Transforming Growth Factor-β pathway activation. When Prom1-expressing cells were ablated with induced Diphtheria toxin in Prom1CreERT-nLacZ/+ ;Rosa26DTA/+ mice, we observed a decrease in ductular reactions and biliary fibrosis typically present in BDL as well as decreased expression of numerous fibrogenic gene markers. Our data indicate that Prom1-expressing HPCs promote biliary fibrosis associated with activation of myofibroblasts in cholestatic liver injury.

CD133 suppression increases the sensitivity of prostate cancer cells to paclitaxel

One of the major barriers in cancer therapy is the resistance to conventional therapies and cancer stem cells (CSCs) are among the main causes of this problem. CD133 as a CSC marker displays stem cell-like properties, tumorigenic capacity, and drug resistance in various cancers. However, the molecular mechanism behind CD133 function in prostate cancer (PC) still remains unclear. This research aimed to illustrate the probabilistic mechanism of CD133-siRNA and paclitaxel in the reduction of chemoresistance in PC cells. To measure the cell viability, migratory capacity, CSCs properties, invasive potential, apoptosis and cell cycle progression of the cells, the MTT, wound healing, spheroid assay, colony formation assay, DAPI staining and flow cytometry assays were applied in the LNCaP cell line, respectively. Also, quantitative real-time PCR (qRT-PCR) and western blot method were used for measuring the expression of CD133 and the effects of CD133 silencing on the AKT/mTOR/c-myc axis and pro-metastatic genes expression. We showed that the CD133-siRNA considerably decreased the CD133 expression. Moreover, CD133-siRNA and paclitaxel treatment significantly decreased cell proliferation and also inhibited the ability of cell migration and invasion and reduced pro-metastatic genes expression. Additionally, we found that the simultaneous use of CD133-siRNA and paclitaxel increased the paclitaxel-induced apoptosis. Our results confirmed that CD133 silencing combined with paclitaxel synergistically could suppress cell migration, invasion, and proliferation and enhance the chemosensitivity compared with mono treatment. Therefore, CD133 silencing therapy could be viewed as a promising and efficient strategy in PC targeted therapies.

PROM1 and PROM2 expression differentially modulates clinical prognosis of cancer: a multiomics analysis

Prominin 1 (PROM1) is considered a biomarker for cancer stem cells, although its biological role is unclear. Prominin 2 (PROM2) has also been associated with certain cancers. However, the prognostic value of PROM1 and PROM2 in cancer is controversial. Here, we performed a systematic data analysis to examine whether prominins can function as prognostic markers in human cancers. The expression of prominins was assessed and their prognostic value in human cancers was determined using univariate and multivariate survival analyses, via various online platforms. We selected a group of prominent functional protein partners of prominins by protein-protein interaction analysis. Subsequently, we investigated the relationship between mutations and copy number alterations in prominin genes and various types of cancers. Furthermore, we identified genes that correlated with PROM1 and PROM2 in certain cancers, based on their levels of expression. Gene ontology and pathway analyses were performed to assess the effect of these correlated genes on various cancers. We observed that PROM1 was frequently overexpressed in esophageal, liver, and ovarian cancers and its expression was negatively associated with prognosis, whereas PROM2 overexpression was associated with poor overall survival in lung and ovarian cancers. Based on the varying characteristics of prominins, we conclude that PROM1 and PROM2 expression differentially modulates the clinical outcomes of cancers.

Promoter hypermethylation of CD133/PROM1 is an independent poor prognosis factor for head and neck squamous cell carcinoma

PROM1 has played a pivotal role in the identification and isolation of tumor stem cells. This study aimed to assess the association between PROM1 promoter methylation and head and neck squamous cell carcinoma (HNSCC), and its diagnostic and prognostic value.Bioinformatic analysis was performed using data from the Cancer Genome Atlas-HNSC and Gene Expression Omnibus datasets.The results showed that PROM1 promoter was hypermethylated in HNSCCs compared with normal head and neck tissues (P = 4.58E-37). The area under the receiver-operating characteristic curve based on methylated PROM1 data was 0.799. In addition, PROM1 hypermethylation independently predicted poor overall survival (hazard ratio [HR]: 1.459, 95% confidence interval [CI]: 1.071-1.987, P = .016) and recurrence-free survival (HR: 1.729, 95% CI: 1.088-2.749, P = .021) in HNSCC patients. Moreover, PROM1 methylation was weakly negatively correlated with its mRNA expression (Pearson r = -0.148, P < .001).In summary, our study reveals that methylated PROM1 might serve as a valuable diagnostic biomarker and predictor of poor survival for HNSCC patients. PROM1 hypermethylation might partially contribute to its downregulation in HNSCC.

HDAC and MAPK/ERK Inhibitors Cooperate To Reduce Viability and Stemness in Medulloblastoma

Medulloblastoma (MB), which originates from embryonic neural stem cells (NSCs) or neural precursors in the developing cerebellum, is the most common malignant brain tumor of childhood. Recurrent and metastatic disease is the principal cause of death and may be related to resistance within cancer stem cells (CSCs). Chromatin state is involved in maintaining signaling pathways related to stemness, and inhibition of histone deacetylase enzymes (HDAC) has emerged as an experimental therapeutic strategy to target this cell population. Here, we observed antitumor actions and changes in stemness induced by HDAC inhibition in MB. Analyses of tumor samples from patients with MB showed that the stemness markers BMI1 and CD133 are expressed in all molecular subgroups of MB. The HDAC inhibitor (HDACi) NaB reduced cell viability and expression of BMI1 and CD133 and increased acetylation in human MB cells. Enrichment analysis of genes associated with CD133 or BMI1 expression showed mitogen-activated protein kinase (MAPK)/ERK signaling as the most enriched processes in MB tumors. MAPK/ERK inhibition reduced expression of the stemness markers, hindered MB neurosphere formation, and its antiproliferative effect was enhanced by combination with NaB. These results suggest that combining HDAC and MAPK/ERK inhibitors may be a novel and more effective approach in reducing MB proliferation when compared to single-drug treatments, through modulation of the stemness phenotype of MB cells.

Expanded Phenotypic Spectrum of Retinopathies Associated with Autosomal Recessive and Dominant Mutations in PROM1

PURPOSE

To describe the genetic and phenotypic characteristics of a cohort of patients with PROM1 variants.

DESIGN

Case-case study.

METHODS

We screened a cohort of 2216 families with inherited retinal dystrophies using classical molecular techniques and next-generation sequencing approaches. The clinical histories of 25 patients were reviewed to determine age of onset of symptoms and the results of ophthalmoscopy, best-corrected visual acuity, full-field electroretinography, and visual field studies. Fundus autofluorescence and spectral-domain optical coherence tomography were further assessed in 7 patients.

RESULTS

PROM1 variants were identified in 32 families. Disease-causing variants were found in 18 autosomal recessive and 4 autosomal dominant families. Monoallelic pathogenic variants or variants of unknown significance were identified in the remaining 10 families. Comprehensive phenotyping of 25 patients from 22 families carrying likely disease-causing variants revealed clinical heterogeneity associated with the PROM1 gene. Most of these patients presented cone-rod dystrophy and some exhibited macular dystrophy or retinitis pigmentosa, while all presented with macular damage. Phenotypic association of a dominant splicing variant with late-onset mild maculopathy was established. This variant is one of the 3 likely founder variants identified in our Spanish cohort.

CONCLUSIONS

We report the largest cohort of patients with PROM1 variants, describing in detail the phenotype in 25 of them. Interestingly, within the variability of phenotypes related to this gene, macular involvement is a common feature in all patients.

Adverse prognosis of glioblastoma contacting the subventricular zone: Biological correlates

INTRODUCTION

The subventricular zone (SVZ) in the brain is associated with gliomagenesis and resistance to treatment in glioblastoma. In this study, we investigate the prognostic role and biological characteristics of subventricular zone (SVZ) involvement in glioblastoma.

METHODS

We analyzed T1-weighted, gadolinium-enhanced MR images of a retrospective cohort of 647 primary glioblastoma patients diagnosed between 2005-2013, and performed a multivariable Cox regression analysis to adjust the prognostic effect of SVZ involvement for clinical patient- and tumor-related factors. Protein expression patterns of a.o. markers of neural stem cellness (CD133 and GFAP-δ) and (epithelial-) mesenchymal transition (NF-κB, C/EBP-β and STAT3) were determined with immunohistochemistry on tissue microarrays containing 220 of the tumors. Molecular classification and mRNA expression-based gene set enrichment analyses, miRNA expression and SNP copy number analyses were performed on fresh frozen tissue obtained from 76 tumors. Confirmatory analyses were performed on glioblastoma TCGA/TCIA data.

RESULTS

Involvement of the SVZ was a significant adverse prognostic factor in glioblastoma, independent of age, KPS, surgery type and postoperative treatment. Tumor volume and postoperative complications did not explain this prognostic effect. SVZ contact was associated with increased nuclear expression of the (epithelial-) mesenchymal transition markers C/EBP-β and phospho-STAT3. SVZ contact was not associated with molecular subtype, distinct gene expression patterns, or markers of stem cellness. Our main findings were confirmed in a cohort of 229 TCGA/TCIA glioblastomas.

CONCLUSION

In conclusion, involvement of the SVZ is an independent prognostic factor in glioblastoma, and associates with increased expression of key markers of (epithelial-) mesenchymal transformation, but does not correlate with stem cellness, molecular subtype, or specific (mi)RNA expression patterns.

CRISPR-Cas9 mediated CD133 knockout inhibits colon cancer invasion through reduced epithelial-mesenchymal transition

We previously reported that CD133, as a putative cancer stem cell marker, plays an important role in cell proliferation and invasion in colon cancer. To understand the role of CD133 expression in colon cancer, we evaluated the inhibitory effect of CD133 in colon cancer cells. In this study, we generated CD133^knockout colon cancer cells (LoVo) using the CRISPR-Cas9 gene editing system. CD133⁺ colon cancer cells (LoVo) were infected with the lentiviral vector carrying CD133 gRNA and purified cell by culturing single cell colonies. CD133^knockout cells was validated by western blot and flow cytometry analysis. In functional study, we observed a significant reduction in cell proliferation and colony formation in CRISPR-Cas9 mediated CD133 ^knockout cells in compare with control (P < 0.001). We also found the anticancer effect of stattic was dependent on CD133 expression in colon cancer cells. Although CD133^knockout cells could not completely block the tumorigenic property, they showed remarkable inhibitory effects on the ability of cell migration and invasion (P < 0.001). In addition, we examined the epithelial mesenchymal transition (EMT)-related protein expression by western blot. The result clearly showed a loss of vimentin expression in CD133^knockout cells. Therefore, CRISPR-Cas9 mediated CD133^knockout can be an effective treatment modality for CD133⁺ colon cancer through reducing the characteristics of cancer stem cells.

Dynamic secretome of bone marrow-derived stromal cells reveals a cardioprotective biochemical cocktail

Transplanted stromal cells have demonstrated considerable promise as therapeutic agents in diverse disease settings. Paracrine signaling can be an important mediator of these therapeutic effects at the sites of acute or persistent injury and inflammation. As many stromal cell types, including bone marrow-derived stromal cells (BMSCs), display tissue-specific responses, there is a need to explore their secretory dynamics in the context of tissue and injury type. Paracrine signals are not static, and could encode contextual dynamics in the kinetic changes of the concentrations of the secreted ligands. However, precise measurement of dynamic and context-specific cellular secretory signatures, particularly in adherent cells, remains challenging. Here, by creating an experimental and computational analysis platform, we reconstructed dynamic secretory signatures of cells based on a very limited number of time points. By using this approach, we demonstrate that the secretory signatures of CD133-positive BMSCs are uniquely defined by distinct biological contexts, including signals from injured cardiac cells undergoing oxidative stress, characteristic of cardiac infarction. Furthermore, we show that the mixture of recombinant factors reproducing the dynamics of BMSC-generated secretion can mediate a highly effective rescue of cells injured by oxidative stress and an improved cardiac output. These results support the importance of the dynamic multifactorial paracrine signals in mediating remedial effects of stromal stem cells, and pave the way for stem cell-inspired cell-free treatments of cardiac and other injuries.

Aberrant expression of CD13 and stem cell markers in CD133-induced liver cancer in mice

PURPOSE

The purpose of the study is to identify the Cancer Stem Cells (CSCs) and to determine their expression profiles in different pathological stages of liver cancer by using multiple markers Methods: In this study, the expression profiles of CD133 and CD13, along with those of stem cell markers Oct4 and SOX2, were analyzed using immunohistochemistry and immunoblotting to clarify the character of CSCs in different stages of liver cancer.

RESULTS

CD133 liver cancer cells were injected into mice, and the tissues were processed for histology. The histological data revealed the progression of liver cancer. Immunohistochemical analysis showed the strong expression of CD133 in metastatic cancer. In contrast, the expression of CD13 in both primary and metastatic liver cancer was found to be very strong. Interestingly, the expression levels of Oct4 and SOX2 were found to be upregulated in primary tumors, but, in the metastatic stage, their expression was downregulated. The immunoblot analysis also confirmed the same result.

CONCLUSIONS

Our findings demonstrate that tumor-suppressor proteins Oct4 and SOX2 have a prominent expression profile in the primary stage of cancer, but, in the metastatic stage, their expression is downregulated, leading to the failure to prevent metastatic cancer.

Clinical and Molecular Characterization of PROM1-Related Retinal Degeneration

IMPORTANCE

The PROM1 gene, commonly associated with cone-rod dystrophies, may have dominant or recessive phenotypes that influence disease onset and severity.

OBJECTIVE

To characterize the clinical phenotype and molecular genetic variations in patients with PROM1 variants.

DESIGN, SETTING, AND PARTICIPANTS

This case-series study was conducted at 2 specialist retinal genetics clinics and examined 19 consecutively enrolled patients with PROM1-related retinal degeneration. Data were collected and analyzed from May 2018 to December 2018.

MAIN OUTCOMES AND MEASURES

Results of ophthalmic examination, retinal imaging, and molecular genetic analysis by next-generation sequencing.

RESULTS

Of 19 patients, 13 (68%) were women, and age ranged from 11 to 70 years. All patients presented with central visual loss, with or without photophobia. Individuals with recessive variants commonly had severe loss of visual acuity by their 20s, whereas the dominant variant was associated with a milder phenotype, with most patients retaining good vision into late adulthood. The recessive cases were associated with a panretinal dystrophy of cone-rod phenotype with early macular involvement, whereas the dominant variants were associated with a cone-rod phenotype that was restricted to the macula with predominantly cone dysfunction. Next-generation sequencing identified 3 novel and 9 previously reported variants in PROM1. Recessive mutations included 6 truncating variants (3 nonsense and 3 frameshift), 4 splice site variants, and 1 missense variant. All 6 dominant variants were associated with a c.1117C>T missense variant. The variants were distributed throughout the PROM1 genomic sequence with no specific clustering on protein domains.

CONCLUSIONS AND RELEVANCE

In this case-series study, PROM1 recessive variants were associated with early-onset, severe panretinal degeneration. The similar phenotypes observed in patients with homozygous missense variants and splice site variants compared with similarly aged patients with truncating variants suggests that all recessive variants have a null (or loss of function close to null) outcome on PROM1 function. In contrast, the dominant missense cases were associated with a milder, cone-driven phenotype, suggesting that the dominant disease is preferentially associated with cones. This has implications for the development of treatments for this severely blinding disease, and adeno-associated viral vector-based gene therapy and optogenetics could become successful treatment options.

Metformin Regulates the Expression of CD133 Through the AMPK-CEBPβ Pathway in Hepatocellular Carcinoma Cell Lines

CD133 is a cellular surface protein, which has been reported to be a cancer stem cell marker, and thus is considered a potential target for cancer treatment. Metformin, one of the biguanides used for the treatment of diabetes, is also known to reduce the risk of cancer development and cancer stem-like cells (CSCs), including the expression of CD133. However, the mechanism underlying the reduction of the expression of CD133 by metformin is not yet understood. This study shows that metformin suppressed CD133 expression mainly by affecting the CD133 P1 promoter via adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling but not the mammalian target of rapamycin (mTOR). AMPK inhibition rescued the reduction of CD133 by metformin. Further experiments demonstrated that CCAAT/enhancer-binding protein beta (CEBPβ) was upregulated by metformin and that two isoforms of CEBPβ reciprocally regulated the expression of CD133. Specifically, the liver-enriched activator protein (LAP) isoform increased the expression of CD133 by directly binding to the P1 promoter region, whereas the liver-enriched inhibitory protein (LIP) isoform suppressed the expression of CD133. Consistent with these findings, a three dimensional (3D) culture assay and drug sensitivity assay demonstrated that LAP-overexpressing cells formed large spheroids and were more resistant to 5-fluorouracil (5-FU) treatment, whereas LIP-overexpressing cells were more sensitive to 5-FU and showed combined effects with metformin. Our results indicated that metformin-AMPK-CEBPβ signaling plays a crucial role in regulating the gene expression of CD133. Additionally, regulating the ratio of LAP/LIP may be a novel strategy for targeting CSCs for the treatment of cancer.

High expression of HMBOX1 contributes to poor prognosis of gastric cancer by promoting cell proliferation and migration

Homeobox-containing 1 (HMBOX1) has been reported to be associated with biological characteristics of some tumors, but its roles in gastric cancer have never been reported. In the present study, we found that HMBOX1 expression was significantly upregulated in gastric cancer tissues and cell lines and correlated with the TNM stage, lymph-node metastatic and the overall survival (OS) of patients of gastric cancer. The overexpression of HMBOX1 in gastric cancer cells enhanced cell proliferation by accelerating cell cycle, induced cell migration. In contrast, silencing HMBOX1 inhibited these processes. And the expression of HMBOX1 was related with the expression of vascular endothelial growth factor receptor (VEGFR), transforming growth factor-β (TGF-β) and CD133. What's more, we found that the expression of CD133 had a significantly positive correlation with HMBOX1 in gastric cancer tissues, and the co-expression of HMBOX1 and CD133 was significantly correlated with poor prognosis of gastric cancer patients, especially for patients at III and IV stage. In conclusion, HMBOX1 was upregulated in gastric cancer and correlated with gastric cancer cell proliferation and migration. Moreover, HMBOX1 combined CD133 might be useful to predict survival of patients with advanced gastric cancer.

A Pan-ALDH1A Inhibitor Induces Necroptosis in Ovarian Cancer Stem-like Cells

Ovarian cancer is typified by the development of chemotherapy resistance. Chemotherapy resistance is associated with high aldehyde dehydrogenase (ALDH) enzymatic activity, increased cancer "stemness," and expression of the stem cell marker CD133. As such, ALDH activity has been proposed as a therapeutic target. Although it remains controversial which of the 19 ALDH family members drive chemotherapy resistance, ALDH1A family members have been primarily linked with chemotherapy resistant and stemness. We identified two ALDH1A family selective inhibitors (ALDH1Ai). ALDH1Ai preferentially kills CD133+ ovarian cancer stem-like cells (CSCs). ALDH1Ai induce necroptotic CSC death, mediated, in part, by the induction of mitochondrial uncoupling proteins and reduction in oxidative phosphorylation. ALDH1Ai is highly synergistic with chemotherapy, reducing tumor initiation capacity and increasing tumor eradication in vivo. These studies link ALDH1A with necroptosis and confirm the family as a critical therapeutic target to overcome chemotherapy resistance and improve patient outcomes.

Melatonin reduces lung cancer stemness through inhibiting of PLC, ERK, p38, β-catenin, and Twist pathways

Lung cancer is one of the most common cancer in cancer-related deaths worldwide, which is characterized by its strong metastatic potential. The melatonin hormone secreted by the pineal grand has an antioxidant effect and protects cells against carcinogenic substances. However, the effects of melatonin in lung cancer stemness are largely unknown. We found that melatonin reduces CD133 expression by ~50% in lung cancer cell lines, while results of a sphere formation assay showed that melatonin inhibits lung cancer stemness. These effects of melatonin were reversed when the cell lines were incubated with phospholipase C (PLC), ERK/p38, and a β-catenin activator. Transfection with Twist siRNA augmented the inhibitory effects of melatonin, indicating that melatonin suppresses lung cancer stemness by inhibiting the PLC, ERK/p38, β-catenin, and Twist signaling pathways. We also found CD133 expression is positively correlated with Twist expression in lung cancer specimens. Melatonin shows promise in the treatment of lung cancer stemness and deserves further study.

Lipid-polymer nanoparticles with CD133 aptamers for targeted delivery of all-trans retinoic acid to osteosarcoma initiating cells

Osteosarcoma, a common type of bone cancer in children, and represents an aggressive and fetal cancer worldwide. Osteosarcoma initiating cells are considered to be a subpopulation of cancer cells which contribute to the progression, recurrence, metastasis and multi-drug resistance of osteosarcoma. CD133 is considered to be one marker for osteosarcoma initiating cells. All-trans retinoic acid (ATRA), an active metabolite of vitamin A under the family retinoid, is an up-and-coming drug which was able to effectively treat various cancer initiating cells. Nevertheless, there have been no research that reported the activity of ATRA against osteosarcoma initiating cells. In this research, we hereby examined the potential activity of ATRA in osteosarcoma initiating cells, and developed lipid-polymer nanoparticles with CD133 aptamers for targeted ATRA delivery to osteosarcoma initiating cells. Using the cytotoxicity assay, colony formation assay, tumorsphere formation assay and flow cytometry, the therapeutic effect of ATRA and ATRA-loaded lipid-polymer nanoparticles conjugated with CD133 aptamers (ATRA-PLNP-CD133) against osteosarcoma initiating cells were investigated. The results showed that ATRA exerted potent activity towards osteosarcoma initiating cells. ATRA-PLNP-CD133, which showed a size of 129.9 nm and a sustained release of ATRA during 144 h, was demonstrated to efficiently and specifically promote the ATRA delivery to osteosarcoma initiating cells, and achieve superior therapeutic efficacy in osteosarcoma compared with ATRA and non-targeted nanoparticles. This is the first report of the therapeutic efficacy of ATRA towards osteosarcoma initiating cells, and the increased ATRA delivery by nanoparticles to osteosarcoma initiating cells using CD133 aptamers. ATRA-PLNP-CD133 represent an up-and coming approach for the therapy of osteosarcoma initiating cells.

Selective Targeting of CD133-Expressing Glioblastoma Stem Cells Using Lentiviral Vectors

Several lines of evidence suggest a cellular hierarchy in glioblastoma (GBM). In this hierarchy, GBM stem-like cells (GSCs) play critical roles in tumor progression and recurrence, by virtue of their robust tumor-propagating potential and resistance to conventional chemoradiotherapy. Therefore, targeting GSCs holds significant therapeutic promise. Expression of CD133 (PROM1), a cell surface glycoprotein, has been associated with the GSC phenotype and used as a GSC marker. Here, we describe a protocol that allows the selective lentiviral transduction of CD133-expressing GBM cells. This selectivity is conferred by pseudotyping the lentiviral envelope with a single-chain antibody against an extracellular epitope on CD133. We previously demonstrated the efficacy and specificity of this lentiviral vector using patient-derived GBM cultures. This chapter outlines the preparation of the vector and the transduction of human GBM cells.

PLK1 inhibitor facilitates the suppressing effect of temozolomide on human brain glioma stem cells

Glioblastoma is the most frequent and most aggressive brain tumour in adults. Temozolomide is an oral chemotherapy drug and one of the major components of chemotherapy regimens used as a treatment of some brain cancers. We examined the tolerance of stem cells isolated from glioma cell line U87 and U251 to temozolomide (TMZ) and explored the effect of PLK1 (Polo like kinase 1) protein expression on TMZ sensibility. In our results, the inhibitory effects of TMZ on glioma cells U87, U251 and its stem cells were confirmed to be dose dependent and time dependent. Compared with glioma cells, the glioma stem cells showed a greater degree of tolerance. As the concentration of TMZ increased, the expression of PLK1 protein increased in U87 cells, CD133+ U87 stem cells and CD133- U87 cells. The increase range of PLK1 protein was large in CD133+ U87 stem cells and small in CD133- U87 cells. TMZ treatment in cells with low PLK1 protein expression efficiently suppressed the cell proliferation and sphere formation, while G2/M arrest was strongly induced. What's more, TMZ and PLK1 inhibitor synergize to inhibit glioma growth in vivo. In conclusion, our results suggest that down-regulation of PLK1 protein enhanced the inhibition of TMZ on glioma stem cells, suggesting its clinical value to adverse TMZ resistance in glioma treatment.

Establishment of five immortalized human ovarian surface epithelial cell lines via SV40 T antigen or HPV E6/E7 expression

Background

Human ovarian surface epithelial (HOSE) cells are a critical cell source for ovarian cancer research; however, they are difficult to obtain and maintain under standard laboratory conditions in large quantities. The aim of this study was to generate immortalized HOSE (IHOSE) cells with maintained properties to the original cell source, thereby guaranteeing a sufficiently large cell quantity for ovarian cancer research.

Methods

HOSE cells isolated from four non-cancer patients and five IHOSE cell lines were established by induction of HPV-E6/E7 expression or SV40 large T antigen using a lenti-viral system. Each of IHOSE cells was confirmed to be distinct by STR profiling. RNA-sequencing was used to compare gene expression profiles in HOSE, IHOSE and ovarian cancer cells.

Results

RNA-sequencing results revealed a stronger linear correlation in gene expression between IHOSE and HOSE cells (R² = 0.9288) than between IHOSE or HOSE cells and ovarian cancer cells (R² = 0.8562 and R² = 0.7982, respectively). The gene expression pattern of 319 differentially expressed genes revealed minimal differences between HOSE and IHOSE cells, while a strong difference between ovarian cancer cells and HOSE or IHOSE cells was observed. Furthermore, the five IHOSE cell lines displayed morphological characteristics typical of epithelial cells but showed a lower level of EpCAM, CD133 and E-cadherin, as cancer stem marker, than ovarian cancer cells. Moreover, unlike cancer cells, IHOSE cells could not form colonies in the anchorage-independent soft agar growth assay.

Conclusion

These findings demonstrate that five newly established IHOSE cell lines have characteristics of progenitor HOSE cells while exhibiting continuous growth, and thus, should be highly useful as control cells for ovarian cancer research.

Replication Stress Drives Constitutive Activation of the DNA Damage Response and Radioresistance in Glioblastoma Stem-like Cells

Glioblastoma (GBM) is a lethal primary brain tumor characterized by treatment resistance and inevitable tumor recurrence, both of which are driven by a subpopulation of GBM cancer stem-like cells (GSC) with tumorigenic and self-renewal properties. Despite having broad implications for understanding GSC phenotype, the determinants of upregulated DNA-damage response (DDR) and subsequent radiation resistance in GSC are unknown and represent a significant barrier to developing effective GBM treatments. In this study, we show that constitutive DDR activation and radiation resistance are driven by high levels of DNA replication stress (RS). CD133+ GSC exhibited reduced DNA replication velocity and a higher frequency of stalled replication forks than CD133- non-GSC in vitro; immunofluorescence studies confirmed these observations in a panel of orthotopic xenografts and human GBM specimens. Exposure of non-GSC to low-level exogenous RS generated radiation resistance in vitro, confirming RS as a novel determinant of radiation resistance in tumor cells. GSC exhibited DNA double-strand breaks, which colocalized with "replication factories" and RNA: DNA hybrids. GSC also demonstrated increased expression of long neural genes (>1 Mbp) containing common fragile sites, supporting the hypothesis that replication/transcription collisions are the likely cause of RS in GSC. Targeting RS by combined inhibition of ATR and PARP (CAiPi) provided GSC-specific cytotoxicity and complete abrogation of GSC radiation resistance in vitro These data identify RS as a cancer stem cell-specific target with significant clinical potential.Significance: These findings shed new light on cancer stem cell biology and reveal novel therapeutics with the potential to improve clinical outcomes by overcoming inherent radioresistance in GBM. Cancer Res; 78(17); 5060-71. ©2018 AACR.

Long non-coding RNA AFAP1-AS1/miR-320a/RBPJ axis regulates laryngeal carcinoma cell stemness and chemoresistance

AFAP1-AS1 is a long non-coding RNA that is associated with tumorigenesis and poor prognosis in a variety of cancers. We have been suggested that AFAP1-AS1 increases tumorigenesis in laryngeal carcinoma specifically by enhancing stemness and chemoresistance. We assessed AFAP1-AS1 expression in human laryngeal specimens, paired adjacent normal tissues and human HEp-2 cells. Indeed, we found not only that AFAP1-AS1 was up-regulated in laryngeal carcinoma specimens and cells, but also that stemness-associated genes were overexpressed. Silencing of AFAP1-AS1 promoted HEp-2 cell chemoresistance under cisplatin treatment. Expression of AFAP1-AS1 was increased in drug-resistant Hep-2 cells. We then probed the mechanism of AFAP1-AS1 activity and determined that miR-320a was a potential molecular target of AFAP1-AS1. Luciferase reporter and qRT-PCR assays of AFAP1-AS1 and miR-320a levels in human specimens and cell cultures indicated that AFAP1-AS1 negatively regulates miR-320a. To discover the molecular mechanism of miR-320a, we again used the DIANA Tools algorithm to predict its genetic target, RBPJ. After cloning the 3'-untranslated regions (3'-UTR) of RBPJ into a luciferase reporter, we determined that miR-320a did in fact reduce RBPJ mRNA and protein levels. Ultimately, we determined that AFAP1-AS1 increases RBPJ expression by negatively regulating miR-320a and RBPJ overexpression rescues stemness and chemoresistance inhibited by AFAP1-AS1 silencing. Taken together, these results suggest that AFAP1-AS1 can serve as a prognostic biomarker in laryngeal carcinoma and that miR-320a has the potential to improve standard therapeutic approaches to the disease, especially for cases in which cancer cell stemness and drug resistance present significant barriers to effective treatment.

Circulating Progenitor Cells and Racial Differences

RATIONALE

Blacks compared with whites have a greater risk of adverse cardiovascular outcomes. Impaired regenerative capacity, measured as lower levels of circulating progenitor cells (CPCs), is a novel determinant of adverse outcomes; however, little is known about racial differences in CPCs.

OBJECTIVE

To investigate the number of CPCs, PC-mobilizing factors, PC mobilization during acute myocardial infarction and the predictive value of CPC counts in blacks compared with whites.

METHODS AND RESULTS

CPCs were enumerated by flow cytometry as CD45med+ blood mononuclear cells expressing CD34+, CD133+, VEGF2R+, and CXCR4+ epitopes in 1747 subjects, mean age 58.4±13, 55% male, and 26% self-reported black. Patients presenting with acute myocardial infarction (n=91) were analyzed separately. Models were adjusted for relevant clinical variables. SDF-1α (stromal cell-derived factor-1α), VEGF (vascular endothelial growth factor), and MMP-9 (matrix metallopeptidase-9) levels were measured (n=561), and 623 patients were followed for median of 2.2 years for survival analysis. Blacks were younger, more often female, with a higher burden of cardiovascular risk, and lower CPC counts. Blacks had fewer CD34+ cells (-17.6%; [95% confidence interval (CI), -23.5% to -11.3%]; P<0.001), CD34+/CD133+ cells (-15.5%; [95% CI, -22.4% to -8.1%]; P<0.001), CD34+/CXCR4+ cells (-17.3%; [95% CI, -23.9% to -10.2%]; P<0.001), and CD34+/VEGF2R+ cells (-27.9%; [95% CI, -46.9% to -2.0%]; P=0.04) compared with whites. The association between lower CPC counts and black race was not affected by risk factors or cardiovascular disease. Results were validated in a separate cohort of 411 patients. Blacks with acute myocardial infarction had significantly fewer CPCs compared with whites ( P=0.02). Blacks had significantly lower plasma MMP-9 levels ( P<0.001) which attenuated the association between low CD34+ and black race by 19% (95% CI, 13%-33%). However, VEGF and SDF-1α levels were not significantly different between the races. Lower CD34+ counts were similarly predictive of mortality in blacks (hazard ratio, 2.83; [95% CI, 1.12-7.20]; P=0.03) and whites (hazard ratio, 1.79; [95% CI, 1.09-2.94]; P=0.02) without significant interaction.

CONCLUSIONS

Black subjects have lower levels of CPCs compared with whites which is partially dependent on lower circulating MMP-9 levels. Impaired regenerative capacity is predictive of adverse outcomes in blacks and may partly account for their increased risk of cardiovascular events.