scholarly journals Exome sequencing of glioblastoma-derived cancer stem cells reveals rare clinically relevant frameshift deletion in MLLT1 gene

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Hany E. Marei ◽  
Asmaa Althani ◽  
Nahla Afifi ◽  
Anwarul Hasan ◽  
Thomas Caceci ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Allelic Frequency ◽  
Response To Therapy ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Tissue Samples ◽  
Frameshift Deletion ◽  
Prognostic Outcome ◽  
The Common

Abstract Background Glioblastoma multiforme (GBM) is a heterogeneous CNS neoplasm which causes significant morbidity and mortality. One reason for the poor prognostic outcome of GBM is attributed to the presence of cancer stem cells (CSC) which confer resistance against standard chemo- and radiotherapeutics modalities. Two types of GBM-associated CSC were isolated from the same patient: tumor core- (c-CSC) and peritumor tissue-derived cancer stem cells (p-CSC). Our experiments are focused on glioblastoma–IDH-wild type, and no disease-defining alterations were present in histone, BRAF or other genes. Methods In the present study, potential differences in genetic variants between c-CSC versus p-CSC derived from four GBM patients were investigated with the aims of (1) comparing the exome sequences between all the c-CSC or p-CSC to identify the common variants; (2) identifying the variants affecting the function of genes known to be involved in cancer origin and development. Results By comparative analyses, we identified common gene single nucleotide variants (SNV) in all GBM c-CSC and p-CSC, a potentially deleterious variant was a frameshift deletion at Gln461fs in the MLLT1 gene, that was encountered only in p-CSC samples with different allelic frequency. Conclusions We discovered a potentially harmful frameshift deletion at Gln461fs in the MLLT1 gene. Further investigation is required to confirm the presence of the identified mutations in patient tissue samples, as well as the significance of the frameshift mutation in the MLLT1 gene on GBM biology and response to therapy based on genomic functional experiments.

scholarly journals Exome Sequencing of Glioblastoma-Derived Cancer Stem Cells Reveals Rare Clinically Relevant Frameshift Deletion in MLLT1 Gene

2021 ◽  
Author(s):  
Hany Marei ◽  
Asmaa Althani ◽  
Nahla Afifi ◽  
Anwarul Hasan ◽  
Thomas Caceci ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Allelic Frequency ◽  
Common Variants ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Frameshift Deletion ◽  
Prognostic Outcome ◽  
The Common ◽  
Recurrent Nature

Abstract Background: Glioblastoma multiforme (GBM) is a heterogeneous CNS neoplasm which causes significant morbidity and mortality. One reason for the poor prognostic outcome of GBM is attributed to the presence of cancer stem cells (CSC) which confer resistance against standard chemo- and radiotherapeutics modalities. Two types of GBM-associated CSC were isolated from the same patient: tumor core- (c-CSC) and peritumor tissue-derived cancer stem cells (p-CSC).Methods: In the present study, potential differences in genetic variants between c-CSC versus p-CSC derived from four GBM patients were investigated with the aims of 1) comparing the exome sequences between all the c-CSC or p-CSC to identify the common variants; 2) identifying the variants affecting the function of genes known to be involved in cancer origin and development.Results: By comparative analyses, we identified common gene single nucleotide variants (SNV) in all GBM c-CSC and p-CSC, a potentially deleterious variant was a frameshift deletion at Gln461fs in the MLLT1 gene, that was encountered only in p-CSC samples with different allelic frequency.Conclusions: Our study supports the hypothesis that the varied genetic composition of GBM-associated c-CSC and p-CSC may be involved in different therapeutic responses or the recurrent nature of GBM.

scholarly journals Cancer stem cells enrichment with surface markers CD271 and CD44 in human head and neck squamous cell carcinomas

2019 ◽  
Vol 41 (4) ◽  
pp. 458-466 ◽  
Author(s):  
Osama A Elkashty ◽  
Ghada Abu Elghanam ◽  
Xinyun Su ◽  
Younan Liu ◽  
Peter J Chauvin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Head And Neck ◽  
Cell Lines ◽  
Squamous Cell ◽  
Colony Formation ◽  
Self Renewal ◽  
Tissue Samples ◽  
Hnscc Cell

Abstract Head and neck squamous cell carcinoma (HNSCC) has a poor 5-year survival rate of 50%. One potential reason for treatment failure is the presence of cancer stem cells (CSCs). Several cell markers, particularly CD44, have been used to isolate CSCs. However, isolating a pure population of CSC in HNSCC still remains a challenging task. Recent findings show that normal oral stem cells were isolated using CD271 as a marker. Thus, we investigated the combined use of CD271 and CD44 to isolate an enriched subpopulation of CSCs, followed by their characterization in vitro, in vivo, and in patients’ tissue samples. Fluorescent-activated cell sorting was used to isolate CD44+/CD271+ and CD44+/CD271− from two human HNSCC cell lines. Cell growth and self-renewal were measured with MTT and sphere/colony formation assays. Treatment-resistance was tested against chemotherapy (cisplatin and 5-fluorouracil) and ionizing radiation. Self-renewal, resistance, and stemness-related genes expression were measured with qRT-PCR. In vivo tumorigenicity was tested with an orthotopic immunodeficient mouse model of oral cancer. Finally, we examined the co-localization of CD44+/CD271+ in patients’ tissue samples. We found that CD271+ cells were a subpopulation of CD44+ cells in human HNSCC cell lines and tissues. CD44+/CD271+ cells exhibited higher cell proliferation, sphere/colony formation, chemo- and radio-resistance, upregulation of CSCs-related genes, and in vivo tumorigenicity when compared to CD44+/CD271− or the parental cell line. These cell markers showed increased expression in patients with the increase of the tumor stage. In conclusion, using both CD44 and CD271 allowed the isolation of CSCs from HNSCC. These enriched CSCs will be more relevant in future treatment and HNSCC progression studies.

scholarly journals Low rate of somatic mutations in a long-lived oak tree

2017 ◽  
Author(s):  
Namrata Sarkar ◽  
Emanuel Schmid-Siegert ◽  
Christian Iseli ◽  
Sandra Calderon ◽  
Caroline Gouhier-Darimont ◽  
...  
Keyword(s):  
Stem Cells ◽  
Somatic Mutations ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Cell Divisions ◽  
Gamete Formation ◽  
Oak Tree ◽  
Sequential Appearance ◽  
Low Rate ◽  
Shoot Meristems

Because plants do not possess a proper germline, deleterious somatic mutations can be passed to gametes and a large number of cell divisions separating zygote from gamete formation in long-lived plants may lead to many mutations. We sequenced the genome of two terminal branches of a 234-year-old oak tree and found few fixed somatic single-nucleotide variants (SNVs), whose sequential appearance in the tree could be traced along nested sectors of younger branches. Our data suggest that stem cells of shoot meristems are robustly protected from accumulation of mutations in trees.

scholarly journals Liver cancer stem cells as a hierarchical society: yes or no?

2020 ◽  
Vol 52 (7) ◽  
pp. 723-735 ◽  
Author(s):  
Yuanzhuo Gu ◽  
Xin Zheng ◽  
Junfang Ji
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Recent Decade ◽  
Regulatory Pathways ◽  
Molecular Features ◽  
The Hierarchical Structure ◽  
Multiple Cell ◽  
The Common ◽  
Relationship Of ◽  
The Relationship

Abstract Cancer stem cells (CSCs) are cells possessing abilities of self-renewal, differentiation, and tumorigenicity in NOD/SCID mice. Based on this definition, multiple cell surface markers (such as CD24, CD133, CD90, and EpCAM) as well as chemical methods are discovered to enrich liver CSCs in the recent decade. Accumulated studies have revealed molecular signatures and signaling pathways involved in regulating different liver CSCs. Among liver CSCs positive for different markers, some molecular features and regulatory pathways are commonly shared, while some are only unique in certain CSC populations. These studies imply that liver CSCs exhibit diverse heterogeneity, while a functional relationship also exists. The aim of this review is to revisit the society of liver CSCs and summarize the common or unique molecular features of known liver CSCs. We hope to call for attention of researchers on the relationship of the liver CSC subgroups and to provide clues on the hierarchical structure of the liver CSC society.

scholarly journals Controlling homology-directed repair outcomes in human stem cells with dCas9

2021 ◽  
Author(s):  
William C Skarnes ◽  
Gang Ning ◽  
Sofia Giansiracusa ◽  
Alexander S Cruz ◽  
Cornelis Blauwendraat ◽  
...  
Keyword(s):  
Stem Cells ◽  
High Activity ◽  
Human Disease ◽  
Human Stem Cells ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Homology Directed Repair ◽  
Guide Rnas

Modeling human disease in human stem cells requires precise, scarless editing of single nucleotide variants (SNV) on one or both chromosomes. Here we describe improved conditions for Cas9 RNP editing of SNVs that yield high rates of biallelic homology-directed repair. To recover both heterozygous and homozygous SNV clones, catalytically inactive dCas9 was added to moderate high activity Cas9 RNPs. dCas9 can also block re-cutting and damage to SNV alleles engineered with non-overlapping guide RNAs.

scholarly journals Cancer Stem Cells in Head and Neck Metastatic Malignant Melanoma Express Components of the Renin-Angiotensin System

Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 268
Author(s):  
Sam Siljee ◽  
Tessa Pilkington ◽  
Helen D. Brasch ◽  
Nicholas Bockett ◽  
Josie Patel ◽  
...  
Keyword(s):  
Stem Cells ◽  
Malignant Melanoma ◽  
Cancer Stem Cells ◽  
Cell Lines ◽  
Renin Angiotensin System ◽  
Metastatic Malignant Melanoma ◽  
Primary Cell ◽  
Tissue Samples ◽  
Angiotensin System ◽  
Primary Cell Lines

Components of the renin-angiotensin system (RAS) are expressed by cancer stem cells (CSCs) in many cancer types. We here investigated expression of the RAS by the CSC subpopulations in human head and neck metastatic malignant melanoma (HNmMM) tissue samples and HNmMM-derived primary cell lines. Immunohistochemical staining demonstrated expression of pro-renin receptor (PRR), angiotensin-converting enzyme (ACE), and angiotensin II receptor 2 (AT2R) in all; renin in one; and ACE2 in none of the 20 HNmMM tissue samples. PRR was localized to cells within the tumor nests (TNs), while AT2R was expressed by cells within the TNs and the peritumoral stroma (PTS). ACE was localized to the endothelium of the tumor microvessels within the PTS. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) detected transcripts for PRR, ACE, ACE2, and AT1R, in all the five HNmMM tissue samples and four HNmMM-derived primary cell lines; renin in one tissue sample and one cell line, and AT2R in none of the five HNmMM tissue samples and cell lines. Western blotting showed variable expression of ACE, PRR, and AT2R, but not ACE2, in six HNmMM tissue samples and two HNmMM-derived primary cell lines. Immunofluorescence staining of two HNmMM tissue samples demonstrated expression of PRR and AT2R by the SOX2+ CSCs within the TNs and the OCT4+ CSCs within the PTS, with ACE localized to the endothelium of the tumor microvessels within the PTS.

scholarly journals STEM-02. GLIOBLASTOMA CANCER STEM CELLS UTILIZE ASYMMETRIC CELL DIVISION TO PROMOTE THERAPEUTIC RESISTANCE

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi234-vi234
Author(s):  
Masahiro Hitomi ◽  
Anastasia P Chumakova ◽  
Daniel Silver ◽  
Arnon Knudsen ◽  
Bjarne Kristensen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Division ◽  
Growth Factor ◽  
Cancer Stem Cells ◽  
Asymmetric Cell Division ◽  
Response To Therapy ◽  
Neurotrophin Receptor ◽  
Stem Cell Population ◽  
Reporter System ◽  
Egfr Inhibition

Abstract Asymmetric cell division (ACD) enables the maintenance of a stem cell population while simultaneously generating differentiated progeny. Cancer stem cells (CSCs) undergo multiple modes of cell division during tumor expansion and in response to therapy, yet the functional consequences of these division modes has yet to be determined. Using a fluorescence-based system that reports the mitotic distribution of lipid rafts enriched in cell surface receptors, we found that ACD in glioblastoma CSCs generated a daughter cell with enhanced resistance to radiation and temozolomide. Single-cell analyses using our reporter system revealed that ACD also increased the co-inheritance of epidermal growth factor receptor (EGFR) and neurotrophin receptor (p75NTR), which was validated across four additional glioblastoma CSC models. Stimulation of both receptors maintained self-renewal under differentiation conditions, and stimulation with p75NTR ligands rescued the reduction in STAT3, AKT, and ERK induced by erlotinib-mediated EGFR inhibition. Finally, knockdown of p75NTR enhanced the therapeutic efficacy of EGFR inhibition in vivo. Taken together, our data indicate that co-inheritance of p75NTR and EGFR promotes resistance to EGFR inhibition through a redundant mechanism. Overall, these findings demonstrate that ACD produces progeny with enhanced growth factor receptors, which contributes to the generation of a more therapeutically resistant CSC population, and suggest that ACD needs to be considered in the development of next-generation targeting strategies.

scholarly journals Genetic variants in the SHISA6 gene are associated with delayed cognitive impairment in two family datasets

2021 ◽  
Author(s):  
Jairo Ramos ◽  
Laura J Caywood ◽  
Michael B. Prough ◽  
Jason E. Clouse ◽  
Sharlene D. Herington ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Statistical Significance ◽  
Age At Onset ◽  
Chromosome 17 ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Genome Wide ◽  
Cultural Isolation ◽  
A Genome ◽  
The Common

Background: Studies of cognitive impairment (CI) in Amish communities have identified sibships containing multiple CI and cognitively unimpaired (CU; unaffected after age 75) individuals. We hypothesize that these CU individuals may carry protective alleles delaying age at onset (AAO) of CI, preserving cognition in older age despite increased genetic risk. As well, the genetic and cultural isolation in the Amish since the early 1800s may have reduced the complexity of the genetic architecture of CI, increasing the power to detect protective alleles in this population. With this in mind we conducted a genome-wide study (GWAS) to identify loci associated with AAO of CI in a sample of Amish adults over age 75. Methods: 1,522 individuals aged 43-99 (mean age 73.1, 42% men) screened at least once for CI using the Modified Mini-Mental State exam (3MS) were genotyped using Illumina chipsets. Genotypes were imputed for 7,815,951 single nucleotide variants (SNV) with minor allele frequency (MAF) > 1%. The outcome studied was age, defined as 1) age at the first 3MS result indicating impairment (AAO; 3MS <87; 362 CI individuals) or 2) age at last normal exam (3MS >=87, 1,160 CU individuals). Cox mixed-effects models examined association between age and each SNV, adjusting for sex and familial relationships. To replicate genome-wide significant findings, SNVs in a 1 Megabase region centered on the peak SNV were examined for association with age using these same methods in the NIA-LOAD family study dataset (1,785 AD cases, 1,565 unaffected controls, mean age 73.5. Results: Three SNV were significantly associated (p<5 x 10-8) with AAO in the Amish, on chromosomes 6 (rs14538074; HR=3.35), 9 (rs534551495; HR=2.82), and 17 (rs146729640; Hazard Ratio (HR)=6.38). Each region found the common allele associated with later AAO. Replication analysis detected association at rs146729640, with nominal statistical significance (HR=1.49, p=0.02). Conclusions: The replicated genome-wide significant association with AAO on chromosome 17 suggest this may be novel locus associated with delayed onset of AD. The associated SNP is located in the SHISA6 gene, which is involved in post-synaptic transmission in the hippocampus and is a biologically plausible candidate gene for AD.

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