scholarly journals Non-homologous DNA increases gene disruption efficiency by altering DNA repair outcomes

2016 ◽  
Author(s):  
Christopher D Richardson ◽  
Grahm J Ray ◽  
Jacob E Corn
Keyword(s):  
Cell Lines ◽  
Gene Disruption ◽  
Genomic Sequence ◽  
Cell Types ◽  
Polyploid Cell ◽  
Guide Rna ◽  
Homology Directed Repair ◽  
Specific Manner ◽  
A Cell ◽  
Different Cell Types

Cas9 endonuclease can be targeted to genomic sequences by varying the sequence of the single guide RNA (sgRNA). The activity of these Cas9-sgRNA combinations varies widely at different genomic loci and in different cell types. Thus, disrupting genes in polyploid cell lines, or using inefficient sgRNAs, can require extensive downstream screening to identify homozygous clones. We have found that linear, non-homologous oligonucleotide DNA greatly stimulates Cas9-mediated gene disruption in the absence of homology-directed repair. This stimulation greatly increases the frequency of clones with homozygous gene disruptions, even in polyploid cell lines, and rescues otherwise ineffective sgRNAs. The mechanism of enhanced gene disruption differs between human cell lines, stimulating deletion of genomic sequence and/or insertion of non-homologous oligonucleotide DNA at the edited locus in a cell line specific manner. Thus, the addition of non-homologous DNA appears to drive cells towards error-prone instead of error-free repair pathways, dramatically increasing the frequency of gene disruption.

scholarly journals The complement of desmosomal plaque proteins in different cell types.

1985 ◽  
Vol 101 (4) ◽  
pp. 1442-1454 ◽  
Author(s):  
P Cowin ◽  
H P Kapprell ◽  
W W Franke
Keyword(s):  
Guinea Pig ◽  
Cell Types ◽  
Cardiac Cells ◽  
Myocardial Tissue ◽  
Cell Type ◽  
Wide Range ◽  
Specific Manner ◽  
A Cell ◽  
Cell Type Specific ◽  
Different Cell Types

Desmosomal plaque proteins have been identified in immunoblotting and immunolocalization experiments on a wide range of cell types from several species, using a panel of monoclonal murine antibodies to desmoplakins I and II and a guinea pig antiserum to desmosomal band 5 protein. Specifically, we have taken advantage of the fact that certain antibodies react with both desmoplakins I and II, whereas others react only with desmoplakin I, indicating that desmoplakin I contains unique regions not present on the closely related desmoplakin II. While some of these antibodies recognize epitopes conserved between chick and man, others display a narrow species specificity. The results show that proteins whose size, charge, and biochemical behavior are very similar to those of desmoplakin I and band 5 protein of cow snout epidermis are present in all desmosomes examined. These include examples of simple and pseudostratified epithelia and myocardial tissue, in addition to those of stratified epithelia. In contrast, in immunoblotting experiments, we have detected desmoplakin II only among cells of stratified and pseudostratified epithelial tissues. This suggests that the desmosomal plaque structure varies in its complement of polypeptides in a cell-type specific manner. We conclude that the obligatory desmosomal plaque proteins, desmoplakin I and band 5 protein, are expressed in a coordinate fashion but independently from other differentiation programs of expression such as those specific for either epithelial or cardiac cells.

scholarly journals CRISPR-Cas9 delivery to hard-to-transfect cells via membrane deformation

2015 ◽  
Vol 1 (7) ◽  
pp. e1500454 ◽  
Author(s):  
Xin Han ◽  
Zongbin Liu ◽  
Myeong chan Jo ◽  
Kai Zhang ◽  
Ying Li ◽  
...  
Keyword(s):  
Genome Editing ◽  
Function Analysis ◽  
Embryonic Stem ◽  
Cell Types ◽  
Disease Genes ◽  
Deformation Method ◽  
Targeting Therapy ◽  
Membrane Deformation ◽  
Guide Rna ◽  
Different Cell Types

The CRISPR (clustered regularly interspaced short palindromic repeats)–Cas (CRISPR-associated) nuclease system represents an efficient tool for genome editing and gene function analysis. It consists of two components: single-guide RNA (sgRNA) and the enzyme Cas9. Typical sgRNA and Cas9 intracellular delivery techniques are limited by their reliance on cell type and exogenous materials as well as their toxic effects on cells (for example, electroporation). We introduce and optimize a microfluidic membrane deformation method to deliver sgRNA and Cas9 into different cell types and achieve successful genome editing. This approach uses rapid cell mechanical deformation to generate transient membrane holes to enable delivery of biomaterials in the medium. We achieved high delivery efficiency of different macromolecules into different cell types, including hard-to-transfect lymphoma cells and embryonic stem cells, while maintaining high cell viability. With the advantages of broad applicability across different cell types, particularly hard-to-transfect cells, and flexibility of application, this method could potentially enable new avenues of biomedical research and gene targeting therapy such as mutation correction of disease genes through combination of the CRISPR-Cas9–mediated knockin system.

Novel ROR1 Antibody Is Able to Trigger Specific and Superior Complement-Dependent Cytotoxicity (CDC) on Primary CLL Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2052-2052
Author(s):  
Solange R Paredes-Moscosso ◽  
Marco Della Peruta ◽  
Satyen Harish Gohil ◽  
Micaela Harrasser ◽  
Amit C Nathwani
Keyword(s):  
B Cells ◽  
Cell Lines ◽  
The Elderly ◽  
Cell Types ◽  
Orphan Receptor ◽  
Complement Dependent Cytotoxicity ◽  
Clinical Benefits ◽  
Human Igg1 ◽  
Functional Analyses ◽  
Different Cell Types

Abstract Chronic Lymphocytic Leukaemia (CLL), the most common leukaemia of the elderly, remains largely incurable despite chemotherapy and small molecule inhibitors. Treatment targeting CD19 and CD20 has achieved important clinical benefits; however, these antigens are also present on normal B-cells rendering the patients immunodeficient and at a higher risk of infections. In view of this, our immunotherapy strategy is to produce therapeutic antibodies targeting the receptor-tyrosine-kinase-like orphan receptor 1 (ROR1), a protein present on the surface of malignant B-cells and cancer stem cell-like cells (CSC), but absent on most normal tissue. In order to produce new ROR1 monoclonal antibodies (MAbs), we generated a rat hybridoma library and screened >150 anti-ROR1+clones. We then cloned 16 of our own novel antibodies as well as previously published clones: 4a5 and R12 to human IgG1, kappa constant regions. A total of 13 chimeric antibodies recognised human ROR1 on different cell types, out of which, clone SA1 showed superior complement-dependent cytotoxicity (CDC) than other ROR1 MAbs, including clones 4a5 and R12. To determine the binding domain of our ROR1 MAbs, we generated stable cell lines expressing either full length-ROR1 or various forms of truncated ROR1 extracellular domains. Flow cytometry evaluation using these cells, and Epitope Mapping ELISA using a ROR1 peptide library, showed that our antibodies preferentially bind the Ig-like and Frizzled domains. Additionally, we fused clone SA1 to a mouse IgG2a, kappa constant regions in order to perform competition assays amongst our ROR1 MAbs and previously reported clones. We found that there was no epitope overlap amongst any of the tested clones. Moreover, by substituting single amino acids in a relevant region within the Ig-like domain, which we previously determined to be critical for SA1 binding, we found that this epitope is unique to SA1 and, notably is not shared by other clones previously reported in the literature; including clone D10, the prototype of Cirmtuzumab. Importantly, further characterisation of clone SA1 revealed that it can get internalised by both SKW 6.4 cells and CLL cells. As a whole, we have generated and identified a novel anti-human ROR1 monoclonal antibody able to trigger specific CDC of ROR1+ cells. More than that, clone SA1 has a unique epitope and it is able to get internalised by both cell lines and CLL cells that endogenously express ROR1. Additional characterisation and functional analyses are ongoing in order to also develop this antibody as a drug-antibody conjugate (ADC). Importantly, effective targeting of ROR1 expressed on malignant cells and CSC cells but not healthy tissue would provide a safer and more effective treatment of CLL and, in turn, other ROR1+ malignancies. Disclosures Paredes-Moscosso: UCL Business: Patents & Royalties: ROR1 based immunotherapies. Della Peruta:UCL Business: Patents & Royalties: ROR1 based immunotherapies. Gohil:UCL Business: Patents & Royalties: ROR1 based immunotherapies. Nathwani:UCL Business: Patents & Royalties: ROR1 based Immunotherapies.

TEMPLATE-BASED ISOCONTOURING

2006 ◽  
Vol 06 (02) ◽  
pp. 187-204 ◽  
Author(s):  
JAGANNATHAN LAKSHMIPATHY ◽  
WIESLAW L. NOWINSKI ◽  
ERIC A. WERNERT
Keyword(s):  
Linear Time ◽  
Cell Types ◽  
Extraction Process ◽  
Extraction Methods ◽  
Lookup Table ◽  
Graphics Hardware ◽  
A Cell ◽  
Triangle Strips ◽  
Different Cell Types

Different isocontour extraction methods use different cell types (tetrahedral, hexahedral, etc.) depending on the nature of the acquisition grids (structured, unstructured, etc.). The existing isocontouring methods have the following pre-steps for the actual extraction process: (a) identification of cell types, (b) identification of topologically independent instances for each cell type, (c) determination of surface primitives contained in the topologically independent instances and (d) generation of a lookup table such that the name of the entry is an instance of a cell and the entry is the triangle set for that instance. The extraction process outputs the triangles from the lookup table. In this paper we present a novel generic method that enables us to list topologically independent surface primitives called "templates" within any n-polytope cell namely tetrahedra, hexahedra etc. We have also modified the traditional lookup table such that name is the cell instance and the entry is face index representations of all template instances contained in that cell. To show an example, we have applied this approach on a hexahedron and listed the templates and subsequently we have showed how to construct a lookup table. Most modern graphics hardware render triangles faster if they are rendered collectively as triangle strips as opposed to individual triangles. With our modified lookup table approach we can identify triangles in the neighboring cell in a linear time and hence we are able to connect two triangle strips into a longer triangle strip on the fly during the extraction process. We have compared our approach with some existing methods. The following are some of the important features of the method: (1) Simplicity, (2) procedural triangulation and (3) face-index representation.

scholarly journals Complex regulation and functional versatility of mammalian alpha- and beta-tubulin isotypes during the differentiation of testis and muscle cells.

1988 ◽  
Vol 106 (6) ◽  
pp. 2023-2033 ◽  
Author(s):  
S A Lewis ◽  
N J Cowan
Keyword(s):  
Cell Types ◽  
Beta Tubulin ◽  
Specific Expression ◽  
Alpha Tubulin ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
A Cell ◽  
Complex Regulation ◽  
Carboxy Terminal ◽  
Different Cell Types

In the accompanying paper (Gu, W., S. A. Lewis, and N. J. Cowan. 1988. J. Cell Biol. 106: 2011-2022), we report the generation of three antisera, each of which uniquely recognizes a different mammalian alpha-tubulin isotype, plus a fourth antibody that distinguishes between microtubules containing the tyrosinated and nontyrosinated form of the only known mammalian alpha-tubulin gene product that lacks an encoded carboxy-terminal tyrosine residue. These sera, together with five sera we raised that distinguish among the known mammalian beta-tubulin isotypes, have been used to study patterns of tubulin isotype-specific expression in muscle and testis, two tissues in which characteristic developmental changes are accompanied by dramatic rearrangements in microtubule structures. As in the case of cells in culture, there is no evidence to suggest that there is subcellular sorting of different tubulin isotypes among different kinds of microtubule, even in a cell type (the developing spermatid) that simultaneously contains such functionally distinct structures as the manchette and the flagellum. On the other hand, the patterns of expression of the various tubulin isotypes show marked and distinctive differences in different cell types and, in at least one case, evidence is presented for regulation at the translational or posttranslational level. The significance of these observations is discussed in terms of the existence of the mammalian alpha- and beta-tubulin multigene families.

scholarly journals Intervertebral disc decellularisation: progress and challenges

2021 ◽  
Vol 42 ◽  
pp. 196-219
Author(s):  
MF Fiordalisi ◽  
◽  
AJ Silva ◽  
M Barbosa ◽  
RM Gonçalves ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Life Quality ◽  
Cell Types ◽  
Host Cells ◽  
Low Back ◽  
Therapeutic Success ◽  
A Cell ◽  
Antigen Removal ◽  
Ivd Degeneration ◽  
Different Cell Types

Intervertebral disc (IVD) degeneration and the consequent low-back pain (LBP) affect over 80 % of people in western societies, constituting a tremendous socio-economic burden worldwide and largely impairing patients’ life quality. Extracellular matrix (ECM)-based scaffolds, derived from decellularised tissues, are being increasingly explored in regenerative medicine for tissue repair. Decellularisation plays an essential role for host cells and antigen removal, while maintaining native microenvironmental signals, including ECM structure, composition and mechanical properties, which are essential for driving tissue regeneration. With the lack of clinical solutions for IVD repair/regeneration, implantation of decellularised IVD tissues has been explored to halt and/or revert the degenerative cascade and the associated LBP symptoms. Over the last few years, several researchers have focused on the optimisation of IVD decellularisation methods, combining physical, chemical and enzymatic treatments, in order to successfully develop a cell-free matrix. Recellularisation of IVD-based scaffolds with different cell types has been attempted and numerous methods have been explored to address proper IVD regeneration. Herein, the advances in IVD decellularisation methods, sterilisation procedures, repopulation and biocompatibility tests are reviewed. Additionally, the importance of the donor profile for therapeutic success is also addressed. Finally, the perspectives and major hurdles for clinical use of the decellularised ECM-based biomaterials for IVD are discussed. The studies reviewed support the notion that tissue-engineering-based strategies resorting to decellularised IVD may represent a major advancement in the treatment of disc degeneration and consequent LBP.

Use of Crispr/Cas Genome Editing in Ba/F3 Cells to Generate the Fip1l1-Pdgfra and Nup214-Abl1 Fusion Genes

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3575-3575
Author(s):  
Marlies Vanden Bempt ◽  
Charles E de Bock ◽  
Nicole Mentens ◽  
Olga Gielen ◽  
Ellen Geerdens ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Protein Expression ◽  
Genome Editing ◽  
Fusion Gene ◽  
Stop Codon ◽  
Chromosomal Rearrangements ◽  
Guide Rna ◽  
Homology Directed Repair ◽  
Fusion Protein Expression ◽  
A Cell

Abstract CRISPR/Cas genome editing is a powerful tool to precisely induce chromosomal breaks and to modify genes of interest. Cas9, an RNA-guided DNA endonuclease derived from Streptococcus pyogenes, is able to generate double stranded breaks (DSBs) in the genomic locus to where it is directed by its guide RNA (gRNA) component. The DSBs are subsequently repaired by one of the two main host repair mechanisms: the error-prone Non-homologous end joining (NHEJ) pathway or the very specific Homology-directed repair (HDR) pathway. We aimed to use CRISPR/Cas genome editing to generate the Fip1l1-Pdgfra and Nup214-Abl1 fusion genes by inducing chromosomal rearrangements in the interleukin-3 dependent Ba/F3 cell line. Prior to generating the chromosomal rearrangements, we optimized CRISPR/Cas genome editing in Ba/F3 cells, by targeting Cas9 to exon 24 of CD45, a cell surface transmembrane protein, of which inactivation can be easily detected by flow cytometry. Electroporation of Ba/F3 cells with plasmids expressing Cas9 and the specific guide RNA led to efficient inactivation of the CD45 gene, as measured by flow cytometry (30% of the cells showed loss of CD45 expression). The use of the Cas9 nickase variant led to an increased efficiency of CD45 inactivation with 58% of the cells showing loss of CD45 expression. We then extended these studies to assess the efficiency of homology-directed repair to introduce a specific mutation, using a single strand donor template to generate a premature stop codon in exon 24 of CD45. The successful introduction of the novel stop codon in CD45 was confirmed by PCR amplification of the targeted exon followed by massive parallel sequencing (MiSeq, Illumina) and we observed this endogenous mutation in 80% of the Ba/F3 clones. Having optimised the use and efficiency of CRISPR/Cas in Ba/F3 cells, we aimed to introduce double stranded breaks simultaneously in the genes Fip1l1 and Pdgfra to generate a cell based model for the FIP1L1-PDGFRA fusion gene as observed in chronic eosinophilic leukemia. Double strand breaks were introduced in Fip1l1 exon 23, 31, 32 or 34 together with simultaneous breaks in Pdgfra exon 12, both located on mouse chromosome 5. Upon IL3 removal, cells harbouring the deletion and fusion gene were able to survive, grow and form colonies in semi-solid medium, as was shown before for Ba/F3 cells transduced with retroviral vectors expressing FIP1L1-PDGFRA. The presence of the deletion was confirmed by PCR, and fusion protein expression was detected by Western blotting. A fusion between exon 1 of Fip1l1 and exon 12 of Pdgfra could also transform the cells, which confirmed earlier findings that the transforming capacities of the fusion protein are independent of Fip1l1 and dependent on the interruption of the juxtamembrane region of PDGFRA. The expression and phosphorylation levels of Fip1l1-Pdgfra were compared between the CRISPR/Cas generated Ba/F3 cells and retrovirally transduced cells overexpressing FIP1L1-PDGFRA. As expected, retrovirally transduced cells showed a much higher protein expression level of FIP1L1-PDGFRA, and much stronger phosphorylation compared to the CRISPR/Cas generated cells, in which the endogenous Fip1l1 promoter is used to drive the expression of the fusion protein. We also observed a difference in sensitivity to inhibition by imatinib, a kinase inhibitor with strong activity against PDGFRA. The same strategy was followed to generate a fusion between Nup214 and Abl1, as observed in a subset of T-cell acute lymphoblastic leukemia cases. Ba/F3 cells harbouring the Nup214-Abl1 fusion gene were able to survive and grow independent of IL3. The presence of the fusion gene was confirmed by PCR, and fusion protein expression was detected by Western blotting. Taken together, these data show that CRISPR/Cas induced chromosomal translocations in cells more faithfully recapitulate gene expression levels and sensitivity to chemotherapeutics when compared to retroviral transduction based expression of an oncogene. In conclusion, we have now designed and implemented an optimised platform to use CRISPR/Cas genome editing in Ba/F3 cells and measure gRNA efficacy by massive parallel sequencing. Our data confirm that the CRISPR/Cas genome editing system can be used to generate chromosomal rearrangements in Ba/F3 cells and provides a method to generate improved cell based models for the study of oncogenic tyrosine kinases. Disclosures No relevant conflicts of interest to declare.

scholarly journals Long Non-Coding RNA Expression Levels Modulate Cell-Type-Specific Splicing Patterns by Altering Their Interaction Landscape with RNA-Binding Proteins

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 593 ◽  
Author(s):  
Felipe Wendt Porto ◽  
Swapna Vidhur Daulatabad ◽  
Sarath Chandra Janga
Keyword(s):  
Alternative Splicing ◽  
Cell Lines ◽  
Rna Binding ◽  
Cell Type ◽  
Specific Manner ◽  
Alternatively Spliced ◽  
A Cell ◽  
Specific Alternative ◽  
Cell Type Specific ◽  
Rna Interaction

Recent developments in our understanding of the interactions between long non-coding RNAs (lncRNAs) and cellular components have improved treatment approaches for various human diseases including cancer, vascular diseases, and neurological diseases. Although investigation of specific lncRNAs revealed their role in the metabolism of cellular RNA, our understanding of their contribution to post-transcriptional regulation is relatively limited. In this study, we explore the role of lncRNAs in modulating alternative splicing and their impact on downstream protein–RNA interaction networks. Analysis of alternative splicing events across 39 lncRNA knockdown and wildtype RNA-sequencing datasets from three human cell lines—HeLa (cervical cancer), K562 (myeloid leukemia), and U87 (glioblastoma)—resulted in the high-confidence (false discovery rate (fdr) < 0.01) identification of 11,630 skipped exon events and 5895 retained intron events, implicating 759 genes to be impacted at the post-transcriptional level due to the loss of lncRNAs. We observed that a majority of the alternatively spliced genes in a lncRNA knockdown were specific to the cell type. In tandem, the functions annotated to the genes affected by alternative splicing across each lncRNA knockdown also displayed cell-type specificity. To understand the mechanism behind this cell-type-specific alternative splicing pattern, we analyzed RNA-binding protein (RBP)–RNA interaction profiles across the spliced regions in order to observe cell-type-specific alternative splice event RBP binding preference. Despite limited RBP binding data across cell lines, alternatively spliced events detected in lncRNA perturbation experiments were associated with RBPs binding in proximal intron–exon junctions in a cell-type-specific manner. The cellular functions affected by alternative splicing were also affected in a cell-type-specific manner. Based on the RBP binding profiles in HeLa and K562 cells, we hypothesize that several lncRNAs are likely to exhibit a sponge effect in disease contexts, resulting in the functional disruption of RBPs and their downstream functions. We propose that such lncRNA sponges can extensively rewire post-transcriptional gene regulatory networks by altering the protein–RNA interaction landscape in a cell-type-specific manner.

Biophotons, hallucinogens, and fluorescence

2011 ◽  
Vol 26 (S2) ◽  
pp. 1202-1202
Author(s):  
F. Grass
Keyword(s):  
Thermal Noise ◽  
Signal To Noise Ratio ◽  
Cell Communication ◽  
Cell Types ◽  
Ambient Light ◽  
A Cell ◽  
Inner Diameter ◽  
Different Cell Types ◽  
Light Guidance ◽  
Baby Hamster Kidney Cells

Several experiments show that there is a cell to cell communicaton by light in different cell types. The most convincing experiment shows that baby hamster kidney cells can communicate their spatial orientation through a glass film, this can only happen by photon signals. If so, it can be assumed that the cells with the highest differentiation, the neurons also use this mechanism. The nervous system would have excellent conditions for a cell to cell communication by light. Neurons are large, metabolically very active (lightproducing) cells with wide arborisation, contain little pigment and are protected from ambient light by bone and connective tissue. Signal to noise ratio should be high for photon signals. It has been shown that light can be propagated along the axis tracts. Also the hollow microtubules (neurofibrillae) could act as light guiding structures. According to Jibu et al. their inner diameter of 15 nm is ideal for light guidance free of thermal noise and loss. Other findings that may be of importance in this context, are the strong flurescence properties of the major hallucinogens: LSD, bufetonine, dimethyl-tryptamine, psilocybine, psilocin, iboguanin, harmine, cannabidinol and mescaline. Furthermore it has been shown that hallucinogenic properties of these substances have a direct correlation to their fluorescence properties and their readyness to donate electrons. As hypothesis we propose that the fluorescence interacts physically with the proposed Biophoton mediated cell to cell communication thus producing hallucinations. This would be an easy and plausible explanation for the strong hallucinogenic properties of these fluorescent substances.

scholarly journals Early Induction of Apoptosis in Hematopoietic Cell Lines After Exposure to Flavopiridol

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 458-465 ◽  
Author(s):  
Bernard W. Parker ◽  
Gurmeet Kaur ◽  
Wilberto Nieves-Neira ◽  
Mohammed Taimi ◽  
Glenda Kohlhagen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Prostate Carcinoma ◽  
Cell Types ◽  
Carcinoma Cells ◽  
Cycle Arrest ◽  
Induced Apoptosis ◽  
Different Cell Types ◽  
Hematopoietic Cell Lines

Abstract Flavopiridol (NSC 649890; Behringwerke L86-8275, Marburg, Germany), is a potent inhibitor of cyclin dependent kinases (CDKs) 1, 2, and 4. It has potent antiproliferative effects in vitro and is active in tumor models in vivo. While surveying the effect of flavopiridol on cell cycle progression in different cell types, we discovered that hematopoietic cell lines, including SUDHL4, SUDHL6 (B-cell lines), Jurkat, and MOLT4 (T-cell lines), and HL60 (myeloid), displayed notable sensitivity to flavopiridol-induced apoptosis. For example, after 100 nmol/L for 12 hours, SUDHL4 cells displayed a similar degree of DNA fragmentation to that shown by the apoptosis-resistant PC3 prostate carcinoma cells only after 3,000 nmol/L for 48 hours. After exposure to 1,000 nmol/L flavopiridol for 12 hours, typical apoptotic morphology was observed in SUDHL4 cells, but not in PC3 prostate carcinoma cells despite comparable potency (SUDHL4:120 nmol/L; PC3: 203 nmol/L) in causing growth inhibition by 50% (IC50). Flavopiridol did not induce topoisomerase I or II cleavable complex activity. A relation of p53, bcl2, or bax protein levels to apoptosis in SUDHL4 was not appreciated. While flavopiridol caused cell cycle arrest with decline in CDK1 activity in PC3 cells, apoptosis of SUDHL4 cells occurred without evidence of cell cycle arrest. These results suggest that antiproliferative activity of flavopiridol (manifest by cell cycle arrest) may be separated in different cell types from a capacity to induce apoptosis. Cells from hematopoietic neoplasms appear in this limited sample to be very susceptible to flavopiridol-induced apoptosis and therefore clinical trials in hematopoietic neoplasms should be of high priority.

Sign in / Sign up

Export Citation Format

Share Document