Main roads to melanoma Palmieri, Giuseppe; Capone, Mariaelena; Ascierto, Maria Libera ...
Journal of translational medicine,
10/2009, Letnik:
7, Številka:
1
Journal Article
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The characterization of the molecular mechanisms involved in development and progression of melanoma could be helpful to identify the molecular profiles underlying aggressiveness, clinical behavior, ...and response to therapy as well as to better classify the subsets of melanoma patients with different prognosis and/or clinical outcome. Actually, some aspects regarding the main molecular changes responsible for the onset as well as the progression of melanoma toward a more aggressive phenotype have been described. Genes and molecules which control either cell proliferation, apoptosis, or cell senescence have been implicated. Here we provided an overview of the main molecular changes underlying the pathogenesis of melanoma. All evidence clearly indicates the existence of a complex molecular machinery that provides checks and balances in normal melanocytes. Progression from normal melanocytes to malignant metastatic cells in melanoma patients is the result of a combination of down- or up-regulation of various effectors acting on different molecular pathways.
Adoptive cell therapy of metastatic melanoma with autologous tumor infiltrating lymphocytes (TIL) is clinically effective, but TIL production can be challenging. Here we describe a simplified method ...for initial TIL culture and rapid expansion in gas-permeable flasks. TIL were initially cultured from tumor digests and fragments in 40 mL capacity flasks with a 10 cm² gas-permeable silicone bottom, G-Rex10. A TIL rapid expansion protocol (REP) was developed using 500 mL capacity flasks with a 100 cm² gas-permeable silicone bottom, G-Rex100. TIL growth was successfully initiated in G-Rex10 flasks from tumor digests from 13 of 14 patients and from tumor fragments in all 11 tumor samples tested. TIL could then be expanded to 8-10×10⁹ cells in a 2-step REP that began by seeding 5×10⁶ TIL into a G-Rex100 flask, followed by expansion at day 7 into 3 G-Rex100 flasks. To obtain the 30-60×10⁹ cells used for patient treatment, we seeded 6 G-Rex100 flasks with 5×10⁶ cells and expanded into 18 G-Rex100 flasks. Large-scale TIL REP in gas-permeable flasks requires approximately 9-10 L of media, about 3-4 times less than other methods. In conclusion, TIL initiation and REP in gas-permeable G-Rex flasks require fewer total vessels, less media, less incubator space, and less labor than initiation and REP in 24-well plates, tissue culture flasks, and bags. TIL culture in G-Rex flasks will facilitate the production of TIL at the numbers required for patient treatment at most cell processing laboratories.
Whether as a cure or bridge to transplant, chimeric antigen receptor (CAR)-T cell therapies have shown dramatic outcomes for the treatment of hematologic malignancies, and particularly ...relapsed/refractory B cell leukemia and lymphoma. However, these therapies are not effective for all patients, and are not without toxicities. The challenge now is to optimize these products and their manufacture. The manufacturing process is complex and subject to numerous variabilities at each step. These variabilities can affect the critical quality attributes of the final product, and this can ultimately impact clinical outcomes. This review will focus on optimizing the manufacturing variables that can impact the safety, purity, potency, consistency and durability of CAR-T cells.
Genetically engineered T cells have become an important therapy for B-cell malignancies. Measuring the efficiency of vector integration into the T cell genome is important for assessing the potency ...and safety of these cancer immunotherapies.
A digital droplet polymerase chain reaction (ddPCR) assay was developed and evaluated for assessing the average number of lenti- and retroviral vectors integrated into Chimeric Antigen Receptor (CAR) and T Cell Receptor (TCR)-engineered T cells.
The ddPCR assay consistently measured the concentration of an empty vector in solution and the average number of CAR and TCR vectors integrated into T cell populations. There was a linear relationship between the average vector copy number per cell measured by ddPCR and the proportion of cells transduced as measured by flow cytometry. Similar vector copy number measurements were obtained by different staff using the ddPCR assay, highlighting the assays reproducibility among technicians. Analysis of fresh and cryopreserved CAR T and TCR engineered T cells yielded similar results.
ddPCR is a robust tool for accurate quantitation of average vector copy number in CAR and TCR engineered T cells. The assay is also applicable to other types of genetically engineered cells including Natural Killer cells and hematopoietic stem cells.
Clinical CAR T-cell therapy using integrating vector systems represents a promising approach for the treatment of hematological malignancies. Lentiviral and γ-retroviral vectors are the most commonly ...used vectors in the manufacturing process. However, the integration pattern of these viral vectors and subsequent effect on CAR T-cell products is still unclear.
We used a modified viral integration sites analysis (VISA) pipeline to evaluate viral integration events around the whole genome in pre-infusion CAR T-cell products. We compared the differences of integration pattern between lentiviral and γ-retroviral products. We also explored whether the integration sites correlated with clinical outcomes.
We found that γ-retroviral vectors were more likely to insert than lentiviral vectors into promoter, untranslated, and exon regions, while lentiviral vector integration sites were more likely to occur in intron and intergenic regions. Some integration events affected gene expression at the transcriptional and post-transcriptional level. Moreover, γ-retroviral vectors showed a stronger impact on the host transcriptome. Analysis of individuals with different clinical outcomes revealed genes with differential enrichment of integration events. These genes may affect biological functions by interrupting amino acid sequences and generating abnormal proteins, instead of by affecting mRNA expression. These results suggest that vector integration is associated with CAR T-cell efficacy and clinical responses.
We found differences in integration patterns, insertion hotspots and effects on gene expression vary between lentiviral and γ-retroviral vectors used in CAR T-cell products and established a foundation upon which we can conduct further analyses.
Gene therapy simplified Ren, Jiaqiang; Stroncek, David F.
Blood,
11/2016, Letnik:
128, Številka:
18
Journal Article
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In this issue of
Blood,
Richter et al
report their work on an in vivo gene transduction system using the adenovirus-based vector and hyperactive SB transposase (SB100×) system. Their results show ...that this system is effective and safe and performs without needing ex vivo expansion and transduction of hematopoietic stem cells (HSCs).
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This system may overcome some of the difficulties associated with cell collection and manufacturing and provide technical advances for the field of gene therapy.
Successful implementation of adoptive cell therapy (ACT) of cancer requires comprehensively addressing biological and practical challenges. This approach has been largely overlooked, resulting in a ...gap between the potential of ACT and its actual effectiveness. We summarize the most promising technical strategies in creating an “ideal” ACT product, focusing on chimeric antigen receptor (CAR)-engineered cells. Since many requirements for effective ACT are common to most cancers, what we outline here might have a broader impact.
Successful implementation of adoptive cell therapy (ACT) of cancer requires comprehensively addressing biological and practical challenges. This approach has been largely overlooked, resulting in a gap between the potential of ACT and its actual effectiveness. We summarize the most promising technical strategies in creating an “ideal” ACT product, focusing on chimeric antigen receptor (CAR)-engineered cells. Since many requirements for effective ACT are common to most cancers, what we outline here might have a broader impact.
As clinical applications for chimeric antigen receptor T cell (CART) therapy extend beyond early phase trials, commercial manufacture incorporating cryopreservation steps becomes a logistical ...necessity. The effect of cryopreservation on CART characteristics is unclear. We retrospectively evaluated the effect of cryopreservation on product release criteria and in vivo characteristics in 158 autologous CART products from 6 single-center clinical trials. Further, from 3 healthy donor manufacturing runs, we prospectively identified differentially expressed cell surface markers and gene signatures among fresh versus cryopreserved CARTs. Within 2 days of culture initiation, cell viability of the starting fraction (peripheral blood mononuclear cells PBMNCs) decreased significantly in the cryo-thawed arm compared to the fresh arm. Despite this, PBMNC cryopreservation did not affect final CART fold expansion, transduction efficiency, CD3%, or CD4:CD8 ratios. In vivo CART persistence and clinical responses did not differ among fresh and cryopreserved final products. In healthy donors, compared to fresh CARTs, early apoptotic cell-surface markers were significantly elevated in cryo-thawed CARTs. Cryo-thawed CARTs also demonstrated significantly elevated expression of mitochondrial dysfunction, apoptosis signaling, and cell cycle damage pathways. Cryopreservation during CART manufacture is a viable strategy, based on standard product release parameters. The clinical impact of cryopreservation-related subtle micro-cellular damage needs further study.
Panch et al. demonstrate that CART cryopreservation during manufacture minimally affects final product characteristics, in vivo levels, persistence, and clinical response. However, increases in early apoptotic markers and cell damage pathways in cryo-thawed CARTs require careful consideration to better formulate dosing strategies.
Bone marrow stromal cells (BMSCs) are a heterogeneous population that participates in wound healing, immune modulation and tissue regeneration. Next generation sequencing was used to analyze ...transcripts from single BMSCs in order to better characterize BMSC subpopulations.
Cryopreserved passage 2 BMSCs from one healthy subject were cultured through passage 10. The transcriptomes of bulk BMSCs from designated passages were analyzed with microarrays and RNA sequencing (RNA-Seq). For some passages, single BMSCs were separated using microfluidics and their transcriptomes were analyzed by RNA-Seq.
Transcriptome analysis by microarray and RNA-Seq of unseparated BMSCs from passages 2, 4, 6, 8, 9 and 10 yielded similar results; both data sets grouped passages 4 and 6 and passages 9 and 10 together and genes differentially expressed among these early and late passage BMSCs were similar. 3D Diffusion map visualization of single BMSCs from passages 3, 4, 6, 8 and 9 clustered passages 3 and 9 into two distinct groups, but there was considerable overlap for passages 4, 6 and 8 cells. Markers for early passage, FGFR2, and late passage BMSCs, PLAT, were able to identify three subpopulations within passage 3 BMSCs; one that expressed high levels of FGFR2 and low levels of PLAT; one that expressed low levels of FGFR2 and high levels of PLAT and one that expressed intermediate levels of FGFR2 and low levels of PLAT.
Single BMSCs can be separated by microfluidics and their transcriptome analyzed by next generation sequencing. Single cell analysis of early passage BMSCs identified a subpopulation of cells expressing high levels of FGFR2 that might include skeletal stem cells.
Although the sequence of events leading to wound repair has been described at the cellular and, to a limited extent, at the protein level this process has yet to be fully elucidated. Genome wide ...transcriptional analysis tools promise to further define the global picture of this complex progression of events.
This study was part of a placebo-controlled double-blind clinical trial in which basal cell carcinomas were treated topically with an immunomodifier--toll-like receptor 7 agonist: imiquimod. The fourteen patients with basal cell carcinoma in the placebo arm of the trial received placebo treatment consisting solely of vehicle cream. A skin punch biopsy was obtained immediately before treatment and at the end of the placebo treatment (after 2, 4 or 8 days). 17.5K cDNA microarrays were utilized to profile the biopsy material.
Four gene signatures whose expression changed relative to baseline (before wound induction by the pre-treatment biopsy) were identified. The largest group was comprised predominantly of inflammatory genes whose expression was increased throughout the study. Two additional signatures were observed which included preferentially pro-inflammatory genes in the early post-treatment biopsies (2 days after pre-treatment biopsies) and repair and angiogenesis genes in the later (4 to 8 days) biopsies. The fourth and smallest set of genes was down-regulated throughout the study. Early in wound healing the expression of markers of both M1 and M2 macrophages were increased, but later M2 markers predominated.
The initial response to a cutaneous wound induces powerful transcriptional activation of pro-inflammatory stimuli which may alert the host defense. Subsequently and in the absence of infection, inflammation subsides and it is replaced by angiogenesis and remodeling. Understanding this transition which may be driven by a change from a mixed macrophage population to predominantly M2 macrophages, may help the interpretation of the cellular and molecular events occurring in the microenvironment of serially biopsied tissues.
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