The adult respiratory distress syndrome (ARDS) is an important and common medical emergency and is likely to occur in all hospitals dealing in respiratory care. The syndrome occurs from a variety of diffuse pulmonary injuries which are either direct or indirect attacks on the lung parenchyma. Once lung damage occurs, exudation of fluid and loss of surfactant activity leads to impaired gas exchange and reduced pulmonary compliance. The syndrome presents clinically as marked respiratory distress, tachypnea, cyanosis, refractory hypoxemia, high inflation pressure requirements during ventilatory support, diffuse alveolar infiltrates on chest roentgenograms and postmortem pulmonary congestion, hyperemia and hyaline membrane formation. Principles of management include adequate support of oxygen transport, ventilation and circulation employing volume respirators with positive end-expiratory pressure (PEEP). During the support phase, further pulmonary injury in terms of fluid overload, oxygen toxicity or infection, must be prevented or treated. When these principles of management are followed, recovery often occurs in spite of severe pulmonary injury as indicated by the first two illustrative cases.

https://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=1739&context=mcvq

The Adult Respiratory Distress Syndrome: Clinical Features, Factors Influencing Prognosis and Principles of Management

The use of biomarkers in diagnosis, therapy and prognosis has gained increasing interest over the last decades. In particular, the analysis of biomarkers in cancer patients within the pre- and post-therapeutic period is required to identify several types of cells, which carry a risk for a disease progression and subsequent post-therapeutic relapse. Cancer stem cells (CSCs) are a subpopulation of tumor cells that can drive tumor initiation and can cause relapses. At the time point of tumor initiation, CSCs originate from either differentiated cells or adult tissue resident stem cells. Due to their importance, several biomarkers that characterize CSCs have been identified and correlated to diagnosis, therapy and prognosis. However, CSCs have been shown to display a high plasticity, which changes their phenotypic and functional appearance. Such changes are induced by chemo- and radiotherapeutics as well as senescent tumor cells, which cause alterations in the tumor microenvironment. Induction of senescence causes tumor shrinkage by modulating an anti-tumorigenic environment in which tumor cells undergo growth arrest and immune cells are attracted. Besides these positive effects after therapy, senescence can also have negative effects displayed post-therapeutically. These unfavorable effects can directly promote cancer stemness by increasing CSC plasticity phenotypes, by activating stemness pathways in non-CSCs, as well as by promoting senescence escape and subsequent activation of stemness pathways. At the end, all these effects can lead to tumor relapse and metastasis. This review provides an overview of the most frequently used CSC markers and their implementation as biomarkers by focussing on deadliest solid (lung, stomach, liver, breast and colorectal cancers) and hematological (acute myeloid leukemia, chronic myeloid leukemia) cancers. Furthermore, it gives examples on how the CSC markers might be influenced by therapeutics, such as chemo- and radiotherapy, and the tumor microenvironment. It points out, that it is crucial to identify and monitor residual CSCs, senescent tumor cells, and the pro-tumorigenic senescence-associated secretory phenotype in a therapy follow-up using specific biomarkers. As a future perspective, a targeted immune-mediated strategy using chimeric antigen receptor based approaches for the removal of remaining chemotherapy-resistant cells as well as CSCs in a personalized therapeutic approach are discussed.

/pdf/cancer-stem-cells-origins-and-biomarkers-perspectives-for-3dc13vtybn.pdf

Cancer Stem Cells-Origins and Biomarkers: Perspectives for Targeted Personalized Therapies.

Extracellular vesicles (EVs), a class of heterogeneous membrane vesicles, are generally divided into exosomes and microvesicles on basis of their origination from the endosomal membrane or the plasma membrane, respectively. EV-mediated bidirectional communication among various cell types supports cancer cell growth and metastasis. EVs derived from different cell types and status have been shown to have distinct RNA profiles, comprising messenger RNAs and non-coding RNAs (ncRNAs). Recently, ncRNAs have attracted great interests in the field of EV-RNA research, and growing numbers of ncRNAs ranging from microRNAs to long ncRNAs have been investigated to reveal their specific functions and underlying mechanisms in the tumor microenvironment and premetastatic niches. Emerging evidence has indicated that EV-RNAs are essential functional cargoes in modulating hallmarks of cancers and in reciprocal crosstalk within tumor cells and between tumor and stromal cells over short and long distance, thereby regulating the initiation, development and progression of cancers. In this review, we discuss current findings regarding EV biogenesis, release and interaction with target cells as well as EV-RNA sorting, and highlight biological roles and molecular mechanisms of EV-ncRNAs in cancer biology.

/pdf/comprehensive-landscape-of-extracellular-vesicle-derived-1t7nrirkhl.pdf

Comprehensive landscape of extracellular vesicle-derived RNAs in cancer initiation, progression, metastasis and cancer immunology

MicroRNAs (miRNAs) are naturally occurring, small non-coding RNAs that mediate posttranscriptional regulation. Based on the level of sequence complementarity, miRNAs lead to the degradation of target mRNAs or the suppression of mRNA translation, thereby inhibiting the synthesis of proteins and achieving the regulation of genes. miRNAs, which exhibit tissue- and temporal- specific expression, are important negative regulatory RNAs that decrease the levels of other functional genes. miRNAs play a crucial role in disease progression and prognosis and thus exhibit potential for developing novel therapeutics. Due to the instability of miRNAs and their complex environment, including degradation by nucleases in vivo, the safety and effectiveness of miRNA delivery has become the focus of recent attention. Therefore, we discuss some representative advances related to the application of viral- and nonviral-mediated miRNA delivery systems and provide a new perspective on the future of miRNA-based therapeutic strategies.

/pdf/recent-progress-in-microrna-based-delivery-systems-for-the-1uxf5yp7u4.pdf

Recent progress in microRNA-based delivery systems for the treatment of human disease

The tumor milieu is characteristically acidic as a consequence of the fermentative metabolism of glucose that results in massive accumulation of lactic acid within the cytoplasm. Tumor cells get rid of excessive protons through exchangers that are responsible for the extracellular acidification that selects cellular clones that are more apt at surviving in this challenging and culling environment. Extracellular vesicles (EVs) are vesicles with diameters ranging from nm to μm that are released from the cells to deliver nucleic acids, proteins, and lipids to adjacent or distant cells. EVs are involved in a plethora of biological events that promote tumor progression including unrestricted proliferation, angiogenesis, migration, local invasion, preparation of the metastatic niche, metastasis, downregulation or hijacking of the immune system, and drug resistance. There is evidence that the release of specific exosomes is increased many folds in cancer patients, as shown by many techniques aimed at evaluating "liquid biopsies". The quality of the exosomal contents has been shown to vary at the different moments of tumor life such as local invasion or metastasis. In vitro studies have recently pointed out that cancer acidity is a major determinant in inducing increased exosome release by human cancer cells, by showing that exosomal release was increased as the pH moved from 7.4 pH to the typical pH of cancer that is 6.5. In this review, we emphasize the recent evidence that tumor acidity and exosomes levels are strictly related and strongly contribute to the malignant tumor phenotypes.

Extracellular acidity and increased exosome release as key phenotypes of malignant tumors

T cell function in cancer patients is usually impaired due to the constitutive activation of immune checkpoint inhibitors. This state is known as 'exhaustion' and is often associated with the inefficient control of tumors or persistent infections. In this work, we investigated the role of leukemia cell-derived microvesicles (MVs) in T cell exhaustion. Following incubation with MVs from various sources, all T cell subtypes exhibited the exhaustion phonotype and impaired cytokine secretion in vitro. Mice models also showed the connection between immune checkpoint inhibitors and MV injection. Sequencing and bioinformatics analyses indicated that a number of transcription factors and microRNAs (miRNAs) were attributable to the dysregulation of pathways and exhaustion in T cells. Further work revealed that functional miR-92a-3p, miR-21-5p, miR-16-5p, miR-126 and miR-182-5p in MVs could be delivered into T cells to induce the exhaustion phenotype. SerpinB2, IL-1β and CXCL5, which are mediators of the NF-κB pathway, were identified as the targets of the miRNAs mentioned above. We demonstrated that leukemia-derived MVs could initiate T cell exhaustion via the progressive temporal delivery of multiple exogenous miRNAs into T cells and the subsequent interaction of these miRNAs with their targets. Therefore, MVs can be expected not only to become new indicators of the T cell status in patients but also to be used as novel targets for personalized patient treatment.

https://www.tandfonline.com/doi/pdf/10.1080/2162402X.2018.1448330

Leukemia cell-derived microvesicles induce T cell exhaustion via miRNA delivery

Chimeric antigen receptor (CAR) T-cell immunotherapy is rapidly emerging as a promising novel treatment for malignancies. To broaden the success of CAR T-cell treatment for chronic myeloid leukaemia (CML), we attempted to construct a CD26 CAR T-cell product to target tyrosine kinase inhibitor-insensitive leukaemia stem cells (LSCs), which have been a challenge to cure for several decades and can be discriminated from healthy stem cells by the robust biomarker CD26. Of additional interest is that CD26 has also been reported to be a multi-purpose therapeutic target for other malignancies. Here, we constructed CD26 CAR T cells utilizing lentiviral transduction methods and verified them by flow cytometry analysis and RNA-seq. We found that the initial expansion of CD26 CAR-transduced T cells was delayed due to transient fratricide, but subsequent expansion was accelerated. CD26 CAR T cells exhibited cytotoxicity against the CD26+ T-cell lymphoma cell line Karpas 299, CD26-overexpressing K562 cells and primary CML LSCs, activated multiple effector functions in co-culture assays, and limited tumour progression in a mouse model; but there was some off-tumour cytotoxicity towards activated lymphocytes. In conclusion, these results establish the feasibility of using CD26 as an antigen for CAR T cells targeting CD26+ tumour cells.

A novel chimeric antigen receptor redirecting T-cell specificity towards CD26+ cancer cells

Ruxolitinib add-on in corticosteroid-refractory graft-vs-host disease after allogeneic stem cell transplantation: Results from a retrospective study on 38 Chinese patients

Ruxolitinib add-on in corticosteroid-refractory graft- vs-host disease after allogeneic stem cell transplantation: Results from a retrospective study on 38 Chinese patients

Background: Immunotherapy utilizing T cells genetically modified to express chimeric antigen receptors (CARs) is rapidly emerging as a promising novel treatment for hematological and nonhematological malignancies. In order to target the TKI-insensitive leukemia stem cells (LSCs) in chronic myeloid leukemia (CML) by CAR T cells, we chose CD26 as a cell surface tumor-associated antigen due to preferentially expression on LSCs. Additionally, CD26 has also been suggested to be a multipurpose therapeutic target for other cancer. Therefore, developing the CD26-targeting CAR T cells may be a promising therapy for not only LSCs but also other CD26+ cancer cells. Methods: We designed the second-generation CD26-targeting CAR utilizing 4-1BB (CD137) as costimulatory domain, and transduced T cells with CD26-CAR containing lentiviral. Then we evaluated the transduction efficiency and expansion ability, and demonstrated the existence of self-antigen-driven fratricide by cytokine assay and cytotoxicity assay. Results: Anti-CD26-4-1BB-CAR T cells exhibited poor viability, multiple cytokine secretion, down-regulation of CD26 and direct cytotoxicity against themselves, indicating self-antigen-driven fratricide. Conclusion: Eradicating CML-LSCs via anti-CD26-4-1BB-CAR T cells is not applicable, and optimized design or alternative target is needed.

T cells expressing CD26-specific chimeric antigen receptors exhibit extensive self-antigen-driven fratricide.

Abstract Background Chimeric antigen receptor T‐cell (CAR‐T) therapy for acute myeloid leukaemia (AML) has thus far been elusive, in part due to target restriction and phenotypic heterogeneity of AML cells. Mutations of the FMS‐like tyrosine kinase 3 (FLT3) and DNA methyltransferase 3A (DNMT3A) genes are common driver mutations that present with a poor prognosis in AML patients. We found that AML patients with FLT3 or DNMT3A mutations had higher expression of CD44 isoform 6 (CD44v6) compared to normal specimens. Therefore, we intended to demonstrate CD44v6 could be a specific option for AML with FLT3 or DNMT3A mutations. Methods Internal tandem duplication (ITD) mutations of FLT3 (FLT3/ITD) knock‐in clone and DNMT3A‐R882H mutant clones of SKM‐1 cells were generated using CRISPR/Cas9 and lentiviral transfection, respectively. CD44v6 CAR‐T cells were constructed by transfecting T cells with lentivirus containing CD44v6 CAR. CD44v6 expression in AML cell lines, AML patients and healthy donors was evaluated by flow cytometry. DNA methylation assays were used to analyse the mechanisms of FLT3 and DNMT3A mutations affecting CD44v6 expression. Results Aberrant overexpression of CD44v6 was observed in AML cell lines with FLT3 or DNMT3A mutations compared to the wild‐type SKM‐1 or K562 cells. AML patients with FLT3 or DNMT3A mutations had higher expression of CD44v6 compared to normal specimens. Then we constructed CD44v6 CAR‐T cells and found that CD44v6 CAR‐T specifically lysed CD44v6+ cells, accompanied by cytokines release. No significant killing effect was observed from CD44v6‐ AML cells and normal cells after co‐culture with CD44v6 CAR‐T. These results were also observed in vivo. Furthermore, we found that FLT3 or DNMT3A mutations induced CD44v6 overexpression by downregulating the CpG methylation of CD44 promoter. Conclusions Collectively, CD44v6 is a promising target of CAR‐T for AML patients with FLT3 or DNMT3A mutations.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9513046

Shu Zhou

Papers

Leukemia cell-derived microvesicles induce T cell exhaustion via miRNA delivery

A novel chimeric antigen receptor redirecting T-cell specificity towards CD26+ cancer cells

Ruxolitinib add-on in corticosteroid-refractory graft- vs-host disease after allogeneic stem cell transplantation: Results from a retrospective study on 38 Chinese patients

T cells expressing CD26-specific chimeric antigen receptors exhibit extensive self-antigen-driven fratricide.

CD44v6 chimeric antigen receptor T cell specificity towards AML with FLT3 or DNMT3A mutations