Colony-forming Activity Research Articles

Peculiarities of the influence of recombinant cytokines on the functional activity of hematopoietic progenitor cells in myelodysplastic syndrome in vitro

Populations of hematopoietic progenitor cells are the closest descendants of stem cells. It is at their level that the processes of proliferation and differentiation occur, since they are sensitive, unlike stem cells, to the action of cytokines, which are released in the event of a shortage of blood cells in the periphery. However, for a long time the role of hematopoietic progenitor cells in the implementation of the pathological process in disorders of hematopoiesis was underestimated, while now it has turned out to be more significant than previously thought. This is especially true of myelodysplastic syndrome, which, despite its name, is a clonal disease that precedes acute leukemia. The purpose of the study was to determine the peculiarities of the functioning of hematopoietic progenitor cells in normal and impaired hematopoiesis at the initial stages of the malignant process of MDS (MDS-IB) under the conditions of exposure to different concentrations of cytokines to assess the hematopoietic potential of these cells. Their colony-forming activity (CFU) was studied in two groups of patients — control (10 people) and experimental (20 people) in culture in vitro. It was found that CFU increases with increasing concentration of cytokines and requires twice as much stimulus when culturing hematopoietic cells from patients with MDS-IB. The optimal concentration in the control for G-CSF, GM-CSF, IL-3 was 20 ng/ml, and for cells from patients with MDS-IB — 40 ng/ml. It has been proven that in the case of using a complex of cytokines (GM-CSF, G-CSF, IL-3), the colonyforming ability of progenitor cells from patients with MDS-IB increases significantly, compared to such indicators for cytokines acting alone (28.7±3.2 to 18.3±1.8, 12.1±1.5 and 24.5±2.1, respectively). The paper reveals the latent potential for cell proliferation from patients with MDS-IB, which can be used both in experimental studies and in the creation of protocols for the treatment of patients with MDS in the initial stage of the disease.

Bazedoxifene Inhibits Cell Viability, Colony-Forming Activity, and Cell Migration in Human Non-Small Cell Lung Cancer Cells and Improves the Treatment Efficacy of Paclitaxel and Gemcitabine.

Bazedoxifene is a third-generation selective estrogen receptor modulator that inhibits the IL6/IL6R/GP130 signaling pathway by inhibiting IL6-induced homodimerization of GP130. Considering that the IL6/IL6R/GP130 signaling pathway is important in tumorigenesis and metastasis, bazedoxifene is thought to have an antitumor effect, which has been proven preliminarily in breast cancer and pancreatic cancer but has not yet been studied in non-small cell lung cancer (NSCLC). This study is aimed at evaluating the antitumor effect of bazedoxifene in NSCLC. A549 and H1299 NSCLC cell lines were employed and exposed to various concentrations of bazedoxifene, paclitaxel, gemcitabine, and their combinations for cell viability, colony formation, and wound healing assays to demonstrate the antitumor effect of bazedoxifene with or without paclitaxel or gemcitabine. MTT cell viability, colony formation, and wound healing assays showed that bazedoxifene was capable of inhibiting cell viability, colony formation, and cell migration in a dose-dependent manner. In addition, bazedoxifene was capable of working with paclitaxel or gemcitabine synergistically to inhibit cell viability, colony formation, and cell migration. This study demonstrated the potential antitumor effect of bazedoxifene and its ability to improve the treatment efficacy of paclitaxel and gemcitabine.

Myricetin inhibits 4 T1 breast tumor growth in mice via induction of Nrf-2/GPX4 pathway-mediated Ferroptosis

Ferroptosis is a recently identified form of programmed cell death that is iron-dependent and closely involved in the pathogenesis of breast cancer. Past studies have identified myricetin as being able to inhibit breast cancer growth through its targeting of apoptotic mechanisms, but the precise mechanisms whereby it exerts its antitumoral effects in breast cancer remain to be characterized in detail. Here, the effects of myricetin on the induction of ferroptosis in breast cancer cells were investigated. It was found that myricetin was able to significantly inhibit 4 T1 tumor cell viability and colony forming activity, increasing the level of MDA, Fe2+, and ROS within these cells. From a mechanistic perspective, myricetin was found to induce ferroptotic 4 T1 cell death via downregulating Nrf-2 and GPX4. In vivo experimentation demonstrated that myricetin treatment was sufficient to reduce the growth of subcutaneous breast tumors in female mice as evidenced by decreases in tumor weight and volume, while significantly inhibiting Nrf-2 and GPX4 expression within the tumors of treated mice. Myricetin is capable of readily suppressing breast tumor growth in mice via the induction of ferroptotic activity through the Nrf-2/GPX4 pathway. Myricetin may thus offer utility as a therapeutic agent for the management of breast cancer in clinical settings.

A randomized, multicenter, open-label, phase 2 study of TRK-950 in combination with ramucirumab and paclitaxel as second-line therapy in patients with Caprin-1 positive gastric or gastroesophageal junction (G/GEJ) adenocarcinoma.

TPS4181 Background: Caprin-1 is strongly expressed on the cell membrane of many cancer types including G/GEJ and on cancer stem cells. High expression is associated with enhanced in vitro colony-forming activity and in vivo tumorigenicity. TRK-950 is a first in class humanized antibody targeting CAPRIN-11). In the phase I study (NCT02990481), TRK-950 was well tolerated as monotherapy with no DLTs and MTD not reached at doses of 3-30mg/kg IV weekly. Subsequently the Phase 1b study demonstrated that TRK-950 was well tolerated with a high potential for synergistic anti-tumor activity when used in combination with standard of care treatment(s) in selected advanced solid tumors (NCT03872947). Specifically, Regimen D which evaluated TRK-950 in combination with Ramucirumab and Paclitaxel in G/GEJ showed a DCR of 100% in all nine patients receiving 10 mg/kg and partial responses were seen in 5/9 (55%) patients. Caprin-1 strong expression was observed in 4/9 patients and an ORR of 100% was seen in those patients2). A Phase II clinical trial in gastric/GEJ cancer patients with strong Caprin-1 expressions is now enrolling patients. Methods: The phase II study is a multi-national, open-label, randomized, multicenter study evaluating the efficacy of TRK-950 in combination with ramucirumab (Ram) + paclitaxel (PTX ) as compared with Ram + PTX treatment alone in patients with previously treated metastatic G/GEJ adenocarcinoma (NCT06038578). Patients enrolled across 10 sites in Japan, South Korea and the United States are randomized 1:1:1 by the permuted block method to (arm A) TRK-950 5mg/kg plus Ram + PTX, (arm B) TRK-950 10mg/kg plus Ram + PTX or (arm C) Ram + PTX alone. Inclusion criteria include patients with Caprin-1 positive (cutoff; 30% at ≥ 2+ staining) advanced/metastatic G/GEJ adenocarcinoma who have received first line therapy. Key exclusion criteria include HER2 positive disease. The primary endpoint is progression free survival (PFS) based on Independent Central Review (ICR) assessment per RECIST v1.1. Key secondary and exploratory endpoints include overall survival (OS), ORR, DoR, and biomarker evaluation. An interim analysis will be performed after 105 patients are randomized in stage 1 to determine the optimal dose of TRK-950 (5mg/kg or 10mg/kg) that will be evaluated in arm stage 2. In total 146 patients will be enrolled (40 patients in one arm and each 53 patients in two arms). This study opened in September 2023. 1. Okano F, et al. Cancer Res Commun. 2023 Apr 18;3(4):640-658. 2. Cassier P, et al. J Clin Oncol. 2023 Vol. 41, No. 4, suppl. Clinical trial information: NCT06038578 .

Lysine demethylase LSD1 is associated with stemness in EBV-positive B cell lymphoma

EBV-infected lymphoma has a poor prognosis and various treatment strategies are being explored. Reports suggesting that B cell lymphoma can be induced by epigenetic regulation have piqued interest in studying mechanisms targeting epigenetic regulation. Here, we set out to identify an epigenetic regulator drug that acts synergistically with doxorubicin in EBV-positive lymphoma. We expressed the major EBV protein, LMP1, in B-cell lymphoma cell lines and used them to screen 100 epigenetic modifiers in combination with doxorubicin. The screening results identified TCP, which is an inhibitor of LSD1. Further analyses revealed that LMP1 increased the activity of LSD1 to enhance stemness ability under doxorubicin treatment, as evidenced by colony-forming and ALDEFLUOR activity assays. Quantseq 3′ mRNA sequencing analysis of potential targets regulated by LSD1 in modulating stemness revealed that the LMP1-induced upregulation of CHAC2 was decreased when LSD1 was inhibited by TCP or downregulated by siRNA. We further observed that SOX2 expression was altered in response to CHAC2 expression, suggesting that stemness is regulated. Collectively, these findings suggest that LSD1 inhibitors could serve as promising therapeutic candidates for EBV-positive lymphoma, potentially reducing stemness activity when combined with conventional drugs to offer an effective treatment approach.

Depletion of Ppp6c in hematopoietic and vascular endothelial cells causes embryonic lethality and decreased hematopoietic potential

Protein phosphatase 6 (PP6) is a serine/threonine (Ser/Thr) protein phosphatase, and its catalytic subunit is Ppp6c. PP6 forms the PP2A subfamily with PP2A and PP4. The diverse phenotypes observed following small interfering RNA (siRNA)-based knockdown of Ppp6c in cultured mammalian cells suggest that PP6 plays roles in cell growth and DNA repair. There is also evidence that PP6 regulates nuclear factor kappa B (NF-κB) signaling and mitogen-activated protein kinases and inactivates transforming growth factor-β-activated kinase 1 (TAK1). Loss of Ppp6c causes several abnormalities, including those of T cell and regulatory T cell function, neurogenesis, oogenesis, and spermatogenesis. PP2A has been reported to play an important role in erythropoiesis. However, the roles of PP6 in other hematopoietic cells have not been investigated. We generated Ppp6cfl/fl;Tie2-Cre (Ppp6cTKO) mice, in which Ppp6c was specifically deleted in hematopoietic and vascular endothelial cells. Ppp6cTKO mice displayed embryonic lethality. Ppp6c deficiency increased the number of dead cells and decreased the percentages of erythroid and monocytic cells during fetal hematopoiesis. By contrast, the number of Lin-Sca-1+c-Kit+ cells, which give rise to all hematopoietic cells, was slightly increased, but their colony-forming cell activity was markedly decreased. Ppp6c deficiency also increased phosphorylation of extracellular signal-regulated kinase 1/2 and c-Jun amino (N)-terminal kinase in fetal liver hematopoietic cells.

A randomized, multicenter, open-label, phase 2 study of TRK-950 in combination with ramucirumab and paclitaxel as second-line therapy in patients with CAPRIN-1 positive gastric or gastroesophageal junction (G/GEJ) adenocarcinoma.

TPS420 Background: CAPRIN-1 is strongly expressed on the cell membrane of many cancer types including G/GEJ and on cancer stem cells. High expression is associated with enhanced in vitro colony-forming activity and in vivo tumorigenicity. TRK-950 is a first in class humanized antibody targeting CAPRIN-1.1 In the phase I study (NCT02990481), TRK-950 was well tolerated as monotherapy with no DLTs and MTD not reached at doses of 3-30mg/kg IV weekly. Subsequently the Phase 1b demonstrated that TRK-950 was well tolerated with a high potential for synergistic anti-tumor activity when used in combination with standard of care treatment(s) in selected advanced solid tumors (NCT03872947). Specifically, Regimen D which evaluated TRK-950 in combination with Ramucirumab and Paclitaxel in G/GEJ showed a DCR of 100% in all nine patients receiving 10 mg/kg and partial responses were seen in 5/9 (55%) patients. CAPRIN-1 strong expression was observed in 4/9 patients and an ORR of 100% was seen in those patients.2 A Phase II clinical trial in gastric/GEJ cancer patients with strong CAPRIN-1 is now enrolling patients. Methods: The phase II study is a multi-national, open-label, randomized, multicenter study evaluating the efficacy of TRK-950 in combination with ramucirumab (Ram) + paclitaxel (PTX) as compared with Ram + PTX treatment alone in patients with previously treated metastatic G/GEJ adenocarcinoma (NCT06038578). Patients enrolled across 10 sites in Japan, South Korea and the United States are randomized 1:1:1 by the permuted block method to (arm A) TRK-950 5mg/kg plus Ram + PTX, (arm B) TRK-950 10mg/kg plus Ram + PTX or (arm C) Ram + PTX alone. Inclusion criteria include patients with CAPRIN-1 positive (cutoff; 30% at ≥ 2+ staining) advanced/metastatic G/GEJ adenocarcinoma who have received first line therapy. Key exclusion criteria include HER2 positive disease. The primary endpoint is progression free survival (PFS) based on Independent Central Review (ICR) assessment per RECIST v1.1. Key secondary and exploratory endpoints include overall survival (OS), ORR, DoR, and biomarker evaluation. An interim analysis will be performed after 105 patients are randomized in stage 1 to determine the optimal dose of TRK-950 (5mg/kg or 10mg/kg) that will be evaluated in stage 2. In total 146 patients will be enrolled (40 patients in one arm and 53 patients in the other two arms). This study opened in September 2023. 1. Okano F, et al. Cancer Res Commun. 2023 Apr 18;3(4):640-658. 2. Cassier P, et al. J Clin Oncol. 2023 Vol. 41, No. 4, suppl. Clinical trial information: NCT06038578 .

Design and Synthesis of Novel Chalcone Derivatives: Anti-Breast Cancer Activity Evaluation and Docking Study.

Chalcone is a common simple fragment of natural products with anticancer activity. In a previous study, the research group discovered a series of chalcone derivatives with stronger anticancer activities. To find better anticancer drugs, novel chalcone derivatives A1-A14, B1-B14 have continuously been designed and synthesized. The antiproliferative activity of these compounds against breast cancer cells (MCF-7) was investigated by the Cell Counting Kit-8 (CCK-8) method with 5-fluorouracil (5-Fu) as the control drug. The results showed that compound A14 exhibited excellent antiproliferative ability compared to the control drug 5-Fu. Scratch experiments and cloning experiments further confirmed that compound A14 could inhibit the proliferation and colony formation activity of MCF-7 cells. In addition, molecular docking primarily explains the interaction between compound and protein. These results suggested that compound A14 could be a promising chalcone derivative for further anti-breast cancer research.

Combination of 3PO analog PFK15 and siPFKL efficiently suppresses the migration, colony formation ability, and PFK-1 activity of triple-negative breast cancers by reducing the glycolysis.

Among all the subtypes of breast cancer, triple-negative breast cancer (TNBC) has been associated with the worst prognosis. Recently, for many solid tumors (including breast cancer) metabolic reprogramming has appeared as a cancer cell hallmark, and the elevated glycolytic pathway has been linked to their aggressive phenotype. In the present study, we evaluated the prognostic and therapeutic relevance of PFKFB3 (6-phosphofructo-2- kinase/fructose-2,6-bisphosphatase) in TNBCs. Prognostic significance of PFKFB3 expression was evaluated in overall breast cancers as well as in TNBCs. PFKFB3 inhibitor (3PO potent analogue i.e., PFK15) cytotoxicity in TNBC cell lines (MDA-MB-231 and MDA-MB-468) was analyzed using an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cancer cell physiological characteristics like clonogenicity and migration were also investigated after PFK15 treatment. As fructose-2,6-bisphosphate (F-2,6-BP), has been associated with increased PFK-1 activity, the effect of PFKFB3 inhibition by PFK15 was investigated on two major isoforms of phosphofructokinase-1 (PFK-1) in breast cancer, that is, phosphofructokinase-platelet type (PFKP) and phosphofructokinase-liver type (PFKL) (relevant to breast cancer). For PFKL inhibition, the siRNA approach was used. PFKFB3 expression was significantly correlated with inferior overall survival in breast cancer patients including TNBCs. PFK15 treatment in TNBC cells (i.e., MDA-MB-231 and MDA-MB-468) resulted in a decreased PFKP expression, thereby leading to reduced colony formation ability, migration rate, and extracellular lactate levels. However, to our surprise PFK15 treatment in both TNBC cells also resulted in elevated PFKL levels. Our results demonstrated that the combinatorial inhibition of PFK15 with siPFKL was more effective in TNBC cells, as it led to a decrease in colony formation ability, migration rate, extracellular lactate levels, and PFK-1 activity when compared with individual treatments. Using bona fide PFKFB3 inhibitor, that is, AZ67, we further show that AZ67 treatment to TNBC cells has no effect either on the expression of PFKP and PFKL, or on the lactate production. In summary, our present in vitro study demonstrated that 3PO derived PFK15 mechanism of action is totally different from AZ67 in TNBC cells. However, we advocate that the PFK15-mediated inhibition (along with PFKL) on the TNBCs migration, colony formation, and PFK-1 activity can be further explored for the therapeutic advantage of TNBC patients.

Activation of distinct inflammatory pathways in subgroups of LR-MDS

Aberrant innate immune signaling has been identified as a potential key driver of the complex pathophysiology of myelodysplastic neoplasms (MDS). This study of a large, clinically and genetically well-characterized cohort of treatment-naïve MDS patients confirms intrinsic activation of inflammatory pathways in general mediated by caspase-1, interleukin (IL)-1β and IL-18 in low-risk (LR)-MDS bone marrow and reveals a previously unrecognized heterogeneity of inflammation between genetically defined LR-MDS subgroups. Principal component analysis resolved two LR-MDS phenotypes with low (cluster 1) and high (cluster 2) levels of IL1B gene expression, respectively. Cluster 1 contained 14/17 SF3B1-mutated cases, while cluster 2 contained 8/8 del(5q) cases. Targeted gene expression analysis of sorted cell populations showed that the majority of the inflammasome-related genes, including IL1B, were primarily expressed in the monocyte compartment, consistent with a dominant role in determining the inflammatory bone marrow environment. However, the highest levels of IL18 expression were found in hematopoietic stem and progenitor cells (HSPCs). The colony forming activity of healthy donor HSPCs exposed to monocytes from LR-MDS was increased by the IL-1β-neutralizing antibody canakinumab. This work reveals distinct inflammatory profiles in LR-MDS that are of likely relevance to the personalization of emerging anti-inflammatory therapies.

Targeting Poly(ADP)ribose polymerase in BCR/ABL1-positive cells

BCR/ABL1 causes dysregulated cell proliferation and is responsible for chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph1-ALL). In addition to the deregulatory effects of its kinase activity on cell proliferation, BCR/ABL1 induces genomic instability by downregulating BRCA1. PARP inhibitors (PARPi) effectively induce cell death in BRCA-defective cells. Therefore, PARPi are expected to inhibit growth of CML and Ph1-ALL cells showing downregulated expression of BRCA1. Here, we show that PARPi effectively induced cell death in BCR/ABL1 positive cells and suppressed colony forming activity. Prevention of BCR/ABL1-mediated leukemogenesis by PARP inhibition was tested in two in vivo models: wild-type mice that had undergone hematopoietic cell transplantation with BCR/ABL1-transduced cells, and a genetic model constructed by crossing Parp1 knockout mice with BCR/ABL1 transgenic mice. The results showed that a PARPi, olaparib, attenuates BCR/ABL1-mediated leukemogenesis. One possible mechanism underlying PARPi-dependent inhibition of leukemogenesis is increased interferon signaling via activation of the cGAS/STING pathway. This is compatible with the use of interferon as a first-line therapy for CML. Because tyrosine kinase inhibitor (TKI) monotherapy does not completely eradicate leukemic cells in all patients, combined use of PARPi and a TKI is an attractive option that may eradicate CML stem cells.

Abstract A09: Targeting of FOXM1 recapitulates NPM1 mutations in chemo-sensitization of AML

Abstract NPM1 mutations are among the most common mutations in CN-AML (Cytogenetically Normal-AML) and are known to enhance chemosensitivity in AML patients. Across multiple co-operative group studies, in the absence of deleterious mutations, patients with NPM1 mutations show superior overall and relapse-free survival. The FOXM1 regulatory network is a major predictor of poor prognosis in human cancers of different origin, including AML. Early AML cell line and patient sample data from our lab demonstrated that nuclear NPM colocalizes with nuclear FOXM1 while mutant NPM sequesters FOXM1 in the cytoplasm. Applying RNAseq differential expression results from published FOXM1 knockout experiments on KG-1 cells and MLL-AF9-transformed mice to Beat AML RNAseq data, we developed a ~200-gene FOXM1 signature that was significantly associated with inferior CR/CRi rate (OR=0.44 [95% CI: 0.21–0.95], p=0.037) in wild type NPM1, wild type FLT3 de novo AML patients. Notably, this FOXM1 signature was not significantly associated with CR/CRi in mutated NPM1, wild type FLT3 patients (OR=1.78 [95% CI: 0.15–21.51], p=0.651). These data suggest that inactivation of FOXM1 may underlie the chemosensitivity conferred by the highly prevalent NPM1 mutation in favorable risk AML. Using our novel network-centric approach, we found a first-in-class small molecule (STL427944) that affects a pathway that limits FOXM1 expression and significantly disrupts the associated regulatory network. To directly address the role of FOXM1 in chemosensitivity of AML cells, we tested two FOXM1-specific inhibitory compounds: STL427944 and its derivative, STL001 (their structures will be disclosed). From a medicinal chemistry standpoint, STL427944 has two main metabolic liabilities, a hydrolytically labile furane-carboxylic acid phenolic ester and a hydrazone. We applied several paths of structural activity relationship (SAR) optimization to overcome these issues from removal of liabilities to bio-isosteric replacement to cyclizations. The ring replacement is likely to have significantly improved the overall stability observed in STL001, resulting in at least !0-fold more active compound with better ‘drug-like’ properties and thus enhanced potency. We showed that 500nM of STL001 partially suppressed expression of FOXM1 protein in AML, while 5mM of STL001 (versus 50mM of STL427944) fully suppressed FOXM1 and sensitized AML cells to venetoclax and cytarabine treatment. Ex vivo treatment of AML patient samples with STL427944 and STL001 resulted in inhibition of nuclear FOXM1 expression according to IHC and downregulation of canonical FOXM1 transcriptional targets as indicated by real-time PCR. This treatment potentiated the efficacy of venetoclax in inhibiting colony forming activity in AML patient samples. Our data suggest that targeting FOXM1 in AML patients with wild type NPM1 may recapitulate NPM1 mutations and will have a robust therapeutic effect leading to more favorable outcome for AML patients. Citation Format: Irum Khan, Sandjeev Raghuwanshi, Andy Kaempf, Jeff Tyner, Alex Domling, Carlos Camacho, Andrei Gartel. Targeting of FOXM1 recapitulates NPM1 mutations in chemo-sensitization of AML [abstract]. In: Proceedings of the AACR Special Conference: Acute Myeloid Leukemia and Myelodysplastic Syndrome; 2023 Jan 23-25; Austin, TX. Philadelphia (PA): AACR; Blood Cancer Discov 2023;4(3_Suppl):Abstract nr A09.

Detection of Glycolytically Active Lacticaseibacillus paracasei Strain Shirota by Flow Cytometry Targeting the Efflux Activity of Fluorescent Dye: a Potential Tool for Quality Assessment of Probiotic Cells in Milk Products.

The rapid and accurate detection of viable probiotic cells in dairy products is important for assessing product quality in manufacturing. Flow cytometry is widely used for the rapid analysis of bacterial cells. However, further investigation is needed into the optimum property to use it for assessing cell viability. Here, we proposed using the efflux activity of a fluorescent dye, carboxyfluorescein (CF), as an indicator of cell viability. CF is generated from 5(6)-carboxyfluorescein diacetate as a result of cleavage by intracellular esterase. It generally accumulates in the cell, but certain bacterial species are known to extrude it. We found here that the probiotic strain Lacticaseibacillus paracasei strain Shirota (LcS) also extruded CF in the presence of energy sources, such as glucose. To investigate the mechanism of its CF-efflux activity, we screened CF-efflux-negative mutants from a random mutagenesis LcS library and examined the whole genome for genes responsible for CF efflux. We identified a base substitution in the pfkA gene in the glycolytic pathway, and we demonstrated that intact pfkA was essential for CF efflux, indicating that CF-efflux-positive cells must have uncompromised glycolytic activity. We also confirmed that there was a good correlation between the rate of CF-efflux-positive cells and that of colony-forming cells of LcS in a fermented milk product, whereas other properties, such as esterase activity and cell membrane integrity, lost their correlation with the colony-forming activity after long storage. We propose that CF-efflux activity could be an appropriate indicator of cell viability in certain probiotic strains. IMPORTANCE To our knowledge, this is the first report to demonstrate that CF efflux requires uncompromised glycolytic activity in certain lactic acid bacteria. Compared with the cell properties currently widely used for cell viability assessment, such as intracellular esterase activity and membrane integrity, CF-efflux activity enables the accurate detection of culturable cells, especially in products stored for long periods at cold temperatures. These results indicate strongly that CF-efflux activity can be an adequate cell-viability indicator and that flow cytometric quantification could be an alternative to conventional CFU counting. Our findings should be especially informative for dairy/probiotic product manufacturing.

LINC01023 Promotes the Hepatoblastoma Tumorigenesis via miR-378a-5p/WNT3 Axis.

Hepatoblastoma is the most common type of hepatic tumors occurring in children between 0 and 5years. And the exact pathophysiology of the disease is still mysterious. Accumulating studies on LncRNA have shown its pivotal role in the development and progression of distinct human cancers. However, the role of LINC01023 in hepatoblastoma is unknown. The relative expression of LINC01023, miR-378a-5p, and Wnt3 on hepatoblastoma tissue and cell lines was determined by quantitative polymerase chain reaction (qRT-PCR). The effect of LINC01023 downregulation and upregulation on cell proliferation, colony formation and apoptosis activities in HUH6 and HepG2 Cells was assessed by CKK8, clonogenic and flow cytometry analysis, respectively. Dual luciferase, RNA immunoprecipitation (RIP), and RNA pull-down were performed to confirm the interaction between LINC01023 and miR-378a-5p. Similarly, Dual luciferase assay was performed to confirmed the interaction between Wnt3 and miR-378a-5p. The xenograft tumorgenicity test was performed to elucidate the tumorgenicity potential of LINC01023. LINC01023 was significantly upregulated in hepatoblastoma tissue and cell lines rather than in adjacent normal hepatic tissue and QSG7701 cell lines. LINC01023 silencing attenuated cell proliferation, colony formation and increased cell apoptosis. Conversely, LINC01023 upregulation results in significant increase in cell proliferation, and colony formation activities however, a significant reduction in apoptosis activity was reported. Interaction between the LINC01023 and WNT3 was confirmed by dual luciferase assay. Xenograft animal tumorgenicity test confirmed the in-vivo tumorigenesis potential of LINC01203. To the best of our knowledge, this study is the first study demonstrating the role of LINC01023 in hepatoblastoma tumorigenesis through the LINC01023/miR-378a-5p/Wnt3 axis. It could be a potential therapeutic target and a prognostic biomarker in hepatoblastoma.

Функціональна активність гемопоетичних клітин-попередників кордової крові у довготривалій культурі на гідрогелевій підложці in vitro

Development of new and improvement of existing models of long-term cultivation of hematopoietic stem cells (HSC) and cord blood progenitor cells is one of the most important directions in modern cell biology, related to obtaining a sufficient amount of hematopoietic tissue for experimental and clinical use. The aim of the work was to investigate the functional activity of hematopoietic progenitor cells from cord blood during long-term cultivation on a soft polyacrylamide gel substrate in the presence of a cytokine complex and to determine the advantages of this method of maintaining hematopoiesis for further use in transplantation. To realize this purpose, the following methods were used: the method of long-term cultivation in vitro on a hydrogel substrate, the method of colony formation in semi-liquid agar, cytological research methods, light and inverted microscopy, statistical research methods. Due to the use of the hydrogel substrate together with the cytokine complex, a high proliferative activity of hematopoietic cells is observed, which is reflected in their expansion during long-term cultivation (5 weeks), as well as of high colony-forming activity (521.5 ± 7.5.105 per explanted cells). Thus, the stiffness of the substrate must be taken into account for the expansion of stem cells and their immediate descendants. The presence of a soft substrate made of polyacrylamide gel along with a complex of cytokines ensures the expansion of hematopoietic cells due to the long- term support of hematopoiesis.

EVI1 Promotes Immune-Evasive Microenvironment Via Cyclin D1 in Acute Myeloid Leukemia

Inappropriate expression of Ecotropic viral integration site 1 (EVI1) has been associated with dismal clinical outcomes in acute myeloid leukemia (AML), while EVI1high (EVI1+) AML cells do not show clear resistance to cytotoxic agents in vitro. Since EVI1 is essential for normal hematopoietic stem cells (HSCs), we performed chromatin-immunoprecipitation (ChIP)- and RNA-sequencing of murine EVI1+ AML cells and normal hematopoietic cells to identify factors involved explicitly in AML, and thereby to elucidate molecular cues to refractory EVI1+ AML. We firstly employed a murine EVI1-transformed AML (EVI1-AML) model, where murine hematopoietic cells exogenously expressing 3×FLAG-tagged EVI1 were transplanted into syngeneic mice. Using EVI1-AML cells, we next performed ChIP coupled to next-generation sequencing (ChIP-seq) by anti-FLAG tag antibody and transcriptome analysis by RNA-seq. We further generated another murine EVI1+ AML model by retrovirally transducing the KMT2A-MLLT1 fusion gene into Lineage- Sca-1+ c-kit+ cells from EVI1-GFP knock-in mice, where Evi1-IRES-GFP allele was inserted into the Evi1 locus to enable real-time monitoring of Evi1 expression by GFP, followed by transplantation into lethally irradiated syngeneic mice. Intriguingly, GFPhigh L-GMPs from KMT2A-MLLT1 AML mice showed distinct expression profiles from GFPlow L-GMPs, including high NF-kB activity and low stem cell activity, along with the lower frequency of leukemia-initiating cells in GFPhigh fraction. Consistently, an exogenous expression of EVI1 in KMT2A-MLLT1 AML cells without Evi1 expression decreased colony-forming and leukemia-initiating activity, suggesting a differential role of EVI1 in AML from normal HSCs, where EVI1 is essential in maintaining stem cell function. Combined with functional screening by cell proliferation-related short hairpin RNAs (shRNAs), we identified that cyclin D1 (CCND1) was a downstream target, commonly implied in the above analyses, and a potential therapeutic vulnerability of EVI1-AML. EVI1 bound to the region 3.8 kb upstream of the transcription start site of Ccnd1, through which EVI1 demonstrated strong transcriptional activity in a luciferase reporter assay. Genetic silencing of Ccnd1 and pharmacologic inhibition of Cyclin D1 in EVI1- and EVI1+ KMT2A-MLLT1 AML cells negatively affected proliferation and colony-forming activity in vitro. Moreover, in vivo knockdown of Ccnd1 strikingly impaired the leukemogenic capacity of murine EVI1-AML models. It was surprising that transcriptomic analysis of EVI1-AML cells with Ccnd1 silencing showed the downregulation of genes involved in chemokine production and response to interferon instead of cell cycle-related genes. The expression of Cd274 (PD-L1) as well as Stat1, the primary signaling mediator for type I and II IFN, was decreased in EVI1-AML cells with Ccnd1 knockdown. EVI1 directly bound to the promoter region of Stat1 and activated its transcription in line with a previous report, and indirectly up-regulated STAT1 expression via Cyclin D1. Accordingly, infiltrating CD4 and CD8 T cells from EVI1-shCcnd1 AML mice demonstrated decreased exhaustion markers, including LAG3, PDCD1, and TIGIT. Silencing of Stat1 and Ifngr, the receptor for IFN-γ, impaired the leukemogenic capacity of EVI1-AML in vivo, with a decrease in T and NK cells with exhaustion phenotypes, while Ifnar, the receptor for IFN-α, was not involved in this process. Genetic inhibition of the IFN-γ-STAT1 axis in non-EVI1+ AML models did not affect AML development, nor the frequency of immune cells expressing exhaustion-related molecules, suggesting this axis is specifically important in EVI1+ AML. By using human AML datasets, overexpression of EVI1 and CCND1 were associated with IFN-γ signature, including up-regulation of STAT1 and CD274, and elevated expression of chemokines, with increased exhaustion molecules in T cells. These data collectively suggest that cyclin D1 is implicated in the development of EVI1-AML through the formation of IFN-γ signature and exhausted T cell phenotypes, which could be potentially targeted.

Activation of Distinct Inflammatory Pathways in LR-MDS Is Determined By Genetics

Background Dysregulated innate immune signaling has been identified as a driver of the complex pathophysiology of myelodysplastic syndromes (MDS), predominantly in low risk (LR)-MDS (Basiorka et al., Blood 2016). The pharmacological targeting of inflammation may therefore help to retard disease development. However, since MDS is a heterogeneous disease, a personalized approach is likely to be necessary, requiring a more detailed knowledge of distinct inflammatory patterns and their variation between genetically defined subgroups of LR-MDS patients (Winter et al., J Clin Oncol 2020). Aims The aim of this work was to describe inflammation states in the bone marrow of LR-MDS patients (IPSS-R ≤ 3.5) compared to controls with and without clonal hematopoiesis of indeterminate potential (CHIP) and to high-risk (HR)-MDS patients (IPSS-R ≥ 4). Methods Cryopreserved bone marrow mononuclear cells (BM-MNCs) and corresponding bone marrow plasma samples from non-CHIP controls (n = 15), CHIP individuals (n = 12) and patients with LR-MDS (n = 47) or HR-MDS (n = 14) were obtained from the MDS registry and the BoHemE study (NCT02867085) at the University Hospitals in Dresden and Leipzig. Targeted expression analysis of 11 inflammasome-related genes (S100A9, NLRP3, PYCARD, CASP1, IL1B, IL18, NLRP1, NLRC4, AIM2, CASP3, CASP4) and multiplex cytokine measurements were performed. To investigate heterogeneity in the LR-MDS cohort, a principle component analysis (PCA) was performed and a cumulative gene expression score was calculated as summed log2 fold changes (mean non-CHIP = 0) of all 11 mRNA expression values for each sample. Furthermore, BM-MNCs of selected non-CHIP (n = 3) and CHIP (n = 3) individuals as well as LR-MDS (n = 14) and HR-MDS (n = 5) patients were FACS-sorted for hematopoietic stem and progenitor cells (HSPCs), monocytes, monocytic and polymorphonuclear myeloid-derived suppressor cells (MDSCs) and lymphocytes. The expression of IL1B, IL18, S100A9, NLRP3, PYCARD, CASP1 and NLRC4 was assessed in each population by qRT-PCR. Finally, colony forming assays were used to assess the effect of the IL-1β-neutralizing antibody canakinumab (100 µg/ml) on the hematopoietic potential of healthy CD34+ HSPCs pre-cultured with CD14+ monocytes from patients with SF3B1-mutated (n = 3) or del(5q) (n = 3) LR-MDS. Results The expression of inflammasome-related genes in the bone marrow increased from non-CHIP through CHIP to LR-MDS individuals, with overall levels of inflammasome-related gene expression being 40% higher in LR-MDS than in non-CHIP controls (p = 0.002). The precise signature of inflammation gene expression varied widely within LR-MDS patients. A PCA identified two separable inflammation states with low (cluster 1, n = 24) and high (cluster 2, n = 23) inflammation patterns (Figure 1), with CASP1, PYCARD and NLRC4 contributing most to the PCA dimensions. The clusters were associated with distinct clinical features and disease genotypes: more than 80% of the SF3B1 mutations were found in cluster 1, while all del(5q) cases were in cluster 2 (Figure 1). Compared to del(5q) samples, those with SF3B1-mutation showed lower expression of IL-1β at both mRNA (3.9-fold decrease, p = 0.0005) and protein level (8.3-fold decrease, p = 0.03). Targeted gene expression analysis of sorted cell populations revealed distinct contributions to the differential patterns of inflammation. IL1B, NLRP3, NLRC4 and S100A9 were expressed in all disease states predominantly by monocytes and monocytic MDSCs, consistent with a dominant role for monocytic cells in determining the inflammatory bone marrow environment. However, IL18 mRNA levels were highest in HSPCs. Compared to untreated controls, canakinumab augmented the colony forming activity of healthy HSPCs pre-cultured with monocytes from SF3B1-mutated MDS (+70%, p = 0.002). The effect in co-cultures with del(5q) MDS-derived monocytes was weaker (+56%, p = 0.188), showing that canakinumab efficacy in this assay does not depend on IL-1β expression level alone. Conclusion We conclude that inflammation patterns in LR-MDS are heterogeneous, highlighting the need for personalization of targeted anti-inflammatory therapies currently entering clinical trials. Our analysis suggests that high resolution studies of gene expression in specific populations or single cells will further resolve a spectrum of inflammation states relevant to prognosis and personalized therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Deletion of Micro RNA-15/16 Clusters Promotes Leukemic Initiation in AML Via the Deregulation of Hematopoietic Progenitors

The microRNA 15a/16-1 cluster on chromosome 13 is commonly lost in chronic lymphocytic leukemia (CLL). Even though this deletion is considered to be a CLL-associated genomic aberration, loss of miR-15/16 occurs in 79% of primary acute myeloid leukemia (AML) and in patients with myelodysplastic syndrome (MDS) that transformed into AML. A second highly homologous locus, miR-15b/16-2, is present in both human and mice, and deletion of either miR-15/16 cluster in mice leads to CLL. Unexpectedly, when both loci are deleted, only 23% of miR-15/16 double knock out (DKO) mice develop various non-Hodgkin's lymphomas, whereas 77% develop AML. Consistent with this, DKO mice have an expanded Gr-1+CD11b+ granulocytic population in both bone marrow (BM) and spleen. These observations led us to hypothesize that the miR-15/16 clusters can act coordinately to regulate lineage determination and proliferation in early hematopoiesis. Their loss might influence leukemogenesis in CLL and AML by altering the number and function of hematopoietic stem cells (HSCs) and/or their downstream lineages and potentially increasing a population of preleukemic stem cells. To test this, using flow cytometry, we analyzed the numbers and frequency of HSCs and progenitors in DKO and C57BL/6 (B6) mice. We discovered major changes in HSCs and the common myeloid progenitors (CMP) but similar numbers of common lymphoid progenitors. Therefore, we focused on the myeloid lineage, finding that CD16/32-CD34- megakaryocyte/erythroid progenitors (MEP) were significantly increased in the Lin- cKit+ compartment of DKO mice (44.9% vs 29.8% P = 0.01), but CD16/32+CD34+ granulocyte-macrophage progenitors (GMP) were decreased (19.1% vs 40.1% P = 0.01). This was surprising since we also found that a GMP progeny population, CD11b+Gr-1+ cells, was enriched in DKO compared to B6 BM (60-70% vs 40%). To determine if this was a result of a differentiation defect in an earlier progenitor, we assessed the frequency of Lin-Sca1+cKit+ (LSK) populations, finding that DKO mice had significantly more CD150+CD48-CD34- LT-HSCs among LSK cells (14.3% vs 7.8% P = 0.03), and fewer CD150-CD48+ multipotent progenitors (MPP) (58.5% vs 68.6% P = 0.04). Of note, there was an increased absolute count for all progenitors analyzed, possibly due to an increase in BM cells and/or disproportional increases of certain cell types. Since the observed myeloproliferative phenotype could be due to 1) an absolute increase of progenitor cells; 2) malfunctioning progenitor cells that aberrantly differentiate and proliferate; 3) or both, we tested whether DKO LSK cells had distinct functional characteristics in vitro. Methylcellulose replating of LT-HSC and MPP in the presence of SCF, IL-3, and IL-6 indicated that DKO LT-HSC gave rise to consistently fewer colonies as compared to B6 LT-HSC (21.5 vs 37.2 colonies/100 cells plated P = 0.02). Unexpectedly, we found the opposite for MPP, as DKO MPP consistently exhibited higher colony-forming activity than B6 MPP (16.6 vs 5.1 colonies/100 cells plated P = 0.04) over the course of serial replating experiments. This was surprising in light of the significant decrease in MPP frequency we had observed by immunophenotyping. Furthermore, B6 MPP cells ceased forming colonies after 3 rounds of replating, whereas DKO MPP continued for 5 rounds, suggesting that the absence of miR-15/16 increased the self-renewal potential of the CD150-CD48+ MPP cells. This was further supported by immunophenotyping analysis showing increased LSK cells derived from DKO MPP colonies (25.8% vs 4.4% P = 0.03). In concordance with the initial observation, an increase in DKO MPP colony-derived CD11b+Gr-1+ cells was at least partly responsible for the myeloproliferative defect in the mature cell compartment (76.1% vs 56.9%P = 0.01). Together, these results suggest that in miR-15/16 DKO mice, the phenotypically defined MPP compartment contains leukemia-initiating cells. Overall, our findings reveal a novel role for the miR-15/16 clusters at the top of the hematopoietic hierarchy. Future experiments focusing on these DKO progenitors that appears to be endowed with leukemic stem cell potential may provide clues to understand how the targets of miR-15a, miR-15b and miR-16 orchestrate their effects on lineage commitment and how their absence may lead to initiation of AML and CLL. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Alantolactone induces concurrent apoptosis and GSDME-dependent pyroptosis of anaplastic thyroid cancer through ROS mitochondria-dependent caspase pathway

BackgroundAnaplastic thyroid cancer (ATC) is one of the fatal cancers and has not effective treatments. Alantolactone (ATL), a terpenoid extracted from traditional Chinese medicinal herb Inula helenium L., confers significant anti-inflammatory, antibacterial and antitumor activity. However, the activity and mechanisms of ATL in ATC remain unclear. PurposeTo investigate the potential anti-ATC effects in vitro and in vivo and the mechanisms involved. MethodsThe anti-proliferative activity of Alantolactone (ATL) against ATC cells was analyzed through CCK-8 and colony formation assays. Flow cytometry assay was performed to assess the cell cycle, cell apoptosis, ROS, and mitochondrial membrane potential (ΔΨm), whereas the cellular localization of cytochrome c and calreticulin were determined using cellular immunofluorescence assays. The lactate dehydrogenase (LDH) enzyme activity in the cell culture medium was measured using a commercial LDH kit, whereas ELISA was conducted to assess the secretory function of IL-1β. Western blot assays were conducted to determine the expression or regulation of proteins associated with apoptosis and pyroptosis. Subcutaneous tumor model of nude mice was established to evaluate the anticancer activity of ATL in vivo. The expression of Ki67, cyclin B1, cleaved-PARP, cleaved-caspase 3, and IL-1β in the animal tumor tissues was profiled using immunohistochemistry analyses. ResultsOur data showed that ATL significantly inhibited the proliferation and colony formation activity of ATC cells. ATL induced ATC cell cycle arrest at G2/M phase, and downregulated the expression of cyclin B1 and CDC2. Furthermore, ATL induced concurrent apoptosis and pyroptosis in the ATC cells, and the cleavage of PARP and GSDME. It also significantly increased the release of LDH and IL-1β. Mechanically, ATL-mediated increase in ROS suppressed the Bcl-2/Bax ratio, downregulated the mitochondrial membrane potential and increased the release of cytochrome c, leading to caspase 9 and caspase 3 cleavage. We also found that ATL induced the translocation of an immunogenic cell death marker (calreticulin) to the cell membrane. In addition, it inhibited the growth of the ATC subcutaneous xenograft model, and activated proteins associated with apoptosis and pyroptosis, with a high safety profile. ConclusionTaken together, these results firstly demonstrated that ATL exerted an anti-ATC activity by inducing concurrent apoptosis and GSDME-dependent pyroptosis through ROS-mediated mitochondria-dependent caspase activation. Meanwhile, these cell deaths exhibited obvious characteristics of immunogenic cell death, which may synergistically increase the potential of cancer immunotherapy in ATC. Further studies are needed to explore deeper mechanisms for the anti- ATC activity of ATL.

Cisplatin Induces Senescent Lung Cancer Cell-Mediated Stemness Induction via GRP78/Akt-Dependent Mechanism.

Cellular senescence is linked with chemotherapy resistance. Based on previous studies, GRP78 is a signal transducer in senescent cells. However, the association between GRP78 and stem cell phenotype remains unknown. Cisplatin treatment was clarified to induce cellular senescence leading to stemness induction via GRP78/Akt signal transduction. H460 cells were treated with 5 μM of cisplatin for 6 days to develop senescence. The colony formation assay and cell cycle analysis were performed. SA-β-galactosidase staining indicated senescence. Western blot analysis and RT-PCR were operated. Immunoprecipitation (IP) and immunocytochemistry assays (ICC) were also performed. Colony-forming activity was completely inhibited, and 87.07% of the cell population was arrested in the G2 phase of the cell cycle. mRNA of p21 and p53 increased approximately by 15.91- and 19.32-fold, respectively. The protein level of p21 and p53 was elevated by 9.57- and 5.9-fold, respectively. In addition, the c-Myc protein level was decreased by 0.2-fold when compared with the non-treatment control. Even though, the total of GRP78 protein was downregulated after cisplatin treatment, but the MTJ1 and downstream regulator, p-Akt/Akt ratio were upregulated by approximately 3.38 and 1.44-fold, respectively. GRP78 and MTJ1 were found at the cell surface membrane. Results showed that the GRP78/MTJ1 complex and stemness markers, including CD44, CD133, Nanog, Oct4, and Sox2, were concomitantly increased in senescent cells. MTJ1 anchored GRP78, facilitating the signal transduction of stem-like phenotypes. The strategy that could interrupt the binding between these crucial proteins or inhibit the translocation of GRP78 might beuseful for cancer therapy.