Blood Stem Cell Research Articles

Menstrual Blood-Derived Endometrial Stem Cells Ameliorate Ovarian Senescence by Relieving Oxidative Stress-Induced Inflammation.

Senescence is a degenerative process that occurs with ageing, and in the female reproductive system, senescence occurs earlier in the ovaries than in other tissues and organs, which implies a decrease in oocyte quality and exhaustion of the primordial follicular pool, leading to impaired ovarian function and an inability to maintain normal fertility. Unfortunately, the development of curative and effective treatments for ovarian senescence is still a considerable challenge. Currently, mesenchymal stem cells (MSCs)-based therapies for treating various refractory diseases, especially ovarian dysfunction, have been extensively studied and confirmed. However, the mechanisms by which MSCs improve ovarian senescence are not yet clear. Therefore, in this study, a mouse ageing model was generated via the intraperitoneal injection of a D-galactose (D-gal) solution, and the effects of menstrual blood-derived endometrial stem cells (MenSCs) transplantation on the ovarian follicle count, fibrosis level, and degree of apoptosis were evaluated. Subsequently, an ovarian granulosa cell ageing model was induced with H2O2, and CCK-8 assays, flow cytometry, mitochondrial membrane potential analysis and Western blotting were subsequently performed to further investigate the potential mechanism by which MenSCs ameliorate cellular oxidative damage. Overall, our findings demonstrated that MenSCs treatment can increase the cellular antioxidant capacity by activating the NRF2/HO-1 signalling pathway and further ameliorate the inflammatory ovarian microenvironment, apoptosis and dysfunction in ageing mice. These results provide reliable evidence and support for MenSCs-based therapy for ovarian senescence.

Ameliorative Potential of Menstrual Blood-derived Endometrial Stem Cells in Alcohol-Induced Fatty Liver Disease

Background: Alcohol-induced fatty liver disease (AFLD) begins with steatosis and may progress to a range of pathological liver changes, including fibrosis, cirrhosis, and complications. Menstrual blood-derived endometrial stem cells (MenSCs) have shown potential therapeutic effects against various types of liver damage. However, the liver-protective effects of MenSCs in AFLD are not well understood. This study aimed to evaluate the therapeutic effects of MenSCs on AFLD progression. Methods: MenSCs were sourced from women in good health (N=5, 25-34 years old). Male C57BL/6 mice were separated into three distinct groups to establish the mouse models. The AH/- MenSCs group received MenSCs (5×105 cells/mouse) transplantation through tail injection on the 7th and 13th days following the initiation of the alcohol-induced fatty liver model. The therapeutic effects of MenSCs transplantation in AFLD mouse models were subsequently explored using qPCR, Western blotting, histopathological examination, and mRNA sequencing analysis. Results: MenSCs significantly improved liver function and reduced lipid accumulation in AFLD. Treatment with MenSCs was also found to reduce the expression levels of inflammatory cytokines and profibrotic markers in the liver tissues of the mouse model. Additionally, the MenSCs- treated group demonstrated a significant reduction in endoplasmic reticulum (ER) stress and oxidative stress, along with an increase in autophagic activity. Conclusion: The findings provided preliminary evidence of the multifaced protective effects of MenSCs in AFLD.

SRSF12 is a prognostic biomarker involved in immune infiltration in acute myeloid leukemia

ABSTRACT Background Acute myeloid leukemia (AML) is a disease characterized by the proliferation of abnormal cells originating from blood stem cells. Understanding the pathogenesis and progression of AML, as well as identifying molecular markers for early diagnosis and prognosis assessment, is of paramount importance. Methods The AML dataset was obtained from the Cancer Genome Atlas (TCGA), while the normal sample dataset was derived from the Genotype-Tissue Expression(GTEx) dataset. Furthermore, the association between SRSF12 expression and drug response was assessed using the Cancer Therapeutic Response Portal (CTRP) database to evaluate its potential therapeutic value. Finally, SRSF12 expression in AML cells was measured using quantitative real-time PCR (qRT-PCR). Result The difference in SRSF12 expression between 13 types of tumors and normal tissue samples was found to be statistically significant (P < 0.05). SRSF12 exhibited predominantly high expression in AML, indicating its potential as a diagnostic and prognostic marker for AML patients. High expression of SRSF12, along with age and cytogenetic risk, emerged as independent predictors of favorable prognosis in AML patients (P < 0.05). PCR demonstrated a significant increase in SRSF12 expression in AML patients. Conclusion Overall, our findings suggest that the high expression of SRSF12 in AML patients is a poor prognostic factor, which may provide a new option for the diagnosis, and targeted therapy of AML.

A thermosensitive hydrogel for the sustained delivery of exosomes extracted from menstrual blood mesenchymal stem cells and frizzled antibody on triple-negative breast cancer cells in vitro

Due to the heterogeneity of triple-negative breast cancer (TNBC), conventional treatments usually respond poorly and effective targeted therapies for this type of cancer are rare. Wnt signaling plays an important role in breast cancer metastasis and proliferation, as shown by analyzes of gene expression profiling and genome-wide sequencing. In addition, the role of endometrial cells in regulating angiogenesis during the menstrual cycle as an angiostatic state associated with the end of the cycle has been well established. Therefore, exosomes of menstrual blood-derived stem cells (Exo-Mens) could play a role as effective inhibitors of tumor-induced angiogenesis. However, repeated administration and systemic toxicity are major problems with conventional drug delivery methods. To minimize these drawbacks and maximize the therapeutic benefits of the drugs, hydrogels provide convenient methods for drug delivery. The aim of this study was therefore to investigate the effects of hydrogels containing Exo-Mens and Frizzled antibodies (anti-FZ) on breast cancer cells. First, the optimization and characterization of the hydrogel were performed, then the cell lines (MDA-MB-231 and HUVEC) were studied in four groups: Hydrogel (control), Hydrogel with anti-FZ, Exo-Mens and FZ + Exo. First, the IC50 of anti-FZ and Exo-Mens was determined and the degradability and release pattern of the investigated groups were measured. Western blot (VEGF, HIF-1α) and qRT-PCR (VEGF, HIF-α and KDR) were performed for the HUVEC cell line and scratch tests, colony formation and apoptosis for the MDA-MB-231 cell line. In addition, invasion and migration were performed for both cell lines. Our results showed that the optimal hydrogel is a suitable option for sustained release of the studied groups. The loaded compounds could be released within 7 days. The angiogenic activity of dual anti-FZ and Exo-Mens within the hydrogel, showed a significant shift in the expression of pro-angiogenic genes and related proteins, including HIF-1α, VEGF-A and KDR, in the treated HUVECs. The hydrogel treatment groups were also able to reduce migration and invasion in both cell lines compared to the control group. In addition, a reduction in colony formation and an increase in apoptosis were observed, especially in the cancer cells exposed to anti-FZ. Angiogenesis as well as proliferation and invasion of tumor cells were inhibited by the developed hydrogel system containing anti-FZ, Exo-Mens and a combination of both with slow release.

Transcripts of repetitive DNA elements signal to block phagocytosis of hematopoietic stem cells.

Macrophages maintain hematopoietic stem cell (HSC) quality by assessing cell surface Calreticulin (Calr), an "eat-me" signal induced by reactive oxygen species (ROS). Using zebrafish genetics, we identified Beta-2-microglobulin (B2m) as a crucial "don't eat-me" signal on blood stem cells. A chemical screen revealed inducers of surface Calr that promoted HSC proliferation without triggering ROS or macrophage clearance. Whole-genome CRISPR-Cas9 screening showed that Toll-like receptor 3 (Tlr3) signaling regulated b2m expression. Targeting b2m or tlr3 reduced the HSC clonality. Elevated B2m levels correlated with high expression of repetitive element (RE) transcripts. Overall, our data suggest that RE-associated double-stranded RNA could interact with TLR3 to stimulate surface expression of B2m on hematopoietic stem and progenitor cells. These findings suggest that the balance of Calr and B2m regulates macrophage-HSC interactions and defines hematopoietic clonality.

Endogenous Adult Telomerase Positive Stem Cells Increase in Equine Peripheral Blood Following Exercise

Stout, et al., 2007 reported a base-line level of primitive endogenous adult Telomerase Positive Stem Cells (aTPSCs) circulating within adult porcine peripheral blood which increased dramatically, i.e., 23.5-fold, after just 90 minutes of trauma. Ongoing studies from our laboratory have shown the presence of similar primitive stem cells in adult equine blood and that the base-line levels of stem cells varied according to the particular breed of horse. The current study was undertaken to test the hypothesis that aTPSCs would increase in number in the peripheral blood following stress in the same horse. Stress in this study was defined as moderate exercise, i.e., 10 minutes of cantering. Blood withdrawal followed the guidelines of Fort Valley State University’s IACUC. Adult horses had their blood withdrawn immediately prior to and immediately after exercising. The blood was obtained by venipuncture. Isolated aTPSCs were assayed by trypan blue staining, CEA-CAM-1 for totipotent stem cells and SSEA-4 for pluripotent stem cells. This study demonstrates that moderate exercise will increase the level of these primitive pluripotent stem cells in the blood of adult equines. Studies are ongoing to address their functional significance during injury and repair.

Prediction of CD34+ hematopoietic stem cells in healthy allogeneic stem cell donors on the Optia cell separator based on CE2: Which formula is more correlated with actual CD34+?

Peripheral blood-derived hematopoietic stem cells (HSCs) are widely used for various adult stem cell transplants. To obtain sufficient HSCs from healthy volunteer donors during the apheresis process and ensure that the donors are exposed to fewer apheresis-related side effects, calculation methods have been developed for the prediction of processed blood volume or CD34+ count. However, there is no consensus on a formula to predict the volume of blood to be processed or the number of stem cells to be obtained. This study aimed to estimate the predicted blood volume and CD34+ cell counts using collection efficiency (CE)-based formulas and evaluate their accuracy compared to the actual CD34+ cell counts. It also seeks to identify the factors that affect CE. Data from 397 healthy, unrelated stem cell donors were retrospectively analyzed. An algorithm using four different CE2 metrics (1st quartile, mean, 3rd quartile, and median) was developed to predict the volume of blood to be processed using the Spectra Optia continuous mononuclear cell collection procedure. When employing the mean CE2 algorithm, the results revealed a strong correlation (r = .894, p < .001) between predicted and actual CD34+ values. The study also identified strong associations between pre-apheresis CD34+, pre-apheresis leukocyte count, the use of two doses of G-CSF, and low CE2. These findings suggest that the mean CE2 algorithm could be a potent, straightforward, and accurate tool for predicting CD34+ stem cell counts in healthy allogeneic stem cell donors and potentially optimizing stem cell collection procedures.

Granulosa cell insight: unraveling the potential of menstrual blood-derived stem cells and their exosomes on mitochondrial mechanisms in polycystic ovary syndrome (PCOS)

BackgroundPolycystic ovary syndrome (PCOS) presents a significant challenge in women’s reproductive health, characterized by disrupted folliculogenesis and ovulatory dysfunction. Central to PCOS pathogenesis are granulosa cells, whose dysfunction contributes to aberrant steroid hormone production and oxidative stress. Mitochondrial dysfunction emerges as a key player, influencing cellular energetics, oxidative stress, and steroidogenesis. This study investigates the therapeutic potential of menstrual blood-derived stem cells (MenSCs) and their exosomes in mitigating mitochondrial dysfunction and oxidative stress in PCOS granulosa cells.MethodsUsing a rat model of PCOS induced by letrozole, granulosa cells were harvested and cultured. MenSCs and their exosomes were employed to assess their effects on mitochondrial biogenesis, oxidative stress, and estrogen production in PCOS granulosa cells.ResultsResults showed diminished mitochondrial biogenesis and increased oxidative stress in PCOS granulosa cells, alongside reduced estrogen production. Treatment with MenSCs and their exosomes demonstrated significant improvements in mitochondrial biogenesis, oxidative stress levels, and estrogen production in PCOS granulosa cells. Further analysis showed MenSCs' superior efficacy over exosomes, attributed to their sustained secretion of bioactive factors. Mechanistically, MenSCs and exosomes activated pathways related to mitochondrial biogenesis and antioxidative defense, highlighting their therapeutic potential for PCOS.ConclusionsThis study offers insights into granulosa cells mitochondria’s role in PCOS pathogenesis and proposes MenSCs and exosomes as a potential strategy for mitigating mitochondrial dysfunction and oxidative stress in PCOS. Further research is needed to understand underlying mechanisms and validate clinical efficacy, presenting promising avenues for addressing PCOS complexity.

Menstrual Blood Stem Cells-Derived Exosomes as Promising Therapeutic Tools in Premature Ovarian Insufficiency Induced by Gonadotoxic Systemic Anticancer Treatment.

Gonadotoxicity resulting from systemic and locoregional cancer treatments significantly threatens women's reproductive health, often culminating in premature ovarian insufficiency. These therapies, particularly alkylating agents and ionizing radiation, induce DNA damage and apoptosis in ovarian follicles, leading to infertility, amenorrhea, and estrogen deficiency, which exacerbate risks of osteoporosis and cardiovascular diseases. Existing fertility preservation methods do not prevent immediate ovarian damage, underscoring the need for innovative protective strategies. Menstrual blood-derived stem cells (MenSC) and their extracellular vesicles (EV) present promising regenerative potential due to their therapeutic cargo delivery and pathway modulation capabilities. Preclinical studies demonstrate that MenSC-derived EV ameliorate premature ovarian insufficiency by inhibiting granulosa cell apoptosis, promoting angiogenesis, and activating pivotal pathways such as SMAD3/AKT/MDM2/P53. However, comprehensive research is imperative to ensure the safety, efficacy, and long-term effects of MenSC-derived EV in clinical practice. In this review, we update the current knowledge and research regarding the use of MenSC-derived EV as a novel therapeutic weapon for ovarian regeneration in the context of gonadotoxicity induced by systemic anticancer treatment.

Generation of Neuronal Cells from Blood-Derived Pluripotent Stem Cells

Generation of Neuronal Cells from Blood-Derived Pluripotent Stem Cells

Generation of Neuronal Cells from Blood-Derived Pluripotent Stem Cells

Generation of Neuronal Cells from Blood-Derived Pluripotent Stem Cells

Transplantation of hyaluronic acid and menstrual blood-derived stem cells accelerated wound healing in a diabetic rat model

Diabetic wounds require a multifactorial approach because several factors are involved in its occurrence. Herein we investigated whether transplantation of hyaluronic acid (HA) in combination with menstrual blood derived stem cells (MenSCs) could promote healing in diabetic rats. Thirty days after induction of diabetes, sixty animals were randomly planned into four equal groups: the untreated group, HA group, MenSC group, and HA+MenSC group. Sampling was done for histological, molecular, and tensiometrical assessments. Our results indicated that the wound contraction rate, volumes of new epidermis and dermis, collagen density, as well as tensiometrical parameter were considerably increased in the treatment groups compared to the untreated group and these changes were more obvious in the HA+MenSC ones. In addition, the expression levels of TGF-β and VEGF genes were significantly upregulated in treatment groups in comparison with the untreated group and were greater in the HA+MenSC group. This is while expression levels of TNF-α and IL-1β genes were more considerably downregulated in the HA+MenSC group than the other groups. We concluded that the combined use of HA and MenSCs has more effects on diabetic wound healing.

Human Menstrual Blood-Derived Stem Cells Protect against Tacrolimus-Induced Islet Dysfunction via Cystathionine β-Synthase Mediated IL-6/STAT3 Inactivation.

Diabetes imposes a huge burden worldwide. Islet transplantation is an alternative therapy for diabetes. However, tacrolimus, a kind of immunosuppressant after organ transplantation, is closely related to post-transplant diabetes mellitus. Mesenchymal stem cells (MSCs) have attracted interest for their potential to alleviate diabetes. In vivo experiments revealed that human menstrual blood-derived stem cells (MenSCs) treatment improved tacrolimus-induced blood glucose, body weight, and glucose tolerance disorders in mice. RNA sequencing was used to analyze the potential therapeutic targets of MenSCs. In this study, we illustrated that cystathionine β-synthase (CBS) contributed to tacrolimus -induced islet dysfunction. Using β-cell lines (MIN6, β-TC-6), we demonstrated that MenSCs ameliorated tacrolimus-induced islet dysfunction in vitro. Moreover, MenSC reduced the tacrolimus-induced elevation of CBS levels and significantly enhanced the viability, anti-apoptotic ability, glucose-stimulated insulin secretion (GSIS), and glycolytic flux of β-cells. We further revealed that MenSCs exerted their therapeutic effects by inhibiting CBS expression to activate the IL6/JAK2/STAT3 pathway. In conclusion, we showed that MenSCs may be a potential strategy to improve tacrolimus-induced islet dysfunction.

Enhanced therapeutic potential of Flotillins-modified MenSCs by improve the survival, proliferation and migration.

Menstrual blood-derived endometrial stem cells (MenSCs) have attracted increasing interest due to their excellent safety, and lack of ethical dilemma as well as their ability to be periodically obtained in a noninvasive manner. However, although preclinical research as shown the therapeutic potential of MenSCs in several diseases, their poor cell survival and low engraftment at disease sites reduce their clinical efficacy. Flotillins (including Flot1 and Flot2) are implicated in various cellular processes, such as vesicular trafficking, signal transduction, cell proliferation, migration and apoptosis. In this study, we aimed to determine the effects of Flotillins on MenSCs survival, proliferation and migration. Our experimental results show that MenSCs were modified to overexpress Flot1 and/or Flot2 without altering their intrinsic characteristics. Flot1 and Flot2 co-overexpression promoted MenSC viability and proliferation capacity. Moreover, Flot1 or Flot2 overexpression significantly promoted the migration and inhibited the apoptosis of MenSCs compared with the negative control group, and these effects were stronger in the Flot1 and Flot2 gene co-overexpression group. However, these effects were significantly reversed after Flot1 and/or Flot2 knockdown. In conclusion, our results indicate that Flot1 and Flot2 overexpression in MenSCs improved their proliferation and migration and inhibited their apoptosis, and this might be an effective approach to improve the efficiency of cell-based therapies.

Experimental study on the effects of human amniotic membrane in combination with menstrual blood-derived stem cells on wound healing in a diabetic rat model

One of the serious challenges in diabetic patients is the occurrence of complications caused by the disease. One of the most important side effects is wounding in limbs. Due to the multifactorial nature of these wounds, treatments require a multifaceted approach. Therefore, the aim of the present study was whether the human amniotic membrane (HAM) in combination with menstrual blood-derived stem cells (MenSCs) could promote wound healing in diabetic rats. Thirty days after induction of diabetes, the animals were randomly allocated into four equal groups (n=15): the control group, HAM group, MenSC group, and HAM+MenSC group. Sampling was done on days 7, 14, and 21 for histological, molecular, and tensiometrical evaluations. The results showed that the wound healing rate, collagen deposition, volumes of new epidermis and dermis, as well as tensiometrical characteristics were significantly increased in the treatment groups compared to the control group, and these changes were more obvious in the HAM+MenSC ones (P<0.05). Moreover, the expression levels of TGF-β, bFGF, and VEGF genes were considerably increased in treatment groups compared to the control group and were greater in the HAM+MenSC group (P<0.05). This is while expression levels of TNF-α and IL-1β decreased more significantly in the HAM+MenSC group than the other groups (P<0.05). We concluded that the combined use of HAM and MenSCs has a more significant effect on diabetic wound healing.

Role of Human Umbilical Cord Blood-derived Stem Cells versus their Conditioned Medium on the Regeneration of Pancreatic Beta Cells in a Rat Model of Diabetes Mellitus

Role of Human Umbilical Cord Blood-derived Stem Cells versus their Conditioned Medium on the Regeneration of Pancreatic Beta Cells in a Rat Model of Diabetes Mellitus

The Evaluation of Mass/DNA Copy Number of Mitochondria in Umbilical Cord Blood-derived Hematopoietic Stem Cells Cocultured with MSCs.

Over recent decades, UCB has been widely used as an excellent alternative source of HSCs for treating many hematologic disorders. Recent studies suggest using mesenchymal stroma cell co-cultures to increase the number of HSCs prior to transplantation. Considering the critical role of mitochondria in the cell's fate and the importance of the self-renewal capacity of HSCs in HSCT, we decided to investigate the mass/DNA copy number of mitochondria in HSCs while co-cultured with MSCs and alone after seven days. UCB units were collected from full-term deliveries. MSCs and HSCs were isolated from UCB and the purity of cells was confirmed by flow cytometry. The mtDNA-Copy Number of HSCs was calculated using prob-based real-time PCR. Furthermore, Mito Tracker Green dye measured the mass of mitochondria of HSCs. HSCs from MSC co-culture group showed significantly fewer mtDNA-CN compared to HSCs alone after seven days (p < 0.001). Besides, by comparing the two groups on day seven to HSCs on day zero, we observed a mild increase in the mitochondrial mass of HSCs alone compared to the MSC-HSC co-culture group (p < 0.05). Concerning previous studies that have proved the association between lower mass/DNA-copy number of mitochondria in CD34 + HSCs and lower metabolic activity along with higher quiescence maintenance, and by considering the results of this experiment, it seems that the MSC-HSC co-cultures might be associated with a higher expansion of HSCs as well as stemness maintenance leading to the improvement in engraftment. Nevertheless, further investigations are required to clarify the exact connection between lower mass/DNA-copy number of mitochondria and stemness maintenance in HSCs.

Establishment of a humanized mouse model using steady-state peripheral blood-derived hematopoietic stem and progenitor cells facilitates screening of cancer-targeted T-cell repertoires.

Cancer-targeted T-cell receptor T (TCR-T) cells hold promise in treating cancers such as hematological malignancies and breast cancers. However, approaches to obtain cancer-reactive TCR-T cells have been unsuccessful. Here, we developed a novel strategy to screen for cancer-targeted TCR-T cells using a special humanized mouse model with person-specific immune fingerprints. Rare steady-state circulating hematopoietic stem and progenitor cells were expanded via three-dimensionalculture of steady-state peripheral blood mononuclear cells, and thenthe expanded cells were applied to establish humanized mice. The human immune system was evaluated according to the kinetics of dendritic cells, monocytes, T-cell subsets, and cytokines. To fully stimulate the immune response and to obtain B-cell precursor NAML-6- and triple-negative breast cancer MDA-MB-231-targeted TCR-T cells, we used the inactivated cells above to treat humanized mice twice a day every 7 days. Then, human T cells were processed for TCR β-chain (TRB) sequencing analysis. After the repertoires had been constructed, features such as the fraction, diversity, and immune signature were investigated. The results demonstrated an increase in diversity and clonality of T cells after treatment. The preferential usage and features of TRBV, TRBJ, and the V-J combination were also changed. The stress also induced highly clonal expansion. Tumor burden and survival analysis demonstrated that stress induction could significantly inhibit the growth of subsequently transfused live tumor cells and prolong the survival of the humanized mice. We constructed a personalized humanized mouse model to screen cancer-targeted TCR-T pools. Our platform provides an effective source of cancer-targeted TCR-T cells and allows for the design of patient-specific engineered T cells. It therefore has the potential to greatly benefit cancer treatment.

Abstract 1420: Mechanism of NPRL2 gene therapy induced antitumor immunity in KRAS/STK11mt aPD1 resistant metastatic NSCLC

Abstract NPRL2/TUSC4 is a tumor suppressor gene whose expression is reduced in many cancers including NSCLC. Restoration of NPRL2 induces cell cycle arrest and apoptosis. We investigated the antitumor immune responses to NPRL2 gene therapy in aPD1 resistant KRAS/STK11mt NSCLC in a humanized mouse model. Humanized mice were generated by transplanting human cord blood-derived CD34 stem cells into NSG mice. Mice harboring &amp;gt; 25% human CD45 cells were considered humanized. Lung metastases were developed in humanized mice by injecting KRAS/STK11mt/aPD1R A549 cells, which were treated with i.v. injection of NPRL2 nanoparticles (DOTAP-NPRL2) with or without pembrolizumab (aPD1). NPRL2 treatment reduced lung metastases, whereas pembrolizumab was ineffective. The antitumor effect was greater in humanized than non-humanized mice suggesting the role of immune cells. The antitumor effect was associated with increased infiltration of human cytotoxic immune cells and decreased numbers of Treg in tumors. NPRL2+ pembrolizumab was not synergistic in this resistant model but was synergistic in KRASwt/aPD1S H1299 tumors. Cytotoxic immune cells in tumors were associated with the antitumor effect. Consistent with A549, NPRL2 showed a significantly strong antitumor effect on other KRASmt/aPD1R syngeneic LLC2 tumors whereas aPD1 was not effective. The antitumor effect of NPRL2 was correlated with HLA-DR+ DC, CD11c DC, TILs and NK cells in TME. The antitumor effect of NPRL2 was abolished upon in-vivo depletion of CD4, CD8 T, and MΦ in the LLC2 tumor model. However, no effect was found on in-vivo depletion of NK cells. Nanostring analysis on lung metastasis resulted in a distinct pattern of human gene expression by NPRL2. T cell functional genes, including IFNγ, CD8b, CD7, TNFSF18, ITGA1, GATA3 and TBX21 were significantly increased. Conversely, the negative regulatory genes, including FOXP3, TGFB1, TGFB2, and IL-10RA were inhibited. NPRL2 also downregulated T cell co-inhibitory molecules, including CTLA4, ICOS, LAG3, PDCD1, CD274, IDO1, PDCD1LG2, CD47, and KLRB1. Stably expressing NPRL2 clones were established, and tumors in humanized mice with these clones exhibited significantly slower growth compared to controls. TME analysis showed an upregulation of human CD45, CD3, CD8 T, HLA-DR+ DC and a downregulation of Tregs, CD3+PD1+T, MDSC, and CD163+ TAM in tumors expressing NPRL2. The stable cells showed a substantial increase in both colony formation inhibition and apoptosis. Stable clones showed heightened sensitivity to carboplatin in colony formation, apoptosis, and PARP cleavage assays. Stable expression of NPRL2 resulted in the downregulation of both AKT-mTOR and MAPK pathways by inhibition of pAKT, pmTOR, pPRAS40, p4E-BP1, pS6, and pERK1/2. Taken together, NPRL2 gene therapy induces antitumor activity on KRAS/STK11mt/aPD1R tumors through DC-mediated antigen presentation and cytotoxic immune cell activation Citation Format: Ismail M. Meraz, Mourad Majidi, Renduo Song, Feng Meng, Lihui Gao, Qi Wang, Jing Wang, Elizabeth Shpall, Jack A. Roth. Mechanism of NPRL2 gene therapy induced antitumor immunity in KRAS/STK11mt aPD1 resistant metastatic NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1420.

Allogeneic hematopoietic stem-cell transplantation for patients with Richter transformation: a retrospective study on behalf of the Chronic Malignancies Working Party of the EBMT.

Management of Richter transformation (RT) is particularly challenging, with survival estimates <1 year. We report on outcomes of 66 RT patients undergoing allogeneic-HCT (allo-HCT) between 2008 and 2018 registered with the EBMT. Median age at allo-HCT was 56.2 years (interquartile range (IQR), 51.3-63.1). Median time from RT to allo-HCT was 6.9 months (IQR, 4.9-11) and 28 (42.4%) were in complete remission (CR). The majority underwent reduced intensity conditioning (66.2%) using peripheral blood derived stem cells. Eighteen (27.3%) patients had a matched sibling donor, 24 (36.4%) a matched unrelated donor and the remaining were mismatched. Median follow-up was 6.6 years; 1- and 3- year overall and progression free survival (PFS) (95% CI) was 65% (54-77) and 39% (27-51) and 53% (41-65) and 29% (18-40), respectively. Patients in CR at time of allo-HCT had significantly better 3-year PFS (39% vs. 21%, p = 0.032). Cumulative incidences of grade II-IV acute graft versus host disease (GVHD) at day +100 was 41% (95% CI 29-53) and chronic GVHD at 3years was 53% (95% CI 41-65). High rates of non-relapse mortality (NRM) were observed; 38% (95% CI, 26-50) at 3 years. Although potentially curative, approaches to reduce considerable NRM and chronic GVHD rates are required.