A novel combination therapy of arginine deiminase and an arginase inhibitor targeting arginine metabolism in the tumor and immune microenvironment.

Tumor progression is dependent on tumor cells and their microenvironment. It is important to identify therapies that inhibit cancer cells and activate immune cells. Arginine modulation plays a dual role in cancer therapy. Arginase inhibition induced an anti-tumor effect via T-cell activation through an increase in arginine in the tumor environment. In contrast, arginine depletion by arginine deiminase pegylated with 20,000-molecular-weight polyethylene glycol (ADI-PEG 20) induced an anti-tumor response in argininosuccinate synthase 1 (ASS1)-deficient tumor cells. ADI-PEG 20 did not cause toxicity to normal immune cells, which can recycle the ADI-degraded product citrulline back to arginine. To target tumor cells and their neighboring immune cells, we hypothesized that the combination of an arginase inhibitor (L-Norvaline) and ADI-PEG 20 may trigger a stronger anticancer response. In this study, we found that L-Norvaline inhibits tumor growth in vivo. Pathway analysis based on RNA-seq data indicated that the differentially expressed genes (DEGs) were significantly enriched in some immune-related pathways. Significantly, L-Norvaline did not inhibit tumor growth in immunodeficient mice. In addition, combination treatment with L-Norvaline and ADI-PEG 20 induced a more robust anti-tumor response against B16F10 melanoma. Furthermore, single-cell RNA-seq data demonstrated that the combination therapy increased tumor-infiltrating CD8+ T cells and CCR7+ dendritic cells. The increase in infiltrated dendritic cells may enhance the anti-tumor response of CD8+ cytotoxic T cells, indicating a potential mechanism for the observed anti-tumor effect of the combination treatment. In addition, populations of immunosuppressive-like immune cells, such as S100a8+ S100a9+ monocytes and Retnla+ Retnlg+ TAMs, in tumors were dramatically decreased. Importantly, mechanistic analysis indicated that the processes of the cell cycle, ribonucleoprotein complex biogenesis, and ribosome biogenesis were upregulated after combination treatment. This study implied the possibility of L-Norvaline as a modulator of the immune response in cancer and provided a new potential therapy combined with ADI-PEG 20.

Crystal structures of dimeric and heptameric mtHsp60 reveal the mechanism of chaperonin inactivation.

Mitochondrial Hsp60 (mtHsp60) plays a crucial role in maintaining the proper folding of proteins in the mitochondria. mtHsp60 self-assembles into a ring-shaped heptamer, which can further form a double-ring tetradecamer in the presence of ATP and mtHsp10. However, mtHsp60 tends to dissociate in vitro, unlike its prokaryotic homologue, GroEL. The molecular structure of dissociated mtHsp60 and the mechanism behind its dissociation remain unclear. In this study, we demonstrated that Epinephelus coioides mtHsp60 (EcHsp60) can form a dimeric structure with inactive ATPase activity. The crystal structure of this dimer reveals symmetrical subunit interactions and a rearranged equatorial domain. The α4 helix of each subunit extends and interacts with its adjacent subunit, leading to the disruption of the ATP-binding pocket. Furthermore, an RLK motif in the apical domain contributes to stabilizing the dimeric complex. These structural and biochemical findings provide new insights into the conformational transitions and functional regulation of this ancient chaperonin.

Teniposide-intensified hematopoietic stem cell transplantation with acute graft versus host disease prophylaxis with anti-thymocyte globulin provides good results in high-risk or refractory recurrent hematopoietic malignant diseases.

BACKGROUND: Teniposide, as a more potent inhibitor of topoisomerase II compared with etoposide, shows less damage on hematopoietic stem cells. Few data are available on teniposide in hematopoietic stem cell transplantation (HSCT) for high-risk or refractory recurrent hematopoietic malignant diseases, particularly for acute myeloid leukemia (AML). METHODS: A retrospective single arm study was conducted to confirm the feasibility of teniposide (300 mg/m2) -intensified HSCT in the treatment of high-risk or refractory recurrent hematopoietic malignant disease by analysing the outcomes of 32 patients, who received transplantation between January 2016 and December 2018. Univariate and multivariate analyses were performed to evaluate prognostic factors of the endpoints. Statistically significant factors (P<0.05) in multivariate analyses were regarded to be predictive. RESULTS: All patients achieved myeloid engraftment at a median of 13 days (range, 9-28 days), platelet engraftment at 15.5 days (range, 6-142 days), with a cumulative incidence (CI) of platelet engraftment of 93.75%±0.26%. The CI of grade II-IV acute graft versus host disease (aGVHD) was 43.75%±0.80% and that of grade III-IV aGVHD 12.50%±0.35%. The CI of chronic (c)GVHD was 74.07%±0.82% and that of extensive cGVHD 33.33%±0.87%. The CI of relapse was 35.03%±0.76%. The one-year probability of overall survival (OS) was 62.50%±0.09%, while 2-year OS was 46.90%±0.09%, and those of 1- and 2-year leukemia-free-survival (LFS) were 56.30%±0.09% and 46.90%±0.09%, respectively. Generally, the OS and LFS until the end of our follow up were 43.50%±0.09% and 34.80%±0.11%, respectively. The probability of GVHD-free and relapse-free survival (GRFS) was 24.60%±0.08%. Multivariate analysis indicated that the probability of OS was significantly lower in patients with a disease duration of more than 280 days before receiving HSCT and in those with fewer mononuclear cells. For LFS, other than the above two factors, failure to achieve complete response (CR) before HSCT was another independent risk factor. Similarly, the probability of GRFS was significantly lower in patients with longer disease duration (≥280 days) and those receiving stem cells from female donors. CONCLUSIONS: For patients with high-risk or refractory recurrent hematopoietic malignant disease, teniposide-based conditioning regimens followed by allo-HSCT can be considered as an alternative therapy with encouraging prognoses.

[Clinical Analysis of Treating EBV Infection Accompanied with GVHD after Allon-HSCT by EBV-Specific Cytotoxic T Lymphocytes].

OBJECTIVE: To investigate the efficiency and safety of treating Epstein-Barr virus (EBV) infection of acute graft versus host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) by EBV specific cytotoxic T lymphocytes (EBV-CTL). METHODS: The Clinical characteristics, therapeutic efficacy and safety of 12 patients with EBV infection treated by EBV-CTL infusion after allo-HSCT in Department of Hemahlogy of Aero Space Center Hospital between Jan 2015 and May 2017 were analyzed retrospectioely. RESULTS: Our of 12 cases received EBV-CTL infusion after transplantation, 9 did not received Rituximab therapy due to the active infection, 4 cases including 3 received Ritaximab progressed into posttransplantation lymphoroliferetive disease (PTLD). The median time of EBV infection was 47 (22-71) days, median time of antivirus therapy before tramplantation was 10 (8-33) days, median time of first CTL infusion was 59(34-86) days after transplatation. The 43 cases-time CTL infusion was performed smoothly, no related harmful evnts occoured, no progression of GVHD was observed. After the first course of infusion, complete remission (CR), Partial remssion (PR) and no remssion (NR) were obtained in 9, 1 and 2 patients respectively, the relapse was observed in 4 patients who then received the socond course of infusion and all reached CR, the patient in PR did not reathed CR finally and died of GVGD at 5 months after transpplantation . Only 1 out of 2 cases of NR obtained CR, another 1 still was in NR, and died of transplantation related infection at 5 months after transplantation. 4 cases of PTLD were all cared. CONCLUSION: Preliminary results of this study suggest that EBV-CTL infusion is safe for the EBV infection combined with acute GVHD after all-HSCT. However, a further larger scale clinical studies are needed to prove the efficiency.

Surgical debridement for acute invasive fungal rhinosinusitis during the pre-engraftment phase of allogeneic hematopoietic stem cell transplantation: Two case reports.

RATIONALE: Surgical intervention may be not a contraindication for acute invasive fungal rhinosinusitis (AIFR) during the pre-engraftment period of allogeneic hematopoietic stem cell transplantation (allo-HSCT). PATIENT CONCERNS: We present 2 cases involving patients with AIFR in the pre-engraftment phase of allo-HSCT. DIAGNOSES: Both patients received surgical debridement combined with systemic antifungal treatment. The biopsies identified the diagnosis of AIFR in these 2 cases. OUTCOMES: The 2 patients obtained normal hematopoiesis without recurrence of AIFR. LESSON: Our experience with these 2 cases suggests that prompt endoscopic surgical debridement is not an absolute contraindication for allo-HSCT recipients with AIFR during the pre-engraftment period. If permitted, urgent, radical, and aggressive but careful endoscopic debridement should be performed together with systemic antifungal treatment once AIFR has been diagnosed or suspected.

[Four Cases of Wernicke's Encephalopathy Following Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To make through introduction of Wernicke's encephalopathy (WE) following hematopoietic stem cell transplantation (HSCT) in terms of clinical characteristics, diagnostic process and treatment. METHODS: The clinical charactaristics, diagnostic and therapeutic process and prognostic follow-up in 4 patients diagnosed of WE following HSCT between January 2016 to January 2017 at Department of Hematology, Chinese Aerospace Center Hospital were retrospectively analyzed. RESULTS: Four patients included 2 ALL and 2 AML, and 3 males and 1 female, their age ranged from 8 to 20 years old. 4 patients accouted for about 3% of all petients who received HSCT at that time. Typical triad syndrome consisting of ocular motility disorders, ataxia, global confusion was seen in only 1 patient. However, confusion and heterophthongia as onset of this complication were seen in all patients. Cerebral computed tomograph scan was universally unremarkable and useless. Cerebral MRI scan disclosed that typical involvement including thalamus, fourth ventricle, third ventricle, middle cerebral aqueduct was seen in 3, while untypical site including mamillary body was in the remaining 1 patient. All received vitamin B1 supplement therapy by intramuscular injection at a dose of 100 mg each day. Initial response was observed at 2, unknown, 3, 4 days after treatment and all obtained complete remission within 2 weeks without any event of relapse after median follow-up period of 8 (7-12) months. CONCLUSION: Any recipient of HSCT with clinical signs or symptoms of central nervous system should receive vitamin B1 supplementary therapy immediately to decrease risk of mortality of WE even if the diagnosis of WE is uncertain.

[Prognostic Analysis of Minimal Residual Disease from Acute Myeloid Leukemia after Allogeneic Hematopoietic Stem Cell Transplant by Flow Cytometry].

OBJECTIVE: To investigate the value of flow cytometry (FCM) detection in prognostic evaluation of minimal residual disease (MRD) of acute myeloid leukemia (AML) patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: Eighty-two cases of AML (except M3) after allo-HSCT who accord to enrolled condition (no MRD positive after allo-HSCT confirmed by regular flow cytometry detection and followed-up for 2 years) from April 2012 to September 2016 in our department were selected. Among 82 cases males were 50 and females were 32 with average age of 27.27 (2-57) years old. According to FAB classification, 2 cases were classified as M0/M1, 51 cases as M2, 24 cases as M4/M5 and 5 cases as M6. The antibody panels were selected accordingly to the initial leukemia associated immunophentype(LAIP) of patients. RESULTS: Twenty patients (24.39%) were identified as MRD+ (0.10%-4.91%, mean 1.64%) in 82 AML patients after allo-HSCT (all the patients were in complete remission phase based on bone marrow morphology). During follow-up, 16 cases relapsed (relapse rate 80%)in 20 MRD+ cases, including 1 case with extramedullary relapse; 4 out of 62 MRD- cases relapsed (relapse rate 6.45%)in bone marrow, and 2 cases extramedullary relapsed. The average survival time of leukemia- free survival (LFS) in group MRD+ was 15.19 ± 3.99 months, median LFS was 10± 3.84 months. The average LFS time was 53.50 ± 1.69 months in MRD- group (P<0.001). The average overall survival (OS) of the MRD+ group was 22.52 ± 5.72 months, the median OS was 18 ± 3.27 months; the average OS time was 42.86 ± 2.83 months in MRD- group(P=0.008). CONCLUSION: For the patients with morphologically complete remission after allo-SCT, the FCM regular monitoring of bone marrow MRD closely relates with its relapse rate, LFS and OS. Compared with the MRD- group, the relapse rate of MRD+ group is significantly increases, and the LFS and OS significantly decreases.

Differentiation of cryopreserved human umbilical cord blood-derived stromal cells into cells with an oligodendrocyte phenotype.

In this study, we examined the phenotypic characteristics of human umbilical cord blood-derived mesenchymal stromal cells (UCB-derived MSCs) differentiated along an oligodendrocyte pathway. We induced human UCB-derived MSCs to form floating neurospheres, and these neurospheres were then induced to differentiate into oligodendrocyte progenitor-like cells using multiple induction factors. Differentiated UCB-derived MSCs showed morphologic characteristics of an oligodendrocyte phenotype. The expression of cell surface markers characteristic of oligodendrocyte progenitor cells or oligodendrocytes was determined by immunocytochemical staining. These results suggest that human UCB-derived MSCs can be induced to differentiate into cells with an oligodendrocyte phenotype and that these cells may have potential in the future cellular therapy of central neurological disorders.

Comparison of adult neurospheres derived from different origins for treatment of rat spinal cord injury.

This study is designed to evaluate the therapeutic effects of three types of neurospheres (NSs) derived from brain, bone marrow and adipose tissue in a rat model of spinal contusive injury. As shown by BBB locomotor rating scale and grid test, the optimal therapeutic responses generated by subventricular zone-derived NSs (SVZ-NSs), and followed by adipose-derived (AD-NSs) and bone marrow-derived NSs (BM-NSs) after being grafted into the injured spinal cord. In three cell-treated groups, very few (<1%) grafted cells survived and these survived cells mainly differentiated into oligodendrocytes at week 12 after injury. Additionally, all the cell-treated groups, especially in the SVZ-treated group showed an increase in host oligodendrocytes than control group. Moreover, the level of selective neurotrophins (NTs) in the SVZ-NSs group were significantly higher than those in the BM-NSs and AD-NSs groups, and the level of NTs in the saline group was also significantly higher than sham group. Therefore, not cell replacement or infusion but neuroprotective action associated with endogenous oligodendrocytes and NTs that active by the grafted NSs may contribute to the functional recovery.

Umbilical cord blood cell-derived neurospheres differentiate into Schwann-like cells.

In this study, we examined the phenotypic and bioassay characteristics of human umbilical cord blood-derived mesenchymal stromal cells (UCB-MSCs) differentiated along a Schwann cells lineage. Initially, we induced human UCB-MSCs into floating neurospheres, and then, neurospheres were induced to differentiate into Schwann-like cells using glia growth factors. Differentiated UCB-MSCs showed morphological changes similar to those of Schwann cells. Expression of the Schwann cell markers was determined by immunocytochemical staining and western blotting. Furthermore, differentiated UCB-MSCs could promote neurite outgrowth in coculture with dorsal root ganglia neurons. These results show that UCB-MSCs can be differentiated into cells that are Schwann-like in terms of morphology, phenotype, and function.