Long-term remission and survival in patients with relapsed or refractory multiple myeloma after treatment with LCAR-B38M CAR T cells: 5-year follow-up of the LEGEND-2 trial

BACKGROUND

The autologous anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell therapy LCAR-B38M has been approved for the treatment of relapsed and refractory multiple myeloma in many countries across the world under the name ciltacabtagene autoleucel. LEGEND-2 was the first-in-human trial of LCAR-B38M and yielded deep and durable therapeutic responses. Here, we reported the outcomes in LEGEND-2 after a minimal 5-year follow-up.

METHODS

Participants received an average dose of 0.5 × 106 cells/kg LCAR-B38M in split or single unfractionated infusions after cyclophosphamide-based lymphodepletion therapy. Investigator-assessed response, survival, safety and pharmacokinetics were evaluated.

RESULTS

Seventy-four participants enrolled and had a median follow-up of 65.4 months. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 21.0% and 49.1%, with progressive flattening of the survival curves over time. Patients with complete response (CR) had longer PFS and OS, with 5-year rates of 28.4% and 65.7%, respectively. Twelve patients (16.2%) remained relapse-free irrespective of baseline high-risk cytogenetic abnormality and all had normal humoral immunity reconstituted. An ongoing CR closely correlated with several prognostic baseline indices including favorable performance status, immunoglobulin G subtype, and absence of extramedullary disease, as well as a combination cyclophosphamide and fludarabine preconditioning strategy. Sixty-two (83.8%) suffered progressive disease (PD) and/or death; however, 61.1% of PD patients could well respond to subsequent therapies, among which, the proteasome inhibitor-based regimens benefited the most. Concerning the safety, hematologic and hepatic function recovery were not significantly different between non-PD and PD/Death groups. A low rate of second primary malignancy (5.4%) and no severe virus infection were observed. The patients who tested positive for COVID-19 merely presented self-limiting symptoms. In addition, a sustainable CAR T population of one case with persistent remission was delineated, which was enriched with indolently proliferative and lowly cytotoxic CD4/CD8 double-negative functional T lymphocytes.

CONCLUSIONS

These data, representing the longest follow-up of BCMA-redirected CAR T-cell therapy to date, demonstrate long-term remission and survival with LCAR-B38M for advanced myeloma.

TRIAL REGISTRATION

LEGEND-2 was registered under the trial numbers NCT03090659, ChiCTRONH-17012285.

Oral arsenic plus imatinib versus imatinib solely for newly diagnosed chronic myeloid leukemia: a randomized phase 3 trial with 5-year outcomes

PURPOSE

The synergistic effects of combining arsenic compounds with imatinib against chronic myeloid leukemia (CML) have been established using in vitro data. We conducted a clinical trial to compare the efficacy of the arsenic realgar-indigo naturalis formula (RIF) plus imatinib with that of imatinib monotherapy in patients with newly diagnosed chronic phase CML (CP-CML).

METHODS

In this multicenter, randomized, double-blind, phase 3 trial, 191 outpatients with newly diagnosed CP-CML were randomly assigned to receive oral RIF plus imatinib (n = 96) or placebo plus imatinib (n = 95). The primary end point was the major molecular response (MMR) at 6 months. Secondary end points include molecular response 4 (MR4), molecular response 4.5 (MR4.5), progression-free survival (PFS), overall survival (OS), and adverse events.

RESULTS

The median follow-up duration was 51 months. Due to the COVID-19 pandemic, the recruitment to this study had to be terminated early, on May 28, 2020. The rates of MMR had no significant statistical difference between combination and imatinib arms at 6 months and any other time during the trial. MR4 rates were similar in both arms. However, the 12-month cumulative rates of MR4.5 in the combination and imatinib arms were 20.8% and 10.5%, respectively (p = 0.043). In core treatment since the 2-year analysis, the frequency of MR4.5 was 55.6% in the combination arm and 38.6% in the imatinib arm (p = 0.063). PFS and OS were similar at five years. The safety profiles were similar and serious adverse events were uncommon in both groups.

CONCLUSION

The results of imatinib plus RIF as a first-line treatment of CP-CML compared with imatinib might be more effective for achieving a deeper molecular response (Chinadrugtrials number, CTR20170221).

PD-1 downregulation enhances CAR-T cell antitumor efficiency by preserving a cell memory phenotype and reducing exhaustion

BACKGROUND

Despite the encouraging outcome of chimeric antigen receptor T cell (CAR-T) targeting B cell maturation antigen (BCMA) in managing relapsed or refractory multiple myeloma (RRMM) patients, the therapeutic side effects and dysfunctions of CAR-T cells have limited the efficacy and clinical application of this promising approach.

METHODS

In this study, we incorporated a short hairpin RNA cassette targeting PD-1 into a BCMA-CAR with an OX-40 costimulatory domain. The transduced PD-1KD BCMA CAR-T cells were evaluated for surface CAR expression, T-cell proliferation, cytotoxicity, cytokine production, and subsets when they were exposed to a single or repetitive antigen stimulation. Safety and efficacy were initially observed in a phase I clinical trial for RRMM patients.

RESULTS

Compared with parental BCMA CAR-T cells, PD-1KD BCMA CAR-T cell therapy showed reduced T-cell exhaustion and increased percentage of memory T cells in vitro. Better antitumor activity in vivo was also observed in PD-1KD BCMA CAR-T group. In the phase I clinical trial of the CAR-T cell therapy for seven RRMM patients, safety and efficacy were initially observed in all seven patients, including four patients (4/7, 57.1%) with at least one extramedullary site and four patients (4/7, 57.1%) with high-risk cytogenetics. The overall response rate was 85.7% (6/7). Four patients had a stringent complete response (sCR), one patient had a CR, one patient had a partial response, and one patient had stable disease. Safety profile was also observed in these patients, with an incidence of manageable mild to moderate cytokine release syndrome and without the occurrence of neurological toxicity.

CONCLUSIONS

Our study demonstrates a design concept of CAR-T cells independent of antigen specificity and provides an alternative approach for improving the efficacy of CAR-T cell therapy.

ETV6::ACSL6 translocation-driven super-enhancer activation leads to eosinophilia in acute lymphoblastic leukemia through IL-3 overexpression

ETV6::ACSL6 represents a rare genetic aberration in hematopoietic neoplasms and is often associated with severe eosinophilia, which confers an unfavorable prognosis requiring additional anti-inflammatory treatment. However, since the translocation is unlikely to produce a fusion protein, the mechanism of ETV6::ACSL6 action remains unclear. Here, we performed multi-omics analyses of primary leukemia cells and patient-derived xenografts from an acute lymphoblastic leukemia (ALL) patient with ETV6::ACSL6 translocation. We identified a super-enhancer located within the ETV6 gene locus and revealed translocation and activation of the super-enhancer associated with the ETV6::ACSL6 fusion. The translocated super-enhancer exhibited intense interactions with genomic regions adjacent to and distal from the breakpoint at chromosomes 5 and 12, including genes coding inflammatory factors such as IL-3. This led to modulations in DNA methylation, histone modifications, and chromatin structures, triggering transcription of inflammatory factors leading to eosinophilia. Furthermore, the bromodomain and extraterminal domain (BET) inhibitor synergized with standard-of-care drugs for ALL, effectively reducing IL-3 expression and inhibiting ETV6::ACSL6 ALL growth in vitro and in vivo. Overall, our study revealed for the first time a cis-regulatory mechanism of super-enhancer translocation in ETV6::ACSL6 ALL, leading to ALL-accompanying clinical syndrome. These findings may stimulate novel treatment approaches for this challenging ALL subtype.

Neutrophil activation and clonal CAR-T re-expansion underpinning cytokine release syndrome during ciltacabtagene autoleucel therapy in multiple myeloma

Cytokine release syndrome (CRS) is the most common complication of chimeric antigen receptor redirected T cells (CAR-T) therapy. CAR-T toxicity management has been greatly improved, but CRS remains a prime safety concern. Here we follow serum cytokine levels and circulating immune cell transcriptomes longitudinally in 26 relapsed/refractory multiple myeloma patients receiving the CAR-T product, ciltacabtagene autoleucel, to understand the immunological kinetics of CRS. We find that although T lymphocytes and monocytes/macrophages are the major overall cytokine source in manifest CRS, neutrophil activation peaks earlier, before the onset of severe symptoms. Intracellularly, signaling activation dominated by JAK/STAT pathway occurred prior to cytokine cascade and displayed regular kinetic changes. CRS severity is accurately described and potentially predicted by temporal cytokine secretion signatures. Notably, CAR-T re-expansion is found in three patients, including a fatal case characterized by somatic TET2-mutation, clonal expanded cytotoxic CAR-T, broadened cytokine profiles and irreversible hepatic toxicity. Together, our findings show that a latent phase with distinct immunological changes precedes manifest CRS, providing an optimal window and potential targets for CRS therapeutic intervention and that CAR-T re-expansion warrants close clinical attention and laboratory investigation to mitigate the lethal risk.

Antigen-induced chimeric antigen receptor multimerization amplifies on-tumor cytotoxicity

Ligand-induced receptor dimerization or oligomerization is a widespread mechanism for ensuring communication specificity, safeguarding receptor activation, and facilitating amplification of signal transduction across the cellular membrane. However, cell-surface antigen-induced multimerization (dubbed AIM herein) has not yet been consciously leveraged in chimeric antigen receptor (CAR) engineering for enriching T cell-based therapies. We co-developed ciltacabtagene autoleucel (cilta-cel), whose CAR incorporates two B-cell maturation antigen (BCMA)-targeted nanobodies in tandem, for treating multiple myeloma. Here we elucidated a structural and functional model in which BCMA-induced cilta-cel CAR multimerization amplifies myeloma-targeted T cell-mediated cytotoxicity. Crystallographic analysis of BCMA-nanobody complexes revealed atomic details of antigen-antibody hetero-multimerization whilst analytical ultracentrifugation and small-angle X-ray scattering characterized interdependent BCMA apposition and CAR juxtaposition in solution. BCMA-induced nanobody CAR multimerization enhanced cytotoxicity, alongside elevated immune synapse formation and cytotoxicity-mediating cytokine release, towards myeloma-derived cells. Our results provide a framework for contemplating the AIM approach in designing next-generation CARs.

[Effect of a Novel Dihydroartemisinin Dimer Containing Nitrogen Atoms SM 1044 on Apoptosis of Human Leukemia Cell Line NB4-R1]

OBJECTIVE

To investigate the effect of a water-soluble novel dihydroartemisinin dimer containing nitrogen atoms SM 1044 on the apoptosis of all-trans retinoic acid (ATRA) resistant acute promyelocytic leukemia (APL) NB4-R1 cells and its potential mechanism.

METHODS

The effects of SM 1044 on cell apoptosis, mitochondrial transmembrane potential, and the level of reactive oxygen species (ROS) were assessed by flow cytometry. Expressions of apoptosis-related proteins were determined by Western blot. The effects of SM 1044 on MAPK (ERK, JNK) signaling pathway, PML/RARα fusion protein, and expressions of apoptosis-related proteins were detected by Western blot.

RESULTS

SM 1044 could significantly induce apoptosis and the loss of mitochondrial transmembrane potential in NB4-R1 cells, and activate apoptosis-related proteins caspase-3, caspase-8, caspase-9 and poly (ADP-ribose) polymerase (PARP). SM 1044 could also induce NB4-R1 cells to produce ROS. Western blot showed that SM 1044 activated the phosphorylation of MAPK (ERK, JNK) signaling pathway and down-regulated the expression of PML/RARα fusion protein.

CONCLUSION

SM 1044 can induce apoptosis of ATRA resistant APL NB4-R1 cells, which may be related to ROS/ERK and ROS/JNK signaling pathway, and can also induce by down-regulating PML/RARα fusion protein.

[Current status of diagnosis and treatment of chronic lymphocytic leukemia in China: A national multicenter survey research]

Objective: To understand the current status of diagnosis and treatment of chronic lymphocytic leukemia (CLL) /small lymphocytic lymphoma (SLL) among hematologists, oncologists, and lymphoma physicians from hospitals of different levels in China. Methods: This multicenter questionnaire survey was conducted from March 2021 to July 2021 and included 1,000 eligible physicians. A combination of face-to-face interviews and online questionnaire surveys was used. A standardized questionnaire regarding the composition of patients treated for CLL/SLL, disease diagnosis and prognosis evaluation, concomitant diseases, organ function evaluation, treatment selection, and Bruton tyrosine kinase (BTK) inhibitor was used. Results: ①The interviewed physicians stated that the proportion of male patients treated for CLL/SLL is higher than that of females, and the age is mainly concentrated in 61-70 years old. ②Most of the interviewed physicians conducted tests, such as bone marrow biopsies and immunohistochemistry, for patient diagnosis, in addition to the blood test. ③Only 13.7% of the interviewed physicians fully grasped the initial treatment indications recommended by the existing guidelines. ④In terms of cognition of high-risk prognostic factors, physicians' knowledge of unmutated immunoglobulin heavy-chain variable and 11q- is far inferior to that of TP53 mutation and complex karyotype, which are two high-risk prognostic factors, and only 17.1% of the interviewed physicians fully mastered CLL International Prognostic Index scoring system. ⑤Among the first-line treatment strategy, BTK inhibitors are used for different types of patients, and physicians have formed a certain understanding that BTK inhibitors should be preferentially used in patients with high-risk factors and elderly patients, but the actual use of BTK inhibitors in different types of patients is not high (31.6%-46.0%). ⑥BTK inhibitors at a reduced dose in actual clinical treatment were used by 69.0% of the physicians, and 66.8% of the physicians had interrupted the BTK inhibitor for >12 days in actual clinical treatment. The use of BTK inhibitors is reduced or interrupted mainly because of adverse reactions, such as atrial fibrillation, severe bone marrow suppression, hemorrhage, and pulmonary infection, as well as patients' payment capacity and effective disease progression control. ⑦Some differences were found in the perceptions and behaviors of hematologists and oncologists regarding the prognostic assessment of CLL/SLL, the choice of treatment options, the clinical use of BTK inhibitors, etc. Conclusion: At present, a gap remains between the diagnosis and treatment of CLL/SLL among Chinese physicians compared with the recommendations in the guidelines regarding the diagnostic criteria, treatment indications, prognosis assessment, accompanying disease assessment, treatment strategy selection, and rational BTK inhibitor use, especially the proportion of dose reduction or BTK inhibitor discontinuation due to high adverse events.

Real-World Experience of PD-1 Inhibitors for Relapsed and Refractory Hodgkin Lymphoma: A Multicenter Retrospective Analysis of Patients in China

INTRODUCTION

Despite the promising clinical trial data regarding programmed death 1 (PD-1) inhibitors in relapsed/refractory classical Hodgkin lymphoma (R/R cHL), there remains a paucity of studies describing the outcomes of patients in a real-world setting, especially for Asian cohort.

METHODS

We present a multicenter retrospective analysis of patients with R/R cHL who had failed ≥2 prior lines of therapies and received sintilimab or tislelizumab developed in China (sintilimab or tislelizumab monotherapy) at 3 medical centers from January 2019 to September 2021. Efficacy was evaluated with progression-free survival (PFS), overall survival, duration of response (DOR), best overall response (BOR) including objective response rate (ORR), complete response rate (CRR). Safety data were also recorded.

RESULTS

74 patients were reviewed. The median age was 38 years (range, 14-85 years). The ORR, CRR, and disease control rate were 78.3%, 52.7%, and 91.9%, respectively. The median duration of follow-up was 22 (4-36) months. Four patients (5.4%) died of disease progression. The median PFS and DOR was 22.1 and 23.5 months. BOR as a new emergent endpoint was found to be the only independent prognostic factor for PFS in our study (HR = 6.234, p = 0.005), suggesting this endpoint carries stronger prognostic value over traditional endpoints in the immunotherapy era. 66 (89.2%) patients reported adverse event (AE) with any grade, with the majority of AEs being grade 1 or 2.

CONCLUSION

We presented a unique real-life experience and conducted a relatively long follow-up of PD-1 antibodies developed in China for R/R HL patients which confirmed their promising effectiveness and manageable side effects given in real world in an Asian cohort. Even for those who would usually be excluded in most of clinical trials such as elderly or minor patients, anti-PD-1 monotherapy also showed a significant improvement of outcomes. Furthermore, the depth of response seemed to be a more powerful predictive tool in new era, which might serve as a basis for future immune risk-adapted strategies.

All-trans retinoic acid improves NSD2-mediated RARα phase separation and efficacy of anti-CD38 CAR T-cell therapy in multiple myeloma

BACKGROUND

Immunotherapies targeting CD38 have demonstrated salient efficacy in relapsed/refractory multiple myeloma (MM). However, loss of CD38 antigen and outgrowth of CD38 negative plasma cells have emerged as a major obstacle in clinics. All-trans retinoic acid (ATRA) has been reported to upregulate CD38 expression, but the mechanism and adaptive genetic background remain unexplored.

METHODS

The efficacy of ATRA in upregulating CD38 expression in MM cells is evaluated by flow cytometry. The interaction between NSD2 and the RARα is analyzed by immunoprecipitation, and the nuclear condensation of RARα is evaluated under laser confocal microscope. A graft model of MM is established in NOD.Cg-Prkdc^scidIl2rg^tm1Wjl /SzJ mice, and the tumor burden is assessed by in vivo fluorescence imaging.

RESULTS

We report that ATRA upregulates MM cells CD38 in a non-linear manner, which is t(4;14) translocation dependent, and t(4;14) translocation-induced NSD2 shows positive correlation with ATRA-induced level of, but not with basal level of CD38 expression. Mechanistically, NSD2 interacts with the ATRA receptor, RARα, and protects it from degradation. Meanwhile, NSD2 enhances the nuclear condensation of RARα and modifies the histone H3 dimethylation at lysine 36 on CD38 promoter. Knockdown of NSD2 attenuates the sensitization of MM against ATRA induced CD38 upregulation. Translationally, ATRA is prone to augment the efficacy of anti-CD38 CAR T cells in NSD2^high MM cells in vitro and in vivo.

CONCLUSION

This study elucidates a mechanism of ATRA in regulating CD38 expression and expands the clinical potential of ATRA in improving immunotherapies against CD38 in patients with MM.Cite Now.

Phase II, Open-Label Study of Ciltacabtagene Autoleucel, an Anti-B-Cell Maturation Antigen Chimeric Antigen Receptor-T-Cell Therapy, in Chinese Patients With Relapsed/Refractory Multiple Myeloma (CARTIFAN-1)

PURPOSE

CARTIFAN-1 aimed to evaluate the efficacy and safety of ciltacabtagene autoleucel (cilta-cel), a B-cell maturation antigen-targeting chimeric antigen receptor T-cell therapy, in Chinese patients with relapsed/refractory multiple myeloma (RRMM).

METHODS

This pivotal phase II, open-label study (ClinicalTrials.gov identifier: NCT03758417), conducted across eight sites in China, enrolled adult patients with RRMM who had received ≥ 3 lines of prior therapy, including a proteasome inhibitor and immunomodulatory drug. Patients received a single infusion of cilta-cel (target dose 0.75 × 10⁶ chimeric antigen receptor-positive viable T cells/kg). The primary end point was overall response rate. Secondary end points included progression-free survival (PFS), overall survival (OS), and incidence and severity of adverse events (AEs).

RESULTS

As of the clinical cutoff of July 19, 2021, 48 patients received a cilta-cel infusion. At an 18-month median follow-up, the overall response rate was 89.6% (95% CI, 77.3 to 96.5), with a median time to first response of approximately 1 month; 77.1% of patients (95% CI, 62.7 to 88.0) achieved complete response or better. Medians for duration of response, PFS, and OS were not reached. The 18-month PFS and OS rates were 66.8% (95% CI, 49.4 to 79.4) and 78.7% (95% CI, 64.0 to 88.0), respectively. Hematologic AEs were common, including anemia (100%), neutropenia (97.9%), lymphopenia (95.8%), and thrombocytopenia (87.5%). Cytokine release syndrome occurred in 97.9% of patients (35.4% grade 3/4); the median time to onset was 7 days, and the median duration was 5 days. Infections occurred in 85.4% of patients (37.5% grade 3/4). Ten deaths occurred after cilta-cel infusion, eight of which were due to treatment-related AEs.

CONCLUSION

These data demonstrate a favorable risk-benefit profile for a single infusion of cilta-cel, resulting in early, deep, and durable responses in heavily pretreated patients with RRMM in China.

[Effects of extramedullary disease on patients with newly diagnosed multiple myeloma]

Objective: To summarize the characteristics of patients with newly diagnosed multiple myeloma (NDMM) admitted at Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine. We compared the clinical characteristics and prognoses among patients with non-extramedullary disease (EMD), bone-related extramedullary (EM-B) disease, and extraosseous extramedullary (EM-E) disease and further explored the effects of autologous hematopoietic stem cell transplantation (ASCT) for EMD. Methods: From January 2015 to January 2022, data of 114 patients (22%) with EMD out of 515 patients with NDMM were retrospectively analyzed; 91 (18%) and 23 (4%) patients comprised the EM-B and EM-E groups, respectively. The clinical characteristics of patients in all groups were compared with the Chi-square test. Progression-free survival (PFS) and overall survival (OS) of patients were analyzed by the Kaplan-Meier method. Independent prognostic factors were determined using multivariate Cox proportional hazard model. Results: There were no significant differences in age, gender, ISS stage, light chain, creatinine clearance, cytogenetic risk, 17p deletion, ASCT, and induction regimens among the three groups. Overall, 13% of EM-E patients had IgD-type M protein, which was significantly higher than that in EM-B patients (P=0.021). The median PFS of patients in the non-EMD, EM-B, and EM-E groups was 27.4, 23.1, and 14.0 months; the median OS was not reached, 76.8 months, and 25.6 months, respectively. The PFS (vs non-EMD, P=0.004; vs EM-B, P=0.036) and OS (vs non-EMD, P<0.001; vs EM-B, P=0.002) were significantly worse in patients with EM-E, while those were not significantly different between patients with EM-B and those with non-EMD. In the multivariate analysis, EM-E was an independent prognostic factor for OS in patients with NDMM (HR=8.779, P<0.001) and negatively impacted PFS (HR=1.874, P=0.050). In those who did not undergo ASCT, patients with EM-B had significantly worse OS than those with non-EMD (median 76.8 months vs. not reached, P=0.029). However, no significant difference was observed in the PFS and OS of patients with EM-B and those with non-EMD who underwent ASCT. Conclusions: Compared to patients with either non-EMD or EM-B, those with EM-E had the worst prognosis. EM-E was an independent risk factor for OS in patients with NDMM. ASCT can overcome the poor prognosis of EM-B.

Modulating glycosphingolipid metabolism and autophagy improves outcomes in pre-clinical models of myeloma bone disease

Patients with multiple myeloma, an incurable malignancy of plasma cells, frequently develop osteolytic bone lesions that severely impact quality of life and clinical outcomes. Eliglustat, a U.S. Food and Drug Administration-approved glucosylceramide synthase inhibitor, reduced osteoclast-driven bone loss in preclinical in vivo models of myeloma. In combination with zoledronic acid, a bisphosphonate that treats myeloma bone disease, eliglustat provided further protection from bone loss. Autophagic degradation of TRAF3, a key step for osteoclast differentiation, was inhibited by eliglustat as evidenced by TRAF3 lysosomal and cytoplasmic accumulation. Eliglustat blocked autophagy by altering glycosphingolipid composition whilst restoration of missing glycosphingolipids rescued autophagy markers and TRAF3 degradation thus restoring osteoclastogenesis in bone marrow cells from myeloma patients. This work delineates both the mechanism by which glucosylceramide synthase inhibition prevents autophagic degradation of TRAF3 to reduce osteoclastogenesis as well as highlighting the clinical translational potential of eliglustat for the treatment of myeloma bone disease.

[Clinical features and prognosis of eight patients with splenic diffuse red pulp small B-cell lymphoma]

Objective: To investigate the clinical characteristics, response, and prognosis of splenic diffuse red pulp small B-cell lymphoma (SDRPL) . Methods: Eight cases of SDRPL were diagnosed and treated at Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, between May 2017 and April 2022. Data on the clinical features, laboratory results, bone marrow and spleen biopsy results, response, and prognosis were collected and analyzed. Results: The median age at diagnosis was 54 (42-69) years. Splenomegaly and lymphocytosis were present in all cases, and PET/CT revealed normal to slightly elevated splenic FDG uptake. All cases were in stage Ⅳ, with spleen, peripheral blood, and bone marrow but no proximal lymph nodes involved. The cytoplasm of neoplastic villous cells was abundant, and splenic pathology showed that small homogenous lymphocytes permeated the splenic sinus and splenic cord, and the white pulp atrophied. Immunohistochemistry was not typical, and B-cell markers including CD19, CD20 and CD79α were positive. After a median follow up of 35.5 (4-60) months, 7 cases were alive after splenectomy with or without chemoimmunotherapy. The patient with CCND3 P284A and MYC S146L mutation developed to B-cell prolymphocytic leukemia (B-PLL) 1 month after splenectomy and died at 16 months of follow-up. Conclusion: A rare indolent B-cell lymphoma that primarily affects the elderly, SDRPL. Most patients achieved long-term survival, but the prognosis of patients who progress to B-PLL was poor.

[Clinical characteristics and prognosis of patients with newly-diagnosed multiple myeloma with t(11;14)]

Objective: To explore the clinical characteristics and prognosis of multiple myeloma (MM) patients with t(11;14). Methods: The clinical data of patients newly diagnosed with MM with t(11;14), which confirmed by fluorescence in situ hybridization (FISH), from January 1, 2016 to May 31, 2021 in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine was retrospectively collected. A total of 45 patients were included. Bortezomib based induction therapy were given to 88.9% (40/45) patients, while 11.1% (5/45) received Imids-based therapy. Fourteen patients underwent the autologous hematopoietic stem cell transplantation (AHSCT). The clinical characteristics, overall response rate (ORR), progression free survival (PFS), overall survival (OS) and risk factors affecting survival were analyzed. Results: The average age of patients were (58.8±9.6) years, and 62.2%(28/45)were male. A relatively high incidence of bone lesion 82.2%(37/45)was observed. After 4 cycles induction therapy, the ORR was 66.7% (30/45), and ≥very good partial response (VGPR) was 31.3% (14/45). The rate of ≥VGPR increased to 92.9% (13/14) after AHSCT. The follow-up time [M(Q₁,Q₃)] was 27(20,42)months. The PFS was 34 (95%CI: 23-45) months, the median OS was 44 (95%CI:33-51) months. Median PFS were 48 (only 3 cases of progressive disease, CI not available) months and 24 (95%CI:13-35) months in the transplantation group and non-transplant group respectively (P=0.115). Median OS were 60 (only 1 case of death, CI not available) months and 48 (95%CI:22-74) months in the transplantation group and non-transplantation group, respectively (P=0.238). Cox regression analysis indicated that the number of plasma cell ≥50% in bone marrow and CD20 expression on myeloma cells were the risk factors for PFS[OR=3.272,95%CI:1.167-9.170,P=0.024;OR=3.480,95%CI:1.082-11.234,P=0.036]. No significant effective factor on OS was found. Conclusions: For multiple myeloma patient with t(11;14), the response rate with novel agents induction therapy is not high, but autologous stem cell transplantation can deepen remission. The high burden of bone marrow plasma cells and the expression of CD20 may be associated with the poor prognosis.

Four-year follow-up of LCAR-B38M in relapsed or refractory multiple myeloma: a phase 1, single-arm, open-label, multicenter study in China (LEGEND-2)

Background

LCAR-B38M is a chimeric antigen receptor T cell product with two binding domains targeting B cell maturation antigen. Our previous reports showed a remarkable efficacy of LCAR-B38M in patients with relapsed/refractory multiple myeloma (RRMM) at a median follow-up of 2 years. Here, we report long-term safety and efficacy data from a median follow-up of 4 years.

Methods

LEGEND-2 was a phase 1, single-arm, open-label study conducted in four registered sites in China. Seventy-four participants with RRMM received LCAR-B38M treatment. Lymphodepletion was performed using cyclophosphamide or cyclophosphamide plus fludarabine. LCAR-B38M, at a median dose of 0.513 × 10⁶ cells/kg, was intravenously administered either in three split infusions or in a single infusion. The primary objective was the safety of LCAR-B38M, and the secondary objective was efficacy.

Results

As of May 25, 2021, the median follow-up was 47.8 months. All patients experienced ≥ 1 adverse events (AEs). Grade ≥ 3 AEs were observed in 45/74 (60.8%) patients. Cytokine release syndrome (CRS) occurred in 68/74 (91.9%) cases; 7 (9.5%) had grade ≥ 3 CRS. One patient experienced grade 1 central nervous system toxicity. The overall response rate was 87.8%. Fifty-four out of 74 (73.0%) patients achieved complete response. The median progression-free survival was 18.0 months, and the median overall survival for all patients was not reached. The median duration of response was 23.3 months. Four patients experienced viral infection more than 6 months post-infusion, and four patients developed second primary non-hematological malignancies at a median time of 11.5 months post-CAR-T cell transfer.

Conclusions

The 4-year follow-up data of LCAR-B38M therapy demonstrated a favorable long-term safety profile and a durable response in patients with RRMM.

Trial registration Clinicaltrials.gov NCT03090659 (retrospectively registered on March 27, 2017); ChiCTR-ONH-17012285.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-022-01301-8.

Ectopic expression of a combination of 5 genes detects high risk forms of T-cell acute lymphoblastic leukemia

BACKGROUND

T cell acute lymphoblastic leukemia (T-ALL) defines a group of hematological malignancies with heterogeneous aggressiveness and highly variable outcome, making therapeutic decisions a challenging task. We tried to discover new predictive model for T-ALL before treatment by using a specific pipeline designed to discover aberrantly active gene.

RESULTS

The expression of 18 genes was significantly associated with shorter survival, including ACTRT2, GOT1L1, SPATA45, TOPAZ1 and ZPBP (5-GEC), which were used as a basis to design a prognostic classifier for T-ALL patients. The molecular characterization of the 5-GEC positive T-ALL unveiled specific characteristics inherent to the most aggressive T leukemic cells, including a drastic shut-down of genes located on the mitochondrial genome and an upregulation of histone genes, the latter characterizing high risk forms in adult patients. These cases fail to respond to the induction treatment, since 5-GEC either predicted positive minimal residual disease (MRD) or a short-term relapse in MRD negative patients.

CONCLUSION

Overall, our investigations led to the discovery of a homogenous group of leukemic cells with profound alterations of their biology. It also resulted in an accurate predictive tool that could significantly improve the management of T-ALL patients.

A case report of the metagenomics next-generation sequencing for early detection of central nervous system mucormycosis with successful rescue in patient with recurrent chronic lymphocytic leukemia

Background

Central nervous system (CNS) mucormycosis is insidious and difficult to diagnose. It progresses rapidly and causes high mortality. Rare cases have been reported during ibrutinib use, which have poor prognosis. Through this case, we share the experience of successful diagnosis and treatment. We also emphasize the importance of focusing on high-risk groups, early diagnosis and prompt management.

Case Description

In this case, a 52-year-old patient was diagnosed with chronic lymphocytic leukemia (CLL) for more than 5 years. He was in remission after rituximab plus fludarabine and cyclophosphamide (RFC) regimen, and relapsed in the fourth year. During the ibrutinib monotherapy, the patient presented with sudden headache. Cranial imaging examination revealed a definite right occipitoparietal lobe mass with extensive edema. A rapid diagnosis of mucormycosis infection was made using metagenomic next-generation sequencing (mNGS). The patient at that time didn't have neutropenia, but he had hypogammaglobulinemia. The infection was treated with amphotericin B cholesteryl sulfate complex, posaconazole, and interventional surgery, and the treatment was successful. At the same time, we considered the control of disease progression in this relapsed patient with, as well as to the drug interaction with posaconazole. We chose the next generation Bruton's tyrosine kinase (BTK) inhibitor zanubrutinib as the treatment, whose safety has been identified. As of the submission date, the patient has been followed up for nearly 1 year, and his disease is stable.

Conclusions

When new clinical problems arise in recurrent CLL patients, it is important to identify multiple factors, especially the insidious fungal infections. In particular, the immunocompromised patients should be concerned. CNS mucormycosis is extremely deadly, the early diagnosis will improve the prognosis. In clinical practice, the gold standard diagnosis of mucormycosis is difficult to obtain through pathology. In this case, mNGS was applied to quickly diagnose mucormycosis, enabling earlier treatment and ameliorating the prognosis. Thus, it will help us to early detect this group of people who may be potentially infected. Current guidelines do not recommend the prophylactic use of antifungal agents in treated CLL patients. However, in patients with prior severe infection or hypogammaglobulinemia, intravenous immunoglobulin is recommended to reduce the associated infection rate.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is one of the most dangerous hematological malignancies, with high tumor heterogeneity and poor prognosis. More than 60% of T-ALL patients carry NOTCH1 gene mutations, leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways. We found that chidamide, an HDAC inhibitor, exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity. In particular, chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1 (NICD1) as well as MYC, partly through their ubiquitination and degradation by the proteasome pathway. We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease (MRD) in patients and is well tolerated. Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients, including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

Characteristics of the Thrombus Formation in Transgenic Mice with Platelet-Targeted Factor VIII Expression

Platelet-targeted FVIII gene therapy can efficiently recover bleeding phenotype for hemophilia A (HA), yet characteristics of thrombus formation with this ectopic expression of factor VIII (FVIII) in platelets remain unclear. Here, we generated 2bF8^trans mice restrictively expressing human B-domain-deleted FVIII (hBDD FVIII) in platelets on a hemophilic (FVIII^null) mice background. The results showed no statistical difference in clot strength and stability between wild-type (WT) and 2bF8^trans mice, but with a prolonged reaction time (R-time), by thromboelastography. Fluid dynamics analysis showed that at the shear rates of 500 to 1,500 s^-1, where physiological hemostasis often develops, the thrombi formed in 2bF8^trans mice were more stable than those in FVIII^null mice, while at high pathological shear rates (2,500 s^-1), mimicking atherosclerosis, thrombus size and fibrin deposition in 2bF8^trans mice were less than those in WT mice. Thrombus morphology analysis showed that there was a locally concentrated deposition of fibrin in thrombus at the injured site and fibrin co-localized with activated platelets in 2bF8^trans mice. Moreover, a higher ratio of fibrin to platelets was found in thrombus from 2bF8^trans mice following laser-induced injury in cremaster arterioles, which might be the underlying mechanism of thrombus stability in 2bF8^trans mice at physiological arterial circumstance. These observations suggest that specific morphological features of the thrombi might contribute to the efficacy and safety of platelet-targeted FVIII gene therapy for HA.

Preclinical characterization and comparison between CD3/CD19 bispecific and novel CD3/CD19/CD20 trispecific antibodies against B-cell acute lymphoblastic leukemia: targeted immunotherapy for acute lymphoblastic leukemia

The CD19-targeting bispecific T-cell engager blinatumomab has shown remarkable efficacy in patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia. However, several studies showed that blinatumomab has a short plasma half-life due to its low molecular weight, and thus its clinical use is limited. Furthermore, multiple trials have shown that approximately 30% of blinatumomab-relapsed cases are characterized by CD19 negative leukemic cells. Here, we design and characterize two novel antibodies, A-319 and A-2019. Blinatumomab and A-319 are CD3/CD19 bispecific antibodies with different molecular sizes and structures, and A-2019 is a novel CD3/CD19/CD20 trispecific antibody with an additional anti-CD20 function. Our in vitro, ex vivo, and in vivo experiments demonstrated that A-319 and A-2019 are potent antitumor agents and capable of recruiting CD3 positive T cells, enhancing T-cell function, mediating B-cell depletion, and eventually inhibiting tumor growth in Raji xenograft models. The two molecules are complementary in terms of efficacy and specificity profile. The activity of A-319 demonstrated superior to that of A-2019, whereas A-2019 has an additional capability to target CD20 in cells missing CD19, suggesting its potential function against CD19 weak or negative CD20 positive leukemic cells.

IRF4 and IRF8 expression are associated with clinical phenotype and clinico-hematological response to hydroxyurea in essential thrombocythemia

The morbidity and mortality of myeloproliferative neoplasms (MPNs) are primarily caused by arterial and venous complications, progression to myelofibrosis, and transformation to acute leukemia. However, identifying molecular-based biomarkers for risk stratification of patients with MPNs remains a challenge. We have previously shown that interferon regulatory factor-8 (IRF8) and IRF4 serve as tumor suppressors in myeloid cells. In this study, we evaluated the expression of IRF4 and IRF8 and the JAK2V617F mutant allele burden in patients with MPNs. Patients with decreased IRF4 expression were correlated with a more developed MPN phenotype in myelofibrosis (MF) and secondary AML (sAML) transformed from MPNs versus essential thrombocythemia (ET). Negative correlations between the JAK2V617F allele burden and the expression of IRF8 (P < 0.05) and IRF4 (P < 0.001) and between white blood cell (WBC) count and IRF4 expression (P < 0.05) were found in ET patients. IRF8 expression was negatively correlated with the JAK2V617F allele burden (P < 0.05) in polycythemia vera patients. Complete response (CR), partial response (PR), and no response (NR) were observed in 67.5%,10%, and 22.5% of ET patients treated with hydroxyurea (HU), respectively, in 12 months. At 3 months, patients in the CR group showed high IRF4 and IRF8 expression compared with patients in the PR and NR groups. In the 12-month therapy period, low IRF4 and IRF8 expression were independently associated with the unfavorable response to HU and high WBC count. Our data indicate that the expression of IRF4 and IRF8 was associated with the MPN phenotype, which may serve as biomarkers for the response to HU in ET.

Metabolically controlled histone H4K5 acylation/acetylation ratio drives BRD4 genomic distribution

In addition to acetylation, histones are modified by a series of competing longer-chain acylations. Most of these acylation marks are enriched and co-exist with acetylation on active gene regulatory elements. Their seemingly redundant functions hinder our understanding of histone acylations' specific roles. Here, by using an acute lymphoblastic leukemia (ALL) cell model and blasts from individuals with B-precusor ALL (B-ALL), we demonstrate a role of mitochondrial activity in controlling the histone acylation/acetylation ratio, especially at histone H4 lysine 5 (H4K5). An increase in the ratio of non-acetyl acylations (crotonylation or butyrylation) over acetylation on H4K5 weakens bromodomain containing protein 4 (BRD4) bromodomain-dependent chromatin interaction and enhances BRD4 nuclear mobility and availability for binding transcription start site regions of active genes. Our data suggest that the metabolism-driven control of the histone acetylation/longer-chain acylation(s) ratio could be a common mechanism regulating the bromodomain factors' functional genomic distribution.

Inactivation of PBX3 and HOXA9 by down-regulating H3K79 methylation represses NPM1-mutated leukemic cell survival

Acute myeloid leukemia (AML) with an NPM1 mutation (NPMc+) has a distinct gene expression signature and displays molecular abnormalities similar to mixed lineage leukemia (MLL), including aberrant expression of the PBX3 and HOXA gene cluster. However, it is unclear if the aberrant expression of PBX3 and HOXA is essential for the survival of NPM1-mutated leukemic cells.

Methods: Using the gene expression profiling of TCGA and E-MTAB-3444 datasets, we screened for high co-expression of PBX3 and HOXA9 in NPMc+ leukemia patients. We performed NPMc+ depletion and overexpression experiments to examine aberrant H3K79 methylation through epigenetic regulation. Through RNA interference technology and small-molecule inhibitor treatment, we evaluated the effect of methyl-modified H3K79 on cell survival and explored the possible underlying mechanism.

Results: We showed that NPMc+ increased the expression of PBX3 and HOXA9, which are both poor prognosis indicators in AML. High PBX3 and HOXA9 expression was accompanied by increased dimethylated and trimethylated H3K79 in transgenic murine Lin^-Sca-1⁺c-Kit⁺ cells and human NPMc+ leukemia cells. Using chromatin immunoprecipitation sequencing (ChIP-seq) assays of NPMc+ cells, we determined that hypermethylated H3K79 was present at the expressed HOXA9 gene but not the PBX3 gene. PBX3 expression was positively regulated by HOXA9, and a reduction in either PBX3 or HOXA9 resulted in NPMc+ cell apoptosis. Importantly, an inhibitor of DOT1L, EPZ5676, effectively and selectively promoted NPMc+ human leukemic cell apoptosis by reducing HOXA9 and PBX3 expression.

Conclusion: Our data indicate that NPMc+ leukemic cell survival requires upregulation of PBX3 and HOXA9, and this action can be largely attenuated by a DOT1L inhibitor.

Discriminating Depth of Response to Therapy in Multiple Myeloma Using Whole-body Diffusion-weighted MRI with Apparent Diffusion Coefficient: Preliminary Results From a Single-center Study

RATIONALE AND OBJECTIVES

This study aimed to measure apparent diffusion coefficient (ADC) in Chinese patients with newly diagnosed multiple myeloma by whole-body diffusion-weighted magnetic resonance imaging (WB-DWI MRI) and assess the diagnostic accuracy of ADC in the discrimination of deep response to induction chemotherapy.

MATERIALS AND METHODS

Seventeen patients underwent WB-DWI MRI before and after induction chemotherapy (week 20). DWI images and ADC maps were produced and 89 regions of interest were chosen. ADC percent changes were compared between deep (complete response or very good partial response) and non-deep responders (partial response, minimal response, stable disease, or progressive disease) as International Myeloma Working Group criteria. Diagnostic accuracy of ADC was calculated using specific cut offs. Predictive positive value of ADC was calculated to predict deep response to consolidation therapy.

RESULTS

Lesions reduced in size and number and signal intensity decreased in follow-up DWI, which did not differ between deep and non-deep responders. ADC percent changes were significantly higher in deep responders (36.79%) than in non-deep responders (11.50%) after induction therapy (P = .02) in per lesion analysis. ADC percent increases by 46.96%, 78.0% yielded specificity at 81.4%, 90.7% in discriminating deep response to induction therapy. Predictive positive value predicting deep response to consolidation therapy was 60.5% by using ADC cutoff >1.00 × 10^-3 mm²/s at week 20.

CONCLUSIONS

ADC from WB-DWI MRI increased remarkably in patients who achieved deep response at the end of induction chemotherapy, which represented a confirmatory diagnostic tool to discriminate deep response to induction therapy for patients with multiple myeloma. ADC may have a potential to predict deep response to consolidation therapy.

Clinical Features and Prognosis Analysis of Hodgkin Lymphoma: A Multicenter Retrospective Study Over a Decade of Patients in China

OBJECTIVE

There is little information available regarding Chinese patients with Hodgkin lymphoma (HL). We analyzed the clinical features, outcome, and prognostic factors of Chinese patients with HL, aiming to establish a new risk model for better risk-adapted therapeutic strategy.

PATIENTS AND METHODS

Patients with newly diagnosed HL at 4 medical centers from January 2000 to August 2014 were recruited.

RESULTS

A total of 150 patients were reviewed. The median age was 30 years (range, 15-91 years). At completion of initial therapy, 73.65% of patients achieved complete remission. The 5-year event-free survival (EFS) of the entire cohort was 61.1%, the overall survival was 84.7%, and the disease-free survival was 78.8%. B symptoms, extranodal involvement, and International Prognostic Score ≥ 3 remained as independent prognostic factors of EFS. Patients who failed to reach complete remission on interim positron emission tomography/computed tomography or computed tomography had a significantly worse outcome than those who did. A new risk model incorporating traditional risk factors and interim response stratified patients into 3 classes, with a 5-year EFS of 100%, 83.1%, and 33.1%, respectively (P < .0001).

CONCLUSIONS

General clinical features were comparable with those of Western patients, whereas therapeutic outcomes were slightly inferior. The novel risk assessment model showed potential as a more powerful prognostic tool by identifying 3 subsets of patients with significantly distinct outcomes, which warrants further validations.

DNMT3A mutation leads to leukemic extramedullary infiltration mediated by TWIST1

BACKGROUND

DNMT3A mutations are frequently discovered in acute myeloid leukemia (AML), associated with poor outcome. Recently, a relapse case report of AML extramedullary disease has showed that AML cells harboring DNMT3A variation were detected in the cerebral spinal fluid. However, whether a causal relationship exists between DNMT3A mutation (D3Amut) and extramedullary infiltration (EMI) is unclear.

METHODS

We took advantage of DNMT3A (R882C) mutation-carrying AML cell strain, that is, OCI-AML3, assessing its migration ability in vitro and in vivo. By RNA interfering technology and a xenograft mouse model, we evaluated the effect of DNMT3A mutation on cell mobility and explored the possible mechanism.

RESULTS

OCI-AML3 displayed extraordinary migration ability in vitro and infiltrated into meninges of NOD/SCID mice after intravenous transfusion. We found that this leukemic migration or infiltration capacity was significantly compromised by the knockdown of DNMT3A mutant. Notably, TWIST1, a critical inducer of epithelial-mesenchymal transition, which underlies the metastasis of carcinomas, was highly expressed in association with R882 mutations. Abrogation of TWIST1 in DNMT3A mutated cells considerably weakened their mobility or infiltration.

CONCLUSIONS

Our results demonstrate that D3Amut in OCI-AML3 strain enhances leukemic aggressiveness by promoting EMI process, which is partially through upregulating TWIST1.

Arsenic trioxide rewires mantle cell lymphoma response to bortezomib

Although most of the mantle cell lymphoma (MCL) patients initially responded well to bortezomib (BTZ), the dose-dependent toxicities have greatly limited the application of BTZ to MCL. To investigate the efficacy and mechanism of arsenic trioxide (ATO) with BTZ in inducing apoptosis of MCL cells, two MCL cell lines, along with primary cells from MCL patients (n = 4), were used. Additionally, the NOD-SCID mice xenograft model of Jeko-1 cells was established to study the anti-MCL mechanisms in an in vivo setting. ATO treatment highly improved BTZ capacity to inhibit proliferation and induce apoptosis of MCL cells. Furthermore, the interaction of Noxa and Mcl-1 leads Bak to release from Mcl-1 or from Bcl-xl, which could further activate Bak and Bax and then induce cell apoptosis. We also found that when lower doses of BTZ were used in combination with ATO, more effective proapoptotic effects in both the cell lines and the primary cells were obtained compared to the effects of BTZ used alone at higher doses. Simultaneously, the combination of these two drugs delayed the tumor growth in mice more effectively than BTZ alone. The cooperative anti-MCL effects of this combination therapy both in vitro and in vivo strongly provided a new strategy to the clinical treatment of MCL.

Mutations of Epigenetic Modifier Genes as a Poor Prognostic Factor in Acute Promyelocytic Leukemia Under Treatment With All-Trans Retinoic Acid and Arsenic Trioxide

BACKGROUND

Acute promyelocytic leukemia (APL) is a model for synergistic target cancer therapy using all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), which yields a very high 5-year overall survival (OS) rate of 85 to 90%. Nevertheless, about 15% of APL patients still get early death or relapse. We performed this study to address the possible impact of additional gene mutations on the outcome of APL.

METHODS

We included a consecutive series of 266 cases as training group, and then validated the results in a testing group of 269 patients to investigate the potential prognostic gene mutations, including FLT3-ITD or -TKD, N-RAS, C-KIT, NPM1, CEPBA, WT1, ASXL1, DNMT3A, MLL (fusions and PTD), IDH1, IDH2 and TET2.

RESULTS

More high-risk patients (50.4%) carried additional mutations, as compared with intermediate- and low-risk ones. The mutations of epigenetic modifier genes were associated with poor prognosis in terms of disease-free survival in both training (HR = 6.761, 95% CI 2.179-20.984; P = 0.001) and validation (HR = 4.026, 95% CI 1.089-14.878; P = 0.037) groups. Sanz risk stratification was associated with CR induction and OS.

CONCLUSION

In an era of ATRA/ATO treatment, both molecular markers and clinical parameter based stratification systems should be used as prognostic factors for APL.

Leukemia propagating cells rebuild an evolving niche in response to therapy

Residence of cancer-propagating cells (CPCs) within preferential microenvironmental niches has a major part in evading therapy. However, the nature of niches involved and the mechanisms protecting CPCs remain largely unknown. We addressed these issues in mouse transplantation models of acute lymphoblastic leukemia (ALL). When the engrafted leukemic cells substantially damaged adjacent microenvironment in the bone marrow (BM), after chemotherapy small foci of CPCs were retained, surrounded by sheaths of supporting cells that comprise a protective niche. We investigated patients' BM biopsies and found evidence of a similar process in patients receiving induction therapy. The efficacy of chemotherapy was enhanced by interfering with the niche formation or function. We therefore identified a therapy-induced niche that protects CPCs.

Rapid diagnosis and prognosis of de novo acute myeloid leukemia by serum metabonomic analysis

Acute myeloid leukemia (AML) is a life-threatening hematological disease. Novel diagnostic and prognostic markers will be essential for new therapeutics and for significantly improving the disease prognosis. To characterize the metabolic features associated with AML and search for potential diagnostic and prognostic methods, here we analyzed the phenotypic characteristics of serum metabolite composition (metabonome) in a cohort of 183 patients with de novo acute myeloid leukemia together with 232 age- and gender-matched healthy controls using (1)H NMR spectroscopy in conjunction with multivariate data analysis. We observed significant serum metabonomic differences between AML patients and healthy controls and between AML patients with favorable and intermediate cytogenetic risks. Such differences were highlighted by systems differentiations in multiple metabolic pathways including glycolysis/gluconeogenesis, TCA cycle, biosynthesis of proteins and lipoproteins, and metabolism of fatty acids and cell membrane components, especially choline and its phosphorylated derivatives. This demonstrated the NMR-based metabonomics as a rapid and less invasive method for potential AML diagnosis and prognosis. The serum metabolic phenotypes observed here indicated that integration of metabonomics with other techniques will be useful for better understanding the biochemistry of pathogenesis and progression of leukemia.

Celecoxib radiosensitizes the human cervical cancer HeLa cell line via a mechanism dependent on reduced cyclo-oxygenase-2 and vascular endothelial growth factor C expression

OBJECTIVE

The effects of celecoxib, a selective cyclo-oxygenase-2 (COX-2) inhibitor, on HeLa cervical cancer cell growth and radiosensitivity were investigated.

METHODS

Cytotoxicity was quantified using a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium assay and effects on radiosensitivity were assessed using the lethal dose, quasithreshold dose, fraction surviving after 2 Gy irradiation and the radiosensitization ratio (SER, based on average lethal dose) determined using a single-hit multitarget model.

RESULTS

Celecoxib inhibited HeLa cell proliferation in a concentration- and time-dependent manner, with a half-maximal inhibitory concentration at 72 h of 44 μmol/l. Treatment with 20 μmol/l celecoxib for 72 h before irradiation was associated with an SER of 2.01. The SER of irradiated cells was 2.41 when treated with 40 μmol/l celecoxib before irradiation, 1.89 when treated simultaneously and 1.44 when treated after irradiation. Celecoxib downregulated COX-2 and vascular endothelial growth factor C (VEGF-C) expression evaluated immunohistochemically.

CONCLUSION

Celecoxib pretreatment radiosensitizes HeLa cells via a mechanism dependent on down-regulation of COX-2 and VEGF-C.

[A new artemisinin derivative SM1044 induces apoptosis of Kasumi-1 cells and its mechanism]

The aim of this study was to investigate the apoptosis-inducing effect of artemisinin derivative SM1044 on Kasumi-1 cells and its possible mechanism. Kasumi-1 cells were treated with different concentrations of SM1044, the cell viability was evaluated by MTT assay. Cell apoptosis and cell cycle progression were assessed by using flow cytometry with Annexin-V/PI double staining and flow cytometry with PI staining respectively. The expression of apoptosis-related proteins caspase 3, PARP and the fusion protein AML1-ETO were detected by Western blot. The results indicated that SM1044 inhibited cell growth of Kasumi-1 cells in time- and dose-dependent manners. After exposure of Kasumi-1 cells to 1 µmol/L SM1044 for 24 hours, the cell viability was decreased to 50%. IC(50) of SM1044 to Kasumi-1 cells at 48 hours was 0.17 ± 0.067 µmol/L. SM1044 induced cell apoptosis in a caspase-dependent manner, and the apoptotic rate of Kasumi-1 cells increased as SM1044 concentration increased. Flow cytometry with PI staining revealed that SM1044 induced cell cycle arrest, and the proportion of cells in G(0)/G(1) phase increased from 58.33 ± 4.46% to 71.75 ± 2.24% after exposure to 5 µmol/L SM1044 for 24 hours. Western blot showed that SM1044 increased the expression of apoptosis-related proteins cPARP and cleaved caspase 3 and also degraded the AML1-ETO fusion protein. It is concluded that SM1044 can inhibit the proliferation of Kasumi-1 cells, induce cell apoptosis which may be related to the increased level of cleaved PARP and cleaved caspase 3. SM1044 can also induce cell arrest in G(0)/G(1) phase. As the fusion protein AML1-ETO degrades obviously, it can be the potential target of SM1044 in Kasumi-1 cells.

[Effect of arsenic trioxide on induction of apoptosis in MCL cell line and its possible mechanisms]

This study was aimed to explore the effect of arsenic trioxide (ATO) on proliferation and apoptosis of mantle cell lymphoma (MCL) cell lines and the underlying mechanisms of the apoptosis. MCL cell lines (jeko-1, mino, JVM-2) were treated with different concentrations of ATO, then growth profile of these cells were detected by MTT. Apoptosis of ATO-treated jeko-1 cells were detected by flow cytometry with Annexin V-FITC/PI double staining. The loss of mitochondrial membrane potential of ATO-treated jeko-1 cells were detected by FCM with DiOC₆(3) staining. The expressions of cyclin D1 and apoptosis related proteins MCL-1, BCL-2, PUMA, NOXA, cCaspase-3 (cleaved caspase-3), cCaspase-9 (cleaved caspase-9), cPARP (cleaved PARP) were detected by Western blot. The results indicated that ATO inhibited cell growth, induced apoptosis of MCL cells and disrupted mitochondrial membrane potential. ATO could decrease expressions of MCL-1, PUMA and cyclin D1, increase expressions of cPARP, cCaspase-3, cCaspase-9 and the expressions of BLC-2 and NOXA were not changed. It is concluded that ATO can induce cell growth arrest and apoptosis of MCL cells. The mitochondrial pathway plays a very important role in cell apoptosis.

Development of autologous cytotoxic CD4+T clones in a human model of B-cell non-Hodgkin follicular lymphoma

Immunotherapy for cancer aims to generate cytotoxic cells that are capable of eradicating tumour cells. It has been well demonstrated that helper, non-cytotoxic CD4(+) T cells are important for the induction and maintenance of anti-tumour immunity exerted by cytotoxic CD8(+) T cells. In contrast, the existence of direct anti-tumour, effector cytotoxic CD4(+) T cells remains elusive, mainly due to the paucity of reliable experimental data, especially in human B-cell non-Hodgkin lymphomas. This study developed an appropriate, autologous follicular B-cell non-Hodgkin follicular lymphoma model, including the in vitro establishment of a malignant, human leucocyte antigen class I (HLA-I) deficient B-cell line, and the generation of three autologous anti-tumour cytotoxic CD4(+) T-cell clones originating from the peripheral blood of the same patient. These three clones were considered as tumour specific, because they were capable of killing the malignant, HLA-I-deficient B-cell line through a classical HLA-II restricted perforin-mediated pathway, but did not lyse the Epstein-Barr virus-infected autologous normal B lymphocytes. All three CD4(+)clones were T-cell receptor Vbeta17-Dbeta1-Jbeta1.2 and exhibited an identical complementarity-determining region 3, suggesting the immunodominance of a single peptide antigen presented by tumour cells. Such lymphoma models would provide a useful tool for in vivo expansion and the adoptive transfer of selected CD4(+) cytotoxic cells in immunotherapeutic strategies.

Quantitating Effector and Regulatory T Lymphocytes in Immune Responses by Limiting Dilution Analysis Modeling

Although there is currently no doubt that regulatory lymphocytes represent a master player in the immune system, a major unresolved problem is the accurate quantitation of these cells among unfractionated cell populations. This difficulty mainly arises because there are no specific immunophenotypic markers that can reliably discriminate between effector and regulatory lymphocytes. To face this problem, we have developed computational models of limiting dilution analyses addressing the question of the accurate estimation of the frequencies of effector and regulatory cells functionally engaged in an immune response. A set of generic equations were provided to form a framework for modeling limiting dilution data, enabling discrimination between qualitatively different models of suppression. These models include either one or two subpopulations of regulatory cells, featured by either low or potent regulatory activity. The potential of this modeling approach was illustrated by the accurate determination of the frequencies of effector and regulatory T lymphocytes in one real limiting dilution experiment of CD4+ CD25+ T lymphocytes performed in the context of an allogeneic response in the human system. The crucial advantage of the limiting dilution method over the "static, phenotype-based" method is the dynamic evaluation of effector and regulatory T cell biology through their actual functional activity.

Detection of suppressor T lymphocytes and estimation of their frequency in limiting dilution assays by generalized linear regression modeling

The estimate of the frequency of suppressor T lymphocytes in unfractionated cell populations remains challenging, mainly because these regulatory cells do not display specific immunophenotypic markers. In this paper, we describe a novel theoretical approach for quantifying the frequency of suppressor cells. This method is based on limiting dilution data modeling, and allows the simultaneous estimation of the frequencies of both proliferating and suppressor cells. We used previously published biological data, characterizing the inhibiting activity of suppressor T cell clones. Starting from these data, we propose a mathematical model describing the interaction between suppressor and proliferating T cells, and applied to a Poisson process. Limiting dilution data corresponding to this non-single-hit, suppressor two-target Poisson model were artificially generated, then modeled according to a generalized linear regression procedure. Deviation from the single-hit Poisson model was revealed by a statistical slope test, and a stepwise analysis of the regression appeared to be an efficient method that strongly argued in favor of the presence of suppressor cells. By using the frequency of proliferating T cells calculated in the first step of the regression, we demonstrated the possibility to provide a reasonable estimate of the frequency of suppressor T cells. Based on these findings, a practical decision-making procedure is given to perform standard analyses of limiting dilution data.

Endogenous megakaryocytic colony formation and thrombopoietin sensitivity of megakaryocytic progenitor cells are useful to distinguish between essential thrombocythemia and reactive thrombocytosis

Diagnosis of essential thrombocythemia (ET) is controversial and remains mainly an exclusion diagnosis. Endogenous megakaryocyte colony (EMC) formation have been largely evaluated to identify specific criteria for ET, but results are impeded by the lack of medium standardization. We evaluated megakaryocyte (MK) colony formation in a serum-free collagen-based medium, without cytokine and in the presence of various concentrations of thrombopoietin (TPO). Thirty-six bone marrows from patients diagnosed with ET (n = 11), polycythemia vera (PV; n = 12), reactive thrombocytosis (RT; n = 6) and healthy donors (n = 7) were assessed. We demonstrate that 11 out 11 of the ET patients had spontaneous megakaryocyte colony-forming unit (CFU-MK) formation, in contrast to none of the RT patients and healthy donors. MK progenitors from ET patients remained responsive to TPO, because exogenous addition of TPO significantly increased cloning efficiency. Moreover, at low doses of TPO (0.5 ng/ml and 5 ng/ml), the number of positive cultures and mean number of TPO stimulated CFU-MK were significantly higher in cultures of cells from patients with ET than in patients with RT. In summary, we have described a standardized serum-free, collagen-based assay that allows differential diagnosis of ET and RT, according to endogenous CFU-MK formation and sensitivity to TPO.

[Expression of EGF-R in gastric carcinoma and precancerous lesion]

The expression of epidermal growth factor receptor (EGF-R) in normal gastric mucosa, gastric mucosal dysplasia, early and advanced gastric carcinoma was studied with the monoclonal antibody to EGF-R by using immunohistochemical ABC method. Normal gastric mucosa was negative for EGF-R, but a relatively high positive rate was found in dysplasia. When gastric carcinoma occurred, the positive rate decreased. The expression of EGF-R was related to the poor differentiation and strong infiltration of gastric carcinoma. The carcinoma with the expression of EGF-R was easy to metastasize to lymph nodes. The result suggests that EGF-R might play some role in the process of carcinogenesis of gastric mucosa, and be used as a useful marker for the assessment of the biological behavior of gastric carcinoma.