Erratum: CD31 promotes diffuse large B-cell lymphoma metastasis by upregulating OPN through the AKT pathway and inhibiting CD8+ T cells through the mTOR pathway.

[This corrects the article on p. 2656 in vol. 15, PMID: 37193155.].

CD31 promotes diffuse large B-cell lymphoma metastasis by upregulating OPN through the AKT pathway and inhibiting CD8+ T cells through the mTOR pathway.

OBJECTIVE: Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell non-Hodgkin's lymphoma. Invasive DLBCL cells are likely to metastasize into extranodal tissue (e.g., the central nervous system) that is difficult for chemotherapy drugs to penetrate, seriously affecting patient prognosis. The mechanism of DLBCL invasion remains unclear. This study investigated the association between invasiveness and platelet endothelial cell adhesion molecule-1 (CD31) in DLBCL. METHODS: This study consisted of 40 newly diagnosed DLBCL patients. Differentially expressed genes and pathways in invasive DLBCL cells were identified using real-time polymerase chain reaction, western blotting, immunofluorescence, and immunohistochemical staining, RNA sequencing, and animal experiments. The effect of CD31-overexpressing DLBCL cells on the interactions between endothelial cells was determined using scanning electron microscopy. The interactions between CD8+ T cells and DLBCL cells were examined using xenograft models and single-cell RNA sequencing. RESULTS: CD31 was upregulated in patients with multiple metastatic tumor foci compared to patients with a single tumor focus. CD31-overexpressing DLBCL cells formed more metastatic foci in mice and shortened mouse survival time. CD31 disrupted the tight junctions between endothelial cells of the blood-brain barrier by activating the osteopontin-epidermal growth factor receptor-tight junction protein 1/tight junction protein-2 axis through the protein kinase B (AKT) pathway, enabling DLBCL to enter the central nervous system to form central nervous system lymphoma. Furthermore, CD31-overexpressing DLBCL cells recruited CD31+ CD8+ T cells that failed to synthesize interferon-γ (INF-γ), tumor necrosis factor-α (TNF-α), and perforin via the activated mTOR pathway. Some target genes, such as those encoding S100 calcium-binding protein A4, macrophage-activating factor, and class I b-tubulin, may be used to treat this type of DLBCL surrounded by functionally suppressed CD31+ memory T cells. CONCLUSIONS: Our study suggests that DLBCL invasion is associated with CD31. The presence of CD31 in DLBCL lesions could represent a valuable target for treating central nervous system lymphoma and restoring CD8+ T-cell function.

Cancer-related fatigue in hospitalised patients treated for lymphoma and its burden on family caregivers.

OBJECTIVE: To investigate the prevalence of cancer-related fatigue (CRF) in patients with lymphoma and to explore the burden of CRF on the family caregivers (FCs). METHODS: A cross-sectional study was conducted in a university-affiliated tertiary care hospital in China. Patients with lymphoma who received treatment in the in-patient ward of the Haematology Department were consecutively recruited. Face-to-face interviews were conducted to gather information related to the patients' sociodemographic characteristics and perceived CRF and its burden on the FCs. Cochran-Armitage trend analysis and Multivariable logistic regression analyses were employed to determine the association between CRF and the FCs' burden. RESULTS: Of the 116 cancer patient-FC dyads, about 70% of patients experienced some level of fatigue, while 51% of unpaid family members suffered some degree of depression. The Cochran-Armitage trend analysis showed that the FCs' burden significantly increased with the severity of CRF. Logistic regression indicated that the FCs of the patients reporting fatigue experienced a higher burden in both the unadjusted and adjusted models. CONCLUSION: The prevalence of CRF appeared to be high among patients with lymphoma. It might be important to design innovative health-promoting practices for ameliorating or preventing the impact of fatigue.

HDAC3 Silencing Enhances Acute B Lymphoblastic Leukaemia Cells Sensitivity to MG-132 by Inhibiting the JAK/Signal Transducer and Activator of Transcription 3 Signaling Pathway.

PURPOSE: HDAC3, which is associated with smurf2, has been shown to be associated with poor prognosis in B-ALL. This study examined the efficacy of targeting HDAC3 combined with MG-132 as a possible therapeutic strategy for B-ALL patients. METHODS: Real-time PCR and western blot were used to measure the expression of smurf2 and HDAC3 from B-ALL patients bone marrow samples. Sup-B15 and CCRF-SB cells were treated with MG-132, small interfering RNA of smurf2 or HDAC3. A plasmid designed to up-regulate smurf2 expression was transfected into B-ALL cells. Flow cytometry and western blot were used to measure variation due to these treatments in terms of apoptosis and cell cycle arrest. RESULTS: Expression of Smurf2 and HDAC3 mRNA were inversely related in B-ALL patients. Up-regulation of smurf2 or MG-132 influenced HDAC3, further inhibiting the JAK/signal transducer and activator of transcription 3 (STAT3) signal pathway and inducing apoptosis in B-ALL cells. When we treated Sup-B15 and CCRF-SB cells with siHDAC3 and MG-132 for 24 h, silencing HDAC3 enhanced the apoptosis rate induced by MG-132 in B-ALL cells and further inhibited the JAK/STAT3 pathway. Furthermore, MG-132 was observed to cause G2/M phase arrest in B-ALL cells and inhibited the JAK/STAT3 pathway, leading to apoptosis. CONCLUSIONS: Silencing of HDAC3 enhanced the sensitivity of B-ALL cells to MG-132. The combination of targeting HDAC3 and MG-132 may provide a new avenue for clinical treatment of acute B lymphocytic leukaemia and improve the poor survival of leukaemia patients.

HO-1 promotes resistance to an EZH2 inhibitor through the pRB-E2F pathway: correlation with the progression of myelodysplastic syndrome into acute myeloid leukemia.

BACKGROUND: Myelodysplastic syndrome (MDS) can progress to acute myeloid leukemia (AML), and conventional chemotherapy (decitabine) does not effectively inhibit tumor cells. Enhancer of zeste homologue 2 (EZH2) and Heme oxygenase-1 (HO-1) are two key factors in patients resistance and deterioration. METHODS: In total, 58 MDS patients were divided into four groups. We analyzed the difference in HO-1 and EZH2 expression among the groups by real-time PCR. After treatment with Hemin or Znpp IX, flow cytometry was used to detect apoptosis and assess the cell cycle distribution of tumor cells. Following injection of mice with very high-risk MDS cells, spleen and bone marrow samples were studied by immunohistochemistry (IHC) and hematoxylin and eosin (H&E) staining. MDS cells overexpressing EZH2 and HO-1 were analyzed by high-throughput sequencing. The effect of HO-1 on the pRB-E2F pathway was analyzed by Western blotting. The effects of decitabine on P15INK4B and TP53 in MDS cells after inhibiting HO-1 were detected by Western blotting. RESULTS: Real-time PCR results showed that EZH2 and HO-1 expression levels were higher in MDS patients than in normal donors. The levels of HO-1 and EZH2 were simultaneously increased in the high-risk and very high-risk groups. Linear correlation analysis and laser scanning confocal microscopy results indicated that EZH2 was related to HO-1. MDS cells that highly expressed EZH2 and HO-1 infiltrated the tissues of experimental mice. IHC results indicated that these phenomena were related to the pRB-E2F pathway. High-throughput sequencing indicated that the progression of MDS to AML was related to EZH2. Using the E2F inhibitor HLM006474 and the EZH2 inhibitor JQEZ5, we showed that HO-1 could regulate EZH2 expression. HO-1 could stimulate the transcription and activation of EZH2 through the pRB-E2F pathway in MDS patients during chemotherapy, which reduced TP53 and P15INK4B expression. CONCLUSIONS: EZH2 was associated with HO-1 in high-risk and very high-risk MDS patients. HO-1 could influence MDS resistance and progression to AML.

Entinostat combined with Fludarabine synergistically enhances the induction of apoptosis in TP53 mutated CLL cells via the HDAC1/HO-1 pathway.

TP53 mutation is an indicator of poor prognostic in chronic lymphocytic leukemia (CLL). Worse still, CLL patients with TP53 mutation are associated with poor efficacy to current chemotherapeutic, such as Fludarabine. Here, we confirmed that high expression of HDAC1 in CLL patients with TP53 mutation, which is closely related to poor prognosis and drug-resistance. Subsequently, we demonstrated Entinostat (HDAC1 inhibitor) combination with Fludarabine significantly induced apoptosis in TP53 mutations CLL cells. Its mechanism was associated with up-regulation of the pro-apoptotic protein Bax and the down-regulation of HDAC1, HO-1 and BCL-2 proteins. More importantly, we also confirmed that upregulation of HDAC1 could resistant Entinostat-induced apoptosis in TP53 mutations CLL cells by activating the HDAC1/P38/HO-1 pathway. In vivo, we found that Entinostat combination with Fludarabine significantly induced tumor cells apoptosis and prolong survival time in xenograft mouse model. Finally, combining vitro and vivo experiments, we presented the first demonstration that Entinostat combination with Fludarabine had a synergistic effect on the induction of apoptosis in TP53 mutations CLL cells. In conclusion, we provide valuable pre-clinical experimental evidence for the treatment of CLL patients with poor prognosis, especially for TP53 mutations.

Effect of BCLAF1 on HDAC inhibitor LMK-235-mediated apoptosis of diffuse large B cell lymphoma cells and its mechanism.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of adult lymphoma. It is a group of malignant tumors with a large number of clinical manifestations and prognoses. Therefore, it is necessary to explore its unknown potential therapeutic targets. Histone deacetylase inhibitor (HDACi) is a novel drug for the treatment of DLBCL, however pan-HDACis cannot be ignored because of their clinical efficacy. By contrast, specific HDACi is well-tolerated, and LMK-235 is a novel HDACi that is a specific inhibitor of HDAC4 and HDAC5. In this study, we investigated the up-regulation of BCLAF1 through NF-κB signaling pathways in LMK-235, mediating the apoptosis of two diffuse large B-cell lymphoma cell lines, OCI-LY10 and OCI-LY3. Further studies showed that BCLAF1 expression was increased in DLBCL cells after treatment with the NF-κB inhibitor Bay11-7082. The combination of Bay11-7082 and siRNA si-HDAC4 significantly increased BCLAF1 expression and further increased apoptosis. These results indicate that BCLAF1 plays an important role in LMK-235-mediated apoptosis and may be a potential target for the treatment of diffuse large B-cell lymphoma.

Low-dose staurosporine selectively reverses BCR-ABL-independent IM resistance through PKC-α-mediated G2/M phase arrest in chronic myeloid leukaemia.

Imatinib (IM) resistance has become a critical problem for the treatment of patients with relapsed chronic myeloid leukaemia (CML), so novel therapies are in need. Various isotypes of protein kinases C (PKCs) are up-regulated in CML and related with BCR-ABL regulating several signalling pathways that are crucial to malignant cellular transformation. However, it is still unknown whether PKC isotypes play crucial roles in IM resistance. Therefore, we herein used a PKC pan-inhibitor staurosporine (St). To protect normal cells from damage, a proper dose of St was used, at which IM-resistant CML cells were selectively killed in combination with IM but normal cells survived. The IM resistance of CML cells was best reversed by 4 nM St alone, mainly depending on the G2/M phase arrest. Cell cycle-related proteins p21, CDK2, cyclin A and cyclin B were down-regulated. Meanwhile, PKC-α was more significantly decreased than other PKC isotypes at this concentration. The PKC-α-dependent G2/M phase arrest was induced by down-regulation of CDC23, an important regulator of mitotic progression. Low-dose St also reversed IM resistance in vivo. In conclusion, low-dose St selectively increased the sensitivity of IM-resistant CML to IM by arresting cell cycle in the G2/M phase through PKC-α-dependent CDC23 inhibition.