BACKGROUND: Exploring the underlying mechanism of rituximab resistance is critical to improve the outcomes of patients with diffuse large B-cell lymphoma (DLBCL). Here, we tried to identify the effects of the axon guidance factor semaphorin-3F (SEMA3F) on rituximab resistance as well as its therapeutic value in DLBCL. METHODS: The effects of SEMA3F on the treatment response to rituximab were investigated by gain- or loss-of-function experiments. The role of the Hippo pathway in SEMA3F-mediated activity was explored. A xenograft mouse model generated by SEMA3F knockdown in cells was used to evaluate rituximab sensitivity and combined therapeutic effects. The prognostic value of SEMA3F and TAZ (WW domain-containing transcription regulator protein 1) was examined in the Gene Expression Omnibus (GEO) database and human DLBCL specimens. RESULTS: We found that loss of SEMA3F was related to a poor prognosis in patients who received rituximab-based immunochemotherapy instead of chemotherapy regimen. Knockdown of SEMA3F significantly repressed the expression of CD20 and reduced the proapoptotic activity and complement-dependent cytotoxicity (CDC) activity induced by rituximab. We further demonstrated that the Hippo pathway was involved in the SEMA3F-mediated regulation of CD20. Knockdown of SEMA3F expression induced the nuclear accumulation of TAZ and inhibited CD20 transcriptional levels via direct binding of the transcription factor TEAD2 and the CD20 promoter. Moreover, in patients with DLBCL, SEMA3F expression was negatively correlated with TAZ, and patients with SEMA3F low TAZ high had a limited benefit from a rituximab-based strategy. Specifically, treatment of DLBCL cells with rituximab and a YAP/TAZ inhibitor showed promising therapeutic effects in vitro and in vivo . CONCLUSION Our study thus defined a previously unknown mechanism of SEMA3F-mediated rituximab resistance through TAZ activation in DLBCL and identified potential therapeutic targets in patients.
Humans ; Animals ; Mice ; Rituximab/therapeutic use* ; Hippo Signaling Pathway ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Prognosis ; Semaphorins/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Membrane Proteins/genetics* ; Nerve Tissue Proteins/genetics*

OBJECTIVE: Diffuse large B-cell lymphoma (DLBCL) is often associated with bone marrow infiltration, and 2-deoxy-2-(18F) fluorodeoxyglucose positron emission tomography/computed tomography ( ¹⁸F-FDG PET/CT) has potential diagnostic significance for bone marrow infiltration in DLBCL. METHODS: A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included. Bone marrow biopsy and ¹⁸F-FDG PET/CT examinations were performed at the time of initial diagnosis. Kappa tests were used to evaluate the agreement of ¹⁸F-FDG PET/CT with the gold standard, and the imaging features of DLBCL bone marrow infiltration on PET/CT were described. RESULTS: The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy ( P = 0.302) or between the two bone marrow biopsies ( P = 0.826). The sensitivity, specificity, and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923 (95% CI, 0.759-0.979), 0.934 (95% CI, 0.855-0.972), and 0.857, respectively. CONCLUSION ¹⁸F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration. PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.
Humans ; Positron Emission Tomography Computed Tomography/methods* ; Fluorodeoxyglucose F18 ; Bone Marrow/pathology* ; Retrospective Studies ; Positron-Emission Tomography/methods* ; Lymphoma, Large B-Cell, Diffuse/pathology*

OBJECTIVE: To investigate the expressions of Notch1 and Hes1 in diffuse large B-cell lymphoma (DLBCL), and their correlations with clinical features. METHODS: Immunohistochemistry (IHC) was performed on DLBCL samples (54 cases) and lymphadenitis tissues (20 cases) to evaluate the expressions of Notch1 and Hes1, and analyze their correlations with clinical characteristics of patients. Based on Oncomine database, the expressions of Notch1 and Hes1 mRNA and DNA were also explored. RESULTS: IHC result showed that the positive expression rates of Notch1 and Hes1 in DLBCL patients were significantly higher than those in the control group (P <0.05). In DLBCL patients, the expression of Notch1 was closely associated with B symptoms, Ann Arbor stage, lymphocyte count and the level of lactate dehydrogenase (P <0.05), while the expression level of Hes1 was significantly higher in patients with B symptoms (P <0.05). Notch⁺/Hes1⁺ expression was found in 21 DLBCL tissues (38.9%), and there was a correlation between Notch1 and Hes1 expression (r =0.296, P <0.05). Bioinformatics analysis (Oncomine database) showed that the mRNA expressions of Notch1 and Hes1 in the Brune dataset were significantly higher than those in the control tissues (P <0.05). CONCLUSION The expressions of Notch1 and Hes1 in DLBCL are significantly higher than those in lymphadenitis, and correlated with B symptoms and Ann Arbor stage, suggesting that Notch1 and Hes1 play important roles in the occurrence and development of DLBCL.
Humans ; Cell Line ; Clinical Relevance ; Lymphadenitis ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Prognosis ; RNA, Messenger

OBJECTIVE: To investigate the effect of MELK inhibitor OTSSP167 against diffuse large B-cell lymphoma (DLBCL). METHODS: The effect of OTSSP167 on activity, proliferation, and apoptosis of DLBCL cell line (SUDHL2 and HBL1) was detected by CCK-8 assay, 5-ethynyl-2'-deoxyuridine (EdU) staining, and Annexin V-FITC/PI double staining, respectively. DLBCL cells were inoculated into nude mice, after 4 weeks of OTSSP167 treatment, the effect of OTSSP167 on DLBCL growth in vivo was detected. Caspase-Glo^TM 3/7 enzyme activity assay kit was used to detect the effect of OTSSP167 on Caspase 3/7 enzyme activity of DLBCL cells. The expression levels of apoptosis and cycle-related proteins were detected by Western blot. RESULTS: OTSSP167 significantly inhibited the activity of SUDHL2 and HBL1 cells in a dose-dependent manner (r =-0.61, r =-0.52). EdU staining showed that OTSSP167 could significantly inhibit the proliferation of SUDHL2 and HBL1 cells. Annexin V-FITC/PI result showed that OTSSP167 could significantly promote the apoptosis of SUDHL2 and HBL1 cells (P <0.001). The result of in vivo experiment showed that OTSSP167 could inhibit the growth of SUDHL2 cells in nude mice. The result of TUNEL staining of tumor further confirmed that OTSSP167 could promote the apoptosis of SUDHL2 cells. Caspase 3/7 enzyme activity test demonstrated that OTSSP167 could significantly increase caspase activity in SUDHL2 and HBL1 cells (r =0.98, r =0.87). Western blot showed that OTSSP167 could dose-dependently inhibit the expression of PARP, Bcl-xL, and Bcl-2 in apoptosis signaling pathway (r =-0.93, r =-0.66, r =-0.87), while p53 protein was significantly up-regulated (r =0.82). The expression of cell cycle-related proteins cdc2, Cyclin E1, Cyclin A2, and Cyclin B1 also showed a dose-dependent down-regulation (r =-0.89, r =-0.83, r =-0.61, r =-0.93). CONCLUSION The MELK inhibitor OTSSP167 can inhibit the proliferation and promote the apoptosis of DLBCL cells by inhibiting the expression of cycle-related proteins and anti-apoptosis-related proteins.
Mice ; Animals ; Mice, Nude ; Cell Line, Tumor ; Cell Proliferation ; Caspase 3 ; Apoptosis Regulatory Proteins ; Caspases ; Lymphoma, Large B-Cell, Diffuse/pathology*

Humans ; Adult ; Lymphoma, Mantle-Cell/drug therapy* ; Rituximab/therapeutic use* ; Bendamustine Hydrochloride/therapeutic use* ; Lymphoma, B-Cell/pathology* ; Lymphoma, Non-Hodgkin/drug therapy* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use*

Humans ; White Matter/pathology* ; Central Nervous System Neoplasms/pathology* ; Lymphoma, Large B-Cell, Diffuse/pathology*

Male ; Humans ; Prostate/pathology* ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Adenocarcinoma/pathology*

Objective:b> To investigate the clinical, pathological and immunophenotypic features, molecular biology and prognosis of fibrin-associated large B-cell lymphoma (LBCL-FA) in various sites. Methods:b> Six cases of LBCL-FA diagnosed from April 2016 to November 2021 at the Beijing Friendship Hospital, Capital Medical University, Beijing, China and the First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China were collected. The cases were divided into atrial myxoma and cyst-related groups. Clinical characteristics, pathological morphology, immunophenotype, Epstein Barr virus infection status, B-cell gene rearrangement and fluorescence in situ hybridization of MYC, bcl-2, bcl-6 were summarized. Results:b> The patients' mean age was 60 years. All of them were male. Three cases occurred in atrial myxoma background, while the others were in cyst-related background, including adrenal gland, abdominal cavity and subdura. All cases showed tumor cells located in pink fibrin clot. However, three cyst-related cases showed the cyst wall with obviously fibrosis and inflammatory cells. All cases tested were non germinal center B cell origin, positive for PD-L1, EBER and EBNA2, and were negative for MYC, bcl-2 and bcl-6 rearrangements, except one case with MYC, bcl-2 and bcl-6 amplification. All of the 5 cases showed monoclonal rearrangement of the Ig gene using PCR based analysis. The patients had detailed follow-ups of 9-120 months, were treated surgically without radiotherapy or chemotherapy, and had long-term disease-free survivals. Conclusions:b> LBCL-FA is a group of rare diseases occurring in various sites, with predilection in the context of atrial myxoma and cyst-related lesions. Cyst-related lesions with obvious chronic inflammatory background show more scarcity of lymphoid cells and obvious degeneration, which are easy to be missed or misdiagnosed. LBCL-FA overall has a good prognosis with the potential for cure by surgery alone and postoperative chemotherapy may not be necessary.
Humans ; Male ; Middle Aged ; Atrial Fibrillation ; Epstein-Barr Virus Infections ; Fibrin/genetics* ; Herpesvirus 4, Human/genetics* ; In Situ Hybridization, Fluorescence ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Myxoma ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Proto-Oncogene Proteins c-bcl-6/genetics*

Humans ; Herpesvirus 4, Human ; Epstein-Barr Virus Infections/complications* ; Multiple Myeloma/complications* ; Lymphoma, Large B-Cell, Diffuse/pathology*

Humans ; Lymphoma, Large B-Cell, Diffuse/genetics* ; Herpesvirus 4, Human/genetics* ; Mutation ; Epstein-Barr Virus Infections/pathology* ; Hepatitis A Virus Cellular Receptor 2/genetics*