Copy Number Analysis of 9p24.1 in Classic Hodgkin Lymphoma Arising in Immune Deficiency/Dysregulation.

A subset of patients with rheumatoid arthritis receiving methotrexate develop immune deficiencies and dysregulation-associated lymphoproliferative disorders. Patients with these disorders often exhibit spontaneous regression after MTX withdrawal; however, chemotherapeutic intervention is frequently required in patients with classic Hodgkin lymphoma arising in immune deficiency/dysregulation. In this study, we examined PD-L1 expression levels and 9p24.1 copy number alterations in 27 patients with classic Hodgkin lymphoma arising from immune deficiency/dysregulation. All patients demonstrated PD-L1 protein expression and harbored 9p24.1 copy number alterations on the tumor cells. When comparing clinicopathological data and associations with 9p24.1 copy number features, the copy gain group showed a significantly higher incidence of extranodal lesions and clinical stages than the amplification group. Notably, all cases in the amplification group had latency type II, while 6/8 (75%) in the copy gain group had latency type II, and 2/8 (25%) had latency type I. Thus, a subset of the copy-gain group demonstrated more extensive extranodal lesions and higher clinical stages. This finding speculates the presence of a genetically distinct subgroup within the group of patients who develop immune deficiencies and dysregulation-associated lymphoproliferative disorders, which may explain certain characteristic features.

Thermoneutral Housing Enables Studies of Vertical Transmission of Obesogenic Diet-Driven Metabolic Diseases.

Vertical transmission of obesity is a critical contributor to the unabated obesity pandemic and the associated surge in metabolic diseases. Existing experimental models insufficiently recapitulate "human-like" obesity phenotypes, limiting the discovery of how severe obesity in pregnancy instructs vertical transmission of obesity. Here, via utility of thermoneutral housing and obesogenic diet feeding coupled to syngeneic mating of WT obese female and lean male mice on a C57BL/6 background, we present a tractable, more "human-like" approach to specifically investigate how maternal obesity contributes to offspring health. Using this model, we found that maternal obesity decreased neonatal survival, increased offspring adiposity, and accelerated offspring predisposition to obesity and metabolic disease. We also show that severe maternal obesity was sufficient to skew offspring microbiome and create a proinflammatory gestational environment that correlated with inflammatory changes in the offspring in utero and adulthood. Analysis of a human birth cohort study of mothers with and without obesity and their infants was consistent with mouse study findings of maternal inflammation and offspring weight gain propensity. Together, our results show that dietary induction of obesity in female mice coupled to thermoneutral housing can be used for future mechanistic interrogations of obesity and metabolic disease in pregnancy and vertical transmission of pathogenic traits.

The bidirectional immune crosstalk in metabolic dysfunction-associated steatotic liver disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an unabated risk factor for end-stage liver diseases with no available therapies. Dysregulated immune responses are critical culprits of MASLD pathogenesis. Independent contributions from either the innate or adaptive arms of the immune system or their unidirectional interplay are commonly studied in MASLD. However, the bidirectional communication between innate and adaptive immune systems and its impact on MASLD remain insufficiently understood. Given that both innate and adaptive immune cells are indispensable for the development and progression of inflammation in MASLD, elucidating pathogenic contributions stemming from the bidirectional interplay between these two arms holds potential for development of novel therapeutics for MASLD. Here, we review the immune cell types and bidirectional pathways that influence the pathogenesis of MASLD and highlight potential pharmacologic approaches to combat MASLD based on current knowledge of this bidirectional crosstalk.

Trends in teicoplanin loading dose implementation from 2010 to 2019 and evaluation of safety and efficacy factors: a retrospective cohort study based on a Japanese administrative claims database.

BACKGROUND: The loading dose of teicoplanin (TEIC) is recommended for implementation. However, there is significant discrepancy between the dose settings in the package insert and, in the guidelines, and the actual status of loading doses in Japan is unclear. Furthermore, TEIC causes liver injury as side effect. Although the risk of developing liver injury has not been reported to be increased following a loading dose based on the guidelines, there is a lack of reports in large populations. Therefore, we evaluated the trend in the loading dose and factors affecting the efficacy and safety of TEIC administration. METHODS: A Japanese administrative claims database was used in this study. Trends in loading doses were evaluated in target populations administered TEIC between 2010 and 2019. Patient characteristics were adjusted by propensity score matching based on the guideline group (total dose of 3 days > 1,600 mg) and non-guideline group (≤ 1,600 mg) of the loading dose. Finally, univariable and multivariable conditional logistic regression analysis was performed to evaluate factors affecting 30-day mortality and liver injury. RESULTS: A total of 10,030 patients were selected based on these criteria. The proportion of loading doses based on the recommended guidelines showed an increase over time, regardless of the implementation of therapeutic drug monitoring (TDM), but especially so in cases where TDM was implemented, the loading doses were administered in accordance with the recommendations of the guidelines. Conditional logistic regression analysis showed a relationship between drug management and guidance fees (odds ratio [OR]: 0.45, 95% confidence interval [CI]: 0.36‒0.55), a reimbursement indicating pharmacist intervention, and a reduction in 30-day mortality. In addition, loading doses based on the recommended guidelines had no influence on liver injury, and other factors were not significantly associated with increased incidence of liver injury. CONCLUSION: Thus, this study implies the benefits of pharmacological management as indicated by drug management and guidance fee and supports the implementation of loading doses based on the guideline on TEIC administration.

Determination and gas-phase stability evaluation of metal complexes by nanoelectrospray ionization and collision-induced dissociation tandem mass spectrometry.

RATIONALE: The structures of metal complexes determine their stable functioning in product performance. Electrospray ionization mass spectrometry (ESI-MS) is used in studying metal complexes despite exhibiting limitations in analyzing labile complexes. Therefore, identifying a method for detecting unstable complexes and evaluating their stabilities is necessary, providing a theoretical basis for material selection and performance evaluation. METHODS: The standard complexes Zn(BTZ)2 , Fe(acac)3 , and Sn(Oct)2 were analyzed using nanoESI quadrupole orbitrap MS (nanoESI-MS) and compared with ESI-MS for two temperature modes. The three complexes and alkylamine-Ag+ complexes were analyzed using nanoESI and collision-induced dissociation MS/MS (CID-MS/MS). Breakdown plots of the survival yield against collision energies expressed in terms of the center-of-mass were constructed according to the obtained product ion spectra. Quantum chemical calculations based on density functional theory were performed to calculate the binding energies between the alkylamines and Ag+ . RESULTS: The three standard complexes were detected in the native structures using nanoESI-MS, confirming the advantage of nanoESI over ESI for detecting unstable complexes. The gas-phase stabilities of the amine-Ag+ complexes, estimated using the breakdown plots constructed by plotting the data obtained via nanoESI and CID-MS/MS, were consistent with the established theories, previous studies, and binding energies calculated using computational methods. CONCLUSIONS: NanoESI-MS is suitable for detecting labile complexes and enables the structural analyses of unknown complex additives. A novel approach based on nanoESI and CID-MS/MS was developed to determine the gas-phase stabilities of complexes, enabling their quantification and comparison and providing a technical basis for product improvement, which is essential in developing industrial materials.

Obesity amplifies influenza virus-driven disease severity in male and female mice.

Influenza virus-induced respiratory pneumonia remains a major public health concern. Obesity, metabolic diseases, and female sex are viewed as independent risk factors for worsened influenza virus-induced lung disease severity. However, lack of experimental models of severe obesity in female mice limits discovery-based studies. Here, via utility of thermoneutral housing (30 °C) and high-fat diet (HFD) feeding, we induced severe obesity and metabolic disease in female C57BL/6 mice and compared their responses to severely obese male C57BL/6 counterparts during influenza virus infection. We show that lean male and female mice have similar lung edema, inflammation, and immune cell infiltration during influenza virus infection. At standard housing conditions, HFD-fed male, but not female, mice exhibit severe obesity, metabolic disease, and exacerbated influenza disease severity. However, combining thermoneutral housing and HFD feeding in female mice induces severe obesity and metabolic disease, which is sufficient to amplify influenza virus-driven disease severity to a level comparable to severely obese male counterparts. Lastly, increased total body weights of male and female mice at time of infection correlated with worsened influenza virus-driven disease severity metrics. Together, our findings confirm the impact of obesity and metabolic disease as key risk factors to influenza disease severity and present a novel mouse experimental model suitable for future mechanistic interrogation of sex, obesity, and metabolic disease traits in influenza virus-driven disease severity.

Distribution and clinical impact of molecular subtypes with dark zone signature of DLBCL in a Japanese real-world study.

The distribution and clinical impact of cell-of-origin (COO) subtypes of diffuse large B-cell lymphoma (DLBCL) outside Western countries remain unknown. Recent literature also suggests that there is an additional COO subtype associated with the germinal center dark zone (DZ) that warrants wider validation to generalize clinical relevance. Here, we assembled a cohort of Japanese patients with untreated DLBCL and determined the refined COO subtypes, which include the DZ signature (DZsig), using the NanoString DLBCL90 assay. To compare the distribution and clinical characteristics of the molecular subtypes, we used a data set from the cohort of British Columbia Cancer (BCC) (n = 804). Through the 1050 patient samples on which DLBCL90 assay was successfully performed in our cohort, 35%, 45%, and 6% of patients were identified to have germinal center B-cell-like (GCB) DLBCL, activated B-cell-like (ABC) DLBCL, and DZsig-positive (DZsigpos) DLBCL, respectively, with the highest prevalence of ABC-DLBCL, differing significantly from the BCC result (P < .001). GCB-DLBCL, ABC-DLBCL, and DZsigpos-DLBCL were associated with 2-year overall survival rates of 88%, 75%, and 66%, respectively (P < .0001), with patients with DZsigpos-DLBCL having the poorest prognosis. In contrast, GCB-DLBCL without DZsig showed excellent outcomes after rituximab-containing immunochemotherapy. DZsigpos-DLBCL was associated with the significant enrichment of tumors with CD10 expression, concurrent MYC/BCL2 expression, and depletion of microenvironmental components (all, P < .05). These results provide evidence of the distinct distribution of clinically relevant molecular subtypes in Japanese DLBCL and that refined COO, as measured by the DLBCL90 assay, is a robust prognostic biomarker that is consistent across geographical areas.

EBV-positive mucocutaneous ulcer arising in methotrexate-treated rheumatoid arthritis patients: a clinicopathological study of 12 cases with analysis of PD-L1 expression.

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a newly recognized disease entity characterized by EBV-positive atypical B-cell proliferation. EBVMCU is a localized self-limited disease that affects mucosa and skin, especially the oral cavity. EBVMCU develops in immunosuppressive patients, such as those with methotrexate (MTX)-administrated rheumatoid arthritis (RA). Here we clinicopathologically analyzed 12 EBVMCU patients in a single institution. All cases were administrated MTX for RA, and five cases occurred in the oral cavity. All cases except one had demonstrated spontaneous regression after withdrawal of the immunosuppressive agent. We found 4 of 5 cases in the oral cavity had preceding traumatic events in the same site within a week before the onset of EBVMCU. Although there is no detailed and large study that has analyzed the trigger of EBVMCU, a traumatic event would indeed be a significant trigger for EBVMCU in the oral cavity. The cases were histologically classified; six cases were diffuse large B-cell lymphoma-type, five were polymorphous-type, and one was Hodgkin-like lesion type due to morphological appearance and immunophenotype. The PD-L1 expression was also examined by two antibodies for PD-L1 (E1J2J and SP142). Both antibodies revealed identical results for PD-L1 expression, and three cases were positive for PD-L1. The application of SP142 for evaluating the immune status of lymphomagenesis has also been proposed. Nine of 12 cases were negative for PD-L1, which implies that most EBVMCU cases may be caused by an immunodeficiency, rather than an immune-evasion, mechanism. However, as three cases were positive for PD-L1, immune escape may underly the pathogenesis in a subset of EBVMCU cases.

Thermoneutral housing shapes hepatic inflammation and damage in mouse models of non-alcoholic fatty liver disease.

Introduction: Inflammation is a common unifying factor in experimental models of non-alcoholic fatty liver disease (NAFLD) progression. Recent evidence suggests that housing temperature-driven alterations in hepatic inflammation correlate with exacerbated hepatic steatosis, development of hepatic fibrosis, and hepatocellular damage in a model of high fat diet-driven NAFLD. However, the congruency of these findings across other, frequently employed, experimental mouse models of NAFLD has not been studied. Methods: Here, we examine the impact of housing temperature on steatosis, hepatocellular damage, hepatic inflammation, and fibrosis in NASH diet, methionine and choline deficient diet, and western diet + carbon tetrachloride experimental models of NAFLD in C57BL/6 mice. Results: We show that differences relevant to NAFLD pathology uncovered by thermoneutral housing include: (i) augmented NASH diet-driven hepatic immune cell accrual, exacerbated serum alanine transaminase levels and increased liver tissue damage as determined by NAFLD activity score; (ii) augmented methionine choline deficient diet-driven hepatic immune cell accrual and increased liver tissue damage as indicated by amplified hepatocellular ballooning, lobular inflammation, fibrosis and overall NAFLD activity score; and (iii) dampened western diet + carbon tetrachloride driven hepatic immune cell accrual and serum alanine aminotransferase levels but similar NAFLD activity score. Discussion: Collectively, our findings demonstrate that thermoneutral housing has broad but divergent effects on hepatic immune cell inflammation and hepatocellular damage across existing experimental NAFLD models in mice. These insights may serve as a foundation for future mechanistic interrogations focused on immune cell function in shaping NAFLD progression.

Effectiveness of Noncertified Pharmacist-Led Antimicrobial Stewardship Programs in a Medium-Sized Hospital Without an Infectious Disease Specialist: A Retrospective Pre-Post Study.

Background: Few studies have reported the outcomes of antimicrobial stewardship programs (ASPs) implemented without infectious disease (ID) physician or pharmacist specialists. We implemented interventions that included providing antimicrobial optimization recommendations through a pharmacist-led team using prospective audit and feedback. This study evaluated different types of interventions and their impact on the outcomes of ASPs in a medium-sized hospital without ID specialists. Methods: This retrospective pre-post study included adult inpatients treated with intravenous antimicrobials between April 2016 and March 2020. Outcome (eg, length of hospital stay [LOS], drug cost) and process measures (eg, type of intervention, length of therapy) were compared between 2 time periods: pre-ASP (April 2016-March 2018) and post-ASP (April 2018-March 2020). Results: We included 5419 and 5634 patients in the pre- and post-ASP periods, respectively. The most common types of interventions were adjusting length of therapy (49.5%), additional laboratory tests (27.1%), antimicrobial change (16.2%), and dosage of antimicrobial (7.1%). After ASP implementation, LOS significantly decreased (14.8 vs 13.8 days, P < .01), along with the length of therapy, empirical use of antipseudomonal and anti-methicillin-resistant Staphylococcus aureus drugs, and number of days to de-escalation. No significant differences were noted in 30-day mortality, 30-day readmission, or de-escalation rates. On average, the antimicrobial cost per hospitalization decreased from US$173.03 to US$120.66. Conclusions: Pharmacist-led ASP interventions that focus on the length of therapy have the potential to reduce LOS in hospitals without ID specialists. Overall, this study showed that ASPs can be effectively implemented in medium-sized hospitals without ID specialists.

Repeated Occurrence and Recurrence of Secondary Oral Solid Cancers after Hematopoietic Stem Cell Transplantation for Leukaemia: Long-Term Follow-Up.

Hematopoietic stem cell transplantation (HSCT) is a common method for patients such as hematologic malignancies. However, HSCT generally has a higher risk of secondary solid cancer development. The aim of this study was to emphasize the need for lifelong follow-up of oral secondary solid cancer. The patient was a male who underwent HSCT for chronic myelogenous leukaemia at the age of 31 years. He underwent ten onsets on oral secondary solid cancers during his subsequent follow-up of more than 20 years. In conclusion, patients after HSCT require lifelong observation of oral secondary solid cancer, which may be accompanied by repeated new and recurrent occurrences.

Terahertz Spectroscopy and Ab-Initio Vibrational Analysis of Two Crystalline Forms of 5,5-Diethylbarbituric Acid.

Terahertz (THz) absorption spectra of the two crystalline forms of 5,5-diethylbarbituric acid (barbital) were measured with THz time-domain spectroscopy (THz-TDS). The spectra exhibited the dissimilarity between the two forms. Identification of the polymorphs and quantitative analysis of the two forms are possible by THz-TDS. Further, we performed ab-initio calculations of the vibrational modes considering the crystal structures of the two forms, and the results were in good agreement with the experimental data. We discuss the difference between the THz absorption spectra of the two forms.

The ubiquitin ligase Cul5 regulates CD4+ T cell fate choice and allergic inflammation.

Antigen encounter directs CD4+ T cells to differentiate into T helper or regulatory cells. This process focuses the immune response on the invading pathogen and limits tissue damage. Mechanisms that govern T helper cell versus T regulatory cell fate remain poorly understood. Here, we show that the E3 ubiquitin ligase Cul5 determines fate selection in CD4+ T cells by regulating IL-4 receptor signaling. Mice lacking Cul5 in T cells develop Th2 and Th9 inflammation and show pathophysiological features of atopic asthma. Following T cell activation, Cul5 forms a complex with CIS and pJak1. Cul5 deletion reduces ubiquitination and subsequent degradation of pJak1, leading to an increase in pJak1 and pSTAT6 levels and reducing the threshold of IL-4 receptor signaling. As a consequence, Cul5 deficient CD4+ T cells deviate from Treg to Th9 differentiation in low IL-4 conditions. These data support the notion that Cul5 promotes a tolerogenic T cell fate choice and reduces susceptibility to allergic asthma.

Hemodialysis-Related Amyloidosis in the Tongue.

Dialysis-related amyloidosis (DRA) represents a group of relatively rare disorders characterized by the systemic extracellular deposition of insoluble fibrils of amyloid protein in long-term dialysis patients. We describe herein a case of relatively early DRA on the tongue of a long-term dialysis patient. A 67-year-old man with a 39-year history of dialysis was referred for diagnosis of a tongue mass. On examination, a collection of whitish-yellow papules was identified on the ventral surface of the tongue tip. The pathological diagnosis was DRA. Clinicians should be aware that long-term dialysis can cause oral amyloidosis of the tongue.

Immunohistochemical staining patterns of p53 predict the mutational status of TP53 in oral epithelial dysplasia.

Next-generation sequencing of oral squamous cell carcinoma (OSCC) has revealed TP53 as the most frequently mutated gene in OSCC mutually exclusive with human papillomavirus infection. Oral epithelial dysplasia (OED) is defined as a precancerous lesion of OSCC by the current World Health Organization (WHO) classification; therefore, it is assumed that TP53 mutations occur in early precancerous conditions such as OED. Here, we conducted an integrated analysis of TP53, including whole coding sequencing of TP53, FISH analysis of the 17p13.1 locus, and immunohistochemical analysis for p53 (p53-IHC), in 40 OED cases. We detected 20 mutations in 16 (40%) OED cases, and four cases, each harbored two mutations. FISH analysis revealed six of 24 cases (25%) had a deletion on 17p13.1, and four cases had concurrent TP53 mutations and 17p13.1 deletion (2-hit). Also, the increased frequency of TP53 mutations in higher degrees of OED implies acquisition of the mutation is a major event toward OSCC. p53-IHC revealed that overall cases could be categorized into four patterns that correlate well with the mutational status of TP53. Especially, two patterns, broad p53 expression type (pattern HI) and p53 null type (pattern LS), strongly correlated with a missense mutation and nonsense mutation, respectively. Furthermore, seven of the 40 cases progressed to SCC, and six of these seven cases presented pattern HI or LS. Therefore, patterns HI and LS have a high risk for malignant transformation if excisional treatment is not performed irrespective of the dysplasia grade. Although the current WHO classification mainly focuses on morphological criteria for the diagnosis of OED, interobserver discrepancy appears in some instances of the OED diagnosis. Our immunohistochemical analysis supports a more accurate pathological diagnosis for OED in cases of low dysplastic changes or of differential diagnosis with non-dysplastic lesions.

[De novo blast phase of chronic myeloid leukemia with 3q26 abnormality diagnosed by cytogenetic analysis of extramedullary lesion].

A 62-year-old woman was presented at our hospital with visual disturbance. An ocular examination revealed bilateral Roth spots. Laboratory data revealed leukocytosis (236,200 µl) with an excess blast (11%). Physical examination and computed tomography (CT) showed systemic lymphadenopathy. A bone marrow examination revealed a composition of 9.2% blast. Chromosomal analysis on bone marrow cells revealed 46,XX,t (3;12)(q26.2;p13),t (9;22)(q34.1;q11.2) in 80% of metaphases (16/20). Inguinal lymph node biopsy revealed diffuse proliferation of myeloperoxidase (MPO)-positive abnormal cells. Fluorescence in situ hybridization analysis was used to detect the BCR-ABL1 fusion gene and split the signals of MECOM and ETV6. She was diagnosed with de-novo chronic myeloid leukemia (CML) extramedullary blast crisis. She received tyrosine kinase inhibitor (TKI) combination chemotherapy and allogeneic hematopoietic stem cell transplantation and achieved a major molecular response. In this study, we reported a case of CML in blast-phase initially presenting as extramedullary, in which cytogenetic and molecular analyses were useful in the staging method.

The E3 ubiquitin ligase Cul4b promotes CD4+ T cell expansion by aiding the repair of damaged DNA.

The capacity for T cells to become activated and clonally expand during pathogen invasion is pivotal for protective immunity. Our understanding of how T cell receptor (TCR) signaling prepares cells for this rapid expansion remains limited. Here we provide evidence that the E3 ubiquitin ligase Cullin-4b (Cul4b) regulates this process. The abundance of total and neddylated Cul4b increased following TCR stimulation. Disruption of Cul4b resulted in impaired proliferation and survival of activated T cells. Additionally, Cul4b-deficient CD4+ T cells accumulated DNA damage. In T cells, Cul4b preferentially associated with the substrate receptor DCAF1, and Cul4b and DCAF1 were found to interact with proteins that promote the sensing or repair of damaged DNA. While Cul4b-deficient CD4+ T cells showed evidence of DNA damage sensing, downstream phosphorylation of SMC1A did not occur. These findings reveal an essential role for Cul4b in promoting the repair of damaged DNA to allow survival and expansion of activated T cells.

Undifferentiated Carcinoma After Laparoscopic Surgery for a Cystic Ovarian Tumour: A Case Study.

Background: Laparoscopic surgery for malignant tumours occasionally results in recurrence at the trocar insertion site or port-site metastasis (PSM). We report on a patient requiring emergency laparoscopic surgery for an ovarian tumour with a review of the relevant literature. Case Report: A 42-year-old woman developed sudden abdominal pain and underwent laparoscopic right adnexectomy because of a suspected ovarian cystic tumour rupture. The postoperative histological diagnosis was a mucinous borderline ovarian tumour; however, an undifferentiated carcinoma was detected at the port site eight months after the initial surgery. The histopathological diagnosis of the abdominal wall tumour at the port site differed from intraoperative pathological findings, which was contradictory to PSM definition. Postoperatively, she received three systemic chemotherapy courses but died consequent to tumour metastasis. Conclusion: This is an atypical PSM case with histopathological differences from the initial tumour. Careful preoperative diagnosis and intraoperative attention are essential in such cases.

Mechanical Regulation Underlies Effects of Exercise on Serotonin-Induced Signaling in the Prefrontal Cortex Neurons.

Mechanical forces are known to be involved in various biological processes. However, it remains unclear whether brain functions are mechanically regulated under physiological conditions. Here, we demonstrate that treadmill running and passive head motion (PHM), both of which produce mechanical impact on the head, have similar effects on the hallucinogenic 5-hydroxytryptamine (5-HT) receptor subtype 2A (5-HT2A) signaling in the prefrontal cortex (PFC) of rodents. PHM generates interstitial fluid movement that is estimated to exert shear stress of a few pascals on cells in the PFC. Fluid shear stress of a relevant magnitude on cultured neuronal cells induces ligand-independent internalization of 5-HT2A receptor, which is observed in mouse PFC neurons after treadmill running or PHM. Furthermore, inhibition of interstitial fluid movement by introducing polyethylene glycol hydrogel eliminates the effect of PHM on 5-HT2A receptor signaling in the PFC. Our findings indicate that neuronal cell function can be physiologically regulated by mechanical forces in the brain.

Abemaciclib, a CDK4/6 inhibitor, exerts preclinical activity against aggressive germinal center-derived B-cell lymphomas.

The revised WHO classification newly defined the entities "High-grade B-cell lymphoma with MYC and BCL2, and/or BCL6 rearrangements (HGBL-DH/TH)" and "HGBL, NOS." Standard immunochemotherapy for diffuse large B-cell lymphoma (DLBCL), R-CHOP, is insufficient for HGBL patients, and there are currently no optimized therapeutic regimens for HGBL. We previously reported that CCND3, which encodes cyclin D3, harbored high mutation rates in Burkitt lymphoma (BL), HGBL and a subset of DLBCL. Furthermore, the knockdown of cyclin D3 expression was toxic to germinal center (GC)-derived B-cell lymphomas. Thus, the fundamental function of cyclin D3 is important for the pathogenesis of GC-derived B-cell lymphoma. We herein used two structurally different CDK4/6 inhibitors, palbociclib and abemaciclib, and examined their suppressive effects on cell proliferation and their ability to induce apoptosis in various aggressive B-cell lymphoma cell lines. The results obtained demonstrated that abemaciclib more strongly suppressed cell proliferation and induced apoptosis in GC-derived B-cell lymphoma cell lines than the control, but only slightly inhibited those features in activated B-cell (ABC)-like DLBCL cell lines. Palbociclib exerted partial or incomplete effects compared with the control and the effect was intermediate between abemaciclib and the control. Moreover, the effects of abemaciclib appeared to depend on cyclin D3 expression levels based on the results of the expression analysis of primary aggressive B-cell lymphoma samples. Therefore, abemaciclib has potential as a therapeutic agent for aggressive GC-derived B-cell lymphomas.