45 research outputs found
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Gene Expression Analysis Of Plasmablastic Lymphoma Identifies Down Regulation Of B Cell Receptor Signaling and Additional Unique Transcriptional Programs
Abstract
Plasmablastic lymphoma (PBL) is currently recognized as a distinct sub-type of diffuse large B-cell lymphoma (DLBCL), but remains a poorly characterized B-cell malignancy. We conducted gene expression profiling of 15 PBL, 10 DLBCL, and 5 EOP (extraosseous isolated plasmacytoma). 864 genes were significantly over- or under-expressed (at<1% false discovery rate) uniquely in one of these diseases relative to the other two. Of these, 102 were highly expressed in PBL relative to DLBCL and EOP, while 166 showed low expression in PBL. This set of 268 genes defined a distinct transcriptional program operating in PBL. Among these were surface markers such as CD320, CD300A, and IL6 receptor, as well as the cytokine Oncostatin M, which was highly expressed in PBL but almost never expressed in DLBCL or EOP. CD320 plays a role in generation and proliferation of plasma cells in the germinal center in response to IL-10 stimulation, while the immunoglobulin superfamily member CD300 is variably expressed across the hematopoietic hierarchy. The apoptosis-inducer BAX (Bcl-2 associated X protein) was highly expressed in PBL, similar to reports in plasma cell neoplasms. In addition the CpG methyltransferase gene Dnmt3b showed high expression levels in PBL.
By comparing malignancy-specific gene expression patterns to known biological pathways, we found that expression of components of the B-cell receptor signaling pathway (Cd79a, Cd79b, Blk, Lyn, Syk, Ptprc, Csk, Pik3cd, Swap70, and Rel) were repressed by 2-fold or more on average in PBL relative to DLBCL. We observed a similar pattern in EOP relative to DLBCL. In contrast, mitochondrial genes were more highly expressed in PBL than in DLBCL. Analysis against a large compendium of sets of transcription factor targets from motif and ChIP analyses identified that targets of MYB, a major transcriptional regulator of hematopoietic differentiation, were up-regulated in PBL; whereas targets of NFKB1 were repressed relative to DLBCL.
Both PBL and EOP highly expressed genes that have previously been described as up-regulated in plasmacytomas. To further investigate the potential cell of origin of these malignancies, we compared genes expressed in PBL, DLBCL, and EOP to genes that are highly expressed in specific sub-types of B-cells. Genes highly expressed in plasma cells relative to other types of B-cells were highly expressed in PBL and EOP compared to DLBCL. Notably, this included the transcription factor XBP1 (X-box binding protein 1), which is a critical regulator of plasma cell differentiation. The plasma cell marker CD138 (syndecan-1, encoded by the Sdc1 gene) was also over-expressed in the PBL and EOP samples.
We have validated the array data by reanalyzing expression of four candidate genes (Lyn, Syk, SPIB, and Swap70) by real time PCR. These four genes were highly expressed in DLBCL, but their expression was low in both in PBL and EOP. The observed overexpression of Swap70 in DLBCL as compared to PBL and EOP was subsequently validated by immunohistochemistry (IHC). Immunostaining for Swap70 was performed in all 30 cases used for array analysis and was negative in all cases of PBL (0/15 positive) and EOP (0/5 positive) but was diffusely positive in all but one of the DLBCLs (9/10 positive). Swap70 analysis by IHC was subsequently performed in 7 additional cases of DLBCL and was diffusely positive in all of these cases (7/7), thus suggesting that immunohistochemical analysis for Swap70 may be useful in differentiating PBL and EOP from DLBCL.
Overall our results provide insight into the unique transcriptional programs distinguishing PBL from morphologic and clinical mimics DLBCL and EOP, as well as identify similarities between them. Most notably, we observed that B-cell receptor signaling pathway genes are significantly down-regulated in PBL and EOP compared to DLBCL. These findings corroborate the downregulation of surface immunoglobulin expression as seen in PBL and EOP and suggest a biologic similarity between these two neoplasms. Among normal B-cell sub-populations, PBL and EOP were most similar in their expression patterns to plasma cells and plasmablasts in that they expressed several well-known plasma cell markers. These findings additionally identify novel candidate genes that provide opportunities for further phenotypic and functional characterization of these neoplasms.
Disclosures:
No relevant conflicts of interest to declare
Signet ring cell melanoma, Brenner sign, and elevated vascular endothelial growth factor
Sphenoid Sinus Basaloid Squamous Cell Carcinoma Presenting as a Sellar Mass: Report a Case with Review of the Literature
Basaloid squamous cell carcinoma (BSCC) is a distinctive variant of squamous cell carcinoma (SCC) with more aggressive behavior. It occurs preferentially in the upper aerodigestive tract. Sinonasal tract BSCC is uncommon, and only limited studies have been reported in literature. In these studies, most BSCCs arose from the nasal mucosa with or without extension to the paranasal sinuses. Rare reported cases of BSCC involved only the paranasal sinus. In this report, we present a case of a female patient with a sphenoid sinus mass. Clinically, the patient had progressively decreasing vision and headache. Magnetic resonance imaging (MRI) and computerized tomographic (CT) scan showed an infiltrating tumor mass involving the sphenoid sinus and the sella with compression of the optic nerve. Pathologic examination revealed an invasive basaloid epithelial neoplasm that was arranged in lobules, nests and cords. The tumor also showed palisading of peripheral cells, focal abrupt squamous differentiation and in situ carcinoma in the surface mucosa. In the immunohistochemical studies, this tumor revealed a strongly positive nuclear staining for p63. The morphologic and ancillary studies indicated a BSCC. To the best of our knowledge, this is the first report of sinonasal tract BSCC that mainly involved the sphenoid bone and sella. In this region, BSCC should be distinguished from benign and malignant neoplasms that more often affect sella and base of skull, such as pituitary adenoma with extensive necrosis, small cell neuroendocrine carcinoma (SCNC), olfactory neuroblastoma, malignant germ cell tumor, paranasal adenoid cystic carcinoma (ACC), and a variety of metastatic malignancies
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Remodeling of the Immune Microenvironment By Oncogenic MYD88 Dictates Immunotherapy Responses across Indolent and Aggressive B-Cell Lymphomas
The MYD88 L265P mutation is detected in a variety of lymphoma subtypes, ranging from indolent MALT or lymphoplasmacytic lymphoma (LPL) to aggressive DLBCL with activated B-cell (ABC) phenotype. Whether oncogenic MYD88 L265P constitutes a common founder mutation and how it drives lymphomas with different clinical, histopathological, and immunological characteristics, remains unknown. To address this fundamental question, we screened mice genetically engineered to express an orthologous MYD88 L252P mutation crossed with animals carrying secondary genetic lesions common in MYD88 L265P lymphomas, triggered at two B-cell differentiation stages. Several mouse strains developed indolent or aggressive lymphomas depending on the cell of origin and the secondary genetic lesion. In two of the models, human-like MALT or LPL were progressively driven by mutant MYD88 activated from immature pre-B lymphocytes with either constitutive BCR signaling or BCL2 expression. High-throughput cellular and molecular characterization of the tumor immune microenvironment (TME) by single-cell RNA sequencing coupled with BCR/TCRseq revealed bi-directional B-cell interactions with CD4 + Tfh and Th1 cells from early disease state, promoting survival of B-cell clones through CD40L:CD40 signaling. During progression, IL10-secreting regulatory T (Treg) cells were recruited into the tumor niche through a Ccl5-Cxcr3 axis to suppress CD8 + T-cell cytotoxicity. In patients with MYD88 L265P LPL characterized at progressive disease states, CD40:CD40L interaction between tumor and immune cells took place early while Tregs accumulated at late stage. In the LPL model and in human MYD88 L265P-LPL cells, CD40 signaling decreased effects of standard-of-care drugs including BTK inhibitors. Accordingly, anti-CD40 therapy disrupted B/T-cell interactions and increased ibrutinib activity. In conclusion, oncogenic MYD88 triggered at early B-cell stages promotes indolent lymphomas that are sustained by CD40 signaling, which restricts therapy responses that can be restored upon CD40 blockade. When MYD88 L265P was activated in mature germinal-center B cells together with either Prdm1 or Trp53 deletion, mice developed extranodal ABC-DLBCL (MCD/C5 genomic class). IHC, flow cytometry and single-cell RNAseq revealed that DLBCL with Prdm1 loss showed morphologically heterogeneous B cells with abundant immune and T cells with activated/exhausted phenotypes, which recapitulated the inflammatory/immunosuppressive TME category in DLBCL patients (IN-LME, Kotlov- Cancer-Discovery-2021). In contrast, DLBCL with Tp53 deletion exhibited monotonous B-cell infiltrates with high proliferation index and a TME with depletion of T cells with effector/memory phenotypes and CD4 +CD25 +Foxp3 + Tregs, consistent with the immune depleted TME category (DP-LME). Analysis of 1,039 DLBCL patients demonstrated that majority of MCD cases with MYD88 L265P showed either an IN-LME (43%) or DP-LME (44%). Consistent with the models, ABC-DLBCL patients with MYD88 L265P and TP53 loss/mutation exhibited highly proliferative disease with a DP-LME, while ABC-DLBCLs with MYD88 L265P but without TP53 abnormalities showed an IN-LME. Notably, the number of infiltrating CD4 + T cells correlated with TP53 activity score (PROGeNY) across MCD-DLBCLs. Overall, the presence or absence of TP53 alterations in MYD88 L265P ABC-DLBCL induces TME characterized as DP-LME or IN-LME, respectively. Since DP-LME carries poor response to immune-chemotherapy (Kotlov-Cancer-Discovery-2021), we tested anti-CD19 CAR T-cells in the models. While CAR T-cells were initially effective in the two DLBCL models, progression occurred earlier in DLBCL with DP-LME than in IN-LME, which remained in remission 100 days after cell infusion. Responses correlated with persistence of circulating CD4 + CAR T cells. These data highlight that a TP53-driven DP-LME may limit immunotherapy activity in DLBCL, providing a scientific explanation to the poor outcome of DLBCL patients with TP53 alterations to CD19-directed CAR T cells (Shouval-JCO-2021). Collectively, our study defines the cellular origins and the stepwise genetic alterations of indolent and aggressive lymphomas with MYD88 L265P, dissects distinct immunological paths underlying progression driven by oncogenic MYD88, and builds proof-of-concept for advancing precision immunotherapy in B-cell lymphomas
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Comparing Clinical Characteristics and Outcomes of MYC and BCL6 Double Hit Lymphoma (DHL- BCL6 ) with Other Aggressive B-Cell Lymphomas: Understanding the Impact of New Who and International Consensus Classifications
Background: High Grade B cell Lymphoma (HGBL) with MYC and BCL2 and/or BCL6 rearrangements(R) was introduced as an entity in 2016 by the WHO revised 4 th edition. In 2022, both the WHO 5 th edition (beta version) and the International Consensus Classification (ICC) separated DHL- BCL2 (+/- BCL6-R)from DHL- BCL6 given differences in biology . However, while the ICC has maintainedDHL- BCL6 as a provisional entity, the WHO has removed the category, thus removing the requirement to FISH for BCL6-R in this setting. Clinical data on DHL- BCL6 is much more limited, as these cases represent only 10-20% of DHL and have been combined with BCL2-R cases in prior studies. Outcomes are variable in retrospective studies with no consistent data on prognosis or optimal therapeutic strategies. By retaining the category of DHL-BCL6 as a provisional entity, the ICC emphasized the need for further, multicenter, prospective studies evaluating the clinical and biological features of this disease. We herein report a comprehensive comparison of clinical characteristics and outcomes in patients with DHL- BCL6 compared to diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS); DLBCL with MYC rearrangement only; DHL- BCL2; and HGBL, NOS in a large, multicenter, prospective cohort of patients from Lymphoma Epidemiology of Outcomes (LEO). Methods: Adult patients with newly diagnosed large B-cell or HGBL were enrolled within 6 months of diagnosis at one the 8 LEO cohort academic medical centers in the US between 2015 and 2020. Baseline characteristics were abstracted at the time of diagnosis per protocol. Based on FISH data patients were further sub mgrouped into DLBCL, NOS (without MYC rearrangement); MYC-R DLBCL, NOS; HGBL, NOS; DHL- BCL2 and DHL- BCL6. Event-free survival (EFS) was defined as the time from diagnosis until progression/relapse, retreatment, or death. Overall survival (OS) was defined as the time from diagnosis until death due to any cause. Results: A total of 1526 eligible patients were identified during this time period. All FISH data was available at the time of diagnosis and the choice of treatment was based on physician discretion. Median age at diagnosis was 63 years (IQR 53-72), with 148 (10%) patients in the AYA category, and 128 (8%) patients > 80 years. 58% (891) were male, 11% self identified as Hispanic or Latino, and 7% as Black/African American. The median diagnosis to treatment interval (DTI) was 20 days (IQR 12-32), and 33% had DTI < 14 days. The FISH-based subgroups were MYC-negative DLBCL, NOS (N=1146, 75%), MYC-R DLBCL,NOS 227 (N = 96, 6%), DHL- BCL2 (N=154, 10%), DHL- BCL6 (N=38, 3%), and HGBL, NOS (N=92, 6%). When available, COO by Hans algorithm was 92% GCB in DHL- BCL2 and 50% GCB in DHL- BCL6. Clinical characteristics can be found in the table. At a median follow-up of 49 months (IQR 36-67), 490 patients (32%) had an event and 356 patients (23%) died. EFS at 24 months (EFS24) was 75% (95% CI: 73-77). Patients with DHL- BCL6 were younger at diagnosis (median 60 years), had more extranodal site involvement (40%), more often stage III/IV disease (70%), and more often treated with a higher intensity regimen than R-CHOP (69%) compared to DLBCL,NOS and MYC-R DLBCL. DHL- BCL6 also had fewer patients that were males (47%), with DTI <=14 days (33%), NCCN IPI ≥ 4 (45%), elevated LDH (53%) than HGBL, NOS and DHL- BCL2. The 2-year EFS and OS rates were noted to be significantly better in the DHL- BCL6 (EFS 79%, 95% CI: 67-93; OS 92%, 95% CI: 84-100) as compared to DHL- BCL2 (EFS 58%, 95% CI: 50-66; OS 70%, 95% CI 63 - 78) and HGBL, NOS (EFS 74%, 95% CI: 65-84; OS 74%, 95% CI: 65-84 ), (Figure 1) but were comparable to that of DLBCL, NOS (EFS 78%, 95% CI: 76-81; OS 87%, 95% CI: 86-89). Conclusions: Our data support separating DHL- BCL6 from DHL -BCL2 as these patients form a unique subgroup with some clinical characteristics comparable to both DLBCL, NOS as well as HGBL, NOS and DHL- BCL2 subtypes. In this cohort, clinical outcomes are more comparable to DLBCL, NOS than DHL- BCL2 or HGBCL, NOS. More frequent use of intensive chemotherapy in DHL- BCL6 compared with DLBCL may account for this finding, although larger multicenter studies are needed. Our results support continued identification of DHL- BCL6 in the clinical setting to better understand optimal therapy and biology of this cohort
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Real-World Impact of Differences in the World Health Organization (WHO) Classification and International Consensus Classification (ICC) Systems on the Diagnosis of Non-Hodgkin Lymphoma: An Analysis from the LEO Cohort Study
Introduction: The use of standardized, evidence-based classification systems is crucial for the accurate diagnosis and treatment of diseases. Moreover, standardized classification facilitates research and epidemiologic studies and promotes consistency in communication among healthcare professionals. Since 2016, the revised 4 th edition of the World Health Organization classification (WHO-HAEM4R) has been the global standard for diagnosis of lymphoid malignancies. With the emergence of new data, 2 new classification systems were developed and published in 2022: the 5 th edition of the WHO Classification (WHO-HAEM5) and the International Consensus Classification (ICC). Both WHO-HAEM5 and ICC maintain a shared fundamental concept of disease classification that integrates clinical, pathologic, and molecular data. However, they differ on nomenclature, establishment of new entities, and/or diagnostic criteria for some disease categories. To evaluate the impact of these differences on real-world diagnosis of non-Hodgkin lymphoma (NHL), we examined the diagnostic classification of NHL in the Lymphoma Epidemiology of Outcomes (LEO) Cohort Study (NCT02736357). Methods: Initiated in 2015, LEO is an ongoing prospective observational study of patients aged ≥18 years with newly diagnosed NHL. Patients are enrolled at 8 major U.S. medical centers. Clinical, epidemiologic, pathologic, and treatment data are abstracted at baseline and active follow-up is conducted for all patients. Lymphoma subtype is coded for each case based on expert hematopathology re-review of the diagnostic pathology slides, the pathology report, biomarker data, and clinical data. Of note, NHL subtype distribution is similar to SEER data. We studied all patients enrolled in LEO between 7/1/2016 (the date LEO pathology review started using WHO-HAEM4R diagnostic codes) and 5/31/2020. WHO-HAEM4R diagnoses and additional clinicopathologic data, when relevant, were used to map cases into the corresponding WHO-HAEM5 and ICC diagnoses. Differences between WHO-HAEM5 and ICC were annotated for each case as: None - same disease entity; Minor - difference in nomenclature with similar diagnostic criteria; Major - difference in disease category and/or diagnostic criteria; or Unevaluable - insufficient data to assign WHO-HAEM5 and/or ICC diagnosis. Results: LEO enrolled 6143 patients during the study period. Of these, comparison between WHO-HAEM5 and ICC was evaluable in 5730 (93.3%). Unevaluable cases included those without a specific WHO-HAEM4R diagnosis at enrollment (N=384; e.g., patients with a low-grade B-cell lymphoma that could not be definitively sub-classified) and those with a specific WHO-HAEM4R diagnosis, but with insufficient clinicopathologic data to assign a specific WHO-HAEM5 and/or ICC diagnosis (N=29). Of the 5730 evaluable cases, 5376 (93.8%) showed no difference between WHO-HAEM5 and/or ICC diagnosis, 311 (5.4%) showed minor differences (nomenclature only), and 43 (0.8%) showed major differences (Table 1). The 43 major differences all involved B-cell NHLs; 20 (46.5%) were attributable to different approaches to classifying double-hit lymphomas, 21 (48.9%) to classification of splenic/leukemic B-cell lymphomas, and 2 (4.6%) to classification of B-cell lymphomas occurring at specific anatomic sites (Table 2). Conclusion: In a large, prospective lymphoma cohort reflecting real-world clinical practice at 8 major U.S. medical centers, major diagnostic differences in the classification of NHL using WHO-HAEM5 or ICC classification criteria were seen in 0.8%, whereas the remaining 99.2% of diagnoses were either the same or showed differences in nomenclature only. The existence of 2 concurrent classification systems presents potential for discrepancies in pathologic diagnosis, clinical practice, clinical trials, and other lymphoma research. Furthermore, some of the differences between WHO-HAEM5 and ICC are clinically and potentially therapeutically significant, and their resolution requires further study. Nevertheless, our findings argue that the proportion of patients affected would be small in real-world practice settings. This appears largely related to incidence rates of specific lymphoma subtypes, with major differences between the 2 classifications predominantly affecting rare entities, while there is general concordance on the most common forms of NHL