scholarly journals RBIO-03. HETEROGENEITY OF HUMAN PATIENT-DERIVED XENOGRAFTS GROWTH RATES RESPONSES TO THE RADIATED MICROENVIRONMENT

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii192-ii192
Author(s):  
Jibo zhang ◽  
Ian E Olson ◽  
Lucas P Carlstrom ◽  
Masum Rahman ◽  
Karishma Rajani ◽  
...  
Keyword(s):  
Cell Lines ◽  
First Line ◽  
Rank Tests ◽  
Human Patient ◽  
Total N ◽  
Paradoxical Response ◽  
Rate Of Growth ◽  
Divergent Behavior ◽  
Human Gbm ◽  
Molecular Phenotypes

Abstract BACKGROUND Radiotherapy, combined with surgical resection and chemotherapy, remains a first-line treatment for infiltrative gliomas. However, these tumors are not surgically curable, and often recur, even within the prior radiation field, and may demonstrate a more aggressive phenotype. Importantly, high grade gliomas display diverse molecular phenotypes, and whether this genetic variability leads to divergent behaviour in the radiated tumor microenvironment is unknown. Herein, we characterize the effects of the irradiated brain microenvinroment on nine additional unique GBM cell lines to better understand the nuances of how tumor molecular phenotypes influence cellular dynamics. METHODS Female athymic nude mice were randomly divided into cranial radiation (15 Gy) and non-radiated groups. Mice then underwent intracranial implantation with one of the selected patient-derived xenograft (PDX) GBM cell lines (GBM 6, 10, 12, 39, 46, 76, 123, 164, 196; total n=8-15, per group, per line). Kaplan-Meyer (K-M) and log-rank tests were performed to compare the survival between irradiated and non-irradiated groups. RESULT Of nine previously untested human GBM lines, we found that five demonstrated shorter survival in the pre-radiated brain (GBM 6, 46, 76, 164, 196). However, two lines yielded prolonged survival in the pre-radiated brain (GBM 10, 12); GBM 39, 123 whose rate of growth was not impacted by the radiated brain. CONCLUSION These results highlight the likely critical impact of the irradiated microenvironment on tumor behaviour, yet illustrate that different tumors may exhibit opposing responses. Although further evaluation will be needed to understand mechanisms of divergent behavior, our data suggest the increased rate of growth in the radiated microenvironment may not apply to the fastest-growing tumor lines, which could instead demonstrate a paradoxical response.

scholarly journals Impact of the radiated brain microenvironment on a panel of human patient-derived xenografts

2020 ◽  
Author(s):  
Jibo Zhang ◽  
Ian E. Olson ◽  
Lucas P. Carlstrom ◽  
Masum Rahman ◽  
Karishma Rajani ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Cell Lines ◽  
Human Patient ◽  
Total N ◽  
Paradoxical Response ◽  
Rate Of Growth ◽  
Divergent Behavior ◽  
Human Gbm ◽  
Molecular Phenotypes ◽  
Fractionated Radiation

AbstractObjectiveRadiotherapy, combined with surgical resection and chemotherapy, remains a first-line treatment for infiltrative gliomas. However, these tumor are not surgically curable, and often recur, even within the prior radiation field, and may demonstrate a more aggressive phenotype. We recently demonstrated that the radiated brain tumor microenvironment promotes tumor aggressiveness in an orthotopic patient-derived xenograft (PDX) model of glioblastoma (Mayo GBM 143). Importantly, high grade gliomas display diverse molecular phenotypes, and whether this genetic variability leads to divergent behaviour in the radiated tumor microenvironment is unknown. Herein, we characterize the effects of the irradiated brain microenvinroment on nine additional unique GBM cell lines to better understand the nuances of how tumor molecular phenotypes influence cellular dynamics.MethodsFemale athymic nude mice were randomly divided into cranial radiation (15 Gy) and non-radiated groups. Mice then underwent intracranial implantation with one of the selected PDX GBM cell lines (GBM 6, 10, 12, 39, 46, 76, 123, 164, 196; total n=8-15, per group, per line). GBM 6 cells were additionally implanted 6 months after completion of fractionated radiation (4Gy × 10 fractions or 2Gy × 30 fractions) vs sham radiation. Kaplan-Meyer (K-M) and log-rank tests were performed to compare the survival between irradiated and non-irradiated groups.ResultOf nine previously untested human GBM lines, we found that five demonstrated shorter survival in the pre-radiated brain (GBM 6, 46, 76, 164, 196); similar to previous observations with GBM 143. GBM 6 was also evaluated 6 months after fractionated radiation yielding similar results. However, two lines yielded prolonged survival in the pre-radiated brain (GBM 10, 12); GBM12 and 10 demonstrated the fastest baseline growth in the non-radiated brain; GBM 39, 123 whose rate of growth was not impacted by the radiated brain, demonstrated a an intermediate baseline growth rate between that of those positively and negatively impacted by the radiated brain microenvironment. No other clinical or molecular phenotype was found to consistently correlate with response to the radiated microenvironment.ConclusionAmong a total of 10 total human GBM lines evaluated to date, 60% induce faster mortality in a radiated microenvironment, and 20% induce slower mortality. These results highlight the likely critical impact of the irradiated microenvironment on tumor behaviour, yet illustrate that different tumors may exhibit opposing responses. Although further evaluation will be needed to understand mechanisms of divergent behavior, our data suggest the increased rate of growth in the radiated microenvironment may not apply to the fastest-growing tumor lines, which could instead demonstrate a paradoxical response.

scholarly journals A Set of Cell Lines Derived from a Genetic Murine Glioblastoma Model Recapitulates Molecular and Morphological Characteristics of Human Tumors

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 230
Author(s):  
Barbara Costa ◽  
Michael N.C. Fletcher ◽  
Pavle Boskovic ◽  
Ekaterina L. Ivanova ◽  
Tanja Eisemann ◽  
...  
Keyword(s):  
Cell Lines ◽  
Immune Cell ◽  
Treatment Options ◽  
Morphological Characteristics ◽  
Molecular Heterogeneity ◽  
Double Knockout ◽  
In Vivo Models ◽  
Human Glioblastoma ◽  
Human Gbm

Glioblastomas (GBM) are the most aggressive tumors affecting the central nervous system in adults, causing death within, on average, 15 months after diagnosis. Immunocompetent in-vivo models that closely mirror human GBM are urgently needed for deciphering glioma biology and for the development of effective treatment options. The murine GBM cell lines currently available for engraftment in immunocompetent mice are not only exiguous but also inadequate in representing prominent characteristics of human GBM such as infiltrative behavior, necrotic areas, and pronounced tumor heterogeneity. Therefore, we generated a set of glioblastoma cell lines by repeated in vivo passaging of cells isolated from a neural stem cell-specific Pten/p53 double-knockout genetic mouse brain tumor model. Transcriptome and genome analyses of the cell lines revealed molecular heterogeneity comparable to that observed in human glioblastoma. Upon orthotopic transplantation into syngeneic hosts, they formed high-grade gliomas that faithfully recapitulated the histopathological features, invasiveness and immune cell infiltration characteristic of human glioblastoma. These features make our cell lines unique and useful tools to study multiple aspects of glioblastoma pathomechanism and to test novel treatments in an intact immune microenvironment.

scholarly journals Ruxolitinib Combined with Gemcitabine against Cholangiocarcinoma Growth via the JAK2/STAT1/3/ALDH1A3 Pathway

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 885
Author(s):  
Shin-Yi Chung ◽  
Yi-Ping Hung ◽  
Yi-Ru Pan ◽  
Yu-Chan Chang ◽  
Chiao-En Wu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Nuclear Translocation ◽  
Vital Role ◽  
First Line ◽  
Current Standard ◽  
Integrated Network ◽  
Jak2 Inhibitor ◽  
Therapeutic Drugs ◽  
Cholangiocarcinoma Cell ◽  
Malignant Behavior

Cholangiocarcinoma is the most common primary malignant tumor of the bile duct. The current standard first-line treatment for advanced or metastatic cholangiocarcinoma is gemcitabine and cisplatin. However, few effective treatment choices exist for refractory cholangiocarcinoma, and additional therapeutic drugs are urgently required. Our previous work demonstrated that the ALDH isoform 1A3 plays a vital role in the malignant behavior of cholangiocarcinoma and may serve as a new therapeutic target. In this study, we found a positive correlation between ALDH1A3 protein expression levels and the cell migration abilities of three cholangiocarcinoma cell lines, which was verified using ALDH1A3-overexpressing and ALDH1A3-knockdown clones. We also used ALDH1A3-high and ALDH1A3-low populations of cholangiocarcinoma cell lines from the library of integrated network-based cellular signatures (LINCS) program and assessed the effects of ruxolitinib, a commercially available JAK2 inhibitor. Ruxolitinib had a higher cytotoxic effect when combined with gemcitabine. Furthermore, the nuclear translocation STAT1 and STAT3 heterodimers were markedly diminished by ruxolitinib treatment, possibly resulting in decreased ALDH1A3 activation. Notably, ruxolitinib alone or combined with gemcitabine led to significantly reduced tumor size and weight. Collectively, our studies suggest that ruxolitinib might suppress the ALDH1A3 activation through the JAK2/STAT1/3 pathway in cholangiocarcinoma, and trials should be undertaken to evaluate its efficacy in clinical therapy.

scholarly journals BCL2 Expression Correlates with Refractory and Relapsed Classic Hodgkin Lymphoma. Its Blokeadge As a Promising Directed-Therapy

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5282-5282
Author(s):  
Angelica Gamboa-Cedeño ◽  
Cristaldo Nancy ◽  
Victoria Otero ◽  
Natalia Paola Schutz ◽  
Dorotea Fantl ◽  
...  
Keyword(s):  
Hodgkin Lymphoma ◽  
Cell Lines ◽  
Target Gene ◽  
Rank Test ◽  
First Line ◽  
Log Rank Test ◽  
Classic Hodgkin Lymphoma ◽  
Nfkb Pathway ◽  
Relapsed Disease ◽  
Bcl2 Expression

Classic Hodgkin Lymphoma (cHL) is a germinal center derived lymphoma with 8,500-9,000 new cases/year diagnosed in the US. Despite 90% stage I cHL patients can respond to current systemic therapy, this drops to 60%, when diagnosed in advanced stages. Furthermore, 20-30% of diagnosed patients, would be refractory or would relapse and have a poor prognosis. Refractory and relapsed disease (RRD) is currently the challenge when treating cHL patients. There is no specific therapy to offer rather than rescue chemotherapy schemes, which fails in 50% of the cases and associates with high risk severe toxicity. This highlights the need to deeper understand the cHL molecular biology, the screening for molecular markers suitable to identify the risk of refractory and relapse disease and specific therapeutic directed-targets. We have previously reported that the alternative NFkB pathway, mediated by Rel-B and NIK (NFkB Inducing Kinase), plays an important role in cHL survival. Its constitutive activation sustains high BCL2 expression levels and seems to be involved in the RRD. BCL2 was found as a specific Rel-B target gene in cHL cells by ChIP-Seq (Chromatin Immunoprecipitation sequencing) and expression arrays. BCL2 exogenous expression was enough to partially rescue the death induce in cHL cells, which highlight the relevance of this alternative NFkB pathway target gene. Since the BCL2 data was obtained in human cHL cell lines established from patients with refractory and relapsed disease, we decided to analyze whether mediators of this pathway and BCL2 could be useful as prognosis markers and would represent potential targetable factors in both refractory and relapsed disease. We analyzed NIK and BCL2 citoplasm expression in Hodgkin Reed-Sternberg cells (HRS) in the lymph node biopsies of 113 cHL naïve of therapy patients by inmunohistochemistry [52 female Md age and (range) 36 (6-88), 61 male 40.7 (9-78)]. The follow-up period range from 6 to 136 months. The univariate analysis showed no correlation between NIK or BCL2 expression and the prognosis clinical and pathological parameters, including the PET Scan indicated at the end of the first line treatment, neither the molecular markers routinely assayed. The statistical significance was maintained in multivariate analysis (Logistic and Cox Regression p=0.01). NIK expression did not associate with prognosis but the BCL2 expression level correlated with lack of response to conventional therapy and both early and late disease progression. The survival analysis, using the Kaplan-Meir curves, showed that patients with ≥60% positive HRS cells had a shorter disease-free survival (DFS) [Log Rank Test (Mantel Cox) p=0.002] and a reduced overall survival (OS) [Log Rank Test (Mantel Cox) p=0.02]. L1236, U-H01, KM-H2, SUPDH1 and L540, human cHL cell lines that express BCL2 protein, were sensitive to venetoclax, a specific BCL2 inhibitor. The drug induced a cell cycle arrest in S-Phase when treated with 1uM each 24 hours during 10 days, as compared to wild type cells and cells treated with the vehicle. In summary, we found that the alternative NFkB pathway plays a role in the refractory and relapsed classic Hodgkin Lymphoma disease, being BCL2 one of its key downstream target genes. BCL2 can be used as a prognosis marker determined by routine immunohistochemistry at diagnosis of the primary disease. BCL2 expression correlated with refractory disease to first line conventional therapy and disease progression. Based on the venetoclax effect in cHL cell lines we believe BCL2 directed-therapy in cHL should be considered in the subgroup of cHL patients that express this protein in ≥60% HRS cells in the lymph node biopsy performed at diagnosis. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: venetoclax used to specifically block BCL2.

IMMU-12. TUMOR CELL IDO ENHANCES IMMUNE SUPPRESSION AND DECREASES SURVIVAL INDEPENDENT OF TRYPTOPHAN METABOLISM IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi94-vi94
Author(s):  
Lijie Zhai ◽  
April Bell ◽  
Erik Ladomersky ◽  
Kristen Lauing ◽  
Lakshmi Bollu ◽  
...  
Keyword(s):  
Overall Survival ◽  
T Cells ◽  
Regulatory T Cells ◽  
Cell Lines ◽  
Factor H ◽  
Lower Grade ◽  
Complement Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Human Gbm

Abstract OBJECTIVE Indoleamine 2,3-dioxygenase 1 (IDO; IDO1) is an immune checkpoint that’s characterized as a potent immunosuppressive mediator through its ability to metabolize tryptophan and wild-type IDH patient-resected glioblastoma (GBM) expresses IDO in ≥ 95% of cases. Recent findings from our group led us to investigate the alternative hypothesis that IDO possesses immunosuppressive effects that are independent of its associated metabolic activity. METHODS Murine GBM cell lines that overexpress either wild-type or enzyme-null IDO were created for in vivo characterization of IDO enzyme-independent immunosuppressive function. Microarray was conducted to identify human IDO expression-correlated genes, which were further investigated in human GBM cell lines, patient GBM tissues and plasma, as well as the TCGA database. Ex vivo cell co-culture assays and syngeneic mouse orthotopic GBM models were employed to study immunosuppressive mechanisms. RESULTS Here, we demonstrate that non-enzymic IDO activity decreases survival in experimental animals and increases the expression of immunosuppressive complement factor H (CFH) in human GBM. CFH mRNA levels positively correlate with those of IDO and many other immunosuppressive genes in patient resected GBM and can be applied as a prognostic marker in both lower grade gliomas and GBM. Similar to IDO, the increased expression of CFH in patient-resected glioma was positively correlated with an increased signature for regulatory T cells (Tregs) and myeloid-derived suppressive cells (MDSCs). High expression of CFH in tumor cells increases intratumoral Tregs levels and decreases overall survival in mice with GBM, while inducing tumor associated macrophage cell differentiation. CONCLUSIONS Here, we demonstrated that glioblastoma (GBM) cell IDO promotes the accumulation of intratumoral FoxP3+ regulatory T cells (Tregs) and tumor progression while decreasing overall survival - independent of IDO enzyme activity. Our study reveals a targetable non-metabolic IDO-dependent mechanism for future therapeutic intervention in patients with GBM.

Phase II study of pembrolizumab-based therapy in previously treated extrapulmonary poorly differentiated neuroendocrine carcinomas: Results of Part B (pembrolizumab + chemotherapy).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 4148-4148
Author(s):  
Jennifer A. Chan ◽  
Nitya Prabhakar Raj ◽  
Rahul Raj Aggarwal ◽  
Susan Calabrese ◽  
April DeMore ◽  
...  
Keyword(s):  
Objective Response ◽  
Progression Free Survival ◽  
Large Cell ◽  
Small Cell ◽  
Type I ◽  
First Line ◽  
Open Label ◽  
Total N ◽  
Poorly Differentiated ◽  
Neuroendocrine Carcinomas

4148 Background: The efficacy of immune checkpoint inhibitor (CPI) therapy has not been established in extrapulmonary poorly differentiated neuroendocrine carcinomas (EP-PDNECs). In small cell lung cancer, CPI therapy is approved for use in the first-line and salvage settings. We investigated the efficacy and safety of pembrolizumab (PEM)-based therapy in biomarker-unselected patients (pts) with EP-PDNECs. PEM alone (Part A, N=14) was inactive (ASCO GI 2019; Abstr#363). We now report the results of Part B (PEM plus chemotherapy). Methods: We conducted an open label, multicenter, phase 2 study of PEM-based therapy in pts with EP-PDNECs, excluding Merkel cell carcinoma and well differentiated grade 3 neuroendocrine tumors (NET), with disease progression on first-line systemic therapy. In Part B of this trial, patients were treated with PEM 200 mg IV every 3 week cycle plus dealers’ choice chemotherapy (chemo): weekly irinotecan (IRI, 125 mg/m2 day 1,8 of every 21 day cycle) or weekly paclitaxel (PAC, 80 mg/m2). After PEM/IRI safety lead-in (N=6), 16 additional pts (total N=22) were enrolled. This was based on a primary endpoint of objective response rate (ORR) by RECIST 1.1 and a plan to test Ha ORR 31% vs H0 ORR 10% with 80% power at a type I error rate of 0.05. Secondary endpoints include safety, overall survival (OS), and progression-free survival (PFS). Serial blood samples and baseline tumor biopsies were required in all pts. Results: Preliminary data from Part B are available. Of 22 pts enrolled, male/female 15/7; median age 57 years (range 34-75); ECOG PS 0/1: 10/12; 6 large cell, 8 small cell, 8 NOS. Primary sites of disease: GI 73%, GYN 5%, unknown 23%. Ki67 index (available for 18 pts) median 68% (range 30 to >95%). Chemo choice: 17 IRI (77%) and 5 PAC (23%). PEM/IRI was safe based on lead-in. Median number of cycles of therapy administered was 3 (range 0-13). Treatment-related Gr 3 or 4 AE occurred in 7 (32%) of 22 pts overall: 4 (18%) had at least one Gr 3 AE attributed to PEM (1 pt each with pain, ALT increase, or nausea; 2 with fatigue); 7 (32%) had at least one Gr 3/4 AE attributed to chemo (2 with fatigue, 2 with neutropenia; 1 each with pain, ALT increase, hyponatremia, diarrhea, nausea, and/or acute kidney injury). No grade 5 AE. ORR was 9%: PR in 2 pts (9%), SD 3 pts (14%), PD 13 pts (60%); 4 pts (18%) unevaluable (off study before first scheduled scan). Median PFS 2 mo. At last follow-up, 5 pts (23%) were alive with 1 pt still on treatment. Median OS 4 mo. Of 21 pts off treatment, 76% off for PD, 10% off for AE, 14% off for withdrawal of consent/other therapy. Conclusions: PEM + chemotherapy was not effective in this pretreated, biomarker-unselected population of EP-PDNECs arising in different organs. Biomarker studies are planned (Parts A/B). Clinical trial information: NCT03136055.

scholarly journals The Expression of the Chemokine CXCL14 Correlates with Several Aggressive Aspects of Glioblastoma and Promotes Key Properties of Glioblastoma Cells

2019 ◽  
Vol 20 (10) ◽  
pp. 2496 ◽  
Author(s):  
Barbara Fazi ◽  
Carla Proserpio ◽  
Silvia Galardi ◽  
Francesca Annesi ◽  
Mattia Cola ◽  
...  
Keyword(s):  
Cell Lines ◽  
Leading Edge ◽  
Primary Brain Tumor ◽  
Migration Ability ◽  
Tumor Onset ◽  
Stromal Microenvironment ◽  
Cxcr4 Receptor ◽  
Human Gbm ◽  
Tumor Growth And Invasion

Glioblastoma (GBM) is a primary brain tumor whose prognosis is inevitably dismal, leading patients to death in about 15 months from diagnosis. Tumor cells in the mass of the neoplasm are in continuous exchange with cells of the stromal microenvironment, through the production of soluble molecules, among which chemokines play prominent roles. CXCL14 is a chemokine with a pro-tumor role in breast and prostate carcinoma, where it is secreted by cancer associated fibroblasts, and contributes to tumor growth and invasion. We previously observed that CXCL14 expression is higher in GBM tissues than in healthy white matter. Here, we study the effects of exogenously supplemented CXCL14 on key tumorigenic properties of human GBM cell lines. We show that CXCL14 enhances the migration ability and the proliferation of U87MG and LN229 GBM cell lines. None of these effects was affected by the use of AMD3100, an inhibitor of CXCR4 receptor, suggesting that the observed CXCL14 effects are not mediated by this receptor. We also provide evidence that CXCL14 enhances the sphere-forming ability of glioblastoma stem cells, considered the initiating cells, and is responsible for tumor onset, growth and recurrence. In support of our in vitro results, we present data from several GBM expression datasets, demonstrating that CXCL14 expression is inversely correlated with overall survival, that it is enriched at the leading edge of the tumors and in infiltrating tumor areas, and it characterizes mesenchymal and NON G-CIMP tumors, known to have a particularly bad prognosis. Overall, our results point to CXCL14 as a protumorigenic chemokine in GBM.

scholarly journals Patients With Proneural Glioblastoma May Derive Overall Survival Benefit From the Addition of Bevacizumab to First-Line Radiotherapy and Temozolomide: Retrospective Analysis of the AVAglio Trial

2015 ◽  
Vol 33 (25) ◽  
pp. 2735-2744 ◽  
Author(s):  
Thomas Sandmann ◽  
Richard Bourgon ◽  
Josep Garcia ◽  
Congfen Li ◽  
Timothy Cloughesy ◽  
...  
Keyword(s):  
Overall Survival ◽  
Retrospective Analysis ◽  
Molecular Subtype ◽  
Multivariable Analysis ◽  
Phase Iii ◽  
Wild Type ◽  
First Line ◽  
Data Set ◽  
Total N ◽  
Biomarker Analysis

Purpose The AVAglio (Avastin in Glioblastoma) and RTOG-0825 randomized, placebo-controlled phase III trials in newly diagnosed glioblastoma reported prolonged progression-free survival (PFS), but not overall survival (OS), with the addition of bevacizumab to radiotherapy plus temozolomide. To establish whether certain patient subgroups derived an OS benefit from the addition of bevacizumab to first-line standard-of-care therapy, AVAglio patients were retrospectively evaluated for molecular subtype, and bevacizumab efficacy was assessed for each patient subgroup. Patients and Methods A total of 349 pretreatment specimens (bevacizumab arm, n = 171; placebo arm, n = 178) from AVAglio patients (total, N = 921) were available for biomarker analysis. Samples were profiled for gene expression and isocitrate dehydrogenase 1 (IDH1) mutation status and classified into previously identified molecular subtypes. PFS and OS were assessed within each subtype. Results A multivariable analysis accounting for prognostic covariates revealed that bevacizumab conferred a significant OS advantage versus placebo for patients with proneural IDH1 wild-type tumors (17.1 v 12.8 months, respectively; hazard ratio, 0.43; 95% CI, 0.26 to 0.73; P = .002). This analysis also revealed an interaction between the proneural subtype biomarker and treatment arm (P = .023). The group of patients with mesenchymal and proneural tumors derived a PFS benefit from bevacizumab compared with placebo; however, this translated to an OS benefit in the proneural subset only. Conclusion Retrospective analysis of AVAglio data suggests that patients with IDH1 wild-type proneural glioblastoma may derive an OS benefit from first-line bevacizumab treatment. The predictive value of the proneural subtype observed in AVAglio should be validated in an independent data set.

Aberrant Somatic Hypermutation Targets an Extensive Set of Genes in Diffuse Large B-Cell Lymphoma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1528-1528 ◽  
Author(s):  
Laura Pasqualucci ◽  
Roberta Guglielmino ◽  
Sami N. Malek ◽  
Urban Novak ◽  
Mara Compagno ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Somatic Hypermutation ◽  
B Cell Lymphoma ◽  
Chromosomal Translocations ◽  
Total N ◽  
Large B Cell Lymphoma ◽  
Large B Cell

Abstract Genomic instability is a driving force in tumor development that can be achieved by a variety of mechanisms, such as defective chromosome segregation or inactivation of the DNA mismatch repair pathway. Although B-cell lymphomas are associated with chromosomal translocations deregulating oncogene expression, a mechanism for genome-wide instability during lymphomagenesis has long not been described. We have reported that the somatic hypermutation process (SHM), which normally targets the immunoglobulin variable region (IgV) and BCL6 genes in germinal center (GC) B-cells, functions aberrantly in >50% of diffuse large B-cell lymphoma (DLBCL), the most common type of B-cell non-Hodgkin lymphoma (Pasqualucci et al., Nature412:341, 2001). As a consequence, multiple somatic mutations are introduced into the 5′ region of genes that do not represent physiologic SHM targets, including known proto-oncogenes such as PIM1, PAX5, RhoH/TTF and cMYC. To further define the extent of this phenomenon, termed aberrant somatic hypermutation (ASHM), and to identify additional hypermutated loci of possible pathogenetic significance in DLBCL, we screened 113 genes for the presence of mutations affecting their 5′ sequences (≥1.3 Kb from the transcription start site, the target region for SHM) in 10 DLBCL cell lines. Fifteen genes (13.3%) were found to harbor a significant number of mutations (p<0.05), with 70% of the cell lines being mutated in 7 or more genes; among these, six B-cell specific loci -BCL7A, CIITA, IRF4, LRMP, NCOA3 and SIAT1- carried 9–53 mutational events distributed in 20 to 70% of the cases, corresponding to an overall mutation frequency of 0.032–0.15% (frequency in the mutated cases: 0.07–0.25%). The same genes were found hypermutated in a panel of 20 primary DLBCL biopsies, which displayed an overall mutation load of 7 to 45 distinct events/gene (total N=125). Mutations were of somatic origin, independent of chromosomal translocations to the Ig loci and were restricted to the first 1.5–2 Kb from the promoter. In addition, analogous to previously identified SHM and ASHM targets, the mutations exhibited characteristic features, including a bias for transitions over transversions, preferential hotspot (RGYW/WRCY motifs) targeting, and higher frequencies at G:C pairs. However, in contrast to physiologic SHM targets such as IgV and BCL6, none of the 4 newly identified hypermutated genes that have been analyzed so far (BCL7A, CIITA, SIAT1, LRMP) displayed significant levels of mutations in purified normal GC B-cells as well as in other B-cell malignancies. This finding indicates that these genes represent aberrant hypermutation targets resulting from a tumor-associated malfunction, possibly a loss of target specificity of the physiologic SHM process. Considering previous results and the present survey, 17 (13%) out of 130 genes investigated have been found involved in ASHM, suggesting that this aberrant activity may involve an extensive set of target genes in DLBCL. Since the mutations affect both regulatory and coding sequences of the targeted genes, aberrant SHM may represent a major contributor to the pathogenesis of this disease and may explain in part its phenotypic and clinical heterogeneity.

Everolimus (E) plus bevacizumab (B) is effective first-line treatment for patients (pts) with advanced renal cell carcinoma (RCC) with papillary features (PF): Results from a phase II trial.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 627-627 ◽  
Author(s):  
Darren R. Feldman ◽  
Chung-Han Lee ◽  
Ana M. Molina ◽  
Andrea Knezevic ◽  
Yingbei Chen ◽  
...  
Keyword(s):  
Phase Ii ◽  
Phase Ii Trial ◽  
Objective Response ◽  
Significant Activity ◽  
Line Treatment ◽  
First Line ◽  
Total N ◽  
Papillary Rcc ◽  
Expansion Cohort ◽  
First Line Treatment

627 Background: We previously reported on a phase II trial of E+B across various non-clear cell RCC histologies and observed significant activity among pts with papillary or unclassified RCC ( uRCC ) with PF (objective response rate [ORR] 39%, median progression-free survival [PFS] 12.9 months [m]; Voss, JCO, 2016). An expansion cohort limited to these two histologies was conducted to confirm the efficacy of E+B. Methods: E + B was administered at standard doses until progressive disease (PD) or intolerance to therapy. The current analysis included 19 pts with pRCC or uRCC with PF in the initial cohort and 20 pts in the expansion cohort (total n=39). The primary endpoint was 6 month PFS with secondary endpoints of ORR, median PFS, and overall survival (OS). Correlative analyses included next generation sequencing (NGS) from tumor and germline across >341 genes of interest. Results: Of 39 pts, 24 had uRCC with PF, 14 had papillary RCC, and 1 had translocation RCC with PF. Among 37 evaluable pts, the ORR was 35%; 43% for uRCC with PF and 23% for papillary RCC. Six-month PFS for all 39 pts was 78%; 82% for uRCC with PF and 68% for papillary RCC. Median PFS was 13.7m; 13.7m for uRCC with PF and 8.4m for papillary RCC (Table). With median followup of 17.6m, median OS is 33.9m. Toxicity with E+B was similar to previous reports. 33 of 39 pts had NGS performed and partial responses were observed across a wide spectrum of genomic alterations, including several recurrently seen in papillary RCC variants such as mutations in FH, MET, NF2, and ARID1a. Conclusions: The expansion cohort confirms the activity of E+B for pts with advanced papillary RCC or uRCC with PF with superior ORR, PFS, and OS compared to historical results with sunitinib for these histologies. E+B represents a new standard first-line treatment option for these pts. Clinical trial information: NCT01399918. [Table: see text]

Sign in / Sign up

Export Citation Format

Share Document