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175 citation(s) found for "Doǧan, Ahmet".

Elevated serum IL-10 levels in diffuse large B-cell lymphoma: a mechanism of aberrant JAK2 activation
Han, Jing , Stenson, Mary, Maurer, Matthew J. , Wellik, Linda, Hu, Guangzhen , Ziesmer, Steve, Gupta, Mamta , Doǧan, Ahmet , Witzig, Thomas E. , Maurer, Matthew

Mayo Clinic

Blood | February 9, 2012 | Volume: 119 | Issue: 12 | Pages: 2844-2853

10.1182/blood-2011-10-388538 | PMID 22323454 Get It

AbstractCytokines are deregulated in cancers and can contribute to tumor growth. In patients with diffuse large-cell lymphoma (DLBCL), we observed higher levels of JAK/STAT pathway-related serum cytokines (ie, IL-6, IL-10, epidermal growth factor, and IL-2) compared with controls. Of these, only IL-10 activated the JAK2 pathway in lymphoma cells in vitro. Patients with high serum IL-10 had shorter event-free survival (EFS) than patients with low levels (P > .01) and high IL-10 was correlated with high lactase dehydrogenase (P = .0085) and higher International Prognostic Index scores (P = .01). To explore the mechanism by which IL-10 may contribute to an inferior EFS, we investigated the effect of IL-10 on the JAK2 pathway and found that the IL-10/IL-10 receptor complex up-regulated JAK2 signaling. Neutralizing Ab to IL-10 inhibited constitutive and IL-10–induced JAK2/STAT3 phosphorylation. JAK2 inhibition dephosphorylated JAK2 and STAT3 and caused an inhibitory effect on phospho-JAK2–positive DLBCL cells; there was a minimal effect on phospho-JAK2–negative cells. Apoptosis induced by JAK2 inhibition was dependent on inhibition of autocrine IL-10 and c-myc expression and independent of Bcl-2 family expression. These results provide the rationale for testing JAK2 inhibitors in DLBCL patients, and indicate that serum IL-10 may be a biomarker to identify patients more likely to respond to JAK2-targeted therapy.
LIM domain only 2 protein expression,LMO2germline genetic variation, and overall survival in diffuse large B-cell lymphoma in the pre-rituximab era
Cerhan, James R. , Morton, Lindsay M. , Maurer, Matthew J. , Asmann, Yan W. , Vasef, Mohammad A., Lynch, Charles F. , Allmer, Cristine, Lossos, Izidore S. , Rothman, Nathaniel , Hartge, Patricia, Wang, Sophia , Natkunam, Yasodha , Habermann, Thomas M. , Cozen, Wendy , Slager, Susan L. , Chanock, Stephen Jacob , Doǧan, Ahmet , Maurer, Matthew , Cerhan, James R , Morton, Lindsay M , Wang, Sophia S

Mayo Clinic

Leukemia & Lymphoma | November 9, 2011 | Volume: 53 | Issue: 6 | Pages: 1105-1112

10.3109/10428194.2011.638717 | PMID 22066713 Get It

Plasma Cell Myeloma and Related Neoplasms
Lorsbach, Robert B., Hsi, Eric D. , Doǧan, Ahmet , Fend, Falko

Mayo Clinic

American Journal of Clinical Pathology | July 14, 2011 | Volume: 136 | Issue: 2 | Pages: 168-182

10.1309/ajcpenj68ffbriyb | PMID 21757591 Get It

Abstract Session 1 of the 2009 Workshop of the Society for Hematopathology/European Association of Haematopathology, Cleveland, OH, focused on plasma cell neoplasms. This report summarizes the salient diagnostic, clinical, and genetic features of plasma cell myeloma (PCM) and related neoplasms. Based on the cases submitted to the workshop, we highlight common diagnostic issues and unusual manifestations of plasma cell neoplasms, such as t(11;14)+ PCM, plasma cell leukemia, and nonsecretory plasmacytoma, as well as plasmablastic transformation of PCM. Additional issues repeatedly raised at the workshop included the differential diagnosis of extramedullary dissemination of PCM vs primary extramedullary plasmacytoma and plasmablastic lymphoma; systemic plasma cell neoplasms in immunocompromised people; and Epstein-Barr virus–associated plasma cell neoplasms. Difficult cases with borderline features presented by submitters emphasized the necessity of integrating clinical, immunophenotypic, and genetic features for appropriate classification of these disorders.
Primary Central Nervous System Lymphomas: A Validation Study of Array-Based Comparative Genomic Hybridization in Formalin-Fixed Paraffin-Embedded Tumor Specimens
Braggio, Esteban , McPhail, Ellen Remstein, Macon, William R. , Lopes, M. Beatriz S. , Schiff, David , Fink, Stephanie, Sprau, Debra, Fonseca, Rafaël , McPhail, Ellen D. , McPhail, Ellen Remstein, Law, Mark E. , Giannini, Caterina , Doǧan, Ahmet , O’Neill, Brian Patrick , McPhail, Ellen Darcy , Braggio, Esteban , Fonseca, Rafael

Mayo Clinic

Clinical Cancer Research | May 12, 2011 | Volume: 17 | Issue: 13 | Pages: 4245-4253

10.1158/1078-0432.ccr-11-0395 | PMID 21562036 Get It

Abstract Purpose: Only a limited number of genetic studies have been conducted in primary central nervous system lymphomas (PCNSL), partly due to the rarity of the tumors and the very limited amount of available tissue. In this report, we present the first molecular characterization of copy number abnormalities (CNA) of newly diagnosed PCNSL by array-based comparative genomic hybridization (aCGH) in formalin-fixed paraffin-embedded (FFPE) specimens and compare the results with matched, frozen tumor specimens. Experimental Design: We conducted aCGH in FFPE tissues from PCNSL. Results were compared with matched, paired, frozen tumors. Results: Our analysis confirmed the good to fair quality and reliability of the data generated from limited amounts of tumoral FFPE tissue. Overall, all PCNSL cases were characterized by highly complex karyotypes, with a median of 23 CNAs per patient (range, 17–47). Overall, 20 chromosomal regions were recurrently found in more than 40% of cases. Deletions of 6p21, 6q, and 9p21.3 and gain of 12q12-q24.33 were the commonest CNAs. Other minimal affected regions were defined, and novel recurrent CNAs affecting single genes were identified in 3q26.32 (TBL1XR1) and 8q12.1 (TOX). Conclusions: The results obtained are encouraging. Larger archival tissue collections can now be analyzed to complement the still fragmented knowledge we have of the genetic basis of the PCNSL. Clin Cancer Res; 17(13); 4245–53. ©2011 AACR.
Germline Variation in Apoptosis Pathway Genes and Risk of Non–Hodgkin's Lymphoma
Kelly, Jennifer L., Novak, Anne J. , Fredericksen, Zachary S., Liebow, Mark , Ansell, Stephen M. , Wang, Alice H., Call, Timothy G. , Cerhan, James R. , Doǧan, Ahmet , Witzig, Thomas E. , Kay, Neil E. , Habermann, Thomas M. , Slager, Susan L. , Cerhan, James R

Mayo Clinic

Cancer Epidemiology, Biomarkers & Prevention | November 8, 2010 | Volume: 19 | Issue: 11 | Pages: 2847-2858

10.1158/1055-9965.epi-10-0581 | PMID 20855536 Get It

Abstract Background: The t(14;18)(q32;q21) translocation is the most commonly observed chromosomal translocation in non–Hodgkin's lymphoma (NHL), resulting in constitutive Bcl-2 expression and apoptosis inhibition. In addition, germline variation in both BCL2L11 (BIM) and CASP9, known regulators of apoptosis, has recently been linked to NHL risk. We conducted a comprehensive evaluation of 36 apoptosis pathway genes with risk of NHL. Methods: We genotyped 226 single-nucleotide polymorphisms (SNP) from 36 candidate genes in a clinic-based study of 441 newly diagnosed NHL cases and 475 frequency-matched controls. We used principal components analysis to assess gene-level associations, and logistic regression to assess SNP-level associations. MACH was used for imputation of SNPs in BCL2L11 and CASP9. Results: In gene-level analyses, BCL2L11 (P = 0.0019), BCLAF1 (P = 0.0097), BAG5 (P = 0.026), and CASP9 (P = 0.0022) were associated with NHL risk after accounting for multiple testing (tail strength, 0.38; 95% confidence interval, 0.05-0.70). Two of the five BCL2L11 tagSNPs (rs6746608 and rs12613243), both genotyped BCLAF1 tagSNPs (rs797558 and rs703193), the single genotyped BAG5 tagSNP (rs7693), and three of the seven genotyped CASP9 tagSNPs (rs6685648, rs2020902, and rs2042370) were significant at P < 0.05. We successfully imputed BCL2L11 and CASP9 SNPs previously linked to NHL, and replicated all four BCL2L11 and two of three CASP9 SNPs. Conclusion: We replicated the association of BCL2L11 and CASP9 with NHL risk at the gene and SNP level, and identified novel associations with BCLAF1 and BAG5. Impact: Closer evaluation of germline variation of genes in the apoptosis pathway with risk of NHL and its subtypes is warranted. Cancer Epidemiol Biomarkers Prev; 19(11); 2847–58. ©2010 AACR.
Discovery of recurrent t(6;7)(p25.3;q32.3) translocations in ALK-negative anaplastic large cell lymphomas by massively parallel genomic sequencing
Feldman, Andrew L. , Smith, David I., Ansell, Stephen M. , Johnson, Sarah H. , Porcher, Julie C., Özsan, Nazan , Wieben, Eric D. , Eckloff, Bruce W., Vasmatzis, George , Doǧan, Ahmet , Smith, David I., Law, Mark E. , Feldman, Andrew L

Mayo Clinic

Blood | October 29, 2010 | Volume: 117 | Issue: 3 | Pages: 915-919

10.1182/blood-2010-08-303305 | PMID 21030553 Get It

Abstract The genetics of peripheral T-cell lymphomas are poorly understood. The most well-characterized abnormalities are translocations involving ALK, occurring in approximately half of anaplastic large cell lymphomas (ALCLs). To gain insight into the genetics of ALCLs lacking ALK translocations, we combined mate-pair DNA library construction, massively parallel (“Next Generation”) sequencing, and a novel bioinformatic algorithm. We identified a balanced translocation disrupting the DUSP22 phosphatase gene on 6p25.3 and adjoining the FRA7H fragile site on 7q32.3 in a systemic ALK-negative ALCL. Using fluorescence in situ hybridization, we demonstrated that the t(6;7)(p25.3;q32.3) was recurrent in ALK-negative ALCLs. Furthermore, t(6;7)(p25.3;q32.3) was associated with down-regulation of DUSP22 and up-regulation of MIR29 microRNAs on 7q32.3. These findings represent the first recurrent translocation reported in ALK-negative ALCL and highlight the utility of massively parallel genomic sequencing to discover novel translocations in lymphoma and other cancers.
Classification of amyloidosis by laser microdissection and mass spectrometry–based proteomic analysis in clinical biopsy specimens
Vrana, Julie A., Gamez, Jeffrey D., Theis, Jason D. , Bergen, H. Robert, Madden, Benjamin J. , Doǧan, Ahmet

Mayo Clinic

Blood | October 2, 2009 | Volume: 114 | Issue: 24 | Pages: 4957-4959

10.1182/blood-2009-07-230722 | PMID 19797517 Get It

AbstractThe clinical management of amyloidosis is based on the treatment of the underlying etiology, and accurate identification of the protein causing the amyloidosis is of paramount importance. Current methods used for typing of amyloidosis such as immunohistochemistry have low specificity and sensitivity. In this study, we report the development of a highly specific and sensitive novel test for the typing of amyloidosis in routine clinical biopsy specimens. Our approach combines specific sampling by laser microdissection (LMD) and analytical power of tandem mass spectrometry (MS)–based proteomic analysis. We studied 50 cases of amyloidosis that were well-characterized by gold standard clinicopathologic criteria (training set) and an independent validation set comprising 41 cases of cardiac amyloidosis. By use of LMD/MS, we identified the amyloid type with 100% specificity and sensitivity in the training set and with 98% in validation set. Use of the LMD/MS method will enhance our ability to type amyloidosis accurately in clinical biopsy specimens.
Early Clinical Outcomes with the Use of Decellularized Nerve Allograft for Repair of Sensory Defects within the Hand
Karabekmez, Furkan Erol , Duymaz, Ahmet, Moran, Steven L.

Mayo Clinic

HAND | May 4, 2009 | Volume: 4 | Issue: 3 | Pages: 245-249

10.1007/s11552-009-9195-6 | PMID 19412640 Get It

Nerve conduits have become an established option for repair of sensory deficits of up to 2 cm. More recently, decellularized nerve allograft has also been advocated as an option for nerve repair; however, no clinical studies have examined its efficacy for the treatment of sensory nerve defects. The aim of this study was to examine our early experience with the use of decellularized nerve allograft for repair of segmental nerve defects within the hand and fingers. From July 2007 to March 2008, seven patients who had ten nerve gaps were treated surgically using decellularized nerve allograft. Eight digital and two dorsal sensory nerves were repaired. The etiologies of the nerve defects were traumatic nerve transection in eight defects and neuroma resection and reconstruction in two defects. All of the affected nerves were pure sensory fibers. Functional recovery was evaluated by blinded hand therapist using moving and static two point discrimination tests. Implantation sites were also evaluated for any signs of infection, rejection, or graft extrusion. There were five men and two women with a mean age of 44 years (range 23–65). Mean nerve graft length was 2.23 cm with a range of 0.5–3 cm. Mean follow up time was 9 months (range 5–12). Average two point discrimination was 4.4 mm moving and 5.5 mm static at last recorded follow-up. There were no wound infections observed around the graft material and sensory improvement was observed in all of the patients despite this short-term follow-up. Re-exploration of two fingers was required for flexor tendon rupture in one and flexor tendon tenolysis in the other. In both cases, the nerve allograft was visualized and appeared well incorporated in the repair site. Decellularized nerve allografts were capable of returning adequate sensation in nerve defects ranging from 0.5 to 3 cm. There were no cases of infection or rejection. Decellularized nerve allograft may provide an option for segmental nerve gaps beyond 2 cm. Randomized comparative studies will be required to determine efficacy in comparison to collagen conduits or nerve autograft.
Identification of Copy Number Abnormalities and Inactivating Mutations in Two Negative Regulators of Nuclear Factor-κB Signaling Pathways in Waldenström's Macroglobulinemia
Braggio, Esteban , Keats, Jonathan J. , Leleu, Xavier , Wier, Scott Van, Jiménez‐Zepeda, Víctor H. , Valdez, Riccardo, Schop, Roelandt F.J., Price-Troska, Tammy, Henderson, Kimberly J., Sacco, Antonio , Azab, Feda, Greipp, Philip R., Hayman, Suzanne R. , Rajkumar, S. Vincent , Carpten, John D. , Chesi, Marta , Barrett, Michael T. , Stewart, A. Keith, Bergsagel, P. Leif , Fonseca, Rafaël , Gertz, Morie A. , Doǧan, Ahmet , Ghobrial, Irene M. , Bergsagel, P. Leif , Rajkumar, S Vincent , Braggio, Esteban , Keats, Jonathan J , Fonseca, Rafael

Mayo Clinic

Cancer Research | April 7, 2009 | Volume: 69 | Issue: 8 | Pages: 3579-3588

10.1158/0008-5472.can-08-3701 | PMID 19351844 Get It

Abstract Waldenström's macroglobulinemia (WM) is a distinct clinicobiological entity defined as a B-cell neoplasm characterized by a lymphoplasmacytic infiltrate in bone marrow (BM) and IgM paraprotein production. Cytogenetic analyses were historically limited by difficulty in obtaining tumor metaphases, and the genetic basis of the disease remains poorly defined. Here, we performed a comprehensive analysis in 42 WM patients by using a high-resolution, array-based comparative genomic hybridization approach to unravel the genetic mechanisms associated with WM pathogenesis. Overall, 83% of cases have chromosomal abnormalities, with a median of three abnormalities per patient. Gain of 6p was the second most common abnormality (17%), and its presence was always concomitant with 6q loss. A minimal deleted region, including MIRN15A and MIRN16-1, was delineated on 13q14 in 10% of patients. Of interest, we reported biallelic deletions and/or inactivating mutations with uniparental disomy in tumor necrosis factor (TNF) receptor–associated factor 3 and TNFα-induced protein 3, two negative regulators of the nuclear factor-κB (NF-κB) signaling pathway. Furthermore, we confirmed the association between TRAF3 inactivation and increased transcriptional activity of NF-κB target genes. Mutational activation of the NF-κB pathway, which is normally activated by ligand receptor interactions within the BM microenvironment, highlights its biological importance, and suggests a therapeutic role for inhibitors of NF-κB pathway activation in the treatment of WM. [Cancer Res 2009;69(8):3579–88]
Genetic Variation in Tumor Necrosis Factor and the Nuclear Factor-κB Canonical Pathway and Risk of Non-Hodgkin's Lymphoma
Cerhan, James R. , Liu‐Mares, Wen, Fredericksen, Zachary S., Novak, Anne J. , Cunningham, Julie M. , Liebow, Mark , Wang, Alice H., Call, Timothy G. , Ansell, Stephen M. , Kay, Neil E. , Doǧan, Ahmet , Habermann, Thomas M. , Slager, Susan L. , Cerhan, James R

Mayo Clinic

Cancer Epidemiology, Biomarkers & Prevention | November 6, 2008 | Volume: 17 | Issue: 11 | Pages: 3161-3169

10.1158/1055-9965.epi-08-0536 | PMID 18990758 Get It

Abstract Non-Hodgkin's lymphoma (NHL) is a cancer closely associated with immune function, and the tumor necrosis factor (TNF) G-308A promoter polymorphism, which influences immune function and regulation, was recently reported by the InterLymph Consortium to be associated with NHL risk. TNF signaling activates the nuclear factor-κB (NF-κB) canonical pathway, leading to transcriptional activation of multiple genes that influence inflammation and immune response. We hypothesized that, in addition to TNF signaling, common genetic variation in genes from the NF-κB canonical pathway may affect risk of NHL. We genotyped 54 single nucleotide polymorphisms (SNP) within TNF, lymphotoxin A LTA, and nine NF-κB genes from the canonical pathway (TNFRSF1A, TRADD, TRAF2, TRAF5, RIPK1, CHUK, IKBKB, NFKB1, and REL) in a clinic-based study of 441 incident cases and 475 frequency-matched controls. Tagging SNPs were selected from HapMap supplemented by putative functional SNPs for LTA/TNF. We used principal components and haplo.stats to model gene-level associations and logistic regression to model SNP-level associations. Compared with the wild-type (GG), the AA genotype for the TNF promoter polymorphism G-308A (rs1800629) was associated with increased risk of NHL [odds ratio (OR), 2.14; 95% confidence interval (95% CI), 0.94-4.85], whereas the GA genotype was not (OR, 1.00; 95% CI, 0.74-1.34). This association was similar for follicular lymphoma and diffuse large B-cell lymphoma. A previously reported LTA/TNF haplotype was also associated with NHL risk. In gene-level analysis of the NF-κB pathway, only NFKB1 showed a statistically significant association with NHL (P = 0.049), and one NFKB1 tagSNP (rs4648022) was associated with NHL risk overall (ordinal OR, 0.59; 95% CI, 0.41-0.84; Ptrend = 0.0037) and for each of the common subtypes. In conclusion, we provide additional evidence for the role of genetic variation in TNF and LTA SNPs and haplotypes with risk of NHL and also provide some of the first preliminary evidence for an association of genetic variation in NFKB1, a downstream target of TNF signaling, with risk of NHL. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3161–9)