Cross-platform assessment of genomic imbalance confirms the clinical relevance of genomic complexity and reveals loci with potential pathogenic roles in diffuse large B-cell lymphoma
LEUKEMIA & LYMPHOMA
Authors: Dias, Lizalynn M.; Thodima, Venkata; Friedman, Julia; Ma, Charles; Guttapalli, Asha; Mendiratta, Geetu; Siddiqi, Imran N.; Syrbu, Sergei; Chaganti, R. S. K.; Houldsworth, Jane
Abstract
Genomic copy number alterations (CNAs) in diffuse large B-cell lymphoma (DLBCL) have roles in disease pathogenesis, but overall clinical relevance remains unclear. Herein, an unbiased algorithm was uniformly applied across three genome profiling datasets comprising 392 newly-diagnosed DLBCL specimens that defined 32 overlapping CNAs, involving 36 minimal common regions (MCRs). Scoring criteria were established for 50 aberrations within the MCRs while considering peak gains/losses. Application of these criteria to independent datasets revealed novel candidate genes with coordinated expression, such as CNOT2, potentially with pathogenic roles. No one single aberration significantly associated with patient outcome across datasets, but genomic complexity, defined by imbalance in more than one MCR, significantly portended adverse outcome in two of three independent datasets. Thus, the standardized scoring of CNAs currently developed can be uniformly applied across platforms, affording robust validation of genomic imbalance and complexity in DLBCL and overall clinical utility as biomarkers of patient outcome.
CCR4-NOT transcription complex subunit 2 regulates TRAIL sensitivity in non-small-cell lung cancer cells via the STAT3 pathway
INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE
Authors: Kim, Eun-Ok; Kang, Shi-Eun; Choi, Minji; Rhee, Ki-Jong; Yun, Miyong
Abstract
TRAIL is an attractive candidate for anticancer therapy in a variety of tumors since it targets only tumors and not normal tissue. However, a remaining major hurdle is that the majority of tumors exhibit a resistance mechanism against the effects of TRAIL via the induction of anti-apoptotic signaling pathways. In this study, we aimed to evaluate whether the modulation of CCR4-NOT transcription complex subunit 2 (CNOT2) function can promote TRAIL sensitivity in non-small-cell lung cancer (NSCLC) cells. CNOT2 depletion partially decreased colony numbers and the proliferation of NSCLC cells. When combined with TRAIL, the suppression of CNOT2 expression markedly decreased the survival rate and increased apoptosis, as compared with TRAIL treatment alone in TRAIL-resistant NSCLC cells. Of note, CNOT2 overexpression in TRAIL-sensitive H460 cells enhanced the survival rate and decreased apoptosis when compared with TRAIL treatment alone. Gene expression analysis indicated that genes involved in the signal transducer and activator of transcription 3 (STAT3) signaling pathway were dominantly altered in the CNOT2-depleted A549 cells. Under this condition, Src homology region 2 domain containing phosphatase-1 (SHP1) was significantly upregulated and subsequently increased apoptosis. On the whole, the findings of this study demonstrate that CNOT2 participates in TRAIL sensitivity in NSCLC cells via the regulation of the STAT3 signaling pathway, and suggest that combination therapy with CNOT2 depletion and TRAIL treatment may prove to be a useful strategy for overcoming TRAIL resistance in NSCLC.