Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
LanguageLanguage
-
SubjectSubject
-
Item TypeItem Type
-
DisciplineDiscipline
-
YearFrom:-To:
-
More FiltersMore FiltersIs Peer Reviewed
Done
Filters
Reset
775
result(s) for
"Chan, Wing C."
Sort by:
Cancer Genome Scanning in Plasma: Detection of Tumor-Associated Copy Number Aberrations, Single-Nucleotide Variants, and Tumoral Heterogeneity by Massively Parallel Sequencing
by
Liao, Gary JW
,
Lai, Paul BS
,
Lo, YMD
in
Biomarkers
,
Breast Neoplasms - blood
,
Breast Neoplasms - genetics
2013
Tumor-derived DNA can be found in the plasma of cancer patients. In this study, we explored the use of shotgun massively parallel sequencing (MPS) of plasma DNA from cancer patients to scan a cancer genome noninvasively.
Four hepatocellular carcinoma patients and a patient with synchronous breast and ovarian cancers were recruited. DNA was extracted from the tumor tissues, and the preoperative and postoperative plasma samples of these patients were analyzed with shotgun MPS.
We achieved the genomewide profiling of copy number aberrations and point mutations in the plasma of the cancer patients. By detecting and quantifying the genomewide aggregated allelic loss and point mutations, we determined the fractional concentrations of tumor-derived DNA in plasma and correlated these values with tumor size and surgical treatment. We also demonstrated the potential utility of this approach for the analysis of complex oncologic scenarios by studying the patient with 2 synchronous cancers. Through the use of multiregional sequencing of tumoral tissues and shotgun sequencing of plasma DNA, we have shown that plasma DNA sequencing is a valuable approach for studying tumoral heterogeneity.
Shotgun DNA sequencing of plasma is a potentially powerful tool for cancer detection, monitoring, and research.
Journal Article
Survival of human lymphoma cells requires B-cell receptor engagement by self-antigens
by
Dawood, Moez
,
Meffre, Eric
,
Gascoyne, Randy D.
in
Amino Acid Sequence
,
Apoptosis - genetics
,
Autoantigens - metabolism
2015
The activated B-cell–like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) relies on chronic active B-cell receptor (BCR) signaling. BCR pathway inhibitors induce remissions in a subset of ABC DLBCL patients. BCR microclusters on the surface of ABC cells resemble those generated following antigen engagement of normal B cells. We speculated that binding of lymphoma BCRs to self-antigens initiates and maintains chronic active BCR signaling in ABC DLBCL. To assess whether antigenic engagement of the BCR is required for the ongoing survival of ABC cells, we developed isogenic ABC cells that differed solely with respect to the IgH V region of their BCRs. In competitive assays with wild-type cells, substitution of a heterologous V region impaired the survival of three ABC lines. The viability of one VH4-34⁺ ABC line and the ability of its BCR to bind to its own cell surface depended on V region residues that mediate the intrinsic autoreactivity of VH4-34 to self-glycoproteins. The BCR of another ABC line reacted with self-antigens in apoptotic debris, and the survival of a third ABC line was sustained by reactivity of its BCR to an idiotypic epitope in its own V region. Hence, a diverse set of self-antigens is responsible for maintaining the malignant survival of ABC DLBCL cells. IgH V regions used by the BCRs of ABC DLBCL biopsy samples varied in their ability to sustain survival of these ABC lines, suggesting a screening procedure to identify patients who might benefit from BCR pathway inhibition.
Journal Article
Discrimination of consonants in quiet and in noise in Mandarin-speaking children with normal hearing
2023
Given the critical role of consonants in speech perception and the lack of knowledge on consonant perception in noise in Mandarin-speaking children, the current study aimed to investigate Mandarin consonant discrimination in normal-hearing children, in relation to the effects of age and signal-to-noise ratios (S/N).
A discrimination task consisting of 33 minimal pairs in monosyllabic words was designed to explore the development of consonant discrimination in five test conditions: 0, -5, -10, -15 dB S/Ns, and quiet.
Forty Mandarin-speaking, normal-hearing children aged from 4;0 to 8;9 in one-year-age increment were recruited and their performance was compared to 10 adult listeners.
A significant main effect of age, test conditions, and an interaction effect between these variables was noted. Consonant discrimination in quiet and in noise improved as children became older. Consonants that were difficult to discriminate in quiet and in noise were mainly velar contrasts. Noise seemed to have less effect on the discrimination of affricates and fricatives, and plosives appeared to be to be more difficult to discriminate in noise than in quiet. Place contrasts between alveolar and palato-alveolar consonants were difficult in quiet.
The findings were the first to reveal typical perceptual development of Mandarin consonant discrimination in children and can serve as a reference for comparison with children with disordered perceptual development, such as those with hearing loss.
Journal Article
Aggressive natural killer-cell leukemia mutational landscape and drug profiling highlight JAK-STAT signaling as therapeutic target
2018
Aggressive natural killer-cell (NK-cell) leukemia (ANKL) is an extremely aggressive malignancy with dismal prognosis and lack of targeted therapies. Here, we elucidate the molecular pathogenesis of ANKL using a combination of genomic and drug sensitivity profiling. We study 14 ANKL patients using whole-exome sequencing (WES) and identify mutations in
STAT3
(21%) and RAS-MAPK pathway genes (21%) as well as in
DDX3X
(29%) and epigenetic modifiers (50%). Additional alterations include JAK-STAT copy gains and tyrosine phosphatase mutations, which we show recurrent also in extranodal NK/T-cell lymphoma, nasal type (NKTCL) through integration of public genomic data. Drug sensitivity profiling further demonstrates the role of the JAK-STAT pathway in the pathogenesis of NK-cell malignancies, identifying NK cells to be highly sensitive to JAK and BCL2 inhibition compared to other hematopoietic cell lineages. Our results provide insight into ANKL genetics and a framework for application of targeted therapies in NK-cell malignancies.
Aggressive natural killer-cell leukemia (ANKL) has few targeted therapies. Here ANKL patients are reported to harbor STAT3, RAS-MAPK pathway, DDX3X and epigenetic modifier mutations; and drug sensitivity profiling uncovers the importance of the JAK-STAT pathway, revealing potential ANKL therapeutic targets.
Journal Article
Mutations Affecting Genes in the Proximal T-Cell Receptor Signaling Pathway in Peripheral T-Cell Lymphoma
by
Liu, Xiaoqian
,
Ning, Jinyao
,
Liu, Xuxiang
in
1-Phosphatidylinositol 3-kinase
,
Adapter proteins
,
Amino acids
2022
Peripheral T-cell lymphoma (PTCL) comprises a heterogeneous group of mature T-cell malignancies. Recurrent activating mutations and fusions in genes related to the proximal TCR signaling pathway have been identified in preclinical and clinical studies. This review summarizes the genetic alterations affecting proximal TCR signaling identified from different subgroups of PTCL and the functional impact on TCR signaling and downstream pathways. These genetic abnormalities include mostly missense mutations, occasional indels, and gene fusions involving CD28, CARD11, the GTPase RHOA, the guanine nucleotide exchange factor VAV1, and kinases including FYN, ITK, PLCG1, PKCB, and PI3K subunits. Most of these aberrations are activating mutations that can potentially be targeted by inhibitors, some of which are being tested in clinical trials that are briefly outlined in this review. Finally, we focus on the molecular pathology of recently identified subgroups of PTCL-NOS and highlight the unique genetic profiles associated with PTCL-GATA3.
Journal Article
Tumor-Associated Macrophages and Survival in Classic Hodgkin's Lymphoma
by
Muller-Hermelink, Hans-Konrad
,
Braziel, Rita M
,
Weisenburger, Dennis D
in
Adolescent
,
Adult
,
Aged
2010
Clinically relevant biomarkers for predicting the outcome of treatment in patients with Hodgkin's disease have not been established. In this study, gene profiling and immunohistochemical analysis were used to find such a marker. A strong association was found between a poor outcome of treatment and an increased number of CD68+ cells in the microenvironment of Reed–Sternberg cells. CD68, a marker of macrophages, outperformed the conventional International Prognostic Score and is available for immunohistochemical staining of diagnostic samples of Hodgkin's lymphoma.
A strong association was found between a poor outcome of treatment and an increased number of CD68+ cells in the microenvironment of Reed–Sternberg cells.
Current therapies do not cure at least 20% of patients with classic Hodgkin's lymphoma, and a similar proportion of patients are overtreated.
1
It remains a challenge to identify patients whose disease will not be eradicated by standard therapies. Currently, most patients receive at least four cycles of polychemotherapy and, if indicated, radiotherapy.
2
Autologous hematopoietic stem-cell transplantation can rescue about 50% of patients in whom primary therapy has failed.
Initial clinical decisions and risk stratification for patients with Hodgkin's lymphoma are largely based on clinical variables that distinguish those who are at high risk from those at standard risk. Classic Hodgkin's . . .
Journal Article
MiRNA-363-3p/DUSP10/JNK axis mediates chemoresistance by enhancing DNA damage repair in diffuse large B-cell lymphoma
2022
Anthracycline-based chemotherapy resistance represents a major challenge in diffuse large B-cell lymphoma (DLBCL). MiRNA and gene expression profiles (n = 47) were determined to uncover potential chemoresistance mechanisms and therapeutic approaches. An independent correlation between high expression of miRNA-363-3p and chemoresistance was observed and validated in a larger cohort (n = 106). MiRNA-363-3p was shown to reduce doxorubicin-induced apoptosis and tumor shrinkage in in vitro and in vivo experiments by ectopic expression and CRISPR/Cas9-mediated knockout in DLBCL cell lines. DNA methylation was found to participate in transcriptional regulation of miRNA-363-3p. Further investigation revealed that dual specificity phosphatase 10 (DUSP10) is a target of miRNA-363-3p and its suppression promotes the phosphorylation of c-Jun N-terminal kinase (JNK). The miRNA-363-3p/DUSP10/JNK axis was predominantly associated with negative regulation of homologous recombination (HR) and DNA repair pathways. Ectopic expression of miRNA-363-3p more effectively repaired doxorubicin-induced double-strand break (DSB) while enhancing non-homologous end joining repair and reducing HR repair. Targeting JNK and poly (ADP-ribose) polymerase 1 significantly inhibited doxorubicin-induced DSB repair, increased doxorubicin-induced cell apoptosis and tumor shrinkage, and improved the survival of tumor-bearing mice. In conclusion, the miRNA-363-3p/DUSP10/JNK axis is a novel chemoresistance mechanism in DLBCL that may be reversed by targeted therapy.
Journal Article
PRDM1 is a tumor suppressor gene in natural killer cell malignancies
by
Küçük, Can
,
Gaulard, Phillip
,
Chan, Wing C
in
Apoptosis
,
Apoptosis - drug effects
,
B cell lymphoma
2011
Natural killer cell lymphoma (NKCL) constitutes a rare and aggressive form of non-Hodgkin lymphoma, and there is little insight into its pathogenesis. Here we show that PRDM1 is a tumor suppressor gene in NKCLs that is inactivated by a combination of monoallelic deletion and promoter CpG island hypermethylation. We observed monoallelic deletion of PRDM1 loci in 8 of 18 (44%) NKCL cases. The other allele showed significant promoter methylation in 12 of 17 (71%) cases. In support of its role as a tumor suppressor gene, the reconstitution of PRDM1 in PRDM1-null NK cell lines led to G2/M cell cycle arrest, increased apoptosis, and a strong negative selection pressure with progressive elimination of PRDM1-expressing cells, which was enhanced when IL-2 concentration is limiting. We observed a progressive increase in PRDM1 expression—in particular, PRDM1α—in normal NK cells in response to IL-2 and in normal NK cells activated with an engineered NK cell target, K562-Cl9-mb21, suggesting its role in NK cell homeostasis. In support of this role, knockdown of PRDM1 by shRNA in normal NK cells resulted in the positive selection of these cells. We identified MYC and 4-1BBL as targets of PRDM1 in NK cells. Disruption of homeostatic control by PRDM1 may be an important pathogenetic mechanism for NKCL.
Journal Article
CEACAM1 as a mediator of B-cell receptor signaling in mantle cell lymphoma
2025
B-cell receptor (BCR) signaling plays an important role in the pathogenesis of mantle cell lymphoma (MCL), but the detailed mechanisms are not fully understood. In this study, through a genome-wide loss-of-function screen, we identify carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) as an essential factor in a subset of MCL tumors. Our signal transduction studies reveal that CEACAM1 plays a critical role in BCR activation through involvement in two dynamic processes. First, following BCR engagement, CEACAM1 co-localizes to the membrane microdomains (lipid rafts) by anchoring to the F-actin cytoskeleton through the adaptor protein filamin A. Second, CEACAM1 recruits and increases the abundance of SYK in the BCR complex leading to BCR activation. These activities of CEACAM1 require its cytoplasmic tail and the N-terminal ectodomain. Considering that previous studies have extensively characterized CEACAM1 as an ITIM-bearing inhibitory receptor, our findings regarding its activating role are both surprising and context-dependent, which may have implications for BCR-targeting therapies.
Pathological B-cell receptor (BCR) signaling is a key driver of mantle cell lymphoma tumorigenesis. Here, the authors discover that CEACAM1, an immunoglobulin-like transmembrane protein, is essential for a subset of mantle cell lymphoma through activation of the BCR.
Journal Article
Essential Role of MALT1 Protease Activity in Activated B Cell-Like Diffuse Large B-Cell Lymphoma
by
Ngo, Vu
,
Penas, Eva-Maria Murga
,
Thome, Margot
in
Adaptor Proteins, Signal Transducing - genetics
,
Adaptor Proteins, Signal Transducing - metabolism
,
Animals
2009
A key element for the development of suitable anti-cancer drugs is the identification of cancer-specific enzymatic activities that can be therapeutically targeted. Mucosa-associated lymphoid tissue transformation protein 1 (MALT1) is a proto-oncogene that contributes to tumorigenesis in diffuse large B-cell lymphoma (DLBCL) of the activated B-cell (ABC) subtype, the least curable subtype of DLBCL. Recent data suggest that MALT1 has proteolytic activity, but it is unknown whether this activity is relevant for tumor growth. Here we report that MALT1 is constitutively active in DLBCL lines of the ABC but not the GCB subtype. Inhibition of the MALT1 proteolytic activity led to reduced expression of growth factors and apoptosis inhibitors, and specifically affected the growth and survival of ABC DLBCL lines. These results demonstrate a key role for the proteolytic activity of MALT1 in DLBCL of the ABC subtype, and provide a rationale for the development of pharmacological inhibitors of MALT1 in DLBCL therapy.
Journal Article