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1.
Heliyon ; 10(11): e32280, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38933951

RESUMO

This research tries to investigate the dynamic link between higher education institution (HEIs) transformational leaders (TFL) and follower's outcome innovative work behavior (IWB) and Task Performance) through Knowledge sharing (KNS) in Pakistan. Using quantitative design an adopted construct was used to obtain response from HEIs leaders and employees behavior. The obtained information was analyzed through structural equation modeling (SEM) technique via Smart PLS. Results depict that direct link between University Transformational leadership and employees Innovative work behavior as well as Task Performance. The results further postulate that KNS mediate the relationship between Transformational leadership and employees TSP in the context of HEIs. Surprisingly, KNS could not evident to become a mediating variable to strengthen the relationship between transformational Leadership and employees IWB in the HEIs sector of Pakistan. In addition to enhancing the theoretical comprehension of higher education leadership, the outcomes of this article provide that promoting knowledge sharing culture is valuable asset for both existing and future HEIs leaders in order to promote the culture of innovation and creativity. Although recent studies investigate the role of KNS as a mediator, however the current study use KNS as contemporaneous intervening variable for IWB and Task Performance for the first time. The study also confirms theoretical underpinning of social exchange mechanism in strengthening the relationship between leader member's continuum.

2.
F1000Res ; 11: 264, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36035882

RESUMO

Background: Companies need to go green to remain relevant. Previous studies have confirmed that going green leads to superior performance for companies. However, research of green practices in a value chain requires further attention, especially in identifying the green value chain activities that lead to superior performance. A value chain analysis focuses on identifying competitive advantages of firms through five primary and four support activities. Methods: This study extends from Ong et al. (2019), who developed and validated the instrument for the nine green value chain activities, to also examine their effect on firm performance. The 207 valid responses in this study are collected through a questionnaire survey of the sampling frame consisting of companies in Bursa Malaysia and the Federation of Malaysian Manufacturers Directory. Results: The findings reveal that the companies' green practices in primary value chain activities are higher than in the supporting value chain activities. Technological development is the activity with the lowest green attention among the nine value chain activities. Our multiple regression analysis shows that 25% of the variation in firm performance can be significantly explained by the nine green value chain activities. In terms of the individual green value chain activities, green technology development is the only activity that can positively and significantly explain firm performance. Conclusions: The findings of the study suggest that companies intending to build their green core competence need to engage in green technology development. Companies that go green for the purpose of complying to regulations and fulfilling minimum customers' demands can still embed green practices into their green value chain without compromising their performance.


Assuntos
Conservação dos Recursos Naturais , Países em Desenvolvimento , Malásia
3.
Methods Mol Biol ; 1878: 217-226, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30378079

RESUMO

Cancer is an evolutionary process. Recent advances in sequencing technologies have allowed us to investigate intratumor heterogeneity at the single nucleotide level. Here, we describe computational methods that use sequencing data to identify genetically distinct tumor subclones and reconstruct tumor evolutionary histories.


Assuntos
Neoplasias/genética , Polimorfismo de Nucleotídeo Único/genética , Biologia Computacional/métodos , Evolução Molecular , Heterogeneidade Genética , Humanos , Mutação/genética , Filogenia
4.
PLoS Med ; 13(12): e1002136, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27923043

RESUMO

BACKGROUND: Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer associated with HER2 amplification, with high risk of metastasis and an estimated median survival of 2.9 y. We performed an open-label, single-arm phase II clinical trial (ClinicalTrials.gov NCT01325428) to investigate the efficacy and safety of afatinib, an irreversible ErbB family inhibitor, alone and in combination with vinorelbine in patients with HER2-positive IBC. This trial included prospectively planned exome analysis before and after afatinib monotherapy. METHODS AND FINDINGS: HER2-positive IBC patients received afatinib 40 mg daily until progression, and thereafter afatinib 40 mg daily and intravenous vinorelbine 25 mg/m2 weekly. The primary endpoint was clinical benefit; secondary endpoints were objective response (OR), duration of OR, and progression-free survival (PFS). Of 26 patients treated with afatinib monotherapy, clinical benefit was achieved in 9 patients (35%), 0 of 7 trastuzumab-treated patients and 9 of 19 trastuzumab-naïve patients. Following disease progression, 10 patients received afatinib plus vinorelbine, and clinical benefit was achieved in 2 of 4 trastuzumab-treated and 0 of 6 trastuzumab-naïve patients. All patients had treatment-related adverse events (AEs). Whole-exome sequencing of tumour biopsies taken before treatment and following disease progression on afatinib monotherapy was performed to assess the mutational landscape of IBC and evolutionary trajectories during therapy. Compared to a cohort of The Cancer Genome Atlas (TCGA) patients with HER2-positive non-IBC, HER2-positive IBC patients had significantly higher mutational and neoantigenic burden, more frequent gain-of-function TP53 mutations and a recurrent 11q13.5 amplification overlapping PAK1. Planned exploratory analysis revealed that trastuzumab-naïve patients with tumours harbouring somatic activation of PI3K/Akt signalling had significantly shorter PFS compared to those without (p = 0.03). High genomic concordance between biopsies taken before and following afatinib resistance was observed with stable clonal structures in non-responding tumours, and evidence of branched evolution in 8 of 9 tumours analysed. Recruitment to the trial was terminated early following the LUX-Breast 1 trial, which showed that afatinib combined with vinorelbine had similar PFS and OR rates to trastuzumab plus vinorelbine but shorter overall survival (OS), and was less tolerable. The main limitations of this study are that the results should be interpreted with caution given the relatively small patient cohort and the potential for tumour sampling bias between pre- and post-treatment tumour biopsies. CONCLUSIONS: Afatinib, with or without vinorelbine, showed activity in trastuzumab-naïve HER2-positive IBC patients in a planned subgroup analysis. HER2-positive IBC is characterized by frequent TP53 gain-of-function mutations and a high mutational burden. The high mutational load associated with HER2-positive IBC suggests a potential role for checkpoint inhibitor therapy in this disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT01325428.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quinazolinas/uso terapêutico , Receptor ErbB-2/antagonistas & inibidores , Vimblastina/análogos & derivados , Adolescente , Adulto , Afatinib , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Estudos de Coortes , Feminino , Humanos , Neoplasias Inflamatórias Mamárias , Pessoa de Meia-Idade , Quinazolinas/efeitos adversos , Vimblastina/efeitos adversos , Vimblastina/uso terapêutico , Vinorelbina , Adulto Jovem
5.
Genome Biol ; 17(1): 185, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27634334

RESUMO

BACKGROUND: The APOBEC3 family of cytidine deaminases mutate the cancer genome in a range of cancer types. Although many studies have documented the downstream effects of APOBEC3 activity through next-generation sequencing, less is known about their upstream regulation. In this study, we sought to identify a molecular basis for APOBEC3 expression and activation. RESULTS: HER2 amplification and PTEN loss promote DNA replication stress and APOBEC3B activity in vitro and correlate with APOBEC3 mutagenesis in vivo. HER2-enriched breast carcinomas display evidence of elevated levels of replication stress-associated DNA damage in vivo. Chemical and cytotoxic induction of replication stress, through aphidicolin, gemcitabine, camptothecin or hydroxyurea exposure, activates transcription of APOBEC3B via an ATR/Chk1-dependent pathway in vitro. APOBEC3B activation can be attenuated through repression of oncogenic signalling, small molecule inhibition of receptor tyrosine kinase signalling and alleviation of replication stress through nucleoside supplementation. CONCLUSION: These data link oncogene, loss of tumour suppressor gene and drug-induced replication stress with APOBEC3B activity, providing new insights into how cytidine deaminase-induced mutagenesis might be activated in tumourigenesis and limited therapeutically.


Assuntos
Neoplasias da Mama/genética , Citosina Desaminase/genética , Replicação do DNA , Família Multigênica , Mutagênese , Estresse Fisiológico , Desaminases APOBEC , Antineoplásicos/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Biomarcadores Tumorais , Neoplasias da Mama/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Citidina Desaminase , Citosina Desaminase/metabolismo , Dano ao DNA , Replicação do DNA/efeitos dos fármacos , Ativação Enzimática , Feminino , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Mutação , Oncogenes , Transdução de Sinais , Estresse Fisiológico/efeitos dos fármacos
6.
BMC Cancer ; 16: 646, 2016 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-27538953

RESUMO

BACKGROUND: Cancer is increasingly understood to arise in the context of dynamically evolving genomes with continuously generated variants subject to selective pressures. Diverse mutations have been identified in papillary thyroid carcinoma (PTC), but unifying theories underlying genomic change are lacking. Applying a framework of somatic evolution, we sought to broaden understanding of the PTC genome through identification of global trends that help explain risk of tumorigenesis. METHODS: Exome sequencing was performed on 53 PTC and matched adjacent non-tumor thyroid tissues (ANT). Single nucleotide substitution (SNS) signatures from each sample pair were divided into three subsets based on their presence in tumor, non-tumor thyroid, or both. Nine matched blood samples were sequenced and SNS signatures intersected with these three subsets. The intersected genomic signatures were used to define branch-points in the evolution of the tumor genome, distinguishing variants present in the tissues' common ancestor cells from those unique to each tissue type and therefore acquired after genomic divergence of the tumor, non-tumor, and blood samples. RESULTS: Single nucleotide substitutions shared by the tumor and the non-tumor thyroid were dominated by C-to-T transitions, whereas those unique to either tissue type were enriched for C-to-A transversions encoding non-synonymous, predicted-deleterious variants. On average, SNSs of matched blood samples were 81 % identical to those shared by tumor and non-tumor thyroid, but only 12.5 % identical to those unique to either tissue. Older age and BRAF mutation were associated with increased SNS burden. CONCLUSIONS: The current study demonstrates novel patterns of genomic change in PTC, supporting a theory of somatic evolution in which the zygote's germline genome undergoes continuous remodeling to produce progressively differentiated, tissue-specific signatures. Late somatic events in thyroid tissue demonstrate shifted mutational spectra compared to earlier polymorphisms. These late events are enriched for predicted-deleterious variants, suggesting a mechanism of genomic instability in PTC tumorigenesis.


Assuntos
Carcinoma/genética , Redes Reguladoras de Genes , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/métodos , Neoplasias da Glândula Tireoide/genética , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar , Evolução Clonal , Exoma , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Câncer Papilífero da Tireoide , Adulto Jovem
9.
Surgery ; 159(1): 296-301, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26453132

RESUMO

BACKGROUND: Familial syndromes with specific genetic drivers account for a subset of adrenocortical carcinomas (ACCs), but the genomic underpinnings of sporadic cases remain poorly understood. Recent advances in copy number variation (CNV) prediction from exome sequencing are facilitating exploration of genomic rearrangements common to these carcinomas. METHODS: ACC and matched, nontumor samples underwent exome sequencing. CNVs were predicted using coverage-depth comparison. Clinicopathologic characteristics of amplification- and deletion-dominant samples were compared and pathway enrichment analysis performed for regions with significant variation. RESULTS: CNVs are distributed broadly across the ACC genome. Individual signatures demonstrate amplification or deletion dominance. Areas of recurrent amplification include chromosomes 5, 12, 19, and 20, whereas chromosomes 1, 10, 18, and 22 are deletion prone. Large-scale amplification of chromosome 19 occurred in 12 of 19 cases (63%), including 6 of 8 amplification-dominant samples (75%) and was associated with stage III/IV disease (P = .002). Genes within this amplified region are overrepresented among the adrenal hyperplasia and steroid biosynthesis pathways (P = 4.2(-5) and 2.5(-5), respectively). CONCLUSION: CNV detection via exome sequencing allows high-resolution cataloging of structural variations in ACC. Large-scale, recurrent amplifications encompassing known adrenal-specific gene pathways correlate with tumor stage. Further functional analysis of individual genes within these regions could provide mechanistic insight into specific drivers underlying pathogenesis and progression of ACC.


Assuntos
Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/patologia , Cromossomos Humanos Par 19/genética , Variações do Número de Cópias de DNA , Neoplasias do Córtex Suprarrenal/genética , Carcinoma Adrenocortical/genética , Exoma , Feminino , Amplificação de Genes , Humanos , Masculino , Pessoa de Meia-Idade
10.
Oncotarget ; 7(3): 3403-15, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26655088

RESUMO

Merkel cell carcinoma (MCC) is a rare but highly aggressive cutaneous neuroendocrine carcinoma, associated with the Merkel cell polyomavirus (MCPyV) in 80% of cases. To define the genetic basis of MCCs, we performed exome sequencing of 49 MCCs. We show that MCPyV-negative MCCs have a high mutation burden (median of 1121 somatic single nucleotide variants (SSNVs) per-exome with frequent mutations in RB1 and TP53 and additional damaging mutations in genes in the chromatin modification (ASXL1, MLL2, and MLL3), JNK (MAP3K1 and TRAF7), and DNA-damage pathways (ATM, MSH2, and BRCA1). In contrast, MCPyV-positive MCCs harbor few SSNVs (median of 12.5 SSNVs/tumor) with none in the genes listed above. In both subgroups, there are rare cancer-promoting mutations predicted to activate the PI3K pathway (HRAS, KRAS, PIK3CA, PTEN, and TSC1) and to inactivate the Notch pathway (Notch1 and Notch2). TP53 mutations appear to be clinically relevant in virus-negative MCCs as 37% of these tumors harbor potentially targetable gain-of-function mutations in TP53 at p.R248 and p.P278. Moreover, TP53 mutational status predicts death in early stage MCC (5-year survival in TP53 mutant vs wild-type stage I and II MCCs is 20% vs. 92%, respectively; P = 0.0036). Lastly, we identified the tumor neoantigens in MCPyV-negative and MCPyV-positive MCCs. We found that virus-negative MCCs harbor more tumor neoantigens than melanomas or non-small cell lung cancers (median of 173, 65, and 111 neoantigens/sample, respectively), two cancers for which immune checkpoint blockade can produce durable clinical responses. Collectively, these data support the use of immunotherapies for virus-negative MCCs.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Célula de Merkel/genética , Poliomavírus das Células de Merkel/imunologia , Mutação/genética , Neoplasias Cutâneas/genética , Infecções Tumorais por Vírus/genética , Carcinoma de Célula de Merkel/imunologia , Carcinoma de Célula de Merkel/virologia , Exoma/genética , Genes Supressores de Tumor , Humanos , Imunoterapia , Oncogenes/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/virologia , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia
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