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1.
Life Sci ; 352: 122868, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38936604

RESUMO

Membrane trafficking within the Golgi apparatus plays a pivotal role in the intracellular transportation of lipids and proteins. Dysregulation of this process can give rise to various pathological manifestations, including cancer. Exploiting Golgi defects, cancer cells capitalise on aberrant membrane trafficking to facilitate signal transduction, proliferation, invasion, immune modulation, angiogenesis, and metastasis. Despite the identification of several molecular signalling pathways associated with Golgi abnormalities, there remains a lack of approved drugs specifically targeting cancer cells through the manipulation of the Golgi apparatus. In the initial section of this comprehensive review, the focus is directed towards delineating the abnormal Golgi genes and proteins implicated in carcinogenesis. Subsequently, a thorough examination is conducted on the impact of these variations on Golgi function, encompassing aspects such as vesicular trafficking, glycosylation, autophagy, oxidative mechanisms, and pH alterations. Lastly, the review provides a current update on promising Golgi apparatus-targeted inhibitors undergoing preclinical and/or clinical trials, offering insights into their potential as therapeutic interventions. Significantly more effort is required to advance these potential inhibitors to benefit patients in clinical settings.

2.
Digit Health ; 9: 20552076231216275, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38025110

RESUMO

Background: Telehealth services have gained popularity in Malaysia, providing convenient consultations during the COVID-19 pandemic. However, there is limited research on their usage, user demographics and prescribed medications. This study aims to fill that gap by investigating telehealth service utilisation in community pharmacies and identifying trends in common diagnoses and medications prescribed. Methods: A retrospective observational study was conducted using a telehealth services database in Malaysian community pharmacies. Consultation records from January 2019 to December 2021 were extracted using a data collection form. The study identified the service usage over time, demographic profiles of users and the most common diagnoses and prescribed medications. Diagnoses were classified using the International Classification of Disease, 10th Revision (ICD-10), and medications were classified using the Anatomical Therapeutic Chemical (ATC) system. Results: The study included 835,826 telehealth service records, with 88.8% being assisted consultations with e-prescriptions and 11.2% direct consultations. The user population consisted of primarily Malaysians (96.9%), with a mean age of 50 ± 21 years. Both telehealth services saw an increase in unique users over the 3-year study period. There was a moderate correlation between active COVID-19 cases and monthly user count. Assisted consultations were more widely used than direct consultations. Conclusion: This study found an increased usage of telehealth services and its potential to remain as a healthcare system feature in community pharmacies. Further investigation into the impact on medication safety, quality and healthcare delivery is warranted.

3.
Int J Pharm Pract ; 31(5): 489-495, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37526297

RESUMO

OBJECTIVES: To determine the adoption and perception of mobile health (mHealth) applications among community pharmacists in Malaysia. METHODS: A cross-sectional survey using a self-administered questionnaire was conducted with 300 community pharmacists in the Klang Valley, Malaysia using a stratified sampling approach. The questionnaire consisted of 36 questions with three sections: demographic data, adoption of mHealth applications and perception towards mHealth applications. Descriptive and inferential tests as well as exploratory factor analysis were used to analyse the data. KEY FINDINGS: Adoption of mHealth applications by community pharmacists for both professional and personal use was relatively high at 79.7%. Utilised mHealth applications were primarily from the medical references category, while applications for patient monitoring, personal care and fitness were used to a lesser degree. Among mHealth application users, only 65.7% recommended them to their patients. Overall perception towards mHealth applications was positive, but perception towards the benefits and favour of mHealth applications for their patients was lower. This was corroborated by the factor analysis, which identified four main factors explaining 59.9% of variance in the dataset. These factors were perception towards use in their own professional practice, perception on benefits and use in their patients, perception on specific features of mHealth applications, and reliability of mHealth applications. CONCLUSIONS: Adoption of mHealth applications among community pharmacists in Malaysia is high. Community pharmacists are more likely to use mHealth applications professionally and personally but less likely to recommend them to patients due to less favourable perceptions on how patients will benefit from mHealth applications.

4.
Phytochemistry ; 211: 113685, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37088350

RESUMO

Four previously undescribed alkaloids, aspergillinine A-D, and four known diterpene pyrones were isolated from the potato dextrose agar (PDA) culture of Aspergillus sp. HAB10R12. The chemical structures of the isolated compounds were elucidated based on a detailed analysis of their NMR and MS data. The absolute configuration of the isolated compounds was determined by Electronic Circular Dichroism analysis coupled with computational methods. Aspergillinine A represents the first example of a diketopiperazine dipeptide containing the unnatural amino acid N-methyl kynurenine. Its absolute configuration revealed that it adopts a rather unusual conformation. Aspergillinine B represents a previously unencountered skeleton containing an isoindolinone ring. Aspergillinine C and D were similar to previously isolated diketopiperazine alkaloids, namely, lumpidin and brevianamide F, respectively. The diterpene pyrones were isolated twice previously, once from a soil-derived Aspergillus species, and once from the liquid culture of Aspergillus sp. HAB10R12. The alkaloids isolated in this study showed no antiproliferative activity when tested against HepG2 and A549 cancer cell lines.


Assuntos
Alcaloides , Dicetopiperazinas , Dicetopiperazinas/química , Pironas/metabolismo , Estrutura Molecular , Aspergillus/química , Fungos/química , Alcaloides/química
5.
Chem Biol Interact ; 379: 110503, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37084996

RESUMO

Hydroxylated polymethoxyflavones (HPMFs) have been shown to possess various anti-disease effects, including against obesity. This study investigates the anti-obesity effects of HPMFs in further detail, aiming to gain understanding of their mechanism of action in this context. The current study demonstrates that two HPMFs; 3'-hydroxy-5,7,4',5'-tetramethoxyflavone (3'OH-TetMF) and 4'-hydroxy-5,7,3',5'-tetramethoxyflavone (4'OH-TetMF) possess anti-obesity effects. They both significantly reduced pancreatic lipase activity in a competitive manner as demonstrated by molecular docking and kinetic studies. In cell studies, it was revealed that both of the HPMFs suppress differentiation of 3T3-L1 mouse embryonic fibroblast cells during the early stages of adipogenesis. They also reduced expression of key adipogenic and lipogenic marker genes, namely peroxisome proliferator-activated receptor-gamma (PPARγ), CCAAT/enhancer-binding protein α and ß (C/EBP α and ß), adipocyte binding protein 2 (aP2), fatty acid synthase (FASN), and sterol regulatory element-binding protein 1 (SREBF 1). They also enhanced the expression of cell cycle genes, i.e., cyclin D1 (CCND1) and C-Myc, and reduced cyclin A2 expression. When further investigated, it was also observed that these HPMFs accelerate lipid breakdown (lipolysis) and enhance lipolytic genes expression. Moreover, they also reduced the secretion of proteins (adipokines), including pro-inflammatory cytokines, from mature adipocytes. Taken together, this study concludes that these HPMFs have anti-obesity effects, which are worthy of further investigation.


Assuntos
Adipogenia , Lipólise , Animais , Camundongos , Lipase/metabolismo , Lipase/farmacologia , Células 3T3-L1 , Cinética , Simulação de Acoplamento Molecular , Fibroblastos/metabolismo , Diferenciação Celular , Obesidade/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , PPAR gama/genética , PPAR gama/metabolismo
6.
Eur J Pharmacol ; 938: 175445, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36473593

RESUMO

In this study, the anti-obesity effects of 5,7,3',4',5-pentamethoxyflavone (PMF) and 6,2',4'-trimethoxyflavone (TMF) were evaluated through two distinct mechanisms of action: inhibition of crude porcine pancreatic lipase (PL), and inhibition of adipogenesis in 3T3-L1 pre-adipocytes. Both flavones show dose dependent, competitive inhibition of PL activity. Molecular docking studies revealed binding of the flavones to the active site of PL. In 3T3-L1 adipocytes, both flavones reduced the accumulation of lipids and triglycerides. PMF and TMF also lowered the expression of adipogenic and lipogenic genes. They both reduced the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and ß (C/EBP α and ß), sterol regulatory element-binding protein 1 (SREBF 1), fatty acid synthase (FASN), adipocyte binding protein 2 (aP2), and leptin gene. In addition, these flavones enhanced adiponectin mRNA expression, increased lipolysis and enhanced the expression of lipolytic genes: adipose triglycerides lipase (ATGL), hormone sensitive lipase (HSL) and monoglycerides lipase (MAGL) in mature 3T3-L1 adipocytes. Overall, PMF was seen to be a more potent inhibitor of both PL activity and adipogenesis versus TMF. These results suggest that PMF and TMF possess anti-obesity activities and can be further evaluated for their anti-obesity effects.


Assuntos
Adipogenia , Flavonas , Camundongos , Suínos , Animais , Lipase/metabolismo , Simulação de Acoplamento Molecular , Células 3T3-L1 , Proteína alfa Estimuladora de Ligação a CCAAT/genética , PPAR gama/genética , PPAR gama/metabolismo , Flavonas/farmacologia , Triglicerídeos/metabolismo , Obesidade , Diferenciação Celular
7.
Toxicol Rep ; 9: 759-768, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36518400

RESUMO

Cathinone is the psychostimulatory major active ingredient of khat (Catha edulis Forsk) and are often co-abused with alcohols and polydrugs. With the increased consumption of khat and cathinones on a global scale, efforts should be channelled into understanding and minimising the excruciating effects of possible khat-drug interactions. This study aimed to determine the in vitro inhibitory effects of cathinone on CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 and the in silico identification of their type of interactions and residues involved. The activities of CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 were examined by fluorescence based assays using recombinant cDNA-expressed human CYPs in Vivid® P450 screening kits. Cathinone reversibly inhibited CYP1A2, CYP2A6 and CYP3A5 via competitive, uncompetitive and noncompetitive modes with inhibition constant (Ki) values of 57.12, 13.75 and 23.57 µM respectively. Cathinone showed negligible inhibitory effects on CYP2B6, CYP2C8, CYP2C19, CYP2E1 and CYP2J2. Cathinone showed negligible time dependent inhibition on all 8 CYPs. Docking studies was performed on cathinone with CYP1A2, CYP2A6 and CYP3A5 following their inhibition in vitro. Cathinone is bound to a few key amino acid residues in the active sites while π-π interactions are formed in aromatic clusters of CYP1A2 and CYP3A5. These findings offer valuable reference for the use of cathinones and khat when combined with therapeutic drugs that are metabolised by CYP enzymes especially patients on medications metabolised by CYP1A2, CYP2A6 and CYP3A5.

8.
Int J Toxicol ; 41(5): 355-366, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35658727

RESUMO

Cathine is the stable form of cathinone, the major active compound found in khat (Catha edulis Forsk) plant. Khat was found to inhibit major phase I drug metabolizing cytochrome P450 (CYP) enzyme activities in vitro and in vivo. With the upsurge of khat consumption and the potential use of cathine to combat obesity, efforts should be channelled into understanding potential cathine-drug interactions, which have been rather limited. The present study aimed to assess CYPs activity and inhibition by cathine in a high-throughput in vitro fluorescence-based enzyme assay and molecular docking analysis to identify how cathine interacts within various CYPs' active sites. The half maximal inhibitory concentration (IC50) values of cathine determined for CYP2A6 and CYP3A4 were 80 and 90 µM, while CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP2J2 and CYP3A5 showed no significant inhibition. Furthermore, in Ki analysis, the Lineweaver-Burk plots depicted non-competitive mixed inhibition of cathine on both CYP2A6 and CYP3A4 with Ki value of 63 and 100 µM, respectively. Cathine showed negligible time-dependent inhibition on CYPs. Further, molecular docking studies showed that cathine was bound to CYP2A6 via hydrophobic, hydrogen and π-stacking interactions and formed hydrophobic and hydrogen bonds with active site residues in CYP3A4. Both molecular docking prediction and in vitro outcome are in agreement, granting more detailed insights for predicting CYPs metabolism besides the possible cathine-drug interactions. Cathine-drug interactions may occur with concomitant consumption of khat or cathine-containing products with medications metabolized by CYP2A6 and CYP3A4.


Assuntos
Citocromo P-450 CYP3A , Sistema Enzimático do Citocromo P-450 , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Ligantes , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Fenilpropanolamina
9.
J Comput Aided Mol Des ; 36(6): 427-441, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35581483

RESUMO

The recent availability of large numbers of GPCR crystal structures has provided an unprecedented opportunity to evaluate their performance in virtual screening protocols using established benchmarking datasets. In this study, we evaluated the ability of MM/GBSA in consensus scoring-based virtual screening enrichment together with nine classical scoring functions, using the GPCR-Bench dataset consisting of 24 GPCR crystal structures and 254,646 actives and decoys. While the performance of consensus scoring was modest overall, combinations which included MM/GBSA performed relatively well compared to combinations of classical scoring functions. Combinations of MM/GBSA and good-performing scoring functions provided the highest proportion of improvements, with improvements observed in 32% and 19% of all combinations across all targets at the EF1% and EF5% levels respectively. Combinations of MM/GBSA and poor-performing scoring functions still outperformed classical scoring functions, with improvements observed in 26% and 17% of all combinations at the EF1% and EF5% levels. In comparison, only 14-22% and 6-11% of combinations of classical scoring functions produced improvements at EF1% and EF5% respectively. Efforts to improve performance by increasing the number of scoring functions in consensus scoring to three were mostly ineffective. We also observed that consensus scoring performed better for individual scoring functions possessing initially low enrichment factors, potentially implying their benefits are more relevant in such scenarios. Overall, this study demonstrated the first implementation of MM/GBSA in consensus scoring using the GPCR-Bench dataset and could provide a valuable benchmark of the performance of MM/GBSA in comparison to classical scoring functions in consensus scoring for GPCRs.


Assuntos
Consenso , Ligantes , Ligação Proteica
10.
Int J Pharm Pract ; 30(1): 59-66, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34962576

RESUMO

OBJECTIVES: To determine the prescribing patterns and identify potentially inappropriate prescribing practices among general practitioners in the private primary care sector by analysing a large electronic health insurance claims database. METHODS: Medical claims records from February 2019 to February 2020 were extracted from a health insurance claims database. Data cleaning and data analysis were performed using Python 3.7 with the Pandas, NumPy and Matplotlib libraries. The top five most common diagnoses were identified, and for each diagnosis, the most common medication classes and medications prescribed were quantified. Potentially inappropriate prescribing practices were identified by comparing the medications prescribed with relevant clinical guidelines. KEY FINDINGS: The five most common diagnoses were upper respiratory tract infection (41.5%), diarrhoea (7.7%), musculoskeletal pain (7.6%), headache (6.7%) and gastritis (4.0%). Medications prescribed by general practitioners were largely as expected for symptomatic management of the respective conditions. One area of potentially inappropriate prescribing identified was inappropriate antibiotic choice. Same-class polypharmacy that may lead to an increased risk of adverse events were also identified, primarily involving multiple paracetamol-containing products, non-steroidal anti-inflammatory drugs (NSAIDs), and antihistamines. Other areas of non-adherence to guidelines identified included the potential overuse of oral corticosteroids and oral salbutamol, and inappropriate gastroprotection for patients receiving NSAIDs. CONCLUSIONS: While prescribing practices are generally appropriate within the private primary care sector, there remain several areas where some potentially inappropriate prescribing occurs. The areas identified should be the focus in continuing efforts to improve prescribing practices to obtain the optimal clinical outcomes while reducing unnecessary risks and healthcare costs.


Assuntos
Clínicos Gerais , Humanos , Prescrição Inadequada , Seguro Saúde , Malásia , Polimedicação , Padrões de Prática Médica
11.
Carbohydr Res ; 508: 108395, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34280804

RESUMO

Dysregulation of glycosylation pathways has been well documented in several types of cancer, where it often participates in cancer development and progression, especially cancer metastasis. Hence, inhibition of glycosidases such as mannosidases can disrupt the biosynthesis of glycans on cell surface glycoproteins and modify their role in carcinogenesis and metastasis. Several reviews have delineated the role of N-glycosylation in cancer, but the data regarding effective inhibitors remains sparse. Golgi α-mannosidase has been an attractive therapeutic target for preventing the formation of ß1,6-branched complex type N-glycans. However, due to its high structural similarity to the broadly specific lysosomal α-mannosidase, undesired co-inhibition occurs and this leads to serious side effects that complicates its potential role as a therapeutic agent. Even though extensive efforts have been geared towards the discovery of effective inhibitors, no breakthrough has been achieved thus far which could allow for their use in clinical settings. Improving the specificity of current inhibitors towards Golgi α-mannosidase is requisite in progressing this class of compounds in cancer chemotherapy. In this review, we highlight a few potent and selective inhibitors discovered up to the present to guide researchers for rational design of further effective inhibitors to overcome the issue of specificity.


Assuntos
Manosidases , Complexo de Golgi , alfa-Manosidase
12.
Int J Clin Pharm ; 43(3): 604-612, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33507463

RESUMO

Background The incidence of osteoporosis in Malaysia is increasing due to a fast-ageing population. Because of its silent nature, various osteoporosis risk assessment tools exist to detect high-risk patients and facilitate referrals for bone mineral density measurements. As an accessible point of contact, community pharmacists would benefit from the utilization of these tools and familiarity with guideline recommendations for osteoporosis screening. Aim This study aimed to investigate the awareness of osteoporosis risk assessment tools, practice behaviour towards osteoporosis, and knowledge of guideline recommendations among community pharmacists in the Klang Valley, Malaysia. Setting Community pharmacies. Methods This study was a cross-sectional study which sampled 284 community pharmacists practicing in the Klang Valley, using a stratified sampling approach. The study was conducted using a self-administered questionnaire which was divided into three sections: demographic data, knowledge of osteoporosis risk assessment tools and guideline recommendations, and practice behaviour towards osteoporosis. Practice behaviour was assessed with 15 items using a 5-point Likert scale. Main outcome measure. Proportion of respondents aware of osteoporosis risk assessment tools and respondent knowledge on guideline recommendations for osteoporosis screening. Results A total of 284 community pharmacists participated in the study. 84.1% of the respondents were aware of at least one risk assessment tool. However, only a small proportion of pharmacists (14.9%) regularly used these tools in their practice. Respondents perceived these tools to be relevant and beneficial, but perception towards their accessibility, ease-of-use, and administration time was mixed, suggesting unfamiliarity. Respondents preferred to conduct clinical assessments based on risk factors, with respondents identifying a mean of 10.1 ± 3.4 out of 15 risk factors. However, several clinically relevant risk factors were frequently unidentified. Knowledge of guideline recommendations among respondents was low. Conclusion There is some awareness of osteoporosis risk assessment tools but use in practice remains low among community pharmacists in Malaysia. There is potential to increase the use of these tools and knowledge of recommendations for osteoporosis screening and referral among community pharmacists.


Assuntos
Serviços Comunitários de Farmácia , Osteoporose , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Malásia/epidemiologia , Osteoporose/diagnóstico , Osteoporose/epidemiologia , Farmacêuticos , Medição de Risco , Inquéritos e Questionários
13.
Int J Pharm Pract ; 29(1): 29-36, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32715568

RESUMO

OBJECTIVES: Self-medication, while potentially beneficial, also brings certain risks such as inappropriate treatment and adverse effects. In this study, we determine the prevalence and perception towards self-medication among adults living in the Klang Valley, Malaysia. METHODS: This study was a cross-sectional study which sampled 562 respondents across the Klang Valley, Malaysia using a stratified quota sampling method and a self-administered questionnaire. The questionnaire consisted of three sections: demographic data, self-medication practices and perception towards self-medication. Perception towards self-medication was measured using 20 statements with a 5-point Likert scale. Descriptive and inferential tests as well as factor analysis were used to analyse the data. KEY FINDINGS: The overall prevalence of self-medication for minor ailments was 63.5%. Self-medication was practised to a similar degree regardless of respondent demographics. Respondents most frequently obtained their medicines for self-medication of minor ailments from pharmacies without consulting the pharmacist (68.6%), followed by using leftover medications at home (44.8%) and obtaining medicines from friends and family (16.0%). Factor analysis revealed that self-medication behaviour is driven by good perception towards self-medication in terms of efficacy, safety and convenience, as well as by previous personal or shared experiences. CONCLUSION: The prevalence of self-medication is high among adults in the Klang Valley, Malaysia. Adults who self-medicate view the consequences of self-medication in a positive light and may be influenced by previous personal or shared experiences. As certain risks with self-medication may be underestimated, efforts to educate the public while promoting a more proactive approach among healthcare professionals should be encouraged.


Assuntos
Percepção , Automedicação , Adulto , Estudos Transversais , Humanos , Malásia , Prevalência
14.
J Comput Aided Mol Des ; 34(11): 1133-1145, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32851579

RESUMO

Recent breakthroughs in G protein-coupled receptor (GPCR) crystallography and the subsequent increase in number of solved GPCR structures has allowed for the unprecedented opportunity to utilize their experimental structures for structure-based drug discovery applications. As virtual screening represents one of the primary computational methods used for the discovery of novel leads, the GPCR-Bench dataset was created to facilitate comparison among various virtual screening protocols. In this study, we have benchmarked the performance of Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) in improving virtual screening enrichment in comparison to docking with Glide, using the entire GPCR-Bench dataset of 24 GPCR targets and 254,646 actives and decoys. Reranking the top 10% of the docked dataset using MM/PBSA resulted in improvements for six targets at EF1% and nine targets at EF5%, with the gains in enrichment being more pronounced at the EF1% level. We additionally assessed the utility of rescoring the top ten poses from docking and the ability of short MD simulations to refine the binding poses prior to MM/PBSA calculations. There was no clear trend of the benefit observed in both cases, suggesting that utilizing a single energy minimized structure for MM/PBSA calculations may be the most computationally efficient approach in virtual screening. Overall, the performance of MM/PBSA rescoring in improving virtual screening enrichment obtained from docking of the GPCR-Bench dataset was found to be relatively modest and target-specific, highlighting the need for validation of MM/PBSA-based protocols prior to prospective use.


Assuntos
Receptores Acoplados a Proteínas G/química , Benchmarking , Sítios de Ligação , Bases de Dados de Compostos Químicos , Avaliação Pré-Clínica de Medicamentos , Humanos , Simulação de Acoplamento Molecular , Distribuição de Poisson , Ligação Proteica , Conformação Proteica , Termodinâmica
15.
Genetics ; 215(4): 959-974, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513814

RESUMO

Mutations affecting DNA polymerase exonuclease domains or mismatch repair (MMR) generate "mutator" phenotypes capable of driving tumorigenesis. Cancers with both defects exhibit an explosive increase in mutation burden that appears to reach a threshold, consistent with selection acting against further mutation accumulation. In Saccharomyces cerevisiae haploid yeast, simultaneous defects in polymerase proofreading and MMR select for "antimutator" mutants that suppress the mutator phenotype. We report here that spontaneous polyploids also escape this "error-induced extinction" and routinely outcompete antimutators in evolved haploid cultures. We performed similar experiments to explore how diploid yeast adapt to the mutator phenotype. We first evolved cells with homozygous mutations affecting polymerase δ proofreading and MMR, which we anticipated would favor tetraploid emergence. While tetraploids arose with a low frequency, in most cultures, a single antimutator clone rose to prominence carrying biallelic mutations affecting the polymerase mutator alleles. Variation in mutation rate between subclones from the same culture suggests that there exists continued selection pressure for additional antimutator alleles. We then evolved diploid yeast modeling MMR-deficient cancers with the most common heterozygous exonuclease domain mutation (POLE-P286R). Although these cells grew robustly, within 120 generations, all subclones carried truncating or nonsynonymous mutations in the POLE-P286R homologous allele (pol2-P301R) that suppressed the mutator phenotype as much as 100-fold. Independent adaptive events in the same culture were common. Our findings suggest that analogous tumor cell populations may adapt to the threat of extinction by polyclonal mutations that neutralize the POLE mutator allele and preserve intratumoral genetic diversity for future adaptation.


Assuntos
Adaptação Fisiológica , Evolução Molecular , Genoma Fúngico , Poliploidia , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Mutação , Taxa de Mutação , Fenótipo , Saccharomyces cerevisiae/crescimento & desenvolvimento
16.
Chem Biol Drug Des ; 96(5): 1244-1254, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32462752

RESUMO

Both the inactive- and active-state CB1 receptor crystal structures have now been solved, allowing their application in various structure-based drug design methods. One potential method utilizing these crystal structures is the Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) method of predicting relative binding free.


Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Simulação de Dinâmica Molecular , Receptor CB1 de Canabinoide/antagonistas & inibidores , Agonistas de Receptores de Canabinoides/metabolismo , Distribuição de Poisson , Ligação Proteica , Receptor CB1 de Canabinoide/metabolismo
17.
J Eval Clin Pract ; 26(1): 165-171, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31168913

RESUMO

BACKGROUND: Potentially inappropriate medications (PIMs) in older adults are detrimental to both clinical outcomes and health care costs, with their prominence set to increase in tandem with a fast-growing ageing population. Beers Criteria is one of the most commonly used guidelines that lists specific PIMs. Community pharmacists would therefore benefit from knowledge of Beers Criteria in detecting PIMs in primary care. This study therefore investigates the awareness of Beers Criteria and knowledge of PIMs among community pharmacists in the Klang Valley, Malaysia. METHODS: The study was conducted using a self-administered questionnaire. Knowledge of PIMs was assessed using 10 clinical vignettes based on the 2015 Beers Criteria. Practice behaviour towards older customers was assessed using 10 items with a 5-point Likert scale. Descriptive and inferential statistics were used to analyse the data. RESULTS: A total of 277 community pharmacists participated in the study. Only 27.1% of the pharmacists were aware of Beers Criteria, and of these, only 37.3% were aware of the latest 2015 update. The respondents demonstrated moderate knowledge of PIMs with a mean total score of 5.46 ± 1.89 out of a maximum of 10. Pharmacists who were aware of Beers Criteria had significantly higher scores (6.31 vs 5.14, P < .001). Only a small proportion of pharmacists (17.0%) regularly used Beers Criteria in practice. However, most pharmacists reported good practices when dealing with older customers in terms of asking relevant questions, considering age, referring to other resources, and regularly updating their knowledge through continuous professional development. CONCLUSION: Awareness of Beers Criteria remains low among community pharmacists in Malaysia. Pharmacists who are aware of Beers Criteria have improved knowledge regarding PIMs in the older adults. There is a need to increase the awareness and use of Beers Criteria among community pharmacists.


Assuntos
Farmacêuticos , Lista de Medicamentos Potencialmente Inapropriados , Idoso , Estudos Transversais , Humanos , Prescrição Inadequada/prevenção & controle , Malásia
18.
Molecules ; 24(20)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614517

RESUMO

Human A3 adenosine receptor hA3AR has been implicated in gastrointestinal cancer, where its cellular expression has been found increased, thus suggesting its potential as a molecular target for novel anticancer compounds. Observation made in our previous work indicated the importance of the carbonyl group of amide in the indolylpyrimidylpiperazine (IPP) for its human A2A adenosine receptor (hA2AAR) subtype binding selectivity over the other AR subtypes. Taking this observation into account, we structurally modified an indolylpyrimidylpiperazine (IPP) scaffold, 1 (a non-selective adenosine receptors' ligand) into a modified IPP (mIPP) scaffold by switching the position of the carbonyl group, resulting in the formation of both ketone and tertiary amine groups in the new scaffold. Results showed that such modification diminished the A2A activity and instead conferred hA3AR agonistic activity. Among the new mIPP derivatives (3-6), compound 4 showed potential as a hA3AR partial agonist, with an Emax of 30% and EC50 of 2.89 ± 0.55 µM. In the cytotoxicity assays, compound 4 also exhibited higher cytotoxicity against both colorectal and liver cancer cells as compared to normal cells. Overall, this new series of compounds provide a promising starting point for further development of potent and selective hA3AR partial agonists for the treatment of gastrointestinal cancers.


Assuntos
Neoplasias Gastrointestinais/tratamento farmacológico , Pirimidinonas/química , Receptor A2A de Adenosina/genética , Receptor A3 de Adenosina/genética , Antagonistas do Receptor A2 de Adenosina/síntese química , Antagonistas do Receptor A2 de Adenosina/química , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Células CHO , Proliferação de Células/efeitos dos fármacos , Cricetinae , Cricetulus , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/patologia , Humanos , Indóis/síntese química , Indóis/química , Indóis/farmacologia , Modelos Moleculares , Piperazina/síntese química , Piperazina/química , Piperazina/farmacologia , Pirimidinonas/síntese química , Pirimidinonas/farmacologia , Receptor A2A de Adenosina/química , Relação Estrutura-Atividade
19.
J Comput Aided Mol Des ; 33(5): 487-496, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30989574

RESUMO

The recent expansion of GPCR crystal structures provides the opportunity to assess the performance of structure-based drug design methods for the GPCR superfamily. Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA)-based methods are commonly used for binding affinity prediction, as they provide an intermediate compromise of speed and accuracy between the empirical scoring functions used in docking and more robust free energy perturbation methods. In this study, we systematically assessed the performance of MM/PBSA in predicting experimental binding free energies using twenty Class A GPCR crystal structures and 934 known ligands. Correlations between predicted and experimental binding free energies varied significantly between individual targets, ranging from r = - 0.334 in the inactive-state CB1 cannabinoid receptor to r = 0.781 in the active-state CB1 cannabinoid receptor, while average correlation across all twenty targets was relatively poor (r = 0.183). MM/PBSA provided better predictions of binding free energies compared to docking scores in eight out of the twenty GPCR targets while performing worse for four targets. MM/PBSA binding affinity predictions calculated using a single, energy minimized structure provided comparable predictions to sampling from molecular dynamics simulations and may be more efficient when computational cost becomes restrictive. Additionally, we observed that restricting MM/PBSA calculations to ligands with a high degree of structural similarity to the crystal structure ligands improved performance in several cases. In conclusion, while MM/PBSA remains a valuable tool for GPCR structure-based drug design, its performance in predicting the binding free energies of GPCR ligands remains highly system-specific as demonstrated in a subset of twenty Class A GPCRs, and validation of MM/PBSA-based methods for each individual case is recommended before prospective use.


Assuntos
Receptores Acoplados a Proteínas G/química , Desenho de Fármacos , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Receptores Acoplados a Proteínas G/metabolismo , Termodinâmica
20.
RSC Adv ; 9(32): 18359-18370, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35515266

RESUMO

Copper complexes have the potential to be developed as targeted therapy for cancer because cancer cells take up larger amounts of copper than normal cells. Copper complex Cu(SBCM)2 has been reported to induce cell cycle arrest and apoptosis towards triple-negative breast cancer cells. Nevertheless, its effect towards other breast cancer subtypes has not been explored. Therefore, the present study was conducted to investigate the effect of Cu(SBCM)2 towards oestrogen-receptor positive MCF-7 breast cancer cells. Growth inhibition of Cu(SBCM)2 towards MCF-7 and human non-cancerous MCF-10A breast cells was determined by MTT assay. Morphological changes of Cu(SBCM)2-treated-MCF-7 cells were observed under an inverted microscope. Annexin V/PI apoptosis assay and cell cycle analysis were evaluated by flow cytometry. The expression of wild-type p53 protein was evaluated by Western blot analysis. The intracellular ROS levels of MCF-7 treated with Cu(SBCM)2 were detected using DCFH-DA under a fluorescence microscope. The cells were then co-treated with Cu(SBCM)2 and antioxidants to evaluate the involvement of ROS in the cytotoxicity of Cu(SBCM)2. Docking studies of Cu(SBCM)2 with DNA, DNA topoisomerase I, and human ribonucleotide reductase were also performed. The growth of MCF-7 cells was inhibited by Cu(SBCM)2 in a dose-dependent manner with less toxicity towards MCF-10A cells. It was found that Cu(SBCM)2 induced G2/M cell cycle arrest and apoptosis in MCF-7 cells, possibly via a p53 pathway. Induction of intracellular ROS was not detected in MCF-7 cells. Interestingly, antioxidants enhance the cytotoxicity of Cu(SBCM)2 towards MCF-7 cells. DNA topoisomerase I may be the most likely target that accounts for the cytotoxicity of Cu(SBCM)2.

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