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Gene Silencing by RNAi in Mammalian Cells

Ponthan F, Yusoff NM, Soria NM, Heidenreich O, Coffey K

Curr Protoc Mol Biol, 2015 Jul 01;111:26.2.1-26.2.17.
PMID: 26131850 DOI: 10.1002/0471142727.mb2602s111

This unit provides information how to use short interfering RNA (siRNA) for sequence-specific gene silencing in mammalian cells. Several methods for siRNA generation and optimization, as well as recommendations for cell transfection and transduction, are presented.

Matched MeSH terms: Cell Line
Synthesis and characterization of silver nanoparticles using fruit extract of Momordica cymbalaria and assessment of their in vitro antimicrobial, antioxidant and cytotoxicity activities

Swamy MK, Akhtar MS, Mohanty SK, Sinniah UR

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Dec 5;151:939-44.
PMID: 26186612 DOI: 10.1016/j.saa.2015.07.009

Plant mediated synthesis of nanoparticles has been considered as green route and a reliable technique for the synthesis of nanoparticles due to its eco-friendly approach. In this study, we report a simple and eco-friendly approach for the synthesis of silver nanoparticles (AgNPs) using methanolic Momordica cymbalaria fruit extract as reducing agent. The fruit extract of M. cymbalaria exposed to AgNO3 solution showed the change in color from green to light yellow at room temperature within 1h of incubation confirms the synthesis of AgNPs. UV-vis spectra analysis revealed that the synthesized AgNPs had a sharp surface plasmon resonance at around 450 nm, while, the X-ray Diffraction (XRD) patterns confirmed distinctive peaks indices to the crystalline planes of the face centered cubic silver. The Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analysis results confirmed the presence of spherical shaped AgNPs by a huge disparity in the particle size distribution with an average size of 15.5 nm. The synthesized AgNPs showed strong antibacterial activity against all the tested multidrug resistant human pathogenic bacterial strains and also exhibited highest free radical scavenging activity (74.2%) compared to fruit extract (60.4%). Moreover, both fruit extract and the synthesized AgNPs showed the cytotoxicity towards Rat L6 skeletal muscle cell line at different concentrations, but the highest inhibition percentage was recorded for AgNPs at concentration of 100 μg/ml.

Matched MeSH terms: Cell Line
Fulltext Neural Differentiation of Human Pluripotent Stem Cells for Nontherapeutic Applications: Toxicology, Pharmacology, and In Vitro Disease Modeling

Yap MS, Nathan KR, Yeo Y, Lim LW, Poh CL, Richards M, et al.

Stem Cells Int, 2015;2015:105172.
PMID: 26089911 DOI: 10.1155/2015/105172

Human pluripotent stem cells (hPSCs) derived from either blastocyst stage embryos (hESCs) or reprogrammed somatic cells (iPSCs) can provide an abundant source of human neuronal lineages that were previously sourced from human cadavers, abortuses, and discarded surgical waste. In addition to the well-known potential therapeutic application of these cells in regenerative medicine, these are also various promising nontherapeutic applications in toxicological and pharmacological screening of neuroactive compounds, as well as for in vitro modeling of neurodegenerative and neurodevelopmental disorders. Compared to alternative research models based on laboratory animals and immortalized cancer-derived human neural cell lines, neuronal cells differentiated from hPSCs possess the advantages of species specificity together with genetic and physiological normality, which could more closely recapitulate in vivo conditions within the human central nervous system. This review critically examines the various potential nontherapeutic applications of hPSC-derived neuronal lineages and gives a brief overview of differentiation protocols utilized to generate these cells from hESCs and iPSCs.

Matched MeSH terms: Cell Line
Fulltext Inhibitory and apoptosis-inducing effects of Newcastle disease virus strain AF2240 on mammary carcinoma cell line

Ahmad U, Ahmed I, Keong YY, Abd Manan N, Othman F

Biomed Res Int, 2015;2015:127828.
PMID: 25821783 DOI: 10.1155/2015/127828

Breast cancer is the malignant tumour that developed from cells of the breast and is the first leading cause of cancer death among women worldwide. Surgery, radiotherapy, and chemotherapy are the available treatments for breast cancer, but these were reported to have side effects. Newcastle disease virus (NDV) known as Avian paramyxovirus type-1 (APMV1) belongs to the genus Avulavirus in a family Paramyxoviridae. NDV is shown to be a promising anticancer agent, killing tumour cells while sparing normal cells unharmed. In this study, the oncolytic and cytotoxic activities of NDV AF2240 strain were evaluated on MDA-MB-231, human mammary carcinoma cell line, using MTT assay, and its inhibitory effects were further studied using proliferation and migration assays. Morphological and apoptotic-inducing effects of NDV on MD-MB-231 cells were observed using phase contrast and fluorescence microscopes. Detection of DNA fragmentation was done following terminal deoxyribonucleotide transferase-mediated Br-dUTP nick end labeling staining (TUNEL) assay, which confirmed that the mode of death was through apoptosis and was quantified by flow cytometry. Furthermore, analysis of cellular DNA content demonstrated that the virus caused an increase in the sub-G1 phase (apoptotic peak) of the cell cycle. It appears that NDV AF2240 strain is a potent anticancer agent that induced apoptosis in time-dependent manner.

Matched MeSH terms: Cell Line, Tumor
Effects of 14-deoxyandrographolide and 14-deoxy-11,12-didehydroandrographolide on nitric oxide production in cultured human endothelial cells

Zhang CY, Tan BK

Phytother Res, 1999 Mar;13(2):157-9.
PMID: 10190192

14-deoxyandrographolide (DA) and 14-deoxy-11,12-didehydroandrographolide (DDA) are two diterpenoids isolated from A. paniculata, a popular folk medicine used as an antihypertensive drug in Malaysia. We have previously reported that DDA exhibited a greater hypotensive effect in anaesthetized rats and a vasorelaxant activity in isolated rat aorta, compared with DA. Their vasorelaxant activities were mediated through the activation of the enzymes, nitric oxide synthase (NOS) and guanylyl cyclase. The present study demonstrated that both DA and DDA stimulated nitric oxide (NO) release from human endothelial cells. DDA compared with DA caused a greater production of NO; this is in line with the finding of the earlier study that the vasorelaxant effect of DDA was more dependent on endothelium than DA.

Matched MeSH terms: Cell Line
Antimicrobial, antioxidant, antitumour-promoting and cytotoxic activities of different plant part extracts of Garcinia atroviridis griff. ex T. anders

Mackeen MM, Ali AM, Lajis NH, Kawazu K, Hassan Z, Amran M, et al.

J Ethnopharmacol, 2000 Oct;72(3):395-402.
PMID: 10996278

Crude extracts (methanol) of various parts, viz. the leaves, fruits, roots, stem and trunk bark, of Garcinia atroviridis were screened for antimicrobial, cytotoxic, brine shrimp toxic, antitumour-promoting and antioxidant activities. The crude extracts exhibited predominantly antibacterial activity with the root extract showing the strongest inhibition against the test bacteria at a minimum inhibitory dose (MID) of 15.6 microg/disc. Although all the extracts failed to inhibit the growth of most of the test fungi, significant antifungal activity against Cladosporium herbarum was exhibited by most notably the fruit (MID: 100 microg), and the leaf (MID: 400 microg) extracts. None of the extracts were significantly cytotoxic, and lethal towards brine shrimps. The root, leaf, trunk and stem bark extracts (except for the fruits) showed strong antioxidant activity exceeding that of the standard antioxidant, alpha-tocopherol. Antitumour-promoting activity (>95% inhibition) was shown by the fruit, leaf, stem and trunk bark extracts.

Matched MeSH terms: Cell Line
Abundance, parity, and Japanese encephalitis virus infection of mosquitoes (Diptera:Culicidae) in Sepang District, Malaysia

Vythilingam I, Oda K, Mahadevan S, Abdullah G, Thim CS, Hong CC, et al.

J Med Entomol, 1997 May;34(3):257-62.
PMID: 9151487

A 2-yr study of Japanese encephalitis (JE) virus in Sepang District, Selangor, Malaysia, was carried out to identify the mosquito vectors and to determine their seasonal abundance, parity, and infection rates. In total, 81,889 mosquitoes belonging to 9 genera and > 50 species were identified from CDC trap collections augmented with dry ice during 1992 and 1993. Culex tritaeniorhynchus Giles and Culex gelidus Giles were the most abundant species, and both increased in numbers with increases in rainfall. Overall, 45 JE virus isolations were made from 7 species-Cx. tritaeniorhynchus (24), Cx. gelidus (12), Culex fuscocephala Theobald (2), Aedes butleri Theobald (4), Culex quinquefasciatus Say (1), Aedes lineatopennis Ludlow (1), and Aedes (Cancraedes) sp. (1). Based on elevated abundance and JE infection rates, Cx. tritaeniorhynchus appears to be the most important vector of JE virus in Sepang.

Matched MeSH terms: Cell Line
Multicentre evaluation of dengue IgM dot enzyme immunoassay

Lam SK, Fong MY, Chungue E, Doraisingham S, Igarashi A, Khin MA, et al.

Clin Diagn Virol, 1996 Nov;7(2):93-8.
PMID: 9137865 DOI: 10.1016/S0928-0197(96)00257-7

The traditional methods used in the diagnosis of dengue infection do not lend themselves to field application. As such, clinical specimens have to be sent to a central laboratory for processing which invariably leads to delay. This affects patient management and disease control. The development of the dengue IgM dot enzyme immunoassay has opened up the possibility of carrying out the test in peripheral health settings.

Matched MeSH terms: Cell Line
Tumour promoter activity in Malaysian Euphorbiaceae

Norhanom AW, Yadav M

Br. J. Cancer, 1995 Apr;71(4):776-9.
PMID: 7710943

Herbal medication has been practised by the rural Malaysian Malays for a long time. However, the long-term side-effects have never been studied. In the present study, 48 species of Euphorbiaceae were screened for tumour-promoter activity by means of an in vitro assay using a human lymphoblastoid cell line harbouring the Epstein-Barr virus (EBV) genome. Twenty-seven per cent (13 out of 48) of the species tested were found to be positive, and in four species, namely Breynia coronata Hk.f, Codiaeum variegatum (L) Bl, Euphorbia atoto and Exocoecaria agallocha, EBV-inducing activity was observed when the plant extracts were tested at low concentrations of between 0.2 and 1.2 micrograms ml-1 in cell culture. This observation warrants attention from the regular users of these plants because regular use of plants with tumour-promoting activity could well be an aetiological factor for the promotion of tumours among rural Malaysian Malays.

Matched MeSH terms: Cell Line
T cell-mediated cytotoxicity against dengue-infected target cells

Pang T, Devi S, Blanden RV, Lam SK

Microbiol. Immunol., 1988;32(5):511-8.
PMID: 3262810 DOI: 10.1111/j.1348-0421.1988.tb01411.x

A cytotoxic T lymphocyte (CTL) response to dengue virus-infected target cells is described. Effector cells were generated in an in vitro secondary culture and appeared to be T cells possessing both the Lyt 1.1 and Lyt 2.1 surface antigens. A stronger CTL response was noted with the H-2k haplotype compared to H-2d, and H-2 compatibility was required between CTL and target cells. CTL generated showed some cross-reactivity with target cells infected with Japanese encephalitis virus (JEV), another flavivirus, but not with target cells infected with an alphavirus, Sindbis. The significance and importance of these findings are discussed.

Matched MeSH terms: Cell Line
Attenuation of virulence of flaviviruses following passage in HeLa cells

Dunster LM, Gibson CA, Stephenson JR, Minor PD, Barrett AD

J Gen Virol, 1990 Mar;71 ( Pt 3):601-7.
PMID: 2155996

The ability of passage in HeLa cells to attenuate flaviviruses was investigated for three different strains of the mosquito-borne West Nile (WN) virus and two tick-borne viruses, louping-ill and Langat. One strain of WN virus, Sarawak, was attenuated 4000-fold for adult mice by intraperitoneal or intranasal challenge after six HeLa passages. The HeLa-passaged virus was also found to be antigenically different and temperature-sensitive in its growth characteristics compared with the parent. After six HeLa cell passages the Egypt 101 and Smithburn strains of WN virus lost their ability to infect monkey kidney cells and no longer killed adult mice, although inoculated animals became sick for several days. In contrast, two tick-borne flaviviruses remained as virulent for mice after six HeLa passages as the parent non-HeLa-passaged virus. Neither of the tick-borne viruses exhibited characteristics associated with temperature sensitivity. The results, therefore, indicate that the mosquito-borne, but not tick-borne, flaviviruses can be attenuated by very few passages in HeLa cells. This observation may provide a model system with which to analyse the molecular basis of attenuation and/or virulence of mosquito-borne flaviviruses.

Matched MeSH terms: Cell Line
Fatty acid binding protein 7 mediates linoleic acid-induced cell death in triple negative breast cancer cells by modulating 13-HODE

Kwong SC, Abd Jamil AH, Rhodes A, Taib NA, Chung I

Biochimie, 2020 Dec;179:23-31.
PMID: 32931863 DOI: 10.1016/j.biochi.2020.09.005

Different fatty acids have distinct effects on the survival of breast cancer cells, which could be mediated by fatty acid binding proteins (FABPs), a family of lipid chaperones. Due to the diverse structures of the members of FABP family, each FABP demonstrates distinct binding affinities to different fatty acids. Of note, FABP7 is predominantly expressed in triple negative breast cancer (TNBC), the most aggressive subtype of breast cancer. Yet, the role of FABP7 in modulating the effects of fatty acids on TNBC survival was unclear. In contrast to the high expression of FABP7 in human TNBC tumours, FABP7 protein was undetectable in TNBC cell lines. Hence, a FABP7 overexpression model was used for this study, in which the transduced TNBC cell lines (MDA-MB-231 and Hs578T) were treated with various mono- and polyunsaturated fatty acids. Oleic acid (OA), docosahexaenoic acid (DHA) and arachidonic acid (AA) inhibited TNBC cell growth at high concentrations, with no differences resulted from FABP7 overexpression. Interestingly, overexpression of FABP7 augmented linoleic acid-induced cell death in MDA-MB-231 cells. The increased cell death may be explained by a decrease in 13-HODE, a pro-tumorigenic oxidation product of linoleic acid. The phenotype was, however, attenuated with a rescue treatment using 25 nM 13-HODE. The decrease in 13-HODE was potentially due to fatty acid partitioning modulated by FABP7, as demonstrated by a 3-fold increase in fatty acid oxidation. Our findings suggest that linoleic acid could be a potential therapeutic strategy for FABP7-overexpressing TNBC patients.

Matched MeSH terms: Cell Line
Fulltext Targeting bladder cancer stem cells using Newcastle disease virus

Arcana Thirumorthy, De-Ming Chau, Khatijah Yusoff, Abhi Veerakumarasivam

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):24-24.
MyJurnal

Introduction: Bladder cancer is associated with high risk of tumour recurrence and therapeutic resistance. Cancer stem cells (CSC) within a particular tumour are postulated to drive tumorigenesis and influence tumour behaviour. Recent studies have shown that Newcastle disease virus (NDV) is able to selectively kill and exert a strong oncolytic effect against various cancer types. However little is known about the oncolytic effect of NDV against CSC. In this study, the oncolytic effect of NDV against putative bladder CSC was examined. Methods: Putative bladder CSC was selectively grown in the form of 3D-spheroids from six different bladder cancer cell lines. The spheroid cells were characterised for their stemness properties to ensure that these cells truly represent CSC. This was conducted via the analysis of CSC associated genes and cell surface markers expression. Subsequently, the oncolytic effect of the wild-type NDV-AF2240 strain against the bladder cancer spheroids was investigated. Results: All the spheroids expressed significantly high levels of CSC-associated genes. Flow-cytometry analysis revealed that the expression pattern of the CSC-associated surface markers was different in the spheroid cells; suggesting heterogeneity in the expression signatures of these cells. The infection of spheroids with NDV showed that the NDV was able to target bladder cancer spheroids but there was a spectrum of response across the different spheroids. Intriguingly, NDV was able to persistently infect bladder cancer spheroids that were not sensitive towards NDV infection as the presence of NDV viral genes were detected in the spheroid cells. The NDV persistently infected bladder cancer spheroids were resistant to superinfection and developed an antiviral state by expressing low levels of interferon-beta (IFN-b). NDV persistency of infection affects the process of epithelial to mesenchymal transition (EMT) of cancer cells as the spheroid forming ability of an established NDV persistently infected bladder cancer cell line, EJ28-PI was shown to be impaired. The EJ28-PI cells expressed significantly high levels of the EN2 gene. Knockdown of the EN2 expression reduced the viability of EJ28-PI cells; suggesting a role for EN2 in mediating NDV persistency of infection in cancer cells. Conclusion: Bladder CSC gene expression signatures influence the efficacy of NDV-mediated oncolysis. Our current work is focused on identifying genes and signalling pathways that influence NDV-mediated oncolysis us-ing whole-transcriptomic sequencing. The findings of this study can potentially be used to enhance the efficacy of NDV-mediated oncolysis and accelerate the translation of NDV as an oncotherapeutic agent in the clinic.

Matched MeSH terms: Cell Line
Genetic Structure and Diversity Among Historic and Modern Populations of the Sumatran Rhinoceros (Dicerorhinus sumatrensis)

Brandt JR, van Coeverden de Groot PJ, Witt KE, Engelbrektsson PK, Helgen KM, Malhi RS, et al.

J Hered, 2018 06 27;109(5):553-565.
PMID: 29684146 DOI: 10.1093/jhered/esy019

The Sumatran rhinoceros (Dicerorhinus sumatrensis), once widespread across Southeast Asia, now consists of as few as 30 individuals within Sumatra and Borneo. To aid in conservation planning, we sequenced 218 bp of control region mitochondrial (mt) DNA, identifying 17 distinct mitochondrial haplotypes across modern (N = 13) and museum (N = 26) samples. Museum specimens from Laos and Myanmar had divergent mtDNA, consistent with the placement of western mainland rhinos into the distinct subspecies D. s. lasiotis (presumed extinct). Haplotypes from Bornean rhinos were highly diverse, but dissimilar from those of other regions, supporting the distinctiveness of the subspecies D. s. harrissoni. Rhinos from Sumatra and Peninsular Malaysia shared mtDNA haplotypes, consistent with their traditional placement into a single subspecies D. s sumatrensis. Modern samples of D. s. sumatrensis were genotyped at 18 microsatellite loci. Rhinos within Sumatra formed 2 sub-populations, likely separated by the Barisan Mountains, though with only modest genetic differentiation between them. There are so few remaining Sumatran rhinoceros that separate management strategies for subspecies or subpopulations may not be viable, while each surviving rhino pedigree is likely to retain alleles found in no other individuals. Given the low population size and low reproductive potential of Sumatran rhinos, rapid genetic erosion is inevitable, though an under-appreciated concern is the potential for fixation of harmful genetic variants. Both concerns underscore 2 overriding priorities for the species: 1) translocation of wild rhinos to ex situ facilities, and 2) collection and storage of gametes and cell lines from every surviving captive and wild individual.

Matched MeSH terms: Cell Line
Robust dengue virus infection in bat cells and limited innate immune responses coupled with positive serology from bats in IndoMalaya and Australasia

Irving AT, Rozario P, Kong PS, Luko K, Gorman JJ, Hastie ML, et al.

Cell Mol Life Sci, 2020 Apr;77(8):1607-1622.
PMID: 31352533 DOI: 10.1007/s00018-019-03242-x

Natural reservoir hosts can sustain infection of pathogens without succumbing to overt disease. Multiple bat species host a plethora of viruses, pathogenic to other mammals, without clinical symptoms. Here, we detail infection of bat primary cells, immune cells, and cell lines with Dengue virus. While antibodies and viral RNA were previously detected in wild bats, their ability to sustain infection is not conclusive. Old-world fruitbat cells can be infected, producing high titres of virus with limited cellular responses. In addition, there is minimal interferon (IFN) response in cells infected with MOIs leading to dengue production. The ability to support in vitro replication/production raises the possibility of bats as a transient host in the life cycle of dengue or similar flaviviruses. New antibody serology evidence from Asia/Pacific highlights the previous exposure and raises awareness that bats may be involved in flavivirus dynamics and infection of other hosts.

Matched MeSH terms: Cell Line
Fulltext Ultrastructure of Felis catus whole fetus (Fcwf-4) cell culture following infection with feline coronavirus

Alazawy A, Arshad SS, Bejo MH, Omar AR, Tengku Ibrahim TA, Sharif S, et al.

J Electron Microsc (Tokyo), 2011;60(4):275-82.
PMID: 21593079 DOI: 10.1093/jmicro/dfr031

Feline coronavirus (FCoV) consists of two biotypes based on their growth in cell culture and their antigenicity. Infections with FCoV are highly prevalent in the cat population worldwide. In this study, Felis catus whole fetus (Fcwf-4)cell culture was infected with FCoV UPM11C/08. Virus multiplication in cell culture was monitored and examined under the transmission electron microscope. The virus particles revealed the characteristic morphology of feline FCoV represented by envelope viruses surrounded by peplomers. Virus attachment and entry into the cell occurred 15 h post-infection (pi), and the myriad of virus particles were observed both extracellularly and intracellularly after 48 h pi. Thereafter, intracellular virus particles were observed to be present in vacuoles or present freely in the cytoplasm.

Matched MeSH terms: Cell Line
Replication of a malaysian strain avian influenza a virus H5N1 in madin-darby canine kidney and african green monkey kidney cells

Tan TS, Sharifah Syed Hassan, Yap WB

Sains Malaysiana, 2016;45:787-793.

The use of cell lines such as Madin-Darby Canine Kidney (MDCK) and African Green Monkey Kidney (Vero) cells in
influenza vaccine production is much advocated presently as a safer alternative to chicken embryonated eggs. It is
thus essential to understand the influenza virus replication patterns in these cell lines prior to utilizing them in vaccine
production. The infectivity of avian influenza A virus (A/Chicken/Malaysia/5858/2004) H5N1 in MDCK and Vero cell
lines was first assessed by comparing the cytopathic effect (CPE) caused by the virus infection. The viral loads in both
of the infected media and cells were also compared. The results showed that both of the MDCK and Vero cells began to
exhibit significant CPE (p<0.05) after 48 h post-infection (h p.i). The MDCK cell line was more susceptible to the virus
infection compared to Vero cell line throughout the incubation period. A higher viral load was also detected in the host
cells compared to their respective culturing media. Interestingly, after reaching its maximum titer at 48 h p.i, the viral
load in MDCK cells declined meanwhile the viral load in Vero cells increased gradually and peaked at 120 h p.i. Overall,
both cell lines support efficient H5N1 virus replication. While the peak viral loads measured in the two cell lines did
not differ much, a more rapid replication was observed in the infected MDCK samples. The finding showed that MDCK
cell line might serve as a more time-saving and cost-effective cell culture-based system compared to Vero cell line for
influenza vaccine production.

Matched MeSH terms: Cell Line
Malaysian tualang honey and its potential anti-cancer properties: a review

Ahmad Firdaus Khalid, Yoke KY, Jun JT

Sains Malaysiana, 2018;47:2705-2711.

The use of honey as a therapeutic agent dates back at 8000 years and has markedly increased interest into its potential
health benefits. The by-products of the flower nectar have a complex chemical composition which promotes benefits in
underlying mechanism of human diseases. Malaysian Tualang Honey (MTH) is a multifloral jungle honey produced by
the rock bee (Apis dorsata). This review consolidates the results of carious studies involving biochemical assays of tissue
culture and animal trials of anti-cancer properties of MTH. Often studied in the context of breast cancer cell lines, MTH
has promising data for possible mechanisms in anti-cancer activity. These include apoptosis via depolarization of the
mitochondrial membrane, caspase-dependent apoptosis, reduction of angiogenesis and the promotion of cell cycle arrest
without posing cytotoxic effect on normal cell lines. Despite positive outcomes in tissue cultures, the oral administration
of MTH in breast cancer animal models showed slower tumour progression, reduction in tumour size and better grading
of histological features. The alleviation of breast carcinogenesis via modulation of hematologic, estrogenic and apoptotic
activities promotes MTH as a promising anticancer agent. With confidence in a conclusion that MTH is a useful treatment
for cancer, further experimental and clinical studies should be conducted.

Matched MeSH terms: Cell Line
Effects of palbociclib on oral squamous cell carcinoma and the role of PIK3CA in conferring resistance

Zainal NS, Lee BKB, Wong ZW, Chin IS, Yee PS, Gan CP, et al.

Cancer Biol Med, 2019 May;16(2):264-275.
PMID: 31516747 DOI: 10.20892/j.issn.2095-3941.2018.0257

Objective: Lack of effective therapies remains a problem in the treatment of oral squamous cell carcinoma (OSCC), especially in patients with advanced tumors. OSCC development is driven by multiple aberrancies within the cell cycle pathway, including amplification of cyclin D1 and loss of p16. Hence, cell cycle inhibitors of the CDK4/6-cyclin D axis are appealing targets for OSCC treatment. Here, we determined the potency of palbociclib and identified genetic features that are associated with the response of palbociclib in OSCC.
Methods: The effect of palbociclib was evaluated in a panel of well-characterized OSCC cell lines by cell proliferation assays and further confirmed by in vivo evaluation in xenograft models. PIK3CA-mutant isogenic cell lines were used to investigate the effect of PIK3CA mutation towards palbociclib response.
Results: We demonstrated that 80% of OSCC cell lines are sensitive to palbociclib at sub-micromolar concentrations. Consistently, palbociclib was effective in controlling tumor growth in mice. We identified that palbociclib-resistant cells harbored mutations in PIK3CA. Using isogenic cell lines, we showed that PIK3CA mutant cells are less responsive to palbociclib as compared to wild-type cells with concurrent upregulation of CDK2 and cyclin E1 protein levels. We further demonstrated that the combination of a PI3K/mTOR inhibitor (PF-04691502) and palbociclib completely controlled tumor growth in mice.
Conclusions: This study demonstrated the potency of palbociclib in OSCC models and provides a rationale for the inclusion of PIK3CA testing in the clinical evaluation of CDK4/6 inhibitors and suggests combination approaches for further clinical studies.

Matched MeSH terms: Cell Line
Assessment of the Blood-Brain Barrier Permeability of Potential Neuroprotective Aurones in Parallel Artificial Membrane Permeability Assay and Porcine Brain Endothelial Cell Models

Liew KF, Hanapi NA, Chan KL, Yusof SR, Lee CY

J Pharm Sci, 2017 02;106(2):502-510.
PMID: 27855959 DOI: 10.1016/j.xphs.2016.10.006

Previously, several aurone derivatives were identified with promising neuroprotective activities. In developing these compounds to target the central nervous system (CNS), an assessment of their blood-brain barrier (BBB) permeability was performed using in vitro BBB models: parallel artificial membrane permeability assay-BBB which measures passive permeability and primary porcine brain endothelial cell model which enables determination of the involvement of active transport mechanism. Parallel artificial membrane permeability assay-BBB identified most compounds with high passive permeability, with 3 aurones having exceptional Pevalues highlighting the importance of basic amine moieties and optimal lipophilicity for good passive permeability. Bidirectional permeability assays with porcine brain endothelial cell showed a significant net influx permeation of the aurones indicating a facilitated uptake mechanism in contrast to donepezil, a CNS drug included in the evaluation which only displayed passive permeation. From pH-dependent permeability assay coupled with data analysis using pCEL-X software, intrinsic transcellular permeability (Po) of a representative aurone 4-3 was determined, considering factors such as the aqueous boundary layer that may hinder accurate in vitro to in vivo correlation. The Po value determined supported the in vivo feasibility of the aurone as a CNS-active compound.

Matched MeSH terms: Cell Line

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