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1.
Proc Natl Acad Sci U S A ; 120(23): e2122053120, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37252969

RESUMO

The causes and consequences of abnormal biogenesis of extracellular vesicles (EVs) are not yet well understood in malignancies, including in breast cancers (BCs). Given the hormonal signaling dependence of estrogen receptor-positive (ER+) BC, we hypothesized that 17ß-estradiol (estrogen) might influence EV production and microRNA (miRNA) loading. We report that physiological doses of 17ß-estradiol promote EV secretion specifically from ER+ BC cells via inhibition of miR-149-5p, hindering its regulatory activity on SP1, a transcription factor that regulates the EV biogenesis factor nSMase2. Additionally, miR-149-5p downregulation promotes hnRNPA1 expression, responsible for the loading of let-7's miRNAs into EVs. In multiple patient cohorts, we observed increased levels of let-7a-5p and let-7d-5p in EVs derived from the blood of premenopausal ER+ BC patients, and elevated EV levels in patients with high BMI, both conditions associated with higher levels of 17ß-estradiol. In brief, we identified a unique estrogen-driven mechanism by which ER+ BC cells eliminate tumor suppressor miRNAs in EVs, with effects on modulating tumor-associated macrophages in the microenvironment.


Assuntos
Neoplasias da Mama , Vesículas Extracelulares , MicroRNAs , Humanos , Feminino , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias da Mama/patologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Estradiol/farmacologia , Estradiol/metabolismo , Estrogênios/metabolismo , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Microambiente Tumoral
2.
Pharmacol Res ; 192: 106757, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37023992

RESUMO

The liver is a major organ that is involved in essential biological functions such as digestion, nutrient storage, and detoxification. Furthermore, it is one of the most metabolically active organs with active roles in regulating carbohydrate, protein, and lipid metabolism. Hepatocellular carcinoma is a cancer of the liver that is associated in settings of chronic inflammation such as viral hepatitis, repeated toxin exposure, and fatty liver disease. Furthermore, liver cancer is the most common cause of death associated with cirrhosis and is the 3rd leading cause of global cancer deaths. LKB1 signaling has been demonstrated to play a role in regulating cellular metabolism under normal and nutrient deficient conditions. Furthermore, LKB1 signaling has been found to be involved in many cancers with most reports identifying LKB1 to have a tumor suppressive role. In this review, we use the KMPlotter database to correlate RNA levels of LKB1 signaling genes and hepatocellular carcinoma patient survival outcomes with the hopes of identifying potential biomarkers clinical usage. Based on our results STRADß, CAB39L, AMPKα, MARK2, SIK1, SIK2, BRSK1, BRSK2, and SNRK expression has a statistically significant impact on patient survival.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Quinases Proteína-Quinases Ativadas por AMP , Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo
3.
Mol Cancer ; 21(1): 138, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768871

RESUMO

BACKGROUND: Triple-negative breast cancers (TNBCs) are clinically aggressive subtypes of breast cancer. TNBC is difficult to treat with targeted agents due to the lack of commonly targeted therapies within this subtype. Androgen receptor (AR) has been detected in 12-55% of TNBCs. AR stimulates breast tumor growth in the absence of estrogen receptor (ER), and it has become an emerging molecular target in TNBC treatment. METHODS: Ceritinib is a small molecule inhibitor of tyrosine kinase and it is used in the therapy of non-small lung cancer patients. Enzalutamide is a small molecule compound targeting the androgen receptor and it is used to treat prostate cancer. Combination therapy of these drugs were investigated using AR positive breast cancer mouse xenograft models. Also, combination treatment of ceritinib and paclitaxel investigated using AR- and AR low mouse xenograft and patient derived xenograft models. RESULTS: We screened 133 FDA approved drugs that have a therapeutic effect of AR+ TNBC cells. From the screen, we identified two drugs, ceritinib and crizotinib. Since ceritinib has a well- defined role in androgen independent AR signaling pathways, we further investigated the effect of ceritinib. Ceritinib treatment inhibited RTK/ACK/AR pathway and other downstream pathways in AR+ TNBC cells. The combination of ceritinib and enzalutamide showed a robust inhibitory effect on cell growth of AR+ TNBC cells in vitro and in vivo. Interestingly Ceritinib inhibits FAK-YB-1 signaling pathway that leads to paclitaxel resistance in all types of TNBC cells. The combination of paclitaxel and ceritinib showed drastic inhibition of tumor growth compared to a single drug alone. CONCLUSIONS: To improve the response of AR antagonist in AR positive TNBC, we designed a novel combinational strategy comprised of enzalutamide and ceritinib to treat AR+ TNBC tumors through the dual blockade of androgen-dependent and androgen-independent AR signaling pathways. Furthermore, we introduced a novel therapeutic combination of ceritinib and paclitaxel for AR negative or AR-low TNBCs and this combination inhibited tumor growth to a great extent. All agents used in our study are FDA-approved, and thus the proposed combination therapy will likely be useful in the clinic.


Assuntos
Neoplasias de Mama Triplo Negativas , Androgênios/uso terapêutico , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Pirimidinas , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Sulfonas , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo
4.
Int J Mol Sci ; 23(3)2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35163298

RESUMO

Nischarin (Nisch) is a cytosolic scaffolding protein that harbors tumor-suppressor-like characteristics. Previous studies have shown that Nisch functions as a scaffolding protein and regulates multiple biological activities. In the current study, we prepared a complete Nisch knockout model, for the first time, by deletion of exons 5 and 6. This knockout model was confirmed by Qrt-PCR and Western blotting with products from mouse embryonic fibroblast (MEF) cells. Embryos and adult mice of knockouts are significantly smaller than their wild-type counterparts. Deletion of Nisch enhanced cell migration, as demonstrated by wound type and transwell migration assays. Since the animals were small in size, we investigated Nisch's effect on metabolism by conducting several assays using the Seahorse analyzer system. These data indicate that Nisch null cells have lower oxygen consumption rates, lower ATP production, and lower levels of proton leak. We examined the expression of 15 genes involved in lipid and fat metabolism, as well as cell growth, and noted a significant increase in expression for many genes in Nischarin null animals. In summary, our results show that Nischarin plays an important physiological role in metabolic homeostasis.


Assuntos
Trifosfato de Adenosina/metabolismo , Receptores de Imidazolinas/metabolismo , Consumo de Oxigênio/genética , Trifosfato de Adenosina/genética , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Respiração Celular , Fibroblastos , Expressão Gênica/genética , Receptores de Imidazolinas/genética , Peptídeos e Proteínas de Sinalização Intracelular , Metabolismo dos Lipídeos/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estresse Oxidativo , Consumo de Oxigênio/fisiologia
5.
Int J Cancer ; 146(9): 2576-2587, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31525254

RESUMO

Previously, our lab discovered the protein Nischarin and uncovered its role in regulating cell migration and invasion via its interactions with several proteins. We subsequently described a role for Nischarin in breast cancer, in which it is frequently underexpressed. To characterize Nischarin's role in breast tumorigenesis and mammary gland development more completely, we deleted a critical region of the Nisch gene (exons 7-10) from the mouse genome and observed the effects. Mammary glands in mutant animals showed delayed terminal end bud formation but did not develop breast tumors spontaneously. Therefore, we interbred the animals with transgenic mice expressing the mouse mammary tumor virus-polyoma middle T-antigen (MMTV-PyMT) oncogene. The MMTV-PyMT mammary glands lacking Nischarin showed increased hyperplasia compared to wild-type animal tissues. Furthermore, we observed significantly increased tumor growth and metastasis in Nischarin mutant animals. Surprisingly, Nischarin deletion decreased activity of AMPK and subsequently its downstream effectors. Given this finding, we treated these animals with metformin, which enhances AMPK activity. Here, we show for the first time, metformin activates AMPK signaling and inhibits tumor growth of Nischarin lacking PyMT tumors suggesting a potential use for metformin as a cancer therapeutic, particularly in the case of Nischarin-deficient breast cancers.


Assuntos
Transformação Celular Neoplásica/patologia , Receptores de Imidazolinas/fisiologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Animais/tratamento farmacológico , Neoplasias Mamárias Animais/patologia , Metformina/farmacologia , Animais , Antígenos Transformantes de Poliomavirus/genética , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Feminino , Hipoglicemiantes/farmacologia , Neoplasias Pulmonares/metabolismo , Neoplasias Mamárias Animais/metabolismo , Vírus do Tumor Mamário do Camundongo/genética , Camundongos , Camundongos Knockout , Invasividade Neoplásica
6.
Anticancer Drugs ; 31(4): 359-367, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31917699

RESUMO

Triple-negative breast cancers account for approximately 15-20% of breast cancer patients. Due to lack of expression of estrogen receptor, PR and human epidermal growth factor receptor 2 in triple-negative breast cancers, there are no targeted therapies available for these cancers. Therefore, a major research priority is to find potential therapeutic targets. Androgen receptor is present in 80-90% of all breast cancers, including 55% of estrogen receptor-α-negative cancers and 12%-35% of triple-negative breast cancers. Androgen receptor stimulates growth and survival in triple-negative breast cancer cells. Treatment with bicalutamide, an androgen receptor antagonist, has a good benefit for AR triple-negative breast cancer patients. AR triple-negative breast cancer cells were treated with curcumin or bicalutamide alone or in combination of both together. Cell growth, apoptosis and Wnt signaling pathways were examined. We found that curcumin dramatically suppressed Wnt signaling pathway in AR triple-negative breast cancer cells. Curcumin treatment inhibited androgen receptor protein expression in AR triple-negative breast cancer cells. Combination treatment of curcumin and bicalutamide has a robust increase in apoptosis. Furthermore, the combination treatment suppressed the growth of AR triple-negative breast cancer cells more effectively than with the single drug alone. Our data indicate that androgen receptor inhibition is a potential therapeutic approach for AR triple-negative breast cancers. In summary, our study for the first time shows that the combination treatment of curcumin and bicalutamide is effective in AR triple-negative breast cancer cells.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Animais , Apoptose , Biomarcadores Tumorais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Ciclo Celular , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Mol Cancer ; 18(1): 75, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30940145

RESUMO

Tumor-derived exosomes (TDEs) participate in formation and progression of different cancer processes, including tumor microenvironment (TME) remodeling, angiogenesis, invasion, metastasis and drug-resistance. Exosomes initiate or suppress various signaling pathways in the recipient cells via transmitting heterogeneous cargoes. In this review we discuss exosome biogenesis, exosome mediated metastasis and chemoresistance. Furthermore, tumor derived exosomes role in tumor microenvironment remodeling, and angiogenesis is reviewed. Also, exosome induction of epithelial mesenchymal transition (EMT) is highlighted. More importantly, we discuss extensively how exosomes regulate drug resistance in several cancers. Thus, understanding exosome biogenesis, their contents and the molecular mechanisms and signaling pathways that are responsible for metastasis and drug-resistance mediated by TDEs may help to devise novel therapeutic approaches for cancer progression particularly to overcome therapy-resistance and preventing metastasis as major factors of cancer mortality.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Exossomos/metabolismo , Neoplasias/metabolismo , Progressão da Doença , Humanos , Metástase Neoplásica , Transdução de Sinais , Microambiente Tumoral
8.
Int J Obes (Lond) ; 43(5): 1046-1057, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30546133

RESUMO

BACKGROUND/OBJECTIVES: NISCH-STAB1 is a newly identified locus correlated to human waist-hip ratio (WHR), which is a risk indicator of developing obesity-associated diabetes. Our previous studies have shown that Nisch mutant male mice increased glucose tolerance in chow-fed conditions. Thus we hypothesized that Nisch mutant mice will have changes in insulin resistance, adipocytes, hepatic steatosis when mice are fed with high-fat diet (HFD). METHODS: Insulin resistance was assessed in Nisch mutant mice and WT mice fed with high-fat diet (60% by kCal) or chow diet. Whole-body energy metabolism was examined using an indirect calorimeter. Adipose depots including inguinal white adipose tissue (WAT), perigonadal WAT, retroperitoneal WAT, and mesenteric WAT were extracted. Area and eqdiameter of each adipocyte were determined, and insulin signaling was examined as well. Paired samples of subcutaneous and omental visceral adipose tissue were obtained from 400 individuals (267 women, 133 men), and examined the expression of Nischarin. RESULTS: We found that insulin signaling was impaired in major insulin-sensitive tissues of Nisch mutant female mice. When mice were fed with HFD for 15 weeks, the Nisch mutant female mice not only developed severe insulin resistance and decreased glucose tolerance compared with wild-type control mice, but also accumulated more white fat, had larger adipocytes and developed severe hepatic steatosis than wild-type control mice. To link our animal studies to human diseases, we further analyzed Nischarin expression in the paired human samples of visceral and subcutaneous adipose tissue from Caucasians. In humans, we found that Nischarin expression is attenuated in adipose tissue with obesity. More importantly, we found that Nischarin mRNA inversely correlated with parameters of obesity, fat distribution, lipid and glucose metabolism. CONCLUSIONS: Taken together, our data revealed sexual dimorphism of Nischarin in body fat distribution, insulin resistance, and glucose tolerance in mice.


Assuntos
Adipócitos/patologia , Resistência à Insulina/fisiologia , Gordura Intra-Abdominal/patologia , Metabolismo dos Lipídeos/fisiologia , Mutação , Obesidade/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Distribuição da Gordura Corporal , Dieta Hiperlipídica , Modelos Animais de Doenças , Feminino , Humanos , Receptores de Imidazolinas/genética , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Masculino , Camundongos , Pessoa de Meia-Idade , RNA Mensageiro/fisiologia , Caracteres Sexuais
9.
J Biol Chem ; 292(41): 16833-16846, 2017 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-28842496

RESUMO

Nischarin (Nisch) is a key protein functioning as a molecular scaffold and thereby hosting interactions with several protein partners. To explore the physiological importance of Nisch, here we generated Nisch loss-of-function mutant mice and analyzed their metabolic phenotype. Nisch-mutant embryos exhibited delayed development, characterized by small size and attenuated weight gain. We uncovered the reason for this phenotype by showing that Nisch binds to and inhibits the activity of AMP-activated protein kinase (AMPK), which regulates energy homeostasis by suppressing anabolic and activating catabolic processes. The Nisch mutations enhanced AMPK activation and inhibited mechanistic target of rapamycin signaling in mouse embryonic fibroblasts as well as in muscle and liver tissues of mutant mice. Nisch-mutant mice also exhibited increased rates of glucose oxidation with increased energy expenditure, despite reduced overall food intake. Moreover, the Nisch-mutant mice had reduced expression of liver markers of gluconeogenesis associated with increased glucose tolerance. As a result, these mice displayed decreased growth and body weight. Taken together, our results indicate that Nisch is an important AMPK inhibitor and a critical regulator of energy homeostasis, including lipid and glucose metabolism.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Metabolismo Energético , Gluconeogênese , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Linhagem Celular , Glucose/genética , Glucose/metabolismo , Humanos , Receptores de Imidazolinas , Peptídeos e Proteínas de Sinalização Intracelular/genética , Fígado/patologia , Camundongos , Camundongos Mutantes , Mutação , Oxirredução , Ligação Proteica
10.
Mol Cancer ; 17(1): 100, 2018 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-30012170

RESUMO

BACKGROUND: The disruption of normal gene regulation due to microRNA dysfunction is a common event in cancer pathogenesis. MicroRNA-27b is an example of an oncogenic miRNA, and it is frequently upregulated in breast cancer. MicroRNAs have been found to deregulate tumor metabolism, which typically manifests as heightened cellular glucose uptake in consort with increased flux through glycolysis, followed by the preferential conversion of glycolytic pyruvate into lactate (a phenomenon known as the Warburg Effect). Pyruvate Dehydrogenase, an enzyme complex linking glycolysis with downstream oxidative metabolism, represents a key location where regulation of metabolism occurs; PDHX is a key structural component of this complex and is essential for its function. METHODS: We sought to characterize the role of miR-27b in breast cancer by identifying novel transcripts under its control. We began by utilizing luciferase, RNA, and protein assays to establish PDHX as a novel target of miR-27b. We then tested whether miR-27b could alter metabolism using several metabolite assay kits and performed a seahorse analysis. We also examined how the altered metabolism might affect cell proliferation. Lastly, we confirmed the relevance of our findings in human breast tumor samples. RESULTS: Our data indicate that Pyruvate Dehydrogenase Protein X is a credible target of miR-27b in breast cancer. Mechanistically, by suppressing PDHX, miR-27b altered levels of pyruvate, lactate and citrate, as well as reducing mitochondrial oxidation and promoting extracellular acidification. These changes corresponded with an increased capacity for cell proliferation. In human breast tumor samples, PDHX expression was deficient, and low levels of PDHX were associated with reduced patient survival. CONCLUSIONS: MicroRNA-27b targets PDHX, resulting in an altered metabolic configuration that is better suited to fuel biosynthetic processes and cell proliferation, thereby promoting breast cancer progression.


Assuntos
Neoplasias da Mama/genética , Regulação para Baixo , MicroRNAs/genética , Complexo Piruvato Desidrogenase/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Ácido Cítrico/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Glicólise , Humanos , Ácido Láctico/metabolismo , Células MCF-7 , Complexo Piruvato Desidrogenase/metabolismo , Ácido Pirúvico/metabolismo , Análise de Sobrevida
11.
Mol Cancer ; 17(1): 21, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29415725

RESUMO

BACKGROUND: During metastasis, tumor cells move through the tracks of extracellular matrix (ECM). Focal adhesions (FAs) are the protein complexes that link the cell cytoskeleton to the ECM and their presence is necessary for cell attachment. The tumor suppressor Nischarin interacts with a number of signaling proteins such as Integrin α5, PAK1, LIMK1, LKB1, and Rac1 to prevent cancer cell migration. Although previous findings have shown that Nischarin exerts this migratory inhibition by interacting with other proteins, the effects of these interactions on the entire FA machinery are unknown. METHODS: RT-PCR, Western Blotting, invadopodia assays, and immunofluorescence were used to examine FA gene expression and determine whether Nischarin affects cell attachment, as well as the proteins that regulate it. RESULTS: Our data show that Nischarin prevents cell migration and invasion by altering the expression of key focal adhesion proteins. Furthermore, we have found that Nischarin-expressing cells have reduced ability to attach the ECM, which in turn leads to a decrease in invadopodia-mediated matrix degradation. CONCLUSIONS: These experiments demonstrate an important role of Nischarin in regulating cell attachment, which adds to our understanding of the early events of the metastatic process in breast cancer.


Assuntos
Neoplasias da Mama/genética , Adesão Celular/genética , Receptores de Imidazolinas/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Podossomos/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Matriz Extracelular/metabolismo , Feminino , Expressão Gênica , Regulação da Expressão Gênica , Humanos , Receptores de Imidazolinas/metabolismo , Integrinas/genética , Integrinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Modelos Biológicos , Podossomos/metabolismo
12.
EMBO J ; 32(5): 713-27, 2013 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-23386062

RESUMO

The intracellular pathogenic bacterium Salmonella enterica serovar typhimurium (Salmonella) relies on acidification of the Salmonella-containing vacuole (SCV) for survival inside host cells. The transport and fusion of membrane-bound compartments in a cell is regulated by small GTPases, including Rac and members of the Rab GTPase family, and their effector proteins. However, the role of these components in survival of intracellular pathogens is not completely understood. Here, we identify Nischarin as a novel dual effector that can interact with members of Rac and Rab GTPase (Rab4, Rab14 and Rab9) families at different endosomal compartments. Nischarin interacts with GTP-bound Rab14 and PI(3)P to direct the maturation of early endosomes to Rab9/CD63-containing late endosomes. Nischarin is recruited to the SCV in a Rab14-dependent manner and enhances acidification of the SCV. Depletion of Nischarin or the Nischarin binding partners--Rac1, Rab14 and Rab9 GTPases--reduced the intracellular growth of Salmonella. Thus, interaction of Nischarin with GTPases may regulate maturation and subsequent acidification of vacuoles produced after phagocytosis of pathogens.


Assuntos
Endossomos/microbiologia , Receptores de Imidazolinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Salmonella typhimurium/crescimento & desenvolvimento , Vacúolos/microbiologia , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Transporte Biológico , Western Blotting , Endossomos/metabolismo , Guanosina Trifosfato/metabolismo , Células HeLa , Humanos , Receptores de Imidazolinas/genética , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lisossomos/metabolismo , Lisossomos/microbiologia , Fosfatos de Fosfatidilinositol/metabolismo , Transporte Proteico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecções por Salmonella/microbiologia , Técnicas do Sistema de Duplo-Híbrido , Vacúolos/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rac de Ligação ao GTP/genética
13.
Biomed Microdevices ; 19(4): 97, 2017 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-29103075

RESUMO

Adherent cells produce cellular traction force (CTF) on a substrate to maintain their physical morphologies, sense external environment, and perform essential cellular functions. Precise characterization of the CTF can expand our knowledge of various cellular processes as well as lead to the development of novel mechanical biomarkers. However, current methods that measure CTF require special substrates and fluorescent microscopy, rendering them less suitable in a clinical setting. Here, we demonstrate a rapid and direct approach to measure the combined CTF of a large cell population using thin polydimethylsiloxane (PDMS) cantilevers. Cells attached to the top surface of the PDMS cantilever produce CTF, which causes the cantilever to bend. The side view of the cantilever was imaged with a low-cost camera to extract the CTF. We characterized the CTF of fibroblasts and breast cancer cells. In addition, we were able to directly measure the contractile force of a suspended cell sheet, which is similar to the CTF of the confluent cell layer before detachment. The demonstrated technique can provide rapid and real-time measurement of the CTF of a large cell population and can directly characterize its temporal dynamics. The developed thin film PDMS cantilever can be fabricated affordably and the CTF extraction technique does not require expensive equipment. Thus, we believe that the developed method can provide an easy-to-use and affordable platform for CTF characterization in clinical settings and laboratories.


Assuntos
Fenômenos Fisiológicos Celulares , Dimetilpolisiloxanos/química , Animais , Linhagem Celular Tumoral , Fibroblastos , Análise de Elementos Finitos , Humanos , Processamento de Imagem Assistida por Computador , Camundongos , Modelos Teóricos , Células NIH 3T3
14.
Mol Cancer ; 15: 18, 2016 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-26905733

RESUMO

The epithelial to mesenchymal transition (EMT) is a biological process in which a non-motile epithelial cell changes to a mesenchymal phenotype with invasive capacities. This phenomenon has been well documented in multiple biological processes including embryogenesis, fibrosis, tumor progression and metastasis. The hallmark of EMT is the loss of epithelial surface markers, most notably E-cadherin, and the acquisition of mesenchymal markers including vimentin and N-cadherin. The downregulation of E-cadherin during EMT can be mediated by its transcriptional repression through the binding of EMT transcription factors (EMT-TFs) such as SNAIL, SLUG and TWIST to E-boxes present in the E-cadherin promoter. Additionally, EMT-TFs can also cooperate with several enzymes to repress the expression of E-cadherin and regulate EMT at the epigenetic and post- translational level. In this review, we will focus on epigenetic and post- translational modifications that are important in EMT. In addition, we will provide an overview of the various therapeutic approaches currently being investigated to undermine EMT and hence, the metastatic progression of cancer as well.


Assuntos
Epigênese Genética , Transição Epitelial-Mesenquimal/genética , Processamento de Proteína Pós-Traducional/genética , Biomarcadores Tumorais/genética , Caderinas/metabolismo , Humanos , Modelos Biológicos
15.
J Biol Chem ; 288(22): 15495-509, 2013 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-23572524

RESUMO

Biallelic inactivation of LKB1, a serine/threonine kinase, has been detected in 30% of lung adenocarcinomas, and inhibition of breast tumor growth has been demonstrated. We have identified the tumor suppressor, Nischarin, as a novel binding partner of LKB1. Our mapping analysis shows that the N terminus of Nischarin interacts with amino acids 44-436 of LKB1. Time lapse microscopy and Transwell migration data show that the absence of both Nischarin and LKB1 from an invasive breast cancer cell line (MDA-MB-231) enhances migration as measured by increased distance and speed of migrating cells. Our data suggest that this is a result of elevated PAK1 and LIMK1 phosphorylation. Moreover, the absence of Nischarin and LKB1 increased tumor growth in vivo. Consistent with this, the percentage of S phase cells was increased, as demonstrated by flow cytometry and enhanced cyclin D1. The absence of Nischarin and LKB1 also led to a dramatic increase in the formation of lung metastases. Our studies, for the first time, demonstrate functional interaction between LKB1 and Nischarin to inhibit cell migration and breast tumor progression. Mechanistically, we show that these two proteins together regulate PAK-LIMK-Cofilin and cyclin D1/CDK4 pathways.


Assuntos
Neoplasias da Mama/metabolismo , Movimento Celular , Células Epiteliais/metabolismo , Receptores de Imidazolinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Glândulas Mamárias Humanas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Quinases Proteína-Quinases Ativadas por AMP , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Receptores de Imidazolinas/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Quinases Lim/genética , Quinases Lim/metabolismo , Glândulas Mamárias Humanas/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Proteínas Serina-Treonina Quinases/genética , Transplante Heterólogo , Proteínas Supressoras de Tumor/genética
16.
Front Cell Dev Biol ; 12: 1408107, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39372954

RESUMO

Apoptosis is an evolutionarily conserved cell death pathway that plays a crucial role in maintaining tissue homeostasis, orchestrating organismal development, and eliminating damaged cells. Dysregulation of apoptosis can contribute to the pathogenesis of malignant tumors and neurodegenerative diseases. Anticancer drugs typically possess the capacity to induce apoptosis in tumor cells. The Bcl-2 protein family, consisting of 27 members in humans, serves as the key regulator of mitochondrial function. This family can be divided into two functional groups: anti-apoptotic proteins (e.g., Bcl-2, Bcl-xl, Mcl-1) and pro-apoptotic proteins (e.g., Bad, Bax). Mcl-1 exerts its function by binding pro-apoptotic Bcl-2 proteins thereby preventing apoptosis induction. Overexpression of Mcl-1 not only correlates closely with tumorigenesis but also associates significantly with resistance towards targeted therapy and conventional chemotherapy. Effective induction of apoptosis can be achieved through inhibition or interference with Mcl-1. Thus, this mini review discusses existing Mcl-1 inhibitors.

17.
Cancers (Basel) ; 16(17)2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39272919

RESUMO

Colorectal cancer (CRC) is a heterogeneous disease and classified into various subtypes, among which transcriptional alterations result in CRC progression, metastasis, and drug resistance. Forkhead-box M1 (FOXM1) is a proliferation-associated transcription factor which is overexpressed in CRC and the mechanisms of FOXM1 regulation have been under investigation. Previously, we showed that FOXM1 binds to promoters of certain microRNAs. Database mining led to several microRNAs that might interact with FOXM1 3'UTR. The interactions between shortlisted microRNAs and FOXM1 3'UTR were quantitated by a dual-luciferase reporter assay. MicroRNA-532-3p interacted with the 3'UTR of the FOXM1 mRNA transcript most efficiently. MicroRNA-532-3p was ectopically overexpressed in colorectal cancer (CRC) cell lines, leading to reduced transcript and protein levels of FOXM1 and cyclin B1, a direct transcriptional target of FOXM1. Further, a clonogenic assay was conducted in overexpressed miR-532-3p CRC cells that revealed a decline in the ability of cells to form colonies and a reduction in migratory and invading potential. These alterations were reinforced at molecular levels by the altered transcript and protein levels of the conventional EMT markers E-cadherin and vimentin. Overall, this study identifies the regulation of FOXM1 by microRNA-532-3p via its interaction with FOXM1 3'UTR, resulting in the suppression of proliferation, migration, and invasion, suggesting its role as a tumor suppressor in CRC.

18.
Oncogene ; 43(11): 763-775, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38310162

RESUMO

Both breast cancer and obesity can regulate epigenetic changes or be regulated by epigenetic changes. Due to the well-established link between obesity and an increased risk of developing breast cancer, understanding how obesity-mediated epigenetic changes affect breast cancer pathogenesis is critical. Researchers have described how obesity and breast cancer modulate the epigenome individually and synergistically. In this review, the epigenetic alterations that occur in obesity, including DNA methylation, histone, and chromatin modification, accelerated epigenetic age, carcinogenesis, metastasis, and tumor microenvironment modulation, are discussed. Delineating the relationship between obesity and epigenetic regulation is vital to furthering our understanding of breast cancer pathogenesis.


Assuntos
Neoplasias da Mama , Epigênese Genética , Humanos , Feminino , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Metilação de DNA , Histonas/metabolismo , Obesidade/complicações , Obesidade/genética , Microambiente Tumoral/genética
19.
Sci Rep ; 13(1): 11843, 2023 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-37481672

RESUMO

Triple-negative breast cancers (TNBCs) are aggressive forms of breast cancer and tend to grow and spread more quickly than most other types of breast cancer. TNBCs can neither be targeted by hormonal therapies nor the antibody trastuzumab that targets the HER2 protein. There are urgent unmet medical needs to develop targeted drugs for TNBCs. We identified a small molecule NSC260594 from the NCI diversity set IV compound library. NSC260594 exhibited dramatic cytotoxicity in multiple TNBCs in a dose-and time-dependent manner. NSC260594 inhibited the Myeloid cell leukemia-1 (Mcl-1) expression through downregulation of Wnt signaling proteins. Consistent with this, NSC260594 treatment increased apoptosis, which was confirmed by using an Annexin-V/PI assay. Interestingly, NSC260594 treatment reduced the cancer stem cell (CSC) population in TNBCs. To make NSC260594 more clinically relevant, we treated NSC260594 with TNBC cell derived xenograft (CDX) mouse model, and with patient-derived xenograft (PDX) organoids. NSC260594 significantly suppressed MDA-MB-231 tumor growth in vivo, and furthermore, the combination treatment of NSC260594 and everolimus acted synergistically to decrease growth of TNBC PDX organoids. Together, we found that NSC260594 might serve as a lead compound for triple-negative breast cancer therapy through targeting Mcl-1.


Assuntos
Antineoplásicos , Neoplasias de Mama Triplo Negativas , Animais , Humanos , Camundongos , Anexina A5 , Anticorpos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Modelos Animais de Doenças , Neoplasias de Mama Triplo Negativas/tratamento farmacológico
20.
Noncoding RNA ; 9(6)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38133210

RESUMO

We are delighted to share with you our thirteenth Journal Club and highlight some of the most interesting papers published recently [...].

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