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Parathyroid hormone (PTH) serves dual roles in bone metabolism, exhibiting both anabolic and catabolic effects. The anabolic properties of PTH have been utilized in the treatment of osteoporosis with proven efficacy in preventing fractures. Despite these benefits, PTH can be administered therapeutically for up to 2 years, and its use in patients with underlying malignancies remains a subject of ongoing debate. These considerations underscore the need for a more comprehensive understanding of the underlying mechanisms. p21-activated kinase 4 (PAK4) is involved in bone resorption and cancer-associated osteolysis; however, its role in osteoblast function and PTH action remains unknown. Therefore, in this study, we aimed to clarify the role of PAK4 in osteoblast function and its effects on PTH-induced anabolic activity. PAK4 enhanced MC3T3-E1 osteoblast viability and proliferation and upregulated cyclin D1 expression. PAK4 also augmented osteoblast differentiation, as indicated by increased mineralization found by alkaline phosphatase and Alizarin Red staining. Treatment with PTH (1-34), an active PTH fragment, stimulated PAK4 expression and phosphorylation in a protein kinase A-dependent manner. In addition, bone morphogenetic protein-2 (which is known to promote bone formation) increased phosphorylated PAK4 (p-PAK4) and PAK4 levels. PAK4 regulated the expression of both phosphorylated and total ß-catenin, which are critical for osteoblast proliferation and differentiation. Moreover, p-PAK4 directly interacted with ß-catenin, and disruption of ß-catenin's binding to T-cell factor impaired PAK4- and PTH-induced osteoblast differentiation. Our findings elucidate the effect of PAK4 on enhancing bone formation in osteoblasts and its pivotal role in the anabolic activity of PTH mediated through its interaction with ß-catenin. These insights improve the understanding of the mechanisms underlying PTH activity and should inform the development of more effective and safer osteoporosis treatments.
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Diferenciação Celular , Proliferação de Células , Osteoblastos , Hormônio Paratireóideo , beta Catenina , Quinases Ativadas por p21 , Animais , Humanos , Camundongos , beta Catenina/metabolismo , beta Catenina/genética , Calcificação Fisiológica/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclina D1/metabolismo , Ciclina D1/genética , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/genética , Hormônio Paratireóideo/farmacologia , Hormônio Paratireóideo/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Células CultivadasRESUMO
Targeting p21-activated kinase 4 (PAK4) is a potential therapeutic strategy against human colorectal cancer (CRC). In this study, we synthesized a series of novel thiazolo[4,5-d]pyrimidine derivatives (PB-1-12) and identified PB-10 (PAK4 IC50â¯=â¯15.12⯵M) as a potential and potent PAK4 inhibitor. Our results showed that PB-10 significantly suppressed the proliferation and colony formation of human CRC cells. PB-10 also arrested HCT-116 CRC cells at sub G0/G1 phase while promoting the expression of proapoptotic proteins. In addition, PB-10 inhibited migration, invasion, and adhesion as well as the PAK4 downstream signaling pathway in HCT-116 cells. Molecular docking analysis showed possible binding modes between PB-10 and PAK4. Our study provides a novel compound that may block the PAK4 signaling in CRC cells.
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Inibidores de Proteínas Quinases/química , Pirimidinas/química , Tiazóis/química , Quinases Ativadas por p21/metabolismo , Sítios de Ligação , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Desenho de Fármacos , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Células HCT116 , Humanos , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/metabolismo , Pirimidinas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Tiazóis/metabolismo , Tiazóis/farmacologia , Quinases Ativadas por p21/antagonistas & inibidores , Quinases Ativadas por p21/genéticaRESUMO
PAK4 is overexpressed in a variety of human cancers and considered a promising candidate for therapeutic target. However, its functions remain poorly understood, especially in liver carcinogenesis which could be triggered by inflammation. In the present study, endogenous PAK4 was knockdown using siRNA in HepG2 and SK-Hep1 cells. The two cell lines performed reduced cell viability, altered cell cycle composed of decreased S and arrest in G2, and apoptosis. Meanwhile, expression of NF-κB p65 in the nuclei and caspase-8 activity did not show significant differences from control. However, after treating cells with TNF-α, an inflammatory cytokine, we investigated repressed nuclear expression and localization of NF-κB p65, and induced apoptosis with increased caspase-8 activity in PAK4-knockdown cells. The findings revealed that ablation of PAK4 inhibited cell viability via blocking cell cycle and progressing apoptosis. The apoptosis was partially dependent upon caspase-8 concomitant with attenuated NF-κB survival signal due to stimulus of TNF-α. It suggests that PAK4 as target is a switch between caspase-8 apoptosis and NF-κB survival signals induced by TNF-α in hepatocarcinoma cells.
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Apoptose , Caspase 8/imunologia , Inflamação/imunologia , Neoplasias Hepáticas/imunologia , NF-kappa B/imunologia , Fator de Necrose Tumoral alfa/imunologia , Quinases Ativadas por p21/imunologia , Pontos de Checagem do Ciclo Celular , Linhagem Celular , Sobrevivência Celular , Células Hep G2 , Humanos , Inflamação/genética , Inflamação/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Interferência de RNA , Quinases Ativadas por p21/genéticaRESUMO
BACKGROUND: Oral squamous carcinoma (OSCC), the most common head and neck malignancy, has a strong propensity for malignant proliferation and metastasis, which will decrease the survival of patients. P21-activated kinase 4 (PAK4), a classical serine/threonine protein kinase with multiple cellular functions, has an essential role in cancer cell migration and invasion. Here, we elucidated the function and possible molecular mechanisms of the effect of PAK4 on the biological behaviors of OSCC. METHODS: The expression of genes and protein was detected by real-time PCR and western blotting. We used oral squamous carcinoma cell lines, Tca8117, Cal 27, SCC 4, and SCC 9 for validation of our cell function data. Flow cytometry, 3D cultures, and clone formation assay were used to detect proliferation of cells. RNA sequencing and bioinformatic analysis was performed to determine the potential function of PAK4. RESULTS: Immunohistochemistry, western blotting and real-time PCR demonstrated that PAK4 expression was up-regulated in OSCC tissues. Overexpression of PAK4 promoted the proliferation, migration and invasion of OSCC cell lines. RNA sequencing (RNA-seq) for the transcriptome-wide analysis of differential gene expression followed by bioinformatic analysis was performed to determine the potential function of PAK4. Based on the KEGG enrichment analysis and GO analysis of differential expression genes (DEGs) we found that PAK4 promotes the cell-cycle machinery, which associated with 44 regulated genes, thereby promoting cancer cell differentiation. CONCLUSIONS: This study demonstrates that the PAK4 regulates the biological behaviors of OSCC by PI3K-AKT signaling pathway, and these findings might provide a novel strategy for OSCC treatment.
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Carcinoma de Células Escamosas , Neoplasias Bucais , Quinases Ativadas por p21 , Humanos , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Bucais/patologia , Quinases Ativadas por p21/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
Cancer accounts for more than 10 million deaths in the year 2020. Development of drugs that specifically target cancer signaling pathways and proteins attain significant importance in the recent past. The p21-activated kinase 4 enzyme, which plays diverse functions in cancer and is reported in elevated expression makes this enzyme an attractive anti-cancer drug target. Similarly, cancer cells' DNA could also serve as a good platform for anti-cancer drug development. Herein, a robust in silico framework is designed to virtually screen multiple drug libraries from diverse sources to identify potential binders of the mentioned cancer targets. The virtual screening process identified three compounds (BAS_01059603, ASN_10027856, and ASN_06916672) as best docked molecules with a binding energy score of ≤ -10 kcal/mol for p21-activated kinase 4 and ≤ -6 kcal/mol for D(CGATCG). In the docking analysis, the filtered compounds revealed stable binding to the same site to which controls bind in X-ray structures. The binding interactions of the compounds with receptors are dominated by van der Waals interactions. The average root mean square deviation (rmsd) value for p21-activated kinase 4 systems is noticed at â¼2 Å, while for D(CGATCG), the average rmsd is 2.7 Å. The MMGB/PBSA interpreted ASN_12674021 to show strong intermolecular binding energy compared to the other two systems and control in both receptors. Moreover, the entropy energy contribution is less than the mean binding energy. In short, the compounds are showing promising binding to the biomolecules and therefore must be evaluated for anti-cancer activity in experimental studies.Communicated by Ramaswamy H. Sarma.
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Antineoplásicos , Neoplasias , Humanos , Quinases Ativadas por p21 , Neoplasias/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Desenvolvimento de Medicamentos , Antineoplásicos/farmacologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica MolecularRESUMO
Background: P21-activated kinase 4 (PAK4) involves in cell proliferation in cancer and mutually regulates with p53, a molecule is demonstrated to control cell autophagy by mammalian target of rapamycin (mTOR)/protein kinase B (AKT) signaling. Since the signaling exhibits an association with PAK family members in cell autophagy, it implies that PAK4-relevant proliferation may be impacted by autophagy via p53 with a lack of evidence in cancer cells. Methods: In this research, transient and stable PAK4-knockdown human hepatocarcinoma cell lines (HepG2) were constructed by transfection of PAK4-RNA interference (RNAi) plasmid and lentivirus containing PAK4-RNAi plasmid, respectively. We investigated cell proliferation using methyl thiazolyl tetrazolium (MTT) and Cell Counting Kit 8 (CCK8) assays, cell cycle by flow cytometry (FCM) and cell autophagy by monodansylcadaverine (MDC) staining and autophagic biomarker's expression, and detected the expressions of p53, mTOR, phosphorylated-AKT (p-AKT) and AKT by immunofluorescence and western blot to explore the mechanism. Results: We successfully constructed transient and stable PAK4-knockdown HepG2 cell lines, and detected dysfunction of the cells' proliferation. An increased expression of p53, as a molecule of cell-cycle-surveillance on G1/S phase, was demonstrated in the cells although the cell cycle blocked at G2/M. And then, we detected increased autophagosome and autophagic biomarker LC3-II, and decreased expressions in p-AKT and mTOR. Conclusions: The proliferation is reduced in PAK4-knockdown HepG2 cells, which is relative to not only cell cycle arrest but also cell autophagy, and p53/mTOR/p-AKT signaling involves in the cell progress. The findings provide a new mechanism on PAK4 block in cancer therapy.
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Pleural mesothelioma (PM) comprises three main subtypes: epithelioid, biphasic and sarcomatoid, which have different impacts on prognosis and treatment definition. However, PM subtyping can be complex given the inter- and intra-tumour morphological heterogeneity. We aim to use immunohistochemistry (IHC) to evaluate five markers (Mesothelin, Claudin-15, Complement Factor B, Plasminogen Activator Inhibitor 1 and p21-activated Kinase 4), whose encoding genes have been previously reported as deregulated among PM subtypes. Immunohistochemical expressions were determined in a case series of 73 PMs, and cut-offs for the epithelioid and non-epithelioid subtypes were selected. Further validation was performed on an independent cohort (30 PMs). For biphasic PM, the percentage of the epithelioid component was assessed, and IHC evaluation was also performed on the individual components separately. Mesothelin and Claudin-15 showed good sensitivity (79% and 84%) and specificity (84% and 73%) for the epithelioid subtype. CFB and PAK4 had inferior performance, with higher sensitivity (89% and 84%) but lower specificity (64% and 36%). In the biphasic group, all markers showed different expression when comparing epithelioid with sarcomatoid areas. Mesothelin, Claudin-15 and CFB can be useful in subtype discrimination. PAI1 and PAK4 can improve component distinction in biphasic PM.
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Immunotherapy has revolutionized the landscape of cancer treatment. However, single immunotherapy only works well in a small subset of patients. Combined immunotherapy with antitumor synergism holds considerable potential to boost the therapeutic outcome. Nevertheless, the synergistic, additive or antagonistic antitumor effects of combined immunotherapies have been rarely explored. Herein, we established a novel combined cancer treatment modality by synergizing p21-activated kinase 4 (PAK4) silencing with immunogenic phototherapy in engineered extracellular vesicles (EVs) that were fabricated by coating M1 macrophage-derived EVs on the surface of the nano-complex cores assembled with siRNA against PAK4 and a photoactivatable polyethyleneimine. The engineered EVs induced potent PAK4 silencing and robust immunogenic phototherapy, thus contributing to effective antitumor effects in vitro and in vivo. Moreover, the antitumor synergism of the combined treatment was quantitatively determined by the CompuSyn method. The combination index (CI) and isobologram results confirmed that there was an antitumor synergism for the combined treatment. Furthermore, the dose reduction index (DRI) showed favorable dose reduction, revealing lower toxicity and higher biocompatibility of the engineered EVs. Collectively, the study presents a synergistically potentiated cancer treatment modality by combining PAK4 silencing with immunogenic phototherapy in engineered EVs, which is promising for boosting the therapeutic outcome of cancer immunotherapy.
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Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the data shown for the Transwell cell migration and invasion assays in Figs. 2C, 5D and 6D were strikingly similar to data appearing in different form in other articles by different authors, several of which have been retracted. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 19: 711718, 2019; DOI: 10.3892/mmr.2018.9652].
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Glioblastoma is a devastating malignant disease with poor patient overall survival. Strong invasiveness and resistance to radiochemotherapy have challenged the identification of molecular targets that can finally improve treatment outcomes. This study evaluates the influence of all six known p21-activated kinase (PAK) protein family members on the invasion capacity and radio-response of glioblastoma cells by employing a siRNA-based screen. In a panel of human glioblastoma cell models, we identified PAK4 as the main PAK isoform regulating invasion and clonogenic survival upon irradiation and demonstrated the radiosensitizing potential of PAK4 inhibition. Mechanistically, we show that PAK4 depletion and pharmacological inhibition enhanced the number of irradiation-induced DNA double-strand breaks and reduced the expression levels of various DNA repair proteins. In conclusion, our data suggest PAK4 as a putative target for radiosensitization and impairing DNA repair in glioblastoma, deserving further scrutiny in extended combinatorial treatment testing.
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Glioblastoma , Quinases Ativadas por p21 , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/efeitos da radiação , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/radioterapia , Humanos , RNA Interferente Pequeno , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismoRESUMO
The p21-activated kinase 4 (PAK4) is a member of the PAKs family. It is overexpressed in multiple tumor tissues. Pharmacological inhibition of PAK4 attenuates proliferation, migration, and invasion of cancer cells. Recent studies revealed that inhibition of PAK4 sensitizes immunotherapy which has been extensively exploited as a new strategy to treat cancer. In the past few years, a large number of PAK4 inhibitors have been reported. Of note, the allosteric inhibitor KPT-9274 has been tested in phase â clinic trials. Herein, we provide an update on recent research progress on the PAK4 mediated signaling pathway and highlight the development of the PAK4 small molecular inhibitors in recent 5 years. Meanwhile, challenges, limitations, and future developmental directions will be discussed as well.
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p21-activated kinase 4 (PAK4), a member of the serine-threonine kinase family, was initially identified as a protein kinase that functions downstream of the Rho GTPases cdc42 and Rac1. Recently, it has been proven that PAK4 not only regulates many cellular physiological processes, but also plays an important role in the occurrence and development of various cancers. Here, we provide a systematic overview of PAK4, including its structure, localization, expression and aberration, upstream regulators, and key functions in almost every aspect of cancer hallmarks, including cancer cell proliferation, invasion and metastasis, angiogenesis, metabolism reprogramming, and immune escape. Subsequently, we also discuss the existing small molecule PAK4 inhibitors according to their structure types and their potential applications in cancer treatment. We hope our systematic review will provide the most comprehensive description of the current advancements in PAK4 research and new enlightenment for the individualized diagnosis and treatment of cancer.
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Neoplasias , Quinases Ativadas por p21 , Proliferação de Células , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas Quinases , Proteínas Serina-Treonina Quinases , Quinases Ativadas por p21/metabolismoRESUMO
PURPOSE: P21-activated kinase 4 (PAK4), a serine/threonine kinase that regulates a number of fundamental cellular processes, has been suggested as a prognostic factor for various human tumors. The aim of the present study was to evaluate the clinical implications of phospho-Ser474 PAK4 (pPAK4S474), an activated form of PAK4, in surgically treated renal cell carcinoma (RCC). MATERIALS AND METHODS: Samples from 131 patients with surgically treated RCC were immunostained to detect PAK4 and pPAK4S474. Expression of PAK4 and pPAK4S474 was compared with clinicopathological characteristics and survival after nephrectomy. RESULTS: PAK4 and pPAK4S474 were expressed predominantly in the nucleus. Overall, 57.3% (75/131) and 24.4% (29/119) of specimens exhibited high expression of pPAK4S474 and PAK4, respectively. High expression of pPAK4S474 was associated with adverse pathologic characteristics, including advanced tumor stage and grade (p=0.036 and p=0.002, respectively), whereas this association was not significant for PAK4 expression (each p>0.05). Kaplan-Meier estimates showed that high expression of pPAK4S474 was associated with shorter recurrence-free survival in a subgroup with localized RCC and with cancer-specific survival in the total RCC cohort (log-rank test: p=0.001 and p=0.005, respectively), whereas PAK4 expression was not. Multivariate Cox regression analysis identified that high pPAK4S474 expression was an independent predictor of recurrence in the subgroup with localized RCC. CONCLUSIONS: pPAK4S474 may be a more accurate prognostic factor than total PAK4 in RCC patients. This marker would be useful for identifying patients with pathologically localized disease who may require further interventions.
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Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Recidiva Local de Neoplasia/metabolismo , Quinases Ativadas por p21/metabolismo , Idoso , Carcinoma de Células Renais/cirurgia , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Fosforilação , Prognóstico , Modelos de Riscos Proporcionais , Taxa de SobrevidaRESUMO
The coat color of mammals is primarily determined by the type, quantity, and distribution of melanin in the skin and hair. As an endogenous gas molecule, nitric oxide (NO) regulates tyrosinase production by modulating the cGMP-dependent protein kinase (PKG) pathway, which enhances melanin synthesis. However, some interrelationships have not been fully elucidated. In the present study, mouse melanocytes co-cultured with mouse keratinocytes in vitro, or as monocultures, were used as research models. The results indicated that ultraviolet B irradiation increased nitric oxide synthase (NOS) activity and NO production, and increased PKG, p21-activated kinase 4 (PAK4), and microphthalmia-associated transcription factor (MITF) levels, as well as tyrosinase (TYR), tyrosinase-related protein 1 and 2 expression, and melanin synthesis. During PKG inhibition, the expression of NO-regulated PAK4 and MITF was decreased. Pigment production was also affected, but remained higher than that in the control and NO inhibitor groups. These findings suggest that ultraviolet light regulates melanin production by activating the NO/cGMP/PKG pathway, which mediates the expression of PAK4, affecting melanin synthesis. On this basis, further elucidation of this regulatory network may improve our understanding of patterns of animal hair color formation.
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Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Melaninas/biossíntese , Óxido Nítrico/metabolismo , Raios Ultravioleta , Quinases Ativadas por p21/metabolismo , Animais , Animais Recém-Nascidos , Proliferação de Células/efeitos da radiação , Técnicas de Cocultura , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Queratinócitos/citologia , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Melanócitos/citologia , Melanócitos/metabolismo , Melanócitos/efeitos da radiação , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase/metabolismoRESUMO
It is suggested that aberrantly expressed microRNAs are involved in the pathogenesis of endometriosis. Our previous study demonstrated that expression of the microRNA hsa-miR-199a-3p is attenuated in human endometriotic cyst stromal cells (ECSCs). The current study aimed to define the roles of hsa-miR-199a-3p in the development of endometriosis. ECSCs and normal endometrial stromal cells (NESCs) were isolated from ovarian endometrioma and normal endometrial tissues, respectively. We evaluated the effect of transfected hsa-miR-199a-3p on the migration, invasion, and contractility of ECSCs using Transwell migration assays, in vitro wound healing assays, Transwell invasion assays, and collagen gel contraction assays. We also examined the downstream target of hsa-miR-199a-3p with an online public database search and luciferase reporter assay. Expression of hsa-miR-199a-3p in ECSCs was significantly lower than that in NESCs, whereas the expression of p21-activated kinase 4 (PAK4) mRNA was significantly higher. Transfection of hsa-miR-199a-3p inhibited the migration, invasion, and contractility of ECSCs via inhibition of PAK4 mRNA expression. PAK4 was confirmed to be the direct target of hsa-miR-199a-3p. Transfection of PAK4 small interfering RNA and the PAK4 inhibitor PF-3758309 also inhibited ECSC migration, invasion, and contractility. These findings suggest that hsa-miR-199a-3p may act as a tumor suppressor in endometriosis development. Attenuation of hsa-miR-199a-3p expression was favorable for ECSCs to acquire the highly invasive, motile, and contractile characteristics of endometriotic cells and is involved in the development of endometriosis. Accordingly, PAK4 inhibitors may be promising for the treatment of endometriosis.
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Movimento Celular/fisiologia , Endometriose/metabolismo , Endométrio/metabolismo , MicroRNAs/biossíntese , Ovário/metabolismo , Células Estromais/metabolismo , Adulto , Endometriose/genética , Endometriose/patologia , Endométrio/patologia , Feminino , Humanos , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Ovário/patologia , Células Estromais/patologia , Adulto JovemRESUMO
Introduction: The Ser/Thr protein kinase PAK4 is a downstream regulator of Cdc42, mediating cytoskeleton remodeling, and cell motility, and inhibiting apoptosis and transcriptional regulation. Nowadays, efforts in PAK4 inhibitor development are focusing on improving inhibitory selectivity, cellular potency, and in vivo pharmacokinetic properties, and identifying the feasibility of immunotherapy combination in oncology therapy.Areas covered: This review summarized the development of PAK4 inhibitors that reported on patents in the past two decades. According to their binding features, these inhibitors were classified into type I, type I 1/2, and PAMs. Their designing ideas and SAR were elucidated in this review. Moreover, synergistic therapy of PAK4 inhibitors with PD-1/PD-L1 or CAR-T were also summarized .Expert opinion: In the past years, preclinical and clinical studies of PAK4 inhibitors ended in failure due to poor selectivity, cellular activity, or pharmacokinetic issues. There are researchers questioning the reliability of PAK4 as a drug target, particularly PAK4-related therapy is concerned with the distinguishment of the non-kinase functions and catalytic functions triggered by PAK4 phosphorylation. Meanwhile, synergistic effects of PAK4 inhibitors with PD-1/PD-L1 and CAR-T immunotherapy shed light for the development of PAK4 inhibitors.
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Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Quinases Ativadas por p21/antagonistas & inibidores , Animais , Desenvolvimento de Medicamentos , Humanos , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Patentes como Assunto , Quinases Ativadas por p21/metabolismoRESUMO
We have previously disclosed compound 3 (CZh-226), a potent and selective PAK4 inhibitor, but its development was delayed due to poor oral pharmacokinetics. In an attempt to improve this issue, we synthesised a series of prodrugs by masking its terminal nitrogen of the piperazine moiety. Most synthesised prodrugs of 3 have low or no inhibition of PAK4 activity. The stability of synthetic prodrugs was evaluated in PBS, SGF, SIF, rat plasma and liver S9 fraction. Of these, prodrug 19 was not only stable under both acidic and neutral conditions but also could be quickly converted to parent drug 3 in rat plasma and liver S9 fraction. Such effective conversion into parent drug 3 was observed in rats, providing higher exposure of 3 compared to its direct administration. When given via oral route at daily doses of 25 and 50â¯mg/kg, the prodrug 19 was effective and well tolerated in mouse model of HCT-116 and B16F10.
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Antineoplásicos/farmacologia , Piperazinas/farmacologia , Pró-Fármacos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinases Ativadas por p21/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Fígado/química , Fígado/metabolismo , Masculino , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Piperazinas/síntese química , Piperazinas/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Quinases Ativadas por p21/metabolismoRESUMO
PURPOSE: A long noncoding RNA called small nucleolar RNA host gene 7 (SNHG7) is known to be a key regulator of biological processes in multiple human cancer types. In this study, our aims were to determine the expression status of SNHG7 in cervical cancer, to figure out the detailed roles of SNHG7 in cervical cancer cells, and to identify the mechanism underlying the activity of SNHG7 in cervical cancer. METHODS: Reverse-transcription quantitative PCR was performed to measure SNHG7 expression in cervical cancer. A Cell Counting Kit-8 assay, flow-cytometric analysis, cell migration and invasion assays, and a tumor xenograft experiment were conducted to respectively determine the effects of SNHG7 on cervical cancer cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo. RESULTS: SNHG7 was found to be markedly upregulated in cervical cancer tissues and cell lines. Higher SNHG7 expression significantly correlated with FIGO stage, lymph node metastasis, the depth of cervical invasion, and shorter overall survival in patients with cervical cancer. Functional experiments indicated that a SNHG7 knockdown attenuated proliferation, migration, and invasiveness and promoted apoptosis of cervical cancer cells in vitro. The SNHG7 knockdown also slowed tumor growth in vivo. Further investigation showed that SNHG7 acts as a competing endogenous RNA for microRNA-485 (miR-485) in cervical cancer cells, and the inhibitory actions of the SNHG7 knockdown on the malignant phenotype were reversed by miR-485 inhibition. P21-activated kinase 4 (PAK4) was identified as a direct target gene of miR-485 in cervical cancer, and PAK4 expression was promoted by SNHG7. CONCLUSION: SNHG7 functions as an oncogenic RNA in cervical cancer, competitively binds to miR-485, and thereby upregulates PAK4. This SNHG7-miR-485-PAK4 regulatory network may provide insights into the pathogenesis of cervical cancer, and can help in the identification of novel diagnostic and therapeutic approaches for cervical cancer.
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P21-activated kinase 4 (PAK4) is a serine/threonine protein kinase, which is associated with many cancer diseases, and thus being considered as a potential drug target. In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR), molecular docking and molecular dynamics (MD) simulations were performed to explore the structure-activity relationship of a series of pyrropyrazole PAK4 inhibitors. The statistical parameters of comparative molecular field analysis (CoMFA, Q 2 = 0.837, R 2 = 0.990, and R 2 pred = 0.967) and comparative molecular similarity indices analysis (CoMSIA, Q 2 = 0.720, R 2 = 0.972, and R 2 pred = 0.946) were obtained from 3D-QSAR model, which exhibited good predictive ability and significant statistical reliability. The binding mode of PAK4 with its inhibitors was obtained through molecular docking study, which indicated that the residues of GLU396, LEU398, LYS350, and ASP458 were important for activity. Molecular mechanics generalized born surface area (MM-GBSA) method was performed to calculate the binding free energy, which indicated that the coulomb, lipophilic and van der Waals (vdW) interactions made major contributions to the binding affinity. Furthermore, through 100 ns MD simulations, we obtained the key amino acid residues and the types of interactions they participated in. Based on the constructed 3D-QSAR model, some novel pyrropyrazole derivatives targeting PAK4 were designed with improved predicted activities. Pharmacokinetic and toxicity predictions of the designed PAK4 inhibitors were obtained by the pkCSM, indicating these compounds had better absorption, distribution, metabolism, excretion and toxicity (ADMET) properties. Above research provided a valuable insight for developing novel and effective pyrropyrazole compounds targeting PAK4.
Assuntos
Simulação de Dinâmica Molecular , Relação Quantitativa Estrutura-Atividade , Simulação de Acoplamento Molecular , Reprodutibilidade dos Testes , Quinases Ativadas por p21RESUMO
LIM kinase 1 (LIMK1) and p21-activated kinase 4 (PAK4) are often over-expressed in breast tumors, which causes aggressive cancer phenotypes and unfavorable clinical outcomes. In addition to the well-defined role in regulating cell division, proliferation and invasion, the two kinases promote activation of the MAPK pathway and cause endocrine resistance through phosphorylating estrogen receptor alpha (ERα). PAK4 specifically phosphorylates LIMK1 and its functional partners, indicating possible value of suppressing both kinases in cancers that over-express PAK4 and/or LIMK1. Here, for the first time, we assessed the impact of combining LIMK1 inhibitor LIMKi 3 and PAK4 inhibitor PF-3758309 in preclinical breast cancer models. LIMK1 and PAK4 pharmacological inhibition synergistically reduced the survival of various cancer cell lines, exhibiting specific efficacy in luminal and HER2-enriched models, and suppressed development and ERα-driven signals in a BT474 xenograft model. In silico analysis demonstrated the cell lines with reliance on LIMK1 were the most prone to be susceptible to PAK4 inhibition. Double LIMK1 and PAK4 targeting therapy can be a successful therapeutic strategy for breast cancer, with a unique efficiency in the subtypes of luminal and HER2-enriched tumors.