RESUMEN
HER2-positive breast cancer, representing 15-20% of all breast cancer cases, often develops resistance to the HER2-targeted therapy trastuzumab. Unfortunately, effective treatments for advanced HER2-positive breast cancer remain scarce. This study aims to investigate the roles of ITGß3, and Hedgehog signaling in trastuzumab resistance and explore the potential of combining trastuzumab with cilengitide as a therapeutic strategy. Quantitative gene expression analysis was performed to assess the transcription of EMT (epithelial-mesenchymal transition) markers Slug, Snail, Twist2, and Zeb1 in trastuzumab-resistant HER2-positive breast cancer cells. The effects of ITGß3 and Hedgehog signaling were investigated. Additionally, the combination therapy of trastuzumab and cilengitide was evaluated. Acquired trastuzumab resistance induced the transcription of Slug, Snail, Twist2, and Zeb1, indicating increased EMT. This increased EMT was mediated by ITGB3 and Hedgehog signaling. ITGß3 regulated both the Hedgehog pathway and EMT, with the latter being independent of the Hedgehog pathway. The combination of trastuzumab and cilengitide showed a synergistic effect, reducing both EMT and Hedgehog pathway activity. Targeting ITGß3 with cilengitide, combined with trastuzumab, effectively suppresses the Hedgehog pathway and EMT, offering a potential strategy to overcome trastuzumab resistance and improve outcomes for HER2-positive breast cancer patients.
Asunto(s)
Neoplasias de la Mama , Resistencia a Antineoplásicos , Transición Epitelial-Mesenquimal , Integrina beta3 , Receptor ErbB-2 , Trastuzumab , Humanos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Transición Epitelial-Mesenquimal/genética , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Trastuzumab/farmacología , Trastuzumab/uso terapéutico , Integrina beta3/metabolismo , Integrina beta3/genética , Receptor ErbB-2/metabolismo , Receptor ErbB-2/genética , Línea Celular Tumoral , Transducción de Señal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas Hedgehog/metabolismo , Venenos de SerpienteRESUMEN
HER2-positive breast cancer is a significant cause of mortality. Overcoming trastuzumab resistance requires a deeper understanding of its molecular mechanisms to develop effective therapies. This study investigates the role of plasminogen activator inhibitor-1 (PAI1) in migration and drug resistance in trastuzumab-resistant HER2-positive breast cancer. Trastuzumab resistance poses a significant challenge in clinical management due to its association with aggressive disease behaviour and limited treatment options. This study focuses on PAI1, a key player in the TGF-ß signalling pathway, which is implicated in cancer progression and metastasis. Trastuzumab-resistant cell lines (SKBR3 and HCC1954) demonstrated markedly elevated PAI1 expression levels, up to 40-fold compared to parental lines. This elevation was accompanied by increased expression of migration markers such as Col4a1, Fibronectin, ICAM1, Timp2, and Vimentin. Through overexpression and silencing experiments, we observed that modulating PAI1 levels significantly impacts cell morphology, transitioning cells from an epithelial to mesenchymal phenotype. Importantly, combining trastuzumab with aleplasinin, a PAI1 inhibitor, synergistically reduced PAI1 expression in both parental and resistant cell lines. This suggests a potential therapeutic strategy to overcome trastuzumab resistance. These findings emphasise PAI1 as a critical mediator of migration and therapeutic response in HER2-positive breast cancer, offering insights into novel treatment approaches targeting PAI1 to improve clinical outcomes in drug resistance.
RESUMEN
Bartsocas-Papas syndrome (BPS) is a rare autosomal recessive disorder characterized by popliteal pterygia, syndactyly, ankyloblepharon, filiform bands between the jaws, cleft lip and palate, and genital malformations. Most of the BPS cases reported to date are fatal either in the prenatal or neonatal period. Causative genetic defects of BPS were mapped on the RIPK4 gene encoding receptor-interacting serine/threonine kinase 4, which is critical for epidermal differentiation and development. RIPK4 variants are associated with a wide range of clinical features ranging from milder ectodermal dysplasia to severe BPS. Here, we evaluated a consanguineous Turkish family, who had two pregnancies with severe multiple malformations compatible with BPS phenotype. In order to identify the underlying genetic defect, direct sequencing of the coding region and exon-intron boundaries of RIPK4 was carried out. A homozygous transversion (c.481G>C) that leads to the substitution of a conserved aspartic acid to histidine (p.Asp161His) in the kinase domain of the protein was detected. Pathogenicity predictions, molecular modeling, and cell-based functional assays showed that Asp161 residue is required for the kinase activity of the protein, which indicates that the identified variant is responsible for the severe BPS phenotype in the family.
Asunto(s)
Labio Leporino/genética , Fisura del Paladar/genética , Anomalías del Ojo/genética , Dedos/anomalías , Articulación de la Rodilla/anomalías , Rodilla/anomalías , Deformidades Congénitas de las Extremidades Inferiores/genética , Proteínas Serina-Treonina Quinasas/genética , Anomalías Cutáneas/genética , Sindactilia/genética , Anomalías Urogenitales/genética , Anomalías Múltiples/epidemiología , Anomalías Múltiples/genética , Anomalías Múltiples/patología , Feto Abortado/patología , Labio Leporino/epidemiología , Labio Leporino/patología , Fisura del Paladar/epidemiología , Fisura del Paladar/patología , Exoma/genética , Anomalías del Ojo/epidemiología , Anomalías del Ojo/patología , Femenino , Dedos/patología , Predisposición Genética a la Enfermedad , Homocigoto , Humanos , Recién Nacido , Rodilla/patología , Articulación de la Rodilla/patología , Deformidades Congénitas de las Extremidades Inferiores/epidemiología , Deformidades Congénitas de las Extremidades Inferiores/patología , Mutación/genética , Fosforilación , Embarazo , Anomalías Cutáneas/epidemiología , Anomalías Cutáneas/patología , Sindactilia/epidemiología , Sindactilia/patología , Anomalías Urogenitales/epidemiología , Anomalías Urogenitales/patologíaRESUMEN
Receptor-interacting serine/threonine kinase 4 (RIPK4) and transforming growth factor-ß 1 (TGF-ß1) play critical roles in the development and maintenance of the epidermis. A negative correlation between the expression patterns of RIPK4 and TGF-ß signaling during epidermal homeostasis-related events and suppression of RIPK4 expression by TGF-ß1 in keratinocyte cell lines suggest the presence of a negative regulatory loop between the two factors. So far, RIPK4 has been shown to regulate nuclear factor-κB (NF-κB), protein kinase C (PKC), wingless-type MMTV integration site family (Wnt), and (mitogen-activated protein kinase) MAPK signaling pathways. In this study, we examined the effect of RIPK4 on the canonical Smad-mediated TGF-ß1 signaling pathway by using the immortalized human keratinocyte HaCaT cell line. According to our results, RIPK4 inhibits intracellular Smad-mediated TGF-ß1 signaling events through suppression of TGF-ß1-induced Smad2/3 phosphorylation, which is reflected in the upcoming intracellular events including Smad2/3-Smad4 interaction, nuclear localization, and TGF-ß1-induced gene expression. Moreover, the kinase activity of RIPK4 is required for this process. The in vitro wound-scratch assay demonstrated that RIPK4 suppressed TGF-ß1-mediated wound healing through blocking TGF-ß1-induced cell migration. In conclusion, our results showed the antagonistic effect of RIPK4 on TGF-ß1 signaling in keratinocytes for the first time and have the potential to contribute to the understanding and treatment of skin diseases associated with aberrant TGF-ß1 signaling.
Asunto(s)
Queratinocitos/metabolismo , Proteínas Serina-Treonina Quinasas/fisiología , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Proteína Smad4/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Línea Celular , Movimiento Celular , Humanos , Transducción de Señal , Cicatrización de HeridasRESUMEN
Microcephalic primordial dwarfism (MPD) is a group of autosomal recessive inherited single-gene disorders with intrauterine and postnatal global growth failure. Seckel syndrome is the most common form of the MPD. Ten genes are known with Seckel syndrome. Using genome-wide SNP genotyping and homozygosity mapping we mapped a Seckel syndrome gene to chromosomal region 4q28.1-q28.3 in a Turkish family. Direct sequencing of PLK4 (polo-like kinase 4) revealed a homozygous splicing acceptor site transition (c.31-3 A>G) that results in a premature translation termination (p.[=,Asp11Profs*14]) causing deletion of all known functional domains of the protein. PLK4 is a master regulator of centriole biogenesis and its deficiency has recently been associated with Seckel syndrome. However, the role of PLK4 in genomic stability and the DNA damage response is unclear. Evaluation of the PLK4-Seckel fibroblasts obtained from patient revealed the expected impaired centriole biogenesis, disrupted mitotic morphology, G2/M delay, and extended cell doubling time. Analysis of the PLK4-Seckel cells indicated that PLK4 is also essential for genomic stability and DNA damage response. These findings provide mechanistic insight into the pathogenesis of the severe growth failure associated with PLK4-deficiency.