RESUMO
Epithelial-to-mesenchymal transition (EMT) regulates tumour initiation, progression, metastasis and resistance to anti-cancer therapy1-7. Although great progress has been made in understanding the role of EMT and its regulatory mechanisms in cancer, no therapeutic strategy to pharmacologically target EMT has been identified. Here we found that netrin-1 is upregulated in a primary mouse model of skin squamous cell carcinoma (SCC) exhibiting spontaneous EMT. Pharmacological inhibition of netrin-1 by administration of NP137, a netrin-1-blocking monoclonal antibody currently used in clinical trials in human cancer (ClinicalTrials.gov identifier NCT02977195 ), decreased the proportion of EMT tumour cells in skin SCC, decreased the number of metastases and increased the sensitivity of tumour cells to chemotherapy. Single-cell RNA sequencing revealed the presence of different EMT states, including epithelial, early and late hybrid EMT, and full EMT states, in control SCC. By contrast, administration of NP137 prevented the progression of cancer cells towards a late EMT state and sustained tumour epithelial states. Short hairpin RNA knockdown of netrin-1 and its receptor UNC5B in EPCAM+ tumour cells inhibited EMT in vitro in the absence of stromal cells and regulated a common gene signature that promotes tumour epithelial state and restricts EMT. To assess the relevance of these findings to human cancers, we treated mice transplanted with the A549 human cancer cell line-which undergoes EMT following TGFß1 administration8,9-with NP137. Netrin-1 inhibition decreased EMT in these transplanted A549 cells. Together, our results identify a pharmacological strategy for targeting EMT in cancer, opening up novel therapeutic interventions for anti-cancer therapy.
Assuntos
Anticorpos Monoclonais , Carcinoma de Células Escamosas , Transição Epitelial-Mesenquimal , Netrina-1 , Neoplasias Cutâneas , Animais , Humanos , Camundongos , Células A549 , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Receptores de Netrina/antagonistas & inibidores , Receptores de Netrina/deficiência , Receptores de Netrina/genética , Netrina-1/antagonistas & inibidores , Netrina-1/deficiência , Netrina-1/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Modelos Animais de Doenças , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Metástase Neoplásica/tratamento farmacológico , Análise da Expressão Gênica de Célula Única , RNA-Seq , Molécula de Adesão da Célula Epitelial/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
Wnt signaling plays a pivotal role in regulating activation, proliferation, stem cell renewal, and differentiation of hair follicle stem cells (HFSCs). Secreted frizzled-related protein 1 (Sfrp1), a Wnt antagonist is upregulated in the HFSCs; however, its role in the HFSCs regulation is still obscure. Here, we show that Sfrp1 loss showed a depletion of HFSCs, enhanced HFSC proliferation, and faster hair follicle cycle at PD21-PD28; HFSC markers, such as Lgr5 and Axin2, were decreased in both the Sfrp1+/- and Sfrp1-/- HFSCs. In addition, the second hair follicle cycle was also faster compared with WT. Importantly, Sfrp1-/- showed a restoration of HFSC by second telogen (PD49), whereas Sfrp1+/- did not show restoration with still having a decreased HFSC. In fact, restoration of HFSCs was due to a pronounced downregulation of ß-catenin activity mediated through a cross-talk of BMP-AKT-GSK3ß signaling in Sfrp1-/- compared with Sfrp1+/-, where downregulation was less pronounced. In cultured keratinocytes, Sfrp1 loss resulted in enhanced proliferation and clonogenicity, which were reversed by treating with either BMPR1A or GSK3ß inhibitor thereby confirming BMP-AKT-GSK3ß signaling involved in ß-catenin regulation in both the Sfrp1+/- and Sfrp1-/- mice. Our study reveals a novel function of Sfrp1 by unraveling an in vivo molecular mechanism that regulates the HFSCs pool mediated through a hitherto unknown cross-talk of BMP-AKT-GSK3ß signaling that maintains stem cell pool balance, which in turn maintains skin tissue homeostasis.
Assuntos
Folículo Piloso , Proteínas de Membrana/metabolismo , beta Catenina , Animais , Glicogênio Sintase Quinase 3 beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/genética , Camundongos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células-Tronco/metabolismo , Via de Sinalização Wnt/fisiologia , beta Catenina/metabolismoRESUMO
Secretory phospholipase A2 Group-IIA (sPLA2 -IIA) catalyzes the hydrolysis of the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. sPLA2 -IIA is deregulated in various cancers; however, its role in hair follicle stem cell (HFSC) regulation is obscure. Here we report a transgenic mice overexpressing sPLA2 -IIA (K14-sPLA2 -IIA) showed depletion of HFSC pool. This was accompanied with increased differentiation, loss of ortho-parakeratotic organization and enlargement of sebaceous gland, infundibulum and junctional zone. The colony forming efficiency of keratinocytes was significantly reduced. Microarray profiling of HFSCs revealed enhanced level of epithelial mitogens and transcription factors, c-Jun and FosB that may be involved in proliferation and differentiation. Moreover, K14-sPLA2 -IIA keratinocytes showed enhanced activation of EGFR and JNK1/2 that led to c-Jun activation, which co-related with enhanced differentiation. Further, depletion of stem cells in bulge is associated with high levels of chromatin silencing mark, H3K27me3 and low levels of an activator mark, H3K9ac suggestive of alteration in gene expression contributing toward stem cells differentiation. Our results, first time uncovered that overexpression of sPLA2 -IIA lead to depletion of HFSCs and differentiation associated with altered histone modification. Thus involvement of sPLA2 -IIA in stem cells regulation and disease pathogenesis suggest its prospective clinical implications. Stem Cells 2016;34:2407-2417.
Assuntos
Diferenciação Celular , Epiderme/enzimologia , Fosfolipases A2 do Grupo II/metabolismo , Folículo Piloso/citologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Células-Tronco/citologia , Envelhecimento/metabolismo , Animais , Proliferação de Células , Ativação Enzimática , Receptores ErbB/metabolismo , Perfilação da Expressão Gênica , Histonas/metabolismo , Homeostase , Hiperplasia , Queratinócitos/metabolismo , Lisina/metabolismo , Metilação , Camundongos Transgênicos , Paraceratose/patologia , Glândulas Sebáceas/patologia , Transdução de Sinais , Células-Tronco/metabolismoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Wnt signaling is involved in the regulation of cancer stem cells (CSCs); however, the molecular mechanism involved is still obscure. SFRP1, a Wnt inhibitor, is downregulated in various human cancers; however, its role in tumor initiation and CSC regulation remains unexplored. Here, we used a skin carcinogenesis model, which showed early tumor initiation in Sfrp1-/- (Sfrp1 knockout) mice and increased tumorigenic potential of Sfrp1-/- CSCs. Expression profiling on Sfrp1-/- CSCs showed upregulation of genes involved in epithelial to mesenchymal transition, stemness, proliferation, and metastasis. Further, SOX-2 and SFRP1 expression was validated in human skin cutaneous squamous cell carcinoma, head and neck squamous cell carcinoma, and breast cancer. The data showed downregulation of SFRP1 and upregulation of SOX-2, establishing their inverse correlation. Importantly, we broadly uncover an inverse correlation of SFRP1 and SOX-2 in epithelial cancers that may be used as a potential prognostic marker in the management of cancer.
Assuntos
Carcinogênese/metabolismo , Epitélio/patologia , Proteínas de Membrana/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Cutâneas/patologia , Animais , Carcinogênese/patologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana/deficiência , Camundongos , Células-Tronco Neoplásicas/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Transdução de Sinais , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Regulação para Cima/genéticaRESUMO
Secretory phospholipase A2 Group-IIA (sPLA2-IIA) is involved in lipid catabolism and growth promoting activity. sPLA2-IIA is deregulated in many pathological conditions including various cancers. Here, we have studied the role of sPLA2-IIA in the development of cyclic alopecia and wound healing response in relation to complete loss of hair follicle stem cells (HFSCs). Our data showed that overexpression of sPLA2-IIA in homozygous mice results in hyperproliferation and terminal epidermal differentiation followed by hair follicle cycle being halted at anagen like stage. In addition, sPLA2-IIA induced hyperproliferation leads to compl pathological conditions including various cancers. Here ete exhaustion of hair follicle stem cell pool at PD28 (Postnatal day). Importantly, sPLA2-IIA overexpression affects the hair shaft differentiation leading to development of cyclic alopecia. Molecular investigation study showed aberrant expression of Sox21, Msx2 and signalling modulators necessary for proper differentiation of inner root sheath (IRS) and hair shaft formation. Further, full-thickness skin wounding on dorsal skin of K14-sPLA2-IIA homozygous mice displayed impaired initial healing response. Our results showed the involvement of sPLA2-IIA in regulation of matrix cells differentiation, hair shaft formation and complete loss of HFSCs mediated impaired wound healing response. These novel functions of sPLA2-IIA may have clinical implications in alopecia, cancer development and ageing.