Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET

El pdf del artículo es el manuscrito de autor.-- et al.Tumor-derived exosomes are emerging mediators of tumorigenesis. We explored the function of melanoma-derived exosomes in the formation of primary tumors and metastases in mice and human subjects. Exosomes from highly metastatic melanomas increased the metastatic behavior of primary tumors by permanently 'educating' bone marrow progenitors through the receptor tyrosine kinase MET. Melanoma-derived exosomes also induced vascular leakiness at pre-metastatic sites and reprogrammed bone marrow progenitors toward a pro-vasculogenic phenotype that was positive for c-Kit, the receptor tyrosine kinase Tie2 and Met. Reducing Met expression in exosomes diminished the pro-metastatic behavior of bone marrow cells. Notably, MET expression was elevated in circulating CD45(-)C-KIT(low/+)TIE2(+) bone marrow progenitors from individuals with metastatic melanoma. RAB1A, RAB5B, RAB7 and RAB27A, regulators of membrane trafficking and exosome formation, were highly expressed in melanoma cells. Rab27A RNA interference decreased exosome production, preventing bone marrow education and reducing, tumor growth and metastasis. In addition, we identified an exosome-specific melanoma signature with prognostic and therapeutic potential comprised of TYRP2, VLA-4, HSP70, an HSP90 isoform and the MET oncoprotein. Our data show that exosome production, transfer and education of bone marrow cells supports tumor growth and metastasis, has prognostic value and offers promise for new therapeutic directions in the metastatic process.Peer Reviewe

Mast cells impair melanoma cell homing and metastasis by inhibiting HMGA1 secretion

Mast cells; Melanoma; MetastasisMastòcits; Melanoma; MetàstasiMastocitos; Melanoma; MetástasisMetastatic disease is the major cause of death from cancer. From the primary tumour, cells remotely prepare the environment of the future metastatic sites by secreted factors and extracellular vesicles. During this process, known as pre-metastatic niche formation, immune cells play a crucial role. Mast cells are haematopoietic bone marrow-derived innate immune cells whose function in lung immune response to invading tumours remains to be defined. We found reduced melanoma lung metastasis in mast cell-deficient mouse models (Wsh and MCTP5-Cre-RDTR), supporting a pro-metastatic role for mast cells in vivo. However, due to evidence pointing to their antitumorigenic role, we studied the impact of mast cells in melanoma cell function in vitro. Surprisingly, in vitro co-culture of bone-marrow-derived mast cells with melanoma cells showed that they have an intrinsic anti-metastatic activity. Mass spectrometry analysis of melanoma-mast cell co-cultures secretome showed that HMGA1 secretion by melanoma cells was significantly impaired. Consistently, HMGA1 knockdown in B16-F10 cells reduced their metastatic capacity in vivo. Importantly, analysis of HMGA1 expression in human melanoma tumours showed that metastatic tumours with high HMGA1 expression are associated with reduced overall and disease-free survival. Moreover, we show that HMGA1 is reduced in the nuclei and enriched in the cytoplasm of melanoma metastatic lesions when compared to primary tumours. These data suggest that high HMGA1 expression and secretion from melanoma cells promote metastatic behaviour. Targeting HMGA1 expression intrinsically or extrinsically by mast cells actions reduce melanoma metastasis. Our results pave the way to the use of HMGA1 as anti-metastatic target in melanoma as previously suggested in other cancer types.US NIH (R01-CA169416); Children's Cancer and Blood Foundation; Feldestein Foundation; Melanoma Research Alliance; Nancy C. and Daniel P. Paduano Foundation; Starr Foundation; Translational NeTwork for the CLinical application of Extracellular Vesicle

Inactivation of EMILIN-1 by Proteolysis and Secretion in Small Extracellular Vesicles Favors Melanoma Progression and Metastasis

EMILIN-1; Melanoma; MetàstasiEMILIN-1; Melanoma; MetástasisEMILIN-1; Melanoma; MetastasisSeveral studies have demonstrated that melanoma-derived extracellular vesicles (EVs) are involved in lymph node metastasis; however, the molecular mechanisms involved are not completely defined. Here, we found that EMILIN-1 is proteolyzed and secreted in small EVs (sEVs) as a novel mechanism to reduce its intracellular levels favoring metastasis in mouse melanoma lymph node metastatic cells. Interestingly, we observed that EMILIN-1 has intrinsic tumor and metastasis suppressive-like properties reducing effective migration, cell viability, primary tumor growth, and metastasis. Overall, our analysis suggests that the inactivation of EMILIN-1 by proteolysis and secretion in sEVs reduce its intrinsic tumor suppressive activities in melanoma favoring tumor progression and metastasis.The authors gratefully acknowledge the support of the following sources of funding: Fundación Ramon Areces, MINECO (SAF2014-54541-R), Ramón y Cajal Programme, Asociación Española Contra el Cáncer, Constantes y Vitales (ATRES MEDIA/AXA Foundation) and FERO Foundation. We are also grateful for the support of the support of the Translational NeTwork for the CLinical application of Extracellular VesicleS, TeNTaCLES. RED2018-102411-T (AEI/10.13039/501100011033) and MINECO-Severo Ochoa predoctoral program to support A.A.L thesis and short term stay in Italy to perform this study. The CNIO, certified as Severo Ochoa Excellence Centre, is supported by the Spanish Government through the Instituto de Salud Carlos III (ISCIII)

A Novel Human Ghrelin Variant (In1-Ghrelin) and Ghrelin-O-Acyltransferase Are Overexpressed in Breast Cancer: Potential Pathophysiological Relevance

The human ghrelin gene, which encodes the ghrelin and obestatin peptides, contains 5 exons (Ex), with Ex1-Ex4 encoding a 117 amino-acid (aa) preproprotein that is known to be processed to yield a 28-aa (ghrelin) and/or a 23-aa (obestatin) mature peptides, which possess biological activities in multiple tissues. However, the ghrelin gene also encodes additional peptides through alternative splicing or post-translational modifications. Indeed, we previously identified a spliced mRNA ghrelin variant in mouse (In2-ghrelin-variant), which is regulated in a tissue-dependent manner by metabolic status and may thus be of biological relevance. Here, we have characterized a new human ghrelin variant that contains Ex0-1, intron (In) 1, and Ex2 and lacks Ex3-4. This human In1-ghrelin variant would encode a new prepropeptide that conserves the first 12aa of native-ghrelin (including the Ser3-potential octanoylation site) but has a different C-terminal tail. Expression of In1-variant was detected in 22 human tissues and its levels were positively correlated with those of ghrelin-O-acyltransferase (GOAT; p = 0.0001) but not with native-ghrelin expression, suggesting that In1-ghrelin could be a primary substrate for GOAT in human tissues. Interestingly, levels of In1-ghrelin variant expression in breast cancer samples were 8-times higher than those of normal mammary tissue, and showed a strong correlation in breast tumors with GOAT (p = 0.0001), ghrelin receptor-type 1b (GHSR1b; p = 0.049) and cyclin-D3 (a cell-cycle inducer/proliferation marker; p = 0.009), but not with nativeghrelin or GHSR1a expression. Interestingly, In1-ghrelin variant overexpression increased basal proliferation of MDA-MB-231 breast cancer cells. Taken together, our results provide evidence that In1-ghrelin is a novel element of the ghrelin family with a potential pathophysiological role in breast cance

Gasdermin-B promotes invasion and metastasis in breast cancer cells

Gasdermin B (GSDMB) belongs to the Gasdermin protein family that comprises four members (GSDMA-D). Gasdermin B expression has been detected in some tumor types such as hepatocarcinomas, gastric and cervix cancers; and its overexpression has been related to tumor progression. At least four splicing isoforms of GSDMB have been identified, which may play differential roles in cancer. However, the implication of GSDMB in carcinogenesis and tumor progression is not well understood. Here, we uncover for the first time the functional implication of GSDMB in breast cancer. Our data shows that high levels of GSDMB expression is correlated with reduced survival and increased metastasis in breast cancer patients included in an expression dataset (>1,000 cases). We demonstrate that GSDMB is upregulated in breast carcinomas compared to normal breast tissue, being the isoform 2 (GSDMB-2) the most differentially expressed. In order to evaluate the functional role of GSDMB in breast cancer two GSDMB isoforms were studied (GSDMB-1 and GSDMB-2). The overexpression of both isoforms in the MCF7 breast carcinoma cell line promotes cell motility and invasion, while its silencing in HCC1954 breast carcinoma cells decreases the migratory and invasive phenotype. Importantly, we demonstrate that both isoforms have a differential role on the activation of Rac-1 and Cdc-42 Rho-GTPases. Moreover, our data support that GSMDB-2 induces a pro-tumorigenic and pro-metastatic behavior in mouse xenograft models as compared to GSDMB-1. Finally, we observed that although both GSDMB isoforms interact in vitro with the chaperone Hsp90, only the GSDMB-2 isoform relies on this chaperone for its stability. Taken together, our results provide for the first time evidences that GSDMB-2 induces invasion, tumor progression and metastasis in MCF7 cells and that GSDMB can be considered as a new potential prognostic marker in breast cancerThis work was supported by grants from the Spanish Ministry of Science and Innovation, MICINN (SAF2007-63075 and SAF2010-20175), AVON Foundation 2012, Comunidad de Madrid (S2010/BMD-2302), AECC network 2011, Instituto de Salud Carlos III (ISCIII) (PI13_00132) to GMB and Breast Network from ISCIII RD12036/0007 to AC. MHR has been funded by a predoctoral contract associated to SAF2007-63075 and now has a postdoc contract from S2010/BMD- 23. DS and PGS are funded by postdoc contracts from the AECC Scientific Foundation, AM is funded by a predoctoral fellowship from MECD; ACM is funded by ISCIII RD12036/0007. Dr HP’s work is supported by the Melanoma Research Alliance, Pediatric Oncology Experimental Therapeutics Investigators Consortium, The Nancy C. and Daniel P. Paduano Foundation, The Manning Foundation, NCI (U01 CA169538, RO1 CA169416-01) and the DoD (BC123187, BC12198

Gasdermin B expression predicts poor clinical outcome in HER2-positive breast cancer

Altres ajuts: This work has been supported by the Community of Madrid (grant S2010/BMD-2303 to GMB), the Breast Cancer Research Foundation (BCRF) to JA. Alba Mota is a predoctoral student supported by a FPU fellowship (Spanish Ministry of Education, Culture and Sport). David Sarrio is a postdoctoral researcher funded by the AECC Scientific Foundation.Around, 30-40% of HER2-positive breast cancers do not show substantial clinical benefit from the targeted therapy and, thus, the mechanisms underlying resistance remain partially unknown. Interestingly, ERBB2 is frequently co-amplified and co-expressed with neighbour genes that may play a relevant role in this cancer subtype. Here, using an in silico analysis of data from 2,096 breast tumours, we reveal a significant correlation between Gasdermin B (GSDMB) gene (located 175 kilo bases distal from ERBB2) expression and the pathological and clinical parameters of poor prognosis in HER2-positive breast cancer. Next, the analysis of three independent cohorts (totalizing 286 tumours) showed that approximately 65% of the HER2-positive cases have GSDMB gene amplification and protein over-expression. Moreover, GSDMB expression was also linked to poor therapeutic responses in terms of lower relapse free survival and pathologic complete response as well as positive lymph node status and the development of distant metastasis under neoadjuvant and adjuvant treatment settings, respectively. Importantly, GSDMB expression promotes survival to trastuzumab in different HER2-positive breast carcinoma cells, and is associated with trastuzumab resistance phenotype in vivo in Patient Derived Xenografts. In summary, our data identifies the ERBB2 co-amplified and co-expressed gene GSDMB as a critical determinant of poor prognosis and therapeutic response in HER2-positive breast cancer

Therapeutic targeting of HER2–CB2R heteromers in HER2-positive breast cancer

There is a subtype of breast cancer characterized by the overexpression of the oncogene HER2. Although most patients with this diagnosis benefit from HER2-targeted treatments, some do not respond to these therapies and others develop resistance with time. New tools are therefore warranted for the treatment of this patient population, and for early identification of those individuals at a higher risk of developing innate or acquired resistance to current treatments. Here, we show that HER2 forms heteromer complexes with the cannabinoid receptor CB2R, the expression of these structures correlates with poor patient prognosis, and their disruption promotes antitumor responses. Collectively, our results support HER2–CB2R heteromers as new therapeutic targets and prognostic tools in HER2+ breast cancer

"New" molecular taxonomy in breast cancer

Advances in the analysis of expression profiles, using genomic techniques, have revealed the high heterogeneity present in breast cancers. These approaches have served to identify different breast cancer subgroups with specific molecular characteristics that could sub-classify these tumours as carcinomas expressing hormone receptors, denominated Luminal subtype, and tumours with negative expression of hormone receptors, the Basal and HER2+ phenotypes. Therefore, during recent years, identification of markers characteristic of each subtype has been the focus of many research groups. All of these breast tumour subtypes probably have specific clinical and morphological features; however, this hypothesis needs to be confirmed by analysing more homogenous series. Although this >new> classification has limitations, it could be useful in the clinical practice, allowing not only a more accurate prognosis in breast cancer patients but also a selective treatment for each predefined subtype.GM-B is a junior research contract of the Ramón y Cajal program 2004. MH-R is founded by the FPI fellowship from SAF2007-63075 Project (Spanish Innovation and Science Minister).Peer Reviewe

The truncated somatostatin receptor sst5TMD4 stimulates the angiogenic process and is associated to lymphatic metastasis and disease-free survival in breast cancer patients

Gahete et al.The truncated somatostatin receptor sst5TMD4 is associated with poor prognosis in breast cancer and increases breast cancer cell malignancy. Here, we examined the cellular/molecular mechanisms underlying this association, aiming to identify new molecular tools to improve diagnosis, prognosis or therapy. A gene expression array comparing sst5TMD4 stably-transfected MCF-7 cells and their controls (empty-plasmid) revealed the existence of profound alterations in the expression of genes involved in key tumoral processes, such as cell survival or angiogenesis. Moreover, sst5TMD4- overexpressing MCF-7 and MDA-MB-231 cells demonstrated increased expression/ production of pro-angiogenic factors and enhanced capacity to form mammospheres. Consistently, sst5TMD4-expressing MCF-7 cells induced xenografted tumors with higher VEGF levels and elevated number of blood vessels. Importantly, sst5TMD4 was expressed in a subset of breast cancers, where it correlated with angiogenic markers, lymphatic metastasis, and reduced disease-free survival. These results, coupled to our previous data, support a relevant role of sst5TMD4 in the angiogenic process and reinforce the role of sst5TMD4 in breast cancer malignancy and metastatic potential, supporting its possible utility to develop new molecular biomarkers and drug therapies for these tumors.This work has been funded by the following grants: BIO-0139, CTS-1406, PI-0639-2012, BFU2010-19300, BFU2013-43282-R, PI13/00651 and CIBERobn (to RML and JPC); PI-0541-2013 and “Miguel Servet” program (to MDG); PI13/00132, RETICC RD12/0036/0007, S2010/BMD-2303 (to GMB). CIBER is an initiative of Instituto de Salud Carlos III, Ministerio de Sanidad, Servicios Sociales e Igualdad, Spain.Peer Reviewe

Gasdermin-B promotes invasion and metastasis in breast cancer cells

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Gasdermin B (GSDMB) belongs to the Gasdermin protein family that comprises four members (GSDMA-D). Gasdermin B expression has been detected in some tumor types such as hepatocarcinomas, gastric and cervix cancers; and its overexpression has been related to tumor progression. At least four splicing isoforms of GSDMB have been identified, which may play differential roles in cancer. However, the implication of GSDMB in carcinogenesis and tumor progression is not well understood. Here, we uncover for the first time the functional implication of GSDMB in breast cancer. Our data shows that high levels of GSDMB expression is correlated with reduced survival and increased metastasis in breast cancer patients included in an expression dataset (>1,000 cases). We demonstrate that GSDMB is upregulated in breast carcinomas compared to normal breast tissue, being the isoform 2 (GSDMB-2) the most differentially expressed. In order to evaluate the functional role of GSDMB in breast cancer two GSDMB isoforms were studied (GSDMB-1 and GSDMB-2). The overexpression of both isoforms in the MCF7 breast carcinoma cell line promotes cell motility and invasion, while its silencing in HCC1954 breast carcinoma cells decreases the migratory and invasive phenotype. Importantly, we demonstrate that both isoforms have a differential role on the activation of Rac-1 and Cdc-42 Rho-GTPases. Moreover, our data support that GSMDB-2 induces a pro-tumorigenic and pro-metastatic behavior in mouse xenograft models as compared to GSDMB-1. Finally, we observed that although both GSDMB isoforms interact in vitro with the chaperone Hsp90, only the GSDMB-2 isoform relies on this chaperone for its stability. Taken together, our results provide for the first time evidences that GSDMB-2 induces invasion, tumor progression and metastasis in MCF7 cells and that GSDMB can be considered as a new potential prognostic marker in breast cancer.This work was supported by grants from the Spanish Ministry of Science and Innovation, MICINN (SAF2007-63075 and SAF2010-20175), AVON Foundation 2012, Comunidad de Madrid (S2010/BMD-2302), AECC network 2011, Instituto de Salud Carlos III (ISCIII) (PI13_00132) to GMB and Breast Network from ISCIII RD12036/0007 to AC. MHR has been funded by a predoctoral contract associated to SAF2007-63075 and now has a postdoc contract from S2010/BMD-23. DS and PGS are funded by postdoc contracts from the AECC Scientific Foundation, AM is funded by a predoctoral fellowship from MECD; ACM is funded by ISCIII RD12036/0007. Dr HP’s work is supported by the Melanoma Research Alliance, Pediatric Oncology Experimental Therapeutics Investigators Consortium, The Nancy C. and Daniel P. Paduano Foundation, The Manning Foundation, NCI (U01 CA169538, RO1 CA169416-01) and the DoD (BC123187, BC121988).Peer Reviewe